THE 19th
INTERNATIONAL CONFERENCE
ON MAGNETISM
July 8 - 13, 2012 Bexco, Busan, Korea
www.icm2012.org

Hosted by

The Korean Physical Society
The Korean Magnetics SocietyInternational Union of Pure and Applied Physics

CONTENTS
Welcome Address • 3Organizing Committee • 4Int’l Advisory Committee • 5
Program Committee • 7
Editors & Speakers • 10
Program at-a-Glance • 11
Venue Layout • 18
Ceremony & Event Program • 20
General Information • 22
Exhibition • 25
Sponsor • 26

THE 19th
INTERNATIONAL CONFERENCE
ON MAGNETISM
Oral Presentation • 27
- Plenary Lecture • 28
- Half-Plenary Lecture • 30
- Invited & Contributed Presentation • 33

Poster Presentation • 115- July 9 (PA~PO) • 116- July 10 (QA~QP) • 182- July 12 (RA~RR) • 249- July 13 (SA~SO) • 316
Author Index • 373

List of Abstracts

Welcome Address
28

Half-Plenary Lecture

30

Invited & Contributed Presentation

33

On behalf of the Organizing Committee, and all of those who were involved in preparing for the 19th International Conference on

July 9 (Mon)33

Magnetism (ICM2012), we wish to extend a warm-hearted welcome to all participants of ICM2012. It is our great honor and privilege

AA: Multiferroics I - mainly manganites
AD: Surface and interface effects I
AG: Arrays of magnetic nanostructures I
AJ: Crystalline, nanocrystalline and amorphous materials
BC: Organic and molecular magnetism / Spin ladder
BF: 3d transition metal oxides
BI: STT MRAM and magnetic logic

AB: Non-fermi liquids and quantum phase transitions I
AE: Electric field effect on magnetic systems
AH: Magnetic transducers in biomedicine
BA: Superconductivity I - cuprate and other superconductors
BD: Exchange bias
BG: Energy assisted magnetic recording
BJ: Ferrites, garnets and other materials

AC: Low-dimensional / Frustrated spin systems
AF: Advanced methods of spin structure determination
AI: Semiconductor spintronics I - group IV materials
BB: Valence fluctuations I
BE: Magnetic semiconductor
BH: Interdisciplinary technology

CA: Superconductivity II - cuprate and other superconductors
CD: Heavy fermions I
CG: Semiconductor spintronics II - group III~V materials
CJ: Magneto-dielectric materials or meta-materials
DC: Spin-orbit / Spin-lattice / Spin-oribital physics
DF: Chiral magnet and magnetic skyrmions
DI: Spin caloritronics l
EB: SCES theory I
EE: Spin-orbit spin torque
EH: Novel materials and devices I

CB: Magnetic nanoparticles l
CE: Spin transfer oscillators
CH: Heusler alloys etc
DA: Superconductivity III - Fe-based superconductors
DD: Diluted magnetic semiconductors and others
DG: Magnetic nanowires
DJ: Applications
EC: Electronic structure / Spintronic materials
EF: Intermetallic compounds
EI: Perpendicular magnetic anisotropy materials

CC: Spin liquid / Spin ice
CF: Actinides and lanthanides
CI: Multiferroics II – scattering
DB: Kondo systems I
DE: Magnetic memories and logics
DH: Oxide
EA: Non-Fermi liquids and quantum phase transitions II
ED: Magnetic thin films and nanostructures l
EG: Metal spintronics l
EJ: Rare-earth hard magnetic materials

FB: Heavy fermions II
FE: SCES theory II

FC: Ultrafast switching I

JA: Superconductivity VI - Fe-based and other superconductors
JD: Magnetism theory / Simulation of quantum and classical systems
JG: Spin waves II
JJ: Magnetocaloric effects / Magnetoelastic materials
KC: Magnetic thin films and nanostructures ll
KF: Novel spintronic devices and materials
KI: Theoretical calculation

JC: Heavy fermions IV
JF: Metal spintronics III
JI: Strong magnetic anisotropy materials
KB: Magnetic nanoparticles ll
KE: Domain walls and spin ice system
KH: Coercivity mechanism

115

We wish you all a fruitful meeting and hope that you will benefit from the rich scientific programs, and your visit to wonderful Busan
will last forever as a pleasant memory.

Prof. Sung-Chul Shin
Chairperson, ICM2012
President, DGIST116
PB: Superconductivity I
PE: Kondo Impurity and kondo lattice systems
PH: 3d transition metal oxides I
PK: Perpendicular magnetic anisotropy and strong anisotrorpy
PN: Dilutedmagnetic semiconductor/nano-composite l

PC: Superconductivity V
PF: Theory of strongly correlated matter I
PI: 3d transition metal oxides II
PL: Surface and interface effects including exchange bias
PO: Interdisciplinary topics

QB: Superconductivity II
QE: Frustrated systems, kagome, triangular systems
QH: Intermetallic compounds ll
QK: Spin-dependent transport ll
QN: Soft magnetic materials ll

QC: Heavy fermions II
QF: 1D, low-dimensional systems
QI: Lanthanides I
QL: Diluted magnetic semiconductors and others
QO: Novel magnetic materials and devices ll

RB: Superconductivity III
RE: Non-fermi liquids and quantum phase transitions I
RH: Theory, spin, magnetic materials
RK: Ultrafast dynamics
RN: Magnetic nanoparticles
RQ: Measuring techniques and Instrumentation ll

RC: TopologicaI insulators I
RF: Theory of strongly correlated matter II
RI: Phase transition
RL: Spin electronics l
RO: Hard magnetic materials l
RR: Industrial applications

SB: Superconductivity IV
SE: Heavy fermions IV
SH: Domain and domain walls
SK: Spin electronics ll
SN: Hard magnetic materials II

SC: Superconductivity VI
SF: Non-fermi liquids and quantum phase transitions II
SI: Spin waves
SL: Magnetic nanostructures and arrays
SO: Novel magnetic materials and devices l

182

249

July 13 (Fri)The 19th International Conference on Magnetism

committee for their tremendous efforts in making this conference a success.

98

July 12 (Thu)

SA: Multiferroics IV
SD: Topologicai insulators II
SG: New developments
SJ: Modeling
SM: Magnetic thin films and others

I wish to take this opportunity to thank all the sponsors for their generous support for the ICM2012. Also, I would like to convey mysincere gratitude to the international advisory members for their valuable advices and to the members of the ICM2012 organizing

JB: Multiferroics IV - noncollinear magnets
JE: Domain wall motion lll
JH: Nanostructured and composite hard magnetic materials
KA: Kondo systems II
KD: Characterization of magnetic properties
KG: SCES theory III
KJ: New developments

July 10 (Tue)

RA: Multiferroics III
RD: Heavy fermions III
RG: Theory of strongly correlated matter III
RJ: Vortex dynamics
RM: Theoretical calculation
RP: Measuring techniques and instrumentation lwith 1,502 poster presentations. In addition, 7 satellite symposia will be held before or after the ICM2012.

GC: Heavy fermions III
GF: Spin glasses and diluted magnets
GI: Organic spintronics and carbon-based spintronics
HB: [Symposium] High performance soft magnetic materials and their applications I
HE: Metal spintronics II
HH: Magnetometry in macro-scale
IA: Non-fermi liquids and quantum phase transitions III
ID: Vortex dynamics II
IG: Valence fluctuations II
IJ: Ferrites and other materials

July 9 (Mon)

QA: Multiferroics II
QD: Valence fluctuations
QG: Intermetallic compounds I
QJ: Lanthanides ll
QM: Magnetic characterization
QP: Magnetic recording and memories /

lectures including 3 Nobel laureates’ lectures, 14 Half-plenary lectures, 509 oral presentations including 135 invited lectures, along

GB: Multiferroics III - nonreciprocal effect and elecgtronic ferroelectricity
GE: Domain wall motion I
GH: Novel materials and devices II
HA: Superconductivity V - Fe-based superconductors
HD: Spin waves I
HG: Magnetometery in nano-scale
HJ: 4d and 5d compounds
IC: Magnetic phase transition
IF: Magnetic tunnel junctions
II: Topological insulators II

Poster Presentation
PA: Multiferroics I
PD: Heavy fermions I
PG: Magnetic materials and characterization methods
PJ: Spin-dependent transport l
PM: Soft magnetic materials I

world. In this conference, we expect over 1,700 participants around the world. For the scientific program, we have planned 7 plenary

75

July 13 (Fri)International Conference on Strongly Correlated Electron Systems (SCES) held annually.
As the most highly acclaimed conference, a considerable number of abstracts have been submitted from 52 countries around the72

July 12 (Thu)
GA: Superconductivity IV - Fe-based superconductors
GD: Ultrafast switching II
GG: Arrays of magnetic nanostructures ll
GJ: Intermetallic and other hard magnets
HC: Magnetism in s,p electron systems
HF: Spin transfer torque switching
HI: Topological insulators I
IB: [Symposium] High performance soft magnetic materials and their applications II
IE: Domain wall motion II
IH: Surface and interface effects II

The major scientific societies in Korea, the Korean Physical Society (KPS) and the Korean Magnetics Society (KMS) are pleased to co48

July 11 (Wed)
FA: Spin caloritronics II
FD: Vortex dynamics I

to host the ICM2012 in Korea.

host the ICM2012, under the auspices of the International Union of Pure and Applied Physics (IUPAP). The ICM2012 incorporates theJuly 10 (Tue)2

Dear Colleagues,

Welcome Address

List of Abstracts

Plenary Lecture

316

July 8-13, 2012 Busan, Korea

3

Chairperson Sung-Chul Shin
Secretary General Kungwon Rhie

Int’l Advisory Committee

DGIST

Korea

		 Gabriel Aeppli

Korea University

Korea

Organizing Committee

		 Program Committee
Co-Chair Yoon Hee Jeong
		 Samuel Bader

UK

		 Jun Akimitsu

Aoyama Gakuin University

Japan		 Koji Ando

National Institute of Advanced Industrial Science and Technology (AIST) Japan

		 David Awschalom

University of California

USA

POSTECH

Korea

		 Elisa Baggio-Saitovitch

Brazilian Center for Research in Physics - CBPF

BrazilArgonne National Lab.

USA

		 Mario Baibich

Ministry of Science and Technology of Brazil

BrazilTohoku University

Japan		 Ganapathy Baskaran

The Institute of Mathematical Sciences

India

		 Byung Il Min

POSTECH

Korea

		 Ernst Bauer

Vienna University of Technology

Austria

		 Sang Ho Lim

Korea University

Korea

		 Robert Buhrman

Cornell University

USA		 Tae Won Noh

Seoul National University

Korea

		 Ching-Ray Chang

National Taiwan University

Taiwan		 Yong-Seung Kwon

DGIST

Korea

		 John Chapman

University of Glasgow

UK		 Yunkyu Bang

Chonnam National University

Korea

		 Sang-Wook Cheong

Rutgers University

USA		 Tuson Park

Sungkyunkwan University

Korea

		 Lesley Cohen

Imperial College

UK		 Cathy Stampfl

Sydney University

Australia

		 Alessandra Continenza Universita' degli studi dell'Aquila

Italy

		 Sang-Koog Kim

Seoul National University

Korea

		 E. Dan Dahlberg

University of Minnesota

USA		 Bernard Dieny

Commissariat à lE'nergie AtomiqueFrance		 Tomasz Dietl

University of Warsaw

PolandExecutive Member Hideo Ohno

		 Publication Committee
Chair Jae Il Lee

Inha University

Korea

		 You-Wei Du

Nanjing University

China

Yeungnam University

Korea

		 Albert Fert

Universite Paris-Sud

France		 Soonchil Lee

KAIST

Korea

		 Dino Fiorani

National Research Council

Italy

		 Joo Yull Rhee

Sungkyunkwan University

Korea

		 Peter Fischer

Lawrence Berkeley National Laboratory

USA		 Zachary Fisk

University of California

USA		 Catherine Foley

The Commonwealth Scientific and Industrial Research Organisation Australia

Member Dong Ho Kim

		 Treasurers Committee
Chair Bo Wha Lee
Member Sug-Bong Choe

Hankuk University of Foreign Studies

Korea

		 Mark Freeman

University of Alberta

CanadaSeoul National University

Korea

		 Hiroyasu Fujimori

Tohoku University

Japan		 Peter Fulde

Asia Pacific Center for Theoretical Physics

Germany		 Mohammad Ghafari

Karlsruhe Instiute of Technology

Germany		 Public Relation Committee
Chair Chun-Yeol You

Inha University

Korea

		 Amitabha Ghoshray

Saha Institute of Nuclear Physics

India

Kookmin University

Korea

		 Laura Greene

University of Illinois at Urbana Champaign

USA		 Bongjin Simon Mun

Hanyang University

Korea

		 Peter A. Grünberg

Institute of Solid State Resaerch

Germany		 Hae-In Yim

Sookmyung University

Korea

		 Ott Hans Rudolf

Eidgenössische Technische Hochschule Zürich

Switzerland

		 Bret Heinrich

Simon Fraser University

Canada		 Laura Heyderman

Paul Scherrer Institute

Switzerland

Member Taejoon Kouh

		 Industrial Support Committee
Chair Kyung-Ho Shin
Member Derac Son

Korea Institute of Science and Technology

Korea

		 Burkard Hillebrands

TU Kaiserslautern

Germany

Hannam University

Korea

		 Axel Hoffman

Argonne National Laboratory

USA		 Nguyen Huu Duc

Vietnam National University

Vietnam		 Manuel Ricardo Ibarra

Zaragoza University

Spain

		 Exhibition Committee
Chair Chan Yong Hwang
Member Jae-Hoon Park

Korea Reserch Institute of Standards and Science

Korea

		 Flouquet JacquesCommissariat à lE'nergie AtomiqueFrancePohang University of Science and Technology

Korea

		 Sung-Ho Jin

UC San Diego

USA			

		 Xiaofeng Jin

Fudan University

China		 Borje Johansson

University of Uppsala

Sweden		 Local Committee
Chair Hae-Woong Kwon

Pukyung National University

Korea

		 Il Koo Kang

The Korean Magnetics Society

Korea

University of Ulsan

Korea

		 Bernhard Keimer

Max Planck Institute for Solid State Research

Germany

		 Myung Hwa Jung

Sogang University

Korea

		 Zheong Gou Khim

Seoul National University

Korea

		 Gwan Soo Park

Pusan National University

Korea

		 Chul Koo Kim

Yonsei University

Korea

		 Chul Sung Kim

Kookmin University

Korea

		 Jürgen Kirschner

Max Planck Institute of Microstructure Physics

Germany		 Guangli Kuang

Chinese Academy of Sciences

China

		 Budhy Kurniawan

University of Indonesia

Indonesia

Member Sunglae Cho

4

University College London

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Int’l Advisory Committee

Organizing Committee

56Program Committee

		 J. Raynien Kwo

National Tsing Hua University

Taiwan

		 Patrick Lee

MIT

USA

		 Liang Li

Huazhong University of Science and Technology

China

		 Peter Littlewood

Argonne National Laboratory

USA		 Bo Liu

Data Storage InstituteSingapore

		 Hilbert Löhneysen

Karlsruhe Institute of Technology

Germany

		 Jan Cees Maan

Radboud University Nijmegen

Netherlands

		 Allan MacDonald

University of Texas at Austin

USA		 Sadamichi Maekawa

The Japan Atomic Energy Agency

Japan

		 Yoshiteru Maeno

Kyoto University

Japan		 Brian Maple

University of California, San Diego

USA

		 Andrew Millis

Columbia University

USA		 Laurens W. Molenkamp Wuerzburg University

Germany		 John MydoshLeiden University

Netherlands

		 Kevin O’Grady

The University of YorkUK

		 Yoshichika Onuki

Osaka Univeristy

Japan

		 Martha Pardavi-Horvath The George Washington University

USA		 Stuart Parkin

IBM Almaden Research Center

USA		 Massimo Pasquale

L'Istituto Nazionale di Ricerca Metrologica

Italy		 Danilo Pescia

Eidgenössische Technische Hochschule Zürich

Switzerland

		 Stefania Pizzini

Centre National de la Recherche Scientifique

France		 Sergio Rezende

Universidade Federal de Pernambuco

Brazil		 John Sarrao

Los Alamos National Laboratory

USA		 Ivan Schuller

University of California-San Diego

USA		 Zhi-Xun Shen

Stanford University

USA		 Teruya Shinjo

International Institute for Advanced Studies

Japan		 Qimiao Si

Rice University

USA		 Manfred Sigrist

ETH Zürich

Switzerland

		 John Slonczewski

IBM Research Center

USA		 Robert Stamps

University of Glasgow

UK		 Frank Steglich

Max Planck Institute for Chemical Physics of Solids

Germany

		 Takao Suzuki

University of Alabama

USA

		 Henryk Szymczak

Polish Academy of Sciences

Poland		 Toshiro Takabatake

Hiroshima University

Japan

		 Hidenori Takagi

University of TokyoJapan

		 Migaku Takahashi

Tohoku University

Japan		 Koki Takanashi

Tohoku University

Japan

		 Yoshinori Tokura

University of TokyoJapan

		 Kazuo Ueda

University of Tokyo

Japan

		 Chandra Varma

University of California, Riverside

USA		 Manuel Vazquez

Spanish National Council for Research

Spain

		 Hai-Hu Wen

Nanjing University

China		 Yeong-Der Yao

Fu Jen University

TaiwanThe 19th International Conference on Magnetism

Co-Chairs Yoon Hee Jeong
Samuel Bader
Executive Member Hideo Ohno		 Byung Il Min
		 Sang Ho Lim
		 Tae Won Noh
		 Yong-Seung Kwon
		 Yunkyu Bang		 Tuson Park
		 Cathy Stampfl
		 Sang-Koog Kim

POSTECH
Argonne National Lab.

Korea
USA

Tohoku University
POSTECH
Korea University
Seoul National University
DGIST
Chonnam National University
Sungkyunkwan University
Sydney University
Seoul National University

Japan
Korea
Korea
Korea
Korea
Korea
Korea
Australia
Korea

Program Committee

Int’l Advisory Committee

Int’l Advisory Committee

1. Strongly Correlated Electron System (SCES) (including Superconductivity/ Multiferroics)
1-1 Keehoon Kim
Multiferroics Taka-hisa Arima
		 M. Fiebig
		 Tsuyoshi Kimura
		 Tae Won Noh
		 Je-Geun Park		 L. P. Regnault

Seoul Natonal University
University of Tokyo
ETH
Osaka University
Seoul Natonal University
Seoul Natonal University
ILL

Korea
Japan
Switzerland		
Japan
Korea
Korea
France1-2 T. DevereauxSuperconductivity Yunkyu Bang		 D. L. Feng
		 Changyoung Kim
		 Matthias Vojta

Standford University
Co-chair / Chonnam National Universityty
Fudan University
Yonsei University
Technische Universitaet Dresden

USA
Korea
China			KoreaGermany

1-3 Hu-Jong Lee
Topological Insulators Mahn-Soo Choi
		 Jun Sung Kim
		 Young-Woo Son
		 Han Woong Yeom

POSTECH
Korea University
Pohang University of Science and Technology
Korea Institute for Advanced Study
Pohang University of Science and Technology

Korea
Korea
Korea
Korea
Korea

1-4 Joe D. Thompson
Heavy Fermion Systems Meigan Aronson
Piers Coleman		 Noriaki Sato

Co-chair / Los Alamos National Laboratory
Brookhaven National Laboratory
Rutgers University
Nagoya University

USA
USA
UK
Japan

1-5 Tuson Park
Valence Fluctuations Jeongsoo Kang		 Kazumasa Miyake
		 Huiqiu Yuan

Sungkyunkwan University
The Catholic University of Korea
Osaka University
Zhejiang University

Korea
Korea
Japan
China

1-6 Suchitra Sebastian
Non-Fermi Liquids and A. Huxley
Quantum Phase Yuji Matsuda
Transitions Toby Perring

University of Cambridge
University Edinburgh
Kyoto University
ISIS

UK
UK
Japan
UK

1-7 Steffen Wirth
Konndo Impurity and Bernard Coqblin
Kondo Lattice Systems Jeongsoo Kang
Yongseung Kwon

Max Planck Institute for Chemical Physics of Solids
University Paris
The Catholic University of Korea
DGIST

Germany
FranceKorea
Korea

1-8 Takami Tohyama
Theory of Strongly T. Devereaux
Correlated Matter Dirk Manske
		 Jaejun Yu

Kyoto University
Standford University
Max Planck Institute for Solid State Research
Seoul National University

Japan
USA
Germany
Korea

July 8-13, 2012 Busan, Korea

7

Program Committee

Program Committee

Program Committee

		 Byungil Min
		 Giniyat Khaliullin		 Mi Young Kim
		 Jae-Hoon Park
		 Myriam P. Sarachik

10. Magnetic Recording and Memories
POSTECHMax Planck Institute for Solid State Research
Ajou University
POSTECH
City College of New York-CUNY

Korea
Germany
Korea
Korea
USA

		 Eunsik Kim
		 Sung Woong Chung
		 Katsuji Nakagawa
		 Shin Saito

Samsung Electronic Co.
Hynix
Nihon University
Tohoku University

Korea
Korea
Japan
Japan

Program Committee

2. Quantum and Classical Spin Systems

11. Measuring Techniques and Instrumentation
3. Magnetic Structures and Interactions
		 Kibong Lee
		 Des McMorrow
		 Seung-Hun Lee
		 Je-Geun Park
		 Kazuyoshi Yamada

POSTECH
University College London
University of Virginia
Seoul Natonal University
KEK

Korea
UK
USA
Korea
Japan

Korea
USA
Korea
Spain
UK
Germany

Hannam University
National Physical Laboratory
INRIM
KRISS

Korea
UK
Italy
Korea

KIST
POSCO

Korea
Korea

Chungnam National University
AIT Austrian Institute of Technology GmbH
Yonsei University
University of Minnesota

Korea
Austria
Korea
USA

12. Industrial Applications
		 Kyung-Ho Shin		 Sang Yun Cha

4. Magnetization Dynamics and Micromagnetics
		 Sang-Koog Kim
Seoul Natonal University
		 Kristen BuchananColorado State University
		 Sug-Bong Choe
Seoul Natonal University		
Oksana Chubykalo-Fesenko Instituto de Ciencia de Materiales de Madrid, CSIC
		 Volodymyr Kruglyak
University of Exeter
		 Guido Meier
University of Hamburg

		 Derac Son
Michael Hall
		 Massimo Pasquale
		 Kwon Sang Yoo

13. Interdisciplinary Topics
		 Cheol Gi Kim
Hubert Brueckl
		 Wooyoung Lee
		 Jian-Ping Wang

5. Spin-Dependent Transport
		 Hyun-Woo Lee
		 Myung-Hwa Jung
		 Stephen Russek
		 Henk Swagten
		 Suzuki Yoshishige

POSTECH
Sogang University
NIST
Eindhoven University of Technology
Osaka University

Korea
Korea
USA
Netherlands
Japan

KIST
SPINTEC
State Key Laboratory of Magnetism
Korea University
Kyoto University
Hitachi Cambridge Lab

Korea
France
China
Korea
Japan
UK

6. Spin Electronics
		 Byoung Chul Min
		 Ursula Ebels
		 Xiufeng Han
		 Kyung-Jin Lee
		 Teruo Ono
		 Joerg Wunderlich

7. Magnetic Thin Films, Particles and Nanostructure
		 Sang Ho Lim
		 Chan Yong Hwang
		 Tae Hee Kim
Seiji Mitani
		 Zi Q. Qiu

Korea University
KRISS
Ewha Wonans University
NIMS
UC-Berkeley

Korea
Korea
Korea
Japan
USA

8. Soft and Hard Magnetic Materials and their Applications
		 Hae-Woong Kwon
Hirotoshi Fukunaga
		 Satoshi Sugimoto
		 Seong-cho Yu

Pukyong National University
Nagasaki University
Tohoku University
Chungbuk National University

Korea
Japan
Japan
Korea

University of Ulsan
Gwangju Institute of Science and Technology (GIST)
Universita' degli studi dell'Aquila
Kurume Institute of Technology

Korea
Korea
Italy
Japan

9. Novel Materials and Device Applications
		 Sunglae Cho
		 Beongki Cho
		 Alessandra Continenza		 Gendo Oomi

8

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

9Program at-a-Glance

Editors
Chief Jae Il Lee

Editors & Speakers

Member Joonyeon Chang
		 Soon Cheol Hong
		 Namjung Hur		 Young-Rok Jang
		 Gun Sang Jeon
		 Kee Hoon Kim
		 Dong-Hyun Kim
		 Dong Ho Kim
		 Tae Wan Kim
		 Sang-Suk Lee
		 Soonchil Lee
		 Joo Yull Rhee
		 Seok-Soo Yoon

Inha University

Korea

KIST
University of Ulsan
Inha University
University of Inchoen
Ewha Womans University
Seoul National University
Chungbuk National University
Yeungnam University
Sejong University
Sangji University
KAIST
Sungkyunkwan University
Andong National University

Korea
Korea
Korea
Korea
Korea
Korea
Korea
Korea
Korea
Korea
Korea
Korea
Korea

Time

July 8 (Sun)

08:30

July 9 (Mon)

July 10 (Tue)Opening & Award

09:00

Plenary 1
PP01

10:00

July 12 (Thu)

July 13 (Fri)Half-Plenary
9~14

Invited &Contributed

Plenary 4
PP04

Half-Plenary
1~6
HP11~HP32

Plenary 5
PP05

Coffee Break

11:00

July 11 (Wed)

Program at-a-Glance

Editors & SPEAKERS

HP51~HP72

JA~JJ

Plenary 2

Coffee BreakCoffee BreakCoffee BreakCoffee BreakPlenary 3

Invited &Contributed

Invited &Contributed Half-Plenary
FA~FE
7~8

Invited &Contributed

Invited &Contributed

PP02

12:00

PP02

CA~CJ

HP41~HP42

GA~GJ

KA~KJ

Plenary Speakers
		 Albert Fert

CNRS/Thales and University Paris-Sud

France		 *Nobel laureate in Physics (2007)

		 Andre Geim

University of Manchester

13:00

Lunch

Lunch

Lunch

Lunch

PosterPresentation I

PosterPresentation II

PosterPresentation III

PosterPresentation IV

Invited &Contributed

Invited &Contributed

Invited &Contributed

Plenary 6

Break

Break

UK

		 *Nobel laureate in Physics (2010)

		 Klaus von Klitzing

Max Planck Institute for Solid State Research

Germany

		 *Nobel laureate in Physics (1985)

		
Sang-Wook Cheong

Rutgers University

USA		 Zachary Fisk

University of California, Irvine

USA		 Sadamichi Maekawa

Japan Atomic Energy Agency

Japan		 Roland Wiesendanger

University of Hamburg

Germany

University College London
Rutgers University
Max Planck Institute for Chemical Physics of Solids
Paul Scherrer InstituteMax Planck Institute for Solid State Research
POSTECH
Seoul National University
Tohoku University
Osaka University
IBM Almaden Research Center
Massachusetts Institute of Technology
University of Tokyo
Stanford University
Tsinghua University

UK
UK
Germany
Switzerland
Germany
Korea
Korea
Japan
Japan
USA
USA
Japan
USA
China

Half-Plenary Speakers
		 Gabriel Aeppli
		 Piers Coleman
		 Claudia Felser
		 Laura Heyderman
		 Bernhard Keimer
		 Hyun-Woo Lee
		 Tae Won Noh
		 Hideo Ohno
		 Yoshichika Onuki
		 Stuart Parkin		 Caroline Ross
		 Yoshinori Tokura
		 Shoucheng Zhang
		 Xiaozhong Zhang

14:00

Registration

15:00

16:00

PA~PO

KPS 60th
Anniversary
Nobel laureatein Physics
Public Lecture

17:00

18:00

Welcome
Reception

AA~KJ

QA~QP

DA~DJ

RA~RR

Excursion

SA~SO

PP06

HA~HJ

Plenary 7

Break

PP07

Closing
Invited &Contributed
BA~BJ

Invited &Contributed
EA~EJ

Invited &Contributed
IA~IJ

19:00
Banquet20:00

10

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

1112
The 19th International Conference on Magnetism

20:00

19:00

18:00

17:00

16:00

15:00

14:00

13:00

12:00

11:00

10:00

09:00

08:00

20:00

19:00

18:00

17:00

16:00

15:00

14:00

13:00

12:00

11:00

10:00

09:00

08:00

Zachary Fisk

Plenary 3

PP03

Sadamichi
Maekawa

Plenary 2

PP02

Coffee BreakAlbert Fert

Plenary 1

PP01

Opening&Award

Auditorium

1) Albert Fert
2) Klaus von Klitzing

KPS 60th
Anniversary
Nobel laureatein Physics
Public Lecture

Auditorium

Superconductivity I- cuprate and othersuperconductors

BA

AA

Multiferroics I mainly manganites

Valencefluctuations I

BBAB

Non-fermi liquids
and quantum
phase transitions I

Organic andmolecular
magnetism / SpinladderBC

AC

Low-dimensional /Frustrated spin
systems

Exchange bias

BD

AD

Surface andinterface effects I

Room 101~3 Room 106~8 Room 104~5 Room 109~10

1F

Room 101~3 Room 106~8 Room 104~5 Room 109~10

1F
Room 202

AF

AG

Room 203

Room 203

2F

2F

BF

BG

3d transition metal
Energy assistedoxidesmagnetic recording

Break
Magnetic
semiconductor

BEElectric field effect Advanced methods Arrays of magnetic
on magnetic
of spin structure
nanostructures I
systems
determination

AE

Room 202

Lunch

Room 201

July 9 (Mon)

Welcome Reception(2F, Lobby)

Room 201

July 8 (Sun)Interdisciplinary
technology

BH

AH

Magnetictransducers inbiomedicine

Room 204

Room 204

Ferrites, garnets
and other materials

BJ

AJ

Crystalline,
nanocrystalline
and amorphousmaterials

Room 206

Room 206

Room 301

3F

Room 301

Program at-a-Glance

STT MRAM andmagnetic logic

BI

AI

Semiconductor
spintronics I group IV materials

Room 205

Room 205

3F

Program at-a-Glance

Exhibition

PosterPresentation
I

PA~PO

Exhibition

Exhibition

Registration

Exhibition

Program at a Glance
Program at a Glance

July 8-13, 2012 Busan, Korea

13

14
The 19th International Conference on Magnetism

Auditorium

20:00

19:00

18:00

17:00

16:00

15:00

14:00

13:00

12:00

11:00

10:00

09:00

08:00

20:00

19:00

18:00

17:00

16:00

15:00

14:00

13:00

12:00

PP04

Roland Wisendanger

Plenary 5

PP05

Klaus von Klitzing

Plenary 4

HP22

SCES Theory IEBDB

Kondo systems I

Magnetic
nanoparticles l

CB

1F

ED

DD

Diluted magnetic
semiconductors
and others

Heavy fermions I

CDElectronic structure Magnetic thin films/ Spintronic
and nanostructuresmaterials
l

EC

DC

Spin-orbit /Spin-lattice /Spin-oribital
physics

Spin liquid /Spin iceCC

FA

Spin caloritronics ll

FB

Heavy fermions II

Room 101~3 Room 106~8 Room 104~5 Room 109~10

Non-fermi liquids
and quantum
phase transitions II

EA

DASuperconductivity
III - Fe-based
superconductors

Superconductivity
II - cuprate andothersuperconductors

CA

Half-Plenary 4
Piers Coleman

HP12

10:00
Half-Plenary 2
Tae-Won Noh

HP11

HP21

Half-Plenary 3
Hyun-Woo Lee

Half-Plenary 1
Yoshichika Onuki

11:00

1F
Room 101~3 Room 106~8 Room 104~5 Room 109~10

09:00

08:00

Auditorium

FC

FD

Room 202

Excursion

Ultrafast switching I Vortex dynamics I

Coffee BreakRoom 201

July 11 (Wed)Intermetallic
compounds

EF

DF

Chiral magnet
and magnetic
skyrmions

Lunch

CF

Actinides andLanthanides

Coffee BreakRoom 202

Break
Spin-orbit spin
torqueEE

DE

Magnetic
memories andlogicsSpin transfer
oscillators

CE

Room 201

July 10 (Tue)FE

SCES theory II

Room 203

2F

Metal spintronics l

EG

DG

Magnetic
nanowiresCG

Semiconductor
spintronics II group III~V
materials

Room 203

2F

Room 204

Novel materials
and devices I

EH

DH

Oxide

CH

Heusler alloys etc

Room 204

Half-Plenary 8
Gabriel Aeppli

HP42

HP41

Half-Plenary 7
Stuart Parkin

Room 206

Rare-earth hardmagnetic materials

EJ

DJ

Applications

CJ

Magneto-dielectricmaterials or
meta-materials

Room 206

Room 301

3F

Room 301

Program at-a-Glance

Room 205

Perpendicularmagnetic
anisotropy
materials

EI

DI

Spin caloritronics lCI

Multiferroics II scattering

HP32

Half-Plenary 6
Bernhard Keimer

HP31

Half-Plenary 5
Yoshinori Tokura

Room 205

3F

Program at-a-Glance

Exhibition

Exhibition

Exhibition

Exhibition

PosterPresentation
II

QA~QP

Exhibition

Exhibition

Program at a Glance
Program at a Glance

July 8-13, 2012 Busan, Korea

15

16
The 19th International Conference on Magnetism

Auditorium

20:00

19:00

18:00

17:00

16:00

15:00

14:00

13:00

12:00

11:00

10:00

09:00

08:00

20:00

19:00

18:00

17:00

16:00

15:00

14:00

13:00

12:00

ClosingAndre Geim

Plenary 7

PP07

Sang-Wook Cheong

PP06

Plenary 6

HP62

1F

[Symposium]
High performance
soft magnetic
materials and theirapplications II

IB

HB

Magnetic phasetransition

IC

HC

Magnetism in s,pelectron systems

Heavy fermions III

GC

Vortex dynamics IIID

HDSpin waves I

Ultrafast switching
II

GD

KA

Kondo systems II

JASuperconductivity
VI - Fe-based andothersuperconductors

KB

Magnetic
nanoparticles ll

JB

Multiferroics IV noncollinear
magnets

KC

KD

JD

Magnetic thin films Characterization ofand nanostructures
magneticllproperties

JC

Heavy fermions IV Magnetism theory /Simulation ofquantum andclassical systems

Room 101~3 Room 106~8 Room 104~5 Room 109~10

Non-fermi liquids
and quantum
phase transitions
III

IA

HA

Multiferroics III nonreciprocal
effect andelecgtronic
ferroelectricity

GBSuperconductivity V[Symposium]- Fe-basedHigh performancesuperconductors
soft magnetic
materials and theirapplications I

Superconductivity
IV - Fe-based
superconductors

GA

Half-Plenary 12
LJ Heyderman

HP52

10:00
Half-Plenary 10
Hideo Ohno

HP51

HP61

Half-Plenary 11
Xiaozhong Zhang

Half-Plenary 9
Caroline A. Ross

11:00

1F
Room 101~3 Room 106~8 Room 104~5 Room 109~10

09:00

08:00

Auditorium

HE

Domain walls andspin ice system

Domain wallmotion lll

KEIF

Magnetic tunnel
junctions

Break

Room 201

JE

HF

Spin transfer
torque switching

Lunch

KF

Novel spintronic
devicesand materials

Coffee BreakJF

Metal spintronics
III

Room 202

July 13 (Fri)Domain wallmotion II

IE

Metal spintronics ll

LunchSpin glasses anddiluted magnets

GF

Room 202

Coffee BreakDomain wallmotion I

GE

Room 201

July 12 (Thu)

KG

SCES theory III

JG

Spin waves II

Room 203

Valencefluctuations II

IG

HG

KH

Coercivity
mechanism

JH

Nanostructured
and composite
hard magnetic
materials

Room 204

IH

HH

Magnetometry inmacro-scale

GH

Novel materials
and devices II

Room 204

Surface andinterface effects II

2F

Magnetometery in
nano-scale

GG

Arrays of magnetic
nanostructures ll

Room 203

2F

KI

Theoretical
calculation

JI

KJ

New developments

JJ

Magnetocaloric
effects /Magnetoelastic
materials

Room 206

Ferrites and othermaterials

IJ

HJ

4d and 5dcompounds

GJ

Intermetallic andother hardmagnets

Room 206

Room 301

3F

BanquetRoom 301

Program at-a-Glance

Strong magnetic
anisotropy
materials

Room 205

Topologicalinsulators IIII

HITopologicalinsulators I

GI

Organic spintronics
and carbon-based
spintronics

HP72

Half-Plenary 14
Claudia Felser

HP71

Half-Plenary 13
Shoucheng Zhang

Room 205

3F

Program at-a-Glance

Exhibition

PosterPresentation
IV

SA~SO

Exhibition

Exhibition

Exhibition

PosterPresentation
III

RA~RR

Exhibition

Exhibition

Program at a Glance
Program at a Glance

July 8-13, 2012 Busan, Korea

17

Venue Layout

Venue Layout
Convention Hall (1F)BEXCO

Invited ·· Contributed
Contributed
Invited

106

107

108

109

110

101

102

103

104

105

Venue Layout

Venue Layout

Half-Plenary //Half-Plenary
Invited ·· Contributed
Contributed
InvitedInvited ·· Contributed
Contributed
InvitedBusan Museumof Art Station, Line 2

Half-Plenary //Half-Plenary
Invited ·· Contributed
Contributed
InvitedPublication Room
Room
Publication

Glass Room

Exhibition
Center I

Poster & Exhibition

Exhibition
Hall 1

Airport Limousine
to Airport

Registration

Banquet (3F)

Convention Hall (2F)ICM Meeting
Meeting Room
Room
ICM

Convention
Hall

Opening Ceremony
Closing Ceremony
Plenary Session

Secretariat
Secretariat

Invited ·· Contributed
Contributed
InvitedHalf-Plenary //Half-Plenary
Invited ·· Contributed
Contributed
Invited

Auditorium
Parking Lot

Centum City Station(BEXCO), Line 2

Airport Limousinefrom Airport

203

204

201

202

206

207

208

205

Exhibition
Center II

Access toto Auditorium
Auditorium
Access

Welcome Reception
Reception
WelcomeBanquet18

The 19th International Conference on Magnetism

301

July 8-13, 2012 Busan, Korea

19

CEREMONY & EVENT Program

KPS 60th Anniversary Nobel Laureate Public Lectures in Physics

Closing Ceremony

In celebration of the KPS’s 60th anniversary, the Public Lecture of Nobel laureate in Physics will be a program allowing the general public tolearn about the interesting aspects of Physics. This public lecture program will be an exciting and enjoyable experience. Please do not miss thischange to take the lectures on free.

Have the opportunity to say farewell to friends and colleagues and to preview the next venue of ICM2015.

This public lecture program will be an exciting and enjoyable experience for Korean audience interested in Physics.
· Date & Time: July 8 (Sun), 15:00~17:00· Venue:
Auditorium· Lecture:
1. Prof. Albert Fert - Spintronics and its impact on inforamtion and communication technologies		
2. Prof. Klaus von Klitzing - New applications of my Nobel prize· Date & Time: July 13 (Fri), 17:30~18:00· Venue:
Auditorium

Ceremony & Event Program

Ceremony & Event Program

CEREMONY & EVENT Program

Industrial Tour
Participants those who applied for industrial tour of Samsung Heavy Industries Co., Ltd. should be gathered at 13:20 on July 11 (Wed)at the lobby. We will leave 13:30 on time. Application can be acceptable until 10:00 on July 9 at the information desk (Max. 100
people).
· Date & Time: July 11 (Wed), 13:30~18:00· Destination: Samsung Heavy Industries Co., Ltd.

Welcome Reception
You will experience a warm welcome from the host of ICM2012. All participants are highly welcome.
Light refreshments and beer will be provided free of charge.
· Date & Time: July 8 (Sun), 17:00~19:00· Venue:
Lobby of Convention Hall, 2F

Opening Ceremony
ICM2012 will officially get started with a ceremony at Auditorium in Bexco. All registered participants are cordially invited to join us
and celebrate the official opening.
· Date & Time: July 9 (Mon), 08:30~09:00· Venue:
Auditorium

ICM Award 2012
The IUPAP Magnetism Award and Néel Medal are presented every three years at the International Magnetism Conference to a scientist
in recognition of an outstanding contribution to the field of magnetism. The award is sponsored by Elsevier Science B.V.. The IUPAP
Young Scientist Medals in the field of magnetism are presented every three years at the International Magnetism Conference. The
medals are sponsored by IUPAP.
· Date & Time: July 9 (Mon), 08:30~09:00· Venue:
Auditorium

Magnetism Award and Néel Medal 2012
· Sadamichi Maekawa (Japan Atomic Energy Agency, Japan)
Heat and spin
· Yoshinori Tokura (University of Tokyo, Japan)
Electrodynamics of skyrmions

Young Scientist Medals in the Field of Magnetism· Suchitra E. Sebastian (University of Cambridge, UK)
Nodal pocket revealed by quantum oscillations in an underdopedcuprate superconductor

BanquetPlease join us to share an unforgettable evening. A delicious dinner with a traditional Korean music show, Samulnori (traditional
percussion quartet) and ‘B-boy’, is combined to recreate the wonderful excitement performance.
· Date & Time: July 12 (Thu), 19:00~20:30· Venue:
Room 301 (3F), Convention Hall20

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

21

General Information

Scientific Program

Poster Presentation Guideline

ICM2012 program will consist of 7 plenary talks (1 hr), 14 half-plenary talks (45 min) and 135 invited talks (30 min). Over 2,000
contributed papers will be presented, 353 of them have been selected for oral presentation (15 min). In addition, poster presentations
with ample time for discussion will be conducted. The official conference language is English. The program will focus on following topics;

Posters are displayed in the Exhibition Hall 1 (1F). Poster should be posted by 08:30 and dismantled after 18:00 on the allotted date. The
secretariat will not be held liable for any lost or damaged posters. All poster presenters are encouraged to be at their poster panels fordiscussion with participants during the time. All posters will be eligible for nomination for the best poster awards in each day.

1. Strongly Correlated Electron System (SCES)
2. Quantum and Classical Spin Systems
3. Magnetic Structures and Interactions
4. Magnetization Dynamics and Micromagnetics
5. Spin-Dependent Transport
6. Spin Electronics
7. Magnetic Thin Films, Particles and Nanostructures
8. Soft and Hard Magnetic Materials and Their Applications
9. Novel Materials and Device Applications
10. Magnetic Recording and Memories
11. Measuring Techniques and Instrumentation
12. Industrial Applications
13. Interdisciplinary Topics· Venue:			 Exhibition Hall 1· Operation: 			 July 9, 10, 12, 13 (4days), 13:30~15:30
				 Affixation: 08:30~13:00 / Presentation: 13:30~15:30 / Removal: 18:00~19:00· Affixation & Removal: All presenters are requested to affix their posters and remove them after their presentationaccording to the above schedule.The secretariat will not be held liable for any posters lost or damaged.
· Best Poster Award: There is a competition for the best poster. This award is given to recognize excellence inresearch and presentation. There will be two awards for each day. Each session chair is to nominate a single
poster. The final review will be run by program executive members and the best awards are announced 30
minutes before the closing of the session.

Coffee BreakEnjoy your break with a cup of coffee or tea that will be prepared as below;

Registration
All attendees will be required to wear the ICM2012 badge to access to all session.
· Venue:
Lobby, Exhibition Hall 1· Operation: July 8 (Sun) / 13:00~19:00
		July 9 (Mon) ~ 12 (Thu) / 08:00~19:00
		July 13 (Fri) / 08:00~13:00
Registration Fee
Category
Registration Fee

On-site Registration

Regular Participant

KRW 750,000

Student/Retired Participant

KRW 400,000

Accompanying Person

KRW 250,000

All Participants

KRW 60,000

Banquet Fee (July 12)

General Information

General Information

General Information* Participant's registration includes: Welcome reception, coffee breaks, admission to all scientific sessions, and a conference bag including abstract book* Accompanying person's registration includes: Welcome reception, coffee breaks, banquet coupon and conference bag. Admission to scientific sessions is not included.

Certificate of Attendance
The certificate of attendance is provided at the information desk on request or available for download via the website after the
conference (www.icm2012.org).

Internet Lounge

Morning

July 9 (Mon)

July 10 (Tue)July 11 (Wed)July 12 (Thu)

July 13 (Fri)10:00~10:20

10:30~11:00

10:30~11:00

10:30~11:00

10:30~11:00

Lobby
Auditorium

1F, 2F Lobby
Conventional Hall

1F, 2F Lobby
Conventional Hall

1F, 2F Lobby
Conventional Hall

1F, 2F Lobby
Conventional Hall

13:30~15:30

13:30~15:30-

13:30~15:30

13:30~15:30

Exhibition Hall

Exhibition Hall-

Exhibition Hall

Exhibition Hall

Afternoon

Complimentary Shuttle Service
Shuttle bus will run between the conference venue and hotels. You may check the schedule and shuttle bus stop.
The bus stop will be marked with banner stands at BEXCO.
July 8 (Sun)
H→B
B →H

July 9 (Mon)
H →B
B →H

July 10 (Tue)
H →B
B →H

July 11 (Wed)
H →B
B →H

July 12 (Thu)
H →B
B →H

July 13 (Fri)
H →B
B →H

The Westin Chosun Busan

13:00
14:00

18:00
19:00

08:00
08:30

19:10
19:40

08:00
08:30

19:10
19:40

08:00
08:30

13:00
14:00

08:00
08:30

19:10
21:00

08:00
08:30

18:30
19:00

Paradise Hotel Busan
Seacloud Hotel

13:00
14:00

18:00
19:00

08:00
08:30

19:10
19:40

08:00
08:30

19:10
19:40

08:00
08:30

13:00
14:00

08:00
08:30

19:10
21:00

08:00
08:30

18:30
19:00

Hotel Riviera Haeundae

13:00
14:00

18:00
19:00

08:00
08:30

19:10
19:40

08:00
08:30

19:10
19:40

08:00
08:30

13:00
14:00

08:00
08:30

19:10
21:00

08:00
08:30

18:30
19:00

Novotel HotelBusan Ambassador

13:00
14:00

18:00
19:00

08:00
08:30

19:10
19:40

08:00
08:30

19:10
19:40

08:00
08:30

13:00
14:00

08:00
08:30

19:10
21:00

08:00
08:30

18:30
19:00

Lotte Hotel Busan

14:00

19:00

8:00

19:10

8:00

19:10

8:00

13:00

8:00

19:10

8:00

18:30

Hanwha Resort

13:00
14:00

18:00
19:00

08:00
08:30

19:10
19:40

08:00
08:30

19:10
19:40

08:00
08:30

13:00
14:00

08:00
08:30

19:10
21:00

08:00
08:30

18:30
19:00

Hotel

Internet access will be available during the conference at the Exhibition Hall where a PC computer pool will be provided.

Publication Room
Authors can check the status of their manuscripts in the Publication Room, located in the Glass Room on the first floor of convention
hall. Office hour of the Publication Room for authors will be as follows.
· Operation Hours: July 9 (Mon), 15:00~17:00
				 July 10 (Tue), 12 (Thu), 10:00~12:00, 15:00~17:00
				 July 11 (Wed), 13 (Fri), 10:00~12:00

Oral Presentation Guideline

H → B: From Hotel to Bexco, B → H: From Bexco to Hotel* Shuttle Service won`t be provided for Haeundae Centum Hotel and ARPINA Buasn Youth Hostel located in walking distance.
* Participant who is staying in Haeundae Grand Hotel, please take a shuttle bus at the Westin Chosun Busan.

Authors are expected to bring their presentations on their own laptop computer, and to have it powered up and ready to connect tothe projector. Only standard PC-style VGA connections to the LCD projector will be supplied, therefore you must supply any required
adaptor to connect up your computer.

22

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

23

General Information
Cloak Room
The cloakroom will be located in the exhibition hall so that you could keep your luggage during the conference.

Exhibition
Exhibition Hall (1F)
Exhibition

General Information

Water Station
One or two bottles of water will be provided each day. The Water Coupons will be given to all participants when you register. It will becontributed at the cloak room.

Venue: BEXCO (Busan Exhibition Convention Center)
BEXCO, a landmark in the world-famous port city of Korea, has emerged as the most competitive exhibition and convention center inNortheast Asia.
· Address		 43 APEC-ro, Haeundae-gu, Busan 612-740, Korea· Tel		+82-51-740-7300· Fax		+82-51-740-7320· Website		www.bexco.co.kr

ICM2012 Secretariat· Onsite Secretariat Office: Room 208, Convention Hall, Tel: 051-740-3730· After the Conference: 1f Haeoreum Bldg.,16, Yeoksamro 17 gil, Gangnam-gu, Seoul 135-925, Korea
					
Tel: +82-2-557-8422 Fax: +82-2-566-6087 Email: icm@icm2012.org
					Website: www.icm2012.org

Venue: Exhibition Hall 1
Exhibition Schedule· Installation: Shell Scheme Booth: July 8 (Sun) 08:00~
Exhibits & Display: July 8 (Sun) 18:00~24:00· Exhibition Hours: July 9 (Mon)~12 (Thu), 09:00~19:00
July 13 (Fri), 09:00~16:00· Removal: July 13 (Fri),16:00~20:00

Exhibitor

The 19th International Conference on Magnetism

Exhibitor

Booth No.

Quantum Design

Booth No.

16

Hyundai Motor Company

Ask Co.

9

ICM2015-Barcelona

40

ReC-SDSW(Seoul National
University)

7

Carl Zeiss

27

Korea I.T.S.

17,18

Rigong International Inc.

13

Lake Shore Cryotronics

8

Semi-Ence Co., Ltd.

32
11

19, 2021, 22, 23

Exhibitor

Aaron. Co., Ltd.

ChangSung Co.

24

Booth No.

24, 25

Coxem

31

Namotec

15

SmartTip BV

Cryogenic Ltd.

30

Nanomagnetics Instruments

10

Springer

DGIST

1, 2

NT-MDT ANT Co.

26

Surface Systems Korea

12Effucell33

Oxford University Press

38

The Physical Society of Japan

39

ExaTech29

PANalytical Korea

34

Top Techology Ltd.

14

HANARO @ KAERI

6Park Systems Co.

35

UNIST

3

Hinds Instruments Inc.

28

Pohang Accelerator Laboratory

4,5

36, 37

July 8-13, 2012 Busan, Korea

25

SPONSOR

SponsorGold

SilverBronzeoRAL PRESENTATION
Plenary Lecture • 28
Half-Plenary Lecture • 30
Invited & Contributed Presentation • 33

26

The 19th International Conference on Magnetism

pLENARY LECTURE

pLENARY LECTURE
PP01

PP04

PP07

Recent developments and emerging directions in spintronics

Correlated electrons in quantum hall systems

Graphene's magnetism

Spintronics develops today in many promising directions. We focus on three topics. First: “Microwave
generation by spin transfer”, a field with fast recent advances anticipating short term applications. Second
topic: “Spintronics with graphene or carbon nanotubes (CNT)”, with fascinating long term prospects for“beyond CMOS”. Finally: “Oxitronics”, overview of results on devices associating magnetic, ferroelectricand multiferroic oxides. 1) Microwave generation by spin transfer: Microwave oscillations are obtainedby using spin transfer to induce magnetization precessions or gyrations of magnetic vortices. Large
powers (μW range) and narrow emission widths (≈ 0.1 MHz) can be today obtained at zero field byvortex gyration [1]. Synchronization is an additional way to increase the power and reduce the emission
width [2]. 2) Spintronics with graphene and CNT: Several concepts of spintronics (logic gates, “spin only
logic circuits”, etc) are based on spin transport in lateral channels between magnetic contacts. Recent
experiments show the outstanding potential of graphene and CNT for spin transport to long distance (above
100 μm) in such devices [3]. 3) Oxitronics: We illustrate the potential of oxitronics by results on tunnel
junctions with ferroelectric barriers: giant electro-resistance [4], interplay between ferroelectric and spinpolarizations, prospects for ferroelectric memories and memristors.

Klaus V. Klitzing*
Max-Planck-Institut fur Festkorperforschung, Heisenbergstr.1, D-70569 Stuttgart,
Germany
The narrow energy bands of a two-dimensional electron system in strong magnetic
fields lead to characteristic electron-electron interaction phenomena related to quantum
Hall physics. The talk summarizes some of the most prominent correlation phenomenain quantum Hall devices including exciton condensation/superfluidity in bilayers
and roton minima in the excitation spectrum of fractional quantum Hall states. * In
cooperation with W.Dietsche, X. Huang, I. Kukushkin, and J.H. Smet

Andre Geim
University of Manchester, United Kingdom

Plenary

Plenary

Albert Fert
Unité Mixte de Physique CNRS/Thales, Palaiseau, and Université Paris-Sud, Orsay, France

Graphene - a free-standing atomic plane of graphite - has turned out to be a wondermaterial. Like a magnet, it has attracted a large and still rapidly growing researchcommunity. After a short introduction describing reasons for this interest, I will focus
on the main topics of this conference (namely, magnetism and correlations) andoverview our recent work on magnetic properties of graphene, which are still poorly
understood, and pronounced correlation effects observed in graphene double-layer
heterostructures. As for magnetism, I will discuss the spin Hall effect [1] and (para)magnetism of pristine and defected graphene [2,3]. As for correlations, I plan to touchon renormalization of graphene’s linear spectrum [4] and Coulomb drag between two
Dirac-like systems in the limit of maximum interaction (unpublished but see [5]).
1. D. Abanin et al, Science 332, 328 (2011) 2. M. Sepioni et al, PRL 105, 207205 (2010) 3. R. Nairet al, Nature Phys. 8, 199 (2012) 4. D. Elias et al, Nature Phys. 7, 701 (2011) 5. L. Ponomarenko etal, Nature Phys. 7, 958 (2011)[1] A. Dussaux, B. Georges, J. Grollier, V. Cros, A.V. Khvalkovski, A. Fukushima, M. Konoto, H. Kubota, K. Yakushiji, S. Yuasa, K. A.
Zvczdi, K. Ando, A. Fert Nature Communications 1, 8, 2010. [2] A. Dussaux, A. V. Khvalkovskiy, J. Grollier, V. Cros, A. Fukushima, M.
Konoto , H. Kubota, K. Yakushiji, S. Yuasa, K. Ando, and A. Fert. Appl. Phys. Lett. 98, 132506, 2011. [3] B. Dlubak, P. Seneor, A. Anane,
M-B. Martin, C. Deranlot, B. Servet, S. Xavier, R. Mattana, M. Sprinkle, C. Berger, W. A. de Heer, F. Petroff, and A. Fert, Nat. Phys., DOI:
10.1038. [4] V. Garcia, S. Fusil, K. Bouzehouane, S. Enouz-Vedrenne, N.D. Mathur, A. Barthélémy, M. Bibes, Nature 600, 81, 2009.

PP02

PP05

Heat and spin

From single-atom magnetometry to tailored nanomagnets and atomicscale spintronic devices

Sadamichi Maekawa
Japan Atomic Energy Agency, Japan
When metals and semiconductors are placed in a temperature gradient, the electric
voltage is generated. This mechanism to convert heat into electric energy, the so-called
Seebeck effect, has attracted much attention as the mechanism for utilizing wasted
heat energy. The Seebeck effect is due to the entropy carried by the electric current
so that it may be enhanced by the internal degrees of freedom of electrons, i.e., spinand orbital [1]. Ferromagnetic insulators are good conductors of spin current, i.e., theflow of electron spins [2]. When they are placed in a temperature gradient, generated
is the spin voltage [3], i.e., spin accumulation. Once the spin voltage is converted into
the electric voltage by spin Hall effect in attached metal films such as Pt, the electric
voltage is obtained from heat. This is called the spin Seebeck effect. Here, we discuss
the Seebeck effect and spin Seebeck effect based on the fluctuation-dissipation theorem
and introduce a variety of the devices.
[1] S. Maekawa et al, Physics of Transition Metal Oxides (Springer, 2004). [2] S. Maekawa: Nature
Materials 8, 777 (2009). [3] Concept in Spin Electronics, eds. S. Maekawa (Oxford University
Press, 2006).

The developments of novel magnetic materials as well as spin-based electronics
are hot topics of current research in magnetism. Both research fields could profit
tremendously from atomic-scale insight into magnetic properties and spin-dependentinteractions at the atomic level. Based on the development of spin-polarized scanningtunneling microscopy (SP-STM) we have recently established the novel method ofsingle-atom magnetometry which allows the measurement of magnetization curves
and the determination of magnetic moments on an atom-by-atom basis. While thesensitivity level of single-atom magnetometry is below one Bohr magneton, it caneasily be combined with the atomic-resolution imaging and manipulation capabilities
of conventional STM, thereby offering a novel approach towards a rational material
design based on the knowledge of the atomic-level properties and interactions
within the solid state. Moreover, an atom-by-atom design and realization of all-spin
logic devices has recently been demonstrated by our group based on the combined
knowledge derived from surface physics, nanoscience, and magnetism. Alternatively,
self-assembly of atomic magnetic chains on nanostructured substrates has been
employed in order to create model-type systems for atomic-scale information transfer
based on the concept of vector-spin chirality.

PP03

PP06

Heavy electrons and superconductivity

Multiferroic vortex network with Z2xZ3 symmetry

Heavy electron materials are the only class of materials in which we know where
to look for superconductivity. We discuss the relation between single ion and dense
Kondo heavy electron physics, what sets the energy scale in these materials, and theways in which their low temperature exotic superconductivity is a prototype for all
highly correlated electron superconductivity.

Hexagonal REMnO3 (RE= rare earths) with RE=Ho-Lu, Y, and Sc, exhibit uniquepatterns of trimerization and ferrelectric domains, which meet in cloverleaf
arrangements that cycle through all six-possible domain configurations. Occurringin pairs, the cloverleafs can be viewed as vortices and antivortices, in which thecycle of domain configurations is reversed. Vortices and antivortices are topologicaldefects: even in a strong electric field they won’t annihilate readily. These ferroelectricvortices/antivortices are also associated with a vortex configuration of magnetism. The
seemingly irregular configurations of a zoo of multiferroic vortices and antivortices in
h-REMnO3 can be neatly analyzed in terms of graph theory and this graph theoreticalanalysis reflects the nature of self-organized criticality in complexity phenomena.
These numerous multiferroic vortices/antivortices can be understood as an arrested
Kosterlitz-Thouless phase. We have also discovered the emergence of Z2×Z3
symmetry in the seemingly-random network of numerous ferroelectric vortices, andelectric poling or self-poling due to a surface charge boundary condition induces global
topological condensation through breaking of the Z2 part of the Z2×Z3 symmetry.
The opposite process of restoring the Z2 symmetry can be considered as topologicalevaporation.

Zachary Fisk*
University of California, Irvine, USA

28

Roland Wiesendanger*
Institute of Applied Physics, University of Hamburg, Germany

The 19th International Conference on Magnetism

Sang-wook Cheong*
Rutgers University, USA

July 8-13, 2012 Busan, Korea

29

hALF-PLENARY LECTURE
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HP22

HP41

Heavy fermions and unconventional superconductivity in high-Quality
single crystals of rare earth and actinide compounds

Giant Ising anisotropy and hastaticorder in URu2Si2 (1,2)

The spin on domain walls!

Stuart Parkin
IBM Almaden Research Center, USA

Hideo Ohno*
CSIS/RIEC, Tohoku University, JapanThe hidden order that develops below 17.5K in the heavy fermion compound URu2Si2
has eluded identification for twenty five years. We show that the recent observationof Ising quasiparticles in URu2Si2 suggests a novel two-component order describing
hybridization between electrons and the Ising 5f2 states of the uranium atoms. This``hastatic order'' is distinct from conventional magnetism, breaking both single
and double time-reversal symmetry operations, mixing states of different Kramersparity. It accounts for the magnetic anomalies in torque magnetometry and thepseudo-Goldstone mode in neutron scattering. Hastatic order is predicted to inducea basal-plane magnetic moment of order $0.01\mu_{B}$, a gap to longitudinal spin
fluctuations that vanishes continuously at the first-order antiferromagnetic transition,a giant Ising anisotropy in the non-linear susceptibilty and a narrow resonant nematicfeature in the scanning tunneling spectra.

The formation and manipulation of magnetic domain walls (DWs) is of considerable
interest both from a scientific as well as a technological perspective. A number of very
interesting and potentially useful memory and logic devices based on the controlled
manipulation of DWs in magnetic nano-elements have recently been proposed and areunder intensive investigation. Using spin torque transfer from spin-polarized currents a
series of domain walls can be moved in lock-step at high speed along magnetic nano-wires,
enabling the Racetrack Memory [1]. We contrast the current induced motion of DWs in
nano-wires with in-plane and out-of-plane magnetization and demonstrate an additional
interface induced driving force in the latter case, which leads to very high domain wall
velocities of up to almost 1 km/sec. Even higher efficiencies result from temperature
gradient induced spin currents which we show are ~1,000 times more efficient in moving
DWs than electrically generated spin polarized currents. Many of these devices depend
critically on the detailed structure of the DW: we discuss methods by which the chirality
and polarity of a vortex DW can be deterministically controlled and we use this to create achirality based biplexer and ultra-stable domain wall topological bound states.

bcc(100) CoFeB-(100) MgO is a preferred system for spintronics applications, because it
offers a large tunnel magnetoresistance (TMR) of > 100% in magnetic tunnel junctions (MTJs)
through symmetry filtering of wavefunctions, which is required for nonvolatile memory cells.
Integration of high performance MTJs in the CMOS back-end not only enables non-volatile,
high density, and fast stand-alone and embedded RAMs, but also makes it possible to realize
nonvolatile logic-in-memory CMOS VLSIs [1]. To this end, we showed that a perpendicularinterface anisotropy at the CoFeB-MgO interface [2, 3], strong enough (Ki = 1.3 mJ/m2) toovercome the demagnetization, can be used to realize 40 nm perpendicular MgO-CoFeB
MTJs with high TMR (>100 %) and low switching current of 49 μA [3]. We further showedthat “activation volume” of the system plays an important role in determining the thermal
stability of the MTJs [4]. It was also shown that the CoFeB-MgO system withstands a highannealing temperature of 400 oC required for logic integrated circuit applications [5]. If timeallows, I will touch upon current-induced domain wall motion and related phenomena inperpendicular CoFeB-MgO films [6, 7], where perpendicular anisotropy is required to reducethe critical current density for domain wall motion.

[1] S.S.P. Parkin, US Patent 6,834,005 (2004); S.S.P. Parkin et al., Science 320, 190 (2008); S.S.P. Parkin, Scientific
American (June 2009); M. Hayashi, L. Thomas, R. Moriya, C. Rettner and S.S.P. Parkin, Science 320, 209 (2008); L.
Thomas et al., Science 330, 1810 (2010); X. Jiang et al. Nat. Comm. 1:25 (2010) and Nano Lett. 11, 96 (2011); L. Thomas, M.
Hayashi, R. Moriya, C. Rettner and S.S.P. Parkin, Nat. Commun. (accepted).

This work was supported by the FIRST program from JSPS. [1] S. Ikeda, et al. IEEE Trans. Electron Devices,54, 991, 2007. [2] M. Endo, et al. Appl. Phys. Lett., 96, 212503, 2010. [3] S. Ikeda, et al. Nature Mat., 9, 721,
2010. [4] H. Sato, et al. Appl. Phys. Lett. 99, 042501, 2011. [5] H. D. Gan et al. Appl. Phys. Lett. 99, 252507,
2011. [6] S. Fukami et al. Appl. Phys. Lett. 98, 082504, 2011. [7] T. Suzuki et al. Appl. Phys. Lett. 98, 142505,
2011.

The f electrons in rare earth and actinide compounds exhibit variety of characteristic
properties including heavy fermions and unconventional superconductivity. Fermi
surface properties in rare earth and actinide compounds such as CeSn3, USi3, NpGe3
and PuIn3 are clarified by the de Haas-van Alphen experiments on the basis of theresults of energy band calculations. An abrupt nonlinear increase of magnetization,
namely metamagnetic behavior is found in the heavy fermion compounds including
YbT2Zn20 (T: Co, Rh, Ir). An effect of pressure on the electronic state of YbIr2Zn20
and antiferromagnets CeRhIn5 and CeIrSi3 are also studied in magnetic fields. The
electronic instability including unconventional superconductivity occurs at about 2.4
GPa in CeRhIn5 and 2.6 GPa in CeIrS3.

Piers Coleman*
Dept of Physics and Astronomy, Rutgers University, United Kingdom(1) R. Flint, P. Chandra and P. Coleman to be published. (2) Work supported by the Simons
Foundation and NSF grant 0907179. (3) M. M. Altarawarneh et al, Phys. Rev. Lett. 108, 066407(2012).

HP52
Perpendicular CoFeB-MgO for spintronics devices

HP12

HP31

HP42

HP61

Effects of spin-orbit-coupling in the electronic structures of 5dtransition metal oxides

Electrodynamics of skyrmionsOrbitronics in silicon

Geometric enhancement of low field magnetoresistance in silicon

Skyrmions are nanometric spin-swirling vortex-like objects in solids, typicallyobserved in the helimagnets of B20 type (FeSi type) transition-metal silicides andgermanides. Due to their topological nature, the spin chirality or skyrmion number cangive rise to the fictitious magnetic field acting on conduction electrons; in the strong
coupling limit one skyrmion works as a single flux quantum. There, the topologicalHall effect of conduction electron is observed in proportion to skyrmion density, while
as its counteraction the Hall motion of skrymions is anticipated in addition to thecurrent-driven sliding motion. Here, we overview the late progress in experimental
observations of skyrmions and skyrmion lattices in bulk and thin film forms as well as
their spectacular topological transport phenomena. The materials family is now being
extended to some multiferroic oxides, in which electric-field drive of the skyrmion
would be possible.

We describe the control and observation of coherent superpositions of defect orbitals insilicon using both scanning tunneling microscopy and pulsed THz radiation generated
by the Dutch-UK free electron laser FELIX. The results are contrasted with thosefor the microwave control of defect spins, and implications for future silicon-based
information processing are discussed.

The magnetic sensing industry are greatly dependent on the use of both GMR andTMR devices. Both of them are made of magnetic/rare earth materials. However, therare earth materials are getting more and more difficult to obtain. Magnetoresistance(MR) reported in some non-magnetic semiconductors particularly silicon has triggeredconsiderable interest owing to the large magnitude of the effect. Here we showedthat MR in lightly doped n-Si can be significantly enhanced by introducing a p-njunction and proper design of the carrier path [1]. We designed an MR device whoseroom-temperature MR ratio reaching 30% at 0.065 T, 5000% at 0.4 T, and 20000%
at 1.2T, respectively, approaching the performance of commercial MR devices. The
combination of high sensitivity to low magnetic fields and large high-field response
should make this device concept attractive to the magnetic field sensing industry.
Moreover, because our device is based on a conventional silicon platform, it should
be possible to integrate it with existing silicon devices and so aid the development ofsilicon-based magnetoelectronics. Also combining MR devices and semiconducting
devices in a single Si chip may lead to some novel devices.

T. W. NohPhysics and Astronomy, Seoul National University, Korea

In 5d transition metal oxides, the magnitude of spin-orbit (SO) coupling becomescomparable to those of other fundamental interactions, such as electron-phononand on-site Coulomb interactions. Recent investigations of 5d transition metaloxides indeed reveal that the SO coupling can modify their electronic and magnetic
structures significantly. Especially, it produces a novel quantum state that has neverbeen observed in 3d and 4d transition metal oxides. Namely, the large SO couplingcombined with the on-site Coulomb repulsion results in an unusual Jeff=1/2 Mott
insulating state in Sr2IrO4. By changing the dimensionality in Ruddlesden-Popper
series, the irridates change from insulator (n=1 and 2) to metal (n=∞). Further studies
on double perovskite A2FeReO6 and perovskite (Ca,Sr)IrO3 thin films showed that
their electronic structures are indeed determined by subtle interplay of the SO coupling,
electron correlation, and lattice distortion. We will present the interesting role of SO
coupling by combining the spectroscopic tools with first-principles band calculations.
In addition, the layered honeycomb lattice Na2IrO3 and pyrochlore A2Ir2O7 wererecently suggested as possible topological insulators, though topological insulatorswith transition metal d electrons have not been fully investigated. Spectroscopic resulton these irridate systems will be also discussed.

Yoshinori Tokura
Department of Applied Physics, University of Tokyo, Japan

Gabriel Aeppli
University College London, United Kingdom

PNAS 105 10649-10653 (2008) Nature 465 1057-61 (2010) Nature Materials 9 725-9 (2010)

Xiaozhong Zhang
Department of Materials Science and Engineering, Tsinghua University, China[1] Caihua Wan, Xiaozhong Zhang, et al., Nature, 477, 304 (2011).

HP21

HP32

HP51

HP62

Magnetization dynamics of rashba ferromagnet

Spin and charge fluctuations in cuprate superconductors

360 degree domain walls in magnetic nanowires

Artificial spin ice systems: exploring frustration and emergent
magnetic monopoles with nanomagnets

Kyoung-whan Kim1, Soo-man Seo2, Jisu Ryu1, Jung-hwan Moon2, Kyung-jin Lee2 andHyun-woo Lee1*
1
Department of Physics, POSTECH, Korea
2
Department of Materials Science and Engineering, Korea University, Korea
Rashba spin-orbit coupling (RSOC) arises generically when structural inversion symmetry is broken.
Surface electronic structure of heavy atomic elements such as Bi/Ag alloy [1] is known to exhibit large
RSOC with characteristic RSOC parameter of the order of 1 eV•A. Topological insulator [2,3] is anotherclass of material with large RSOC. Recently it was reported [4] that ultrathin magnetic layers may besubject to large RSOC when in contact with proper heavy metallic elements in strongly asymmetricenvironment. In this talk, we explore magnetization dynamics of such ultrathin magnetic layers withstrong RSOC. It will be demonstrated that RSOC induces the deviation of conduction electron spin
direction from local magnetization direction and thus modifies the spin torque [5,6] and current-driven
magnetization dynamics properties considerably. We also discuss the phenomenon of the spin-dependent
electric field induction [7,8,9] by magnetization dynamics. It will be illustrated that RSOC can strengthen
the spin-dependent electric field more than one order of magnitude, so that the field can induce spincurrent sufficiently large enough to modify the magnetization dynamics itself. Thus ultrathin magnetic
layers with strong RSOC are good systems to test various aspects of RSOC effects.
[1] C. R. Ast et al., Phys. Rev. Lett. 98, 186807 (2007). [2] K. Ishizaka et al., Nature Mater. 10, 521 (2011). [3] M.
S. Bahramy, B.-J. Yang, R. Arita, and N. Nagaosa, arXiv:1110.6846. [4] I. M. Miron et al., Nature Mater. 9, 230(2010). [5] J. C. Slonczewski, J. Magn. Mag. Mater. 159, L1 (1996). [6] L. Berger, Phys. Rev. B 54, 9353 (1996).
[7] L. Berger, Phys. Rev. B 33, 1572 (1986). [8] G. E. Volovik, J. Physc C 20, L83 (1987). [9] S. E. Barnes and S.
Maekawa, Phys. Rev. Lett. 98, 246601 (2007).

The 19th International Conference on Magnetism

half-plenary

half-plenary

Yoshichika Onuki1, Rikio Settai1, Tetsuya Takeuchi2, Kiyohiro Sugiyama1, Fuminori
Honda1, Yoshinori Haga3, Etsuji Yamamoto3, Tatsuma Daruma Matsuda3, Naoyuki
Tateiwa3, Dai Aoki4, Ilya Sheikin5, Hisatomo Harima6 and Hiroshi Yamagami7
1
Graduate School of Science, Osaka University, Japan2
Low temperature Center, Osaka University, Japan
3
Advanced Science Research Center, JAEA, Japan
4
IMR, Tohoku University, Japan
5
LNCMI-G, CNRS, France
6
Department of Physics, Kobe University, Japan
7
Department of Physics, Kyoto Sangyo University, Japan30

hALF-PLENARY LECTURE

Bernhard Keimer
Max Planck Institute for Solid State Research, Germany

I will present recent inelastic neutron scattering and resonant inelastic x-ray scattering(RIXS) data that throw new light on the role of low-energy spin and charge fluctuationsin the mechanism of high-temperature superconductivity and its interplay withcompeting spin- and charge-density-wave order. I will also discuss parallels andcontrasts with iron pnictide superconductors.
M. Le Tacon, G. Ghiringhelli, J. Chaloupka, M. Moretti Sala, V. Hinkov, M.W. Haverkort, M.
Minola, M. Bakr, K. J. Zhou, S. Blanco-Canosa, C. Monney, Y. T. Song, G. L. Sun, C. T. Lin, G. M.
De Luca, M. Salluzzo, G. Khaliullin, T. Schmitt, L. Braicovich and B. Keimer, Nature Physics 7, 725(2011).

Caroline A Ross
Department of Materials Science and Engineering, Massachusetts Institute ofTechnology, USA
Domain walls are important in a wide range of magnetic memory and logic devices.
Most work has focussed on isolated 180 degree domain walls in magnetic wires,but impingement of two 180 degree walls can create 360 degree walls which exhibit
facinating behavior. 360, 540 and higher order walls are created by successive injectionof 180 degree walls into a wire or during reversal of a thin film ring. Current-driven
motion of 360 degree domain walls is qualitatively different from that of 180 degree
walls. The velocity of a 360 degree wall scales with dc current but is independent ofapplied field along the stripe, and an annihilation process occurs at a field-dependent
critical current density. 360 degree walls oscillate at a characteristic field-tunablefrequency in the gigahertz range. The stray field from a 360 degree wall in one layer ofa multilayer can affect the reversal of an adjacent soft magnetic layer, allowing the wall
to be used as a gate for the reversal of the soft layer. 360 degree walls can be created,
moved, annihilated to deliver spinwave energy, and detected, and could serve as a data
token in a magnetoelectronic device.

Laura Heyderman*
Paul Scherrer Institute, Switzerland

Artificial spin ice systems, consisting of two-dimensional arrangements of dipolar coupled singledomain nanomagnets, are in the focus of scientific interest since they allow the study of the effects
of frustration. Our work has concentrated on artificial kagome spin ice, with elongated nanomagnets
forming an array of hexagonal rings, using synchrotron x-ray photoemission electron microscopy to
directly image the magnetic states. Focussing on finite building blocks comprising one, two and threehexagonal rings, allows the full characterization of the energy levels and indicated that an effective
thermal anneal via demagnetisation does not lead to the ground state for the larger structures [1]. Morerecent observations demonstrate the existence of emergent magnetic monopoles in a quasi-infinite
nanomagnet array [2]. In an applied magnetic field, monopole-antimonopole pairs nucleate andseparate in an avalanche-type manner along one-dimensional Dirac strings consisting of overturned
dipoles, and the behaviour is quantitatively explained by Monte Carlo simulations. This work opens
the way to making use of the multiple states in coupled nanomagnet systems [3] and the controlled
manipulation of magnetic charges that may lead to new spintronic devices.
[1] E. Mengotti, L.J. Heyderman, A. Fraile Rodriguez, A. Bisig, L. Le Guyader, F. Nolting, and H.B. Braun,
Phys. Rev. B 78, 144402 (2008) [2] E. Mengotti, L.J. Heyderman, A. Fraile Rodriguez, F. Nolting, R.V.
Hugli, H.B. Braun Nature Physics 7, 68 (2011) [3] L.J. Heyderman, T. Jung, E. Mengotti, A. Bisig, A. Fraile
Rodriguez, F. Nolting, H.B. Braun, T. Schrefl United States Patent US 8,085,578 B2, 27.12.2011

July 8-13, 2012 Busan, Korea

31

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AA01

AA04

Topological Insulators

Orbital and spin states of bi-layered manganites La2-2xSr1+2xMn2O7

Magnetoelectric coupling in hematite amplified by the collective
transition

Shoucheng Zhang
Physics, Stanford University, USA

half-plenary

Invited & Contributed Presentation

Jae-Hoon Park
Pohang University of Science and Technology, Korea

J. L. Musfeldt1*, P. Chen1, N. Lee2, S. Mc Gill3 and S. W. Cheong2
Department of Chemistry, University of Tennessee, USA
2
Department of Physics, Rutgers University, USA
3
National High Magnetic Field Laboratory, USA

Invited & Contributed Presentation

hALF-PLENARY LECTURE

1

The bi-layer manganites La2-2xSr1+2xMn2O7 display variety of ordering behaviors
involving charge, spin, and orbital degrees of freedom and exhibits various intriguing
physical properties. Here I will present soft x-ray scattering study results on the spinstates of bi-layer manganites with x = 0.5 and x = 0.3. The x = 0.5 half-doped system
exhibits two types of antiferromagnetic spin orders, A-type and CE-type, which both
involves the CE-type charge and orbital orders. The results show coupling behaviors
between the spin and orbital ordering and also between different spin ordered states.
On the other hand, the x = 0.3 system, known as a colossal magnetoresistancemanganite, shows a large magneto-elastic response. We found that the spin state iscoupled with the orbital state and the magnetic field affects both states resulting in thelarge magneto-elastic response.

We investigated the magneto-optical properties of alpha-Fe2O3 in order to understandthe interplay between charge and magnetism in a model transition metal oxide.
We discovered that hematite appears more red in applied magnetic field than inzero field conditions, an effect that is amplified by the presence of the spin floptransition. Analysis of the exciton pattern on the edge of the d-d color band reveals
C2/c monoclinic symmetry in the high field phase. These findings advance ourunderstanding of magnetoelectric coupling away from the static limit and motivate
spectroscopic work on other iron-based materials under extreme conditions.

HP72

AA02

AA05

Heusler compounds: from semiconductors to spintronics

First-principles calculation of multiferroic bilayer manganite

Time dependence of multiferroic switching

Heusler compounds are a remarkable class of intermetallic materials with 1:1:1 (often called
Half- Heusler) or 2:1:1 composition comprising more than 1500 members [1]. New properties
and potential fields of applications emerge constantly; the prediction of topological insulators
is the most recent example [2]. Surprisingly, the properties of many Heusler compounds
can easily be predicted by the valence electron count or within a rigid band approach. The
subgroup of more than 250 semiconductors is of high relevance for the development of novel
materials for energy technologies. Their band gaps can readily be tuned from zero to 4 eV
by changing the chemical composition. Thus, great interest has been attracted in the fields ofthermoelectrics and topological insulator research. Ternary materials based on multifunctional
properties, i.e. the combination of two or more functions such as superconductivity andtopological edge states will revolutionize technological applications. The wide range of themultifunctional properties of Heusler compounds is reflected in extraordinary magnetooptical, magneto-electronic, and magneto-caloric properties. Tetragonal Heusler compounds
Mn2YZ as potential materials for STT applications can be easily designed by positioning the
Fermi energy at the van Hove singularity in one of the spin channels [3].

'Improper multiferroics', materials where ferroelectricity is driven by spin ordering,
charge ordering or orbital ordering, constitute a playground for the physics of crosscorrelation between the different long-range orderings [1]. Recently, a complex
mechanism of ferroelectricity driven by spin- and charge-orderings has been proposedin hole-doped manganites, supported by theoretical studies [2]. In such system, it
is considered that slightly charge-disproportionated two magnetic ions (i.e. Mn3+
and Mn4+) form dimers via double exchange interaction, resulting in sizable electric
dipoles. In the particular case of bilayer-manganite Pr(Sr0.1Ca0.9)2Mn2O7, it has been
experimentally suggested that the transition between two different CO phases isaccompanied by the rotation of orbital stripes, in turn related to ferroelectricity [3].
In this paper, we provide insights into the cross-correlation phenomena and theferroelectric instability in the bilayer manganite via first-principles approaches. Alongthis line, we also discuss the magnetic property and the stability of charge- and orbitalorderings.

In this talk I plan to give an overview of the recent progress on topological insulators. I
will focus on the interplay between topological and magnetic orders in novel materials,
and discuss the topological magneto-electric effect.
X. L. Qi, S. C. Zhang, Phys. Today 63, 33 (2010). X. L. Qi, S. C. Zhang, Rev. Mod. Phys. 83, 1057
(2011).

Claudia Felser*
Max Planck Institute for Chemical Physics of Solids, Germany[1] Simple Rules for the Understanding of Heusler Compounds, Tanja Graf, Stuart S.
P. Parkin, and Claudia Felser, Progress in Solid State Chemistry (2011), doi:10.1016/
j.progsolidstchem.2011.02.001, invited review [2] Tunable Multifunctional Topological Insulators
in Ternary Heusler Compounds, S. Chadov, X.-L. Qi, J Kubler, G. H. Fecher, C. Felser, S.-C. Zhang,
Nature Mat. 9 (2010) 541, arXiv:1003.0193

Kunihiko Yamauchi1* and Silvia Picozzi2
1
ISIR-Sanken, Osaka University, Japan
2
CNR-SPIN, L'Aquila, Italy

AA03

AB01

Coupling between lattice and spin degrees of freedom in multiferroic
h-RMnO3

Quantum criticality, non-fermi liquid and unconventional
superconductivity

Xavier Fabreges1*, Sylvain Petit2 and Isabelle Mirebeau2
LNCMI, Toulouse, CNRS, France
2
Laboratoire Leon Brillouin, CEA Saclay, France

Hexagonal RMnO3 forms a class of triangle-based multiferroic materials, which have been widely
studied in the recent years [1]. Magnetic frustration combined with a striking magneto-elastic
coupling seems to be at the origin of their properties, a cocktail that has a strong potential for
novel physics. Here, we report on neutron scattering experiments carried out to study the structureand spin dynamics in this series of compounds. The spinwave spectra can be accounted for bynumerical calculations, giving precious informations on exchange and anisotropy parameters [24]. Meanwhile, the 120° Neel order due to geometric frustration is accompanied by an isostructuraltransition [4,5]. This transition is a systematic feature in this series as shown by our high-resolution
neutron diffraction and inelastic neutron scattering. In addition, we have established a correlation
between the atomic positions, the type of magnetic structure, and the nature of the spin waves,
depending on the compound and its magnetic structure. The key parameter is the Mn position
within the triangular plane, which tunes the sign of the exchange interaction [4]. Our inelastic
neutron scattering experiments also reveal a strong coupling of the Mn sublattice with the rare-earthmagnetic moments. The cases of HoMnO3 and YbMnO3 are presented.
[1] Cheong S.W and Mostovoy M. Nature materials, 6, 13 (2007) and references therein, [2] S. Petitel al, PRL 99, 266604 (2007), [3] S. Pailhes et al, PRB 79, 134409 (2009), [4] X. Fabreges et al,
PRL 103, 067204 (2009), [5] S. Lee et al. Nature 451,805 (2008)

The 19th International Conference on Magnetism

Neutron scattering with spherical polarization analysis gives direct access to thechiral components of the magnetic structure which is directly linked to the electric
polarization and thus may be controlled by an electric field. We applied stroboscopic
techniques in order to investigate how fast the magnetic chirality adapts to an
instantaneously switched electric field in MnWO4 finding quite long relaxation times
in the range of 10 milliseconds. We will discuss the dependence of the multiferroic
relaxation on electric field strength, sample thickness and temperature. Furthermore
we present the first results on controlling ferrotoridal domains in LiFeSi2O6 by verticalmagnetic and electric fields.

[1] S. Picozzi, and C. Ederer, J. Phys.: Cond. Mat. 21, 303201 (2009). [2] D. V. Efremov, J. van den
Brink, and D. Khomskii, Nature Matt. 12, 856 (2004). [3] Y. Tokunaga et al., Nature Mater. 5, 937(2006).

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Max Baum1, Thomas Finger1, Simon Holbein1, Jonas Stein1, Jeannis Leist2, Gotz
Eckold2, Paul Steffens3, Arno Hiess3, Karin Schmalzl3, Petra Becker4, Ladislav
Bohaty4 and Markus Braden1
1
II. Physikalisches Institut, Universitat zu Koln, Germany
2
Institut fur Physikalische Chemie, Georg-August-Universitat Gottingen, Germany
3Institut Laue-Langevin (ILL), Grenoble, France
4
Institut fur Kristallographie, Universitat zu Koln, Germany

Qimiao Si
Department of Physics and Astronomy, Rice University, USA

Competing orders frequently arise in strongly correlated electron systems, and the accompanying
quantum criticality provides a route towards both non-Fermi liquid behavior and unconventional
superconductivity. Among the many important questions is whether the theoretical descriptionof quantum criticality conforms to, or goes beyond, the Landau framework of order-parameter
fluctuations. Using heavy fermions as a concrete setting, I will summarize the theoreticalaspects of local quantum criticality, which is based on the “beyond-Landau” physics ofKondo destruction, as well as the experimental evidence for this picture [1]; the latter includes
anomalous dynamical scaling, multiple scales of collapsing energies, and Fermi surface jump. I
will also discuss the theoretical reasoning for the emergence of novel magnetic phases and thecorresponding global phase diagram [2,3], and attempt to place various quantum-critical heavy
fermion compounds in this global phase diagram. Finally, I will outline some promising issues to
explore in the future, including the interplay among electron localization (in the form of Kondo
destruction in the present context), magnetism and unconventional superconductivity, both inconnection with existing experiments [4,5] and as a general theoretical issue.
[1] Q. Si and F. Steglich, Science 329, 1161 (2010). [2] Q. Si, Physica B378, 23 (2006); Phys. Status
Solidi B247, 476 (2010). [3] P. Goswami and Q. Si, Phys. Rev. Lett. 107, 126404 (2011). [4] T. Parket al., J. Phys.: Condens. Matter 23, 094218 (2011); H. Shishido et al., J. Phys. Soc. Jpn. 74, 1103
(2005). [5] O. Stockert et al., Nature Phys. 7, 119 (2011).

July 8-13, 2012 Busan, Korea

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Ternary compounds with ZrFe4Si2 structure type: A new playgroundfor ferromagnetic and antiferromagnetic quantum criticality

HgTe as a topological insulator

Origin and signatures of magnetic chirality in the frustrated
multiferroic Ba3NbFe3Si2O14

Magnetism of ultrathin Fe films on BaTiO3(001)

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Invited & Contributed Presentation

Christoph Geibel *, Cornelius Krellner , Nadang Mufti , Helge Rosner , Manuel Brando , Frank Steglich ,Stefan Lausberg1, Alexander Steppke1, Luis Pedrero1, Lucia Steinke1, Robert Kuchler1, Edith Lengyel1,
Michael Nicklas1, Christoph Bergmann1, Katharina Weber1, Till Goltz2, Johannes Spehling2, Nicolas
Yeche2, Hans-henning Klauss2, Theo Woike3, Hubertus Luetkens4, Kamil Sedlak4 and Christopher Baines4
1
Max Planck Institute for Chemical Physics of Solids, Germany
2
Institute for Solid State Physics, Technical University Dresden, Germany
3Institute for structural Physics, Technical Universty Dresden, Germany
4
Laboratory for Muon-Spin-Spectroscopy, Paul-Scherrer-Institute, Switzerland

The ZrFe4Si2 structure type is promising for the search of quantum critical systems because both the Fe
and the Zr sublattices present a quasi-one-dimensional character with geometrical frustration. In the lastyears we prepared several compounds crystalizing in this structure and found two very different kindsof systems close to a quantum critical point (QCP) separating a magnetic ordered ground state from a
non-ordered one: in YbNi4P2 a strong Kondo interaction acting on the magnetic trivalent Yb-Ions (Niatoms are non-magnetic) results in a strongly reduced ferromagnetic (FM) ordering temperature of only
170 mK, locating this system close to a FM QCP. In contrast in the AFe4X2 family of compounds (A =Sc, Y, Lu, Zr; X = Si, Ge) it is the 3d metal Fe which is magnetic while the A-element is non-magnetic.
Although the energy scale of magnetic interactions in these compounds is of the order of 200 K, their
ground state can be tuned from a frustrated antiferromagnetic ground state with a rather low T_N of
32 K in LuFe4Ge2 to a ground state dominated by critical fluctuations in ZrFe4Si2. We studied thesecompounds using different kinds of techniques and shall present and discuss our results.

Laurens Wigbolt Molenkamp
Experimental Physics 3, University of Wuerzburg, Physics Institute, Germany
HgTe is a zincblende-type semiconductor with an inverted band structure. While thebulk material is a semimetal, lowering the crystalline symmetry opens up a gap, turning
the compound into a topological insulator. The most straightforward way to do so is by
growing a quantum well with (Hg,Cd)Te barriers. Such structures exhibit the quantum
spin Hall effect, where a pair of spin polarized helical edge channels develops when
the bulk of the material is insulating. Our transport data provide very direct evidence
for the existence of this third quantum Hall effect, which now is seen as the prime
manifestation of a 2-dimensional topological insulator. To turn the material into a
3-dimensional topological insulator, we utilize growth induced strain in relatively thick(ca. 100 nm) HgTe epitaxial layers. The high electronic quality of such layers allows a
direct observation of the quantum Hall effect of the 2-dimensional topological surface
states. Moreover, on contacting these structures with Nb electrodes, a supercurrent is
induced in the surface states.

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2

Andrej Zorko , Virginie Simonet and Rafik Ballou
1
Jozef Stefan Institute, Slovenia
2
Institut Neel, CNRS and Universite Joseph Fourier, France

Geometrical frustration is the key promoter of exotic collective magnetic ground states in condensed
matter, including spin liquids, spin ice and unconventional spin orders. On frustrated lattices, thedominant isotropic exchange interactions are often unable to raise the degeneracy of the ground state.
Then, minute magnetic-anisotropy terms can become crucial for selecting the ground state. The acentric
Fe-Langasite Ba3NbFe3Si2O14 features a frustrated arrangement of spin-5/2 Fe3+ ions on vertices of
equilateral triangles arranged into 2D triangular lattice [1]. It has been drawing considerable attention due
to its multiferroic properties and its unique magnetic ground state. The long-range magnetic order thatdevelops simultaneously with the electric polarization below TN = 26 K is a unique double-chiral singledomain state, whose realization appears mysterious [1]. Recently, we have extended research of the chiralproperties of Ba3NbFe3Si2O14. Our inelastic neutron scattering study has revealed that one of the two
excitation branches is completely chiral over the whole energy spectrum, which is a unique dynamical
fingerprint of the chiral ground state [2]. Moreover, our electron spin resonance investigation has unveiled
the origin of the mysterious selection of the ground state [3]. We will highlight the crucial role of minute
Dzyaloshinsky-Moriya magnetic anisotropy in this system.

Seolun Yang1, Jae-sung Kim1*, Xumin Chen2, Axel Enders2, Jan Honolka3, Violetta
Sessi4, Tiffany Santos5 and Matthias Bode6
1
SookMyung Women's University, Korea
2
University of Nebraska, Lincoln, USA
3
Max Plank Institute for Solis state physics, Germany
4
European syncrotron research facility, France
5
Argon National laboratory, USA
6
University of Wuerzburg, Germany
Pristine (< 1 monolayer (ML)) Fe films can be grown on BaTiO3(001) template [1] around 10
K by thermal evaporation. X-ray magnetic circular dichroism revealed superparamagnetismof the Fe films due to their cluster formation. Their saturation magnetic moments increase
with the increase of the coverage, reaching beyond that of bulk Fe for 0.7 ML, which indicatesthat the clusters coalesce to form extended film, while the thickness of the clusters are thicker
than 1 ML as found in our scanning tunneling microscopy. Fe films show in-plane easy axis,
in contrast to the prediction of perpendicular magnetic anisotropy for flat 1 ML film. Theirin-plane easy axis may be attributed to magnetoelastic anisotropy of the strain, multilayer
formation of the Fe films and also atoms at highly populated edge sites. Fe films are foundto induce magnetic moments of Ti, but none of Ba ions as predicted by first principles
calculations.[1][1] K. Marty, V. Simonet, E. Ressouche, R. Ballou, P. Lejay, and P. Bordet, Phys. Rev. Lett. 101, 247201 (2008). [2] M.
Loire, V. Simonet, S. Petit, K. Marty, P. Bordet, P. Lejay, J. Ollivier, M. Enderle, P. Steffens, E. Ressouche, A. Zorko, and R.
Ballou, Phys. Rev. Lett. 106, 207201 (2011). [3] A. Zorko, M. Pregelj, A. Potocnik, J. van Tol, A. Ozarowski, V. Simonet, P.
Lejay, S. Petit, and R. Ballou, Phys. Rev. Lett. 107, 257203 (2011).

[1]X. Chen, S. Yang, J. -H. Ki., H. -D. Kim, J. -S. Kim, G. Rojas, R. Skomski, H. Lu, A. Bhattacharya, T. Santos, N. Guisinger, M. Bode, A.
Gruvermann, and A. Enders, submitted to New J. Phys.13 083037 (2011). [2]C. -C. Duan, S. S. Jaswal, and E. Y. Tsymbal, Phys. Rev.
Lett. 97 047201 (2006).

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Anomalous thermoelectric effects in the heavy fermion superconductor
Ce2PdIn8

Spin liquid and spin glass states in frustrated magnets

Investigating magnetic dipolar interactions between Co nano-islands
with spin-polarized scanning tunneling microscopy

Thickness-dependent exchange splitting of EuO ultrathin films

Marcin Matusiak, Daniel Gnida and Dariusz Kaczorowski*
Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Poland

Ce2PdIn8 is a recently discovered [1,2] ambient-pressure heavy-fermion superconductor that in many aspects
closely resembles the structurally related compound CeCoIn5. In particular, the superconducting gap that
opens at Tc = 0.7 K [3-5] exhibits a nodal character and a magnetic-field-induced quantum critical point (QCP)
resides near the upper critical field Hc2(0) = 2.4 T [3,4]. Moreover, the necessary conditions for the formationof modulated FFLO phase are met in the superconducting state of Ce2PdIn8, and this unique phase possibly
appears in the low-temperature-high-field corner of the H-T phase diagram [3]. The reported Nernst effect(ν) and thermoelectric power (S) studies were performed for Ce2PdIn8 with the main aim at probing QCP in
the temperature region, in which distinct non-Fermi liquid features were previously revealed in the electricalresistivity and heat capacity data [1-5]. In a manner markedly similar to CeCoIn5, the Nernst coefficient ofCe2PdIn8 becomes greatly enhanced and field-dependent in the coherent Kondo state. Both thermoelectriccoefficients behave highly anomalously at low temperatures, namely the ratios S/T and ν/T diverge
logarithmically towards T = 0. The observed behaviors strongly support a 2D antiferromagnetic spin-densitywave scenario of the quantum criticality in Ce2PdIn8, recently inferred from the thermodynamic data [4].

Seung-hun Lee
University of Virginia, USAIn frustrated magnets, the topology of the magnetic interactions between magnetic
moments leads to macroscopic ground state degeneracy. The nature of the ground statesthat emerge in frustrated magnets is yet to be understood. In this talk, I will discuss a
few examples that exhibit spin liquid and spin glass behaviors at low temperatures. I
will present some simple and eloquent ways of thinking about the complex frustrated
magnetic interactions that help us greatly to understand the nature of the ground states
and their low energy excitations.

[1] D.Kaczorowski, A.Pikul, D.Gnida, and V.H.Tran, Phys. Rev. Lett. 103 (2009) 027003; ibid 104 (2010) 059702. [2]
D.Kaczorowski, D.Gnida, A.Pikul, and V.H.Tran, Solid State Commun. 150 (2010) 411. [3] J.K.Dong, H.Zhang, X.Qiu,
B.Y.Pan, Y.F.Dai, T.Y.Guan, S.Y.Zhou, D.Gnida, D.Kaczorowski, and S.Y.Li, Phys. Rev. X 1 (2011) 011010. [4] Y.Tokiwa,
P.Gegenwart, D.Gnida, and D.Kaczorowski, Phys. Rev. B 84 (2011) 140507(R). [5] V.H.Tran, D.Kaczorowski, R.T.Khan,and E.Bauer, Phys. Rev. B 83 (2011) 064504.

Chun-i Lu, Pin-jui Hsu, Szu-wei Chen, Yu-hsun Chu, Chuang-han Hsu, Wang-jung
Hsueh and Minn-tsong Lin1,2*
1
Department of Physics, National Taiwan University, 10617 Taipei, Taiwan
2
Institute of Atomic and Molecular Sciences, Academia Sinica, 10617 Taipei, Taiwan
In application of spin-polarized scanning tunneling microscopy (SP-STM), we
investigated magnetic interaction in nanometer scale between triangular Co nanoislands formed in the sub-monolayer Co deposited on Cu(111) substrate. The SP-STM
images the magnetization or the relative spin configuration of the Co islands. The
results indicate a competition between exchange coupling and dipolar interaction in
nanometer scale among the conjoint Co islands. The parallel magnetization of a set of
conjoint Co nano-islands is anticipated due to the ferromagnetic exchange coupling.
However, significant numbers of sets with anti-parallel ordering can still be observed.
In order to explain the anti-parallel data, we calculate the dipolar interaction between
conjoint Co islands to realize if it is comparable with the exchange coupling strength,
which could be correlated to the length of contact region. As a result, the SP-STM
images and the statistical data indicate a competition between the dipolar interaction
and the exchange coupling in nanometer scale. The anti-parallel configuration, in
which dipolar energy dominates, is shown to be limited by the contact length of two
conjoint islands, which scales the strength of exchange coupling.

Hidetoshi Miyazaki1*, Tetsuya Hajiri2, Masaharu Matsunami3, Takahiro Ito2 and Shinichi Kimura3
1
Center for Fostering Young and Innovative Researchers, Nagoya Institute ofTechnology, Japan
2
Graduate School of Engineering, Nagoya University, Japan
3
UVSOR, The Graduate University for Advanced Studies, JapanEuO is a ferromagnetic semiconductor with the Curie temperature (TC) of about 70 K [1]. In
the electron doping case by the substitution of trivalent ions, such as La3+, TC increases to thetemperature as high as 200 K [2]. To apply EuO to spintronics devices such as spin filter tunnel
barriers, it is important to fabricate ultrathin films with a few atomic layers and to clarify theelectronic structure including the exchange splitting energy as well as the TC . Recently, we
succeeded to fabricate single-crystalline EuO ultrathin films by a molecular beam epitaxy method [3].
Using the three-dimensional angle-resolved photoemission spectroscopy, we observed the electronic
structure of the EuO ultrathin films. Then we could determine the thickness-dependent exchange
splitting energy and clarify the mechanism of the changing magnetic property with decreasing
thickness. Both of TC and the exchange splitting energy gradually decrease with decreasing
thickness. The decrease of the hybridization intensities between the Eu 4f and O 2p states andbetween the Eu 4f and Eu 5d states due to the decrease of the neighbor atom number are the originof the change of the magnetic properties of EuO ultrathin films.
[1] A. Mauger et al., J. Phys. (Paris) 39, 1125 (1978). [2] H. Miyazaki et al., Appl. Phys. Lett. 96, 232503 (2010). [3] H.
Miyazaki et al., Submitted to J. Phys. Conf. Series.

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Pressure driven quantum critical point in CeNiAsO

A novel magnetic order of ZnCr2O4 revealed by magneto-opticalmeasurements in ultra-high magnetic fields of up to 600 T

Temperature-driven oscillatory magnetic anisotropy in ultrathin
ferromagnetic films

Magnetoelectric control of magnetic anisotropy in ultrathin Fe films
using a charge-trap heterostructure

A contribution of quantum well states (QWS) to magnetic anisotropy energy (MAE) canbe expected if the spread of the Fermi function is much smaller than the energy difference
between the two states of each QWS pair contributing to the MAE [1]. Such a temperatureeffect on MAE is shown and discussed e.g. for fcc-Co films on vicinal surfaces of Cu(001) [2]and for bcc-Fe films on vicinal surfaces of Ag(001) [3]. In particular, the role of QWS in thevicinity of a spin reorientation transition is analyzed in the context of a model describing theanisotropy of ferromagnetic (FM) films grown on vicinal surfaces. The model reproduces not
only oscillatory behavior of the uniaxial step-induced anisotropy, but also of the oscillatorytilting angle of magnetization. Interestingly, a small amount of e.g. Au on top of an Fe film
completely changes how the magnetic anisotropy evolves with varying thicknesses of an Fe
film. More details on the depth profile of the FM magnetization due to QWS are obtained
from soft x-ray resonant magnetic reflectivity (SXRMR). In particular, it is found that themagnetization is not homogeneous in all Fe atomic lyers.

Magnetoelectric switching of the magnetization vector could enable new low-power logic
devices and non-volatile memory cells. Magnetoelectric switching typically requires complex
multiferroic oxides or strain coupled magnetostrictive/piezoelectric composites. However,recently it has been shown that surface magnetic anisotropy in ultrathin ferromagnetic metal
films can be directly controlled by application of a gate voltage across an adjacent oxide layer[1]. Unfortunately, magnetoelectric effects in metals require a relatively large electric field andare inherently volatile. In this work [2], we examine magneto-electric switching in ultrathin
epitaxial Fe films on Ag(001). We show that a charge-trapping layer integrated into the gate
dielectric can provide the missing non-volatility to the magnetoelectric effect and enhances
its efficiency by an order of magnitude. We report the largest voltage-induced change tosurface magnetic anisotropy yet demonstrated for a metallic thin film, and directly correlate
this change with the density of trapped charge in an adjacent charge storage layer. We also
demonstrate a novel optical charge pumping mechanism, which offers the unique possibilityof optical imprinting of the magnetic state in a continuous Fe film. Supported by the National
Science Foundation through grant ECCS-1128439.

Yongkang Luo1, Leonid Pourovskii2, Stephen Rowley3, Yuke Li4, Chunmu Feng1,
Antoine Georges2, N. P. Ong3, Jianhui Dai4, Guanghan Cao1 and Zhuan Xu1*
1
Department of Physics, Zhejiang University, China
2Centre de Physique Theorique, Ecole Polytechnique, France
3
Department of Physics, Princeton University, USA
4
Department of Physics, Hangzhou Normal University, China
We perform a systematic investigation on the pressure effect on the antiferromagnetic dense Kondo lattice
CeNiAsO[1]. Both hydrostatic pressure and chemical pressure (i.e. P-for-As doping) are successful in tuning
the electronic state to get a pressure driven quantum critical point. We found that $T_{N1}$ decreases slowly
with initial pressure, but 'suddenly' disappears around 4 kbar. In contrary to the first-order-like quantum
phase transition of $T_{N1}$, $T_{N2}$ is continuously suppressed with increasing pressure. A QCP like
phase transition is observed near 6.7 kbar, where $T_{N2}$ is totally suppressed, and non-Fermi-liquid(non-FL) behavior is observed, accompanied with a 'divergent' density of state (DOS) and a sign change ofHall coefficient. In the highly pressurized condition, it exhibits as a typical Kondo lattice metal. In P doped
CeNiAs1-xPx samples, the chemical pressure leads to similar phenomena, with the critical doping level x_
c=$0.4. Magnetic susceptibility measurement points to the delocalization of Ce-4f electrons. Band structure
and Fermi surface topology of CeNiAsO and CeNiPO were calculated by the method of LDA+DMFT. A
new hole pocket contributed by Ce 4f band emerges in CeNiPO. The calculated Kondo scales for CeNiAsO
and CeNiPO are TK = 15 K and 527 K respectively, which qualitively agrees with the experiment.
[1] Yongkang Luo. at al. CeNiAsO: an antiferromagnetic dense Kondo lattice. J. Phys.: Condens. Matter 23, 175701 (2011).
[2] Philipp Gegenwart, et al., Quantum criticality in heavy-fermion metals. Nature Physics 4, 186-197 (2008).

34

Invited & Contributed Presentation

The 19th International Conference on Magnetism

Atsuhiko Miyata1*, Shojiro Takeyama1 and Hiroaki Ueda2
1
Institute for Solid State Physics, University of Tokyo, Japan2
Department of Chemistry, Graduate School of Science, Kyoto University, Japan

Cr3+ ions in ACr2O4 (A = Zn, Cd, Hg) form a pyrochlore lattice and these compounds
are regarded as geometrically frustrated magnets. CdCr2O4 and HgCr2O4 exhibit
diverse magnetic phases including a 1/2 plateau phase under magnetic fields, which
can be described by a theory taking account of a spin-lattice coupling by Penc et al..
On the other hand, ZnCr2O4 shows a quite-small spin-lattice coupling, and there arehigh possibilities that another novel magnetic phases exist in ZnCr2O4. We investigatedmagnetic phases of ZnCr2O4 by the Faraday rotation and magneto-optical absorption
spectral measurements up to 600 T by the electro-magnetic flux compression method.
A ferromagnetic phase transition was observed at 410 T and 4.6 K. Furthermore, anunambiguous anomaly was found in magneto-optical absorption spectra at lower
magnetic field side of the ferromagnetic phase. This indicates existence of a novel
magnetic phase which could only be explained by a theory beyond that by Penc et al..
A magnetic structure of the novel phase was inferred from analogical consideration
with quantum phases in 4He, based upon similarity of a symmetry breaking. As aresult, we concluded that the novel phase corresponds to a magnetic “superfluid” statewith an umbrella-like magnetic structure.

Maciej Dabrowski1, Uwe Bauer1, Marek Przybylski1*, Marek Cinal2, Emmanuelle
Jal3, Jean-marc Tonnerre3 and Jurgen Kirschner11
Max-Planck-Institut fur Mikrostrukturphysik, Halle, Germany
2
Institute of Physical Chemistry of Polish Academy of Sciences, Warszawa, Poland
3
Institut Neel, CNRS & Universite J. Fourier, Grenoble, France[1] M. Przybylski, M. Dabrowski, U. Bauer, M. Cinal, M. Przybylski, J. Kirschner, J. Appl. Phys., in print (2012). [2] U.
Bauer, M. Dabrowski, M. Przybylski, J. Kirschner, Phys. Rev. B 84, 144433 (2011). [3] J. Li, M. Przybylski, F. Yildiz, X.-D.
Ma, Y. Wu, Phys. Rev. Lett. 102, 207206 (2009).

Invited & Contributed Presentation

Invited & Contributed Presentation

Uwe Bauer1, Marek Przybylski2, Jurgen Kirschner2 and Geoffrey Beach1*
1Materials Science and Engineering, MIT, USA
2
Max-Planck-Institut fur Mikrostrukturphysik, Germany[1] T. Maruyama et al. Nature Nanotechnology 4, 158 - 161 (2009) [2] U. Bauer, M. Przybylski, J.
Kirschner, and G. S. D. Beach, Nano Letters ASAP DOI: 10.1021/nl204114t (2012).

July 8-13, 2012 Busan, Korea

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The origin of electric-field effects on magnetic anisotropy in FePd
ultrathin film

Zeeman-type spin splitting controlled by an electric field

Magnetic nanodomains in manganites revealed by Lorentz TEM andsmall-angle electron scattering

Magnetic nanodots induced novel magnetic phenomena

Invited & Contributed Presentation

Shinya Haraguchi1, Yuusaku Taguchi1, Masahito Tsujikawa2 and Tatsuki Oda3*
1
Graduate School of Natural Science and Technology, Kanazawa University, Japan
2
CSIS, Tohoku University, Japan
3
Institute of Science and Engineering, Kanazawa University, JapanThe electric-field (EF) (assisted) magnetization reversal technique that has the advantage of lowpower consumption has been suggested. The EF dependence measurement on the coercivity or themagnetic anisotropy in FePt[1] and FePd[1,2] thin films has been reported. We have performed
theoretical analysis for EF effects on magnetic anisotropy energy (MAE) in Pt/Fe/Pt(001)[3] andPd/Fe/Pd(001)[4] thin films and found that these systems show the inverse EF effect between the Pt
and Pd systems. It was also found that this effect corresponds well to the experimental observations[1,2]. The microscopic origin for the inverse issue has not been discussed deeply, although thesystems of Pt and Pd are similar to each other. The distinct property of Pd against Pt is magnetic
polarization. In order to clarify origins for the inverse effect in Pd/Fe/Pd(001), by using the density
functional calculation, we have further estimated MAE and its EF effect in the several sets of spinorbit coupling choice for atoms. As a result, we found that the contribution from the Pd substrate isvery important in the inverse issue. In the presentation, we will show results of MAE density map inreal space and discuss comparison with the Pt system.

Hongtao Yuan1*, Mohammad Saeed Bahramy 2, Kazuhiro Morimoto1, Kentaro
Nomura3, Hidekazu Shimotani1, Ryotaro Arita1, Christian Kloc4, Naoto Nagaosa1 andYoshihiro Iwasa1
1
Department of Applied Physics, University of Tokyo, Japan
2
CREG, RIKEN, Japan3
Department of Physics, Tohoku University, Japan
4
School of Materials Science and Engineering,, Nanyang Technological University,
Singapore

Yoshihiko Togawa1, Tsukasa Koyama2, Ken Harada2 and Shigeo Mori2
1
Nanoscience and Nanotechnology Research Center, Osaka Prefecture University,Japan
2
Department of Materials Science, Osaka Prefecture University, Japan
La1-xSrxMnO3 (LSMO) shows a complex variety of magnetic and electronic groundstates, which depend on the Sr doping concentration (x). Here, we have thoroughly
examined magnetic microstructures in single crystals of LSMO by using lowtemperature Lorentz transmission electron microscopic (TEM) and small angle
electron scattering experiments. The magnetic stripe domains with periodic separationof approximately 200 nm are formed in the orthorhombic structure of La1-xSrxMnO3forx ~ 0.175 in the zero magnetic field. An in-situ Lorentz TEM observation revealed that,when the vertical magnetic field is applied by utilizing the magnetic field of object lens,
the magnetic stripe domains change into a form of the magnetic vortex with the 100 nm
size. These magnetic nanodomains with chiral spin configuration (magnetic vortex) are
new kinds of magnetic ground states (spin textures) in manganites. In the presentation,
we will explain detailed responses of magnetic vortices to external magnetic fields anddiscuss the nucleation and growth mechanism of magnetic vortices in the magnetic
stripe domains.

Jian Shen
Department of Physics, Fudan University, China

Study of Magnetic nanodots is at central in the field of nanomagnetism. Besides theinteresting properties caused by dimensionality effect, magnetic nanodots can induce
many novel phenomena when forming heterostructures with other materials. In thiswork, I will use several examples to demonstrate their effect. These examples include
collective ferromagnetism of nanodot arrays on 2-dimensional electron gas, colossal
Coulomb blockade magnetoresistance in tri-layers, and dramatic enhancement ofmetal-insulator transition temperature in manganites. All these fascinating phenomena
originate directly from the presence of magnetic nanodots. Their underlying
mechanisms, while somewhat understood, need further theoretical studies.

[1] M. Weisheit et al., Science 315, 349 (2007). [2] F. Bonell et al., Appl. Phys. Lett. 98, 232510(2011). [3] M. Tsujikawa and T. Oda, Phys. Rev. Lett. 102, 247203 (2009). [4] S. Haraguchi et al., J.
Phys. D: Appl. Phys. 44, 064005 (2011).

Electrically manipulating electron spins based on Rashba-type spin-orbit interaction(SOI) is a key path-way for applications of spintronics and spin-based quantum
computing. Two-dimensional electronic system (2DES) is a particularly important
SOI platform, where the in-plane spin polarization can be tuned with an electric field
perpendicular to the 2DES (also spins). In contrast, electric manipulation of outof-plane polarized spins remains elusive and a great challenge though it is known
beneficial for longer spin lifetime. Here, we present a new concept, in which an out-ofplane spin polarization is realized and further controlled with the external perpendicularelectric field (parallel to polarized spins), by combining the first-principle calculations
and magnetotransport experiments in a field effect transistor made of the transition
metal dichalcogenide WSe2. Such an out-of-plane spin splitting is shown to take placeat the corners of WSe2 Brillouin Zone in a form of Zeeman-type spin polarization, due
to the exposure of a large but hidden in-plane electric dipole of WSe2 layers, thereby
enabling new degrees of control for quantum confined spintronic devices.

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Ferroelectric control of spin polarization

Femtoscale magnetically induced lattice distortions in multiferroic
TbMnO3Morin transition control of antiferromagnetic α-Fe2O3 films withepitaxial strains

Magnetic properties of Fe-(Pt,Pd) thin films patterned by selfassembling of polystyrene nanospheres

Manuel Bibes1*, Vincent Garcia1, Sergio Valencia2, Arnaud Crassous1, Laura Bocher3,
Alexandre Gloter3, Stephane Fusil1, Karim Bouzehouane1, Xavier Moya4, Neil D
Mathur4 and Agnes Barthelemy1
1
Unite Mixte de Physique CNRS/Thales, France
2
HZB Berlin, Germany
3
Lab. Physique des Solides, Orsay, France
4
University of Cambridge, United Kingdom[1] Y. Togawa, T. Koyama, M. Kobayashi, K. Takayanagi, K. Harada, and S. Mori, submitted.

Paola Tiberto1, Luca Boarino1, Gabriele Barrera1, Federica Celegato1, Marco Coisson1,
Natascia De Leo1, Franco Vinai1, Franca Albertini2, Francesca Casoli2 and P. Ranzieri2
1Electromagnetics, INRIM, Italy
2
IMEM-CNR, Italy

It is well known that hematite(α-Fe2O3) undergoes a spin reorientation transition at around
263 K. It is Morin transition only found in hematite and some orthoferrites. J.O. Artman, J.C.
Murphy, and S. Foner suggested that it is caused by the competition between the single ion
anisotropy and the magnetic dipole anisotropy[1]. Their model has been confirmed with thefine particles and pressurized single crystal and it becomes clear that the lattice constants inc-plane are critical to determining the Morin temperature [2,3]. However, when Fe2O3 aregrown in the form of epitaxial films, no one has observed the transition despite the expectationthat the epitaxial strain can be controlled better in the form of films [4,5]. In this work, we havegrown a series of epitaxial α-Fe2O3 films on Al2O3 substrates. The lattice constants of them
are successfully controlled with the Cr2O3 buffer layer and the strain relaxation. We found that
the Morin temperature changes consistently with the lattice constants and it reaches 360 K for
thinnest film. The results are well in accordance with the theoretical model. This research was
supported by NRF funded by MEST (2009-0088969, 2010-0018733).

Arrays of nanoparticles with high magnetic anisotropy are studied for magnetorecording. Nanolithography
techniques are employed to prepare arrays of magnetic dots/holes. Polystyrene nanosphere (PN)
lithography has been recently exploited for magnetic thin films nanostructuring, due to its low-cost andlarge covering area [1,2]. Dot arrays of Fe53Pt47 (MgO(100) substrate heated at 400 °C) were obtained byassembling PN monolayers on a continuous film (10 nm), followed by sputter etching with Ar+ ions (final
dots diameter 80 ÷ 400 nm) [1]. Antidot arrays of Fe50Pd50 (50 nm, Si substrate, post deposition annealingat 550 °C) have been created by exploiting PN as diffraction masks in combination with a mercury lamp [2].
In this alternative lithography technique, the PN behave as optical lenses to generate regular diffraction
patterns (holes, diameter = 300 nm) on a photoresist. In both cases, the annealing induces the orderdisorder transformation towards the L10 tetragonal phase. Sample microstructure was studied with SEM
and AFM microscopy. Parallel and perpendicular hysteresis loops were measured by AGFM, confirming
the presence of the tetragonal phase. The complex multidomain magnetic pattern was studied in bothcompositions with MFM and related to dot/hole diameter and their mutual distance.

[1] T. Kimura et al., Nature 426 55 (2003) [2] I. A. Sergienko & E. Dagotto, Phys. Rev. B 73 094434 (2006) [3] H. Katsura, N.
Nagaosa, A. V. Balatsky, Phys. Rev. Lett. 95 057205 (2005) [4] H. C. Walker et al., Science 333, 1273 (2011)

1. J.O. Artman, J.C. Murphy, and S. Foner, Phys. Rev. 138, 912 (1965). 2. N. Yamamoto, J. Phys. Soc. Jpn. 24, 23 (1968) 3. R.C. Wayne and D.H.
Anderson, Phys. Rev. 155, 496 (1967) 4. S. Gota, M. Gautier-Soyer, and M. Sacchi, Phys. Rev. B, 64, 224407 (2007) 5. A. Barbier, R. Belkhou, P.
Ohresser, M. Gautier-Soyer, O. Bezencenet, M. Mulazzi, M.-J. Guittet, and J.-B. Moussy, Phys. Rev. B, 72, 245423 (2005)[1] P. Tiberto, L. Boarino, F. Celegato, M. Coisson, N. De Leo, F. Vinai, J. Appl. Phys. 107, 09B502 (2010) [2] P.
Tiberto, L. Boarino, , F. Celegato, G. Barrera, M. Coisson, N. De Leo, F. Vinai, P. Allia, MRS Proc. (2012) in press

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Voltage controlled spin transport channel

Direct measurement of the interatomic distance dependence of themagnetic exchange interaction

Surface plasmons and magneto-optical activity in hexagonal Ni antidot arrays

Position dependence of vortex core oscillation in polygonal
nanomagnets

Recently, we demonstrated the feasibility to utilize the short-ranged magnetic exchangeinteraction to map spin textures of surfaces with atomic resolution on insulators [1] as wellas on metals [2] with magnetic exchange force microscopy. Even more promising is the
spectroscopic mode, i.e., magnetic exchange force spectroscopy (MExFS), which enabled
us to directly probe the distance dependence of magnetic exchange interaction [3]. The
experimental data were acquired with a magnetically coated tip on the antiferromagnetic
Fe monolayer on W(110). First, the distance dependence of the total tip-sample interaction
was measured on Fe surface atoms of oppositely oriented magnetic moments. Thereafter,
the magnetic contribution was obtained by subtracting both curves from each other. Thisapproach guarantees that all non-magnetic interactions, e.g., the short-ranged chemicalinteraction and the long-range van der Waals interaction, cancel out. The result, i.e., themagnetic exchange interaction, exhibits excellent agreement with ab-initio calculations
based on density functional theory performed for the same tip-sample system.

The interaction between the surface plasmon polaritons (SPPs) and a magnetic field ina pure magnetic metal is presented in this work. By utilizing nano patterned structures
one can create plasmonic resonances on magnetic surfaces. We have investigated
how hexagonal arrays of circular holes (250-275 nm) in a Ni matrix (anti-dot arrays)
couple to plasmonic resonances and therefore how it changes the optical and magnetooptical spectra. We have performed angularly resolved scans of the reflectivity andtransmission with and without application of magnetic field and compared themto theoretical calculations. We present signatures of SPPs as troughs in reflectivity
and extraordinary transmission through the holes. In the plasmonic regimes a big
enhancement of the magneto-optical response (polar moke) is observed. Application ofa transverse magnetic field influences the excitation of SPPs as it can be seen by the big
increase of magnetic contrast measured in the transverse Moke configuration. These
effects pave the road for the development of new optical components and sensors withgreat application potential

A magnetic vortex structure formed in a micron-scale ferromagnetic dot has been gathering attention
because of its superior performance for a unit cell in spintronic devices[1] and intriguing magnetic
responses such as bloch point reversal[2]. Control and further understanding of vortex properties are
required for the practical application. Previously, we showed that the vortex chirality can be controlled
simply by the application of the in-plane magnetic field in a regular polygonal-shape nanomagnet[3].
This enables us to control the core position precisely by applying the external magnetic field. Since
the potential distribution for the core in the polygonal nanomagnet should be different from a simple
harmonic potential formed in a circular magnetic dot, we expect that the resonant frequency depends onthe core position. In the present work, we investigate the vortex core dynamics in a triangular nanomagnet
under the external magnetic field using an electrical homodyne detection technique and the transmission
impedance measurements using a vector network analyzer. The resonant frequency was found to increase
with decreasing the distance between the core and the vertex.

V. Garcia et al, Science 327, 1106 (2010) ; S. Valencia et al, Nature Mater. 10, 753 (2011) ; L.
Bocher et al, Nano Lett. 12, 376 (2012) ; Financial support from ERC advanced grant no. 267579.

Hyuk-jae Jang1*, Oleg A. Kirillov2, Oana D. Jurchescu3 and Curt A. Richter2
1
NIST & WFU, USA
2
NIST, USA3
Physics, Wake Forest University, USA
Two-terminal metal-oxide-based devices in which memory-resistive(memristive) switchingoccurs show great potential for use in next generation technologies such as non-volatile memories
and neural networks[1,2]. It has been reported that TaOx-based devices combined with Cu and Pt
electrodes show memristive behavior utilizing metal precipitation to create conductive channel (tensof nanometers in diameter) inside of the oxide thin film when an electric voltage (only around 1V
between two electrodes sandwiching the oxide layer) is applied[3]. This unique mechanism candeliver an opportunity to explore a new type of technological application, an electron spin transportchannel controlled by an external voltage. We have explored this possibility by investigating devices
with a TaOx thin film sandwiched between two ferromagnetic metal electrodes. Three different setsof devices, Co/TaOx/Cu/Py, Py/TaOx/Cu/Co, and Co/TaOx/Py were prepared in cross-bar shape.
Only devices with a Cu layer show memristive behavior having a typical OFF/ON resistance ratioof 105. Magnetoresistance measurements performed by sweeping an external magnetic field display
evidence of spin transport in the low-resistance ON-state at 77 K. No magnetoresistance was detectedin the OFF-state indicating spin transport vanishes. Our study illustrates that we experimentallyrealized a continuous electron spin transport channel controlled by a low power voltage[4].
[1] J. J. Yang et al., Appl. Phys. Lett. 97, 232102 (2010). [2] S. H. Jo et al., Nano Lett. 10, 1297 (2010). [3] T. Sakamoto etal., Appl. Phys. Lett. 91, 092110 (2007). [4] H.-J. Jang et al., Appl. Phys. Lett. 100, 043510 (2012).

The 19th International Conference on Magnetism

Helen Walker1*, Francois De Bergevin2, Federica Fabrizi3, Luigi Paolasini2, Andrew
Boothroyd3, Dharmalingam Prabhakaran3 and Desmond Mcmorrow4
1
Resonant Scattering and Diffraction Beamline P09, PETRA III, HASYLAB at DESY, Germany
2
European Synchrotron Radiation Facility, France
3
Department of Physics, University of Oxford, United Kingdom
4
London Centre for Nanotechnology, University College London, United Kingdom

1. T.Z. Ward, Z. Gai, X.Y. Xu, H.W.Guo, L.F. Yin, J. Shen, Phys. Rev. Lett. 106, 157207 (2011). 2.
Dali Sun, Lifeng Yin, Chengjun Sun, Hangwen Guo, Zheng Gai, X.-G. Zhang, T. Z. Ward, Zhaohua
Cheng, and Jian Shen, Phys. Rev. Lett. 104, 236602 (2010). 3. Lifeng Yin, Di Xiao, Zheng Gai,
Thomas Z. Ward, Noppi Widjaja, G. Malcolm Stocks, Zhao-hua Cheng, E. Ward Plummer, Zhenyu
Zhang, and Jian Shen, Phys. Rev. Lett. 104, 167202 (2010).

Seonghun Park1, Jae-hoon Park2 and Jae-young Kim3*
1
deparment of physics, POSTECH, Korea
2
department of physics, POSTECH, Korea
3
Pohang Accelerator Laboratory, Korea

A current drawback of spintronics is the large power required for magnetic writing. Aiming at a nonvolatile low-power electrical control of spintronics properties we have combined two ferromagnetic
electrodes (namely La2/3Sr1/3MnO3 and Fe or Co) with a ferroelectric BaTiO3 tunnel barrier. We havefound that the TMR depends on the direction of the ferroelectric polarization in the barrier. This
demonstrates a local, large, and nonvolatile control of spin polarization by electrically switching
ferroelectric polarization. Interestingly, just as ferroelectricity in the BaTiO3 influences the spinpolarization of the adjacent Fe or Co magnetic electrodes, magnetism is induced by the electrodes in
the ferroelectric. We have used soft X-ray resonant magnetic scattering to evidence that, in addition
to being ferroelectric, the BaTiO3 barrier possesses a hysteretic magnetization at room temperature.
Ab initio calculations of realistic interface structures provide insight into the origin of the induced
moments and perspectives towards new multifunctional interfaces for spintronics.

36

Invited & Contributed Presentation

The discovery of the canonical spin-cycloid multiferroic TbMnO3 [1], in which the onset of a spontaneous ferroelectric
polarization is concomitant with a magnetic phase transition, has generated considerable interest in the control of electric
polarization by magnetic fields, and vice versa. Although comprehensive, microscopic descriptions of the magnetic
structure have been obtained, our understanding of the ferroelectric state is still developing. Competing theoretical models
proposed to explain the ferroelectricity are associated with either ionic displacements, arising due to antisymmetricexchange interactions [2], or charge transfer [3]. By exploiting the magneto-electric coupling in TbMnO3, we used anelectric field to produce a single magnetic domain state, and a magnetic field to induce ionic displacements. Under these
conditions, interference charge-magnetic x-ray scattering arose, encoding the amplitude and phase of the displacements.
When combined with a theoretical analysis, our data allow us to resolve ionic displacements at the femtoscale which
contribute a significant fraction of the zero-field ferroelectric moment, and reveal that both symmetric and antisymmetric
Dzyaloshiskii-Moriya interactions need to be included into the microscopic models [4]. Thus our results represent an
important step forward towards the goal of realising the technological potential of these materials.

Alexander Schwarz1*, Rene Schmidt1, Cesar Lazo2, Stefan Heinze2 and Roland
Wiesendanger1
1
Institute of Applied Physics, University of Hamburg, Germany
2
Christian-Albrecht University Kiel, Germany[1] U. Kaiser, A. Schwarz and R. Wiesendanger, Nature 446, 522 (2007). [2] R. Schmidt et al., Nano
Lett. 9, 200 (2009). [3] R. Schmidt et al., Phys. Rev. Lett. 106, 257202 (2011).

Invited & Contributed Presentation

Invited & Contributed Presentation

Emil Melander*, Evangelos Papaioannou, Vassilios Kapaklis and Bjorgvin
Hjorvarsson
Department of Physics and Astronomy, Division of Materials Physics, Uppsala
University, Sweden

E. T. Papaioannou, V. Kapaklis, E. Melander, B. Hjorvarsson, S. D. Pappas, P. Patoka, M. Giersig, P. Fum-agalli, A. GarciaMartin and G. Ctistis, “Surface plasmons and magneto-optic activity in hexagonal Ni anti-dot arrays”, Opt. Express 19, 23867(2011)

Satoshi Yakata1, Masahiko Miyata2, Kohei Kiseki3, Hirofumi Wada2 and Takashi
Kimura1*
1
INAMORI Frontier Research Center, Kyushu University, Japan2
Department of Physics, Kyushu University, Japan3
Department of Electronics, Kyushu University, Japan[1] V. S. Pribiag, I. N. Krivorotov, G. D. Fuchs, P. M. Braganca, O. Ozatay, J. C. Sankey, D. C. Ralph, and R. a. Buhrman,
Nature Physics 3, 498-503 (2007). [2] A. Thiaville, J. Garcia, R. Dittrich, J. Miltat, and T. Schrefl, Physical Review B 67,
1-12 (2003). [3] S. Yakata, M. Miyata, S. Nonoguchi, H. Wada, and T. Kimura, Applied Physics Letters 97, 222503 (2010)

July 8-13, 2012 Busan, Korea

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Huge magnetic anisotropy and coercivity in Fe island and atomic wireon

Control of the living cell machinery with nanomagnets

Quantum control of single spins in diamond and silicon carbide

Transition from spin injection into interface states to the channel in n-Ge

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Invited & Contributed Presentation

Takeshi Nakagawa *, Toshihiko Yokoyama , Torsten Methfessel , Sandra Perkert andHans-joachim Elmers2
1
Institute for Molecular Science, Japan
2
Mainz University, Germany

We have investigated huge magnetic anisotropy energy and coercivity of Fe nanoislands and nano stripes on flat and stepped W(110) using x-ray circular dichroism(XMCD) and scanning tunneling microscope, which has not been directly decided
so far due to its large anisotropy [1]. The anisotropy energy is 1 meV per Fe atom as
determined from magnetization curve by XMCD at Fe L edge, almost constant bothfor the nano island and the nano stripe below one monolayer. This anisotropy energy
corresponds to an anisotropy field of 17 T. The coercivity, Hc, for the nano islands at
0.25 ML is very large, ~5 T, but it rapidly decreases to 1 T at 0.6 ML, which follows
Hc ~ 1/r (radius of island). On the other hand, the coercivity for the nano stripes isalmost constant, Hc ~ 3 T below 0.5 ML. The obtained coercivity is much smaller than
the anisotropy field, suggesting that the magnetization reversal process is via a domain
wall creation, not a coherent rotation. This contrasted behavior is explained by theshape of deposited Fe on the stepped and flat W surfaces and the creation of domain
wall.

Vitalii Zablotskii1*, Alexandr Dejneka1, Oleg Lunov2, Lubomir Jastrabik1, Tatiana
Syrovets2 and Thomas Simmet2
1
Applied Optics, Institute of Physics, Czech Republic
2
Institute of Pharmacology of Natural Products & Clinical Pharmacology, Ulm
University, Germany
We present proof-of-concept experiments on magnetically controlled cellular endocytosis offunctionalized magnetic nanoparticles. The possibility of remote control of the cellular endocytosis
and/or exocytosis rates by an externally applied magnetic field without using various types ofinhibitors seems to be a very intriguing direction in nanomedicine [1]. By pharmacological and invitro knockdown approaches, the principal cellular uptake mechanism for two types of magnetic
nanoparticles was identified [2]. A model of the uptake process that allows determination of
key parameters of endocytosis, including the rate of uptake, the number of nanoparticles percell in saturation, the mean uptake time, and the correlation between the number of internalized
nanoparticles and their extracellular concentration was developed. We also describe our recent
progress in the applications of nanomagnets for magnetic hyperthermia treatments and targeted
drug delivery [3]. In particular, we will propose a new mode of hyperthermia that we haveanalyzed. The obtained results have important implications for the fundamental knowledge on
intracellular nanomechanics and open ways for magnetic controlling of the living cell machinery.

David D. Awschalom*
Center for Spintronics and Quantum Computation, University of California, USA
A motivation behind modern research into quantum physics has been to identify robust quantum statesthat can be easily controlled for future use in advanced information technologies. Recently, a defectin diamond known as the nitrogen-vacancy (N-V) center has attracted interest because it possesses anatomic scale electronic spin state that can be used as an individually addressable, solid state quantum
bit (qubit) even at room temperature. The N-V center’s optical transitions become coherent, spindependent, and may be precisely controlled with gate voltages in micron-scale devices [1]. Moreover,engineered coupling of this electron spin with the proximal single nitrogen nuclear spin enables ascalable quantum memory [2]. These exceptional coherent properties have motivated theoreticalefforts to predict similar defects in other semiconductors with expanded functionality [3].We showthat spin states in various polytypes of SiC can be optically addressed and coherently controlled
at temperatures ranging from 20 to 300 K with coherence properties comparable to diamond N-V
centers. These spins are optically active near telecom wavelengths within an industrial scale material
having advanced microfabrication techniques. This makes them promising candidates for photonic,
spintronic, and quantum information applications that merge quantum degrees of freedom withclassical electronic and optical technologies [4].

[1] M. Pratzer, et al., Phys. Rev. Lett. , 87, 127201(2001)[1] V. Zablotskii, O. Lunov, A. Dejneka, L. Jastrabik, T. Polyakova, T. Syrovets, Th. Simmet. Appl. Phys. Lett. 99, 183701 (2011). [2]O. Lunov, V. Zablotskii, T. Syrovets, C. Rocker, K. Tron, G. U. Nienhaus, Th. Simmet. Biomaterials 32, 547 (2011). [3] O. Lunov,
V. Zablotskii, M. P. Gutierrez, J. I. Perez-Landazabal, C. Gomez-Polo, T. Syrovets, Th. Simmet. American Institute of Physics,
Conference Proceeding Series 1311, 288 (2010).

[1] L.C. Bassett, F.J. Heremans, C.G. Yale, B.B. Buckley, & D.D. Awschalom, Phys. Rev. Lett.107,
266403 (2011). [2] G. D. Fuchs, G. Burkard, P. V. Klimov, and D. D. Awschalom, Nature Physics7,
789 (2011). [3] J. R. Weber, W. F. Koehl, J. B. Varley, A. Janotti, B. B. Buckley, C. G. Van de Walle,and D. D. Awschalom, Proc. Natl Acad. Sci.107, 8513 (2010). [4] W. F. Koehl, B. B. Buckley, F. J.
Heremans, G. Calusine, &D. D. Awschalom, Nature 479, 84 (2011).

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Oscillation of critical fields in highly dense arrays of magnetic
nanodisks

Bio-functionalized magnetic nanoparticles for in-vitro diagnosis ofcolorectal cancer

Dynamical spin injection into p-type Si using the spin pumping andspin transport at room temperature

Alexey Ognev*, Maxim Stebliy, Alexander Samardak and Ludmila Chebotkevich
Far Eastern Federal University, Institute of Automation and Control Processes
FEBRAS, Russia

Magnetostatic interaction between magnetic nanostructures composing a highly dense
array influences on its magnetization reversal and micromagnetic configuration. In
this paper we demonstrate the effect of nanodisk array dimension N on magnetic
properties. The nanodisk patterns with 600 nm in diameter and distance between
disk’s centers d from 700 nm to 1um were fabricated by electron-beam lithography.
The number of disks on a boundary N was varied from 2 to 20. After sputtering of
Py films and lift-off process the nanodisks with thickness t =9, 22 and 30 nm wereprepared. Using magnetic hysteresis curves we found out that with an increase of N
the fields of magnetic vortex nucleation Hn and annihilation Ha decreased. At the firsttime we demonstrate the oscillations of function Hn = f(N) in arrays. The maximum
amplitude of oscillations was observed in case of nanodisks with t=22 nm and d=800
nm. Magnetic force microscopy shown that at t=22 nm the magnetization reversal was
occurred mainly via vortex core motion. We were carried out the calculation of criticalfields Hn and Ha with in “rigid” vortex model for different N. The theoretical result isin a good qualitative agreement with the experimental data.

Charles Shieh-yueh Yang1*, Herng-er Horng2, Hong-chang Yang3, K.w. Huang4 and Chau-chung Wu5
1
MagQu Co., Ltd., Taiwan
2
Institute of Electro-optical Science and Technology, National Taiwan Normal University, Taiwan
3
Department of Physics, National Taiwan University, Taiwan
4Department of Surgery & Hepatitis Research Center, National Taiwan University Hospital, Taiwan
5Departments of Internal Medicine and Primary Care Medicine, National Taiwan University, Taiwan

Colorectal cancer (CRC) is the most popular cancer. Carcinoembryonic antigen (CEA) has been usedas bio-markers for CRC. The signals for CEA solutions of various concentrations, or with interfering
materials are detected via immunomagnetic reduction (IMR), the assay technology involves theutilities of bio-functionalized magnetic nanoparticles to label CEA. By using the bio-functionalized
magnetic nanoparticles and the analyzer, the detection threshold and interference tests for assaying
CEA are examined. Several serum samples from normal people and CRC patients are used for thedetections of CEA concentration via IMR. The results of assaying CEA with IMR and enzyme-linked
immunosorbent assay (ELISA) were compared. As compared to ELISA, the detection threshold forassaying CEA with IMR is lowered by at least two orders of magnitude. For the interfering materials
noted commonly in serum such as hemoglobin, bilirubin, triglyceride, and vascular endothelial
growth factor, there is no detectable interfering effect for assaying CEA with IMR. These results
reveal the feasibilities of assaying CEA in the blood using IMR, as well as achieving a high-sensitiveand high-specific assay for CEA.

Kazuki Kubo1*, Eiji Shikoh1, Kazuya Ando2, Eiji Saitoh2, Teruya Shinjo1 and Masashi
Shiraishi1
1
Graduate School of Eng. Sci.,, Osaka Univ., Japan
2
Inst. for Materials Research, Tohoku Univ., JapanFor observation of spin-transport in p-type Si, ferromagnetic Ni80Fe20 and paramagnetic
Pd were separately formed with various gap distances on a p-Si with doping
concentration of 1×1019 cm-3. The sample was placed near the center of a microwave
cavity in ESR system. In a ferromagnetic resonance condition of the Ni80Fe20, thesteady magnetization precession was maintained by the absorption of the microwave
and the angular momentum was transferred from the local spins to conduction
electrons. Then conservation of spin angular momentum induced spin pumping into thep-Si, which generated pure spin current in the p-Si. The spin current propagated in thep-Si, and was absorbed into the Pd, where the spin current was converted to a charge
current by the inverse spin-Hall effect(ISHE) in Pd. When the gap length was 490 nm,
the output voltage of 1.4 μV due to the ISHE was obtained. Using the results, the spin
diffusion length and spin coherence time in p-Si at room temperature were estimatedto be at least 130 nm and 94 ps, respectively[1]. In the presentation, we will discuss thedetail of the research.

Abhinav Jain1, Juan-carlos Rojas1, Murat Cubukcu1, Julian Peiro2, Jean-christophe Le Breton2,
Eric Prestat1, Celine Vergnaud1, Lamis Louahadj1, Celine Portemont3, Clarisse Ducruet1, Vincent
Baltz1, Andre Barski1, Pascale Bayle-guillemaud1, Laurent Vila1, Jean-philippe Attane1, Emmanuel
Augendre4, Serge Gambarelli1, Henri Jaffres2, Jean-marie George2 and Matthieu Jamet1*
1

INAC, Commissariat a l'Energie Atomique et aux Energies Alternatives, France
Unite Mixte de Physique CNRS-Thales, CNRS, France
CROCUS Technology, France
4
LETI, Commissariat a l'Energie Atomique et aux Energies Alternatives, France
2
3

Spin injection into semiconductors is crucial for exploring spin physics and new spintronic devices. Unlike GaAs
or Si, very few studies have dealt with spin injection in Ge [1,2,3,4]. This material is of great interest for highcarrier mobility, long spin diffusion length and large spin-orbit coupling to perform electric field spin manipulation
through Rashba interaction. However the exact role of interface states in spin injection mechanism in n-Ge has
not been clarified yet and except in ref. [1] no clear evidence of spin accumulation in the channel has been given.
In this paper, we show a clear transition from spin injection into interface states to the channel. For this purpose,
we have grown CoFeB/MgO spin injector on GOI [2]. We observe spin signal amplification at low temperature
due to spin accumulation into interface states. At 200 K, we observe a clear transition to spin injection in thechannel up to room temperature: the spin signal is reduced to a value compatible with spin diffusion model andmore interesting we could demonstrate spin signal modulation applying a back gate voltage and spin-pumping
by the ferromagnetic resonance of the CoFeB layer which are clear manifestations of spin accumulated in thechannel.
[1] Y. Zhou, W. Han, L.-T. Chang, F. Xiu, et al., Phys. Rev. B 84, 125323 (2011). [2] A. Jain, L. Louahadj, J. Peiro, J. C. Le Breton, C. Vergnaud, A. Barski, C. Beigne,
L. Notin, A. Marty, V. Baltz, S. Auffret, E. Augendre, H. Jaffres, J.-M. George, M. Jamet, Appl. Phys. Lett. 99, 162102 (2011). [3] H. Saito, S. Watanabe, Y. Mineno, S.
Sharma, et al., Solid State Comm. 151, 1159 (2011). [4] K. R. Jeon, B.-C. Min, Y. H. Jo, H.-S. Lee, I. J. Shin, C.-Y. Park, S.-Y. Park, S. C. Shin, Phys. Rev. B 84, 165315 (2011).

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Tunneling anisotropy in crystalline Si/MgO/Fe devices

Sandeep Sharma1*, Aurelie Spiesser1, Hidekazu Saito1, Shinji Yuasa1, Bart J. Van
Wees2 and Ron Jansen1
1
AIST Tsukuba, Japan
2
Zernike Institute for Advanced Materials, Univ. of Groningen, Netherlands
Key advances in the electrical creation of spins in silicon at room temperature haverecently been made, using ferromagnetic tunnel contacts to inject a spin accumulation,and to detect it [1,2]. This enables the systematic study of the various parametersthat govern spin injection into silicon. Here we demonstrate that spin transport inferromagnet/oxide/silicon tunnel devices is anisotropic, i.e., depends on the absoluteorientation of the magnetization direction of the ferromagnetic electrode. In particular,
we show that the magnitude of the spin accumulation induced in the Si is anisotropic
and changes when the magnetization is rotated either in the in-plane or the out-ofplane direction. We present a systematic study of the anisotropic tunnel conductanceof crystalline Si/MgO/Fe spin tunnel contacts at 300 K. We observe an in-planeanisotropy that reflects the crystal symmetry of the tunnel contact. The out-of-planeanisotropy shows a bias-dependent, non-trivial variation with magnetization angle
that arises from a superposition of different contributions to the anisotropy, one ofwhich is the anisotropy of the tunnel spin polarization. The results will be compared toanisotropy data on contacts with an amorphous Al2O3 tunnel barrier, n-type and p-typesilicon, and Ni and Fe as the ferromagnet.

1. C.C. Yang, S.Y. Yang, J.J. Chieh, H.E. Horng, C.Y. Hong, H.C. Yang, K.H. Chen, B.Y. Shih, T.F. Chen, and M.J. Chiu, ACS Chem. Neurosci. 2, 500 (2011). 2.
K.W. Huang, S.Y. Yang, C.Y. Yu, J.J. Chieh, C.C. Yang, H.E. Horng, C.Y. Hong, H.C. Yang, and C.C. Wu, J. Biomed. Nanotechnol. 7, 535 (2011). 3. S.Y. Yang, J.J.
Chieh, W.C. Wang, C.Y. Yu, N.S. Hing, H.E. Horng, C.Y. Hong, H.C. Yang, C.F. Chang, and H.Y. Lin, J. Magn. Magn. Mater. 323, 681 (2011).

[1] E. Shikoh, K. Kubo, et al., arXiv:1107.0376.

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Magnetic tools for molecular diagnosis

Multiplexing capabilities of multi-frequency magnetic ratchets

Studying the optical spin orientation in Ge by exploiting the spin
filtering in Fe/MgO/Ge photodiodes

Micromagnetic models in glass-coated microwires with circumferential
anisotropy

Joerg Schotter1*, Astrit Shoshi1, Stefan Schrittwieser1, Hubert Brueckl1, Frank Ludwig2, Katerina Soulantika3, Manfred
Meindl4 and Christian Zilch5
1
Health & Environment Department, AIT Austrian Institute of Technology, Austria
2Institute of Electrical Measurement and Fundamental Electrical Engineering, TU Braunschweig, Germany
3
LPCNO, Universite de Toulouse; INSA, UPS, LPCNO, and CNRS, France
4
Danube Mobile Communications Engineering (DMCE), Austria
5Magna Diagnostics GmbH, Germany

This talk shows examples for the application of magnetic transducers such as magnetoresistive sensors (→‘Lab-on-a-chip’) or multifunctional magnetic nanoparticles (→ ‘Lab-on-a-bead’) as tools for moleculardiagnosis. Regarding Lab-on-a-chip systems, we demonstrate in-vitro studies of magnetic particle uptake(phagocytosis) by cell cultures (e.g. NHDF or DU145 cells). The method is based on distance changes of themagnetic particles to embedded magnetoresistive sensors during phagocytosis and allows analysis of factorsthat are relevant for applications like magnetofection or hypothermia. As a second Lab-on-a-chip application,
we show the concept and progress of a CMOS-integrated tunneling magnetoresistance sensor chip currently
under development for a point-of-care device for sepsis diagnosis. Our Lab-on-a-bead approach focuses on
homogeneous immunodiagnostics based on manipulation and observation of multi-functional nanoparticles.
This new biosensor concept is based on highly sensitive plasmon-optical detection of the rotational dynamics
of anisotropic magnetic nanoparticles immersed in the sample solution, which changes on the bindingof analyte molecules to the nanoparticles. We present model calculations of the optical, magnetic andhydrodynamic properties of both the required nanoparticles and measurement conditions. Experimentally, weshow transmission measurements on plain ferromagnetic nanorod dispersions in rotating magnetic fields.
Schrittwieser S, Ludwig F, Dieckhoff J, Soulantica K, Viau G, Lacroix L-M, Lentijo SM, Boubekri R, Maynadie J, Huetten A, Brueckl H, Schotter J.
Modeling and Development of a Biosensor Based on Optical Relaxation Measurements of Hybrid Nanoparticles. ACS Nano, 2012;6:791

38

Invited & Contributed Presentation

The 19th International Conference on Magnetism

Benjamin B. Yellen1,2, Yuyu Ouyang1, Lu Gao2, Mukarram A. Tahir2, Daniel J.
Lichtenwalner3 and Lawrence. N. Virgin2
1
University of Michigan – Shanghai Jiao Tong University Joint Institute, Shanghai
Jiao Tong University, Shanghai, P.R.C.
2
Duke University, Department of Mechanical Engineering and Materials Science,Center for Biologically Inspired Materials and Material Systems, Durham, NC 27708
3
North Carolina State University, Department of Materials Science and Engineering,Raleigh, NC 27606
Through a combination of theory, numerical simulation, and experiment, we investigate
the motion of magnetic beads on the surface of a magnetic ratchet driven by multifrequency fields. We demonstrate that in multifrequency driving fields, two different
bead types experience differential motion by modulating the phase difference between
the two driving frequencies. We use perturbation analysis to demonstrate that static
forcing terms are the origin for why two different bead types can move in opposite
directions on the same ratchet potential. Based on these theoretical results, we conduct
experimental investigations that explore the effects of bead size and static forcing
coefficient on the direction of bead motion, which confirm most of the expected trends.
These results shed light both on past experimental work both by ourselves and others,
as well as elucidate the more general multiplexing capabilities of ratchets.

Christian Rinaldi*, Matteo Cantoni, Daniela Petti and Riccardo Bertacco
Department of Physics, CNISM and L NESS - Politecnico di Milano, Via Anzani 42,
22100, Italy
Spin-polarized carriers can be photo-excited in a semiconductor by monochromatic
circularly polarized light. To date, several techniques have been introduced to detect theexcited spin polarization. In this work, the spin filtering effect at the Fe/MgO interface has
been employed to measure the degree of spin polarization of both electrons and holes in
Ge. We have fabricated photodiodes by means of optical lithography, starting from fully
epitaxial Fe/MgO/Ge(001) heterostructures [1,2]. Spin-detection experiments are performedby illuminating photodiodes with circularly polarized light in a magnetic field applied
parallel to the light helicity. Photo-generated carriers in Ge are spin-filtered by the MgObarrier depending on the direction of the spin. The degree of spin polarization (DSP) isrelated to the variation of the photocurrent due to full reversal of the Fe magnetization. As
predicted by Rioux and Sipe [3], the DSP is maximum when the photon energy is resonantwith the direct energy gap of Ge and decreases with the photon energy for both holes andelectrons. Moreover, as the DSP is different from zero in the frequency range from 1300
nm to 1550 nm, the device is suitable for integrated detection of light helicity at room
temperature in novel spin-optoelectronics systems.
[1] M. Cantoni et al., Appl. Phys. Lett. 98 (2011) 032104. [2] D. Petti et al., J. Appl. Phys. 109 (2011)084909. [3] J. Rioux and J. E. Sipe, Phys. Rev. B 81 (2010) 155215.

Invited & Contributed Presentation

Invited & Contributed Presentation[1] S.P. Dash, S. Sharma, R.S. Patel, M.P. de Jong and R. Jansen, Nature 462, 491 (2009). [2] S.P. Dash, S. Sharma, J.C. Le Breton, H. Jaffres, J.
Peiro, J.M George, A. Lemaitre and R. Jansen, PRB 84, 054410 (2011).

Jacob Torrejon1, Andre Thiaville1*, Anne Lise Adenot Engelvin2 and Manuel Vazquez3
Laboratoire de Physique des Solides, Univ. Paris-Sud, CNRS , 91405 Orsay, France, France
2 CEA, DAM, Le Ripault, 37260 Monts, France, France
3 Instituto de Ciencia des Materiales, CSIC, 28049 Madrid, Spain, Spain
1

The magnetic behaviour of amorphous glass-coated microwires, with ultrasoft magnetic
behaviour, has been modelled by quasi-analytical 1D micromagnetics. Co-based alloys withnegative magnetostriction present a noticeable circumferential anisotropy where an axial
core responds to the minimization of exchange energy. The theoretical approach is based on
one-dimensional micromagnetic model where exchange, magnetoelastic and magnetostatic
energies are considered. We assume that magnetization profile varies only along radial direction
and magnetoelastic anisotropy does not depend to the radial coordinate. Solving firstly thevariational problem that leads to Euler-Lagrange equation, we estimate the size of the core andthe axial hysteresis loops as a function of radius, exchange coefficient A and anisotropy constant
K [1]. The critical nucleus radius below which the magnetization is fully axial was analyticallyobtained. The model was extended to high frequency dynamics under axial ac field. The
microwave permeability has been computed as a sum of eigenmodes. These modes are obtained
as solution of a Schrodinger equation where the potential derives from static solution. Finally,
comparison with experimental measurements shows the important role of the skin effect for
thicker wires.
[1] J. Torrejon et al; J. Magn. Magn. Mater., 323 (2011) 283.

July 8-13, 2012 Busan, Korea

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Manipulation of domain wall dynamics in microwires by transverse
magnetic field

Investigations of the magnetic and structural properties of a metalloidfree Co80Zr10V10 amorphous alloy

Low-Dimensional Superconductivity in δ -Doped SrTiO3

Valence fluctuations and their possible role in stabilizing the correlated
electron state in the system Ce1-xYbxCoIn5

Invited & Contributed Presentation

Juan Maria Blanco1, Alexandr Chizhik2, Valeria Rodionova3, Mihail Ipatov2, Valentina
Zhukova2, Ahmed Talaat2 and Arcady Zhukov4*
1

Dpto. de Fisica Aplicada, Basque Country University, UPV/EHU, Spain
Dpto. Fisica de Materiales, Fac. Quimicas,, Basque Country University, UPV/EHU, Spain
Dpto. Fisica de Materiales, Fac. Quimicas and Faculty of Physics, Basque Country University, Moscow State
University and Immanuel Kant Baltic Federal University, Spain
4
Dpto. Fisica de Materiales, Fac. Quimicas,, Basque Country University, UPV/EHU, and Ikerbasque, BasqueFoundation for Science, Spain
2
3

Recently fast domain wall (DW) propagation of thin magnetic wires gained considerable interest owing
to possibility of applications for data storage devices and extremely fast DW propagation in composite
glass-coated amorphous microwires. A number of interesting effect, such as collisions between two DWs,
trapping and injecting of DWs by local fields and DW dynamics manipulation through the magnetoelastic
energy have been reported. In this paper we studied effect of transversal magnetic field on DW propagationin microwires. In order to activate DW propagation from the determined wire end in our experiment weplaced one end of the sample outside the magnetization solenoid. Under certain transversal magnetic
field, Ht, we were able to create additional DW on the opposite wire end. Changing the Ht we were able
to tailor propagation field of this additional DW and observe DW collision in different parts of microwire.
Previously we observed spontaneous DW nucleation on local defects limiting single DW dynamics
regime in microwires. The collisions realized by us by application of transversal magnetic field can beused to release such additional DWs to achieve higher DW velocity extending single DW regime to higher
external magnetic fields.

Eric Fleury1*, Christian Meny2 and Shashank N. Kane3
1
Center for High Temperature Energy MAaterials, Korea Institute of Science andTechnology, Seoul, Korea
2
UMR 7504 CNRS-UDS, Institut de Physique et Chimie des Materiaux de Strasbourg,
67034 Strasbourg, France
3
School of Physics, D. A. University, Khandwa road Campus, Indore 452001, India
Nanocrystalline ferromagnetic materials used in magnetic applications are obtained from Fe- and Cobased amorphous alloys containing metalloid elements. In these systems, the magnetic properties are
optimized by adjusting the size of the nanocrystals forming from the metastable amorphous phaseupon annealing. This study was undertaken to investigate the correlation between the variations in themagnetic properties upon annealing of a metalloid-free Co-based amorphous alloy. For that purposethe measurements of the magnetic properties have been complemented by a microstructural analysis
by means of nuclear magnetic resonance. The hysteresis loops of as-cast and annealed samples were
measured at 50 Hz (Hmax = 1 kA/m) to get information on the dependence of the coercive field(Hc) and saturation induction (B1000) with the annealing treatment. Zero field 59Co NMR spectra
have been recorded with an automated broadband spectrometer. The lowest value of coercivity was
found to be 5.8 A/m and highest saturation induction of 0.7 Tesla in the sample annealed at 425oC
for 20 minutes. The NMR investigation suggested an important contribution of pure Co atoms. The
dependency of the magnetic properties upon the annealing treatment will be discussed based on local
atomic arrangement in the amorphous structure.

Harold Hwang*
Stanford University & SLAC, USA

SrTiO3 is the lowest density bulk superconductor, which when incorporated
in heterostructures provides an opportunity for band-structure engineering thissuperconducting semiconductor. We take this opportunity by selectively doping achannel of finite thickness in an undoped matrix, which is analogous to δ -doping insemiconductors. By varying the thickness of a Nb doped channel, we have studied thecrossover from 3D to 2D in the superconducting and normal state properties, as the
thickness of the doped layer is decreased. A notable feature of these structures is thatthe mobility strongly increases in the 2D limit. This aspect suggests that a new regimeof 2D superconducting phase transitions can be experimentally accessed approaching
the clean limit. Prospects and progress in understanding the spin-orbit coupling andcoupling bi-layer structures will be discussed.

M. Brian Maple*
Physics, University of California, San Diego, USA

The extraordinary correlated electron phenomena found in compounds containing lanthanide ionswith an unstable valence (Ce, Pr, Sm, Eu, Tm, Yb) can be traced to the hybridization of localized
4f and conduction electron states. The physics underlying the correlated electron phenomena
is associated with the Kondo effect for moderate hybridization in which the valence (4f shell
occupation) is nearly integral and “valence fluctuations” for strong hybridization where the valence
is nonintegral. After a brief review of “valence fluctuation” phenomena, we describe recent
experiments on the superconducting heavy fermion system Ce1-xYbxCoIn5 which reveal that thecorrelated electron state is stabilized throughout the range 0 ≤ x ≤ 0.8, apparently due to cooperative
behavior of Ce and Yb ions involving their unstable valences [1]. Interestingly, the superconducting
critical temperature decreases linearly with x from 2.3 K at x = 0 towards 0 K at x = 1. Non-Fermi
liquid behavior is observed at low temperature, although there is no readily identifiable quantum
critical point [2]. The intermediate valence of Yb in Ce1-xYbxCoIn5 has been verified by ARPES,
EXAFS, and XANES measurements [3,4]. Research supported by U.S. DOE Grant No. DE-FG0204ER46105 (crystal growth) and NSF Grant No. 0802478 (low temperature measurements).
[1] L. Shu, R. E. Baumbach, M. Janoschek, E. Gonzales, K. Huang, T. A. Sayles, J. Paglione, J. O’Brien, D. A. Zocco, P.-C. Ho,
C. A. McElroy, M. B. Maple, Phys. Rev. Lett. 106, 156403 (2011). [2] M. B. Maple, R. E. Baumbach, N. P. Butch, J. J. Hamlin, M.
Janoschek, J. Low Temp. Phys. 161, 4 (2010). [3] C. H. Booth, T. Durakiewicz, C. Capan, D. Hurt, A. D. Bianchi, J. J. Joyce, Z.
Fisk, Phys. Rev. B 83, 235117 (2011). [4] L. Dudy, J. D. Denlinger, L. Shu, M. Janoschek, J. W. Allen, M. B. Maple, in preparation.

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Effect of process parameters on the microstrucutre and magnetic
properties of electrodeposited FeCo thin films

Magnetocaloric effect in Fe-Ni-Zr alloys prepared by rapidly quenchedmethodResonant x-ray scattering from YBCO family

Electronic structures of novel Ce-based systems via photoemission
spectroscopy

Wei Lu1*, Chenchong He2, Zhe Chen2 and Biao Yan2
1
School of Materials Science and Engineering, Tongji University, Shanghai, China
2
Tongji University, China

FeCo alloys have been extensively studied as soft magnetic materials due to theirsuperior properties relative to Fe-Ni alloys as write head core materials in harddisk-drives. Electrodeposition represents a simple, cost-effective way of fabricating
thin film recording heads, although stable plating baths are needed for commercial
processing. It has been a challenge to fabricate FeCo films that have high saturation
magnetizations (>2 T) with good soft magnetic properties (low coercivities Hc) byelectrodeposition methods. In this study, the magnetic properties of FeCo thin films
plated, under a number of different processing conditions, are investigated. The aim
is to optimize the microstructure and magnetic properties such as saturation magnetic
flux density and coercivity. The effect of current density (15-50 mA/cm2), cobalt/iron ions concentration and bath temperature (room temperature to 45oC) on the films
microstructure and properties were studied. The microstructure of electrodepositedfilms was characterized by XRD, TEM and scanning probe microscope. The magnetic
properties of electrodeposited films were investigated by VSM and show dependence
on the deposition conditions. After optimizaiton of process parameters, high saturation
magnetization (~2.1T) and low coercivity (~10Oe) were obtained for electrodeopsited
FeCo thin film in present study.

Nguyen Huy Dan1*, Nguyen Huu Duc1, Tran Dang Thanh1, Nguyen Hai Yen1, PhamThi Thanh1, Ngac An Bang2, Do Thi Kim Anh2, Phan The Long3 and Seong Cho Yu3
1
Institute of Materials Science, 18 Hoang Quoc Viet, Hanoi, Viet Nam
2
Hanoi University of Science, 334 Nguyen Trai, Hanoi, Viet nam
3
Department of Physics, Chungbuk National University, Cheongju 361 - 763, Korea
Fe90-xNixZr10 (x = 0, 5, 10, 15, 20 and 25) ribbons with various thickness were preparedby melt-spinning technique. Curie temperature, TC, of the alloys is dramaticallydecreased from ~960 K to room temperature region by high quenching rates. When thealloys are in amorphous structure, their TC strongly depends on the Ni-concentration.
Maximum entropy change, |∆Sm|max, with H = 12 kOe, of the alloys is around 1 J.kg1 -1
K in room temperature region. On the other hand, the full width at haft the maximum
peak of the entropy change is quite large, FWHM ~ 85 K, making it possible forapplication in magnetic refrigerators at room temperature.
PACS number: 75.30.Sg, 07.20.Mc, 75.50.Kj
Keywords: Magnetocaloric effect, Refrigeration, Amorphous magnetic materials

Matthieu Le Tacon1*, Giacomo Ghiringhelli2, Jiri Chaloupka1, Marco Moretti Sala3, Santiago Blancocanosa1, Matteo Minola4, Giniyat Khaliullin1, Thorsten Schmitt5, Lucio Braicovich6 and Bernhard
Keimer1
1
Max Planck Institute For Solid State Research, Germany
2
CNR-SPIN, Dipartimento di Fisica,Politecnico di Milano, I-20133 Milano, Italy
3
European Synchrotron Research Facility, France
4
CNR-SPIN, Dipartimento di Fisica, Politecnico di Milano, Italy
5
Swiss Light Source, Switzerland
6
CNR-SPIN, Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy

Motivated by the search for the mechanism of high-temperature superconductivity, an intense research
effort has been focused on the evolution of the spin excitation spectrum upon doping from theantiferromagnetic insulating to the superconducting states of the cuprates. Here we take advantage of therecent developments of high-resolution resonant inelastic x-ray scattering [1]to show that a large familyof superconductors, encompassing the model compounds YBa2Cu4O8 and YBa2Cu3O7, exhibits
damped spin excitations - or paramagnons - with dispersions and spectral weights closely similar to thoseof magnons in undoped, antiferromagnetically ordered cuprates over much of the Brillouin zone[2]. A
numerical solution of the Eliashberg equations based on the experimental spin excitation spectrum of
YBa2Cu3O7 reproduces its superconducting transition temperature within a factor of two and strongly
supports magnetic Cooper pairing models for the cuprates. Charge excitations are also investigated andreveal evidences for charge order in the pseudogap state of underdoped compounds [3].

J.-S. Kang*
Department of Physics, The Catholic University of Korea, Korea

Ce-based intermetallic compounds exhibit novel physical properties due to theunique character of the localized Ce 4f electrons that have a large hybridization
with the conduction-band electrons. In this talk we will describe the photoemission
spectroscopy (PES) study of the electronic structures of the Ce compounds that show
diverse physical properties, such as superconductivity, pseudo-gap formation, chargedensity-wave (CDW) formation, and colossal magneto-resistance. We will discuss
on CeNiSn, CeTe2, CeRu2, and La0.7Ce0.3MnO3, for which the valence states of Ceions vary from being trivalent (Ce3+) to being mixed-valent and tetravalent (Ce4+),
depending on the strength of the hybridization. Our study shows the different roles ofCe 4f states in determining their ground states. In particular, we will report our recent
angle-resolved PES (ARPES) study of the quasi-two dimensional CDW system CeTe2
in comparison with the band-structure calculations [1,2]. Our ARPES study provides
the information on the role of the Ce 4f states in the CDW formation, the carriers near
the Fermi level, the effect of band-folding due to the interaction with Ce-Te(2) layers
on the Fermi surface, and the CDW modulation vector in CeTe2. Keywords: ARPES,
CDW, electronic structure, quasi-two dimensional system[1] 1 Braicovich, L. et al. Magnetic Excitations and Phase Separation in the Underdoped La2-xSrxCuO4 Superconductor Measured by
Resonant Inelastic X-Ray Scattering. Phys. Rev. Lett. 104, 077002 (2010). [2] Le Tacon, M. et al. Intense paramagnon excitations in a large
family of high-temperature superconductors. Nat Phys 7, 725-730 (2011). [3] Ghiringhelli, G. et al. in preparation.

[1] J. H. Shim, J.-S. Kang, and B. I. Min, Phys. Rev. Lett. 93, 156406 (2004). [2] J.-S. Kang, D. H. Kim, H. J. Lee, J. H. Hwang, H. K.
Lee, H.-D. Kim, B. H. Min, K. E. Lee, Y. S. Kwon, J. W. Kim, Kyoo Kim, B. H. Kim, B. I. Min, Phys. Rev. B 85, 085104 (2012).

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Structure and magnetic properties of FeCo alloy synthesized by a onestep polyol process

Nodal pocket revealed by quantum oscillations in an underdoped
cuprate superconductor

Evolving electronic structures of high-tc cuprates studied by compton
scattering

Valence state and spin state of Fe in SrFe1-x(Sc,Sn)xO3 perovskites

Prakash Karipoth, Arun Thirumurugan and Raphael Justin Joseyphus*
Department of Physics, National Institute of Technology, Tiruchirappalli 620 015,
India
Most of the chemical methods for the synthesis of FeCo employ complex experimental
conditions, expensive chemicals and carbonyl precursors which are less preferable [1].
Moreover each chemical method results in FeCo of various composition, particle size, orderdisorder behaviour and oxide fraction which subsequently affect its magnetic properties [2]. In
this report, we present the synthesis of FeCo nanoparticles of varying composition by a unique
one-step polyol process and report its magnetic properties. The synthesis of FeCo alloys were
undertaken in ethylene glycol using hydrated FeCl2 and Co(II)acetate and NaOH. The samples
were prepared at various temperatures upto 190 oC. The samples are characterized using
XRD, TEM-EDX and VSM. The variation of Curie temperature is determined using ThermoMagnetic Analysis and is found to be in accordance with the composition of the FeCo alloy.
The fcc to bcc phase transition temperatures is also evident from the Differential Thermal
Analysis. The morphology of the particles is studied using TEM and it showed spherical or
cubic nature depending on the hydrous precursors used in the synthesis. The present synthesis
method can be employed for large scale synthesis of FeCo alloys with controlled structure andmagnetic properties which shall be discussed in detail.
[1] D. Sudfeld et al., J. Appl. Phys. 93 (2003) 7328. [2] F. Dumestre et al., Science 303 (2004) 821

40

Invited & Contributed Presentation

The 19th International Conference on Magnetism

Suchitra Sebastian1, Gil Lonzarich1, Neil Harrison2, Moaz Altarawneh2, Chuck
Mielke2, Ruixing Liang3, Doug Bonn3 and Walter Hardy3
1
Department of Physics, University of Cambridge, United Kingdom
2
National High Magnetic Field Laboratory, Los Alamos National Laboratory, USA
3
Department of Physics, University of British Columbia, Canada
Quantum oscillations have proved a vital tool in uncovering the electronic structure
underlying the normal state of the underdoped cuprates. Our experiments haveestablished that quasiparticles in this regime are governed by fermi dirac statistics, yet
a comprehensive description of the fermi surface geometry remains elusive. We use
an array of quantum oscillation measurements in the underdoped cuprate YBa2Cu3O6+x
in tandem with results from complementary experimental techniques to distinguishbetween alternative Fermi surface possibilities. We present evidence including quantum
oscillations that persist down to low magnetic fields, a low doping quantum criticalpoint that mirrors the nodal Fermi velocity collapse in photoemission, and oscillationsof the chemical potential, all of which strongly point to a Fermi surface comprisingsolely nodal pockets. Possibilities for the origin of the antinodal gapping of density ofstates at the Fermi level are discussed.
S. E. Sebastian et al. Nature Communications 2, Article number: 471

Invited & Contributed Presentation

Invited & Contributed Presentation

Yoshiharu Sakurai1*, Masayoshi Itou1, Bernardo Barbiellini2, Susmita Basak2, Robert
S. Markiewicz2, Peter E. Mijnarends3, Shuichi Wakimoto4, Masaki Fujita5, Arun
Bansil2 and Kazuyoshi Yamada5
1Japan Synchrotron Radiation Research Institute, Japan
2
Northeastern University, USA
3
Delft University of Technology, Netherlands
4Japan Atomic Energy Agency, Japan
5
Tohoku University, JapanThe evolution of electronic structures with carrier doping is essential to understanding the mechanism of hightemperature superconductivity. Several spectroscopies, such as photoemission [1], x-ray absorption [2] andCompton scattering [3] have succeeded in probing the evolving nature of high-Tc cuprates and provided
information about the electronic dispersions, Fermi surfaces, and orbital characters of doped carriers. In thispresentation, we provide a new piece of information on the evolving electronic structure of La2-xSrxCuO4 (LSCO)
by means of Compton scattering. Compton scattering is complementary to other spectroscopies and uniquely
measures the ground-state electron momentum distribution, i.e. Compton profile, of all electrons in a compound.
This is bulk-sensitive because of a high-energy photon-in and photon-out technique. We have performed
Compton profiles measurements of LSCO with x=0, 0.08, 0.15 and 0.3, and obtained two-dimensional electron
momentum density (EMD) and k-space electron occupation density (EOD) projected along the c-axis. The EMD
and EOD show a doping x dependency and their evolution is discussed in the light of some scenarios.
[1] A. Damascelli et al., Rev. Mod. Phys. 75, 473 (2003) [2] D. C. Peets et al., Phys. Rev. Lett. 103, 087402 (2009) [3] Y. Sakurai et al., Science 332, 698 (2011)

Youssef Rizki1, Jean-marie Le Breton1*, Yohann Breard2, Emeric Folcke1 and Antoine
Maignan2
1
Groupe de Physique des Materiaux - UMR 6634, CNRS - Universite de Rouen,
France2
CRISMAT, UMR 6508 CNRS, ENSICAEN - Universite de Caen, France
The coexistence of Fe3+ and Fe4+ in SrFeO3-d, in relation with oxygen vacancies, influences theelectronic conductivity and is at the origin of the giant negative magnetoresistance effect [1,2].
With the aim to investigate the influence of the valence state of Fe on the physical properties(magnetism, transport) in SrFe1-xMxO3-d perovskites (M=Sc,Sn and 0≤x≤1) were preparedby solid state synthesis method and investigated by X-ray diffraction, 57Fe Mossbauer
spectrometry and susceptibility measurements. Replacing Fe ions with ions with a fixedvalence state (Sc3+ or Sn4+) modifies the Fe3+/Fe4+ ratio and the oxygen content. Introducing
Sc3+ ions leads to a decrease of both Fe4+ and oxygen contents without affecting the crystal
structure. However, the substitution is limited. In the SrFe0.5Sc0.5O2.5 limit compound, only Fe3+
ions are detected, in two different spin states. Introducing Sn4+ ions leads to a decrease of the
Fe4+ content and to an increase of the oxygen content. The substitution is not limited, and Fe3+
and Fe4+ ions coexist in the whole composition range. The spin state of the Fe3+ and Fe4+ ions is
discussed. This work was supported by the French Agence Nationale de la Recherche (project
ANR-08-BLAN-0005-01).
[1] Y.M. Zhao, R Mahendiran, N. Nguyen, B. Raveau and R.H. Yao, Phys. Rev. B 664 (2001) 024414 [2] A. Maignan, C. Martin, N.
Nguyen and B. Raveau, Sol. State Sci. 3 (2001) 57

July 8-13, 2012 Busan, Korea

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Physics of cerusn studied on a single crystal

Magnetic -filed and angular dependence of magnetism in thetriangular mott insulator κ-(BEDT-TTF)2Cu2(CN)3 investigated by
13C NMR

Exchange bias; where are the pinned uncompensated spins

Invited & Contributed Presentation

Jan Fikacek1*, Jiri Prchal1, Jan Prokleska1, Martin Misek1, Ivana Cisarova2, Jeroen
Custers1 and Vladimir Sechovsky1
1
Department of Condensed Matter Physics, Charles University in Prague, Czech
Republic2
Department of Inorganic Chemistry, Charles University in Prague, Czech Republic
The recently reported hysteretic anomalies of electrical resistivity and magnetization of
CeRuSn between 160 K and 290 K are most probably associated with crystal structuretransitions intimately coupled with charge ordering at a Ce ion of unstable valence [1,2]. To
shed light on the intriguing phenomena in this monoclinic compound, we have grown a single
crystal and measured single crystal X-ray diffraction, thermal expansion, magnetization, andelectrical resistivity in a wide temperature and pressure range. We also investigated the roleof the lattice volume. Contrary to reports our high-quality single crystal shows two distinct
anomalies at ~ 290 and 220 K (when cooling), respectively. The anomalies are strongly
anisotropic and show a large temperature hysteresis (~ 15-20 K). The crystal shrinks by 0.7% along the c-axis between 300 and 200 K while it changes little along a- and b-. Exertinghydrostatic pressure shifts both anomalies to higher temperatures by more than 11 K.kbar-1.
This corroborates the scenario attributing the anomalies to transitions coupled with Ce-ion
valence changes. Antiferromagnetism below TN = 2.7 K has been suggested [1]. We will
present the low-temperature magnetization, resistivity and specific heat behavior of the single
crystal and discuss the antiferromagnetism in detail.

Kazuya Miyagawa, Kentaro Uneda and Kazushi Kanoda
Department of Applied Physics, University of Tokyo, JapanThe organic conductors, κ-(BEDT-TTF)2X, are prototype for investigating Mott physics and spin
frustrations. The X=Cu[N(CN)2]Cl is a Mott insulator which undergoes an antiferromagnetic phasetransition[1]. On the other hand, X=Cu2(CN)3 which has a triangular lattice does not show a longrange magnetic ordering[2]. This suppression is believed to deeply relate to strong spin frustrations.
Both salts change to non-BCS-type superconductors via band-width control Mott transition[3].
While X=Cu2(CN)3 does not show magnetic ordering, we previously reported anomalous behaviors
in 13C NMR around 6 K[4], where heat capacity, thermal conductivity and lattice constant show
anomalies as well[5]. NMR line broadening is enhanced below 6 K. The 1/T1 monotonicallydecreases down to 6 K, and then becomes temperature-insensitive, followed by a decrease below 1
K under 8 T. So, the 6 K anomaly is a key phenomenon for understanding the origin of absence ofmagnetic order. We have measured external-filed angular dependence of 13C NMR under magnetic
fields up to 15 T for clarifying the origins of the line broadening and the 1/T1 anomaly around 6K.
At room temperature, angular dependence of spectra is well explained by a crystal structure. We willshow the detailed experimental results and discuss the low temperature states.

Ivan K Schuller1*, M. Erekhinsky2, R. Morales3, I. V. Roshchin4, M. Kovylina5, A.
Labarta5, X. Batlle5, M. Fitzsimmons6, S. Bar-ad7 and S. K. Sinha8
1

Physics, University of California, San Diego, USA
Physics and Center for Advanced Nanoscience, University of California San Diego, USA
University of the Basque Country and IKERBASQUE Basque Foundation for Science, Spain
4
Texas A & M University, USA
5
University of Barcelona, Spain
6
Los Alamos National Labs, USA
7
Tel Aviv University, Israel
8
University of California, San Diego, USA
2
3

BD04
Tuning exchange bias in Ni/FeF2 heterostructures using antidot arrays

Miroslavna Kovylina1, Rafael Morales2, M. Erekhinsky3, Javier E. Villegas4, Ivan K. Schuller3,
Amilcar Labarta1 and Xavier Batlle1*
1
Departament Fisica Fonamental and Institut de Nanociencia i Nanotecnologia, Universitat deBarcelona, Barcelona, Catalonia, Spain
2
University of the Basque Country & IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
3
Physics Department, University of California San Diego, La Jolla CA, USA
4
Unite Mixte de Physique CNRS/Thales, Universite Paris Sud, Orsay, France

The transition from negative to positive exchange bias (NEB/PEB) can be systematically tuned with antidot
arrays artificially introduced into Ni/FeF2 ferromagnetic (FM)/antiferromagnetic (AF) heterostructures [1].
This is a consequence of the energy balance between the Zeeman coupling of AF spins and the AF coupling at
the FM/AF interface. The nanostructure plays a key role [1,2]: the antidot carving produces regions of locallypinned uncompensated spins throughout the antidot faces of the FeF2 and these non interfacial magnetic
moments favor the onset of PEB at lower cooling fields, by increasing the Zeeman energy of AF domains andfavoring the alignment with the external field. Those non interfacial AF spins, and the pinned uncompensatedinterfacial AF spins responsible for the EB (loop shift), align simultaneously with the cooling field since they
belong to the same domain and become pinned below the Neel temperature. As a result, the cooling fieldrequired for PEB decreases one order of magnitude for the antidot arrays, as compared to the unpatterned
heterostructures. This is relevant concerning the applicability of FM/AF bilayers as multi-state storage media [3],since the minimum cooling field necessary to obtain PEB establishes the magnetic field required for multi-statestorage writing.

[1] J.A. Mydosh et al., Phys. Rev. B 83, 054411 (2011). [2] R. Feyerherm et al., arXiv:1111.5693v1.

[1] K. Miyagawa et al., Phys. Rev. Lett. 75, 1174 (1995) [2] Y. Shimizu et al., Phys. Rev. Lett. 91, 107001 (2003) [3] K. Kanoda et al.,Phys. Rev. B, Y. Shimizu et al., Phys. Rev. B 81, 224508 (2010) [4] Y. Shimizu et al., Phys. Rev. B, 73, 140407 (2006) [5] S. Yamashita
et al., Nature Phys. 4, 459 (2008). M. Yamashita et al., Nature Phys. 5, 44 (2009), R. S. Manna et al., cond-mat, 0909.0718

Exchange bias in ferromagnetic-antiferromagnetic (FM- AFM) nanostructures has resisted a universal explanationin spite of its importance in the sensors and storage industries. Unusual phenomena such as; i) asymmetric
FM reversal, ii) changes of the superparamagnetic transition temperature of magnetic nanostructures, iii) large
exchange bias in nominally fully compensated surfaces, iv) positive exchange bias emergence for certain classesof bilayers, v) anomalous reversal at fast time scales (<300psec), vii) effect of the bulk AFM magnetic structure of
the AFM and vii) noticeable change in the microscopic spin configuration appear. We have used nanostructured
systems prepared by Molecular Beam Epitaxy, electron beam lithography, self-assembly and focused ion beams
to investigate the common origin of all these phenomena. Comprehensive magnetization, magnetotransport,
Kerr effect, neutron scattering and synchrotron radiation studies together with theoretical investigations provide a
universal explanation regarding the origin of the exchange bias and location of the crucial pinned uncompensatedspins. This opens up the possibility for the design of new systems and provides a road for the understanding of themechanism controlling Exchange Bias. Work supported by the US Department of Energy, TAMU-CONACyT
and the Air Force Office of Scientific Research.

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Quantum effects in molecular single-ion magnets

NMR study of quantum spin liquid in an organic triangular lattice
antiferromagnet EtMe3Sb[Pd(dmit)2]2

Atomic diffusion in (Pt/Co)3/IrMn multilayers

Correlation between training effect and hysteretic behavior of angulardependence of exchange biasing in polycrystalline ferromagnet/
antiferromagnet bilayers

Eugenio Coronado1, J. Baldovi1, S. Cardona1, J. M. Clemente-juan1, A. Gaita-arino1, F.
Luis2 and M. J. Martinez-perez2
1
Instituto Ciencia Molecular - Universidad Valencia, Spain
2
Instituto de Ciencia de Materiales de Aragon (ICMA), CSIC-Universidad deZaragoza, Spain
Crystals of single-molecule magnets provide unique opportunities for the investigationof quantum magnetism. Generally, these systems are formed by clusters made ofa polynuclear magnetic core. However, it has been recently shown that molecules
encapsulating an individual magnetic ion can also exhibit SMM behavior. In thesesystems, known as single-ion magnets, the quantum effects are much more pronounced
than in the more complex cluster-type SMMs. In this paper we will show that the
spin dynamics, and in particular the quantum tunneling effects of these systems, canbe controlled by chemical design (symmetry control of the magnetic site, magnetic
dilution of the crystals,…). On the other hand, we will show that these molecules canbe potential candidates to act as spin qubits as they possess a well defined ground state
doublet with a high quantum coherence.
[1] a) M. A. AlDamen, J. M. Clemente-Juan, E. Coronado, C. Marti-Gastaldo and A. Gaita-Arino,
J. Am. Chem. Soc. 2008, 130, 8874; b) M. A. AlDamen, S. Cardona-Serra, J. M. Clemente-Juan, E.
Coronado, C. Marti-Gastaldo, F. Luis, and O. Montero, Inorg. Chem. 2009, 48, 3467. [2] F. Luis, M.
J. Martinez-Perez, O. Montero, E. Coronado, S. Cardona-Serra, C. Marti-Gastaldo, J.M. ClementeJuan, J. Sese, D. Drung, T. Schurig, Phys. Rev. B 2010, 82, 060403 R.

Satoru Maegawa1*, Tetsuaki Itou1, Eri Watanabe1, Tatsuro Kubota1, Masahide Nishiyama1, Akira
Oyamada1, Kazuya Kubo2 and Reizo Kato3
1
Graduate School of Human and Environmental Studies, Kyoto University, Japan
2
Condensed Molecular Materials Laboratory, RIKEN, Present address: Hokkaido University, Japan
3
Condensed Molecular Materials Laboratory, RIKEN, Japan

A quantum spin liquid state is realized in an organic spin 1/2 antiferromagnet on the triangular lattice,
EtMe3Sb[Pd(dmit)2]2 [1, 2, 3]. No classical magnetic ordering exists down to 19 mK due to the quantum
fluctuation and spin frustration, although the exchange interaction is 240 K [2, 4]. The enriched 13C
nuclear spin-lattice relaxation rate 1/T1 under a field of 7.65 T shows an exotic transition at 1.0 K
accompanied with symmetry breaking or topological ordering. The rate 1/T1 indicates that the excitations
have no spin-gap above 1.0 K [1, 2], while below 1 K 1/T1 shows the appearance of an excitation gap,
which is a nodal one rather than a full gap [3]. We have confirmed that our NMR data surely reflect the
spin state of this system by using two kinds of enriched samples [5]. The transition temperature has thefield dependence, which is opposite to that of an ordinary spin system accompanied with a spin-gap
formation owing to dimerization. Our recent measurement for a single crystal has revealed that 1/T1
depends on the field direction below 5K. We will discuss the nature of quantum spin liquid, comparing
with another thermal properties of this material.

Florent Letellier1, Amjaad Zarefy1, Jean-marie Le Breton1*, Luc Lechevallier1,
Rodrigue Larde1, Didier Blavette1, Vincent Baltz2, Bernard Rodmacq2 and Bernard
Dieny2
1Groupe de Physique des Materiaux - UMR 6634, CNRS - Universite de Rouen,
France2
SPINTEC, URA 2512 CNRS/CEA, CEA Grenoble, France
The magnetic properties of exchanged-coupled multilayers strongly depend on the structure and chemistryof the interfaces. This is the case in particular for exchange-bias multilayers, in which a ferromagnetic layer iscoupled with an antiferromagnetic layer, leading to a shift of the hysteresis loop [1]. Recent developments of
the 3D Atom Probe Tomography (APT) in the Groupe de Physique des Materiaux allowed investigating theinterfaces in exchange-bias (Pt/Co)3/IrMn magnetic multilayers with perpendicular magnetic anisotropy [2,3].
The APT analysis allows determining the chemical composition of the nanometric layers, thus providing an
accurate structural characterization of the layers, leading to an estimation of their thickness, roughness, atomic
concentration and width of their interfaces. The magnetic properties can thus be correlated with the structuralproperties. It has been showed that the presence of a Pt spacer at the Co/IrMn interface plays a determiningrole on the exchange-bias phenomenon, in relation with the Mn/Co interdiffusion process. We present here an
investigation of the diffusion process at high temperature (300-700°C) by APT. The results are discussed inrelation with the thermodynamic properties of the Pt-Co-Ir-Mn system.

[1] M. Kovylina, M. Erekhinsky, R. Morales, J.E. Villegas, I.K. Schuller, A. Labarta, and X. Batlle, Appl. Phys. Lett. 95, 152507 (2009); ibid.
Nanotechnology 21, 175301 (2010). [2] M. Kovylina, M. Erekhinsky, R. Morales, I. K. Schuller, A. Labarta, and X. Batlle, Appl. Phys. Lett. 98,
152507 (2011). [3] I.V. Roshchin, O. Petracic, R. Morales, Z.-P. Li, X. Batlle, and I. K. Schuller, US Patent 7,764,454 (2010).

Zhong Shi1, Shiming Zhou1*, Tie Ren Gao2 and Xue Peng Qiu3
Department of Physics, Tongji University, China
2
Department of Physics, Fudan Univerisity, China
3
Department of Physics, Fudan University, China
1

EB training effect is important to the spintronic devices, where the exchange field HE and the coercivity
HC decrease during consecutive hysteresis loops. Alternatively, hysteretic behavior of angular dependenceof EB has also been studied extensively. AFM spins are believed to play a crucial role in above two EBrelated phenomena. Simultaneous studies of these two phenomena in polycrystalline FM/AFM bilayers
will be helpful to further reveal the effect of AFM spins. In this work, we report on the EB training
effect and hysteretic behavior between clock-wise (CW) and counter clock-wise (CCW) rotations inpolycrystalline NiFe/FeMn bilayers. Using the vector VSM, we have measured the pinning direction atremanent state after each hysteresis loop. When the external magnetic field is off-aligned the initial pinning
direction, HE and HC are reduced. At the same time, the pinning direction is rotated during consecutive
hysteresis loops. During CW and CCW rotations, the angular dependence of either HE or HC, or pinning
direction does not overlap with each other. The hysteretic behavior and training effect become weak withincreasing FeMn layer thickness. At ultrathin FeMn layers, these two effects vanish. These experimental
results can be explained in the framework of the thermal activation model.

[1]. T. Itou, A. Oyamada, S. Maegawa, M. Tamura and R. Kato, J. Phys. Condens. Matter 19, 145247 (2007). [2]. T. Itou, A.
Oyamada, S. Maegawa, M. Tamura and R. Kato, Phys. Rev. B 77, 104413 (2008). [3]. T. Itou, A. Oyamada, S. Maegawa and R.
Kato, Nature Phys. 6, 673 (2010). [4]. M. Tamura and R. Kato, J. Phys. Condens. Matter 14, L729 (2002). [5]. T. Itou, K. Yamashita,
M. Nishiyama, A. Oyamada, S. Maegawa, K. Kubo, and R. Kato, Phys. Rev. B 84, 094405 (2011).

[1] J. Nogues, I.K. Schuller, J. Magn. Magn. Mater. 192 (1999) 203 [2 ] L. Lechevallier, A. Zarefy, R. Larde, H. Chiron, J.M. Le
Breton, V. Baltz, B. Rodmacq, B. Dieny, Physical Review B 79 (2009) 174434 [3] A. Zarefy, L. Lechevallier, R. Larde, H. Chiron, J.M.
Le Breton, V. Baltz, B. Rodmacq, B. Dieny, Journal of Physics D: Applied Physics 43 (2010) 215004

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Direct observation of a ferri-to-ferromagnetic transition in a fluoridebridged 3d-4f molecular cluster

Wilson ratio of a Tomonaga-Luttinger liquid in a spin-1/2 Heisenberg ladder

Magnetic properties of ferromagnetic-antiferromagnetic bi-layers withdifferent spin configuration

Interlayer exchange coupling in ferromagnetic semiconductor
GaMnAs-based multilayers

Jan Gui-hyon Dreiser1*, Kasper Steen Pedersen2, Cinthia Piamonteze1, Stefano Rusponi3, Zaher Salman4, Md.
Ehesan Ali5, Magnus Schau-magnussen2, Christian Aa. Thuesen2, Stergios Piligkos2, Hoegni Weihe2, Hannu
Mutka6, Oliver Waldmann7, Peter Oppeneer8, Jesper Bendix2, Frithjof Nolting1 and Harald Brune3
1
Swiss Light Source, Paul Scherrer Institut, Switzerland
2
Department of Chemistry, Copenhagen University, Denmark3
Institute of Condensed Matter Physics, Ecole Polytechnique Federale de Lausanne, Switzerland
4
Laboratory for Muon Spectroscopy, Paul Scherrer Institut, Switzerland
5
Center for Theoretical Chemistry, Ruhr-Universitaet Bochum, Germany
6
Institut Laue-Langevin, France
7
Physikalisches Institut, Universitaet Freiburg, Germany
8
Department of Physics and Astronomy, Uppsala University, Sweden

Single-molecule magnets are exchange-coupled molecular clusters exhibiting slow relaxation of magnetization.
Introduction of rare-earth ions into such clusters may boost the magnetic anisotropy and thus increase the barrier
for magnetization reversal. In this contribution we present a X-ray magnetic circular dichroism (XMCD) study ofa novel fluoride-bridged molecular nanomagnet DyCrDy. By measuring element-specific magnetization curves
we are able to directly observe the field-induced transition from a ferrimagnetic to a ferromagnetic arrangementof the Dy and Cr magnetic moments. Using a spin-Hamiltonian model we obtain excellent fits to the XMCD data
and, further, we are able to extract the strength of the Dy-Cr exchange coupling. The value found from XMCD is
consistent with SQUID magnetometry and inelastic neutron scattering measurements. Furthermore, based on thisapproach we investigate other 3d-4f molecular nanomagnets.
J. Dreiser, K. S. Pedersen, C. Piamonteze, S. Rusponi, Z. Salman, Md. E. Ali, M. Schau-Magnussen, C. Aa. Thuesen, S. Piligkos, H. Weihe, H. Mutka, O.
Waldmann, P. Oppeneer, J. Bendix, F. Nolting, H. Brune, Chemical Science, DOI:10.1039/C2SC00794K, in press.

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Invited & Contributed Presentation

The 19th International Conference on Magnetism

Kostas Ninios1, Tao Hong2, Chisa Hotta3, Yasu Takano1*, Manabe Takuya3, S N Herringer4, M M
Turnbull5, C P Landee5 and Ho Bun Chan6
1
Physics, University of Florida, USA
2
Neutron Scattering Science Division, Oak Ridge National Laboratory, USA
3
Physics, Kyoto Sangyo University, Japan4
Physics, Carlson School of Chemistry and Department of Physics, USA
5
Carlson School of Chemistry and Department of Physics, Clark University, USA
6
Physics, The Hong Kong University of Science and Technology, China

The Wilson ratio R_w, one of the crucial parameters that characterize Fermi liquids, has served as a powerfultool to classify heavy fermion systems by quantifying the strength of spin fluctuations. This parameter remains
crucial even in one dimension. In particular, in one-dimensional antiferromagnets, R_K is related to theTomonaga-Luttinger parameter K through the relation R_W=4K. We have tested this hitherto overlooked
relation in (C5H12N)2CuCl4 (DIMPY), an S=1/2 quantum spin ladder with strong leg interactions [1]. Using
micromechanical force magnetometry, we have measured the magnetization at temperatures down to 45 mK
in magnetic fields up to 9 T. Both the temperature and field dependences are in good agreement with quantum
Monte Carlo results, evidence for the excellent onedimensionality of the material. Particularly, a minimum ofmagnetization as a function of temperature is found, which is an onset of a Tomonaga-Luttinger liquid statepredicted by theory[2]. The magnetic susceptibility in conjunction with specific heat yields R_W [3] which, alongwith density-matrix renormalization-group calculations, supports the above relation between R_W and K.
[1] K. Ninios, Tao Hong, T. Manabe, C. Hotta, S. N. Herringer, M. M. Turnbull, C. P. Landee, Y. Takano, and H. B. Chan,arXiv/1110.5653; Phys. Rev. Lett. in press. [2] Y. Maeda, C. Hotta, and M. Oshikawa, Phys. Rev. Lett. 99, 057205 (2007). [3]
Tao Hong, Y. H. Kim, Chisa Hotta, Yasu Takano, G. Tremelling, C. P. Landee, H.-J. Kang, N. B. Christensen, K. P. Schmidt, K.
Lefmann, G. S. Uhrig, and C. Broholm , Phys. Rev. Lett. 105, 137207 (2010).

Wondong Kim1*, Chanyong Hwang1, Z.-Q. Qiu2 and J.-Y. Kim3
1
Korea Research Institute of Standards and Science, Korea
2
Physics Department, University of California at Berkeley, USA
3
Pohang Accelerator Laboratory, Korea

We investigated the effect of different spin direction of anti-ferromagnetic(AFM) layer on themagnetic properties of ferromagnetic(FM) layer in Fe-NiO and Fe-CoO bi-layer systems. For
Fe-NiO system, we prepared successfully Fe/NiO/Ag(001) and Fe/NiO/MgO(001) systems ona single MgO(001) substrate. We examined magnetic properties of the bi-layer system using thesurface magnetic optical Kerr effect(SMOKE) and X-ray magnetic linear dichroism(XMLD).
From SMOKE measurement we observed the coercivity enhancement due to the set-up of
AFM order of NiO films in both of the Fe/NiO/MgO(001) and Fe/NiO/Ag/MgO(001) system.
The most remarkable results in our observation is that the coercivity enhancement of Fe/NiO/
Ag/MgO(001) is much larger than that of Fe/NiO/MgO(001). XMLD experiments confirmed
the out-of-plane spin direction of NiO layers in Fe/NiO/MgO(001) and in-plane spin-directionof NiO layers in Fe/NiO/Ag/MgO(001), and we concluded that the origin of large enhancementof coercivity is due to the strong parallel coupling between Fe layers and NiO layers. We
also confirmed that this strong parallel coupling maintained across the thin Ag layer inserted
between Fe and NiO layers. With this Ag inserted Fe/NiO system, we could estimate the
Neel temperature of the NiO layers. For Fe-CoO system, we observed much larger coercivity
enhancement in Fe/CoO/Ag(001) than in Fe/CoO/MnO(001).

Invited & Contributed Presentation

Invited & Contributed Presentation

1. S. Brems, D. Buntinx, K. Temst, C. Van Haesendonck, F. Radu, and H.Zabel, Phys. Rev. Lett. 95, 157202 (2005). 2. A.
Hoffmann, Phys. Rev. Lett. 93, 097203(2004) 3. T. R. Gao, D. Z. Yang, S. M. Zhou, R. Chantell, P. Asselin, J. Du, and X.
S. Wu, Phys. Rev. Lett. 99, 057201(2007)

Sanghoon Lee*
Korea University, Korea

The study of ferromagnetic (FM) dilute magnetic semiconductors (DMSs) continues
to be of great interest because of their potential for spin-electronic device application.
The nature of interlayer exchange coupling (IEC) in GaMnAs-based multilayers is
an important issue from the point of view of possible spin-electronic (“spintronic”)
applications. The ability to manipulate such IEC enables us to control the relative
direction of magnetization in one magnetic layer relative to the other, which lies at theheart of giant magnetoresistance (GMR) devices in wide use in information processing.
In this connection, it is important to establish under what conditions the IEC between
adjacent GaMnAs layers is antiferromagnetic (AF) or ferromagnetic (FM), since
manipulation of the IEC can then be directly applied to achieve GMR devices basedon this material. In this talk we will describe magneto-transport, magnetization, andneutron reflectometry experiments applied to GaMnAs-based multilayer structuresconsisting of GaMnAs layers separated by non-magnetic GaAs spacers. These
measurements serve to identify conditions under which AFM coupling will occur insuch GaMnAs/GaAs multilayer systems, thus providing us the information which canbe used for manipulating magnetization (and thus also GMR) in structures based on the
ferromagnetic semiconductor GaMnAs.

July 8-13, 2012 Busan, Korea

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Experimental probing of the magnetic order in ultrathin (Ga,Mn)As

I-Mn-V room temperature antiferromagnetic semiconductors

Slow magnetic crossover in the frustrated magnet Ca3Co2O6

L10 ordered FePt based granular films for thermally assisted magnetic
recording

M. Sawicki1, D. Chiba2, O. Proselkov3, A. Korbecka4, Y. Nishitani5, F. Matsukura6, J. A. Majewski4, J.
Sadowski7, T. Dietl8 and H. Ohno6
1
Institute of Physics, Warsaw, Poland,and RIEC,Tohoku University, Sendai, Japan, Poland
2
Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan
3
Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
4
Institute of Theoretical Physics, University of Warsaw, Poland
5
Laboratory for Nanoelectronics and Spintronics, RIEC, Tohoku University, Sendai, Japan
6
Laboratory for Nanoelectronics and Spintronics, and CSIS, Tohoku University, Sendai, Japan
7
Institute of Physics, Warsaw, Poland, and MAX-Lab, Lund University, Lund, Sweden
8
Institute of Physics, Warsaw, and Institute of Theoretical Physics, University of Warsaw, Poland

Invited & Contributed Presentation

Invited & Contributed Presentation

Xavier Marti1*, Peter Wadley2, Helena Reichlova2, Premysl Beran3, Olya Stelmakhovych4, Ineke Wijnheijmer5, Paul Koenraad6,
Frantisek Maca2, Jan Masek2, Klara Uhlirova1, Vit Novak2 and Tomas Jungwirth2
1
Condensed Matter Physics, Charles Unviersity in Prague, Czech Republic
2
Institute of Physics ASCR, Czech Republic
3
Nuclear Physics Institute ASCR, Czech Republic
4Charles Unviersity in Prague, Czech Republic
5
COBRA Inter-University Research Institute, Netherlands
6
COBRA, Inter-University Research Institute, Netherlands

Stefano Agrestini1*, Martin R Lees2, Catherine L Fleck2, Oleg A Petrenko2, Laurent C Chapon3, Claudio
Mazzoli4 and Alessandro Bombardi5
1
Max-Planck Institut CPfS, Dresden, Germany
2
Department of Physics, University of Warwick, Coventry, United Kingdom
3ILL, Grenoble, France
4
Dipartimento di Fisica, Politecnico di Milano, Milano, Italy5
Diamond Light Source, Didcot, United Kingdom

Y K Takahashi*, B Varaprasad, C Min, L Zhang and K Hono
National Institute for Materials Science, Japan

L10 ordered FePt is considered to be one of the candidate for ultrahigh density
perpendicular recording media beyond 1 Tb/in2 due to its high magnetocrystalline
anisotropy. We recently reported well controlled microstructure of FePtAg-C granularfilm with an average particle size of about 6 nm and small size distribution of about
20 % [1]. Furthermore, we demonstrated areal density of 550 Gb/in2 by a static test
using a head for thermally assisted magnetic recording [2]. Although we achieved aparticle size of 6 nm with narrow size distribution, the FePt-C system has a weakness
in attaining small surface roughness with a columnar structure due to the strong phaseseparation tendency between FePt and C in not only the lateral direction but also thegrowth direction. To attain columnar structure with smooth surface, we chose TiO2 as
a matrix. In this presentation, we will show FePt granular film with columnar structureand smooth roughness.

[1] B. G. Park et al, Nature Materials 10, 347 (2011) [2] F. Maca et al, J. Magn. Magn. Mater. 324, 1606 (2012) [3] T. Jungwirth, et al, Phys. Rev. B
83, 035321 (2011) [4] I. Wijnheijmer, et al, submitted

Time-dependent phenomena play a crucial role in the properties of many magnetic systems,
including spin-glasses, single-molecule magnets and superparamagnets. However time-dependent
magnetism is not expected to be observed in the presence of long-range magnetic order. Herewe challenge this view by reporting the observation of a new time-dependent behavior where atransition from one long-range magnetically ordered state to another occurs in zero magnetic fieldover a time scale of several hours. We performed an extensive neutron diffraction study of the spin
chain system Ca3Co2O6 whose step-like magnetization versus magnetic field aroused great interestin the scientific community. Our data show that for T< 14K< TN =25K the spin-density-wave orderobserved immediately below TN, becomes unstable and a commensurate antiferromagnetic phaseappears via a very slow transformation process. As the temperature is reduced the characteristic
time of the transition process increases rapidly and at low temperatures the magnetic states becomefrozen. The transition is also noteworthy because the two phases have different propagation vectors.
Very rarely transitions between two magnetically ordered phases involve a change of translational
symmetry. This discovery sheds new light on the peculiar dynamic properties of Ca3Co2O6. S.
Agrestini et al., Phys. Rev. Lett. 106, 197204 (2011).

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Origin of ferromagnetism in Ga1-xMnxN

The verway phase of magnetite - a long-running mystery in magnetism

Incommensurate magnetic states in itinerant systems

Nanogranular FePt films for thermally assisted recording

Magnetite (Fe3O4) undergoes a complex structural distortion and becomes electricallyinsulating below 125 K. Verwey proposed in 1939 that this transition is driven bya charge ordering of Fe2+ and Fe3+ ions, but the low temperature state has remained
contentious as twinning of crystal domains hampers diffraction studies of the structure.
A variety of ground state models has been proposed over seven decades of study.
We have recently reported the full low temperature superstructure of magnetite,
determined by high energy x-ray diffraction from a 40 μm grain, and we identify the
emergent order. The acentric structure is described by a superposition of 168 frozen
phonon modes all with amplitude <0.24 A. Distortions of the FeO6 octahedra showthat Verwey’s hypothesis is correct to a first approximation. However, anomalous
shortening of some Fe-Fe distances shows that the localised electrons are distributed
over linear three-Fe-site units that we describe as ‘trimerons’ - this description is
supported by band structure calculations. The charge order and trimeron distortions
induce substantial off-centre atomic displacements and couple the resulting large
electrical polarisation to the magnetisation so that multiferroic behaviour is expected.
Trimerons may be significant quasiparticles above the Verwey transition and in othertransition metal oxides.

We study the ground state of the Hubbard model within the Hartree-Fockapproximation taking into account both the incommensurate magnetic phases (spiraland collinear spin-density waves) and their possible participation in the phaseseparation (PS). We construct magnetic phase diagrams for 2D and 3D lattices withdifferent values of the parameter of the electron hopping between the next-nearest
neighbors [1]. We show that the incommensurate magnetic state is the ground one in awide range of the model parameters. There is a large region of the PS in the vicinity ofhalf-filling. The data obtained agree well on a qualitative level with experimental dataon the magnetic state of a superconducting compound La2-pSrpCuO4 [2]. We consider
the metal-insulator transition (MIT) at half-filling taking into account incommensurate
magnetic states. Calculations show that, for the square lattice, MIT coincides with thefirst-order magnetic transition from a spin-spiral to antiferromagnetic state. To ourknowledge this result is the first example of MIT between two magnetically orderedstates in the 2D lattice. Previously, the critical dimension for this transition wasconsidered to be in a range from 2 to 3. Thus, our investigation proves this value to be
below 2.

In order to extend the data storage density in hard disk drives beyond 1 Tb/in2, using
a high crystalline anisotropy (Ku) material as the magnetic media layer is required
to reduce the grain size further while maintaining thermal stability. However, themagnetic field applied by a conventional write head is not strong enough to reverse themagnetization of the high-Ku media. A promising approach to recording using high-Ku
materials is thermally-assisted recording (TAR), in which the media is locally heatednear the Curie temperature by an optically-generated heat pulse in the presence of amagnetic field, both applied by a laser-integrated write head, in order to write a bit.
Given its moderate Tc, high Ku, corrosion durability, and high dKu/dT near Tc, FePt
alloy with L10 crystalline order is a potential candidate for TAR media. We deposit
FePt nano-granular films by sputtering on glass substrates at elevated temperature.
Underlayer materials are selected for heat-sinking and to obtain high, out-of-plane L10
order. Structural and magnetic characterization and transmission electron microscopyof the media show that we can achieve properties that are promising for TAR, suchas isolated grains with an average grain size <7.5nm, a low size distribution andKu>4.5x107 erg/cm3.

Colossal negative magnetoresistance and the associated insulator-to-metal transition are arguably the mostcharacteristic features of magnetic and dilute magnetic semiconductors. Particularly intriguing is the caseof (Ga,Mn)As and related systems in which spin-spin coupling is mediated by holes. In order to find out
how magnetism evolves when the carrier density is diminished, we have probed magnetization changes
induced by: (i) electric field in metal/insulator/(Ga,Mn)As structures [1] and (ii) thinning of the channel
by sequential chemical etching. Our findings show that both the channel depletion and thinning results ina monotonic decrease of Curie temperature and spontaneous magnetic moment, with no evidence for the
maximum expected within the impurity-band models but explained theoretically in terms of the p-d Zenermodel, modified for the thin film case [1]. They also confirm the presence of the theoretically predictedspin reorientation transition. We have found that the transformation to a non-magnetic state proceeds via
the emergence of a hitherto non-revealed superparamagnetic-like spin arrangement, driven by criticalfluctuations in the local density of states, specific to the Anderson-Mott quantum transition. Within ourmodel, these nanoscale fluctuations of magnetization give rise to critical scattering which vanishes whenlocalized spins are ordered by an external magnetic field.
[1] M. Sawicki, D. Chiba, A. Korbecka, Y. Nishitani, J.A. Majewski, F. Matsukura, T. Dietl, H. Ohno, Nature Phys. 6, 22 (2010).

Thibaut Devillers1*, Maciej Sawicki2, Wiktor Stefanowicz2, Sylwia Dobkowska2, Bogdan Faina1,
Andrea Navarro-quezada1, Tian Li1, Andreas Grois1, Mauro Rovezzi3, Tomasz Dietl2 and Alberta
Bonanni11
Institute for Semiconductor and Solid State Phys., Johannes Kepler University, Austria
2Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
3
European Synchrotron Radiation Facility, Grenoble, France

Despite Ga1-xMnxN is the model system for a broad class of dilute magnetic semiconductors andoxides, diverging opinions about its magnetic ground state have been reported: this material was
found to be either spin glass, or an antiferromagnet or a ferromagnet with rather disperse valuesof the Tc, ranging from below 10 K up to over 300 K [1,2]. By employing a range of ion beam,diffraction, and spectroscopy methods we have demonstrated [3,4] that particular magnetic signatures
can be linked to a specific distribution of the magnetic ions and to their charge state, both affected by
growth conditions and by the presence of shallow impurities. By combining extensive epitaxy andnanocharacterization programs with high sensitivity mK-SQUID measurements, we demonstrate that
Ga1-xMnxN with randomly distributed Mn3+ ions is a ferromagnet with Tc below 5 K for x < 5%. To
clarify the origin of ferromagnetism in this material with no band carriers, we examine Tc(x) ~ xm
and show that the value m = 2 is consistent with ferromagnetic superexchange. We discuss our resultsin the light of the available ab initio studies and compare our system to Cr chalcogenide and oxide
spinels, where ferromagnetic and antiferromagnetic superexchange coexist.

[1] A. Bonanni and T. Dietl, Chem. Soc. Rev. 39, 528-539 (2010) [2] T. Dietl, Nature Mat. 9, 965-974 (2010) [3] W.
Stefanowicz, D. Sztenkiel, B. Faina, A. Grois, M. Rovezzi, T. Devillers, A. Navarro-Quezada, T. Li, R. Jakiela, M. Sawicki,
T. Dietl, and A. Bonanni, Phys. Rev. B 81, 235210.1-14 (2010) [4] A. Bonanni, M. Sawicki, T. Devillers, W. Stefanowicz, B.
Faina, Tian Li, T. E. Winkler, D. Sztenkiel, A. Navarro-Quezada, M. Rovezzi, R. Jakiela, A. Grois, M. Wegscheider, W. Jantsch, J.
Suffczynski, F. D'Acapito, A. Meingast, G. Kothleitner, and T. Dietl, Phys. Rev. B 84, 035206.1-11 (2011).

Recent observation of a large magnetoresistance in an antiferromagnet (AFM) based spin-valve opens theprospect for utilizing AFMs in spintronics [1]. This motivates a search for new materials which may besuitable for spintronics and are room-temperature AFMs. The desired control of devices via electrical fields
could be further exploited if the materials involved would be also semiconductors. We present our results [2]in the growth and characterization of a new family of room-temperature antiferromagnetic semiconductors
and semimetals. We show X-ray diffraction, magnetization, transport, and differential thermal analysis
measurements of chemically synthesized bulk CuMnAs and CuMnSb. Experiments are complemented
by theory calculations of band structure and magnetic structure. The progress in bulk I-Mn-V materials
encourages also the investigation of thin layers. We will show the epitaxial growth of LiMnAs [3] andCuMnAs on conventional GaAs. Scanning tunneling microscopy has shown that in the case of LiMnAs
there is a bandgap [4].

J Paul Attfield
University of Edinburgh, United Kingdom

M.S. Senn, J.P. Wright and J.P. Attfield, Nature 481, 173 (2012). M.S. Senn, I. Loa, J.P. Wright and J.P.
Attfield, Phys. Rev. B, in press (2012).

Marat Timirgazin and Anatoly Arzhnikov
Physical-Technical Institute of Ural Branch of Russian Academy of Sciences, Russia[1] L. Zhang, Y.K. Takahashi, A. Perumal and K. Hono, JMMM322,2658 (2010). [2] L. Zhang, Y. K.
Takahashi, K. Hono, B. C. Stipe, J.-Y. Juang, and M. Grobis, IEEE Trans. Magn. 47, 4062 (2011).

Tiffany Santos, O. Mosendz, J. Reiner, S. Pisana, G. Parker and D. Weller
Hitachi GST, USA[1] Igoshev P. A., Timirgazin M.A., Katanin A.A., Arzhnikov A.K., and Irkhin V.Yu. Phys. Rev. B 81,
094407 (2010) [2] Fujita M. et al., Phys. Rev. B 65, 064505 (2002)

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The effects of non-magnetic dopant on semiconductor materials

Possible link of a structurally driven spin flip transition and theinsulator-metal transition in the perovskite La1-xBaxCoO3Canted spins of Mn3o4 investigated by 55Mn2+ and 55Mn3+ nuclear
magnetic resonance in magnetic field

Single crystalline isolated grains of L10-ordered FeCuPt preparedby combination of rapid thermal annealing with rapid cooling andadditional annealing

Caihong Zhang* and Dickon H. I. Ng
Physics Department, The Chinese University of HongKong, China

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Despina Louca and Peng Tong
Department of Physics, University of Virginia, USA

The intricate nature of the magnetic ground state near the insulator-metal transition(IMT) in La1-xBaxCoO3 was investigated via neutron scattering. For x less than thecritical concentration, xc~0.22, a commensurate antiferromagnetic (AFM) phase
initially appears. As x approaches xc, the AFM component continuously weakens
while ferromagnetic (FM) order sets in the rhombohedral lattice. The two magnetic
phases appear to be growing in different domains and have different ordering
temperatures, with the FM order parameter setting in first at higher temperatures while
the AFM order parameter occurs at lower temperatures. At xc, a spin flip to a new FM
state occurs while the crystal transforms to an orthorhombic (Pnma) symmetry. The
magnetic Pnma phase coincides with the minimum saturation reached in the resistivity.
It is proposed that the orbital overlap in the Pnma phase is the most conducive tocharge hopping. The structurally driven spin flip creates metallic FM droplets andthe percolation of these droplets drives the system to become metallic. This, in turn,suggests that the FM domains in the rhombohedral phase are in fact insulating. Thisis fundamentally distinct from other magnetoresistive perovskites where only one FMtransition is observed prior to the IMT.

Invited & Contributed Presentation

Invited & Contributed Presentation

Changsoo Kim, Jeong Hyun Shim, Euna Jo, Byeongki Kang, Sangil Kwon andSoonchil Lee*
Department of Physics, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Korea

For a long time, huge magnetic anisotropy in Mn3O4 has attracted a lot of interest
from researchers. The magnetization along the c-axis is smaller than that along theab-plane even in 30 Tesla. It has been believed that this phenomena occurs due to auniaxial anisotropy of Mn3+ along the c-axis. However, there has been no experimentto verify this theory. We measured 55Mn2+ and 55Mn3+ Nuclear Magnetic Resonanceof a Mn3O4 single crystal in 7 Tesla external magnetic field. The angle between eachmagnetic moment and the field was calculated from the spectral shifts obtained forvarious magnetic field directions between the a, b and c-axes. From the fact that Mn3+
moments are tied to the ab-plane when the magnetic field is in the direction along thec-axis, we concluded that the Mn3+ moment has a large in-plane anisotropy contrary to
the previous reports. In contrast, Mn2+ moments were tilted toward the field direction,
implying that the Zeeman energy of a Mn2+ moment is competing with the energy ofthe exchange interaction between Mn2+ and Mn3+ moments and the magnetic anisotropy
energy of Mn2+.

Tatsuya Ubana1, Arata Tsukamoto2* and Akiyoshi Itoh2
1
Graduate School of Science and Technology, Nihon university, Japan
2
Collage of Science and Technology, Nihon university, Japan

We reported1),2), that the Rapid Thermal Annealing (RTA) of Fe/Cu/Pt multilayered continuous films
are effective to obtain perpendicularly magnetized small L10-FeCuPt grains on thermally oxidized Si
substrate. In this report, we introduced a rapid cooling process (RCP) into RTA and compared with thenatural cooling processes. FeCuPt grains were fabricated under the variety of heating up rate (TR) and the
maximum temperature (Tm). Isolated grains are obtained at higher TR and Tm. With RCP, growing ofgrains are prevented, however new peaks in XRD (X-ray diffractometer) profile are appeared at slightly
lower angle of (002) and it may be correspond to the disordered structure of FeCuPt. From electron
diffraction patterns and dark field images by TEM, mostly L10-ordered polycrystalline structure wasobserved. Therefore, we preformed additional annealing for above isolated FeCuPt grains (600 degree C,
1 hour). Annealing condition was decided from an estimation of atomic diffusion length3). After additional
annealing, grains kept almost similar size and the new peak was banished in XRD profile. Furthermore, we
observed single crystalline L10-ordered structure from electron diffraction pattern of a single grain. As aresult, single crystalline L10-FeCuPt isolated grains are obtained by RTA with rapid cooling and additional
annealing.
1) Y. Itoh, T. Aoyagi, A. Tsukamoto, K. Nakagawa, A. Itoh and T. Katayama: Jpn. J. Appl. Phys., 43, 12, 8040(2004). 2) A. Itoh, Y. Itoh, K.
Nanba, Y.Adachi, M. Motohashi, and A.Tsukamoto: J. Appl. Phys., 99, 08Q906(2006). 3) M. Rennhofer, B. Sepiol, M. Sladecek, D. Kmiec, S.
Stankov, G. Vogl, M.Kozlowski, R. Kozubski, A. Vantomme, J. Meersschaut, R. Ruffer, and A.Gupta, Phys. Rev. B 74, 104301, (2006).

44

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

45

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Oscillation characteristics of spin-torque oscillator calculated using
integrated simulator with spt writer

Magnetic targeting of mesenchymal stem cells in the spinal cord

Depth-resolved XMCD spectroscopy on single-layer graphene / Ni
structure

Spin gating a transistor and spintronics with antiferromagnets

Invited & Contributed Presentation

Kazuetsu Yoshida1, Souta Asaka2, Takuya Hashimoto2 and Yasushi Kanai3
1
Information and Communications Engineering, Kogakuin University, Japan
2
Graduate school of electrical engineering and electronics, Kogakuin University, Japan
3
Information and Electronics Engineering, Niigata Institute of Technology, Japan

Microwave-assisted magnetic recording (MAMR) requires a spin-torque oscillator (STO) to
induce magnetic resonance in the recording medium. The oscillation characteristics of an STO havepreviously been investigated using micromagnetic simulators based on spatially isolated models [1][3], which neglect the magnetostatic interactions between an STO and a Single-Pole-Type (SPT)
writer. We have developed a new simulator that takes into account the magnetostatic interaction
between an SPT writer and an STO, and we refer to this as an integrated MAMR simulator. This
interaction was found to have considerable influences on the oscillation behaviors of an STO.
Simulations were carried out for an STO with a lateral length of 30 nm and a thickness of 10 nm
inserted in the gap between a main-pole and a floating-type trailing shield. The stray field in the gap
increased by approximately 30 % by inserting the STO and its oscillation frequency was 8 GHz. For
comparison, the oscillation frequency calculated using a conventional isolated STO simulator was
found to be 16 GHz. This decrease in frequency may be the result of an energy loss in the main-poleof an SPT writer that is excited by the high-frequency field from an STO.

Vaclav Vanecek1, Jiri Ruzicka1, Serhiy Forostiak1, Michal Babic2, Vit Herynek3, Alexandr Dejneka4, Vitalii
Zablotskii4*, Sarka Kubinova1, Pavla Jendelova1 and Eva Sykova1
1
Institute of Experimental Medicine, Czech Republic
2
Institute of Macromolecular Chemistry, Czech Republic
3
MR-Unit, Institute for Clinical and Experimental Medicine, Czech Republic
4
Institute of Physics, Czech Republic

Yoshihiro Matsumoto1*, Shiro Entani1, Manabu Ohtomo1, Pavel V Avramov1, Hiroshi Naramoto1,
Kenta Amemiya2 and Seiji Sakai1
1Advanced Science Research Center, Japan Atomic Energy Agency, Japan
2
Institute of Materials Structure Science, High Energy Accelerator Research Organaization, Japan

Tomas JungwirthInstitute of Physics ASCR, v.v.i., Prague and University of Nottingham, Czech
Republic
Spintronics is among leading technologies for reading, writing, and storing
information. Spintronic sensors and memory bits rely on spin-dependent electrontransport through the device and the same applies to the currently explored concepts
for spintronic transistors. Here we demonstrate a new route for using spin in transistors
by moving the spin functionality from the transport channel to the capacitively
coupled gate. In our transistor, the spin state of the gate controls the charge transport
through a conventional non-magnetic electron channel. We explain the phenomenonusing the relativistic, spin-orbit coupling theory framework employed in recent
studies of anisotropic magnetotransport in spintronic nanodevices. The relativistic
magnetic anisotropy phenomena are an even function of the microscopic magnetic
moment vector. This means that they can be equally strong in antiferromagnets as inferromagnets which opens the possibility to realize spin dependent microdevices basedon antiferromagnets. As a demonstration we present our experimental observation of>100% tunneling anisotropic magnetoresistance in a device with an antiferromagnetic
tunnel electrode.

Mesenchymal stem cells (MSC) are currently under intensive study as a possible therapeutic agent inspinal cord injury [1]. MSCs labeled with superparamagnetic iron oxide nanoparticles (SPIO) can be
manipulated by an externally applied magnetic field and successfully targeted to different organs. We
transplanted SPIO-labeled MSC into rats with a magnetic implant or a non-magnetic substitution inserted
above the spinal cord intrathecally via lumbar puncture one week after spinal cord injury. The fate of
the grafted cells was monitored by means of magnetic resonance imaging (MRI) [2] and histologically.
In our experiments, the transplanted cells were present mostly on the surface of the spinal cord (in thesubarachnoid space) in both the magnetic and non-magnetic (control) groups. In the lesion area of the
spinal cord, there was a significant difference in cell distribution between the magnetic and non-magnetic
groups. The SPIO-loaded cells circulating in the subarachnoid space were gathered under the magnetic
implant near the site of injury. Additionally, we suggest how magnetic cell targeting can be improvedby using a magnet specially designed to produce spatially modulated multigradient stray fields [3]. The
proposed magnetic delivery system might be attractive for clinical application development. Supported by
P304/12/1370, AVOZ503905703.

The graphene-metal interaction is not only of fundamental interest but also of technologicalimportance in view of spintronic applications. For example, a recent theoretical calculation predictsa spin filtering effect of graphene attached on the ferromagnetic metal surface under the currentperpendicular-to-the-plane configuration [1]. For the purpose of clarifying the electronic andmagnetic states of the single layer graphene (SLG)/FM structure especially at the interface region,
depth-resolved X-ray absorption and X-ray magnetic circular dichroism (XMCD) spectroscopy
are performed on the SLG/Ni(111) structure grown by using the ultrahigh vacuum chemical vapor
deposition and molecular beam epitaxy techniques. An intense XMCD signal is observed in the C
K-edge XMCD spectrum taken under the surface sensitive condition. This indicates that there exists
the Ni-induced spin polarization in the orbitals of SLG even at room temperature. It is also foundthat the XMCD intensity shows a dramatic change with the probing depth. The depth-resolved
analysis of the Ni L-edge XMCD spectrum makes clear that the magnetization of Ni is decreased
by 20-30 % within a few atomic layers from the interface with SLG, possibly associated with theformation of C-Ni bonds.

1. E. Sykova, et al., Cell Mol Neurobiol, 26 (7-8) 1113 (2006). 2. E. Sykova and P. Jendelova, Ann N Y Acad Sci., 1049,
146 (2005). 3. V. Zablotskii, et al., American Institute of Physics, Conference Proceeding Series 1311, 152 (2010).

[1] V. M. Karpan et al., PRL 99 (2007) 176602.

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Magnetic nanotechnology for cancer treatment

Tilted bianchi type - I magnetised viscous fluid cosmological model

Magnetoresistance and spin-transfer torque in magnetic tunnel
junctions

Co2y-nicuzn ferrite composites with high permeability

1

Hexagonal structure magnetoplumbite ferrites have revealed a higher dispersion
frequency than that of nickel ferrites because of the magnetoplumbite’s magnetic
anisotropy. The magnetoplumbite ferrite densification temperature always exceeds
1000oC and the initial low temperature firing permeability of magnetoplumbite ferrites
with added glass is too low (μi = 2-4). Therefore, it is desirable to develop a material
that has a higher permeability at above 300 MHz and can be densified at temperatures
below 900°C. The Bi2O3-B2O3-ZnO-SiO2 (BBSZ) glass addition effects on thedensification and magnetic properties of Co2Y-NiCuZn ferrite composites with various
Co2Y/NiCuZn ferrite ratios were investigated. The densification of Co2Y-NiCuZnferrite composites was enhanced by the addition of glass at low sintering temperatures(<900oC) due to the liquid phase sintering. Co2Y-NiCuZn ferrite composites with 4
wt% BBSZ glass sintered at 900°C show a relative density above 90%, a high-initialpermeability of 5-6, a quality factor of above 30 in the 200-300 MHz frequency anda resonance frequency above 1 GHz, which can be used in high frequency multilayer
chip inductors.

[1] J- G. Zhu, X. Zhu, and Y. Tang, “Microwave Assist Magnetic Recording,” IEEE Trans. Magn., 44, No.1, 125-131(2008). [2] D. Houssameddine, et al., “Spin-torque oscillator using a perpendicular polarizer and a planar free layer,” Nature Mater., l6, 447-453(2007). [3] K. Yoshida, M. Yokoe, Y. Ishikawa, and Y. Kanai, “Spin-Torque Oscillator with
Negative Magnetic Anisotropy,” IEEE Trans. Magn. 46, 2466-2469(2010).

Thanos Mitrelias1, Valerii Orel2, Marina Tselepi3, Crispin Barnes4, I Schepotin2, A Romanov2 and A
Shevchenko5
1
Cavendish Laboratory, University of Cambridge and Cavendish NanoTherapeutics Ltd, United Kingdom
2
National Cancer Institute, Kiev, Ukraine
3
Cavendish Laboratory, University of Cambridge and Cavendish NanoTherapeutics, United Kingdom
4
Cavendish Laboratory, University of Cambridge, United Kingdom
5
Kurdyumov Institute for Metal Physics, Kiev, Ukraine

Subrata Kumar Sahu
Mathematics, Lingayas university, India

Tilted Bianchi type - I cosmological model for viscous fluid distribution embedded in amagnetic field is investigated. The role of the bulk viscosity and electromagnetic fieldin getting an inflationary phase and in establishing the tilted universe is discussed.

Shinji Yuasa1,2*, Kay Yakushiji1, Akio Fukushima1, Hitoshi Kubota1, Takayuki
Nozaki1 and Koji Ando1
2

Spintronics Research Center, National Institute of Advanced Industrial Science and technology (AIST), Japan
Distinguished Lecturer of IEEE Magnetic Society, Japan

A magnetic tunnel junction (MTJ) consisting of a tunnel barrier sandwiched between two ferromagnetic
electrodes exhibits the tunnel magnetoresistance (TMR) effect due to spin-dependent electron tunneling.
Since the discovery of room-temperature TMR in the mid-1990s, MTJs with an amorphous aluminumoxide (Al-O) tunnel barrier have been studied extensively. Such MTJs exhibit a magnetoresistance (MR)ratio of several tens of percent at room temperature (RT) and have been applied to magnetoresistive
random access memory (MRAM) and the read heads of hard disk drives. MTJs with MR ratios
substantially higher than 100%, however, are desired for next-generation spintronic devices. In 2001, firstprinciple theories predicted that the MR ratios of epitaxial Fe/MgO/Fe MTJs with a crystalline MgO(001)barrier would be over 1000% due to the coherent tunneling of specific Bloch states. In 2004, MR ratios
of about 200% were obtained for MgO-based MTJs [1]. MTJs with a CoFeB/MgO/CoFeB structure
were developed for practical application and found to have MR ratios of above 200% and other practicalproperties [1,2]. The talk focuses on the physics of magnetoresistance and spin-transfer torque in MTJs
and the application of MTJs to various spintronic devices such as magnetic sensors and spin-transfertorque MRAM especially with perpendicularly magnetized electrodes.

Often the conventional therapies needed to annihilate cancer cells have high systemic
toxicity effects. We are developing systems which utilise magnetic nanoparticles loaded withtherapeutic agents, directed and guided towards the tumour site and preferentially attachedto the tumour to destroy it. The cancer cells are killed by the combined action of the drugs
and a local temperature increase in the area around the tumour site using externally applied
electromagnetic irradiation (hyperthermia). The aim is to avoid most side effects since thenanoparticles target specifically the tumour area and leave most of the surrounding tissues
unaffected, therefore higher doses of the drug reach the target area even if lower overall
doses are administered. Our preliminary clinical trials and pilot studies have demonstrated
significant effects in the reduction of the tumour size and a 50% increase in the survival rates (onaverage) of patients with breast, lung, endometrial, colorectal, malignant melanoma, etc. For
example, in patients with lung cancer IIIA stage we have demonstrated a tripling in the 5-year
survival rates. The unique aspects of our platform technology are (i) synthesis of nanoparticles
with high magnetization, (ii) less tendency to agglomerate, (iii) generation of spatially nonhomogeneous electromagnetic fields.

B. G. Park et al. Nature Mater. 10, 347 (2011) X. Marti et al. Phys. Rev. Lett. 108, 017201 (2011)

Hsing-i Hsiang* and Po-wen Cheng
Resources Engineering, National Cheng Kung University, Taiwan[1] S. Yuasa and D. D. Djayaprawira, J. Phys. D: Appl. Phys. 40, p.R337 (2007). [2] D. D. Djayaprawira, K. Tsunekawa, M.
Nagai, H. Maehara, S. Yamagata, N. Watanabe, S. Yuasa, Y. Suzuki and K. Ando, Appl. Phys. Lett. 86, 092502 (2005).

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The low magnetic field effect of sanals of primo vascular system

Growth of highly uniform graphene for spintronic applications

MTJ based non volatile logic for ultimate power management

Investigation of Fe2YZ (Y=Ni, Cu; Z=Sn, Ga): The Heusler compoundswith tetragonal structure

Sang-suk Lee1, Kwang-sup Soh2, Min-suk Rho3, Yeong-min Yoo4, Jong-gu Choi5, Sung-ah Shim1, Youngil No1, Jun-yeong Shin1 and Ran-hyang Kim1
1
Oriental Biomedical Engineering, Sangji University, Korea
2
Nano-Primo Research Center, Seoul National University, Korea
3
Sangji University, Korea
4
Biomedical Engineering, Yonsei University, Korea
5
Eastern-Western Biomedical Engineering, Sangji University, Korea

The motion features of sanals inside of the primo vascular system (PVS), that is so-called the Kyungrak
system, are investigated under a low static magnetic field by using the anatomy technology and optical
microscope. The sanals with a size of about 1 selected and separated from the primo vessel and node of
the real PVS inside of the surface of the internal organs are observed from rabbits' abdominal wall anddipped with PBS liquid inside of petri dish. The sanal's moving velocity along the direction of magnetic
field (xdirection) and perpendicular to the direction of magnetic field (y-direction) under the low magnetic
field of 0 Oe, 20 Oe, 40 Oe, 60 Oe, and 80 Oe, respectively, is observed below a internal temperature of
38 oC. Ten sanals' moving velocities versus magnetic field are shown two differently dominant tendencies
with an average velocity of 0.9 pixel/s and a random velocity according to the x-direction and y-direction,
respectively. This experimental results imply that the rotating motion of sanal with nuclei DNA composedof many inorganic magnetic materials of Mn and Co is monotonically weakened by the increase of appliedmagnetic field.
[1] K. S. Soh, J. Kor. Phys. Soc. 45, 1196 (2004). [2] K. S. Soh, J. Acupunct. Meridian Stud. 2, 93 (2009). [3] B. C. Lee, K. W.
Kim, and K. S. Soh, J. Acupunct. Meridian Stud. 2, 66 (2009). B. H. Kim, J. Jo Sun Med. 9, (Korean) 5 (1962). [4] B. H. Kim, J.
Jo Sun Med. 90, (Korean) 6 (1963). [5] B. H. Kim, J. Jo Sun Med. 108, (Korean) 1 (1965). [6] B. H. Kim, J. Jo Sun Med. 108,
(Korean) 39 (1965). [7] B. H. Kim, J. Jo Sun Med. 108, (Korean) 1 (1965).

46

Invited & Contributed Presentation

The 19th International Conference on Magnetism

Invited & Contributed Presentation

Invited & Contributed Presentation

Shiro Entani, Yoshihiro Matsumoto, Manabu Ohtomo, Pavel V Avramov, Hiroshi
Naramoto and Seiji Sakai
Advanced Science Research Center, Japan Atomic Energy Agency, Japan
Graphene has attracted wide attention for nanoelectronics and spintronics. In thisstudy, in-situ analysis were performed on the graphene growth in ultrahigh vacuum
chemical vapor deposition (UHV-CVD) by exposing the epitaxial Ni(111) thinfilm to benzene vapor at 873 K. It is shown that the uniform single- and bi-layer
graphenes can be synthesized by the control of benzene exposure in the range of 10105 langmuirs, reflecting a change in the graphene growth-rate by three orders ofmagnitude in between the first and second layer. It is also suggested that the chemicalinteraction between bi-layer graphene and Ni(111) is weak in comparison with thatbetween single-layer graphene and Ni(111). Ex-situ micro-Raman analysis on the large
area graphene film transformed on a SiO2 substrate makes it clear that the structuraland electrical uniformities can be improved remarkably under the specific exposure
conditions at which the growth of the respective graphene layers are completed. The
present results demonstrate that the UHV-CVD method enables the growth of highly
uniform graphene which would be necessary for controlling the spin transport process
as well as realizing a long spin-relaxation length in the graphene-based spintronic
devices by optimizing the dosage of precursors and the growth temperature.

Tetsuo Endoh, Takashi Ohsawa, Takahiro Hanyu and Hideo Ohno
Tohoku University, Japan

Recently, the achievement of the silicon-LSI’s target performance is becoming difficult only byscaling technologies. First, the speed-gap between the operation speed of logic and each memory
has expanded. Moreover, its power consumption increases rapidly, too. In this paper, we describe
both MTJ based Non Volatile (NV-) Embedded SRAM and MTJ based NV-Logic circuit. Firstly, weshow the proposed MTJ based SRAM that consists of 4 MOSFETs and 2 MTJs. This STT-SRAM
achieves an excellent static noise margin that is larger than the resistive load SRAM counterpart bytaking advantage of the MTJ’s switching characteristics. The cell size becomes comparable with theconventional 6-transistor SRAM and even smaller as the MTJ size shrinks along with the MOSFET
scaling. Next, from the viewpoint of super-low power consumption systems, MTJ based NV-Logic,
that fuses the STTRAM with semiconductor CMOS logic, is discussed. Especially, we describe
the proposed MTJ based NV-Latch circuit with high speed operation of 600MHz. It is shown thatwith using our novel MTJ based NV-Latch circuit, the NV-F/F type NV-Logic can be realized.
Finally, we discuss the Logic-in-Memory type NV-Logic. From all, we show novel ultimate power
management technique with both MTJ based Embedded NV-Memory and MTJ based NV-Logic.
[1] T. Endoh, SEMI Technology Symposium in SEMICON Japan, 2007 (Invited Paper) [2] S. Matsunaga et al. APEX 1,
091301, 2008. [3] D. Suzuki et al. VLSI Circuit Symposium 2009 [4] H. Ohno et al. IEDM 2010 (Invited Paper) [5] T.
Endoh, 2011 CMOS ET Workshop 2011(Invited Paper) [6] T. Endoh, ITRS Emerging Research Memory Technologies
Workshop 2010 [7] T. Endoh, SEMICON Korea2010 (Invited Paper) [8] T. Endoh, Materials R esearch Society 2010
Spring Meeting, 2010 (Invited Paper) [9] T. Endoh, INC7, 2011 [10] T. Ohsawa et al., SSDM, pp. 959-960, 2011 [11] T.
Endoh, et al., IEDM 2011

Margarit Gjoka1, Dimitris G Niarchos1, Eamon Devlin1 and George Hadjipanayis2
1
Institute of Materials Science, NCSR DEMOKRITOS, Greece
2
Physics and Astronomy, University of Delaware, USA

Heusler compounds, a remarkable class of intermetallic materials with 1:1:1 (often
called Half-Heusler) or 2:1:1 composition, have attracted considerable interest since
their discovery, mainly because of their versatile magnetic properties. Recently has been
published a computational study on X2YZ full Heusler alloys. According to this work,
the predicted enthalpies of formation evidence 27 phases to be thermochemically stableagainst the elements and the regular X2YZ type. A chemical-bonding study yields aninherent tendency for structural distortion in a majority of these alloys, so they predict theexistence of the new tetragonal phase Fe2CuGa (P42/ncm; a = 5.072 A, c = 7.634 A; c/a ≈1.51) with a saturation moment of μ = 4.69 μB per formula unit. In this work is reported
the attempt to synthesize experimentally this new phase. Fe2-xMnxNiSn and Fe2CuGa(x = 0, 1, 2) alloys were prepared by arc-melting and annealed at different temperaturesin the interval 800-1300K. The Curie temperature (TC) was determined from the hightemperature magnetization measurements carried out in a field of 0.05 T using a vibrating
sample magnetometer (VSM). The indexing of all XRD patterns of annealed samples
and microstructure characterization are in progress and will be present in conference.
Supported by the project REFREEPERMAG of the EU

July 8-13, 2012 Busan, Korea

47

ORAL PRESENTATION
BJ03

BJ06

CA03

CB03

Crystallite growth kinetics and microwave properties of Fe-Ti
substituted (La,Sr)MnO3 prepared by mechanical alloying

Resistivity and complex permeability dependence on isochronal
recovery in polycrystalline yttrium iron garnet (Y3Fe5O12)

Feedback effect on high-energy magnetic fluctuations in the model
high-temperature superconductor HgBa2CuO4+d

Numerical study of the exchange bias effects in assemblies of core/shell
nanoparticles

WN
A
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D

TH
I
W

Ismayadi Ismail1, Mansor Hashim1* and Nor Hapishah Abdullah2
1
Advanced Materials and Nanotechnology Laboratory, Universiti Putra Malaysia,
Malaysia
2
Physiscs Department, Faculty of Science, Universiti Putra Malaysia, Malaysia
We propose to establish whether or not crystal atomic defects have any influence on thevalue of its complex permeability and electrical resistivity after undergoing heat treatments.
A technique involving defects creation and their subsequent elimination within equal
time-length durations was used: this is a technique for establishing isochronal recovery
behavior of any atomic defects-dependent properties. YIG was prepared via mechanicalalloying with a mixture of Y2O3 and Fe2O3 involving a 24 hours milling time. They werethen sintered at different temperatures between 900°C to 1350°C and subsequently heatedfor 2 hours at 1000°C and quenched in cooking oil. Then, annealing of the samples at
1000°C for 2 hours was carried out. The magnetic and electrical properties before andafter quenching and also after annealing were studied. The permeability and loss factor
showed an isochronal recovery behaviour in which a parameter’s value was decreased
after quenching and increased back even higher after annealing suggesting that magnetic
permeability and energy loss in YIG could significantly show an atomic defect-dependent
behaviour. The resistivity value of the samples was observed to have an isochronal
recovery behavior which the value dropped after quenching and increased almost graduallyback even higher after isochronal annealing series.

Yuan Li1*, Mathieu Le Tacon1, Mohammed Bakr1, Damien Terrade1, Dirk Manske1, Rudi Hackl2, Lina Ji3,
Mun K. Chan3, Neven Barisic3, Xudong Zhao3, Martin Greven3 and Bernhard Keimer1
1 Max Planck Institute for Solid State Research, Germany
2 Walther Meissner Institute, Bavarian Academy of Sciences, Germany
3 University of Minnesota, USA
It is widely accepted that magnetic excitations make important contribution to the Cooper-pairing
mechanism in cuprate high-temperature superconductors. Contribution from excitations below ~60meV
is manifested by a generic 'resonance' feature observed by neutrons, which signifies a feedback effect ofpairing on the magnetic excitations. However, the insufficient spectral weight of the resonance is unable
to explain the high superconducting temperature (Tc). Recent research has demonstrated that intense
excitations above 100meV are available as a possible resource for pairing, but it remains largely unknown
whether this resource is actually utilized. Here we present a systematic electronic Raman scattering studyof the model single-layer cuprate superconductor HgBa2CuO4+d. In an overdoped sample, we observe a
pronounced enhancement of a high-energy peak related to two-magnon excitations in insulating cuprates
upon cooling below Tc. This is accompanied by the appearance of the superconducting gap and a pairing
peak above the gap in the Raman spectrum, and it can be understood as a high-energy feedback effectwhich evinces a direct involvement of the high-energy excitations in the Cooper-pairing mechanism. Allof these effects occur already above Tc in two underdoped samples, demonstrating a related feedback
mechanism associated with the pseudogap.

Kalliopi Trohidou*, Marianna Vasilakaki and George Margaris
Institute of Materials Science, National Center for Scientific Research 'Demokritos',
GreeceThe study of the magnetic behaviour of random assemblies of nanoparticles with core /shell structure is a relatively new field of experimental and theoretical interest. We study
numerically using the Monte Carlo simulations technique with the implementation of theMetropolis algorithm the role of the magnetostatic and exchange interactions on the magnetic
behaviour of composite nanoparticle assemblies. The aim of our work is to determine thefactors that influence the exchange bias behaviour in the assemblies. We have developed asimplified model that describes the complex internal structure of the nanoparticles and also
includes the interparticle interactions. We have calculated the hysteresis loops and the Zero
Field Cooled magnetization curves of the assemblies for different sizes of the shell thicknessfor each nanoparticle and as a function of the particle concentration and the size of the dipolar
and interparticle exchange strength in the assembly. Our simulations show that for small shell
thickness and at high particle concentration the interparticle exchange interactions cause a big
increase in the exchange bias field (Hex) and the coercive field (Hc). As the shell thickness
increase the effect of the exchange interparticle interactions is Our results are compared withexperimental findings [1,2].

[1] Y. Li et al., arXiv:1112.2725

1. J. Nogues, V. Skumryev, J. Sort, S. Stoyanov, D.Givord, Phys. Rev. Lett. 97 (2006) 157203 ; 2. N.Domingo, A. M.
Testa, D. Fiorani, C. Binns, S. Baker, J.Tejada J. M. M. M. 316 (2007) 155-158

BJ04

CA01

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CB04

Electromagnetic characteristics of Cu substituted Co2Z-type ferrites
Ba3Co2-xCuxFe24O41

Spin and charge excitations in cuprates and iron pnictides revealed by

Ferromagnetism of Au nanoparticle assemblies: Role of chemical andstructural parameters in magnetic properties

Exploring the effect of Co doping in the magnetic and magneto-opticalproperties of fine maghemite nanoparticles

Ji Yeon Song and Young Ho Han*
Materials Engineering, Sungkyunkwan University, Korea

Cu substituted Z-type hexaferrites (Ba3Co2-xCuxFe24O41 with x=0-1.0, Z-hex) wereprepared by two step calcinations [1]. The stoichiometric mixture for M-typeferrite was precalcined at 900°C, and then single phase Z-type ferrite powders weresynthesized at 1300°C by replacing CoO with various amounts of CuO. The frequency
dependence of initial permeability of all samples was measured from 0.01 to 3GHz.
The permeability varied with Cu contents, a maximum permeability of μ'= 9.8 at
10MHz was observed for x=0.8. The permeability behavior was dependent on thecontent of Z-type ferrite phase and microstructure [2]. For x=0.8 the content of Z-typeferrite phase was estimated to be 89%, and the average grain size was around 2μm.
The density of (Cu1.2Co0.8)Z-hex showed almost complete densification. However,
the resonance frequency decreased to 700MHz as the permeability of Cu substituted
Z-type hexaferrites (Ba3Co2-xCuxFe24O41) increased. Cu substituted Co2Z hexagonal
ferrites could be a candidate material for wireless device applications.
[1] J. Jeong, K.W. Cho, D.W. Hahn, B.C. Moon, Y.H. Han, Mater. Lett. 59 (2005) 3959-62 [2] M.
Aoyama, J. Temuujin, M. Senna, T. Masuko, C. Ando, H. Kishi, J. Electroceram 17 (2006) 61-4

simulated resonant inelastic x-ray scattering
Takami Tohyama1, Eiji Kaneshita2 and Kenji Tsutsui3
1
Yukawa Institute for Theoretical Physics, Kyoto University, Japan
2
Sendai National College of Technology, Japan
3
Synchrotron Radiation Research Center, Japan Atomic Energy Agency, Japan

We first examine Cu L3-edge resonant inelastic x-ray scattering (RIXS) spectra for
cuprates based on the exact diagonalization results of the t-t'-t''-J model. Both spin andcharge excitations are included in the calculations on the same footing. The calculated
results are compared with recent experimental data [1]. We next examine the orbital
excitations coupled to the spin degree of freedom in the iron pnictides, based on
the calculation in a five-band itinerant model [2]. The calculated Fe L3-edge RIXS
spectra disclose the presence of spin-flip excitations involving several specific orbitals.
Magnon excitations predominantly composed of a single orbital component can be seen
in experiments, although its spectral weight is smaller than spin-flipped interorbital
high-energy excitations. The detailed polarization and momentum dependence is also
discussed.
[1] T. Tohyama and K. Tsutsui, in preparation. [2] E. Kaneshita, K. Tsutsui, and T. Tohyama, Phys.
Rev. B 84, 020511(R) (2011).

Tae Hee Kim1*, Eun Ju Her1, Yu Jeong Bae1, Seung Hyo Ko1, Seung Ho Moon2, Jungtak Jang2, Jinwoo Cheon2 and Eisuke Ito3
1
Physics Department, Ewha Womans University, Korea
2
Chemistry Department, Yonsei University, Korea
3
3Flucto-Order Functions Research Team, RIKEN Advanced Science Institute, Japan

Ferromagnetism induced by the surface atoms and protective organic molecules in Au nanoparticles has
been investigated for both fundamental and application interests of magnetism.[1] Possible explanationsof the ferromagnetism could be attributed to 5d localized holes generated by the surface atoms and thehigh spin-orbit coupling of Au. Further understanding of this mechanism requires to study the magnetic
properties of the particles related to their relative distance (change of the ligand length) and the nature of
the ligand-particle binding. In this work, we explored the effect of these parameters for Au nanoparticles
assemblies which were cast in the form of compact pellet made by cold-pressing technique. The
magnetic behaviors in thiol and octylamine-capped Au nanoparticle assemblies were investigated bydifferent spectrometers and magnetometers. The evidence of ferromagnetic behavior at 300K was seenclearly in ~ 6nm size dodecanethiolated Au nanoparticles: surprisingly, for the diameter much lager than
2nm, a typical ferromagnetic magnetization curve with the saturation value of 0.25emu/g observed,
while superparamagnetism with a blocking temperature around 50K shown in octylamine-capped Au
nanoparticles. The surface analyses by XPS, ESR and FTIR indicated that the magnetic properties could
be tuned upon not only the particle size but also their surface environments.

Elvira Fantechi1, Giulio Campo1, Daniela Carta2, Anna Corrias2, Cesar De Julian
Fernandez3*, Claudia Innocenti1, Francesco Pineider4, Francesco Rugi1 and Claudio
Sangregorio3
1
INSTM and University of Florence, Italy
2
INSTM and Department of Chemical Sciences, Universita di Cagliari, Italy3
CNR - ISTM Milano @ INSTM Udr Florence, Italy4
CNR - ISTM Padova @ INSTM Udr Florence, Italy[1] P. Crespo et al. Phys. Rev. Lett. 98, 087204 (2004)

Nanosized spinel ferrites are the subject of increasing interest due to their remarkable magnetic, catalytic,
electric and optical properties, which, in most cases, differ from bulk. Cobalt ferrite is the ferrite withlarger magnetic anisotropy that can be directly controlled by varying the cobalt content. However otherfactors, like chemical state or inversion degree, determine the final magnetic properties. We present
a study of the structural, magnetic and magneto-optical properties of a series of Co substituted ferrite
nanoparticles prepared by thermal decomposition. The structural characterization, carried out by using
several techniques (TEM, XRD, XAS) showed all the samples are high crystalline, 5-6 nm spherical NPs
with the cubic spinel structure typical of ferrites. The evolution of lattice parameters with cobalt content
suggests that the material is Co-substituted maghemite, also confirmed by XAS and Magneto optical
spectroscopy. The investigation of the magnetic and magneto-optical properties displays peculiar trends
with the cobalt content, the main features being the large increase of the saturation magnetization andthe anomalous dependence of magnetic anisotropy which reaches its maximum values for intermediate
compositions. The large tuneability of this material makes it possible to implement the performances ofdevices used in biomedical and sensing applications.

BJ05

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CB05

Electrical and magnetic properties of nickel and magnesium cosubstituted lithium ferrites

Discovery of fermi surface near anti-node in pseudogap phase of the under-doped Bi-2212

Air-stable Fe@Au nanoparticles synthesized by the microemulsion’s method

Novel technique for self assembly of magnetic nanoparticles by cluster
beam deposition

Ramesh M.1, Rao G.s.n.2, Parvatheeswara Rao B.1* and Samatha K.1
1
Physics Department, Andhra University, India
2
Physics Department, Dr. V.S. Krishna College, Visakhapatnam, India

Lithium ferrites are widely used in electronics and telecommunication applications owing to their
low dielectric loss, high resistivity coupled with good magnetic properties. There is a need to further
improve their performance by incorporating different cationic substitutions for microwave device
applications [1,2]. Most of the reports in the literature focused only on single ion substitutions forenhancement of one property at the cost of other. However, only a scanty research work has beenreported so far on cationic co-substitutions in these ferrites. It is therefore interesting to study andfind out the influence of co-substitution of nickel and magnesium in place of lithum and iron inlithium ferrites. For this purpose, Li0.5-xNixMgxFe2.5-xO4 where x = 0.00 to 0.25 in steps of 0.05,
are prepared by conventional ceramic method. Structural, magnetic, resistivity and dielectricmeasurements have been carried out on all the samples. Lattice parameter has been observed toincrease with the concentration where as Curie temperature, grain size and initial permeability
gradually decreased. High resistivity and low dielectric loss apart from reasonable magnetization
and Curie temperature are obtained at concentrations. The results are explained on the basis ofcation influences on the electromagnetic properties at different crystallographic sites.
[1] X. Qi, J. Zhou, Z. Yue, Z. Gui, and L. Li, Mater. Sci. Eng., B 99, 278, 2003. [2] K. U. Kang, S. W. Hyun, and C. S.
Kim, J. Appl. Phys. 99, 08M917,2006. Authors & Affliations: M. Ramesh1, G.S.N.Rao2, B. Parvatheeswara Rao1 andK. Samatha1 1Department of Physics, Andhra University, Visakhapatnam-530003, India 2Dr. V.S. Krishna College,
Visakhapatnam, India.

The 19th International Conference on Magnetism

Chung Koo Kim1, Jhinhwan Lee2, Kazuhiro Fujita3, Hiroshi Eisaki4, Shinichi Uchida5, J. C. Seamus
Davis6 and Jinho Lee7*
1
BNL/Cornell, USA
2
KAIST, Korea
3
Cornell, USA
4
AIST, Japan
5
Tokyo U., Japan
6
Cornell/BNL, USA
7
BNL/SNU, Korea

Quasi-Particle Interference (QPI) measured by spectroscopic-imaging scanning tunneling microscope (SI-STM)
became an extremely useful tool in the study of correlated electron systems (CES). Particle-hole (p-h) symmetric
QPI observed in the superconducting cuprates revealed many interesting phenomena including the disappearanceof the QPI signal around the reduced zone boundary [1]. Recently, the most dominating band of Sr3Ru2O7 was
identified[2] and p-h asymmetric QPI in the parent compound of the ferro-pnictide superconductor revealed anematic like features [3]. On the other hand, identification of the exact Fermi surface (FS) topology in “pseudogap”(PG) phase of the cuprate superconductors is one of the central issues of the modern condensed matter physics.
ARPES data indicates “Fermi arc” develops in PG phase while quantum oscillation (QO) results show evidence ofthe electron pockets. To resolve this PG mystery, we investigated deeply under-doped Bi2Sr2CaCu2O8+δ above andbelow Tc using SI-STM and found that there is a QPI showing continuous, p-h asymmetric dispersion through EF
above Tc which originates from anti-nodal FS which is disconnected from the nodal FS. This observation implies
existence of Fermi surface with very low quasiparticle(QP) weight Zk in anti-node in PG phase. We also try to
explain nodal anti-nodal dichotomy in terms of Zk.
[1] Y. Kohsaka et al., Nature 454, 1072 (2008) [2] Jinho Lee et al., Nature Physics 5, 800 (2009) [3] T. -M. Chuang et al., Science 327, 181 (2010)

J. Rivas1*, E. Iglesias-silva2, J. M. Vilas-vilela3, L. M. Leon3 and M. A. Lopez-quintela4
1
INL-International Iberian Nanotechnology Laboratory; University of Santiago de Compostela, Spain
2
Universtiy of Santiago de Compostela; University of the Basque Country, Spain
3
University of the Basque Country, Spain
4
University of Santiago de Compostela, Spain

Magnetic particles covered by gold are very important in many biological applications. However, there
are not simple methods to produce small (< 5-10nm) nanoparticles. One of the main reasons for that is thegeneral use of iron oxides as magnetic cores, which have a large crystalline mismatch with gold. The use of
Fe would be more appropriate, but its high tendency to oxidation has largely precluded it from being used
as a core. Here, we will show that using a simple “one-pot” successive reaction method in microemulsions,can avoid such problems and is able to produce very stable core-shell Fe@Au nanoparticles. By thissuccessive “one-pot” procedure, nanoparticles of ~ 6 nm with an Fe core of 1.5 nm can easily be obtained.
These Fe@Au nanoparticles, with a saturation magnetization of 1.7 emu/g, are very stable even in air aftermagnetic separation from the solution, which shows the good covering of the Fe core by the Au shell. In
this contribution we will report the key parameters, which have to be taken into account, to prepare suchstable Fe@Au dispersions and analyze their optical and magnetic properties, as well as their possible
applications as biosensors, targeted magnetic separation, etc.
1. J. Rivas, A. J. Garcia-Bastida, M. A. Lopez-Quintela and C. Ramos. “Magnetic properties of Co/Ag
core/shell nanoparticles prepared by successive reactions in microemulsions”. J.Magn.Magn.Mat. 2006,
300, 185-191. 2. J.Vidal Vidal, J. Rivas, M.A. Lopez-Quintela. “Synthesis of monodisperse maghemite
nanoparticles by the microemulsion method”. Colloids and Surfaces A, 2006, 288, 44-51.

Oral Tuesday

Oral Tuesday

Nastiti Elwindari, Hinu Pramuji and Azwar Manaf*
Departement of Physics, Faculty of Natural Sciences Universitas Indonesia, Indonesia

48

oRAL PRSENTATION

Ozan Akdogan1*, Wanfeng Li2, George Hadjipanayis2 and David Sellmyer3
1
University of Delaware, USA
2
Physics and Astronomy, University of Delaware, USA
3
Physics and Astronomy, University of Nebraska, USA

Mono-layer dispersion and self-assembly of nanoparticles are of a key importance in many fields of science andindustry. In chemical synthesis [1] and recent high-energy ball milling studies [2] self assembled nanoparticles
have been obtained by the aid of surfactants and wet processing. Another promising technique for nanoparticle
production is cluster beam deposition which provides excellent material purity. However, it lacks the ability
to form nanoparticles in the self-assembled array form. In recent studies, particles have been deposited ontopoly(vinyl alcohol) [3] and phospholipid [4] coated substrates to form arrays. Nevertheless, these coatings either
lack the continuous array formation or need time consuming coating steps and post deposition treatments. In thisstudy, we have chosen Oleic Acid (OA) as a cost effective and easier alternative to the above mentioned coatings.
SmCo5 nanoparticles have been deposited for 10 sec. at 25 W sputtering power onto both bare and OA-coatedsingle crystalline Si substrates for comparison. Mono dispersed particles with self-assembly formation havebeen observed on OA coated substrates while a non-uniform distribution has been observed on bare substrates.
Such dispersion can reduce the exchange interactions between the nanoparticles which is expected to effect thecoercivity of the nanoparticles.
[1] S. Sun, C.B. Murray, D. Weller, L. Folks and A. Moser, Science 287, 1989 (2000) [2] N. G. Akdogan, G. C. Hadjipanayis and D. J. Sellmyer,
Nanotechnology 21, 295705 (2010). [3] J. Wang, J. Qiu , T. A. Taton and B. Kim, IEEE Trans. Magn. 42, 3042 (2006). [4] A. Terheiden, C.
Mayer, K. Moh, B. Stahlmecke, S. Stappert, M. Acet and B. Rellinghaus, Appl. Phys. Lett. 84, 3891(2004).

July 8-13, 2012 Busan, Korea

49

ORAL PRESENTATION
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Magnetricity and magnetic monopoles in spin ice

Nonstationary processes in the spin-ice materials Dy 2Ti 2O 7 andHo2Ti2O7 investigated by ultrasoundAnomalous metals with strong valence / orbital fluctuations

Self-modulation in perpendicular anisotropy Co/Ni based spin-torqueoscillators

Oral Tuesday

The analogy between spin configurations in spin ice materials like Ho2Ti2O7 andproton configurations in water ice, H2O, has been appreciated for many years (seeRef. [1] for a review). However it is only in the last few years that this equivalence
has been extended into the realm of electrodynamics [2]. In this talk I shall describe
our recent experimental work that identifies emergent magnetic charges ('monopoles'),transient magnetic currents ('magnetricity') and the universal properties expected of an
ideal magnetic Coulomb gas (magnetic electrolyte - 'magnetolyte'). These universal
properties include the Onsager-Wien effect, 'corresponding states' behaviour, DebyeHuckel screening and Bjerrum pairing [4-6]. I will describe experimental results forboth traditional spin ice materials (Ho2Ti2O7, Dy2Ti2O7) and a recently discovered
system (Dy2Ge2O7).
[1] Bramwell and Gingras, Science, 294 1495 2001 [2] Ryzhkin, JETP 101 481 (2005); Castelnovo
et al., Nature 451 42 (2008) [4] Bramwell et al. Nature 461 956 (2009) [5] Fennell et al., &Bramwell Science 326 415 (2009) [6] Giblin, Bramwell et al., Nature Physics 7 252 (2011) [7]Zhou, Bramwell et al., Nat Comm. 478, 1483 (2011)

S. Zherlitsyn1*, S. Erfanifam1, J. Wosnitza1, R. Moessner2, O. A. Petrenko3, G.
Balakrishnan3 and A. A. Zvyagin4
1
Hochfeld-Magnetlabor Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Germany
2
Max-Planck Institut fuer Physik komplexer Systeme, Germany
3
Department of Physics, University of Warwick, United Kingdom
4
B. I. Verkin Institute for Low Temperature Physics and Engineering, Ukraine

We report on a low-temperature comparative study of two spin-ice materials, Dy2Ti2O7 andHo2Ti2O7, by use of longitudinal and transverse ultrasound waves. In both materials the soundvelocity and the sound attenuation exhibit a number of anomalies versus applied magnetic field
for temperatures below the freezing temperature. The anomalies show a broad hysteresis with avery clear signature of the transition to the saturated state for magnetic fields applied along the[111] direction. Additionally, in Dy2Ti2O7 the sound velocity and the sound attenuation exhibit
a number of well-defined spikes which are highly asymmetric due to the fundamentally distinct
nonequilibrium mechanisms involved: the release of the Zeeman energy from the spins andthe transfer of energy out of the sample [1]. In case of Ho2Ti2O7, both acoustic characteristics
demonstrate much smoother anomalies. We discuss some possible reasons for the observed
differences in the ultrasound features of these spin-ice materials.

Satoru Nakatsuji, Yosuke Matsumoto, Kentaro Kuga, Eoin T. C. O' Farrell and Akito Sakai
Institute for Solid State Physics, University of Tokyo, Japan
In strongly correlated electron systems, quantum criticality normally emerges on the borderof magnetism accompanied by critical spin fluctuations. In particular for the 4f based heavy
fermions, it has been discussed using Doniach type picture based on the Kondo lattice withinteger valence. Here we discuss unconventional type of quantum criticality and anomalous
metallic phases found with strong valence and orbital fluctuations. The first material is theYb based heavy fermion superconductor β-YbAlB4 [1]. Interestingly, this exhibits a zero field
quantum criticality without tuning as the first example in a metal [2]. Doping and pressure
effects indicate no magnetic phase in the immediate vicinity of the ambient pressure quantum
criticality. The instability associated with electronic structure or valence may be the originof the novel quantum criticality. Secondly, we discuss the anomalous metallic phase foundin the Pr based cubic compounds PrTr2Al20 (Tr: transition metal) [3]. These allow us to study
the competition between the strong hybridization effects and quadrupolar ordering. Orbital
fluctuations under strong hybridization with conduction electrons suppresses orbital orderingand lead to prominent non-Fermi liquid behavior, suggesting the possibility of a nonmagnetic
type of Kondo effect.

Johan Akerman
Physics Department, University of Gothenburg, Sweden

Nano-contact spin-torque oscillators (NC-STO) are nanoscale microwave signal
generators based on the transfer of spin angular momentum from a spin polarized
current to the local magnetization of a thin magnetic layer. While standard, NiFe based,
NC-STOs require large external fields of about 1 T for operation, we here present lowfield operation of Co/Ni based NC-STOs comprising a 50-300 nm diameter nanocontact on top of a Co8nm(IP)/Cu8nm/Co0.3nm-[Ni0.8nm/Co0.4nm]×4(PMA)
orthogonal spin valve. Frequencies above 12 GHz are observed for close to zero-field(0.02 T) operation, which further increase up to 24 GHz in moderate fields of 0.4 T [1].
When the applied is further increased, we find a discontinuity in STO frequency around0.68 T. The STO frequency drops by almost 10 GHz and at the same time sidebands
appear with the main STO signal. These sidebands indicate a self-modulation of themain high-frequency mode with a low-frequency (~1 to 2 GHz) oscillatory mode. We
interpret this transition as the formation of a magnetic bubble underneath the NC. The
low-frequency magnetodynamics of the bubble then modulates the NC-STO precession
frequency.

[1]. S. Erfanifam, S. Zherlitsyn, J. Wosnitza, R. Moessner, O. A. Petrenko, G. Balakrishnan, and A. A.
Zvyagin, Phys. Rev. B 84, 220404(R) (2011).

[1] S. Nakatsuji, K. Kuga, Y. Machida, T. Tayama, T. Sakakibara, Y. Karaki, H. Ishimoto, S. Yonezawa, Y. Maeno,
E. Pearson, G. G. Lonzarich, L. Balicas, H. Lee, and Z. Fisk, Nature Physics 4, 603 (2008). [2] Y. Matsumoto, S.
Nakatsuji, K. Kuga, Y. Karaki, N. Horie, Y. Shimura, T. Sakakibara, A. H. Nevidomskyy, and P. Coleman, Science 331,
316 (2011). [3] A. Sakai and S. Nakatsuji, Journal of the Physical Society of Japan, Letter 80, 063701 (2011). Editor’s
Choice

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Recent developments in quantum spin liquid candidates

Study of low-temperature magnetism in a pr-based pyrochlore magnet

Ce-based iron-pnictides: Intermediate valence and heavy-fermion
behavior versus magnetism and superconductivity

Magnetization tilt angles in [Pd/Co]/Cu/[Co/Pd]-NiFe pseudo spin
valvesLuis Balicas*
Condensed Matter Sciences, NHMFL, USA

We discuss a few geometrically frustrated magnetic systems exhibiting ground states
characterized by correlated spin excitations. The first system, Pr2Ir2O7 is a metallic pyrochlore,
which does not exhibit a spin-ice ground state but a state which is claimed to be a chiralspin-liquid where the interaction between the Pr moments and the itinerant Ir carriers leads
to an anomalous Hall-effect (AHE), which remains finite even in the absence of an external
magnetic field and of long range magnetic order 1. We show that this spontaneous AHE ishysteretic and anisotropic depending strongly on the previous application of an external fieldalong specific crystallographic directions 2. We will argue that our observations suggest thepossibility that Dirac monopole and antimonopole pairs are deconfined acquiring a finite
quantum-mechanical average in the zero-field state of Pr2Ir2O7. Finally, we briefly discussand compare two new triangular lattice systems 4,5, Ba3CuSb2O9 and Ba3NiSb2O9 having
S=1/2 and S=1 moments respectively, which despite their insulating character, exhibit large
electronic specific heat coefficients of 43.4 and 168 mJ/molK2, respectively. This can beunderstood if the spin excitations behave as coherent fermionic (or charge-like) excitations
which in these systems form a Fermi surface at low temperatures.

Kenta Kimura1*, Satoru Nakatsuji1, Agung Nugroho2, Yoshitomo Karaki3, Kazuyuki
Matsuhira4, Yasuyuki Shimura1 and Toshiro Sakakibara1
1
ISSP, Univ. of Tokyo, Japan
2
Bandung Inst. Tech, Indonesia
3
Ryukyu Univ., Japan
4
Kyusyu Inst. Tech., JapanPr-based pyrochlore magnets have been recognized as a fascinating venue to search
unconventional magnetism as a result of frustration and quantum effects. For example,
Pr2Ir2O7 exhibits a novel spin liquid state, which has the “2-in, 2-out” short-range
correlation, the same as a spin ice system, and simultaneously breaks time reversal
symmetry [1, 2]. Here we report the detailed physical properties of single crystals of
the related insulating compound Pr2Zr2O7. Magnetic susceptibility fits to the CurieWeiss law below 10 K, yielding the effective moment of 2.5μB and Weiss temperatureof -0.4 K, consistent with the previous powder results [3]. Furthermore, magnetization
measurement at very low temperature confirmed a magnetic anomaly signaling spin ice
correlation. In the presentation, we will discuss the low temperature magnetism basedon the results including specific heat and AC susceptibility measurements.

Matthias Holder1, Denis V. Vyalikh1, Steffen Danzenbacher1, Anton Jesche2, Cornelius Krellner2,
Christoph Geibel2, Pierre Lombardo3, Roland Hayn3, Rolf Follath4, Serguei L. Molodtsov5 andClemens Laubschat1*
1
Institut fur Festkorperphysik, Technische Universitat Dresden, D-01062 Dresden, Germany
2
Max-Planck-Institut fur Chemische Physik fester Stoffe, D-01187 Dresden, Germany
3Institut Materiaux, Microelectronique et Nanosciences de Provence, FR-13397 Marsaille, France
4
Helmholtz-Zentrum Berlin, Elektronenspeicherring BESSY II, D-12489 Berlin, Germany
5
European XFEL GmbH, D-22671 Hamburg, Germany

In the last few years layered iron pnictides have attracted considerable interest due to theirsuperconducting properties characterized by critical temperatures, TC, up to 55 K. In Ce-based
compounds of these series superconductivity competes with heavy Fermion behavior, spin
density wave formation and magnetic order. High-resolution angle-resolved photoemission
allows for direct insight into the correlated electronic structure of these systems. We showthat the dispersion of Fe-3d derived bands close to the Fermi energy is strongly modified byhybridization with localized Ce 4f states what affects possible participation of these bands inother many-body interactions. Spectral 4f signatures as probed by resonant photoemission
consist on a weakly dispersive peak just at the Fermi energy (in addition to an ionization peakat about 2 eV binding energy) and admixtures to the valence bands. The spectroscopic data
are discussed in the light of band-structure calculations and a novel approach to the periodic
Anderson model.

[1] High frequency operation of a spin-torque oscillator at low field. S. M. Mohseni, S. R. Sani, J.
Persson, T. N. Anh Nguyen, S. Chung, Ye. Pogoryelov and Johan Akerman, Phys. Status Solidi RRL,
5, 432 (2011).

Anh T. N Nguyen1, Sunjea Chung1, S. M. Mohseni1, R. K. Dumas2 and Johan
Akerman2*
1
Materials Physics, KTH, Royal Institute of Technology, Sweden
2
Department of Physics, University of Gothenburg, 412 96 Gothenburg, Sweden
Future spintronic devices based on spin-transfer torque require a delicate engineering of theconstituent magnetic layers. A fixed layer magnetization that is tilted out of the plane allows
for zero-field operation, as well as increased output efficiency and quality, e.g. linewidth.
We recently proposed a [Co/Pd]-NiFe exchange spring for use as a spin polarizing layer
with a tilted magnetization for applications in spin torque oscillators (STOs) [1]. We haveshown that it is possible to easily tune the spin configuration by engineering the effective
exchange coupling between a NiFe layer with in-plane anisotropy and [Co/Pd] multilayer
with perpendicular anisotropy. Here, we report on magnetization tilt angles in complete [Pd/Co]/Cu/[Co/Pd]-NiFe(tNiFe) pseudo spin valves (PSVs) using angular dependent transportmeasurements. The tilt angle of the [Co/Pd]-NiFe is deduced from the angular dependenceof the effective switching fields. As tNiFe is increased, the tilt angle of the [Co/Pd]-NiFe
increases. These results provide a first observation of the tilt angle in a PSVs structure,
which are similarly used in real STOs. This work provides meaningful insights for the
future realization and optimization of tilted STO devices.

In collaboration with S. Nakatsuji (ISSP-Tokyo) and H. D. Zhou (NHMFL - Tallahassee) 1. Y. Machida et al., Nature
463, 210 (2010). 2. L. Balicas et al., Phys. Rev. Lett. 106, 217204 (2011). 3. H. D. Zhou, E. S. Choi, G. Li, L. Balicas, C. R.
Wiebe, Y. Qiu, J. R. D. Copley, and J. S. Gardner Phys. Rev. Lett. 106, 147204 (2011). 4. J. G. Cheng, G. Li, L. Balicas,
J. S. Zhou, J. B. Goodenough, Cenke Xu, and H. D. Zhou, Phys. Rev. Lett. 107, 197204 (2011).

[1] S. Nakatsuji et al., PRL. 96, 087204 (2006). [2] Y. Machida et al., Nature 463, 210 (2010). [3] K.
Matsuhira et al., J. Phys.: Conference Series 145 (2009) 012031

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Static and dynamic properties of a strong-leg spin ladder

A materials-based global phase diagram for heavy-fermion quantum
criticality

Observation of the quantum critical point in CeRhSi3 with the muon
spin rotation technique

Temperature dependence of microwave voltage emission associated tospin-transfer induced vortex oscillations in magnetic tunnel junctions

David Jan Schmidiger1, Pierre Bouillot2, Sebastian Muhlbauer1, Severian Gvasaliya1, Georg Ehlers3, Corinna
Kollath4, Thierry Giamarchi2 and Andrey Zheludev1*
1
Neutron Scattering and Magnetism, Laboratory for Solid State Physics, ETH Zurich, Switzerland
2
DPMC-MaNEP, University of Geneva, CH-1211, Geneva, Switzerland
3
Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6475, USA
4
DPT-MaNEP, University of Geneva, CH-1211, Geneva, Switzerland

S. Paschen1*, J. Custers1, J. Larrea J.1, K. - A. Lorenzer1, M. Mueller1, A. Prokofiev1, A. Sidorenko1, H.
Winkler1, A. M. Strydom2, Y. Shimura3, T. Sakakibara3, R. Yu4 and Q. Si4
1
Institute of Solid State Physics, Vienna University of Technology, Austria
2
Physics Department, University of Johannesburg, South Africa
3Institute for Solid State Physics, University of Tokyo, Japan
4
Department of Physics and Astronomy, Rice University, USA

Static and dynamic properties of the strong-leg S=1/2 Heisenberg spin ladder system (C7H10N)2CuBr4
are studied using inelastic neutron scattering and bulk magneto-thermodynamic measurements. The
leg-odd excitation channel is dominated by long-lived single-magnon states in the entire Brillouinzone, which supports a symmetric ladder model with exchange constants J_leg = 1.42(6) meV
and J_rung = 0.82(2) meV [1,2]. In the leg-even channel, a considerable fraction of the spectral
weight is contained in a novel long-lived two-magnon bound state [2]. In applied magnetic fields
we observe a Bose-Einstein condensation of magnons that manifests itself in 3D long-range
antiferromagnetic ordering emerging beyond H_c = 2.8 T. The field-temperature phase diagram
showing the spin liquid, Tomonaga-Luttinger spin liquid and BEC phase is mapped out by specificheat measurements. The experimental results are in spectacular agreement with state-of-the art
DMRG calculations [2]. The latter provide additional insight on certain spin ladder properties
specific to the strong-leg regime. This work was partially supported by the Swiss National Fund and
MANEP.

Heavy fermion compounds have in recent years emerged as prototypical quantum critical systems. Studies in
the anisotropic heavy-fermion compound YbRh2Si2 have shown that different types of quantum critical points(QCPs) are induced by variations of the magnetic field, chemical or external pressure, raising the question of
the extent to which heavy-fermion quantum criticality is universal. We have identified a cubic heavy-fermion
material, Ce3Pd20Si6, as exhibiting a field-induced quantum phase transition as the lower of two consecutive
phase transitions is suppressed to zero. Thus, here the QCP separates two different ordered phases. This transitionis accompanied by an abrupt change of Fermi surface, reminiscent of what happens across the field-induced
antiferromagnetic to paramagnetic transition in YbRh2Si2. From these results we have proposed a materialsbased global phase diagram that points to the importance of dimensionality - and may serve as guide in the search
for a unified theoretical description [1]. To weaken the lower phase transition temperature and possibly detach
the Kondo destruction scale from the phase transition scale, we are now studying (Ce,La)3Pd20Si6 and Ce3Pd20Si6
under hydrostatic pressure. We acknowledge financial support from the European Research Council (ERC
Advanced Grant No 227378).

[1] D. Schmidiger, S. Muhlbauer, S. Gvasaliya, T. Yankova, A. Zheludev, Phys. Rev. B 84, 144421 (2011) [2] D.
Schmidiger, P. Bouillot, S. Muhlbauer, S. Gvasaliya, C. Kollath, T. Giamarchi, A. Zheludev, arXiv:1112.4307 (2011)[1] J. Custers, K.-A. Lorenzer, M. Muller, A. Prokofiev, A. Sidorenko, H. Winkler, A. M. Strydom, Y. Shimura, T.
Sakakibara, R. Yu, Q. Si, and S. Paschen, Nature Materials, doi:10.1038/nmat3214.

The 19th International Conference on Magnetism

Nikola Egetenmeyer1*, Jorge L. Gavilano1, Alexander Maisuradze2, Alexander Maisuradze3, Simon
Gerber1, Michel Kenzelmann4, Gabriel Seyfarth5, Daniel Andreica6, Alexandre Desilets-benoit7, Andrea D.
Bianchi7, Christopher Baines2, Rustem Khasanov2 and Douglas E. Maclaughlin8
1
Laboratory for Neutron Scattering, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
2
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
3
Physik-Institut, Universitat Zurich, 8057 Zurich, Switzerland
4
Laboratory for Developments and Methods, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
5
Departement de physique de la matiere condensee, Universite de Geneve, 1211 Geneva, Switzerland
6
Faculty of Physics, Babes-Bolyai University, 400084 Cluj-Napoca, Romania
7
Departement de Physique, Univerisite de Montreal, Montreal H3C 3J7, Canada
8
Department of Physics and Astronomy, University of California, Riverside, USA

The interplay of superconductivity and magnetism has been a central issue of research for many years. A
variety of these systems have been found to display a so-called quantum critical point which marks thetransition point between a nonmagnetic and a magnetic metal phase. The external tuning parameter canbe doping, an external magnetic field or external pressure. We conducted a muon spin rotation study on
the heavy fermion and noncentrosymmetric compound CeRhSi3 which is an antiferromagnet at ambientpressure and displays superconductivity at high pressure. In this system, we were able to unravel thequantum critical point hidden inside of the pressure-induced superconducting phase of the pressuretemperature phase diagram. We directly observed the continuous suppression of the internal fields, andthus the magnetic moments at the critical pressure p* = 23.6 kbar. Simultaneously the Neel temperaturegoes to zero and we conjecture a spin density wave type quantum critical point.

Oral Tuesday

Steven Bramwell
London Centre for Nanotechnology and DepartMent of Physics and Astronomy,
University College London, United Kingdom

50

oRAL PRSENTATION[1] T. N. Anh Nguyen, , Y. Fang, V. Fallahi, N. Benatmane, S. M. Mohseni, R.K. Dumas, and Johan
Akerman, Appl. Phys. Lett. 98, 172502 (2011)

Paolo Bortolotti1*, A. Dussaux1, J. Grollier1, V. Cros1, A. Fukushima2, H. Kubota2, K. Yakushiji2, S.
Yuasa2, K. Ando2 and A. Fert1
1
Unite Mixte de Physique CNRS/Thales, France
2
National Institute of Advanced Industrial Science and Technology (AIST), JapanThe growing market of telecommunication applications demands reduction of energy consumptions anddevices miniaturization. Spin transfer-torque nanoscillators (STO) can fulfill such necessities and, given
their rapidly improving characteristics, will might be able to replace conventional oscillators. In the past,their drawbacks were the low emitted power and large linewidth. We recently proved[1,2] that these issues
can be overcome by considering a MgO-based magnetic tunnel junction[3,4] with a vortex free layer, i.e.,
spin transfer-torque vortex nano-oscillator (STVO). The obtained signal has large output power (>50 nW)
and small linewidth (<1 MHz). In order to further optimize its characteristics, we have to understand themechanisms underlying the linewidth generation. Thus, we consider the effect of temperature on such
STVO by ranging T from 20 to 300 K. We first observe a linear decrease of the linewidth with decreasing
temperature and a bottom limit of the linewidth (700 kHz) at lower temperature[5]. Thermal effects
and spin torque non-linearities are not sufficient to explain such behaviour and one additional source ofphase noise should be considered. To clarify the origin of such phase noise, frequency and time-domain
measurements are compared. Support from ANR VOICE PNANO-09_P231-36, EU MASTER NMPFP7-212257, CANON-ANELVA for MTJ film are acknowledged.
[1] A. Dussaux et al., Nat. Comm. 1 1 (2010) [2] A.V. Khvalkovskiy et al., Phys. Rev. B 80 140401(R) (2009) [3] A.M.
Deac et al., Nat. Phys. 4 803 (2008) [4] D. Houssamedine et al., Appl. Phys. Lett. 93 022505 (2008) [5] P. Bortolotti etal., Appl. Phys. Lett. 100 042408 (2012)

July 8-13, 2012 Busan, Korea

51

ORAL PRESENTATION
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Zero external-field microwave oscillations in MgO magnetic tunnel
junctions

Spin-orbital short-range order on a honeycomb based lattice

Effect of R ion size variance on spin and orbital order in RVO3 (R=rare
earth and Y)

Spin accumulation and decoherence mechanisms at ferromagnetic/
tunnel barrier/semiconductor interfaces

We report a potential solution to overcome major challenges for the implementation ofspin transfer nano-oscillators (STNOs) in real microwave applications, namely a weakoutput power and broad spectral linewidth of STNO microwave signals. In addition
to the challenges, an external magnetic field is often required for the microwave
generation from STNOs. We have observed high-power microwave oscillations having
a narrow linewidth, even without applying external magnetic fields, from STNOs basedon MgO magnetic tunnel junctions (MTJs). The MTJs consist of SiO2 substrate/ buffer
layer/ synthetic antiferromagnet/ Co60Fe20B20 (5)/ MgO (1)/ Co60Fe20B20 (2)/ capping
layer (in nm). A typical STNO has a resistance of 45 Ohm in the parallel state and 75
Ohm in the antiparallel state, showing a tunnel magnetoresistance of 67%. The STNO
exhibits an oscillation peak of 70 nV/Hz½ at 3 GHz at zero external magnetic field,
and the full width at half maximum of the peak is less than 60 MHz. The microwave
spectra as a function of bias current and in-plane external magnetic field (Hext) will be
discussed in detail.

C. Broholm1*, S. Nakatsuji2, H. Sawa3, M. Hagiwara4 and F. Bridges5
1
Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins
University, USA
2
Institute for Solid State Physics, University of Tokyo, Japan3
Department of Applied Physics, Graduate School of Engineering Nagoya University, Japan
4
KYOKUGEN, Osaka University, Japan5
Physics Department, University of California, Santa Cruz, USA
Strong antiferromagnetic interactions indicated by ΘCW=-47 K, fail to produce static spincorrelations above T=0.1 K in Ba3CuSb2O9. Magnetic neutron scattering at T=1.5 K is inelastic witha broad peak at 5.5 meV that shifts to higher energies upon warming and wave vector dependence
indicating near neighbor singlet formation. While these features are difficult to reconcile withthe previously inferred triangular lattice structure, short-range correlations of CuSbO9 dumbbells
resulting from structural frustration as revealed by synchrotron x-ray diffraction and EXAFS
provides the essential lead. The resulting magnetic sub-lattice forms a nano-structured honeycomb
lattice with nearest neighbor interactions. Based on the new structure we propose the unusual
magnetic properties and the absence of a coherent, static Jahn-Teller transition indicate a twodimensional random singlet phase or a spin-orbital quantum liquid.
* This work is partially supported by Grant-in-Aid for Scientific Research from JSPS (No. 20340089, 21684019) and from
MEXT on Priority Areas (No. 19051010, 19052003), by Global COE Programs “the Physical Sciences Frontier” and “CoreResearch and Engineering of Advanced Materials” MEXT, Japan, by a Toray Science and Technology Grant and by the
US- Japan Cooperative Program, ISSP. Work at IQM was supported by DoE, Office of Basic Energy Sciences, Division ofMaterials Sciences and Engineering under Award DE-FG02-08ER46544.

S. Miyasaka1*, R. Fukuta1, K. Hemmi1, N. Sasaki1, S. Tajima1, D. Kawana2, K. Ikeuchi2, Y.
Yamasaki2, A. Nakao2, H. Nakao2, R. Kumai2, Y. Murakami2 and K. Iwasa3
1
Department of Physics, Osaka University, Japan
2
KEK-PF/CMRC, Japan3
Department of Physics, Tohoku University, Japan
Perovskite RVO3 has orbital degrees of freedom between dyz and dzx orbitals in V3+ ions,and shows two types of spin/orbital order (SO/OO): C-type SO (C-SO)/G-type OO (G-OO),
and G-SO/C-OO. In this system, the transition temperature of each SO/OO depends on the
R-site ionic radius1 and structural randomness caused by the size mismatch of R ions2. We
have investigated the single crystals of Y1-x(La0.195Lu0.805)xVO3, Eu1-x(La0.2542Y0.7458)xVO3, Sm1x(La0.322Y0.678)xVO3, and Nd1-x(La0.491Y0.509)xVO3 in order to clarify the effect of R ion size
variance on SO/OO in RVO3. In the present systems, the average ionic radius of R-site isconstant, while the size variance of R ion is proportional to x. In R=Y1-x(La0.195Lu0.805)x, Eu1x(La0.2542Y0.7458)x, and Sm1-x(La0.322Y0.678)x systems, the R ion size variance suppresses C-SO/
G-OO, while it stabilizes the other SO/OO. By the neutron and resonant X-ray scattering
measurements, other order is confirmed as G-SO/C-OO. In Nd1-x(La0.491Y0.509)xVO3 with larger
R-site ions, however, C-SO/G-OO is so stable that the R ion size variance cannot induce theother SO/OO.
1 S. Miyasaka et al., Phys. Rev. B 68, 100406(R) (2003). 2 R. Fukuta et al., Phys. Rev. B 84, 140409(R) (2011).

The ability to inject spins into a semiconductor (SC) by electrical means and the possibility to convert a spin
accumulation into an electrical signal is expected to bring new functionalities. However, it has been shown thatthe injection of spin-polarized carriers from a ferromagnetic transition metal (FM) into a SC requires the addition
and the fine tuning of a spin-conserving resistance at the FM/SC interface. Following the work on Co/Al2O3/
GaAs interface [1], we now carry out a systematic study on the enhancement of spin accumulation involving
modification of the interfacial properties by probing several semiconductor materials involving GaAs, Ge and
InP as well as MgO and Al2O3 barriers. Inverted Hanle effect measurements reveals the influence of a fluctuating
magnetic field leading to decoherence of the spin accumulation at the FM/SC interface whose origin resides instray magnetic field due interface roughness [2-3], or in hyperfine interaction in case of transport through localizedstates of GaAs. Both 3-terminal Hanle and Inverted Hanle measurements highlight effects of spin accumulation
at the FM/SC interface, few orders of magnitude larger than the expected. The amplitude of the effects can beunderstood by a sequential injection mechanism through localized interfacial states at the barrier/SC interface.
[1] M. Tran, et al.: Enhancement of the Spin Accumulation at the Interface between a Spin-Polarized Tunnel Junction and a
Semiconductor. Physical Review Letters 102, 3:036601, 2009. [2] S.P. Dash, et al.: Spin precession and decoherence nearan interface with a ferromagnet, Phys. Rev. B 84, 054410 (2011) [3] A. Jain, et al.: Electrical spin injection and detection at
Al2O3/n-type germanium interface using three terminal geometry Appl. Phys. Lett. 99, 162102 (2011)

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NCMR based spin-torque microwave generator and detector with highsignal purity

Quadrupolar waves in uranium dioxide

Spin Hall effects in n-GaAs near the metal-insulator transition

Electrical spin accumulation and detection in Fe 3O 4/MgO/GaAs
systems

Yuuki Kozono1*, Yoshihito Okutomi1, Kohsaku Miyake1, Susumu Hashimoto2, Hitoshi Iwasaki2 andMasashi Sahashi1
1Department of Electronic Engineering, Tohoku University, Japan
2
Corporate Research and Development Center, Toshiba Corporation, Japan
Nano-contacts magnetoresistive (NCMR) devices have many ferromagnetic ohmic nano-contacts (NCs) withthe diameter of around 1nm, which connect the free and reference layer in the spacer layer called nano-oxide
layer (NOL). In each NC, the domain wall is geometrically confined and produces the magnetoresistance byspin accumulation [1] and miss-tracking effect [2]. Furthermore, in injecting current, these NCs can increase thedensity of current and provide the high emission power with narrow linewidth. In this study, we systematicallyinvestigated the spin-transfer induced microwave oscillation [3], unique frequency modulation characteristics[4] and spin-torque ferromagnetic resonance (ST-FMR) [5] for the NCMR devices with thick free-layer with the
thickness of ~15nm. In the microwave measurement, the high emission power (up to 100nW) with the narrow
linewidth (down to 6.5MHz) was excited at the frequency of around 1GHz caused by auto-oscillation at multidomain state, which is the intermediate state between parallel and antiparallel state. In the same magnetic state,
ST-FMR signal also showed high sensitivity of ~250µV/100μW at almost same frequency as dc current induced
microwave oscillation. As a result, we confirmed that NCMR device has the possibility to become the nano-sized
microwave generator and detector.

Paolo Santini
University of Parma, Italy

In solids with d- and f-electrons, under certain conditions the orbitals align to form anordered pattern. Collective excitations breaking this arrangement can take the formof oscillations of electric quadrupoles, so-called quadrupolar waves. These represent
a propagating pattern of charge densities implying a modulation of quadrupolar
moments. We show that quadrupolar waves constitute a major component of the
dynamics of uranium dioxide in its magneto-quadrupolar ordered phase [1,2]. The
distinct roles of Jahn-Teller and superexchange mechanisms as sources of quadrupolarinteractions are identified. The theory is fully consistent with earlier and recent [3]inelastic neutron scattering data.
[1] P. Santini et al., Rev. Mod. Phys. 81, 807 (2009) [2] S. Carretta, P. Santini, R. Caciuffo, G. Amoretti, Phys.
Rev. Lett. 105, 167201 (2010) [3] R. Caciuffo, P. Santini, S. Carretta, G. Amoretti, A. Hiess, N. Magnani, L.-P.
Regnault, G. H. Lander, Phys. Rev. B 84, 104409 (2011)

Paul A Crowell
School of Physics and Astronomy, University of Minnesota, USA

We have measured the direct and inverse spin Hall effects in GaAs and InxGa1-xAs
in samples doped near the metal-insulator transition. The direct spin Hall effect ismeasured through the spin accumulation induced at the edges of the semiconductor
channel in the presence of a charge current. The inverse spin Hall effect is measured asa Hall voltage induced by injection of a spin current. We find that the magnitude andtemperature dependence of the direct spin Hall effect is consistent with simple models
for spin-orbit scattering from ionized impurities. The inverse spin Hall effect shows
both an anomalously large magnitude and an unusual magnetic field dependence,suggesting that hyperfine interactions play an important role. I will review this workwith an emphasis on our attempts to understand spin transport in GaAs near the metalinsulator transition.
This work was carried out in collaboration with C. Geppert, K. Christie, E. Garlid, Q. Hu, S. Patel,and C. J. Palmstrøm and was supported by the National Science Foundation and the Office of Naval
Research.

Shwetha G. Bhat*, Cijy Mathai and Anil P. S. Kumar
Department of Physics, Indian Institute of Science, Bangalore, India

The Hanle effect is one of the effective and direct methods for studying the spin
injection from a ferromagnet and it is useful for understanding the decay of these
injected spins in the semiconductor [1,2]. We have chosen Fe 3O 4/MgO/GaAs(n-doped) system for our study, where the spin polarized electrons are injected fromFe3O4 (10nm) to GaAs through thin MgO layer (2nm). This is the first ever attempt instudying the spin injection and decay of spins in the above mentioned system. Fe3O4
is a room temperature ferrimagnet which is reported to have 100% spin polarization.
The 3-terminal non local Hanle measurement [3,4] is usually carried out in thesesystems. From our studies, the I-V measurements on the structured junctions of size
varying from 200x150μm² to 200x25μm² exhibit tunnel behavior with no considerable
rectification. The 3-terminal non local measurements on these devices show a clear
indication of the variation of non local voltage ΔV as a function of perpendicularmagnetic field for the biasing current I≥1μA. Also, the Hanle plots show thedependency on the extraction and injection of the bias electrons to the above mentioned
devices accordingly.
[1] M. Johnson et.al, PRL 55, 1790 (1985), [2] M. Johnson et.al, PRB 37, 5326 (1988) [3] M. Tranet.al, PRL 102, 036601 (2009) [4] C. H. Li et.al, Nat. Commun. 2, 245 (2011)[1]J. Sato, K. Matsushita, and H. Imamura, J. Appl. Phys. 105, 07D101(2009) [2]M. Takagishi, H. N. Fuke, S. Hashimoto, H. Iwasaki, S. Kawasaki, R . Shiozaki,
and M. Sahashi J. App. Phys 105 07B725(2009) [3] Y. Okutomi, Y. Kozono, K. Miyake, S. Hashimoto, H. Iwasaki, and M. Sahashi , Appl. Phys. Letters, submitted [4]M. A. Mahdawi, M. Doi, S. Hashimoto, H. N. Fuke, H. Iwasaki, and M. Sahashi, IEEE Trans. Magn. 47, 3380(2011). [5] A. A. Tulapurkar, Y . Suzuki, A.Fukushima,
H.Kubota, Hmaehara, K.Tsunekawa, D. D. Djayaprawira, N. Watanabe, and S.Yuasa , Nature(London)438, 339(2005)

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CG05

Conditions for zero field spin transfer induced vortex oscillations witha perpendicular spin polarizer

Magnon gap formation and charge density wave effect onthermoelectric properties in SmNiC2 compound

The effect of an inhomogeneous interface on the transport properties
across Fe/GaAs(001) films

Spin relaxation in defect-free InGaN/GaN quantum wells

E. Grimaldi1*, A. Dussaux1, B. Salles2, J. Grollier1, A. Fukushima2, H. Kubota2, K. Yakushiji2, S. Yuasa2, V.
Cros1 and A. Fert1
1
Unite Mixte de Physique CNRS/Thales, 1 Av Fresnel, Campus de l’Ecole Polytechnique, 91767
Palaiseau, France
2
National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Japan
Despite the theoretical and experimental progress achieved, power, linewidth and zerofield emission remain critical issues for spin transfer nano-oscillators (STNOs) [1,2] intelecommunication applications. Here we investigate spin transfer induced vortex dynamics
in specific STNOs [SAF / MgO / NiFe (vortex magnetization) / Cu / [Co/Ni] (perpendicularpolarizer)]. Such a hybrid GMR/TMR system has been designed to obtain large amplitude
spin torque induced magnetization oscillations at zero field owing to the perpendicularpolarized spin current. In the best MTJ we measure large emitted power (600 nW) and narrow
linewidth (590 kHz) at zero magnetic field, making these hybrid devices very promising forradiofrequency applications. In addition we investigate in detail the strong impact of vortex
configuration (polarity, chirality) on the frequency and the linewidth of the signal [3]. These
results are analysed in the frame of a nonlinear analytical model for the vortex dynamics[4]. We thank CANON ANELVA for preparing the MTJ films, the ANR VOICE grant and
MASTER grant and E.G. acknowledge financial support from CNES and DGA.
[1] V.S. Pribiag et al., Nat. Phys. 3, 498 (2007) [2] A. Dussaux et al., Nat. Comm. 1, 8 (2010) [3] A. V. Khvalkovskiy et al.,Phys. Rev. B 80, 140401 (R) (2009). [4] A. Dussaux et al., to be published

52

Julian Peiro1, Jean-christophe Lebreton1, Cyrile Deranlot1, Aristide Lemaitre2, Abhinav Jain3, Celine Vergnaud3,
Matthieu Jamet3, Henri Jaffres1 and Jean-marie George1*
1
Unite Mixte de Physique CNRS/Thales, Campus Polytechnique, 1 av. Augustin Fresnel, 91767 Palaiseau,, France
2
CNRS-Laboratoire de Photonique et Nanostructures, route de Nozay, 91460 Marcoussis, France
3
INAC/SP2M, CEA-Universite Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble, France

The 19th International Conference on Magnetism

Oral Tuesday

Jae Hyun Park1, Seung-young Park2, Byoung-chul Min1*, Jung-hwan Moon3, Kyungjin Lee3, Young-hun Jo2 and Kyung-ho Shin1
1
Korea Institute of Science and Technology, Korea
2
Korea Basic Science Institute, Korea
3
Korea University, Korea

Oral Tuesday

oRAL PRSENTATION

Jin-hee Kim1, Gyeong Im Min2, Jong-soo Rhyee1 and Yong Seung Kwon2*
1
Applied Physics, KyungHee University, Korea
2
Physics, Sungkyunkwan University, Korea

We studied the magnetic, electrical, and thermal properties of polycrystalline compoundof SmNiC2. The electrical resistivity and magnetization measurement show theinterplay between the charge density wave at T(CDW) = 157 K and the ferromagnetic
ordering of Tc = 18 K. Below the ferromagnetic transition temperature, we observed
the magnon gap formation of 4.3 ~ 4.4 meV by ρ(T) and Cp(T) measurements. The
charge density wave is attributed to the increase of Seebeck coefficient resulting in
the increase of power factor S2σ. The thermal conductivity anomalously increases withincreasing temperature as the whole measured temperature range which implies the
weak attribution of Umklapp phonon scattering. The thermoelectric figure-of-merit ZT
significantly increases due to the increase of power factor at T(CDW) = 157 K. Here
we argue that the competing interaction between electron-phonon and electron-magnon
couplings exhibits the unconventional behavior of electrical and thermal properties.

Luke Fleet1, K. Yoshida2, H. Kobayashi3, Y. Kaneko3, S. Matsuzaka3, Y. Ohno3, H. Ohno3,
S. Honda4, J. Inoue2 and A. Horihata1*
1
The University of York, United Kingdom
2
Nagoya University, Japan
3
Tohoku University, Japan
4
University of Tsukuba, Japan

Efficient electrical spin-injection is the greatest challenges for semiconductor spintronics. Fe/GaAs
remains one of the leading candidate systems for achieving this feat due to the small lattice mismatch.
We report the first observation of different interface structures in Fe/GaAs(001) films. Both theideal and mixed interfaces were observed leading to a distribution of Schottky barrier properties[1]. Regions with mixing have a lower barrier height creating pin-hole type areas where transport
will be focused, leading to heating. This increases the contribution to the transport from thermionicemission, therefore reducing the spin injection efficiency. Using ab-initio calculations we showthat resonance states form in the minority spin DOS for the mixed interface causing a polarization
inversion. We show it is possible to create well behaved reproducible devices if an abrupt interface iscreated. Transport properties of 3-terminal devices which have a predominantly abrupt interface givespin lifetimes of over 30 ns at 5 K with a spin diffusion length of 16 μm at 10 K. Full details of theinterface structures and transport properties of Fe/GaAs(001) films will be presented in the full paper.
[1] L. R. Fleet et al., IEEE T Magn 47, 2756 (2011).

Animesh Banerjee1*, Fatih Dogan2, Aurelien Manchon2 and Pallab Bhattacharya1
Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor,
MI 48109-2122, USA
2
Division of Physical Science and Engineering, King Abdullah University of Science andTechnology, Thuwal 23955, Saudi Arabia
1

Due to ferromagnetic (FM) properties it presents at room temperature in its n-doped state (withrare-earth metals), and combination of wide-gap and low spin-orbit coupling (SOC), GaN has
been identified as a promising compound for spintronics applications. In this work [1], we
present numerical analysis of spin relaxation time in defect-free two-dimensional In doped
GaN quantum wells grown on GaN nanowires [2]. Data, of wurtzite crystalline structure, hasbeen collected in a range of temperatures, from 100 K to room temperature and at different
doping concentrations and energy levels using photoluminescence techniques. In the analysis,
spin relaxation mechanisms considered are Elliot-Yafet (EY) and D’yakanov-Perel’(DP).
Relative importance and relevance of EY vs. DP mechanism [3] has been investigated. It was
found that EY mechanism is very ineffective while DP mechanism dominates as the source ofspin relaxation. We have also calculated Rashba and Dresselhaus coefficients for each doping
concentrations and shown that increase in doping also changes Rashba and Dresselhaus
coefficients in accordance with accepted values for InN and GaN.
1. A. Banerjee, F. Dogan, A. Manchon, and P. K. Battacharya Nano Lett., 11, 5396-5400 (2011) 2. W.
Guo, M. Zhang, A. Banerjee, and P. Bhattacharya, Nano Lett. 10, 3355-3359 (2010) 3. N. J. Harmon, W. O.
Putikka, and R. Joynt, Appl. Phys. Lett. 98, 073108 (2011)

July 8-13, 2012 Busan, Korea

53

ORAL PRESENTATION
CH01

CH04

CI02

CJ01

Magnetic, magnetotransport and magnetocaloric properties ofquaternary Ni-Mn-In-Z Heusler alloys

Verification of band structure calculations for the Heusler compound
Co2MnGa

Ferroelectricity from magnetic helicity in ferroaxial crystals

Spin excitations and transformation of domain structure innanocrystalline CoFeB-SiO2 films with growth induced anisotropy

We present recent results on structural, magnetic, magnetotransport, and magnetocaloric properties of Ni50Mn35In15xZx (Z=In, Ge, Al, B, Si) and Ni50Mn34.8In15.2-xBx Heusler alloys in the austenitic and martensitic state focusing
on behavior of magnetocaloric effect, ordinary and anomalous Hall effect (OHE and AHE) in the close vicinityof phase transitions. The adiabatic changes of temperature ΔTad at the phase transitions have been found bydirect measurements using an adiabatic magnetocalorimeter as well as by indirect method using heat capacitancemeasurements and thermomagnetic curves M(H,T). Negative and positive values of ?Tad of about -2K and +2K
have been observed in the vicinity of the martensitic transition (MT) and Curie temperatures, respectively, forapplied magnetic field ΔH=1.8T. To find OHE and AHE coefficients we used asymptotic values of the Hall resistancein weak and strong magnetic fields as well as thermomagnetic curves M(H,T) and magnetoresistance. It was shownthat OHE and AHE coefficients near MT depend on magnetization. In spite of strong change of resistivity near MT
the temperature dependence of AHE coefficient is weak. It clearly indicates that both Berry phase contribution andside-jump mechanism are not responsible for AHE in inhomogeneous alloys.
This work was partly supported by the Russian Foundation for Basic Research and by the Office of Basic Energy Sciences,
Material Science Division of the U.S. Department of Energy (Grant No. DE-FG02-06ER46291).

Michaela Kolbe1, Stanislav Chadov2, Elena Arbelo Jorge1, Claudia Felser2, Hans-joachim Elmers1, Gerd
Schonhense1, Mathias Klaui1 and Martin Jourdan1*
1Institute of Physics, University Mainz, Germany
2
CA, Max-Planck-Institut fur Chemische Physik fester Stoffe, Germany

Among ferromagnetic Heusler materials many compounds are predicted to be half metals, which makes
them highly attractive for spintronics applications. However, direct experimental evidence for the validityof band structure calculations for this class of materials is scarce. Here, the electronic density of states
is probed by spin averaged and spin resolved ultraviolet photoemission spectroscopy for the Heusler
compound Co2MnGa using a novel spin filter [Kol10]. The spectroscopy is performed in-situ on epitaxial
thin films which show almost complete absence of oxidation after the measurement. This means afurther reduction of sample degradation compared to our recent experiments [Hah10]. The experiments
show several characteristic features such as a clear Fermi egde and two pronounced emission intensity
maxima in the spin averaged data. In spin resolved photoemission a Heusler record polarization of 55%
at the Fermi edge is followed by a sign change at E-E_F= -0.7eV. Calculations of the band structure
accounting for the many-body effects and the related photoemission spectrum were performed using the
LSDA+DMFT approach in the framework of a fully relativistic spin-polarized Korringa-Kohn-Rostoker(SPRKKR) formalism. Good agreement observed between the experimental data and the calculations
demonstrates the feasibility to predict the electronic properties of Heusler compounds in general.

Laurent C Chapon
Institut Laue-Langevin, FranceSpin-driven ferroelectricity in most non-collinear magnets, such as TbMnO3, is
induced by the so-called inverse Dzyalonshinskii-Moriya mechanism and requires
a cycloidal magnetic structure, an ordered magnetic state that is not truly chiral (orlacks helicity). Conversely, in a truly chiral magnetic state (proper helix), the pseudoscalar helicity can not couple directly to the electric polarization, and therefore can't
induce ferroelectric order. However, in systems of specific crystal symmetry, named
here "ferroaxials,'' the presence of collective structural rotations mediates an indirect
coupling between magnetic helicity and ferroelectricity. I will review our recent
experimental results for new compounds of this class, obtained by magnetic X-ray
and neutron diffraction techniques, including a clear demonstration that the magnetic
helicity can be controlled by an electric field in RbFe(MoO4)2, and the existence of'giant' improper ferroelectricity in CaMn7O12.

[Kol10] M. Kolbe, P. Lushchyk, B. Petereit, H. J. Elmers, G. Schonhense, A. Oelsner, C. Tusche, and J. Kirschner, Phys. Rev. Lett.
107, 207601 (2011). [Hah10] M. Hahn, G. Schonhense, E. Arbelo Jorge, and M. Jourdan, Appl. Phys. Lett. 98, 232503 (2011)

Alexander Grishin*
Department of Condensed Matter Physics, KTH Royal Institute of Technology,
SwedenWe survey results on strong in-plane magnetic anisotropy of electrical transport andbroad frequency band spin dynamics in (CoFeB)1-x-(SiO2)x films. Samples with lessmetallic content show higher anisotropy of electric conductivity and isotropic giant
magnetoresistance (GMR), while films with smaller x have less anisotropic resistivity
and show a mixture of GMR and anisotropic magnetoresistance (AMR). Oppositely,field of magnetic anisotropy Hp increases with “metallization” reaching 535 Oe forthe film with x = 0.235. “Soft” magnonic modes were observed in a whole range ofoblique orientations of magnetic field perpendicular to the “easy” magnetic axis. FMR
frequency nullifies at the line of “spinodal decomposition”. At descending branchof magnetization curve we found the sequence of domain structure transformations.
Uniformly magnetized film breaks to stripe domains separated by low-angle Neeldomain walls (DWs). Then, spontaneous nucleation of kinks of Bloch-type DWs
occurs. DWs have different chirality and are separated by segments of Neel DW. WhenH → 0, they shrink converting to the vertical Bloch lines (VBL). After field reversal,
Bloch DW loaded with VBLs becomes energetically unfavorable and transforms
instantaneously into Neel DW which gradually disappears with film’s saturation.

CH02

CH05

CI03

CJ02

Composition dependence of magnetic properties in tetragonal Heuslerlike Mn-Ga alloy films with large perpendicular magnetic anisotropy

Field-driven domain-wall ratchet shift register

Chemical-doping control of magnetoelectric multiferroics

GMI effect of amorphous microwires with enhanced magnetic softness

Shigemi Mizukami1*, Takahide Kubota1, Qinli Ma1, Zhang Xianmin1, Hiroshi Naganuma2, Mikihiko Oogane2,
Akimasa Sakuma2, Yasuo Ando2 and Terunobu Miyazaki1
1
WPI-Advanced Institute for Materials Research, Tohoku University, Japan2
Department of Applied Physics, Graduate School of Engineering, Tohoku University, Japan

Magnetic films with perpendicular magnetic anisotropy (PMA) are advantageous to spin torqueapplications using magnetic tunnel junctions, such as magnetic random access memory, because PMA
reduces switching current and increase thermal stability. It has been predicted that a tetragonal Heuslerlike alloy Mn3Ga exhibits large spin polarization as well as large uniaxial magnetic anisotropy [1]. We
have obtained Mn3-xGa (x=0.5) epitaxial films and reported a large perpendicular magnetic anisotropy
energy Ku ~ 12 Merg/cc and also low saturation magnetization Ms ~ 250 emu/cc, so far [2]. Furthermore,
Gilbert damping for the alloys were relatively smaller than those in other PMA films [3]. We report
here composition dependence of magnetic properties for Mn3-xGa alloy films. The Mn3-xGa films were
fabricated using UHV magnetron sputtering on Cr buffered MgO substrates. X-ray diffraction showed
all the films were of c-axis oriented epitaxial structures. Magnetization curves for the films show
perpendicular magnetizations with squareness close to unity. The Ms for the films decreased linearly withincreasing Mn content, whereas Ku show no remarkable decreases [4]. The results will be discussed withthe ab-initio calculations [5]. This work was partially supported by the Strategic International Cooperative
Program ASPIMATT (JST) and WPI program (MEXT) in Japan.
[1] B. Balke et al., Appl. Phys. Lett. 90, 152504 (2007). [2] F. Wu et al., Appl. Phys. Lett. 94, 122503 (2009). [3] S.
Mizukami et al., Phys. Rev. Lett. 106, 117201 (2011). [4] S. Mizukami et al., Phys. Rev. B 85, 014416 (2012). [5]
J. Winterlik et al. Phys. Rev. B 77, 054406 (2008).

Jeroen Franken*, Henk Swagten and Bert Koopmans
Department of Applied Physics, Eindhoven University of Technology, Netherlands
Magnetic domain wall shift registers are considered for application in memory [1]and logic circuits [2]. However, to shift all domain walls in a nanowire in the same
direction, one requires either impractically high current densities [1] or rotating
magnetic fields [2]. Other issues include strict geometrical restrictions, and randomness
in the domain wall displacement. We propose a new domain wall shift registersuitable for magnetic materials with perpendicular anisotropy (PMA). Using focusedion beam irradiation [3], we engineer an energy landscape for the domain walls thatis asymmetric along the propagation direction. This favors ratchet propagation of
domain walls in one direction through a nanotrack. Whereas it is often believed thatdomain walls of opposite polarity cannot be shifted in the same direction since themagnetization will align with the magnetic field, we simply use an AC field to achievea domain wall shift register. In a proof of principle experiment, indefinite propagationof two domain walls along a closed loop is shown.
[1] S. S. P. Parkin, M. Hayashi, and L. Thomas, Science 320, 190 (2008). [2] D. A. Allwood, G.
Xiong, M. D. Cooke, C. C. Faulkner, D. Atkinson, N. Vernier, and R. P. Cowburn, Science 296, 2003
(2002). [3] J. H. Franken, M. Hoeijmakers, R. Lavrijsen, and H. J. M. Swagten, J. Phys. Cond.
Matter 24, 024216 (2012).

Jae-ho Chung1*, Young-sang Song1, Hak-bong Lee1, Hun Chang1 and Kee Hoon Kim2
1
Dept. of Physics, Korea University, Korea
2
Dept. of Physics & Astronomy, Seoul National University, Korea
In magnetoelectric multiferroics, electric polarizations can establish without ionicdisplacements via spin-orbit coupling that involves spin moments with noncollinear
spatial arrangements. In this spin-current multiferroics the direction of electric
polarization is determined by the spatial arrangement of interacting magnetic moments,
for which inversion symmetry should be absent. In our most recent works, we havedemonstrated the ability to control the magnetoelectricity in two different multiferroic
materials via chemical doing, namely Mn1-xCoxWO4 and Ba0.5Sr1.5Zn2(Fe1-xAlx)12O22.
It is found that the substitution of Co2+ ions on Mn2+ sites not only stabilizes theincommensurate spiral phase, but also changes the orientation of its easy plane. The
direction of the ferroelectric polarization subsequently changes from the b to the aaxis. In Ba0.5Sr1.5Zn20.5Sr1.5Zn2(Fe1-xAlx)12O22, on the other hand, the substitution ofnonmagnetic Al3+ ions on Fe3+ sites induces the transition from planar proper screw toconical spin structures by additionally introducing commensurate axial components.
This change in magnetic structure is ascribed to the reduction in planar magnetic
anisotropy, which eventually leads to the reduction of low critical field for the fieldinduced magnetoelectric phase. These results indicate that it is possible to manipulate
the magnetoelectricity of certain multiferroics materials by selective and precise
control of chemical doping.

Arcady Zhukov1, Mihail Ipatov2, Ahmed Talaat2 and Valentina Zhukova2
Dpto. Fisica de Materiales, Fac. Quimicas, Basque Country University, UPV/EHU
and Ikerbasque, Basque Foundation for Science, Spain
2
Dpto. Fisica de Materiales, Fac. Quimicas, Basque Country University, UPV/EHU,
Spain
1

Amorphous microwires exhibit outstanding magnetic properties such as magnetic
bistabilty, fast domain wall propagation, magnetically soft properties and GMI
effect. We studied hysteresis loops and GMI effect (GMI ratio, ΔZ/Z, impedance
tensor components and pulsed GMI effect) at frequencies, f, till 4 GHz in amorphousmicrowires with different ratios, ρ, of metallic nucleus diameter, d, and total diameter,
D. This allowed us to control the magnetoelastic anisotropy, since the strength ofinternal stresses is determined by the ρ-ratio. GMI effect and hysteresis loops exhibitedstrong sensitivity to the ρ-ratio. Hysteresis loops of Co-rich low-magnetostrictive
microwires exhibit low coercivity (<10A/m). Magnetic anisotropy field increases whenρ decreases. Field dependence of the off-diagonal voltage response measured in pulsed
scheme exhibits anti-symmetrical shape with monotonic growth within the certain field
range. Annealing (under stress and/or magnetic field) significantly affects magnetic
anisotropy and GMI effect of microwires. After stress annealing GMI effect of Fe-richmicrowires (which did not exhibit detectable GMI effect in as-prepared state, ΔZ/Z<1%
at f=10 MHz) can be considerable improved (ΔZ/Z=60% at f=10 MHz) as a result ofstress-annealing induced magnetic anisotropy. Low field GMI hysteresis, related withhelical magnetic anisotropy, can be suppressed by the circular bias magnetic field.

CH03

CI01

CI04

CJ03

Optical spectroscopy of half-metallic and thermoelectric Heusler
compounds

Solitonic lattice and Yukawa forces in the rare earth orthoferrite
TbFeO3Magnetic x-ray scattering studies on multiferroic SmFe3(BO3)4

Micro-fabricated silicon spiral spring based electromagnetic energy
harvester

Jaroslav Hamrle1*, Dominik Legut1, Kamil Postava1, Jaromir Pistora1, Enrique Vilanova2, Mirko Emmel2,
Gerhard Jakob2, Siham Ouardi3, Gerhard H. Fecher3 and Claudia Felser3
1
Department of Physics and Nanotechnology Centre, VSB - Technical University of Ostrava, Czech
Republic
2
Institute of Physics, Mainz University, Germany
3Institute of Inorganic Chemistry and Analytical Chemistry, Mainz University, Germany

Heusler compounds are versatile material class allowing to design desired properties through various
constituent atoms, i.e. properties intrinsically related to the modification of the atomic electronic structure.
Among the studied classes are half-metallic and thermoelectric materials. Although Heusler compounds
are thoroughly studied by number of techniques, optical spectroscopies are often omitted. However, they
can provide information of phonon energies, gap size and its purity, shape of critical points, presence ofquasi-particles such as exciton, conductivity estimation from IR absorption, etc. Knowledge of complex
refraction index is important for mass production control check of thin films, to check e.g. their thickness
and roughness. Also, half-metallic Heusler compounds are promising materials for magneto-opticalapplications, due to low photon absorption for energies below half-metalic gap. Within this contribution we
present complex refractivity index, determined in wide spectral range from far-infrared to near-ultraviolet,of half-metallic Heusler compounds Co2FeSi, Co2FeAl0.4Si0.6 and Co2FeGa0.5Ge0.5 and thermoelectric on
CoTiSb and NiTiSn (later also doped with Sc and V) measured by ellipsometry and infrared reflectometry.
The features of optical spectra are related with details of the electronic structure. The experimental opticalproperties are compared with ab-initio calculations.

The 19th International Conference on Magnetism

Sergey Artyukhin1, Maxim Mostovoy1 and Dimitrios Argyriou2*
1
Zernike Institute for Advanced Materials, University of Groningen, Netherlands
2
European Spallation Source ESS AB, Sweden

The control of domains in ferroic devices lies at the heart of their potential fortechnological applications. Multiferroic materials offer another level of complexity as
domains can be either or both of a ferroelectric and magnetic nature. Here we report thediscovery of a novel magnetic state in the orthoferrite TbFeO3 using neutron diffraction
under an applied magnetic field. This state has a very long incommensurate period of
340 A at 3 K and exhibits an anomalously large number of higher-order harmonics,
allowing us to identify it with the periodic array of sharp domain walls separated bymany lattice constants. These domain walls are formed by Ising-like Tb spins. Theyinteract by exchanging spin waves propagating through the Fe magnetic sublattice. The
resulting force between the domain walls has a large but finite range that determines
the period of the incommensurate state. It is analogous to the pion-mediated Yukawa
interaction between protons and neutrons in nuclei.

Dinesh Kumar Shukla1*, Joerg Strempfer1, Arvid Skaugen1, Sonia Francoual1, Martin
Von Zimmermann1, Leonard N Bezmaternykh2, Irina A Gudim2 and Vladislav L
Temerov2
1
Deutsches Elektronen-Synchrotron DESY,22607 Hamburg, Germany
2
L.V. Kirensky Institute of Physics, Krasnoyarsk 660036, Russia
In recent years rare-earth ferroborates, RFe3(BO3)4, have been identified as potential
multiferroic materials from both, application as well as fundamental physics pointof view. Due to the presence of two magnetic sublattices these materials offer aplatform for understanding several interesting physics problems related to structuraland magnetic anisotropy. We here present resonant and non-resonant x-ray scattering
measurements on single crystalline SmFe3(BO3)4. This compound crystallizes intrigonal structure (s.g. R32) and preserves this structure at all temperatures. Below TN,
magnetic reflections are found at (h k l) ± (0 0 3/2). Resonant x-ray measurements are
performed using photon energies close to the Sm L-edges and Fe K edge. Non-resonant
measurements are performed using photon energies above and below the edges aswell as at 100 keV photon energy. The temperature dependence of the magnetic peakat the Sm L3 edge reveals the polarization of the Sm moments by the Fe moments inform of an accelerated ordering of the Sm moments upon decreasing temperature.
Our measurements confirm the easy-plane magnetic anisotropy for the two magnetic
sublattices of Sm and Fe. Non-resonant measurements performed at 100 keV photon
energy, with and without magnetic field indicate spin rotations in the basal plane.

Oral Tuesday

Oral Tuesday

Alexander Kazakov1, Valerii Prudnikov1, Igor Rodionov1, Denis Mettus1, Nikolai Perov1, Alexander
Granovsky1*, Arcady Zhukov2, Julian Gonzalez2, Igor Dubenko3, Arjun Kumar Pathak3, Tapas Samanta3,
Shane Stadler4, Philip Adam4, Joseph Prestigiacomo4 and Naushad Ali3
1
Lomonosov Moscow State University, Russia
2
Universidad del Pais Vasco, Spain
3
Southern Illinois University, Carbondale, USA
4Louisiana State University, USA

54

oRAL PRSENTATION

Jong C. Park, Dong H. Bang and Jae Y. Park*
Electronic Engineering, Kwangwoon University, Korea

In this study, a micro-fabricated electromagnetic energy harvester was newly designed, fabricated, andcharacterized to generate electrical energy from ultra-low ambient vibrations under 0.3g. The proposedenergy harvester was comprised of a highly miniaturized Neodymium Iron Boron (NdFeB) magnet,
silicon spiral spring, multi-turned copper coil, and polydimethylsiloxane (PDMS) housing. When an
external vibration directly moves the magnet mounted as a seismic mass at the center of the spiral spring,the mechanical energy of the moving mass is transformed into electrical energy through the 183 turns of
the solenoid copper coils. The silicon spiral spring was used to generate a high electrical output power by
maximizing the deflection of the movable mass in response to low level vibrations. The fabricated energy
harvester exhibited a self resonant frequency of 36Hz and an optimal load resistance of 99Ω, respectively.
It generated an output power of 29.02μW and load voltage of 107.3mV at a vibration acceleration of 0.3g.
It also exhibited a power density and normalized power density of 48.37μW/cm3 and 537.41μW/cm3 g2,
respectively. The total volume of the fabricated energy harvesters was 1cm x 1cm x 0.6cm (height).
[1] S. Roundy, P. K. Wright, J. Rabaey, A study of low level vibrations as a power source for wirelesssensor nodes, Comput. Commun. 26 (2003) 1131-1144. [2] D. P. Arnold, Review of microscale magnetic
power generation, IEEE Trans. Magn. 43 (11) (2007) 3940-3951. [3] S. P. Beeby, M. J. Tudor, N. M.
White, Energy harvesting vibration sources for Microsystems applications, Meas. Sci. Technol. 17 (2006)
R175-R195. [4] N. S. Hudak, G. G. Amatucci, Small-scale energy harvesting through thermoelectric,
vibration, and radiofrequency power conversion, J. Appl. Phys. 103 (2008) 010301.

July 8-13, 2012 Busan, Korea

55

ORAL PRESENTATIONoRAL PRSENTATION

CJ04

DA02

DB01

DB04

Magneto-optical study of magnetization reversal in sub-micrometricglass covered wires

Carrier doping versus impurity effects in transition metal-substitutediron-based superconductors revealed by ARPES

Ultrahigh-resolution and time-resolved laser photoemission study on
kondo materials

Quantum criticality out of equilibrium in the pseudogap Kondo model

In the electron-doped Fe pnictides, superconductivity is realized by substitution oftransition-metal atoms for Fe. However, it has been controversial whether itinerant
carriers are indeed doped into the system and how the impurity potential affects
the electronic properties [1]. In order to address these issues, we have performed asystematic ARPES study of Ba(Fe,M)2As2, where M = Mn to Zn. For M = Co, Ni, andCu, the substitution expands the electron Fermi surfaces and shrinks the hole Fermi
surfaces, as expected. However, the number of doped electrons estimated from theFermi surface volumes is generally smaller than the nominal value, indicating that partof the doped electrons do not become itinerant. Such a tendency becomes stronger ingoing from Co, Ni to Cu. Concomitantly, energy bands are distorted and M 3d-likestates are split off below the Fe 3d bands. As for Mn and Zn, on the other hand, ARPES
shows characteristic features of the antiferromagnetic state without any signatureof carrier doping. This indicates that the half-filled and fully occupied 3d shells arestabilized in the divalent state of Mn and Zn, respectively.

Recently, photoemission spectroscopy has been developed very rapidly and found to bevery powerful for the study of Kondo materials. For example, 1. The resolution of 150
μeV at 1.8K is achieved by the development of laser photoemission. 2. High resolution
hard X-ray photoemission becomes possible using high brilliant synchrotron radiation.
3. The angle resolved photoemission in soft X-ray region also shows beautiful results
using high brilliant synchrotron radiation. 4. Time resolved photoemission becomes
possible very recently using Femto-second laser. I would like to talk on these newexperimental results on YbAlB4 [1] and YbS and Yb metal [2] as well as several Ce, U,
and Pr compounds using ultra-high resolution laser-photoemission and high resolution
hard X-ray photoemission. I will also talk on the possibilities of time resolved
photoemission spectroscopy on heavy electron systems.

2

1

Oral Tuesday

Alexander Chizhik *, Arcady Zhukov and Julian Gonzalez
1
Universidad del Pais Vasco UPV/EHU, Spain
2
Universidad del Pais Vasco UPV/EHU, IKERBASQUE, Basque Foundation for
Science, Bilbao, Spain, Spain
With the purpose of the miniaturization of basic elements of magnetic sensors themagneto-optical Kerr effect (MOKE) [1] investigation of the magnetization reversal has
been performed in Fe-rich sub-micrometric amorphous wires. The axial tensile stress andtorsion stress have been applied during the experiments. The series of the microwires
with different values of radius of metallic nucleus (400 nm, 700 nm, 1000 nm) has beenstudied. In the extremely thin sub-micrometric wires, the magnetic bistable behavior
is observed. It confirms the existence of the Surface Large Barkhausen Jump in submicrometric glass covered wires like in glass covered wires of micro-scale. The highest
value of the surface coercive field is observed for the smallest value of the radius. It
has been attributed to the increasing of the strength of internal stresses as increasing
the glass coating thickness. The performed analysis of the tensile and torsion stresses
transformation of surface hysteresis loop demonstrates that about one order decreaseof the wire scale does not abolish the basic effects observed earlier in thicker wires. It
permits to reduce considerably the size of basic elements of magnetic sensors.

Atsushi Fujimori
Department of Physics, University of Tokyo, Japan

Shik SHIN
University of Tokyo, Japan

Chung-hou Chung1* and Yi-jie Zhang2
1Electrophysics Dept., National Chiao-Tung University, HsinChu, Taiwan, R.O.C.,
Taiwan2
Electrophysics Dept., National Chiao-Tung University, HsinChi, Taiwan, R.O.C.,
TaiwanOral Tuesday

1

WN
A
R

D

TH
I
W

[1] Okawa et. al., Phys Rev. Lett., 104(2010) 247201. [2] Matsunami et. al., PRB 78(2008)195118.

[1] H. Wadati et al., Phys. Rev. Lett. 105, 157004 (2010).

[1] J. Gonzalez et al., Journ. of Physics: A, 208 (2011) 502.

CJ05

DA03

DB02

DB05

The magnetic transition and large magnetoresistance effect inperovskite Nd1-xSrxMnO3 system

Specific heat measurements on fepn in fields up to Hc2 - a probe of
nodal structure

Magnetic moment screening in the correlated Kondo lattice modelA spin-selective kondo-insulator - cooperation between ferromagnetismand kondo-effectWe report the specific heat gamma as a function of field up to 30 T in Co- andNi-doped 122, as well as in LiFeAs. The overdoped Co-doped sample displays
qualitatively different behavior than the underdoped. Preliminary gamma as a functionof angle data will also be discussed.

The magnetic correlations, local moments and susceptibility in the correlated 2D
Kondo lattice model at half filling are investigated. We calculate their systematic
dependence on the Kondo coupling J_K and Coulomb repulsion U. Exactdiagonalisation (ED) approach for ground state properties as well as finite temperature
Lanczos method (FTLM) for specific heat and the uniform susceptibility are employed
for small tiles on the square lattice. The competition of on-site screening and induced
inter-site correlations are monitored and a phase diagram is constructed. In particular it
is shown that the screened local moment exhibits nonmonotonic behavior as functionof U for weak Kondo coupling J_K. In the large U limit the model is equivalent to the
2D Kondo necklace model with two types of localized spins. In this limit the numericalresults are compared to those of the analytical bond operator method in mean field
treatment and excellent agreement for the total paramagnetic moment is found. The
temperature dependence of the susceptibility allows to extract the dependence of the
Kondo temperature scale on the correlation strength U. A monotonic increase for small
U is found in agreement with earlier analytical impurity calculations.

The Kondolattice model has been intensively studied for the last thirty years as afundamental model for heavy fermions, Kondo insulators, and transition metals, e.g.
the manganites. Yet, the understanding is far from complete. Taking ferromagnetic
heavy fermion compounds as motivation we analyze the mechanism stabilizing theferromagnetic state in the antiferromagnetically coupled Kondo lattice model. We
find that even for this ferromagnetic state Kondo screening plays an essential rolein stabilizing the ferromagnetic state at zero temperature leading to very interesting
properties: while the majority-spin electrons are metallic, the minority-spin electrons
form an insulating state. We clarify that this state is due to partial Kondo screening, sothat parts of the local moments are bound to the electrons, resulting in a dynamicallyinduced commensurability which is essential for producing the gap in the minority-spin
electrons. We believe that the mechanism proposed here, the dynamically generated
commensurability, is generic for the ferromagnetic phase in the antiferromagneticallycoupled Kondo lattice model, thus providing new insights into the zero temperaturephysics for the Kondo lattice model.

DA01

DA04

DB03

DC01

Superconducting symmetry of Fe-based systems studied by impurity
effects and neutron inelastic measurements

NMR study on high temperature Fe-pnictide superconductor Ln-FeAs-O with Tc=50 K

Influence of magnetic anisotropy on the underscreened Kondo effect in
the presence of ferromagnetism

Spin-orbit entangled ground states and excitations in iridium oxides

Khai Van Vu1*, Thang Viet Do2, Sinh Huy Nguyen3 and Anh Thi Kim Do3
1
Construction Mechanical Faculty, National University of Civil Engineering, Viet
Nam
2
Faculty of Science, Haiphong University, Viet Nam
3
Faculty of Physics, University of Science, Vietnam National University, Hanoi, VietNam
The magnetic transition of Nd1-xSrxMnO3 (with x = 1/3, 0.40 and 0.50) has been
investigated with zero field cooling (ZFC) and field cooling (FC) measurements in thetemperature range of 77 K - 350 K. It is indicated that the temperature dependence ofmagnetization of all samples complied with Block’s law in the area of T < TC. The
magnetoresistance of Nd1-xSrxMnO3 system has been determined with magnetic fieldof 0.0-0.4T. It is found that the obtained magnetoresistance ratio (CMR%) decreased
with increasing doped Sr concentrations. The maximum value of CMR(%) is out of theCurie temperature (TC) and metal-insulator transition temperature (Tp ) regions. The
magnetoresistance ratio nearly linearly increased by decreasing temperature at x = 0.50
compound. The dependence of CMR(%) on the doping Sr in this system has been fittedwith hyperbol function.

Masatoshi Sato1*, Yoshiaki Kobayashi2, Takayuki Kawamata3, Yukio Yasui2, Kazunori Suzuki2, Masayuki
Itoh2, Ryoichi Kajimoto1, Kazuhiko Ikeuchi1, Masatoshi Arai4 and Philippe Bourges5
1
Research Center for Neutron Science and Technology, Comprehensive Research Organization for
Science and Society, Japan2
Department of Physics, Nagoya University, Japan3
Department of Applied Physics, Tohoku University, Japan
4
Materials and Life Sccience Division, J-PARC Center, JAEA, Japan
5
Laboratoire Leon Brillouin, CEA/Saclay, France

We have focused on the superconducting symmetry of Fe-pnictides, because it is directly connected with the pairing
mechanism. Effects of nonmagnetic-impurities on Tc, magnetic excitation spectra χ” and NMR 1/T1-T curve, all ofwhich are sensitive to the relative signs between the order parameters on their disconnected Fermi surfaces around Γ
and M points, have been studied: If the signs are opposite (symmetry S±) the magnetic mechanism is relevant, while thesame signs (symmetry S++) indicate a novel mechanism, because the ordinary phonon mechanism cannot realize Tc ashigh as ~55 K in Ln1111 (Ln=lanthanides). Results are as follows. (a)Very small rates of Tc-suppression by M impurities
in LnFe1-yMyAs0.89-xF0.11+x (M=Ni, Co, Ru) can be explained only by S++[1, 2]. (b) χ”-data for Ba(Fe, Co)2As2 (Tc~23
K) and Ca-Fe-Pt-As crystals (Tc~33 K) can be well explained by S++ rather than by S±[3]. (c)The NMR data can beunderstood by S++, too. They strongly support S++ and the existence of a novel pairing mechanism. The symmetry
is consistent with the observed elastic softening of C66[4]expected from the orbital-fluctuation (OF) mechanism.
Anomalous behavior of phonons by neutron studies are also presented in relation to the OF.
[1] M. Sato et al. J. Phys. Soc. Jpn. 79 (2010) 014710. [2]T. Kawamata et al. J. Phys. Soc. Jpn. 80 (2011) 084720. [3] J.
Phys. Soc. Jpn. 80 (2011) 093709. [4] T. Goto et al. J. Phys. Soc. Jpn. 80 (2011) 073702.

56

The 19th International Conference on Magnetism

Greg Stewart*
Physics, Univ. Florida, USA

Hidekazu Mukuda1*, Satoshi Furukawa1, Mitsuharu Yashima1, Yoshio Kitaoka1,
Parasharam M Shirage2, Hiroshi Eisaki2 and Akira Iyo2
1
Osaka University, Japan
2
National institute of Advanced Industrial Science and Technology (AIST), Japan
Superconducting(SC) transition temperature (Tc) of Ln-FeAsO (1111)-based
compounds (Ln: Rare earth) rises to 55 K when the Ln=Sm. In NMR investigation,
however, the high-Tc Ln-1111 compounds are affected by the magnetism of rare earth
ions, which prevents us from probing the intrinsic nuclear relaxation rate(1/T1) of thequasi-particles in the SC state. In order to reveal the mechanism of high Tc more than
50 K in Ln-1111 system, we have investigated the normal-state and SC characteristicsof (La0.05Y0.95)FeAsOy (La0.05Y0.951111) with Tc=50 K by means of 57Fe/75As-NMR
measurements. In the SC state, the measurements of 1/T1 have revealed in terms ofa multiple fully-gapped s(+-)-wave model that the SC gap becomes larger than thatin optimally-doped LaFeAsOy (La111(OPT)) with Tc=28 K. In the normal state,
the increase of 1/T1T upon cooling indicates that the antiferromagnetic(AFM) spin
fluctuations develop toward Tc, which is more significant than in La1111(OPT) and(La0.8Y0.21111) (Tc=34K)[3]. However, these antiferromagnetic spin fluctuations were
weaker than in Ba0.6K0.4Fe2As2 (Tc=38K) and (Ca4Al2O6)(Fe2As2) (Tc=27K), whichhave lower Tc values than in La0.05Y0.951111, suggesting that the AFM spin fluctuations
are not an unique factor to increase the Tc in Fe-pnictide superconductors.

Peter Thalmeier1, Mohammad Siahatgar1, Burkhard Schmidt1 and Gertrud Zwicknagl2
1
Max Planck Institute for Chemical Physics of Solids, Germany
2
Technical University Braunschweig, Germany

Maciej Misiorny1,2*, Ireneusz Weymann2 and Jozef Barnas2,3
1Peter Grünberg Institut (PGI-2), Forschungszentrum Jülich & JARA Jülich Aachen Research Alliance,
52425 Jülich, Germany
2
Faculty of Physics, Adam Mickiewicz University, 61-614 Poznań, Poland
3
Institute of Molecular Physics, Polish Academy of Sciences, 60–179 Poznań, Poland

The prominent role of magnetic anisotropy (MA) in formation of the Kondo effect has recently been
demonstrated experimentally [1,2]. In particular, it turned out that in systems of spin S>1/2, such as
magnetic adatoms (i.e. Fe, Co or Mn) or magnetic molecules, the Kondo effect can be tuned by modifying
the system’s MA. Furthermore, theoretical studies also indicate that MA can be a key factor determining
spin-polarized transport through a magnetic nanosystem [3]. Motivated by the recent experiment [2],in this communication we address how the MA affects the underscreened Kondo effect (i.e. partial
compensation of the molecular spin by conduction electrons) in the case of an artificial molecule of spin
S=1 coupled to a reservoir of spin-polarized conduction electrons [4]. The crucial ingredient of the modelis the presence of uniaxial MA. The problem is analyzed by means of Wilson’s numerical renormalizationgroup (NRG) method, which allows for calculating the spectral function of the molecule. We show thatthe interplay of MA and ferromagnetism has a fundamental significance for occurring of the Kondo effect.
Most importantly, despite the presence of the effective exchange field [5] the Kondo effect can be restoredby adjusting the magnitude of MA.

Robert Peters and Norio Kawakami
Kyoto University, Japan

Giniyat Khaliullin
Max Planck Institute for Solid State Research,Germany

A relativistic spin-orbit coupling may drive unusual interactions and orderings in Mott
insulators. This coupling entangles the spin and orbital subspaces leading to a richvariety of effective Hamiltonians and exotic phases depending on the lattice geometry
and orbital structure. Particular examples to be discussed are: (i)Iridium perovskite
Sr2IrO4 where the magnetic order and excitations closely resemble those of high-Tc
cuprates [1,2]; (ii)The honeycomb lattice Li2IrO3 and Na2IrO3 where the celebrated
Kitaev model with spin liquid ground state might be at work [1,3]; (iii)Vanadate
Sr2VO4 which is predicted to exhibit a magnetically hidden octupolar order [4].
[1] G. Jackeli, G. Khaliullin, Phys. Rev. Lett. {102}, 017205 (2009). [2] J. Kim {\it et al.},arXiv:1110.0759. [3] J. Chaloupka, G. Jackeli, G. Khaliullin, Phys. Rev. Lett. {105}, 027204 (2010).
[4] G. Jackeli, G. Khaliullin, Phys. Rev. Lett. {103}, 067205 (2009).

1. A.F. Otte et al., Nature Phys. 4, 847 (2008). 2. J.J. Parks et al., Science 328, 1370 (2010). 3. M. Misiorny, I. Weymann and
J. Barnas, Phys. Rev. Lett. 106, 126602 (2011); Phys. Rev. B 84, 035445 (2011). 4. I. Weymann and L. Borda, Phys. Rev. B 81,
115445 (2010). 5. J. Martinek et al., Phys. Rev. Lett. 91, 127203 (2003); Phys. Rev. B 72, 121302 (2005).

July 8-13, 2012 Busan, Korea

57

ORAL PRESENTATION
DC02

DD01

DD04

DE01

Elementary magnetic excitations of iridates and cuprates probed byresonant inelastic X-ray scattering

Modulated spinodal decomposition and magnetotransport in (Ge,Mn)films grown on GaAs(001)Formation and investigation of structural and magnetic properties of
Ni-Mn-In Heusler alloy thin films

Micromagnetic simulation of magnetic nanostructures

In this work we report on the different methods of formation of the Ni-Mn-In Heusler
alloy thin films by pulsed laser deposition and the dramatic dependence of martensitic
transition temperatures (Tm) and Curie temperatures (Tc) on the alloy composition.
Using two-lasers co-deposition approach we have implemented various methodsof the thin films formation with controlled stoichiometry: by ablation of one target(Ni50Mn35In15), by simultaneous ablation of two targets (Ni50Mn35In15 and In) or by
simultaneous ablation in the appropriate ratio of three pure metals targets (Ni, Mn and
In). The phase and chemical composition, structural and magnetic properties of asgrown Ni-Mn-In thin films have been probed by X-ray Diffraction (XRD), Raman
scattering, Auger electron spectroscopy, Rutherford backscattering spectrometry andvibrating sample magnetometery. Temperature dependences of magnetic and structuralproperties are investigated by Physical properties measurement system (PPMS) andhigh-resolution XRD. It was shown that the films are not susceptible to degradation.
We have observed that increasing of In concentration from 14 to 20% leads to Tc
decreasing by 30K (from 330 to 300K). At the same time temperature hysteresis,
corresponding to martensitic transitions changes from temperature range Tm=250310K to Tm= 260-370K. The low-temperature phase transition has been found for all
samples.

Magnets are key elements of modern society. Examples of the wide spread use ofmagnets are magnetic data storage, permanent magnets for energy applications,
wireless sensors, and biomedical systems. The design and development of magnetic
devices heavily relies on simulations. Recent advances in hard- and software make itpossible to bridge the length scales. In magnetic recording simulations the input andoutput are the write current and the read back voltage while magnetization dynamics
is treated at the nano-scale. Nano-scale non-coherent magnetization reversal decouples
the switching field and the thermal stability of magnetic recording media. In the talkwe will show the potential of bit patterned magnetic recording systems for storage
densities reaching 5 Tbit/in². In addition to the physics of magnetization reversal, we
will review the methods and algorithms that are applied in numerical micromagnetics.
Further examples of micromagnetic simulations will include low-rare earth containing
permanent magnets and wireless magnetostrictive sensors.

Resonant Inelastic X-ray Scattering (RIXS) provides direct access to elementarycharge, spin and orbital excitations in complex oxides. As a technique it has madetremendous progress with the advent high-brilliance synchrotron X-ray sources. From
the theoretical perspective the fundamental question is to precisely which low-energy
correlation functions RIXS is sensitive. Depending on the experimental RIXS setup,the measured charge dynamics can include charge-transfer, phonon, d-d and orbital
excitations [1]. The focus of this talk will be on RIXS as a probe of spin dynamics,
in particular magnon and bi-magnon dispersions [2,3]. Based on the experimental
observations, the novelties that RIXS reveals on the spin dynamics of high-Tc cuprates[4,5] and strongly spin-orbit coupled iridium-oxides will be discussed [6].
[1] L. Ament, M. van Veenendaal, T. Devereaux, J.P. Hill and JvdB, Rev. Mod. Phys. 83, 705 (2011).
[2] L. Braicovich et al., PRL 102, 167401 (2009). [3] L. Ament, G. Ghiringhelli, M. Moretti Sala, L.
Braicovich and JvdB, PRL 103, 117003 (2009). [4] L. Braicovich et al., PRL 104, 077002 (2010). [5]
M. Guarise et al., PRL 105, 157006 (2010). [6] L. Ament, G. Khaliullin and JvdB, PRB 84, 020403(2011).

Ing-song Yu1, Thibaut Devillers1, Andre Barski1, Pascale Bayle-guillemaud1, Cyrille
Beigne1, Johan Rothman2, Vincent Baltz1, Joel Cibert3 and Matthieu Jamet1*
1
INAC, Commissariat a l'Energie Atomique et aux Energies Alternatives, France
2
LETI, Commissariat a l'Energie Atomique et aux Energies Alternatives, France
3
Institute NEEL, CNRS, France
The field of ferromagnetic semiconductors evolves very fast nowadays for their potential use in
spintronic devices. Up to now, efforts have mainly focused on Diluted Magnetic Semiconductors but
Curie temperatures in these materials still remain modest. One possible route to increase at least locallytransition temperatures is to use spinodal decomposition leading to transition metal-rich high-TC
nanostructures. We focus here on (Ge,Mn) considered as a model system for spinodal decomposition andcompatible with Si-based microelectronics. While the growth of (Ge,Mn) films on Ge substrates leads
systematically to Mn-rich self-assembled nanocolumns exhibiting high-TC, we demonstrate the finecontrol of spinodal decomposition in (Ge,Mn) films grown on GaAs. Using different surface preparations,
we clearly identify the role of surface morphology and impurity diffusion from the substrate (Ga or As)
on the nanocolumns growth and the electrical properties (MR and AHE)[1]. In particular holes exhibit ananomalous Hall effect, and electrons exhibit a tunneling magnetoresistance, both with a clear dependence
on the magnetization of the Mn-rich inclusions; holes exhibit orbital MR, and electrons show only thenormal Hall effect, and an additional component of magnetoresistance due to weak localization, all three
being independent of the magnetic state of the Mn-rich inclusions.
[1] I. S. Yu, M. Jamet, T. Devillers, A. Barski, P. Bayle-Guillemaud, C. Beigne, J. Rothman, V. Baltz, J. Cibert, Phys. Rev. B
82, 035308 (2010).

Thomas Schrefl*, Simon Bance, Lukas Exl, Johann Fischbacher, Harald Oezelt andFranz Reichel
St. Poelten University of Applied Sciences, Austria

DC03

DD02

DD05

DE02

Resonant Inelastic X-ray Scattering study of Na2IrO3

Homogenous and heterogeneous magnetism in (Zn,Co)O

Magnetic excitations in rare earth based nanosystems

Multi-bit magnetic memory based on the extraordinary Hall effect.

Hlynur Gretarsson1, Heungsik Kim2, Xuerong Liu3, John Hill3, Yogesh Singh4, P Gegenwart4,
Jungho Kim5, Diego Casa5, Thomas Gog5, Mary Upton5, Jaejun Yu2 and Young-june Kim1*
1
Department of Physics, University of Toronto, Canada
2
Department of Physics, Seoul National University, Korea
3
Brookhaven National Laboratory, USA
4
Georg-August-Universitat Gottingen, Germany
5
Advanced Photon Source, Argonne National Laboratory, USA

Maciej Sawicki1, Ela Guziewicz1, Malgorzata I Lukasiewicz1, Oleg Proselkov1, Iwona Kowalik1, W.
Lisowski2, Piotr Dluzewski1, Wojciech Paszkowicz1, Rafal Jakiela1, Bartlomiej S Witkowski1, Lukasz
Wachnicki1, F.j. Luque3, D. Arvanitis4, W. Sobczak2, M. Krawczyk2, A. Jablonski2, Wiktor Stefanowicz1,
Dariusz Sztenkiel1, Marek Godlewski1 and Tomasz Dietl1
1
Institute of Physics, Polish Academy of Sciences, Poland
2
Institute of Physical Chemistry, Polish Academy of Sciences, Poland
3
Depto. de Fisica de la Materia Condensada, Universidad Autonoma de Madrid, Spain
4
Department of Physics and Astronomy, Uppsala University, Sweden

Recently there are intensive research efforts to elucidate physics of materials with 5d electrons,
for which spin orbit coupling (SOC) is comparable to other energy scale of the system, suchas Coulomb repulsion and crystal field splitting [1-3]. The layered iridate Na2IrO3, with
Ir4+ spins sitting on a distorted honeycomb lattice, is such an example [4-7]. Depending on
the value of the Coulomb repulsion in such a lattice, the SOC can give rise to a topologicalinsulator or a Kitaev-Heisenberg system for the possible spin-liquid phase [5]. The electronic
structure of Na2IrO3 has been investigated using resonant inelastic x-ray scattering (RIXS)
and density functional theory calculations. Crystal field split d-d excitations are resolved in thehigh-resolution RIXS spectra. We observe a large splitting between the two eg orbitals, whicharises from the dimerization of Ir atoms due to the metal-metal bonding. The low energy d-d
excitations exhibit small momentum dependence, which can be described as due to spinorbital coupled excitation.

For more than a decade ZnO doped with Mn and Co has remained as one of the most prospected DMS
for the room temperature (intrinsic) ferromagnetism resulting in numerous reports on room temperature
ferromagnetism conflicted with those which deny existence of any coupling at all. In order to clarify this issue
we investigate ZnCoO layers grown by ALD at low temperatures [1]. We employ and relay on wide rangeof extensive material characterisation which in combination with SQUID magnetometry allow us decisively
exemplify the growth temperature Tg as the key factor discriminating between paramagnetic (obtained at
Tg=160oC) and various forms of ferromagnetic responses (seen when Tg>200oC). When the ferromagnetism
is found, our data indicate presence of nearly temperature independent and highly anisotropic response which
we unambiguously associate with few nm thin metallic Co-mesh located at the (Zn,Co)O/substrate interface.
It explains why the magnitude of the ferromagnetic-like signal is virtually independent of the film thickness aswell as elucidates the origin of magnetic anisotropy, as observed by us and others [2]. Furthermore, it makes
it possible to understand significant deviations from the standard superparamagnetic behavior visible in our
samples as well as in many high-temperature DMSs and DMOs [3].

[1] Y. Okamoto et al. Phys. Rev. Lett. 99, 137207 (2007). [2] B. J. Kim et al., Phys. Rev. Lett. 101, 076402(2008). [3] D. Pesin and L. Balents, Nat. Phys. 6, 376 (2010). [4] A. Shitade et al., Phys. Rev. Lett. 102,

256403 (2009). [5] G. Jackeli and G. Khaliullin, Phys. Rev. Lett. 102,017205 (2009). [6] Y. Singh and P.
Gegenwart, Phys. Rev. B 82, 064412 (2010). [7] X. Liu et al., Phys. Rev. B 83, 220403 (2011).

DC04
Magnetization plateaus in generalized Shastry-Sutherland models

Pinaki Sengupta1*, Keola Wierschem1, Takafumi Suzuki2 and Naoki Kawashima3
1
Nanyang Technological University, Singapore
2
Hyogo University, Japan
3
University of Tokyo, JapanThe Shastry-Sutherland model is known to exhibit a novel sequence of magnetization
plateaus in the presence of an applied field. It has been shown in the recent pastthat inclusion of anisotropic and/or additional interactions to the standard SahstrySutherland model can change the magnetization profile completely - resulting indifferent sequences of magnetization plateaus. In the present work, we use large
scale numerical simulations to systematically study the effects of Ising-like exchange
anisotropy and a 3rd nearest neighbor ferromagnetic interaction on the field induced
magnetization behavior. In particular we follow the evolution of the m/m_s=1/3 and1/2 plateaus as the strength of the additional terms are varied. The results are valuable
in understanding the behavior of the rare-earth tetraboride family of quantum magnets
whose magnetic properties are described by generalized Shastry-Sutherland models of
the kind considered in this study.

58

Alexey Grunin*, Alexander Goikhman and Valeria Rodionova
Immanuel Kant Baltic Federal University, Russia

The 19th International Conference on Magnetism

Karine Dumesnil1*, Catherine Dufour1, Sylvain Petit2 and Alexandre Bataille2
1
Institut Jean Lamour - Lorraine University, France
2
Laboratoire Leon Brillouin - CEA, France

WN
A
R

D

TH
I
W

Oral Tuesday

Jeroen Van Den Brink*
IFW Dresden, Germany

Oral Tuesday

oRAL PRSENTATION

Alexander Gerber and Amir Segal
School of Physics and Astronomy, Tel Aviv University, Israel

We propose a principle of multi-bit magnetic random access memory in which eachmemory cell is split among several multilevel dots exhibiting perpendicular anisotropy,
and the extraordinary Hall effect (EHE) is used to extract the stored information. Four-,eight- and sixteen- memory state cells have been realized in the proof-of-concept study.
In addition to multiplicity of states, probably the most important advantage of the split
cell architecture is freedom in positioning dots of the same cell at separate locations
and different levels, thus building an effective three-dimensional memory.

[1] M. Sawicki et al., cond-mat arXiv:1201.5268 [2] Venkatesan et al, Phys. Rev. Lett., 93, 177206 (2004). [3] J.M.D. Coeyet al., New J. Phys., 12, 053025 (2010).

DD03

DD06

DE03

Magnetic and optical studies of hydrogenated Cu-doped ZnO film

Exchange coupled L10 FePt (hard)/ soft (A1 FePt or Co)
nanocomposites

Epitaxial Fe/MgO/Fe tunnelling junctions on BaTiO3 (001)Tong Li, Wen Xiao, Tun Seng Herng, Nina Bao and Jun Ding*
National University of Singapore, Singapore

ZnO doping with Cu has provoked broad interest recently.1,2 Some interesting findings, such as
surface ferromagnetism (FM) in hydrogenated ZnO3 and hydrogen enhanced green emission (GE)in ZnO film4 were reported previously. In this work, we focused on hydrogenated ZnO:Cu film.
This study reported hydrogen enhanced FM and strong GE in ZnO:Cu (2 at%) film and possible
mechanism. ZnO:Cu films (002) with different thickness were deposited on quartz (110) by PLD at
600 oC. Prior to H2 treatment, the areal saturation magnetization Msa (1×10-5 emu/cm2) was foundto be insensitive to thickness, suggesting surface/interface magnetism5. After H2 treatment at up to
500 oC, Ms of ZnO:Cu (20 nm) reached 3.1×10-5 emu/cm2 (15.4 emu/cm3), which was three times
stronger than hydrogenated ZnO3. Surprisingly, unlike hydrogenated ZnO, this hydrogen induced
Msa drastically decreased with increasing thickness. It thus indicated that apart from surface FM
resulting from OH attachment4, Cu dopants play a dominant role in FM enhancement in response
to H2 treatment. Furthermore, although light emission of ZnO:Cu showed an obvious blue shiftcompared to ZnO, a similar strong GE was observed after 500 oC-H2 treatment. This GE is
attributed to defect complexes and formation of porous structure that creates optical cavities.
1.Dietl, T., et al., Zener Model Description of Ferromagnetism in Zinc-Blende Magnetic Semiconductors. Science,
2000. 287(5455): p. 1019-1022. 2.Herng, T.S., et al., Room-Temperature Ferromagnetism of Cu-Doped ZnO
Films Probed by Soft X-Ray Magnetic Circular Dichroism. Physical Review Letters, 2010. 105(20). 3. Li, T., etal., Surface ferromagnetism in hydrogenated-ZnO film. Applied Physics Letters, 2011. 98(15). 4.Li, T., etal., Green
random lasing in hydrogenated ZnO film. Journal of Physics D, under review. 5.Ong, C.S., et al., Strain-Induced
ZnO Spinterfaces. The Journal of Physical Chemistry C, 2011. 116(1): p. 610-617.

Thanassis Speliotis1, George Giannopoulos1, Dimitris G Niarchos1, W F Li2 andGeorge Hadjipanayis3
1
Institute of Materials Science, NCSR DEMOKRITOS, Greece2
Department of Physics and Astronomy, U of Delaware, Newark, Delaware, USA
3
Department of Physics and Astronomy, U of Delaware, Newark Delaware, USA
L10 ordered FePt is one of the most promising materials for ultra high density perpendicularmagnetic recording, however its high coercivity greatly exceeds the writing field of available
heads. Thus new media structures proposed in order to decrease the required writing field
named as exchange coupled composites (ECC) or so-called exchange spring media. The
ECC media consists of two or more exchange coupled sub-regions, in which the hard region
stores the information and the soft region(s) promotes the magnetization reversal of the hardregion, while keeping high thermal stability.In this work structural and magnetic propertiesof core-shell type hard/soft (L10 FePt / A1 FePt or Co) exchange coupled nanocomposites
are presented. Semi spherical core-shell nanocomposites with L10 FePt core and A1 FePt(fcc) or Co shell were obtained by depositing A1-FePt or Co cap layers on type L10 FePt
nanoparticles in order to understand the influence of the soft magnetic layer thickness on themagnetic properties of the system. Epitaxial growth is confirmed by x-ray diffraction and
TEM, while the coercivity decreases dramatically for the L10/A1-FePt or Co system when the
thickness of the A1-FePt or Co cap layers is increased.

Greta Radaelli* and Riccardo Bertacco
LNESS center - Polo regionale di Como - Politecnico di Milano, via Anzani 42 (Como),
Italy

Novel schemes for magnetic recording and reading are based on spintronic devices where adeterminant role is played by materials or interfaces displaying magnetoelectric coupling. In
this context the study of the Fe/BaTiO3 (BTO) interface is particularly interesting in view ofa possible magnetoelectric coupling at the interface as suggested by Duan et al [1] and Sahooet al [2]. After an initial study of the magnetoelectric coupling at the interface between thinFe films and BTO single crystal substrates [3] epitaxial Fe/BTO//Nb:SrTiO3(001) and Fe/
BTO/La0.7Sr0.3MnO3//SrTiO3(001) interfaces have been grown by combined use of molecularbeam epitaxy and pulsed laser deposition. Finally, fully epitaxial Co/Fe/MgO/Fe/BTO
heterostructures have been deposited and magnetic tunnelling junctions (MTJs) fabricated via
optical lithography. I(V) curves clearly indicate that tunnelling is the dominant mechanism
in our MgO junctions. Preliminary experiments testing the electric control of the TMR havebeen performed at different temperatures. A modulation of the TMR on the order of 10%,induced by application of an electric field across the BTO template, has been detected at 150 K.
This result attests the great potential of this system for the electric control of magnetization offerromagnetic electrodes in spintronic devices.
[1] C. Duan et al. Phys. Rev. Lett. 97 (2006) 047201 [2] S. Sahoo et al. Phys. Rev. B 76 (2007) 092108 [3]S. Brivio et al. Appl. Phys. Lett. 98 (2011) 092505

Supported by the ARPA-E

July 8-13, 2012 Busan, Korea

59

ORAL PRESENTATION
DE04

DF02

DG01

DG04

Experimentally performed periodic NOT/AND/OR magnetic quantum
dots cellular automata gateLong-range crystalline nature of the skyrmion lattice in MnSi

Preparation and analysis of ni nanowires on si gratings

FMR behavior of Co nanowire arrays

Oral Tuesday

A magnetic quantum dots cellular automata (MQCA) [1, 2] can perform NAND/
NOR logic operation [3] via magnetostatic interaction between the dots. The MQCA
is composed of elliptical dots, and digital information of “0” and “1” are stored witha direction of dot magnetization. In general, the logic operations are executed byapplying a uniform external magnetic field (clock field). However, in arrayed MQCA
structures, it is difficult to control a data flow direction between the MQCA gateswith the uniform clock field. Here we demonstrate a NOT/AND/OR logic operationin arrayed structure with a localized clock field from magnetic force microscopy(MFM) tip. As the NOT/AND/OR MQCA gate, four elliptical Ni-20at.%Fe dots withlong/short axis of 110 nm/65 nm, thickness of 20 nm, were fabricated on a thermally
oxidized Si(100) substrate with electron-beam lithography, ion beam sputtering, andlift-off technique. To write digital information to the dots, we use a magnetization
manipulation method with MFM. With all possible initial states of the NOT/AND/OR
MQCA gate, we confirm that the gate can perform expected logic operation at room
temperature. With arrayed MLG structures, high functional circuits, such as addercircuit will be realized in the near future.

Tim Adams1, Sebastian Muhlbauer2, Christian Pfleiderer3, Florian Jonietz3, Andreas Bauer3, Andreas
Neubauer3, Robert Georgii3, Peter Boni3, Uwe Keiderling4, Karin Everschor5, Markus Garst5 andAchim Rosch5
1
TU Munchen, E21, Germany
2
Institut fur Festkorperphysik, ETH Zurich, Zurich, Switzerland, Germany
3
Physik-Department E21, Technische Universitat Munchen, D-85748 Garching, Germany
4Helmholtz Zentrum Berlin, BENSC, D-14109 Berlin, Germany
5
Institute of Theoretical Physics, Universitat zu Koln, D-50937 Koln, Germany

We report small angle neutron scattering of the Skyrmion lattice in MnSi using anexperimental setup that minimizes the effects of demagnetizing fields and double scattering.
Under these conditions, the Skyrmion lattice displays resolution-limited Gaussian rocking
peaks that correspond to a magnetic correlation length in excess of several hundred
micrometers. This is consistent with exceptionally well-defined long-range order. We further
establish the existence of higher-order scattering, discriminating parasitic double scatteringwith Renninger scans. The field and temperature dependence of the higher-order scattering
arises from an interference effect. It is characteristic for the long-range crystalline nature of theSkyrmion lattice as shown by simple mean-field calculations. A peculiar change of the pinningand a meandering around the direction parallel to the magnetic field suggests a symmetry
breaking transition and a more complex interplay of the skyrmion lattice with the crystal
structure.

Wolfgang Kreuzpaintner1*, Boris P. Toperverg2, Dieter Lott3, Michael Stoermer3, Volker Neu4, Christina Bran4, Stefan
Mattauch5, Andreas Schreyer3 and Peter Boeni1
1Physik Department E21, Technische Universitaet Muenchen James-Franck-Strasse 1 85748 Garching, Germany
2
Fakultaet fuer Physik und Astronomie Ruhr-Universitaet Bochum 44780 Bochum, Germany
3Helmholtz-Zentrum Geesthacht Max-Planck-Strasse 1 21502 Geesthacht, Germany
4Magnetic Microstructures, IFW Dresden, Institute for Metallic Materials Helmholtzstrasse 20 01069 Dresden, Germany
5
JCNS Outstation at FRM II Forschungszentrum Juelich GmbH Lichtenbergstrasse 1 85747 Garching, Germany

Ni was e-beam evaporated onto a lithographically prepared Si grating under a shallow angle ofincidence. By geometrical self-shading effects, Ni nanowires of 10nm x 10nm cross-section, aspacing of 750nm and a length of several cm, could be deposited homogeneously on a surface
of approx. 4cm. 10nm of Al were sputter deposited as capping layer. The structural and magnetic
properties of this sample will be presented: Initial structural analyses of the prepared Ni-nanowires
were performed by SEM imaging. To confirm these results and to probe the magnetic character of
the Ni nanowire sample, AFM and MFM micrographs were taken. The lateral periodicity over a
macroscopic distance and the buried sample structures were probed by off-specular x-ray scatteringand a Distorted-Wave Born Approximation based analysis was performed: first the specularreflectivity was extracted and a corresponding theoretical model was found by computer aided fitting.
The obtained transverse layer structure with corresponding averaged scattering length densities wasthen modified by lateral variations and used to simulate the off-specular scattering behavior withexcellent agreement between the measured and simulated intensities. These outstanding off-specular
x-ray scattering results motivated polarized off-specular neutron scattering measurements which will
also be presented.

Massimo Pasquale*, Carlo Paolo Sasso, Elena Sonia Olivetti, Marco Coisson andFederica Celegato
Divisione Elettromagnetismo, INRIM, Italy
We characterize and analyze the microwave behavior of columnar arrays of Co
nanowires (NW). The 50-60 nm diameter wires were electrochemically grown withdifferent lengths from 5 to 50 microns within anodic alumina templates. The NW
arrays present a high Ms, close to the Co bulk value and variable remanence states.
Depending on the combination of shape, magnetocrystalline anisotropy and dipolarinteractions, FMR frequencies from 7 to 25 GHz at 0 applied field were observed.
The wire composition, structure and the morphology were determined by XRD and
FESEM. The magnetic properties were measured using by AGFM, with field applied
perpendicularly or parallel to the wire axis. The macroscopic magnetic behavior appears
to be dominated by long-range magnetostatic interactions, but the magnetization stateof each nanowire, as determined by the AFM/MFM at the membrane surface[1], issaturated in the up or down direction. A complete characterization and analysis of the
field-and-frequency modulated microwave behavior of the arrays was performed using
an electromagnet to sweep the magnetic field from -1.3 T to + 1.3 T along the wireaxis, while measuring the absorption at single frequency values, from 1 to 40 GHz[2].
The results are interpreted with reference to measured magnetization curves.

[1] R. P. Cowburn and M. E. Welland 2000 Science 287 1466 [2] A. Imre, G. Csaba, L. Ji, A. Orlov, G. H. Bernstein and W.
Porod 2006 Science 311 205 [3] H. Nomura and R. Nakatani 2011 Appl. Phys. Express 4 013004

T. Adams et al., Phys. Rev. Lett. 107, 217206 (2011) S. Muhlbauer et al., Science 323, 915 (2009) A.
Neubauer et al., Phys. Rev. Lett. 102, 186602 (2009)

DE05

DF03

DG02

DG05

Energy-efficient control of vortex-core polarizations by tailoredorthogonal pulse currents in cross-point architecture

Magnetic textures and electron transport in chiral helimagnets

Elaboration and characterization of Cu/Co multilayered nanowires

In situ magnetic field dependent Lorentz microscopy in Co nanowires
grown by focused electron beam induced deposition

Young-sang Yu1, Ki-suk Lee1, Hyunsung Jung1, Youn-seok Choi1, Dong-soo Han1, Myoung-woo Yoo1, Mi-young Im2,
Peter Fischer2 and Sang-koog Kim1*
1
National Creative Research Initiative Center for Spin Dynamics & Spin-Wave Devices & Nanospinics Lab, ResearchInstitute of Adv. Materials, Dep. of Materials Sci. & Eng., Seoul Nat'l Univ., Seoul, Korea
2Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley CA 94720, USA

Magnetic vortices have been considered to be a potential candidate for information-storage applications due to their corebinary states, as well as energetically stable configurations. Recent findings [1] of vortex-core switching with low-power
consumption have stimulated further studies towards implementation of the magnetic vortices into actual nonvolatile random
access memory [2]. In this presentation, we are going to report a low-power-consumption and reliable manipulation ofvortex-core magnetizations in patterned magnetic disks. To achieve an alternative to switch the vortex-core magnetizations,
we applied rotating fields that are generated by two orthogonal Gaussian-pulse currents. The threshold field strength
required for vortex-core switching can be significantly reduced by optimizing the pulse widths and the time delay between
the orthogonal pulses [3]. We also demonstrated a remarkable reduction in the threshold strength using a coherent train ofrotating fields with their optimized time interval. For reliable memory-bit selection and information recording, we fabricated2 × 2 vortex-state disks with crossed electrodes and demonstrated selective vortex-core switching at the intersection of
the two crossed electrodes [4]. These results imply that the optimized pulse-type rotating fields in the basic cross-pointarchitecture are energy-efficient and reliable means of selective information recording based on magnetic vortex arrays.

Jun-ichiro Kishine1, Alexander Ovchinnikov2, Igor Proskurin2, Yoshihiko Togawa3, Yusuke Kousaka4 and
Jun Akimitsu4
1
Graduate School of Arts and Sciences, The Open University of Japan, Japan2
Department of Physics, Ural Federal University, Russia
3
N2RC, Osaka Prefecture University, Japan
4
Department of Physics, Aoyama Gakuin University, Japan

Julien Bran1, Malick Jean1, Rodrigue Larde1, Jean-marie Le Breton1* and Alain
Pautrat2
1Groupe de Physique des Materiaux - UMR 6634, CNRS - Universite de Rouen,
France2
CRISMAT, UMR 6508 CNRS, ENSICAEN - Universite de Caen, France

A coupling of free electrons with non-trivial spin textures has recently attracted a great attention because of anability to manipulate magneto-transport properties through a control of the background spin subsystem. In thispresentation, based on our recent two papers[1,2], I report magnetic texture formation and anomalous mangetotransport phenomena in magnetic crystals belonging to chiral space groups. In this class of magnets, the left- orright-handed helical spin texture along the crystallographic axis is stabilized by a competition between symmetricexchange and antisymmetric Dzyaloshinkii-Moriya (DM) exchange interactions. Then so-called chiral soliton
lattice (CSL) is formed under weak magnetic field applied perpendicular to the helical axis. The CSL behaves
as a magnetic superlattice potential and results in Bragg scattering of conduction electrons. Tuning of the weakmagnetic field enables us to control a size of the superlattice Brillouin zone and gives rise to a series of resistivity
anomalies originating from resonant Bragg scatterings. I will also mention CSL-related phenomena fromtheoretical viewpoints [3-5]. This talk is given from theoretical sides. A report from experimental sides will begiven in the same session by Prof. Yoshihiko Togawa from Osaka Prefectural University.

The Giant Magnetoresistance (GMR) effect discovered in 1988 [1] had inspired many researches onmagnetoresistive materials. It has been predicted by the Valet-Fert model [2] that this effect is higher when thecurrent is perpendicular to the layers (Current-Perpendicular-to-Plane CPP geometry). Over the past ten years, a
lot of research works were focused on multilayered nanowires. Indeed, these structures, exhibiting a large aspectratio (length/diameter), provide an ideal opportunity to investigate the CPP-GMR effect and represent goodcandidates for the development of new technologies in the high density storage domain. In our study, Cu/Co
multilayered nanowires were elaborated by a low cost electrochemical process consisting of reducing alternatively
the Cu2+ and Co2+ ions on a metallic substrate through a nanoporous template. Transmission Electron Microscopy(TEM) with Energy Dispersive Spectrometry was used to determine the roughness and the composition of eachlayer. Atom Probe Tomography (ATP) [3] was also used, additionally to conventional techniques, to characterize
our samples. The (Cu20nm/Co20nm) nanowires exhibit a ferromagnetic behaviour, with a strong anisotropy. The
magnetoresistance reaches 6% after a heat treatment at 450°C for 1 hour. The correlation between nanostructure
and both magnetic and magnetoresistive properties of the nanowires will be discussed.

*Corresponding author: sangkoog@snu.ac.kr [1] B. Van Waeyenberge et al., Nature 444, 461 (2006); M. Curcic et al., Phys.
Rev. Lett. 101, 197204 (2008); K.-S. Lee et al., Phys. Rev. Lett. 101, 267206 (2008). [2] S. -K. Kim et al., Appl. Phys. Lett. 92,
022509 (2008). [3] Y.-S. Yu et al., Phys. Rev. B 83, 174429 (2011). [4] Y.-S. Yu et al., Appl. Phys. Lett. 98, 052507 (2011). [5]This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF)
funded by the Ministry of Education, Science, and Technology (Grant No. 20110000441).

[1] J. Kishine, I. Proskurin and A. S. Ovchinnikov, Phys. Rev. Lett. 107, 017205 (2011). [2] Y. Togawa, T. Koyama, K.
Takayanagi, S. Mori, Y. Kousaka, J. Akimitsu, S. Nishihara, K. Inoue, A. S. Ovchinnikov, and J. Kishine, to appear in Phys. Rev.
Lett. [3] J. Kishine, A. S. Ovchinnikov, and I. Proskurin, Phys. Rev. B 82, 064407 (2010). [4] J. Kishine and A. S. Ovchinnikov,
Phys. Rev. B 79, 220405(R) (2009). [5] I. Bostrem, J. Kishine and A. S. Ovchinnikov, Phys. Rev. B78, 064425(2008).

DF01
Skyrmion dynamics in metallic chiral ferromagnet

Jung Hoon Han1, Jin-hong Park 1, Jiadong Zang 2, Naoto Nagaosa3 and Maxim
Mostovoy4
1
Physics, Sungkyunkwan University, Korea
2
Physics, Fudan University, China
3
Applied Physics, The University of Tokyo, Japan
4
Zernike Institute for Advanced Materials, University of Groningen, Netherlands
Chiral ferromagnetic materials have recently been shown to be important platforms
for the generation of novel topological spin texture called Skyrmions. Their easy
generation by moderate magnetic field at relatively high temperature is beginningto open up the potential for device and memory applications. In this talk, I will
review some history of its recent rapid development and present basic theory ofthermodynamics and dynamics of Skyrmions. To conclude, a possible means ofgenerating Skyrmions by purely electrical means, without relying on magnetic field,
will be discussed.
[1] Dynamics of Skyrmion Crystals in Metallic Thin Films, Jiadong Zang, Maxim Mostovoy, Jung
Hoon Han, and Naoto Nagaosa, Phys. Rev. Lett 107, 136804 (2011) [2] Skyrmion Lattice in TwoDimensional Chiral Magnet, Jung Hoon Han, Jiadong Zang, Zhihua Yang, Jin-Hong Park andNaoto Nagaosa, Phys. Rev. B 82, 094429 (2010) [3] Real-space observation of a two-dimensionalskyrmion crystal, X. Z. Yu, Y. Onose, N. Kanazawa, J. H. Park, J. H. Han, Y. Matsui, N. Nagaosaand Y. Tokura, Nature 465, 901 (2010)

The 19th International Conference on Magnetism[1] J. De La Torre Medina, et al., PRB 81, 144411 (2010) [2] B.K. Kuanr JMMM 286 (2005) 276281

Luis Alfredo Rodriguez1, Cesar Magen2*, Luis Serrano-ramon3, Etienne Snoeck4, Rosa Cordoba1, JoseMaria De Teresa3 and Manuel Ricardo Ibarra1
1
LMA-INA, Universidad de Zaragoza, 50018, Zaragoza, Spain
2
LMA-INA and ARAID, Universidad de Zaragoza, 50018, Zaragoza, Spain
3
ICMA, Universidad de Zaragoza-CSIC, 50009, Zaragoza, Spain
4
CEMES-CNRS 29, rue Jeanne Marvig B.P. 94347 F-31055, Tolouse Cedex, France

The accurate characterization and control of the magnetic configuration in nanostructures, namely domain
walls (DWs) or vortex structures, by external parameters such as the magnetic field is essential for applications
such as information storage, sensing or magnetic logic [1]. Transmission electron microscopy (TEM) allows
the observation of the magnetic nanostructures with nanometer-range spatial resolution by Lorentz microscopy(LM). In this work, we performed in 1situ characterization and magnetic-field manipulation of DWs by LM in
Co nanowires (NWs) in a FEI Titan Cube 60-300 TEM. These NWs were fabricated by focused electron beam
induced deposition (FEBID) with purity higher than 90% on Si3N4 membranes [2]. We determined the nucleationand propagation field of DWs by direct observation of the magnetic structure by LM of curved L-shape Co NW
with varying width (w=125-1000 nm) and thickness (t=5-30 nm), demonstrating that for specific dimensions they
are good DW propagators [3]. Focal series in LM were acquired in order to map the in-plane magnetic induction
by solving the Transport-of-Intensity Equation. The nucleation process gives rise to transversal DW in the thinner
NWs (t < 13 nm). Above this value, the crossover to complex structures was investigated, including multiple
vortex walls on the thicker NWs.

[1] M. N. Baibich, J. M. Broto, A. Fert, F. Nguyen Van Dau, F. Petroff, P. Etienne, G. Creuzet, A. Friederich, and J.
Chazelas, Phys. Rev. Lett., 61(21) (1988) 2472-2475. [2] T. Valet and A. Fert, Phys. Rev. B, 48 (1993) 7099-7113. [3]
D. Blavette, B. Deconihout, A. Bostel, J.M. Sarrau, A. Menand, Rev. Sci. Instrum., 64 (1993) 2911.

[1] C. Chappert, A. Fert, F. N. Van Dau, Nature Materials., 6 813-823 (2007). [2] L. Serrano-Ramon et al., ACS Nano,
5 7781-7787 2011. [3] L. A. Rodriguez et al., in preparation.

DF04

DG03

DG06

The hexagonal spin structure of A-phase in MnSi

Microstructure and magnetic properties of as-deposited and annealed
FeCo-based nanowires

Morphology and magnetic properties of GaAs/(Ga,Mn)As core-shell
nanowires on Si (111) synthesized by self-catalyzed method

Ordered arrays of ferromagnetic nanowires are recently becoming the subject of intense research due totheir potential as magnetic memory and sensor devices, as well as in spintronic and medical applications[1-2]. FeCo nanowires exhibit the necessary capability to be employed in novel generation of rareearth free nanocomposite permanent magnets due to their high Curie temperature, large saturation
magnetization, and relatively strong magnetocrystalline and inherent large shape anisotropies. Magnetic
properties of FeCo alloys can be further tailored by adding other elements [3]. Anodic Aluminum Oxide
membranes have been employed as templates to prepare highly ordered FeCo, FeCoCu alloy single
nanowire and FeCo/Cu multilayer nanowire arrays with different diameters and alloy concentrations.
As-deposited nanowire arrays were annealed in the temperature range up to 600ºC, and their structure
and magnetic properties analyzed. The angular and temperature dependence of magnetic behavior havebeen investigated revealing the role of the effective magnetic anisotropy in the coercivity mechanism.
With increasing the annealing temperature both, the coercivity and squareness of hysteresis loop increase.
Furthermore, the influence of applied magnetic field during the deposition is investigated to result in the
improvement of the alignment of easy axis and induction of magnetic anisotropy.

Diluted magnetic semiconductors, of which (Ga,Mn)As as a representative, andsemiconductor nanowires (NWs) both have been hot issues of research in thepast decade, due to their potential to enlarge and strengthen semiconductor based
technology. Much work has been done on both systems respectively while few efforts
are invested in their combined system until recently. It is of advantage to integrate
such system on silicon, the most commonly used semiconductor, which our workfeatures. Here, we present our work on GaAs/(Ga,Mn)As core-shell NWs synthesizedon Si (111) substrate. Another characteristic of our work is self-catalyzed growthwhich utilizes no foreigner particles as seeds. We have attempted to incorporate
different manganese content but it is found only a narrow growth window is permitted
for successful fabrication. Magnetic properties of GaAs/(Ga,Mn)As core-shell aremeasured by SQUID. Magnetic hysteresis loops (M-H) along in-plane and out-of plane
direction at 5 K show robust ferromagnetism and temperature dependence of remanent
magnetization (M-T) reveals the Curie temperature of 20 K.

Sergey Grigoriev1*, Nadezhda M. Potapova1, Evgeny V. Moskvin1, Vadim A.
Dyadkin1, Charles Dewhurst2 and Sergey V. Maleyev1
1
Condensed Matter Department, Petersburg Nuclear Physics Institute, Russia
2
Institute Laue-Langevin, France
Inspired by recent work [1] we have revisited the cubic helimagnet MnSi to address
the question of the origin of A-phase in the (H-T) phase diagram. In the present
experiments we used the experimental geometry described in [1] when the magnetic
field was applied along the neutron beam. We have mapped the A-phase boundaries
in the field-temperature (H-T) phase diagram for three principal crystal-to-fieldorientations (H || [111], H || [110], H || [100]). The A-phase revealed itself on theneutron diffraction map as a hexagonal pattern of Bragg spots in a narrow range ofthe fields [0.12-0.20] T close to $T_C$ = 29 K. The orientational and translational
orders (the directions and value of structure wavevectors k) are well preserved within
the A-phase over the whole crystal of the size of 100 mm3. The small angle neutron
scattering ascribed to the orientationally disordered hexagon spin structure wasobserved beyond the A-phase boundaries in the field range from H_D1 = 0.1 T to H_
D2 = 0.25 T at temperatures down to 25 K. Contrary to the A-phase boundaries, thevalues of H_D1 and H_D2 are temperature independent for all the field-to-crystal
orientations.
[1] S. Muhlbauer, B. Binz, F. Jonietz, C. Pfleiderer, A. Rosch, A. Neubauer, R. Georgii, P. Boni,
Science 323 (2009) 915-919.

Cristina Bran1*, Javier Garcia2, Victor Prida2, Rafael Perez Del Real1 and Manuel Vazquez1
1
Institute of Materials Science of Madrid, CSIC. 28049 Madrid, Spain
2
Dept. Fisica, Universidad de Oviedo. 33007 Oviedo, Spain

Oral Tuesday

Hikaru Nomura*, Yukihiro Imanaga, Yusuke Hiratsuka and Ryoichi Nakatani
Division of Materials and Manufacturing Science, Osaka University, Japan

60

oRAL PRSENTATION

Xuezhe Yu, Hailong Wang and Jianhua Zhao*
State Key Laboratory of Superlattices and Microstructures, Institute of
Semiconductors, Chinese Academy of Sciences, China[1] Zheng, H.; Wang, J.; Lofland, S. E.; Ma, Z.; Mohaddes-Ardabili,L.; Zhao, T.; Salamanca-Riba, L.; Shinde,
S. R.; Ogale, S. B.; Bai,F.; Viehland, D.; Jia, Y.; Schlom, D. G.; Wuttig, M.; Roytburd, A.;Ramesh, R. Science,
303, 661-663, 2004. [2] Skomski, R. J. Phys.: Condens. Matter, 15, R841-R896, 2003. [3] Ramazani, A.,
Kashi, M. A. Kabiri, S., Zanguri, M., J of Crystal Growth 327, 78-83,2011.

July 8-13, 2012 Busan, Korea

61

ORAL PRESENTATION
DH01

DH04

DI02

DJ02

Novel functionality and devices via complex oxide heteroepitaxy

Electrical switching of the magnetic phase in semiconductor oxides

Seebeck spin tunneling in silicon

Magnetocaloric properties of doped La0.7Sr0.3MnO3 bulk ceramic andthick films

Antonio Ruotolo1, Xiao Lei Wang1, Chi Wah Leung2 and Rolf Lortz3
1
Department of Physics and Materials Science, City University of Hong Kong, Hong
Kong
2
Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong
3
Department of Physics, Hong Kong University of Science and Technology, Hong
Kong

Jong-woo Kim*, Jungho Ryu, Byung-dong Hahn, Jong-jin Choi, Woon-ha Yoon,
Cheol-woo Ahn, Joon-hwan Choi and Dong-soo Park
Korea Institute of Materials Science (KIMS), Korea

The combination of thermoelectrics and spintronics offers unique possibilities. On the
one hand, it provides a new, spin-based approach to thermoelectric power generationand cooling. On the other hand, it provides a thermal route to create and control theflow of spin in spintronic devices that make functional use of heat and temperature
gradients. Here we describe and report the demonstration of Seebeck spin tunneling a thermally driven spin flow, of purely interfacial nature - generated in a tunnel contact
between electrodes of different temperatures. Seebeck spin tunneling arises fromthe spin dependence of the Seebeck coefficient of a tunnel junction and is thus thethermoelectric analog of spin-polarized tunneling. By exploiting this in ferromagnetoxide-silicon tunnel junctions, we observe a thermal flow of spin angular momentum
from the ferromagnet to the silicon without a charge tunnel current. The spin
accumulation induced in the silicon scales linearly with heating power and changes
sign when the temperature differential is reversed. This thermal spin current can beused by itself, or in combination with electrical spin injection. The results highlight theengineering of heat transport in spintronic devices and enable the (re-)use of heat toincrease device efficiency and reduce energy consumption.

The LaSrMnO3 manganite has attracted research interests due to its colossal magneto resistanceeffect, half-metallic behavior and magnetocaloric effect [1-3]. The magnetocaloric effect is thereversible temperature change of a magnetic material associated with external magnetic field change
in an adiabatic process. These properties are strongly related with the interactions between the rareearth and transition metal’s charge states which can be varied by doping elements [4, 5]. In this study,
the physical properties of magnetocaloric La0.7Sr0.3MnO3 (LSMO) ceramic system, in both bulk andthick film, have been investigated according to various B-site elements doping. The substituted B-siteelements were transition metal elements, i.e. Cr, Co, Ni, Cu with its contents of 0 ~ 3 %. The ceramic
samples were prepared by conventional solid-state reaction process. The thick films were grown
by Aerosol Deposition (AD) method [6, 7] on various substrates. The magnetocaloric properties
measured by physical property measurement system (PPMS) in magnetic field up to 30 kOe andtemperature range up to 400 K. In this presentation, the magnetocaloric properties of the entropychange, TC variation, Banerjee criterion [8] etc. according to the B-site doping and substrate effects
will be discussed in detail.

[1] Ohno, Nature 408, 944-946 (2000). [2] Yang, Nat. Nanotech. 3, 429 (2008). [3] Lee, Nat. Mater. 10, 625 (2011).

J.C. Le Breton, S. Sharma, H. Saito, S. Yuasa and R. Jansen, Nature 475, 82 (2011). R. Jansen, A.M.
Deac, H. Saito and S. Yuasa, Preprint at http://arxiv.org/abs/1112.3430 (2011).

[1] Physical Review Letters, 71 (1993) 2331-2333. [2] Reports on Progress in Physics, 68 (2005) 1479-1539. [3] J Magn Magn
Mater, 308 (2007) 325-340. [4] Physical Review Letters, 74 (1995) 5144-5147. [5] Journal of Physics Condensed Matter, 20 (2008).
[6] Sensor Actuat a-Phys, 153 (2009) 89-95. [7] Materials Letters, 65 (2011) 2762-2764. [8] Physics Letters, 12 (1964) 16-17.

DH02

DH05

DI03

DJ03

Quantum oscillations and subband properties of the LaAlO3/SrTiO3
heterointerface

An approach to achieve layered spintronics material using
Brownmillerite compound Ca2.5Sr0.5GaMn2O8

Tunneling magneto Seebeck effect

Structural ,magnetic and magnetocaloric properties of Ni50Mn37.5Sn12.5
ribbon Heusler alloys

Interfaces of complex oxides materials provide a rich playground for the explorationof novel properties not found in the bulk constituents but also for the development offunctional interfaces to be incorporated into technological applications. In this talk,I will present two recent examples of our work. We have demonstrated metallicity
in epitaxial LaTiO3 and LaVO3 thin films under compressive epitaxial strain,
although both are Mott insulators in the bulk; films under little to no epitaxial strain
exhibit insulating behavior. The metallicity in LaTiO3 can be understood in termsof a modification of the electronic structure due to anisotropic lattice distortions.
The metallicity in LaVO3 is an interface effect that may be attributed to electronic
reconstruction. We have also developed a new class of spin filter devices composed
entirely of magnetic layers. In these devices, spin polarized conduction is dominatedby interface scattering or localized states depending on temperature. Throughcareful investigation of the magnetism at the interfaces, we have found that there
is no magnetic coupling at one interface and strong interface coupling at the other.
The nature of magnetism at these interfaces is essential in the realization of our allferromagnet junction device.

Alix Mccollam1*, Sander Wenderich2, Michelle Kruize2, Veerendra Guduru1, Hajo Molegraaf2, Mark
Huijben2, Gertjan Koster2, Dave Blank2, Guus Rijnders2, Alexander Brinkman2, Hans Hilgenkamp2, Ulrich
Zeitler1 and Jan Kees Maan1
1High Field Magnet Laboratory, Radboud University Nijmegen, Netherlands
2
MESA+ Institute for Nanotechnology, University of Twente, Netherlands

Heterostructures of transition metal oxides offer myriad possibilities for multifunctional materials and device
applications, as well as demonstrating new and complex fundamental properties [1-4]. Much of their potential
stems from the possibility of interface properties that differ dramatically from those of the bulk components,
and the discovery of a 2-dimensional electron gas at the interface between band insulators LaAlO3 andSrTiO3[1] is a striking realisation of this. Understanding and controlling this 2D electron gas is currently thecentral problem in the field. Here I will present the results of recent magnetotransport measurements of the
LaAlO3/SrTiO3 interface, performed at millikelvin temperatures and in magnetic fields of up to 30 T. Quantum
oscillations observed in the resistivity allow us to probe the bandstructure of the interface electron gas, andextract important information about the band energies and the properties of the mobile charge carriers. The
strong dependence of the oscillations on magnetic field, temperature, and orientation with respect to the planeof the interface, reveals a complex 2D system of closely-spaced multiple electronic subbands with different
carrier effective masses and mobilities. Measurements in tilted magnetic fields show evidence of inter-subband
scattering and diamagnetic shift of the 2D confinement energies.

The magnetic properties of thin-film ferromagnetic semiconductors can be alteredby applying an electric field[1]. The effect is reversible but volatile. However, fortechnological applications, it would be desirable to have a film that retains the induced
magnetic state until a reset command is given. We here demonstrate that the magnetic
moment of a ferromagnetic oxide can be altered in a non-volatile and reversible manner.
The studied system consists of Zn0.98Mn0.02O (ZMO) film sandwiched between a highly
conductive Niobium Strontium Titanate (NSTO) substrates and a Platinum (Pt) top
electrode. The current-voltage curves revealed that the electrical behavior was dominatedby the Schottky interface between the NSTO and the ZMO. Reversable resistive
switching[2,3] could be induced in the samples with high reliability and good retention
time. By measuring the full magnetization loop, we found that a switching of theresistance corresponds to a switching of the magnetic phase. Remarkably, the thresholdswitching current was ~ 1 A/cm2 in film devices, as well as in patterned devices. This isorders of magnitude smaller than that reported in similar, non-magnetic systems[2,3].

S. M. Yusuf* and A. K. Bera
Solid state physics division, bhabha atomic research centre, mumbai 400 085, India

Naturally occurring layered magnetic materials can play a significant role inshaping the next generation technology in the area of magnetic storage. We have,therefore, studied the magnetic and magnetotransport properties of the La-substituted
compounds Ca2.5-xLaxSr0.5GaMn2O8 (x = 0, 0.05, 0.075, and 0.1). We have succeeded
to introduce the double exchange (DE) interaction in the pure antiferromagnetic
system Ca2.5Sr00.5GaMn2O8 by varying the ratio between Mn3+ and Mn4+ ions. The
experimental results of dc magnetization, magnetotransport and neutron diffraction
studies were interpreted on the basis of an electronic phase separation model, wherea formation of ferromagnetic clusters (due to DE interaction) inside the layered
antiferromagnetic matrix (due to superexchange interaction) in the La-substituted
compounds is proposed. Significantly, the present study shows that the magnetic andelectronic properties of the layered system Ca2.5Sr00.5GaMn2O8 can be tuned/optimized
by appropriate chemical substitution to achieve a new spintronic material based onnaturally occurring layered system for practical applications.

[1] A. Ohtomo et al., Nature 427, 423 (2004). [2] A. Brinkman et al., Nature Materials 6, 493 (2007). [3] N. Reyren et al.,Science 317, 1196 (2007). [4] H.Y. Hwang et al., Nature Materials 11, 103 (2012).

62

Ron Jansen
National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba,
Ibaraki, Japan

Andy Thomas1, Markus Munzenberg2 and Christian Heiliger3
1
Physics, Bielefeld University, Germany
2
Physics, Gottingen University, Germany
3
Physics, Gießen University, Germany
Creating temperature gradients in magnetic nanostructures has resulted in a newresearch direction, that is, the combination of magneto- and thermoelectric effects.
Here, we demonstrate the observation of one effect of this class: the tunneling magnetoSeebeck effect. It is observed when a magnetic configuration changes the charge-based
Seebeck coefficient. In particular, the Seebeck coefficient changes during the transition
from a parallel to an antiparallel magnetic configuration in a tunnel junction. In thisrespect, it is the analog of the tunnelling magnetoresistance. The Seebeck coefficientsin parallel and antiparallel configurations are of the order of the voltages known fromthe charge Seebeck effect. The size and sign of the effect can be controlled by thecomposition of the electrodes’ atomic layers adjacent to the barrier and the temperature.
We realized up to 40% tunneling magneto-Seebeck effect and up to 330% TMR
ratio in MgO based magnetic tunnel junctions. We show the temperature dependent
investigations of this effect, supported by TEM studies of the microstructure, numeric
simulations of the temperature profile in the junction and possible devices utilizing thetunneling magneto Seebeck effect.

Mst. Nazmunnahar1*, Lorena Gonzalez2, Juanjose Delval1, Joanjosep Sunyol3,
Julianmaria Gonzalez1 and Blanca Hernando2
1
Material Physics Department, University of Basque Country(UPV/EHU), Spain
2
Material Physics Department, University of Oviedo, Spain
3
Material Physics Department, University of Girona, Spain
We present a detailed study of the magnetic and microstructural behavior of Ni50Mn37.5Sn12.5 Heusler
ribbon alloy, which valence electron concentration per atom = 8.12. This ribbon, as flakes, around
1.5 - 2.0 mm width and 4 -5 mm length, was obtained after quenching the master alloy by the meltspinning technique in Ar atmosphere. Scanning Electron Microscopy (SEM, JEOL 6100) revealed
a columnar structure of the Heusler-Based alloy. The averaged composition was determined by
EDX (Inca Energy 200) from measurements taken at different points of the sample, obtaining
Ni49.4Mn36.7Sn13.9. Differential Scanning Calorimetry (DSC) and thermomagnetic curves confirm an
austenite-martensite structural transformation below 400K. The start and finish temperatures of themartensitic phase transformation for the ribbon alloy were Ms = 279 K and Mf = 260 K, while theones for austenite were As = 272 K and Af = 288 K, in agreement with previously reported values
in similar compositions [1]. Moreover, it has been performed a study of magnetocaloric effect (MCE)by thermomagnetic measurements from which a direct and inverse magnetocaloric effects nearCurie point and martensitic transformation temperature have been respectively observed.

[1] M. Walter et al., Seebeck effect in magnetic tunnel junctions, Nature Materials 10 (2011) 742[1] S.E. Muthu et al., J. Phys. D : Appl. Phys., 43 (2010) 425002

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Electronic ordering in sodium cobaltate

Magnon-drag thermopile

Novel clathrate-based composite materials for energy-efficientmagnetic refrigeration

Dependence of the magnetocaloric effect in ferromagnetic shapememory Heusler alloys on measurement protocol

Daniel Graham Porter1, Michel Roger2, Andrew Boothroyd3, Carlo Vecchini4, Steve
Collins4, S. Uthayakumar1, D. Prabhakaran3, Manoj Pandiyan1 and Jon Goff1
1
Department of Physics, Royal Holloway University of London, United Kingdom2Service de Physique de l'Etat Condense, CEA Sarclay, France
3
Clarendon Laboratory, University of Oxford, United Kingdom
4
Diamond Light Source, Harwell Science and Innovation Campus, United Kingdom

M. V. Costache1, G. Bridoux1, I. Neumann2 and S. O. Valenzuela3
1
Catalan Institute of Nanotechnology (ICN), Spain
2
Catalan Institute of Nanotechnology (ICN) and Universitat Autonoma de Barcelona(UAB), Spain
3
ICREA, Catalan Institute of Nanotechnology (ICN) and Universitat Autonoma deBarcelona (UAB), Spain

Sodium cobaltate (NaxCoO2) has emerged as a material of exceptional scientific interest
due to the potential for thermoelectric applications, and because the strong interplay
between the magnetic and superconducting properties has led to close comparisons withthe physics of the superconducting copper oxides. The density x of the sodium in theintercalation layers can be altered electrochemically, directly changing the number ofconduction electrons on the triangular Co layers. Previous measurements have determined
the long range ordering of sodium superstructures for different values of x, and numericalcalculations have found that this ordering has a profound effect on the charge carrying
cobalt layer. Multiple valence states have been detected by NMR, but here we report new
spatial measurements using Resonant X-ray Scattering on the Materials and Magnetism
beamline I16 at Diamond. The sodium vacancies are found to condense into tri-vacancy
clusters, and these order long range into stripes. We find resonant x-ray scatteringwith the same periodicity as the sodium superstructure, directly demonstrating that theelectronic ordering in these cobalt layers is controlled by the sodium ordering. We areable to reproduce the energy, polarisation and azimuthal dependencies of the resonant
x-ray scattering in calculations using the FDMNES code.

Thermoelectric effects in spintronics are gathering increasing attention as a means of controlling spin
information by using heat flow. Thermal magnons (spin-wave quanta) are expected to play a majorrole, however, the coupling between electrons and magnons in ferromagnetic metals remains poorly
understood. We demonstrate a conceptually new device that enables us to gather information on magnonelectron scattering and magnon-drag effects[1]. The device resembles a thermopile formed by a large
number of pairs of ferromagnetic wires placed between a hot and a cold source and connected thermallyin parallel and electrically in series. By controlling the relative orientation of the magnetization in pairsof wires, the magnon drag can be studied independently of the electron and phonon drag thermoelectriceffects. Measurements as a function of temperature reveal the effect on magnon drag following a variationof magnon and phonon populations. These results demonstrate the feasibility of directly converting
magnon dynamics of nanomagnets into an electrical signal and could pave the way to novel thermoelectric
devices for energy harvesting. This research was supported by the Spanish Ministry of Science (MICINN/
MAT2010-18065) and by the European Community (FP7/NANOFUNCTION-257375).

The 19th International Conference on Magnetism

Anurag Chaturvedi, Stevce Stefanoski, George S. Nolas, Hariharan Srikanth andManh-huong Phan*
Department of Physics, University of South Florida, USA

Magnetic refrigeration based on the magneto-caloric effect (MCE) is an area of
exciting research. The grand challenge in this technology is to seek new material
that exhibits large MCE over a wide temperature range, namely, the large refrigerant
capacity (RC). In this talk, we will present our recent discoveries of the large MCE and
RC in Eu8Ga16Ge30 type-I and type-VIII clathrates and Eu8Ga16Ge30 - EuO composite
materials. We demonstrate that the tunneling of Eu2+ ions in the Eu8Ga16Ge30 type I
clathrate leads to the broadened MCE curve thus enhancing the RC in this material.
This new finding may provide a route for improving the cooling efficiency in type-I
clathrate materials for active magnetic refrigeration (AMR). The large table-like MCE
and enhanced RC have been achieved in the Eu8Ga16Ge30 type I - EuO composite
materials, making them one of the best candidates for AMR in the liquid nitrogentemperature range.

Oral Tuesday

Yuri Suzuki1*, Franklin Wong2, Chunyong He2, Brittany Nelson- Cheeseman2 andElke Arenholz3
1
Applied Physics, Stanford University, USA
2
Materials Science and Engineering, University of California, Berkeley, USA
3
Advanced Light Source, Lawrence Berkeley National Laboratory, USA

Oral Tuesday

oRAL PRSENTATION

Vladimir Khovaylo1*, Konstantin Skokov2, Hiroyuki Miki3 and Oliver Gutfleisch2
1
National University of Science and Technology 'MISiS', Moscow 119049, Russia
2
Institute for Metallic Materials, P.O. Box 270016, D-01171 Dresden, Germany
3Institute of Fluid Science, Tohoku University, Sendai 980-8577, Japan

Results of direct measurements of the magnetocaloric effect in ferromagnetic shapememory alloys (FSMAs) Ni-Mn-X (X = Ga, In, Sn) showed that the adiabatic
temperature change ΔTad is (i) small (typically smaller than in prototypicalmagnetocaloric material Gadolinium) and (ii) depends on thermal as well as on
magnetic history of FSMAs samples. Here we discuss these features of ΔTad andshow that the measurement protocol determines whether the adiabatic temperaturechange is reversible or irreversible. These characteristic of ΔTad are easy to understandconsidering thermodynamics of temperature- and magnetic field-induced thermoelastic
martensitic transformations in the vicinity of the magnetostructural phase transition.

[1] M.V. Costache, G.A. Bridoux, I. Neumann and S.O. Valenzuela, Nat. Mater. Advanced Online
Publication (2011). http://dx.doi.org/10.1038/NMAT3201

July 8-13, 2012 Busan, Korea

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ORAL PRESENTATION
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EB02

Magnetocaloric effects in manganites with perovskite structure

Sequential spin polarization of the fermi surface pockets in URu2Si2
and its implications for the hidden order

Correlated electrons in strong electric fields

Magnetocaloric refrigeration is a promising alternative technique to replace theconventional gas expansion-compression one based on the use of toxic gases. This
novel technology presents several advantages, in fact besides the property of being
environmentally friendly (it does not use coolants or emit greenhouse gases), it
undergoes a higher efficiency and it is compact in size. Magnetocaloric materials, whensubjected to a magnetic applied field at their phase transition temperature, undergoa magnetic transition which results in the entropy change of the magnetocaloric
materials. This phenomenon is known as the magnetocaloric effect (MCE). The familyof magnetic oxides with perovskite structure known as manganites have also shown
interesting MCE, for a large temperature range around room temperature. In this work,
we were interested in the study of the MCE in manganites with several compositions.
Several compounds with general formula La1-xMxMnO3 (M is a divalent alkali-earth
or monovalent elements) have been elaborated and characterized. The entropy change
versus temperature and versus magnetic applied field will be presented. Our results,
compared to that observed in Gd or GdSiGe, show that the manganites exhibit a
giant MCE around or above room temperature and are suitable for applications in themagnetic refrigeration area.

1

1

2

1

3

Neil Harrison , Moaz Altarawneh , Luis Balicas , P H Tobash , J D Thompson , F
Ronning3 and E D Bauer3
1
National High Magnetic Field Laboratory, Los Alamos National Laboratory, USA
2
National High Magnetic Field Laboratory, Tallahassee, USA
3
Los Alamos National Laboratory, USA

Using Shubnikov-de Haas oscillations measured in URu2Si2 over a broad range in amagnetic field of 11-45 T, we find a cascade of field-induced Fermi surface changes
within the hidden order phase I and further signatures of oscillations within fieldinduced phases III and V. A comparison of kinetic and Zeeman energies indicatesa pocket-by-pocket polarization of the Fermi surface leading up to the destructionof the hidden order phase I at ~35 T. The anisotropy of the Zeeman energy driving
the transitions in URu2Si2 points to an itinerant hidden order parameter involving
quasiparticles whose spin degrees of freedom depart significantly from those of freeelectrons.

Philipp Werner1, Martin Eckstein2, Naoto Tsuji1, Takashi Oka3 and Hideo Aoki3
1
Department of Physics, University of Fribourg, Switzerland
2
Max Planck Research Department for Structural Dynamics, University of Hamburg- CFEL, Germany
3
Department of Physics, University of Tokyo, Japan
We use the nonequilibrium extension of dynamical mean field theory to study the
dynamics of the Hubbard model in the presence of external electric fields. Specifically,
we discuss the transition from a Bloch oscillating to a direct current regime in weaklyinteracting systems subject to static electric fields [1], and the dielectric breakdown of
the Mott insulator [2]. In periodically driven metallic systems, the electric field maylead to a dynamical band inversion and an associated conversion of the effective onsite interaction from repulsive to attractive [3].
[1] M. Eckstein and P. Werner, Phys. Rev. Lett. 107, 186406 (2011) [2] M. Eckstein, T. Oka, and P.
Werner, Phys. Rev. Lett. 105, 146404 (2010) [3] N. Tsuji, T. Oka, P. Werner, and H. Aoki, Phys. Rev.
Lett. 106, 236401 (2011)

Physical Review Letters 106 (14):146403 [2011]

Electronic structure and phonons in the high pressure phases of cerium
Borje Johansson1,2 * and D.y. Kim3

1
2
3

Department of Materials and Engineering, Royal Institute of Technology, Stockholm, Sweden
Department of Physics, Uppsala University, Uppsala, Sweden
Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC, USA

The isostructural γ-α transition in cerium under pressure has attracted a very extensive interest bothexperimentally and theoretically over the years. Since long it has also been known that at a pressurearound 6.5 GPa cerium adopts the α-uranium crystal structure (oC4). Recent developments have madeit possible to use inelastic X-ray scattering to determine the phonon dispersions of elemental ceriumin these high pressure structures1,2. This opened the possibility to compare the experimental data withtheoretical calculations. When the 4f electrons in cerium are treated as itinerant a very good agreement
was obtained. Very interestingly, also the observed pronounced phonon anomalies in Ce-oC4 were
well described by theory and points out a very close similarity between uranium and Ce-oC4. At
the low-pressure end of its stability range, theory suggests that Ce-oC4 is on the verge of a latticedynamical instability and possibly a charge density wave. When this success of the itinerant picture
for the 4f behavior in the high pressure phases of cerium is combined with the well-known knowledge
that the 4f electron in γ-cerium is well described by a localized picture, one arrives at the conclusionthat the γ-α transition in cerium is a Mott transition3.
1. M. Krisch, D. L. Farber, R. Xu, D. Antonangeli, C. M. Aracne, A. Beraud, T.-C. Chiang, J. Zarestky, D. Y. Kim, Eyvaz I.
Isaev, R. Ahuja, and B. Johansson, Proceedings of the National Academy of Sciences of the United States of America(PNAS), 108, 9342 (2011) 2. I. Loa, Eyvaz. I. Isaev,M. I. McMahon, D.Y. Kim, B. Johansson, A. Bosak and M. Krisch,Phys. Rev. Letters 108, 045502 (2012) 3. B. Johansson, Philos. Mag. 30, 469 (1974).

A. CHEIKHROUHOU1,2, W. CHEIKHROUHOU-KOUBAA1, M. KOUBAA1 1Laboratoire de Physique des Materiaux,
Faculte des Sciences de Sfax, B. P. 1171, Sfax, Tunisia 2Institut Neel, CNRS, B. P. 166, 38042 Grenoble Cedex 9, France

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EB03

EC02

Quantum phase transitions in heavy-fermion systems

Hydrostatic pressure study of the nematicity of Sr3Ru2O7

Photoinduced charge order enhancement in one-dimensional extended
hubbard model

From SOC induced phenomena to non-collinear magnetism andelectric field effects in magnetic systems

Hilbert V. Lohneysen*
Karlsruher Institut fur Technologie, Physikalisches Institut and Institut fur
Festkorperphysik, Germany
The canonical heavy-fermion system CeCu6-xAux exhibits a quantum phase transition(QPT) that can be accessed by varying the Au concentration x, hydrostatic pressurep, and magnetic field B. Its unusual features have prompted the suggestion of a novel
type of QPT not envisaged by the extension of the Landau-Ginzburg-Wilson theoryof (classical) phase transitions to T = 0 by Hertz, Millis and Moriya. We will review
a range of new experiments on this system: (1) probing the Kondo resonance upon
approaching the QPT by photoelectron spectroscopy, (2) establishing a link between thepressure and concentration dependence of the magnetic ordering vector as determinedby elastic neutron scattering, (3) comparing the volume and magnetic Gruneisenparameters obtained from thermal expansion and magnetocaloric effect, repectively,and (4) determining the thermoelectric power close to the critical concentration xc. CePdAl is a heavy-fermion system with partial geometric frustration of one of the three
Ce atoms in the unit cell. We will report on first experiments exploring the possible roleof frustration on quantum criticality which can be accessed by Ni doping.

Dan Sun1, Wenlong Wu1, Santiago Grigera2, Robin Perry3, Andrew Mackenzie2 andStephen Julian1*
1
The Department of Physics, University of Toronto, Canada
2
Scottish Universities Physics Alliance, School of Physics and Astronomy, Universityof St. Andrews, United Kingdom
3
Centre for Science at Extreme Conditions, School of Physics, University of
Edinburgh, United Kingdom

Hantao Lu 1, Shigetoshi Sota 1, Hiroaki Matsueda 2, Janez Bonča 3,4 and Takami
Tohyama1
1
Yukawa Institute for Theoretical Physics, Kyoto University, Japan
2
Sendai National College of Technology, Sendai, Japan
3
Faculty of Mathematics and Physics, University of Ljubljana, Slovenia
4
J. Stefan Institute, Slovenia

A 'electron-nematic phase' occurs in the bilayer ruthenate Sr3Ru2O7, at very low temperaturein the vicinity of a metamagnetic transition. It has been seen when the applied magnetic field,
B, makes a large angle with the ab-plane [1,2,3]. The nematic phase is characterized by aspontaneously broken rotational symmetry for resistivity within the ab-plane. The underlying
physics is not understood, but it is believed to be associated with a 'quantum critical endpoint' (QCEP) for the metamagnetic transition [2]. We show, using transport and magnetic
susceptibility measurements on ultra-pure crystals, that this metamagnetic transition does notproduce a nematic phase when the QCEP is reached by applying hydrostatic pressure [4] withthe field applied in ab-plane. Moreover, a nearby region of nematicity is found to be robust
against the application of pressure. Taken together our results suggest that proximity to aquantum critical point may not be the crucial ingredient for the nematicity.

We present a compelling response of a low-dimensional strongly correlated system
to an external optical perturbation[1]. By using time-dependent Lanczos method, thenonequilibrium evolution of one-dimensional Hubbard model at half-filling driven bytransient laser pulse is investigated. When the system is close to the phase boundary,by tuning the laser frequency and strength, a sustainable charge order enhancement
is found that is absent in the Mott insulating phase. We analyze the conditions andinvestigate possible mechanisms of emerging charge order enhancement. From thespectrum analysis on small size systems, it can be shown that with increasing thenearest-neighbor interactions, charge-order favorite eigenstates proliferate in the low
energy regime, leaving themselves prone to be picked up by laser pulse. Feasible
experimental realizations are proposed.

[1] S. A. Grigera et al., Science 306, 1154 (2004). [2] R. A. Borzi, S. A. Grigera, J. Farrell, S. J. S. Lister, S. L. Lee, D.
A. Tennant, Y. Maeno, and A. P. Mackenzie, Science 315, 214 (2007). [3] A.W. Rost, R. S. Perry, J. F. Mercure, A. P.
Mackenzie, and S. A. Grigera, Science 325, 1360 (2009). [4] W. Wu et al., Rev. B 83, 045106 (2011).

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EB01

Lifshitz transitions and non-fermi liquid behavior in heavy-fermion
metalsPump-probe response for correlated electron systems out of
equilibrium

Matthias Vojta*
Institut fuer Theoretische Physik, Technische Universitaet Dresden, Germany

The field-driven non-Fermi liquid behavior in YbRh2Si2 has been proposed to arise
from a reconstruction of the Fermi surface due to a breakdown of Kondo screening.
Here we discuss an alternative scenario, namely a Zeeman-driven Lifshitz transition ofa narrow heavy-fermion band, with Kondo screening remaining intact. Apparent nonFermi liquid behavior emerges in a crossover regime above a small effective Fermi
energy. As carrier doping provides a unique knob to tune the Lifshitz transition, we
discuss the evolution of heavy-fermion bands with doping in a quantitative fashion andconnect our results to recent data obtained on Fe-doped YbRh2Si2.

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The 19th International Conference on Magnetism

Oral Tuesday

DJ05
Abdelwaheb Cheikhrouhou*, Wissem Cheikhrouhou-koubaa and Mohamed Koubaa
Materials Physics Laboratory, Faculty of Sciences of Sfax, Tunisia

Oral Tuesday

oRAL PRSENTATION

T. Devereaux*Stanford University, USA

Pump-probe techniques have been used to extend equilibrium spectroscopic methods
to the time-domain, revealing temporal dynamics associated with lattice degrees of
freedom, collective modes of novel electronic phases and decay and recovery processes
with typical time scales of several picoseconds. Recent advances have extended thetemporal resolution of these techniques to femtosecond and attosecond time scales. In
this talk I will present several severalKeldsyh-based calculations and simulations forpump-probe spectroscopy across a metal-insulator transition, across a charge-density
wave transition, and for electron-phonon coupled lattices. These results illuminate
the intricate dynamics of how correlated materials return to equilibrium after photoexcitation.

[1]Hantao Lu, S. Sota, H. Matsueda, Janez Bonča, and T. Tohyama, arXiv:1204.1107.

EB04
Electric-Field Effects on Complex Oxide Interfaces: Possible TwoBand Superconductivity

Jason T Haraldsen1*, Alexander V Balatsky1, Peter Woelfle2 and Quanxi Jia3
1
Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos
National Laboratory, USA
2
Institute for Condensed Matter Theory and Institute for Nanotechnology, Karlsruhe
Institute of Technology, Germany
3
Center for Integrated Nanotechnology, Los Alamos National Laboratory, USA
We examine the superconductivity produced at the complex oxide interface of LaAlO3
and SrTiO3 (Tc = ~0.3 K). Through a phenomenological and semi-classical approach,
we investigate the effects of local and global electric fields on the superconducting orderparameter, carrier density, and transition temperature for this system. We show that the generalshape of the superconducting dome can be reproduced through basic electrostatics and astandard BCS formalism using the density of states. Given the similarity between the transition
temperature for the interface and of bulk SrTiO3, which is also superconducting at ~0.3 K upon
optimal electron doping, we provide evidence that the interface superconductivity is intrinsic
to SrTiO3 and we infer that superconducting mechanism must also be similar. By examining
bulk SrTiO3, we show that the superconductivity may be described through weakly-coupled,
two-band model. Finally, we predict that the superconductivity at the interface is most likely
produced through a two-band coupling of the surface states of SrTiO3 provided by an electron
doping from a carrier source (in this case LaAlO3).

Arthur Freeman1 and Kohji Nakamura2
1
Northwestern University, USA
2
Mie University, Japan

Quantum computational electronic structure theory, based on accurate density functional theory
and structural modeling, has taken a leadership role in providing insight into the underlying physics
of magnetism. Challenges currently lie in understanding non-collinear magnetism and magnetotransport properties in magnetic domain walls [1] and, more recently, externally driven electric-fieldmagnetocrystalline anisotropy (MA) [2] in transition-metals that arise not only through the spin-orbit
coupling (SOC): these phenomena provide new pathways for future magnetic devices at the nanoscale with the promise of ultra-low energy power consumption. This talk will present our recent firstprinciple predictions for magnetism and transport properties for i) magnetic domain walls (modeledby a spin-spiral) and ii) electric-field-driven MA in transition-metals, carried out using our noncollinear magnetism full-potential linearized augmented plane-wave (FLAPW) method in which theexternal electric field is directly incorporated and the conductivity tensor is obtained by applying the
Kubo formula of linear response theory. *Supported at Northwestern by the U.S. D.O.E. and the Japan
Society for the Promotion of Science.
[1] K. Nakamura, N. Mizuno, T. Akiyama, T. Ito, and A. J. Freeman, JAP 105, 07C304 (2009); JAP
101, 09G521 (2007); PRL 93, 057202 (2004). [2] K. Nakamura, R. Shimabukuro, Y. Fujiwara,
T. Akiyama, T. Ito, A.J. Freeman, PRL 102, 187201 (2009); K. Nakamura, T. Akiyama, T. Ito, M.
Weinert, A.J. Freeman, PRB 81, 220409R (2010).

EC03First-principles calculation of the A-site ordered perovskite
CaCu3Fe4O12
Takuya Ueda1, Mitsuru Kodera1, Kunihiko Yamauchi1 and Tamio Oguchi2*
1
Osaka University, Japan
2
Osaka University & JST-CREST, Japan

Oxides with anomalous-valence ion Fe4+ have been studied for many years and such
systems have been recently found among the so-called A-site ordered perovskites
AA’3B4O12. In the AA’3B4O12 perovskites, A and A’ cations occupy the A-site of theoriginal simple perovskite ABO3 and the A’ cations are coordinated by four O ionsin a planar fashion instead of the original twelve coordination. The cation sites may
consist of magnetic ions, leading to several possible magnetic interactions between
them. CaCu3Fe4O12 reveals charge disproportionation 2Fe4+ −> Fe3++Fe5+ at 210K witha transition from paramagnetic to ferrimagnetic state. Quite recently, the magnetic
couplings between cations in CaCu3Fe4O12 are experimentally determined by x-ray
magnetic circular dichroism (XMCD) measurements [1]. In this paper, the electronic
structure of the A-site ordered perovskite CaCu3Fe4O12 is studied by means of firstprinciples calculations. X-ray absorption spectroscopy and XMCD spectra at the Fe
and Cu L2,3 edges and O K edge are calculated and compared with experiments todiscuss the magnetic order and coupling.
[1] M. Mizumaki et al., Phys. Rev. B 84, 094418 (2011).

July 8-13, 2012 Busan, Korea

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Pr partial electron donation and Co spin state changes at the metal-insulatortransition in (Pr1-yYy)1-xCaxCoO3 as seen by x-ray absorption and emission

Neel temperature and the thickness of surface NiO

Emergent magnetic switching in spin glass La0.7Sr 0.3(Mn,Fe)O 3/
La0.7Sr0.3MnO3 thin films

Spin transfer torques in magnetic bilayers with strong spin orbit
coupling

The electronic and magnetic properties of cobalt-based perovskites are largely determined by the electronic fillingof the Co 3d valence band. The characteristic spin state degree of freedom in many cobaltites is correlated to theelectron mobility and thus it can play an important role in metal-insulator transitions (MIT). MIT are found in awide range of compositions of the (Pr1-yYy)1-xCaxCoO3 series, coupled to magnetic and structural changes [1,2].
At low temperatures, x-ray diffraction confirms a crystal cell volume contraction occurs due to the appearanceof a certain quantity of Pr4+ ions. The electrons lost by Pr ions move to Co sites. The expected increase of theaverage Co-O distance is not observed, may be due to a compensation effect by a likely Co ions spin state change[3]. We present here a comprehensive study of these compounds by means of x-ray absorption and emission
spectroscopies, which leads us to confirm these hypothesis also quantifying the intersite charge donation acrossthe MIT [4]. The observed photoinduced phase transition in Pr0.5Ca0.5CoO3 under illumination by laser radiation,
where metallic domains can be stimulated [5], could thus be related to induced spin state changes.

Wei Pan*, Ying-ta Shih and Chien-yu Su
National Chung Cheng University, Taiwan

The surface oxidation on Ni/Cu(001) or CoNi alloy on Cu(001) have been studied
for the spin reorientation transition and other magnetic interactions, such as magnetic
demolishment, canted state, coercivity enhancement, and antiferromagnetic induced
ferromagnetism. It is found that a transition temperature of 200 K for these phenomena.
This study is to confirm that the transition temperature of 200 K is the Neel temperatureof NiO formed by oxygen treatment on the surface of Ni/Cu(001) films. We depositedfilms of x ML Ni/10 ML Co/Cu(001), where x = 0, 2, 3, 4, and 6. The films were thentreated by oxygen exposure of 1800 Langmuir for the formation of y ML NiO/(x-y)
ML Ni/10 ML Co/Cu(001). The coercivity is enhanced for all x below 200 K after fieldcooling. For x of 3, 4, and 6, the coercivity is the same and the coercivity enhancement
phenomenon disappears when the temperature is above 200 K. It indicates that the
thickness of the surface NiO is 3 ML and the Neel temperature is 200 K. Thus, all
the phenomena mentioned above is induced by the formation of antiferromagnetic
ordering of the surface NiO.

[1] Tsubouchi et al, Phys. Rev. B 66, 052418 (2002) [2] J. Hejtmanek et al, Phys. Rev. B 82, 165107 (2010) [3] A.
Baron-Gonzalez et al, Phys. Rev. B 81, 054427 (2010) [4] J. Herrero-Martin et al, Phys. Rev. B 84, 115131 (2011); J.

Zhi-hong Wang1*, Bao-gen Shen1, Ji-rong Sun1, G. Cristiani2 and H. -U. Habermeier2
1
Institute of Physics, Chinese Academy of Sciences, P. O. Box 603, Beijing 100190.,
China
2
Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569,
Stuttgart., Germany

The emergent magnetic switching has been investigated in exchange coupledbilayers composed of spin glass (La0.7Sr0.3Mn1-yFeyO3, y=0.18~0.20) and ferromagnet(La0.7Sr0.3MnO3) epitaxial thin films. It was found that, i) the magnetization reversal
develops from single magnetic switching into double magnetic switching as the
sample is cooled below the spin freezing temperature; ii) both the critical field andthe transition region for the second magnetic switching (SMS) increase upon coolingbut decrease with increasing the cooling magnetic field; iii) at 1.8 K the SMS is only
exhibited in the descending branch of the hysteresis loop; however its presence in theascending branch can be partially restored via enlarging the cooling field; iv) there
occurs an obvious training effect for the SMS observed at 1.8 K. The rich features
and the micro-origin of the emergent magnetic switching are discussed in terms ofa phenomenological domain wall model which involves the exchange anisotropy
depending on the alterable spin frustration due to the frozen and activated spins at the
spin glass-ferromagnet interface.

Herrero-Martin et al (in preparation) [5] Y. Okimoto et al, Phys. Rev. Lett. 103, 027402 (2009)Mark D. Stiles1*, Paul M. Haney1, Kyung-jin Lee2 and Hyun-woo Lee3
Center for Nanoscale Science and Technology, National Institute of Standards andTechnology, USA
2
Department of Materials Science and Engineering, Korea University, Korea
3
PCTP and Department of Physics, Pohang University of Science and Technology,
Korea
1Current driven magnetic dynamics in ferromagnetic thin films on top of non-magnetic
films with strong spin orbit coupling combines several topics of significant recent
interest. The current flowing through the ferromagnetic layer gives rise to adiabatic andnon-adiabatic spin transfer torques when the magnetization is non-uniform. The current
flowing through the non-magnetic layer gives rise to a spin Hall current, leading to a spincurrent incident on the interface between the two layers. This spin current causes spintransfer torques similar to those that are important in magnetic multilayers with current
flowing perpendicular to the plane. Recent experiments, models, and simulations raise
the possibility of an additional torque due to the spin-orbit coupling at the interface where
the inversion symmetry found in the bulk materials is broken. All of the currents andtorques are coupled to each other and are non-uniform in the layers. We compute thiscoupling and spatial variation using a Boltzmann equation approach. We determine thedependence of the torque on the thickness of the layers and study how the torque changes
as the contribution from the interfacial spin orbit coupling is increased.

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EE03

Spin transport in the anisotropic Heisenberg chain at finite
temperature and momentum

Reduced exchange bias field in antiferromagnet-patterned FeF2/Ni
stripes

FM-AFM crossover in vanadium oxide nanomaterials.

Diffusive spin dynamics in ferromagnetic thin films with a Rashba
interaction

Wolfram Brenig1* and Robin Steinigeweg2
1
Technical University Braunschweig, Institute for Theoretical Physics, Germany
2
J. Stefan Institute Ljubljana, Slovenia

Magnetic transport in one-dimensional quantum spin systems displays many new
features beyond a conventional Boltzmann description. Among them is the dissipationof spin currents. At zero momentum, integrability, such as for the one-dimensional
Heisenberg (XXZ) model, can lead to ballistic transport. Transport at finite momentum
is an open issue. Here we investigate the role of momentum for the transport ofmagnetization in the spin-1/2 Heisenberg chain above the isotropic point at finite
temperature and momentum. Using numerical and analytical approaches, we analyze
the autocorrelations of density and current and observe a finite region of the Brillouinzone with diffusive dynamics below a cut-off momentum, and a diffusion constant
independent of momentum and time, which scales inversely with anisotropy. Lowering
the temperature over a wide range, starting from infinity, the diffusion constant is foundto increase strongly while the momentum space cut-off for diffusion decreases. Abovethe cut-off momentum diffusion breaks down completely.
Phys. Rev. Lett. 107, 250602 (2011)

R. Morales1*, J. E. Villegas2, D. Navas3, N. Soriano3, E. Castellano-hernandez3, X. Batlle4, F. Castano3 andIvan K. Schuller5
1
University of the Basque Country and IKERBASQUE Basque Foundation for Science, Bilbao, Spain
2
Unite Mixte de Physique CNRS/Thales and Universite Paris Sud, Orsay, France
3
Universtity of the Basque Country, Leioa, Spain
4
Universitat de Barcelona, Barcelona, Spain
5
University of California San Diego, La Jolla, USA

The exchange interaction in antiferromagnetic/ferromagnetic (AF/FM) bilayers gives rise to the exchange bias
phenomenon. In addition to the shift of the FM hysteresis loop, the exchange coupling can also modify the magnetization
reversal mechanism. Incomplete domains walls (IDWs) have been observed in FeF2/Ni below the AF Neel temperature[1,2]. However, reversal of the FM moments is expected to have little effect on the FeF2 spin structure due to the strong
AF anisotropy [3]. We show using variable thickness FM layers that this scenario changes as the AF becomes patterned.
A wedged substrate/FeF2 (70nm)/Ni (tNi=2-74 nm)/Al (4nm) sample was patterned into stripes by photolithography.
Only the FM layer was patterned for the thickest tNi whilst the FeF2 layer becomes gradually patterned as tNi decreases.
The exchange-bias field-dependence Heb (tNi) shows an increasing difference compared to the value expected withdecreasing Ni thickness. This result originates from spring-like DWs parallel to the AF/FM interface formed in both theNi and FeF2 layers. Simulations of IDWs account for the experimental values of Heb(tNi). Work supported by MICINN
grants FIS2008-06249, MAT2010-20798, MAT2009-08667 and the US Department of Energy DE FG03-87ER-45332.

Sergey Demishev 1*, Alexey Chernobrovkin 1, Vladimir Glushkov 1, Nickolay
Sluchanko1, Nickolay Samarin1, Alexey Semeno1, Sergey Balakhonov2, Bulat
Churagulov2, Anastasiya Grigorieva2 and Evgenii Goodilin2
1
Low Temperatures and Cryogenic Engineering, General Physics Institute of RAS,
Russia2
Faculty of Materials Sciences, Moscow State University, Moscow, 119991 Russia,
RussiaThe magnetic properties of nanomaterials based on vanadium oxide (multiwall
nanotubes, nanorods, whiskers and nanolayers) have been investigated in thetemperature range of 1.8-220 K by high frequency (60 GHz) EPR. A transition
from a ferromagnetic temperature dependence to an antiferromagnetic temperaturedependence has been observed in nanorods, whiskers and nanotubes with a decreasein the temperature. The FM-AFM crossover observed near 100 K is accompanied bya low temperature increase in the Curie constant by a factor of 2.7-7. The comparisonof the experimental data for various VOx nanoparticles indicates that the most probablecause of the change in the type of magnetic interaction is a change in the concentrationof V4+ magnetic ions due to temperature dependent electron localization [1].

Xuhui Wang* and Aurelien Manchon
KAUST, Saudi Arabia

Injection of a charge current into an asymmetrically sandwiched thin magnetic
layer generates an effective Rashba field that reverses the magnetization [1, 2] andimproves current-driven domain wall motion [3]. In a ferromagnetic metal layer, westudy theoretically the coupled charge and spin diffusion equations in the presenceof both Rashba spin-orbit interaction and magnetism. The mis-alignment between
the magnetization and the non-equilibrium spin density induced by the Rashba fieldgives rise to Rashba spin torque acting on the ferromagnetic order parameter. Using
Keldysh formalism and gradient expansion, we find that the Rashba torque consistsof both in-plane and out-of-plane components [4]. This provides an explanation to themagnetization switching mechanism in a single ferromagnet as observed in the recent
experiments [5]. While providing a coherent framework to describe the diffusive spin
dynamics in magnetic media with or without Rashba spin-orbit interaction, we also
show particularly that the in-plane Rashba torque can be tuned by varying the width ofthe magnetic nano-wire and its materials parameters.

1. S.V.Demishev et al., JETP Letters, 91, 11 (2010)[1] A. Manchon and S. Zhang, Phys. Rev. B. 78, 212405 (2008); 79, 094422 (2009). [2] I. M. Mironet al., Nature Mater. 9, 230 (2010); 10, 419 (2011). [3] K. Obata and G. Tatara, Phys Rev. B 77,
214429 (2008). [4] X. Wang and A. Manchon, arXiv:1111.1216; arXiv:1111.5466. [5] I. M. Miron,et al. Nature (London) 476, 189 (2011).

[1] R. Morales,Z-P. Li, O. Petracic, X. Batlle, and Ivan K. Schuller, Appl. Phys. Lett. 89, 072504(2006) [2] R. Morales et al., Appl. Phys. Lett. 95, 092503 (2009) [3] M. Kiwi, J. Mejia-Lopez, R. D.
Portugal, and R. Ramirez, Europhys. Lett., 48, 573 (1999)

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EE04

Growth of metastable fcc-Fe film on Cu(100) single-crystal underlayer
and phase transformation from fcc to bcc

Experimental verification of the magnetic interactions between Co
particles in C60-Co granular films

Spin Hall effect from first principles

Emergence of magnetic monopoles in magnetic systems with spin-orbit
coupling

Theoretical studies suggest that the magnetic property of metastable fcc iron (Fe) varies
in a wide range from nonmagnetic to high-spin ferromagnetic state depending on the
distance between Fe atoms [1]. The structure of bulk Fe crystal is bcc up to 912 °C,
whereas metastable fcc structure can be stabilized in a form of film at RT. However,
the metastable fcc structure is reported to transform into more stable bcc structurewith increasing the film thickness [2]. In the present study, Fe films were preparedon Cu(100) single-crystal underlayers at RT by UHV-MBE in order to investigate
the growth behavior of fcc-Fe crystal and the fcc-bcc phase transformation process.
In an early stage of film growth, metastable fcc-Fe(100) structure was stabilized
through hetero-epitaxial growth. With increasing the thickness, the fcc structure
started to transform into bcc structure. High-resolution cross-sectional TEM and polefigure XRD analyses showed that the fcc structure transformed into bcc structure byatomic rearrangement from fcc{100} to bcc{100}. The transformation orientation
relationship was thus bcc{100}<011> || fcc{100}<001>. The transformation occurred
not only along the perpendicular direction but also along the in-plane directions. The
relationship between film thickness and magnetic property will also be discussed at theconference.

Spintronics devices using molecular materials have attracted growing attention over the
past decade because of their long spin coherence. Various researches have accomplished
about the electrical conduction characteristic and the magnetic transportation characteristicof the C60-Co granular film[1-5], which has a structure that Co nanoparticles are dispersed
in C60 matrix. We observed the following two phenomena below the blocking temperaturein the sample (C60:Co = 9.2:1): 1) Hysteresis of the magnetization curve. (Ferromagnetic
characteristic.), and 2) Magnetic field dependence of the coulomb blockade-electric fieldcharacteristic. (This characteristic require the antiferromagnetic basis in our idea) These
contradictory characteristics were assumed due to the dipole interaction between the Co
nanoparticles, and identified by the following method. We calculated the two particles
model with dipole interaction and compared the numerical results and magnetization curveof the samples(C60:Co = 6.0:1, 9.0:1). The measured M-H curves are good agreement withthe theoretical curves. The above 1) and 2) can be explained with this model. In this way,
the dipole interactions between Co nanoparticles in C60 matrix were identified.

Mitsuru Ohtake*, Kohei Shimamoto and Masaaki Futamoto
Faculty of Science and Engineering, Chuo University, Japan

Shuhei Toyokawa*, Eiiti Tamura, Eiji Shikoh, Teruya Shinjo and Masashi Shiraishi
Osaka Univ., Japan[1] S.Miwa, M.Shiraishi, et al., Jpn. J. Appl. Phys. (2006). [2] S.Sakai, et al., Appl. Phys. Lett. (2006).
[3] S.Miwa, M.Shiraishi, et al., Phys. Rev. B (2007). [4] S.Sakai, et al., Appl. Phys. Lett. (2007). [5]Y.Matsumoto, et al., Chem. Phys. Lett. (2009).

Christian Herschbach1, Katarina Tauber1, Dmitry Fedorov1, Martin Gradhand2 and Ingrid
Mertig3*
1
Theory Department, Max Planck Institute of Microstructure Physics Halle, 06120 Halle, Germany
2
H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TH, United Kingdom
3
Institute of Physics, Martin Luther University Halle, 06099 Halle, Germany

Oral Tuesday

Javier Herrero-martin1*, Jose Luis Garcia-munoz1, Carlos Frontera1, Aura Janeth Baron-gonzalez1, Jessica Padilla1,
Sergio Valencia2, Ralf Feyerherm2, Esther Dudzik2, Florin Radu2, Radu Abrudan3, Gloria Subias4 and Javier Blasco4
1
Institute of Materials Science of Barcelona - CSIC, Spain
2
Helmholtz-Zentrum Berlin, BESSY, Germany
3Institut fur Experimentalphysik/Festkorperphysik, Ruhr-Universitat Bochum, Germany
4
Instituto de Ciencia de Materiales de Aragon, CSIC-Univ. Zaragoza, Spain

Oral Tuesday

oRAL PRSENTATION

Akihito Takeuchi* and Gen Tatara
Department of Physics, Tokyo Metropolitan University, Japan

Spintronics without magnetic materials would be an interesting alternative to the existing spintronics
applications. The spin Hall effect creates spin currents in nonmagnetic materials and avoids the
problem of spin injection. Future applications of the spin Hall effect require two properties of thematerials used in the spin Hall device, a large spin Hall angle and a long spin diffusion length.
Ab intio calculations based on density functional theory are a powerful tool to design the desired
materials and to get insight into the underlying microscopic processes. We investigated the spin
Hall effect in dilute alloys, in particular the intrinsic effect based on the Berry curvature as well as
the skew scattering contribution. By means of a relativistic Korringa-Kohn-Rostoker method we
calculated the scattering potentials of several impurities in Cu, Ag, Au, and Pt hosts self-consistently.
We solve the linearized Boltzmann equation to calculate the conductivity tensor taking as well as thescattering-out and the scattering-in term into account. We identify systems, e.g. Cu(Bi) and Au(C)with a Hall angle larger than 0.06 and a spin diffusion length of about 100 nm.

In spintronics, a spin current plays an essential role. Today, various spin-related
phenomena have been discovered and understood through the spin current.
However, the spin current is not conserved, and the relation between spintronics
and electromagnetism is still an open question. For overcoming this difficulty, wetheoretically analyze the spintornic phenomena from the viewpoint of the Maxwell’sequations. In particular, we focus on the electron transport driven by a dynamic
magnetization or an electric field in the presence of spin-orbit interactions. We calculate
an electric current and density, and derive the Maxwell's equations. The Maxwell'sequations constructed by this way involve a magnetic monopole contribution [1]. We
will discuss this magnetic monopole generated by the magnetization dynamics or theapplied electric field in a ferromagnetic-nonmagnetic junction, and we will discuss
also the magnetic monopole induces an electric current via the Ampere’s law for themonopoles. Therefore, the monopole signal is expected in a similar geometry as theinverse spin Hall signal [2,3].

M. Gradhand, D. V. Fedorov, P. Zahn, and I. Mertig, Phys. Rev. Lett. 104, 186403 (2010); S. Lowitzer, M. Gradhand, D.
Kodderitzsch, D. V. Fedorov, I. Mertig, and H. Ebert, Phys. Rev. Lett. 106, 056601 (2011); M. Gradhand, D. V. Fedorov, F.

[1] A. Takeuchi and G. Tatara, arXiv:1104.4215 (to be published in J. Phys. Soc. Jpn.). [2] E. Saitoh
et al., Appl. Phys. Lett. 88, 182509 (2006). [3] T. Kimura et al., Phys. Rev. Lett. 98, 156601 (2007).

Pientka, P. Zahn, I. Mertig, and B. Gyorffy, Phys. Rev. B 84, 075113 (2011)[1] L. T. Kong and B. X. Liu: J. Alloys Comp., 414, 36 (2006). [2] T. Detzel et al.: Surf. Sci., 293, 227 (1993).

66

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

67

ORAL PRESENTATION
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EG04

Generalization of Gilbert damping in Rashba systems

Observations of magnetic and ferroelastic nanoclusters in RCo2

Negative spin current polarization in amorphous CoFeB measured via
the spin-wave Doppler effectClarification of oxygen impurity effect on NCMR with the film
resistivity and bulk scattering spin asymmetry for [FeCo/Natural
Oxidation] multi-layers

Oral Tuesday

Mutual interaction between spin current and magnetization dynamics is describedby spin-transfer torque (STT) [1] and spin motive force (SMF) [2]. Spin-transfer
torque results in magnetization dynamics due to spin current. In contrast, SMF isspin dependent motive force induced by magnetization dynamics. As a result ofcombination of these two, magnetization dynamics affects magnetization dynamics
itself mediated by spin current. This self-feedback of magnetization dynamics giverise to generalization of Gilbert damping as a second rank tensor [3], but it has been
almost ignored since it is negligibly small. However, in an ultrathin magnetic systemwith strong Rashba spin-orbit coupling (RSOC) [4], which is of recent interest in
spintronics, we demonstrate that SMF can be orders of magnitude enhanced so the selffeedback becomes now relevant. We derive the generalized Gilbert damping tensor
including RSOC-induced SMF and discuss its effects on magnetization dynamics
qualitatively. Our work implies that ultrathin magnetic films are not mere thin limits ofthicker ferromagnets but systems governed by qualitatively different physics.
[1] J. C. Slonczewski, J. Magn. Mag. Mater. 159, L1 (1996). [2] L. Berger, Phys. Rev. B 33, 1572
(1986). [3] S. Zhang and S.-L. Zhang, Phys. Rev. Lett. 102, 086601 (2009). [4] Y. A. Bychkov and E.
I. Rashba, J. Exp. Theor. Phys. Lett. 39, 78 (1984).

Julia Herrero-albillos1, Marcela Bonilla2*, Sarah L Driver3, Irene Calvo2, Celia
Castan2, Adriana I Figueroa2, Juan Bartolome2, Michael A Carpenter3, Luis Garcia2
and Fernando Bartolome2
1
CUD, Centro Universitario de la Defensa de Zaragoza, C/ Huesca s/n, Zaragoza,
Spain
2
ICMA and Dpto. de Fisica de la Mat. Cond. CSIC - Universidad de Zaragoza, Pedro
Cerbuna 12, Zaragoza, Spain
3
Department of Earth Sciences, University of Cambridge, Downing Street,
Cambridge CB2 3EQ, United Kingdom
New findings of short-range order (SRO) correlations in magnetic materials haverecently been reported, even on compounds previously studied for decades, as aresult of the use of new and improved experimental techniques. In particular, X-ray
Magnetic Circular Dichroism (XMCD) and transverse susceptibility have revealed
the existence of several new magnetic configurations in the phase diagram of thefamily of compounds RCo2 (R = Er, Ho, Tb, Tm). The presence of magnetic SRO(magnetic nanoclusters) has been shown to be a prerequisite for the existence of
these configurations. Relaxation of the magnetic nanoclusters leads to anomalies in
the ac susceptibility, observed within the paramagnetic phase of RCo2 compounds.
Additionally, Resonant Ultrasound Spectroscopy (RUS) studies have shown thepresence of fluctuations in local strain, also described as ferroelastic clusters, above themagnetic ordering temperature. Comparing RUS and magnetic measurements sheds
light on the interrelationship between ferroelastic and magnetic nanoclusters.

Konrad Hsu Aschenbach1, Meng Zhu†1 and Robert D Mcmichael2*
1
Center for Nanoscale Science and Technology, NIST / Maryland Nanocenter, University of Maryland, USA
2
Center for Nanoscale Science and Technology, NIST, Gaithersburg, MD 20899, USA

We use the spin-wave Doppler technique[1-4] to measure and compare the spin polarization of the current(P) of Co72Fe18B10 before and after thermal annealing. The technique involves inductively launching anddetecting spin waves in ferromagnetic wires carrying electrical current. The adiabatic spin transfer torqueproduces a transmission frequency Doppler shift of Δf = v/λ where λ is the spin wave wavelength and v =J μB P/(e Ms) is the spin drift velocity, which is a function of the current density J, and the magnetization
Ms. We find that the as-deposited amorphous film has a small negative value of P, in contrast to thepositive values obtained via point-contact Andreev reflection (PCAR)[5]. Measurements on several other
CoFeB samples with different composition also yield small or slightly negative values of P. On the other
hand, the annealed film has a positive value of P, in agreement with other techniques[5,6], and as measured
for Co50Fe50 without boron[3]. Relatively little has been reported about the current polarization propertiesof amorphous CoFeB. The spin wave Doppler technique, with its immunity to interfacial effects, yields
bulk polarization results that challenge the previous Andreev reflection results.
[1] Vlaminck, V. & Bailleul, Science 322, 410 -413 (2008). [2] Zhu, M., Dennis, C. L. & McMichael, R. D. Phys. Rev.
B 81, 140407 (2010). [3] Zhu, M. et al. Appl. Phys. Lett. 98, 072510 (2011). [4] Thomas, R. L., Zhu, M., Dennis, C. L.,
Misra, V. & McMichael, R. D. Journal of Applied Physics 110, 033902-033902-4 (2011). [5] Huang, S. X., Chen, T. Y.
& Chien, C. L. Applied Physics Letters 92, 242509-242509-3 (2008). [6] Fukami, S. et al. Applied Physics Letters 98,
082504-082504-3 (2011). [†] Current Address: Seagate Technology, Bloomington MN 55435

Yohei Shiokawa
Tohoku university, Japan

Nano-Contacts Magnetoresistance (NCMR) with Fe0.5Co0.5 AlOx-NOL (Nano-OxideLayer) has been reported to show MR ratio of more 30 % at RA of 0.3 Ωμm2[1]. However,
NCMR-SV is predicted to have potentially huge MR ratio of more than 100 % using highbulk spin scattering asymmetry β of ferromagnetic material Fe0.5Co0.5 with 0.81[2]. It wassurmised this difference of MR ratio between experiments and theory is caused by the
impurity of oxygen in FeCo NCs. we investigated the quantitative evaluation of oxygen
impurity effect on NCMR with the relation between the resistivity and bulk scattering spin
asymmetry for [FeCo/Natural Oxidation] multi-layers. We estimated the resistivity and β of
FeCo(O). The resistivity and β of FeCo(O) with [FeCo 2 nm / N.O.]n were 37.4 μΩcm and
0.75, and those of FeCo(O) with [FeCo 1 nm / N.O.]n were obtained 76.7 μΩcm and 0.35.
These results suggest the increase of the resistivity by oxygen impurity decreases the β. On
the other hand, the resistivity of the single NC in our NCMR was estimated 60 μΩcm byconductive-AFM. The cause of low NCMR ratio is considered to be the impurity of oxygenin NCs. So, reducing oxygen impurity in NC leads to higher NCMR ratio.
[1] H. Iwasaki, and M. Sahashi et al, MMM 2011, AS-05 (2011) [2] H. Imamura, et al, J. Phys: Conf.
Seri. 266, 012090 (2011)

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Superconducting, antiferroquadrupolar, and structural transitions in
caged compounds PrT2Zn20 (T=Ru, Rh, and Ir)First-principles molecular dynamics study on the magnetic structureof Mn3Pt

Switching the conductance of a magnetostrictive nanocontact bymagnetic fieldRoom-temperature magnetoresistance properties of planar-type Ninanostructures controlled from nanoconstrictions to nanogaps

There has been considerable interest in praseodymium-based intermetallic compounds, because an abundanceof unusual phenomena has been intensively studied such as ferromagnetic order of hyperfine-enhanced nuclearspins in PrNi5[1], incommensurate antiferroquadrupolar order in PrPb3[2], and heavy-fermion superconductivity
in filled-skutterudite PrOs4Sb12[3]. We have recently focused on Pr-based compounds with caged structures,
where large coordination number of the Pr ion leads to weak crystalline electric field effect, whereas hybridizationof the f electrons with electrons of cage atoms is strengthened. Such conditions may enable the compounds toshow strongly correlated electronic phenomena. Keeping this in mind, we have synthesized and studied a new
family of caged compounds PrT2Zn20 (T=Ru, Rh, and Ir). PrRh2Zn20 and PrIr2Zn20 with a nonmagnetic gamma3
doublet ground state undergo superconducting transitions at TSC=0.0 6K and 0.05 K, respectively, in the presenceof antiferroquadrupolar order below TQ=0.06 K and 0.11 K[4,5]. The entropy releases at TQ are 6% and 20%
of Rln2 for PrRh2Zn20 and PrIr2Zn20, respectively, suggesting interplay between the quadrupolar fluctuations andformation of the superconducting pair. On the other hand, in PrRu2Zn20, the symmetry of the Pr ion is lowered by
the structural phase transition at TS=138 K. Therefore, no phase transition manifests itself down to 0.04K

The ordered Mn3Pt is a three-dimensional frustrated magnet with an octahedral
configuration of Mn local magnetic moments, and exhibits two ordered phases below
the Neel temperature: collinear antiferromagnetic (AF) phase for 400K < T < 475K,
and noncollinear AF phase for T < 400 K. To investigate the origin and details of
the magnetic structures of Mn3Pt, we have applied the first-principles molecular
dynamics (MD) approach to this alloy. The theory is based on the first-principles TBLMTO Hamiltonian, the functional integral method and the isothermal MD technique,and can determine automatically the magnetic structures of itinerant magnets at
finite temperatures. Numerical results at 25 K using 4*4*4 FCC unit cell reveal thetriangular shaped noncollinear magnetic structure, being consistent with experiment. It
is found that with increasing temperature up to 300 K, the amplitude and the thermal
average of Mn local moment decrease gradually, and the d-electron density of states(DOS) near the Fermi energy increases. Based on the numerical results for further
increasing temperature above 400 K, a discussion is given as to the relationshipbetween frustration, the d-electron DOS, the magnetic structures, and their temperaturedependence.

The electrical conductance G of magnetostrictive nanocontacts fabricated from Dybreak junctions has been investigated at 4.2 K where Dy is in the ferromagnetic state.
In addition to the variation of the conductance while breaking the wire mechanically,
the conductance can be changed by variation of an applied magnetic field H due tothe large magnetostriction of Dy. The behavior of G(H) and its angular dependence
can be explained by taking into account the magnetostrictive properties of Dy. This
demonstrates the possibility of tuning the conductance of magnetic nanocontacts bya magnetic field [1]. We also investigate the effect of a magnetic field on the contact
shape created during mechanical training and find that the shape can be controlled by
the applied field due to the strong magnetoelastic coupling of Dy.

Innovative devices called ferromagnetic single-electron transistors (FMSETs), which are based on theinterplay of single-electron charging phenomena and spin-dependent tunneling effects, have attracted
much interest. For the realization of FMSETs, we have reported the magnetoresistance (MR) propertiesof planar-type tunnel junctions with ferromagnetic nanogap system at 16 K, formed by electromigration
methods. [1, 2]. In this paper, we study the room-temperature MR properties of planar-type Ninanostructures controlled from nanoconstrictions to nanogaps using novel electromigration method, withthe aim of fabricating FMSET with higher operation temperature. The stepwise feedback-controlled
electromigration (SFCE) methods [3] were performed at room temperature in a vacuum chamber for Ni
initial nanochannels with a constriction of a few hundreds of nanometers. We obtained anisotropic MR(AMR) of 0.14 % in the Ni initial nanochannel before performing SFCE procedure. Then, the resistanceof the Ni nanochannel was gradually increased from 60 Ω to 76 kΩ by SFCE approach with atomic scale
controllability. Positive tunnel MRs (TMRs) with the ratios of between 6 % and 9 % were observed fromthe controlled structures at room temperature. These results strongly suggest the possibilities of roomtemperature operation of planar-type FMSETs with Ni/vacuum/Ni ferromagnetic tunnel junctions.

EF02

EF05

EG03

EH01

Structural and magnetic phase separation in PrMn 2Ge 2-xSix andrelated compounds

One-dimentional magnetism in metallic MnB4

Spin wave and spin pumping in permalloy strips

New materials for enhancing device perpormance in spintronics

T. Onimaru1, K. T. Matsumoto1, N. Nagasawa1, Y. F. Inoue1, K. Umeo2,
S. Kittaka4, T. Sakakibara4, Y. Karaki5, M. Kubota4 and T. Takabatake1,3
1
AdSM, 2N-BARD, 3IAMRHiroshima Univ., Higashi-Hiroshima, Japan
4
ISSP, Univ. of Tokyo, Kashiwa, Japan
5
Fac. Edu., Univ. of the Ryukyus, Okinawa, Japan[1] M. Kubota et al., Phys. Rev. Lett. 51,1382 (1983). [2] T. Onimaru et al., Phys. Rev. Lett. 94, 197201 (2005). [3] E. D.
Bauer et al., Phys. Rev. B 65, 100506 (2002). [4] T. Onimaru et al., J. Phys. Soc. Jpn. 79, 033704 (2010). [5] T. Onimaru etal., Phys. Rev. Lett. 106, 177001 (2011)

Shane Joseph Kennedy1*, Jianli Wang2, Stewart Campbell3, Michael Hofmann4 and Shixue Dou5
1
Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
2
Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
3
School of Physical, environmental and Mathematical Sciences, The University of NSW, Canberra, ACT 2600, Australia
4
FRM-II, Technische Universitat Munchen, 85747 Garching, Germany
5
Institute of Superconducting and Electronic Materials, The University of Wollongong, Wollongong NSW, 2522, Australia

We report a comprehensive study of the thermal and magnetic properties of PrMn2Ge2-xSix
compounds along with neutron and synchrotron X-ray diffraction studies of their atomic andmagnetic structure. Generally, the Mn atoms display the same antiferromagnetic configurations as
the broad family of RMn2X2 compounds (R = rare-earth, X = Si, Ge). However, between x= 1.0
and 1.4 we see phase separation at low temperatures, into Fmc and AFmc forms. This is causedby spontaneous magnetostriction which differs greatly between the two magnetic phases, andis linked to a subtle structural phase separation over a broader concentration range (from x= 0.4
to 1.6). Clearly two separate & unique structures exist depending on the local concentration of
Silicon and Germanium on the mixed (X) site. Our interpretation brings into question whether arandom substitution on the X site could produce such remarkable magneto-elastic phenomena orwhether atomic short range order plays a significant role in the physical properties of the mixed
122 compounds. Indeed we find ample evidence in the broader family of RMn2X2 compounds tosupport a claim that systematic variation in local order of the R & X sites drives the complicatedmagnetic and physical properties observed in this system

The 19th International Conference on Magnetism

Takashi Uchida1*, Yoshiro Kakehashi2 and Nobuyuki Kimura1
1
Hokkaido Institute of Technology, Japan
2
University of the Ryukyus, Japan

Sergii Khmelevskyi, Josef Redinger and Peter Mohn
Institute of Applied Physics, Vienna University of Technology, Austria
We have investigated from first-principles an electronic structure and magnetism in
MnB4 compound with experimentally observed orthorhombic C12/m1 structure. It isfound that Mn tetra-borides (MnB4) is found to have metallic ground state with welldefined local Mn magnetic moments. This conclusion was drawn from calculation
within full potential Linear Augmented Plane Wave method and Korringa-KohnRostocker method using Disordered Local Moment Approximation. We have shownusing Lichtenstein Green function method for first-principle calculation of theexchange constants that magnetic exchange interactions between Mn moments arestrongly ferromagnetic along 1D-chains of Mn atoms and they are practically vanishing
between the chains. The metallic state appears to exhibit a strongly one-dimensional
character since the metallic bands show dispersion only in one reciprocal latticedimension. Thus it is appears that MnB4 is a novel one-dimensional metallic magnet.

Marc Mueller, Christoph Suergers*, Richard Montbrun and Hilbert V. Lohneysen
Physikalisches Institut and DFG Center for Functional Nanostructures, Karlsruhe
Institute of Technology (KIT), Germany[1] M. Mueller, R. Montbrun, M. Marz, V. Fritsch, C. Suergers, H. v. Loehneysen, Nano Letters 11,574 (2011)

Oral Tuesday

Kyoung-whan Kim1*, Jung-hwan Moon2, Kyung-jin Lee2 and Hyun-woo Lee1
1
Department of Physics, POSTECH, Korea
2
Department of Materials Science and Engineering, Korea University, Korea

68

oRAL PRSENTATION

Jun Kitagawa, Ryutaro Suda and Jun-ichi Shirakashi*
Department of Electrical and Electronic Engineering, Tokyo University of Agriculture
and Technology, Japan[1] Y. Tomoda, M. Hanada, W. Kume, S. Itami, T. Watanabe and J. Shirakashi, J. Phys. Conf. Ser. 200, 062035 (2010).
[2] T. Watanabe, K. Takiya, and J. Shirakashi, J. Appl. Phys. 109, 07C919 (2011). [3] S. Itami, Y. Tomoda, R. Yasutake,and J. Shirakashi, J. Nanosci. Nanotechnol. 45, 3480 (2010).

Sankha Subhra Mukherjee, Jae Hyun Kwon, Mahdi Jamali, Praveen Deorani andHyunsoo Yang*
National University of Singapore, Singapore
Microfabrication techniques have made it possible to characterize both the resonant as well as thetravelling characteristics of spin waves in permalloy [1, 2]. Among variety of methods for measuring
spin waves, pulse inductive microwave magnetometry [3-5] is the electrical technique for travellingspin waves. We investigate the effect of the pulse width of excitation pulses on the generated spinwave packets using both experimental results and micromagnetic simulations. We show that spin wave
packets generated from electrical pulses are a superposition of two separate spin wave packets, one
generated from the rising edge and the other from the falling edge, which interfere either constructively or
destructively with one another, depending upon the magnitude and direction of the field bias conditions.
A method of spin wave amplitude modulation is also presented by the linear superposition of spin waves.
We use interfering spin waves resulting from two closely spaced voltage impulses for the modulation of
the magnitude of the resultant spin wave packets. We also investigate the contribution of the surface spinwaves to spin pumping. We show that spin waves can be used as a very efficient method for increasing thespin pumping signal compared to the ferromagnetic resonance case.
1. M. Covington, T. M. Crawford, and G. J. Parker, Physical Review Letters 89, 237202 (2002). 2. M. Bailleul, D.
Olligs, and C. Fermon, Applied Physics Letters 83, 972 (2003). 3. T. J. Silva, C. S. Lee, T. M. Crawford, and C. T.
Rogers, Journal of Applied Physics 85, 7849 (1999). 4. S. S. Kalarickal, P. Krivosik, M. Wu, C. E. Patton, M. L.
Schneider, P. Kabos, T. J. Silva, and J. P. Nibarger, Journal of Applied Physics 99, 093909 (2006). 5. J. H. Kwon, S.
Mukherjee, M. Jamali, M. Hayashi, and H. Yang, Applied Physics Letters 99, 132505 (2011).

Koichiro Inomata, Hiroaki Sukegawa, Zhechao Wen and Seiji Mitani
Magnetic Materials Unit, National Institute for Materials Science (NIMS), Japan
Spin current creates significant effects such as tunneling magnetoresitance (TMR),
current perpendicular to plane magnetoresistance (CPP-GMR) and spin transfer torque(STT), which are key factors in spintronics. They are anticipated to be applied forspintronic devices such as ultrahigh density HDD exceeding Tb/in2, STT-MRAM,
high frequency oscillators, spin logics etc. Perfectly spin-polarized half-metals are
essential materials for enhancing the polarization of spin currents and the resultant
device performance in spintronics. Full-Heusler allys with L21 structure have beenpractically expected as half-metals, because they have a large Curie temperature,and their Fermi level can be tuned by the composition. We have demonstrated thatFermi-level-tuned Co2FeAl0.5Si0.5 Heusler alloy provides half-metallicity even at room
temperature [1]. MgO barrier has been used in MTJs because it exhibits a large TMR
due to the coherent tunneling in epitaxials MTJs. Very recently we have discovered a
new tunnel barrier, spinel (MgAl2O4), bringing a large TMR due to coherent tunnelingas MgO barrier [2]. Spinel barrier has a benefit of very good lattice matching with bcc
metals and Heusler alloys. In this talk we will show half-metallic full-Heusler alloys
and their applications to MTJs with in-plane and out-of plane magnetizations [3], andMTJs with an MgAl2O4 barrier.
[1] R. Shan et al., Phys. Rev. Lett. 102, 246601 (2009). [2] H. Sukegawa et al., Appl. Phys. Lett. 96,
212505 (2010). [3] Zhenchao Wen et al., Appl. Phys. Lett. 98, 242507 (2011).

July 8-13, 2012 Busan, Korea

69

EH02

EH05

EI03

EI06

Organic high temperature ferromagnetic compositions

Formation of FeSi thin films and magnetic properties

Magnetic properties of tetragonally strained Fe/(W,Re) multilayers

Controlling domain wall motion by electric fields in perpendicularly
magnetized materials

Young-wan Kwon1*, Chang Hoon Lee2, Dong Hoon Choi1, Jung-il Jin1, Eui-kwan Koh3 and Y. H. Geerts4
1
Chemistry, Korea University, Korea
2
Polymer Science & Engineering, Chosun University, Korea
3
Seoul Branch, Korea Basic Science Institute, Korea
4
Chemistry, Universite Libre de Bruxelles, Belgium

Yooleemi Shin1, Tuan Anh Duong1, Seungmok Jeon1, Dung Duc Dang2, Thiet Van
Duong1 and Sunglae Cho1*
1
Department of Physics, University of Ulsan, Korea
2
Department of General Physics, School of Engineering Physics, Ha Noi Universityof Science and Technology, Viet Nam

Developments of the high temperature organic ferromagnetic materials have been attempted by many
researchers. To achieve the ferromagnetic ordering by using organic materials, the high spin multiplicity polymers
are also proposed by Itoh et al.[1] in 1968, because they may realize the magnetic storage devices with a versatile
processability. Recently, we found that high temperature ferromagnetism could be achieved by intercalating anorganic discotic liquid crystalline (DLC) compound with an iron-phthalocyanine [Fe(III)Pc] complex[2] andalso with stable organic free radicals. This discovery is originated from our earlier studies[3-5] on the magnetic
properties of DNA. We find an analogy between the ferromagnetic properties of inorganic dilute magnetic
semiconductors and DNA and DLC compositions. Herein, we will discuss the high temperature ferromagnetic
properties of DLC compositions doped with Fe(III)Pc complexes and also with organic free radicals. We also will
discuss a preliminary result on the room temperature ferromagnetic properties of polymeric composites consistingof some of polyconjugated polymers and paramagnetic dopants. We studied in details their magnetic properties
by electron paramagnetic resonance and SQUID studies. These findings are expected to open a new research
field as well as high technological applications of organic materials.

The deposition of transition metal layers on silicon and their reaction with substrate areimportant issues in semiconductor device technology. The interface between metal andsemiconductor determines the device performance. whereby both an ohmic contact and a
Schottky barrier, i.e., an active electronic element can be realized. The 3d transition metalmonosilicides such as FeSi, CoSi, MnSi and CrSi have attracted much attentions because
they are easily formed in the interface between transition metal and Si. FeSi is a narrow band
gap semiconductor. The activation energy for exciting electrons from the filled band to theempty band is estimated to be 0.05 eV from the experiments on the temperature dependenceof the Mossbauer effect, magnetic susceptibility and NMR shift. In this work, Fe thin films
were grown on Si(100) substrates using MBE. The structure and surface morphologies of
Fe films were determined by X-ray diffraction and atomic force microscopy measurements,
respectively. We have observed that all samples grown at 100, 400 and 600 oC have a phase of
CsCl crystal structure (c-FeSi). In order to investigate the correlation between magnetizationand charge carrier transport, we performed magnetoresistance and Hall resistancemeasurements by using a physical property measurement system.

[1] S. Morimoto, K. Itoh, F. Tanaka, and N. Mataga, Preprints of symposium on the Molecular Structure, Tokyo, 1968. [2]C. H. Lee, Y. -W. Kwon, D. H. Choi, E. K. Koh, Y. H. Geerts, and J. -I. Jin, Adv. Mater., 2010, 22(39), 4405-4409. [3] C. H.
Lee, Y. -W. Kwon, E.-D. Do, D. H. Choi, J.-I. Jin, D. -K. Oh, and J. Kim, Phys. Rev. B, 2006, 73, 224417. [4] Y.-W. Kwon, E.
-D. Do, D. H. Choi, J. -I. Jin, C. H. Lee, J. S. Kang, and E. -K. Koh, Bull. Korean Chem. Soc., 2008, 29, 1233-1242. [5]Cristina Bran1, Matthias Hudl2, Matts Bjorck1, Vassilios Kapaklis1 and Gabriella
Andersson1*
1
Department of Physics and Astronomy, Uppsala University, Sweden
2
Department of Engineering Sciences, Uppsala University, Sweden
Following recent theoretical predictions on perpendicular uniaxial magnetocrystalline
anisotropy in multilayers of 5 monolayers of Fe and 2 monolayers of (W,Re) withtetragonally strained components [1], we have investigated the magnetization anddetailed atomic structure in a series of samples with 20-80 at% W. Experimental
techniques used were SQUID magnetometry, Magneto-Optic Kerr Effect, Energy
Dispersive X-ray Spectroscopy, and X-ray Diffraction including reciprocal space
mapping around (002) and (103) body-centered-tetragonal Bragg peaks to measure inplane atomic distances. Although all the samples exhibit considerably smaller strain
in the (W,Re) alloy layers than the previously modelled multilayers, and consequently
in-plane easy magnetization axes, we do observe an enhancement of the saturation
magnetization that corresponds well to the predicted hybridization-induced moments
on individual Fe and (W,Re) atomic layers.
[1] S. Bhandary et al., Phys. Rev. B 84, 092401 (2011)

Adrianus Schellekens*, Arno Van Den Brink, Jeroen Franken, Henk Swagten andBert Koopmans
Applied Physics, Eindhoven University of Technology, Netherlands
Magnetic domain walls (DWs) are excellent candidates to store and transport
information in future memory devices [1]. Up until now, control of DWs has only beenpossible through the application of a magnetic field or current. Here, we demonstrate
a novel approach to control DW motion, namely by altering the magnetic properties
with an electric field [2]. Pt/Co/AlOx wires exhibiting perpendicular magnetic
anisotropy (PMA) are fabricated to investigate the influence of the electric field on
DW propagation. By applying a voltage over the insulating AlOx barrier charges are
induced at the Co/AlOx interface, locally changing the magnetic properties. Dependingon the sign of the voltage, it is observed that DW velocities can be increased or
decreased up to an order of magnitude. By analyzing the experimental results with theDW creep law, we were able to attribute the voltage-induced changes in DW motion to
the sensitivity of PMA to an electric field. Comparing the obtained changes in PMA tovalues in the literature [2], we estimate that controlling DW motion over five orders ofmagnitude should be well within experimental reach.
[1] S. Parkin, Science 320, 190 (2008). [2]. T. Maruyama, Nature Nanotechnology 4, 158 (2009).

[1] U. Starke, W. Weiss, M. Kutschera, R. Bandorf, and K. Heinz, J. Appl. Phys 91, 6154 (2002).

EH03

EI01

EI04

EJ01

Structure and magnetic properties of the new ferrimagnetic
AFe3O(PO4)3 (A=Ca,Sr,Cd,Pb) compounds

Perpendicular magnetic anisotropy in Fe/Fe1-xCox multilayers

Alloying as a possible mechanism in annealing induced perpendicularmagnetic anisotropy in alumina/Co/M (where M=Pd,Pt or Au)
trilayers

Evaluation of interlayer exchange coupling in α-Fe(100)/Nd2Fe14B(001)Films

Hassan El Hafid1, Matias Velazquez1*, Olivier Perez2, Abdelaziz El Jazouli3, Alain
Pautrat2, Rodolphe Decourt1, Philippe Veber1, Oudomsack Viraphong1, EmmanuelVeron4 and Claude Delmas1
1
Institut de la Chimie de la Matiere Condensee de Bordeaux, CNRS, France
2
CRISMAT, CNRS/ENSICaen, France
3
LCMS, Universite de Casablanca, Morocco
4
CEMHTI-CNRS, France
The crystal structure of the novel monoclinic oxyphosphate PbFe3O(PO4)3 was characterized by single crystal(SC) XRD between 293 and 973 K. χ measurements performed on SCs unveiled an unusual sequence offerromagnetic-like divergences at Tc1=31.8 K, Tc2=23.4 K and Tc3~10 K, whereas Cp measurements performedon SCs confirmed only the two phase transitions at Tc1 and Tc3, and a slight cusp around Tc2. In powder
samples however, the second χ divergence at Tc2 is absent, but they do exhibit a λ-type peak on the Cp(T) curve.
A set of χac measurements, (logarithmic) long time remanent magnetization decay measurements, modified
ZFC magnetization measurements, were performed on both powders and SCs. Mean-field critical exponents
were obtained in powders and SCs above Tc1, consistently with the low development of magnetic correlations
observed in χ curves, but not with the asymmetric λ-type Cp peak. We have clear evidence for two dissipative
mechanisms, giving peaks at 27 and 13 K on χac measurements. While the former spectrum shows a Debye
profile with a well defined Eact~240 K, the latter one shows a distribution of Eact typical of spin glass systems.
Finally, FC/ZFC magnetization cycles and χ measurements in the AFe3O(PO4)3 (A=Ca,Sr,Cd,Pb) compounds
will be presented.

Maciej Dabrowski1, Pedro Gastelois1, Fikret Yildiz1, Takeshi Nakagawa2, Yasushi
Takagi2, Toshihiko Yokoyama2, Marek Przybylski1* and Jurgen Kirschner11
Max-Planck-Institut fur Mikrostrukturphysik, Halle, Germany
2
Institute for Molecular Science, Okazaki, Japan
A uniaxial anisotropy of a volume character that can keep perpendicular magnetization in
relatively thick films is rare. The concept relates to the lattice distortion that modifies theelectronic band structure. A model system is provided by Fe1-xCox alloy films tetragonally
distorted due to their pseudomorphic growth on fcc mismatching substrates like Rh(001)and Ir(001) [1]. In particular, the Fe0.5Co0.5 films show perpendicular magnetic anisotropy,
whereas Fe layers (x=0) are magnetized in-plane. The Fe1-xCox and Fe layers can be separated
by a spacer that mediates a ferro- or antiferromagnetic exchange coupling [2]. As MOKE
measurements provide only a signal from the average magnetization, a layer resolved
knowledge of the spin structure is required. Soft x-ray magnetic circular dichroism allows us
to probe the magnetization separately for Fe1-xCox (measurements at the Co edges enabled
us to investigate the magnetism of the alloy layer independently from the pure Fe layer). We
found that non-collinear magnetization configurations can be produced also if there is nospacer, but there is a direct exchange coupling between the Fe and Fe1-xCox layers. A final
magnetization distribution depends on the composition of the constituent layers, and how thick
Fe is with respect to Fe1-xCox.
[1] F. Yildiz, M. Przybylski, X.-D. Ma, J. Kirschner, Phys. Rev. B 80, 064415 (2009). [2] F. Yildiz, M.
Przybylski, J. Kirschner, Phys. Rev. Lett. 103, 147203 (2009).

Patrick Warin, Alain Marty, Ariel Brenac, Lucien Notin, Stephanie Pouget, Celine
Vergnaud, Cyrille Beigne and Matthieu Jamet*
INAC, Commissariat a l'Energie Atomique et aux Energies Alternatives, France

Daisuke Ogawa1, Kunihiro Koike1, Shigemi Mizukami2, Takamichi Miyazaki3, Mikihiko Oogane3,
Yasuo Ando3 and Hiroaki Kato1
1
Graduate School of Science and Engineering, Yamagata University, Japan
2
WPI-AIMR, Tohoku University, Japan
3
Graduate School of Engineering, Tohoku University, Japan

Since the work of Carcia[1], perpendicular magnetic anisotropy (PMA) in ferromagnetic/nonmagnetic trilayers or multilayers has attracted much attention. Spin-orbit interaction is the maincause for PMA. Recently it has been shown that in MgO/CoFeB/Ta2 and Oxide/Co/Pt3, PMA canbe induced by annealing. In particular, it has been argued in [4] that the origin of this PMA is the
hybridization between Co and O orbitals enhanced by annealing. We demonstrate in this work that
another explanation is alloying between cobalt and the capping layer. We have grown and annealed
at different temperatures trilayers of alumina(3nm)/Co(tnm)/M(3nm) where t varies from 1 to 2
nm and M= Pd, Pt and Au. For Ta=300°C, PMA is observed in Co/Pd and Co/Pt for t<1.6 nm and1.4 nm respectively. However no PMA is observed for any thickness in Co/Au. At Ta= 400 °C
Co/Pd and Co/Pt show PMA for all thicknesses whereas for Co/Au no PMA is observed. It seems
that the influence of Co-O bonds is not enough to drive the magnetization out-of-plane in Co/Au.
We propose that the observed effect is due to alloying between Co and Pt or Pd, as Co and Au are
immiscible no effect is observed in Co/Au.

Exchange-coupled hard/soft nanocomposite magnets have a potential to exhibit a large maximum
energy product[1]. Recently, a new issue has been proposed by the first-principle calculations[2]for the α-Fe/Nd2Fe14B system, which suggest that a magnitude of the hard/soft exchange-coupling
depends strongly on the Miller indices of the crystallographic planes at the interface between thetwo phases, and that even antiparallel coupling would be stabilized in particular combination ofplanes. Recently, we fabricated the α-Fe(100)/Nd2Fe14B(001) bilayer on the MgO(100) substrateby using UHV magnetron sputtering system. Q-band FMR measurements revealed the positive
interlayer coupling in this sample [3]. In this work, similar films with different values of the α-Fe
layer thickness tFe were fabricated in order to evaluate the exchange-coupling constant more
precisely. With increasing tFe, the shift in the α-Fe resonance field decreased, as compared withthe resonance field for the α-Fe single layer film. These FMR spectra and the magnetization curves
are found to be in consistent with the simulation assuming the positive exchange coupling in the
α-Fe(100)/Nd2Fe14B(001) interfaces.

[1] Carcia et al, Appl. Phys. Lett. 47, 178 (1985). [2] Ikeda et al, Nature Mater. 9, 721 (2010). [3]Nistor et al, Appl. Phys. Lett. 94, 012512 (2009). [4] Rodmacq et al, Phys. Rev. B 79, 024423 (2009)[1] R. Skomski and J. M. D. Coey, Phys. Rev. B48 (1993) 15812. [2] Y. Toga, H. Tsuchiura and A. Sakuma, J. Phys:
Conf. Ser, 266, 012046 (2011). [3] D. Ogawa, K. Koike, S. Mizukami, M. Oogane, Y. Ando, T. Miyazaki, H. Kato, J.
Magn. Soc. Jpn., 36, 5 (2012).

EH04

EI02

EI05

EJ02

Magnonic metamaterials formed by arrays of Co antidots on
continuous NiFe films

Effect of annealing temperature on L1ο ordering and perpendicularmagnetic anisotropy of FePd/CoFeB films

High perpendicular magnetic anisotropy at CoxNi1-x(x = 0.0~1.0)/
α-Cr2O3 interface

Morphology and magnetic properties of SmCo3/Fe and Sm2Co7/FeCo
nanocomposite magnets prepared via severe plastic deformation

Magnonic crystals periodic magnetic media represent one of the central objects in the research
field of magnonics [1]. Usually, the periodic modulation of the effective magnetic field inmagnonic crystals is achieved as a compositional modulation created either during growthor using lithographic processing. In this report, we demonstrate a method of producing
magnonic crystals by periodically modulating the internal magnetic field inside a continuous
thin film of NiFe (Permalloy). The modulation of the internal magnetic field is achieved via
fabrication of a Co nanostructure (an array of antidots) on top of the Permalloy film, withthe latter experiencing the stray magneto-dipole field from uncompensated magnetic chargesin Co. The dynamical properties of the fabricated magnonic crystals are characterized using
the time resolved scanning Kerr microscopy (TRSKM) [2]. The measurements reveal astrong modification of the magnonic spectrum the strength of which increases as the valueof the bias magnetic field decreases. The finding opens new ways for creation of magnonic
metamaterials. The research leading to these results has received funding from the EC’s 7th
Framework Programme (FP7/2007-2013) under GA 228673 (MAGNONICS) and fromEPSRC of the UK under project EP/E055087/1.

Spin-transfer-torque random access memory (STT-RAM) using perpendicular magnetized
L1o-ordered alloy for magnetic tunnel junctions (p-MTJs) has considerable interest because ofadvantages for scalability and stability of memory. However, tunnel magnetoresistance (TMR) ratio
was a few percent at room temperature using L1o-ordered alloys. [1,2] A high TMR ratio as wellas perpendicular magnetic anisotropy (PMA) was obtained using the thin CoFeB combined with
MgO barrier due to interfacial effect. [3] In this study, we systematically investigated annealing
temperature effects on PMA with the insertion of thin CoFeB layer between L1o-FePd and MgOfilms for use as free layer in the p-MTJs. Stacking structure is Cr40/Pd10/FePdt/CoFeB0.5/MgO2/
Ta3 (unit in nm, and t=1.5-5.0) and these were epitaxially grown on MgO (100) substrates. FePd
and CoFeB were deposited at 300°C and ambient temperature, respectively. After post-annealing,
the perpendicular anisotropy was observed at Ta≥ 300°C and 250°C for t= 2.0 nm and 2.5 nm,
respectively, whereas it was observed for all samples above t ≥3.0 nm which might be attributed
to the crystallization of CoFeB and increased of PMA. The results show that annealing is aneffective method to improve the PMA of a FePd/CoFeB system. Acknowledgement: This study was
supported by FIRST program from JSPS.

α-Cr2O3(0001) surface offers a high perpendicular exchange bias when it is attached to aferromagnetic layer [1] because the topmost Cr spins on the α-Cr2O3(0001) surface are fully
uncompensated and align normal to the surface. In particular to the perpendicular exchange bias,
the perpendicular magnetic anisotropy (PMA) at a ferromagnetic(FM)/antiferromagnetic(AFM)
interface is essential, which has not been reported. In this work, we have investigated the interface
magnetic anisotropy of the CoxNi1-x(111)/α-Cr2O3(0001) interface with the Co composition x =0-100 at %. From the structural characterizations, we confirmed that the fabricated samples were in
the epitaxial manner, i.e. Pt(111) || CoxNi1-x(111) || α-Cr2O3(0001) || Pt(111) || α-Al2O3(0001)-sub.
We precisely determined the PMA at the Co(111)/α-Cr2O3(0001) interface through the change in the
PMA energy with the number of stacking-period of Pt/[Co/Pt]n/α-Cr2O3/Pt epitaxial superlattices.
The PMA energy increases with increasing the number of stacking-period, which indicates thatthe strong PMA is generated at the Co(111)/α-Cr2O3(0001) interface and that the PMA energyof the Co(111)/α-Cr2O3(0001) interface is comparable to that of the Co/Pt interface. For the Pt/
CoxNi1-x(111)/α-Cr2O3(0001)/Pt films, the PMA energy monotonically decreases with increasing
Ni composition. The change in the PMA with the Ni composition is similar to that of Pt/CoxNi1-x/Pt
multilayer [2].

1. V. V. Kruglyak, S. O. Demokritov, and D. Grundler, J. Phys. D: Appl. Phys. 43, 264001 (2010). 2. Y. Au, T.
Davison, E. Ahmad, P. S. Keatley, R. J. Hicken, and V. V. Kruglyak, Appl. Phys. Lett. 98, 122506 (2011).

[1] N. Inami et al., J. Mag. Sco. Jpn. 34, 293 (2010) [2] G. Kim et al., Appl. Phys. Lett. 92, 172502 (2008).
[3] S. Ikeda et al., Nat. Mat. 9, 721 (2011).

[1] Y. Shiratsuchi, T. Fujita, H. Oikawa, H. Noutom and R. Nakatani, Appl. Phys. Exp., Vol. 3, pp. 113001 (3pp) (2010).
[2] R. Krishinan and H. Lassri, J. Magn. Magn. Mater., Vol. 133, pp. 453-456 (1994).

SmCo5 and Sm2Co17 compounds have been widely applied as the first and the second
generations of rare-earth permanent magnets respectively. There are other SmCo internmetallic phases with lower Co concentration that have been ignored aspermanent magnetic materials for their relatively low magnetization and anisotropy.
Those phases, including SmCo3 and Sm2Co7, have been systematically investigated inour recent research as the hard-phase component in hard/soft nanocomposite systems.
It has been found that the nanocomposites magnets having SmCo3 and Sm2Co7 as
the hard phases have excellent properties. The composites can incorporate more softphase compared to SmCo5 and Sm2Co17. Here, we report SmCo3/Fe and Sm2Co7/FeCo
nanocomposites prepared by high energy ball-milling and subsequent heat treatments.
The evolution of morphology and magnetic properties with ball milling time andthe soft phase content has been studied. The α-Fe phase distributed in the matrix ofhard magnetic Sm-Co phases has grain size less than 20 nm after the severe plastic
deformation. Enhanced remanence and maximum energy product up to 13.5 and 17.6
MGOe in the nanocomposites with 25 and 40 % of the soft phase are obtained for
SmCo3 and Sm2Co7 respectively, which is up to 300 % higher than that of single-phasecounterparts.

Ehsan Ahmad, Yat-yin Au, Toby Davison, Mykola Dvornik and Volodymyr
Kruglyak*University of Exeter, United Kingdom

70

oRAL PRSENTATION

The 19th International Conference on Magnetism

Oral Tuesday

Oral Tuesday

ORAL PRESENTATION

Mohammed Nazrul Islam Khan*, Hiroshi Naganuma, Nobuhito Inami, Yusuke
Ohdaira, Mikihiko Oogane and Yasuo Ando
Applied Physics, Tohoku University, Japan

Yu Shiratsuchi*, Hiroto Oikawa, Shin-ichi Kawahara and Ryoichi Nakatani
Osaka University, Japan

Narayan Poudyal, Nguyen Van Vuong, Ying Zhang and J. Ping Liu*
Department of Physics, University of Texas at Arlington, USA

July 8-13, 2012 Busan, Korea

71

ORAL PRESENTATION
FA02

Atomic scale investigation of Sm-Co/Fe nanocomposites: Influence of
Fe/Co interdiffusion on the magnetic properties

Domain wall motion by the magnonic spin Seebeck effect

The nanostructure of SmCo5/Fe nanocomposites elaborated by high energy ball milling was investigatedusing atom probe tomography. This high resolution technique allowed obtaining in the real space a three
dimensional mapping of the chemical species (Sm, Co and Fe) at the atomic scale [1]. 3D reconstructionsof the nanostructure of the analysed samples were realised from the data and show that the majority of
the SmCo5/Fe nanocomposite is composed of Fe(Co) soft magnetic nano-sized crystallites embedded
in a Sm-(Co,Fe) hard magnetic matrix. These results confirm the formation of the Fe(Co) phase and thecontamination of the initial SmCo5 by Fe atoms. The interfaces between the Fe(Co) soft magnetic phaseand the Sm-(Co,Fe) hard magnetic phase were also chemically analysed at the atomic scale. Large gradedinterfaces were evidenced. These observations were correlated with Monte Carlo simulations and confirm
the benefit of the Fe/Co interdiffusion on the magnetic exchange coupling.

Ulrike Ritzmann, Denise Hinzke and Ulrich Nowak
Department of Physics, University of Konstanz, Germany

In the last years it was demonstrated that in ferromagnetic materials spatial temperature
grandients can lead to spin accumulation [1], even in magnetic insulators [2]. In
this context, it is important to note that in addition to a spin polarized charge current
also a chargeless angular momentum current driven by spin waves can exist. Here,
we propose the existence of domain wall (DW) dynamics driven by magnonic spincurrents due to temperature gradients. To get some insight into this effect we introduce
two different approaches: the stochastic Landau-Lifshitz-Gilbert equation, applied
to spin models, and the Landau-Lifshitz-Bloch equation describing the dynamics
of the thermally averaged spin polarization on micromagnetic length scales. We
show that these approaches describe this new type of DW motion, where chargelessspin currents following from a temperature gradient drag a DW into the hotter
region [3]. Furthermore, for a better understanding of the relevant length scales, weinvestigate the propagation and frequency range of thermally induced magnons. We
acknowledge financial support by the Deutsche Forschungsgemeinschaft throughSchwerpunktprogramm SpinCaT.

FB01
Textured superconductivity in the heavy fermion CeRhIn5

Xin Lu1, Tuson Park2, Han-oh Lee1, I. Martin1, V. A. Sidorov3, K. Gofryk1, F.
Ronning1, E. D. Bauer1 and J. D. Thompson1
1
Los Alamos National Lab, USA
2
Department of Physics, Sungkyunkwan University, Korea
3
Vereshchagin Institute of High Pressure Physics, RAS, 142190 Troitsk, Russia
In the coexistence region of antiferromagnetism (AFM) and superconductivity (SC)of CeRhIn5, the superconducting transition temperatures determined resistively andthermodynamically display a significant difference while the difference disappears at
higher pressures where AFM is suppressed and only SC exists. In the coexisting stateof AFM and SC, anisotropic transport near the SC transition reveals the emergenceof textured SC planes that appear without a change in translational symmetry of thelattice. Similar behaviors have also been observed in other strongly correlated electron
systems where there are coexisting and competing orders with SC.
Tuson Park et al. Phys. Rev. Lett. in press.

[1] K. Uchida et al., Nature 455, 778 (2008). [2] K. Uchida et al., Nat. Mater. 9, 894(2010). [3] D.
Hinzke and U. Nowak, Phys. Rev. Lett. 107, 027205(2011)

FB04
Electronic structure of ferromagnetic heavy fermion YbNi4P2

Sven Friedemann1*, Swee K Goh1, Lina Klintberg1, F Malte Grosche1, Cornelius
Krellner2, Christoph Geibel2, Frank Steglich2 and Helge Roßner2
1
Cavendish Laboratory, University of Cambridge, United Kingdom
2
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
Quantum critical phenomena can be studied in great detail in lanthanide based heavyfermion systems. Up to now, however, only materials with antiferromagnetic groundstate were found among the 4f based heavy fermions. In the new heavy fermion
material YbNi4P2 a clear ferromagnetic transition is observed at TC = 0.17 K. YbNi4P2
has the prospect to study ferromagnetic quantum criticality accessible by either
composition tuning or transverse-field tuning. Above the transition temperature in
YbNi4P2 strong evidence is found for its vicinity to a quantum critical point, the specificheat diverges in a power-law form and the resistivity follows a linear temperaturedependence. We present first Shubnikov-de Haas measurements in combination withelectronic band structure calculations. The electronic structure is dominated by parallel
disconnected sheets in accordance with the crystal structure featuring quasi-onedimensional chains of Yb. The observed Shubnikov-de Haas oscillations are assigned
to quasi-two-dimensional features of the Fermi surface. The experimentally observed
mass enhancement of these orbits reflects the heavy-fermion character of YbNi4P2.

Oral Wednesday

EJ03
Jean-marie Le Breton1*, Rodrigue Larde1, Adeline Maitre1, Denis Ledue1, Olivier
Isnard2, Ionel Chicinas3, Viorel Pop4 and Dominique Givord2
1
Groupe de Physique des Materiaux - UMR 6634, CNRS - Universite de Rouen,
France2
Institut Neel, CNRS - Universite Joseph Fourier Grenoble, France
3
Materials Science and Technology Department, Technical University Cluj-Napoca,
Romania
4
Faculty of Physics, Babes-Bolyai University Romania, Romania

Oral Wednesday

oRAL PRSENTATION[1] J.M. Le Breton, R. Larde, H. Chiron, V. Pop, D. Givord, O. Isnard, I. Chicinas, Journal of Physics D:
Applied Physics, 43 (2010) 085001

EJ04

FA03

Effect of particle size on the coercivity of Nd-Fe-B and Sm-Co
nanoparticles prepared by surfactant-assisted ball milling

Phonon-drag spin Seebeck effectNilay Gunduz Akdogan 1 *, Wanfeng Li 1 , Dimitrios Niarchos 2 and George
Hadjipanayis1
1Physics and Astonomy, University of Delaware, USA
2
Institute of Material Science, N. C. S. R., Greece
Anisotropic Nd2Fe14B and SmCo5 nanoparticles have been produced by surfactant-assisted
high-energy ball milling (HEBM) of nanocrystalline precursor alloys. A two-stage HEBM was
performed to obtain the nanoparticles; first the coarse powders were made nanocrystalline bymilling, and then were subjected to surfactant-assisted milling for different time. Nanoparticles
with different shape (irregular, square and spherical shapes) and size have been obtained byvarying the grain size of nanocrystalline precursors. The size of the nanoparticles is foundto depend strongly on the grain size of nanocrystalline precursors. For a surfactant-free wet
milling of 0.5 to 4 hr, anisotropic Nd2Fe14B and SmCo5 nanoparticles have been found witha size from 25 to 2.8 nm. The nanoparticles had coercivity values at 50 K of 9 kOe for the
15 nm Nd2Fe14B and 15 kOe for the 25 nm SmCo5. The room temperature coercivities werelower with the values of 2.5 and 5 kOe, respectively. The coercivity was found to decrease
with the particle size suggesting a decrease in the overall anisotropy because of surface effects.
In the Nd2Fe14B nanoparticles, a lower spin reorientation temperature was observed (117 K) as
compared to bulk (135 K).

Hiroto Adachi1, Jun-ichiro Ohe2, Saburo Takahashi3 and Sadamichi Maekawa1
1
Japan Atomic Energy Agency, Japan2
Toho University, Japan
3
Tohoku University, Japan

Exotic superconductivity of heavy electrons in artificial twodimensional Kondo lattices

Spin Seebeck effect refers to a thermal spin injection from a ferromagnet into an
attached nonmagnetic metal that occurs over macroscopic scale of several millimeters[Uchida et al., Nature 455, 778 (2008)]. The spin Seebeck effect is now established asa universal aspect of ferromagnets since it is observed in a variety of materials ranging
from a metallic ferromagnet (NiFe) and semiconducting ferromagnet (GaMnAs) toan insulating magnet (YIG). Recent theoretical and experimental efforts have clarified
that the phonon degrees of freedom are of crucial importance in this intriguing
phenomenon. Here we theoretically discuss the phonon-drag contribution to the spin
Seebeck effect [Adachi et al., Appl. Phys. Lett. 97, 252506 (2010)]. The spin Seebeck
effect is driven by nonequilibrium phonons that drag the low-lying spin excitations.
This scenario explains simultaneously the local nature of the spin Seebeck effect[Jaworski et al., Nature Materials 9, 898 (2010); Uchida et al., Nature Materials 10,
737 (2011)] and the signal enhancement at low temperatures [Jaworski et al., Phys.
Rev. Lett. 106, 186601 (2011)].

When interacting electrons are confined to low-dimensions, the electron-electron correlation effect isenhanced dramatically, which often drives the system into exhibiting behaviours that are otherwise
highly improbable. Superconductivity with the strongest electron correlations is achieved in heavyfermion compounds, which contain a dense lattice of localized magnetic moments interacting with a seaof conduction electrons to form a three-dimensional (3D) Kondo lattice. It had remained an unansweredquestion whether superconductivity would persist upon effectively reducing the dimensionality of thesematerials from three to two. We report on the observation of superconductivity in such an ultimately
strongly-correlated system of heavy electrons confined within a 2D square-lattice of Ce-atoms (2D
Kondo lattice), which was realized by fabricating epitaxial superlattices[1] built of alternating layersof heavy-fermion CeCoIn5 and conventional metal YbCoIn5 [2]. The field-temperature phase diagramof the superlattices exhibits highly unusual behaviours, including a striking enhancement of the upper
critical field relative to the transition temperature. Possible origins of this enhancement will be discussed,
including extremely strong coupled nature as a result of two-dimensionalization[2], formation of FFLO
state, and local spatial inversion symmetry breaking [3].

Takasada Shibauchi
Department of Physics, Kyoto University, Japan[1] H. Shishido, T. Shibauchi, K. Yasu, T. Kato, H. Kontani, T. Terashima, and Y. Matsuda, Science 327, 980-983 (2010). [2] Y.
Mizukami, H. Shishido, T. Shibauchi, M. Shimozawa, T. Yasumoto, M. Yamashita, H. Ikeda, T. Terashima, H. Kontani, and Y.
M atsuda, Nature Physics 7, 849-853 (2011). [3] D. Maruyama, M. Sigrist, and Y. Yanase, arXiv:1111.4293.

Work supported by NSF DMR-1005871 and Marie Curie.

FC01
Models of spin dynamics; ultrafast heat pulses as a sufficient stimulus
for reversal in a ferrimagnet

Roy W Chantrell1, J Barker1, Rfl Evans1, U Atxitia22, O Chubykalo-fesenko2 and Rw
Chantrell1
1
Physics, University of York, United Kingdom
2
ICMM, Spain
The response of magnetic materials to the heating effect of ultrafast laser pulses is achallenging problem which is giving important insight into spin dynamics at elevatedtemperatures and sub-picosecond timescales. We have developed a model of ultrafast spin
dynamics using an atomistic model based on the Heisenberg exchange Hamiltonian and using
the Landau-Lifshitz-Gilbert equation with Langevin dynamics to calculate the evolution of themagnetisation following a laser pulse. Here we describe studies of the properties of amorphous
ferromagnetic Rare Earth (RE) Transition Metal (TM)alloys, which are shown to exhibit
interesting and unexpected properties. Firstly, the model demonstrates differential sublatticedynamics, specifically a different rate of demagnetisation for the RE and TM sub-lattices,even though these are coupled by a strong exchange interaction. Even more surprising is theexistence of a transient ferromagnetic state, stable for around 300fs. It is shown theoreticallythat this leads to magnetisation reversal, in the absence of a magnetic field, driven by a heatpulse alone. The underlying physics of this effect and its confirmation in recent experiments [1]will be discussed.
[1] T Ostler et al., Nat. Commun., 3:666 doi: 10.1038/ncomms1666 (2012)

FA01

FA04

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FC02

Dynamical generation of spin currents

Entanglement of spin Seebeck effect and anomalous Nernst effectEvolution of quasiparticle entropy in high-field superconducting phasein CeCoIn5

Coherent spin-photon interaction and ultrafast magnetism: Fromprinciples to applications

Eiji Saitoh
Institute for Materials Research, Tohoku University, ASRC, Japan Atomic Energy
Agency, Japan
Spin current, a flow of electrons’ spins in a solid, is the key concept in spintronics thatwill allow the achievement of efficient magnetic memories, computing devices, andenergy converters. I here review phenomena which allow us to use spin currents ininsulators [1]: inverse spin-Hall effect [2,4], spin pumping, and spin Seebeck effect[4-6]. We found that spin pumping and spin torque effects appear at an interface
between an insulator YIG and Pt. Using this effect, we can connect a spin current
carried by conduction electrons and a spin-wave spin current flowing in insulators. We
demonstrate electric signal transmission by using these effects and interconversion of
the spin currents [1]. Seebeck effect (SSE) is the thermal spin pumping [5]. The SSE
allows us to generate spin voltage, potential for driving nonequilibrium spin currents,
by placing a ferromagnet in a temperature gradient. Using the inverse spin-Hall effectin Pt films, we measured the spin voltage generated from a temperature gradient invarious ferromagnetic insulators. This research is collaboration with K. Ando, K.
Uchida, Y. Kajiwara, S. Maekawa, G. E. W. Bauer, S. Takahashi, and J. Ieda.
References 1. Y. Kajiwara & E. Saitoh et al. Nature 464 (2010) 262. 2 E. Saitoh et al., Appl. Phys.
Lett. 88 (2006) 182509. 3 A. Ando & E. Saitoh et al., Nature materials 10 (2011) 655 -659. 4 K.
Uchida & E. Saitoh et al., Nature 455 (2008)778. 5 K. Uchida & E. Saitoh et al., Nature materials 9(2010) 894 - 897. 6 K. Uchida & E. Saitoh et al., Nature materials 10 (2011) 737-741.

72

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The 19th International Conference on Magnetism

Chia-ling Chien
Department of Physics and Astronomy, The Johns Hopkins University, Baltimore MD
21218, USA
Spin Seebeck effect (SSE) is a spin caloritronic effect that generates a pure spin current.
The studies of SSE have often been made on a patterned Pt strip on a ferromagnetic(FM) thin metallic film on substrate, where the in-plane temperature gradient (∇ xT)
generates in the FM film a spin current, which is detected by the inverse spin Hall
effect as a voltage in the Pt strip. However, there is also the propensity of an out-ofplane temperature gradient (∇ zT), which gives rise to the anomalous Nernst effect(ANE) due to the larger thermal conduction through the substrate.1 While SSE with∇ xT and ANE with ∇ zT are two different effects, they can be simultaneously present.
More importantly, the voltages of the two effects are additive with the same fielddependence and symmetry, and therefore cannot be easily separated. In such cases, theestablishment of the SSE is contingent upon the ANE measurements before the Pt strip
is in place.
Work supported by the US NSF DMR 05-20491 and Taiwan NSC 99-2911-I-007-510. 1 S. Y. Huang,
W. G. Wang, S. F. Lee, R. Kwo, and C. L. Chien, Phys. Rev. Lett,. 107, 216604 (2011).

Yoshi Tokiwa1, Philipp Gegenwart1 and Eric D Bauer2
1
I. Physikalisches Institut, Georg-August-Universitaet Goettingen, 37077 Goettingen,Germany2
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
Unambiguous detection of Fulde and Ferrell and Larkin and Ovchinnikov (FFLO) superconducting(SC) phase in solid state systems is still a challenge in the comunity of strongly correlated electron
systems (SCES). A heavy fermion superconductor, CeCoIn5, is one of the best candidates for theformation of FFLO state. Existence of FFLO phase in this material has been extensively discussed
in the past decade and is still one of the most debated current topics in the field of SCES[1]. Entropy
as a function of field can capture the characteristic nature of FFLO state, namely the additional
increase of quasi-particles, leading to a steep increase of entropy at the transition field from
uniform to FFLO SC state. We have obtained the entropy, derived from combined specific heat andmagnetocaloric effect measurements at temperatures $T\geq 100$~mK and fields $H\leq 12$~Taligned parallel, perpendicular and $18^\circ$ off the tetragonal [100] direction. In any direction,
we do not observe an additional quasiparticle entropy expected in a FFLO SC state. By contrast,
for $H\parallel [100]$ a negative entropy contribution, compatible with spin-density-wave (SDW)
ordering, is found. Our data exclude the formation of a FFLO state in CeCoIn5 for out-of-plane field
directions, where no SDW order exists.
[1] Y. Matsuda and H. Shimahara, J. Phys. Soc. Jpn., 76, 051005 (2007)

Jean-Yves Bigot, Ji-Wan Kim, Mircea Vomir, and Marie Barthelemy
IPCMS, CNRS, Universite de Strasbourg, France

How fast can one manipulate the magnetization of materials using ultrashort opticalpulses? This question is at the heart of several fundamental and applied researches withthe prospective of making ultrafast magnetic devices. An important related topic is thecoherent time dependent interaction between spins and photons. In the present talk we
review the state of the art understandings in that field, describing the spin dynamics
from first principles and showing some applications. First, we show that the spin-orbit
interaction is a crucial concept when manipulating the spins with a laser field. Second,
we distinguish between different mechanisms resulting from the time ordering between
a sequence of pump and probe pulses when performing a time resolved magnetooptical experiment. In particular we distinguish between the coherent and population
components associated to the spins dynamics. Third, we demonstrate the validity ofthese theoretical concepts by considering the time dependent magneto-optical responseof garnets or transition metals (Ni, CoPt) excited by femtosecond laser pulses. In thecase of ferrimagnetic Bi-doped garnets the coherent contribution is most important,leading to the generation of efficient magneto-optical four-wave mixing signals. In
the case of ferromagnetic transition metals, the population dynamics dominates with aweaker coherent response.

July 8-13, 2012 Busan, Korea

73

ORAL PRESENTATION
FC03

FD03

FE02

GA01

Ultrafast switching of ferrimagnets

Oersted field contribution on the magnetic vortex core dynamics
proved by homodyne detection

Coarse graining tensor renormalization by the higher-order singularvalue decomposition

Detection of orbital fluctuations above the structural transition
temperature in iron pnictides and chalcogenides

The ultrafast manipulation of magnetisation by fs laser pulses promises tobecome a real alternative to conventional techniques based on magnetic fields. It
was demonstrated that a 80 fs, circularly polarised laser pulse is able to reverse
magnetisation on a ps time scale, as if it acts as a short magnetic field pulse causedby the inverse Faraday effect [1]. In single-shot time-resolved imaging of magnetic
structures [2] it has been shown that the magnetisation reverses via a linear pathway [3]without any precession. Even with linearly polarized light switching was demonstrated
recently [4], probably on a purely thermal basis. These new types of switching
have been demonstrated only in ferrimagnetic materials like GdFeCo, probably
because of the antiferromagnetic coupling of the two different sub-lattices in thesematerials, leading to completely different dynamics as compared to a ferromagnet. To
understand this new type of dynamics we perform atomistic spin model simulations offerrimagnets and investigate their switching mechanisms in detail. Funded by the EU
project FemtoSpin and the CAP in Konstanz.
[1] C. D. Stanciu et al., Phys. Rev. Lett. 99, 047601 (2007). [2] K. Vahaplar et al., Phys. Rev. Lett.
103, 117201 (2009) [3] N. Kazantseva et al., Europhys. Lett. 86, 27006 (2009) [4] I. Radu et al.,Nature 472, 205 (2011)

June Seo Kim1, Martin Staerk2, Jungbum Yoon3, Chun Yeol You3, Florian Kronast4,
Christian Ulysse5, Giancarlo Faini5 and Mathias Klaeui1*1Institut fuer Physik, Johanes Gutenberg-Universitaet Mainz, Germany
2
Fachbereich Physik, Universitaet Konstanz, Germany
3
Department of Physics, Inha University, Korea
4
Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Germany
5
Phynano Team, Laboratoire de Photonique et de Nanostructures, CNRS, France
The recent discovery that a spin-polarized current can induce magnetic vortex dynamics openeda new way to manipulate magnetization. Here, we report on the resonant excitation of a magnetic
vortex core in a permalloy disc due to the injection of the high frequency current. The Oersted field
contribution due to the inhomogeneous current distribution in the magnetic vortex core dynamics
on a magnetic circular disc is experimentally investigated using a homodyne detection scheme. The
homodyne technique allows us to obtain the resonance frequency, the amplitude of the vortex core
gyration, and the phase shift between the microwave current and the magnetoresistance oscillation.
By the vortex core position dependent measurements, the amplitude of the vortex core gyration
obviously increases due to the enhancement of the Oersted field contribution. From systematic
phase measurements as a function of microwave frequency, two phenomena are observed: (i) the
trajectory of the vortex core gyration is distorted by the bounding effect due to the strong shapeanisotropy close to the edge and (ii) the Oersted field contribution is dominant driving the vortex
core close to the edge.

Tao Xiang
Institute of Theoretical Physics/Institute of Physics, Chinese Academy of Sciences,
China

We propose a novel coarse graining tensor renormalization group method based on
the higher-order singular value decomposition (HOSVD). This method provides anaccurate but low computational cost technique for studying two- or three-dimensional(3D) lattice models. The method is demonstrated using the Ising model on the squareand cubic lattices. By keeping up to 16 bond basis states, we obtain by far the mostaccurate numerical renormalization group results for the 3D Ising model.

L. H. Greene1*, H. Z. Arhan1, C. R. Hunt1, W. K. Park1, J. Gillett2, S. D. Das2, S. E. Sebastian2, Z. J. Xu3, J.
S. Wen3, Z. W. Lin3, Q. Li3, G. Gu3, A. Thaler4, S. Ran4, S. L. Bud'ko4, P. C. Canfield4, D. Y. Chung5, M. G.
Kanatzidis5, Wei-cheng Lee1 and P. Phillips1
1
Physics, University of Illinois at Urbana-Champaign, USA
2
Physics, Cavendish Laboratory, University of Cambridge, United Kingdom
3
Physics, Brookhaven National Laboratory, USA
4
Physics and Astronomy, Ames Laboratory and Iowa State University, USA
5
Materials Science, Argonne National Laboratory, USA

The electronic structure of AEFe2As2 (AE=Ca,Sr,Ba) and Fe1+yTe is studied using point contact orquasiparticle scattering spectroscopy (QPS). [1] For AE=Sr,Ba and Fe1+yTe, a conductance enhancement
reproducibly appears at To, well above the structural transition temperature, Ts. For Ba(Fe1-xCox)2 As2,
the conductance enhancement exists only in the underdoped regime. Thus, we add a new region of strong
correlations to the phase diagram: For x = 0 to 5.5, To ~ 175 K to ~ 150 K, respectively. These strong
correlations arise from orbital fluctuations, and the prediction [2] that the excess conductance above Ts isonly observed in detwinned crystals that exhibit resistance anisotropy above Ts [3] has been verified [1].
The role of orbital fluctuations and nematicity in quantum criticality of these materials will be discussed.
[4] Supported by the Center for Emergent Superconductivity, an EFRC, US DOE, DE-AC0298CH1088;
Cambridge EPSRC, and Ames Lab US DOE, DE-AC02-07CH11358.
1. H. Z. Arham et al, arXiv:1201.2479. 2. W.-C. Lee and P. Phillips, arXiv:1110.5917. 3. I. R. Fisher et al., Rep. Prog.
Phys. 74, 124506 (2011) and references therein. 4. S. Kasahara et al, Phys. Rev. B 81, 184519 (2010); S. Kasahara etal., Bull. Am. Phys. Soc. 56, Z26.00010 (2011); Y. Matsuda, private communication.

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Spin wave mediated magnetic vortex core reversal. Towards a 100 ps
V(ortex)MRAM

Vortex core switching driven by the novel inverse Faraday effect

Hermann Stoll*
MPI for Intelligent Systems (formerly MPI for Metals Research), Germany

Katsuhisa Taguchi1*, Jun-ichiro Ohe2 and Gen Tatara1
1
Physics, Tokyo Metropolitan University, Japan2
Physics, Toho University, Japan

Monte-carlo approach to stationary non-equilibrium of mesoscopic
systems

Nature of magnetic excitations in superconducting ironsuperconductors

The discovery of magnetic vortex core reversal by excitation of the sub-GHz gyromode [1] not only
opened a new chapter in vortex dynamics but also enabled the use of the magnetic vortex core polarization
p as memory bit for spintronic applications. Suggestions for V(ortex)MRAMs published so far [2-6] arebased on the excitation of the vortex gyromode at sub-GHz frequencies and allow switching times ofa few ns. Last year we have demonstrated [7] that much faster vortex core reversal can be achieved byexciting azimuthal spin wave modes with external alternating magnetic fields at multi-GHz frequencies.
Depending on the sample geometry, lower limits exist [8] for the time needed for spin wave mediatedvortex core reversal, which cannot be overcome by shortening the excitation length or by increasing
the excitation amplitude. These limits are explained by a finite time needed for the energy transfer ofthe global excitation towards the center of the sample [8]. In the present talk it will be demonstrated byexperiments [9] and micromagnetic simulations, how both, the duration of excitation and the time needed
for unidirectional vortex core reversal can be reduced to well below 100 ps, allowing a fast writing ofV(ortex)MRAMs.

Many researchers have investigated the mechanisms of the ultrafast vortex coreswitching by electric current experimentally and theoretically [1]. In this presentation,
we theoretically predict a novel mechanism of the core switching by an optical means.
We show that for vortex structures, an unconventional inverse Faraday effect [2]without the spin-orbit interaction induces strong magnetic field when a circularly
polarized light is applied and is useful for fast core reversal. The magnetic dynamics
of the vortex core is calculated with the help of the simulation in the framework of
the Landau-Lifshitz-equation, and the switching time is obtained to be 0.2 ns. This
switching time is two orders shorter than one for the electrical switching, 20ns [1].
This ultrafast optical core switching is realized in the following process: first the orbital
angular momentum of the circularly polarized light is converted to the electron’s orbital
angular momentum, and then the spin chirality, which is a solid angle of the vortex
spin structure, converts it to the spin angular momentum.

Calculating properties of correlated systems out of equilibrium is a challenging task,even if on targets only stationary situations. In particular, transport through nanoobjects like molecules or quantum dots is of strong interest, and a theory to calculatetransport properties or merely local quantities in a reliable way for reasonably strong
correlations very desirable. Based on a suggestion by Han and Heary [1] we use
advanced quantum Monte-Carlo techniques to calculate quantities for stationary nonequilibrium of a single-impurity Anderson model with high accuracy [2]. Employing
a two-dimensional analytical continuation based on maximum entropy, we are able tocalculate different local quantities like current, magentization or double occupancy.
We compare our results to those obtained by different methods like time-dependent
numerical renormalization, real-time quantum Monte-Carlo or real-time density-matrix
renormalization group.

Since the discovery of the metallic antiferromagnetic (AF) ground state nearsuperconductivity in iron-pnictide superconductors, a central question has been
whether magnetism in these materials arises from weakly correlated electrons, as in thecase of spin-density-wave in pure chromium, requires strong electron correlations, or
can even be described in terms of localized electrons such as the AF insulating state ofcopper oxides. We use inelastic neutron scattering to determine the absolute intensityof the magnetic excitations throughout the Brillouin zone in a number of iron-based
superconductors, which allows us to obtain the size of the fluctuating magnetic momentin absolute units. We find that superconducting BaFe1.9Ni0.1As2 and AF BaFe2As2 bothhave fluctuating magnetic moments similar to those found in the AF insulating copperoxides. The common theme in both classes of high temperature superconductors is thatmagnetic excitations have partly localized character, thus showing the importance ofstrong correlations for high temperature superconductivity.

[1] B. Van Waeyenberge et al., Nature 444, 461 (2006), [2] S. Kim et al., Appl. Phys. Lett. 92, 022509 (2008), [3] S. Bohlens et al.
Appl. Phys. Lett. 93, 142508 (2008), [4] B. Pigeau et al., Appl. Phys. Lett. 96, 132506 (2010), [5] Y.-S. Yu et al., Appl. Phys. Lett. 98,
052507 (2011), [6] K. Nakano et al., Appl. Phys. Lett. 99, 262505 (2011), [7] M. Kammerer et al., Nature Communications 2, 279(2011), [8] M. Kammerer et al., http://arxiv.org/abs/1112.1903, [9] Performed by scanning transmission X-ray microscopy (STXM)
at the MAXYMUS endstation at BESSY II, Berlin, Germany.

[1] K. Yamada, S. Kasai, Y. Nakatani, K. Kobayashi, and T. Ono, Nature Mater. 6, 270 (2007). [2] A.
Kirilyuk, A. V. Kimel, and Th. Rasing, Rev. Mod. Phys. 82, 2731 (2010).

[1] J.E. Han and R.J. Heary, Phys. Rev. Lett. 99, 236808 (2007). [2] A. Dirks, Ph. Werner, M.
Jarrell, and Th. Pruschke, Phys. Rev. E 82, 26701 (2010).

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Magnetic vortices and antivortices - From time-resolved imaging to
the influence of temperature

Ab initio studies of strongly correlated electron systems

SU(4) symmetry for strongly correlated electrons: Kondo and mixedvalence effects in terms of gell-mann matrices

Universal microscopic description of the infrared conductivity of 122
iron arsenides

Thomas Kamionka, Michael Martens, Andre Drews, Benjamin Krueger, Ole Albrecht
and Guido Meier*
University of Hamburg, Germany
Subnanosecond dynamics and potential memory applications give rise to a broad scientificinterest in properties of ferromagnetic microstructures with vortex and antivortex magnetization
configuration. Such singularities can be excited to gyrate resonantly at a characteristic
eigenfrequency. Dynamics are studied by time-resolved scanning transmission X-ray microscopy
and broadband-ferromagnetic resonance measurements. The influence of temperature on the
gyrotropic eigenfrequency of vortices in micrometer-sized permalloy squares is studied [1].
Ferromagnetic absorption measurements around room temperature show that the eigenfrequency
is decreased by 5.4% when the temperature is increased by 100 °C. The lowering of the saturation
magnetization and the associated modification of the potential of gyration is discussed as a reason
for the frequency shift within the model of the harmonic oscillator. Micromagnetic simulations
confirm a linear relation between the eigenfrequency and the saturation magnetization. Absorption
measurements under application of static external magnetic fields yield the same percentage
frequency shift as without external field when gyrations around equally displaced equilibrium
positions are compared. Financial support by the DAAD via the Project 50725506 and by
DFG via the SFB 668 and the GrK 1286 as well as the Forschungs- und Wissenschaftsstiftung
Hamburg via the Exzellenzcluster “Nano-Spintronik” is gratefully acknowledged.

Masatoshi Imada
Department of Applied Physics, University of Tokyo, Japan

Recent trends of ab initio studies and progress in methodologies for electronic structure
calculations of strongly correlated electron systems are discussed. The interest fordeveloping efficient methods is motivated by recent discoveries and characterizationsof strongly correlated electron materials and by requirements for understanding
mechanisms of intriguing phenomena beyond a single-particle picture. A multiscale ab initio scheme for correlated electrons (MACE) is developed by utilizing thehierarchical electronic structure in the energy space[1]. It provides us with a firstprinciples downfolding of the global band structure into low-energy effective models
followed by accurate low-energy solvers for the models. The applications of MACE
is illustrated with examples of several materials. In particular, we focus on electron
correlations in iron-based superconductors[2], interplay of spin-orbit interaction in 5d
systems such as Sr2IrO4[3], and Mott physics in organic conductors [4].
[1] M. Imada and T. Miyake, J. Phys. Soc. Jpn. 79 (2010) 112001. [2] T. Misawa, K. Nakamura and
M. Imada, arXiv:1112.4682. [3] R. Arita, J. Kunes, A.V. Kozhevnikov, A.G. Eguiluz, and M. Imada,arXiv:1107.0835. [4] H. Shinaoka, T. Misawa, K. Nakamura, and M. Imada, arXiv:1110.6299.

Oral Wednesday

Sonke Wienholdt1, Denise Hinzke1, Peter Openeer2 and Uli Nowak1
1
Department of Physics, University of Konstanz, Germany
2
Department of Physics, Uppsala University, Sweden

Oral Wednesday

oRAL PRSENTATION

Thomas Pruschke1* and Andreas Dirks2
1
Theoretical Physics, Universtat Gottingen, Germany
2
Theoretical Physics, University of Goettingen, Germany

Konstantin Kikoin
School of Physics and Astronomy, Tel-Aviv university, Israel

The concept of dynamical symmetries [1] is used for formulation of the renormalizationgroup approach to the Kondo effect in the Anderson model with repulsive andattractive interaction U in the Kondo and mixed valence regimes. It is shown that thegeneric local symmetry of the Anderson Hamiltonian is determined by the SU(4) Liegroup. The Anderson Hamiltonian is rewritten in terms of the Gell-Mann matricesof 4-th rank, which form the set of group generators and the basis for constructionof the irreducible vector operators describing the excitation spectra in the charge andspin sectors. The multistage Kondo screening is also interpreted as a manifestationof the local SU(4) dynamical symmetry. It is shown that the similarity between theconventional Kondo cotunneling effect for spin 1/2 in the positive U model and the
Kondo resonance for pair tunneling in the negative U model is a direct manifestationof implicit SU(4) symmetry of the Anderson/Kondo model. The transformation fromlocal SU(4) symmetry to the global SO(4) symmetry in the Hubbard chain model isalso discussed.

Pengcheng Dai
U. of Tennessee/Institute of Physics, CAS, USA

Aliaksei Charnukha1*, O. V. Dolgov1, A. A. Golubov2, Y. Matiks1, D. L. Sun1, C. T.
Lin1, B. Keimer1 and A. V. Boris1
1
Max Planck Institute for Solid-State Research, Germany
2
Faculty of Science and Technology and MESA+ Institute of Nanotechnology
Enschede, Netherlands

We report the full complex dielectric function of high-purity Ba0.68K0.32Fe2As2 single
crystals with Tc=38.5K determined by wide-band spectroscopic ellipsometry attemperatures 10<=T<=300K. We discuss the microscopic origin of superconductivityinduced infrared optical anomalies in the framework of a multiband Eliashberg theory
with two distinct superconducting gap energies 2∆A = 6kBTc and 2∆B = 2.2kBTc. The
observed unusual suppression of the optical conductivity in the superconducting state
at energies up to 14kBTc can be ascribed to spin-fluctuation--assisted in the clean limitof the strong-coupling regime. We further demonstrate that the same model provides agood description of the infrared conductivity of electron-doped compounds in this classof superconductors.

[1] K. Kikoin, M.N. Kiselev, and Y. Avishai, Dynamical Symmetries for Nanostructures (Springer,
Wien, 2012).

[1] T. Kamionka, M. Martens, A. Drews, B. Kruger, O. Albrecht, and G. Meier, Phys. Rev. B 83, 224424 (2011).

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Various fabricating conditions of potassium doped BaFe2As2 films bypulsed laser deposition system

Interplay between electronic ferroelectricity and magnetism inmolecular TMTTF salts

Field-dependent Fermi surface and high-field superconductivity in
URhGe

Spin fluctuations and Lifshitz transition in UGe2 probed by Larmor
neutron diffraction under pressure

Among the various Fe-based superconductors, potassium doped BaFe2As2 is favorable
for application because of its higher transition temperature and a low anisotropy
compared to other iron based superconductors. To study the superconductivity andapplicable aspects, high quality thin films should be fabricated. However, it is difficult
to fabricate thin films because of the high volatility of potassium. In this paper, weshow the details of fabricating technique of Ba1-xKxFe2As2 films by ex-situ PLD
method in various conditions and physical properties of these films. Barium ratio intarget is controlled to make films with various potassium doping rate. An annealing
temperature and amount of potassium are also controlled to find out optimal conditionof fabricating films.

Kazuyoshi Yoshimi1, Hitoshi Seo2*, Shoji Ishibashi3 and Stuart E. Brown4
1
University of Tokyo, and AIST, Japan
2
RIKEN and JST-CREST, Japan
3
AIST, Japan
4
UCLA, USA

We theoretically investigate the interplay between charge ordering and magnetic
states in quasi-one-dimensional molecular conductors TMTTF2X, motivated by theobservation of a complex variation of competing/coexisting phases. We show that theferroelectric-type charge order (electronic ferroelectricity) increases two-dimensional
antiferromagnetic spin correlation, whereas in the one-dimensional regime twodifferent spin-Peierls states are stabilized. By using first-principles band calculations
for the estimation for the transfer integrals and comparing our results with theexperiments, we identify the controlling parameters in the experimental phase diagram
to be not only the inter-chain transfer integrals but also the amplitude of the chargeorder. We also discuss the effect of a diagonal inter-chain transfer integral, whichcauses spin frustration in the dimer-Mott insulating state, but conversely enhances themagnetic ordering in the charge ordered phase.
K. Yoshimi, H. Seo, S. Ishibashi, and S. E. Brown, arXiv:1110.3573 (to be published in Phys. Rev.
Lett.); arXiv:1110.3575 (to be published in Physica B).

Ed Yelland1,2*, J. M. Barraclough2, M. Kepa3, I. Sheikin4, D. Sokolov3, W. Wang2, K. V. Kamenev3 and A. D. Huxley1,21School of Physics and Astronomy and Centre for Science at Extreme Conditions, University of Edinburgh, United
Kingdom2
School of Physics and Astronomy, University of St Andrews, United Kingdom
3
School of Engineering and Centre for Science at Extreme Conditions, University of Edinburgh, United Kingdom
4
LNCMI, CNRS, Grenoble, France

We present the first observation of the Fermi surface in the ferromagnetic superconductor URhGe [1]. A small class ofheavy fermion ferromagnets including URhGe show bulk superconductivity deep within the ferromagnetic state. Existing
results for URhGe [2] strongly suggest that the superconductivity arises from p-wave Cooper pairing of electronic
quasiparticles with equal spin. Uniquely within this class, URhGe shows a second, field-induced superconducting phasewith critical fields in excess of 32 tesla [3]. Our measurements of the Shubnikov-de Haas effect, made on the verge offield-induced superconductivity, reveal a small Fermi surface pocket that shrinks with increasing applied magnetic field,
eventually disappearing at a topological transition of the Fermi surface (a Lifshitz transition). The quasiparticle massdecreases and remains finite, implying that the Fermi velocity vanishes due to the collapse of the Fermi wavevector. A
simple model calculation of the orbitally limited critical field for the shrinking Fermi pocket reproduces the experimental
phase diagram for high-field superconductivity, suggesting that it is the slowing down of quasiparticles at a Lifshitz
transition that allows superconductivity to survive above 30 T, without a divergence of the quasiparticle mass. This
represents an important departure from all present theoretical treatments of the phase formation.

We present high resolution measurements of the lattice constants of UGe2 under pressure probed
by a novel technique that utilizes Larmor precession of polarized neutrons to surpass the resolutionof conventional scattering methods by an order of magnitude. At low temperature UGe2 isferromagnetic up to critical pressure p_c but superconductivity is peaked at a lower pressure p_
x coinciding with a less understood transition within the ferromagnetic state [1]. At ambientpressure we observed sharp anomalies in the lattice parameters at the Curie temperature, T_C. At
higher pressure sharp anomalies in the lattice parameters at both T_C and T_X (the characteristic
temperature for the transition that occurs at p_x) shift to lower temperatures in agreement with the
known phase diagram. We show that the magnetic thermal expansion is dominated by the criticalfluctuations near T_C and is well explained by the spin fluctuation theory at p<p_x, however at p=p_
x we identify an additional contribution to the magnetic thermal expansion which is due to pressure
driven Lifshitz transition [2] in spin bands of UGe2. Together with the magnetic correlation length
diverging under pressure, this may play an important role in stabilising superconductivity.

[1] E. A. Yelland et al., Nature Physics7, 890 (2011) [2] F. Hardy and A. D. Huxley, Phys. Rev.
Lett.94, 247006 (2005) [3] F. Levy, I. Sheikin, and A. Huxley, Nature Physics3, 460 (2007)[1] S. S. Saxena, et al., Nature 406, 587 (2000) [2]I. M. Lifshitz, Sov. Phys. JETP 11, 1130 (1960)

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Nonreciprocal directional dichroism and toroidalmagnons in
multiferroic materials

Dielectric anomaly in dimer-Mott insulator β'-(BEDT-TTF)2ICl2 withsquare lattice

Conventional quantum criticality in CeCu2Si2

Ultrafast manipulation of magnetic order

The heavy-fermion compound CeCu2Si2 displays unconventional superconductivity
around the magnetic quantum critical point (QCP) where antiferromagnetic ordervanishes. The superconducting state is characterized by a spin excitation gap, andalmost critical spin fluctuations are responsible for the Cooper pair formation. Theenergy and wave-vector dependence of the normal state spin fluctuations as measured
by inelastic neutron scattering indicate a three-dimensional spin-density-wave
QCP in agreement with macroscopic properties. Furthermore, muon spin rotation
under pressure allowed to tune through the QCP and to study the interplay between
magnetism and superconductivity in more detail. Both phenomena are connected bya first-order transition with the occurrence of phase separation. Small magneticallyordered regions are observed well below the superconducting Tc. The results are inline with the findings obtained by neutron scattering and will be compared to otherquantum-critical heavy-fermion compounds.

The interaction of sub-picosecond laser pulses with magnetically ordered materials
has developed into an extremely exciting research topic in modern magnetism andspintronics. From the discovery of sub-picosecond demagnetization over a decade ago
to the recent demonstration of magnetization reversal by a single 40 femtosecond laser
pulse, the manipulation of spins by ultra short laser pulses has become a fundamentallychallenging topic with a potentially high impact for future spintronics, data storageand manipulation and quantum computation. In addition, when the time-scale of theperturbation approaches the characteristic time of the exchange interaction (~10-100fs), the magnetic dynamics enters a novel, highly non-equilibrium, regime where theexchange interaction might even become time dependent. Using ultrashort excitations,
we may be able to manipulate the exchange interaction itself or use it strength tomanipulate or even switch magnetization. Such studies require the excitation andprobing of the spin and angular momentum contributions to the magnetic order attimescales of 10fs and below, a challenge that could be met by the future fs X-ray
FEL’s.

Nobuo Furukawa1* and Shin Miyahara2
1
Department of Physics, Aoyama Gakuin University, Japan
2
ERATO-Multiferroics Project, Japan Science and Technology Agency, Japan
We investigate dynamical magnetoelectric effect at electromagnon resonances in
multiferroic materials. One of the typical phenomena caused by interferences between
the magnetic and electric responses is the nonreciprocal directional dichroism (NDD),
where differences in the absorption spectra of electromagnetic wave are observed
when propagation directions of the incident wave are inverted. We show that NDD isobserved at a magnon excitation that is accompanied by a dynamical toroidal moment,i.e., at a toroidalmagnon excitation. As examples, we discuss toroidalmagnons in
multiferroic materials RMnO3 and Ba2CoGe2O7.
S. Miyahara and N. Furukawa, J. Phys. Soc. Jpn. 81 (2012) 023712/1-4. S. Miyahara and N.
Furukawa, J. Phys. Soc. Jpn. 80 (2011) 073708/1-4.

Satoshi Iguchi1, Satoru Sasaki1, Naoki Yoneyama2, Hiromi Taniguchi3 and Takahiko Sasaki4
1
IMR, Tohoku Univ., Japan2
Univ. of Yamanashi, JST-CREST, Japan
3
Saitama Univ., Japan
4
IMR, Tohoku Univ., JST-CREST, Japan

Organic dimer-Mott insulator κ-(BEDT-TTF)2Cu2(CN)3 with triangular lattice has been extensively
investigated as a candidate for spin liquid materials. Moreover, the recent discovery of a relaxorlike dielectric response [1] in this system paved the way to a new phenomenon of purely electronic
ferroelectricity as well as the strong charge fluctuation or charge disproportionation on dimers [2, 3].
Here, we have investigated the dielectric property of a typical antiferromagnetic dimer-Mott insulator
β'-(BEDT-TTF)2ICl2 with square lattice, which is compared to that of a spin liquid candidate κ-(BEDTTTF)2Cu2(CN)3. Anomalous broad peak structure in dielectric constant was observed in β'-(BEDTTTF)2ICl2, which shows a Curie type temperature dependence with higher Curie temperature than theantiferromagnetic transition and a strong frequency dependence similar to ferroelectric relaxors. The
dielectric constant parallel to the BEDT-TTF dimer layer is larger than perpendicular to it, which suggeststhat the charge degrees of freedom within a dimer of BEDT-TTF molecule has significant role in the
dielectric anomaly in dimer-Mott type organic insulator. The coupling between the charge and spin degrees
of freedom will be discussed.

Oliver Stockert*
Max-Planck-Institute for Chemical Physics of Solids, Germany

Theo Rasing
SSI, Radboud University, Netherlands

A.V.Kimel, et al, Nature 435 (2005), 655-657 C.D.Stanciu, et al, Phys.Rev.Lett.99, 047601 (2007)
A.V.Kimel, et al, Nature Physics 10, 727-731 (2009) K.Vahaplar, et al, Phys.Rev.Lett.103, 117201(2009) A.Kirilyuk, et al, Rev. Mod. Phys. 82, 2731-2784 (2010) I.Radu et al, Nature 472, 205 (2011)
T. Ostler et al, Nature Comm. 3, #666 (2012)[1] M. Abdel-Jawad, I. Terasaki, T. Sasaki, N. Yoneyama, N. Kobayashi, Y. Uesu, and C. Hotta, Phys. Rev. B 82 (2010)
125119. [2] M. Naka and S. Ishihara, J. Phys. Soc. Jpn. 79 (2010) 063707. [3] C. Hotta, Phys. Rev. B 82 (2010) 241104(R).

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Electronic ferroelectricity in correlated electron systems

Multiferroic transition in a quasi-layered bismuth ferrite

Shubnikov-de Haas oscillation in PuIn3

Ultrafast emergence of nanoscale ferromagnetism far from equilibrium

Exotic ferroelectrics and mutiferroics are one of the attractive topics in recent correlated electron systems.
It is widely known that ionic lattice distortions responsible for the electric dipole moments in conventional
ferroelectric compounds. Recently new class of ferroelectricity, termed “electronic ferroelectricity”
where electronic charge order brings about the electric polarization, has attracted much attention fromfundamental and application view points. We study theoretically ferroelectric and multiferroelectric
properties of the electronic ferroelectricity in correlated electron systems. We mainly focus on the layered
iron oxides, LuFe2O4, and the low-dimensional organic salts, kappa-(BEDT-TTF)2Cu2(CN)3. In the ironoxide, we examine the electronic and dielectric properties by analyzing the model Hamiltonian. It isfound that a low-lying charge fluctuation due to a geometrical frustration plays a key role on an origin offerroelectricity. This fluctuation is expected to be detected by the inelastic x-ray scattering experiments. As
for the molecular organic salts, we found that the ferroelectric charge order strongly competes with a Mott
insulator based on molecular dimerization, termed a dimmer Mott insulating phase, as well as a metallic
phase. A collective excitation mode for an electric polarization and superconductivity due to polarization
fluctuation are examined near the phase boundaries.

Usually magnetic transition temperature is insensitive to structural modification by
external strain, while ferroelectric transition temperature can be largely tuned by strain.
As a counter-example of the generic tendency of the magnetic transition, we will focus
on a highly elongated multiferroic BiFeO3 thin film, which has been newly discovered
as a quasi-layered perovskite phase stabilized through a misfit strain. Special attention
has been paid to the phase competition between the new highly elongated phase and thenormal phase leading to colossal electron-strain. However the magnetic properties of
the new highly elongated phase has not been fully unveiled yet. Here we will provide
experimental evidence for the large suppression of the magnetic order indicating strong
spin-lattice coupling and discuss underlying physics inherent in the highly-elongatedquasi-layered perovskite.

Sumio Ishihara*, Makoto Naka and Akihiko Sekine
Department of Physics,, Tohoku University, Japan[1] A. Nagano, M. Naka, J. Nasu, & S. Ishihara, Phys. Rev. Lett. 99, 217202 (2007). [2] M. Naka,
A. Nagano, & S. Ishihara, Phys. Rev. B 77, 224441 (2008). (Editor’s suggestion) [3] J. Nasu, A.
Nagano, M. Naka, & S. Ishihara, Phys. Rev. B 78, 024416 (2008). [4] T. Watanabe, & S. Ishihara, J.
Phys. Soc. Jpn. 78, 113702 (2009). [5] S. Ishihara J. Phys. Soc. Jpn. 79, 011010 (2010) (Review) [6]
M. Naka, & S. Ishihara, J. Phys. Soc. Jpn. 79, 063707 (2010) (Editor’s choice). [7] T. Watanabe, & S.
Ishihara, J. Phys. Soc. Jpn. 79, 114714 (2010)76

Dmitry Sokolov1*, Robert Ritz2, Christian Pfleiderer2, Thomas Keller3 and Andrew
Huxley1
1
The University of Edinburgh, United Kingdom
2Technische Universitat Munchen, Germany
3
MPI Stuttgart, Germany

The 19th International Conference on Magnetism

Chan-ho Yang
Physics, KAIST, Korea

Oral Thursday

Nam Hoon Lee, Soon-gil Jung and W. N. Kang*
Department of Physics, SungKyunKwan Univ., Korea

Oral Thursday

oRAL PRSENTATION

Yoshinori Haga1, Oscar Ayala-valenzuela2, Ross Mcdonald2, Chuck Mielke2, Eric D.
Bauer2, J N Mitchell2, P. H. Tobash2, Joe D. Thompson2 and Zachary Fisk1
1
Advanced Science Research Center, Japan Atomic Energy Agency, Japan2
Los Alamos National Laboratory, USA
Highly correlated f-electron systems are extensively studied because of their unusualphysical properties. While the electronic state of 4f rare earth compounds is understoodbased on the localized 4f state hybridized with conduction bands, that of 5f electronsin actinide compounds is not well defined. In this context, direct observation of
Fermi surface provides strong implication whether the 5f electrons are localized ordelocalized to participate in Fermi surface. In the present study, we report Shubnikovde Haas (SdH) study in a plutonium compound PuIn3 with the cubic AuCu3-type
structure. We succeeded in observing a clear SdH oscillation as a function of inverse
magnetic field, where the SdH frequency is proportional to the cross sectional area of
the Fermi surface along the magnetic field direction. The obtained SdH frequency canbe explained by the band calculations assuming the 5f electrons are delocalized. The
SdH oscillation was only observed when the field is applied near the <111> direction
and suddenly vanishes, which cannot be explained from the calculated Fermi surface
properties and needs further investigations.

Hermann Andreas Durr
Photon Science, SLAC National Accelerator Laboratory, USA

Long-range magnetic order in solids is usually ascribed to the exchange interaction
between electron spins. Close to equilibrium this leads to spontaneous magnetization
when the system cools below the magnetic ordering temperature. We show that the far
from equilibrium flow of angular momentum via spin currents can also achieve longrange ferromagnetic order even above the ordering temperature. To reveal this process,we use ultrafast x-ray diffraction at SLAC's Linac Coherent Light Source to probe thenucleation, growth and transient existence of ferromagnetic order on the nm length andfs timescale after fs optical laser excitation has brought a metallic 3d - 4f alloy system
into a highly non-equilibrium chaotic spin state. The technological exploitation ofthis effect could pave the way for novel ways to manipulate and transport information
within the smallest space-time dimensions.

July 8-13, 2012 Busan, Korea

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Modeling of ultra-fast magnetisation dynamics

Tunable resistivity of individual magnetic DWs

Current-induced domain wall motion in perpendicularly magnetizednanowireLow temperature magnetic studies of geometrically frustrated
SrHo2O4

The ultra-fast laser-induced magnetisation dynamics is currently an attractive topic of modern magnetism due
to a new physical phenomena appearing during these strongly non-equilibrium processes and the possibility
to extend magnetic switching speed down to femtoseconds. While in ferromagnetic metals such as Ni,
Fe, Gd only ultra-fast demagnetisation has been observed, in ferrimagnetic materials such as FeCoGd thecontrollable magnetization switching in several ps has been reported [1]. Recently we have reported that thisswitching occurs under ultra-fast heat alone without the necessity of any other external stimulus [2].
Our modeling of the underlying processes is based on two approaches: (i) atomistic simulations using theLandau-Lifshitz-Gilbert equation and (ii) micromagnetic approach using classical and quantum LandauLifshitz-Bloch (LLB) equation. Both models assume thermal magnetization dynamics via the coupling
to electron (and phonon for Gd) temperature bath. The comparison of our modeling based on the LLB
approach with the experiments in Ni [3] and Gd shows an excellent agreement providing a validation ofthermal magnetization dynamics mechanism. In agreement with the experiment the modeling reveals
different timescales for demagnetisation: fast (100 fs) in Ni and slow (50 ps) in Gd. We will present our
atomistic modeling on the switching of a ferrimagnetic CoFeGd compound with the only external stimulus
provided by the ultra-fast heating. The atomistic results will be explained in terms of the dynamical system
based on the recently-derived two-component LLB micromagnetic equation.

Jeroen Franken*, Mark Hoeijmakers, Henk Swagten and Bert Koopmans
Department of Applied Physics, Eindhoven University of Technology, Netherlands
Despite the broad interest in current-induced magnetic domain wall (DW) motion,
the current-DW interaction is still not fully understood. A property strongly related tothis interaction is the intrinsic DW resistivity. Measuring this property is therefore an
important step in unraveling the physics behind DW motion and in particular the nonadiabatic spin torque. However, measurements of the DW resistivity as a functionof the main property of the DW, its width, are still lacking. Here, we investigate
in a unique way how the resistivity of individual DWs depends on their width [1],by using focused ion beam irradiation to tune the DW width D in perpendicularly
magnetized Pt/Co/Pt strips. We use a very direct way to measure the resistivity of
individually appearing domain walls, by monitoring in real-time the domain structure
in a Kerr microscope. We find that convincingly, the DW resistivity scales with 1/D2, inquantitative agreement with the theory of Levy and Zhang [2].
[1] J. H. Franken, M. Hoeijmakers, H. J. M. Swagten, and B. Koopmans, Phys. Rev. Lett. 108,037205 (2012). [2] P. M. Levy and S. Zhang, Phys. Rev. Lett. 79, 5110-5113 (1997).

Teruo Ono
Kyoto University, Japan

Electrical displacement of a domain wall (DW) is a prospective method for information processing
in new type of magnetic non-volatile memories and logic devices. Such novel spintronic devices
require a low DW drive current and a high DW de-pinning field for stable information retention.
We show that Co/Ni multilayer with perpendicular magnetic anisotropy is a promising material thatsatisfies these requirements. An electric current can drive a DW in one direction regardless of thepolarity of a magnetic field in a Co/Ni nano-wire with perpendicular magnetization, i.e., the current
can drive a DW against a magnetic field. Furthermore, both the DW velocity and the thresholdcurrent density for the DW motion show almost no dependence on the external magnetic field.
These counter-intuitive behaviors can be interpreted as the consequence that the intrinsic pinningmechanism determines the threshold current, and the adiabatic spin torque dominates the DW motionin this system [1-6]. The established field-insensitivity of the electrical DW motion is promising for
future spintronics applications based on the DW motion. This work was partly supported by the
NEDO Spintronics nonvolatile devices project and a Grant-in-Aid for Scientific Research (S) fromthe Japan Society for the Promotion of Science.
[1] T. Koyama et al., Nature Materials, 10 (2011) 194. [2] T. Koyama et al., Appl. Phys. Lett. 98 (2011) 192509. [3]K. Ueda et al., Appl. Phys. Express 4 (2011) 063003. [4] D. Chiba et al., Appl. Phys. Express 3 (2010) 073004. [5] H.
Tanigawa et al., Appl. Phys. Express 2 (2009) 053002. [6] T. Koyama et al., Appl. Phys. Express 1 (2008) 101303.

1. K.Vahaplar et al, Phys. Rev. Lett. 103, 117201 (2009) 2. T.Ostler et al. , Nature Commun., 3, 666(2012) 3. U.Atxitia et al., Phys. Rev. B 81, 174401 (2010)

Olga Young1*, Geetha Balakrishnan1, Andrew R. Wildes2, Laurent C. Chapon2 and Oleg A. Petrenko1
Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
2
Institut Laue-Langevin, Jules Horowitz, BP156, 38042 Grenoble Cedex 9, France
1

SrHo2O4 is a geometrically frustrated compound as its structure allows the magnetic
ions to be arranged in a network of triangles and hexagons [1]. Magnetic susceptibility
measurements on single crystals of SrHo2O4 show a disparity between the Curie-Weiss
constant (-16.9 K) and the establishment of Neel order at 0.68 K [2], which is typicalfor frustrated systems. Low-temperature measurements of magnetisation [3] show thehighly anisotropic nature of this crystal, and more intriguingly, the dM/dH curve for H//b shows double peak behaviour indicating a rich H-T phase diagram. We have performed
powder neutron diffraction experiments using the GEM diffractometer (ISIS) [2]. At low
temperatures, both k=0 magnetic Bragg reflections and a strong diffuse scattering feature- a broad peak near the position (0 0 1/2) - were observed. Recent experiments on single
crystals of SrHo2O4 using the D7 instrument (ILL), reveal that this feature can be attributed
to a one-dimensional collinear ordering with the spins pointing along the b-axis. Thissuggests a highly unusual magnetic ground state for SrHo2O4, as it is made up of two distinct
components: one of the crystallographically inequivalent Ho3+ sites orders in a long-range
magnetic structure, while the other orders in a short-range one-dimensional structure.
[1] H. Karunadasa et al., Phys. Rev. B 71, 144414 (2005) [2] O. Young et al., arXiv:1110.3521 (2011) [3]
T.J. Hayes et al., J. Phys. Soc. Japan 81 024708 (2012)

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Ultrafast inverse Faraday effect in paramagnetic dielectrics

Observation of domain-wall capacitance in permalloy nanowires

Melting spin ice

Spin densities in manganese molecular cluster : [Mn3L4](ClO4)2(H2O)2

We present a critical and thorough analysis of the concept of a light induced effective
magnetic field. The analysis reveals incontinency in the theoretical interpretation ofultrafast femtomagnetic phenomena in paramagnetic dielectrics. Furthermore, we
discuss the validity of the assumption of equivalence of origins of opto-magnetic andmagneto-optical effects, which has not been rigorously tested so far. We support ourarguments by the all-optical femtosecond time-resolved measurements of the ultrafast
inverse Faraday Effect in terbium gallium garnet crystal. The measurement of thetransient rotation of polarization of the probe pulse induced by a pump pulse allows
us perform a systematic study of the full nonlinear optical response of the sample. The
magneto-optical contribution attributed to inverse Faraday effect is then extracted bythoroughly studying the dependence of the signal upon the pump polarization. The
amplitude of the Faraday rotation was found to significantly exceed that predicted byphenomenological theory relying on the static Verdet constant value. The discrepancy
demonstrates that the nature of the inverse Faraday Effect on femtosecond timescale isdifferent from that of the quasi-static inverse Faraday Effect observed by Pershan andcoworkers [1,2] and that it cannot be described in terms of the effective magnetic field.

Studies on domain walls have attracted interest due to its potential applications on
storage and logic devices. Domain walls can be detected by magneto-resistance effectsuch as the giant magneto-resistance effect and by magnonic effect [1]. We here report
the detection of a domain wall by employing the capacitive effect of a single domain
wall in a Permalloy nanowire. Spin-capacitance has been reported as a phenomenon inmagnetic tunnel junctions and interfacial oxides where the spin configuration affects
not only the resistance across the tunnel junction, but also the capacitance known asmagneto-capacitance [2]. Semi-circular nanowires are patterned with the film structureof Ta (5 nm)/ NiFe (30 nm)/ Ta (5 nm) and the capacitance and magneto-resistance ismeasured. We observe that the magneto-capacitance is a reciprocal of the magnetoresistance. In addition to the resistive component, the capacitance due to the domain
wall spin structure enables us to detect the presence of a domain wall. In angularmeasurements with externally applied magnetic fields, large changes in the fielddependent capacitance are discussed.

Rostislav V. Mikhaylovskiy*, Euan Hendry and Volodymyr V. Kruglyak
School of Physics, University of Exeter, United Kingdom

1. J. P. van der Ziel, P. S. Pershan, and L. D. Malmstrom, Phys. Rev. Lett. 15, 190 (1965) 2. P. S.
Pershan, J. P. van der Ziel, and L. D. Malmstrom, Phys. Rev. 143, 574 (1966).

Kulothungasagaran Narayanapillai, Mahdi Jamali, Ajeesh Sahadevan and Hyunsoo
Yang*Electrical and Computer Engineering, National University of Singapore, Singapore[1] V. D. Nguyen et al., Phys Rev Lett 107, 136605 (2011). [2] J. M. Rondinelli, M. Stengel, and N. A.
Spaldin, Nat Nanotechnol 3, 46 (2008).

Sarah Ruth Dunsiger1, A. A. Aczel2, C. Arguello3, H. Dabkowska4, A. Dabkowski5, M-h Du6, T. Goko3, B. Javanparast7, T.
Lin7, F. L. Ning3, H. M. L. Noad2, D. J. Singh6, T. J. Williams2, Y. J. Uemura3, M. J. P. Gingras7 and G. M. Luke2
1
Physics Department E21, Technical University of Munich, Germany
2
Dept of Physics and Astronomy, McMaster University, Canada
3
Dept of Physics, Columbia University, USA
4
Brockhouse Institute for Materials Research, McMaster University, Canada
5
Brockhouse Institute for Materials Research,, McMaster University, Canada
6
Materials Science and Technology Division, Oak Ridge National Laboratory, USA
7
Dept of Physics and Astronomy, University of Waterloo, Canada
Geometric magnetic frustration is a ubiquitous phenomenon within condensed matter physics. The
magnetic ground states are highly degenerate, leading to competing low temperature phases and enhanced
quantum fluctuations. The nature of the magnetic fluctuations in these systems is currently the subject of
lively investigation. “Spin ice” model magnetic systems combine the rich phenomenology associated withgeometric frustration with the theoretically tractable nature of Ising models, drawing on a close analogy
with the statistical mechanics of proton disorder in water ice. Theory predicts the low-temperature magnetic
excitations in spin ices consist of deconfined magnetic charges, or monopoles. A recent transverse-field (TF)
muon spin rotation (μSR) experiment [S T Bramwell et al, Nature 461, 956 (2009)] reports results claiming
to be consistent with the temperature and magnetic field dependence anticipated for monopole nucleation- the so-called second Wien effect. We demonstrate via a new series of μSR experiments in Dy2Ti2O7 thatsuch an effect is not observable in a TF μSR experiment. Rather, as found in many highly frustrated magnetic
materials, we observe spin fluctuations which become temperature independent at low temperatures,
behaviour which dominates over any possible signature of thermally nucleated monopole excitations.

Clara Rodriguez-blanco1, Javier Campo1*, Jose Alberto Rodriguez-velamazan1,
Beatrice Gillon2, Javier Luzon3 and Jose Sanchez-costa4
1
Materials Science Institute of Aragon, (CSIC-University of Zaragoza), Spain
2
Laboratoire Leon Brillouin, CEA-Saclay, France
3
Centro Universitario de la Defensa, Zaragoza, Spain
4
University of Barcelona, Spain
The molecular cluster [Mn 3L 4](ClO 4) 2(H 2O) 2, (HL=2-methoxy-6-(pyridine-2ylhydrazono-methyl)-phenol) has been described as an almost lineal trimer of Mn(II) in ahigh spin configuration with two isotropic magnetic interactions: nearest neighbours andnext nearest neighbours interactions1. One striking fact is the experimental EPR g factorof 2.14 for such an isotropic system. Due to its isotropic and not degenerated nature, thesystem is an ideal benchmark to investigate the interplay of the magnetic interactions
in systems with several magnetic centers and more than one electron per magnetic
center. In this contribution we will show how an in deep study of the system throughthe combination of several experimental and theoretical methods (polarized neutron
diffraction at ILL and LLB, magnetic measurements, Density Functional Theory and spin
Hamiltonian models) has allowed us to demonstrate the isotropic nature of the systemand the anti-ferromagnetic character of the intra-molecular magnetic interactions.
[1] J. Tang et al., 2007 Eur. J. Inorg. Chem 4119

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Detection of domain wall position and magnetization reversal innanostructures using the magnon contribution to the resistivity

Proposal new type of low current driven spin logic in PMA TbFeCo
wire

Artificial spin ice: Dimensional reduction, avalanches and disorderElectronic structure and magnetic properties of Cr-doped rutile TiO2:
Charge and magnetic state of Crimpurity

Jean-philippe Attane, Van Dai Nguyen, Alain Marty, Piotr Laczkowski, Cyrille
Beigne, Lucien Notin, Matthieu Jamet, Williams Savero-torres, Murat Cubukcu andLaurent Vila*
Universite Joseph Fourier, BP 53, 38041, Grenoble and INAC/ CEA Grenoble,
FranceWe present a new magnetoresistance (MR) based on the contribution of the magnons to theresistivity, i.e., Magnon Magnetoresistance (MMR). We show that the MMR can be used to study
the magnetization reversal in systems with either perpendicular (FePt) or in-plane anisotropy(NiFe), including domain wall (DW) position detection. MMR measurement exhibits a linear
dependence of the resistivity on the applied field, originating from electron-magnon scattering. The
drop of resistivity, due to the abrupt change of magnon density, corresponds to the magnetization
switching. MMR measurement allows detecting precisely the position of a DW along a FePt
nanowire, and following the dynamic of DW motion. In system with in-plane magnetization as NiFe
nanowires, we show that the enhancement of the shape anisotropy in the narrowest widths leads tothe disappearance of the AMR, the remaining contribution to the MR being that of the MMR. We
also show that the MMR signal allows detecting the position of the DW along the NiFe wire. We
emphasize that the observation of MMR in in-plane anisotropy nanowires can provide a changeof paradigm in the study of in-plane magnetized nanowires: for certain field directions the magnon
contribution dominates the MR, clearly overcoming the AMR.

Toma Kanehira and Hiroyuki Awano
Toyota Technological Institute Information Storage Material Lab., Japan

We have performed a current driven magnetic domain AND logic circuit by designing
a TbFeCo wire which has a large perpendicular magnetic anisotropy and high domain
wall motion seed in ‘Y’ shape with two inputs and an output. The TbFeCo wire
thickness is 4.8 nm. Well-defined starting states of as single domain wall from two
inputs were recorded by pulse currents. The domain walls propagate into the output
as a combined domain wall and detected by anomalous Hall voltage through a pair ofelectrodes (J=3.8×1010 [A/m2 ]). In the case of two input domain walls are recorded asa couple bits of ‘1’ /‘1’, a sharp-changed anomalous Hall voltage is detected as a bitof ‘1’. In another case of only one input domain wall is recorded, there is no change
in anomalous Hall voltage which corresponds to a bit of ‘0’ due to a different widthof input and output wires which causes annihilated the domain wall. These results
indicated that the circuit of TbFeCo wire work as a logic AND function. Moreover, OR
and NOT function can be also designed. This technique expectedly promises lowerpowered, higher-speed, nonvolatile devices with which to build the next generation ofcomputing technology.

Remo Viktor Hugli, Gerard Duff and Hans - Benjamin Braun*
Physics, University College Dublin, Ireland

Regular arrays of nanomagnets have proven to serve as ideal models for the study ofspin-ice phenomena [1]. In contrast to their 3D analogues, the pyrochlore systems,
the magnetic moments in 2D artificial spin ice systems exhibit high anisotropies
which renders them stable at room temperature. This allows imaging with various
experimental techniques in real space and at room temperature, which makes such
metamaterials ideal candidates for comparison with theoretical models. Here we
explore the nonequilibrium properties of a model that combines long range dipolarinteraction, frustration and disorder which explains experiments on 2D artificial
kagome spin ice [2]. We show how frustration induced by dipolar interaction leads
to unusual 1D avalanches, an example of dimension reduction due to frustration. In
particular, magnetization reversal proceeds via nucleation and subsequent avalanchetype dissociation of emergent monopole-antimonopole pairs along 1D Dirac strings.
We show how the flow of these emergent monopoles or charges can be controlled via
judicious modification of the islands' anisotropy and magnetic fields, thus paving theway for magnetic information processing devices.
[1] R.F. Wang et al., Nature 439, 303 (2006). [2] E. Mengotti, L. J. Heyderman, A. Fraile Rodriguez,
F. Nolting, R.V. Hugli, and H. B. Braun, Nature Physics 7, 68 (2011).

Oral Thursday

O. Chubykalo-Fesenko1*, U Atxitia1,2, T.Ostler2, R.Evans2 and R.W.Chantrell2
1
Material Science Institute of Madrid, CSIC, Spain
2
Physics Department, University of York, UK

Oral Thursday

oRAL PRSENTATION

Rokyeon Kim1, Suyeon Cho1, Wongoo Park1, Je-geun Park1, Se-jung Oh1, Patrick
Berthet2 and Jaejun Yu1*
1
Department of Physics and Astronomy, Seoul National University, Korea
2
University of Paris-Sud, France
We report theoretical and experimental studies of Cr-doped rutile TiO2. In experiment
we observe that the electronic and magnetic properties of Cr-doped rutile TiO2 arehighly dependent on the growth conditions. The ferromagnetic component in magnetic
susceptibility and the Cr defect concentration are enhanced for the sample grown under
the oxygen flow in comparison with those grown under the Ar flow. To understand thecharge state of Cr dopants and their role in response to the external magnetic field, we
carried out density functional theory (DFT) calculations for the Cr-doped rutile TiO2.
From the results of the formation energy calculations for the Cr atom substituting theTi site and the O vacancy, assuming the thermodynamic equilibrium, we demonstratethat the Cr3+ state is a source of Curie-Weiss-type magnetic response in the O-poor
limit, whereas the Cr4+ defect states contribute to the ferromagnetic component in themoderately reduced condition. We also provide the electronic structures of various
defect configurations and attempt to explain the optical and electronic properties of the
Cr-doped system.

V. D. Nguyen et al., Phys. Rev. Lett. 107, 136605 (2011) V. D. Nguyen et al., Appl. Phys. Lett. 99, 262504 (2011)78

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

79

ORAL PRESENTATION
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Magnetic nanoparticle arrays by nanomasking pattern transfer

Tailored magnetic anisotropy of Py /Co bilayer ordered nanohole
arraysSpin resolved measurements of single molecular magnets on surfaces

Pressure effects on the magnetic properties of Emim[FeCl 4], amagnetic ionic liquid with antiferromagnetic ordering

Oral Thursday

In nanomasking, self-assembled nanoparticle monolayers are used as etch masks topattern underlying thin films [1]. Here we apply this technique to prepare two typesof magnetic nanodot arrays, and characterize their structural and magnetic properties.
Large area nanoparticle arrays were fabricated by a Langmuir film method andtransferred to a solid substrate. After electron irradiation curing and brief exposure toan oxygen plasma, most of the surfactant has been removed yet the ordered pattern ofthe particle cores has been preserved. We examined direct pattern transfer by methanolbased reactive ion etching into a FePt film. A second strategy prepares nanodot arraysby filling an antidot lattice. Here 2 nm of titanium is deposited on the array of barenanoparticle cores, which are then removed with phosphoric acid to leave an alumina
antidot mask. Here the mask was prepared on a silica film. RIE was then used togenerate an array of pits, and permalloy was sputtered to overfill the pits. Magnetic
measurements as a function of methanol etching show the transition from a continuous
film to an array of nanodots.

Karla J. Merazzo, Giovanni A. Badini Confalonieri, Rafael P. Del Real and Manuel Vazquez
Materials for Information Technologies, Instituto de Ciencia de Materiales de Madrid, CSIC., Spain

Highly ordered arrays of magnetic nanoholes show a great potential for technological applications, as
high-density magnetic storage media [1 ] or magnonic devices [2 ]. Magnetism of ordered nanohole arraysis determined by composition and particularly by geometry characteristics [3 ]. In this work, magnetic
nanohole arrays have been sputtered onto hexagonally self-assembled anodic alumina membranes (AAM)[4 ] with 35 nm hole diameter and 105 nm interhole distance. Thickness of Py/Co bilayer nanohole arrays
were: 10nm, 20nm and 43 nm for the Py layer, with a constant thickness of 28 nm for Co layer. Theirmagnetic properties were determined by vibrating sample magnetometer and magneto optical Kerr effect.
The in-plane angular dependence of coercivity shows that the magnetic behaviour of the Py layer strongly
depends on its interaction with the Co, which reminds that of a spring-like system. The sample withthinnest Py layer exhibits highest coercivity (Hc=140 Oe) which decreases with Py thickness (Hc=16 Oe).
A bimagnetic-like behaviour is observed in some samples indicating the relevance of local magnetostaticinteractions. The overall results have been compared to those of continuous Py/Co bilayer films, showing
an increase of five times its coercivity by the only presence of the nanoholes.

Jens Brede1*, Jorg Schwobel1, Regis Decker1, Andrew Dilullo2, Germar Hoffmann1,
Svetlana Klyatskaya3, Mario Ruben3 and Roland Wiesendanger1
1
Institute of Applied Physics, University of Hamburg, Germany
2
Department of Physics and Astronomy, Ohio University, Germany
3Institute of Nanotechnology, Karlsruhe Institute of Technology, Germany

A. Garcia-saiz1, I. De Pedro1, J. C. Gomez Sal1, J. A. Blanco2 and J. Rodriguez
Fernandez1*
1
CITIMAC, Fac. de Ciencias, Universidad de Cantabria, Spain
2
Departamento de Fisica, Universidad de Oviedo, Spain

1.R. P. Cowburn, A. O. Adeyeye, J. A. Bland, Appl. Phys. Lett. 1997, 70, 2309. 2. V. V. Kruglyak, S. O. Demokritov, D.
Grundler, J. Phys. D: Appl. Phys. 2010, 43, 264001 3. M. Vazquez, K.R. Pirota, D. Navas, A. Asenjo, M. HernandezVelez, P. Prieto and J.M. Sanz JMMM, 320 (2008)1978-1983 4. K J Merazzo, D C Leitao, E Jimenez, J P Araujo, J
Camarero, R P del Real, A Asenjo and M Vazquez. 2011 J. Phys. D: Appl. Phys. 44 505001

The use of magnetic molecules opens a gateway to a flexible design of novel spintronic
devices to store, manipulate, and read spin information at the nanoscale. Crucial is
the precise knowledge of molecular properties at the interface towards an electrode.
Progress in this field relies on resolving and understanding the physics at the relevantinterfaces. In particular the role of individual molecular constituents and the impact of
the atomic environment on molecular properties, determine device relevant parameters,such as conductance and spin polarization. Here, we applied spin-polarized scanningtunneling microscopy to resolve the physics of the molecule-ferromagnet interface.
The analysis focuses on different phthalocyanine molecules. The phthalocyanine
constitutes of an organic macrocyclic ligand and can be functionalized with various
metal ions in order to modify, e.g. the molecular spin state. We will discuss the spindependent transport from magnetic surfaces through such molecules. In particular,
spin-split molecular orbitals were resolved with sub-molecular spatial resolution. The
magnitude of the exchange splitting is directly determined by spin-resolved tunnelingspectroscopy.

GG02

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Spin wave bands and bandgaps in a two-dimensional ferromagnetic
antidot array

Tailoring magnetic properties of Co thin films through antidot arrays:
crossover from antidot to dot regime

MgO tunnel junction magnetic field sensors at high frequencies

Magnetic proximity and spin behavior at organic semiconductor/
ferromagnet interfaces towards molecular spintronics

1. C. R. Hogg, S. A. Majetich, and J. A. Bain, IEEE Trans. Magn. 46, 2307-2310 (2010)

Roberto Zivieri1*, Silvia Tacchi2, Federico Montoncello1, Loris Giovannini1, Fabrizio
Nizzoli1, Marco Madami 2, Gianluca Gubbiotti2, Giovanni Carlotti2, Sebastian
Neusser3, George Duerr3 and Dirk Grundler3
1
Department of Physics, University of Ferrara, Italy2
Department of Physics, University of Perugia, Italy
3
Department of Physics, University of Muenchen, Germany

The spin wave band structure of a two-dimensional square array of NiFe circular antidots having
diameter of 120 nm and periodicity of 800 nm has been investigated by using Brillouin lightscattering and micromagnetic calculations based on the dynamical matrix method. The external
magnetic field was applied in the plane and perpendicularly to the transferred wave vector.
Extended and localized spin modes having a propagative nature were found. Opening of bandgaps
is interpreted in terms of Bragg diffraction of spin waves from the antidot lattice and this effectis explained by studying the behavior of the internal field. According to an analytical model, therelevant scattering potential for Bragg reflection is not provided by the holes themselves, but by
the concomitant internal field inhomogeneity between holes [1]. This is in contrast to antidots inphotonics and electronics where the back-reflection is directly caused by the presence of holes. The
research leading to these results has received funding from the European Community's Seventh
Framework Programme (FP7/2007-2013) under Grant Agreement n228673 (MAGNONICS).

1

2

1,3

4

Celia Castán-Guerrero *, Javier Sese , Julia Herrero-Albillos , Florian Kronast , Luis Alfredo
Rodriguez2, Cesar Magen2, Karla J. Merazzo5, Manuel Vazquez5, Juan Bartolome1, Fernando Bartolome1,
Pavel Strichovanec2, Paolo Vavassori6 and Luis Miguel Garcia1
1
Instituto de Ciencia de Materiales de Aragon (Universidad de Zaragoza - CSIC), Spain
2
Instituto de Nanociencia de Aragon (Universidad de Zaragoza), Spain
3
Centro Universitario de la Defensa (Academia General Militar), Spain
4
Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH, Germany
5
Instituto de Ciencia de Materiales de Madrid (CSIC), Spain
6
CIC nanoGUNE Consolider, IKERBASKE, Spain

Magnetic properties of thin films are hardly controllable, since they depend strongly on the microstructure
and the presence of defects. Nanopatterning of dot [1] and antidot [2] arrays are two different approaches
to tailor magnetic properties only as a function of geometry. In this study, a series of antidot arrays havebeen fabricated with square symmetry, varying the periodicity from 500nm, that is in the diluted regime,to 105nm, almost in the percolation limit. The holes were etched using a focused gallium ion beam, thatallows the control of the geometrical parameters with nanometric resolution. Magnetic characterizationby MOKE and magnetic imaging by XPEEM show a change in the dependence of coercivity withperiodicity below 140nm that can be correlated with a change in the magnetic domain configuration.
HRTEM chemical and morphological analysis show gallium ion implantation and amorphization in thecobalt around the holes, that could have turned it into non-magnetic. Then, the effective diameter of thenon-magnetic area becomes greater than the antidot one itself. As antidot-antidot distance decreases, themagnetic percolation is lost and a crossover from antidot to dot regime is encountered.

Information storage bit size and computing is inching towards molecular level. Spin transport in organic
semiconductors (OS) has the potential in realizing this goal in a straightforward way. The charge and spintransport at OS and ferromagnetic (FM) metal interface, although complex, has the needed ingredients forachieving to reach molecular level spintronics. Spin tunneling through a few monolayers to 30nm thickfilms of several types of OS, all the way to room temperature combined with spectroscopic and polarized
neutron reflectometry studies show unique morphology driven signatures of weakened magnetic behaviorof OS/ferromagnet interfaces. However, our recent studies show surprising magnetic interaction of thephenalenyl molecules over the surface of a ferromagnet (Co, permalloy etc), driving the molecular layer
to be magnetic and coupled. In addition, the second molecular layer shows spin-filtering property, serving
as a spin-sensing layer. As such the FM surface layer and the adjacent two molecular layers of phenalenyl
combination demonstrates a well-defined and large interface magnetoresistance (IMR), persisting to nearroom temperature. With spin valve structures such as Co/Zn-methyl phenaleny/permalloy an IMR of 50%
is measured at 4K which only reduced to ~22% by 250K. With this study the potential for molecular level
spintronics is demonstrated.

GH04

GI02

Bio-functional magnetic nanoparticles in biomedical applications

LaSrVMoO6 : a compensated half metal or not?

Spin specific transport properties of chiral molecules

With distinctive characteristics of magnetic properties and a variety of bio-functions byconjugated some specific bio-probes, bio-functional magnetic nanoparticles (MNPs)
have been widely investigated in the biomedical applications currently. In this report,
several applications using MNPs will be mentioned as examples of such applications.
For the immunoassay, an innovative method, ImmunoMagnetoReduction (IMR)(1),will be introduced at first. Secondly, the cancer images by using low field MRI(2-3)
will be demonstrated to reveal the possibility of this instrument in the cancer study.
Next, the hyperthermia with MNPs, including metabolism of MNPs study(4) , theinstrument and the temperature manipulation etc., will be declared. Finally, some otherexamples, such as magnetofection(5) etc., will be alao reviewed in this talk.

LaSrVMoO6 was first synthesized in 2004. The crystal structure is uncertain andwas suggested to be cubic (Fm-3m). compensated half metal (i.e., half metallic
compound with zero magnetization) is suggested. Theoretical study in 2005 indicatedthat it is a normal metal and ferrimagnet. In 2009, LaSrVMoO6 has been revisitedby the experimental study. The crystal structure is determined to be cubic (Fm-3m).
It was concluded that LaSrVMoO6 is a compensated half metal. Theoretical study
in 2010 based on the cubic structure indicated that LaSrVMoO6 is a ferrimagnetic
half metal, in contrast to compensated half metal suggested experimentally. Recently
in 2010, LaSrVMoO6 was found to be orthorhombic (Pnma) and metallic. Further
theoretical study in 2011 indicated that LaSrVMoO6 in disordered states for V and
Mo is compensated half metal. So the studied system poses great challenge for bothexperiment and theory.

Spin effects normally are seen either in magnetic materials or in systems containing
heavy atoms that facilitate spin-orbit coupling. We report spin-selective transmissionof electrons through self-assembled monolayers of double-stranded DNA. The spinpolarization exceeds 60% at room temperature. The spin filtration efficiency depended
on the length of the DNA. In addition, we show that conduction through double
stranded DNA oligomers is spin selective, demonstrating a true organic spin filter. The
selectivity exceeds that of any known system at room temperature. The spin dependent
resistivity indicates that the effect cannot result solely from the atomic spin-orbit
coupling and must relate to a special property resulting from the chirality symmetry.
A theoretical model indicates that the spin selectivity is related to relative narrow
resonances through which the electrons are transmitted. Based on the theory new typeof spintronics devices are constructed. The results may reflect on the importance ofspin in determining electron transfer rates through biological systems.

Ratchet effect in magnetic domain wall motion induced by 2D arraysof triangular submicrometric holes

The 19th International Conference on Magnetism

Micron sized MgO magnetic tunnel junctions with 1.7 nm tunnel barrier were fabricated andcharacterized at DC and high frequencies to be used as magnetic field sensors. Both DC and AC
properties of the sensors were measured by tunneling magnetoresistance (TMR) and impedance
spectroscopy between 100 Hz and 40 MHz as a function of applied external magnetic field. Several
different types of sensors were investigated: Single and multiple MTJ-sensors. In the first case, single
junctions were measured. A simple RLC circuit model was applied to impedance spectroscopy
results to investigate magnetocapacitance properties in order to evaluate and compare different
sensing schemes such as resistive and capacitive sensing. Contrary to the previous reports in theliterature we didn't observe field dependent spin capacitance despite excellent agreements in otherparameters such as resistance of the junction and interface capacitance. We attribute this discrepancy
to the size of our junctions and reach a conclusion that limits the applicability of the spin-capacitanceconcept to large area devices. Then multiple tunnel junctions in serpentine geometry were measured.
Using the same circuit model, we measured non-zero magnetocapacitance in multiple junction
sensors unlike single junction devices. We explain this as a result of the sensor geometry.

Jagadeesh S. Moodera
Massachusetts Institute of Technology, USA

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[1] D. A. Allwood et al., Appl. Phys. Lett. 85, 2848 (2004) [2] A. Himeno et al., J. Appl. Phys. 97, 066101 (2005); M. Hayashi et al.,Phys. Rev. Lett. 97, 207205 (2006) [3] A. Perez-Junquera, V. I. Marconi, A. B. Kolton, L. M.Alvarez-Prado, Y. Souche, A. Alija, M.
Velez, J.V. Anguita, J. M. Alameda, J. I. Martin, and J. M. R. Parrondo, Phys. Rev. Lett. 100, 037203 (2008) [4] A. Alija, A. HierroRodriguez, A. Perez-Junquera, J. M. Alameda, J. I. Martin and M. Velez, J. Phys. D: Appl. Phys. 44, 325002 (2011)

Mustafa Arikan1*, Matthew Carter2, Gang Xiao3 and Snorri Ingvarsson4
1
Science Institute, University of Iceland, Iceland2
Micro Magnetics, Inc., USA
3
Department of Physics, Brown University, USA
4
Science Institutte, University of Iceland, Iceland

S. Ingvarsson et al., Appl. Phys. Lett. 96, 232506 (2010). X. Liu et al., Appl. Phys. Lett. 89, 023504 (2006).
P. Padhan et al., Appl. Phys. Lett. 90, 142105 (2007). H. Kaiju et al., J. Appl. Phys. 91, 7430 (2002).

[1] R. Zivieri, S. Tacchi, F. Montoncello, L. Giovannini, F. Nizzoli, M. Madami, G. Gubbiotti, G.
Carlotti, S. Neusser, G. Duerr, and D. Grundler, Phys. Rev. B 85, 012403 (2012).

Controlling magnetic domain wall motion in ferromagnetic materials is essential for the development of spintronics. The
introduction of asymmetric pinning potentials has proved itself as an efficient tool to induce ratchet effects in domain wallmotion, as observed in nanowires with triangular section [1] or asymmetric notches [2]. Similar effects can be induced inextended ferromagnetic thin films when introducing 2D arrays of asymmetric holes[3], although the study is rather more
complex due to the higher dimensionality of domain walls [4]. In the present study, antidot arrays have been fabricatedon amorphous thin films of Co73Si27 with in-plane uniaxial anisotropy. Arrays of triangular antidots of size 500nm and1um and edge-to-edge separation of three, four and five times their size have been studied. Equivalent arrays withrhombohedral antidots have been fabricated for comparison. A Kerr effect microscope has been used for the magnetic
imaging. Magnetic domain walls are observed to move through the triangular antidot arrays only in the forward direction,
defined from the base of the triangles to the vertex. The cause of the ratchet effect is confirmed to be the holes asymmetry,
as domain wall motion is symmetric when crossing rhombohedral (symmetric) antidot arrays.

[1] R. E del Sesto et al. Chemical. Communications (2008) 4, 447. [2] I. de Pedro et al., J. Phys: Condens. Matter, (2010)22, 296006. [3] I. de Pedro et al., . J. Magn. Magn. Mat. (2011) 323, 1254. [4] A. Garcia Saiz et al, to be published.

This work was done with Karthik Raman*1,2‡†, Tiffany Santos, Jenny Shim, Shannon Watson, Julie
Borchers, Alexander Kamerbeek, Nicolae Atodiresei, Arup Mukherjee, Tamal Sen, Predrag Lazic,
Vasile Caciuc, Reent Michel, Dietmar Stalke, Swadhin Mandal, Stefan Blugel and Markus Munzenberg.
Research is supported by grants from ONR, NSF and KIST-MIT program.

[1] L. J. Heyderman, H. H. Solak, C. David, D. Atkinson, R. P. Cowburn and F. Nolting, Appl. Phys. Lett. 85, 4989 (2004) [2] I. Ruiz, L. Lopez, A.
Hirorata, J. Rothman, C. M. Guertler, J. A. C. Bland, L. M. Garcia, J. M. Torres, J. Bartolome, F. Bartolome, M. Natali, D. Decanini, Y. Chen,
J. Magn. Magn. Mater. 2002, 242-245, 597-600; L. J. Heyderman, F. Nolting, D. Backes, S. Czekaj, Phys. Rev. B 2006, 73, 214429; X. K. Hu, S.
Sievers, A. Muller, V. Janke and H. W. Schumacher, Phys. Rev. B 2011, 84, 024404

Celia Cástan-Guerrero1*, Aurelio Hierro-Rodriguez2, Fernando Valdés-Bango2, Jose Ignacio Martin2, Javier Sese3, Julia
Herrero-Albillos4, Fernando Bartolome1, Juan Bartolome1, Jose Maria Alameda2 and Luis Miguel Garcia1
1
Instituto de Ciencia de Materiales de Aragon (Universidad de Zaragoza - CSIC), Spain
2
Departamento de Fisica, Universidad de Oviedo - CINN, Spain
3
Instituto de Nanociencia de Aragon (Universidad de Zaragoza), Spain
4
Centro Universitario de la Defensa, Academia General Militar, Spain

The magnetic ionic liquids (MILs) are a new class of materials which can favourably
combine the properties of ionic liquids with the magnetism that is originated fromthe metal incorporated in the complex anion [1]. Most of the MILs are paramagnetic,
being the Emim[FeCl4] the first one in which a long-range magnetic order was foundat low temperatures [2]. The physical properties of 1-ethyl-3-methylimidazolium
tetrachloroferrate Emim[FeCl4] clearly show antiferromagnetic ordering when it issolidified (in polycrystalline state at 285 K), with a Neel temperature TN ~ 3.8 K [3].
Recent Mossbauer and muon spin relaxation spectroscopies, as well as neutron powder
diffraction experiments [4], confirm the three-dimensional magnetic ordering. In thiswork, we present the effects of pressure on the Χ(T) and M(H) curves up to 10 kbar. It
is observed that the pressure modifies the magnetic interactions, increasing the ordertemperature and inducing a ferrimagnetic behaviour. Additionally, from the Χ(T), it isobserved that the solid-liquid transition is very sensitive to pressure, being above 300
K for pressures larger than 0.72 kbar.

Herng-er Horng*
National Taiwan Normal University, Taiwan

References: 1. Wash-free immunomagnetic detection for serum through magnetic susceptibility
reduction, Appl. Phys. Lett., 90, 74105 (2007). 2. Bio-functionalized magnetic nanoparticles forin-vitro labeling and in-vivo locating specific bio-molecules, Appl. Phys. Lett., 92, 142504(2008).
3. Characterization of tumors using high-Tc SQUID-detected nuclear magnetic resonance andimaging, Appl. Phys. Lett. , 97, 263701, 2010.( Cover page) 4. In-vivo and real-time measurementof magnetic-nanoparticles distribution in animals by scanning SQUID Biosusceptometry forbiomedicine study, IEEE Transactions on Biomedical Engineering ,58, 2719-2724, 2011. 5. Ex Vivo
Magnetofection With Magnetic Nanoparticles: A Novel Platform for Nonviral Tissue Engineering,
Artificial Organs, 32, 195-204 (2008).

Oral Thursday

Sara Majetich
Physics, Carnegie Mellon University, USA

80oRAL PRSENTATION

Zhijian Wu and Jing Wang
Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, China

Ron Naaman
Dep. of Chemical Physics, Weizmann Institute, Israel

1) B. Gohler,V. Hamelbeck, T.Z. Markus, M. Kettner, G.F. Hanne,Z. Vager, R. Naaman,H. Zacharias,
Science331,894-897 (2011). 2) Z. Xie, T. Z. Markus, S. R. Cohen, Z.Vager, R. Gutierrez, R. Naaman,
Nano Letters, 11, 4652-4655 (2011).

July 8-13, 2012 Busan, Korea

81

ORAL PRESENTATION
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Reversible and deterministic spin state switching of individual
spincrossover molecules on a surface

Science and technology of modern permanent magnet materials

Electrodeposited FePt films on Ag underlayer with high coercivity

Ultrafast transient generation of spin density wave order in the normal
state of BaFe2As2 driven by coherent lattice vibrations

A nano-scale molecular switch composed of a single molecule mainly utilizes its
conductance change by external stimuli. Adding spin switching functionality tomolecular switches is the key concept for realizing molecular spintronics devices withultimate density. For this purpose, spincrossover (SCO) molecules are promising since
their spin state is also switchable between a high spin (HS) state and a low spin (LS)state, in addition to the conductance. We show scanning tunneling microscopy (STM)
study of individual SCO molecules, Fe(phen)2(NCS)2 (phen = 1,10-phenanthroline).
While the molecules lose their switching functionality on a metallic Cu(100) surface
due to a strong coupling of the NCS-groups to the surface, reducing the interaction
with the surface by introducing thin CuN layer enables them to switch. Injecting acurrent with a tip of STM changes the conformation of the molecules between two
states, resulting in on (HS-state) and off (LS-state) of a Kondo resonance accompaniedwith a conductance change. Observed reversible and deterministic switching behaviorsof the molecules, which are vital for memory operation, give perspective on future
molecular spiontronics devices with the smallest unit.

George C. Hadjipanayis*
Physics and Astronomy, University of Delaware, USA

Permanent magnets (PMs) are indispensable for the electric, electronic and automobile
industries, information technologies, automatic control engineering and many othercommercial and military applications. In most of these applications, an increase in
the magnetic energy density of the PM, usually presented via the maximum energy
product (BH)max, immediately increases the efficiency of the whole device and makes
it smaller and lighter. Worldwide demand for high performance PMs has increased
substantially in the past few years driven by hybrid and electric cars, wind turbinesand other power generation systems. This talk will cover the major principles guiding
the development of PMs, including the important role of microstructure on coercivity,and overview state-of-the-art theoretical and experimental research. Recent progress inthe development of nanocomposite PMs, consisting of a fine (at the scale of magnetic
exchange length) mixture of phases with high magnetization and large magnetic
hardness will be discussed. Fabrication of such PMs is currently the most promising
way to boost the (BH)max, while simultaneously decreasing, at least partially,
the reliance on the rare earth elements. Current efforts in the development of highperformance non-rare earth magnets and their future prospects will also be discussed.
Work supported by DOE and ARPA-E

Sirikanjana Thongmee
Department of Physics, Faculty of Science, Kasetsart University, Thailand

FePt films with a composition close to Fe50Pt50 were fabricated following with post
annealing. The films were deposited onto Si substrate with a under layer of Ag. The phaseformation temperature, microstructure evolution by annealing and the magnetic properties
were investigated in detail. The L10 FePt phase started to form after annealing at 500 °C.
From TEM results, as-deposited FePt films consisted of randomly oriented nanograin.
The average grain sizes are about 5-10 nm. The increasing of temperature led to grain
growth. The grain sizes of FePt films on Ag underlayer were about 50 nm after the film wasannealed at 800 °C and SAED result was consistent with XRD. High coercivity of 15 kOe
was obtained after annealing at 600 °C. After annealing at 800 °C, the coercivity increased
to 18 kOe with a significant perpendicular anisotropy of FePt films. Out of plane anisotropy
was observed in relatively thick film (800 nm). The work has shown that FePt film with ahigh coercivity can be achieved by electro-deposition and the thickness, anisotropy can betuned, which may provide a method to fabricate FePt film for the potential applications bothrecording media and MEMS.
[1]. O. Gutfleisch, J. Lyubina, K. H. Muller, and L. Schultz, Adv. Eng. Mater. 7, 208 (2005) [2]. T. Maeda,
T. Kai, A. Kikitsu, and J. I. Akiyame, Appl. Phys. Lett. 80, 2147 (2002). [3]. C. P. Luo and D. J. Sellmyer,
Appl. Phys. Lett. 75, 3162 (1999) [4]. K. Leistner, M. Weisheit, L. Schultz, and S. Fahler, Appl. Phys. Lett.
85, 3498 (2004) [5]. S. Inoue, T. Namazu, and K. Inoue, Mater. Res. Soc. Symp. Proc., 426, 2213 (2003) [6].
Z.L. Zhao, J. Ding, K. Inaba, J.S. Chen, J.P. Wang, Appl. Phys. Lett. 83, 2196 (2003)

Kyungwan Kim1*, Alexej Pashkin2, Hanjo Schafer2, Markus Beyer2, Michael Porer3, Thomas Wolf4, Christian
Bernhard5, Jure Demsar2, Rupert Huber3 and Alfred Leitenstorfer2
1
Department of Physics, Chungbuk National University, Korea
2
Department of Physics, University of Konstanz, Germany
3
Department of Physics, University of Regensburg, Germany
4Karlsruhe Institute of Technology, Institute for Solid-State Physics, Germany
5
Department of Physics, University of Fribourg, Switzerland
The proximity of magnetic ground states to the superconductivity in cuprates and pnictides as well as in otherunconventional superconductors has put the magnetism at the heart of the discussion concerning the mechanism of hightemperature superconductivity. The recent development of the pump-probe time domain spectroscopy, which was typicallylimited in the terahertz region below 10 meV, has extended its spectral window to the infrared (IR) region allowing aresonant probe of important elementary excitations such as phonons, excitations across a superconducting gap as well asa density wave gap. We study the ultrafast dynamics of the spin density waves (SDWs) in BaFe2As2, a parent compoundof pnictide high temperature superconductors. We monitor the SDW gap resonantly by the near-infrared (NIR) pump-IR
probe technique. In the SDW state, we observe that the NIR excitation of the carriers breaks the SDW order. The excitation
with yet higher fluence launches strong coherent lattice vibrations. Strikingly, these coherent oscillations give rise to atransient SDW order even in the normal state. We discuss that the strong electron-phonon/spin-phonon coupling effects inpnictides result in the modulations of the SDW order parameter in real time in response to the coherent phonon vibrations.
K. W. Kim et al., Nature Materials (2012, to be published)

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Graphene-based spintronic components

Differential thermal analysis on MnBi in high magnetic fields up to 45 T

Magnetic properties of BaMg0.4Al0.4Fe11.2O19+SiO2 nanocomposites forhigh frequency applications

High- and low-energy ARPES study of spin-density wave order in
FeTe single crystals and FeTeOx films

Lei Shen, Minggang Zeng and Yuanping Feng*
Physics, National University of Singapore, Singapore
Using non-equilibrium Green's function method combined with density functional
theory, we propose a complete set of basic spintronics devices including bipolar spin
diode, transistor and logic gates based on zigzag graphene nanoribbons (ZGNRs).
Nearly ±100% spin-polarized current can be generated and tuned by a source-drain
voltage in the bipolar spin diode. This transport property is attributed to the intrinsic
transmission selection rule of the spin subbands near the Fermi level in ZGNRs. The
bias voltage and magnetic configurations of the two-terminal ZGNR-based spin diodes
provide a rich variety of ways to control the spin current which can be used to design
three-terminal spin transistors and logic gates. These spintronic components makepossible the manipulation of spin-polarized current, such as rectification, amplificationand logic operation.
1) M. G. Zeng, L. Shen, M. Zhou, C. Zhang, and Y. P. Feng. “Graphene-based bipolar spin diodeand spin transistor: Rectification and amplification of spin-polarized current” Phys. Rev. B 83,
115427 (2011). 2) M. G. Zeng, L. Shen, H. B. Su, C. Zhang, and Y. P. Feng. “Graphene-based logic
devices” App. Phys. Lett. 98, 092110 (2011).

Keiichi Koyama1*, Yoshifuru Mitsui2, Eun Sang Choi3, Yuki Ikehara2, Eric Palm3 andKazuo Watanabe2
1
Kagoshima University, Japan
2
Tohoku University, Japan
3
National High Magnetic Field Laboratory, USA
Differential thermal analysis was carried out for hard magnetic material MnBi in thetemperature range 300-773 K in magnetic fields up to 45 T to investigate the effect ofhigh magnetic fields on its decomposition process and corresponding phase diagram.
The decomposition temperature Tt (MnBi → Mn1.08Bi + liquid Bi) increases from632 K (at a zero field) to 714 K by applying a magnetic field of 45 T. Furthermore,
the magnetocaloric effect of MnBi is observed in 11.5-45 T in the vicinity of 689 K,
showing that a field-induced composition process occurs. The obtained results showthat the equilibrium state of MnBi can be controlled by a high magnetic field [1].
[1] K. Koyama et al., J. Alloys. Comp. 509 (2011) L78-L80.

K Sadhana and K Praveena
Materials Research Centre, Indian Institute of Science, Banglore-560012, India

The nanomcomposites of Ba0.5Mg0.4Al0.4Fe11.2O19/SiO2 were prepared using MicrowaveHydrothermal method at 160°C/45min. The as synthesized composites werecharacterized using X-ray diffraction and Transmission Electron microscopy (TEM).
The average particle size is found to be 62nm.The present composites were densified
using microwave sintering method at 900°C/60min. The frequency dependent complex
permeability of the composites were measured in the range of 1MHz to 1.8GHz.The
real part of permeability of the composites found to decreases with an addition of SiO2
but the resonant frequency is shifted towards higher frequency side. The magnetic
properties such as saturation magnetization and coercive field of sintered composites
were calculated based on M-H curves. A possible relation between the magnetic
hysteresis curves and the microstructure of the sintered composites was investigated.

Oral Thursday

Toshio Miyamachi1*, Manuel Gruber2, Vincent Davesne2, Eric Beaurepaire2 and Wulf
Wulfhekel1
1
Physikalisches Institut, Karlsruhe Institute of Technology, Germany
2
Institute of Physics and Chemistry of Materials of Strasbourg (IPCMS), UMR 7504
UdS-CNRS, France

Oral Thursday

oRAL PRSENTATION

Martin Mansson1*, Yuefeng Nie2, Yasmine Sassa1, Christof Niedermayer3, Genda Gu 4, Masaki
Kobayashi5, Vladimir Strokov5, Johan Chang6, Magnus Berntsen7, Olof Gotberg7, Bastian M. Wojek7,
Oscar Tjernberg7, Joseph I. Budnick2 and Barrett O. Wells2
1Lab. for Solid State Physics, ETH Zurich, Switzerland
2
Department of Physics, University of Connecticut, USA
3Lab. for Neutron Scattering, Paul Scherrer Institut, Switzerland
4
Brookhaven National Laboratory, USA
5
Swiss Light Source, Paul Scherrer Institut, Switzerland
6
LSNS, EPF Lausanne, Switzerland
7
Materials Physics, Royal Institute of Technology, KTH Stockholm, Sweden

We have performed a high-resolution (synchrotron- and laser-based) ARPES investigation of FeTe single crystals/films,
as well as thin films of the novel superconductor FeTeOx [1]. Our results from the single crystals reflect the previously
reported Fermi surface pocket around the X-point [(π, 0)], possibly connected to a spin-density wave (SDW) order [2].
Unlike such previous report, our results also reveal the presence of an energy gap (Δ), which would be expected fromthe SDW order. The temperature dependence shows that Δ closes in the vicinity of the magnetic transition temperature,
supporting its interpretation as reflecting the SDW state. We also present bulk sensitive results acquired using a soft x-ray
ARPES technique. Photon-energy (i.e. kz) dependent measurements reveal a strongly 3D electronic structure that can be
uniquely connected to the SDW-gap symmetry found in the low-energy data. Our results clearly illustrate the importanceof acquiring not only the true intrinsic bulk-electronic structure but also that it is imperative to consider the full 3Dband dispersion in iron-based superconductors and their parent compound in order to obtain an adequate theoreticalunderstanding. Finally, we also acquired novel ARPES data from cleaved FeTe and FeTeOx thin films.
[1] Y.F. Nie et al., Phys. Rev. B 82, 020508(R) (2010) [2] Y. Xia, PRL 103, 037002 (2009) Funding Source: DOE-BES throughcontract DE-FG02-00ER45801 and the Swiss National Science Foundation (Project 6, NCCR MaNEP).

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Detection and manipulation of spin currents in graphene with nonmagnetic electrodes

Magnetization of Dy2Fe17 in fields up to 85 Tesla

Coexistence of competing orders in unconventional superconductors

Magnetic fluctuations - a driving force for superconductivity Neutron
scattering investigations in Fe-based superconductors.

Ivan J. Vera-marun*, Vishal Ranjan, Paul J. Zomer, Marcos H. D. Guimaraes and Bart
J. Van Wees
Physics of Nanodevices, Zernike Institute for Advanced Materials, University ofGroningen, Netherlands
We present an interplay between charge currents and spin currents which allows the useof nonmagnetic contacts for both detection [1] and manipulation of spin accumulation
in a paramagnet. These effects are the result of a nonlinear interaction between spinand charge transport solely given by the energy dependence of the conductivity [2],analogous to the case of thermoelectrics. A conductivity spin polarization is inducedby the presence of a spin accumulation, even in a paramagnet, when the conductivity
is energy dependent. We use graphene as a model system to study these effects innonlocal spin valve devices, including its dependence on charge carrier density andspin amplification under nonmagnetic contacts and in bipolar graphene p-n junctions.
The general concept is applicable to the field of semiconductor spintronics.
[1] I.J. Vera-Marun, V. Ranjan and B.J. van Wees, Nature Phys. (accepted) [2] I.J. Vera-Marun, V.
Ranjan and B.J. van Wees, Phys. Rev. B 84, 241408(R) (2011)82

The 19th International Conference on Magnetism

Y. Skourski 1, A.V. Andreev 2, M.D. Kuz'min 3, Y. Narumi 4, K. Kindo 5, N.V.
Kudrevatykh6 and J. Wosnitza1
1
Dresden High Magnetic Field Laboratory, Germany
2
Institute of Physics ASCR, Prague, Czech Republic
3
IFW Dresden, Germany
4
IMR, Tohoku University, Sendai, Japan
5
ISSP, Tokyo University, Kashiwa, Japan
6
Ural Federal University, Ekaterinburg, Russia
Dy2Fe17 is an easy-plane rare-earth ferrimagnet. Applying sufficiently high magnetic field
one can break the antiparallel alignment of the sublattice moments and drive the system
towards the ferromagnetic state via intermediate non-collinear phases. In this particularcase, if the magnetic field is applied within the easy plane, the moment direction of the
Fe sublattice deviates only slightly from the field direction. The Dy-moment instead
starts from the direction opposite to the field and the Fe moment, and subsequently
passes several energetic minima. This manifests itself in corresponding jumps on themagnetization curve. Measurements in fields up to 67 Tesla have shown a field-induced
jump on the magnetization curve for field aligned along the a axis. According to a theory
developed for hexagonal ferrimagnets and having the field and the jump height along
the a axis, we expected the jump along the b direction to appear at 78 T. To check thisprediction, we have measured the high-field magnetization curve of a Dy2Fe17 single
crystal for fields up to 85 Tesla along the b axis . We have observed a sharp magnetization
jump at 77.8 Tesla, which agrees perfectly with the theory.

Setsuko Tajima*, E. Uykur, K. Tanaka, T. Masui and S. Miyasaka
Dept. of Physics, Osaka University, Japan

In my talk, I will focus on the problem of the coexistence of competing orders which isprobably inevitable in strongly interacted systems. A typical example is the pseudogap
state in high Tc superconducting cuprates, which has been a long-standing puzzle.
In order to address this problem, we have carefully measured the c-axis polarized
optical spectra of YBa2(Cu,Zn)3Oy. Removing an additional spectral feature due tothe transverse Josephson plasma by Zn-doping, we could unambiguously discuss
the spectral weight transfer. The result clearly showed that the pseudogap originatesfrom some competing order but not a precursor of superconductivity. Moreover,
we found that the pseudogap persists even below Tc, which becomes pronounced
by Zn-substitution. This indicates that the pseudogap and the superconducting gap
are coexisting, presumably in a phase separated form. The most interesting problem
is whether or not such a coexistence of competing order plays a positive role insuperconductivity mechanism. One of the interesting facts is that the onset temperaturefor superconducting fluctuation increases with decreasing doping. Its energy scale isunusually large (~ 0.4eV). This suggests that the competing order with a large energy
scale contributes to superconducting fluctuation and possibly to pairing mechanism.

Alice Elizabeth Taylor1*, Russell A. Ewings2, Toby G. Perring2, Simon J. Clarke3 andAndrew T Boothroyd4
1
Department, University of Oxford, United Kingdom
2
ISIS Facility, Rutherford Appleton Laboratory, STFC, United Kingdom
3
Department of Chemistry, University of Oxford, United Kingdom
4Department of Physics, University of Oxford, United Kingdom

One of the most exciting findings in investigations of High-Tc superconductivity has
been the discovery of a magnetic resonance in the superconducting state, associatedwith a spin excitation with a characteristic position in wavevector and energy space [1].
This resonance has been investigated across the families of Fe-based superconductors
with several common features observed such as the scaling of the resonant energy
with Tc (Er ~ 4.3 Tc in (Ba,K)Fe2As2 [1]) and the position of the resonance either at, orincommensurate about, the antiferromagnetic wavevector [1,2,3]. This work presents
results of inelastic neutron scattering experiments on a broad range of Fe-based
superconducting materials in order to address the question - are these features reallycommon to all these materials? Results from the characteristic 122-arsenide family [4]are contrasted with LiFeAs [2], CsxFe2-ySe2 and phosphorus containing materials.
[1] A. D. Christianson et al., Nature 456, 930 (2008) [2] A. E. Taylor et al., Phys. Rev. B 83.
220514(R) (2011) [3] J. -P. Castellan et al., Phys. Rev. Lett. 107, 177003 (2011) [4] R. A. Ewings etal., Phys. Rev. B 83, 214519 (2011)

July 8-13, 2012 Busan, Korea

83

ORAL PRESENTATION
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Low-energy quasiparticles probed by heat transport in the iron based
superconductor lafepo

FeCoB films with large saturation magnetization and high magnetic
anisotropy field to attain high ferromagnetic resonance frequency

Spin-dependent molecular arrangement of O2-O2 dimer in nanoporous metalorganic solids

Temperature dependence of spin wave resonance frequency in amagnetostatic surface wave mode

Measurements of ultra-low temperature heat transport are an extremely effective probe of thepresence of nodes in the superconducting order parameter. In this study we report the thermal
conductivity of the iron pnictide superconductor LaFePO down to temperatures as low as
T=60mK and in magnetic fields up to 5 T. The data shows a large residual contribution that islinear in temperature, consistent with the presence of low-energy electronic quasiparticles [1].
We interpret the magnitude of the linear term, as well as the field and temperature dependenceof thermal transport in several pairing scenarios, with the aim of distinguishing between
accidental or symmetry imposed nodes. The presence of an unusual supralinear temperaturedependence of the electronic thermal conductivity in zero magnetic field, and a high scattering
rate with minimal Tc suppression argues for a sign-changing nodal s+/- state. We compare
these results to recent thermal transport studies in related iron-based superconductors.

Shigeki Nakagawa
Dept. of Physical Electronics, Tokyo Institute of Technology, Japan

FeCoB films prepared on a Ru underlayer using the Oblique incidence of sputteredand backscattered particles have a high in-plane magnetic anisotropy field of 500 Oe.
Facing targets sputtering system is suitable to attain such deposition condition. In-plane
X-ray diffraction analysis clarified that there is anisotropic residual stress, which is theorigin of the high in-plane magnetic anisotropy. The directional crystalline alignment
and inclination of crystallite growth were also observed. Such anisotropic crystalline
structures may affect the anisotropic residual stress in the FeCoB layer. The B content
of 6 at.% was appropriate to induce such anisotropic residual stress. The anisotropic
residual stress develops according with the film growth. The film with large saturation
magnetization of 22 kG and high magnetic anisotropy field of 500 Oe exhibited highferromagnetic resonance frequency of 9.2 GHz. The large saturation magnetization andthe low coercivity along the hard axis direction assure that the film can be operated in
the high frequency range up to 8 GHz with maintaining high relative permeability.

O2 is a molecular magnet with S = 1. The characteristic magnetic properties related to the moleculararrangement can be expected since the magnetic exchange interaction between O2 is comparable to theelectric interaction between the quadrupole moments. [1] Recently, for a model system of isolated O2-O2
dimer confined in the nanopores of Cu-cyclohexanedicarboxylic acid, the molecular arrangement structure
relating to its magnetic properties was investigated by precise x-ray diffraction analysis. The obtained charge
density level structures revealed that the significant orientational change of the molecular axes occurs withchanging temperature, coupling with the spin states of O2-O2 dimer. The temperature dependence of magnetic
susceptibility and the magnetization process characterized by the absence of half-plateau (S_dimer = 1) can
be consistently explained by a simple model taking into account the orientational change of molecular axes.
Consequently, the present results experimentally proved that the molecular orientation depends on the spinstate, the rectangular parallel H-geometry for the singlet ground state (S_dimer = 0) and the shifted parallel
S-geometry for the thermally excited quintet state (S_dimer = 2), due to the spin-dependent intermolecularpotential which has not been discussed for solid O2.

Jae Hyun Kwon1, Sankha Subhra Mukherjee2 and Hyunsoo Yang1*
1
Electrical and Computer Engineering, National University of Singapore, Korea
2
Electrical and Computer Engineering, National University of Singapore, India

Propagating spin waves in a 20 nm NiFe film, in the magnetostatic surface wave
(MSSW) mode, have been measured at various temperatures in a time domain. Pulse
inductive microwave magnetometry (PIMM) is used for the detection of spin wave
packets. Impulse voltages were applied to the excitation coplanar waveguide (CPW)by a pulse generator, while the resultant dynamic responses were observed through asampling oscilloscope at the detection CPW. The spin wave resonance frequencies (fR)
increases with decreasing temperature. The saturation magnetization (MS) increases
at low temperature, and consequently fR increases in accordance with the dispersion
relation of MSSWs. The change in fR from 300 K to 12 K is approximately 400 MHz
at a bias field of 280 Oe. A second mode is also observable below 100 K, and becomes
progressively clearer at lower temperatures. At higher temperature, there is significant
magnon-phonon interaction. However, the lattice vibrations become subsided at
low temperatures, and magnon-phonon interaction reduces, while electron-electron
scattering decreases. This causes a change in the nature of the damping phenomenon.
The nature of the intrinsic damping has been investigated as a function of temperatureand has been correlated to the difference in the damping mechanisms.

R. Kitaura et al. Science 298, 2358 (2002).

M. Sutherland et. al. Phys. Rev. B 85, 014517 (2012)

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Domains and magnetization processes in electrical steel

Magnetism where you least expect it

Indications for a field-induced 2d collectively-coupled dimer state innitronyl-nitroxid biradicals

Nanoscale spin wave switches and phase shifters

Rudolf Schaefer
Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Germany
Understanding and lowering of energy loss in electrical steel requires knowledge
about the magnetic domains and magnetization processes. In this presentation some
aspects of domains and processes will be addressed, based on domain analysis by Kerr
microscopy and neutron imaging. The former provides information on the surface
domains and requires the support of domain theory to come up with conclusive models.
Examples will be shown for oriented and non-oriented material, including the effectsof mechanical stress [1]. The volume domains, which are relevant for key magnetic
properties like susceptibility, energy loss, noise or coercivity, can be analysed by thenovel method of neutron dark-field microscopy [2,3]. By this grating interferometry
technique, the domains and magnetization propagation in bulk FeSi material can beimaged non-destructively and even tomographic analysis becomes possible [4] with alateral resolution down to 10 μm. The method has the unique potential to visualize themagnetic field penetration in bulk material [3].
[1] O. Perevertov and R. Schafer: Influence of applied compressive stress on the hysteresis curves andmagnetic domain structure of grain-oriented transverse Fe-3%Si steel. Accepted for J. Phys. D: Applied
Physics (2012) [2] C. Grunzweig, et al.: Neutron decoherence imaging for visualizing bulk magnetic
domain structures. Phys. Rev. Lett. 101, 025504 (2008) [3] C. Grunzweig, et al.: Visualizing the
propagation of volume magnetization in bulk ferromagnetic materials by neutron grating interferometry(invited). J. Appl. Phys. 107, 09D308 (2010) [4] I. Manke, et al.: Three-dimensional imaging ofmagnetic domains. Nature Communications, 1:125 doi: 10.1038/ncomms1125 (2010)

Priya Mahadevan
Department of Condensed Matter Physics and Material Science, S.N.Bose National
Centre for Basic Sciences, India
The picture of magnetism that has prevailed over the years has centered around theexistence of localized electrons and their ordering leading to different types of magnetic
order. Recently several unconventional examples of magnetism have been emerged suchas p-band magnetism in alkali metal oxides - a system with no traditional magnetic ionsin them. Unfortunately high magnetic ordering temperatures were not possible and thiswas traced to an orbital ordering transition [1]. While orbital ordering is usually found to
reinforce one type of magnetic order over another, in the present case one found it led to
the loss of any possibility of high magnetic ordering temperature. In another example, we
consider the example of a 4d oxide SrTcO3 where recent experiments [2] have found a Neeltemperature of 1023 K, far higher than its 3d counterpart SrMnO3. A detailed analysis [3]within a microscopic multiband Hubbard model reveals a rather surprising result of higher
bandwidth and smaller Hund's exchange coupling strength resulting in higher magnetic
ordering temperatures in 'SrTcO3-type' oxides. This is work done in collaboration with A.K.
Nandy, S. Middey, P. Sen and D.D. Sarma.
[1]. A. K. Nandy, Priya Mahadevan, P. Sen and D. D. Sarma. Phys. Rev. Lett. 105, 056403 (2010). [2]. E.E.
Rodriguez, F. Poineau, A. Llobet, B. J. Kennedy, M. Avdeev, G. J. Thorogood, M. L. Carter6, R. Seshadri,
D. J. Singh, and A. K. Cheetham, Phys. Rev. Lett. 106, 067201 (2011). [3]. S. Middey, A.K. Nandy, P.
Mahadevan and D.D. Sarma, cond-mat arXiv:1112.5587.

Michael Lang1*, Bernd Wolf1, Pham Thanh Cong1, Ulrich Tutsch1, Martin Baumgarten2, Yulia Borozdina2,
Dominik Strassel3 and Sebastian Eggert3
1
Physics Institute, Goethe-University Frankfurt (M), SFB/TR 49, D-60438 Frankfurt (M), Germany, Germany
2
Max-Planck-Institute for Polymer Research, SFB/TR 49, D-55128 Mainz, Germany, Germany
3
Physics Department and Research Center OPTIMAS, University of Kaiserslautern, D-67663 Kaiserslautern,
Germany
Arrays of coupled spin S = ½ dimers, exposed to a magnetic field, are of general interest as they
can be considered as the source for generating a gas of interacting bosons [1]. We present a novel
coupled spin-dimer system with a double-layer structure based on nitronyl-nitroxid stable radicals
bridged via tolan molecules. The intra-dimer coupling constant is around 10 K, whereas theinter-dimer couplings, mediated via H-bonds, are of the order of 1 K. The moderate size of these
couplings enables us to study the field-induced ordered phase forming for T < 0.3 K and 8 T ≤ B ≤ 9.5
T. The anomaly observed in the ac-susceptibility χ(B) differs significantly from ordinary B-induced
3d ordering, tantamount to Bose-Einstein condensation of magnetic excitations, where χ(B) shows
sharp peaks at the on- and offset fields. Rather we find a rounded double-peak structure where thepeaks remain rounded down to 75 mK, the base temperature of our experiment. These featuresindicate the formation of a 2d collectively-coupled dimer state, implying topological order for T →0. In order to analyze the nature of the B-induced ordered state, the experimental data are comparedwith the results of Quantum-Monte-Carlo calculations.

Yat-yin Au and Volodymyr Kruglyak*
University of Exeter, United Kingdom

The short wavelength of spin waves propagating in nanoscale magnonic waveguides at
microwave frequencies could potentially provide a device miniaturization opportunity
via accomplishing certain tasks with a reduced number of physical devices as compared
to semiconductor circuitry. To utilize this promise of magnonics, it is important tolearn to manipulate the spin wave phase and perhaps magnitude, which is highly
related to data encoding and logical operation, etc. Here, we use OOMMF simulations
to demonstrate a new method of achieving controlled phase shift of spin waves that
relies on the reverse of the recently discovered spin wave emission mechanism [1].
The method could be highly useful for magnonic applications since it depends heavily
on the static magnetization of the control element in the structure. Hence, by changing
static magnetization direction in the element, it is possible to control the magnitude
and phase of propagating spin waves. These switchable, non-volatile devices could
serve as either spin wave valves or phase shifters, all at the nanoscale and low energy
cost. The research leading to these results has received funding from the EC's Seventh
Framework Programme (FP7/2007-2013) under GAs 233552 (DYNAMAG) and
228673 (MAGNONICS) and from the EPSRC of the UK (EP/E055087/1).
[1] Y. Au, E. Ahmad, O. Dmytriiev, M. Dvornik, T. Davison, and V. V. Kruglyak, (submitted).

[1] T. Giamarchi, Ch. Ruegg, O. Tchernyshyov, Nature Physics 4, 198 (2008).

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Iron loss behaviors in 6.5 wt% grain-oriented silicon steel

Exotic magnetism of s-electron cluster array: Ferromagnetism,
ferrimagnetism and antiferromagnetism

Magnon caloritronics

Optically induced tunable magnetization dynamics in nanoscale Co
antidot lattices

Jongryoul Kim* and Heejong Jung
Department of Metallurgy and Material Science, Hanyang University, Korea
6.5 wt% silicon steel has great potential for electrical appliances and devices, suchas transformer and motor cores, due to its high electrical resistance, extremely low
magnetostriction, low magnetocrystalline anisotropy, and low iron loss [1-2]. However,the presence of ordered phases, i.e. B2, D03, deteriorates the workability of the 6.5
wt% silicon steel, which impedes the mass production using the conventional rolling
technique [2]. In addition, there is a lack of research on the effect of the orderedphases on the magnetic behaviors of high silicon steels. In this paper, we, therefore,
investigated the relationship between the ordered phases and the iron loss behaviors
in high silicon steels using transmission electron microscopy and Kerr microscopy.
In order to obtain the high silicon steels, 3 wt% grain-oriented silicon steels inserted
between SiO2 textiles were annealed for the decomposition of the textiles and the
diffusion of Si. The size, shape and amount of the ordered phases were controlled bythermo-mechanical treatment. The microscopical analyses showed that the antiphaseboundaries of the ordered phases cut magnetic domains, which strongly affected theiron loss behaviors of the high silicon steels.
[1] P. R. Swann, W. R. Duff, and R. M. Fischer, Phys. Stat. Sol., 37 (1970) 577-583 [2] B. Viala, J.
Degauque, M. Barico, E.Ferrara, and F. Fiorillo, Mater. Sci. Eng. A, 212 (1996) 62-68

84

Tatsuo C. Kobayashi1, Akihiro Hori2, Yoshiki Kubota3, Akira Matsuo4, Koichi Kindo4, Jungeun
Kim5, Masaki Takata2, Hirotoshi Sakamoto6, Ryotaro Matsuda6 and Susumu Kitagawa7
1
Department of Physics, Okayama University, Japan
2
RIKEN SPring-8 Center, Japan3
Department of Physical Science, Osaka Prefecture University, Japan
4
ISSP, The University of Tokyo, Japan
5
JASRI/SPring-8, Japan
6
ERATO, JST, Japan
7
ICeMS, Kyoto University, JapanThe 19th International Conference on Magnetism

Oral Thursday

Michael Sutherland1, J. Dunn2, W. H. Toews3, Eoin O' Farrell4, James Analytis5, Ian
Fisher5 and R. W. Hill3
1
Department of Physics, Univeristy of Cambridge, United Kingdom
2
Department of Physics, University of Waterloo, Canada
3
Department of Physics, Univeristy of Waterloo, Canada
4
I.S.S.P., University of Tokyo, Japan
5
Geballe Laboratory for Advanced Materials and Department of Applied Physics,
Stanford University, USA

Oral Thursday

oRAL PRSENTATION

Takehito Nakano1, Nguyen Hoang Nam2, Truong Cong Duan3, Duong Thi Hanh1, Shingo Araki4 and Yasuo Nozue1*
1
Department of Physics, Graduate School of Science, Osaka University, Japan
2
Hanoi University of Science, Viet Nam
3
FPT University, Viet Nam
4
Graduate School of Natural Science and Technology, Okayama University, Japan
Alkali metal nanoclusters can be stabilized in the regular cages of zeolite crystals by the loading of guest
alkali metals. Cages are connected by the sharing of windows of aluminosilicate framework, and arrayedin simple cubic, diamond and body centered cubic structures in zeolites A, X and sodalite, respectively.
The s-electrons have the localized nature of nanoclusters with magnetic moments and the mutualinteraction through windows. They show exotic magnetism depending on the structure type of zeolite,
alkali metal and the average loading density of alkali atoms per cage, n. In zeolite A, potassium clusters
are formed in alpha-cages. They exhibit spontaneous magnetization at n > 2. Ferromagnetic properties
are explained by the canted antiferromagnetism of the Mott insulator, where the canting provided by
Dzyaloshinsky-Moriya interaction is strongly enhanced by the 1p-like degenerate molecular orbitals
of clusters[1] and the superlattice structure. Rb clusters generated at alpha- and beta-cages of zeolite A
exhibit ferrimagnetic properties[2]. Na-K alloy clusters generated at supercages and beta-cages of lowsilica X zeolite exhibit ferrimagnetism at specific loading densities of alkali metals, where clusters arein the metallic phase[3]. Alkali metal clusters in sodalite show the Heisenberg antiferromagnetism of theMott insulator[4].
[1] T. Nakano and Y. Nozue, J. Comp. Meth. Sci. Engin. 7, 443 (2007). [2] T.C. Duan, T. Nakano and Y. Nozue, e-J. Surf.
Sci. Nanotech. 5, 6 (2007). [3] D.T. Hanh, T. Nakano and Y. Nozue, J. Phys. Chem. Solids 71, 677 (2010). [4] T. Nakano, R.
Suehiro, A. Hanazawa, K. Watanabe, I. Watanabe, A. Amato, F.L. Pratt and Y. Nozue, J. Phys. Soc. Jpn. 79, 73707 (2010).

Burkard Hillebrands*, Vitaliy Vasyuchka, Bjorn Obry and Aleksandr Serga
Department of Physics, TU Kaiserslautern, Germany
Eigen excitations of a magnetic system, e. g. spin waves and their quanta, magnons, areexpected to play an important role in spin-caloric effects. The recently observed spin
Seebeck effect in a magnetic insulator demonstrates the strong connection between
magnon and heat transport processes. I will address the interplay between magnon andheat transport phenomena and present recent Brillouin light scattering experimentsfrom magnons in an yttrium iron garnet (YIG) waveguide subject to a temperature
gradient. Two issues are addressed in a thermal gradient field: first the propagationof spin waves, and, second, the distribution of thermal magnons. We find, that, first,
magnons adapt their wavelength in a thermal gradient field and stopping effects may
occur. Second, we report direct measurements of the magnon distribution and show,that it does not follow the phonon temperature.

Ruma Mandal, Susmita Saha, Dheeraj Kumar, Saswati Barman, Semanti Pal, Kaustuv Das, Arup Kumar
Raychaudhuri, Yasuhiro Fukuma, Yoshichika Otani and Anjan Barman*
Condensed Matter Physics and Material Sciences, S. N. Bose National Centre For Basic Sciences, India

We present the fabrication of high quality Co antidot lattice structures with 100 nm antidot diameter andwith varying lattice constants S between 200 and 500 nm by using focused ion beam lithography. We haveexcited and detected the magnetization dynamics in those antidot lattice structures by an all-optical timeresolved Kerr microscope. The dynamics shows two prominent magnonic bands for sparsely packed lattices
with a clear bandgap. The bandgap increases with the decrease in the lattice constant and at the lowest valueof the lattice constant S = 200 nm, four distinct magnonic bands appear. The observations are qualitatively
reproduced by micromagnetic simulations and the resonant mode profiles are calculated and interpreted.
The lower frequency mode corresponds to the magnetostatic surface wave mode while the higher frequency
modes are quantized modes with varying quantization number. We further demonstrate the tunability ofmagnonic spectra in composite structures constructing of antidot lattices with varying lattice constantsarranged in varying geometry. The observations are important for potential applications of the antidot lattices
in nanoscale magnonic crystals in the form of composite antidot structures with tunable bandgaps.
1. Kruglyak, V. V.; Demokritov, S. O.; Grundler, D., Magnonics. J. Phys. D: Appl. Phys. 2010, 43, 264001. 2. Neusser, S.;
Duerr, G.; Bauer, H. G.; Tacchi, S.; Madami, M.; Woltersdorf, G.; Gubbiotti, G.; Back, C. H.; Grundler, D., Anisotropic
Propagation and Damping of SpinWaves in a Nanopatterned Antidot Lattice. Phys. Rev. Lett. 2010, 105, 067208. 3. Tacchi,
S.; Madami, M.; Gubbiotti, G.; Carlotti, G.; Adeyeye, A. O.; Neusser, S.; Botters, B.; Grundler, D., Angular Dependence ofMagnetic Normal Modes in NiFe Antidot Lattices with Different Lattice Symmetry. IEEE Trans. Magn. 2010, 46, 1440-1443.

July 8-13, 2012 Busan, Korea

85

ORAL PRESENTATION
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Plasmonic and quantum plasmonic enhancement of magneto-optics

Extrinsic SHE induced by small impurities in copper

Bias-dependence of the spin-transfer torques in MgO-based magnetic
tunnel junctions

Spin-transfer torque and joule heating of field-emitted electrons

We consider two scenarios of magneto-optical transmission lines build on the basisof an array of plasmonic nanoparticles. The first scenario corresponds to the wellknown transmission line of the plasmonic nanoparticles embedded into a magnetooptical medium. We show that the propagation of the dipole-plasmonic mode travelling
along the array is accompanied by the rotation of the polarization (the Faraday effect).
The angle of rotation is dozens times greater than that in the uniform magneto-opticalmaterial. In the second case, we consider a chain of metallic nano-particles exhibiting
magneto-optical properties embedded into a dielectric matrix. When the matrix is
passive, in spite of the plasmonic resonance, the Faraday rotation enhancement is small
due to the small propagation length of the dipole-plasmonic mode. In an active matrix,
the metal nanoparticles are surrounded by active centers (quantum dots or active
molecules) forming magneto-optical spasers. The dipole-plasmonic mode in such anarray of spasers exhibits high values of the Faraday rotation and the propagation length.

Yoshichika Otani*, Yasuhiro Niimi, Yohei Kawanishi and Dahai Wei
ISSP, University of Tokyo, Japan
Spintronic devices manipulating pure spin currents, flow of spins with no net charge
flow, must play an important role in low energy consumption electronics of next
generation. This explains the current interest for the spin Hall effect (SHE) which
provides a purely electrical way to generate spin currents without ferromagnets andmagnetic fields. The inverse SHE (ISHE) is the only means to generate electricalsignals from spin currents. It is indispensable for practical applications to have a large
spin Hall (SH) angle which characterizes the efficiency in conversion between charge
and spin currents. Today platinum is adopted as the best material for this conversion.
The ISHE of Pt, for instance, has been used for the detection of spin currents produced
from heat flows by the spin Seebeck effect. Thus it is a prime task to find materials
with large SH angles and preferably lower cost than Pt. Here we discuss how a giant
SH angle (-12%) can be obtained by simply doping copper with a small amount ofbismuth impurities.

Soeren Boyn1, Rie Matsumoto1, Joao Sampaio1, Vincent Cros1, Julie Grollier1, Akio Fukushima2,
Hitoshi Kubota2, Kay Yakushiji2 and Shinji Yuasa2
1
Unite Mixte de Physique CNRS/Thales, France
2
National Institute of Advanced Industrial Science and Technology, Japan

Understanding the bias dependence of the two spin-transfer torques (IP in-plane and OOP out-ofplane) in Magnetic Tunnel Junctions (MTJs) is important from the fundamental point of view andfor applications. For example, back-hopping phenomena at large bias, unwelcome for MRAM
applications, has been ascribed to a competition between IP and OOP torques [1]. There is stilla debate on the expected bias dependence of both torques. In symmetric tunnel junctions (samethickness and composition for both ferromagnetic electrodes), some results report a OOP torquelinear with bias [2], and others quadratic [3]. It has also been shown that by voluntarily introducing
an asymmetry in the MTJ, it was possible to control the sign of the linear part of the OOP torque[4,5]. The presented work is a systematic study of the bias-dependence of the two torques in MTJs
with different compositions for the electrodes, ranging from symmetric CoFeB/MgO/CoFeB to
asymmetric CoFeB/MgO/NiFe MTJs. We will present the switching phase diagrams of the different
MTJs, from which we infer the evolution of the two torques by comparing our experimental results
to numerical simulations. Financial support by JSPS Postdoctoral Fellowships For Research Abroad
and the ERC 2010 Stg 259068 is acknowledged.
[1] J.Z. Sun et al., J. Appl. Phys. 105 , 07D109 (2009) [2] O. Heinonen et al., Phys. Rev. Lett. 105, 066602 (2010) [3] H.
Kubota et al., Nature Phys. 4, 37 (2007) and J. Sankey, Nature Phys. 4, 67 (2007) [4] S.-C. Oh et al., Nature Phys. 5, 898(2009) [5] A. Chanthbouala et al. , Nature Phys. 7, 626 (2011)

Applying a high electrostatic field results in the emission of electrons from a solid
surface into vacuum. These field-emitted electrons are used for microscopy purposes[1]. For magnetic emitters the spin polarization of the field-emission current has been
detected since the 1960's [2]. However, the microscopic details of the interactionof spin-polarized field-emitted electrons with magnets remain to be discovered.
Here, we utilize spin-polarized scanning tunneling microscopy (SP-STM) in thefield emission mode [3] for the direct observation and manipulation of atomic-scale
superparamagnets. Injecting high spin-polarized currents into the first field emission
resonance (FER) of individual magnets reveals the switching behavior being strongly
affected. Telegraphic noise experiments allow for a current-dependent lifetime analysis[4], thereby quantifying the spin-transfer torque and Joule heating of the field-emitted
electrons. Switching the magnetization of quasistable nanomagnets is realized byramping field emission currents. Our experiments demonstrate the capability of fieldemitted electrons for magnetic observation and manipulation on the atomic scale at nm
distances.
[1] E. W. Muller, Z. Physik 108, 668 (1938). [2] M. Hofmann et al., Phys. Lett. 25A, 270 (1967). [3]A. Kubetzka et al., Appl. Phys. Lett. 91, 012508 (2007). [4] S. Krause et al., Phys. Rev. Lett. 107,
186601 (2011).

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Pure spin current generation using highly spin polarized Co2FeSielectrodes

Spin Injection at the LaAlO3/SrTiO3 Interface

Spin torque assisted magnetization switching in thermally activatedregionPerpendicular spin torque at high bias in MgO-based magnetic tunnel
junctions

Thermal stability is an important quantity of ferromagnets because it determines
performances of spintronics devices. The value of the thermal stability has been
determined by analyzing the spin torque switching in the thermally activated region
with the switching probability formula, P=1-exp[-ftexp[-∆(1-I/Ic)b], where ∆, I, and Ic
are the thermal stability, current, and spin torque critical current at zero temperature,
respectively. The value of the exponent, b, has been assumed to be unity. However,recently, several authors, including us, argued that b=2. The determination of b isimportant because it significantly affects the estimation of the thermal stability.
Recently, Heindl et al. (JAP 109) experimentally found that the current pulse duration
time dependence of the switching current shows nonlinearity, while the theory with
b=1 predicts linear dependence. They concluded that the discrepancy arises from thebreakdown of the thermal model. In this study, we theoretically studied the spin torqueswitching in the thermally activated region. We employed the mean first passage time
approach which reduces the exact solution of the switching probability in the whole
range of the thermally activated region and gives b=2 in several limits. Our theory
reproduced the nonlinearity of the switching current obtained by Heindl et al.

This talk will consist of two parts. One is an experimental study on bias-dependenceof perpendicular spin torque in MgO-based magnetic tunnel junctions (MTJs) and theother is a numerical study on current-induced self-resonant switching of magnetization.
In the first part, we show an experimental method to estimate the bias dependence of theperpendicular spin torque in MTJs based on the switching phase diagrams [1]. A special
attention is paid for high-bias range. Our method utilizes the pulse-width-dependentchange in the switching phase diagram and addresses the perpendicular-torque-driven
precessional switching at high-bias ranges where the in-plane spin torque acts as anadditional damping. The bias dependence of the perpendicular spin torque at high bias
was found to be linear for a voltage polarity. This method will be useful to address spin
torque effects in MTJs at high bias. In the second part, we propose a new type of currentinduced magnetization switching in multilayers. It utilizes spin torques caused by DC
current injection and consequent RF fields caused by magnetization dynamics. We showthat this way of switching magnetization is more efficient than the conventional ways. It
allows a large reduction in the switching current with keeping the thermal stability.

Takashi Kimura*, Soichiro Oki, Shinya Yamada, Masanobu Miyao and Kohei
HamayaKyushu University, Japan

Pure spin current provides attractive means for the efficient operation of spin-based
electronic devices. Efficient generation of the pure spin current may be a key fordeveloping the future spin-based devices. However, the generation efficiency of thepure spin current using the conventional ferromagnetic metal electrodes such as NiFe
and Co is extremely low. This is because most of the injected spin currents return backto the spin injector with the low spin polarization. Such back flows of the spin currents
can be effectively reduced by using highly spin polarized ferromagnetic electrodes.
In the present study, we fabricated lateral spin valves with Co2FeSi electrodes, which
is one of the Heusler compounds expecting half metalicity. Large nonlocal spin valve
signals were observed at room temperature, revealing the high spin polarization of the
Co2FeSi electrodes. From the analysis based on one-dimensional spin diffusion model,
the generation efficiency of the pure spin current is found to be significantly enhanced
compared to those with the conventional ferromagnetic electrodes. [1] Moreover, fromthe systematic study of numerous number of the devices, we found the correlation
between the electrical resistivity and the spin polarization. [2]Nicolas Reyren, Manuel Bibes, Edouard Lesne*, Jean - Marie George, Cyril Deranlot,
Sophie Collin, Agnes Barthelemy and Henri Jaffres
Unite Mixte de Physique CNRS/Thales, France
Future spintronics devices will be built from elemental blocks allowing the electricalinjection, propagation, manipulation and detection of spin-based information.
Owing to their remarkable multifunctional and strongly correlated character, oxidematerials already provide such building blocks for charge-based planar devices suchas ferroelectric field-effect transistors, as well as for spin-based vertical devices likemagnetic tunnel junctions, with giant responses in both cases. In an attempt to bridgethese two areas, we report results of electrical spin injection at the high-mobility quasitwo-dimensional electron system (2-DES) that forms at the LaAlO3/SrTiO3 interface[1]. In a non-local, three-terminal measurement geometry, we analyze the voltage
variation associated with the precession of the injected spin accumulation driven by
perpendicular or transverse magnetic fields (Hanle and inverted Hanle effect) [2].
The influence of bias and back-gate voltages reveals that the spin accumulation signal
is amplified by resonant tunneling through localized states in the LaAlO3 strongly
coupled to the 2-DES by tunneling transfer.
[1] A. Ohtomo, and H. Y. Hwang, Nature 427, 423 (2004). [2] S.P. Dash et al., Phys. Rev. B 84,
054410 (2011).

[1] T. Kimura, N. Hashimoto, S. Yamada, M. Miyao and K. Hamaya, NPG asia materials,To be published [2] K.
Hamaya, N. Hashimoto, S. Oki, S. Yamada, M. Miyao and T. Kimura, Phys. Rev. B, (Rapid comm.) , in press

Tomohiro Taniguchi and Hiroshi Imamura*
Nanosystem Research Institute, National Institute of Advanced Industrial Science andTechnology, Japan

Kyung-jin Lee1*, Seung-young Park2, Younghun Jo2 and Soo-man Seo1
1
Korea University, Korea
2
Korea Basic Science Institute, Korea[1] S.-C. Oh et al., Nature Phys. 5, 898 (2009); S.-Y. Park et al., J. Phys. D: Appl. Phys. 44, 064008 (2011);
S.-Y. Park, Y. Jo, and K.-J. Lee, Phys. Rev. B 84, 214417 (2011).

HE02

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HG01

Highly reproducible lateral spin valves for the study of spin injection
in metals

Coherence in collective spin precession in lateral spin valves

Joule heating and spin-transfer torque investigated on the atomic scale

Recent progress in spin sem

Reorienting the magnetization of a nanostructure by injecting a spin-polarized current
is in the focus of ongoing research because of its relevance for future spintronic andmagnetic memory devices. Recent experiments using spin-polarized scanning tunnelingmicroscopy (SP-STM) demonstrated current-induced magnetization switching (CIMS)
across a vacuum barrier, driven by Joule heating, spin-transfer torque and Oersted field[1,2]. In our study, we specially utilize a superparamagnetic Fe/W(110) nanoisland
to explore CIMS with SPSTM. By simultaneously observing and manipulating its
switching behavior with a spin-polarized tunnel current, we separate and quantitatively
determine the individual contributions of Joule heating and spin-transfer torque, with
the nanoisland serving as a combined local thermometer and spin-transfer torqueanalyzer. Comparing our results to experiments performed on nanopillar MTJs reveals
a very high spin-transfer torque efficiency for SP-STM MTJs. Our studies allow for a
detailed investigation of Joule heat generation and spin-transfer torque switching on
the atomic scale, thereby providing new insight into the details of CIMS.

Spin-polarized scanning electron microscopy (spin SEM) is a magnetic domain
observation method. It has excellent capabilities, including high spatial resolution,high sensitivity to a thin or even a monolayer film, a large dynamic observation
range, and detection of magnetization direction. Since the initial development ofspin SEM by Koike et al. in 1984[1], its capabilities have been greatly improved.
The spatial resolution is now 3 nm[2], the sample can be cooled down to 10 K, andimages of three magnetization components and surface topography can be obtained
simultaneously[3]. Moreover, images of elements and crystallographic orientation
can be obtained for the same area as the magnetic domain image. Taking advantage ofthese capabilities, we have studied recorded bits of high density magnetic recording
media, magnetic coupling between a ferromagnetic Fe thin film and a single-crystal
NiO antiferromagnet[4], a patterned magnetic island array[5], and the temperaturedependent spin structure of a strongly correlated magnetic material: La2-2xSr1+2xMn2O7(x = 0.30, 0.32)[6][7]. In this talk, I will discuss the above topics in detail, anddemonstrate the applicability of spin SEM to various fields related to magnetism.

Estitxu Villamor1, Miren Isasa1, Luis E. Hueso2 and Felix Casanova2*
1
CIC nanoGUNE, Spain2
CIC nanoGUNE and IKERBASQUE, Basque Foundation for Science, Spain

Creation and transport of pure spin currents is a key ingredient in spintronics, which
can be achieved by electrical spin injection using lateral spin valves (LSV) [1].
We fabricated highly reproducible LSV devices by using a two-step electron-beamlithography process. In the first step, ferromagnetic (FM) electrodes (Co or Py) were
deposited and, in the second one, the non-magnetic (NM) metal (Cu, Au or Ag) was
put on top. In these devices, the spin signal was measured at different distances andtemperature (T), from which the spin polarization of the FM (α) and the spin diffusion
length of the NM (λ) are obtained as a function of T. Whereas λ(T) shows the role ofsurface spin-flip scattering [2] in the various NM, the results in α(T) for the various
FM metals help understanding the role of the FM/NM interface in the electrical spin
injection. Furthermore, due to the high reproducibility of our LSV devices, λ(T) for
Co can be independently obtained. The latter parameter has been controversial for its
anomalously large value [3]. These results are relevant to control the role of FM metals
in electrical spin injection and of NM metals in spin transport.
[1] F. J. Jedema, M. S. Nijboer, A. T. Filip, B. J. van Wees, Phys. Rev. B 67, 085319 (2003) [2] T.
Kimura, T. Sato, Y. Otani, Phys. Rev. Lett. 100, 066602 (2008) [3] J. Bass and W. P. Pratt, J. Phys.:
Conden. Matter 19, 183201 (2007)

86

Anika Schlenhoff*, Andreas Sonntag, Stefan Krause and Roland Wiesendanger
Institute of Applied Physics, University of Hamburg, Germany

The 19th International Conference on Magnetism

Hiroshi Idzuchi1*, Yasuhiro Fukuma2 and Yoshichika Otani3
1
ISSP, U Tokyo; ASI RIKEN, Japan
2
ASI RIKEN; Department of Computer Science and Electronics, Kyushu Institute ofTechnology, Japan
3
ISSP U Tokyo; ASI RIKEN, Japan
Pure spin current is a diffusive flow of spins with no charge flow, which has drawn
much attention worldwide due to spintronic application as well as fundamental
interests. Non-local spin injection in a lateral spin valve generates a pure spin current,of which polarization direction can be modulated via Larmor precession [1]. During the
diffusive transport between injector and detector, however, spins lose phase coherency
with frequent collisions, because these events lead to a broad distribution of dwell time.
Here we show that the lateral spin-valves with dual injector Permalloy/MgO/Ag enable
us to detect highly coherent spin precession over a distance of 10 μm with keeping spin
accumulation vector in plane against out of plane magnetization process, which resultsin genuine signal of the in-plane precession. We also experimentally found that thebetter the phase coherency becomes the longer the spins travel. This tendency appears
to fall on a material independent universal curve when the coherence is plotted against
the reduced parameter of the injector-detector distance over spin diffusion length. Thisis useful for the material design of spintronics devices based on pure spin current.
[1] Y. Fukuma, L. Wang, H. Idzuchi, S. Takahashi, S. Maekawa, and Y. Otani, Nature Materials, 10,527 (2011).

Stefan Krause*, Gabriela Herzog, Anika Schlenhoff, Andreas Sonntag and Roland
Wiesendanger
Institute of Applied Physics, University of Hamburg, Germany[1] S. Krause, L. Berbil-Bautista, G. Herzog, M. Bode, and R. Wiesendanger, Science 317, 1537
(2007). [2] G. Herzog, S. Krause, and R. Wiesendanger, Appl. Phys. Lett. 96, 102505 (2010).

Oral Thursday

Alexey P. Vinogradov1*, Denis G. Baranov1 and Alexander A. Lisyansky2
1
ITAE RAS, Russia
2
Department of Physics,, Queens College of the City University of New York, USA

Oral Thursday

oRAL PRSENTATION

Kazuyuki Koike
Division of Physics, Graduate School of Science, Hokkaido University, Japan[1] K. Koike et al. Jpn. J. Appl. Phys. 23 (1984) L187. [2] K. Koike et al. in preparation [3]T. Kohashi et al. Rev. Sci.
Instrum. 75 (2004) 2003. [4] H. Matsuyama et al. Phys. Rev. Lett. 85 (2000) 646. [5] N. Kida et al. Phys. Rev. Lett. 94 (2005)
077205. [6] M. Konoto et al. Phys. Rev. Lett. 93 (2004) 107201. [7] M. Konoto et al. Phys. Rev. B71 (2005) 184441.

July 8-13, 2012 Busan, Korea

87

ORAL PRESENTATION
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Asymmetries in the formation process of magnetic vortex states in apermalloy nanodisk

Recent developments in magnetic measurements: From technicalmethod to physical knowledge

Probing the exotic surface states in topological insulators andsuperconductors

Robustness of 1D topological superconductors with Majorana edge
states against lattice modulation

A topological state of matter is characterized by a nontrivial topological structure of
the quantum-mechanical wavefunctions in the Hilbert space. Due to the bulk-edgecorrespondence, a gapless surface state always accompanies a topologically nontrivial
bulk state. In topological insulators (TIs), a nontrivial Z2 topology of the bulk stateleads to the emergence of Dirac fermions on the surface. Similarly, topologicalsuperconductors (TSCs) are accompanied by surface Andreev bound states that
often consist of Majorana fermions. In this talk, I will present our experiments toaddress those exotic surface states. For TIs, we discovered that the chalcogen-ordered
tetradymite Bi2Te2Se presents a high bulk resistivity, allowing one to observe clear
surface quantum oscillations [1]; more recently, we demonstrated that in a related
solid-solution system Bi2-xSbxTe3-ySey, it is possible to achieve a surface-dominatedtransport even in a bulk crystal [2]. For TSCs, in a superconducting doped-TI material
CuxBi2Se3, we have succeeded in observing an unconventional surface Andreev boundstate, which gives evidence for a new type of topological superconductivity associatedwith helical Majorana fermions [3]. These works were done in collaboration with A. A.
Taskin, Z. Ren, S. Sasaki, and K. Segawa.

Recently there has been a substantial amount of effort to observe Majorana edge states at theedges or vortex cores of topological superconductors. The robustness of such states against
spatial inhomogeneity and electron correlation will be particularly important in observing andmanipulating them. We have studied a one-dimensional quantum wire to analyze the condition
for a topological phase with edge Majorana fermions to appear when an incommensurate(quasiperiodic) lattice modulation is applied. We have adopted the tight-binding model
Hamiltonian by Stoudenmire and coworkers [1], which incorporates the Zeeman effect, thespin-momentum coupling, the proximity effect induced by a bulk superconductor, and the onsite electron-electron interaction U, and analyzed its low-energy behavior when the lattice
modulation is applied by the density-matrix renormalization group method. For U=0 wehave found multiple reentrant transitions between topological phases with edge Majorana
fermions and non-topological phases [2]. The number of transitions increase as the modulation
becomes stronger. For U>0, as in the case without the lattice modulation [1], the region withMajorana fermions is broadened in the phase diagram [2]. The effects of other types of spatial
inhomogeneities, such as a harmonic trapping potential, will also be presented.

Magnetic vortices in nanopatterned elements are attracting increased interest because they offer
fascinating topological spin structures and great potential as novel concepts for data storage technologies[1]. A-priori, one would assume that a magnetic vortex is degenerate with four energetically equal groundstates and therefore the formation of a magnetic vortex state (VS) should exhibit perfect symmetry. In
our work, the formation process of VSs in Ni80Fe20 nanodisks has been investigated by direct imaging ofin-plane and out-of-plane magnetic components in vortex structures utilizing high resolution magnetictransmission soft X-ray microscopy (MTXM). We observe a symmetry breaking in the formation processof VS in individual nanodisks. Micromagnetic simulations confirm that the Dzyaloshinskii-Moriya
interaction on the full surface of nanodisks and surface-related inhomogeneities cause the observed
asymmetric phenomenon [2]. In addition, we have expanded the study of the formation process of VS to
include nanodots with asymmetric geometry. Based on our experimental observation, we will discuss thepossibility to control the generation process of VS by directed modifications of nanodot geometry.
[1] P. Fischer et al., Phys Rev B 83 212402 (2011). [2] M.-Y. Im et al., submitted to Nature Communications (2011).
This work was supported by the DOE, No. DE-AC02-05CH11231.

Vittorio Basso, Fausto Fiorillo*, Alessandro Magni, Cinzia Beatrice, Ambra Caprile,
Michaela Kuepferling and Carlo Paolo Sasso
Istituto Nazionale di Ricerca Metrologica, Italy

Novel magnetic materials and applications call for enhanced measurement methods, where
the goal of increased physical insight is pursued against the requirements of reproducibility
and traceability. We discuss a few examples of measuring techniques where advances havebeen recently achieved. We shall deal, in particular, with the following topics: 1) High-speed
magneto-optical microscopy, where nanosecond time-resolved Kerr microscopy reveals thehigh-frequency domain wall dynamics in a variety of samples: thin films, amorphous ribbons,patterned magnets. It concurrently allows for pulsed inductive magnetometric techniques, bywhich the spin precessional modes and their damping behavior can be observed. 2) Calorimetry
under magnetic field, a technique permitting one to to directly measure the entropy s(Ha,T)
as a function of temperature T and applied magnetic field Ha. It is especially attractive forthe characterization of magnetocaloric materials and the determination of first order phasetransitions with hysteresis. The discussion will focus on the magnetic field induced transitionin La-Fe-Co-Si alloys, Heusler alloys, and materials with spin reorientation transition, like
Er2Fe14B and W-type Co-Zn substituted Ba ferrites. 2) Pulsed field magnetometry in permanent
magnets, an industrially attractive method of characterization of extra-hard rare-earth basedmagnets, overcoming the intrinsic fieldstrength limitations of the standard electromagnet-based
characterization.

Yoichi Ando*
ISIR, Osaka University, Japan[1] Z. Ren et al., PRB 82, 241306(R) (2010). [2] A.A. Taskin et al., PRL 107, 016801 (2011). [3] S.
Sasaki et al., PRL 107, 217001 (2011).

[1] E. M. Stoudenmire, J. Alicea, O. A. Starykh, M. P. A. Fisher: Phys. Rev. B 84, 014503 (2011). [2] M.
Tezuka and N. Kawakami: Phys. Rev. B 85, 140508(R) (2012).
.

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Magnetization switching utilizing the magnetic exchange interaction

So, you need reliable magnetic measurements you can use withconfidence? How the magnetic measurement capabilities at NPL canhelpElectronic structure study of bulk HgTe via angle resolved
photoemission spectroscopy

Floquet theory of photo-induced topological phase transitions:Application to graphene

Rene Schmidt*, Alexander Schwarz and Roland Wiesendanger
Institute of Applied Physics, University of Hamburg, Germany

Magnetization reversal is usually induced by applying sufficiently large external
magnetic fields. More recently, spin transfer torque using a spin polarized current has
been successfully introduced as an alternative approach [1]. Here, we demonstrate thefeasibility to utilize the magnetic exchange interaction with a Magnetic Exchange ForceMicroscopy (MExFM) set-up to reverse the magnetization direction of a magnetic
specimen. MExFM opened up the possibility to map spin structures of insulating [2]as well as conducting surfaces [3] in real space. We use the distance dependence of themagnetic exchange interaction, measured with Magnetic Exchange Force Spectroscopy(MExFS) [4], to induce magnetization reversals. In our case the magnetic tip apex
switches its magnetization direction during scanning an antiferromagnetic surface withatomic resolution. The apex actually behaves like an independent superparamagnetic
cluster with uniaxial anisotropy [5]. We are able to study switching lifetimes, exchangeinteraction dependent energy barriers and the influence of magnetic fields. Our findings
suggest that the magnetic exchange interaction can be employed to monitor and control
magnetization reversal processes with atomic resolution on conducting as well as on
insulating surfaces.

Michael Hall
National Physical Laboratory, United Kingdom

Magnetic quantities have an impact on many aspects of our everyday life; in healthand safety, the magnetic field levels produced by the domestic appliances we use
so regularly is carefully monitored by the manufacturers to meet EMC regulations(we provide measurements that are compliant up to 120 kHz with EN 50366).
In the aerospace industry, soft magnetic materials are used in extreme conditions(temperatures up to 450 °C and stress levels up to 450 MPa) and the material can becharacterised at NPL using unique measurement techniques. In the car industry, thematerial properties of permanent magnets have become very important; some cars now
contain in excess of 70 magnets. The demand for traceable electrical and magnetic
measurements is broadening as new materials and techniques have brought the needfor these measurements to new areas of industry. In this talk the magnetic measurement
facilities, capabilities and field standards available at NPL will be presented. How
these are being developed to meet the demanding conditions of use of instruments andmaterials will be presented and illustrated with case studies.

Chang Liu1, Suyang Xu1, Madhab Neupane1, Helin Cao2, Ireneusz Miotkowski2, L. Andrew
Wray3, Hsin Lin4, R. S. Markiewicz4, A. Bansil4, Yong P. Chen2 and M. Zahid Hasan1
1Joseph Henry Laboratory and Department of Physics, Princeton University, USA
2
Department of Physics, Purdue University, USA
3
Advanced Light Source, Lawrence Berkeley National Laboratory, USA
4
Department of Physics, Northeastern University, USA

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Takashi Oka
The University of Tokyo, JapanThe effect of strong lasers on the topology of electron systems is becoming a hot topic[1-3]. Recently, a theoretical proposal was made in two dimensional Dirac systems
where an application of circularly polarized light was shown to turn the system into aquantum Hall state with a non-trivial photo-induced Chern number and an emergenceof photo-induced edge channels [1,2]. One can see this as a dynamical realization of the
Haldane model of a quantum Hall state without Landau levels [4], i.e., the circularly
polarized light plays the role of the local magnetic fields. This proposal applies to abroad class of multi-band systems including graphene, graphite and surface states of
topological insulators as well as cold atoms in optical lattices with synthetic gauge
fields. Theoretically, this prediction is based on the Floquet extension of linear response
theory and the TKNN formula[1] as well as the Landauer theory of transport[2]. We
also explain possible experimental setups to detect this state using transport, photoemission, and orbital Kerr effect. * This work was done in collaboration with H. Aoki, T.
Kitagawa, T. A. Brataas, L. Fu and E. Demler.
[1] T. Oka and H. Aoki: Phys. Rev. B 79, 081406 (2009). [2] T. Kitagawa, T. Oka, A. Brataas, L. Fu, E.
Demler: Phys. Rev. B 84, 235108 (2011). [3] N. H. Lindner, G. Refael, V. Galitski: Nat. Phys. 7 490(2011). [4] F. D. M. Haldane: Phys. Rev. Lett. 61 2015 (1988).

[1] S. Krause et al., Science 317, 1537 (2007). [2] U. Kaiser, A. Schwarz, and R. Wiesendanger,
Nature 446, 522 (2007). [3] R. Schmidt et al., Nano Lett. 9, 200 (2009). [4] R. Schmidt et al., Phys.
Rev. Lett. 106, 257202 (2011). [5] R. Schmidt, A. Schwarz, and R. Wiesendanger, submitted.

HG04

HH03

HI03

HJ01

X-ray spectroscopy in pulsed high magnetic fields

Application of pulsed eddy current technique to inspect the pipeline of
nuclear plants

Hidden topological order in URu2Si2

Strong coupling of spin, orbital and lattice degrees of freedom in Ru
oxidesCornelius Strohm1*, Olivier Mathon1, Marcin Sikora2, Peter J. E. M. Van Der Linden1, Thomas Roth1, Tom T.
A. Lummen3, Paul H. M. Van Loosdrecht4 and Rudolf Rueffer5
1
European Synchrotron Radiation Facility, 6 rue Jules Horowitz 38000 Grenoble, France
2
Department of Solid State Physics, Faculty of Physics and Applied Computer Science, AGH University of
Science and technology, Krakow, Poland
3
Department of Materials Science and Engineering, The Pennsylvania State University. 121 Steidle Building,
University Park, PA, USA
4
Zernike Institute for Advanced Materials, University of Groningen. Nijenborgh 4, 9747 AG Groningen,
Netherlands
5
European Synchrotron Radiation Facility, France

The combination of synchrotron x-ray spectroscopy and pulsed high magnetic fields provides new opportunities
for the study of magnetic materials. We have developed X-ray magnetic circular dichroism (XMCD) [1] forelement [2] and orbital [3] selective studies of magnetism, and Nuclear Forward Scattering (NFS) of synchrotron
radiation [4] to perform isotope selective hyperfine spectroscopy in high magnetic fields. A miniature coildeveloped by the ESRF Sample Environment Support Laboratory reaches fields of 30 T with a total duration of
1 ms at repetition rates of 5 pulses per minute, and the integrated sample cryostat provides optical access to thesample along the field direction and covers temperatures from 5 K to 250 K [5]. In this contribution we present thecoil [5] and detection schemes [1,2,4] along with application examples such as element selective magnetometryin Erbium Iron Garnet [2], the mapping of a magnetostructural phase transition in double Perovskites [3], the highfield magnetization of alpha iron [4] and a study of the spin structure in Copper Iron Oxide [6].
[1] O. Mathon et al. J. of Synchrotron Rad. 14, 409, (2007). [2] C. Strohm et al. J. of Synchrotron Rad. 18, 224, (2011).
[3] M. Sikora et al. Phys. Rev. B 79, 220402R (2009). [4] C. Strohm, P. van der Linden and R. Rueffer Phys. Rev Lett.
104, 087601 (2010). [5] P. J. E. M. van der Linden et al. Rev. Sci. Instrum. 79, 075104, (2008). [6] C. Strohm, T.T.A.
Lummen, P.H.M. van Loosdrecht et al. unpublished.

88

Masaki Tezuka* and Norio Kawakami
Department of Physics, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, JapanThe 19th International Conference on Magnetism

D. G Park
korea atomic energy research institute, Korea

The local wall thinning is a point of concern in almost all steel structures such as thepipe lines. The present research describes the application of Pulsed Eddy Current (PEC)
for wall thickness monitoring. We have built a PEC system which has the ability todetect the wall-thinning or corrosion, and sub-surface defects. In our PEC probe an
exciting coil in conjunction with a Hall-sensor has been used. The PEC response tovarying metal thickness was measured at various thicknesses of insulations on thetested sample. Excitation coil in the probe is driven by a rectangular current pulse; thetime domain features of the detected pulse, such as ‘peak value’ and ‘time to zero’ wereused to describe the wall thinning in the tested sample. A real time LabVIEW program
was developed for the data acquisition and scanning the probe on the insulated sample.
The scanning results were continuously displayed on the computer monitor. Signal
processing techniques such as energy and power spectrum density (PSD) were devised
to infer the PEC response signal. The results show that the proposed PEC differential
probes.

Oral Thursday

Mi-young Im1, Tomonori Sato2, Yoshinobu Nakatani2, Keisuke Yamada3, Teruo Ono3, Shinya Kasai4,
Andreas Vogel5, Guido Meier5 and Peter Fischer1
1
LBNL/CXRO, USA
2
University of Electro-Communications, Japan
3
Kyoto University, Japan
4
NIMS, Japan
5
Universitat Hamburg, Germany

Oral Thursday

oRAL PRSENTATION

Tanmoy Das
Theoretical Division, Los Alamos National Laboratory, USA
Recently breakthrough studies have discovered series of new state of matters, including
topological insulators, topological Mott insulators, topological Kondo insulators,
topological antiferromagnetic insulators and others. Here we present an analogous, yet
fundamentally novel topological order which arises due to spin-orbit coupling density
wave in the heavy-fermion material URu2Si2.[1] We show via ab-initio calculations
that an incommensurate Fermi surface ‘nesting’ in the partially-filled f-states causes a
staggered spin-orbit coupling in the hidden-order state. In this cause neither the spin(S) nor the orbital (L) alone causes ordered state, rather a modulated spin-momentum
locked density wave propagates along the unidirectional nesting direction with apolarized total angular momentum ?mJ = ±2, in excellent agreement with neutron
scatterings. This is a radically new order parameter and a novel phase of matter. It
breaks spontaneous rotational symmetry, but not the time-reversal symmetry and isthus immune to any time-reversal invariant perturbation such as pressure, whereas
magnetic field will destroy it. We compute the topological quantum number to showthat the hidden-order gap opening causes a trivial to non-trivial topological phasetransition, and hence defines a novel ‘topological quantum critical point’ as a functionof magnetic field.

Je Geun Park
Department of Physics & Astronomy, Seoul National University, Korea

Being a 4d transition element, Ru has more extended wavefunction compared to thoseof 3d transition metal elements, and so is likely to have relatively smaller correlation
effects. However, it turns out that this relatively broader wavefunction produces
strikingly different physical properties from those of 3d transition metal oxides. In thistalk, we will highlight the unique physical properties of two Ru oxides emphasizing its
difference from 3d transition metal oxides. First example is Tl2Ru2O7, which exhibits a
metal-insulator transition at 120 K. We will examine the nature of the metal-insulatortransition both experimentally and theoretically, and are going to discuss how a spindriven spontaneous orbital ordering produces the experimentally observed structuraltransition and leads to the metal-insulator transition at the exactly same temperature.
The second example is the ferromagnetic transition of SrRuO3 with Tc=165 K.
Although it has been known over a half century, the true nature of the ferromagnetictransition is poorly understood. Here combining both neutron diffraction and inelastic
neutron scattering we will show how the ferromagnetic ground state is intimately
coupled to the unusual volume anomaly, i.e. Invar behavior at an atomic scale.

July 8-13, 2012 Busan, Korea

89

ORAL PRESENTATION
HJ02

HJ05

IA03

IB01

Competing magnetic interactions in eta-carbide-type transition-metalcompounds: New class of itinerant-electron frustrated magnets

Unconventional thermal expansion of BaIrO 3 investigated bytemperature dependent x-ray and neutron diffractions

Coupled fermi-bose renormalization group flow for a two-flavor spinfermion model close to its antiferromagnetic quantum critical point

Field-annealed Fe-Ni-Nb-B amorphous and nanocrystalline alloys formagnetic sensor applications

Although a number of ternary transition metal compounds with the cubic eta-carbidetype structure, M3T3X and M6T6X with M = Mo, W, etc., T = Fe, Co, Ni, etc., and X =C or N have been known to exist, their magnetic properties have been less studied. The
T sublattice forms the 'stella quadrangula' lattice, which is a newly found geometricallyfrustrated corner-shared lattice of two nested regular tetrahedrons. Although thestella quadrangula lattice is one of pyrochlore-derived lattices, we anticipate theunique nature of the frustration due to the competition between first- and secondneighbor interactions, J1 and J2, possibly of direct exchange type. Because of thedelicate balance between J1 and J2, the eta-carbide-type compounds shows various
magnetic ground states such as nonmagnetic non-Fermi liquid, ferromagnetism,
antiferromagnetism, etc. [1]. In addition, various types of field-induced transitions areoften observed [2]. Here we summarized comprehensively the magnetism of the etacarbide-type transition metal carbides and nitrides together with resent experimental
data.

Jinwon Jeong1, Bin Chang1, Dahee Jung1, Han-jin Noh1* and Seongsu Lee2
1
Department of Physics, Chonnam National University, Korea
2
Korea Atomic Energy Research Institute, Korea

We have studied the temperature dependence of the unit cell volume of 9R-type BaIrO3
by X-ray and neutron diffractions. The volume and the unit cell parameters show astrong correlation with the weak ferromagnetic charge-density-wave phase of this 5dtransition metal compound. The volume vs. temperature curve is not well described bya Debye function, which indicates that the interplay between charge, spin, and lattice
plays an important role in the thermal expansion behavior. A possible scenario will bepresented in order to understand this unconventional behavior.

[1] T. Waki et al., J. Phys. Soc. Jpn. 79 (2010) 043701, EPL 94 (2011) 37004, J. Alloys Compd. 509(2011) 9451. [2] T. Waki et al., J. Phys. Soc. Jpn. 79 (2010) 093703, J. Phys.: Conf. Ser. 320 (2011)
012069.

Junhyun Lee, Philipp Strack and Subir Sachdev*
Department of Physics, Harvard University, USA

The strong correlations emerging in proximity of antiferromagnetic quantum criticalpoints (QCP) in low-dimensional electronic materials are believed to be one of themain causes for their striking non-Fermi liquid behavior. In this quantum-criticalregime, metallic electrons are strongly coupled to gapless, collective spin fluctuations
rendering theoretical approaches a challenging affair. In this talk, we will present
first results of a renormalization group (RG) analysis of a new, prototypical twoflavor spin-fermion model in the vicinity of its quantum critical point. This model isfree of the sign-problem and therefore ideally suited to compare results of analyticalmethods with quantum Monte Carlo simulations [1]. Our RG method is based on
an exact flow equation for the effective Fermi-Bose action. It allows us to treat theelectrons and spin fluctuations on equal footing, and to extract correlation functions
consistently ordered along a joint energy scale. Solving our flow equations, we present
results for renormalized observables such as the fermion self energy and the magnetic
susceptibility when approaching the QCP from the paramagnetic phase.
[1] arXiv.org:1206.0742

Marek Varga1, Jozef Marcin1, Marek Capik1, Jozef Kovac1, Peter Svec2 and Ivan
Skorvanek1*
1
Institute of Experimental Physics SAS, Kosice, Slovakia
2
Institute of Physics SAS, Bratislava, Slovakia

The amorphous and nanocrystalline alloys have attracted a great deal of technologicalinterest due to their applicability in various types of magnetic sensors. These alloys
often require specific annealing conditions to achieve the desired response to appliedmagnetic field. In this work, we report on the effects of both longitudinal and transverse
magnetic field applied during the heat treatment on the soft magnetic behaviour
and the giant magnetoimpedance (GMI) effect in the series of (Fe1-xNix)81Nb7B12(x=0.25, 0.33 and 0.5) amorphous and nanocrystalline alloys. The melt-spun ribbons
were isothermally annealed under high vacuum in the presence of transverse (TF)or longitudinal (LF) magnetic field with the magnitude up to 640 kA/m. The heat
treatment under LF-conditions results in an appreciable reduction of the coercivity.
Sheared loops with good field linearity were achieved after TF-annealing. The GMI
measurements were performed in dc magnetic field up to ± 9600 A/m over a frequency
range 0.1 - 10 MHz. The nanocrystalline samples show markedly larger values of GMI
ratio (ΔZ/Z) as compared to their amorphous counterparts. The field annealing resultsin the modified the GMI response of both amorphous and nanocrystalline ribbons,
which can be used for tuning their characteristics for magnetic sensor applications.

HJ03

IA01

IA04

IB02

Long-time variation of magnetic structure in (Ce-La)Ir3Si2 : Effect ofrandomness

A quantum phase transition hidden beneath the superconducting
dome of iron-pnictides

Magnetism and filling-controlled mott transition in strongly spin-orbitcoupled iridium oxide

Amorphous and nanocrystalline magnetic materials: Research andproduction in china

Kiyoichiro Motoya1*, Taketo Moyoshi1 and Masaaki Matsuda2
1
Department of Physics, Faculty of Science and Technology, Tokyo University of
Science, Japan
2
Quantum Condensed Matter Division, Oak Ridge National Laboratory, USA

Long-time variations of magnetic properties observed in spin-glasses have been regarded as due to themulti-valley structure of the free energy surface arising from random magnetic interactions. Therefore,
in a system without randomness or imperfections we have not expected to observe a time variation ofmagnetic property within an attainable time scale. Contrary to all expectations, we found a long-time
variation of magnetic structure in a non-diluted uniform magnet CeIr3Si2 by means of time-resolved
neutron scattering measurements.[1,2] We examined other materials and have found similar long-time
variations of magnetic structure in PrCo2Si2, TbNi2Si2, Ca3Co2O6 and some other compounds.[3,4]All these compounds exhibit successive magnetic transitions and multi-step metamagnetic transitions,which suggest that the frustrations coming from competing magnetic interactions causes the longtime variation of magnetic structure. In order to show that randomness caused by inevitable impurities
or imperfections is not the main cause of the long-time variation, we have made macroscopic andneutron scattering measurements of a random system (Ce-La) Ir3Si2. The time variation behavior ofthis random system is basically identical to that of CeIr3Si2. These results have shown that the longtime variation of magnetic structure in CeIr3Si2 does not originate in randomness.

Yuji Matsuda
Physics, Kyoto University, Japan

An enduring question in strongly correlated electron systems is whether high-Tc superconductivity isdriven by an underlying quantum critical point (QCP) separating different ground states. In particular,
whether a QCP lies beneath the superconducting dome or the criticality is avoided by the transition to
the superconducting state has been a central issue. Among iron-based superconductors, the isovalent
pnictogen substituted system BaFe2(As1-xPx)2 appears to be the most suitable system to discussmany physical properties, because BaFe2(As1-xPx)2 can be grown with very clean and homogeneous,as evidenced by the quantum oscillations observed over a wide doping range even in the
superconducting dome giving detailed knowledge on the electronic structure. We report a sharp peakin the x-dependence of zero-temperature London penetration depth L(0) in BaFe2(As1-xPx)2 at the
optimum composition x=0.30 (Tc=30 K). This peak structure most likely results from pronounced
quantum fluctuations associated with the QCP which separates two distinct superconducting phases,
giving the first convincing signature of a second-order quantum phase transition deep inside thesuperconducting dome. Moreover, the ratio of Tc to the superfluid density at x=0.30 is strikingly
enhanced and even approaches the superfluid-4He value, implying a possible crossover towards theBose-Einstein condensate limit driven by quantum criticality.

Kenya Ohgushi1*, Jun-ichi Yamaura1, Hiroyuki Ohsumi2, Soshi Takeshita2, Hidenori
Takagi3, Taka-hisa Arima3 and Yutaka Ueda1
1
Institute for Solid State Physics, University of Tokyo, Japan
2
RIKEN SPring-8 Center, Japan
3
University of Tokyo, JapanBy performing resonant x-ray diffraction experiments for the post-perovskite-type
compound CaIrO3, we revealed that the magnetic structure is a striped-typed order,
which is stabilized by the unique superexchange interaction across the edge-sharing
bonds in the strongly spin-orbit-coupled Jeff = 1/2 state. Moreover, by introducing holecarriers into CaIrO3 through the chemical substitution, we have successfully developed
a novel metallic state, where bandwidth, Coulomb repulsion, spin-orbit coupling, andHund coupling are competing.
[1] K. Ohgushi, et al., arXiv:1108.4523v1. [2] K. Ohgushi, et al., Phys. Rev. B 74, 241104(R) (2006).

Shaoxiong Zhou
China Central Iron and Steel Research Institute Group, Advanced Technology andMaterials Co., Ltd., China

The planar-flow casting (PFC) is a continuous casting method for the productionof a large quantity of rapidly solidified metallic ribbons. In particular, the PFC
attracted great interests in the production of amorphous and nanocrystalline thin
and wide ribbons because of the cost savings process in a single stage and the novel
properties arising from the microstructure of rapidly solidified ribbons. Amorphousand nanocrystalline ribbons are widely used in electrical and electronic system suchas distribution transformers and inductive devices because of low core loss. This
paper seeks to summarize the recent progress in synthesis methods, properties, andapplications in the field of amorphous and nanocrystalline soft magnetic materials informs of ribbon, the emphasis is focused on some key technologies for producing wide
amorphous ribbon and thin nanocrystalline ribbon. In the summary, the total market
demands of amorphous and nanocrystalline alloy ribbons in China are predicted.

1. K. Motoya et al. : J. Phys. Conference Series 200 (2010) 032048. 2. T. Moyoshi et al.: J. Phys. Soc. Jpn. 81 (2012) 014704. 3. K.
Motoya et al. : J. Phys. Conference Series 273 (2011) 012124. 4. T. Moyoshi and K. Motoya: J. Phys. Soc. Jpn. 80 (20112) 034701.

This work has been done in collaboration with T. Shibauchi, K. Hashimoto, S. Kasahara, Y.Mizukami,
T. Terashima, H. Ikeda (Kyoto), A. Carrington (Bristol), K. Cho, R. Prozorov, M. Tanatar (Ames), N.
Salovich, R.,W. Giannetta(Illinois at Urbana-Champaign), and H. Kitano (Aoyama Gakuin)

HJ04

IA02

IA05

IB03

Influence of symmetry on Sm magnetism studied in SmIr 2Si 2polymorphs

Re-entrant quantum criticality in pressurized Yb2Pd2Sn and
Yb2Pd2In1-xSnx

Magnetic field tuned QCP in YbPtBi

Recent status of soft magnetic material applications for renewableenergy and eco-friendly vehicle

Michal Valiska*, Jiri Pospisil, Martin Divis, Jan Prokleska and Vladimir Sechovsky
DCMP, Charles University, Ke Karlovu 5, 121 16, Prague, Czech Republic

SmIr2Si2 crystallizes in two structural polymorphs which make possible unique studyof influence of symmetry on Sm magnetism. One polymorph is the primitive tetragonal
structure of the CaBe2Ge2 structure type stable at high temperatures (high temperaturepolymorph-HTP) and the other is a body centered tetragonal structure of the ThCr2Si2
structure type stable at low temperatures (low temperature phase-LTP). The HTP exists
at room temperature as a metastable phase in the quenched samples while the LTP canbe obtained by proper annealing. We have found three magnetic phase transitions inboth structure polymorphs in specific heat data. The transitions at temperature 1.7, 6.2
and 18.8 K have been found for the HTP and the LTP exhibits transitions at 1.9, 6.1
and 38.9 K. Magnetic moment of 0.034 μB/f.u. has been found for both polymorphs(in the field of 7 T at 2 K). Magnetic features of both polymorphs are discussed on
the basis of the strong influence of the crystal field and the admixture of the low lying
excited multiplet J = 7/2 with the ground multiplet J = 5/2. All experimental results aresupported by first principles calculations.

Tahir Rao Khan1, Herwig Michor1, Ernst Bauer1*, Rustem Khasanov2, Alex Amato3, Veljko
Zlatic4, Ivica Aviani4, Mydeen Kamal5, Michael Nicklas5 and Mauro Giovannini6
1
Institute of Solid State Physics, Vienna University of Technology, Austria
2
Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institute, Switzerland
3
Laboratory for Muon-Spin Spectroscopy, PSI, Paul Scherrer Institute, Switzerland
4
Institute of Physics, Zagreb, Croatia
5
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
6
Dipartimento di Chimica e Chimica Industriale, University of Genova, Italy

Recently we reported on the discovery of two consecutive, pressure driven magnetic instabilities in Yb2Pd2Sn [1].
They emerge in a non-Fermi liquid environment at the initial and the final point of a dome-like, single magnetic
phase at pressures pc1 ~ 1 GPa and pc2 ~ 4 GPa. This unique behavior of Yb2Pd2Sn is supposed to result frommutually competing, pressure modified energy scales, which in case of Yb2Pd2Sn cause a sign change in thepressure dependence of the Kondo temperature TK and magnetic ordering temperature TN. An earlier study [2]demonstrated the occurrence of long range magnetic order in a dome-like phase space for a narrow concentration
range of Sn-rich samples in Yb2Pd2In1-xSnx. Ordered moments of the order of 1 μB are attained and the transition
temperature reveals values above 3 K, although both Yb2Pd2In and Yb2Pd2Sn exhibit paramagnetic ground states.
The aim of the present work is a detailed study of the pressure and field response of Yb2Pd2Sn and of alloys withconcentrations in the “magnetic dome” of Yb2Pd2In1-xSnx. We show how the transition temperatures and theground states modify when applying both pressure and magnetic fields.

E. D. Mun1, H. Kim1, M. A. Tanatar1, G. M. Schmiedeshoff2, J. H. Park3, T. Murphy3, N.
Dilley4, S. L. Bud'ko1*, R. Prozorov1 and P. C. Canfield1
1
Ames Laboratory/Iowa State University, Ames, IA, USA
2
Occidental College, Los Angeles, CA, USA
3
NHMFL, Tallahassee, FL, USA
4
Quantum Design Inc., San Diego, CA, USA
Magnetic field dependence of thermodynamic and transport properties of single
crystals of stoichiometric, heavy fermion (γ ~ 8 J/mol K2), antiferromagnetic (TN~ 0.4 K) compound YbPtBi was studied down to 20 mK. The magnetic order issuppressed on application of ~ 4 kOe magnetic field. The Fermi-liquid state appears to
be separated from the quantum critical point. The H* crossover line (“Hall line”) marks
the emergence of the Fermi-liquid state. The H-T phase diagram will be discussed incontext of results on other Yb-based heavy fermions.

Oral Thursday

Hiroyuki Nakamura*, Takeshi Waki and Yoshikazu Tabata
Department of Materials Science and Engineering, Kyoto University, Japan

Oral Thursday

oRAL PRSENTATION

In-bum Jeong
Changsung Corporation, Korea

Soft magnetic materials have been widely used in electrical and electronic devices
such as inductor, transformer, sensor, motor, EMI absorber and others. Ideal soft
magnetic material which is relevant to modern high power electronics should have thebest combination of high permeability under DC excitation, low loss, good thermal
stability, good frequency behavior, and reasonable cost. But, unfortunately, all thecommercialized soft magnetic materials such as ferrite, laminated silicon steel sheet,wound amorphous and nanocrystalline ribbon, and compressed metallic alloy powder
core do not meet all the requirements perfectly so far. In Renewable energy and electricvehicle applications, especially the soft magnetic materials are getting importantfor high efficiency and reliability. Therefore, there are strong market demands forstrengthening each material’s forte and overcoming each material’s limitations andshortcomings. This presentation is focused on Recent Status of Soft Magnetic Material
Applications for Renewable Energy and Eco-friendly Vehicle.

[1] T. Muramatsu et al., Phys. Rev. B 83, (2011) 180404(R). [2] E. Bauer et al., J. Phys.: Cond. Mat. 17 (2005) S999.

90

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

91

ORAL PRESENTATION
IC01

IC04

ID02

IE01

Random fields in molecular magnets

Review talk about spin superfluidity

Non linear spin transfer induced vortex dynamics

Spin-orbit coupling induced spin torques in diluted magnetic
semiconductors

Measurements of the magnetic susceptibility of single crystals of the usual form of
Mn12-acetate and of a new high-symmetry variant, Mn12ac-MeOH, indicate a transition
to dipolar ferromagnetism below ~ 0.9 K in both materials [1]. In the case of Mn12acMeOH, the suppression of ferromagnetism by a magnetic field applied transverseto the easy axis is consistent with mean-field theory for an ordered single crystal:
Mn12ac-MeOH is a realization of a “Transverse-Field Ising Ferromagnet” (TFIFM).
By contrast, the suppression of ferromagnetism by transverse field is considerably
more rapid in Mn12-acetate, resembling instead the behavior observed in randomly sitediluted LiHo1-xYxF4, the only heretofore known realization of a “Random-Field Ising
Ferromagnet” (RFIFM) [2]. The randomness in Mn12-acetate derives from the intrinsic
distribution of locally tilted magnetic easy axes known to exist in these crystals,
suggesting that this prototypical molecular magnet is a realization of the random field
Ising ferromagnet (RFIFM) in which the random field can be tuned by a field appliedtransverse to the easy axis.

Yury Bunkov
Institut NEEL, France

There is a complete analogy between the Bose-Einstein condensation of atomic gases
and the Bose-Einstein condensation of magnons in antiferromagnets. Five different
states of magnon condensation with Spin Supercurrent have been found in different
states of antiferromagnetic superfluid 3He [1]. All these cases are examples of the
Bose-Einstein condensation of magnons with the interaction potential provided by
specific spin-orbit coupling. The BEC phenomenon in the gas of magnons is readily
accessible owing to the possibility of modifying the spin-orbit coupling. In some cases
the BEC of magnons corresponds to almost 100% condensation. Recently the magnon
BEC state and Spin Supercurrent was found on a 55Mn nuclear in antiferromagnetic
monocristals CsMnF3 and MnCO3 [2].
[1] Yuriy M. Bunkov and Grigoriy Volovik, J. Phys.: Condens. Matter 22 164210 (2010) [2] Yuriy
M.Bunkov et all., Phys. Rev. Lett. 108, 177002 (2012).

* Supported by NSF-DMR-0451605; work done in collaboration with B. Wen, P. Subedi, A. D.
Kent, Y. Yeshurun, A. Millis, and G. Christou. [1] B. Wen, P. Subedi, L. Bo, Y. Yeshurun, M. P.
Sarachik, A. D. Kent, C. Lampropoulos, and G. Christou, Phys. Rev. B 82, 014406 (2010); P.
Subedi, A. D. Kent, B. Wen, M. P. Sarachik, Y. Yeshurun, A. J. Millis, S. Mukherjee, and G. Christou,arXiv:condmat/1202.4963 (2012).

A magnetic vortex can be excited into precessional motion around its equilibrium position throughspin transfer torque[1,2]. The associated microwave emission is weak but very coherent. Here we
present experimental evidences of high power, low linewidth spin-transfer induced vortex oscillationsin MgO based magnetic tunnel junctions with a large TMR ratio[3]. Indeed, a clear picture of how
the spin transfer torque influences the frequency and the amplitude of the gyrotropic vortex motion
in a nano-pillar is still lacking. Here we derive an analytical model that takes into account the nonlinearity of the vortex core confining force and the non-linearity of the effective damping that will becompared to experimental results and micromagnetic simulations. Therefore it allows us to determine
the evolution of the vortex core dynamics with perpendicular field and current. Finally, we show that avery efficient coupling[4] to an external microwave current can be obtained in such spin transfer vortex
oscillators (STVOs) and compare these results to theoretical locking range, taking into account all
possible components of spin transfer torques. Support from ANR through VOICE PNANO-09-P231-36
and EU MASTER No. NMP-FP7-212257 and Canon-Anelva for MTJ films is acknowledged. E. G.
acknowledges support from CNES and DGA.
[1] K. Yu Guslienko, Journal of Nanoscience and Nanotechnology, 8, 2745 (2008) [2] V. Pribiag et al., Nat. Phys. 3,498 (2007); Q. Mistral et al., Phys. Rev. Lett. 100, 257201 (2008) [3] A. Dussaux et al., Nat. Commun. 1, 8 (2010) [4] A.
Dussaux et al, App. Phys. Lett 98, 132506 (2011)

Hang Li, Fatih Dogan and Aurelien Manchon*King Abdullah University of Science and Technology, Saudi Arabia

It has been recently demonstrated that appropriately designed spin-orbit coupling (SOC) can be used to generate
spin torque (SOC-torque) in a single ferromagnet, without the need of an external polarizer [1,2]. This effect has
been observed experimentally in both metallic systems [2] and dilute ferromagnetic semiconductors (DMS)[3]. The case of DMSs is of particular interest due to their tunable bulk inversion asymmetry allowing for thegeneration of both cubic and linear Dresselhaus SOC [3,4]. A theoretical understanding of the microscopic natureof the SOC-torque in DMSs is still needed to accurately interpret the recently obtained experimental results[4]. The present study addresses the nature of SOC-torque in DMS in the framework of Luttinger Hamiltonian(GaMnAs, InMnAs etc…). Based on kinetic-exchange model, the non-equilibrium spin transport in DMS is
studied theoretically within the first-order Born approximation [4]. Both cubic and linear Dresselhaus SOC
are examined and the angular dependence and magnitude of the SOC-torque are studied for a wide range ofparameters. Interestingly, the cubic Dresseulhaus SOC does generate a spin torque as long as the Fermi surface
is not spherical. The role of the carrier concentration and shape of the Fermi surface are emphasized andexperimental implications are discussed.
[1] A. Manchon and S. Zhang, Phys. Rev. B 78, 212405 (2008); 79, 094422 (2009). [2] I. M. Miron et al., Nature
Mater. 9, 230 (2010) ; U. H. Pi, et al. Appl. Phys. Lett. 97, 162507 (2010); I. M. Miron, et al. Nature (London) 476, 189(2011). [3] A. Chernyshov, et al. Nature Phys. 5, 656 (2009); Fang et al. Nature Nanotechnology 6, 413 (2011). [4] T.
Jungwirth, M. Abolfath, J. Sinova, J. Kucera, A. H. MacDonald, Appl. Phys. Lett. 81 4029 (2002); A. W. Rushforth, K.
Vyborny, C. S. Kingn et. al., J. Magn. Magn. Mat. 321 1001 (2009).

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Stability of incommensurate field-induced magnetic order via site-disorder

The spin-1/2 Heisenberg antiferromagnetic chain experimental
confirmation of 2 and 4 spinon terms

Study of spin transfer induced coupled vortices dynamics in a single
spin-valve

Spin orbit torque assisted domain wall depinning in Pt/Co/Pt

Francesco Casola1*, Toni Shiroka1, Shuang Wang2, Christian Rüegg3, Henrik Moodysson Rønnow2, Michael Grbić4,
Mladen Horvatić4, Steffen Krämer4, Sutirtha Mukhopadhyay4, Claude Berthier4, Hans Rudolf Ott1 and Joël Mesot5
1
Laboratorium für Festkörperphysik, ETH Hönggerberg, CH-8093 Zürich, Switzerland
2
Laboratory for Quantum Magnetism, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
3
Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
4
Laboratoire National des Champs Magnétiques Intenses, LNCMI - CNRS (UPR3228), UJF, UPS and INSA, BP
166, 38042 Grenoble Cedex 9, France
5
Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland

Low-dimensional spin-gapped antiferromagnets (AF) can be driven out of their quantum-disordered(QD) regime not only through the application of pressure or magnetic fields, but also via the introductionof disorder. Despite previous observations of these phenomena in a variety of materials such as Haldane
chains, spin ladders or spin-Peierls systems, a limited number of studies has considered the impact ofdefects on the field-induced magnetic order. It was found that disorder can affect the quantum-criticalbehaviour of these materials, induce new phases dominated by triplet confinement or even destroy
completely any phase transition in case of incommensurate correlations in the QD regime. Extending
low-field 31P NMR experiments on the frustrated two-leg spin-1/2 ladder Bi(Cu1-xZnx)2PO6 [1] tomagnetic fields up to 31T we observed for x=0 the onset of incommensurate field-induced magnetic
order at Hc = 20.96 T. The critical exponent for the transition temperature Tc(H)∝(Hc(T)-Hc(0))ν is
ν= 0.42. Remarkably, the same critical behaviour is found for the compound with x=0.01, but with anenhanced Hc(0) of about 24 T. Site disorder introducing non magnetic Zn ions on regular Cu sites opens
the possibility to study finite-size effects in quasi-1D spin systems by directly tuning the chain length via
defect concentration.

Bella Lake1*, D. Alan Tennant1, Jean-sebastien Caux2 and Christopher D Frost3
1
2
3

Helmholtz Zentrum Berlin fur Materialien und Energie, Germany
Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Netherlands
ISIS Facility, Rutherford Appleton Laboratory, United Kingdom

The Spin-1/2 Heisenberg antiferromagnetic chain is the fundamental example of a correlated
quantum system and has been a long-standing problem in condensed matter physics. The problem
was first tackled by Hans Bethe in 1931 who found that the ground state is quantum disordereddown to lowest temperatures [1]. In 1981 Faddeev and Takhtajan realized that the basic excitations
are spinons [2] which have fractional spin quantum number (S=1/2) and are necessarily created inpairs. In neutron scattering experiments the excitations are observed as a multi-spinon continuum
consisting of 2,4,6,8,… spinon states. The dynamical structure factor which is measured by
the neutrons has however only recently been calculated [3,4,5]. Caux, Hagemans and Maillet
have determined it to high precision and were able to show that while the 2-spinon contribution
accounted for 73% of the spectral weight, the 4-spinon contribution was also substantial at 25%.
Here we use inelastic neutron scattering to obtain the dynamical structure factor of the spin-1/2
Heisenberg antiferromagnetic chain compound KCuF3 to high accuracy and in absolute units. The
data show much better agreement with this recent theoretical work than earlier theories (Muller
Ansatz and field theory) and is able to confirm the presence of the 4-spinon term.

Nicolas Locatelli1, Paolo Bortolotti1, Alexey Khvalkovskiy2, Grisha Avanesyan3, Vladimir V. Naletov4, Julie
Grollier1, Gregoire De Loubens4, Konstantin Zvezdin3, Olivier Klein4, Vincent Cros1* and Albert Fert1
1
Unite Mixte de Physique CNRS-Thales et Univ Paris-Sud, Palaiseau, France
2
Grandis Inc, Milpitas, CA, USA
3
A.M. Prokhorov General Physics Institute of RAS, Moscow, Russia
4Service de Physique de l’Etat Condense, CEA, Gif-sur-Yvette, France

In order to address the problem of low coherence of actual spin-transfer nano-oscillators, recent studies havefocused on phase locking phenomena, between an oscillator and an external source, or between assemblies of
two or more oscillators. In the latter case, new collective modes have to be differentiated from the modes ofisolated single oscillators. These appear to be tuned by the amplitude of the coupling, as well as the parameters of
the single oscillators, namely the chirality and polarity in case of a vortex[2,3]. In this work, we suggest to use two
vortices, nucleated in both layers of a Py(15nm)/Cu(10nm)/Py(4nm) spin-valve, as two interacting oscillators.
Fundamental interests of this system lie in the identification of the excited coupled modes and their selection rules.
Besides the observation of highly coherent vortex oscillations, we demonstrate that the dynamic behaviour ishighly dependent on the vortices parameters[3]. We will compare the experimental results to analytical predictions
and simulations, studying the importance of different sources of coupling between the vortices. A careful studyof spin-polarized transport also shows the strong influence of the fast magnetization gradients associated withvortices. This work will be extended further to conditions to synchronize arrays of interacting vortex oscillators.

Elena Mure*, Pascal P. Haazen, Jeroen H. Franken, Henk J. Swagten and Bert
Koopmans
Eindhoven University of Technology, Netherlands
It has been shown that, in perpendicular magnetic anisotropy (PMA) materials, theinjection of a current results in a torque on the magnetization (SO-torque). This
torque could participate to the current-induced (CI) domain wall (DW) motion,
which up to now has been described in terms of spin transfer torque (STT) effect.
This experiment aims at a comparison of SO-torque and STT in a Pt/Co/Pt stack.
Using a focused ion beam technique we create a soft magnetic domain in the centerof the stripe, and we study its evolution under the application of current and magnetic
field. The measurements are done using a pump-probe detection scheme, suitable forstroboscopic experiments with sub-1 ns time-resolution. Our results show that theeffect of the current is a broadening/narrowing of the magnetic domain, indicating that
the SO-torque is dominant over STT and Joule heating. Moreover, we observe somefeatures that are signature of SO-torque, notably the dependence of the CI-effect on
the sign of the in-plane magnetic field and on the relative thickness of the two Pt buffer
layers. Finally, we emphasize the potential of our set-up for time-resolved study of CI
magnetization dynamics, which could help in determining the origin of the SO-torque.

[1] - F. Casola, T. Shiroka, S. Wang, K. Conder, E. Pomjakushina, J. Mesot and H.-R. Ott, Phys. Rev. Lett. 105, 067203 (2010).

[1] H. Bethe, Zeit. fur Physik 71, 205 (1931). [2] L. D. Faddeev and L. A. Takhtajan, Phys. Lett. A 85, 375 (1981). [3]J.-S. Caux and R. Hagemans, J. Stat. Mech: Th. Exp. p. P12013 (2006). [4] J.-S. Caux and J. M. Maillet, Phys. Rev.
Lett. 95, 077201 (2005). [5] J.-S. Caux, R. Hagemans, and J. M. Maillet, J. Stat. Mech.: Th. Exp. 2005, P09003 (2005).

[1] O.V. Sukhostavets et al., App. Phys. Express 4, 065003 (2011), [2] А.V. Khvalkovskiy, N. Locatelli et al.,Appl. Phys. Lett., 96, 212507 (2010), [3] N. Locatelli et al., App. Phys. Lett., 98, 062501 (2011)

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Low-temperature heat transport and field-induced quantum phasetransitions of spin gapped quantum magnets

X-ray microscopy of nanoscale spin dynamics

Collective excitation of magnetostatically coupled two-adjacentmagnetic vortices and their relative phase difference

Piezo-electric control of the motion of a single domain wall

X. F. Sun1*, C. Fan1, L. M. Chen2, W. P. Ke Ke1, Z. Y. Zhao1 and X. M. Wang1
1
Hefei National Laboratory for Physical Sciences at the Microscale, University of
Science and Technology of China, China
2
Department of Physics, University of Science and Technology of China, China

Low-dimensional or frustrated quantum magnets were revealed to exhibit exotic
ground states, magnetic excitations, and quantum phase transitions (QPTs). In the spingapped antiferromagnets, the external magnetic field can close the gap in the spectrum,
which results in a QPT between a low-field disordered paramagnetic phase and a highfield long-range ordered one. An intriguing finding is that this ordered phase can beapproximately described as a Bose-Einstein condensation (BEC) of magnons. In thiswork, we study the low-temperature and high-field thermal conductivity (kappa) of
several spin gapped quantum magnets, including the quasi-one-dimensional S=1 chain
compound NiCl2-4SC(NH2)2 (DTN), the quasi-one-dimensional ladder compound(CH3)2CHNH3CuCl3(IPACuCl3), and the layered spin-dimer compound Ba3Mn2O8 [13]. It is found that the magnetic excitations can contribute to the heat transport rather
strongly in these materials, particularly at the field-induced QPTs, by either transporting
heat or scattering phonons.
[1] X. F. Sun, W. Tao, X. M. Wang, and C. Fan, Phys. Rev. Lett. 102, 167202 (2009). [2] W. P. Ke, X. M.
Wang, C. Fan, Z. Y. Zhao, X. G. Liu, L. M. Chen, Q. J. Li, X. Zhao, and X. F. Sun, Phys. Rev. B 84,
094440 (2011). [3] L. M. Chen, X. F. Sun et al., unpublished.

92

V. Cros1, A. Dussaux1, P. Bortolotti1, E. Grimaldi1, J. Grollier1, A.v. Khvalkovskiy2, K.a Zvezdin3, A.
Fukushima4, H. Kubota4, K. Yakushiji4, S. Yuasa4, K. Ando4 and A. Fert1
1
Unite Mixte de Physique CNRS/Thales, France
2
Unite Mixte de Physique CNRS/Thales and A.M. Prokhorov GPI, Moscow and Istituto P.M., Torino,, France
3
Istituto P.M., Torino, and A.M. Prokhorov GPI, Moscow, Russia, Italy
4
AIST, Tsukuba, JapanThe 19th International Conference on Magnetism

Peter Fischer
CXRO, LBNL, USA

One of the scientific and technological challenges in nanomagnetism research is
to image magnetism down to fundamental length and time scales with elemental
sensitivity in advanced multicomponent materials. Magnetic soft X-ray microscopy isa unique analytical technique combining X-ray magnetic circular dichroism (X-MCD)
as element specific magnetic contrast mechanism with high spatial resolution down toalmost 10nm and a temporal resolution below 100ps [1]. This allows to investigate indetail precessional and relaxation phenomena, which occur e.g. in domain wall motion[2-3] and vortex dynamics [4-8]. In this talk I will review the achievements and future
perspectives of using soft X-rays for magnetic imaging by selected examples fromcurrent research. The collaboration with many colleagues in particular M.-Y.Im, S.K. Kim, D.-H. Kim, G. Meier, S. Kasai, T. Ono, D. Allwood, K. Buchanan, B. Mesler
and S.-C. Shin is highly appreciated. This work is supported by the Director, Officeof Science, Office of Basic Energy Sciences, Materials Sciences and Engineering
Division, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
[1] P. Fischer, Materials Today 13(9) 14 (2010) [2] L. Bocklage, et al. Phys Rev B 81, 054404 (2010) [3] M.T. Bryan, etal. IEEE Trans Mag 46(4) 963 (2010) [4] P. Fischer et al, Phys Rev B Brief Report 83 212402 (2011) [5] S. Kasai, et al
Phys Rev Lett 101, 237203 (2008) [6] Y.-S. Yu, et al. Appl. Phys. Lett. 98, 052507 (2011) [6] H. Jung, et al. NPG - Scientific
Reports 1 59 (2011) [7] B. Mesler et al J.Appl. Phys. (2012) in print [8] J.-H. Shim, et al., J Appl Phys 107 09D302 (2010)

Hiroaki Fujimori1, Yasuhiro Niimi1, Satoshi Sugimoto1, Shinya Kasai2 and Yoshichika
Otani1*1
ISSP, University of Tokyo, Japan
2
National Institute for Material Science, Japan
A magnetic vortex exhibits a core gyration which produces dynamic dipolar interaction between
adjacent magnetic vortices. In our previous experiment, we detected the excitation spectra ofmagnetostatically coupled two gyrating vortices in a pair of magnetic disks by applying theradio frequency ac current only to one of the disks [1].The excitation mode observed in the
single disk splits into two eigenfrequencies. In disk pairs four modes appear depending on
the combination of polarities, which are characterized by rotational directions and the phasedifference in core gyration. We here investigate the effect of the phase difference in gyration on
the excitation of magnetostatically coupled vortices by varying the phase difference between
ac excitation currents separately applied to the both disks. Firstly the collective excitation is
induced by applying the ac current to one of the disks, and then the ac current with variable
phase is applied to another disk to detect its indirect excitation caused by dipolar interaction at
the specific phase difference. We found the indirect excitation signal at lower frequency clearlychanged with respect to that at higher frequency and also the signal changed depending on
chiralities.
[1] S. Sugimoto et al., Phys. Rev. Lett. 106 197203 (2011).

Oral Thursday

Myriam P. Sarachik*Physics Department, City College of New York-CUNY, New York, NY 10031, USA

Oral Thursday

oRAL PRSENTATION

Elisa De Ranieri1, Pierre Roy1, Dong Fang1, Erin Vehsthedt2, Andrew C. Irvine3, Dominik Heiss3, Richard Campion4,
Tomas Jungwirth5 and Joerg Wunderlich6*
1
Hitachi Cambridge Laboratory, JJ Thomson Avenue, Cambridge, CB3 0HE, UK, United Kingdom
2
Department of Physics, Texas A&M University, College Station, Texas 77843-4242, USA, USA
3
Microelectronics Group, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, United
Kingdom4
School of Physics and Astronomy, University of Nottingham, United Kingdom
5Institute of Physics ASCR, v.v.i., Cukrovarnicka ¥ 10, 162 53 Praha 6, Czech Republic
6(a) Hitachi Cambridge Lab, Cambridge, UK (b) Institute of Physics ASCR, Prague, Czech Republic, United Kingdom
We report piezo-electric control of a single domain wall (DW) driven by electrical current in a microbar
fabricated in a perpendicularly magnetized GaMnAsP epilayer and by a magnetic field in the unpatterned
film. By applying the piezo-voltage we tune in situ the magneto-crystalline anisotropy and thus modulating
the stability of the internal wall structure which determines the value of the Walker breakdown. The
low defect density in our high-quality GaMnAsP epilayer allows to study DW propagation in both theviscous and precessional regimes, before and after the Walker breakdown critical current, respectively.
This combined with the piezo-electric controlled DW stability allows us to experimentally identify the
adiabatic torque as the dominant spin-transfer mechanism and to vary the DW velocity by up to 500% at
a fixed driving current and by more than two orders of magnitude at a fixed applied magnetic field. Our
experimental conclusions are supported by a one-dimensional DW motion model and detailed micro
magnetic simulations taking into account the individually measured complex magnetic anisotropies ofthe specific microbars. We conclude that our results are generic and applicable to DW motion in magnetic
films with tunable magnetic anisotropy and Curie temperatures above room temperature.

July 8-13, 2012 Busan, Korea

93

ORAL PRESENTATION
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Domain wall manipulation by spin currents in magnetic tunnel junctions

Enhanced tunnel magnetoresistance in magnetic tunnel junctions with
an epitaxial Mg-Al-O barrier

Transport anomalies due to critical valence fluctuations

Metal-Insurator crossover accompanied by the dual nature of 5f
electrons with localized and itinerant character in US2

Oral Thursday

The spin transfer effect allows the manipulation of magnetic domain walls (DWs) in ferromagnetic wires byinjection of dc currents, which has led in recent years to the proposal of a number of potentially revolutionary
devices [1,2]. In most of these systems, the current is injected along the direction of DW propagation, and thecurrent density required to move the DW has generally remained prohibitively high for applications. Recently, it
was predicted [3] that higher efficiency could be obtained by using vertical current injection through multilayer
devices, specifically in magnetic tunnel junctions (MTJ). Our group has experimentally verified the higher
efficiency DW motion with perpendicularly injected dc currents in MTJs, which was attributed to the out-ofplane spin transfer torque and the Oersted field [4]. We now present time-resolved measurements of DW motion
under vertically injected pulsed currents, and demonstrate that DW speeds in excess of 500 m/s can be attainedusing current densities that are up to 2 orders of magnitude less than those required in devices that use lateralcurrent injection. As such, this work represents an important advance in the race towards energy-efficient, highspeed domain wall devices. We acknowledge the European Research Council (Stg 2010 No.259068).
[1] S.S.P. Parkin et al., “Magnetic domain wall racetrack memory”, Science, vol. 320 pp. 190-194, 2008. [2] X. Wang etal., “Spintronic memristor through spin-torque-induced magnetization motion”, IEEE Elec. Dev. Lett., vol. 30, pp. 294297, 2009. [3] A.V. Khvalkovskiy et al., “High domain wall velocities due to spin currents perpendicular to the plane”,
Phys. Rev. Lett., vol. 102, p.067206, 2009. [4] A. Chanthbouala et al., “Vertical-current-induced domain-wall motion in
MgO-based magnetic tunnel junctions with low current densities”, Nature Physics, vol. 7, pp. 626-630, 2011.

Hiroaki Sukegawa, Seiji Mitani, Tomohiko Niizeki, Tadakatsu Ohkubo, Koichiro
Inomata and Kazuhiro Hono
Magnetic Materials Unit, National Institute for Materials Science (NIMS), Japan

Achievement of defect-free heterostructure is essential to establishment of highperformance spintronics devices such as magnetic tunnel junctions (MTJs), spintransfer devices and spin-transistors. A spinel MgAl2O4 has a potential for a future
tunnel barrier because of the small in-plane lattice mismatch (< 1%) between MgAl2O4
and bcc ferromagnetic alloys such as CoFe alloys and Heusler alloys. In addition,
MgAl2O4 is a nondeliquescent material, which is favorable for practical applications.
Recently a large tunnel magnetoresistance (TMR) ratio of 117% was observed atroom temperature (RT) in a fully epitaxial Fe/MgAl2O4/Fe(001) MTJ, indicating theenhancement of TMR by an epitaxial MgAl2O4 barrier as well as an MgO barrier [1].
In this study we achieved a fully epitaxial CoFe/Mg-Al-O/CoFe(001) MTJ using a
sputter deposition and a plasma oxidation of Mg-Al alloy layers. We demonstrated
the very large TMR ratio of 308% at RT in the MTJ even though the barrier layer had
an off-stoichiometric MgAl2O4 composition (Mg40Al60-Ox). This result suggests that
Mg-Al-O is promising for a tunnel barrier of future spintronics devices using coherent
tunneling.
[1] H. Sukegawa et al., Appl. Phys. Lett. 96, 212505 (2010).

Kazumasa Miyake
Department of Materials Engineering Science, Osaka University, Japan
It has been gradually turned out in this decade that some Ce- and Yb-based heavy
fermion metals exhibit quantum critical phenomena associated with critical end pointof valence transition [1]. In particular, temperature dependences of the specific heat,
the uniform susceptibility, the longitudinal relaxation rates of NMR, and the resistivity
have critical exponents quite different from those of conventional magnetic criticalphenomena of a la Moriya-Hertz-Millis, giving possible explanations of behaviors
observed in beta-YbAlB4, YbAuCu4, YbRh2Si2, CeCu2(Si,Ge)2, CeRhIn5 and so on [2,3].
In this talk, we briefly summarize previous studies on the above aspects, and discusstransport anomalies due to the critical valence fluctuations (CVF). Namely, the effectof collective modes beyond the Boltzmann transport due to quasiparticles is analyzed
generalizing the case of superconducting fluctuations near the transition point [3]. It
is shown that the Hall coefficient, the Nernst coefficient, the Seebeck coefficient, andthe thermal conductivity are greatly affected by the CVF, explaining some anomaliesof the Hall coefficient, the Nernst coefficient, and the Seebeck coefficient observed in
CeCu2Si2 and CeRhIn5 under pressure. This talk is based on collaborations with Shinji
Watanabe and Osamu Narikiyo who are gratefully acknowledged.
[1} K. Miyake: J. Phys.: Condens. Matter 19, (2007) 125201. [2} S. Watanabe and K. Miyake: Phys. Rev. Lett.
105, 186403 (2010). [3] S. Watanabe and K. Miyake: J. Phys.: Condens. Matter 23, 094217 (2011).

Naoto Metoki1, Etsuji Yamamoto2, Hironori Sakai2, Yoshinori Haga2, Tatsuma D
Matsuda2 and Shugo Ikeda2
1
QBus, JAEA, Japan
2
ASRC, JAEA, Japan
Uranium dichalcogenide β-US2 is a low carrier system with metallic behavior at room
temperature, while insulating with opening a charge gap Eg~90K at low temperatureswith colossal magneto-resistance effect 108 for H~10 T. The magnetic properties can bewell described by a localized model. In fact clear CEF excitations have been observed
at ~7 meV, indicative of the localized character of 5f electrons at low temperatures.
With elevating temperature ( > 100 K) above the conduction and magnetic excitation
gap, however, we observed magnetic quasi-elastic response accompanied by the metalinsulator crossover with a large resistivity drop in the order of 106. This suggests a newmechanism of metal-insulator crossover as a consequence of the change in 5f character
between localized and itinerant. We succeeded to separate the magnetic susceptibility
into two parts, the contribution from the localized and itinerant part, by carrying out
Kramers-Kronig transformation of the imaginary part of the dynamical susceptibility
measured by magnetic excitation with neutron inelastic scattering. We revealed a dual
nature of 5f electron system, growing itinerant character with elevating temperature
beyond the charge gap.

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Large magnetoresistance in antiferromagnet tunnel junctions

The memristive magnetic tunnel junction as a nanoscopic synapseneuron system

Fluctuations and quantum criticality in Eu ternary pnictides

Valence transition induced by pressure and magnetic field in
antiferromagnet EuRh2Si2

Byong-guk Park1*, Joerg Wunderlich2, X. Marti3, J. Hayakawa4, H. Takahashi2 and T.
Jungwirth5
1
Material Science and Technology, KAIST, Korea
2
Hitachi Cambridge Laboratory, United Kingdom
3
Faculty of Mathematics and Physics, Charles University, Czech Republic
4
Hitachi Central Laboratory, Japan
5
Institute of Physics, ASCR, Czech Republic
Antiferromagnets (AFM’s) have been used in spintronics devices so far only to pin themagnetization direction of a ferromagnetic electrode through the exchange-bias effect.
Spintronics devices whose transport is governed by AFM’s have been theoretically proposed,
but remain a great challenge for experimental realization. Here, we demonstrate a large
magnetoresistance effect in a tunnel junction with an AFM electrode of IrMn and a nonmagnetic
counter electrode [1]. In the device, the tunneling resistance depends on the magnetization
direction of the IrMn electrode, so-called tunneling anisotropic magnetoresistance (TAMR)
effect, which is based on the spin-orbit coupling. This is quite different from the conventional
spin-valves where the resistance depends on the relative magnetization directions of two
ferromagnetic electrodes. The magnetization direction of the AFM IrMn layer was manipulatedwith a relatively small magnetic field of 50mT by the exchange spring effect of coupled soft
NiFe. In addition, the AFM TAMR provides a means to study the exchange-bias effect by anelectronic transport measurement [2].

Andy Thomas, Patryk Krzysteczko, Gunter Reiss, Jana Munchenberger and Markus
Schafers
Physics, Bielefeld University, Germany

Memristors cover a gap in the capabilities of basic electronic components byremembering the history of the applied electric potentials, and are considered to bringneuromorphic computers closer by imitating the performance of synapses. We usedmemristive magnetic tunnel junctions based on MgO to demonstrate that the synaptic
functionality is complemented by neuron-like behavior in these nanoscopic devices.
The synaptic functionality ordiginates in a resistance change caused by a voltagedriven oxygen vacancy motion within the MgO layer. The additional functionality
provided by magnetic electrodes enabled a current-driven resistance modulation due tospin-transfer torque. We report on memristive magnetic tunnel junctions characterized
by the simultaneous occurrence of resistive switching and tunnel magnetoresistance.
Since resistivity provides a natural measure of the synaptic strength, and because of thebipolar nature of the resistance change, long term potentiation and long term depression
were emulated. Furthermore, we show that the flux is a good variable for describing
voltage-induced resistance variation, which provides the scope for the emulation of
spike timing dependend plasticity as well.

Yuriy Vladimirovich Goryunov1* and Alexandr Nikolaevich Nateprov2
1
Russian Academy of Sciences, Kazan Physical-Technical Institute of the Russian
Academy of Sciences, Russia
2
Academy of Sciences of Moldova, Institute of Applied Physics, Moldova
We have studied the magnetic properties of the Zintl compounds EuZn2(P, As, Sb)2 by ESR. The
ESR was measured on frequency 9.3 GHz in TE102 rectangular cavity at 4.2 - 300 K. Above 150
K in all cases, we observed the symmetric resonance lines Eu2+ with ideal Lorentzian lineshape.
At the temperature decreasing well before the antiferromagnetic ordering temperature we haveobserved an increasing of lineswidth and a decreasing of the resonance fields, which in our casevery good descriebed by Landau’s theory of magnetic fluctuations. The fluctuational nature of such
behaviour is confirmed by changing the shape of the resonance line from Lorentzian to Gaussian.
The paramagnetic temperature θp, obtained from the temperature dependence of the ESR signal
intensity, has the positive sign. We belive such behaviour of θp is connected with the proximity toquantum critical point and with the relevant instability of magnetic and crystal structures (instability
B2X2-layers, competition nonmagnetic 4f6 and magnetic 4f7 states of Eu) The obtained ESR data areinterpreted in terms of Bloembergen-Rowland's indirect exchange interaction through the valence
electrons and the Falicov-Kimball-Kugel model the hybridization of localized electrons with itinerant
electrons. Work was supported by Grants of RFBR and RAS.

Akihiro Mitsuda*, Suguru Hamano and Hirofumi Wada
Department of Physics, Kyushu University, Japan

EuRh 2Si 2, which crystallizes in the tetragonal ThCr 2Si 2 type structure, is an
antiferromagnet with TN=23K and the Eu ion is in the divalent state (4f7, J=7/2).
Recently, we have found that the application of pressure of 1.0GPa collapses theantiferromagnetism and simultaneously induces a first-order valence transition at
Tv~30K [1]. Under higher pressure than 1.0GPa, the sample shows a temperatureindependent Pauli-paramagnetic behavior (a non-magnetic phase) below Tv while aCurie-Weiss paramagnetism corresponding to Eu2+ (a magnetic phase) above Tv. In
this study, we have measured M-B curves under pressure to examine influences ofmagnetic field on the non-magnetic phase. A metamagnetic transition accompanied
by a large hysteresis is observed at 20K under 1.0GPa. The magnetization jumps from
1.0μB/Eu at B=3.6 T to 1.6μB/Eu at B=5.0 T with increasing magnetic field. Thisphenomenon corresponds to a field-induced valence transition from the non-magnetic
phase to the magnetic divalent phase.
[1] A. Mitsuda et al. J. Phys. Soc. Jpn. 81 (2012) 023709[1] B. G. Park et al, Nature Materials 10, 347 (2011) [2] X. Marti, B. G. Park, et al, Phys. Rev. Lett 108, 017201 (2012)[1] Krzysteczko et al., The memristive magnetic tunnel junction as a nanoscopic synapse-neuronsystem, Adv. Materials, DOI: 10.1002/adma.201103723[1] Yu C, Zhu T J, Zhang S N, et al. J. Appl. Phys. 104 013705(2008) [2] C Zheng, R Hoffmann, J. of Solid State Chemistry
72 58 (1988) [3] N Bloembergen, T.J. Rowland, Phys. Rev. 97, 1679 (1955) [4] L M Falicov, J C Kimball, Phys.Rev.Lett. 22997 (1969) [5] K I Kugel, A L Rakhmanov, A O Sboychakov, Phys.Rev.Lett. 95, 267210 (2005)

IF02

IF05

IG03

IH01

A first-principles study on spin-dependent tunneling conductance inmagnetic tunnel junctions with spinel-type MgAl2O4 barrier

Tunnel magnetoresistance in perpendicularly magnetized Co2FeAl/
MgO/CoFeB magnetic tunnel junctions

Synchrotron x-ray spectroscopy study on the valence state in α- andβ-YbAlB4 at low temperatures and high magnetic fields

Orbital ordering and multiphase separation at manganite interfaces

Recently, a normal-spinel type MgAl2O4 was grown on and Co2FeAl0.5Si0.5 and bcc-Fe
electrodes to explore new materials as a barrier layer in magnetic tunnel junctions(MTJs)[1,2]. The MgAl2O4 showed a great advantage in the epitaxial growth compared to the
MgO because of a small lattice mismatch less than 1% with bcc-type ferromagnetic
metals at (001) face. In this study, we investigated the transport properties of Fe/
MgAl2O4/Fe(001) MTJs using the first-principles calculations. We found that Fe/
MgAl2O4/Fe(001) MTJ showed the coherent tunneling conductance through the delta 1
evanescent state as well as Fe/MgO/Fe(001) MTJs. However, the calculated tunnelingmagnetoresistance (TMR) ratio of Fe/MgAl2O4(1nm)/Fe(001) MTJ was about 160%,
which was much smaller than that of Fe/MgO(1nm)/Fe(001) MTJ (1600%). This canbe attributed to appearance of new conductive channels in the antiparallel magnetization
configuration by the band-folding in the two dimensional Brillouin zone of in-plane wave
vector of bcc-Fe, because the in-plane cell-size of MgAl2O4 is twice of that of bcc-Fe.
These results indicate that suppression of band-folding is essential to obtain a large TMR
ratio in Fe/MgAl2O4/Fe(001) MTJs. This work was partially supported by JSPS throughthe FIRST Program and by JST through ASPIMATT program.

Perpendicular magnetization of Co2FeAl (CFA) full-Heusler alloy thin film was achieved withthe high perpendicular magnetic anisotropy (PMA), Ku of 2 ~ 3×106 erg/cm3 in the structures of
CFA/MgO, which is comparable to that of the conventional PMA materials[1]. The CFA thickness
dependence of Ku was investigated at different annealing temperatures, which indicated that theKu of CFA is contributed by the interfacial anisotropy between CFA and MgO. Furthermore,
we successfully fabricated perpendicularly magnetized tunnel junctions (p-MTJs) using CFA
full-Heusler alloy. The out-of-plane tunneling magnetoresistance (TMR) ratio of 53% at room
temperature was observed in CFA/MgO/Co20Fe60B20 p-MTJs on Cr-buffered MgO(001) substrates.
By inserting 0.1 nm Fe (Co50Fe50) between MgO and Co20Fe60B20, TMR ratio was significantly
enhanced to 91% (82%) due to the improved interface. The annealing temperature dependence of
TMR ratio was also investigated. Comparison of the bias voltage dependence of the differential
conductance was carried out between MTJs with the core structures of CFA(1)/MgO(1.8)/
Co50Fe50(5) and CFA(30)/MgO(1.8)/Co50Fe50(5) (unit: nm), which suggested that the improvementsof B2 ordering of ultrathin CFA and interface structures are required for enhancing coherent
tunneling in order to achieve a higher TMR ratio. This work opens up a way for perpendicularly
magnetized MTJs using full-Heusler alloys.

[1] R. Shan, et al., Phys. Rev. Lett. 102, 246601 (2009). [2] H. Sukegawa, et al., Appl. Phys. Lett. 96, 212505 (2010).

[1] Zhenchao Wen, Hiroaki Sukegawa, Seiji Mitani, and Koichiro Inomata, Appl. Phys. Lett. 98, 242507 (2011).

Yoshio Miura1*, Shingo Muramoto2, Kazutaka Abe1 and Masafumi Shirai1
1
RIEC & CSIS, Tohoku University, Japan
2
RIEC, Tohoku University, JapanThe 19th International Conference on Magnetism

Zhenchao Wen*, Hiroaki Sukegawa, Shinya Kasai, Masamitsu Hayashi, Seiji Mitani
and Koichiro Inomata
National Institute for Materials Science (NIMS), Japan

Yasuhiro H. Matsuda1*, Toshiyuki Nakamura1, Kentaro Kuga1, Satoru Nakatsuji1,
Shinji Michimura2, Toshiya Inami2, Naomi Kawamura3 and Masaichiro Mizumaki3
1
Institute for Solid State Physics, University of Tokyo, Japan
2
Japan Atomic Energy Agency, Japan
3
SPring-8/JASRI, Japan
Valence fluctuation phenomena in β-YbAlB4 and its polymorph α-YbAlB4 haveattracted much attention. [1, 2] The possible quantum criticality due to the valencetransition is theoretically predicted. [3] In the present study, valence states of in α- andβ-YbAlB4 have been investigated by the x-ray absorption spectra (XAS) in SPring-8
at temperatures from 2 to 280 K. The partial fluorescence yield mode and directtransmission method were used. High magnetic field XAS measurement was doneon β-YbAlB4 at 40 K in pulsed magnetic fields. Observed Yb valence is 2.8 ± 0.05
in α- and β-YbAlB4 at 5 and 2 K, respectively. This value is slightly higher than thepreviously reported results 2.73± 0.02 for α-YbAlB4 and 2.75± 0.02 for β-YbAlB4.
[1] The valence is found to gradually increase with increasing temperature toward thetrivalent state; the valence increment from the low temperature to 200 K is about 0.02
in both materials. We also found a small increase of Yb valence by a magnetic field of
31 T.
[1] M. Okawa et al, PRL 104, 247201 (2010). [2] Y. Matsumoto et al., Science 331, 316 (2011). [3] S.
Watanabe et al., PRL 105, 186403 (2010).

Oral Thursday

Julie Grollier1, Peter Metaxas1, Joao Sampaio1, Rie Matsumoto1, Andre Chanthbouala1, Alexey
Khvalkovskiy1, Vincent Cros1, Abdelmadjid Anane1, Albert Fert1, Konstantin Zvezdin2, Akio
Fukushima3, Hitoshi Kubota3, Kay Yakushiji3 and Shinji Yuasa3
1
Unite Mixte de Physique CNRS/Thales, France
2
Istituto P.M. s.r.l., Italy
3
National Institute of Advanced Industrial Science and Technology, Japan

94

oRAL PRSENTATION

Sergio Valencia1, Defleft Schmitz1, Luis Pena2, Zorica Konstantinovic2, Lluis
Balcells2, Regina Galceran2, Felip Sandiumenge2, Marie-jose Casanove3 and BenjaminMartinez2*
1
Helmholtz-Zentrum-Berlin fur Materialien und Energie, BESSY, Germany
2Magnetic Materials and Functional Oxides, ICMAB - CSIC, Spain
3
Centre d´Elaboration de Materiaux et d´Etudes Structurales, CNRS - CEMES,FranceInterfacial effects between La2/3Sr1/3MnO3 (LSMO) thin films and different capping
layers are analyzed by using x-ray absorption techniques, x-ray diffraction andtransport measurements. We make use of x-ray linear dichroism (XLD) to show that,independently of the capping layer, LSMO films exhibit a preferential occupation of
Mn 3d 3z2-r2 eg orbitals at the interface. The strength of such an orbitally orderedphase does not depend on the capping layer material neither is related to the previously
observed degradation of the Mn oxidation state nor to the magnetic properties.
Moreover, its intensity is similar to that observed in uncapped films thus indicating its
origin lies on the symmetry breaking at the LSMO surface. Transport measurements
across LSMO/capping layer interfaces allow estimating the scale length of this effectshowing that the disruption of the double exchange ferromagnetic (DE-FM) phaseoccurs only by the interface, in fact around 2 to 4 unit cells.Thus, XAS local techniques
point to a complex scenario at the manganite’s interfaces in which orbital ordering andmultiphase segregation coexist.

July 8-13, 2012 Busan, Korea

95

ORAL PRESENTATION
IH02

IH05

II02

IJ01

Conical spin-spiral state in an ultra-thin film driven by higher-orderspin interactions

A study of antiferromagnetic/ferromagnetic systems using x-ray
magnetic dichroism

A rich rashba system created on the surface of a topological insulator

Magnetic structure of iron borate SmFe3(BO3)4 : A neutron diffraction
study

The magnetic properties of transition-metal nanostructures are commonly explained based on the interplay
of Heisenberg exchange, Dzyaloshinskii-Moriya (DM) interaction and magnetocrystalline anisotropy
while higher order terms such as the biquadratic exchange and the four-spin interaction are typicallyneglected due to their small strength. Here, we demonstrate that higher-order terms can play a crucial role
for the magnetic ground state and report as an example a transverse conical spin-spiral state in an ultra-thinfilm composed of two atomic layers of Mn on W(110) [1]. This spin structure is characterized by magnetic
moments rotating on a cone that is perpendicular to the [001] propagation direction of the spin-spiral with aperiodicity of 2.4 nm. The cones of nearest-neighbor Mn atoms point into opposite directions which resultsin nearly antiferromagnetic alignment. This intriguing spin structure has been resolved on the atomicscale using spin-polarized scanning tunneling microscopy and confirmed to be the ground state by firstprinciples calculations based on DFT. Our calculations also reveal that the canting of the spins is inducedby higher-order exchange interactions while the spiraling along the [001]-direction is due to frustrated
Heisenberg exchange and DM interaction.

Z. Q. Qiu1 and Chanyong Hwang2*
1
Dept. of Physics, University of California at Berkeley, Berkeley, CA 94720, USA
2
Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-340,
Korea
Epitaxial CoO/Fe/Ag(001) system was investigated using X-ray Magnetic Circular
Dichroism (XMCD) and X-ray Magnetic Linear Dichroism (XMLD). XMCD
measurement was used to measure the Fe hysteresis loops and to determine
the unidirectional (exchange bias), uniaxial, and the 4-fold anisotropy. XMLD
measurement was used to determine the response of the CoO spins. We find that the
CoO spins consist of rotatable and frozen spins with respect to the Fe spin rotation, andonly the Fe uniaxial magnetic anisotropy follows the CoO frozen spins. We find that
only uniaxial magnetic anisotropy is correlated to the frozen spins.

[1]Y.Yoshida et al., Phys. Rev. Lett. (in press)

Clemens Ritter1*, Anatolii Pankrats2, Irina Gudim2 and Alexander Vorotynov2
1
Institut Laue Langevin, Boite Postale 156, F-38042 Grenoble, France
2
Kirenskii Institute of Physics, Siberian Branch of RAS, Krasnoyarsk, 660036, Russia

Topological insulators are famed for their unconventional surface states which span from the bulk valence
to conduction bands [1]. Adsorbing n-type dopants at the surface of these compounds in ultra-highvacuum, analogous to the application of an external gate voltage in a device, we show that new electronic
states emerge that co-exist with the topological surface state [2,3]. A strong downward band bending causes
quantization of the bulk conduction band states into a two-dimensional electron gas (2DEG) [2], while thebulk valence band states also become quantized due to the narrow valence bandwidth at the zone centre.
This provides a novel opportunity to probe the interplay of dimensionality and topological order. Moreover,the 2DEG states can be driven to develop a large Rashba spin splitting [3]. The resulting multi-subband
2DEG provides a very rich Rashba system. The inner-most Fermi surface sheets display the chiral in-plane
spin texture characteristic of classic Rashba states such as the L-gap surface state on Au(111). However, theoutermost Fermi pockets display increasing degrees of hexagonal warping, resulting in an increasing outof-plane spin canting. We investigate this system by angle-resolved photoemission and model calculations.

Rare earth ferroborates RFe3(BO3)4 have recently attracted widespread interest due
to their interesting magnetic, magnetoelectric and multiferroic properties [1]. The
magnetic structure is determined by a low dimensional element in the crystallographic
structure which sees well separated chains of helicoidally arranged Fe atoms runningalong the crystallographic c-axis. No direct R-R or R-O-R interactions exist andthe development and arrangement of long range magnetism is determined by thestrongly polarizing Fe-sublattices and the competition between the iron and the rareearth anisotropies [2]. We determined the magnetic structure of SmFe3(BO3)4 by
neutron powder diffraction using a double wall container and diluting the sample
with Al-powder in order to reduce the strong natural neutron absorption of Sm. The
antiferromagnetic structure developed below TN=33K is of the easy plane typeas already found for the R=Er, Y and Ho (above 6K) compounds [3,4]. The fit of
the magnetic peaks was best using a magnetic formfactor for Sm3+ where C2=5.42
giving a total magnetic moment of μSm=0.24μB composed of an orbital moment of
μSmL=1.3μB and an spin moment of μSmS=-1.06μB.

[1] M.Z. Hasan & C.L. Kane, Rev. Mod. Phys. 82 (2010) 3045 [2] M. Bianchi, et al., Nature Commun. 1(2010) 128 [3] P.D.C. King et al., Phys. Rev. Lett. 107 (2011) 096802[1] e.g. : R.P. Chaudhury et al., PRB 81, 2010, 220402 [2] C. Ritter et al., J. Phys. : Condens. Matter 19, 2007, 196227 [3] C.
Ritter et al., J. Phys. : Condens. Matter 20, 2008, 365209 [4] C. Ritter et al., J. Phys. : Condens. Matter 22, 2010, 206002

IH03

IH06

II03

IJ02

Non-collinear magnetic ground state in finite metallic chains

Magnetic properties and microscopic structures of ultrathin Co/√3×√3R30°-Ag/Si(111) films

From topological semimetals towards insulators. First-principles study

Preparation and characterization of Sr3Fe2O7-x for different oxygen
contents

Matthias Menzel1*, Yuriy Mokrousov2, Robert Wieser1, Jessica E. Bickel1, Elena
Vedmedenko1, Stefan Blugel2, Stefan Heinze3, Kirsten Von Bergmann1, Andre
Kubetzka1 and Roland Wiesendanger1
1
Institute of Applied Physics, University of Hamburg, Germany
2
Forschungszentrum Julich, Germany
3Institute of Theoretical Physics and Astrophysics, University of Kiel, Germany

Jyh-shen Tsay1, Tsu-yi Fu1*, Chih-kuei Kao1, Xiao-lan Huang1, Jyh-ron Shue1, Weihsiang Chen1 and Yeong-der Yao2
1physics, National Taiwan Normal University, Taiwan
2physics, Academia Sinica, Taiwan

The investigation of one-dimensional magnetic structures on the atomic scale
is a quite challenging task, since they are very prone to thermal and quantum
fluctuations [1]. Here, we present spin-polarized scanning tunneling microscopy (SPSTM) measurements of bi-atomic Fe chains on (5×1)-Ir(001). The chains exhibit amodulation along the chain axis with a three atom periodicity in an external magnetic
field perpendicular to the surface which is not present without the magnetic field[2]. This is due to a spin spiral ground state, whose thermally induced magnetization
switching leads to a time-averaged SP-STM signal, with the external field preferring
one of the magnetization directions. However, due to the rigid coupling of the Featoms' magnetic moments along the chain axis, the spin spiral order is not affected bythermal fluctuations at the measurement temperature. Therefore, changes in the spin
direction of one chain end can be probed tens of nanometers away, suggesting a new
way of transmitting information about the state of magnetic objects on the nanoscale.

Combined scanning tunneling microscopy and surface magneto-optic Kerr effectstudies were employed to study the relation between magnetic properties andmicroscopic interfacial structures of ultrathin Co/√3×√3-R30° -Ag/Si(111) films.
On the top of √3×√3-R30° -Ag/Si(111), pure Co clusters form without disrupting
the √3×√3-R30° structure of the Ag buffer layer. The great strain due to the large
mismatch between Co and the substrate influences the nucleation of Co atoms toform large clusters. No magnetic hysteresis in the polar configuration was observed
for films thinner than 10 monolayers. The easy axis of magnetization is in the surface
plane. Capping √3×√3-R30° -Ag on the top of Si(111) surface before the depositionof Co overlayers can efficiently reduce the nonferromagnetic Co-Si compound tozero thickness. For Co coverage between 2.9 and 4.2 monolayers, the lowered Curie
temperature in ultrathin films is observed. Due to the existence of a smooth interface
between Co and the √3×√3-R30° -Ag buffer, the coercivity for Co/√3×√3-R30° -Ag/
Si(111) is smaller than that for Co/Si(111).

[1] N.D. Mermin and H. Wagner, Phys. Rev. Lett. 17, 1133 (1966). [2] M. Menzel et al., submitted.

Stanislav Chadov1*, Claudia Felser1, Kristina Chadova2, Diemo Kodderitzsch2 andHubert Ebert2
1
Dept. Inorganic Chemistry, Max-Planck-Institute for Chemical Physics of Solids,
Dresden, Germany
2
Dept. Chemistry and Biochemistry, Ludwig Maximilians University, Munich,Germany
The presence of disorder is often seen as a destructive mechanism which must be
reduced by any means. In present study we attempt to make it constructive using therobustness of the spin current in topologically non-trivial systems with respect to thetime-reversal symmetric perturbations. Based on the fully-relativistic first-principles
calculations involving the Coherent Potential Approximation (CPA) and KuboGreenwood formalism, we inspect the disorder-affected transport properties of random
alloys between topologically non-trivial and trivial materials. The subsequent analysis
encounters few interesting aspects. First, it straightforwardly leads to an alternative
scheme improving the spin-Hall transport in a large class of topological semimetals andindicates the possibility of the topological Anderson insulator state. Second, we obtain
the quantized measure of the spin-Hall conductivity in 3D without explicit calculationof the topological invariants. In addition, the CPA technique provides a very practical
recipe to validate the non-trivial topological state of the material based on a purely bulk
information.

IH04

II01

II04

Magnetism and the thermodynamics of Fe-Pt surface alloy formed at
Pt(110) surface

Giant anomalous Hall effect in magnetic topological insulator

Engineering and manipulating topological qubits in 1D quantum wires

Byong Sun Chun, Wondong Kim and Chanyong Hwang*
Korea Research Institute of Standards and Science, Korea

Surface alloy formation at noble metal surface shows very interesting phenomena.
If one of the constituent atoms is magnetic, then its magnetic behavior evolves
depending on the ratio of composition and the temperature. We will show atomistic
view of Fe-Pt surface alloy formation at Pt(110)-missing low surface using scanningtunneling microscopy. When the external Fe atoms are deposited on top of Pt(110)(2x1) surface, they are located at the missing row position. When the temperature
increases, they exchange the position with the Pt atoms nearby due to the increaseof the entropy term to minimize the free energy. Pt atoms located at the missing row
position is energetically unstable. The change of magnetic characteristics through thisorder-disorder phase transition has been probed with the surface magneto-optic Kerr
effect. With the aid of density functional theory, all the nanoscopic description of thismagnetic surface alloy formation will be discussed.

96

Phil King1*, A De La Torre1, Felix Baumberger1, M. Bianchi2, R. Hatch2, Philip Hofmann2, M.S.
Bahramy3, R. Arita3, N. Nagaosa3, J. I. Mi4, B. Iversen4 and G. Balakrishnan5
1School of Physics and Astronomy, University of St Andrews, United Kingdom
2
Department of Physics and Astronomy, Aarhus University, Denmark
3
Correlated Electron Research Group, RIKEN-ASI, Japan
4
Department of Chemistry, Aarhus University, Denmark
5
Department of Physics, University of Warwick, United Kingdom

The 19th International Conference on Magnetism

Qi-kun Xue
Tsinghua University, China

Topological insulator (TI) is a time-reversal-invariant and therefore magnetic field
free version of the quantum Hall system. Breaking the time-reversal symmetry byferromagnetic order in TIs can induce quantum Hall effect in the absence of external
magnetic field, known as quantized anomalous Hall (QAH) effect. Here we report
the realization of the carrier-independent ferromagnetism in thin films of Cr-doped TI(BixSb1-x)2Te3. Despite the opposite types of carriers and one order of magnitude change
in carrier density, robust ferromagnetism with nearly constant Curie temperature isobserved. Remarkably, anomalous Hall effect is significantly enhanced with decreasing
carrier density, with the anomalous Hall angle reaching an unusually large value of 0.2
and the zero field Hall resistance reaching one quarter of the quantum resistance (h/e2),
indicating the approaching QAH regime. The work paves the way to realize the QAH
effect.

Panagiotis Kotetes1, Alexander Shnirman2 and Gerd Schon1
1
Institut fur Theoretische Festkorperphysik, Karlsruhe Institute of Technology,
Germany2
Institut fur Theorie der Kondensierten Materie, Karlsruhe Institute of Technology,
Germany
Recently, the interest in topological quantum computing has grown due to theappearance of promising platforms for realizing the long sought Majorana boundstates. Among the proposals that seem suitable for engineering Majorana bound states,
the most prominent involves a 1D semiconducting quantum wire in proximity to abulk s-wave superconductor, where in addition a Zeeman field is applied. In this work
we explore novel routes for realizing topological qubits and we further investigate
alternative possibilities for performing qubit operations without for instance the use ofelectrostatic gates. Specifically we focus on the interplay of the phases of the magnetic
field and the superconducting order parameter, illuminating the significance of keeping
intact the spin degree of freedom for engineering and braiding the topological qubits.
Finally, by considering an appropriate junction setup, we demonstrate novel features in
the Josephson effect of these systems, such as the magnetic control of the supercurrent.

Oral Thursday

Yasuo Yoshida1*, Silke Schroeder2, Paolo Ferriani2, David Serrate3, Kirsten Von Bergmann4, Andre
Kubetzka4, Stefan Heinze2 and Roland Wiesendanger4
1
Institute for solid state physics, The University of Tokyo, Japan
2
Institute for Theoretical Physics and Astrophysics, Christian-Albrechts-Universitaet zu Kiel, Germany
3Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Spain
4
Institute of Applied Physics, University of Hamburg, Germany

Oral Thursday

oRAL PRSENTATION

Darren Peets1*, Junghwa Kim1, Andrey Maljuk2, Chengtian Lin1 and Bernhard
Keimer1
1
Max-Planck-Institut fur Festkorperforschung, Germany
2
IFW Dresden, Helmholtzstr. 20, D-01069 Dresden, Germany
Iron(IV)- and ruthenium(IV)-based perovskite phases have proven rich in novel
physics. The SrFeO3-y system exhibits a wide range of unusual magnetic phases, fromfive distinct forms of helical magnetism when fully oxygenated [1] to a phase withfrustrated, disordered Fe4+ moments for an oxygen content of 2¾ [2]. The Ru-based
intergrowth phase Sr3Ru2O7 exhibits metamagnetic quantum critical points in appliedfield [3]. However, the magnetic phase diagram of its Fe4+ analogue Sr3Fe2O7-x remains
largely unexplored. We describe single crystal growth by the floating zone technique,oxygen annealing, and transport and magnetic measurements of large Sr3Fe2O7-x
crystals suitable for neutron diffraction experiments. This work lays the foundation forcomprehensive doping-dependent studies of Sr3Fe2O7-x's magnetic phase diagram andmagnetic excitations.
[1] S. Ishiwata et al., Phys. Rev. B 84, 054427 (2011) [2] M. Schmidt et al., J. Phys.: Condens.
Matter 15, 8691 (2003) [3] R.A. Borzi et al., Science 315, 214 (2007)

IJ03
The magnetic structures of CoPS3 and NiPS3

Andrew Wildes1*, Virginie Simonet2, Garry Mcintyre3, Eric Ressouche4, Emmanuelle Suard1, Giulio
Pepe5, Maxim Avdeev3 and Trevor Hicks6
1
Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble, France
2
Institut Neel, 25 avenue des Martyrs, BP 166, 38042 Grenoble cedex 9, France
3
Bragg Institute, ANSTO, Locked Bag 2001, Kirrawee DC NSW 2232, Australia
4
INAC/SPSMS-MDN, CEA/Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
5
Department of Physics & Astronomy, University College London, Gower Street, London, WC1E
6BT, United Kingdom
6
School of Physics, Monash University, PO Box 27, Vic 3800, Australia
The compounds CoPS3 and NiPS3 are candidates for two dimensional (2D) antiferromagnets, withthe transition metal atoms lying on a honeycomb lattice. Magnetic structures for them were publishedin the 1980s, based on neutron powder diffraction data. Both materials were believed to be collinear
antiferromagnets, although the antiferromagnetic axis differed between the compounds, with a magnetic
propagation vector of [0 1 0]. We have made a careful study of the magnetization and neutron diffraction
from single crystals, taking advantage of recent developments in instrumentation for neutron Lauediffraction, and have also measured neutron powder diffraction for comparison. Our data show that thepowder diffraction has very few observable peaks and can, indeed, be fitted with the quoted magnetic
structure. However, our single crystal data prove that the reported magnetic structures are erroneous, withthe observation of many new Bragg peaks that could be indexed with [1/2 1/2 1/6]. Our experiments havean impact on the interpretations of the magnetic Hamiltonians, and we will contrast our findings with twoother members of the family: MnPS3, which is a good example of a 2D Heisenberg antiferromagnet; andFePS3, which is a good example of a 2D Ising antiferomagnet.

July 8-13, 2012 Busan, Korea

97

ORAL PRESENTATION
IJ04

JA01

JA04

JB02

Magnetic properties in Fe-doped LnCo1-xFexAsO (Ln=La, Sm) systems

Close relationship between superconductivity and the bosonic mode in
Ba0.6K0.4Fe2As2: A pairing glue for superconductivity

Superconductivity in an Einstein solid: AxV2Al20 (A = Ga, Al)Electric field control of nonvolatile four-state magnetization at room
temperature

Hai-hu Wen*
Nanjing University, China

Atsuhi Onosaka, Junichi Yamaura, Yoshihiko Okamoto and Zenji Hiroi*
ISSP, University of Tokyo, Japan

We study a series of intermetallic compounds AxV2Al20 with A = Ga, Al, Sc, Y, La,
and Lu. They crystallize in the CeCr2Al20 structure which contains a large atomic cage
partially occupied by Ga/Al/Sc atoms and completely occupied by Y/La/Lu atoms.
Low-energy local modes, which may be similar with what is now called rattling, havebeen observed for A = Ga and Al. Superconductivity was also reported at 1.6 K for A =Al and Ga, though experimental data was not given. In order to investigate the rattlingand its effect on the superconductivity, we synthesized a series of polycrystalline
samples and measured heat capacity, resistivity and magnetic susceptibility.
Superconductivity is observed at Tc = 1.66, 1.50, 1.84, and 0.69 K for A = Ga0.2, Al0.3,
Sc0.2, and Y, respectively, and not above 0.5 K for A = La and Lu. It is suggested thatthe enhancement in Tc for the Ga, Al and Sc compounds is due to the rattling. In
addition, we found a markedly large diamagnetism for A = Y and La, but not for A =Ga, Al, Sc, and Lu, despite the apparent similarity of the electronic structures among
these compounds.

Sae Hwan Chun1, Yisheng Chai1, Byung-gu Jeon1, Hyung Joon Kim1, Yoon Seok Oh1,
Ingyu Kim1, Hanbit Kim1, Byeong Jo Jeon1, So Young Haam1, Ju-young Park1, Suk
Ho Lee1, Jae-ho Chung2, Jae-hoon Park3 and Kee Hoon Kim1*
1
Department of Physics and Astronomy, Seoul National University, Korea
2
Department of Physics, Korea University, Korea
3
Department of Physics and Division of Advanced Materials Science, POSTECH,
Korea

We study the effect of Fe doping in Co-rich side of LnCo1-xFexAsO (Ln=La,Sm)
systems. As Co is replaced partially by Fe ions, the FM transition temperature Tc wasseriously suppressed to lower temperatures and it disappears around x = 0.3. In the
SmCo1-xFexAsO system, the undoped SmCoAsO undergoes three magnetic phasetransitions with decreasing temperatures, a FM transition around Tc of 80 K, and a FM
to AFM transition below TN1 of about 45 K, and finally an AFM order of Sm3+ ion
at TN2 of 5.6 K. With increasing Fe content, both Tc and TN1 gradually decreases.
Around x = 0.3, the FM order fof Co ions disappears above 2 K, and meanwhile,
the FM-to-AFM transition cannot be observed either. However, the AFM order of
Sm3+ ion is robust, and TN2 slightly decreases in for x =0.3. We concluded that in
the 1111 type Co-based LnCo1-xFexAsO systems, 4f electrons of rare earth elements
have an important effect on the magnetic behaviors of 3d electrons. On the contrast,
the magnetism of rare earth elements is robust to the variations of 3d electrons. A richmagnetic phase diagram of the LnCo1-xFexAsO systems is established.

Center for Superconducting Physics and Materials, National Laboratory of Solid State
Microstructures and Department of Physics, Nanjing University, Nanjing 210093,
China Since the discovery of high temperature superconductivity in the iron pnictides
and chalcogenides in early 2008, it remains unclear whether there is a glue for thepairing and what it is. There is a debate at this moment about whether the pairing isdue to a retarded electron-boson interaction, as in the conventional phonon-mediatedsuperconductors, although here the bosonic excitations may be the antiferromagnetic
spin fluctuations. In this paper, we show the clear evidence of the bosonic mode withthe energy identical to that of the neutron resonance, and its close relationship withsuperconductivity in a strongly coupled superconductor Ba0.6K0.4Fe2As2 based on themeasurements of scanning tunneling microscopy. Our data also indicate an interesting
asymmetric feature of the tunneling spectrum, i.e., both the superconducting coherence
peak and the peak related to the bosonic mode are always stronger on the positive-bias
side, and vanish simultaneously within the vortex cores. Collaborated with Zhenyu
Wang, Huan Yang, Delong Fang, Bing Shen

IJ05

JA02

JA05

JB03

Symmetry argument of cyano-bridged copper-molybdenum complexes

Broken time-reversal symmetry superconducting state in LiFeAs

Non-unitary triplet pairing in the centrosymmetric superconductor
LaNiGa2

Low magnetic field reversal of electric polarization in Y-type
hexaferrites

Jun Ohara* and Shoji Yamamoto
Department of Physics, Hokkaido University, Japan

Photoreactive magnets of general formula Cu2[Mo(CN)8]∙nH2O [1] are composedof ocatacyanomolybdate ions of square antiprism configuration assembled withina tetragonal lattice. CuII2[MoIV(CN)8]∙nH2O irradiated with blue light turns into
CuICuII[MoV(CN)8]∙nH2O exhibiting a spontaneous magnetization. The induced
magnetization is stable for long time below 100 K and is photoreversible. We
group-theoretically study competing magnetic phases in this intriguing material.
While individual octacyanomolybdate ions of square antiprism configuration
are D4d-invariant, the point symmetry of their assembly reads C4h. A single
octacyanomolybdenum complex is invariant to polyaxial rotations but has no
inversion symmetry. The assembly is merely invariant to uniaxial rotations but
is further symmetric with respect to inversion. Besides the paramagnetism (PM)and ferromagnetism (FM), which correspond to the major states before and after
photoirradiation, respectively, we find three antiferromagnetic (AFM) states as well as
nonmagnetic charge-density-wave and bond-order-wave states of no major interest.
The AFM states consist of a spin density wave within the molybdenum sublattice, thatwithin the copper sublattice, and that spreading out in both sublattices, respectively, thelatter two of which closely compete with both PM and FM states and therefore possibly
have significant effects on the photoreactive magnetization mechanism.
[1] S. Ohkoshi et al., JACS 128, 270 (2005).

Gang Li1, Ricardo R. Urbano1, C. Tarantini2, Bin Lv3, Phil Kuhns1, Arneil P. Reyes1,
David Larbalestier2, Alexander Gurevich4, Ching-wu Chu3 and Luis Balicas1*1
Condensed Matter Sciences, NHMFL, USA
2
Center for Applied Superconductivity, NHMFL, USA
3
Texas Center for Superconductivity, University of Houston Houston, Texas, USA
4
Physics Dept., Old Dominion University, USA
Here, and despite the current experimental support for s-wave superconductivity, we show
clear evidence for broken time reversal symmetry within the superconducting state of LiFeAs
through magnetic torque and magnetization measurements at high fields and in high quality
single crystals close to optimal doping. Both the torque and the magnetization reveal a change
in the sign of the magnetic irreversibility/hysteresis as one approaches the upper critical Hc2,
from a clear diamagnetic like response dominated by the pinning of vortices according to
the Bean model, to a state with a 1000 times smaller paramagnetic like irreversibility which
disappears at Hc2. If diamagnetism results from screening super-currents, the paramagnetic like
response results from currents circulating in the opposite sense mimicking a field-dependent
magnetic moment below Hc2. The quality of our samples is indicated by the observation of thede Haas van Alphen effect and the 75As NMR spectrum which reveals a single Lorentzian line,
indicating the absence of magnetism or inhomogeneities. We conclude that the superconducting
state in LiFeAs must undergo a field-induced phase-transition towards a chiral superconducting
state as the smaller superconducting gap(s) is suppressed by the field. Small anomalies in thereversible component of the magnetization supports this scenario

Adrian Hillier1*, Jorge Quintanilla2, Bayan Mazidian3, James Annett4 and Robert Cywinski5
1
ISIS facility, STFC, Oxfordshire,, United Kingdom
2
SEPnet and Hubbard Theory Consortium, School of Physical Sciences,, University of Kent, Canterbury CT2 7NH,,
United Kingdom
3
H. H. Wills Physics Laboratory,, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom
4
H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom
5
School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom

Symmetry breaking is a central concept of physics for which superconductivity provides a paradigm. In a conventional
superconductor gauge symmetry is broken, while unconventional superfluids and superconductors break othersymmetries as well. Recently, we showed experimentally time-reversal symmetry (TRS) breaking in the noncentrosymmetric superconductor LaNiC2 [1]. Using group theory analysis we concluded that LaNiC2 has only four
possible symmetry states consistent with this observation, all of which are non-unitary [2]. This hinges on the low
symmetry, C2v, of this material in which all of the irreducible representations are one dimensional. Here, we report theresults from muon spin relaxation/rotation experiments on the intermetallic superconductor LaNiGa2 (Tc~2K) which,although centrosymmetric, has a similarly low-symmetry structure D2h. We find again that the onset of superconductivity
coincides with the appearance of spontaneous magnetic fields, implying that in the superconducting state TRS is broken.
Group-theoretic analysis of the possible pairing symmetries again suggests only four triplet states compatible with thisobservation, all of which are also non-unitary [3]. A comparison will be made between LaNiGa2 and LaNiC2 and we willpropose that these superconductors represent a new family of paramagnetic non-unitary triplet superconductors.

The control of magnetization by an electric field at room temperature remains as
one of the great challenges in materials science. We demonstrate the realization ofthis long-sought capability in a multiferroic hexaferrite Ba0.52Sr2.48Co2Fe24O41 single
crystal. The electric polarization in this crystal rapidly increases in low magnetic
fields (~5 millitesla), and its magnetoelectric susceptibility reaches the highest value(3200 picosecond per meter) among single-phase materials. The magnetization isthen modulated up to 0.62 μB per formula unit in an electric field of 1.14 MV/m.
Furthermore, this compound allows nonvolatile, magnetoelectric read-and-write
operations entirely at room temperature. Four different magnetic/electric field writing
conditions generate repeatable, distinct magnetization versus electric field curves
without dissipation, offering an unprecedented opportunity for multi-bit memory- or
spintronic device-applications.

Fen Wang, Tao Zou, Li-qin Yan, Yi Liu and Young Sun*
Institute of Physics, Chinese Academy of Sciences, China

Hexaferrites with spiral magnetic structures provide great opportunities forsearching for new multiferroic materials with a high operating temperature and great
magnetoelectric sensitivity. Here we report on the magnetically tunable ferroelectricity
and the giant magnetoelectric sensitivity up to 250 K in a series of Y-type hexaferrite
with the formula of BaSrZnCoFe12-xAlxO22. Not only the magnitude but also the signof electric polarization can be effectively controlled by applying low magnetic fields(a few hundreds of Oe) that modifies the spiral magnetic structures. The magneticallyinduced ferroelectricity is stabilized even in zero magnetic field. Decayless
reproducible flipping of electric polarization by oscillating low magnetic fields isshown. The maximum magnetoelectric coefficient reaches a high value of ~ 3.0×103
ps/m at 200 K.

[1] A. D. Hillier et al Phys. Rev. Lett. 102 117007 (2009) [2] J. Quintanilla et al Phys. Rev. B 82 174511(2010) [3] A. D. Hillier et al submitted to Phys. Rev Lett.

IJ06

JA03

JB01

JB04

Phase diagram of the dzyaloshinskii-moriya helimagnet Ba2CuGe2O7
in canted magnetic fields

Observation of anomalous magneto-resistance behavior near the inplane upper critical field in Sr(Fe,Ni)2As2 single crystals

Magnetoelectric effects and related phenomena in non-collinear spiralspin systems

Nearest - next-nearest neighbor exchange frustrated quantum chain
antiferromagnets: Recent results

Among various multiferroics, extensive studies of ferroelectrics originating frommagnetic orders, i.e., magnetically-induced ferroelectrics in which the inversion
simmetry breaking and resultant ferroelectricity are induced by complex magnetic
orders (e.g., noncollinear spiral order), have been triggered almost a decade ago by thediscovery of multiferroic nature in a perovskite-type rare-earh manganites TbMnO3.
Because the complex magnetic orders often arise from the competition between
nearest-neighbor and further-neighbor magnetic interactions, systems containing
competing magnetic interactions are promising candidates for magnetoelectric
multiferroics [1]. Thus, it is no longer so difficult to find new magnetoelectric
multiferroics. Indeed, on the basis of this strategy several new magnetoelectric
multiferroics related to noncollinear spiral-spin orders have been discovered in the past
few years. In this presentation, I show recent progress on our studies of magnetoelectriceffects and related phenomena in noncollinear spin-spiral systems [2].

Lately, one-dimensional quantum chain antiferromagnets which feature magnetic
frustration due to the presence of nearest and next-nearest-neighbor superexchange
and super-superexchange interaction have attracted considerable attention. Suchsystems can e.g. be realized in compounds which contain MX2 ribbon chains where themagnetic species M are located in a square planar anion environment (X = an oxygenor a halogen atom). Some of these ribbon-chain antiferromagnets exhibit unusual
magnetic ground states which e.g. support effective magnetoelectric coupling andmultiferroic behavior. I review some of our recent investigations on the well-known
nearest - next-nearest neighbor quantum chain antiferromagnetic LiCuVO4 and report
first results gained on some new systems, CuCrO4, TiPO4 and CuCl2.

Sebastian Clemens Muehlbauer1*, Severian Gvasaliya2, Eric Ressouche3, Ekaterina Pomjakushina4 and Andrey
Zheludev2
1
Neutron Scattering and Magnetism Group, Laboratory for Solid State Physics, ETH Zurich, Switzerland
2
Neutron Scattering and Magnetism Group,, Laboratory for Solid State Physics, ETH Zurich, Switzerland
3
INAC/SPSMS-MDN, CEA/Grenoble, France
4
Laboratory for Developments and Methods, Paul Scherrer Institute, Switzerland
The evolution of different magnetic structures of the non-centrosymmetric tetragonal antiferromagnet
Ba2CuGe2O7 is systematically studied as function of the orientation of the magnetic field H. Neutron
diffraction in combination with measurements of magnetic susceptibility and specific heat shows a virtually
identical phase diagram of Ba2CuGe2O7 for H confined in both the (1,0,0) and (1,1,0) plane. The existenceof a recently proposed incommensurate double-k AF-cone phase [1] is confirmed in a narrow range for
H close to the tetragonal c-axis. In contrast, for large angles enclosed by H and the c-axis, a complexly
distorted non-sinusoidal magnetic structure has recently been observed [1]. We show that its critical fieldsystematically increases for larger canting. Measurements of magnetic susceptibility and specific heat
finally indicate the existence of a incommensurate/commensurate (I/C) transition at H =9 T, applied in thebasal (a,b)-plane [2]. The observation of this transition in combination with both odd and even harmonics
of the propagation vector agree with a non-planar, distorted magnetic structure, possibly caused by the
staggered component of the Dzyaloshinskii-Moriya vector.
[1] S. Muehlbauer et al. Phys. Rev. B 84, 180406 (2011) [2] S. Muehlbauer at al. in preparation (2012)

The 19th International Conference on Magnetism

Seunghyun Khim1, Bumsung Lee1, Ki-young Choi1, Kyung Jun Yoo1, Ji Hoon Shim2and Kee Hoon Kim1*
1
Department of Physics and Astronomy, Seoul National University, Korea
2
Department of Chemistry, Pohang University of Science and Technology, Korea
We have investigated Hc2 behaviors in various iron based SC including Sr(Fe,Co)2As2,
Fe(Se,Te) and LiFeAs [1-3]. In this particular work, we measured the resistivity ofSr(Fe,Ni)2As2 up to 35 T and report our unexpected findings in the magneto-resistancejust above the upper critical fields around the H // ab direction at low temperatures.
Apart from the transition in H // c direction, in which the resistivity is saturated after
abruptly appearing from the zero resistive superconducting state with increasing
magnetic field, the resistivity gradually increases after it rapidly appears until it reaches
the value saturated for the H // c direction. This can be interpreted as 1) the rate ofsuperconducting pair breaking changes or 2) the normal state resistivity is suppressedwith emerging an abnormal state with the strong magneto-resistance with the in-plane
field component. We will discuss the origin of this anomalous magneto-transport
behavior based on the band calculation result, in connection with the possible FuldeFerrel-Larkin-Ovchinnikov (FFLO) ground state or the competing ground state.

Oral Friday

Oral Friday

Yuke Li 1, Chenyi Shen 2, Yongkang Luo 2, Chen Lv 2, Qian Tao 2, Jianhui Dai 1,
Guanghan Cao2 and Zhuan Xu2*
1
Department of Physics, Hangzhou Normal University, China
2
Department of Physics, Zhejiang University, China

98

oRAL PRSENTATION

Tsuyoshi Kimura
Osaka University, Japan

Reinhard Kremer*
MPI for Solid State Research, Stuttgart, Germany[1] T. Kimura, “Spiral magnets as magnetoelectrics”Annu. Rev. Mater. Res. 37, 387 (2007). [2] T.
Kimura, “Magnetoelectric hexaferrites”, Annu. Rev. Condens. Matter Phys. (to be published).

[1] S. Khim et al., Physica C 470, S317 (2010). [2] S. Khim et al., Phys. Rev. B 81, 184511 (2010). [3]S. Khim et al., Phys. Rev. B 84, 104502 (2011).

July 8-13, 2012 Busan, Korea

99

ORAL PRESENTATION
JC03

JD02

Multiferroic properties of layered triangular compounds

Switching of magnetic ordering near the quantum critical point of theheavy fermion superconductor CeRhIn5

Unconventional spin-glass behaviors in pyrochlore Heisenberg
antiferromagnets coupled with lattice distortions

Hyun Jung Lee1* and Tetsuya Takimoto2
1
School of Physics, Korea Institute for Advanced Study, Seoul, Korea
2
Asia Pacific Center for Theoretical Physics, POSTECH, Pohang, Korea

Hiroshi Shinaoka , Yusuke Tomita and Yukitoshi Motome
1
Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology, Japan
2
Institute for Solid State Physics, University of Tokyo, Japan3
Department of Applied Physics, University of Tokyo, JapanThe nuclear quadrupole resonance(NQR) and the magnetic neutron diffraction
experiments in CeRhIn5 clearly indicate that the antiferromagnetic long-range ordertakes place uniformly over the entire sample where the bulk superconductivity appears.
The most intriguing feature in this compound is the switching of magnetic ordering
near the quantum critical point, where the spin-density waves (SDW) with different
wave vectors are simultaneously observed in the NQR spectrum as well as the neutron
diffraction profile. In order to understand the switching mechanism, we have calculated
the spin excitation spectrum in the presence of antiferromagnetic and superconducting
long-range order using the RPA and found that the concurrence of commensurate andincommensurate SDW is associated with the van-Hove singularity that occurs with thesuperconducting gap opening.

Spin glass, in which spins are frozen randomly, is one of low-temperature phases widely observed ingeometrically frustrated magnetic materials. However, it is unclear so far how its nature is different from thecanonical one driven solely by randomness. Experimentally, several puzzling spin-glass behaviors have been
pointed out for pyrochlore-based magnets, such as R2Mo2O7 and ACr2O4; i.e., the transition temperature appears
to be almost independent of the strength of randomness, and the value is much higher than the theoreticalprediction. Motivated by these puzzles, we investigate the effect of magnetoelastic coupling in a bond-disordered
Heisenberg antiferromagnet on a pyrochlore lattice [1,2]. Through classical Monte Carlo simulations using
the extended loop algorithm [3,4], we show that the magnetoelastic coupling largely enhances the spin-glasstransition temperature. Furthermore, in a wide range of bond disorder, the transition temperature is set by themagnetoelastic coupling, and becomes almost independent of bond disorder, as observed in experiments. These
peculiar behaviors are ascribed to spin collinearity induced by the magnetoelastic coupling. We also compute thespecific heat and (non)linear susceptibility and compare the results with experiments as well as the canonical spinglass behaviors. The present theory qualitatively explains the puzzling spin-glass behaviors observed in experiments.

One of the most puzzling families of multiferroics is characterized by stackings of triangular planes, on
which geometrically induced frustration of antiferromagnetic exchanges leads to complex non-collinear
magnetic structures, like in the delafossite CuCrO2 [1, 2]. The proposed microscopic origin of this spin-driven
ferroelectricity is based on the variation of the ligand-metal orbital hybridization, as a result of spin-orbit coupling[3]. In this context, tuning hybridization by changing the oxygen ligand ion could give clues in the understandingof the physics of multiferroics. The chalcogenide AgCrS2 has a rhombohedral structure at 300 K [4], in which the
Cr3+ ions form a perfect triangular lattice. Our recent neutron scattering study [5] has shown that a large magnetoelastic effect leads to a crystal symmetry lowering at TN, which releases the geometric frustration of the magnetic
lattice : below TN = 41.5 K, the antiferromagnetic arrangement is an unconventional collinear one, made of double
ferromagnetic stripes coupled antiferromagnetically. Drastic changes in the correlations between spins on coolingthrough TN are observed. Unlike CuCrO2, ferroicity in AgCrS2 is related to the spin-lattice coupling of electric
dipoles and magnetic moments, which results in a polar (P ~ 20 μC/m2 at 5 K [6]) structure below TN.
[1] M. Poienar et al., Phys. Rev. B 79, 014412 (2009), [2] S. Seki et al., Phys. Rev. Letters 101, 067204 (2008,),[3] C. Jia et al., Phys. Rev. B 76, 144424 (2007) ; T. Arima, J. Phys. Soc. Japan 76, 073702 (2007), [4] P.F.
Bongers et al., J. Phys. Chem. Solids 29, 977 (1968), [5] F. Damay et al., Phys. Rev. B 83, 184413 (2011), [6]K. Singh et al., Chem Mater. 21, 5007 (2009)

1

2

3

Spin liquids for spin 1/2 systems with strong charge fluctuation on thetriangular lattice
Eun-gook Moon and Cenke Xu
Physics, UCSB, USA

We describe a new class of spin liquids for organic spin 1/2 triangular lattice systems.
Adopting the Fermionic-spinon representation, d-wave pairings between spinons are
considered, which makes U(1) gauge symmetry down to Z2 one. Finite amount ofenergy gap of the Z2 gauge theory prohibits coupling between the emergent gauge
field and external electro-magnetic field at low energy. Thus external magnetic field
only couples to the Zeeman term and it is argued that the ground state does not show
thermal Hall conductance. Also, the fermionic band structure allows both Diracfermi points and a quadratic band touching point. It is shown how the fermionic band
structure could resolve various puzzling experiments, for example, metallic thermal
conductivity without thermal Hall conductivity.[1,2,3][1]M. Yamashita, et al., Science 328,1246(2010) [2]S. Yamashita, et al., Nature Communication
2,275(2011) [3]E. Pratt, et al., Nature 471, 612(2011)[1] H. Shinaoka, Y. Tomita and Y. Motome, Phys. Rev. Lett. 107, 047204 (2011). [2] H. Shinaoka, Y. Tomita and Y. Motome,
arXiv:1107.4144. [3] H. Shinaoka, Y. Tomita and Y. Motome, J. Phys.: Conf. Ser. 320, 012009 (2011). [4] H. Shinaoka and Y.
Motome, Phys. Rev. B 82, 134420 (2010).

JC01

JC04

JD03

JD06

STM and magnetotransport investigations on the heavy fermion
metals YbRh2Si2 and CeMIn5 (M = Co, Ir)

Resonant magnetic exciton mode in the heavy-fermion antiferromagnet
CeB6

Theory of spin liquids in integer spin pyrochlores

Emergent criticalities and phase transitions in monomer-dimer
mixture system on a honeycomb lattice

Steffen Wirth1*, Andrea Bianchi2, Stefan Ernst1, Christoph Geibel1, Zachary Fisk3, Stefan Kirchner4,
Cornelius Krellner1, Joe D Thompson5 and Frank Steglich1
1
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
2
Departement de Physique, Universite de Montreal, Quebec H3C 3J7, Canada
3
University of California, Irvine, California 92697, USA
4
Max Planck Institute for Physics of Complex Systems, Germany
5
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

Heavy fermion metals are often characterized by a variety of relevant energy scales and competing interactions
which may result in such fascinating phenomena as quantum criticality and unconventional superconductivity.
Here, we focus on results obtained by Scanning Tunneling Microscopy and Spectroscopy (STM/S) and Hall
effect measurements. YbRh2Si2 and its doped counterparts Yb(Rh1-x}Mx)2Si2 (M = Co, Ir) exhibit a quantum
critical point which results from a competition between RKKY and Kondo interaction [1]. The Kondo interaction
is visualized by Scanning Tunneling Spectroscopy on YbRh2Si2 [2]. The hybridization of conduction and 4f
electrons results in a gap-like feature of the tunneling conductance. Importantly, the crystal field excitations
are unambiguously reflected by STS. A strongly temperature dependent peak in tunneling conductance isattributed to a resonance resulting from the Kondo lattice. At even lower temperature, Hall effect measurements
reveal a Kondo break-down of the heavy quasiparticles [3]. In the CeMIn5 class of compounds the relation
between superconductivity and antiferromagnetism will be discussed [4]. Magnetotransport measurements on
CeIrIn5 indicated a precursor state to superconductivity. A gap detected by low-temperature STS in CeCoIn5 iscompatible with $d_{x2 - y2}$ symmetry of the superconducting order parameter and is, again, consistent with aprecursor state to superconductivity.
[1] S. Friedemann {\it et al.}, Nature Phys. {\bf 5} (2009) 465. [2] S. Ernst {\it et al.}, Nature {\bf 474} (2011) 362. [3] S. Friedemann {\it etal.}, Proc. Natl. Acad. Sci. USA {\bf 107} (2010) 14547. [4] S. Nair {\it et al.}, Proc. Natl. Acad. Sci. USA {\bf 107} (2010) 9537.

Gerd Friemel1, Yuan Li1, A. Dukhnenko2, N. Yu. Shitsevalova2, N. E. Sluchanko3,
Alexandre Ivanov4, V. B. Filipov2, Bernhard Keimer1 and Dmytro Inosov1*
1
Max Planck Institute for Solid State Research, Stuttgart, Germany
2
I. M. Frantsevich Institute for Problems of Material Sciences of NAS, Kiev, Ukraine
3
A. M. Prokhorov General Physics Institute of the Russian Academy of Sciences,
Moscow, Russia
4
Institut Laue-Langevin, Grenoble, France
Resonant magnetic excitations are widely recognized as hallmarks of unconventional
superconductivity. Numerous model calculations have related these modes to the microscopic
properties of the pair wave function, but the mechanisms underlying their formation are still
debated. Here we report the discovery of a similar resonant mode in the non-superconducting,antiferromagnetically ordered heavy-fermion metal CeB6. Unlike conventional magnons, themode is non-dispersive, and its intensity is sharply concentrated around a wave vector separate
from those characterizing the antiferromagnetic order. The mode energy increases continuously
below the onset temperature for antiferromagnetism, in parallel to the opening of a nearly
isotropic spin gap throughout the Brillouin zone. These attributes bear strong similarity tothose of the resonant modes observed in unconventional superconductors below their criticaltemperatures. This unexpected commonality between the two disparate ground states throws
new light on the interplay between antiferromagnetism, superconductivity, and 'hidden' orderparameters in correlated-electron materials.

Sungbin Lee1*, Shigeki Onoda2 and Leon Balents3
1
University of California, Santa Barbara, USA
2
Condensed matter theory Laboratory, RIKEN, Japan
3
Kavli Institute for Theoretical Physics, University of California, Santa Barbara, USA
Rare earth pyrochlores, with a chemical formula A2B2O7, exhibit many interesting
features. Depending on A site rare earth elements, spin ice and magnetically orderedphases are shown in several experiments. Moreover, they have been also focused
as possible candidates of U(1) spin liquid. In order to explore such versatile phases,
we study the pseudospin-1/2 model, which is quite generic to describe rare earth
pyrochlores with integer spins, in the presence of spin-orbit coupling and crystalline
electric field. Using a new 'gauge mean field theory', we show the possible groundstates, corresponding to several phases listed above.

Hiromi Otsuka*
Department of Physics, Tokyo Metropolitan University, JapanThe frustrated magnets such as Dy2Ti2O7 are called as the spin ice, and have received
much attention [1]. In particular, a defect representing a breaking the ice rule can be
regarded as the magnetic monopole in solids, so its property is a current interest [2].
Here, we study the spin ice in a magnetic field using a toy model, i.e., a monomerdimer mixture defined on a honeycomb lattice. In a low-doping region of monomers, its
effective description is given by the dual sine-Gordon model [3]. In intermediate- andstrong-doping regions, the Potts lattice gas theory can be employed [4]. Synthesizingthese, we construct a renormalization-group flow diagram, which includes the stableand unstable fixed points corresponding to M5 and M6 in the minimal models of
the conformal field theory. We perform numerical calculations to determine a phase
diagram and also to proffer evidence to check our prediction [5].
[1] M.J. Harris, et al., Phys. Rev. Lett. 79, 2554 (1997). [2] C. Castelnovo, et al., Nature 451, 42(2008). [3] P. Lecheminant, et al., Nucl. Phys. B 639, 502 (2002). [4] B. Nienhuis, J. Phys. A 15, 199(1982). [5] H. Otsuka, Phys. Rev. Lett 101, 227204 (2011).

JC02

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JE01

Fermi surface of URu 2Si 2 in the hidden order state and in theantiferromagnetic state

Magnetostriction to 97.4T in frustrated Shastry-Sutherland compound SrCu2(BO3)2Field-induced spin nematic and spin density wave orders in spatiallyanisotropic frustrated magnets

Domain-wall physics and devices using focused electron and ion beams

Elena Hassinger, Georg Knebel, Dai Aoki, Frederic Bourdarot, Liam Malone,
Tatsuma Matsuda, Valentin Taufour and Jacques Flouquet
INAC/ CEA Grenoble, France

The heavy fermion compound URu2Si2 is famous for its hidden order state appearing
below T0 = 17.5 K at ambient pressure. Inside this phase superconductivity sets in
at 1.5 K. Up to now, the order causing huge signatures in macroscopic quantities at
the transition temperature has not been detected experimentally with microscopic
probes. The proximity of the hidden order state to a usual antiferromagnetic state
appearing under pressure allows a comparison of the two. In this talk a Fermi
surface study of URu2Si2 is presented. New Fermi surface sheets have been detectedwhich puts constrains for theory. The pressure dependence shows that the Fermi
surface is the same in the hidden order state and in the antiferromagnetic state. As aconclusion, the hidden order must reconstruct the Fermi surface in the same way the
antiferromagnetism does.

Marcelo Jaime1*, Ramzi Daou2, Scott A Crooker1, Franziska Weickert3, Atsuko Uchida1, Adrian Feiguin4, Cristian D
Batista5, Hanna A Dabkowska6 and Bruce D Gaulin7
1
NHMFL, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
2
Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
3
MPA-CMMS, MPA-CMMS, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.
4
Department of Physics & Astronomy, University of Wyoming, Laramie, Wyoming 82071, USA
5
Theory Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
6
Brockhouse Institute for Materials Research, McMaster University, Hamilton, ON, L8S 4M1, Canada
7
Department of Physics & Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada
Strong geometrical frustration in magnets leads to exotic states, such as spin liquids, spin supersolids
and complex magnetic textures. SrCu2(BO3)2, a spin-1/2 Heisenberg antiferromagnet in the archetypical
Shastry-Sutherland lattice, exhibits a rich spectrum of magnetization plateaus and stripe-like magnetic
textures in applied fields [1]. The structure of these plateaus is still highly controversial due to the intrinsic
complexity associated with frustration and competing length scales [2,3]. We reveal new magnetic
textures in SrCu2(BO3)2 via magnetostriction and magnetocaloric measurements in fields up to 97.4
Tesla [4]. In addition to observing the low-field fine structure of the plateaus with unprecedented submicrostrain resolution, the data also reveal lattice responses at 82 T and at 73.6 T which we attribute, using
a controlled density matrix renormalization group approach, to the long-predicted 1/2-saturation plateau,
and to a new 2/5 plateau. -AF acknowledges NSF funding under grant DMRG-0955707. Experiments
at the High Magnetic Field Laboratory Dresden (HLD) were sponsored by Euro-MagNET II under the
EU contract 228043. Work at the NHMFL was supported by the National Science Foundation, the US
Department of Energy trough the BES ''Science at 100T' program, and the State of Florida.
[1] K. Kodama, et al. Science 298, 395 (2002). [2] S.E. Sebastian, et al. Proc. Natl. Acad. Sci. 105, 20157(2008). [3] F. Levy, et al. Europhys. Lett. 81, 67004 (2008). [4] M. Jaime, et al. arXiv:1202.0812v1

100

JD05

The 19th International Conference on Magnetism

Oral Friday

JB05
Francoise Damay1, Christine Martin2, Maria Poienar2, Gilles Andre1, Sylvain Petit1, Julien Robert1,
Vincent Hardy2 and Antoine Maignan2
1
Laboratoire Leon Brillouin, CEA-CNRS UMR 12, 91191 GIF-SUR-YVETTE CEDEX, France
2
Laboratoire CRISMAT, CNRS UMR 6508, 6 bvd Marechal Juin, 14050 CAEN CEDEX, France

Oral Friday

oRAL PRSENTATION

Masahiro Sato1, Toshiya Hikihara2 and Tsutomu Momoi3
1Department of Physics and Mathematics, Aoyama Gakuin University, Japan
2
Faculty of Engineering, Gunma University, Japan
3
Condensed Matter Theory Laboratory, RIKEN, Japan

Magnetic multipolar order including spin nematic (magnetic quadrupolar) order is one of the current topics
in frustrated magnetism. Recently, frustrated spin-1/2 chains with ferromagnetic nearest neighbor couplingJ1(<0) and antiferromagnetic next nearest neighbor one J2(>0) have been theoretically shown to exhibit
multipolar quasi long range orders in the wide region of J1/J2 as an external magnetic field is applied [1,2].
In addition, it is known that several kinds of quasi one-dimensional (1D) cuprates [3] can be describedby this J1-J2 spin chain [4,5]. Particularly, recent experiments show that LiCuVO4, one of the quasi-1D
cuprates, possesses a new phase near saturation, and it is expected to be a spin nematic long-range orderedphase [6]. Motivated by these results, we have completed the field-temperature phase diagram for spatiallyanisotropic magnets consisting of weakly coupled J1-J2 spin chains, making use of the accurate results ofthe single J1-J2 spin chain [1,4]. The phase diagram contains spin nematic and spin-density-wave orderedphases, and these two orders compete with each other. We will discuss some universal features of the phase
diagram and the relevance of our result to LiCuVO4.
[1]T.Hikihara, L.Kecke, T.Momoi, and A.Furusaki, PRB78, 144404 (2008). [2]J.Sudan, A.Luscher, and A.M.Lauchli,
PRB80, 140402(R) (2009). [3]See, for example, M.Hase, et al, PRB70, 104426 (2004); M.Enderle, et al, EPL70, 237 (2005);
Y.Yasui, et al, JPSJ80, 033707 (2011); T.Masuda, et al, JPSJ80, 113705 (2011). [4]M.Sato, T.Momoi, and A.Furusaki,
PRB79, 060406(R) (2009); M.Sato, T.Hikihara, and T.Momoi, PRB83, 064405 (2011). [5]S.Furukawa, M.Sato, andS.Onoda, PRL105, 257205 (2010). [6]L.E.Svistov, et al, JETP Lett. 93, 21 (2011).

Henk Swagten*, Jeroen Franken, Christian Geurts, Mark Van Der Heijden, Mark
Hoeijmakers, Tim Ellis, Elena Mure, Beatriz Barcones, Juergen Kohlhepp and Bert
Koopmans
Applied Physics, Eindhoven University of Technology, Netherlands
In domain-wall (DW) devices with perpendicular magnetic anisotropy (PMA) using
e.g. ultrathin Co, a number of exciting phenomena have been observed very recently.
Ion irradiation is shown to be an effective tool to locally modify PMA properties,
with which a kaleidoscope of new DW physics or device directions may be explored.
For example, we have used ion irradiation in PMA strips for (1) controlled pinningof DWs (2) predictions of a novel domain-wall oscillator, (3) intrinsic DW resistivity
as a function of the width of the DW, and (4) a novel ratchet DW memory device bysawtooth shaping of the DW potential. After shortly introducing these developments,
the presentation will focus on the use of electron-beam-induced-deposition (EBID)
for growing Co and Fe-rich nanopillars on top of our magnetic strips, with a diameter
typically 50-150nm. After nucleation of a DW at an ion-irradiated part of the strip, theDW is moved towards the position of the pillar, at which it may be pinned/depinned
using a variable strength of the applied perpendicular field. Apart from controlled (de)pinning due to the altered DW energy landscape induced by the pillar stray field, we
could also uniquely extract the switching fields of these nanopillars.

July 8-13, 2012 Busan, Korea

101

ORAL PRESENTATION
JE02

JF01

JF04

JG02

Real time analysis of spinmotive forces due to domain wall motion

Disentangling and manipulating intrinsic and extrinsic contributionsin the anomalous hall effectMinority band gap and magnetic properties of Co2(Fe,Mn)Z (Z=Al,
Ga ; Si, Ge) in the context of CPP-GMR transport

Theory of static and dynamic properties of magnetic dot arrays
coupled by dipole-dipole interaction

Spinmotive force, which is induced by motion of a nonuniform magnetic
nanostructure, reflects real time dynamics of the magnetization texture [1,2]. It is wellknown that domain wall motion in a permalloy nanowire exhibits nontrivial magnetic
field dependence. In particular, in high field regime far above the Walker breakdown
field, the domain wall shows structural deformation including annihilation and creationof magnetic vortex cores [3]. Using numerical simulations we study the spinmotive
force in such a circumstance and find that its dc component scales with an appliedmagnetic field even in a field range where the wall motion is no longer associated withperiodic angular rotation of the wall magnetization. This feature has been confirmed ina recent experiment [4]. As the field is increased, spikes in the voltage signals start toappear, which are mainly associated with vortex core nucleation and annihilation, andthis tendency is enhanced with further increase in the field. At high fields, the slope ofthe generated dc voltage with the applied field is expected to be only dependent on thespin polarization of conduction electrons and thus can be used to accurately determine
the degree of spin polarization in various materials.

Xiaofeng Jin*
Physics Department, Fudan University, China

Faleev Sergey and Oleg N. Mryasov*Physics and Astronomy and MINT Center, Physics and Astronomy and MINT Center, USA

The anomalous Hall effect is one of the most prominent phenomena existing inmagnetic materials. It has remained unsolved for more than a century because its richphenomenology defies the standard classification methodology, prompting conflicting
reports claiming the dominance of various processes. Working with epitaxial filmsof Fe, Ni, and NixCu1-x, we succeeded in independent controls of different scattering
processes through temperature and layer thickness, which allows an unambiguous
identification and control of the intrinsic mechanism as well as the extrinsic
mechanisms of the anomalous Hall effect.

WN
A
R

D

TH
I
W

[1] S. E. Barnes and S. Maekawa, Phys. Rev. Lett. 98, 246601 (2007). [2] Y. Yamane et al., J. Appl.
Phys. 109, 07C735 (2011). [3] M. Hayashi et al., Appl. Phys. Express 3, 113004 (2010). [4] M.
Hayashi, J. Ieda et al., submitted.

Roman Verba1, Gennady Melkov1, Vasil Tiberkevich2 and Andrei Slavin2*
Radiophysics, Kiev National University, Ukraine2
Physics, Oakland University, USA
1

Arrays of magnetic nano-dots are promising candidates for applications in microwave
signal processing and in magnetic recording technology. Since ground state of an isolated
dot is double-degenerate, there are many possible ground states of an array. Different
ground states, which can be controlled dynamically [1], correspond to different spin-wave(SW) spectra of an array. Thus, using dot arrays it is possible to develop new artificial
magnetic materials: dynamic magnonic crystals. In this paper we present a general theoryof static and linear dynamic properties of magnetic dots arrays coupled by a magnetodipolar interaction. In contrast with the majority of previous analytical methods the theory
presented here is not limited to macrospin approach, as spatially nonuniform static anddynamic magnetization profiles are taken into account by introducing static-static, staticdynamic and dynamic-dynamic effective mutual demagnetization tensors. We showthat all the possible ground states of a finite or infinite array with given periodicity canbe found as solutions of a system of linear equations. The developed theory provides asimple way to calculate mode structure, damping rates and excitation efficiency of SWs,
and microwave response of a magnetic dot array.
[1]. J. Topp et al., Phys. Rev. Lett. 104, 207205 (2010).

JE03

JF02

JF05

JG03

Spin-current induced magnetization dynamics

Spinmotive forces in spin-orbit coupling systems

Anisotropy in the intrinsic anomalous Hall effect

Theoretical study on ferromagnetic resonance of FePt/Py bilayers

Since conventional approaches of manipulating magnetization using magnetic fields exhibit
unfavourable scaling and results in limited switching speed, alternative approaches basedon spin-currents have emerged. The transfer of angular momentum (“spin transfer torqueeffect”) leads for instance to current-induced domain wall motion (CIDM), which has become
the focus of intense research in the last few years. We have comprehensively investigated
CIDM and determined the acting adiabatic and non-adiabatic torque terms [1]. We find thatthe previously neglected diffusive torque term [2] can play an important role for vortex coredisplacement. For out-of-plane magnetized Co/Pt a large non-adiabatic torque is found,while in Co/Ni the adiabatic torque dominates [3]. By separating charge and spin transport
we can generate pure diffusive spin currents with no associated net charge current. Usingsuch diffusive spin currents we find large efficiencies for domain wall displacement due tostrong spin accumulation absorption [4]. To increase the spin diffusion length, we use robust
turbostratic graphene and find spin injection across transparent contacts. Beyond generating
spin currents by spin injection, we have also used the Spin Seebeck Effect, where temperature
gradients generate spin currents that then affect for instance domain wall propagation [5].

Spinmotive force in ferromagnetic conductors with spin-orbit interaction istheoretically studied. We have derived the expression for the spinmotive force including
the contribution from a general form of spin-orbit interaction. We have found that,in addition to the conventional spinmotive force which reflects the time- and spatialdependent magnetization, time variation of the vector product of the magnetization
and an electric field gives rise to a spinmotive force. Therefore, a time-varying
electric field can induce a spinmotive force even in a static and uniform magnetization
configuration. In order to detect this phenomenon, we propose an experimental setup
with a metallic film which is thin enough for an electric field to penetrate. In addition,
considering a two dimensional electron system with the Rashba and Dresselhaus spinorbit couplings, the spinmotive force signals are different for each origin. Therefore
this spinmotive force offers a method to determine the ratio of spin-orbit couplings.

A new scaling for the anomalous Hall effect was recently proposed [Phys.Rev.
Lett.103,087206 (2009)], which can disentangle the intrinsic and extrinsic contributionsin the anomalous Hall effect. Based on the new scaling, we have investigated inexperiment the anisotropic effect of the intrinsic anomalous Hall contribution.
Comparing with Fe(001)/GaAs(001), we find the value of intrinsic AHE contribution
is different in Fe(111)/GaAs(111), which is directly related to the electronic band
structure of Fe.

Mathias Klaui
Institute of Physics, Johannes Gutenberg-Universitaet Mainz, Germany

Yuta Yamane*, Jun'ichi Ieda and Sadamichi Maekawa
Japan Atomic Energy Agency, Japan

Lin Wu, Yufan Li, Jianli Xu and Xiaofeng Jin*
Surface Physics Laboratory and Physics Department, Fudan University, China[1] L. Heyne et al., Phys. Rev. Lett. 105, 187203 (2010); M. Eltschka et al., Phys. Rev. Lett. 105, 056601 (2010). [2]A. Manchon, W.-S. Kim, and K.-J. Lee, arXiv:1110.3487 [3] J. Heinen et al., J. Phys. Cond. Mat. 24, 24220 (2012); T.
Koyama et al., Nature Mat. 10, 194 (2011). [4] D. Ilgaz et al., Phys. Rev. Lett. 105, 076601 (2010). [5] P. Mohrke etal., Sol. Stat. Com. 150, 489 (2010); J. Franken et al., Appl. Phys. Lett. 95, 212502 (2009).

Hiroshi Imamura1, Takeshi Seki2, Kazuhisa Utsumiya2, Yukio Nozaki3 and Koki
Takanashi2
1
NRI-AIST, Japan
2
IMR, Tohoku Univ., Japan
3
Keio Univ., Japan
Twisted magnetic structures such as a domain wall and a magnetic vortex attract muchattention for applications in nano spiontornics. It has been widely known that we canmake a twisted magnetic structure in a ferromagnetic bilayer consisting of materials
with different magnetic anisotropies, which is called an exchange spring bilayer (ESB).
We can control its twist angle by applying an external magnetic field. Recently the spin
dynamics in ESB has attracted much attention since the microwave assisted switching
was proposed by Fal et al. [1]. However the spin dynamics in ESB under oscillating
magnetic field is not fully understood. We theoretically studied the ferromagnetic
resonance of FePt/Py bilayers of which material properties were well studied
experimentally in [2]. We solved the Landau-Lifshitz-Gilbert equation and found thatthe resonance frequency of the perpendicular standing spin wave [3] is lowered bytwisting the spins in ESB. The decrease of the resonance frequency is enhanced when
ESB is about to switch. We shall show the details of our calculation and comparison
with experimental results in our talk.
[1] T. Fal et al., J. Appl. Phys. 109, 093911 (2011) [2] K. Utsumiya et al., J. Appl. Phys. 110, 103911(2011) [3] S.O. Demokritov et al., Phys. Rep. 384, 441 (2001)

JE04

JF03

JG01

JG04

External magnetic field dependence of the magnetic wall drive current
density in a TbFeCo magnetic nanowire

Theory of the spin Hall effect in ferromagnetic metals: Nonlinear
behaviors around the curie temperature

Propagation and scattering of spin waves in curved magnonic
waveguides

NMR observations of level crossings in a Cr8F8 pivalate single crystal:
The solution to the structured enhancement of 1/T1

We give a theory of the spin Hall effect in ferromagnetic metals near the Curie
temperature. We do this by extending Kondo's theory of the Anomalous Hall Effect inferromagnetic metals to include the short range spin-spin correlations. We find a novel
relation between the Spin Hall Effect and a second order nonlinear spin fluctuationin ferromagnetic metals near Curie temperature Tc. In 1962 Kondo gave a relation
between the Anomalous Hall Effect and the first order nonlinear spin fluctuation in pure
ferromagnetic metals near Tc. Thus our results show an essential difference between
the Anomalous and Spin Hall Effects in terms of the nonlinear spin correlations that areprobed. Our theory can be compared to experiments in ferromagnetic alloys near Tc by
Y. Otani et al.

Usually, the modulation of the effective magnetic field in magnonic crystals anddevices is achieved as a compositional modulation created either during growthor using lithographic processing. In this report, we develop a continuous medium
theory of dispersion and scattering of spin waves propagating in thin cylindricalnanowires (therefore acting as magnonic waveguides) with curved regions. The theory
predicts that, assuming that the static magnetization is aligned along the waveguide,
the curvature makes a significant contribution to the effective magnetic field in the
waveguide, scaling inversely with its radius of curvature squared. We calculate
the spectrum and coefficients of reflection and transmission of spin waves that are
created due to this topological nonuniformity and discuss problems arising from andopportunities offered by the discovered effect. The research leading to these results hasreceived funding from the EC’s 7th Framework Programme (FP7/2007-2013) underGA 247556 (NoWaPhen) and from EPSRC of the UK under project EP/E055087/1.

Hiroyuki Awano, Ryo Eguchi, Toma Kanehira and Do Bang
Toyota Technological Institute, Japan

Low current driven domain wall by using amorphous TbFeCo wire has been reported(1), the current density was 5x106A/cm2. Most reported magnetic wire samples ofdomain wall drive by current are prepared by using EB or Photo lithography andetching process. However, this process damages the edge of a magnetic wire andincrease resistance for domain wall displacement. To reduce the resistance, we propose
a new fabrication method of magnetic wire without any etching process. It is named
as nano-imprint magnetic wire method. Using the method, the improved TbFeCowire was fabricated by magnetron sputtering on to the plastic substrate with a groove
shape like a wire pattern. Therefore, relatively smooth roughness nanowire can be
made. This new fabrication method of nanowire can be reduced number of pinningsite. Then, the current density for domain wall driving can be also decreased to 6x105
A/cm2. Moreover, applying an external field to the sample, the current density can be
reduced more. Thus, this new fabrication method of nanowire is attractive for nanowire
memory device.

Oral Friday

Jun'ichi Ieda*, Yuta Yamane and Sadamichi Maekawa
Advanced Science Research Center, Japan Atomic Energy Agency, Japan

Oral Friday

oRAL PRSENTATIONBo Gu1*, Timothy Ziman2 and Sadamichi Maekawa1
1
Advanced Science Research Center, Japan Atomic Energy Agency, Japan
2
CNRS and Institut Laue Langevin, France[1] J. Kondo, Prog. Theor. Phys. 27 772-792 (1962). [2] D. H. Wei, Y. Niimi, B. Gu, T. Ziman, S.
Maekawa, and Y. Otani, unpublished.

Vira Tkachenko1, Andriy Kuchko1, Mykola Dvornik2 and Volodymyr Kruglyak2*
1
Donetsk National University, Ukraine
2
University of Exeter, United Kingdom

Shoji Yamamoto*Department of Physics, Hokkaido University, Japan

Micotti et al. [1] measured 1/T1 of a single crystal of the antiferromagnetic ring
[Cr8F8(piv)16] up to 15.6 T at 0.3 K. Interestingly enough 1/T1 is single- anddouble-peaked at the first and second level crossings, respectively. A single but
twinned crystal would produce such a split peak, but this possibility is ruled out by
x-ray measurements. There is no other observation of such a structured peak. 1/T1
observations of decanuclear ferric wheels [2] are obtainable beyond the third crossing
field, but each structure, if any, could not be resolved due to the use of a powder
sample. Those of hexanuclear [3] and octanuclear [4] ferric wheels are restricted to thefirst level crossing. Diagonalizing a well-equipped microscopic spin Hamiltonian ofeach cluster and then inquiring further into intercluster coupling effects, we reproduce
the spin dynamics in the Cr8 single crystal at sufficiently low temperatures. Here is asolution to the wide-split peak of 1/T1 at the second, rather than the first, level crossing.
[1] E. Micotti et al., PRB 72, 020405(R) (2005). [2] M.-H. Julien et al., PRL 83, 227 (1999). [3] M.
Affronte et al., PRL 88, 167201 (2002). [4] L. Schnelzer et al., PRL 99, 087201 (2007).

(1) Duc The Ngo, Kotaro Ikeda, and Hiroyuki Awano : Appl. Phys. Express 4, 093002 (2011)102

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

103

ORAL PRESENTATION
JG05

JH02

JI01

JI04

Spin state of ferric chloride investigated by Fe NMR

Development of high performance micron-scaled hard magnetic
structures for micro-system applications

Ferromagnetic properties of Co-Pd-SrTiO3 alloy films with highmagnetic anisotropy

Fabrication of highly ordered L10 type FePt thin films by rapid
thermal annealing

Developments of electromagnetic devices require higher frequency soft-magnetic
materials with high magnetic anisotropy (Hk) and electrical resistivity (ρ). Early work has
found Co-based nanocomposite films show good high-frequency magnetic properties[1].
However, it’s difficult to obtain both high Hk and ρ simultaneously. In this work, Pd is
induced to form Co-Pd alloy nanoparticles to enlarge Hk and SrTiO3 (STO) is employed
as nonmagnetic structural phase due to its high ρ. The effect of Pd on structure andmagnetic properties has been investigated. The Co-Pd-STO alloy films were deposited
onto Si and quartz substrates by reactive magnetron sputtering, using a composite
target composed of a STO disk and Co, Pd chips. Film structures were investigated by
XRD. The chemical composition of the films was analyzed by EDS and EPMA. The
magnetization was measured with VSM. The Co-Pd-STO film structures and magnetic
properties are strongly affected by Pd content. At the optimal composition, the films
exhibit Bs of about 7kG, ρ in order of 103 μΩcm, and Hk of around 150 Oe. The filmshows good frequency response of permeability at GHz range. Co-Pd-STO alloy film is agood candidate for the GHz range electromagnetic devices.

Large uniaxial magnetic anisotropy materials are extremely promising for theapplication to high-density magnetic storage devices or permanent magnets. In
particular, an L10 type FePt alloy reveals extremely large magnetic anisotropy,
therefore numerous studies on the fabrication of FePt films have been reported.
However, it is a fatal problem that a high growth-temperature or a high postannealingtemperature is needed to obtain an ordered FePt phase. In this paper, we employeda rapid thermal annealing to promote an L10 ordering of sputtered FePt films evenat a relatively low temperature, and investigated their crystallographic and magnetic
properties. Fe and Pt were deposited simultaneously on thermally oxidized Si
substrates. The thickness of FeNi films was 6.5 nm. After the deposition, films wererapidly annealed by a temperature elevation with a rate of 10˚C/sec in high vacuum. It
was found that a magnetic anisotropy increased by annealing, and a uniaxial magnetic
anisotropy energy (Ku) was estimated to be 3.5×107 erg/cc from magnetization curves.
Ku and coercivity drastically increased with higher rates up to 50˚C/sec. On the other
hand, it was revealed that a chemical order parameter estimated from X-ray diffraction
pattern slightly decreased with the rate. Detailed structural analysis will be also
discussed.

It was reported that ferric chloride(FeCl3) has helical spin structure with period of 15
in the ground state and undergoes two quantum phase transitions at 1.5 T and 4.0 T as
magnetic field increases. Between 1.5 - 4 T, the spins of Fe ions are arranged in two
directions canted along the axis parallel with magnetic field and above 4.0 T, spins
flop. We have measured magnetization curve and magnetic field and temperaturedependences of Fe NMR spectrum of polycrystalline FeCl 3. The temperaturedependence of the NMR resonance frequency in zero magnetic field reveals sublatticemagnetization. The result fits well to Bloch’s T2 law which is expected for a simple
antiferromagnet having no anisotropy. The magnetic field dependence of the NMR
signal line width shows that the directions of the spins hardly change below 2.5 T.
From the field dependence of NMR frequency and line width, we conclude that the
spins are almost perpendicular to the field above 5 T. The results are compatible withthe previously reported transition at 1.5 T but not with that at 4 T. We estimated theexchange coupling constant from the measured angles between the magnetic field andthe spins above 5 T.

Nora Dempsey1, F. Dumas-bouchiat1, Y. Zhang1, G. Ciuta1, L. F. Zanini1,2 and D.
Givord1
Institut Neel CNRS/UJF, France
Micro-systems incorporating magnetic materials have many potential applications in
the fields of bio-medicine, information technology, energy transformation/management.
As the size of the magnetic element is downscaled, the strength of the magnetic field
gradient it produces is up-scaled, and values as high as 10 exp 6 T/m can be achieved
with micron scaled structures. Hard magnetic materials offer the distinct advantagethat they need neither an external magnetic field source nor power supply, and thus
they are particularly well suited for use in autonomous, mobile devices or where spaceis limited. The development of hard magnet based systems has been hindered to-dateby the challenges faced in integrating these materials at the appropriate scale using
techniques compatible with today’s micro-system technologies. In this presentation
we will report on the preparation and patterning of high performance hard magnetic
materials in film and polymer-powder composite form. We will present their magnetic,
structural and mechanical properties and will give examples of a range of bio-related
applications now being developed using these micron-scaled hard magnetic structures.

Yiwen Zhang1*, Syousuke Fukushi1, Hanae Kijima1, Nobukiyo Kobayashi2, Atsushi
Yokoi2, Shigehiro Ohnuma2 and Hiroshi Masumoto1
1
Center for Interdisciplinary Research, Tohoku University, Japan
2
Research Institute for Electromagnetic Materials, Japan

Masaki Mizuguchi*, Takashi Sakurada and Koki Takanashi
Institute for Materials Research, Tohoku University, Japan

Oral Friday

Byeongki Kang, Changsoo Kim, Euna Jo, Sangil Kwon and Soonchil Lee*
Physics, KAIST, Korea

Oral Friday

oRAL PRSENTATION

1. Y. W. Zhang, S. Ohnuma, and H. Masumoto, IEEE Transactions on Magnetics, vol. 47, pp. 3795-3798 (2011).

JG06
Spin dynamics of ferrite nanoparticles studied by 57Fe Mossbauer
spectroscopy

Mathias Kraken1*, Jochen Litterst1, Ilka Marina Grabs2, Ingke Christine Masthoff2
and Georg Garnweitner2
1
IPKM, TU Braunschweig, Germany
2
IPAT, TU Braunschweig, Germany

Due to its specific timescale, Mossbauer spectroscopy is highly suitable to investigate
the dynamic properties of magnetic nanoparticles. The hyperfine magnetic spectra
between the blocking temperature and very low temperatures may exhibit a broad
variety of different shapes. Accordingly, to describe this rich behaviour a whole rangeof different, controversially discussed models can be found in literature [1-4]. We
performed measurements on ZnFe2O4 nanoparticles, prepared by a non-aqueous sol
gel method and characterized by x-ray scattering, dynamic light scattering and TEM.
The spectra were taken on strongly and weakly interacting particles and the fits to thespectra with the different models are compared in order to gain information about thesuitability of the applied models.
[1] D.H. Jones and K.K.P. Srivastava, J. Magn. Magn. Mater. 78, 320 (1989). [2] S. Mørup et al., J.
Magn. Magn. Mater. 40, 163 (1983). [3] S. Bocquet and S.J. Kennedy, J. Magn. Magn. Mater. 109,
260 (1992). [4] M. F. Hansen et al., Phys. Rev. B 62, 1124 (2000).

JH01
Multi-layered nanocomposite thick film-magnet for power MEMS
applications
Hirotoshi Fukunaga1*, Masaki Nakano1, Takeshi Yanai1 and Fumitoshi Yamashita2
1
Graduate School of Engineering, Nagasaki University, Japan
2
Rotary Component Technology Development Division, Minebea Co., Ltd., Japan

An isotropic nanocomposite thick film-magnet is one of candidates for a magnet used in power
MEMS because of its high remanence and the easiness of multi-polar magnetization [1]. Previously,
we developed a method of synthesizing multi-layered nanocomposite thick film-magnets composedof several hundred layers by using PLD (Pulsed Laser Deposition) method, and reported magnetic
properties of Nd-Fe-B/Fe3B and Nd-Fe-B/α-Fe multi-layered thick film-magnets [2,3]. In thisinvestigation, we improved magnetic properties of Nd-Fe-B/α-Fe multi-layered thick film-magnets
and their reproducibility by controlling preparation conditions of films such as energy density of laser
beam and stacking periods of Nd-Fe-B/α-Fe layers, tp. Superior magnetic properties were obtained
for the films with tp of 10-20 nm. This tp value is consistent with the results of the previous computer
simulation. It is also clarified that decrease in the number and/or size of droplets improve(s) magnetic
properties, because the presence of droplets degrades a layered structure and resultantly reduces
effective exchange interaction between soft and hard phases. The obtained (BH)max value, 112 kJ/
m3, is the larger than the values obtained in previous studies for isotropic film-magnets thicker than
10 μm, which suggests that multi-layered nanocomposite thick film-magnets are promising for
power MEMS applications.
[1] F. Yamashita et al., IEEE Trans. Magn. 46, 2012 (2010). [2] H. Fukunaga et al., J. Alloys and Compounds, 408-412,
1355 (2006). [3] H. Fukunaga et al., J. Phys.: Conf. Ser. 266, 012027 (2011).

104

The 19th International Conference on Magnetism

JH03
Exchange spring magnet for rare earth free permanent magnet
Dongyoo Kim and Jisang Hong*
Department of Physics, Pukyong National University, Korea

Using the full potential linearized augmented plane wave (FLAPW) method, we haveinvestigated the thickness dependent magnetic properties of rare earth free exchange
spring magnet FeCo/FePt(001). The FeCo adlayer thickness is increased from one
monolayer (ML) to four ML coverage. It is observed that the FeCo adlayers and Fe
atoms in FePt substrate show almost half metallic behavior, while an ordinary metallic
feature is found in Pt atoms. The average magnetization increases with FeCo thickness
and the estimated energy product reaches 65.61 MGOe in FeCo(4ML)/FePt(001).
A giant perpendicular magnetocrystalline anisotropy (MCA) energy is found in pure
FePt(001) and the MCA energy in FeCo/FePt(001) systems also show quite large
values. For instance, the calculated MCA energy of pure FePt(001) is about 18.2 meV/
cell, and it is about 17.35 meV/cell for FeCo(4ML)/FePt(001). Both MCA energy andestimated energy product values of FeCo/FePt(001) exchange spring magnet structure
are comparable with those found in rare earth substituted permanent magnet. This may
imply that the FeC/FePt can be utilized for potential rare earth free exchange spring
magnet material This work was supported by the KCAP located in Sogang University
funded by MEST through (NRF-2011-C1AAA001-2011-0030278), and by KOSEF
grant founded by MEST (No.R01-2008-000-20014-0).

JH04
Prediction of maximum energy product for exchange coupled coreshell nanomagnets

Jihoon Park1, Yang-ki Hong1*, Jaejin Lee1, Jeevan Jalli2, Gavin Sky Abo1, Woncheol Lee1, Chul-jin Choi3
and Junggoo Lee3
1
Department of Electrical and Computer Engineering and MINT Center, The University of Alabama,
Tuscaloosa, Alabama 35487, USA
2
Schweitzer Engineering Laboratories, 2350 NE Hopkins Court, Pullman, Washington 99163, USA
3
Korea Institute of Materials Science, Changwon, Kyungsangnam-do, Korea

Ferromagnetic τ-phase MnAl possesses a high magnetic moment of 2.4 μB per unit cell [1] and the Curie
temperature (Tc) of 655 K [2], and is also rare-earth free. However, its maximum energy product, (BH)max,
is about 12.3 MGOe at 300 K. This maximum energy product is not enough for high-energy magnetic device
applications. Therefore, we have proposed core (τ-phase MnAl hard magnet)/shell (soft magnet) nanostructure
to enhance the (BH)max, which is higher than that of Sm2Co17. We have modified the Skomski’s approach [3],that is exchange hardening in nanoscale combination of a soft phase and an oriented hard phase, to predict thetheoretical limit of (BH)max for the τ-phase MnAl core-shell nanomagnet. It was found that (BH)max of core
(70 nm τ-phase MnAl hard magnet)/shell (18 nm thick 1.6 T soft magnet) nanomagnet exceeds 40 MGOe at
300 K, where the soft shell thickness is thinner than two times of MnAl domain wall thickness. It is noted that themagnetization of soft shell plays a key role in enhancement of (BH)max. Detailed calculations for (BH)max will
be discussed for various hard-core sizes and soft-shell thickness.
[1] A. Sakuma, J. Phys. Soc. Japan, 63, 1422 (1993). [2] Q. Zeng, I. Baker, J. B. Cui, and Z. C. Yan, J. Magn.
Magn. Mater. 308, 214 (2007). [3] R. Skomski and J.M.D. Coey, Phys. Rev. B, 48, 21 (1993).

JI02

JI05

Effect of change in thickness on the structural and magnetic propertiesof L10-ordered FePd films with (001) texture

Competing intrinsic and side-jump anomalous Hall effects in
Isoelectric L10 FePtPd ternary alloy films

Jungho Ko, Taejin Bae and Jongill Hong*Materials science and engineering, Yonsei Univ., Korea

L10-ordered films with strong perpendicular magnetic anisotropy (PMA), such as
CoPt, FePt and FePd, have received considerable attention since they are a superior
candidate that can overcome superparamagnetism as they become smaller [1, 2]. To
form L10-ordered FePd on an MgO (001) substrate, we prepared samples having
a repetition of a bi-layer composed both Fe and Pd monolayers by a dc ultra-highvacuum magnetron sputtering system at room temperature, and annealed them undera perpendicular magnetic-field of 4 kOe. The total thickness of [Fe/Pd]n was changed
from 3 to 20 nm. As-deposited FePd had a (100) textured FCC disordered phase andshowed in-plane magnetic anisotropy. Interestingly, after annealing at 500 °C for 2 h,
FePd was transformed to a (001) textured FCT L10-ordered phase and showed PMA.
Especially, 3- and 5-nm-thick FePd showed strong PMA with a squareness of unity.
With increasing of thickness of FePd, the FCC (100) texture was gradually increased,
resulted in a decrease in PMA. In fact, the 20-nm-thick L10-FePd showed mixed
anisotropy with both in-plane and out-of-plane magnetic anisotropy components. This
research was supported in part by the IT R&D program of MKE/KEIT. (KI002189,
Technology Development of 30 nm level High Density Perpendicular STT-MRAM)

Pan He1, Li Ma1, Zhong Shi1, Guan Yu Guo2 and Shiming Zhou1*
1
Department of Physics, Tongji University, China
2
Department of Physics and Center for Theoretical Sciences, National Taiwan
University, Taiwan
We have for the first time studied the anomalous Hall effect for isoelectric L10
Fe0.5(PtxPd1-x)0.5 ternary alloy films. When the spin-orbital coupling strength isfeasibly controlled changing the concentration ratio of Pd to Pt atoms, anomalous
Hall conductivity (AHC) can be continuously tuned from 300 S/cm for x = 0 (L10
FePd) to 930 S/cm for x = 1 (L10 FePt). Calculations have shown the intrinsic AHC
increases significantly whereas the side-jump AHC decreases weakly. In particular,
the present results of the side-jump AHC for L10 FePt and FePd films reproduces thecalculated results based on scattering-independent model. Our results will generate
new theoretical interest in the L10-ordered ternary alloys.
[1] N. Nagaosa, Rev. Mod. Phys. 82, 1539-1592 (2010). [2] K. M. Seemann, Y. Mokrousov, A. Aziz,
J. Miguel, F. Kronast, W. Kuch, M. G. Blamire, A. T. Hindmarch, B. J. Hickey, I. Souza, and C. H.
Marrows, Phys. Rev. Lett. 104, 076402 (2010). [3] Y. Tian, L. Ye, and X. Jin, Phys. Rev. Lett. 103,
087206 (2009). [4] M. Chen, Z. Shi, W. J. Xu, X. X. Zhang, J. Du and S. M. Zhou, Appl. Phys. Lett.
98, 082503(2011)[1] M. R. Visokay and R. Sinclair, APL 66 1692 (1995). [2] H. Shima, K. Oikawa, A. Fujita, K.
Fukamichi, and K. Ishida, JMMM 272 2173 (2004).

JI03

JI06

Mechanism of large magnetic anisotropy of thin film m-DO19 Fe3Pt
and analogous 3d-5d compounds

Effect of deposition temperature on the crystallographic structureand first-order magnetic phase transition of FeRh thin films on glass
substrate

Oleg Mryasov* and Takao Suzuki
Materials for Information Technology (MINT) Center, University of Alabama, USA

Wei Lu1, Chenchong He2, Zhe Chen2 and Biao Yan2
School of Materials Science and Engineering, Tongji University, Shanghai, China
2
Tongji University, China
1

TH
I
W

D

WN
A
R

Ordered B2(CsCl)-type FeRh alloy and its nearby compositions have been subject of extensive
theoretical and experimental studies due to a first-order magnetostructural phase transition
from an antiferromagnetic (AFM) to ferromagnetic (FM) state when heating beyond a criticaltransition temperature. Recently, there are many literatures investigating the first-order AFM/
FM transition in FeRh-based thin films. Generally, deposition temperature is expected toinfluence the structure and consequently the magnetic properties of magnetic thin films. In thispresentation, the effect of deposition temperature on the structure and AFM/FM phase transition
is investigated in details. XRD results show that the films fabricated at Ts = 350 and 400 oC aregrown with FeRh(001) planes parallel to the MgO(100) substrate. The temperature dependent
magnetization curves indicate that the as-deposited thin film at Ts = 350oC did not show any
AFM/FM phase transition although it has ordered B2 structure as shown in XRD results. Whilefor the FeRh film deposited at 400oC, it shows a clear AFM/FM phase transition when heatingfrom low temperature to high temperature. But the transition is very broad (range from -50oC
to about 100oC) due to the composition variation, internal stress, defects and so on in the thinfilms.

July 8-13, 2012 Busan, Korea

105

ORAL PRESENTATION
JJ01

JJ04

KA02

KB01

Some new physics and magnetism of rare earth-rich R5T4 and R5T3
compounds

Magneto-volume anomalies and low-temperature inverse magnetocaloric effect in Er2Fe17

Coexistence of antiferromagnetic order and hybridization gap in Cebased kondo semiconductors

Aligning and measuring the magnetic easy axis direction ofsuperparamagnetic nanoparticles at temperatures much greater thanthe blocking temperature

Oral Friday

Intermetallic compounds of the rare earth metals (R) with group 14 elements (T) at
the R5T4 and R5T3 stoichiometries provide numerous opportunities to clarify structureproperty relationships that are generally elusive in compounds formed by metals, and in
the future, to exploit this knowledge. The uniqueness of R5T4 compounds lies in welldefined, self-assembled layers composed of R and T atoms coupled with the flexibility
to modify their arrangements in closely related structures using a variety of triggers.
Interestingly, the R5T3 compounds that also adopt distinctly layered but different
crystal structures exhibit an interesting interplay between their crystal and magnetic
sublattices. In this presentation we will be concerned with some recently discovered,extraordinarily interesting structural, magnetic, and electronic transport phenomenathat are related to structural and microsctructural modifications that facilitate an
unprecedented level of control over the physical behaviors of these compounds.
This work is supported by the U.S. Department of Energy, Materials Sciences andEngineering Division of the Office of Basic Energy Sciences under contract No. DEAC02-07CH11358 with Iowa State University.

Pablo Alvarez1, Pedro Gorria1*, Jose Luis Sanchez Llamazares2, Jorge Sanchez Marcos3, Gabriel Cuello4, Ines Puente-orench5,
Gaston Garbarino6, Imanol De Pedro7, Jesus Rodriguez Fernandez7 and Jesus A. Blanco1
1
Department of Physics, University of Oviedo, c/ Calvo Sotelo, s/n, 33007 Oviedo, Spain
2
Division de Materiales Avanzados, IPCyT, Camino a la presa San Jose 2055, 78216, San Luis Potosi, Mexico
3
Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain
4
Institute Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble, France
5
Instituto de Ciencia de Materiales de Aragon, CSIC-Univ. Zaragoza, 50009 Zaragoza, Spain
6
European Synchrotron Radiation Facility, BP 220, 6 rue Jules Horowitz, 38043 Grenoble, France
7
Department CITIMAC, University of Cantabria, 39005 Santander, Spain
Most of the magnetic properties of Er2Fe17 intermetallic can be understood using a two-sublattice model, corresponding
to the erbium and iron elements, respectively. This compound crystallizes in the hexagonal Th2Ni17-type structure (P63/mmc space group) and exhibits ferrimagnetic behaviour with the Er sublattice moments antiparallel to those of the Fesublattice, and a Curie temperature TC-300K. Combining different experimental techniques, such as neutron powder
thermo-diffraction, x-ray powder diffraction under high hydrostatic pressure (20GPa) and magnetization measurements as afunction of temperature (2-350K), magnetic field (up to 80kOe) and hydrostatic pressure up to 1GPa), we show the presenceof strong magneto-volume anomalies, including Invar effect, from low temperature up to 450 K, indicating the existenceof short-range magnetic correlations well above TC. In addition, this compound exhibits a direct magneto-caloric effect(MCE) around room temperature as well as an inverse MCE below 100K. A mean field Hamiltonian, that incorporates
both crystalline electric field and exchange interactions, has been used to describe the main experimental trends for thetemperature dependences of the MCE and the atomic magnetic moments. Therefore, it seems that a correlation between themagneto-volume anomalies and the MCE is the key to understand the physical properties of this intermetallic compound.
D. Givord and R. Lemaire, IEEE Trans. Magn. 10, 109 (1974). F. Grandjean, O. Isnard, D. Hautot, and G. Long, Phys. Rev. B 63,
014406 (2000). P. Gorria, P. Alvarez, J.Sanchez-Marcos, J.L. Sanchez Llamazares, M.J. Perez, and J.A. Blanco, Acta Mater. 57, 1724
(2009). P. Alvarez, P. Gorria, and J.A. Blanco, Phys. Rev. B 84, 024412 (2011).

D T Adroja1*, T. Takabatake2, Y. Muro3, K. Yutani2, J. Kajino2, K. Umeo4, S. Kimura5, A. D. Hillier1, D. D. Khalyavin1
and A. Severing6
1
ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX, United Kingdom
2
Dept. Quantum Matter, AdSM, Hiroshima University, Higashi-Hiroshima, Japan
3
Liberal Arts and Sciences, Toyama Prefectural University, Imizu, Japan
4
4N-BARD, Hiroshima University, Higashi-Hiroshima, Japan
5
UVSOR Facility, Institute for Molecular Science, Okazaki, Japan
6
Institute of Physics II, University of Cologne, Cologne, Germany

Jean-charles Eloi, Mitsuhiro Okuda, Sarah Ward Jones and Walther Schwarzacher*
H. H. Wills Physics Laboratory, University of Bristol, United Kingdom[1] A. M. Strydom, Physica B 404, 2981(2009). [2] T. Nishiokaet al., JPSJ 78, 123705 (2009). [3] Y. Muroet al., PRB81,
214401 (2010). [4] D. D. Khalyavin et al., PRB82, 100405 (2010). [5] D. T. Adroja, et al., PRB82, 104405 (2010). [6] S.
Kimura, et al., PRL106, 056404 (2011).

Cobalt-doped magnetite nanoparticles with diameter ~8nm and blocking temperature ~60K were fabricated using the protein ferritin as a template. Magnetic measurements ofa solution of the nanoparticle-containing ferritin (magnetoferritin) in 50 mM Tris-HCl
reveal unusual dynamic behaviour. The magnetoferritin is free to rotate at temperatures
down to ~ 210K, although differential scanning calorimetry shows that the bulk of thesolution starts to freeze at ~269K. Cooling the sample through 210K in a 5T appliedfield aligns the easy axes of the magnetoferritin, even though 210K is considerably
higher than the blocking temperature. At low temperatures (5K) the magnetoferritinwith aligned easy axes has significantly higher remanence and coercivity than whenthe easy axes are randomly oriented. For temperatures 60<<T<210K, the aligned
magnetoferritin also has a much higher susceptibility than when the easy axes are
randomly oriented. Warming the sample through 210K, the loss of easy axis alignment
is observed as a decrease in the susceptibility from the aligned towards the randomly
oriented value. The time constant for this decrease depends on the effective viscosity,and is extremely sensitive to temperature. This work has received funding from theEuropean Community's Seventh Framework Programme (FP7/2007-2013) under Grant
Agreement n°228673 (MAGNONICS).

The mechanism of the gap formation in so called Kondo semiconductors (KSs) such as SmB6, YbB12, and CeRhAs remains
elusive. The anisotropic gap structure is thought to originate from the k-dependence of hybridization of a crystal field groundstate of the rare-earth ion with a conduction band. The ground states of all the KSs are paramagnetic except for CeOs4Sb12
which undergoes an SDW transition at 0.9 K. Recently, the compounds CeT2Al10 (T = Ru, Os) have been found to havetransport gaps of approximately 50 K and order antiferromagnetically at exceptionally high temperature, 28 K [1-5]. It ispuzzling that the ordering temperature is much higher than those of the Gd counterparts in spite of the small ordered momentof 0.3-0.4 B/Ce. To answer this puzzle, we have performed bulk and microscopic measurements on single crystalline
samples of CeT2Al10 (T = Fe, Ru, Os) and alloys. We will present the results of magnetic, transport, and optical conductivity
measurements [6] as well as neutron scattering, SR, and XAS experiments. The relation between the anisotropic charge/spin
gaps, the wave functions of the crystal field ground state, and anisotropic electronic states will be discussed.

JJ02

JJ05

KA03

KB02

Morphotropic phase boundary in ferromagnets - A way leading tolarge magnetostriction

Neutron diffraction study of rare-earth compound Ho5Pd2 with large
magnetocaloric effectKondo scattering investigated by Nernst-effect measurements

Exchange-bias in iron-based nanoparticles

Sen Yang1*, Xiaobing Ren2 and Xiaoping Song1
1
Department of Materials Physics, Xi'an Jiaotong University, China
2
National Institute for Materials Science, Japan

Morphotropic phase boundary (MPB), a phase boundary separating two ferroelectric phases ofdifferent crystallographic symmetries in the composition-temperature phase diagram, is crucially
important in ferroelectric materials, because MPB can lead to a great enhancement of piezoelectricity,
the most useful property of this large class of functional materials. From the parallel physics between
ferroelectricity and ferromagnetism, it is tempting to ask if similar MPB can exist in another large
class of functional materials ferromagnetic materials, and if it can lead to significant enhancementof the corresponding properties (magnetostrictive effect, or magnetic-field-induced distortion). Here
we report the existence of a MPB in a ferromagnetic system TbCo2-DyCo2 between a ferromagnetic
rhombohedral phase and a ferromagnetic tetragonal phase. Such a magnetic MPB involves afirst-order magnetoelastic transition, at which both magnetization direction and crystal structurechange simultaneously. The MPB composition demonstrates a 3-6 time larger “figure of merit” ofmagnetostrictive response compared with that of the off-MPB compositions. In-situ observation by
high-resolution synchrotron x-ray diffractometry (XRD) reveals that the MPB region is composedof co-existing rhombohedral and tetragonal phases, indicating the bi-stability of both magnetization
vector and lattice distortion. This accounts for the maximum magnetostrictive property at the MPB.

Hideaki Kitazawa1, Yukihiko Kawamura2, Noriki Terada1, Hiroaki Mamiya1, Hiroyuki S
Suzuki1, Andreas Doenni1, Koji Kaneko3, Naoto Metoki3 and Naoki Igawa3
1
Quantum Beam Unit, National Institute for Materials Science, Japan
2
CROSS-Tokai, Japan
3
Japan Atomic Energy Agency, Japan

In recent years, more efficient magnetic refrigerant materials are desired due to potential applicationin energy-efficient environment-friendly refrigeration technology. Samanta et al. discovered thatthe rare-earth compound Ho5Pd2 shows large magnetocaloric effect (MCE) [1]. The interesting
point is that the large MCE might be originated from field-induced metamagnetic transition below
antiferromagnetic transition temperature TN of 28 K. However, it is not easy to judge whether
Ho5Pd2 is antiferromagnetic or not only from magnetization data. In order to determine its magnetic
structure, neutron diffraction is most powerful technique. We have performed neutron powder
diffraction experiments at JRR-3, Japan using polycrystalline Ho5Pd2. Ho5Pd2 was prepared by arcmelting and annealed at 850 degrees for 72 hours in a vacuum. In this paper, we will present powder
neutron diffraction patterns as a function of temperature. The magnetic peaks with a propagation
vector k = (δ, δ, δ) (δ = 0.18) are gradually developing below about 100 K. The peak width issignificantly broader than an experimental resolution even temperature is 5 K. These results indicatethat Ho5Pd2 is a short-range ordered antiferromagnet with a long wave length.

Peijie Sun1, Christoph Geibel2 and Frank Steglich2
1
Institute of Physics, Chinese Academy of Science, Beijing 100190, China
2
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

The transverse thermoelectric response, known as Nernst effect, was investigated for(CeLa)Cu2Si2 with varying Ce concentrations from 2 K to room temperature. Except
for the non-magnetic LaCu2Si2, all compounds exhibit largely enhanced Nernst signal
in the whole temperature range investigated. Within the standard Boltzmann transport
theory, the Nernst effect measures the relaxation-time spectra of charge carriers as
a function of energy at the Fermi level. This, however, is hardly accessible by thelongitudinal thermoelectric effect, which is mostly dominated by the asymmetricfeature of the electronic density of states. With these considerations in mind, we hopeto gain new insights into the charge-carrier relaxation related to Kondo scattering bystudying the Nernst effect, as well as its correlation with the enhanced thermoelectricity
generally observed in heavy-fermion systems. Our observations of large Nernst
signals in (CeLa)Cu2Si2 point to a remarkable asymmetric character of the chargecarrier relaxation time attributable to the Kondo effect. Furthermore, our analysis
shows that the asymmetric relaxation can account for a major part of the enhanced
thermopower observed in the current systems over a large temperature range, leading
to the conclusion that the asymmetric density of states is of only minor importance inthis respect for Kondo systems

Emeric Folcke1, Jean-marie Le Breton1*, Williams Lefevbre1, Rodrigue Larde1 andJeffrey E Shield2
1
Groupe de Physique des Materiaux - UMR 6634, CNRS - Universite de Rouen,
France2
Nebraska Center for Materials and Nanoscience, University of Nebraska Lincoln,
USA
Iron-based magnetic alloys are much investigated for their good magnetic properties,
especially their high saturation magnetisation. However, large magnetocrystalline anisotropy
is necessary to obtain a support for magnetic recording. This can be achieved in particular for
FePt nanoparticles with the L10 structure [1,2]. In this work, we investigated the magnetic
properties of FePt, FeAu and FeW nanoparticles embedded in a metallic matrix (Cr or W).
The samples were elaborated by inert-gas condensation. The structural properties have been
investigated by high resolution transmission electron microscopy (HRTEM) and laser assisted
atom probe tomography (APT) [3]. Their magnetic properties were characterised by SQUID
magnetometry and Mossbauer spectrometry. SQUID measurements revealed in some cases
an exchange-bias effect which could be due to the occurrence of a core-shell structure in thenanoparticles or to the presence of RKKY interactions through the metallic matrix. This point
will be discussed in relation with the nanostructure characterised by HRTEM and APT.
[1] D.J Sellmyer, C.P. Luo, M.L. Yan, Y. Liu, IEEE Trans. Mag. 4 (2001) 1286-1291. [2] Y.F. Xu, M.L. Yan, D.J. Sellmyer,
J. Nanosci. Nanotechnol. 7 (2007) 206-224. [3] D. Blavette, B. Deconihout, A. Bostel, J. M. Sarrau, M. Bouet, and A.
Menand, Review of Scientific Instruments, 64(10) (1993) 2911-2919.

[1] S. Yang, H. Bao, C. Zhou et al., Phys. Rev. Lett., 104, 197201 (2010). [2] S. Yang, and X. Ren, Phys.
Rev. B, 77, 014407 (2008).

[1] T. Samanta et al, Appl. Phys. Lett. 91, 082551 (2007).

JJ03

KA01

KA04

KB03

Magnetostriction in geometrically frustrated Co3V2O8 single crystals

Probing the Kondo effect on the atomic scale by mapping the itinerant
electrons

Electron spin resonance in antiferro-quadrupolar ordered CeB6

Photocontrolled magnetism through interface strain in core-shellprussian blue analogues

Ryszard Zuberek1, Ritta Szymczak1, Jan Fink- Finowicki1, Victor Nizhankovskii2 andHenryk Szymczak1
1Institute of Physics Polish Academy of Sciences, Warsaw, Poland
2
International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw,,
PolandIn our previous papers (Phys.Rev.B,2006, 2009) we have shown that frustrated
Co3V2O8 single crystals are characterized by a strong magnetocrystalline anisotropy
and that this anisotropy arises due to presence of Co2+ ions strongly connected to
the lattice. In order to check this single-ion mechanism we decided to perform
magnetostriction measurements in Co3V2O8 single crystals. The high-resolution
capacitive dilatometry was used to determine linear (longitudinal and transverse) andvolume magnetostriction as a function of temperature in low temperature region andin magnetic field up to 12 T directed along the main crystallographic directions. The
single crystals of Co3V2O8 were grown by floating zone technique using an opticalimage furnace. The results of measurements are discussed in terms of the singleion model taking into account the competing first and second neighbor Heisenberg
exchange interactions and magnetocrystalline anisotropy constants determined in ourprevious studies. The satisfactory agreement with experimental results shows that themagnetostriction in geometrically frustrated Co3V2O8 is dominated by the single-ion
mechanism . The paper was partly supported by the Ministry of Science and Higher
Education (Poland) through grant No. N202 125135 .

The 19th International Conference on Magnetism

Martin Wenderoth
University of Gottingen, 4. Physikalisches Institut, Germany

Scanning tunneling spectroscopy (STS) has provided an approach to study the Kondo
effect - one of the oldest many particle phenomena known in condensed matterphysics - in real space [1]. In the present work we follow a novel route to investigate
Kondo bulk impurities. It has been shown recently [2] that the anisotropy of thecopper Fermi surface leads to a strongly directional propagation of quasi particles
called electron focusing which gives access to individual bulk impurities in a metal.
Using low temperature scanning tunnelling spectroscopy (STS) we have studied theenergy-dependent scattering characteristics for single isolated atoms of Co and Fe
buried under a Cu(100) surface. For both magnetic impurity atoms we observe a longrange Kondo signature which is periodic with the distance to the impurity [3]. The
comparison of Co and Fe atoms demonstrates that both impurity species show similar
behavior on completely different energy scales, which is determined by the Kondo
temperature. We investigate the scattering amplitude as well as the phase. A theoreticalinterpretation based on a combined approach of band structure and many-bodynumerical renormalization group calculations is able to describe the rich spatially andspectroscopically resolved experimental data.

Pedro Schlottmann*
Department of Physics, Florida State University, USA

CeB6 is the first heavy fermion compound without ferromagnetic short-range
correlations displaying an ESR signal [1]. The ferromagnetic correlations among Ce
or Yb spins in all other compounds showing an ESR signal narrow the resonancewidth rendering it observable [2]. CeB6 is a cubic compound with a Gamma_8 groundquartet. The orbital content of the quartet gives rise to an antiferro-quadrupolar orderedphase below 4 K. Single ions with a Gamma_8 ground-multiplet are expected todisplay four transitions, however, only one was observed. Two fundamental questions
arise: (1) why is only one transition seen, and (2) why is this transition observed if
the Kondo temperature is larger than the linewidth and there are no ferromagnetic
correlations between the ions? While for other Ce and Yb compounds with ESR-signal
it is not possible to distinguish if the resonance is due to localized spins or conducting
heavy electron spins, an itinerant picture within the antiferro-quadrupolar state isnecessary for CeB6. Work supported by the Department of Energy under grant DEFG02-98ER45707.
[1] S.V. Demishev et al, Phys. Rev. B 80, 245106 (2009). [2] E. Abrahams and P. W'olfle, Phys. Rev.
B 78,104423 (2008); 80, 235112 (2009); P. Schlottmann, Phys. Rev. B 79, 045104 (2009).

Oral Friday

Vitalij Pecharsky1*, Yaroslav Mudryk2, Durga Paudyal2 and Karl Gschneidner, Jr.1
1
Ames Laboratory and Department of Materials Science and Engineering, Iowa State
University, USA
2
Ames Laboratory, Iowa State University, USA

106

oRAL PRSENTATION

Elisabeth S. Knowles1, Carissa H. Li2, Matthieu F. Dumont1, Marcus K. Peprah1,
Daniel R. Talham2 and Mark W. Meisel1*
1
Department of Physics and NHMFL, University of Florida, USA
2
Department of Chemistry, University of Florida, USA

Cubic heterostructured (BA) particles of Prussian blue analogues, composed of a shellof ferromagnetic KjNik[Cr(CN)6]l • nH2O (A), Tc ~ 70 K, surrounding a bulk coreof photoactive ferrimagnetic RbaCob[Fe(CN)6]c • mH2O (B), Tc ~ 20 K, have beenstudied. Below Tc ~ 70 K, these samples exhibit a persistent photoinduced decrease in
low-field magnetization, and these results resemble data from other core-shell particles[1] and analogous ABA heterostructured films [2]. This net decrease suggests that thephotoinduced lattice expansion in the B layer generates a strain-induced decrease in
the magnetization of the A layer, similar to a pressure-induced decrease observed byothers in a pure A-like material [3] and by us in our BA cubes. Photocontrol at higher
temperatures is being pursued by applying this strain from the B material to otherhexacyanochromate analogues, which possess higher ordering temperatures for somestoichiometries. Work supported by NSF DMR-1005581 (DRT) and the NHMFL.
[1] M.F. Dumont, et al., Inorg. Chem. 50 (2011) 4295. [2] D.M. Pajerowski, et al., J. Am. Chem.
Soc. 132 (2010) 4058. [3] M. Zentkova et al., J. Phys.: Condens. Matter 19 (2007) 266217.

[1] M. Ternes et al., Journal of Physics: Condensed Matter 053001 (2009) [2] A. Weismann et al.,Science 323, 1190 (2009) [3] H. Prueser et al., Nature Physics 7,203 (2011)

July 8-13, 2012 Busan, Korea

107

ORAL PRESENTATION
KB04

KC01

KC04

KD01

Confinement effect on the A1 to L10 phase transformation of FePt

360 degree domain walls in various magnetic ring thin films

Microstructure and magnetic property of epitaxial Fe/MgO layer on
GaAs and InAs (001) substrates

Spin coupling, orbital angular momentum quenching, and electron
localization in size-selected free transition metal clusters

Oral Friday

The major challenge for the application of chemically synthesized FePt nanoparticles(NPs) in magnetic storage media is the sintering problem encountered during therequired high temperature annealing to obtain the high anisotropy L10 phase. In thiswork, we have used two different methods to avoid sintering; coating the NPs witha protective layer of silica (SiO2) and using porous aluminum oxide (Al2O3) as atemplate to embed the NPs. The NPs were synthesized via the synthesis method of Sun
et al.[1] The NPs were embedded into the Al2O3 by in-situ suctioning of the reaction
solution into the porous Al2O3 template followed by annealing at high temperatures.
Monodispersed FePt NPs with a size of 5.8 and 15 nm were coated with SiO2 shells
using a water-in-oil micro emulsion method. High room temperature coercivities were
only obtained after annealing the samples at 900°C for long times (24-48 h) under
forming gas flow as compared to the usual heat treatment at 600-700°C. Values of 4.7
and 7.8 kOe were observed in SiO2 and Al2O3 samples, respectively after annealingfor 24 h at 900°C. This behavior suggests that the restricted geometry of the samples
suppresses the atomic ordering and the phase transformation drastically.
Work supported by DOE DE-FG02-04ER4612 [1] S. Sun, C. B. Murray, D. Weller, L. Folks, A.
Moser Science 2000, 287, 1989.

Chunghee Nam1 and Caroline A. Ross2
1
Physics, Hannam University, Korea
2
Materials Science and Engineering, MIT, USA

Magnetic domain wall (DW), which is an interface between differently oriented
magnetization regions, becomes an important physical property as the size of magnetic
materials is reduced. DW can be regarded as a rigid particle, which has been verified inexperiments and theoretical study, so that diverse applications have been introduced. In
this presentation, the authors report that 360 degree magnetic domain walls(360DW)
are formed in a circular or ellipse Co rings. In theoretically, 360DWs have been
recently studied in terms of the formation and dynamic as a function of appliedmagnetic fields and electrical currents.[1,2] 360DWs are consisted of two transverse
DWs with opposite polarities but the same chirality. Thus 360DWs are locally in aflux-closure state at remanence, which reduce the magnetostatic energy. Magnetic
force microscopy(MFM) is used to see the formation of 360DWs. Based on the MFM
measurements, the formation of 360DWs gives rise to monitoring the vortex chirality
in various ring-structured thin films. Furthermore, 360DWs generate a low stray field,
which is useful for high density magnetic devices without proximity effects. Theinteraction between 360DWs and a tip of MFM will be shown to verify properties of
360DWs in detail.

Kyung Ho Kim1, Hyung-jun Kim1*, Jun Woo Choi1, Joonyeon Chang1 and Young Keun
Kim2
1
Spin Convergence Research Center, Korea Institute of Science and Technology, Korea
2
Department of Materials Science and Engineering, Korea University, Korea
Epitaxial growths of Fe/MgO layers on GaAs and InAs heterostructures have been extensively
studied for efficient spin injection from ferromagnetic metals into semiconductors. Structural property
related to magnetic anisotropy of the Fe layers is mainly determined by underlying strain of MgOtunnel barrier due to the large lattice mismatch between MgO and substrates. In this presentation, weinvestigated the microstructural evolution and the effect on in-plane magnetic anisotropy of epitaxial
Fe/MgO layers grown on GaAs and InAs(001) substrates with respect to the growth temperature andthickness of the MgO tunnel barrier. The Fe layer grew in three-dimensional(3D) islands with two
different in-plane textures of [010] and [110] on the MgO layers grown at low temperatures, while
it grew in two-dimensional(2D) layer on the MgO layers grown at high temperatures. As the MgOgrowth temperature and the thickness increase, the strain of the MgO and the subsequent Fe layers
are simultaneously relaxed. The partial strain relaxation of the Fe leads to the transition from 3D
islands of no magnetic anisotropy to 2D layer of in-plane cubic anisotropy. Furthermore, the islands
coalesce as the nominal thickness of Fe increases, resulting in the continuous 2D layer of Fe with the
cubic anisotropy.

Konstantin Hirsch1, Markus Niemeyer1, Vicente Zamudio-Bayer1, Andreas Langenberg1, Arkadiusz
Lawicki1, Bruno Langbehn1, Henning Schroeder1, Martin Kossick2, Akira Terasaki3, Thomas Moeller2,
Bernd Von Issendorff4 and Tobias Lau1*
1
Institut fuer Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, HelmholtzZentrum Berlin fuer Materialien und Energie GmbH, Germany
2
Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin, Germany
3
Cluster Research Laboratory and Department of Chemistry, Toyota Technological Institute and Kyushu
University, Japan
4
Fakultaet fuer Physik, Universitaet Freiburg, Germany
X-ray magnetic circular dichroism (XMCD) spectroscopy is a local and element specific technique tostudy spin and orbital magnetization. By applying XMCD spectroscopy to size-selected free clusters, weare able to resolve spin and orbit contributions to the magnetization in particles without any interaction
with a support or matrix. This experimental technique allows us to study magnetic coupling in transition
metal clusters, follow the quenching of the orbital angular momentum, and gain insight into the interactionof a magnetic impurity with a finite, few-atom free electron gas. Recent highlights will be discussed,
including antiferromagnetic coupling of the central atom in Fe_13^+, ferromagnetic spin coupling in
Cr_2^+, and the complex interplay of hybridization and on-site coulomb repulsion which determines themagnetic moment of impurity atoms in transition metal-doped gold clusters.

[1]P. E. Roy, T. Trypiniotis and C. H. W. Barnes, Phys. Rev. B 82, 134411 (2010) [2]Mark D.
Mascaro and C. A. Ross, Phys. Rev. B 82, 214411 (2010)[1] Kim, K. H. et al., Appl. Phys. Lett., V. 95, pp. 164103 (2009) [2] Kim, K. H. et al., Cryst. Growth Des., V. 11, pp. 2889 (2011) [3]Kim, K. H. et al., J. Appl. Phys., V. 110, pp. 114910 (2011) [4] Kim, K. H. et al., J. nano sci. nano tech., V. 12, pp. 1573 (2012)

M. Niemeyer, K. Hirsch, V. Zamudio-Bayer, A. Langenberg, M. Vogel, M. Kossick, C. Ebrecht, K. Egashira, A. Terasaki, T.
Moller, B. v. Issendorff, J. T. Lau, Phys. Rev. Lett. 108 (2012) 057201

KB05

KC02

KC05

KD02

Are small CoPt and FePt nanoparticles mono-L10 domain?

Magneto-optical effect of rare earth doped zinc ferrite thin films
prepared using PLD

Magnetic and transport properties of epitaxial discontinuous Fe/MgO
multilayers

Nm-sized magnetic domains observed by small angle neutron
scattering in exchange coupled superlattices

Florent Tournus1*, Kazuhisa Sato2, Toyohiko J. Konno2, Thierry Epicier3 andVeronique Dupuis1
1
LPMCN, CNRS & Univ. Lyon 1, France
2
Institute for Materials Research, Tohoku University, Japan
3
MATEIS, CNRS & INSA-Lyon, France
Despite the many experimental and theoretical studies, open questions regarding thestructure of small CoPt and FePt nanoparticles remain (threshold size for L10 ordering,
preferential segregation, most favourable geometry). Moreover, while well known
planar defects (c-domain boundaries, antiphase boundaries) are met in macroscopic
materials or thin films, their relevance for particles of a few nanometers has not been
examined. Therefore, an implicit belief is that small CoPt or FePt nanoparticles, if they
can be chemically ordered, would be mono-L10 domain. CoPt and FePt nanoparticles,with a diameter between 2 and 5 nm, have been prepared by cluster deposition andannealed. For both alloys, we observe using transmission electron microscopy acoexistence of fcc nanocrystals and multiply-twinned particles with decahedral or
icosahedral shapes. In addition to mono-L10 domain particles, we put into evidence
that even small particles can display several L10 domains. In particular, the chemicalorder can be preserved among twinning which can give rise to spectacular chemicallyordered decahedral particles made of five L10 domains. The stability of such structures,
which had been recently predicted from theoretical simulations, is thus experimentallyconfirmed. These observations are then confronted to recet experimental results ofmagnetometry and synchrotron measurements (XMCD, EXAFS).

Naoki Wakiya1*, Tekeshi Misu1, Nobuyasu Adachi2, Naonori Sakamoto1, Kazuo
Shinozaki3 and Hisao Suzuki1
1
Shizuoka University, Japan
2
Nagoya Institute of Technology, Japan
3
Tokyo Institute of Technology, Japan
Rare earth elements have large orbital interactions. In addition, electron transition of trivalence rare earth ions exists in the ultra violet regions, and suppresses the absorption
in the visible light region. Therefore, large magneto-optical effect is expected for
ZnFe2O4 thin films doped with rare earth elements even in the visible region. In thiswork, ZnFe2O4 thin films doped with rare earth elements (La, Nd, Sm, Eu, Gd, Dy, Ho,Yb) in the Fe site were prepared on fused SiO2 substrate using pulsed laser deposition.
All films were polycrystalline. Ho doped ZnFe2O4 thin film showed relatively highoptical transmittance in the visible light region (400-800 nm). Faraday rotation angle
changes with the kind of rare earth elements, and maximum angle (12000 deg/cm) was
obtained for Ho doped ZnFe2O4 thin film. This results reflects the large spin orbital
interactions.

A. Garcia - Garcia1, J. A. Pardo2, P. Strichovanec3, A. Vovk4, J. M. De Teresa1, G. N. Kakazei5, Yu. G.
Pogorelov5, P. A. Algarabel1* and M. R. Ibarra2
1
ICMA, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
2
INA, Universidad de Zaragoza, 50018 Zaragoza, Spain
3
INA, Universidad de Zaragoza, 50018, Spain
4
CFMC, Universidade de Lisboa, 1749-016 Lisboa, Portugal
5
IFIMUP Universidade do Porto, 4169-007 Porto, Portugal

Karine Dumesnil1*, Catherine Dufour1, Mike Fitzsimmons2, Julie Borchers3, Kathryn Krycka3, Mark Laver4 andJonghan Won2
1

Institut Jean Lamour - Lorraine University, France
LANSCE, USA
NIST, USA
4
PSI, Switzerland
2
3

Discontinuous metal-insulator multilayers (DMIMs) are cermet structures prepared by repeated alternate deposition of acontinuous insulating and a discontinuous metal layer [1]. However, little attention has been paid to the influence of thesubstrate nature, deposition temperature, and degree of crystallinity of the insulator layer on transport properties of DMIMs.
In recent work [2] we reported tunnelling magnetoresistance (TMR) values for epitaxial Fe/MgO DMIMs deposited on
single-crystalline MgO(001) substrates. Here we report a comparison of the magnetic and transport properties of DMIMs[Fe (0.6 nm)/MgO (3 nm)]10 deposited on two different substrates: Corning Glass (CG) and single-crystalline MgO(001)with deposition temperatures (Ts) ranging from 20 ºC to 250 ºC. Zero field cooled and field cooled magnetic susceptibility
measurements were carried for H=50 Oe and 5K<T<300K. The samples exhibit superparamagnetic behaviour. For
temperatures higher than the bifurcation temperature (TB) the susceptibility measurements were fitted using a CurieWeiss law and the average size (Davg) of the magnetic grains was obtained. More precise determination of Davg. and theirdistribution was done by measuring magnetization isotherms for T>TB. We observed that the Fe grains volume is bigger forthe samples prepared on MgO substrates. The relationship between transport and magnetic properties will be discussed.

WN
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[1]H. G. Silva, A. M. Pereira, J. M. Teixeira, J. M. Moreira, G. N. Kakazei, J. P. Araujo, Yu. G. Pogorelov, J. B. Sousa, M. E. Braga, B. Raquet, H.
Rakoto, C. Gatel, E. Snoeck, S. Cardoso, and P. P. Freitas Phys. Rev. B 82, 144432 (2010). [2]A. Garcia-Garcia, J. A. Pardo, P. Strichovanec, C. Magen, A.
Vovk, J. M. De Teresa, G. N. Kakazei, Y. G. Pogorelov, L. Morellon, P. A. Algarabel, and M. R. Ibarra Appl. Phys. Lett. 98, 122502 (2011).

KB06

KC03

KC06

KD03

Magneto-structural correlations in antiferromagnetic and ferrimagnetic nanoparticles

Electric field control of coercivity of Pt / Co / Al-O trilayer structures

Magnetic and transport properties of submicron Gd strip

Optical and magneto-optical characterization of Y0.5Bi2.5Fe5O12 andBi3Fe5O12thin films prepared by metal-organic decomposition

Nuno Silva1*, Vitor S. Amaral1, Luis D. Carlos1, Ainhoa Urtizberea2, Rodney Bustamante2, Angel Millan2, Fernando Palacio2, Erik Kampert3,
Uli Zeitler3, Sophie De Brion4, Yuki Komorida5, Masaki Mito5, Oscar Iglesias6, Amilcar Labarta6, Ines Puente Orench7 and Javier Campo7
1Dep. Fisica and CICECO, Universidade de Aveiro, Portugal
2
Departamento de Fisica de la Materia Condensada and ICMA Universidade de Zaragoza, Spain
3
Radboud University Nijmegen, High Field Magnet Laboratory, Netherlands
4
CNRS, Inst. Neel, F-38042 Grenoble 9, France and Univ. Grenoble, Grenoble, France, France
5
Faculty of Engineering, Kyushu Institute of Technology, Kitakyushu, Japan, Japan
6
Departament de Fisica Fonamental and Institut de Nanociencia i Nanotecnologia, Univ. Barcelona, Spain
7
ICMA-CSIC/Univ. Zaragoza, Zaragoza Spain and Institut Laue-Langevin, Grenoble, France, Spain
We present structural and magnetic studies performed in ferrimagnetic[1,2] and antiferromagnetic[3-7] nanoparticles.
We focus our attention on the antiferromagnetic ferritin and cobalt oxide and on the ferrimagnetic maghemite. High-fieldstudies in ferritin reveal that the temperature dependence of the antiferromagnetic susceptibility decreases with temperaturewhen correctly determined from high-field data.[5] High-field hysteresis loops also show that coercivity and loop-shifts
are a function of the maximum field, which can be understood in the frame of coherent rotation models considering afield-dependent anisotropy energy.[7] Neutron diffraction is particularly effective in the study of structural and magnetic
coherence sizes of antiferromagnetic nanoparticles. In the case of cobalt oxide, we found that the difference between
both sizes is consistent with a core-shell model where the shell is structurally ordered but magnetically disordered with athickness of ~2 nm.[6] This core shell model was also successfully applied to a series of maghemite nanoparticles, based on
small-angle X-ray scattering and magnetization results, yielding, in this case, a magnetically disordered shell with about 1
nm.[1] Surface and core contribution to anisotropy energy in maghemite can be elegantly separated by using pressure, since
the core/shell volume ratio changes with pressure inducing a change in the average anisotropy energy.[2][1] A. Millan et al. J. Mag. Mag. Mater., 312, L5-L9 (2007). [2] Y. Komorida et al. Appl. Phys. Lett, 94, 202503 (2009) [3] N. J. O. Silva etal. Phys. Rev. B, 71 184408 (2005). [4] N. J. O. Silva et al. Phys. Rev. B 77, 134426 (2008). [5] N. J. O. Silva et al. Phys. Rev. B, 79, 104405(2009). [6] N. J. O. Silva et al. Phys. Rev. B, 82, 094433 (2010). [7] N. J. O. Silva et al. Phys. Rev. B 84, 104427 (2011).

The 19th International Conference on Magnetism

Oral Friday

Andrew Gallagher*, Levent Colak, Ozan Akdogan and George Hadjipanayis
Physics and Astronomy, University of Delaware, USA

108

oRAL PRSENTATION

Tatsuro Ohashi1, Junichi Shiogai1, Tim Yang1, Makoto Kohda1*, Takeshi Seki2,
Kesami Saito2, Koki Takanashi2 and Junsaku Nitta2
1
Department of Materials Science, Tohoku university, Japan2
Department of Materials Science, IMR, Tohoku university, Japan

Seiji Nonoguchi1, Tatsuya Nomura1, Takahiro Matsunaga2, Kohsuke Furukawa2,
Masahiro Hara2 and Takashi Kimura1*
1
Kyushu University, Japan
2
Kumamoto University, Japan

In recent years, much attention has been focused on studies of effective magnetization switching byelectric current1-4 because of lower power consumption and zero-magnetic field operation. Due to its
compatibility with conventional technology, the electric field control of magnetic properties is more
attractive5-8. Here we demonstrated the electrical gate control of coercivity in an ultrathin Co layer
sandwiched between Pt and Al-O. A single wafer, which consists of Pt (3 nm) / Co (0.6 nm) / Al-O (1.0nm) trilayer on SiO2 substrate, was prepared. In order to investigate magnetic properties by anomalous
Hall effect (AHE), the wafer was processed into a Hall bar geometry. Subsequently, a 20nm-thick
Al-O insulating layer was formed by atomic layer deposition at 200 ºC. Finally, an AuGeNi / Au gateelectrode was evaporated on top. The Curie temperature of our sample was determined to be 340 K at
VG = 0 V from the temperature dependence of AHE. The coercivity change of ± 3.0 Oe was observed at
280K by applying the gate voltages of ± 8 V, which correspond to electric fields of ± 3.83 MVcm-1. We
successfully modulated the coercivity of the Pt / Co layer by the electric field application.

Magnetic refrigeration utilizing magnetocaloric effects is expected as futureenvironment-friendly refrigeration system. So far, the magnetocaloric effects havebeen investigated mainly in bulk systems. Recent nanofabrication techniques
enable us to make the magnetocaloric materials with reduced dimensions. However,physical properties in such materials have not been investigated intensively. Here, weinvestigate the magnetic and transport properties of the Gd with reduced dimensions.
Submiron-wide Gd strips have been prepared by the conventional lift-off technique
combined with the electron-beam lithography. The magnetic properties have been
evaluated by using a micro Hall cross based on GaAs/AlGaAs two dimensional
electron gas (2DEG) system, and the transport properties have been evaluated by themagnetoresistance measurements. Clear magnetic hysteresis loops with the shapeanisotropy were observed by the 2DEG Hall measurements, meaning that the Gd
maintains still ferromagnetism even in the reduced dimension. On the other hand, theresistance change related to the magnetization was not observed. Since the f-electrons
play an important role in the magnetocaloric effect of the Gd, this result implies thatthe correlation between the conduction electrons and f-electrons is very small.

[1] S. Mangin et al., Nature Mater. 5, 210 (2006). [2] T. Seki et al.,Appl. Phys. Lett. 88,172504 (2006). [3] M.
Misiorny et al., Phys. Rev. B 76, 054448 (2007). [4] I. M. Miron et al., Nature Mater. 9, 230 (2010). [5] D.
Chiba et al., Nature Mater. 10, 853 (2011). [6] Y. Shiota et al., Nature. Mater. 11, 39 (2011). [7] T. Seki et al.,Appl. Phys. Lett., 98, 212505 (2011). [8] W. G. Wang et al., Nature. Mater. 11, 64 (2012).

Shengjun Tang1, Tomohiko Yoshida1, Martin Veis2, Martin Zahradnik2, Roman Antos2,
Takumi Moriyama3 and Takayuki Ishibashi1*
1
Department of Materials Science of Technology, Nagaoka University of Technology,
Japan
2
Faculty of Mathematics and Physics, Charles University at Prague, Czech Republic
3
HORIBA, Ltd., Japan
In this work, optical and magneto-optical (MO) properties of Y0.5Bi2.5Fe5O12 (Bi:YIG) and Bi3Fe5O12(BIG) thin films prepared by a metal-organic decomposition (MOD) method [1] have been studied.
The Bi:YIG and BIG thin films were prepared on Gd3Ga5O12 (100) substrates. After a spin-coatingprocess, the samples were placed in a furnace with pre-annealing temperatures of 450°C and 400°C for
30 minutes and annealed at 750°C and 490°C for 3 hours to crystallize. Spectroscopic ellipsometry andmagneto-optical spectroscopy were employed to derive a spectral dependence of permittivity tensor atphoton energy range from 0.6 to 5 eV. Magneto-optical spectra displayed spectral features typical for Bi
substituted garnets [2] reflecting fully developed garnet structure in all investigated films. At the energy
range of 3.2~5 eV, Bi:YIG film showed higher amplitude of Kerr rotation than BIG, which is opposite to
Faraday rotation measurements at the energy range 1.7~3.1 eV. This can be explained by higher surface
roughness of BIG film according to atomic force microscopy measurements. Presented results showed
high quality of investigated Bi:YIG films which demonstrates MOD as an effective technique to prepare
highly substituted garnet films suitable for MO applications.
[1] T. Kosaka, et al., J. Magn. Soc. Jpn., 35, 194-198 (2011). [2] S.Wettekoek, et al., Phys. Rev. B., 12, 2777-2788 (1975).

July 8-13, 2012 Busan, Korea

109

ORAL PRESENTATION
KE03

KF03

Fabrication of the epitaxial growth of (100) and (110) oriented Heusler
alloy films for magnetic damping measurement.

Spin-transfer-torques-induced domain-wall motion in ferromagnetic
Pt/Co/Pt nanowires with perpendicular magnetic anisotropy

Effects of mechanical rotation and vibration on spin currents

Oral Friday

It has been reported [1] that the critical current density of MRAM is proportional
to the damping parameter. Various investigations have reported a small damping
parameter on the half metallic heusler alloy but the mechanism of magnetic damping
is not yet clarified [2]. The present work aims at fabricating the epitaxial growthfilms for the damping measurement. Thus, Cr/Co2MnSi/Ru and Ta/Cr/ Co2MnSi/
Ta films were fabricated by sputtering respectively on MgO (100) substrate and on
a-sapphire substrate at annealing temperatures ranging from 350 to 5500C. The pole
figure analysis of the fabricated films show an epitaxial growth of Co2MnSi layeron MgO (100) and a-sapphire substrate. We thus, have successfully fabricated (100)and (110) oriented Heusler alloy films. The films contain also L21 order structure. In
addition, the FMR and the VSM measurements were conducted in order to investigate
the magnetic properties of those films. The line widths of ferromagnetic resonancespectrum depend on the annealing temperature of Co2MnSi layer. Those measurements
displayed optimal conditions (a high Magnetization and a small damping constant) for
the sample with Co2MnSi layer annealed at 4500C. The samples will have Co2MnSi
layer annealed at 450 0C for further investigations.

Kab-jin Kim1, Jae-chul Lee1, Jisu Ryu2, Kyoung-woong Moon1, Sang-jun Yun1,
Kyung-ho Shin3, Hyun-woo Lee2 and Sug-bong Choe1*1Department of Physics, Seoul National Univerisity, Korea
2
Department of Physics, POSTECH, Korea
3
KIST, Korea

The spin-current-based electric controllability of ferromagnetic domain walls (DWs) has been of great interest
because of its feasible applications. In particular, nanowires with perpendicular magnetic anisotropy have been
predicted as more suitable materials for practical applications. However, the experimental verification withmultiple DWs control in such materials has not been explored yet. And also, the physical driving mechanism
resulting from the competition between the spin transfer torques (STTs) adiabatic and nonadiabatic STTs anddisorders is still controversial. By using Pt/Co/Pt nanowires, here we experimentally demonstrate that the purely
current driven multiple DWs motion can be obtained at current densities less than 107 A/cm2, allowing randommagnetic bits recording and transferring. Furthermore, based on the DWs motion driven by magnetic field and/or current, we can unambiguously distinguish the role of STTs on thermally activated magnetic domain wallmotion. The adiabatic STT resulting in quadratic contribution to effective field is found to be dominant for large
current densities, whereas the nonadiabatic STT playing the same role as magnetic field subsisted at low current
densities. This finding will provide a step to the complete understanding of STT induced DW dynamics as well as
the technological progress in DW based emerging nanodevices.

Mamoru Matsuo*, Jun'ichi Ieda, Eiji Saitoh and Sadamichi Maekawa
Advanced Science Reserch Center, Japan Atomic Energy Agency, Japan

In the frontier of spintronics, much attention is paid on the control of spin currents.
Due to the recent progress of nanoelectromechanics, mechanical manipulation of spins
increases its importance. We discuss theoretically the generation of spin currents in bothrotationally and linearly accelerating systems. The spin-orbit interaction argumented
by inertial effects is derived from the low energy limit of the generally covariant Diracequation. It is shown that the spin-orbit interaction is responsible for the generation ofspin currents by mechanical rotation and vibration. We also investigate SU(2) x U(1)gauge theory in accelerating systems, which allows us to extend the spintronic theory
in inertial frame to non-inertial frames.
M. Matsuo, J. Ieda, E. Saitoh, and S. Maekawa, Physical Review Letters 106, 076601 (2011);
Applied Physics Letters 98, 242501 (2011); Physical Review B 84, 104410 (2011).

KG01
Hidden order pseudogap and hybridization modulation in URu2Si2

Alexander Balatsky1, Jason Haraldsen1, Yoni Dubi2, Jian Xin Zhu3, Peter Wolfle4 and Matthias Graf3
1
Center for Integrated Nanotechnologies, LANL, USA
2
Center for Integrated Nanotechnologies, LANL, Israel
3
Theory division, LANL, USA
4
Institute for Theory of Condensed Matter and Center for Functional Nanostructures, Karlsruhe Germany, Germany

A. Balatsky (Los Alamos) URu2Si2 proved to be a compound that has exhibited similarities with othercorrelated materials like HighTc oxides in that it has strong correlations, competing phases and intense
nanoscale inhomogeneity in Kondo lattice. We point out that Hidden order transition is not a mean
field transition, in contrast to prevailing discussion to date. Iit has significant precursor effects, so called
pseudogap. Through an analysis and modeling of data from various experimental techniques, we present
evidence for the presence of a hidden order pseudogap in URu2Si2 in the temperature range between 25
K and 17.5 K. We evaluate the effects that gap fluctuations would produce on observables like tunnelingconductance, neutron scattering and nuclear resonance, and relate them to the experimental findings. We
show that the transition into hidden order phase is preceded by the onset of non-coherent hidden orderfluctuations. We also discuss nanoscale inhomogeneity seen in URu2Si2 with STM as an evidence forhybridization modulation due to local defects and discuss the role of hybridization modulations in Hidden
Order.
Hidden order pseudogap in URu2Si2, J. Haraldsen, 10.1103/PhysRevB.84.214410 (2011) Electronic inhomogeneity in a Kondo
lattice, E. Bauer et al, PNAS 108, 6857 (2011) How Kondo Holes Create Intense Nanoscale Heavy-Fermion Hybridization
Disorder,PNAS 2011 108 (45) 18233-18237; published ahead of print October 17, 2011, doi:10.1073/pnas.1115027108
Anomalous femtosecond quasiparticle dynamics of hidden order state in URu2Si2 Georgi L. Dakovski et al, Phys. Rev. B 84,
161103 (2011) Hybridization Wave as the “Hidden Order” in URu2Si2, Y. Dubi et al, Phys. Rev. Lett. 106, 086401 (2011)
Incommensurate spin resonance in URu2Si2, A. V. Balatsky, et al, Phys. Rev. B 79, 214413[1] D. Kim et al. Applied physics letter99, 072502(2011) [2] Mizukami et al. Journal of Magnetismand Materials 226-230 2001) 1640-1642[1] K.-J. Kim et al., Appl. Phys. Express 3, 083001 (2010). [2] J.-C. Lee et al., Phys. Rev. Lett. 107, 067201 (2011). [3] K.-J.
Kim et al., Phys. Rev. Lett. 47, 217205 (2011).

KE01

KF01

KF04

KG02

Thermalised and frozen magnetization dynamics in artificial spin ice

Non-linear dynamics and high RF detection sensitivity in MgO-based
spin-torque diode

Design of self-organized nanostructures to achieve high blocking
temperatures in MgO-based d0 ferromagnets

Strain-effect on topological quantum phase transition in Ir-oxides

Jason Morgan1, Zoe Budrikis2, Johanna Akerman3, Aaron Stein4, Paolo Politi5, Sean Langridge6, Robert
Stamps7 and Christopher Marrows1*
1
School of Physics and Astronomy, University of Leeds, United Kingdom
2
School of Physics, University of Western Australia, Australia
3
ISOM, Universidad Politecnica Madrid, Spain
4
Center for Functional Nanomaterials, Brookhaven National Laboratory, USA
5
Istituto dei Sistemi Complessi, CNR, Italy
6
ISIS, STFC Rutherford Appleton Laboratory, United Kingdom
7
SUPA School of Physics and Astronomy, University of Glasgow, United Kingdom

Spin ices are rare earth pyrochlores where the crystal geometry leads to frustration of the rare earth moments [1],which meet at tetrahedra in the lattice. Nanotechnology allows many of the essential features of this physical system
can be reproduced in arrays of nanomagnets [2]. This approach offers the opportunity to continuously tune thevarious parameters controlling the magnetic microstate, and also to inspect that microstate using advanced magnetic
microscopy [3,4]. A significant difference with the naturally occurring spin-ices is that the change in symmetry gives
rise to a true long-range ordered ground state, although the frustrated interactions in these athermal systems mean thatits observation is extremely difficult [5]. Most attempts to achieve it rely on a rotating field demagnetisation protocolthat produces states that show reasonably good ice rule fidelity but only short range correlations [2,5]. Here I will
describe our recent work on an array of 250 nm × 80 nm Permalloy islands in the square ice geometry, including
the achievement of a thermalised ground state during fabrication and the observation of the effects of fractionalisedmonopoles on excitations out of it [6], and athermal achievement of the ground state using a suitable field protocol [7].

Yoshishige Suzuki1, Shinji Miwa1, Shota Ishibashi1, Hiroyuki Tomita1, Takayuki Nozaki2, Eiichi Tamura1, Ken
Ando1, Takeshi Saruya2, Hitoshi Kubota2, Kay Yakushiji2, Akio Fukushima2 and Shinji Yuasa2
1
Graduate School of Engineering Science, Osaka University, Japan
2
Spintronics Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Japan
In the emerging field of ‘spintronics’, two electron attributes, namely, charge and spin,
are simultaneously manipulated to obtain new, desirable characteristics, such as large
magnetoresistance, spin-transfer induced magnetization switching, and precession in magnetic nanomaterials. In 2005, a phenomenon called the spin-torque diode effect [1] was demonstrated, whichenabled the rectification of RF signals in magnetic tunnel junctions (MTJs); the rectification output,
however, was several thousand times smaller than that of semiconductor diode detectors. Manyefforts, such as the control of magnetic field direction [2,3] and the use of stochastic resonance [4],have significantly enhanced the sensitivity; nevertheless, the sensitivity of MTJs remain far lower
than that of semiconductor diode detectors. In this study, we show that applying a DC bias current
to MTJs while precisely controlling their magnetic potential profiles provides a high RF detection
sensitivity of 12,000 V/W at room temperature, which exceeds that of semiconductor diodedetectors (3,800 V/W). Analysis based on a macro-spin model reveals that this increase is caused byrotation of the precession axis that depends on RF input power. This rotation, a type of non-linear
ferromagnetic resonance, causes a change in resistance and affords the high sensitivity.

Masayoshi Seike1*, Tetsuya Fukushima2, Kazunori Sato2 and Hiroshi Katayama-yoshida2
1Grad. School of Eng. Sci., Osaka Univ. and Cent. Research Labs., Sysmex Corp., Japan
2
Grad. School of Eng. Sci., Osaka Univ., Japan0d ferromagnetism, a new class of magnetism wherein the ferromagnets contain no magnetic elements,
has created significant interest in the field of dilute magnetic semiconductors [1]. In this study, we present
a materials design of MgO-based d0 ferromagnets with high blocking temperature (TB) based on multiscale simulations [2-4]. Chemical pair interactions between N atoms in Mg(O,N) and VMg in (Mg,VMg)
O were calculated using a generalized gradient approximation and the VASP code. Using the Isingmodel, Monte Carlo simulations of the crystal growth were performed to predict the configurationsof dopant distribution. In Mg(O,N), a strong attractive interaction was found between the 1st and 4thnearest neighbors (NN) in which the 1st-NN interaction is approximately twice as strong as the 4thNN interaction. In (Mg,VMg)O, a strong attractive interaction only occurs between the 2nd NN. Our
simulation showed that self-organized nanostructures can be formed both in Mg(O,N) and (Mg,VMg)
O under layer-by-layer crystal growth, suggesting that these d0 ferromagnets can obtain high TB due tosuperparamagnetic blocking. Furthermore, depending on the simulation condition corresponding to theinterval time between layers in deposition, various self-organized nanostructures can form, such as quasione-dimensional nanowires, two-dimensional nanoplanes and three-dimensional nanoclusters.

Jaejun Yu
Department of Physics and Astronomy and CSCMR, Seoul National University, Korea
We predict that a three-dimensional strong topological insulator (TI) phase can berealized by controlling the electron hopping terms in Na2IrO3. From a realistic tightbinding Hamiltonian, constructed from the results of first-principle calculations, we
identified the crucial parameters of the effective low-energy Hamiltonian, which
determine the topological nature of the spin-orbit coupled ground state. We present
a phase diagram exhibiting a quantum phase transition from normal-to-topologicalinsulators in terms of the spin-orbit coupling strength and the hopping parameter. The
existence of the TI phase has also been verified by the parity analysis from the firstprinciples calculations with a modified crystal structure corresponding to the predicted
tight-binding parameters. We clarified that the topological nature of the Na2IrO3 band
structure is sensitive to the structural variation. The long-range hopping and trigonal
crystal field play a crucial role in addition to the strong spin-orbit coupling in Na2IrO3.
The TI phase realized in Na2IrO3 can be a “good” playground for the study of theinterplay between spin-orbit coupling and on-site Coulomb interaction.
This work was done in collaboration with Choong H. Kim, Heung-Sik Kim, Hogyun Jeong, andHosub Jin and supported by the NRF through the ARP (R17-2008-033-01000-0).

[1] H. Yoshida, et al., P2006-510484 (registered in 2011). [2] M. Seike, et al. Jpn. J. Appl. Phys. 50, 090204 (2011). [3]
M. Seike, et al. Physica B (in press). [4] K. Sato, et al. Rev. Mod. Phys. 82, 1633 (2010).

[1] S. T. Bramwell and M. J. P. Gingras, Science 294, 1495 (2001). [2] R. F. Wang et al., Nature 439, 303 (2006). [3] S. Ladak et al., Nature Physics 6, 359 (2010). [4]E. Mengotti et al., Nature Physics 7, 69 (2011). [5] X. Ke et al., Phys. Rev. Lett. 101, 037205 (2008). [6] J. P. Morgan, A. Stein, S. Langridge, and C. H. Marrows, Nature
Physics 7, 75 (2011). [7] Z. Budrikis, J. P. Morgan, J. Akerman, A. Stein, R. L. Stamps, P.Politi, S. Langridge, and C. H. Marrows, arXiv:1111.6491v1 [cond-mat.mes-hall].

[1] A. A. Tulapurkar, Y. Suzuki et al., Nature 438, 339 (2005). [2] C. Wang et al., J. Appl. Phys. 106, 053905 (2009). [3] S.
Ishibashi, Y. Suzuki et al., IEEE Trans Magn. 47, 3373 (2011). [4] X. Cheng et al., Phys. Rev. Lett. 105, 047202 (2010).

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KF05

KG03

Towards fully 3-dimensional MRAM

Finite tunnel magnetoresistance in junctions with a zero magnetization
ferromagnetic electrode

Negative spin-polarization of Fe 4N observed by spin-resolved
photoemission spectroscopy

Hollandites - theoretical aspects of their unique electronic properties

Russell CowburnCavendish Laboratory, University of Cambridge, United Kingdom
Spintronics could have a revolutionary impact on microelectronics and data storage
if it provides the enabling step for transforming today's planar 2-dimensional devices
into volume-filling 3-dimensional devices, where the data storage and processing
capacity are related to the minimum feature size of the fabrication process, F, by F-3
instead of F-2. Recently, we proposed a new approach to 3-dimensional spintronics
in which topological kink solitons in multi-layered magnetic nanostructures are used
to code and move data. Such solitons can be extremely stable at room temperature,highly compact, and easily injected, detected and synchronously propagated. As such,they are interesting candidates for use in ultrahigh density 3-dimensional MRAM
devices. During this talk I will show the first experimental demonstration of a verticalshift register based on this principle and operating at room temperature. Elevenperpendicularly magnetised CoFeB layers coupled by Ru interlayers allow solitonscoding binary ‘0’ and ‘1’ to be injected into the bottom layer and then propagatedduring eight successive clock edges up the stack, eventually exiting at the top layer.

The 19th International Conference on Magnetism

Karine Dumesnil*, Mathias Bersweiler, Mathieu Da Silva, Catherine Dufour, Michel
Hehn, Daniel Lacour and Francois Montaigne
Institut Jean Lamour - Lorraine University, France

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Oral Friday

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Augustin Lutondo Kwilu, Mikiko Oogane, Hiroshi Naganuma and Yasuo Ando
Department of Applied Physics, Tohoku University, Japan110

oRAL PRSENTATION

Keita Ito1, Kazunori Harada1, Tatsunori Sanai1, Kaoru Toko1, Kazuaki Okamoto2, Shigenori
Ueda3, Yoji Imai4, Koji Miyamoto5, Taichi Okuda5, Akio Kimura2 and Takashi Suemasu1
1
Institute of Applied Physics, University of Tsukuba, Japan
2
Graduate School of Science, Hiroshima University, Japan
3
Synchrotron X-ray Station at SPring-8, NIMS, Japan
4
AIST, Japan
5
HSRC, Hiroshima University, Japan

Ferromagnetic (Co,Fe)4N has attracted a growing interest for application to spintronics devices because the large
negative spin polarization at the Fermi level (EF) is expected. However, there have been no experimental reports
confirming negative spin-polarization in (Co,Fe)4N by photoemission spectroscopy. In this study, we investigate
the valence band (VB) electronic band structure and spin-polarization of Fe4N using hard x-ray photoemission
spectroscopy (HX-PES) and spin resolved photoemission spectroscopy (SRPES) at room temperature. CaF2(1nm)/Fe4N(5 nm) layered structure was epitaxially grown on SrTiO3(001) by molecular beam epitaxy. We
measured VB structure of the Fe4N layer using HX-PES (hν = 5953 eV) at BL15XU of SPring-8, and compared
the obtained spectrum with the calculated photoemission spectrum. After removing the CaF2 capping layer by Ar
ion sputtering, we measured spin resolved density of states (DOS) below EF of the Fe4N using SRPES (hν = 21.2eV) at HiSOR, Hiroshima University. The peak position of measured Fe 3d electron photoemission spectrum by
HX-PES was well explained by the theoretical DOS. We deduced spin-polarization from the obtained SRPES
spectrum by eliminating the background signals of secondary electrons caused by He II resonance line (hν = 40.8eV), and confirmed negative spin-polarization at EF in Fe4N.

Tatsuya Toriyama1, Masayuki Watanabe1, Takehisa Konishi2 and Yukinori Ohta1*
1
Department of Physics, Chiba University, Japan
2
Graduate School of Advanced Integration Science, Chiba University, Japan

Density-functional-theory-based electronic structure calculations are made to clarify
the mechanisms of the observed anomalous electronic properties in transition-metaloxides with hollandite-type crystal structure. We first discuss some general aspectsof the electronic structures of the 3d and 4d series of hollandites, focusing on thevalidity and insufficiency of the rigid-band filling of electrons in the series. Then,
we in particular discuss (i) the Peierls mechanism of the metal-insulator transitionin ferromagnetic hollandite K2Cr8O16 [1], (ii) superatomic-crystal-type electronic
structure emerging in molybdenum hollandites K2Mo8O16 and Rb1.5Mo8O16 [2], and (iii)
Tomonaga-Luttinger-liquid properties emerging in ruthenium hollandite K2Ru8O16 [3].
We also consider the essential role of electron correlations played in the metal-insulatortransition of vanadium hollandite K2V8O16.
[1] T. Toriyama et al., Phys. Rev. Lett.107, 266402 (2011). [2] M. Watanabe et al., unpublished. [3] T.
Toriyama et al., Phys. Rev. B 83, 195101 (2011).

July 8-13, 2012 Busan, Korea

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ORAL PRESENTATION
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KI05

Inter-band pairing and inhomogeneous superconductivity in multiorbital systems

International comparison of the properties of permanent magnets
measured using an electromagnet and a pulse field magnetometer

Ferromagnetic phase at the LaAlO3 /SrTiO3 (001) interface induced by
SrTiO3 lattice deformation

Scrolling effects in vanadium oxide nanotubes and nanolayers

An IEC TC 68 comparison on the measurement of the magnetic properties ofpermanent magnets was recently completed. With permanent magnets being usedin safety critical situations it is necessary to perform 100% quality control at theoperating temperature. An established method using an electromagnetic to measure
the demagnetising curve is not practical for these measurements due to the time taken,
the difficulty in raising the temperature and the operator skill required. A Pulsed
Field Magnetometer (PFM) has been developed that can determine the full BH curvein as little as 100 ms. By comparing measurement made using electromagnet andpulse methods, the influence of the dynamic effects of the latter could be established.
It was found that for the technology significant parameter of intrinsic coercivity asignificant difference exist between the methods. The talk will present the results frommeasurements on 6 NdFeB magnets with intrinsic coercivities ranging from 1000 to
2600 kA/m by 8 institutes based in China, Japan, Italy, Belgium, Germany and theUK. For the electromagnet method, the Influence of local pole piece saturation on themeasurement of the intrinsic coercivity will be discussed.

We address the origin of the ferromagnetic phase formed at the LaO/TiO2 interface in LaAlO3/SrTiO3(001) heterostructures [1]. Using first-principles density functional calculations we show that the chargetransfer to the Ti t2g conduction band, induced by the polar mismatch at the interface, combined with theincipient ferroelectric character of the SrTiO3, lead to a substantial lattice deformation. The ferroelectriclike distortion of the SrTiO3 slab generates the spontaneous spin-polarization of the lowest dxy orbital
parallel to the interface and the emergence of a ferromagnetic ground state. Moreover, it yields differential
occupation of the non-degenerated dxy and degenerated dxz-yz orbital states. We predict the existence of
three different types of electrons, magnetic two-dimensional (2D) dxy electrons and non-magnetic higherlying dxy and dxz-yz quasi-2D electrons. While the former, with a 2D-light effective mass (m*), areconfined to the TiO2 interface plane, the non-spin polarized higher-lying dxy, also with a light m*, and the
Bloch dxz-yz electrons spread over several SrTiO3 layers. Their differences could explain the coexistencein the same sample of superconductivity and magnetism [2-5]. Furthermore, since ferroelectric distortions
and orbital magnetism are coupled, the magnetic state can be controlled by an electric field.

2

Mucio A. Continentino and Heron Caldas
1
Theory, Centro Brasileiro de Pesquisas Fisicas, Brazil
2
Physics, Universidade Federal de S. J. del Rei, Brazil

In multi-band systems, electrons from different orbitals coexist at a common Fermi
surface. An attractive interaction among these quasi-particles gives rise to inter-bandor hybrid pairs, which eventually condense in a superconducting state. These quasiparticles have a natural mismatch of their Fermi wave-vectors, δkF which depends on
the strength of the hybridization between their orbitals. The existence of this naturalscale leads us to consider the possibility of inhomogeneous superconducting groundsates in these systems, even in the absence of an applied magnetic field. Furthermore,since hybridization V depends on pressure, this provides an external parameter tocontrol the wave-vectors mismatch at the Fermi surface. In this work, we study the zerotemperature phase diagram of a two-dimensional, two-band superconductor with interband pairing. We show that as the mismatch between the Fermi wave-vectors of thetwo-bands is reduced, the system presents a normal-to-inhomogeneous superconductor
quantum phase transition of unusual character at a critical value of the hybridization,
Vc = Δ0, below which the system condenses in pair-wave superconducting statecharacterized by a wave-vector qc = Δ0/vf (Δ0 is the homogeneous superconducting
gap and vf the Fermi velocity.

Michael Hall
National Physical Laboratory, United Kingdom

Jichao C Li and Carmen Munoz*
ICMM- Consejo Superior de Investigaciones Cientificas, Spain[1] A. Brinkman, M. Huijben, M. van Zalk, J. Huijben, et al., Nature Materials 6, 493 (2007). [2] Ariando, X. Wang, G.
Baskaran, Z. Q. Liu, et al., Nature Communications 2, 188 (2011). [3] D. A. Dikin, M. Mehta, C. W. Bark, C. M. Folkman,
et al., Phys. Rev. Lett. 107 (2011). [4] L. Li, C. Richter, J. Mannhart, and R. C. Ashoori, Nature Physics 7, 762 (2011). [5] J.
A. Bert, B. Kalisky, C. Bell, M. Kim, et al., Nature Physics 7, 767 (2011).

Sergey Demishev1*, Alexey Chernobrovkin1, Vladimir Glushkov1, Nickolay Sluchanko1,
Nickolay Samarin1, Alexey Semeno1, Anastasiya Grigorieva2, Evgenii Goodilin2, Hitoshi Ohta3,
S. Okubo3, M. Fujisawa3 and T. Sakurai3
1
Low Temperatures and Cryogenic Engineering, General Physics Institute of RAS, Russia
2
Faculty of Materials Sciences, Moscow State University, Moscow, 119991 Russia
3
Molecular Photoscience Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe 6578501, JapanThe comparative analysis of the ESR together with the magnetic susceptibility data [1] hasallowed elucidating effects of scrolling the VOx nanolayers, NLs, (stacks of 4 to 8 distorted
layers of vanadium oxide separated by an organic template) into VOx nanotubes, NTs. First,
scrolling leads to formation of the antiferromagnetic dimers consisting of almost half of thevanadium ions with a spin gap near 720 K. The second effect, specific to NTs, is the correlatedchange in the Curie constant for the nondimerized V4+ quasifree spins and in variations of the
background formed by Van Vleck and Pauli terms: the decreasing temperature in the interval
70<T<120K induces an initial 1.8-fold growth of the Curie constant followed by a decrease,along with a change of the sign of the background. Third, it is found that scrolling results in
reduction of the quasifree electron concentration in the VOx plane by a factor of 2-4. It is foundthat the number of electrons in the V4+ state is always less than the total electron concentration,and the concentration of the “excessive” electrons may vary in the range 0.11-0.46 per
vanadium site.

Oral Friday

1

Oral Friday

oRAL PRSENTATION

1.S.V.Demishev et al., Phys. Rev. B 84, 094426 (2011)

KH01

KH04

KI03

KJ01

High performance permanent magnets for energy applications

Ab initio calculations of magnetic moment and magneto-crystalline
anisotropy: New ternary alloy Mn-Bi-Co permanent magnet

Interfacial magnetic anisotropy of junctions between Fe and transitionmetal nitrides or carbides: A first-principles study

THz Emission from High-Tc Superconductor Bi2Sr2CaCu2O8+ δ
Intrinsic Josephson Junctions

Oliver Gutfleisch1, Tom G Woodcock2, Simon Sawatzki2, Konrad Lowe2 and Konrad
Guth2
1
Material Science, TU Darmstadt, Germany
2
IFW Dresden, Germany
A new energy paradigm, consisting of greater reliance on renewable energy sources
and increased concern for energy efficiency in the total energy lifecycle, has accelerated
research in energy-related technologies. Due to their ubiquity, magnetic materials play
an important role in improving the efficiency and performance of devices in electric
power generation, conversion and transportation. Magnetic materials are essential
components of energy applications (i.e. motors, generators, transformers, actuators,etc.) and improvements in magnetic materials will have significant impact in this area,
on par with many “hot” energy materials efforts. The lecture focuses on the synthesis,characterization, and property evaluation of high performance permanent magnets.
Using multi-scale characterization and modeling the structure-property relationships
will be examined. Options for the development of novel resource efficient magnets will
be discussed in the context of drastically reducing the rare-earth contents or developing
rare earth free magnets. Finally, considering future bottle-necks in raw materials and in
the supply chain, options for recycling of rare-earth metals will be analyzed.
O. Gutfleisch, J.P. Liu, M. Willard, E. Bruck, C. Chen, S.G. Shankar, Magnetic Materials and Devices for the
21st Century: Stronger, Lighter, and More Energy Efficient (review), Adv. Mat. 23 (2011) 821-842.

There are two important issues to address for full utilization of permanent magnets in electric vehicle,
windmill generator, and other motors. One is a technical issue such as low operation temperature ofpermanent magnet, and the other is rare-earth metal source and price. Rare-earth permanent magnets,
including Nd2Fe14B and Dy-doped Nd2Fe14B, Sm2Co17, and Sm2Fe17N3, have been used for motors
for hybrid vehicle and electric vehicle. The Nd2Fe14B possesses 60 MGOe of the highest maximum
energy product (BH)max. All these permanent magnets contain rare-earth metals. Therefore, in order toaddress the second issue, we have proposed rare-earth-free Mn-Bi-Co ternary alloy and performed firstprinciples calculations to investigate the effects of the alloying element Co on magnetic properties of
conventional Mn-Bi binary alloy magnet. Our calculations predict that an addition of Co to the Mn-Bi
magnet will likely to increase the magneto-crystalline anisotropy by more than 300%, while the saturation
magnetization will be increased by 20%. Accordingly, it is predicted that the (BH)max increases to 21
MGOe from 17 MGOe of the Mn-Bi permanent magnet. The proposed Mn-Bi-Co magnet exhibits amuch higher maximum energy product than the conventional Mn-Bi magnet. Experimental verification ofthese results is in progress.

Masahito Tsujikawa1, Miura Yoshio2 and Masafumi Shirai3
1
CSIS, Tohoku University, Japan
2
RIEC and CISI, Tohoku University, Japan
3
RIEC and CSIS, Tohoku University, Japan

Recently, CoFeB/MgO-based perpendicular magnetic tunnel junctions (MTJ) with highthermal stability have been fabricated[1]. For further reduction of MTJ size, larger perpendicularmagnetic anisotropy (PMA) is required. In the MgO/Fe(001) interface, the hybridization
between O-2p and Fe-3d orbital decreases the in-plane magnetic anisotropy (IMA) component.
This effect is also expected for Fe/nitride(carbide) interfaces. In order to design large PMA film,
we investigated magnetic anisotropy of Fe(001) and NaCl-type transition-metal nitride(carbide)
interfaces (Fe/MN(C): M=Sc, Ti, V, Cr, Zr, Nb, Hf, and Ta) by using a first-principles densityfunctional calculations. Large PMA energy is obtained for the Fe/ScN (1.21 mJ/m2) and Fe/
ScC (0.89 mJ/m2) film. The origin of PMA component of these films is attributed to the surface
PMA of Fe(001) (0.60 mJ/m2). In other films, weak PMA or IMA is obtained due to the
reduction of PMA component caused by the strong hybridization between interfacial Fe-3d andtransition-metal-d orbitals. We also discuss the influence of boron atoms at the interfaces. This
work was supported by JSPS though the FIRST Program initiated by the CSTP and a Grant-inAid for Scientific Research (Grant No. 22360014) from JSPS.

K. Kadowaki1,2, T. Kashiwagi1,2, M. Tsujimoto1,2, K. Delfanazari1,2, T. Kitamura1,2,
M. Sawamura1,2, K. Ishida1,2, S. Sekimoto1,2, C. Watanabe1,2, R. A. Klemm3 and M.
Tachiki1
1
Graduate School of Pure and Applied Sciences, University of Tsukuba, Japan
2
CREST & WPI-MANA, Japan3
Department of Physics, University of Central Florida, USA[1] S. Ikeda et. al., Nature Mater. 9, 721 (2010).

After the discovery of THz emission of radiation from high-Tc superconductor
Bi2Sr2CaCu2O8+δ in 2007, intensive studies on the mechanism of radiation from highTc superconductors have been carried out both theoretically and experimentally. So far,two important ingredients are found for the necessary condition of radiation: One isthe ac-Josephson effect working in the individual intrinsic Josephson junction existingin a unit cell of the crystal structure of high-Tc superconductors. This generates theelectromagnetic waves at a fixed frequency according to the ac-Josephson effect andthe power of the radiation at the frequency can be enhanced by the cavity resonance,
which is determined by the geometry of the mesa structure. This mechanism works
as a second important mechanism for the radiation. We show experimental results
confirming these important ingredients for the emission of radiation. In addition byknowing these mechanisms we intend to extend the power of radiation to nearly 1 mW
level by the array of three mesas synchronized together quantum mechanically. We will
also show a prototype imaging machine for the applications.

KH02

KI01

KI04

KJ02

Influence of surface anisotropy on orientation of crystal grain in rareearth permanent magnet

First-principles prediction of large perpendicular magnetocrystalline
anisotropy of 4d-monolayers on bcc-Fe(001) surface

Enhancement of exchange coupling by incoherent quantum resonanceElectric field control of magnetization in spiral magnets

Chiharu Mitsumata*, Hiroki Tsuchiura and Akimasa Sakuma
Tohoku University, JapanThe coercive force of Rare-Earth permanent magnets has been investigated. In
general, the nucleation and the domain wall pinning are discussed to understand themagnetization reversal process [1]. However, the large discrepancy between the ideal
anisotropy field (Hk) and the coercivity (Hc) still remains in an unsolved problem of
the permanent magnet. Recently, we proposed the possible mechanism of the reductionfor Hc in NdFeB system, that was realized owning to the negative anisotropy of
the rare-earth ion at the surface of a crystalline [2, 3]. In this paper, we discuss theinfluence of the surface anisotropy on the mis-orientation of the crystal grain in thepermanent magnets. In the case of simultaneous rotation of the magnetization, the steep
reduction of Hc is obtained when the angle between the direction of external appliedfield and the magnetic easy axis increases. For comparing the ideal simultaneousrotation, we assume the polycrystalline magnet in which the surface anisotropy effects
on the crystal grains. As the result, the surface anisotropy causes the large reduction ofHc from Hk, however, a tolerance of Hc reduction against the mis-orientation of crystal
grains becomes promising.
[1] H. Kronmuller, K.-D. Durst and M. Sagawa, J. Magn. Magn. Mater., 74 (1988) 291. [2] C.
Mitsumata, H. Tsuchiura and A. Sakuma, Appl. Phys. Express, 4 (2011) 113002. [3] H. Moriya, H.
Tsuchiura and A. Sakuma, J. Appl. Phys., 105 (2009) 07A740.

112

Yang-ki Hong1*, Jihoon Park1, Oleg N Mryasov2, Jaejin Lee1, Seong-gon Kim3,
Sungho Kim3, Chul-jin Choi4 and Jung-goo Lee4
1
Department of Electrical and Computer Engineering and MINT Center, The University of Alabama, USA
2
Physics and Astronomy and MINT Center, The University of Alabama, USA
3
Department of Physics & Astronomy and Center for Computational Sciences, Mississippi State University, USA
4
Korea Institute of Materials Science, Korea

The 19th International Conference on Magnetism

Dorj Odkhuu, Tumurbaatar Tsevelmaa, Won Seok Yun, Oryong Kwon, Bharat Kumar
Sharma and Soon Cheol Hong*
Department of Physics, University of Ulsan, Korea
Using the highly precise full-potential linearized augmented plane-wave method
based on general gradient approximation, we investigated the magnetism andmagnetocrystalline anisotropy energy (EMCA) of 4d Ru, Rh, and Pd monolayers (MLs)on a bcc-Fe(001) surface. Coupling with Fe ferromagnetically, the Ru, Rh, and Pd
monolayers are induced to have the magnetic moments of 0.43, 0.92, and 0.36 μB,
respectively, in consistent with experimental [1,2] and previous theoretical results [3].
The calculated magnetic moments of Fe at the interface are significantly enhanced 2.8
μB for Rh and 2.92 μB for Pd, compared to the bulk bcc-Fe value, but Ru makes the Featoms to retain the bulk value (2.2 μB). We predict that the Ru and Rh MLs have theperpendicular huge EMCA of 2.2 and 3.0 meV/atom, whereas the Pd ML has the in-plane
EMCA of -0.2 meV/atom. The huge positive EMCAs with induced magnetic moments of
the Ru and Rh MLs on a Fe(001) surface are expected to be promising in application
to devices such as high-density magnetic recording media and random access memory.
The electronic origins of the induced magnetism and EMCA will be discussed with thedensity of states.
[1] K. Totland, P. Fuchs, J. C. Grobli, and M. Landolt, Phys. Rev. Lett. 70, 2487 (1993). [2] Z. Celinski, B. Heinrich, J. F. Cochran, W.
B. Muir, A. S. Arrott, and J. Kirschner, Phys. Rev. Lett. 65, 1156 (1990). [3] L. Zhong and A. J. Freeman, J. Appl. Phys. 81, (1997).

Ching Hao Chang
National Tsing Hua University, Taiwan

By simulating the nanoscale Fe/Ag/Fe trilayer in the quantum well potential, thecoupling strength is found to oscillate with Fe thickness. This is generated by thecompetition between quantum interferences for ma jority carriers in ferromagnetic
configuration and for carriers in anti- ferromagnetic configuration. Furthermore, we
fix the Fe side-layer thickness and study the coupling as the function of spacer width.
The strength oscillates with the period determined by quantum well states of minority
carriers in ferromagnetic configuration while the amplitude decided by this competitionof interferences. This amplitude can be enhanced almost one time by choosing theproper side-layer thickness that satisfies (1) the conditions for incoherent quantum
interferences and (2) much thinner than the spacer width.

Kee Hoon Kim
CeNSCMR, Department of Physics and Astronomy, Seoul National University, Seoul
151-747, Korea
The control ofmagnetization by an electric field remains as one of greatchallengesin
materials science. Multiferroics, in which magnetism and ferroelectricitycoexist
and couple to each other, could be the most plausible candidate to realize this longsoughtcapability. While recent intensive research on the multiferroics has madesignificant progress in the sensitive magnetoelectric (ME) effects, the electrical controlof magnetization, the converse effect, has been observed only in a limited range far
below room temperature. Here Iwill summarizerecent developments on how the spiralmagnets, particularly based on the hexagonalferrites, can realizethe viable, converse
ME effectin a broad temperature range including room temperature. Starting with thechemical aspect of the hexaferrite materials, I discuss the importance of the strong
magnetoelectric(ME) coupling to achieve the significant converse ME effect. The
three key material parameters, magnetic anisotropy, spin frustration, and spin exchangeinteraction, will be pointed out. By controlling those key parameters, we demonstratethat the four state magnetization curves can be obtained at room temperature by anelectric field. We also show based on the similar mechanism that the magnetization
reversal by an electric field can be realized with fast switching time.
Sae Hwan Chun et al., Phys. Rev. Lett. 108, 177201 (2012); ibid,104, 037204 (2010); Y. S. Chai etal., (unpublished).

July 8-13, 2012 Busan, Korea

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ORAL PRESENTATION
KJ03
Novel Josephson effect in triplet Josephson junctions: The story begins
Dirk Manske
Max Planck Institute for Solid State Research, Germany

Oral Friday

In the theoretical study of Josephson junctions, it is usually assumed that the propertiesof the tunneling barrier are fixed. This assumption breaks down when consideringtunneling between two triplet superconductors with misaligned d-vectors in a TFTjunction (triplet ferromagnet triplet) [1,2]. Such a situation breaks time-reversal
symmetry, which radically alters the behaviour of the junction, stabilizing it in a
fractional state, i.e. the free energy minimum lies at a phase difference intermediate
between 0 and π. Fractional flux quanta are then permitted at the junction [3]. A
further consequence of the d-vector misalignment is the appearance of a Josephson
spin current, which flows even in the absence of an equilibrium charge current. Not
only do our calculations enhance the physical understanding of transport throughtriplet superconductor junctions, but they also open the possibility of novel spintronic
Josephson devices [4].
[1] B. Kastening, D.K. Morr, D. Manske, and K.H. Bennemann, Phys. Rev. Lett. 96, 047009 (2006)[2] P. M. R. Brydon, B. Kastening, D. K. Morr and D. Manske, Phys. Rev. B 77, 104504 (2008). [3]P.M.R. Brydon, C. Iniotakis, D. Manske, and M. Sigrist, Phys. Rev. Lett. 104, 197001 (2010). [4]P.M.R. Brydon and D. Manske, Phys. Rev. Lett. 103, 147001 (2009).

KJ04
Field-induced polarization of dirac valleys in bismuth

Zengwei Zhu1, Aurelie Callaudin1, Benoit Fauque1, Woun Kang2, Kamran Behnia1*
and Yuki Fuseya3
1
CNRS, France
2
Ewha Womans University, Korea
3
Osaka University, Japan
The principal challenge in the field of "valleytronics'' is to lift the valley degeneracyof electrons in a controlled way. In bulk semi-metallic bismuth, the Fermi surface
includes three cigar-shaped electron valleys lying almost perpendicular to the highsymmetry axis known as the trigonal axis. The in-plane mass anisotropy of eachvalley exceeds 200 as a consequence of Dirac dispersion, which drastically reduces
the effective mass along two out of the three orientations. According to our very
recent study of angle-dependent magnetoresistance in bismuth [1], a flow of Dirac
electrons along the trigonal axis is extremely sensitive to the orientation of in-planemagnetic field. Thus, a rotatable magnetic field can be used as a valley valve to tune
the contribution of each valley to the total conductivity. As a consequence of a unique
combination of high mobility and extreme mass anisotropy in bismuth, the effect isvisible even at room temperature in a magnetic field of 1 T. At high temperature andlow magnetic field, the three valleys are interchangeable and the three-fold symmetryof the underlying lattice is respected. As the temperature is decreased or the magnetic
field increased, this symmetry is lost.
1. Z. Zhu, A. Callaudin, B. Fauque, W. Kang and K. Behnia, Nature Phys. 8, 89 (2012)

poster Presentation- July 9 (PA~PO) • 116- July 10 (QA~QP) • 182- July 12 (RA~RR) • 249- July 13 (SA~SO) • 316

114

The 19th International Conference on Magnetism

poster Presentation
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PA07

PA10

Magnetoelectric polarization in the field-induced commensurate phaseof Y-hexaferrite Ba0.7Sr1.3Zn2(Fe1-xAlx)12O22

Chemical control of ferroelectric polarization in Mn1-xCoxWO4Magnetoelectric effects in antiferromagnet Ba2CoGe2O7

Magnetic ordering in multiferroic TbFexMn2-xO5 with x=0.18

Hexagonal ferrites containing Fe3+ (S = 5/2) ions are attracting much attention
because it is expected that solutions for high-temperature low-field multiferroics
can be found in these materials. Y-type Ba0.7Sr1.3Zn2Fe12O22 possesses proper-screw
antiferromagnetic order in zero field, which does not allow spin-current ferroelectric
polarization. Electric polarization can, however, be induced when a strong external
field is applied perpendicular to its c axis. The field-response can greatly be improved
upon Al doping, which is ascribed to the formation of conical spin structures. In thiswork, we investigated the magnetic phase transitions of single crystal Ba0.7Sr1.3Zn2(Fe1xAlx)12O22 (x = 0.04 & x = 0.08) in external magnetic field. Both samples exhibited
incommensurate helical antiferromagnetic order in zero-field cooling down to 10 K.
When the external magnetic field was applied so that electric polarization was induced,
however, the incommensurate order was replaced by a commensurate order in all
samples. Our analysis shows that the commensurate order plays the role of breaking
inversion symmetry, thereby allowing finite electric polarization. We argue that two
different magnetic anisotropies, easy-axis and easy-plane, play an important role inestablishing stable field-induced electric polarization in the observed commensurate
magnetic phase.

Young-sang Song1, Jae-ho Chung1*, Sung-beak Kim2, Jurg Scheffer3, Li Qin Yan4,
Bumsung Lee4, Sae-hwan Chun4, Kee Hoon Kim4, A. Nogami5 and T. Katsufuji51
Department of Physics, Korea University, Seoul, 136-713, Korea
2
Advancement for College Education Center, Konyang University, Chungnam 320711, Korea
3
Laboratory for Neutron Scattering, Paul Scherrer Institut, Villigen, Switzerland
4
Department of Physics, Seoul National University, Seoul, 151-742, Korea
5
Department of Physics, Waseda University, Tokyo 169-8555, Japan
MnWO4 is one of the best known magnetoelectric multiferroics, in which ferroelectric
polarization appears due to long-range spin order. Whereas it exhibits three different
antiferromagnetic phases at low temperatures, ferroelectric polarization along the baxis is observed only in the intermediate phase with an elliptical spiral incommensurate
spin structure. In this work, we present the effect of Co doping on the magnetic phasetransitions and multiferroics properties of Mn1-xCoxWO4 using neutron diffraction,
magnetization and ferroelectric measurements. The main results include thestabilization of the incommensurate phase at x ~ 0.03 and the flop of its spiral plane forx > 0.05. Subsequently, the ferroelectric polarization appears mainly along the a axis
in this range. These results indicate that the multiferroics properties of MnWO4 can becontrolled via Co doping.

We have investigated magnetoelectric effects in Ba2CoGe2O7, which is a quasi twodimensional antiferromagnet[1]. By applying the external magnetic field along certain
directions, electric polarization is induced[2,3]. We consider a spin-dependent d-p
hybridization mechanism[4], where the electric polarization couples to a single spin
structure via the spin-orbit interaction, and we can explain the novel magnetoelectric
behaviors in Ba2CoGe2O7[3]. In this compound, it is recently reported that there
exist magnetic excitations induced by electric components of electromagnetic wave
at THz frequencies[5]. In addition, the magneto-electric excitation in Ba2CoGe2O7
accompanies a non-reciprocal linear directional dichroism, where absorption
coefficient depends on the direction of the incident electromagnetic wave (+k or-k). We theoretically clarify the origin of the peculiar features in these dynamicalmagnetoelectric phenomena[6]. The non-reciprocal dichroism observed in Ba2CoGe2O7
can be explained by cross-correlated effects, i.e., the interference between the magnetic
and the electric responses.
[1] A. Zheludev et al., Phys. Rev. B 68 024428 (2003). [2] H.T. Yi et al., Appl. Phys. Lett 92 212904(2008). [3] H. Murakawa et al., Phys. Rev. Lett. 105 137202 (2010) [4] T. Arima, J. Phys. Soc. Jpn.
76 073702 (2007). [5] I. Kezsmrki et al., Phys. Rev. Lett. 106 057403 (2011) [6] S. Miyahara and N.
Furukawa, J. Phys. Soc. Jpn 80 073708 (2011)

Nadir Aliouane1, Andrey Malyuk2 and Dimitri N. Argyriou3
Laboratory for Neutron scattering, Paul scherrer Institut CH-5232, Villigen-PSI, Switzerland
2
IFW Dresden, Institute for Solid State Research Helmholtzstr. 20 DE-01069 Dresden, Germany
3
Science Directorate, European Spallation Source ESS AB P.O Box 176, SE-221 00 Lund,
Sweden1

Manganite compounds present a large range of functional properties from colossal magnetoresitor tomultiferroicproperties. TbMn2O5 is well known multiferroic materials that exhibit complex magnetic phasetransitions [1] and multifunctional properties which are tunable by a magnetic field [2,3]. Below 38K, the longrange incommensurate anti-ferromagnetic ordering induces the ferroelectric behavior through either an exchange
striction mechanism between neighboring spins wave (Si.Sj≠0) [4] or inverse Dzyaloshinskii-Moriya interaction
due to cycloidal spin arrangement [5]. All the magnetic properties in these systems are controlled by frustrations.
The frustration can be tuned in increasing or decreasing the interactions by substituting Mn3+/Mn4+ with Fe3+/Fe4+(HS, S=5/2) without structural distortion. Fe doped materials in ceramics sample at similar composition haveshown enhancement of Ps. Large single crystals of TbMn2-xFe-xO5 (x=0.18) have been grown by flux method
and characterized by (ac and dc) susceptibility measurements. Single crystal neutron diffraction on E4 and TriCs
diffractometer have been carried out respectively at the Helmoltz Zentrum Berlin and Sing, Paul Scherrer Institut.
Below 38K, Mn/Fe spins order antiferromagnetically (τ(0.5,0,qz) qz~[0.21,0.245]). Below 15K, Tb sublattice
is polarized by Mn/Fe one and orders antiferromagnetically below 5K. Nuclear and magnetic structure has
investigated at 5 and 20K and be presented in this work.
[1] E. F. Berthaut et al. , Solid. Stat. Comm. 5,25 (1925) [2]I. Akinobu and K. Kay, Ferroelectrics 169, 75 (1995) [3] N. Hur et al.
, Nature 429, 392 (2004). [4] L. C. Chapon, Phys. Rev. Lett. 96, 976001 (2006). [5] H. Kimura, J Phys Soc Jpn 76, 074706 (2006).

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Temperature- and field-tuning of magnetic phases in multiferroic
NdFe3(BO3)4

Multiferroic phase competition in orthorhombic RMnO3: Monte Carloapproaches

X-ray non-reciprocal effects in multiferroic single crystal of GaFeO3

Strain-induced ferroelectric instabilities in the epitaxial RMn2O5 (R=Dy
and Tb) thin films

Christie S. Nelson1*, Leonard N. Bezmaternykh2 and Irina A. Gudim2
1
Photon Sciences Directorate, Brookhaven National Laboratory, USA
2
L.V. Kirensky Institute of Physics, Siberian Branch of RAS, Russia

We report the low-temperature coexistence of magnetic phases in NdFe3(BO3)4, which
is a field-induced multiferroic material. The ground state incommensurate magnetic
phase coexists with a strained commensurate magnetic phase that is primarily at thesurface of the crystal. Increasing the temperature or magnetic field decreases theincommensurability and stabilizes the commensurate magnetic phase above Tic ≈ 14
K or Hic = 0.9 T. A comparison to published studies indicates the onset of longitudinalmagnetostriction and electric polarization at the field-induced transition, which may
arise due to a basal plane spin-flop and canting of moments along the field direction.
Use of the National Synchrotron Light Source, Brookhaven National Laboratory, wassupported by the U.S. Department of Energy, Office of Science, Office of Basic Energy
Sciences, under Contract No. DE-AC02-98CH10886.

Jun-ming Liu*
Department of Physics, Nanjing University, China

For type-II multiferroic oxide compounds, the ferroelectricity is believed to be
induced by specific spin orders which can break the spatial inversion symmetry,allowing an electric polarization to respond significantly to external magnetic field.
These phenomena have been receiving attentions due to the underlying physics andpromising application potentials. Nevertheless, conventional understanding of these
multiferroics remains in an early stage since these materials exhibit typical featuresof strongly correlated electron systems in which the spin, charge, orbit, and phonon
degrees of freedom are intrinsically coupled together. So far, rare models other thanthe Mochizuki-Furukawa (M-F) model specifically addressing orthorhombic RMnO3
are available. In this talk, we present our Monte Carlo simulations on the multiferroic
behaviors of orthorhombic RMnO3, based on this model. Our simulations address thephase competition between the ab-plane spiral spin order and bc-plane spiral spin orderas well as their coexistence, including the following cases: (1) nonmagnetic Mn-site
substitution; (2) R-site substitution; (3) interaction between multiferroic RMnO3 thinfilms and magnetic substrates. We will further extend our simulation based on the semiquantum two-orbit double exchange model to the above issues.

Andrei Rogalev*, Fabrice Wilhelm and Alexei Bosak
European Synchrotron Radiation Facility, France

Jong Hyun Song1, Jae Young Kim2, Sun Hee Kang3, Ill Won Kim3, Yoon Hee Jeong4
and Tae Yeong Koo2*
1
Physics Department, Chungnam National University, Korea
2
Pohang Accelerator Laboratory, Korea
3
Physics Department, Ulsan University, Korea
4
Physics Department, Pohang University of Science and Technology, Korea

Ferroelectric and ferrimagnetic ordering coexist in gallium ferrate - GaFeO3. The
multiferroic properties of this compound have been extensively studied since earlysixties by many different experimental techniques. In order to study these properties
on a microscopic level we have measured various X-ray reciprocal and non-reciprocal
dichroisms at the Fe K-edge. The results of these experiments carried out at the ESRF
beamline ID12 on a high quality untwined single crystal of GaFeO3 are presented here.
X-ray magnetochiral dichroism and X-ray non-reciprocal magnetic linear dichroism,
which are a direct measure of the Fe orbital anapole and higher order magnetoelectric
multipole, are disentangled experimentally for the first time. These two dichroic signals
are compared to usual X-ray magnetic circular dichroism which is a measure of orbital
magnetic moment carried by Fe atoms. Moreover, X-ray natural circular dichroism has
been also measured on this biaxial non-enantiomorphous crystal. All these dichroisms
are analyzed with the help of a set of the sum rules. This analysis allowed us to deduce
the expectation values of different effective operators related to multiferroic properties
of GaFeO3.

Epitaxial thin films of DyMn2O5 (DMO) and TbMn2O5 (TMO) were successfullygrown on Nb-doped TiO2 (110) substrates by the pulsed laser deposition to investigate
the effects of substrate-induced strains on multiferroic properties. Synchrotron X-ray
azimuthal angle scans and reciprocal space mappings confirmed the epitaxial qualitiesof the films. Magnetic phase transitions of the films were observed at Tn = 43 K,
showing consistent values with those of the bulk samples. Dielectric constant showed a
steplike anomaly around 16 K, where a magneto-capacitance effect about 10 % at 8 T
was detected. Magnetization-induced ferroelectric phases below Tn appear to become
unstable in the epitaxial thin films due to the substrate-induced tensile strains whichmake the magnetic exchange interactions between nearby manganese ions weaker.

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Control of magnetic anisotropies for stable electric polarization in
multiferroics hexaferrites

Spin-driven electric polarization in akermanite Sr2MSi2O7 crystals

NMR study on Ba0.5Sr1.5Zn2(Fe0.92Al0.08)12O22

Magnetically driven ferroelectric atomic displacements in perovskitetype YMnO3 determined by single-crystal structure analysis

Hun Chang, Hak-bong Lee, Young-sang Song and Jae-ho Chung*Department of phsics, Korea Univ., Korea

Mitsuru Akaki1*, Tomoya Tadokoro1, Takumi Kihara2, Masashi Tokunaga2 and Hideki
Kuwahara1
1
Department of Physics, Sophia University, Japan
2
The Institute for Solid State Physics, The University of Tokyo, Japan

Hexaferrites are widely studied for the hopes of realizing multiferroics working atroom temperature and under low field. It was shown recently that Al-doping caneffectively enhance magnetoelectric susceptibility and low-field behaviors of Y-type
hexaferrite Ba0.5Sr1.5Zn2Fe12O22. The key for such enhancement has been suspected
to be the formation of heliconical spin ordering via reduction of planar anisotropy.
Using single crystal neutron diffraction, we investigated in detail the Al-doping
dependence of the magnetic phase transitions in Ba0.7Sr1.3Zn2(Fe1-xAlx)12O22. We
confirm that the heliconical phases indeed appear upon Al doping, and finally collapse
into commensurate phases at excessive doping concentrations. The observed evolutionof magnetic order coincides with the doping dependence of the magnetoelectricity
previously reported. Analysis of magnetic energy shows, however, that planar
anisotropy alone will not allow the heliconical order to stabilize. We argue that it isimportant to have a competition between easy-axis and easy-plane anisotropies in orderto stabilize the heliconical order, and thereby establish the optimum magnetoelectric
property.

Since the magnetoelectric effect was observed in akermanite Ca2CoSi2O7 [1] and Ba2CoGe2O7 [2,3],
the multiferroicity in these materials has been attracting much attention. The akermanite materials
show the magnetic-field-induced electric polarization which can be explained by the transition-metalligand (p-d) hybridization depending on the spin direction [4]. The multiferroicity of akermanite
materials is, therefore, expected to be influenced by substitution on the transition-metal site. In thisstudy, we have investigated magnetic and dielectric properties of akermanite Sr2MSi2O7 (M: transitionmetal ion) single crystals. In Sr2CoSi2O7, the electric polarization was not observed in a zero magnetic
field. By applying the magnetic field along the [110] direction, the electric polarization emerges along
the c axis below the magnetic transition temperature. According to the p-d hybridization mechanism,
the electric polarization is proportional to the spin quantum number S. However, the induced electric
polarization in Sr2MnSi2O7 (Mn2+: S=5/2) is almost two orders of magnitude smaller than that ofSr2CoSi2O7 (Co2+: S=3/2). These results suggest that the electronic configuration of the transition-metal
ion is of crucial importance for the appearance of electric polarization. We will also present and discuss
the results of the comparative study of magnetoelectric properties in other Sr2MSi2O7 crystals.
[1] M. Akaki et al., Appl. Phys. Lett. 94, 212904 (2009). [2] H. T. Yi et al., Appl. Phys. Lett. 92,
212904 (2008). [3] H. Murakawa et al., Phys. Rev. Lett. 105, 137202 (2010). [4] T. Arima, J. Phys.
Soc. Jpn. 76, 073702 (2007).

116

Shin Miyahara1 and Nobuo Furukawa2
1
JST ERATO-MF, Japan
2
JST ERATO-MF, Aoyama Gakuin University, JapanThe 19th International Conference on Magnetism

Sangil Kwon1, Soonchil Lee1*, Dong Young Yoon1, Sae Hwan Chun2, Yi Sheng Chai2,
Kee Hoon Kim2, Euna Jo1, Changsoo Kim1 and Byeongki Kang1
1
Department of Physics, Korea Advanced Institute of Science and Technology,
Daejeon 305-701, Korea
2
CeNSCMR, Department of Physics and Astronomy, Seoul National University, Seoul
151-747, Korea
We did zero-field NMR study on the annealed single crystal of multiferroic helimagnets
Ba0.5Sr1.5Zn2(Fe0.92Al0.08)12O22 (Al-BSZFO). This material shows extremely highmagnetoelectric susceptibility so that the critical field for switching electric polarizationis less than 1 mT below 90 K [1]. NMR frequency change by the temperature follows
Bloch’s T3/2 law which presents the low temperature excitation is ferromagnetic spinwave. The nuclear spin-lattice relaxation rate and the nuclear spin-spin relaxation
rate were also measured. Both increased rapidly as the temperature increases above
60 K at which the spin structure changes from normal longitudinal cones (NLCs) toalternating longitudinal cones (ALCs) for the case of as-grown (not annealed) sample[2]. Due to rapid shortening of spin-spin relaxation time, the NMR signal intensity
abruptly reduced above 60 K. We also studied rf pulse width and power dependence
and revealed that most of the signal came from the domain walls.
[1] S. H. Chun et al., Phys. Rev. Lett. 104, 037204 (2010). [2] H. B. Lee et al., Phys.
Rev. B 83, 144425 (2011).

July 9 (Mon)

Hak Bong Lee, Hun Chang, Young Sang Song, Jae-ho Chung
Department of Physics, Korea Univ., Korea

July 9 (Mon)poster Presentation

Daisuke Okuyama1, Shintaro Ishiwata2, Youtarou Takahashi2, Kunihiko Yamauchi3, Silvia Picozzi4, Kunihisa
Sugimoto5, Hideaki Sakai6, Masaki Takata7, Ryo Shimano8, Yasujiro Taguchi1, Taka-hisa Arima9 and Yoshinori Tokura2
1
Cross-Correlated Materials Resarch Group (CMRG), and Correlated Electron Research Group (CERG), RIKEN ASI, Japan2
Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Japan
3
The Institute of Scientific and Industrial Research (ISIR)-Sanken, Osaka University, Japan
4
Consiglio Nazionale del le Ricerch-Superconducting and Innovative materials and device (CNR-SPIN), Italy
5
JASRI, SPring-8, Japan
6
School of Physics & Astronomy, University of St Andrews North Haugh, United Kingdom
7
RIKEN, SPring-8 Center, Japan
8
Department of Physics, University of Tokyo, Japan
9
Department of Advanced Materials Science, University of Tokyo, Japan
Multiferroic materials have been intensively studied with a particular focus on the driving mechanism of cross-correlated
interactions between the magnetism and electricity [1]. Many theoretical and experimental works have clarified theorigin of the interplay between magnetism and electricity. However, the lack of information about the crystal structure in
the multiferroic phase has prevented quantitative discussion of the ferroelectricity driven by magnetic order. In order toquantitatively discuss the microscopic origin of the ferroelectricity of multiferroic perovskite-YMnO3, in which the up-updown-down-type (E-type) antiferromagnetic order causes a ferroelectric polarization below 30 K [2], we performed the
crystal structural analysis for a twin-free single crystal by using synchrotron x-ray diffractometer at BL02B1 in SPring-8, andsuccessfully determined the ferroelectric atomic displacements of the order of 0.001 Angstrom. The refined polar structure
shows the characteristic bond alternation, which is consistent with that expected for the exchange striction mechanism giving
rise to a ferroelectric polarization along the a-axis. From the experimental results of x-ray diffraction and a theoretical firstprinciples calculation, we quantitatively discuss the origin of the ferroelectricity in multiferroic YMnO3[3].
[1] Y. Tokura and S. Seki, Adv. Mater. 22, 1554 (2010). [2] S. Ishiwata, Y. Tokunaga, Y. Taguchi, and Y. Tokura, J. Am.
Chem. Soc. 133, 13818 (2011). [3] D. Okuyama, S. Ishiwata, Y. Takahashi, K. Yamauchi, S. Picozzi, K. Sugimoto, H.
Sakai, M. Takata, R. Shimano, Y. Taguchi, T. Arima, and Y. Tokura, Phys. Rev. B 84, 054440 (2011).

July 8-13, 2012 Busan, Korea

117

poster Presentation

poster Presentation

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Magnetic symmetry and electric polarization on Mn1-xCoxWO4 multiferroics

Magnetic and electronic properties of hexagonal RMnO3 (R = Y, Tb)
quantum-wells

Control of coexisting ferroelectric phases in RMnO3 crystals with finetuning of 4f moment

Mössbauer studies of Y-type hexaferrite by Aluminum doping

Ambrose Seo*
Physics and Astronomy, University of Kentucky, USA

July 9 (Mon)

MnWO4 exhibits magnetoelectric effects and belongs to the new class of frustrated multiferroics
in which magnetic and ferroelectric order coexist [1-3]. It undergoes three successive magnetic
phase transitions [1,2]. Below Tn = 13.5 K the spins are collinear and sinusoidally modulated,(AF3, paraelectric). In the AF2 phase (7.5 K<T<12.5 K) a spontaneous polarization along b axis
coexists with a cycloidal spin structure, k = (-0.214, 1/2, 0.457). Below 7.5 K the system is in the
AF1 collinear commensurate phase, k = (±1/4, 1/2,1/2). Addition of Co+2 ions (S=3/2) modifies theoverall magnetic interactions, produces changes in the magnetic anisotropy at 3d- site and stabilizes
the multiferroic behaviour [3-5]. We have studied the temperature induced phase transitions of Mn1xCoxWO4 (x = 0, 0.1) multiferroics by single crystal neutron diffraction experiments, magnetic andpolarization measurements, and we have analyzed the results in the light of the symmetry. All themagnetic models have been refined with JANA2006 [6] using the superspace formalism whichallows predicting the crystal tensor properties, such as the electric polarization. We have observed thatcompared to pure MnWO4, the magnetic symmetry of the multiferroic phase changes in agreementwith the experimentally observed flip of the electric polarization.

WN
A
R

D

TH
I
W

1- G. Lautenschlager et al., Phys. Rev. B 48, 6087 (1993). 2- H. Sagayama et al., Phys. Rev. B 77, 220407(R) (2008). 3- K. Taniguchi et al., Phys.
Rev. Lett. 102, 147201 (2009). 4- F. Ye et al, Phys. Rev. B 78, 193101(2008). 5- Y.-S. Song et al, Phys. Rev. B 79, 224415 (2009). 6- Petricek,V.,
Dusek,M. & Palatinus,L.(2006). Jana2006. The crystallographic computing system. Institute of Physics, Praha, Czech Republic.

Tomoya Tadokoro*, Mitsuru Akaki, Haruhiko Kuroe, Tomoyuki Sekine and Hideki
Kuwahara
Department of Physics, Sophia University, Japan

Recently, a new class of multiferroics with a coexistence of magnetic and ferroelectricordering has been attracting revived interests. RMnO3 (R: rare earth) with distorted
orthorhombic structure is one of the most canonical examples for such a multiferroic material.
In TbMnO3 [1], the electric polarization lies along the c axis in the ferroelectric ground state,
and the polarization does not flop without a magnetic field. Meanwhile, in Eu0.595Y0.405MnO3
without 4f moment [2], the magnetoelectric properties are quite different from those of
TbMnO3, although they have the same ionic radius of R-site. This result suggests that themagnetoelectric properties of the RMnO3 strongly depend on the characteristics of the
R-site 4f-moments [3]. In this study, we have systematically investigated magnetic anddielectric properties of Eu0.595(Y1-xHox)0.405MnO3 (0≤x≤1) single crystals with control of 4f
moments while keeping the average size of the R-site. In the x = 0.3 crystal, the ferroelectric
polarization along the c axis (Pc) emerges at 25K, and then Pc is suppressed and Pa appears
simultaneously with decreasing temperature. On further decreasing temperature, Pa
disappears and Pc appears again. The observed reentrant behavior of the Pc phase indicatesthat Pa and Pc phases are strongly competing with each other.

Jung Tae Lim, Chin Mo Kim, Sung Wook Hyun, Mi Hee Won, Taejoon Kouh andChul Sung Kim*
Department of Physics, Kookmin University, Korea
In recent years, the magnetoelectric effect observed in some of helicalmagnets has
been of great interest. With Al substitution, the improvement of magnetoelectric effecthas been reported due to reduction of the in-plane orbital moment originating fromlowering magnetic anisotropy[1-2]. Therefore, it is important to understand the originof magnetic properties in conjunction with the site distribution in hexagonal structure.
The crystal structure of polycrystalline Ba2Co1.5Mg0.5(Fe1-xAlx)12O22(x = 0, 0.01, 0.02)
samples were determined to be rhombohedral with the space group of R-3m. From thetemperature-dependent of magnetization curves under 100 and 300 Oe, all samples
showed ferrimagnet-to-paramagnet and helimagnet-to-ferrimagnet transitions. Base on
the applied-field dependent magnetization measurements up to 10 kOe at 295 K, thesaturation magnetization (Ms) and coercivity (Hc) of Ba2Co1.5Mg0.5(Fe1-xAlx)12O22(x =0, 0.01, 0.02) samples were found to be Ms = 28.0, 24.7, 23.4 emu/g and Hc = 255.4,
222.0, 196.2 Oe, respectively. Also, from Mössbauer spectra of 295 K, Isomer shift
values of all samples indicate that the charge states are Fe3+. We expect that the decreasein the Ms with Al ion doping is due to the fact that Al ions preferentially occupy the
3bVI, 18hVI and 3aVI octahedral sublattices of up-spin sites[3].

[1] T. Kimura et al., Nature 426, 55 (2003). [2] K. Noda et al., J. Appl. Phys. 99, 08S905 (2003). [3]M. Hitomi et al., J. Phys. Soc. Jpn. 79, 054704 (2010).

[1] S. Ishiwata, Y. Taguchi, H. Murakawa, Y. Onose, and Y. Tokura, Science 319, 1643 (2008). [2] H. B. Lee,Y. S. Song, J. H. Chung, S. H. Chun, Y. S. Chai, K. H. Kim, M. Reehuis, K. Prokes, and S. Matas, Phys. Rev.
B 83, 144425 (2011). [3] A. Collomb, M. A. Hadj Farhat and J. C. Joubert, Mat. Res. Bull. 24, 453 (1989).

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Crystal and magnetic structure of multiferroic Ba2CoGe2O7

Magnetic properties of the pyroxenes

SmCr3(BO3)4 - A new multiferroic?

Optical spectroscopy of the triangular lattice antiferromagnets
CuCrO2 and alpha-CaCr2O4

Vladimir Hutanu1*, Andrew Sazonov2, Martin Meven1, Dmitry Chernyshov3, H.
Murakawa4, Y. Tokura4, Istvan Kezsmarki5, Balint Nafradi6 and Georg Roth1
1
Institut fur Krystallographie, RWTH Aachen University, Germany
2
Laboratoire Leon Brillouin,, CEA, Centre de Saclay; DSM/IRAMIS, France
3
Swiss-Norwegian Beam Lines, ESRF, France
4
Multiferroics Project, ERATO, JST, University of Tokyo, Japan
5
Department of Physics, Budapest University of Technology, Hungary
6
Max Planck Institute for Solid State Research, Stutgart, Germany
The crystal structure of Ba2CoGe2O7 has been precisely determined by single crystal diffraction at four
different temperatures. Room temperature as well as 90 K structure determinations were performed using
x-ray synchrotron radiation. The observation of the superstructure reflections commensurate with thetetragonal cell and violating the 2-1 axis lead to the conclusion that P-421m is a rather good approximation of
the average structure, but the real structure has lower symmetry and most probably corresponds to the Cmm2
SG [1]. Crystal structure above (10 K) and crystal and magnetic structures below (2 K) the antiferromagnetictransition temperature of 6.7 K have been determined using neutron diffraction on single crystal. The
structural results show no significant changes with the temperature indicating no structural phase transition
down to the multiferroic phase. Antiferromagnetic non-collinear magnetic order has been found in the groundstate contrary to the previous literature data [2]. The canting angle and the magnitude of the ordered moment
have been refined. The possibility of the existing of polar structure and week ferromagnetic component in the(a,b) plane shed a new light in the understanding of the multiferroicity in the Ba2CoGe2O7.

Sergey Streltsov1 and Daniel Khomskii2
1
Institute of metal Physics, Russia
2
University of Cologne, Germany

Pyroxenes, silicates of composition AMSi2O6, comprise one of the most importantclasses of minerals both in the Earth’s crust and upper mantle, and as typical (extra)
terrestrial rock-forming materials (A=Li,Na,Ca, and M is a transition metal ion).
Interestingly enough these materials exhibit very different magnetic properties. Someof them have a spin-gapped ground state, like NaTiSi2O6, others show AFM or FM(which is unusual for transition metal insulator) long range magnetic order, Fe-based
pyroxenes were found to be multiferroic and possibly have the spin-state transition
under a high pressure. In the present talk we will review magnetic properties of thepyroxenes and provide a theoretical description for some of their properties. This work
was supported by grants RFBR 10-02-00046 and 10-02-96011.
1) S. Jodlauk et al. J. Phys.: Condens. Matter, 19, 432201 (2007) 2) S.V. Streltsov and D.I. Khomskii
Phys. Rev. B, 77, 064405 (2008) 3) S.V. Streltsov, J. McLeod, A. Moewes, G.J. Redhammer and
E.Z. Kurmaev Phys. Rev. B 81, 045118 (2010) 4) Streltsov S.V. and Skorikov N.A. Phys. Rev. B 83,
214407 (2011)

Kirill N. Boldyrev1*, Marina N. Popova1, Viktor V. Mal'tsev2 and Nicolay I. Leonyuk2
1
Solid State Spectroscopy, Institute of spectroscopy RAS, Russia
2
Faculty of Geology, Moscow State University, Russia
Rare-earth borates with general formula RM3(BO3)4 (R = Y, La-Lu; М = Al, Fe, Cr) are
interesting for science and technology. Iron borates have rich magnetic properties stipulated by
the presence of two interacting magnetic subsystems. It has recently been shown that RFe3(BO3)4
belong to a new class of multiferroics [1,2]. For this reason it is interesting to study rare-earth
borates with other magnetic ion chromium. At present, little is known about these compounds.
Antiferromagnetic phase transition has been found in NdCr3(BO3)4 at TN=8.0 K [3]. This work
describes an optical study in a wide spectral and temperature range of the SmCr3(BO3)4 crystal,
both pure and doped with erbium or neodymium. We have found that SmCr3(BO3)4 undergoes
a cascade of phase transitions at temperatures of 8.0 K, 6.7 K and 4.3 K. The first two ones aresecond-order phase transitions and, supposedly, correspond to the antiferromagnetic and (anti)
ferroelectric ordering, respectively. First-order phase transition at 4.3 K is, most probably, the spin
reorientation of the chromium magnetic moments. The presence of the magnetic and ferroelectricorder allows us to talk about samarium chromium borate as a new multiferroic crystal.
[1] A.E. Zvezdin, S.S. Krotov, A.M. Kadomtseva, G.P. Vorob’ev, Yu.F. Popov, A.P. Pyatakov, L.N. Bezmaternykh,
E.A. Popova, JETP Lett. 81, 272 (2005). [2] A.M. Kadomtseva, Yu.F. Popov, G.P. Vorob’ev, A.P. Pyatakov, S.S.
Krotov, K.I. Kamilov, J. Low Temp. Phys., 36(6), 640 (2010). [3] E.A. Popova, N.I. Leonyuk, M.N. Popova, E.P.
Chukalina, K.N. Boldyrev, N. Tristan, R. Klingeler, B. Buchner, Phys. Rev. B, 76, 054446 (2007).

July 9 (Mon)

Irene Urcelay - Olabarria1*, Eric Ressouche1, Jose Luis Garcia - Munoz2, Vassil
Skumryev3, Alexander Mukhin4 and Juan Manuel Perez - Mato5
1
Institut Laue Langevin, 38042 Grenoble, Cedex 9, France
2
Instituto de Ciencia de Materiales de Barcelona, ICMAB-CSIC, E-08193 Bellaterra, Spain
3
Institut Catala de Recerca i Estudis Avancats (ICREA), E-08193 Barcelona, Spain
4
Prokhorov General Physics Institute of the Russian Acad. Sci., 119991 Moscow, Russia
5
Dpto. De Fisica de la Materia Condensada, Fac. de Ciencia y Tecnologia, Universidad del Pais Vasco, Spain

Michael Schmidt1*, Zhe Wang1, Franz Mayr1, Sandor Toth2, Bella Lake2, A. T. M.
Nazmul Islam2, Vladimir Tsurkan1, Alois Loidl1 and Joachim Deisenhofer1
1
Experimental Physics V, EKM, Institute of Physics, University of Augsburg, Germany
2
Helmholtz Zentrum Berlin fur Materialien und Energie, Germany
We will compare and discuss our results obtained by optical spectroscopy on CuCrO2
and alpha-CaCr2O4. While CuCrO2 is famous for its multiferroicity [1], in alphaCaCr2O4 a polarization can only be observed under the application of electric or
magnetic field, despite having a closely related structure [2]. In alpha-CaCr2O4 we
can see a strong, broad absorption at 57 cm-1 in the magnetically ordered state. The
other compound shows two excitations at 11 and 48 cm-1 below the magnetic ordering
temperature. At near infrared and visible light frequencies we observe Cr3+ crystal fieldabsorptions and below TN excitons and exciton-magnon-transitions appear. The widthof these exciton-magnon transitions is analyzed with respect to the existence of Z2
vortices as proposed by Kojima et al. [3].
[1] S. Seki et al., Phys. Rev. Lett. 101, 067240 (2008) [2] K. Singh et al., Phys. Rev. B 84, 064129(2011) [3] N. Kojima et al., J. Phys. Soc. Jpn. 62, 4137 (1993)[1] V. Hutanu et al, Phys. Rev. B 84, 212101 (2011) [2] A. Zheludev, et al, Phys. Rev. B, 68, 024428 (2003)

PA15

PA18

PA21

PA24

The role of Co-doping in Mn0.85Co0.15WO4 studied by magnetic X-ray
scattering

High-field study of multiferroic Ni3V2O8

Magnetodielectric effect in the antiferromagnet SrNdFeO4

Nuclear forward scattering in high magnetic fields; spin structures in
the magnetic staircase of frustrated multiferroic CuFeO2

Javier Herrero-martin1*, Alexey Dobrynin2, Paul Steadman2, Peter Bencok2, Raymond
Fan2, Claudio Mazzoli3, A. M. Balbashov4 and A. A. Mukhin5
1
Institute of Materials Science of Barcelona - CSIC, Spain2
Diamond Light Source, Didcot, Oxfordshire, United Kingdom
3
Dpto. Fisica, Politecnico di Milano, Milano, Italy
4
Moscow Power Engineering Institute, Moscow, Russia
5
Prokhorov General Physics Institute of the Russian Acad. Sci., Moscow, Russia
MnWO4 is known to show a multiferroic (MF) behaviour at low temperatures (~8-13 K) where thedevelopment of an incommensurate (ICM) Mn cycloidal spin structure (AF2 phase) is responsible for theappearance of a net electric polarization along the crystal b-axis [1-3]. The partial substitution of Mn by Co
in small quantities stabilizes AF2 down to the ground state. A further Co doping produces the appearanceof a new ICM phase, defined as AF2’[4,5]. We have performed resonant magnetic x-ray scattering (RMXS)
with soft x-rays (Mn, Co 2p --> 3d) on Mn0.85Co0.15WO4 to independently analyze the spins orientationin Mn and Co ions in antiferromagnetically (AFM) ordered phases. A full polarization analysis of theincident and scattered x-rays permits us to provide an accurate complete picture of the magnetic structurein the collinear AF4 phase. The latter points to a strong influence of Co doping on the Mn spins alignment
direction. We discuss these results in the frame of a large Co single ion anisotropy as reported in CoWO4 [6].
[1] G. Lautenschlaeger et al, Phys. Rev. B 48, 6087 (1993) [2] D. Meier et al, Phys. Rev. Lett. 102, 147201 (2009)[3] H. Sagayama et al, Phys. Rev. B 77, 220407(R) (2008) [4] Y.-S. Song et al, Phys. Rev. B 79, 224415 (2009) [5]
R. P. Chaudhury et al, Phys. Rev. B 82, 184422 (2010) [6] N. Hollmann et al, Phys. Rev. B 82, 184429 (2010)

118

The 19th International Conference on Magnetism

Junfeng Wang1, Masashi Tokunaga2, Zhangzhen He3 and Koichi Kindo2
1
Wuhan National High Magnetic Field Center, China
2
The Institute for Solid State Physics (ISSP), The University of Tokyo, Japan3
Fujian Institute of Research on the Structure of Matter, Chinese Academy of
Sciences, China

WI

T

HD

WN
A
R

Jungmin Hwang1, Eun Sang Choi2, Haidong Zhou2, Yan Xin2, Jun Lu2 and Pedro
Schlottmann1
1
Florida State University/NHMFL, USA
2
NHMFL (National High Magnetic Field Laboratory), USA
We investigated the magnetic phase diagram of single crystals of the compound
SrNdFeO4 by measuring the magnetic susceptibility, the magnetization, the specificheat and the dielectric constant. The system has two magnetically active ions, namely
Fe3+ and Nd3+. The Fe3+ spins are antiferromagnetically ordered below 360 K withthe moments lying in the ab-plane, and undergo a reorientation transition at about 3537 K to an antiferromagnetic order with the moments along the c-axis. A short-range,
antiferromagnetic ordering of Nd3+ along the c-axis was attributed to the reorientationof Fe3+ followed by a long-range ordering at lower temperature.[1] At low temperaturesand magnetic fields above 8 T the Nd3+ moments are completely spin-polarized. The
dielectric constant also shows anomalies associated with spin configuration changes.
Remarkably, the sign of the dielectric changes are dependent on the direction of the
probing electric field. A possible magnetic structure explaining all the data is presented.
[1] S. Oyama, M. Wakeshima, Y. Hinatsu, and K. Ohoyama, J. Phys.: Condens. Matter. vol. 16, 1823
(2004).

Cornelius Strohm1*, Tom T. A. Lummen2, Puri I. Handayani3, Thomas Roth1, Peter J. E.
M. Van Der Linden1 and Paul H. M. Van Loosdrecht3
1European Synchrotron Radiation Facility, 6 rue Jules Horowitz 38000 Grenoble, France
2
Department of Materials Science and Engineering, The Pennsylvania State University.
121 Steidle Building, University Park, PA, 16802, USA3
Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747
AG Groningen, Netherlands
Geometrically frustrated magnets often show a multitude of nearly degenerate ground states, which may bestabilized individually by the presence of small internal or external perturbations. In Copper Iron Oxide, thecombination of geometrically frustrated interactions, with uniaxial anisotropy and spin-lattice coupling lead toa staircase of metamagnetic phases as a function of applied field [1-3]. We used Nuclear Forward Scatteringof synchrotron radiation in magnetic fields up to 30 T [4, 5] to probe the spin structure of these phases up to
the 1/3-plateau for fields parallel and perpendicular to the c axis [6]. The low field data and all transition fields
agree with previous work. For the parallel configuration, we confirm the low field collinear spin structure. The
data for the ferroelectric phase does not support a cycloid structure, while a 3D distribution approximating a
multi-domain transverse proper helix structure gives qualitative agreement. For the 1/3-plateau, the anticipatedcollinear 3-sublattice structure best represents the data. In the perpendicular configuration we directly
evidence the stability of the canted 4-sublattice phase up to the 1/3-plateau, where a collinear three sublatticeconfiguration provides the best fit when a small amount of the spins oriented in the H-c plane is allowed for.
[1] R. S. Fishman Phys. Rev. Lett. 106, 037206 (2011). [2] T. T. A. Lummen et al. Phys. Rev. B 80, 012406 (2009). [3] T. T. A. Lummen etal. Phys. Rev. B 81, 224420 (2010). [4] P. J. E. M. van der Linden et al. Rev. Sci. Instrum. 79, 075104, (2008). [5] C. Strohm, P. van der
Linden and R. Rueffer Phys. Rev Lett. 104, 087601 (2010). [6] C. Strohm, T.T.A. Lummen, P.H.M. van Loosdrecht et al. unpublished.

July 8-13, 2012 Busan, Korea

119poster Presentation
PA25

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PB09

Magnetic dispersion of the quasi-1D, spin-1/2, multiferroic CuOInfluence of BaSnO3 nanoparticle dispersions on flux pinning propertyof GdBa2Cu3O7-δ multilayered thin films

Hole doping effect for the T’-Ln2CuO4 (Ln = La,Nd) cuprate

Chemically introduced disorder effects on the critical current densityand pinning force of YBaCu2O7-δ single crystals

Cupric Oxide (CuO) exhibits a magnetoelectric multiferroic phase over the narrow
but relatively high temperature range of 213-230K [1]. The mechanism for thismagnetoelectric coupling is not fully understood and there have been various
theoretical models proposed [2]. The excitation spectra of CuO in the collinear
antiferromagnetic phase (T<213K) was measured using inelastic neutron scattering.
We have observed three-dimensional magnetic behaviour transform into a spin1/2 chain regime with increasing energy. Through comparison of the data to a semiclassical spinwave model and a quantum spinon model, we have extracted valuesof the magnetic exchange constants. With these values we can refine the existing
theoretical models of the magnetoelectric mechanism as well as unravel the nature of
one-dimension quantum magnetism in CuO.
[1] T. Kimura et al., Nature Materials, 7, 291 (2008) [2] G. Giovannetti, et al, Phys. Rev. Lett., 106,026401 (2011); G. Jin, et al, ArXiv:1007.2274v2 (2007); A-M. Pradipto, et al, Phys. Rev. B, 85014409 (2012)

Duc H. Tran1, Witha B. K. Putri1, Byeongwon Kang1*, N. H. Lee2, W. N. Kang2, J. Y.
Lee3 and W. K. Seong3
1
Physics, Chungbuk National University, Korea
2
Physics, Sungkyunkwan University, Korea
3
Convergence Technology Laboratory, Korea Institute of Science and Technology,
Korea

Flux pinning property of GdBa2Cu3O7-δ (GdBCO) thin films with embedding BaSnO3(BSO) nanoparticle pseudo-layers structured as (BSO/GdBCO) x N layers was investigated.
The multilayered films whose entire thickness of approximately 200 nm were fabricatedon SrTiO3 (STO) substrate by using the pulsed laser deposition (PLD) technique. Numberof BSO pseudo-layers was varied from 1 to 5 in order to increase the density of pinning
centers along the c-axis of the films. BSO nanoparticle density per layer was estimated tobe approximate 114/μm2 by using an atomic force measurement (AFM). A minor decreasein the transition temperature Tc was observed for (BSO/GdBCO) multilayered films.
Magnetization data showed that BSO pseudo-layers provides enhanced in-field criticalcurrent density Jc up to certain magnetic fields. Jc enhancements were attributed to thedispersions of BSO nanoparticle pseudo-layers confirmed by cross sectional TEM image.

The Ln2CuO4 (Ln=La,Nd) cuprate has two different structure types and shows thesuperconductivity for hole doping of La2CuO4 and electron doping of Nd2CuO4. From
the Madelung energy calculation in hole doping cuprate, Tc is enhanced with increasing
the distance between Cu2+ ions in CuO2-layer and apical oxygens. Nd2CuO4 with T’type structure has exhibited superconductivity by electron carrier doping in CuO2layer. We focused on our attention to synthesize the hole doping to T’-Ln2CuO4,
in which there is no oxygen atom at apical site of CuO2-layer. We successfully
synthesized the polycrystalline samples of T’-(Ln3+,M2+)2CuO4 (Ln=La,Nd, M=Ca,Sr).
In particular, T’-(La3+,Sr2+)2CuO4 was synthesized using CaH2, which is a strong
reducing agent at annealing temperature of 573 K [1]. The powder X-ray diffraction
patterns showed that the samples were a single phase, and diffraction peaks indexed
by a tetragonal symmetry of T’-type cuprate of Nd2CuO4. The lattice constants a andc show the systematic changes by increasing the M2+ concentration. We determinedthe copper ion’s valence state using iodometry method for substituted sample of T’(Ln3+,M2+)2CuO4 and confirmed that the valence of Cu ion is closed to 2+. These facts
indicate that there is oxygen deficiency in Ln2O2- or CuO2-layer of T’-(Ln3+,M2+)2CuO4
and canceled hole carriers.

Rovan Fernandes Lopes1*, Valdemar Das Neves Vieira1, Ana Paula Aguiar De
Mendonca1, Fabio Teixeira Dias1, Douglas Langie Da Silva1, Paulo Pureur2, Jacob
Schaf2 and Frederik Wolff-fabris3
1
Universidade Federal de Pelotas, Brazil
2
Universidade Federal do Rio Grande do Sul, Brazil
3
HZ Dresden-Rossendorf, Germany

We report isotherm dc magnetization hysteresis loops of a series of YBa2-xSrxCu3O7-δ (x = 0, 0.1, 0.25, 0.37
and 0.5) single crystals with the aim to study the influence of the chemically introduced site disorder on
the YBa2Cu3O7-δ critical current density, JC and flux pinning properties, FP. [1,2] The Sr ion size chemical
disorder is introduced in YBa2Cu3O7-δ structure by lattice distortion. Transmission electronic microscopy(TEM) observations of our samples structure revels the existence of a high density of twins, probably,
decorated by many small local precipitates. The JC were determined by application of the modified Beancritical state model.[3-5] Preliminary magnetization data analysis shows a significant and a systematicallydecrease of the critical current density and pinning force intensities as Sr concentration level increases up
to 25%. The normalized FP curves showed no reasonable scaling as a function of the Sr doping level ortemperature range.[4,5] The application of the Dew Hughes law to the normalized FP curves revels thatpinning mechanism in the doped samples are strongly temperature and level doping dependent. We consider
the particular defect structure introduced by Sr substitution as a responsible to the flux pinning properties.

1. A. A. Gapud, D. Kumar, S. K. Viswanathan, C. Cantoni, M. Varela, J. Abiade, S. J. Pennycook and
D. K. Christen, Supercond. Sci. Technol. 18 (2005) 1502-1505. 2. T. A. Campbell, T. J. Haugan, I.
Maartense, J. Murphy, L. Brunke and P. N. Barnes, Physica C 423 (2005) 1-8

T. Takamaysu, M. Kato, T. Noji, and Y. Koike, Physica C 471 (2011) 679-681

1. K. Saito, H. U. Nissen, C. Beeli, T. Wolf, K. H. Schauer, Physical Review B 58, 6645 (1998). 2. V. N. Vieira, J. Schaf, Physica C
408, 533 (2004). 3. L. Civale, M. V. Mcelfresh, A. D. Marwick, F. Holtzberg, C. Field, J. R. Thompson, D. K. Christen, PhysicalReview B 43, 13732 (1991). 4. T. Masui, Y. Takano, K. Yoshida, K. Kajita, S. Tajima, Physica C 412, 515 (2004). 5. G. Fuchs, K.
Nenkov, G. Krabbes, R. Weinstein, A. Gandini, R. Sawh, B. Mayes, D. Parks, Superconductor Science and Technology 20, 197 (2007).

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Hole-doped cuprate panorama and the second neighbor hopping

Highly anisotropic dielectric behavior of insulating Bi2Sr2RECu2O8+δ
(RE = Dy, Y)

Thermodynamic properties of copper oxide Cu6O8YCl1-xBrx

The correlation between the magnetic irreversibility and the zero
resistance temperatures in granular YBa2Cu3O7-δ single crystals

Partha Goswami*
Physics department, D.B.College(University of Delhi),New Delhi, India

We consider the coexistent id-density wave (DDW) order, at the anti-ferromagnetic
wave vector Q = (π,π), representing the pseudo-gap (PG) state, and d-wave
superconductivity (DSC), driven by an assumed attractive interaction, within the BCS
framework for the two-dimensional (2D) fermion system on a square lattice startingwith a mean-field Hamiltonian involving the singlet DDW and the DSC pairings. The
second-neighbor hopping, which is known to be important for cuprates [K. Tanaka etal.,Phys. Rev. B 70 , 092503(2004)]and frustrates the kinetic energy of electrons, leads
to Fermi surface sheets being not connected by Q. The particle-hole asymmetry in the
single-particle excitation spectrum of the pure DDW state is reflected in the coexisting
DDW and DSC states though the latter is characterized by the Bogoluibov quasiparticle bands- a characteristic feature of SC state. Quite significantly, we find that thecoexistence is possible due to the non-nesting property.

PB02
Quantum oscillations from nodal bilayer magnetic breakdown in theunderdoped high temperature superconductor YBa2Cu3O6+x
Neil Harrison
Los Alamos National Laboratory, USA

We report quantum oscillations in underdoped YBa2Cu3O6.56 in magnetic fields over asignificantly large range in magnetic field extending from ≈~25 to 94~T, enabling threewell-spaced low frequencies at ≈~462~T, 532~T, and 602~T to be clearly resolved.
We show that a small nodal bilayer coupling that splits a nodal pocket into bonding
and antibonding orbits yields a sequence of frequencies, F_0-Δ F, $F_0$ and F_0+Δ
F and accompanying beat pattern similar to that observed experimentally on invoking
magnetic breakdown tunneling at the nodes. The relative amplitudes of the multiple
frequencies observed experimentally in quantum oscillation measurements are shown
to be reproduced using a value of nodal bilayer gap quantitatively consistent with thatmeasured in photoemission experiments in the underdoped regime. A clear consistency
between the experimental data and a Fermi surface consisting of nodal pockets isrevealed.

Makoto Maki, Chikano Yukitake and Shigeyuki Yufu
Department of Physics, Saga University, JapanThe 19th International Conference on Magnetism

Kenji Kawashima, Hiroki Takeda and Jun Akimitsu
Physics and Mathematics, Aoyama Gakuin University, Japan

Daniela Goetzke Macedo1*, Valdemar Vieira1, Fabio Dias1, Douglas langie1, Paulo
Pureur2, Jacob Schaf2 and Frederik Fabris3
1
Instituto de Fisica e Matematica, UFPEL, Brazil
2
Instituto de Fisica, UFRGS, Brazil
3
Dresden High Magnetic Field Laboratory, HZ Dresden-Rossendorf, Brazil

The low-frequency dielectric measurements on lightly-doped Bi2Sr2RECu2O8+δ (RE =Dy, Y) single crystals were carried out in order to investigate the electronic structure
and carrier dynamics near the insulator-to-metal transition. We found the unusuallylarge dielectric polarization in the ab plane, whereas the out-of-plane dielectric
constant was reasonably small at low temperatures. With increasing temperature above
about 230 K, the out-of-plane dielectric constant shows a rapid increase followed
by a sharp peak. The large anisotropy and unusual temperature dependence of thedielectric response probably reflect the hopping polarization induced by localized
charge carriers and the spatial charge distribution peculiar to the insulating Bi2212.
Our results seem to imply that the carrier movement is limited within the CuO2 planes
at low temperatures below about 230 K, and the confined carriers start to hop toward
the perpendicular direction at higher temperatures [1, 2]. We also present data for Zndoped Bi2Sr2RECu2O8+δ samples to discuss the relationship between the enhanced
dielectric polarization and a long-range antiferromagnetic ordering of Cu magnetic
moments in the CuO2 planes.

Copper-oxide family Cu6O8MCl (M=cation) has a cubic structure (Fm-3m) with Cu6O8-cageincluding Cl- ion in its crystal structure [1,2]. Cations of M ions are located in the cuboid space
between Cu6O8-cages. The Cu6O8-cages share their face to form a three-dimensional network.
Cu6O8YCl shows the metallic and paramagnetic behavior at low temperature. Moreover, Y and
Cl ions have large atomic displacement parameters, suggesting the anharmonic vibrations likerattling phenomena of other cage structured compounds. We synthesized the polycrystalline
samples of Cu6O8YCl1-xBrx as a single phase to clarify relationship between the thermodynamic
properties including its ground state and Cu6O8 cage size. In thermo-electronic measurementsof Cu6O8YCl, seebeck coefficient is relatively high value (-14 μV/K at 350K), and thermal
conductivity exhibits of low value (~0.3W/Km at 350K). The lattice constant a increases withincreasing Br concentration, indicating expansion of Cu6O8-cage. The temperature dependenceof electrical resistivity of Cu6O8YBr exhibits semiconducting behavior, suggesting that the
ground state of Cu6O8YCl1-xBrx changes from metallic to semiconducting by increasing Br
concentration. Thermal conductivity undergoes very little change. However, S is enhanced bysubstituting Br. These facts indicate that the ground state and physical properties are sensitive on
the Cu6O8-cage size in Cu6O8YCl1-xBrx system.

We report on dc magnetization and ac magnetoresistance measurements of the Y0.09Ca0.01Ba2Cu3O7-δ,YBa1.98Sr0.02Cu3O7-δ and YBa2Cu2.97Zn0.03O7-δ single crystals with the propose of to study the role of thesuperconducting granularity on the correlation between the magnetic irreversibility, Tirr(H) and the zero
resistance, Tr(H) temperatures.[1-3] The results show that in the low field region of the H-T diagramthat the Tr(H) data falls systematically underneath of the Tirr(H) data and at H-T high field region the
Tr(H) data matches the Tirr(H) data. In this scenario, Tirr(H) and Tr(H) do not depend on the same partsof the sample. While the Tirr(H) depends on wellcoupled grain clusters, the Tr(H) depends on grain
arrays traversing the whole sample. Along such long range paths, the Tr(H) can be attained only at sometemperature below the Tirr(H). On the other hand, in fields above several kOe, for which the magnetic
field penetrates the grains, the Tirr(H) is dominated by the intragrain Abrikosov flux dynamics while theTr(H) is still ruled by the grain junctions. It can vanish only after long-range coherence is achieved. The
granular aspects of our results are discussed in terms of the superconducting glass theories.[1-4][1] M. Maki, S. Nakao, K. Machida, M. Shiraishi, X. G. Zheng, T. Naito, and H. Iwasaki, J. Phys.
Soc. Jpn. 76, 044711 (2007) [2] S. Yufu, M. Shu-nan, S. Nakao, and M. Maki, J. Phys. Soc. Jpn. 79,
054709 (2010)[1] G.Zouganel, K.Bushida, I.Yazawa N.Terada, M.Jo, H.Hayakawa, and H.Ihara, Sol. St. Comm. 80(1991) 709. [2] K.Bushida, I.Yazawa, G.Zouganel, T.Connard, N.Terada, K.Kaneko, M.Hirabayashi,
and H.Ihara, Physica C 185-189 (1991) 2727.

1. V. N. Vieira, J. Schaf, and P. Pureur, Phys. Rev. B 66, 224506 (2002). 2. R. Menegotto Costa R, P.
Pureur et al, Phys. Rev. B 64, 214513 (2001). 3. V. N. Vieira, I. C. Rigel, and J. Schaf, Phys. Rev. B
76, 024518 (2007). 4. V. N. Vieira and J. Schaf, Phys. Rev. B 64, 094516 (2001).

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Nodal superconducting gap in Bi2201 investigated by low temperature
specific heat measurements

Paramagnetic Meissner effect and strong time dependence at highfields in melt-textured high-tc superconductors

PB05
Pressure effect on the superconductivity and crystal structure for Hg
cuprateYukihiro Kamada1, Tomoko Kagayama1*, Katsuya Shimizu1, Akira Iyo2 and Shin-ichi
Uchida3
1
KYOKUGEN, Osaka Univ., Japan
2
AIST, Japan
3
Dept. of Phys., The Univ. of Tokyo, Japan
18 years ago, Hg cuprate recorded the highest Tc=164 K under high pressure (31 GPa)in 1994 [1]. But the record has not broken yet. We try to make new world record of
Tc with the high purity Hg1223 (HgBa2Ca2Cu3O8+δ) samples and the high purity Hg1234(HgBa2Ca3Cu4O10+δ) sample. We measured electrical resistance and X-ray diffraction
under the pressure with a diamond-anvil cell (DAC). We measured two different Hg1223
samples, which were under doped sample (Hg1223 UD) and optimal doped sample(Hg1223 OPT), and one Hg1234 sample which was optimal doped sample. We measured
two different pressure conditions, using pressure medium (NaCl) or not (None). The
resistance drop of superconducting transition becomes broader by increasing pressure.
At 80 GPa, we can not find the drop of superconducting transition above 10 K. The Tc
have a maximum at 20-30 GPa accompanied with the anomaly in crystal structure.
[1] L. Gao et al., Phys. Rev. B 50, 4260 (1994)

120

Wataru Ito, Kenji Kawashima, Suguru Igarashi, Michinori Fukuma and Jun Akimitsu
Physics and Mathematics, Aoyama Gakuin University, Japan

Naoki Momono1*, Nobutaka Saikai1, Tohru Kurosawa2, Yusuke Amakai1, Sigeyuki
Murayama1, Hideaki Takano1, Migaku Oda2 and Masayuki Ido2
1
Applied Sciences, Muroran Institute of Technology, Japan2
Department of Physics, Hokkaido University, Japan

In order to examine the gap magnitude near nodes in Bi2201 cuprate superconductors,
we have measured the magnetic field dependence of low temperature electronic
specific heat Cel(T, H), which is much more bulk-sensitive than standard ARPES andSTS. In optimally doped Bi2201, the coefficient of T-linear term in Cel at T<<Tc, whichis almost vanished in zero field, shows a square-root dependence of magnetic field H asis expected in d-wave superconductors. We determined the nodal gap slope v, reflecting
the gap magnitude near nodes, from the square-root dependence of H; v~4.4x10^5 cm/
s. In heavily underdoped Bi2201, the coefficient of T-linear term is not zero even in zero
field, and is nearly independent of H up to 6 T. The comparison of these results withrecent ARPES and STS results will be discussed in detail.

July 9 (Mon)Stephen Michael Gaw
Oxford University, United Kingdom

July 9 (Mon)poster Presentation

Cristol De Paiva Gouvea1*, Fabio Teixeira Dias1, Valdemar Das Neves Vieira1, Douglas Langie
Da Silva1, Frederik Wolff-Fabris2, Erik Kampert2, Jacob Schaf3 and Joan Josep Roa Rovira4
1
Universidade Federal de Pelotas, 96010-900, Pelotas, Brazil
2
Dresden High Magnetic Field Laboratory, HZ Dresden-Rossendorf, 01314, Dresden, Germany
3
Universidade Federal do Rio Grande do Sul, 91501-970, Porto Alegre, Brazil
4
Universite de Poitiers, 86962, Poitiers, France

The conventional Meissner effect is characterized by a diamagnetic response of the superconducting material
when a magnetic field is applied, but in several cases this magnetic response in field-cooled experiments canbe paramagnetic. This effect is known as paramagnetic Meissner effect (PME) [1]. Sometimes the PME
presents a time dependence of the FC magnetization and a paramagnetic signal can be observed when thefield-cooled moment relaxes at constant magnetic field and temperature [2,3]. In this work we report on
systematic field-cooled magnetization experiments in melt-textured YBaCuO samples containing Y211
precipitates. Magnetic fields up to 14 T were applied either parallel or perpendicular to the ab planes and astrong paramagnetic response related to the superconducting state was observed. The magnitude of the PME
increases when the field is augmented. This effect shows a strong paramagnetic relaxation, such that theparamagnetic moment increases as a function of the time. The pinning by the Y211 particles plays a crucialrole in the explanation of this effect and our results suggest that the pinning capacity [4] can produce a strong
flux compression [5] into the sample, originating the PME and the strong time dependence.
[1] P. Svedlindh, K. Niskanen, P. Norling, P. Nordblad, L. Lundgren, B. Lonnberg, and T. Lundstrom. Physica C 162/164, 1365
(1989). [2] A. Terentiev, D. Watkins, L. De Long, D. Morgan, and J. Ketterson, J. Phys. Rev. B 60, R761 (1999). [3] F. Dias, P.
Pureur, P. Rodrigues Jr., and X. Obradors. Phys. Rev. B 70, 224519 (2004). [4] F. Dias, V. Vieira, M. de Almeida, A. Falck, P.
Pureur, J. Pimentel Jr., and X. Obradors. Physica C 470, S111 (2010). [5] A. Koshelev, and A. Larkin. Phys. Rev. B 52, 13559 (1995).

July 8-13, 2012 Busan, Korea

121

poster Presentation
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Enhancement of Ti-Se bonding length in CuxTiSe2

The effect of CdO nanoparticles doping and sintering time on the
structure and critical temperature of Bi2223 superconductor

Effects of various epoxy impregnations on the electrical properties of
GdBCO-coated conductor racetrack pancake coils

Transport properties of the twin boundary of YBa2Cu3O7 thin films on
LaAlO3 substrates

Titanium diselenide (TiSe2) undergoes a charge-density-wave (CDW) instability characterized by
a 2x2x2 real-space superstructure [1]. TiSe2 is not superconducting at low temperature, but CDW
is suppressed and superconductivity stabilized either by Cu intercalation (maximum Tc =4.5 K)[1] or pressure (maximum Tc = 1.8 K) [2]. The resulting phase diagram looks similar to that ofcuprates with the difference that the spin-density wave order has been replaced by a CDW one. The
mechanism at the origin of the CDW and superconducting phases in TiSe2 is currently unknown.
The charge-order instability in pure TiSe2 is known to involve both exciton formation and a strong
electron-phonon coupling, it may be expected that the superconducting phase will likewise involvea combination of both excitonic [3] and phonoic [4] contributions. In order to elucidate the role of
Cu atoms, we have investigated the Cu-doped TiSe2 by employing both x-ray absorption near-edge
structure (XANES) and extended x-ray absorption fine-structure (EXAFS). The Cu atoms enhance
the bonding length of Ti and Se atoms with lowering temperature. Concurrently, the Debye-Waller
factors change at the transition temperatures of CDW and superconductivity, respectively.

Morteza Zargar Shoushtari*, S Ebrahim Musavi Ghahfarokhi and Nahid Hossinzadeh
Physics, Shahid Chamran University of Ahvaz, Iran

The effect of CdO nanoparticles doping and sintering time on the structure and criticaltemperature of Bi2223 superconductor M. Zargar shoushtari1, S. E. Musavi Ghahfarokhi,
N. Hossinzadeh 1 Department of physics, Shahid Chamran University of Ahvaz,
Ahvaz, I. R. Iran Presenting author: zargar@scu.ac.ir In this paper, Bi1.64Pb0.36Sr2Ca2xCdxCu3Oy (x= 0.0, 0.01, 0.02, 0.03, 0.04, 0.1) superconductor is prepared by using thesolid state method. The effect of doping CdO nanoparticles for different sintering times(t= 90, 180 and 270 h) on the stracture and critical temperature has been studied. The
structural analysis was carried out using XRD and SEM measurements. The criticaltemperature was measured by the standard four-probe method. The results showed thatthe more sintering time increases the critical temperature such that the samples prepare
at 270h have maximum critical temperature. Also, our results reveal that, the Bi1.64Pb
0.36Sr2Ca1.97Cd0.03Cu3Oy sample has the highest Tc (Tc= 137.5k) in between the doped
samples.

Hyun-jin Shin, Kwang Lok Kim, Yoon Hyuck Choi, Oh Jun Kwon, Yeonjoo Park and
Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea
A high temperature superconducting (HTS) field coil in a wind turbine generator isgenerally impregnated with epoxy resin to provide high mechanical integrity against
the rotational vibrations. However, if cooled down, the epoxy-impregnated coil woundwith second generation (2G) HTS tape usually encounters superconducting property
degradation and delamination due to the thermal contraction mismatch between theepoxy and the HTS tape. Therefore, to investigate the effect of various epoxies on
the coil’s electrical properties, the GdBCO racetrack pancake coils impregnated with
Stycast 2850-FT, Epikote 828R, or Epon 815 were characterized using Ic testing.
Furthermore, degradation of the coils’ superconducting properties was also examinedusing repetitive cooling tests.
<Acknowledgment> This work was supported by the International Collaborative R&D Program of
the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the
Korean government Ministry of Knowledge Economy (20118520020020).

Sung Hoon Lee1, Sung-hak Hong1, Jae-hyuk Choi2 and Soon-gul Lee1*
1
Department of Display and Semiconductor Physics, Korea University, Korea
2
Division of Convergence Technology, Korea Research Institute of Standards andScience, Korea
We have fabricated superconducting YBa2Cu3O7 (YBCO) twin-boundary junctions andstudied their critical transport properties. The twin boundary junctions were fabricatedby using a focusd-ion-beam (FIB) etching technique and of the size of nominally 150
nm in width, 100 - 120 nm in length, and 100 nm in thickness. The junctions showed
Tc = 91 K with 1 K transition width and a high critical current density of Jc = 15 MA/
cm2 at 77 K. Measured current-voltage (I-V) curves showed the resistively-shuntedjunction (RSJ) characteristics near the transition with excess current associatedwith flux-flow effect. High-resolution X-ray diffraction (HR-XRD) spectra strongly
indicated the possibility that the epitaxially-grown YBCO film was also twinned incommensurate with the twinning of the LAO substrate. Misorientation of the c-axis of
YBCO at the twin boundary is believed to be the major cause of the weak link behaviorof the bridge across the twin boundary.

July 9 (Mon)

Sang Wook Han1, Han-jin Noh2, Daehyun Kim3, Jihoon Hwang3, Jeong Soo Kang3, W.
F. Pong4 and Soon Cheol Hong1*
1
Department of Physics and EHSRC, University of Ulsan, Korea
2
Department of Physics, Chonnam Nation University, Korea
3
Department of Physics, The Catholic University of Korea, Korea
4
Department of Physics, Tamkang University, Taiwan

July 9 (Mon)poster Presentation[1] E. Morsan et al., Nature Phys. 2, 544 (2006). [2] A. F. Kusmartseva et al., Phys. Rev. Lett. 103, 236401 (2009). [3] C.
Monney et al., Phys. Rev. Lett. 106, 106404 (2011). [4] M. Calandra and F. Mauri, Phys. Rev. Lett. 106, 196406 (2011).

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Para-conductivity of (Bi 0.25 Cu 0.25 Li 0.25 Tl 0.25 )Ba 2 Ca 2 Cu 3 O 10-δ
superconductors

Charging/Discharging and overcurrent characteristics of GdBCO coils
using various partial insulation winding methods

Crystal structure of (Ru 0.5Cu 0.5)(Sr 1.47Ba 0.2Nd 0.33)(NdCe)Cu 2O 10-δcompound

Displacement waves of oxygen atoms in the Bi, Pb 2223 lattice ofsuperconducting composites annealed in an oxygen reduced
atmosphere

Qurat-ul Ain and Nawazish Ali Khan
Physics, Quaid-i-azam university islamabad pakistan, Pakistan

Excess conductivity analyses of as-prepared and oxygen post-annealed (Bi0.25Cu0.25Li0.25Tl0.25) Ba2Ca2 Cu3
O10-δ samples were carried out by following Lorentz-Danish (LD) model beyond the transition region and
Ginzburg-Landau (GL) equations in the critical regime. In these studies the effect of oxygen annealing on thethermodynamic fluctuations of the Cooper pairs just above the Tc is performed by using Aslamazov-Larkin (AL)theory. We have observed a major increase in the width of 3D AL and 2D LD regimes after post-annealing inoxygen atmosphere. Moreover, with the oxygen post-annealing the coherence length along the c-axis has also
been found to increase along with inter-plane coupling. The thermodynamic critical magnetic field, the lower
critical magnetic field, the upper critical magnetic field, the critical current density and penetration depth are also
calculated from the analysis of four regions namely critical (cr), three dimensional (3D), two dimensional (2D)and zero dimensional (0D) region that appeared as the temperature increases. The values of Fermi velocity, phaserelaxation time, penetration depth, κ values and energy required to break apart the cooper pairs are increased withthe annealing of oxygen. This shows that in (Bi0.25Cu0.25Li0.25Tl0.25)Ba2Ca2Cu3O10-δ sample, the optimum densityof carriers in the conducting CuO2 is essential for enhanced superconductivity in these compounds.
1) Qiang Lia, M. Suenaga, Junho Gohng, D.K.Finnemore, T. Hikata and K. Sato Phys.Rev. B 46, 3195-3198(1992). 2) V. V. Schmidt, The physics of superconductors (Springer, New York, 1997), p. 45. 3)A.L. Solovjov,
V.M. Dmitriev, and H.-U. Habermeier, Phys. Rev. B 55, 8551 (1997). 4)A.L. Solovjov, H.-U. Habermeier, and T.
Haage, Fiz Nizk. Temp. 28, 144 (2002) [Low Temp. Phys. 28, 99 (2002)] 5] C. J. Lobb, Phys. Rev. B 36 (1987)
3930. 6] A. I. Abu Aly, I. H. Ibrahim, R. A. Awad and A. El-Harizy, J. of Supercond. Nov. Magn. 23 (2010) 1325.

Yoon Hyuck Choi, Kwang Lok Kim, Oh Jun Kwon, Hyun-jin Shin and Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea

Eliminating the insulation in high temperature superconducting (HTS) windings canallow a system to be compact and well protected by bypassing the excessive current
flow that occurs through the turn-to-turn contact between uninsulated turns. However,
the time constant of coils without insulation is much higher than that of completely
insulated coils due to the absence of insulation resistance, resulting in a coil chargedischarge rate that becomes quite slow. Therefore, this study examined the charging,
operating, and discharging behaviors of Gd-Ba-Cu-O (GdBCO) HTS coils with Kapton
insulation every 3, 6, or 9 turns to investigate the effect of changes in insulated turns
on the coil’s time constant. Furthermore, to verify the demagnetization phenomena of
the coils in the excessive current condition, the overcurrent characteristics of partiallyinsulated GdBCO coils were evaluated and discussed in detail.

H.k. Lee1 and Y.i. Kim2
1
Physics, Kangwon National University, Deptartment of Physics, Korea
2
Korea Research Institute of Standards and Science, Korea

WN
A
R

D

TH
WI

<Acknowledgment> This work was supported by the International Collaborative R&D Program of
the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the
Korean government Ministry of Knowledge Economy (20118520020020).

Tatiana Krinitsina*, Svetlana Sudareva, Elena Kuznetsova and Julia Blinova
Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, Russia

The Bi, Pb-2223/Ag composites annealing in oxygen-nitrogen atmosphere is believed toreduce the number of the accompanying phases, to make contacts between crystallites
closer and to increase the critical current. The goals of this study were determining
the 2223 lattice changes at annealing in the reduced oxygen atmosphere, revealing
the reasons of these changes and their effect on the ceramics superconductivity. Aftersuch annealing the transversely-polarized waves of oxygen atoms displacement in[010] direction are observed in the 2223 phase by electron diffraction analysis. Thesewaves may appear due to the lack of oxygen in the 2223 lattice or to the nitrogen
penetration in it. As demonstrated by the X-ray photo-electron spectroscopy andnuclear microanalysis, nitrogen does not interact with the 2223 lattice, and the oxygen
index decreases to 9.67, which is lower than the stoichiometric. Thus, the atomic
displacement waves result from the lack of oxygen in Bi-O bilayers.

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Charge transfer instability governs unconventional behavior of doped
cuprates

Effect of filter shape on the capture efficiency of a high gradientmagnetic separation (HGMS) system

Absence of broken time reversal symmetry below the surface of(110)-oriented YBCO superconductors

Irreversibility line in the CNT and carbon doped YBCO
superconductors

A large body of experimental data points towards an unique charge transfer (CT)instability of parent insulating cuprates. True CT gap in these compounds is believed
to be as small as 0.4-0.5 eV as derived from the midinfrared absorption measurements[1] rather than 1.5-2.0 eV as usually derived from the fundamental absorption
measurements. Actually we deal with a competition of the conventional (3d9) groundstate and a CT state with formation of electron-hole dimers which evolves under doping
to an unconventional bosonic system [1-3]. Making use of a quantum Monte-Carlo(QMC) technique we study the evolution of the phase state of CuO2 planes in a model
CT unstable cuprate La2-xSrxCuO4. Nonisovalent doping gives rise to a suppression ofparent antiferromagnetic phase with the nucleation of the inhomogeneous supersolid
CO+BS phase characterized by a charge (CO) and off-diagonal Bose superfluid(BS) order parameters which competition results in a generic T-x phase diagramwith a distinct pseudogap regime due to a charge ordering and emergence of a local
superconductivity. Our QMC simulation does reproduce all the main features of theT-x phase diagrams for doped cuprates.

High gradient magnetic separation (HGMS) using a ferromagnetic filter enables thecapture of fine particles of even weakly magnetic materials by the high gradient of
the magnetic field. In general, such a field gradient, which can determine the capture
capability of the HGMS system, is mainly affected by the filter’s mesh size, wire
diameters, and materials. Therefore, this study examined the capture efficiency of the
HGMS system with respect to mesh size and wire diameter to investigate the effect offilter shape on gradient magnitude. Furthermore, the capture efficiency of various filter
shapes was also examined and compared with the simulation.

Alexander Moskvin and Alexey Korolev
Department of Theoretical Physics, Ural Federal University, Russia

Young-gyun Kim, Jung-bin Song, Dong Gyu Yang, Jongseok Lee and Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea<Acknowledgment> This study was supported by the Ministry of Knowledge Economy (MKE),
Korea, under the IT R&D Infrastructure Program supervised by the National IT Industry Promotion
Agency (NIPA-2011-(B1110-1101-0002)).

Hassan Saadaoui1*, Zaher Salman1, Thomas Prokscha1, Hannu Huhtinen2 and Elvezio
Morenzoni1
1
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, 5232 Villigen PSI,
Switzerland
2
Department of Physics, Wihuri Physical Laboratory, University of Turku, FI-20014
Turku, Finland
Low-energy muon spin rotation (LE-μSR) is a very sensitive local magnetic probe to
study magnetism on a nanometer length scale near the surface of materials and thinfilms. Here, we report the results of a search for spontaneous magnetization due to atime reversal symmetry breaking phase in the superconducting state of (110)-oriented
YBCO films, expected to develop near the surface in this orientation. Zero field andweak transverse field measurements performed using LE-μSR few nm inside optimallydoped YBCO-(110) films showed no appearance of spontaneous magnetization below
the superconducting temperature up to 2.9 K, contrary to tunneling measurements. Our
results give an upper limit of 0.01 mT for spontaneous internal fields in these films.

Sedigheh Dadras1*, Nallayian Manivannan2, Vahid Daadmehr1 and Kee Hoon Kim3
1physics, Other Academic, Iran2
physics, Other Academic, India
3
Other Academic, Korea

Irreversibility Line in the CNT and Carbon Doped YBCO Superconductors
S. Dadras 1*,N. Manivannan 2, V. Daadmehr 1, and K. H. Kim 2 1Magnetic andSuperconducting Res. Lab., Department of Physics, Alzahra University,
P.C.1993891176, Tehran, Iran. 2eXtreme Multifunctional Physics Laboratory,
FPRD, School of Physics and Astronomy, Seoul National University, Seoul 151-747,
Republic of Korea. *dadras@alzahra.ac.ir s_dadras2001@yahoo.com Abstract. We
investigated the irreversibility line (IL) of the carbon nano tube (CNT) and carbon
doped YBa2Cu3O7-δ superconductor samples using magneto-resistive measurement
results. Irreversibility line moves to higher magnetic fields for CNT doped and to lower
magnetic field for carbon doped YBCO samples respect to the undoped sample.

1. A.S. Moskvin, Phys. Rev. B 84, 075116 (2011). 2. A.S. Moskvin, Low Temp. Phys. 33, 234 (2007). 3.
A.S. Moskvin, Phys. Rev. B 69, 214505 (2004).

122

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

123poster Presentation
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Nonlocal excitations and 1/8 singularity in cuprates

Magnetism and superconductivity in CeCu2Ge2 under high pressuresand magnetic fields

High-energy neutron scattering study of spin excitation in slightlyoverdoed La1.82Sr0.18CuO4High field paramagnetic meissner effect in Ca doped YBa2Cu3O7-δ
single crystals

Fuminori Honda1*, Takashi Maeta2, Yusuke Hirose2, Atsushi Miyake3, Tetsuya Takeuchi4,
Katsuya Shimizu3, Tomoko Kagayama3, Rikio Settai2 and Yoshichika Onuki2
1
Graduate School of Engineering Science, Osaka University, Japan
2
Graduate School of Science, Osaka University, Japan3
KYOKUGEN, Osaka University, Japan
4
Low Temperature Center, Osaka University, Japan

Kentaro Sato1*, Masato Matsuura2, Masaki Fujita2, Kenji Tsutsumi1, Masanori Enoki3
and Kazuyoshi Yamada4
1
Physics, Tohoku University, Japan
2
IMR, Tohoku University, Japan
3
Kyushu Institute of Technology Graduate School of Life Science and Systems Engineering, Japan
4
WPI, Tohoku University, Japan

CeCu2Ge2 with the ThCr2Si2 type tetragonal structure is an antiferromagnet with TN = 4.2 K(AF1) and shows two kinds of superconducting phases named a low-Tsc phase (SC1) anda high-Tsc phase (SC2) under high pressures [1]. We have grown CeCu2Ge2 single crystals
by Sn-flux method and studied an electronic state under high pressures and magnetic fields
by means of the electrical resistivity measurement. We have found two anomalies at TN =4.1 K and TN’= 1.3 K at 2.6 GPa for example, implying a Neel temperature and a change ofmagnetic structures with the first order. In the temperature-pressure phase diagram, two kindsof magnetic phases named AF1 and AF2 appear and merge at 5 GPa. At pressures higher than
5 GPa, the AF2 phase becomes dominant. The AF2 phase can be another antiferromagnetic
phase, since the metamagnetic transition to the AF1 phase is observed around 3 T for the H || [001]direction. At 8.2 GPa, pressure-induced superconductivity (SC1) is induced below Tsc(onset) =0.5 K. The upper critical field is 30 kOe for H || [001]. The AF2 phase coexists with SC1 below
10 GPa and the AF2 phase disappears above 11 GPa, revealing only SC1 phase.

Antiferromagnetism in the doped cuprate Mott-insulator has been investigated due to its rich physics and close
connection with the high-Tc superconductivity. A finding of a generic form of spin excitations showing the“hourglass” shape in the different class of superconductors La2-x(Sr,Ba)xCuO4 (La-214) [1] and YBa2Cu3O6+d [2]suggests a common role of spin fluctuations in the mechanism of high-Tc superconductivity. Recently, Vignolle
and co-workers revealed the existence of two energy scales in the spin excitations of optimally-doped La-214[3] and pointed out the possibility of different origins for the excitation separated by energy. To study the dual
nature of spin excitations in more detail, we have performed a high-energy neutron scattering measurement onslightly-overdoped La1.82Sr0.18CuO4. The constant-energy spectrum at low temperature is a broad single-peak in
a wide energy range below ~150meV, although the peak-slitting was observed below ~10meV. This feature issomehow similar to the dispersion of spin excitation in the overdoped La-214. On the other hand, the integrated
intensity shows sharp and broad maximums at ~18meV and ~45meV, respectively, as is the case of optimallydoped system. In the poster, we will present the temperature dependence of the overall excitation spectrum anddiscuss the dual nature of the hourglass-shaped excitation.

We report on dc magnetization of a series of Y1-xCaxBa2Cu3O7-δ (x = 0, 0.0025, 0.05, 0.1) single
crystals with the goal to study the role of the hole doping on the paramagnetic Meissner effect(PME). [1] The magnetization as a function of the temperature, under constant magnetic field,
was recorded adopting the field-cooled procedure, Mfc(T) as well as magnetic relaxation, Mfc(t)for a measurement time up to 50.000s. The Mfc(T) data of our single crystals shows the usual
superconductor diamagnetic response when magnetic fields up to 0.5 kOe are applied. In contrast,
when H > 0.5 kOe are applied, the Mfc(T) data displays a systematic reduction of the superconductor
diamagnetic response until it became predominantly paramagnetic at higher fields not showing
tendency to a temperature saturation behavior in the doped samples. This behavior is a signature of
the high field paramagnetic Meissner effect (HFPME) in HTSC. [2,3] The Mfc(t) data reveals thatthe paramagnetic moment of the samples increase continuously as a function of the time. In specific,
the Ca doping promotes an enhancement of the HFPME intensity as compared with no doped
sample. We suggest the flux compression scenario to explain the HPME in your samples. [4][1] E. Vargoz and D. Jaccard: J. Magn. Magn. Mater. 177-181 (1998) 294.

[1] J. M. Tranquada et al., Nature 429, 534 (2004). [2] S. M. Hayden et al., Nature 429, 531 (2004).
[3] B. Vignolle et al., Nature Physics, 3, 163 (2007).

[1] V. N. Vieira et al. Phys. Rev. B 76 (2007) 024518-1. [2]F. T. Dias, et al. Physica C 470, S111 (2010).
[3] F.T. Dias et al. Phys. Rev. B 70 (2004) 224519. [4] A.K. Geim et al. Nature 396 (1998) 144.

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Magnetic memory in a ceramic YBCO superconductor composed ofsub-micron size grains

Doping and temperature dependence of Fermi arc in cuprate
superconductors

Quantized massive gauge fields around the doped holes in high-tc
cuprates and the relation to iron pnictides

Growth of a-axis oriented thin films of infinite-layer Sr1-xLaxCuO2

The pseudogap observed in the excitation spectrum as a suppression of spectral weightin the normal-state of cuprate superconductors is thought to be key to understanding
the mechanism of superconductivity. Within the framework of the kinetic energy driven
superconducting mechanism [1], we [2] study the evolution of the Fermi arc withdoping and temperature by considering the interplay between the superconducting gap
and normal-state pseudogap [3]. It is shown that the system in the underdoped regime
is a nodal liquid, and the length of the Fermi arc increases with increasing temperatures,in qualitative agreement with the experimental observation on cuprate superconductors[4]. Our results also show that the unusual behavior of the quasiparticle dispersion andFermi arc in cuprate superconductors is intriguingly related to the effect of the normalstate pseudogap.

Recently Yazdani[1] has suggested strongly that the high-energy(up to about 400meV)
hole-like excitations of the normal state are a direct predictor of the strength ofpairing, although he cannot present a model for the excitations. The present author has
proposed the mechanisms of evolution of the Fermi arc with increasing temperature[2]and with increasing of hole-doping[3] in high-Tc cuprates. In this study, we present
one model for the high-energy excitations, which play an important role on strength of
Cooper pairing, and show that quantized massive gauge fields induce short-range spinfluctuations and short-range orbital fluctuations[4,5].

Low energy excitations and unusual behaviors of electrons in the 2D cuprates havebeen the question under debates. Especially the non Fermi liquid behaviors and thepseudogap remain unresolved theoretically because of the limited range of the intersite correlations and the limitation of the momentum and energy resolutions in thetheory. We present here our results for the momentum-dependent single-particle
excitation spectra of the 2D Hubbard model, which are based on the full self-consistentprojection operator method. The theory self-consistently takes into account the longrange intersite correlations with use of the off-diagonal effective medium, and allows
us to calculate the excitation spectra with high energy and momentum resolutions. We
obtained the excitation spectra being consistent with the QMC results and found at T=0
that the nonlocal excitations enhance the Mott-Hubbard gap and create the shadowband excitations due to strong antiferromagnetic correlations. The present theory yields
the characteristic hole concentration 1-n* = 0.123 (=1/8) at which the van Hove typesingular peak appears just on the Fermi level at T=0, while it is 1-n* = 0.15 at finite
temperatures in the 4x4 DCA. The present result suggests the emergence of the 1/8
stripe phase due to the Fermi surface instability.

Hiroyuki Deguchi1*, Takuya Ashida1, Mitsuhiro Syudou1, Masaki Mito1, Makoto
Hagiwara2, Kuniyuki Koyama3 and Seishi Takagi1
1
Faculty of Engineering, Kyushu Institute of Technology, Japan
2
Faculty of Engineering and Design, Kyoto Institute of Technology, Japan
3
Faculyu of Integrated Arts and Science, The Univercity of Tokushima, JapanThe nonequilibrium nature of a ceramic YBCO composed of sub-micron size grains is investigatedby measurements of the dc magnetizations.The ceramic YBCO is considered as random Josephsoncoupled networks of 0 and π junctions and shows successive phase transition. The first transition
occurs inside each grain at Tc1= 81 K and the second transition occurs among the grains at Tc2=47 K.
The magnetic glass behavior similar to those of spin-glasses is observed below Tc2.[1] Theoretically,
the frustration effect due to the random distribution of π junctions should lead to the chiral-glass state,
as predicted by Kawamura and Li.[2] The memory phenomena are investigated by recording thezero-field-cooled and thermoremanent magnetization temperature dependence measured on heating
after the cooling process with and without field switches.[3] There are memory effects of the halt
at Ts=44 K imprinted in the system on the re-heating the sample. In the case without field switches
at Ts, the influence of the halt is confined to a narrow temperature region near the halt temperature,
whereas the memory effects of the halt employing a field switch is extended over a wide temperature
region below Ts. The results suggest that chiral-glass ordering occurs at Tc2 in the ceramic YBCO.

Shiping Feng*, Huaisong Zhao and Lulin Kuang
Department of Physics, Beijing Normal University, China

Ikuzo Kanazawa*
Physics, Tokyo Gakugei University, Japan[1] A.Yazdani, J.Phys.Condense Matters 21,164214(2009) [2]I.Kanazawa, J.Phys.Chem.Solids
66,1388(2005) [3]I.Kanazawa, Physica C 470,5183(2010) [4]H.Kontani and S.Onari,Phys.Rev.
Lett.104,157001(2010) [5]Y.Yanagi et al. J.Phys.Soc.Jpn. 79,123707(2010)[1] Shiping Feng, Phys. Rev. B 68, 184501 (2003); Shiping Feng et al., Physica C 436, 14 (2006). [2]Huaisong Zhao, Lulin Kuang, and Shiping Feng, unpublished. [3] Shiping Feng, Huaisong Zhao,
and Zheyu Huang, arXiv:1109.3973. [4] A. Kanigel et al., Nature Phys. 2, 447 (2006); U. Chatterjee
et al., Nature Phys. 6, 99 (2010).

Hiroyuki Akatsuka*, Keita Sakuma, Kenji Ueda and Hidehumi Asano
Crystalline Materials Science, Nagoya University, Japan

Electron-doped infinite-layer compound Sr1-xLaxCuO2 has the simplest crystal structure,and is suitable for fundamental studies of high-Tc superconductivity as well as device
applications. The epitaxially grown c-axis oriented Sr1-xLaxCuO2 thin films with Tc of around40 K were fabricated on the lattice matched substrates like DyScO3 and KTaO3[1]. Since
the in-plane coherence length ξab(4.5nm) of Sr1-xLaxCuO2 is larger than the out-of-plane
coherence length ξc(0.3nm)[2], the a-axis oriented film is favorable for junction fabrication.
In this paper, we will make the first report on the preparation and properties of a-axis
oriented thin films. Sr0.9La0.1CuO2(a0=0.3949nm, c0=0.341nm) thin films were preparedby magnetron sputtering. KTaO3(a0=0.3989nm), SrTiO3(a0=0.3905nm), (La0.18Sr0.82)(Al0.59Ta0.41)O3(LSAT)(a0=0.3868nm) and LaAlO3(a0=0.3791nm) substrates were used
to investigate the effect of the lattice mismatch. On KTaO3, LSAT and SrTiO3 substrates,
c-axis oriented films were obtained. In contrast, on LaAlO3 substrates with a large latticemismatch (-4.2%), a-axis oriented films were obtained. One possible reason for the a-axis
growth is due to a higher-order lattice matching, that is, lattice mismatch between ten unit
cell of Sr0.9La0.1CuO2(001)(3.10nm) and nine unit cell of LaAlO3(100)(3.412nm) is 0.03%.
As-grown thin films showed a semiconducting behavior. Post deposition annealing resulted
in the a-axis oriented films with Tconset of around 30 K.
[1] S. Karimoto and M. Naito, Appl. Phys. Lett. 84, (2004) 12. [2] V. P. Jovanovic, Z. Z. Li, and H.
Raffy, Phys. Rev. B 80, (2009) 024501.

[1] H.Deguchi et al. , J. Phys. Conference Series 320 (2011) 012076. [2] H.Kawamura and Li , J.
Phys. Soc. Jpn. 66 (1997) 2110. [3] E.L.Papadopoulou and P.Nordblad , Eur. Phys. J. B 22 (2001) 187.

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Phase diagram of high-tc superconductivity and antiferromagnetism
revealed by Cu-NMR in multilayered cuprates

Static spin correlation in Pr2-xCaxCuO4 Studied by neutron scattering

Ho-doping effect on the static stripe order in La214 superconductor

Thermal stability of an epoxy-impregnated HTS racetrack coil without
turn-to-turn insulation for rotating machines

Hidekazu Mukuda1*, Sunao Shimizu1, Akira Iyo2 and Yoshio Kitaoka1
1Osaka University, Japan
2
National institute of Advanced Industrial Science and Technology (AIST), Japan

We present site-selective nuclear magnetic resonance (NMR) studies on multilayered
cuprates, which have uncovered the intrinsic phase diagram of antiferromagnetism(AFM) and high-temperature superconductivity (HTSC) for a disorder-free CuO2
plane with hole carriers. We revealed the existence of the AFM metallic state in doped
Mott insulators, the uniformly mixed phase of AFM and HTSC, and the emergence ofd-wave SC with a maximum Tc just outside a critical carrier density, at which the AFM
moment on a CuO2 plane disappears. These results can be accounted for by the Mott
physics based on the t-J model, where the superexchange interaction J among spins
within the plane plays a vital role as a glue for Cooper pairs or mobile spin-singlet
pairs.

Kenji Tsutsumi1*, Tomohiro Miura1, Masanori Enoki2, Kentaro Sato3, Masato
Matuura4, Kazuyoshi Yamada5 and Masaki Fujita6
1
Department of Physics, Tohoku University, Japan
2
Kysyu Institute Technology, Japan3
Department of Physics, Tohoku university, Japan
4
IMR, Tohoku University, Japan
5
WPI, Tohoku University, Japan
6
IMR, Tohoku Univesity, Japan
It is well known that a small amount of hole-doping into La2CuO4 having K2NiF4type (attributed as T) crystal structure destroys the antiferromagnetic (AF) order andsuperconducting phase appears with further hole doping. On the other hand, recent
experimental study on Nd2CuO4-type (attributed as T’) structured La2CuO4 with noapical oxygen clarified contrasting properties to that in T-structured La2CuO4; thatis Neel temperature is different in two structured systems. [1] Therefore, the crystal
structure is an important factor to determine the physical properties. In order to gain
further insight into the physics of doped Mott insulator, we performed neutronscattering measurement on T’-Pr2-xCaxCuO4. The as-grown and annealed x=0.10
samples shows the long-range AF order below TN~290 K. This result suggests a weak
Ca doping effect on the AF order, which is contrast to the results in T-La2-xSrxCuO4. In
my poster, the details of doping dependence of magnetic order will be presented.
[1] R. Hord et al., Phys. Rev. B 82, 180508 (2010).

124

Valdemar Vieira1*, Augusto Falck1, Fabio Dias1, Douglas Da Silva1, Paulo Pureur2,
Jacob Schaf2 and Frederik Fabris3
1
Instituto de Fisica e Matematica, UFPEL, Brazil
2
Instituto de Fisica, UFRGS, Brazil
3
Dresden High Magnetic Field Laboratory, HZ Dresden-Rossendorf, Germany

The 19th International Conference on Magnetism

July 9 (Mon)

Yoshiro Kakehashi*, M. Atiqur R. Patoary and Sumal Chandra
Department of Physics, University of the Ryukyus, Japan

July 9 (Mon)poster Presentation

Masaki Fujita1*, Masanori Enoki2, Satoshi Iikubo2, Kenji Tsutsumi3, Kentaro Sato3,
Masato Matsuura1 and Kazuyoshi Yamada4
1
Institute for Materials Research, Tohoku University, Japan
2
Graduate School of Life Science and Systems Engineering, Kyushu Institute ofTechnology, Japan3
Department of Physics, Tohoku University, Japan
4
World Premier International Research Center, Tohoku University, Japan
We have performed elastic neutron scattering experiments on the superconducting
La1.84Ho0.04Sr0.12CuO4 to study the substation effect of cation with the large magnetic
moment at La site on the static spin correlation. In the Ho-free sample with the holeconcentration of 0.12, spatially modulated magnetic order is known to be stabilized
below T_spin ~ 30K [1]. In the present Ho-doped sample, we found the appearance ofmagnetic peaks at (0.5, 0.5±0.118, 0) positions below T_spin ~ 35K, which is similar
to the observation in the pristine sample. Furthermore, the volume corrected intensity
in the Ho-free and Ho-doped samples is comparable, suggesting a negligible effect of
Ho-substitution at La site. These results are quite contrast to the huge enhancementof magnetic intensity and the increase of T_spin by substituting magnetic Fe3+ ions
onto CuO2 planes [2]. Therefore, the stability of stripe order induced by the cation
substitution is sensitive to the substituted site.

Oh Jun Kwon, Kwang Lok Kim, Yoon Hyuck Choi, Hyun-jin Shin and Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea

Since use of the no-insulation (NI) technique creates a compact system with better
thermal and electrical stability, use of a high temperature superconducting (HTS)
coil without turn-to-turn insulation is now being proposed for the field coil in HTS
rotating machines. Epoxy impregnation of field coils is generally needed to protect
the coil against mechanical disturbances by time-varying magnetic fields and toprovide high mechanical integrity against the rotational vibrations. Therefore, to use
the NI technique on the practical HTS field coil of a rotating machine, it is essential
to obtain sufficient information on the thermal and electrical behaviors of the epoxyimpregnated NI coil. In this study, the quench characteristics of epoxy-impregnated
HTS racetrack coils without turn-to-turn insulation were investigated using overcurrent
tests. Furthermore, the thermal stability of the epoxy-impregnated NI coil at various
current charging rates was also investigated and discussed.
<Acknowledgement> This work was supported by a grant from the International Collaborative
R&D Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP)
funded by the Korean government Ministry of Knowledge Economy (20118520020020).

[1] H. Kimura et al., Phys. Rev. B 59, 6517 (1999). [2] M. Fujita et al., J. Phys. and Chem. Solids.
69, 3167 (2008).

July 8-13, 2012 Busan, Korea

125poster Presentation
PB36

PB39

PC02

PC05

Design, fabrication, and testing of a cooling system using solid nitrogenfor a 3 T/60-mm RT bore superconducting HGMS

Removal of silica and copper ions from CMP wastewater via magnetic
seeding aggregation using superconducting HGMSSuperlattice quantum critical point in the cubic metal (Sr/Ca)3Ir4Sn13

Phonon raman scattering of YB6

To develop a compact and stable superconducting high gradient magnetic separator(HGMS) for the removal of copper and silica from chemical mechanical polishingwastewater, a 3 T/60-mm room temperature bore HGMS using solid a nitrogen coolingsystem was fabricated. The HGMS’s magnet was assembled using 18 GdBCOcoated conductor double pancake coils, each of which was wound without turn-toturn insulation. The cooling capabilities of the solid nitrogen cooling system for thesuperconducting HGMS were examined using cool-down, warm-up, and chargingdischarging tests in the temperature range of 10-20 K. The capture efficiency of thesuperconducting HGMS using the solid nitrogen cooling system was also evaluatedusing a filtration test.

With the increased demand for semiconductor devices, the purification of chemicalmechanical polishing (CMP) wastewater in the semiconductor industry has becomeof great importance for worldwide environmental protection. Superconducting highgradient magnetic separation (HGMS) is one promising technique due to its compact
design and efficient and accurate removal of particles. For the HGMS, various
ferromagnetic materials were required to coagulate non-magnetic heavy metal ionsand various nanoparticles in CMP wastewater. In this study, we suggested the use of acoagulation process optimized by magnetic seeding aggregation at various pH values
for the separate yet simultaneous removal of copper ions and silica nanoparticles. The
filtration efficiency of the flocculated substances in an HGMS was evaluated using
turbidity measurements.

<Acknowledgment> This work was supported by the International Collaborative R&D Program of
the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the
Korean government Ministry of Knowledge Economy (20118520020020).

<Acknowledgment> This study was supported by the Ministry of Knowledge Economy (MKE),
Korea, under the IT R&D Infrastructure Program supervised by the National IT Industry Promotion
Agency (NIPA-2011-(B1110-1101-0002)).

PB37

PB40

PC03

PC06

Purification of chemical mechanical polishing wastewater using a 2G
HTS high gradient magnetic separation system

Joint characteristics of ReBCO-coated conductors using various fusion
splicing techniques

Unconventional superconductivity in PuCoIn5: An NQR investigation.

Vortex lattice structures in spin-triplet superconductors with weak
spin-orbit coupling

Magnetic separation efficiency is related to the strength of the applied magnetic field
and the field gradient used to trap the magnetic particles. The use of a magnet woundwith high temperature superconducting (HTS) tape enables the magnetic separation
system to more efficiently remove wastewater contaminants than their conventionalcounterparts due to the facile generation of a higher magnetic field due to the absenceof Joule heating losses. In this study, we fabricated and tested the second generation(2G) HTS high gradient magnetic separation (HGMS) system for the purification ofchemical mechanical polishing wastewater. The capturing efficiencies of the 2G HTSHGMS system were investigated in terms of the wastewater flow velocity and turbidity
using repetitive separation tests. Furthermore, the appropriate purification process forenhancing removal efficiency was also discussed.

For superconductor splicing, it is essential that joint resistance be minimized between
superconducting tapes to operate with the persistent current mode and lengthen them. We havealready proposed the concept of RE-Ba2Cu3O7-δ (ReBCO) tape fusion splicing technologythat is based on the unique ReBCO thermal and structural properties. The melting point of
ReBCO decreases as the surrounding oxygen partial pressure decreases, allowing for low
temperature splicing and recovery of the superconductivity lost during the joining process by asubsequent oxygenation annealing process. In this study, the fusion splices with changing joining
parameters, such as PO2, heating rate, peak temperature and holding time, cooling rate, oxygen
flow rate, temperature and holding time for oxygenation annealing, tape clamping pressure,and so on were performed using the following two splicing methods: 1) the ReBCO-ReBCO
interface was directly connected by fusion, and 2) the Ag layer was diffused in a face-to-facemanner without solder. The joint characteristics were evaluated in terms of joint resistances,critical currents, and index numbers. Furthermore, the sample morphologies and structures wereanalyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively.

Dong Gyu Yang, Jung-bin Song, Young-gyun Kim, Jongseok Lee, Yeonjoo Park and
Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea<Acknowledgment> This study was supported by the Ministry of Knowledge Economy (MKE),
Korea, under the IT R&D Infrastructure Program supervised by the National IT Industry Promotion
Agency (NIPA-2011-(B1110-1101-0002)).

Jongseok Lee, Jung-bin Song, Dong Gyu Yang, Yeonjoo Park and Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea

Yeonjoo Park1, Hyun-jin Shin1, Young-gyun Kim1, Young Kun Oh2 and Haigun Lee1*
1
Department of Materials Science and Engineering, Korea University, Korea
2
K-joins Co., Korea

Lina Esther Klintberg1, Swee Kuan Goh1*, Patricia Alireza1, Paul Saines1, DavidTompsett1, Peter Logg1, Jinhu Yang2, Bin Chen2, Kazuyoshi Yoshimura2 and Malte
Grosche1
1
University of Cambridge, United Kingdom
2
University of Kyoto, Japan
Structural self-organisation is a central theme in condensed matter physics. Often, thesymmetry of a given parent structure is lowered by subtle structural variations which
decrease the electronic degeneracy and thereby the total energy. Examples include
Jahn-Teller and Peierls distortions and, more generally, modulated lattice distortions,or superlattices. The quasi-skutterudite compounds R3T4X13, where R is an earth
alkaline or rare-earth element, T is a transition metal and X is a group-IV element,
form either in a simple cubic structure, called the I-phase, or in the variant I'-phase,
which can be viewed as a superlattice distortion of the I-phase. Here, we investigate
the borderline system (Sr/Ca)3Ir4Sn13, which we report forms in the I-phase, buttransforms into the I'-phase on cooling. Hydrostatic pressure is used to suppress thesecond order structural transition enabling the first comprehensive investigation of astructural quantum critical point in a three-dimensional charge density wave driven
superconductor.

Hiroshi Yasuoka1, Georgios Koutroulakis1*, Hiroyuki Chudo2, Eric D. Bauer1 and Joe
D. Thompson1
1
Los Alamos National Laboratory, USA
2
Advanced Science Research Center, Japan Atomic Energy Agency, Japan

WN
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Koichi Yukawa1*, Hisamitu Bandou1, Norio Ogita1, Masayuki Udagawa1, Fumitoshi
Iga2 and Takumi Hasegawa1
1
Graduate School of Integrated Arts and Sciences, Hiroshima University, HigashiHiroshima 739-8521, Japan
2
Graduate School of Science & Engineering, Ibaraki University, 2-1-1 Bunkyo, Mito
3 10-0056, Japan
YB6 becomes superconducting state below 7.5K. Both tunneling and photoemission
measurements suggested that YB6 is the strong coupling superconductor with 2Δ/
kBTc =3.8 and phonons with 8meV play an important role for superconductivity. We
once reported the results of Raman scattering using 514.5nm laser in SCES2010. Veryrecently we have measured the Raman scattering spectra with the high resolution using
674.1nm laser. Three Raman active phonons are similar with the previous report, thatis, the doublet spectra of the T2g and Eg modes suggest that the crystal symmetryof YB6 is F4/mmm as already reported. The remarkable change has been observedin the low energy spectra below 200cm-1, where the vibration due to Y is dominant.
Below 100K, the peak at about 100cm-1 disappears and two new peaks appear. At
this temperature the resistivity deviated from the linear dependence. This implies the
structural change at low temperature. Furthermore, the energy of two lowest-energy
peaks at 50 and 70cm-1 decreases with decreasing temperature. Below Tc, theirenergies become constant. These results are the experimental evidences that the Y
vibration is highly anharmonic and that the anharmonic vibration or rattling mode due
to Y is important for superconductivity.

July 9 (Mon)Jung-bin Song, Kwang Lok Kim, Dong Gyu Yang, Yoon Hyuck Choi, Jongseok Lee
and Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea

July 9 (Mon)poster Presentation

Shuhei Takamatsu1* and Youichi Yanase2
1
Graduate School of Science and Technology, Niigata University, Japan
2
Faculty of science, Niigata University, JapanThe oxide Sr2RuO4 was discovered to be superconducting by Maeno et al. in 1994[1].
Sr2RuO4 is considered to be a spin-triplet superconductor from both theoretical andexperimental point of view. Recently, the direction of d-vector in the superconducting
state of Sr2RuO4 subjected to the magnetic field is discussed.In order to the determine
the direction of d-vector, we investigate the vortex lattice structure of Sr2RuO4 witha weak spin-orbit coupling for the magnetic field along c-axis.We will report thedifference in vortex lattice structures between chiral state and helical state.
[1]Superconductivity in a layered perovskite without copper, Y. Maeno, H. Hashimoto, K. Yosida, S.
Nishizaki, T. Fujita, J. G. Bednorz and F. Lichtenberg, Nature (London) 372, 532 (1994)<Acknowledgment> This work was supported by the International Collaborative R&D Program of
the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the
Korean government Ministry of Knowledge Economy (20118520020020).

PB38

PC01

PC04

PC07

Effect of liquid cryogen on a 2G HTS magnet using a mixed cryogen
cooling system

Bulk electronic structure of LaRu2P2 probed by soft X-ray angleresolved photoemission spectroscopy (SX-ARPES)

Pressure effect on the structural and superconducting transitions in a
caged compound PrRh2Zn20

Effect of the magnetic trapped flux on the heat capacity of the lowtemperature superconductors: Pb, La, Sn

Kwang Lok Kim, Jung-bin Song, Yoon Hyuck Choi, Dong Gyu Yang and Haigun
Lee*
Department of Materials Science and Engineering, Korea University, Korea
A cooling system employing a mixture of solid cryogen with small amounts of liquid
cryogen was reported for use in high temperature superconducting (HTS) applications.
Although the liquid cryogen in the mixed cryogen cooling system can improve thethermal contact between the solid cryogen and the HTS magnet, it is essential thatfurther studies be performed because there are insufficient data about the thermal/
electrical behaviors of the HTS magnet that has been subjected to mixed cryogen.
Therefore, in this study, the quench/recovery characteristics of mixed cryogen-cooled
2G HTS magnets with respect to liquid cryogen amount were examined to investigate
the influence of the solid/liquid ratio on the thermal/electrical stabilities of the HTS
magnet.
<Acknowledgment> This work was supported by the International Collaborative R&D Program of
the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the
Korean government Ministry of Knowledge Economy (20118520020020).

E. Razzoli1, M. Kobayashi1, V. N. Strocov1, B. Delley1, Z. Bukowski2, J. Karpinski3, N.
C. Plumb1, M. Radovic1, J. Chang1, T. Schmitt1, L. Patthey1, J. Mesot1 and M. Shi1*
1
Paul Scherrer Institute, Switzerland
2
Laboratory for Solid State Physics, ETH Zurich, Switzerland
3
Laboratory for Solid State Physics, ETH Zuurich,, Switzerland

TH
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Y Sugano1, T Ohsuka1, K Umeo2*, N Nagasawa1, T Onimaru1 and T Takabatake1
1
AdSM, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8530,
Japan
2
N-BARD, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526,
Japan
PrRh2Zn20 crystallizes in a cubic CeCr2Al20-type structure, where the Pr3+ ion is
encapsulated in a polyhedron formed by 16 zinc atoms. The crystalline electric field
ground state of 4f2 electrons in the Pr ion was found to be a nonmagnetic Γ3 doublet[1]. The resistivity of this compound shows a superconducting transition at TSC = 0.060
K and a hysteretic behavior in the temperature range from 140 K to 470 K, which
originates from a structural phase transition. In order to reveal the interplay between the
structural and superconducting transitions, we have measured the electrical resistivity
ρ for a single crystalline sample under pressures up to 2 GPa and at temperatures down
to 0.052 K. With increasing pressure up to 2 GPa, the anomaly in ρ(T) at TS = 160
K shifts to higher temperatures by the ratio of 3 K/GPa. This indicates that the lowtemperature phase (T<TS) is stabilized under pressure. At P = 0.85 GPa, TSC was
not observed down to 0.052 K, indicating that the superconducting state is suppressed
under pressure. The opposite responses to the pressure imply that the superconducting
state is in competition with the low-temperature phase below TS.

Sergey Mikhailovich Podgornykh1*, Veronika Myakon'kikh2 and Veronika Dyakina3
Institute of Metal Physics, Ural Federal University, Russia
2
Ural Federal University, Russia
3
Institute of Metal Physics, Russia
1

Effect of the magnetic prehistory on the temperature dependence of the heat capacityof the superconducting Pb, La, Sn has been studied. The intermediate state ischaracterized by a subdivision of the specimen into superconducting and normal
regions that the relative total volumes of these two types of region are determined by
the mean induction. The trapped flux was produced after the magnetic field was turned
off. We observed a difference of the heat capacity between zero field cooling (ZFC)
and field cooling (FC) states in zero magnetic field for the ring specimen. It was foundthat the FC heat capacity has a smaller value than the heat capacity both in the normal
and in superconducting states. We believe that the surface energy changes between thenormal and superconducting phases and gives rise to the change of the heat capacityof the specimen. This result is the first experimental evidence of the surface energy
contribution to the heat capacity. The work was supported by Russian Foundation For
Basic Research Grant No. 10-02-96019-r-ural-a.

[1] N. Nagasawa, to be published in the proceedings of SCES 2011.

126

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

127

poster Presentation
PC08

PC11

PC14

PC17

A novel superconductivity in Ir oxides with large spin-orbit coupling

Superconductivity at 5.2K in ZrTe3 polycrystals

Lateral Josephson junction induced by inverse proximity effectPressure evolution of superconductivity in β-pyrochlore oxides

Recently, the 5d transition metal oxides such as Sr2IrO4 and Ba2IrO4 have attracted
much attention as a novel Mott insulator. In these materials, three t2g orbitals of
Ir atoms are hybridized with each other by the spin-orbit coupling of 5d electrons.
As a result of the quantum entanglement of spin and orbital degrees of freedom,an anomalous Jeff=|L-S|=1/2 state is realized, which causes interesting properties[1]. To clarify the properties of this system, we have studied the ground state of
the three-orbital Hubbard model with a spin-orbit coupling term using variational
Monte Carlo method and variational cluster approximation [2]. Here, we study theelectronic states when carriers are doped in this three-orbital system and discuss thepossibility of superconductivity. The obtained ground state phase diagram reveals
the antiferromagnetic state, stable around the electron density n=5, is destabilizedby carrier doping and the ground state turns to be superconducting under a certain
condition. Similar to the high-Tc cuprates, a large asymmetry between electron doping(n>5) and hole doping (n<5) is also observed. Due to the large spin-orbit coupling,
the spin is no longer a good quantum number. Instead, the pseudospins form a singlet
pairing and a “d-wave like” superconductivity is realized.

Interplay of the Charge Density Wave (CDW) and Superconducting (SC) states is a subjectof significant interest. Low dimensional chalcogenides of transition metals are one of thewell studied systems that show the coexistence of these competing phenomena. Recently
Cu and Ni intercalated single crystals of ZrTe3 are reported to show bulk SC at 3.8K and
3.1K respectively. However single crystalline ZrTe3 show only filamentary SC below
2K, along with CDW at 63K. We have studied the polycrystalline ZrTe3 and the effectof intercalation of Cu and Ag on the superconducting and CDW states of the compound.
Our main finding is the occurrence of filamentary superconductivity at enhanced
temperature of 5.2K in the polycrystalline ZrTe3 at ambient pressure, and the SC coexists
with the CDW phase. Enhancement in Tc mimics the effect of external pressure on SC
in ZrTe3 single crystals. The strains between the agglomerated small single crystallites inpolycrystalline samples could be one possible reason. The intercalation of Cu or Ag, does
not affect the transition temperatures but suppresses the CDW state. We have analyzed theresistivity data to estimate the relative loss of carriers and reduction in the nested Fermi
surface area upon CDW formation in theseP. L. Paulose* and C. S. Yadav
Tata Institute of Fundamental Research, India

A Josephson junction is characterized by a phase coherent transfer of the Cooper pairs
across a weak link between two superconducting electrodes. The proximity effect at
the interface between a superconductor and a ferromagnetic metal occurs, implyingthat the Cooper pairs penetrate into the ferromagnet. It results in spatial oscillationsof the superconducting order parameter in the ferromagnet. Recently an opposite
effect so-called “inverse proximity effect”, i.e. the induction of a magnetic moment in
a superconductor in contact with a ferromagnet attracted much attention. We utilize
the inverse proximity effect in superconductor-ferromagnet bilayer to generate lateral
Josephson junctions. The weak link is created by a strong ferromagnet Py strip acrossa superconductor Nb bridge due to inverse proximity effect and forms a region S’.
Samples with different size of weak link region S’ were fabricated by varying the Py
strip width from 0.5 to 2 μm. The junctions exhibit a modulation of the critical current
in perpendicular magnetic field similar to a Fraunhofer interference pattern even when
the S’ has such long distance as 2 μm, which proves the dc Josephson effect and spin
triple component taking place.

Takeshi Matsubara1, Takayuki Isono2, Daisuke Iguchi1, Yo Machida1, Koichi Izawa1*,
Bernard Salce3, Jacques Flouquet3, Hiroki Ogusu2, Jun-ichi Yamaura2 and Zenji Hiroi2
1
Department of physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551,
Japan
2
ISSP, University of Tokyo,Kashiwa, Chiba 277-8581, Japan
3
SPSMS, CEA-Grenoble, 38054 Grenoble Cedex 9, France
The β-pyrochlore oxides AOs2O6 (A = K, Rb and Cs) have attracted much interest becauseof their unusual electronic properties including the superconductivity[1]. A unique featureof this system is the presence of the remarkable anharmonic vibration of an A ion, called'rattling' motion. Although it has been pointed out by various studies that the rattling motion
plays an important role for the occurrence of superconductivity in this system, its concreterole for superconductivity have not been understood yet. In order to clarify the interplay
between the rattling motion and superconductivity, we study the pressure (P) evolution ofsuperconductivity in magnetic field (H) at low temperatures (T). The rattling motion could be
affected by pressure through the modification of the crystal lattice. In this paper, we report the
T-H-P phase diagram of AOs2O6 and K0.8Rb0.2Os2O6 obtained by specific heat measurements
and discuss the pressure variation of the electron-phonon coupling and phonon frequency.
We demonstrate that the non-monotonous pressure dependence of the transition temperature
can be explained in terms of the competition between the enhancement of the electronphonon coupling and the suppression of the phonon frequency.

[1] B. J. Kim et al., Science 323, 1329 (2009). [2] H. Watanabe et al., Phys. Rev. Lett. 105, 216410(2010)

1. Zhu X, Lei H, and Petrovic C 2011 Phys. Rev. Lett. 106 246404 2. Lei H, Zhu X, and Petrovic
C 2011 Euro Phys. Lett. 95 17011 3. Takahasi S and Sambongi T 1983 J. Physique 44 C-3 1733
4. Yomo R, Yamya K, Abliz M, Hedo M, and Uwatoko Y 2005 Phys. Rev. B 71 132508 5. Ido M,
Okayama Y, Ijiri T and Okajima Y 1990 J. Phys. Soc. Jap. 59 1341

PC09

PC12

PC15

PC18

Fermi surface studies of Sr3Ir4Sn13 via the Shubnikov-de Haas effectCoexistence of superconductivity and antiferromagnetism in CeNi0.8Bi2

13C NMR study of charge fluctuation induced superconductivity inbeta''-(BEDT-TTF)4[(H3O)Ga(C2O4)3]-C6H5NO2

Inverse magnetic proximity effects in superconducting Sn-Ni
nanoparticle assemblies

Superconductivity emerging near antiferromagnetism has been thoroughly investigated.
The antiferromagnetic fluctuations in the vicinity of quantum critical point are believedto induce such superconductivity. In this paper, we report experimental evidence thatpoints to the novel possibility of superconducting state, that is, charge fluctuationinduced superconductivity. The molecular superconductor beta''-(BEDT-TTF)4[(H3O)
Ga(C2O4)3]-C6H5NO2 demonstrates a charge instability at 100 K, before showing thesuperconducting transition at 7.5 K [1]. Besides, this salt is intriguing because of its
high upper critical field of 33 T, which is almost three times the Pauli limiting field[2]. We performed the 13C NMR experiment and revealed on the basis of the Knight
shift measurement that the spin-singlet superconductivity is realized in the charge
disproportionate state. The nuclear spin-lattice relaxation rate measurement detects
the strong electron-electron correlations slightly above superconducting transition
temperature. Since 13C NMR technique can probe only the magnetic properties, wemeasured in-plane resistivity as a complementary probe and found an abrupt increase
below 10 K. These results lead us to address the importance of charge fluctuations to
induce superconductivity.

Although the superconductivity of the element Sn, in their bulk form, is believed
to be associated with the spin-singlet s-wave pairing, it is now known that thesuperconducting parameters are strongly dependent on the physical size of the system.
Here, we report on the results of magnetization, magnetic susceptibility and resistivity
measurements made on Sn, Sn-Ni and Sn-Au nanoparticle assemblies. The thermal
profiles of the magnetic susceptibility of Sn nanoparticle assemblies can be describedby Scalapino’s expression. Inverse magnetic proximity effect is observed, as the TC of
the superconducting nanoparticles is found to be noticeably increased, when magnetic
Ni nanoparticles are introduced into the vicinity of the superconducting nanoparticles.
Closing up the spatial separations between Sn and Ni nanoparticles leads to a further
increase in TC. There is a critical Ni composition and a critical spatial separation
between the magnetic and superconducting nanoparticles that must be reached before
their magnetic proximity will suppress the superconductivity. On the other hand, theinverse proximity effect of the In-Ni nanoparticle assemblies is not observed in the (SnC)14(Au-A)86 nanoparticle assembly, where TC of Sn remains essentially unalteredby cold pressing. A qualitative mechanism is proposed to understand the present
observations.

Swee K. Goh1*, Lina Klintberg1, David A. Tompsett1, Sven Friedemann1, Stan Tozer2,
Jinhu Yang3, Bin Chen3, Kazuyoshi Yoshimura3 and Malte Grosche1
1
University of Cambridge, United Kingdom
2
National High Magnetic Field Laboratory, Florida State University, USA
3
Kyoto University, JapanThe ternary stannide system (Ca,Sr)3Ir4Sn13 is recently reported to feature a superlatticequantum critical point, where the superlattice distortion transition temperature T* issuppressed to 0 K [1]. Sr3Ir4Sn13 lies on the part of the phase diagram where T*~147 K,
and hence the low temperature phase is the superlattice phase. Using the Shubnikovde Haas effect, we directly study the Fermiology of this superlattice phase, andcompare the results with bandstructure calculations performed both with and without
the superlattice distortion. The effective mass and the mean free path associated withvarious Shubnikov-de Haas frequencies will be presented. The relevance of the present
study to superconductivity and quantum criticality will be discussed.
[1] L. E. Klintberg, S. K. Goh, P. L. Alireza, P. J. Saines, D. A. Tompsett, P. W. Logg, J. Yang, B.
Chen, K. Yoshimura and F. M. Grosche, submitted (2012)

Soo-whan Kim1, Soohyun Kim1, Kyujoon Lee1, Adrian Hiller2, Devashibhai Adroja2
and Myung-hwa Jung1*
1
Departmnet of Physics, Sogang University, Korea
2
Science and Technology Facilities Council, United Kingdom
There have been some reports on RNiBi2 (R=rare-earth elements) with ZrCuSiAstype structure[1,2]. Both superconductivity and antiferromagnetism were observedin CeNi0.8Bi2. The previous studies suggested two types of carriers with different
masses; a light electron responsible for superconductivity and a heavy electron for
antiferromagnetism[3]. However, the antiferromagnetic transition was not found in specificheat data. Thus, we have also studied RNi0.8Bi2 (R = La, Ce) in order to take a close lookat the possible coexistence of superconducting and antiferromagnetic order parameters. As
observed previously, both samples are type-II superconductors with the superconducting
transition temperature TC = 4 K. For CeNi0.8Bi2 the lower and upper critical fields arefound to be 62 Oe and 660 Oe. Two antiferromanetic transitions are observed at TN1= 5 K and TN2 = 7 K. These results well agree with the magnetization versus fielddata showing two metamagnetic transitions around 5 kOe and 40 kOe. We suggest thatthey correspond to commensurate and incommensurate antiferromagnetic transitions,
respectively. These results are also in good agreement with the neutron experiments.
1. K. Kodama, S. Wakimoto, N. Igawa, S. Shamoto, H. Mizoguchi, and H. Hosono, Phys. Rev. B 83, 214512 (2011)
2. M. H. Jung, A. H. Lacerda, and T. Takabataka, Phys. Rev. B 65, 132405 (2002) 3. H. Mizoguchi, S. Matsuishi,
M. Hirano, M. Tachibana, E. Takayama-Muromachi, and H. Kawaji, Phys. Rev. Lett. 106, 057002 (2011).

[1]Y.Nagao et al., J.Phys.Soc.Jpn. 78 064702 (2009)

Yoshihiko Ihara*, Harumi Seki and Atsushi Kawamoto
Department of Physics, Graduate School of Science, Hokkaido univerisity, Japan

Chi-hung Lee, Yen-cheng Chen, Chin-wei Wang and Wen-hsien Li*
Physics, National Central University, Taiwan[1] A. I. Coldea et al., PRB 69, 085112 (2004). [2] A. F. Bangura et al., PRB 72, 014543 (2005).

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PC13

PC16

PC19

Magnetism in CeIr(SixGe1-x)3 compounds

Optical studies of superconducting InN thin film

Ac susceptibility components of a thin type-II superconducting
annulus carrying a radial current

Pressure study on anisotropic electrical resistivity of Hg-doped
CeRhIn5

Jan Prokleska*, Jiri Pospisil, Marie Kratochvilova and Vladimir Sechovsky
DCMP, Charles University, Ke Karlovu 5, 121 16, Prague, Czech Republic
The CeMX3 intermetallics adopting the noncentrosymmetric tetragonal BaNiSn3-type
crystal structure recently attracted much attention mainly owing to unconventional
superconductivity observed in some of them [1]. CeIrSi3 and CeIrGe3 were reported to
exhibit antiferromagnetic ordering with TN = 5.0 K and 8.5 K, respectively. CeIrGe3
also undergoes an order-order transition at T1 = 4.7 K. When applying hydrostaticpressure TN gradually decreases and a superconducting dome appears in the vicinity
of QCP for the pressure Pc = 2.2 and 23 GPa, respectively [1, 2]. Our work has been
motivated by the desire to know how the magnetism and superconductivity evolvewith the composition of the SiGe sublattice. For this purpose we have preparedpolycrystalline samples of selected compositions of the SiGe sublattice by arc melting,annealed and characterized them and measured magnetization, resistivity and specificheat in a wide temperature range and various magnetic fields. The solutions keep the
crystal symmetry of the parent compounds and the lattice parameters follow Vegard’s
law. The TN vs. x dependence is not entirely monotonous; a minimum TN is observedfor x between 0.75 and 1. The results of powder neutron diffraction will be presented
as well.
[1] Ch. Pfleiderer, Rev. Mod. Phys. 81, 1551 (2009) and ref. therein [2] F. Honda et al., PRB 81,
140507 (2010)

128

Lu-kuei Lin1, Ssu-yen Huang1, Jin-hua Huang2 and Shang-fan Lee1*
1
Institute of Physics, Academia Sinica, Taiwan
2
Materials Science and Engineering, National Tsing Hua University, Taiwan

The 19th International Conference on Magnetism

H. L. Liu1*, C. Y. Liu1, C. R. Lu1, D. C. Ling2 and P. H. Chang3
1
Department of Physics, National Taiwan Normal University, Taiwan
2
Department of Physics, Tamkang University, Taiwan
3
Department of Materials and Mineral Resources Engineering, National Taipei
University of Technology, Taiwan
The indium nitride (InN) thin film (thickness about 220 nm) was grown on(0001) sapphire substrate by metal-organic vapour phase epitaxy technique. The
superconducting transition temperature determined by dc resistivity and magnetization
gave a Tc about 2 K. Near-infrared photoluminescence from InN thin film can beclearly observed at room temperature. The optical reflectance was measured over awide frequency range (50 ~ 52000 cm-1) and at temperature between 10 and 340 K.
To extract the optical constants of the films, the Drude-Lorentz model was used to fit
all of the layers of this thin-film structure. From the parameters obtained, the opticalconstants were computed. The vibrational spectrum of InN thin film consists of a
A1(TO) and a E1(TO) at about 448 cm-1 and 478 cm-1. The temperature variation of
the phonon parameters can be explained by the anharmonic effect. Notably, the Drude
plasma frequency (~ 3200 cm-1) and the position of the band absorption (~ 6500 cm1) exhibit little temperature dependence, whereas the scattering rate monotonicallydecreases with decreasing temperature. All of these observables suggest the unusual
normal-state behavior in this superconducting thin film.

July 9 (Mon)

Hiroshi Watanabe*, Tomonori Shirakawa and Seiji Yunoki
RIKEN, Japan

July 9 (Mon)poster Presentation

Aliakbar Babaei Brojeny*, Mostafa Molavi, Asghar Sharbaf Zadeh and Mahdi
Sohrabi
Department of Physics, Isfahan University of Technology, 84156-83111, IranBy assuming a spatial dependence on the sheet-current density, we have investigated
the real (χ') and imaginary parts (χ'') of the susceptibility of a thin type-II
superconducting annulus in the absence and also in the presence of a transport radialcurrent, using the Bean critical state model in which the critical current density is
assumed to be independent of the local magnetic field. The results of our calculations
on the components of the magnetic susceptibilities in two cases and for the different
aspect ratios are compared with each other. The comparison shows that by applying aradial current to the sample, the imaginary part of the susceptibility is increased. We
have also studied the variations of the χ'' with respect to χ' for a several aspect ratios.
1-Ali A. Babaei-Brojeny and John R. Clem, Phys. Rev. B 68, 174514 (2003). 2-Ali A. BabaeiBrojeny, Asghar Sharbaf Zadeh and Mostafa Molavi, Journal of Physics:Conference Series…(2012).

Soonbeom Seo1, Sol Ju1, E.d. Bauer2, J.d. Thompson2 and Tuson Park1*
Physics, Sungkyunkwan University, Korea
2
Physics, Los Alamos National Laboratory, USA
1

The stoichiometric compound CeRhIn5 is a prototypical antiferromagnet where Ce 4f
moments align below 3.8 K. With increasing pressure, the antiferromagnetic orderingof CeRhIn5 disappears and the superconducting state emerges. When doped with
Hg, the antiferromagnetic transition TN initially decreases and develops a different
magnetic structure with further increasing Hg concentration. In this research, we
focused on a 0.45 % Hg-doped CeRhIn5, where TN is suppressed from 3.8 K to 3.4 K
and the magnetic structure is same as that of the undoped compound with Q=(1/2, 1/2,
0.298). By applying hydrostatic pressure, we suppressed TN to zero and measured theanisotropic electrical transport measurements for the electrical current applied withinand perpendicular to the Ce-In plane. Evolution of the anisotropic transport property
across the quantum critical point will be discussed.

July 8-13, 2012 Busan, Korea

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poster Presentation
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PC23

PC26

PC29

Control of superconductivity in parity mixing superconductors
Li2T3B(T:Pt,Pd) by non-magnetic impurity and defect doping

Strong enhancement of superconductivity in inorganic electride
12CaO•7Al2O3:e- under high pressure

Non-trivial vortex dynamics in a superconducting Corbino disk

Investigation of the three-dimensional electronic structure of MgB2 bysoft X-ray angle-resolved photoelectron spectroscopy

Recently, superconductors with noncentrosymmetric crystal structures like Li2T3B (T:Pd, Pt) have been the focus
of in-depth research with its parity mixing nature. Previous studies of NMR and penetration depth measurementssuggested that Li2Pt3B is a spin triplet dominant and Li2Pd3B is a s-wave spin singlet dominant superconductor,
approximately 2:3 and 4:1 ratio of spin singlet and spin triplet order parameters, respectively [1-3]. It is known
that s-wave superconductor without the sign inversion of the order parameter on the Fermi surface is not affectedby non-magnetic impurity and defects doping as contrasted to that of a non s-wave superconductor. In thisresearch, we prepared different quality samples by substituting B with Al. Sample qualities were estimated byresidual resistivity. Li2Pd3B exhibits the small Tc suppression attributed by the non-magnetic impurities anddefects, while Hc2(0) value increased. This behavior is similar in ordinary s-wave superconductor. While resultsfor Li2Pt3B show that Tc and Hc2(0) value were found to be suppressed by disorder. However, the rate of Tcsuppression by disorder has been found to be not so large to be explained by the pair-breaking effect expected forthe non s-wave superconductor. Further details will be outlined during the actual presentation.

Shigeki Tanaka1*, Tomoki Kato1, Atsushi Miyake1, Tomoko Kagayama1, Katsuya
Shimizu1, Sung Wng Kim2, Satoru Matsuishi3 and Hideo Hosono4
1
KYOKUGEN, Osaka University, Japan
2
Frontier Research Center, Tokyo Institute of Technology, Japan
3
Materials and Structures Laboratory, Tokyo Institute of Technology, Japan
4
Frontier Research Center, Materials and Structures Laboratory, Tokyo Institute ofTechnology, JapanThe nanoporous main group oxide 12CaO•7Al2O3 (C12A7) is a compound in thesystem CaO-Al2O3 and is used widely as a constituent of aluminous cements. It can betransformed from a wide-gap insulator to a metal with substituting electrons for anions
in cages constituting a positive frame. A superconducting transition was found at Tc= 0.2-0.4 K for C12A7 electride (C12A7:e-) doped with anionic electrons to 2*10^21
per cubic centimeter[1]. We carried out the ac-susceptibility measurement of single
crystalline C12A7:e- under high pressure using a piston-cylinder cell and a diamondanvil cell. With increasing pressure, Tc monotonically increases up to 1.0 K at 2.4 GPa.
In addition, the upper critical field Hc2 (T) and -dHc2/dT becomes larger. The density ofstates at the Fermi level is estimated to increase under high pressure, in agreement with
dTc/dP > 0.

Masaru Kato and David E. Fujibayashi
Department of Mathematical Sciences, Osaka Prefecture University, Japan

Using the molecular dynamics method for vortex motion and the finite element method
for heat transport, we investigate the vortex motion in a superconducting corbino disk,
where an external current is injected at the center of the disk and flows toward theperimeter of the disk. For this geometry, vortices move circularly, but velocity of thevortices is large around the center and small at the edge of the disk, according to themagnitude of the external current density. Moving vortices cause resistivity and heat,and therefore there appear non-uniform temperature distribution. This non-uniform
temperature distribution makes the vortices out of their circular motion through entropy
force. Therefore the motion in the superconducting corbino disk becomes non-trivial
one. We focused on the how heat transport to the outside of superconductors, such asa substrate under the superconductor, affect the vortex motion. And we find that firstly
the vortices move toward the edge of the disk, but finally they form laminar flow forlarge heat resistance to the substrate but they show a peculiar ordered state for smallheat resistance. We show details of these vortex motions.

Y. Sassa1*, M. Mansson1, B. M. Wojek2, M. Kobayashi3, V. Strocov3, O. Tjernberg2, N.
D. Zhigadlo1 and B. Batlogg1
1
Laboratory of Solid State Physics, ETH Zurich, CH-8093 Zurich, Switzerland
2
Materials Physics, Royal Institute of Technology KTH, S-16440 Kista,, Sweden
3
Swiss Light Source, Paul Scherrer Institute, CH- 5234 Villigen PSI, Switzerland

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July 9 (Mon)

Guizhi Bao1, Gaku Eguchi2, Akiko Ono3, Yoshihiko Inada4, Yoshiteru Maeno2 and Guo-qing Zheng1
1
Department of Physics, Okayama University, Japan2
Department of Physics, Graduate School of Science, Kyoto University, Japan
3
Graduate School of Education, Okayama university, Japan
4
Graduate school of Natural Science and Technology, Graduate School of Education,
Okayama university, Japan

July 9 (Mon)poster Presentation[1] Nshiyama M, Inada Y, and Zheng Guo-qing, 2007 Phys.Rev. Lett. 98, 047002 [2] Nshiyama M, Inada Y,
and Zheng Guo-qing, 2005 Phys.Rev. B 71, 220505 [3] H. Q. Yuan et al., Phys. Rev. Lett. 97 (2006) 017006[1] M. Miyakawa et al., J. Am. Chem. Soc. Vol. 129 (2007) 7270.

PC21

PC24

PC27

PC30

Pressure-induced metal-insulator transition of Mott insulator Ba2IrO4Superconductivity in conical magnets

Coexistence of ferromagnetism and superconductivity in single-phase
Bi3Ni nanostructures

Vortex channeled effect in Nb thin film with artificial pinning array

Daisuke Orii1*, Masafumi Sakata1, Atsushi Miyake1, Katsuya Shimizu1, Hirotaka
Okabe2, Masaaki Isobe2, Eiji Muromachi2 and Jun Akimitsu3
1
KYOKUGEN, Osaka Univ., Japan
2
NIMS, Japan3
Aoyama Gakuin Univ., JapanBa 2IrO 4 is an antiferromagnetic Mott insulator, because the large spin-orbit
interactions of the 5d electrons in Ir atoms lift the energy levels. The magnetic
moment is suppressed to ~ 0.34 μB/Ir atom because of the spin fluctuation, and theNeel temperature TN is ~ 240 K. These magnetic properties are similar to ones of
La2CuO4, which is the parent material of a high-Tc superconductor [1-3]. The crystal
structures are also similar. Here, in order to inhibit the insulating state and to search thesuperconducting phase, the electrical resistivity of Ba2IrO4 has been performed underhigh pressure. According to the present results, metal-insulator transition was observed
at 28 GPa, but not the superconducting transition above 50 mK.

Gertrud Zwicknagl
Technische Universitaet Braunschweig, Germany
The influence of spatially modulated exchange fields on superconducting properties
is discussed. Of particular interest are conical magnets where the non-collinear
magnetic structure permits to control the symmetry of the pair wave function. The
limiting cases - homogeneous ferromagnetic and anti-ferromagnetic exchange
field - have been extensively studied. The central focus of the present work is thevariation with modulation length of the superconducting properties. I discuss theevolution of the induced triplet components and analyze their orbital structures. Spinresolved tunnelling spectra highlight the cross-over from typical pair-breaking to pairweakening which occurs when the magnetic modulation length is comparable to thesuperconducting coherence length in the absence of exchange fields.

[1] H. Okabe et al.: Phys. Rev. B, 83, 155118 (2011). [2] D. Vaknin et al.: Phys. Rev. Lett., 58, 2802
(1987). [3] T. Freltoft et al.: Phys. Rev. B, 36, 826 (1987).

Thomas Herrmannsdoerfer1*, Richard Skrotzki1, Rico Schoenemann1, Yurii Skourski1,
Joachim Wosnitza1, Daniel Koehler2, Regine Boldt2 and Michael Ruck2
1
Dresden High Magnetic Field Laboratory, Helmholtz-Zentrum Dresden-Rossendorf, Germany
2
Department of Chemistry and Food Chemistry, TU Dresden, Germany

We have demonstrated the coexistence of superconductivity and ferromagnetism in Bi3Ni
nanostructures which have been prepared by making use of novel chemical-reaction paths [1]. We
have characterized their magnetic and superconducting properties by means of SQUID magnetometry,ac susceptometry, and electrical-transport measurements in a wide field and temperature range. Here,
we also present recent experiments on novel nanostructures, such as monodisperse spherical clusters
with a diameter of 8 nm as well as nanofibers. Pulsed-field susceptibility data up to 60 T allow fora determination of the saturation magnetization of Bi3Ni nanostructures. Resistivity measurements
performed on moderately compacted Bi3Ni nano fibers down to 40 mK have shown clear evidence
for the existence of an isosbestic point. Superconductivity in confined Bi3Ni emerges in the
ferromagnetically ordered phase and is stable up to remarkably high magnetic fields. This coexistence
would most likely be possible in the case of triplet pairing. The absence of an inversion center of thelattice of Bi3Ni nanostructures would allow for the formation of an antisymmetric spatial componentof the electron-wave function and could lead to a significant admixture of a spin-triplet component of
the order parameter. Part of this work was supported by EuroMagNET, EU-contract No. 228043.

Tian-chiuan Wu1*, Lance Horng2, Jong-ching Wu2 and Rong Cao2
1
Department of Electrical Engineering, Nation Formosa University, Taiwan
2
Department of Physics, National Changhua University of Education, Taiwan

The vortex pinning effect is a fundamental characteristic in type II superconductors.
Vortex dynamics in the mixed state in type-II superconductors is strongly influenced by
the pinning centers. We have studied a channeled-like pinning potential in Nb thin films
which is formed by the pinned vortices. Nb films with periodic pinning arrays show
matching effects in the magnetic field dependence of the resistivity and Hall Effect. It
is suggested that the motion of interstitial vortices has great influence by the channel.
When vortices propagate through these arrays, both the longitudinal and transversal
voltages show cusp-like anomalies at matching fields. Vortices can be guided by thechannel formed between pinned vortices.
[1] R. Cao, T.C. Wu, P.C. Kang, J.C. Wu, T.J. Yang, Horng Lance, Solid State Comm. 143 (2007)
171. [2] M. Baert, V.V. Metlushko, R. Jonckheer, V.V. Moshchalkov, Y. Bruynseraede, Phys. Rev. Lett.
74 (1995) 3269. [3] J.E. Villegas, E.M. Gonzalez, M.I. Montero, Ivan K. Schuller, J.L. Vicent, Phys.
Rev. B 68 (2003) 224504.

[1] T. Herrmannsdorfer, R. Skrotzki, J. Wosnitza, D. Kohler, R. Boldt, M. Ruck, Phys. Rev. B 83, 140501(R) (2011)

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PC28

PC31

Charge and spin order of charge stripe ordered La2-xSrxCoO4

Observation of Bose-metallic phase in Ta Films

Observation of twofold symmetry breaking in the gap function ofheavy-fermion superconductor UPt3

Role of the third dimension on the spectral property and transport
behaviour in layered cuprates

Paul G. Freeman1, E. Wechke2, E. Schierle2, A. T. Boothroyd3 and D. P3
1Helmholtz-Zentrum Berlin, Germany; EPFL, Lausanne, Swizerland; ILL, Grenoble,
France2Helmholtz-Zentrum Berlin, Germany
3
Department of Physics, Oxford University, United Kingdom
Since the discovery of charge stripe order in the cuprates, the role of stripes in hightemperature superconductivity, and whether charge stripes are ubiquitous to the cuprates
has been under intensive debate[1]. Recent neutron scattering studies of cobalt andmanganese based charge-stripe ordered materials have demonstrated how the striking
hourglass excitation spectrum of the cuprates is consistent with charge-stripe order[2,3].
One important experimental observation in charge-stripe ordered La2-xSrxCoO4 ishowever presently missing, direct observation of stripe charge order itself. Althoughalternative forms of charge order has been observed in cobaltates in the form of acheckerboard charge ordered state and a proposed charge river state[4,5]. Here we use
the technique of resonant soft x-ray scattering to study by diffraction the spin and chargeordering of the charge-stripe phase of La2-xSrxCoO4. We report our analysis of the diffuse
order recorded in our study, this study completes the evidence for the charge-stripe
model of this system that is used to explain the hourglass spin excitation spectrum.
[1] M. Tranquada, et. al., Nature 375, 561 (1995). [2] A. T. Boothroyd, et. al., Nature 471, 341-344(2011). [3] H. Ulbrich, et. al., arXiv:1112.1799. [4] I. A. Zaliznyak, et. al. Phys. Rev. Let. 85, 4353
(2000). [5] N. Sakiyama, et. al. Phys. Rev. B 78, 180406(R) (2008).

130

The 19th International Conference on Magnetism

Sungyu Park* and Eunseong Kim
Center for Supersolid & Quantum matter Research, Department of Physics, KAIST,
Daejeon, 305-701, Korea
Superconductor-insulator transition has been induced by tuning film thickness ormagnetic field [1-3]. Recent electrical transport measurements of Ta thin films
revealed an interesting intermediate metallic phase which intervened superconducting
and insulating phases in the zero temperature limit [4]. The resistance of Ta films inthis regime exhibited a sharp drop at the transition temperature but a finite saturated
value at low temperatures. In addition, IV characteristic curves showed non-linear
response, indicating possible appearance of a new metallic phase. The intriguing
quantum metallic phase can be interpreted as a consequence of vortex dynamics or
dislocation response in the vortex lattice [5]. Here we present systematic studies on the
superconductor-metal-insulator transition and nonlinear transport in two dimensional
Ta films.
[1] M. P. A. Fisher, PRL 65, 923 (1990) [2] D. B. Haviland, et al. PRL 62. 2180 (1989) [3] V. F.
Gantmakher, et al. JETP Letters 71, 160 (2000) [4] Y. Li, et al. PRB 81, 020505 (2010) [5] D.
Ephron, et al. PRL 76, 1529 (1996)

Yo Machida1, Atsushi Itoh1, Yoshitaka So1, Koichi Izawa1*, Yoshinori Haga2, Etsuji
Yamamoto2, Noriaki Kimura3 and Yoshichika Onuki4
1
Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan
2
Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
3
Graduate School of Science and Center for Low Temperature Science, Tohoku Universit, Miyagi
980-8577, Japan
4
Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan

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Bhagya Sindhu Tewari
Physics, University of Petroleum and Energy Studies, Dehradun, India

In the present work, we have analyzed the influence of the third dimension couplingon the normal state electronic spectra of bilayer cuprates employing Green’s function
equations of motion approach within tight binding extended Hubbard model andmodel, which necessarily includes the three site exchange interaction (J3) and the interunit cell resonant tunneling (T12). The influence of inter unit cell resonant tunneling on
the out of plane (c-axis) conductivity has also been analyzed for cuprates employing
Kubo formula and Green’s function technique. On the basis of numerical computation,
it is found that the inter cell resonant tunneling (T12) introduces a broadening in the
spectral function and increases the c-axis conductivity. It is also found that the J3 term
suppresses the bilayer splitting in the electronic spectra. These results are viewed interms of recent ARPES measurements.
[1] S. Chakravarty, et. al, Science 61 (1993) 337 [2] E.Dagotto, Rev. Mod. Phys. 68(1994)763[3] Y.D.Chaung, et.al, Phys. Rev. Lett. ,87 (2001) 117002, [4] B.S. Tewari et. al, Eur.Phys.J. B,
66(2008)67 [5] Q.P.Li, et. al, Phys. Rev. B, 48(1993) 437 [6] R.kubo, J.Phys soc. Japan, 28, (1957)
1402 [7] W.C. Wu, et. Al, J. Supercond. 11, 305 (1998) 305 [8] B.S. Tewari et. al, Physica C 468(2008) 237 [9] B.E.C. Koltenbah, et. Al, Rev. Mod. Phys. 60 (1997) 23

July 8-13, 2012 Busan, Korea

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poster Presentation

poster Presentation

PD01

PD04

PD07

PD10

Ground dielectric state of the Mott-doped material

The modulated spin liquid and hidden order in URu2Si2

Antiferromagnetic fluctuation in hidden order phase of U(Ru,Rh)2Si2

Bulk compressibility of orthorhombic YbFe2Al10-type CeRu2Al10

The origin of so-called hidden-order (HO) transition observed at To=17.5K in URu2Si2
has been one of the longstanding issues in physics of heavy-fermion systems. In themixed compounds U(Ru1-xRhx)2Si2, it is found that a large-moment antiferromagnetic(AF) order replaces HO for 0.02≤x≤0.03 via a first-order phase transition, and bothorders disappear above x≥0.04. To clarify microscopic features of magnetic fluctuationin both HO and AF phases, we have performed inelastic neutron scattering experimentsfor U(Ru1-xRhx)2Si2 (x≤0.03). At the AF wave vector Q=(1,0,0), the AF excitation
peak is clearly observed in HO phase for 0≤x≤0.02, but it disappears in the AF phasefor 0.02≤x≤0.03. The excitation gap at 1.4K is found to be weakly reduced from 2.4meV(x=0) to 1.8meV (x=0.015) as x is increased. Temperature variations of the staggered
susceptibility χ(Q,T) at x=0 estimated from the inelastic-peak intensities show aweak enhancement in HO phase and a cusp-like anomaly at To. By doping Rh, theenhancement of χ(Q,T) in HO phase becomes pronounced, but a cusp-like anomaly at
To is reduced. These features indicate that the AF fluctuation develops on the verge ofthe first-order phase boundary in HO phase, while it is suppressed in the AF phase.

Orthorhombic YbFe2Al10-type CeRu2Al10 shows antiferromagnetic transition at T0~27
K[1]. This antiferromagnetic transition has various unusual features. One of them isreduced magnetic moment; The neutron experiment reveals that the magnetic momentof Ce in the ordered phase on CeRu2Al10 is 0.34 μB/Ce[2]. Considering this reduced
magnetic moment, T0 should be much lower. Another unusual feature is abrupt
disappearance of antiferromagnetic transition by applying pressure[3]. Structuralmodulation might be occurred at around the pressure of disappearing T0. Thus, we
performed synchrotron X-ray study at room temperature under pressure by using
diamond anvil pressure cell and investigated bulk compressibility of CeRu2Al10. We
revealed that lattice parameters a, b and c monotonically decreases with increasingpressure, which indicates that there is no structural modification up to 9.2 GPa at room
temperature. We also revealed that the decrease ratio of b is smaller than that of a and c.

Using analytic calculations, within the framework of the Russell-Saunders scheme
we investigated the dependence of the number of valence states on a doping level x
in the full package of the valence bands for the Mott-doped material. According toour calculations the total number of valence states Nv(x) coincides with the numberof electrons per unit cell (N-x) if there is a ban (both spin S-, and orbit L-) on the firstremoval quasiparticle states (frs). Thus is formed an insulating ground state of the
doped material at the T=0K. We believe that such materials with the forbidden frs
states can be attributed the manganites with the L-forbidden states and cobaltites with
the S-forbidden states.

Sebastien Burdin
Bordeaux University, France

We have shown that near a Kondo breakdown critical point, a spin liquid with spatial
modulations is likely to be formed. Unlike its uniform counterpart, we find that thisoccurs via a second order phase transition. The amount of entropy quenched when thisordering is manifest is of the same magnitude as for an antiferromagnet. Moreover,these two states are in direct competition with each other, and at low temperatures they
are separated by a first order phase transition. This suggests that the modulated spin
liquid is indeed a viable candidate for the unique phase of matter which is observedin the hidden order phase of URu2Si2. We investigate the modulated spin liquid
proposal taking full account of the tetragonal-body-centered lattice structure whichcharacterizes URu2Si2. We find that the physical quantities predicted from the model
are in very good qualitative and quantitative agreement with recent experiments,
including thermodynamic properties, inelastic neutron scattering, and Fermi surface
measurements. We also present an overview of other f-electron compounds where
similar phases have been observed.

July 9 (Mon)

Refs. : C. Pepin, M.R. Norman, S. Burdin, and A. Ferraz, Phys. Rev. Lett. 106, 106601 (2011) C.
Thomas, S. Burdin, C. Pepin, and A. Ferraz, in preparation.

Yukihiro Kawamura1*, Kazuki Matsui1, Keiichi Yamamoto1, Yusuke Hori1, Junichi
Hayashi1, Keiki Takeda1, Chihiro Sekine1 and Takashi Nishioka2
1
Muroran Institute of Technology, Japan
2
Kochi University, Japan[1] A. M. Strydom, Physica B 404 (2009) 2981-2984 [2] D. D. Khalyavin et al., Phys. Rev. B 82
(2010) 100405 [3] T. Nishioka et al., J. Phys. Soc. Jpn 78 (2009) 123705

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PD05

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PD11

Temperature-dependent phonon anomalies in uranium and plutonium
compounds

Fermi-surface evolution in Yb-substituted CeCoIn5

Pressure effect on the field-induced ordered phase in heavy fermion
compound YbCo2Zn20

Ultrasound measurements on the skutterudite compound SmOs4P12

Joachim Wosnitza1*, Andrey Polyakov1, Andrea D. Bianchi2, S. Blackburn2, B.
Prevost2, G. Seyfarth2 and Michel Cote2
1
Hochfeld-Magnetlabor Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Germany
2
Department de Physique and RQMP, Universite de Montreal, Montreal H3C 3J7,
CanadaTetsuya Takeuchi1, Yuki Taga2, Shingo Yoshiuchi2, Masahiro Ohya2, Yusuke Hirose2,
Fuminori Honda2, Rikio Settai2 and Yoshichika Onuki2
1
Low Temperature Center, Osaka University, Japan
2
Graduate School of Science, Osaka University, Japan

In CeCoIn5, substitution on the rare-earth site has been found to influence the Kondolattice coherence and Cooper pairing in a rapid and uniform way. Yb substitution,
however, shows a different behavior in that Tc and the Kondo-coherence temperature
do not scale, in contrast to other heavy-fermion compounds. We performed acomprehensive dHvA study on Ce1-xYbxCoIn5. For small Yb concentration, x =0.1, the band-structure topology and the ef-fective masses remain nearly unchanged
compared to CeCoIn5. This contrasts clearly modified Fermi surfaces and light, almost
unrenormalized effective masses for x = 0.2 and above. These observations cannot
explain the heavy-fermion physics observed in specific-heat and resistivity data evenfor high Yb concentrations. Thus, we suggest the existence of heavy quasiparticles withshort mean free paths, not detectable by dHvA experiments. However, the mechanism
by which superconductivity can emerge from these charge carriers remains elusive.
Work done in cooperation with K. Gotze, D. Hurt, Z. Fisk, R. G. Goodrich, I. Sheikin,
M. Richter. Part of this work was supported by EuroMagNET II (EU contract No.
228043).

We succeeded in growing high-quality single crystals of heavy fermion compounds
YbT2Zn20 with T = Co, Rh, and Ir, and found a metamagnetic behavior at Hm below
the characteristic temperature Tχmax, where the magnetic susceptibility takes a broad
maximum. For YbCo2Zn20, Hm = 6 kOe and Tχmax = 0.32 K, for example. Hm andTχmax in these compounds were found to satisfy a universal relation Hm (kOe) =15Tχmax (K). Recently, we found a field-induced ordered phase (FIOP) above HQ= 60 kOe for H // <111> in YbCo2Zn20 below TQ = 0.6 K and suggested an antiferroquadrupole order for the FIOP. In this work, we performed pressure experiments in
YbCo2Zn20 with H // <111> in order to study the pressure effect on the FIOP as wellas the pressure-induced antiferromagnetic phase (PIAF) above Pc~2 GPa. When thepressure is applied, the transition field HQ was found to decrease with increasingpressure up to around Pc. Above Pc, there is a pressure region where the PIAF and
FIOP were observed under the same pressure. In order to investigate how the FIOP
disappears or merges with the PIAF, further pressure experiments are in progress underhigher pressures.

PD03

PD06

PD09

PD12

Non-linear conductivity of resistive oxides: truths and myths

Spin exciton formation inside the hidden order phase of CeB6

29Si-NMR Study of antiferromagnet CeRh2Si2 using single crystals

YbRh 2Si 2: Fermi surface and crystal-field splittings of a heavyFermion compoundPeter S Riseborough*Physics, Temple University, USA

There is evidence that a number of heavy-fermion/mixed-valent materials show
strongly renormalized hybridization gaps either at the Fermi-energy or close to the
Fermi-energy. In the former case, a heavy-fermion semiconducting state ensues and in
the later case, the system remains metallic at low temperatures. Due to the temperaturedependence of the electronic correlations, the magnitudes of the hybridization gaps
decrease with increasing temperatures. The existence of a temperature-dependent lowenergy electronic energy scale opens up the possibility that the Born-Oppenheimer
approximation may fail and that there may be a resonant coupling between thephonons and the electronic excitations. It is argued that such a mechanism may be thecause of the anomalous temperature-dependence of the phonon spectrum in Pu and theanomalous phonon mode observed in α-uranium.

B. - Fisher*, J. - Genossar, L. - Patlagan and G. M. Reisner
Physics, Technion, Israel

WN
A
R

D

TH
WI

Alireza Akbari and Peter Thalmeier
MPI-CPfS, Germany

The heavy fermion metal CeB6 exhibits hidden order of antiferroquadrupolar (AFQ)
type below TQ=3.2K and subsequent antiferromagnetic (AFM) order at TN=2.3K.
It was interpreted as ordering of the quadrupole and dipole moments of a Γ8 quartet
of localised Ce 4f1 electrons. This established picture has been profoundly shaken
by recent inelastic neutron scattering[1] that found the evolution of a feedback spin
exciton resonance within the hidden order phase at the AFQ wave vector appears andis stabilized by the AFM order. We develop an alternative theory based on a fourfold
degenerate Anderson lattice model, including both order parameters as particlehole condensates of itinerant heavy quasiparticles. This explains in a natural way
the appearance of the spin exciton resonance and the momentum dependence of its
spectral weight, in particular around the AFQ vector and its rapid disappearance in thedisordered phase. Analogies to the feedback effect in unconventional superconductors
and Kondo semiconductors are pointed out.
[1] G. Friemel, et al, Nature Communications 3, 830 (2012).
[2] A. Akbari and P. Thalmeier, Phys. Rev. Lett. 108, 146403 (2012).

132

Makoto Yokoyama1*, Kenichi Tenya2 and Hiroshi Amitsuka3
1
Faculty of Science, Ibaraki University, Japan
2
Faculty of Education, Shinshu University, Japan
3
Graduate School of Science, Hokkaido University, JapanThe 19th International Conference on Magnetism

Hironori Sakai, Yo Tokunaga, Shinsaku Kambe, Yuji Matsumoto, Tatsuma D Matsuda
and Yoshinori Haga
Advanced Science Research Center, Japan Atomic Energy Agency, Japan
29Si-NMR Study of antiferromagnet CeRh2Si2 has been performed using single
crystals. Heavy fermion material CeRh2Si2 is known to be an antiferromagnet withstrong uniaxial magnetic anisotropy along the crystallographic c-axis under ambientpressure. From our measurements of Knight shifts and relaxation rates, the spin
dynamics of this material have been investigated. At ambient pressure, as seen in thestatic susceptibility, the Ising-type antiferromagnetic spin fluctuations along the c-axis
has been found to be enhanced. In this presentation, we will show our latest data anddiscuss about the anisotropy of hyperfine couplings and spin dynamics.

July 9 (Mon)

Vladimir Gavrichkov*
Krasnoyarsk, Kirensky Institute of Physics, Russia

Yoshiki Nakanishi1*, Gen Koseki1, Dai Tamura1, Kohei Kurita1, Takeshi Saito1,
Minoru Koseki1, Mitsuteru Nakamura1, Masahito Yoshizawa1, Masahito Yoshizawa1,
Yuya Koyota2, Chihiro Sekine2 and Takehiko Yagi3
1
Iwate University, Japan2
Muroran Institute of Technology, Japan
3
ISSP The University of Tokyo, Japan
We present an ultrasound study on the Sm-based filled skutterudite compound SmOs4P12
for the first time. The measurements were performed on a polycrystalline sample usinga phase-sensitive detection technique. The ternary compound SmOs4P12 were preparedat high temperature and high pressures using a wedge-type cubic-anvil high-pressure
apparatus. SmOs4P12 exhibits antiferromagnetic ordering below 4.5 K. A clear decrease
was observed at 4.5 K in the temperature dependence of both longitudinal and transverse
elastic constants. However, less or no elastic softening toward the transition temperature
was observed in the both elastic constants. Absence of the precursor behavior reminds us
a multipolar ordering, possibly octupolar ordering observed in the isostructural system
SmRu4P12, reported previously by our group. The transition is robust against the external
magnetic field. To be more interesting, the elastic constants show a minimum around 180
K, possibly related to a rattling motion due to weakly bounded Sm ion in an oversized P
cage. We argue a low-lying degenerated levels derived from 4f-multiplets ground state of
Sm ion split by crystalline electric field effect in SmOs4P12. Furthermore, we discuss thephononic properties in comparison with other isostructral systems which include an ionic
degrees of freedom of the rattling motion.

Steffen Danzenbacher1, Denis V. Vyalikh1, Kurt Kummer2, Yuri Kucherenko3,
Cornelius Krellner4, Christoph Geibel5, Serguei L. Molodtsov6, Ming Shi7, Luc
Patthey7 and Clemens Laubschat1*
1
Institut fur Festkorperphysik, Technische Universitat Dresden, D-01062 Dresden,
Germany2
European Synchrotron Radiation Facility, FR-38043 Grenoble Cedex, France
3
Institute of Metal Physics, National Academy of Sciences of Ukraine, UA-03142
Kiev, Ukraine
4
Max-Planck-Institut fur Chemische Physik fester Stoffe, D-01187 Dresden, Germany
5
Max-Planck-Institut fur Chemische Physik fester Stoffe, D-01187 Dresden, Germany
6
European XFEL GmbH, , D-22671 Hamburg, Germany
7
Swiss Light source, Paul Scherrer Institute, CH-5232 Villingen-PSI, Switzerland
YbRh2Si2 is a well known heavy Fermion system with a Kondo temperature of 25 K and a mean valence of 2,9.
Due to the mixing of 4f14 and 4f13 configurations in the ground state, the 4f13 state is reproduced as a final
state in a photoemission experiment allowing for direct observation of near ground state properties. Angleresolved photoemission spectra reveal a general dispersion of the 4f13 state with a Fermi-level crossing aroundthe Γ-point. A clear wave-vector dependence of the crystal-field split states is observed that leads to a variationof the energy splittings across the Brillouin zone and even to an interchange of the sequence of states. The bulk
Fermi surface reveals strong similarities with the one expected for a stable trivalent compound, but is slightly
larger, reveals strong 4f character, and deviates from LDA results by a larger region without states around theΓ-point. These properties are well described in the framework of a simple fd-hybridization model.

July 8-13, 2012 Busan, Korea

133

poster Presentation
PD13

PD16

PD19

PD22

Single crystal growth and various electronic states in Yb-based
compounds

Thermoelectric study of the metamagnetic behavior in YbCo2Z20

Magnetic phase diagram of the new heavy fermion compound
Ce2PtIn81

Thermoelectric properties of Kondo semiconductor CeRu 4As 12
prepared under high pressure

To clarify the various electronic states of Yb compounds, we grew single crystals of several Yb compounds suchas YbTIn5 (T : Co, Rh, Ir), YbCoGa5, YbT2Zn20 (T : Co, Rh, Ir) and Yb2Pt2Pb by the flux method, and YbPdGeand YbPd5Al2 by the Bridgman method. YbTIn5 and YbCoGa5 are Pauli paramagnets, but the cyclotron
effective mass of YbCoGa5 is by four times larger than that of YbTIn5. YbT2Zn20 (T : Co, Rh, Ir) compounds areheavy fermion compounds. In fact, the electronic specific heat coefficient γ is 8000 mJ/K2•mol in YbCo2Zn20,
very close to the quantum critical point. YbPdGe is an Ising-type ferromagnet with the Curie temperature TC =11.4 K and a saturated magnetic moment μs = 1.7 μB/Yb, but possesses a relatively large value of γ = 150 mJ/
K2•mol. Yb2Pt2Pb is a Shastry-Sutherland-type antiferromagnet with the Neel temperature TN = 2.1 K. Finally,
YbPd5Al2 of which the analogue is a heavy fermion superconductor NpPd5Al2 is a well-known heavy fermion
superconductor[1] is an antiferromagnet with a very small Neel temperature TN = 0.19 K.

Yo Machida1, Tohru Ikeura1, Koichi Izawa1*, Shingo Yoshiuchi2, Fuminori Honda2,
Rikio Settai2 and Yoshichika Onuki2
1
Department of Physics, Tokyo Institute of Technology, Japan2
Department of Physics, Osaka University, Japan
Despite the intensive studies on the metamagnetic behavior which has been foundin a wide variety of heavy fermion materials such as CeRu2Si2, CeCu6, and UPt3,
the origin remains under debate. The recent discovered heavy fermion compoundYbCo2Zn20 exhibits the metamagnetic behavior under unexpectedly small magnetic
field ~ 0.6 T, providing a new platform for elucidation of the metamagnetism. We
have addressed this issue by means of the thermoelectric transport, which has beena promising probe to unveil the low-energy itinerant excitations and the electronictransformation across the metamagnetic transition. We measured the Seebeck andNernst coefficients of YbCo2Zn20 down to very low temperature. Remarkably, we
found a huge Seebeck coefficient ~ -250 μV/K^2 under zero field, as an indication of
the “super” heavy fermion state. Moreover, on passing through the metamagnetic field
the Seebeck coefficient shows dramatic suppression, being distinct from that observedin CeRu2Si2 in which the Seebeck coefficient is largely enhanced at the metamganetic
field. In our presentation, we will discuss the thermoelectric response of YbCo2Zn20
and its implication to the metamagnetism. The comparison to the other metamagnetic
materials will be also made.

CenTmIn3n+2m (n=1,2; m=1; T=transition metal) type compounds are subject of intense interest in thecondensed-matter community [1]. They are predestinated to investigate the interplay between magnetismand superconductivity. Recently, two new compounds from this heavy fermion family have been found.
Ce2PdIn8 is an ambient pressure superconductor while CePt2In7 orders antiferromagnetically [2]. We reporton the existence of a new compound Ce2PtIn8. Similar to Ce2PdIn8, the synthesis of Ce2PtIn8 is rather
complicated. However, from our studies of solution growth of Ce2PdIn8 and the support by differential
thermal analysis, optimal conditions for growing Ce2PtIn8 were deduced. Single-crystal X-ray diffraction
confirmed that Ce2PtIn8 crystallizes in Ho2CoGa8-type structure with lattice parameters a=4.699A andc=12.185A. We will present specific heat, resistivity (ambient and under hydrostatic pressure) andmagnetization measurements. Ce2PtIn8 orders magnetically below 2.1K. A second transition, likely intoa magnetic commensurate ordering, is observed just below at 2K. Contrary to Ce2RhIn8, the magnetictransitions shift to lower temperatures in applied magnetic field along both principal crystallographic
axes suggesting different character of magnetic ordering. Specific heat measurements reveal an enhanced
Sommerfeld coefficient (γ~740 mJ/mol.K2). The magnetic field-temperature phase diagram will be
discussed in the context of superconductivity and magnetism evolution in related compounds.

Chihiro Sekine1*, Tomokazu Kawata1, Yukihiro Kawamura1 and Takehiko Yagi2
Graduate School of Engineering, Muroran Institute of Technology, Japan
2
Institute for Solid State Physics, The University of Tokyo, Japan1

The filled skutterudite compound CeRu4As12 exhibits a hybridization gap insulatingstate, with a small activation energyΔ/kB of 50K [1]. We report further results for
CeRu4As12 prepared under high pressure (4GPa). Thermoelectric power and thermal
conductivity measurements have been performed on this material. The temperaturedependence of thermoelectric power for CeRu4As12 shows two peaks (around 80K,
200K). The phenomena could be related to Kondo behavior at high temperature andhybridization-gap-formation process at low temperature.
[1] C. Sekine et al., J. Mag. Mag. Mater., 310 (2007) 260.

[1] Ch. Pfleiderer, Rev. Mod. Phys. 81, 2009 [2] E. D. Bauer, et al., Phys. Rev. B 81, 180507 (2010)[1] D. Aoki et al. : J. Phys. Soc. Jpn. 76 (2007) 063701.

PD14

PD17

PD20

PD23

Physical properties under pressure in a heavy fermion superconductor
CeIrIn5

Raman scattering study of the hidden order state of URu2Si2

Coexistence and competition of superconductivity, magnetism andcharge density waves in rare-earth tri-telluride TbTe3

Single crystal growth and physical properties of UT2Al20 (T=transition
metal)

Naofumi Aso1*, Yuki Tamaki1, Yoshinao Takaesu1, Masato Hedo1, Takao Nakama1,
Kiyoharu Uchima2, Kazuyuki Matsubayashi3, Yoshiya Uwatoko3, Yusuke Ishikawa4,
Kazuhiko Deguchi4 and Noriaki K. Sato4
1
Faculty of Science, University of the Ryukyus, Japan
2
General Education, Okinawa Christian Junior College, Japan
3
ISSP, University of Tokyo, Japan
4
Graduate School of Science, Nagoya University, Japan

CeIrIn5 is a heavy fermion superconductor with Tc = 0.4 K and the electronic specific heat γ = 700 mJ/(K2•mol)[1]. To investigate the nature and the pressure effect of the Kondo effect on CeIrIn5, electrical resistivity ρ andmagnetization M under pressure in CeIrIn5 have been measured using the single-crystalline CeIrIn5 whichwere grown by the In-flux method. The temperature dependence between 2.0 K and 300 K of the a-axis andc-axis electrical resistivity ρ of CeIrIn5 under pressure up to 8.0 GPa, which were obtained using a cubic anvil
device, exhibits the typical dense Kondo behavior: on cooling from room temperature at P = 1.0 GPa, the ρ
increases and shows a maximum of the coherence peak, and then goes down into the coherent Kondo state.
We also find that the coherence peak moves to higher temperatures with pressure, indicating that the Kondo
temperature of CeIrIn5 increases by applying the pressure. In the conference, we will also report the M data
under pressure up to 1.5 GPa and compare the ρ data with our recent thermoelectric power S measurements,
which exhibit a large positive value up to 90 μV/K with a sharp maximum in its temperature dependence. [2]Jonathan Buhot1, Marie-aude Measson1*, Yann Gallais1, Maximilien Cazayous1, Alain
Sacuto1 and Dai Aoki2
1
Laboratoire Materiaux et Phenomenes Quantiques, UMR 7162 CNRS, Universite
Paris Diderot, France
2
SPSMS, UMR-E CEA / UJF-Grenoble 1, INAC, 38054 Grenoble, France
For over 25 years, researchers attempt to understand the microscopic origin of the
Hidden Order that appears below T0=17.5 K in the heavy fermions compound
URu2Si2. Mainly, optical measurements on URU2Si2 are far-infrared reflectanceexperiments[1,2]. Only few Raman scattering studies have been performed [3,4] andonly for c axis. We have studied URu2Si2 for both axes, down to low temperature(2K). We have probed the phononic and electronic properties and their interaction.
Softening of phonon modes together with Fano-shape were observed, implying thata phonon-electron coupling is at play. At low energy, electronic Raman signal shows
either fluctuations or more conventional Drude shape for different symmetry. We havestudied both signals through the Hidden Order temperature.
D.A. Bonn et al., PRL 61 1305 (1988), J. Levallois et al., PRB 84, 184420 (2011) S. Cooper et al.,
PRB 36 5743 (1987), D. Lampakis et al., PHYSICA B 378-380, 578 (2006)[1] C. Petrovic et al., Europhys Lett., 53, 354, (2001). [2] Y. Takaesu et al., J. Phys.: Conf. Series, 273, 012058, (2011).

Kazuhiko Deguchi, Hiroaki Iwase, Yuya Imai, Koji Yamamoto and Noriaki Sato
Department of Physics, Graduate School of Science, Nagoya University, Japan

Rare-earth tri-telluride RTe3 (R = Y, La-Sm, Gd-Tm) forms a weakly orthorhombic
crystal lattice, consisting of alternating double layers of corrugated double RTe layers
and nominally square-planar Te sheets. The RTe layers are responsible for magnetism
while the square Te sheets contribute to strongly anisotropic conduction. Interestingly,
the two-dimensional conduction bands originating from Te-5px and 5py orbitals giverise to Fermi surface nesting, and this hidden one-dimensionality leads to a charge
density waves (CDW) with a high transition temperature. Because of this intriguingfeature, RTe3 attracts great interest in recent years. TbTe3 has localized 4f electrons,
and exhibits successive phase transitions of magnetic origin, which all coexist with the
CDW. Surprisingly, superconductivity emerges under high pressure. The question iswhether the superconductivity coexists or competes with the other long range orders.
Therefore, we investigated the long-range orders by the electrical resistivity and ac
magnetic susceptibility at high pressures up to 8 GPa and at low temperatures down
to 2 K using a constant-load cubic-anvil cell with single crystalline samples that weregrown from Te-fluxes. We found that the antiferromagnetism survives even at thehighest pressure of the present experiment. We also confirmed the emergence of thesuperconductivity at high pressures.

Yuji Matsumoto1, Tatsuma D Matsuda1, Naoyuki Tateiwa2, Etsuji Yamamoto1,
Yoshinori Haga1 and Zachary Fisk3
1
advanced science research center, Japan atomic energy agency, Japan
2
Japan atomic energy agency, Japan
3
University of California, USA
Many anomalous physical properties have been observed in RT2X20 (R=Rare metal,
T=transition metal, X=Al, Zn) system. For example, the quadrupolar order takes placein PrT2X20 system, and the extreme heavy fermion state takes place in YbCo2Zn20.
In the uranium analogue, for example, UT2Al20 is worth investigating because theextended 5f wave function in uranium would lead to peculiar features due to strong
hybridization. Therefore we have studied single crystal growth and physical properties
of UT2Al20. The sample preparation is performed by using Al-self flux method. We
have succeeded to prepare the single crystal of UT2Al20 (T=Ti, Nb). We are going topresent about the physical properties of the prepared samples in the Conference.

PD15

PD18

PD21

PD24

Periodic Anderson model with correlated conduction electrons

The evolution of superconductivity and magnetism in Pd-doped
CeRhIn5 and Ce2RhIn8

Magnetic properties of Ce3Rh4Sn13 and Ce3Co4Sn13; a comparative
study

Anisotropic c-f hybridization in a Kondo semiconductor CeFe2Al10

Imre Hagymasi*, Kazumasa Itai and Jeno Solyom
Theoretical Solid State Physics, Wigner Research Centre for Physics, Hungarian
Academy of Sciences, Hungary
We investigate the so-called periodic Anderson-Hubbard model with the aim tounderstand the role of interaction between conduction electrons in the formation of theheavy-fermion and mixed-valence states [1]. We perform variational calculation using
the Gutzwiller wave function and exact diagonalization of the Hamiltonian for shortchains. The f-level occupancy and the renormalization factor of the quasiparticles arecalculated as a function of the energy of the f-orbital for a wide range of the interaction
parameters. The results obtained by the two methods are in reasonably good agreement
for the periodic Anderson model. The agreement remains even for the AndersonHubbard model, except for the half-filled case. We find that due to this interaction theenergy range of the bare f-level, where heavy-fermion behavior can be observed, shifts
and widens. The Gutzwiller method indicates a robust transition from Kondo insulator
to Mott insulator in the half-filled model, while this interaction enhances the quasiparticle mass when the filling is close to half filling.
[1] I. Hagymasi, K. Itai and J. Solyom Periodic Anderson model with correlated conduction
electrons: variational and exact diagonalization study, arXiv::1106.4999

Marie Kratochvilova*, Klara Uhlirova, Jiri Prchal, Alexandra Rudajevova, Jeroen
Custers and Vladimir Sechovsky
Department of Condensed Matter Physics, Faculty of Mathematics and Physics,
Charles University, Czech Republic
CeRhIn5 and Ce2RhIn8 are heavy fermion antiferromagnets. Unconventional superconductivity can be
induced by hydrostatic pressure or doping [1,2]. By contrast, Ce2PdIn8 is a heavy fermion superconductor(Tc=0.7K) at ambient pressure. We have examined the influence of Pd doping in single crystals of CeRh1xPdxIn5 and Ce2Rh1-xPdxIn8. Since the synthesis of Ce2PdIn8 is connected either to intergrowth of CeIn3 orvariation of critical temperature, growth conditions were studied by differential thermal analysis. By this, wehave succeeded in obtaining high-quality single crystals free of CeIn3 and with a critical temperature Tc~0.7K.
The crystals have been subjected to specific heat, resistivity and AC susceptibility measurements. In addition,
resistivity experiments under hydrostatic pressures up to 3GPa were performed. Surprisingly, at ambientpressure the Neel temperature of CeRh1-xPdxIn5 has only slightly decreased with increasing Pd content. And
moreover, the pressure influence on magnetism in CeRh0.75Pd0.25In5 does not significantly differ from CeRhIn5.
Contrary, the superconducting transition increases significantly compared to its 115-counterpart. The less twodimensional Ce2Rh1-xPdxIn8 behaves different. Here, the antiferromagnetic ordering is immediately lowered
upon Pd substitution and vanishes completely at x~0.35 already. The obtained magnetic field-temperaturephase diagrams will be discussed in context of the physical properties of other CenTIn3n+2 compounds.
[1] H. Hegger et al., Phys. Rev. Lett. 84, 4986 (2000). [2] M. Nicklas et al., Phys. Rev. B 67, 020506 (2003).

134

Marie Kratochvilova1*, Klara Uhlirova1, Jiri Prchal1, Ivana Cisarova2, Jeroen Custers1
and Vladimir Sechovsky1­1 Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles
University, Czech Republic2
Department of Inorganic Chemistry, Faculty of Science, Charles University, Czech Republic

July 9 (Mon)

Yusuke Hirose1*, Shingo Yoshiuchi1, Naoto Nishimura1, Jyunya Sakaguchi1, Kentaro Enoki1, Ken
Iwakawa1, Yasunao Miura1, Tetsuya Takeuchi2, Kiyohiro Sugiyama1, Fuminori Honda3, Etsuji
Yamamoto4, Yoshinori Haga4, Masayuki Hagiwara5, Koichi Kindo6, Rikio Settai1 and Yoshichika Onuki1
1
Graduate School of Science, Osaka University, Japan2
Low Temperature Center, Osaka University, Japan
3
Graduate School of Engineering Science, Osaka University, Japan
4
Advanced Science Research Center, Japan Atomic Energy Agency, Japan5
KYOKUGEN, Osaka University, Japan
6
ISSP, University of Tokyo, Japan

July 9 (Mon)poster Presentation

The 19th International Conference on Magnetism

Andrzej Slebarski*, Marcin Fijalkowski and Jerzy Goraus
Institute of Physics, University of Silesia, Poland

We report on the electronic structure (XPS) and basic thermodynamic properties
of Ce3Rh4Sn13 and Ce3Co4Sn13 and the reference La-based compounds. The bothcompounds were classified as a heavy fermion materials with extremely large lowtemperature electronic specific heat C/T [1] of about 4 J/molK2. The data show thateither Ce3Rh4Sn13 or Ce3Co4Sn13 are very sensitive to applied magnetic fields andexhibit a cross-over from magnetically correlated state to a single impurity state, when
the applied magnetic field increases. We noted that the low temperature properties are
dependent on the stoichiometry of the sample. We also present and discuss the lowtemperature properties of Ce3Co4Sn13 doped with La.
1] U. Kohler et al. J. Phys.:Condens. Matter 19 (2007) 386207

Yuji Muro1, Keisuke Yutani2, Jumpei Kajino2, Takahiro Onimaru2 and Toshiro Takabatake3
Liberal Arts and Sciences, Toyama Prefectural University, Kurokawa 5180, Imizu 9390398, Japan
2
AdSM, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8530, Japan
3
AdSM and IAMR, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 7398530, Japan1

We report anisotropic properties of a Kondo semiconductor CeFe2Al10. This compound is the non-magnetic
counterpart of Kondo semiconductors CeT2Al10 (T=Ru and Os) that exhibit an unusual antiferromagnetictransition at about 28 K[1-5]. The magnetic susceptibility for B//a, χa(T), shows a broad peak at 70 K due
to the strong c-f hybridization. The anisotropy in χ, χa>χc>χb, is in common with those for T = Ru and Os.
Electrical resistivity ρ(T) has a broad maximum at 45, 35 and 110 K for I//a, I//b and I//c, respectively. Below
20 K, ρ’s along all axes show an upturn due to the opening of a pseudo gap. Thermopower S(T) also showsa maximum at 190, 150 and 200 K for a-, b- and c-axis, respectively. The temperatures at the maximum in ρ
and S suggest the anisotropy of c-f hybridization strength Vc>Va>Vb in CeFe2Al10 as reported in the studyof optical conductivity[6]. Furthermore, only Sc(T) changes the sign from positive to negative at 100 K on
cooling and shows a minimum at 50 K. The negative minimum was also observed in Sc(T) for T=Ru andOs[7]. This behavior indicates the development of antiferromagnetic correlation along the c-axis in CeT2Al10.
[1] Y. Muro et al. J. Phys. Soc. Jpn. 78 (2009) 083707. [2] T. Nishioka et al. J. Phys. Soc. Jpn. 78(2009) 123705. [3] Y. Muro et al. Phys. Rev. B 81 (2010) 214401. [4] D. D. Khalyavin et al. Phys.
Rev. B 82 (2010) 100405R. [5] D. T. Adroja et al. Phys. Rev. B 82 (2010) 104405. [6] S. Kimura etal. J. Phys. Soc. Jpn. 80 (2011) 033702. [7] H. Tanida et al. J. Phys. Soc. Jpn. 79 (2010) 063709.

July 8-13, 2012 Busan, Korea

135

poster Presentation
PD25

PE03

PE06

PE09

Cu-NMR studies of heavy-Fermion compound CeCu6 under highmagnetic fields

The lattice Kondo effect - A fabric for superconducting correlations?

Kondo effect near the Van Hove singularity in biased bilayer graphene

ESR study of influence of anionic and cationic substitutions in EuB6
on the magnetic phase separation

It is known that the intermetallic compound CeCu6 is a heavy fermion system showing
a huge specific heat coefficient γ ~ 1600 mJ / K2 mol, without magnetic order orsuperconductivity at low temperatures down to 10 mK[1,2]. The electric resistivity
shows characteristic temperature dependence of ? logT above 10 K, which is ascribedto the Kondo effect, and it has a maximum around 10 K. No detailed NMR results havebeen reported yet because of a drawback of the complicated Cu NMR spectrum due toa peculiar orthorhombic crystal structure. We have carried out Cu-NMR measurements
to clarify the heavy fermion state of a single crystal CeCu6 under several magnetic
fields. We have measured Knight shift and the nuclear spin-lattice relaxation time T1
under magnetic fields up to 15 T along the a-axis and c-axis in the temperature range of100-1.5 K. At low temperatures, the Cu-NMR Knight shifts are suppressed as magnetic
field increases. Simultaneously, 1/T1 is suppressed. These features are understood by
the concept that the heavy fermion state in CeCu6 is formed through Kondo effect. We
will report detailed field dependence of the heavy fermion state of CeCu6 for the firsttime.

Oliver Bodensiek1*, Thomas Pruschke1 and Rok Zitko2
1
Department of Physics, University of Goettingen, 37077 Goettingen, Germany
2
Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia

Although the simple Kondo lattice model constitutes one of the paradigms forunderstanding the physics of heavy-fermion materials, a reliable theoreticalinvestigation of superconductivity in this model is still lacking. We present results
based on the dynamical mean-field approximation in combination with the numerical
renormalization group as impurity solver. While superconducting order is commonly
not expected for a correlated lattice model without additional bosonic degrees of
freedom, we observe strong superconducting order in the plain Kondo lattice model
away from half filling. The possible origin of this superconducting order is discussed
in view of the frequency dependence of the order parameter. In addition, close to halffilling we find this ordered phase to appear most pronounced in the vicinity of theantiferromagnetic quantum critical point. Since a characterization of quantum criticality
within dynamical mean-field theory is not possible, we rather discuss questions ofprinciple such as the actual nature of the ordered states, that is, local moment or heavyfermion physics. The latter issue is of considerable interest addressing the question
whether the ordered states stay in direct competition or even cooperate with thecoherent Kondo effect in the lattice.

Stanislaw Lipinski* and Damian Krychowski
Institute of Molecular Physics, Polish Academy of Sciences, Poland

We study Kondo impurity in a bilayer graphene with Bernal stacking for adatom
adsorbed on the outside of the bilayer or intercalated between the two graphene layers.
The density of states (DOS) close to the gap diverges as the square root of energy Van Hove singularity (VHS). The system is modeled by the generalized Anderson
hamiltonian with bilayer described by Hubbard model. The many-body problem isstudied within the mean field Kotliar-Ruckenstein slave boson approach for SU(2)and SU(4) symmetries. We examine the impact of tuning the Fermi level (EF) throughthe VHS. Increase of the DOS at EF increases hybridization of the impurity, whatmoves the system towards mixed valence regime or even completely suppresses themany body peak of DOS. Additionally a competitive influence of magnetic instability
is analyzed. Crossing of the Fermi level with a Van Hove singularity leads to weakferromagnetism of the bilayer graphene with strong spin polarization at EF. The spinsymmetry is broken, what for the case of spin-orbital degeneracy results in a crossoverfrom SU(4) Kondo effect to SU(2) and in the case of only spin degeneracy it leads to astrong suppression of SU(2) Kondo effect.

Tatiana Semenovna Altshuler1*, Yuriy Vladimirovich Goryunov1, Anna Vasilievna
Levchenko2 and Vladimir Borisovich Filippov2
1
Russian Academy of Sciences, Kazan Physical-Technical Institute, Russia
2
National Academy of Sciences of Ukraine, Institute of Problem of Material Science,
UkraineWe performed a comparative study of the features of the magnetic phase separation in europium
hexaboride with anionic and cationic substitution with donor impurities. The ESR (electron spinresonance) were measured on the single crystal plates EuB_{6-x}C_{x} and Eu_{1-x}Gd_{x}B_{6}with x < 0.07 in X-band in the temperature range T = 10-300 K. Both types substitution keep integrityof the magnetic sublattice and they add one electron per the impurity atom in the conduction band. of
EuB6. The magnetic field was oriented perpendicular to the sample plane and along various crystal axis.
In all case we observed the magnetic phase separation and phase transitions. However, the ratio of themagnetic phases and their behavior is slightly different for substitution boron in carbon and europium
gadolinium. In the latter case, there was the coexistence of ferromagnetic and antiferromagnetic phases.
The obtained ESR data are discussed in frame Falicov-Kimball model the hybridization of the localized
electrons with two band (valence and conduction band) itinerant electrons and formation of Kondo-likeelectron states. Work was supported by Grants of RFBR and Presidium of RAS.
[1] Altshuler T S, Goryunov Y V, Shitsevalova N Y, Dukhnenko A, JETP Lett. 88, 779 (2008) [2]
Kunes J, Picket W E, Phys.Rev. B 69, 1651 (2004) [3] Falicov L M, Kimball J C, Phys.Rev.Lett. 22997 (1969) [4] Kugel K I, Rakhmanov A L, Sboychakov A O, Phys.Rev.Lett. 95, 267210 (2005)[1] Y. Onuki, et al.: JPSJ 53 (1984) 1210 [2] Y. Onuki, et al.: JMMM 63-64 (1987) 281

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The underscreened Anderson lattice : A model for uranium
compounds.

Lifshitz transition with interactions in high magnetic fields: application
to CeIn3

Indirect exchange between magnetic atoms on surfaces: From two
impurities to diluted chains

High pressure synthesis of novel boron-cage compounds RB12 (R=Gd, Sm)

The Neel ordered state of CeIn3 is suppressed by a magnetic field of 61 T at
ambient pressure. There is a second transition at ~45 T, which has been associatedwith a Lifshitz transition. Skin depth measurements indicate that the transition is
discontinuous as T -> 0 and that the transition has a weak pressure dependence until
it merges with the Neel transition. We study the effects of Landau quantization andinteraction among carriers on a Lifshitz transition. The Landau quantization leads
to quasi-one-dimensional behavior for the direction parallel to the field. Repulsive
Coulomb interactions give rise to a gas of strongly coupled carriers. The density
correlation function is calculated for a special long-ranged potential [1]. For the lowest
Landau level the problem can be mapped onto the interacting one-dimensional electrongas. It is concluded that in CeIn3 (a) an electron or hole pocket is being emptied as afunction of field and (b) in the ground state the pocket is emptied in a discontinuous
fashion. This discontinuity is gradually smeared by the temperature in agreement withthe skin depth experiments. Work supported by the Department of Energy under grant
DE-FG02-98ER45707.

Magnetic atoms on metallic surfaces are subject to the competition between Kondo
screening and indirect magnetic (RKKY) exchange. To study the crossover of themagnetic properties from the case of a single or two magnetic adatoms to the limitof a dense chain of indirectly coupled adatoms, we model the metal surface as a onedimensional tight-binding system and apply the density-matrix renormalization group(DMRG) to the resulting Kondo model. The case of three magnetic atoms turns out
to be particularly interesting as finite-size gaps are found to qualitatively affect thebalance between Kondo physics and RKKY. With the transition from the diluted casewith a few magnetic atoms to the dense chain with all atoms RKKY-coupled ferroor antiferromagnetically, magnetic long-range order becomes possible. The resulting
phase diagram is studied in the weak (RKKY) but also in the strong-coupling (Kondo)
limit. Besides DMRG we employ real-space dynamical mean-field theory (R-DMFT)
in addition and thereby extend the results to higher dimensions.

Peter S Riseborough1*, Sergio Magalhaes2 and Bernard Coqblin3
1
Physics, Temple University, USA
2
Inst. Fis., Univ. Fed. Fluminense, Rio de Janeiro, Brazil
3
L.P.S., CNRS-Universite Paris-Sud, 91405 Orsay, France

We present a model based on the Underscreened Anderson Lattice (UAL) with two
5f electrons per site to account for the Kondo-ferromagnetism co-existence observedin some actinide compounds. The UAL model allows a description of the decrease of
the number of f-electrons and we present a calculation which explains the pressure
dependence observed in some Uranium compounds and particularly in Uranium
monochalcogenides. On the other hand, we have developed a novel type of phasetransition within the UAL model and we suggest that this model might describe the“Hidden Order” transition in URu2Si2. The gaps that appear in the electronic dispersion
relations of bands of different orbital character are in agreement with experimental
photoemission results.

July 9 (Mon)

Keisuke Kuroda, Kyohei Morita, Hisashi Kotegawa, Hitoshi Sugawara and Hideki
Tou*
Department of Physics, Kobe University, Japan

July 9 (Mon)poster Presentation

Pedro Schlottmann*
Department of Physics, Florida State University, USA

Andrej Schwabe*, Irakli Titvinidze, Daniel Gutersloh, Anke Braun and Michael
Potthoff
I. Institute of theoretical physics, University of Hamburg, Germany[1] P. Schlottmann, Phys. Rev. B 83, 115133 (2011).

Fumitoshi Iga1*, Yusaku Egashira2, Tomoaki Noguchi2, Toshiro Takabatake2, Akinori
Kondo3, Koichi Kindo3, Shoji Yamanaka4, Kei Inumaru4, Norimasa Nishiyama5,
Tetsuo Irifune5 and Hitoshi Yusa6
1
Faculty of Science, Ibaraki University, Japan
2
Graduate School of ADSM, Hiroshima University, Japan
3
Institute for Solid State Physics, University of Tokyo, Japan
4
Graduate School of Engineering, Hiroshima University, Japan
5
Geodynamics Reaearch Center, Ehime University, Japan
6
High pressure Science, National Institute Material Sciences, Japan
Rare-earth compounds with cage structures recently attract much attention because of possibility of new heavy
fermion mechanism using the lattice vibration [1]. Rare-earth borides such as RB6 and RB12 also have such cage
structures composed by boron. However, RB12 series are known from R = Tb to Lu. Cannon has succeeded inhigh-pressure synthesis of GdB12 in pressure of 6.6 GPa and 2,400 C, and reported lattice parameter a = 7.523 A
in the UB12-type structure [2]. We have also succeeded in high-pressure synthesis of polycrystalline GdB12 andSmB12. Magnetic susceptibility of GdB12 shows a kink at 38 K indicating of antiferro-magnetic ordering. Highfield magnetization of GdB12 shows the saturation moment is 7 μB. All the reported Neel ordering temperaturesof RB12 well agree to the values estimated from the trivalent rare-earth dependence of de Gennes factor. From the
x-ray powder diffraction of SmB12, this compound also has the UB12-type structure with lattice parameter of a =7.541 A. Magnetic susceptibility shows two anomalies at 9 K and 19 K different from other RB12.
[1] T. Hotta and K. Ueda: Phys. Rev. B 67 (2003) 104518. [2] J. F. Cannon, et al.: J. Less-Common
Metals 56 (1977) 83.

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Transport properties of intermetallic compounds RCoGe2 (R = Ce andLa)

Dynamical mean-field theory of indirect exchange between magnetic
adatoms on metallic surfaces

ESR study of hybridization in some undoped Yb-based alloys

Magnetic anisotropy of tetragonal rare-earth compounds RRu2Al2B (R:rare-earth metals)

Yung-kang Kuo1*, P. C. Chang2 and C. S. Lue3
1
National Dong Hwa University, Department of Physics, Taiwan
2
Department of Physics, National Dong Hwa University, Taiwan
3
National Cheng Kung University, National Dong Hwa University,, Taiwan

The electronic and magnetic properties of the cerium-based ternary intermetallic
compound compounds with the general formula CeMSi2 (M = transition metals)
has been of considerable interest recently. Among those compounds, CeCoGe2 is ofparticular interest due to its peculiar physical properties, such as it has a rather highKondo temperature TK ~ 250 K, and it is the first Kondo system clearly interpreted by
the Coqblin-Schrieffer model with j = 5/2. In this study, measurements of the electricalresistivity, Seebeck coefficient, and thermal conductivity on CeCoGe2 have been
performed in the temperature range 10 - 300 K to investigate the electronic structure.
For comparison, the nonmagnetic counterpart LaCoGe2 has also been studied. It isfound that CeCoGe2 exhibits a broad maximum in Seebeck coefficient at about 75
K, at which the sudden drop in electrical resistivity occurs. This is a typical behavior
commonly seen in Ce-based Kondo lattice compounds. A theoretical attempt was madeand found that the electrical ransport and thermoelectric properties of CeCoGe2 can bewell described by a two-band model with reliable physical parameters. On the other
hand, both electrical resistivity and Seebeck coefficient show a typical metallic-likebehavior for the nonmagnetic LaCoGe2.

136

The 19th International Conference on Magnetism

Irakli Titvinidze*, Andrej Schwabe, Niklas Rother and Michael Potthoff
I. Institute of theoretical physics, University of Hamburg, Germany

Two magnetic impurities on a metallic substrate surface experience the RudermanKittel-Kasuya-Yosida (RKKY) exchange interaction. This indirect non-local magnetic
exchange competes with the local Kondo effect. While the latter is described inprinciple exactly within single-site dynamical mean-field theory, the effects of the
RKKY coupling are taken into account approximately only. Here, this is demonstrated
by comparing the DMFT results with numerically exact data obtained by the densitymatrix renormalization group for a one-dimensional model with two Anderson
impurities. With the two-site DMFT, we also benchmark a simplified DMFT variant.
Varying the inter-impurity distance d and the local exchange coupling J, different
parameter regimes with dominating Kondo physics or with dominating RKKY
interaction are studied. For the Kondo regime, our calculations show that DMFT isable to reliably describe magnetic nanostructures on metallic surfaces. The prospects of
DMFT (and two-site DMFT) as a reliable approach to study nanomagnetism of more
complex RKKY-interacting systems are discussed.

Vladimir Ivanshin*, Tatyana Litvinova and Eduard Gataullin
Institute of Physics, Kazan University, Russia

The hybridization between a wide conduction band and correlated f-electrons localized
at lattice sites is investigated using method of electron spin resonance (ESR) in somedense heavy-fermion compounds. ESR signals arise here both from the local moment
spins and conduction electrons (CE) due to the strong electronic correlations becauseof the hybridization between 4f-electrons and CE in the presence of ferromagnetic(FM) fluctuations [1]. We review very recent ESR experiments in several undoped Ybbased intermetallics [2, 3] and discuss the role of chemical composition, Kondo effect,
anisotropy, and RKKY interactions for the ESR linewidth. It is shown that an increaseof the Kondo interaction and FM correlations leads to a stronger hybridization and an
essential ESR line narrowing. Possible hybridization mechanisms are proposed.
[1] P. Wolfle, E. Abrahams, Ann. Phys. (Berlin) 523 598 (2011) [2] V.A. Ivanshin et al., J. Phys.:Conf. Ser. 324 012019 (2011) [3] T. Gruner et al., Phys. Rev. B 85 035119 (2012)

Eiichi Matsuoka1*, Yo Tomiyama1, Kotaro Iwasawa1, Hitoshi Sugawara1, Takahiro
Sakurai2 and Hitoshi Ohta3
1
Department of Physics, Graduate School of Science, Kobe University, Japan
2
Center for Supports to Research and Education Activities, Kobe University, Japan3
Molecular Photoscience Research Center, Kobe University, Japan

Recently, we succeeded to synthesize polycrystalline samples of new tetragonalrare-earth compounds CeRu2Al2B and PrRu2Al2B and reported magnetic propertiesof these compounds [1]. Both compounds show successive phase transitions of an
antiferromagnetic and a ferromagnetic ordering. The Neel and Curie temperatures for
CeRu2Al2B are 14.3 K and 13 K, respectively, and those for PrRu2Al2B are 26 K and
11 K, respectively. The values of magnetization vary when the angle between sample
direction and applied magnetic field is changed even in the polycrystalline samples.
This fact implies that the grains of polycrystalline samples are oriented partially and thevariation of magnetization values is due to the magnetic anisotropy. In this study, we
will report on the results of magnetization and magnetic-susceptibility measurementsof grain-oriented powder samples of RRu2Al2B (R: rare-earth metals) and will discuss
the magnetic anisotropy.
[1] E. Matsuoka, Y. Tomiyama, H. Sugawara, T. Sakurai, and H. Ohta, J. Phys. Soc. Jpn. 81 (2012)
043704.

July 8-13, 2012 Busan, Korea

137

poster Presentation
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Collective magnetic resonance mode in CeB6

Insulator-to-metal transition and magnetism of potassium metals
loaded into regular cages of zeolite LSX

Charge ordering in the Kondo lattice model at quarter filling

Superfluid state of repulsively interacting three-component fermionic
atoms in optical lattices

Takehito Nakano1, Duong Thi Hanh1, Nguyen Hoang Nam2, Yasuhiro Owaki1, Shingo
Araki3 and Yasuo Nozue1*
1
Department of Physics, Graduate School of Science, Osaka University, Japan
2
Hanoi University of Science, Viet Nam
3
Graduate School of Natural Science and Technology, Okayama University, Japan

Junki Yoshitake*, Takahiro Misawa and Yukitoshi Motome
Department of Applied Physics, The University of Tokyo, Japan

Seiichiro Suga1* and Kensuke Inaba2
1
University of Hyogo, Japan
2
NTT Basic Research Laboratories and JST CREST, Japan

Zeolite low-silica X (LSX) crystals have an aluminosilicate framework with the regular nanospace of supercages
and beta-cages. They are connected by the double diamond structure. Many K-cations are distributing among
negatively charged framework in K-type LSX. 4s-electrons of guest alkali atoms are shared with K-cations ofzeolite. Loading density of guest K atoms per unit cage, n, can be controlled from 0 to 9. At n < 2, samples arenonmagnetic and insulating[1]. When n is just above 2, number density of magnetic moments suddenly increases
and electrical resistivity decreases as semiconductive materials. For n > 6, electrical resistivity shows metallic
properties suddenly. When n > 8.5, ferrimagnetic properties is observed at low temperatures. A remarkableincrease in resistivity is observed at low temperatures likely Kondo semiconductor. In materials with the strong
electron-phonon interaction, excess electrons are self-trapped quantum mechanically at the deformation potential
well[2]. These immobile electrons are small polarons with magnetic moments. If the electron-phonon interaction
is much stronger than the repulsive interaction between two electrons, nonmagnetic small bipolarons arestabilized. Observed novel properties are explained by small bipolarons, small polarons, metallic large polarons,
and Kondo-like mixing between metallic electrons in supercages and localized electrons in beta-cages.

The Kondo lattice model is one of the fundamental models for heavy-fermion systems,
where exchange interactions between itinerant electrons and localized spins play animportant role. Among many different phases described by this model, emergence of
charge-ordered state [1,2] is interesting possibility, because this model does not include
any bare inter-site repulsions between electrons. The possibility was first pointed out
by a perturbation expansion in the strong Kondo coupling limit at quarter filling in 1D[1], and recently examined by the dynamical mean-field theory in infinite dimensions[2]. However, it remains unclear whether the charge-ordered state appears in two andthree dimensions and what type of magnetic order is accommodated in the chargeordered state. To clarify these issues, we investigate both the ground state and finitetemperature properties of the quarter-filled Kondo lattice model on a square lattice bycomplementarily using the variational Monte Carlo simulation and cluster dynamical
mean-field theory. We found that charge-ordered state appears in a wider region
than the previous result in infinite dimensions, and that the antiferromagnetic order
between charge poor sites is accommodated in the charge-ordered state. We discuss thestabilization mechanism of charge ordering by carefully analyzing the electronic andmagnetic properties.

[1] Y. Ikemoto, T. Nakano, M. Kuno, Y. Nozue and T. Ikeda, J. Mag. Mag. Mat. 226-230, 229 (2001).
[2] Y. Toyozawa, Prog. Theor. Phys. 26, 29 (1961).

[1] J. E. Hirsch, Phys. Rev. B 30, 5383 (1984). [2] J. Otsuki et al., J. Phys. Soc. Jpn. 78, 034719(2009).

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Transport and magnetic properties of CeFe4Sb12 synthesized underhigh pressure

1/(N-1) expansion for a finite U Anderson model with an SU(N)symmetry

Angular-dependent magnetoresistance of the filled skutterudite
CeOs4As12

Magnetism in complex oxides: A challenge for advanced ab-initio
methods

We apply recently developed 1/(N-1) expansion to a particle-hole asymmetric SU(N)
Anderson model with finite Coulomb interaction U. This approach is completely
different from the conventional 1/N expansion, or the non-crossing approximation.
In our approach the factor N-1 corresponds to the number of interacting orbitals,
excluding the one prohibited by the Pauli principle. To leading order in 1/(N-1) it
describes the Hartree-Fock random phase approximation (HF-RPA), and the higherorder corrections describe systematically the fluctuations beyond the HF-RPA. The
low-energy local Fermi-liquid behavior is described properly with this approach. We
show that the next-leading order results of the renormalized parameters agree closelywith the numerical renormalization group results at N=4 in a wide range of the electron
fillings, from the empty to fully occupied orbitals, specifically in the mixed-valence
regions. This ensures the reliability of the next-leading order results for N > 4. Our
expansion scheme uses the standard Feynman diagrams, and thus has wide potential
applications. It can be applied to the Keldysh formalism, and to lattice systems such as
the Hubbard model.

The filled skutterudite CeOs4As12 compound is a narrow-gap semiconductor whose
low-temperature properties originate from a hybridization between 4f and conduction
electrons. Nonmagnetic CeOs4As12 is the cubic system showing a nodal structure of
hybridization energy gap(s) as evidenced from low-temperature (T > 0.08 K) and highmagnetic field (B < 14 T) studies of a directional dependence of the electrical resistivity
ρ (T): At T < 3 K and for j || B, we found remarkable dissimilarities along the [001] and[111] directions, indicative of an anisotropic suppression of energy gap(s). Additionally,
differences observed between the transverse and longitudinal magnetoresistivity cannot
be ascribed to the Lorentz force and thus, provide a further evidence for magnetic-fieldinduced anisotropy of hybridization gap in CeOs4As12. High-quality single crystalsof CeOs4As12 enable studies of a change of Fermi surface via the angular-dependent
magnetoresistivity both in the field-induced metallic as well as semiconducting state.
Our experiments with the use of the commercial one-axis rotator (PPMS) provide an
additional evidence for strongly correlated electron phenomena in CeOs4As12 that we
tentatively relate to the quartet Γ67 ground state of the Ce3+ ion in the Th symmetry.

The observation of the electron spin resonance (ESR) in low temperature phase(phase II) of CeB6 has risen up new questions about the nature of its ground state [1].
In the present work we study the effects of La doping on the ESR parameters in Ce1xLaxB6. Experiments in the doping range 0<x<0.1 have shown that even small La
concentrations x~0.03 cause strong broadening as well as suppression of the ESR line.
Such behavior is accompanied by a tendency of g-factor increase from g≈1.6 in CeB6
to higher values with La doping. The resonance line gets unobservable with further
concentration increase up to x~0.05. At the same time the phase border between thephase II and the paramagnetic phase I observed as a kink in microwave conductivity
remains almost independent on the La concentration in the studied range. Such strong
sensitivity of the ESR parameters to the doping concentration allows suggesting thecollective origin of the electron spin resonance mode.
[1] S. V. Demishev et. al., Phys. Rev. B 80, 245106 (2009)

Hitoshi Sugawara1*, Masahito Sakoda1, Eiichi Matsuoka1, Takashi Saito2, Sho
Tatsuoka2, Kenya Tanaka2 and Hideyuki Sato2
1
Department of Physics, Kobe University, Japan2
Department of Physics, Tokyo Metropolitan University, JapanThe filled skutterudite compounds have attracted much attention, since they exhibit
a variety of novel features such as the heavy fermion behavior, hybridization-gap
semiconducting behavior, and unconventional superconductivity [1]. The filling
fraction of rare-earth site plays the important role for the ground state in certain
compounds, such as PrxFe4Sb12, in which the ferromagnetic ground state for x~0.8
is changed to the non-magnetic one by increasing to x~1 [2]. In this work, we havesucceeded in synthesizing the filled skutterudite CexFe4Sb12 with the Ce-site filling
fraction x~1 under high pressure, and found the semiconducting behavior in thiscompound.
[1] H. Sato, H. Sugawara. Y. Aoki and H. Harima: Handbook of Magnetic Materials, Vol. 18,“Magnetic Properties of Filled Skutterudites' ed. by K.H.J. Buschow. (Amsterdam, Elsevier), p.1-110,
2009. [2] K. Tanaka, Y. Kawahito, Y. Yonezawa , D. Kikuchi, H. Aoki, K. Kuwahara, M. Ichihara, H.
Sugawara, Y. Aoki and H. Sato: J. Phys. Soc. Jpn. Vol. 76 (2007) 103704.

Akira Oguri1 and Rui Sakano2
1
Physics, Osaka City University, Japan
2
Applied Physics, University of Tokyo, JapanŁukasz Bochenek*, Zygmunt Henkie and Tomasz Cichorek
Division of Magnetic Research, Institute of Low Temperature and Structure Research,
Polish Academy of Sciences, Wroclaw, Poland, Poland

We investigate the superfluid state of repulsively interacting three-component(color) fermionic atoms in optical lattices. We first discuss the effective interactions
using diagrammatic approaches. We then investigate the superfluid properties using
complementary two methods: the dynamical mean-field theory with a perturbative
approach and the self-energy functional approach. We show that when the anisotropyof the three repulsive interactions is strong, atoms of two of the three colors form
Cooper pairs and atoms of the third color remain a Fermi liquid. An effective attractive
interaction is induced by density fluctuations of the third-color atoms. This superfluid
state is similar to the color superfluid of the attractively interacting three-component
systems. We show from dynamical properties that the Cooper-pairing mechanism
is basically similar to that of the conventional phonon-mediated superconductivity.
The superfluid state is stable against changes in filling close to half filling. We
determine the phase diagrams in terms of temperature, filling, and the anisotropy of therepulsive interactions. We also discuss the relation between the theoretical results andexperiments.

July 9 (Mon)

A. V. Semeno1*, V. V. Glushkov1, N. E. Sluchanko1, N. Yu. Shitsevalova2, V. B.
Filipov2, A. V. Dukhnenko2 and S. V. Demishev1
1
A.M.Prokhorov General Physics Institute RAS, Russia
2
Institute for Problems of Materials Science NAS, Ukraine

July 9 (Mon)poster Presentation

Alessio Filippetti
Dept. of Physics, CNR-IOM, University of Cagliari, Italy

The accurate description of magnetic properties in complex oxides by first-principles istantamount with the possibility of achieving reliable theoretical design of oxide-based
spintronic devices. Alas, standard first-principles approaches fails to properly describe
strong correlated systems, and more sophisticated approximations are required.
Recently the novel variational pseudo-self-interaction corrected density functional
theory (VPSIC) has been introduced, showing great potential as theoretical tool forthe study of complex oxides and strong-correlated systems in general, and promising
to open the field to reliable designs of magnetic oxide-based devices. Here we apply
the new approach to investigate two prototypical oxide families, i.e. transition metalmonoxides (MnO, NiO) and perovskite titanates (LaTiO3, YTiO3). We give evidence
that the new theory is capable to furnish an unprecedentedly accurate description ofboth ground-state and finite-temperature magnetic properties, both at equilibrium
and under pressure. As highlights of the results obtained in the work, we mention thecorrect determination of critical temperature and the accurate description of orbital
ordering in transition metal oxides.

[1] A. Oguri, R. Sakano, and T. Fujii, Phys. Rev. B 84, 113301 (2011). [2] A. Oguri, arxiv:1112.6051.

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Interplay of Kondo effect and spin orbit coupling

Formation of the Kondo resonance band in CeCoGe2: DFT+DMFT
approach

Spin and charge correlation of electrons at variation of interorbital
Coulomb interaction

Resonating Hartree-Fock Studies for spin fluctuations in the Hubbard
model on triangular lattice

Kalobaran Maiti*, Swapnil Patil, V R R Medicherla, R S Singh and E V
Sampathkumaran
Department of Condensed Matter Physics, Tata Institute of Fundamental Research,
India
Physics near quantum critical point (QCP) has been an interesting unresolved problem
for many decades now. While the ground states on either sides, away from QCP arereasonably well understood, the physics in the vicinity of QCP is a long standing
puzzle. The question is, how the quantum critical fluctuations affects the electronic
excitations and evolves as one goes across QCP. We studied the electronic structure of
Ce2Rh1-xCoxSi3 with varying x using high resolution photoemission spectroscopy. Co
substitution at the Rh sites in antiferromagnetic Ce2RhSi3 leads to transition to a Kondo
system, Ce2CoSi3 via QCP at x = 0.6. High resolution spectra reveal signature of
Kondo resonance feature (KRF) and its spin orbit split component (SOC) in the whole
composition range indicating finite Kondo temperature scale at QCP and applicabilityof spin density wave picture at the approach to QCP. Interestingly, the intensity ratio of
the Kondo resonance feature and its spin orbit split component, KRF/SOC gradually
increases with the decrease in temperature suggesting importance of spin-orbit
interactions in this regime.

138

The 19th International Conference on Magnetism

Hong Chul Choi1, B. I. Min2, K. Halue3, G. Kotliar3 and J. H. Shim1*
1
Department of Chemistry, Pohang University of Science and Technology, Korea
2
Department of Physics, Pohang University of Science and Technology, Korea
3
Department of Physics, Rutgers University, USA

We have investigated the formation of the Kondo resonance (KR) band in the heavy
fermion CeCoGe2 using the combined approach of the density functional theory (DFT)and the dynamical mean field theory (DMFT). The low temperature (T) spectral
function shows the dispersive KR states in momentum space, which is well consistent
with the experimental observation. The size of the induced hybridization gap is rather
insensitive to T. During the evolution from the spdbands at highTto the dispersive KRbands at low T, whose topologies are different each other, we have found the existenceof kinks in the spectral function near EF. We suggested that the kink can be intrinsicallyobserved in measuring spdconduction bands during the formation of the fully coherent
KR band.

Sergey Stepanovich Aplesnin1 and Nataly Ivanovna Piskunova2
1
M.V. Reshetnev Siberian State Aerospace University, Russia
2
Omsk State Agrarian University, Russia

Of great interest for the researches is the ions with orbital degeneration and electron
shell with filling more than half. The aim of our work is to evaluate spin and charge
correlation at variation of interorbital Coulomb interaction and competition of electron
hopping parameters between nearest sites on the same and different orbitales arising
as a result of variation of orbitales filling. Variation of charge gap may be also cause aradical change in the electronic density and spin correlation functions. We calculated
electron spectrum in the Hubbard model with electron filling n=1.5 and following
parameters: energy level of ions, the matrix element of the hopping between thenearest sites and orbitales, U and V is the Coulomb repulsion of the electrons on siteand between orbitales . We calculated the eigenvalue spectrum and the corresponding
state vectors by exact diagonalization for small cluster, based on which we determined
the spin correlation functions on the longitudinal and transverse spin components,
correlator of electron density. As a results, critical parameters Vc of the interorbitales
Coulomb interaction and hopping integral are found at which reveal change in thevalue and sign of exchange interaction and in the correlator of electron density.

Norikazu Tomita*
Yamagata University, Japan

Electron correlation effects in geometrically frustrated systems have attracted muchattention in condensed-matter physics. In fact, these systems show a variety ofinteresting and non-trivial ground states. On the other hand, theoretical description on
the electron correlations in these systems is difficult, and origins of such non-trivial
states are not yet clarified. In this research, the electron correlations are visualized
from the viewpoint of quantum fluctuations. Such visualization is important for thefundamental understanding and applications of the frustrated system. A resonating
Hartree-Fock method constructs a many-body wave-function by superposition of
non-orthogonal Slater determinants, where superposition coefficients and orbitals inall the Slater determinants are simultaneously optimized. We can visualize quantum
fluctuations from the structures of Slater determinants generating the wave-function.
We have previously demonstrated that quantum fluctuations in the doped Hubbard
model on a square lattice are described by vibrations and translations of polarons.
[Phys. Rev. Lett. 103(2009)116401.] Now, the half-filled Hubbard model on a uniform
triangular lattice are considered. The ground state is metallic and non-magnetic when
U is weak. We show that non-magnetic ground state is realized by the large quantum
fluctuations due to hybridization of two different co-linear spin-density waves and theirmodulations. [Phys. Rev. B84(2011)245101.]

July 8-13, 2012 Busan, Korea

139

poster Presentation
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PF08

PF11

PF14

Theory of momentum-dependent variational ansatz to strongly
correlated electron system

The temperature dependence of the staggered magnetisation initinerant weak antiferromagnets

Electric dipolar susceptibility of the Anderson-Holstein model

BCS-BEC crossover in the extended Falicov-Kimball model:
Variational cluster approach

We have recently developed Momentum dependent Local-Ansatz wavefunction (MLA)
approach to describe the correlated electron system in the weak and intermediate
Coulomb interaction (U) regime. The theory did not work best in the strong U
regime because we started from the Hartree-Fock (HF) wavefunction. To overcome
the difficulty, we propose here a new hybrid wavefunction in which the starting
wavefunction can vary via a new variational parameter w from the HF wavefunction(w=0) suitable for the weak interaction regime to the alloy-analogy (AA) wavefunction(w=1) suitable in the strong interaction regime. The extended method overcomes
the standard variational method such as the Gutzwiller wavefunction approach (GA)irrespective of U. We have demonstrate that the energy for the MLA-AA (w=1) islower than those of the MLA-HF (w=0) in the strong U region for the half-filled band
Hubbard model for the hypercubic lattice in infinite dimensions. Moreover, the energyof the MLA (w=0 and 1) is always lower than the GA. We have also verified that the
double occupation number, quasi-particle weight and momentum distribution function
are much improved by the new MLA.

Nobukuni Hatayama1, Rikio Konno1* and Yoshinori Takahashi2
1
Kinki University Technical College, Japan
2
Graduate School of Material Science, University of Hyogo, Japan

Effect of spin fluctuations on the staggered magnetisation in itinerant weak
antiferromagnets is investigated below the Neel temperature TN. It is known that thediscontinuous change of the magnetisation occurs at the critical temperature in therotationally invariant treatment in the self-consistent renormalization spin fluctuation
theory. The difficulty is resolved in itinerant weak ferromagnets by Takahashi [J. Phys.:
Condens. Matter 13 (2001) 6323. ]. In this paper, we extend his theory to the case of
weak antiferromagnets. We have succeeded in deriving the temperature dependenceof the staggered magnetisation below TN, by taking account the effects of spin-waves
excitations into the transverse component of the dynamical magnetic susceptibility
within the small area of wave-vector space around the staggered wave-vector. We
found T3/2-linear behaviour of the staggered magnetisation at low temperaturescompared with TN.

Takahiro Fuse* and Takashi Hotta
Department of Physics, Tokyo Metropolitan University, Japan

Recently, cage structure materials have attracted much attention due to intriguing
magnetic phenomena induced by the coupling effect between electrons and rattling, i.e.,anharmonic local oscillation of guest ion in a cage. When the guest ion oscillates in thecage, there should occur electric dipole moment P, given by P=Zex, where Z denotes
the valence of the guest ion, e indicates electron charge, and x is ion displacement. In
order to investigate properties of electron-rattling system, we evaluate electric dipolarsusceptibility χp on the basis of the Anderson-Holstein model, which consists ofconduction electron term, hybridization between conduction and localized electrons,
Coulomb interaction between localized electrons, and coupling between ion oscillationand local charge density. We analyze the model by using the numerical renormalizationgroup (NRG) method. Note that χp is directly related to the phonon Green’s function D.
For the evaluation of D, we pay due attention to the phonon excited states kept in therenormalization process. We carefully evaluate D with the use of NRG and compare
it with that obtained from charge susceptibility in the combination with the Dyson
equation. Then, we discuss the effects of anharmonicity and Coulomb interaction on
χp.

Kazuhiro Seki1*, Robert Eder2 and Yukinori Ohta1
1
Department of Physics, Chiba University, Japan
2
Institut fuer Festkoerperphysik, Karlsruhe Institute of Technology, Germany

We study the spontaneous symmetry breaking of the excitonic insulator state inducedby the Coulomb interaction U in the two-dimensional extended Falicov-Kimball model.
Using the variational cluster approximation (VCA) and Hartree-Fock approximation(HFA), we evaluate the order parameter, single-particle excitation gap, momentum
distribution functions, coherence length of excitons, and single-particle and anomalous
excitation spectra as functions of U at zero temperature. We find that in the weak-tointermediate coupling regime, the Fermi surface plays an essential role and calculated
results can be understood in close correspondence with the BCS theory, whereas in thestrong-coupling regime, the Fermi surface plays no role and results are consistent withthe picture of a Bose-Einstein condensate (BEC). Moreover, we find that HFA works
well in both the weak and strong-coupling regimes, and that the difference between
the results of VCA and HFA mostly appears in the intermediate-coupling regime. The
reason for this is discussed from a viewpoint of the self-energy. Details are reported inRef. [1].

July 9 (Mon)

M. Atiqur R. Patoary* and Yoshiro Kakehashi
Univ. of the Ryukyus, Nishihara, Okinawa, Japan

July 9 (Mon)poster Presentation[1] K. Seki, R. Eder, and Y. Ohta, Phys. Rev. B 84, 245106 (2011).

PF06

PF09

PF12

PF15

Metal-insulator transition in orthorhombic Perovksite PbRuO3

Theory of excitonic insulator in the two orbital Hubbard model:
Variational cluster approach

Insulator version of the double-exchange ferromagnetism

Theory of the metal-insulator transition and charge/orbital states in
V6O13

Young-joon Song1 and Kwan-woo Lee2*
1
Department of Applied Physics, Graduate School, Korea University, Sejong, Korea
2
Department of Display and Semiconductor Physics, Korea University, Sejong, Korea
Transition metal oxide perovskites show abundant physical phenomena such as
superconductivity, CMR, ferroelectricity, and unusual magnetic behavior. Recently, theorthorhombic perovskite PbRuO3, which was first synthesized 40 years ago, has beenrevisited by two experimental groups. Commonly, the measurements of temperaturedependent magnetic susceptibility show a kink at 90 K, where a structural transition
occurs, but no magnetic ordering has been observed even at very low T. Remarkably,
the resistivity measurements of Kimber et al. indicate a metal-insulator transition, but
ones of Cheng et al. shows a metal-metal transition though a kink appears at 90 K.
To understand this discrepancy, we have carried out first principles calculations using
various approaches: correlated band theory (LDA+U), LDA+U+SOC (spin-orbital
coupling), modified BJ, and fixed spin moment calculations. In this presentation, we
will address the electronic and magnetic structures on PbRuO3 in more detail and a
scenario on the discrepancy.

Tatsuya Kaneko1*, Kazuhiro Seki1, Satoshi Nishimoto2 and Yukinori Ohta1
1
Department of Physics, Chiba university, Japan
2
Institut fur Theoretische Festkorperphysik, IFW Dresden, Germany

Motivated by the recent experimental and theoretical studies of excitonic insulators, weinvestigate the spontaneous symmetry breaking of the excitonic insulator state in the
two-orbital Hubbard model defined on the two-dimensional square lattice. Using thevariational cluster approximation (VCA) and Hartree-Fock approximation (HFA), we
evaluate the number of particles on each orbital, staggered magnetization in the Mott
insulator phase, the order parameter indicating the coherence between electrons andholes in the excitonic insulator phase, and the ground-state phase diagram as functionsof intra-orbital and inter-orbital Coulomb interactions. We also calculate the singleparticle excitation spectra of the band insulator, Mott insulator, and excitonic insulator
phases. We thereby argue that the normal metallic phase is unstable to the formation of
the excitonic insulator phase, which should appear in a wide parameter region between
the band insulator and Mott insulator phases.

Yukinori Ohta1*, Satoshi Nishimoto2 and Kyohei Nakano1
1
Department of Physics, Chiba University, Japan
2
Institute for Theoretical Solid State Physics, IFW-Dresden, Germany
The double-exchange ferromagnetism is known to appear when the coherent motionof electrons occurs in the conduction band that is coupled with the localized spins via
the ferromagnetic Heisenberg-type exchange interaction, i.e., the Hund's rule coupling.
A natural and realistic issue that arises is then what happens with the ferromagnetism
when a gap opens in the conduction band and coherent motion of electrons ceases.
To answer this question quantitatively, we apply the density-matrix renormalizationgroup method to the study of the one-dimensional double-exchange model, where
we introduce the Peierls-type lattice distortion in the conduction band to make thesystem an insulator with the band gap. We find from the analysis that the doubleexchange ferromagnetism persists strongly unless the strength of the lattice distortion
exceeds a certain critical limit; we thus call this an insulator version of the doubleexchange ferromagnetism. We note that this type of ferromagnetism actually occurs ina chromium hollandite K2Cr8O16, where a half-metallic ferromagnet due to the doubleexchange mechanism undergoes a metal-insulator transition, resulting in the realizationof a ferromagnetic insulator [1].

Takayoshi Nakayama1*, Tatsuya Toriyama1, Takehisa Konishi2 and Yukinori Ohta1
1
Department of Physics, Chiba University, Japan
2
Graduate School of Advanced Integration Science, Chiba University, Japan

The Wadsley-phase vanadium oxide V6O13 has the crystal structure composed of thetwo-dimensional single and double trellis lattices, where the V ions are in the mixed
valent state with an average valence of V4.33+ (3d0.66); i.e., there are formally
V5+ (3d0) and V4+ (3d1) in a 1 : 2 ratio. This material undergoes a metal-insulatortransition (MIT) at 150K, which is accompanied by the structural distortion, andshows an antiferromagnetic order below 55K. To clarify the electronic structure of thismaterial, we make the density-functional-theory-based electronic structure calculations
and discuss the mechanism of the MIT, as well as its charge and orbital states aboveand below the MIT. We find that the band structure obtained is in reasonable agreementwith the observed angle-resolved photoemission spectra but that the characteristic
distribution of valence electrons is not necessarily compatible with the results of a
recent NMR experiment. We also find that, if we assume the observed low-temperature
crystal structure in the calculations, we obtain the insulating solution with an
antiferromagnetic order, which is in agreement with experiment.

[1] Toriyama et al., Phys. Rev. Lett. 107, 266402 (2011).

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Ferromagnetic semiconductor-metal transition in heterostructures of
europium monoxide

Layered chalcogenide Ta2NiSe5 as a candidate for excitonic insulators theoretical aspects

Metallic ferromagnetism in the 3D Hubbard model at finite
temperature

Statistical dynamical mean field study of correlated fermions withdisorderThe dynamical mean-field approximation (DMFA), when used to study strongly
correlated electron systems (SCES), allows the obtainment of thermodynamic
properties in a nonperturbative regime. The Hubbard model is the simplest model
capable of describing the essential physics of SCES. Thus, we investigatedthe existence of ferromagnetism in the Hubbard model on fcc lattices, at finite
temperatures, using the DMFA with effective parameters solved by exact numerical
diagonalization. We calculated the magnetization for 0.3 n 0.9 (where n is the numberof electrons per site), with temperature of 0.04t/kB (where t is the hopping integral
between nearest-neighbor sites) and the value of the on-site Coulombian interaction U
equal to 3W (where W denotes the noninteracting energy bandwidth). Our results reveal
a significant magnetization for n = 0.6, 0.7 and 0.8. The densities of states indicate thatthese systems are metallic. In the particular case for n = 0.6, magnetization, internalenergy and specific-heat curves versus temperature were calculated to that value of U.
This work provides an affirmative answer to the question whether the Hubbard modelwith only nearest-neighbor hopping, on a three-dimensional lattice, and finite bothtemperature and on-site Coulombian interaction, exhibits ferromagnetism when solved
using the DMFA.

Disordered systems with strong correlation effects have been studied in solid statephysics, and even now have attracted much interest. Various experiments have been
performed extensively, and in particular a disordered system of strongly interacting
cold atoms has been experimentally realized recently[1]. Statistical dynamical meanfield theory[2,3] to treat disorders and strong correlation effects on equal footing andnon-perturbatively makes it possible to capture essential features of the Andersontransition beyond the coherent-potential approximation. In this work, we analyze thetight-binding fermion model on the Bethe lattice in which the box disorder manifests
itself by random on-site energies. We systematically investigate characteristic behaviorsof the density of states and the conductivity to estimate competitions between disorders
and correlation effects in this system.

Tobias Stollenwerk* and Johann Kroha
Physikalisches Institut, University of Bonn, Germany

WN
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TH
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140

The 19th International Conference on Magnetism

Tatsuya Kaneko1*, Tatsuya Toriyama1, Takehisa Konishi2 and Yukinori Ohta1
1
Department of Physics, Chiba university, Japan
2
Graduate School of Advanced Integration Science, Chiba university, JapanThe electronic structure of layered chalcogenide Ta2NiSe5, a candidate for excitonic
Insulators, is calculated using the generalized gradient approximation in the density
functional theory, where the Hubbard-type repulsive interaction is taken into account.
We find for the low-temperature monoclinic phase that the conduction band has acosinelike quasi-one-dimensional (1D) band dispersion coming mainly from the 5dxy
orbitals of Ta ions arranged along the a-direction of the lattice, whereas the top of
the valence band has a quasi-1D dispersion coming mainly from the Ni 3dxz+3dyz
and Se 4px+4py orbitals arranged alternately along the a-direction. The electronic
state near the Fermi level is thus described by the quasi-1D structural unit consistingof these orbitals. The electronic structure of Ta2NiS5, which has the orthorhombic
crystal structure, is also calculated to clarify the role of the lattice distortion. Three
scenarios are suggested to explain the characteristic temperature dependence of theband structure observed in the angle-resolved photoemission: a scenario of the band
deformation due to the monoclinic lattice distortion, a scenario of the formation of theexcitonic insulator state, and a scenario made from the combination of the former two
where the monoclinic lattice distortion and formation of the excitonic insulator state
occur cooperatively.

Andre Neves Ribeiro and Claudio Andrade Macedo*
Departamento de Fisica, Universidade Federal de Sergipe, Brazil

Masaru Sakaida*, Kazuto Noda and Norio Kawakami
Kyoto university, Japan[1] L. Fallani et al., Phys. Rev. Lett. 98, 130404 (2007) [2] V. Dobrosavljevic et al., Phys. Rev. Lett.
78, 3943 (1997) [3] D. Semmler et al., Phys. Rev. B 84, 115113 (2011)

July 8-13, 2012 Busan, Korea

141

poster Presentation
PF17

PG01

PG04

PG07

Analysis of many-body effects on anisotropic magnetic properties of
YbB12

Ferrimagnetic compensation in a Fe64Er19B17 glass, - the head of adandelion, or the spokes of a wheel?

Pressure effects in the ferromagnetic shape memory alloys Ni2Mn1xCuxGa

Pressure effect of metamagnetic shape memory alloy Pd2Mn1+xSn1-x

YbB12 is one of the typical Kondo insulator and many experiments are already reported.
Although it has cubic structure, critical magnetic fields of insulator-to-metal transition
are anisotropic[1]. Moreover anisotropic magnetization is observed above the criticalfield[2]. One of the authors studied the magnetic properties by means of tight binding
model, composed of Yb 5dε and 4f Γ8 orbitals[3]. The results were qualitatively inagreement with the experiments but a quantitative disagreement was left, because
many-body effects were not taken into account. Therefore, we introduce coulomb
repulsion between f-electrons in the tight binding model. We apply the dynamical mean
field theory, in which we solve the effective impurity problem by using the continuoustime quantum Monte Carlo method. We compare obtained result with the experimental
one’s quantitatively, and discuss the many-body effects in the magnetic properties of
YbB12.
[1] F. Iga et al. : Jpn. J.Appl. Phys. Series 11(1999)88 [2] S. Hiura, et al.: Physica B
281&282(2000)271 [3] T. Izumi, Y. Imai, T. Saso : J. Phys. Soc. Jpn. 76(2007)084715

1

2

3

Andrew R. Wildes *, Neil Cowlam and Nourh A. Al-senany
1
Institut Laue-Langevin, BP 156, 6 rue jules Horowitz, 38042 GRENOBLE Cedex 9,France2
Department of Physics and Astronomy, University of Sheffield, SHEFFIELD, S3
7RH, United Kingdom
3
Department of Physics and Astronomy, University of Sheffield, SHEFFIELD, S3
7RH, King Abdulaziz University, Jeddah, Saudi Arabia, United Kingdom
Magnetization and neutron scattering measurements with polarization analysis weremade on a Fe64Er19B17 glass to investigate its ferrimagnetic compensation at T(comp)= 112 ± 2K. The measurements prove that the glass has a non-collinear magnetic
structure. The two non-spin flip cross-sections interchange between 100K and 125K,
proving the magnetic structure flips at T(comp). They are identical at 112K where
the forward limit of the spin flip cross-sections was greatest. The mean collinear
components of the moments therefore go to zero at T(comp). If the moment vectors
were mapped to originate at a point, the data correspond either to the moments being
randomly oriented like the head of a dandelion, or with a collapse of the moments intoa plane normal to the field, like the spokes of a wheel. The data will be presented andthe possible driving mechanisms for the ferrimagnetic compensation will be discussed.

1

1

2

2

Tomoya Miura , Yoshiya Adachi *, Keita Endo , Ryosuke Kainuma and Takeshi
Kanomata3
1
Graduate School of Science and Engineering, Yamagata University, Japan2
Department of Materials Science, Tohoku University, Japan
3
Faculty of Engineering, Tohoku Gakuin University, JapanThe Heusler alloy Ni2MnGa attracts attention as an actuator material because themagnetic distortion of about 10% is observed just below the martensitic transition
temperature (TM). The pressure dependence coefficient of the Curie temperature ofNi2MnGa is +1.0×10-8 K/Pa.[1] In the Ni2Mn1-xCuxGa alloy system, TC and TM werereported by Kataoka et al.[2] that the samples with the range of x < 0.23, 0.23 < x <0.30 and x > 0.30 are characterized TC > TM, TC = TM and TC < TM, respectively.
We carried out the initial permeability measurements under pressure up to 1 GPa for
Heusler Ni2Mn1-xCuxGa system. TM and TC were determined from the change ofthe initial permeability under each pressure. It was found that TM was considered tocoincide with TC in 0.23 < x < 0.30. Moreover it was obtained dTC/dp is positivein x < 0.23 and dTC/dp is negative in x > 0.30. As a result, the temperature-pressure
magnetic phase diagram was obtained. We’d like to discuss the mechanism of themartensitic transformation in Heusler alloy Ni2Mn1-xCuxGa system.

Yohei Yamazaki1, Takamitsu Akama2, Hironari Okada1*, Takeshi Kanomata1 and
Ryosuke Kainuma3
1
Division of Engineering Graduate School, Tohoku Gakuin University, Japan
2
Faculty of Engineering, Tohoku Gakuin University, Japan
3
Graduate School of Engineering, Tohoku University, Japan
Recently, it has been reported that NiMnX (X = In, Sn and Sb) Heusler alloys show
metamagnetic shape memory effect. In these alloys, the martensitic transformation
temperature decreases with increasing magnetic field, and magnetic field-induced
reverse martensitic transformation associated with metamagnetic transition occurs
below the martensitic transformation temperature. Since the magnetic fieldinduced transformation leads an almost perfect shape memory effect, these alloys
attract attention as new type of ferromagnetic shape memory alloys. Very recently,
similarly to NiMnX Heusler alloys, it has been found that PdMnSn Heusler alloys
show metamagnetic shape memory effects and a drastic change with martensitic
transformation in magnetic and transport properties. In this study, in order to investigatepressure effect on martensitic transformation in PdMnSn Heusler alloys, we performed
electrical resistivity measurements under high pressure. As a result, it was found thatthe pressure-temperature phase diagram is similar to the temperature-Mn content phase
diagram. These results suggest that the atomic distance plays an important role formartensitic transformation in PdMnSn Heusler alloys.

July 9 (Mon)

Yoshihiro Kikuchi*, Yoshiki Imai and Tetsuro Saso
Department of Physics, Saitama University, Japan

July 9 (Mon)poster Presentation[1] T.Kanomata et al.: J. Magn. Magn. Mater 65 (1987) 76. [2] M. Kataoka et al.: Phys. Rev B 82
(2010) 214423.

PF18

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PG08

The ground state energies of spinless free fermions and hard-corebosons in 2D square lattices

Evolution of reverse magnetized seed in monodomain uniaxial garnet
film elements

Electronic state of Cr and collapse-like decrease of Fe magnetic
moment in amorphous (Fe-Cr)B alloys

Engineering of Co atomic 1-D chains on Ag(111) with tailored magnetic
ground state

We compare the ground state energies of hard-core bosons and spinless free fermionson the same lattice. Ground state energy of bosons is usually expected to be lower
than that of fermions, because bosons can condense into the lowest energy state.
However, in the presence of hard-core interaction among bosons, the condensation is
not perfect and comparison is nontrivial. We find that, in the absence of frustration, theground state energy of hard-core bosons is indeed lower than that of free fermions. In
general, however, the hard-core bosons could have higher ground state energy than thefermions on the same lattice if there is a frustration. In fact, there is an exactly solvable
one-dimensional model, in which the ground state energy of bosons is proved to behigher. However, the difference vanishes in the thermodynamic limit. We also studied
the two-dimensional square lattice with uniform magnetic flux perpendicular to thelattice, by numerical diagonalization. As the magnetic flux introduces frustration, we
actually find the ground state energy of hard-core bosons is higher for a range of flux
and particle density. In the two dimensional case, this difference seems to persist in thethermodynamic limit, in contrast to the one-dimensional case.

Evolution of cylindrical domain seeded in monodomain film and film circular element
was investigated numerically and experimentally. It is found that in continuous film inzero external magnetic field cylindrical domain may expand unlimitedly or collapse
independently on initial diameter of the seed. Single seed expansion followed byfilm magnetization reversal is observed if l/h < 1.38 (where l is garnet characteristic
length, h is film thickness). Constant positive external magnetic field antiparallel
to magnetization inside seed supports stable domain diameter which is inverse
proportional to field intensity H. Cylindrical domain inside disk is found stable inzero and negative external magnetic field due radial gradient of inhomogeneous strayfield of the disk boundary. If l/h > 1.38 reverse magnetized seed collapses in zeroexternal field. Stable domain doesn’t exist in constant negative external field parallel
to seed magnetization this case. Unlimited domain expansion takes place if modulusof negative H exceeds critical value which is inverse proportional to initial seeddiameter. Domain is stable if domain wall embraces circular hole in garnet film. Thiscase garnet boundary stray field prevents from domain contraction in zero and positive
external field. Two-domain ring-shape elements can be utilized as fast magnetoopticalmodulators.

Wenxing Nie1 and Masaki Oshikawa2*
1
The Institute for Solid State Physics, The University of Tokyo, Japan2
The institute for Solid State Physics, The University of Tokyo, Japan[1]Phys. Rev. B 14, 2239 (1976) [2]Phys. Rev. Lett. 83, 2246(1999) [3]Phys. Rev. Lett. 96, 036406(2006)

Vladimir Skidanov*Nanoelectronics and Spintronics Department, Institute for Design Problems in
Microelectronics RAS, Russia

Kazuo Yano1*, Tastuo Kamimori2, Hiroaki Kanetsuki2, Hatsuo Tange2, Masayoshi
Itou3, Yoshiharu Sakurai3, Eiji Kita4 and Hiromitsu Ino5
1
College of Science and Technology, Nihon University, Japan
2
Faculty of Science, Ehime University, Japan
3
JASRI/SPring8, Japan
4
Applied Physics, University of Tsukuba, Japan
5
Faculty of Engineering, University of Tokyo, Japan

Magnetic properties in amorphous alloys have been extensively investigated in rare earth (RE)-transition
metal (TM) systems and transition metal (TM)-mettaloids systems. Many interesting and important
problems have been investigated and solved, however, some of the important problems seem to be hardnuts to crack and remain unsolved. One of the unsolved and interesting problems is an anomaly in SlaterPauling curve discovered by Mizoguchi et al. and the Fe magnetic moment decreases abruptly, for examplein (Fe-Cr)80B20 amorphous alloys. For instance, the substitution of Fe by only 10 at% of Cr causes about
50 %decrease of Fe magnetic moment. Mizoguchi et al. suggested that the Cr retained magnetic moment
and coupled anti-parallel to that of Fe, however there have been no decisive experimental results. In orderto detect and examine the Cr magnetic moment, one of the powerful tools for this aim, is the magnetic
Compton scattering profile (MCP) method which can obtain the infornmations of 3d electrons and thespin-polarized outer 4s, 4p electrons, separately. The MCP measurement was carried out for (Fe-Cr)80B20(Cr=0.1, 0.2, 0.3) and the result suggest the existence of Cr magnetic moment coupling antiparallel to thatof Fe. Macroscopic magnetic properties were also measured and analyzed.

Certain magnetic adatoms lying on a metal surface give rise to a Kondo resonance. We used themodel system of Co atoms on Ag(111) to investigate their magnetic interactions through the Kondo
resonance [1,2] . The Co atoms architecture and the substrate LDOS landscape are artificiallyarranged by means of lateral manipulation with a scanning tunneling microscope (STM) tip at 4.8
K. The resonance is subsequently characterized by means of STM spectroscopy. Individual Co
atoms in natural equilibrium positions at minima of the surface LDOS exhibit Kondo temperature
TK=90 K in agreement with earlier studies [3]. TK can be gradually varied from 60 to 145 K bypositioning the same atom in different Ag LDOS values of the interference patterns. The coordination
with neighboring Co atoms increases TK when their distance decreases below four Ag(111) lattice
parameters (2.9 A). In Co chains with N atoms (N=2,3,...,19), both the amplitude and the spatial extent
of the many-body wave function of the Kondo resonance are reduced with increasing coordination. In
the frame of the two impurity Kondo theory, our data unveil the nature of direct Co-Co and substrate
mediated magnetic interactions as a function of the local electronic and structural environment.
[1] A. Otte et al., Nature Phys. 4, 847 (2008) [2] J. Bork et al., Nature Phys. 7, 901 (2011) [3] M.A.
Schneider et al., Phys. Rev. B 65, 121406R (2002)

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Correlation effect in ferromagnetic 3d transition metals

Re-entrant structure and critical behaviour of Fe-Cr and Fe-V sigmaphase alloys

Micromagnetic simulation of CNT-MFM probes under magnetic field

Pressure-induced suppression of magnetic ordering in a chiral magnet
Cr1/3NbS2

Muneyuki Nishishita1, Sudhakar Pandey2 and Dai Hirashima1*
1
Nagoya University, Japan
2
APTPC, Korea

Selfconsistent perturbation theory is applied to ferromagnetic 3d transition metals, Fe
and Ni. Realistic tight-binding model is used to describe the electronic states of thesystem. It is found that a reasonable value of the Curie temperature for Fe is obtained
for realistic strength of the Coulomb interaction. Dynamical transverse susceptibility
is also calculated. Here, vertex corrections are considered so that the spin rotational
symmetry is preserved. Then, the spin-wave energy correctly vanishes in the longwavelength limit. The effect of the electron correlation on the spin stiffness is clarified.
We also compare the spin fluctuation spectra below and above the Curie temperatureand discuss the possible short-range order above the Curie temperature.

Reginaldo Barco1, Paulo Pureur1, G L F Fraga1 and Stanislaw M Dubiel2
1
Physics, UFRGS Porto Alegre, Brazil
2
Physics and Applied Computer Science, AGH University Krakow, Poland

The σ-phase (tetragonal unit cell, space group D144h-P42/mnm) belongs to a familyof a complex Frank-Kasper phases. It can be formed in transition-metal alloys. Only
two alloys, among about 50 examples of σ known to occur in binary systems, viz. FeCr and Fe-V have well-evidenced magnetic properties. The magnetic ordering of σhas been regarded as ferromagnetic (FM) with the Curie temperatures, Tc, below ~40
K for σ-FeCr and below ~315 K for σ-FeV. Here we report a clear evidence that the
ground state of the σ-phase Fe0.53Cr0.47 and Fe0.52V0.48 alloys is a re-entrant spin-glass(RSG). The evidence was found from a study of magnetization versus temperature, T,
and magnetic field, H. Based on the field-cooled and zero-field-cooled magnetization
curves recorded in different fields, H, phase diagrams in the H-T plane could have beendrawn. They display the location of the paramagnetic (P), FM and RSG states, and arein a qualitative accord with predictions of the mean-field theory. Critical behaviour near
Tc was also studied with both conventional and extended protocols, and the criticalexponents β, γ, δ were determined.

Takashi Manago1*, Hironori Asada2 and Hiromi Kuramochi3
1
Department of Applied Physics, Fukuoka university, Japan
2
Graduate School of Science and Engineering, Yamaguchi university, Japan
3
International Center for Materials Nanoarchitectonics, National Institute forMaterials Science(NIMC), Japan
Ferromagnetic-film-coated carbon nanotube in a magnetic force microscope (CNTMFM) demonstrated the high spacial resolution of about 10 nm and low perturbation.
The magnetic strucutres of CNT-MFM probes were investigated using threedimensional micromagnetic simulation and it showed the advantages of the CNT-MFM
probes [1]. In this paper, the stability of the magnetic structure in external magnetic field
was investigated to confirm magnetic robustness using micromagnetic simulation. At aremanent state, the magnetic moments of the CNT-MFM probe align almost along thelongitudinal direction of the CNT lod due to the shape anisotropy. When the opposite
magnetic field applied, the magnetic moments of the probes reversed all at once at
about 200 mT. In the pyramidal probe, the vortex core was appeared around the tip at
a remanent state. When the opposite magnetic field applied, the magnetization of theside wall gradually tilted, and at last the vortex core was reversed. Thus magnetization
reversal process is quite different because of large difference in magnetic structures
between the CNT-MFM and pyramidal probes. We found that the CNT-MFM probes
have better magnetic robustness than the conventional pyramidal probes.
[1] T. Manago et al., Nanotechnology, 23, 035501 (2012).

142

David Serrate1*, Maria Moro1, Marten Piantek2, Jose Ignacio Pascual3 and ManuelRicardo Ibarra1
1
Instituto de Nanociencia de Aragon, University of Zaragoza, Spain
2
Instituto de Ciencia de Materiales de Aragon, CSIC-University of Zaragoza, Spain
3
Institut fur Experimentalphysik, Freie Universitat Berlin, Germany

The 19th International Conference on Magnetism

Takumi Imakyurei1, Kousuke Nagai1, Masaki Mito1, Hiroyuki Deguchi1, Jun-ichiro
Kishine1, Takayuki Tajiri2, Katsuya Inoue3, Yuya Nakao4, Yusuke Kousaka4 and Jun
Akimitsu4
1Faculty of Engineering, Kyushu Institute of Technology, Japan
2
Faculty of Science, Fukuoka University, Japan3
Department of Chemistry and Institute for Advanced Materials Research, Hiroshima
University, Japan
4
Department of Physics and Mathematics, Aoyama-Gakuin University, Japan

Cr1/3NbS2 is a chiral magnet without structural inversion center. The magnetic property
is attributed to the localized moment of Cr, and metallic conductivity is attributed
to conduction electrons of Nb. We expect that Cr1/3NbS2 would become a noncentrosymmetric superconductor after disappearance of magnetic ordering at highpressure. Thus we carried out the AC susceptibility measurements at pressures up to 10
GPa and powder X-ray diffraction experiments at room temperature up to 7 GPa forthe powder sample of Cr1/3NbS2. In the pressure region of below 3 GPa, the anomaly
of magnetic susceptibility due to the magnetic ordering shifted toward low temperatureside and the magnitude was gradually suppressed. At present, the Meissner signal has
not yet been observed in the temperature region down to 2 K and the pressure region
up to 10 GPa. The lattice parameters exhibited the change of contraction at around 3
GPa, where it became difficult to evaluate the magnetic ordering temperature.

July 8-13, 2012 Busan, Korea

143

poster Presentation
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Multiple ESR spectra in a chiral molecule-based magnet [Cr(CN)6][Mn(R )-pnH(H2O)](H2O)

Electron correlation in a mixed valence perovskite system of Sr1xCaxRu0.5Mn0.5O3

Raman scattering of metal-insulator transition in Cd2Os2O7

Magnetic and electrical transport behavior of Ir substituted NiTi
shape memory alloy

Tomohiro Ohnishi1, Soichiro Mizusaki1, Makoto Naito1, Yoshihiko Noro2, Masayoshi
Itou3, Yoshiharu Sakurai3 and Yujiro Nagata1
1
Electrical Engineering and Electronics, Aoyama Gakuin Univ., Japan
2
Kawazoe Frontier Technologies Co. Ltd., Japan
3
Japan Synchrotron Radiation Research Institute, Japan

Cd2Os2O7 is a pyrochlore oxide showing metallic behavior at room temperature,and it shows metal-insulator transition at 225 K [1]. It has been suggested that thismetal-insulator transition is caused by magnetic order [1,2], because any superlatticereflection has not been observed by x-ray and neutron [3] diffraction measurements.
However, to conclude no structural distortion precisely below the transition
temperature, it is necessary to perform symmetry sensitive measurements rather
than diffractions. Raman scattering method is a sensitive tool to observe small lattice
distortion with symmetry breaking. We have measured Raman spectra of Cd2Os2O7
from 4 K to 300 K to investigate possibility of structural distortion in the insulator
phase. Below the transition temperature, we have not observed any new peak indicating
symmetry breaking from the pyrochlore structure with the space group Fd3m.

A molecule-based magnet [Cr(CN)6][Mn(R)-pnH(H2O)](H2O) (abbreviated as R-GN) is a chiralmagnet without inversion center and mirror reflection. The magnetic network is constructed withthe help of a chiral ligand diaminopropane. In R-GN, multiple spectra of ESR were observed
below magnetic order temperature by Morgunov et al. [1]. They concluded that the phenomenon
was caused by the formation of a chiral soliton lattice, which originated from incommensurate
magnetic structure. However, we have a suspicion against their interpretation, because R-GN
indeed exhibits no incommensurate magnetic structure. Now, we conducted the experiment ofX-band ESR measurement in the condition similar to the experiment by Morgunov et al., andperformed the detailed spectrum analyses: In order to reproduce the main ESR spectra, at least
two Lorentz spectra are required, and the multiplicity was explained by assuming the existenceof two characteristic modes when each periodicity is defined as f or f’ (< f), there is a relation of
f = 2f’. We consider that the magnetic fine structure originates from the existence of at least two
nonequivalent magnetic sites owing to the diaminopropane with electric dipole moment.

Mixed valence systems are interesting for their fundamental and practical properties. Perovskite-typeoxides Sr1-xCaxRu1-yMnyO3 is a typical mixed valence system.¹ The host itinerant system Sr1-xCaxRuO3shows various interesting properties such as ferromagnetism and paramagnetism.²,³ Mn-substitution
induces a mixed valence state of Ru4+, Ru5+, Mn4+ and Mn3+ ions and localized ferromagnetism.¹,4 However,understanding of the electron correlation in the mixed valence systems is not yet enough. In this work,
we studied the relationship between electron correlation and mixed valence state through the experiments
for Sr1-xCaxRu0.5Mn0.5O3 using the traditional experimental methods and the synchrotron-based magnetic
Compton scattering. Sr1-xCaxRu0.5Mn0.5O3 is a good system since the Ca-substitution will modify crystal
symmetry and change the electron correlation. The following results have been obtained; 1. Cell volume
decrease for Ca substitution. 2. insulator-metal transition occurs for Ca substitution. 3. Ferromagnetism
appears at x ~ 0.3. 4. Antiferromagnetic coupling between Ru and Mn. These facts can be explained asfollows. The decrease in the cell volume enhances the hybridization between Ru and O orbitals inducing
itinerant electrons. The itinerant electrons enhance the formation of a ferromagnetic order of Ru ions. Mn
ions couples antiferromagnetically with Ru ions by a superexchange interaction via O 2p orbitals.

[1] R. Morgunov et al., Phys. Rev. B 77 (2008) 184419.

1. M. Naito et al., J. Appl. Phys. 103 (2008) 07C906-1. 2. A. Kanbayashi, J. Phys. Soc. Jpn. 44 (1978) 108. 3.
T. Kiyama et al. Phys. Rev. B 54 (1996) R756. 4. T. Taniguchi et al. Phys. Rev. B 77 (2008) 014406-1.

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Valence and spin structures of TFe2O4 spinel oxides (T=Mn, Co, Ni,Cu) investigated by using synchrotron radiation

An x-ray scattering study of magnetic order in a pyrochlore iridate
Eu2Ir2O7

Effects of impurities in the chromic compound CuMoO4

Jihoon Hwang1, D. H. Kim1, Eunsook Lee1, J.-S. Kang1, B.-G. Park2, J.-Y. Kim2, S. W.
Han3, S. C. Hong3, S. B. Kim4, Bongjae Kim5 and B. I. Min5
1
Department of Physics, The Catholic University of Korea (CUK), Bucheon 420-743, Korea
2
Pohang Accelerator Laboratory, POSTECH, Pohang 790-784, Korea
3
Department of Physics, Ulsan University, Ulsan 680-749, Korea
4
ACE center, Konyang University, Nonsan 320-711, Korea
5
Department of Physics, POSTECH, Pohang 790-784, Korea
AB2O4-type spinel oxides have attracted much attention because of the interesting physical phenomena, such as
Jahn-Teller (JT) effects, multiferroic phenomena, and phase separations [1]. In normal spinels of AB2O4, A and
B ions occupy the tetrahedral (Td) and octahedral (Oh) sites, respectively. When both A and B ions are magnetic
ions, a ferrimagnetic (FiM) ordering is often observed because the A-B interaction is mainly antiferromagnetic.
In this work, we have investigated the electronic structures of FiM spinels of TFe2O4 (T=Mn, Co, Ni, Cu) byemploying soft x-ray absorption spectroscopy (XAS) and soft x-ray magnetic circular dichroism (XMCD). It isfound that the valence states of Fe ions are nearly trivalent (-Fe3+) and those of T ions are nearly divalent (-T2+).
The 2p XMCD spectra of MnFe2O4 show that the magnetic moments of Mn2+ and Fe3+ ions are antiparallel toeach other. On the other hand, the magnetic moments of Co2+, Ni2+, and Cu2+ ions are parallel to those of B(Oh)site Fe3+ ions, but are antiparallel to those of A(Td)-site Fe3+ ions, implying that Fe3+ ions occupy both A and B
sites while Co, Ni, Cu ions occupy mainly B sites. *Corresponding Author: kangjs@catholic.ac.kr

Daisuke Uematsu1*, Hajime Sagayama1, Taka-hisa Arima1, Jun J Ishikawa2 andSatoru Nakatsuji2
1
Department of Advanced Materials Science, The University of Tokyo, Japan
2
Institute of Solid State Physics, The University of Tokyo, Japan
The pyrochlore iridate Eu2Ir2O7 undergoes a metal-insulator transition at T_{MI} = 120
K [1]. Since the magnetic Ir4+ ions occupy the pyrochlore B-site, strong geometricalspin frustration is predicted.Nevertheless, a muon spin rotation study [2] indicatedlong-range orderings spins of Ir4+. To determine the spin configuration, we have
performed the resonant X-ray diffraction measurement at the LIII edge of Ir. A clear
magnetic reflection was found at (10,0,0) below T_{MI}. The result proposes the allin-all-out-type magnetic structure.
[1] K. Matsuhira et al., J. Phys. Soc. Jpn. 76, 043706 (2007). [2] S. Zhao et al., Phys. Rev. B. 83,
180402 (2011).

[1] J.-S. Kang, et al., Phys. Rev. B 77, 035121 (2008).

[1] A. W. Sleight, J. L. Gillson, J. F. Weiher and W. Bindloss, Solid State Commun. 14, 357(1974). [2]
D. Mandrus, et al., Phys. Rev. B 63, 195104(2001). [3] J. Reading and M. T. Weller, J. Mater. Chem.
11, 2373(2001).

Takayuki Asano1*, Taizo Nishimura1, Katsutaka Kubo1, Minoru Sanda1, Keisuke
Matsuura1, Akira Matsuo2, Yasuo Narumi3 and Koichi Kindo2
1
Department of Physcs, Kyushu University, Japan
2
Institute for Solid State Physics, University of Tokyo, Japan
3
Institute for Materials Research, Tohoku University, Japan
Recently interest in “Chromism” phenomena for compounds may be attributed to
the fact that a reversible color change of organic and inorganic materials can occur as
the compound experiences various changes in its environmental conditions. Copper
molybdate, CuMoO4, has demonstrated attractive properties of both thermochromism
and piezochromism that are induced by a structural phase transition. We report atunable structural phase transition and magnetic phenomena using substitutional effects
in Cu1-xZnxMoO4(0≤x≤0.1), CuMo1-yWyO4(0≤y≤0.1), and CuMo1-zCrzO4(0≤z≤0.1) overwide ranges of temperatures and magnetic fields. The substitution of magnetic Cu2+ions for nonmagnetic Zn2+ ions causes the hysteresis in the structural phase transition
to shift to remarkably lower temperatures as x increases by means of magnetic
susceptibility measurement. In contrast, replacing Mo6+ ions with W6+ ions results
in a shift of the hysteresis and the structural phase transition to higher temperatures
as y increases. However, in the case of replacing the Mo6+ ions with Cr6+ ions, thestructural phase transition around 200K is completely disappeared and a ferromagnetic
component is induced below 150K as z increases. We are going to discuss the reasonof the shifting structural phase transitions and also show the magnetic properties under
extreme conditions.

Sandhya Dwevedi* and A.k Nigam
Department of Condensed Matter Physics and Material Sciences, Tata Institute ofFundamental Research(TIFR), Mumbai 400 005, India

NiTi shape memory alloys (SMAs) show attractive functional properties for anumber of engineering and medical applications [1]. Recently. Somsen et.al [2] havesynthesized the novel Ni-Ti-Ir alloys and have studied its structural properties. This
motivates us to study the other properties of the alloy. In the present work, we havesystematically studied the structural, kinetics, magnetic and transport properties of theNi-Ti-Ir alloy. The alloy is formed in the B2- type phase with a small amount of Ti2NiIr
as an additional phase. In the DSC curve, two distinct peaks are observed on heating
and cooling. These peaks correspond to the Martensitic transformations (MT) fromthe B2 to R-phase and from R to B19’-phase on cooling and, a reverse transformationfrom B19’-R-B2 phase on heating, respectively. From the temperature dependence ofresistivity curve, the Martensitic Start (MS), Martensitic Finish (Mf), Austenite Start (AS)and Austenite Finish (Af) temperatures are found to be 193 K, 153 K, 267 K and 293 K
respectively. In the Magnetization versus temperature (M-T) curve, no evidence of theferromagnetic ordering temperature is observed. However, the Magnetization versus
Field (M-H) curve at 5 K and 300 K shows existence of ferromagnetic order in the alloy.
[1]K. Otsuka, C. M. Wayman, Shape Memory Materials(Cambridge University Press) [2]Ch.
Somsen, J. Khalil-AllaFib, E.P. George, Mater. Sci. Eng. A, 378, 170-174 (2004)

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X-ray diffuse scattering of pyrochlore niobium oxides R2Nb2O7

Shingo Toyoda1, Hajime Sagayama1, Kunihisa Sugimoto2 and Takahisa Arima1*
1
Department of Advanced Materials Science, The University of Tokyo, Japan
2
SPring-8, Japan
It was reported that Y2Nb2O7 is a non-magnetic insulator, although the electron
configuration of Nb4+ is 4d1 with S=1/2. To reveal the origin, we have performed
X-ray scattering measurement of single crystals of R2Nb2O7 (R=Y,Sm,Dy,and Ho). All
the compounds show diffuse scattering, indicating that there exists short-range order.
Analysis of the average structure suggests that Nb ions are displaced along the (111)
direction. The formation of spin-singlet tetramers cannot explain the observed diffuse
pattern. The short-range correlation implies the formation of spin-singret dimmers,
because the configuration of dimmers in a pyrochlore latiice can be mapped on the icerule problem. In addition, the diffuse pattern changes with R. The diffuse of Y2Nb2O7 isthe broadest, while that of Dy2Nb2O7 is narrowest and almost spot.
[1] H. Fukazawa , Y. Maeno, Phys. Rev. B 67, 054410 (2003)

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Probing the distance dependence of the magnetic exchange interaction
with atomic resolution

Magnetic structure analyses by small-angle electron diffraction

Effective exchange interactions in 5d transition metal oxides

Freezing of local lattice strains in the magnetic martensitic/ferroelastic
material system

Alexander Schwarz1*, Rene Schmidt1, Roland Wiesendanger1, Cesar Lazo2 and Stefan
Heinze31Institute of Applied Physics, University of Hamburg, Germany
2
Christian-Albrechts Universitat zu Kiel, Germany
3
Christian-Albrechts-Universitat zu Kiel, Germany

Quantifying strength and distance dependence of magnetic interactions between atoms is crucial
to gain a deeper understanding of magnetic phenomena on the nanoscale. Magnetic exchange
force microscopy (MExFM) [1] is a new and very versatile tool to study magnetism with atomic
resolution in real space. It utilizes an atomically sharp magnetic tip at the free end of a cantilever
to detect the short-ranged electron-mediated magnetic exchange interaction between tip apex andsurface atoms. This force microscopy based technique can be employed to map spin structuresof insulating [1] as well as conducting [2] magnetic samples with atomic resolution. Here wedemonstrate that its spectroscopic mode, i.e., magnetic exchange force spectroscopy (MExFS),
is able to measure the distance dependence of the magnetic exchange interaction in a very direct
and elegant fashion [3]. Results obtained on the antiferromagnetic Fe monolayer on W(001) arecompared with theoretical calculations based on density functional theory. They were performed
for realistic multiatom tips and agree very well with data acquired using non-dissipative stable tips.
[1] U. Kaiser, A. Schwarz, and R. Wiesendanger, Nature 446, 522 (2007). [2] R. Schmidt, C. Lazo, H.
Holscher, U. H. Pi, V. Caciuc, A. Schwarz, R. Wiesendanger, and S. Heinze, Nano. Lett. 9, 200 (2009). [3] R.
Schmidt, C. Lazo, U. Kaiser, A. Schwarz, S. Heinze, and R. Wiesendanger, Phys. Rev. Lett. 106, 257202 (2011).

144

Takumi Hasegawa1*, Norio Ogita1, Jun-ichi Yamaura2, Zenji Hiroi2 and Masayuki
Udagawa1
1
Graduate School of Integrated Arts and Sciences, Hiroshima University, HigashiHiroshima, Hiroshima 739-8521, Japan
2
Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581,
Japan

The 19th International Conference on Magnetism

Yoshihiko Togawa1*, Tsukasa Koyama2, Shigeo Mori2 and Ken Harada2
1
Nanoscience and Nanotechnology Research Center (N2RC), Osaka Prefecture
University, Japan2
Department of Materials Science, Osaka Prefecture University, Japan
Electrons are deflected at small angles by Lorentz force in magnetic materials. In magnetic
elements in functional materials and spintronic devices, observation of Lorentz deflection ofelectrons at the small angle turns to be of significance because Lorentz deflection angle ofelectrons becomes smaller in modern miniaturized magnetic devices composed of thinnermagnetic films. In the present work, electron optical system is constructed in order to obtainsmall angle diffraction and Lorentz deflection of electrons at the order of down to 10-6
radian in the reciprocal space[1]. Long-distance camera length up to 3000 m is achievedin a conventional transmission electron microscope with LaB6 thermal emission type.
The diffraction pattern at 5 × 10-6 radian is presented in a carbon replica grating with 500
nm lattice spacing while the magnetic deflection pattern at 2 × 10-5 radian is exhibited in
Permalloy elements. A simultaneous recording of electron diffraction and Lorentz deflectionis also demonstrated in 180 degree striped magnetic domains of La0.825Sr0.175MnO3[2].
We believe that small-angle Bragg diffraction and Lorentz deflection analyses provide aquantitative way to analyze structural and magnetic properties in the reciprocal space. This
study is partly supported by SCOPE project from the MIC in Japan.
[1] T. Koyama, K. Takayanagi, Y. Togawa, S. Mori, and K. Harada, submitted. [2] T. Koyama, Y.
Togawa, K. Takenaka, and S. Mori, to appear in J. Appl. Phys.

Tomonori Shirakawa*, Hiroshi Watanabe and Seiji Yunoki
Computational Condensed Matter Physics Laboratory, RIKEN, Japan

5d transition metal oxides, Sr2IrO4 and Ba2IrO4, have attracted much attention
because of their unique properties caused by a strong spin-orbit coupling for 5dtransition element. Both of these compounds behave as Jeff=1/2 Mott insulator at low
temperature [1,2,3]. Recently, these compounds are expected to be a superconductor
as an analogous system to high-Tc cuprates. According to recent experimental results
on magnetic susceptibility and μSR studies, the effective exchange interactions in
Sr2IrO4 and Ba2IrO4 are expected to be very large, and comparable to the ones of highTc cuprates [3]. Motivated by these experiments, we have studied theoretically theelectronic and magnetic properties of Sr2IrO4 and Ba2IrO4 using a three-band Hubbard
model with the spin-orbit coupling [4]. We first obtain the phase diagram of 8-sitecluster in a wide parameter region using exact diagonalization technique. We find that
there are several phases including the Jeff=1/2 Mott insulating phase which is realizedin Sr2IrO4 and Ba2IrO4. We then calculate the dynamical spin structure factor composedby the Jeff=1/2 state in the Jeff=1/2 Mott insulating phase. We then estimate thevalues of effective exchange interactions by comparing the results with the ones of aneffective spin model.
[1] B. J. Kim et al., Science 323 (2009) 1329. [2] B. J. Kim et al., Phys. Rev. Lett. 101 (2008)
076402. [3] H. Okabe et al., Phys. Rev. B 83 (2011) 155118. [4] H. Watanabe et al., Phys. Rev. Lett.
105 (2010) 216410.

July 9 (Mon)

Takuma Nagano1, Masaki Mito1, Seishi Takagi1, Hiroyuki Deguchi1, Jun-ichiro
Kishine1, Yusuke Yoshida2 and Katsuya Inoue2
1
Faculty of Engineering, Kyushu Institute of Technology, Japan2
Department of Chemistry and Institute for Advanced Materials Research, Hiroshima
University, Japan

July 9 (Mon)poster Presentation

Yu Wang*, Chonghui Huang, Xiaoping Song and Xiaobing Ren
Xi'an Jiaotong University, China

Glass state is a frozen disordered state, in which the long range order is destroyed
but short range order persists. Recently, a new glass phenomenon called strain glass
was found in the martensitic/ferroelastic material system [1]. The strain glass stateis a frozen disordered state of local lattice strains (nanosized martensitic/ferroelastic
domains). Experimental measurements show that strain glass possesses obvious glassy
features including dynamic freezing and breaking down of ergodicity in its mechanicalproperties [1, 2], being similar to the glassy features of the cluster-spin glass withfroze local spin order. Strain glass can be obtained by doping point defects into normalmartensitic/ferroelastic system [1]. However, whether strain glass can be achievedin the defect doped magnetic martensitic/ferroelastic system is unknown so far. In
this study, we report that a strain glass transition with freezing of local lattice strains
can exist in the Co doped magnetic martensitic system Ni-Mn-Ga by using dynamic
mechanical analysis. Moreover, our magnetic measurements show that the strain glassin the Co doped Ni-Mn-Ga system is ferromagnetic, which is a new form of strain
glass. The finding of the strain glass in magnetic martensitic/ferroelastic system maylead to novel applications.
[1] S. Sarkar, X. Ren and K. Otsuka, Phys. Rev. Lett. 95, 205702(2005) [2] Y. Wang, X. Ren, K.
Otsuka, and A. Saxena, Phys. Rev. B 76, 132201(2007)

July 8-13, 2012 Busan, Korea

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poster Presentation
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Magnetic structure of the new chiral compound [Cr(CN)6][Mn(S)pnH(DFM)](H2O)

Ferromagnetism in hydrothermally treated glassy carbon

Ionic size effect on the spin gap nature of SrCu2(TeO3)2Cl2

Interplay of magnetic order and structural distortions in multiferroic
GdMnO3 single crystals

Research on magnetic molecular materials has received strong attention in the last years forseveral reasons, among them, the possibility of these materials to be multifunctional, thus
exhibiting more than one functional property at the same time. A very interesting possibility ina molecular material is magneto-chirality. Despite this interest, very few molecular candidates
with likely possibilities have been synthesized, because chirality must be controlled in themolecular structure and at the same time the crystal must exhibit nuclear chirality. In addition,
the arrangement of the magnetic moments must also be chiral. Nowadays, single crystals of
the cyano-bridged bimetallic complexes have been growth, a 2D chiral ferrimagnet [Cr(CN)6][Mn(R)-pnH(DMF)]•(2H2O) (1) and a racemic one [Cr(CN)6][Mn(rac)-pnH(DMF)]•(2H2O)(2), where DFM is N,N-dimethylformamide. Compound 1 consists of two-dimensional
bimetallic sheets, with the same space group P212121, whereas compound 2 crystallizes under
Pnma [1]. These compounds have been studied employing neutron diffraction techniques at theInstitute Laue Langevin. In this communication, we present the nuclear and magnetic structuresfor (1) and (2). The coexistence of nuclear and magnetic chirality has been demonstrated.

Hyun Jin Cho, Kyu Won Lee and Cheol Eui Lee*
Department of physics and institute for Nano Science, Korea University, Korea
We have investigated the magnetic properties of pristine and hydrothermal-treatedglassy carbon by means of superconducting quantum interference device (SQUID)
and electron spin resonance (ESR) measurements. The magnetic properties of thehydrothermally treated glassy carbon showed a sensitive dependence on the solventsand the treatment time. In particular, prominent ferromagnetism was observed insamples hydrothermally treated in ethanol for a properly chosen time, with thesaturation moment and coercive force being comparable to those of iron. The
ferromagnetism in the hydrothermally treated glassy carbon may have to do with therelative fractions of the sp3- and sp2-bonds.
[1] X Wang et al 2002 J. Phys.: Condens. Matter 14 10265

C. N. Kuo, S. C. Chen and C. S. Lue*
Department of physics,, National Cheng Kung University, Tainan 70101, Taiwan,
TaiwanWe report the effects of partial substitution of Br onto the Cl sites of SrCu2(TeO3)2Cl2
by means of magnetic susceptibility measurements. This material has been a subjectof current interest due to indications of spin gap behavior. However, the magnetic spin
couplings responsible for the spin gap nature remains unclear. For each composition of
SrCu2(TeO3)2(Cl1-xBrx)2, the temperature-dependent susceptibility exhibits a characterof low-dimensional magnetism with a broad maximum at Tmax. The magnitude
of Tmax gradually shifts to higher temperatures as increasing the Br concentration.
The experimental data can be well fitted to a coupled spin dimer model, yielding an
increasing trend for the spin gap size from 170 K to 190 K. It thus points out thatthe substitution of Br ions has an effect to reduce the distance between Cu(1) andCu(2), leading to a stronger antiferromagnetic spin interaction. On the other hand,the variation of the interdimer coupling is marginal, indicative of weak effects on the
distances of Cu(1)-Cu(1) and Cu(2)-Cu(2) in SrCu2(TeO3)2Cl2.

[1] H. Imai, K. Inoue, K. Kikuchi, Polyhedron 24, 2808-2812(2005)

PG23
Origin of spin scalar chiral order in frustrated Kondo lattice model- higher-order Kohn anomaly and hidden positive biquadraticinteraction Yutaka Akagi1*, Masafumi Udagawa2 and Yukitoshi Motome1
1
University of Tokyo, Japan
2
University of Tokyo, MPI PKS, Japan

Recently, noncoplanar spin configurations with scalar chirality have drawn considerable attention as an
origin of the anomalous Hall effect. In this mechanism, itinerant electrons acquire an internal magnetic
field through the Berry phase according to the solid angle spanned by three spins, which can result in theanomalous Hall effect. In order to clarify how such nontrivial magnetic states appear in spin-charge coupledsystems, we investigate a ferromagnetic Kondo lattice model on a triangular lattice by variational andperturbative calculations. As a result, we find that a noncoplanar four-sublattice spin ordering emerges near
1/4-filling [1], in a wider parameter region compared to the nesting-driven 3/4-filling phase predicted in theprevious study. We unveil that a kinetic-driven positive biqaudratic interaction is critically enhanced andplays a crucial role on stabilizing a chiral ordering near 1/4-filling. The origin of large positive biquadraticinteraction is ascribed to the Fermi surface connection by the four-sublattice ordering wave vectors, which
we call the higher-order Kohn anomaly [2]. Similar hidden interactions and resultant noncoplanar states
are also found in other frustrated lattices, such as fcc and pyrochlore lattices. Our results suggest a universal
mechanism underlying nontrivial spin configurations in frustrated spin-charge coupled systems.
[1] Y. Akagi and Y. Motome, J. Phys. Soc. Jpn. 79 (2010) 083711. [2] Y. Akagi, M. Udagawa, and Y.
Motome, preprint (arXiv:1201.3053), accepted for publication in Phys. Rev. Lett.

On the structure and symmetry of the spin glass state (SGS)
Jerzy Warczewski*, Pawel Gusin and Daniel Wojcieszyk
Institute of Physics, University of Silesia, Poland

The explanation of uniqueness of SGS has roots in the appearance of a certain
probability function in the second term of the assumed Hamiltonian [1, 2]. This term
describes the random distribution of either dopants or defects in the ferromagnetic
matrix under the percolation threshold. The Gaussian type randomness was derived forboth the global magnetic coupling constant and the magnetization vector M, the latter
effect bringing to the statistical features of the magnetic structure and the magnetic
symmetry group of SGS. In both cases the use has been made of the central limit
theorem of the theory of probability (the Lyapunov theorem) [3]. The authors haveearlier proved that a certain spontaneous minimum magnetic field H is necessary forthe stability of SGS [4]. The structure of SGS can then be described in such a way that
M is situated along a generatrix of a given cone whose axis coincides with the directionof H [4]. Let us call φ the angle between M and H. Any precession of M around the
direction of H at φ = const (at constant energy) makes the symmetry operation of SGS.
Thus the symmetry group of this precession is SO(2) [3].
[1] J. Warczewski, P. Gusin et al., Journal of Non-Linear Optics, Quantum Optics 30 (2003), 301320 [2] P. Gusin, J. Warczewski, Mol. Cryst. Liq. Cryst. 521 (2010), 288-292 [3] J. Warczewski, P.
Gusin, D. Wojcieszyk, Mol. Cryst. Liq. Cryst. 554 (2012), 209-220 [4] J. Warczewski, P. Gusin et al.,J. Phys.: Condens. Matter, 21 (2009), 035402-035407

PH02

Multiferroics are candidates for magneto-electrical applications. Magnetic and dielectric phenomena
in orthorhombic GdMnO3 are strongly intertwined. In addition, electrically induced magnons exist.
Magnetostriction measurements by high-resolution capacitive dilatometry, performed in the different
AFM phases below TN = 42 K, show lattice distortions with striction of about 10-4. All longitudinal
and transversal components of the magnetostriction tensor were measured for the first time. Although
no changes of the lattice symmetry exist, the measurements reveal magneto-structural phenomena,
especially in the canted-AFM phase. A strong anisotropy of the magnetoelastic properties was found,in good agreement with the type and propagation of the magnetic structure. As the capacitive method
is sensitive to expansion effects and changes of permittivity, dielectric anomalies could be detected
and compared to the critical values of H and T of the magnetic transitions. The anomalies especiallyexist in the range 10….22 K in which the structure is characterized by magnetic order on both the
Gd- and Mn-sites. This demonstrates the strong interplay of magnetic, charge and lattice degrees of
freedom. First steps in modelling the magnetization of GdMnO3 by the simulation program McPhaseare presented and exchange mechanisms are discussed. These results are examined in connection
with the magnetostriction data.

PH05
2+

Magnetism of SrM3P4O14 (M = 3d ions) investigated using neutronscattering measurements

Masashi Hase1*, Vladimir Yu. Pomjakushin2, Lukas Keller2, Andreas Doenni1,
Osamu Sakai1, Tao Yang3, Rihong Cong3, Jianhua Lin3, Kiyoshi Ozawa1 and Hideaki
Kitazawa1
1
National Institute for Materials Science (NIMS), Japan
2
Paul Scherrer Institut (PSI), Switzerland
3
Peking University, China
One of intriguing phenomena in magnetism is appearance of qualitatively different magnetism
in isostructural substances. In AM3P4O14 (A = Ca, Sr, Ba or Pb, M2+ = Ni2+: spin-1, Co2+: spin3/2, Fe2+: spin-2 or Mn2+: spin-5/2), magnetism in AMn3P4O14 is qualitatively different frommagnetism in the other substances. A 1/3 quantum magnetization plateau was observed only
in AMn3P4O14. An antiferromagnetic (AFM) long-range order (LRO) without a spontaneous
magnetization appears in AMn3P4O14, while a canted AFM LRO appears in the othersubstances. We studied magnetism of SrM3P4O14 using neutron-scattering measurements. In
SrMn3P4O14, we determined the coplanar spiral magnetic structure that had no spontaneous
magnetization. We confirm that the spin system is a frustrated J1-J1-J2 trimerized spin chain
with dominant AFM J1, small AFM J2, and small next-nearest-neighbor exchange interactions.
The magnetization plateau is possible. In SrM3P4O14 (M = Co or Ni), we determined the canted
magnetic structure (the irreducible representation tau1 in the space group P21/c). We consider
that the spin system consists of ferromagnetic dimers formed by the dominant J2 interaction
and monomers. The magnetization plateau is impossible.

Uniaxial pressure effect on magnetic ordering in a frustrated ising
antiferromagnet CoNb2O6

Satoru Kobayashi1*, Hiromu Tamatsukuri2, Chikafumi Kaneko2, Yuki Honma2, Taro
Nakajima2 and Setsuo Mitsuda2
1 Department of Materials Science and Engineering, Iwate University, Japan
2 Department of Physics, Faculty of Science, Tokyo University of Science, Japan
Uniaxial pressure effect on magnetic ordering has been investigated by magnetization
measurements for a frustrated Ising antiferromagnet CoNb2O6 where quasi-onedimensional ferromagnetic chains along the c axis form a frustrated isosceles triangularlattice on the a-b plane. Under uniaxial pressure and magnetic field along the a axis, acritical field of magnetic phase transitions from antiferromagnetic to incommensurate
magnetic (ICM) phase as well as from ICM to ferromagnetic phase monotonicallyincreases, indicating the strengthening of antiferromagnetic interchain exchangeinteractions. Above 700 MPa, a step-like behavior of the magnetization curve shows
up at around the half of the saturation magnetization. This behavior implies theappearance of a pressure-induced magnetically ordered phase characterized by the
propagation wave vector of qM=(0,0.5,0) and/or (0,0.25,0). These observations wereexplained within mean field calculations with nearest-neighbor and next-nearestneighbor interchain exchange interactions.

PG24

PG27

PH03

PH06

Doping effects on the metal-insulator transition of Li2RuO3Magnetic study of Fe/MgO/Fe and Fe/MgO/Fe/Co multilayer systems

Spin-Peierls-like lattice distortion and incommensurate magnetic
structure of geometrically frustrated spinel CdCr2O4

Thermal and magnetic properties of LiNiPO4 olivine

Seongil Choi1, Junghwan Park1, Sanghyun Lee1, Deo-kyong Cho1, T. Morioka2, H.
Nojiri2 and J.- G. Park3*
1
Center for Strongly Correlated Materials Research, Seoul National University, Seoul
151-742, Korea
2
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan3
Department of Physics & Astronomy, Seoul National University, Seoul 151-742,
Korea
Li2RuO3 has a layered rocksalt-type structure and has attracted much attention
because of its interesting physical properties. In particular, it exhibits a metal-insulatortransition at a very high temperature around 540 K. At the same temperature, themagnetic susceptibility shows a big drop implying the formation of a spin gap. It is alsointeresting to note that all of these physical properties occur on the unusual honeycomb
lattice of Ru ions. In order to understand the origin of the metal-insulator transition andits related physical properties better, we have carried some extensive studies ranging
from bulk properties to neutron scattering experiments. First, we have investigated thedoping effects on the metal-insulator transition by varying Li content. Second, we haveexamined the field dependence of the physical properties by measuring resistivity andmagnetization over a wide temperature range. In this report, we are going to summarize
our experimental results and its importance with respect to the reported metal-insulatortransition.

146

PG26

Mathias Doerr1*, Sahana Roessler2, Martin Rotter2, Aditya A. Wagh3, P. S. Anil
Kumar3, Suja Elizabeth3, Steffen Wirth2 and Michael Loewenhaupt1
1
Institut fur Festkorperphysik (IFP), Technische Universitat Dresden, Germany
2
Max-Planck-Institut fur Chemische Physik fester Stoffe Dresden, Germany
3
Department of Physics, Indian Institute of Science Bangalore, India

The 19th International Conference on Magnetism

Jitendra Pal Singh1, Sanjeev Gautam2, K Asokan1, D. Kabiraj1, D. Kanjilal1, M Raju3,
Braj Bhusan Singh4, S. Chaudhary3, R. Kotnala4 and Keun Hwa Chae2*
1
Inter University Accelerator Centre, Aruna Asaf Ali Marg-110067, New Delhi, India
2
Advanced Analysis Center, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
3
Department of Physics, Indian Institute of Technology, New Delhi - 110 016, India
4
National Physical Laboratory, Dr. K. A. Krishanan Marg, New Delhi -110 012, India
Theoretical calculations [1-3] show high TMR up to 1000% for Fe/MgO/Fe MTJ’s however TMR ratios of200% at room temperature could be realized in these systems [4]. The discrepancy between theoretical andexperimental values of TMR is probably due to the interface properties of the heterostructures, as spin dependent
tunneling is sensitive to the interface [3]. In present work, we investigated the magnetic properties of Fe/MgO/
Fe (MFe) and Fe/MgO/Fe/Co (MFeCO) multilayers by vibrating sample magnetometer (VSM) deposited byelectron beam evaporation method [6]. Attributes of perpendicular magnetic anisotropy (PMA) are observedin MFe multilayer. The PMA arises due to Fe(3d) and O (2p) hybridization at metal-oxide layer interface andgenerally observed in MTJs [6]. The asymmetric coercivity observed in this structure is due to the presence of
exchange bias which arises probably due to oxidation of Fe at surface; resulting in antiferromagnetic Fe2O3. The
positive vertical shift along magnetization axis may be due to the pinned interfacial uncompensated spins of
unwantedly formed Fe2O3 [7]. Apart from this MFeCo multilayer do not exhibit any feature observed in MFe
multilayers. The absence of these is expected almost 3 times increase of Fe layers in MFeCo system [5].
References: 1. A. Lyle, et al. App. Phys. Lett. 97 152504 (2010) 2. J-G. Zhu and C. Park, Materials Today, 9 36 (2006) 3. J.
Mathon and A. Umerski, Phys. Rev. B 63 220403 (2001). 4. S.S.P. Parkin, , et al., Nat Mater, 3 862 (2004) 5. J. P. Singh et al.,AIP Conf. Proc. (in Press) 6. S. Ikeda et al. Nature Mater. 9 (2010) 721-722 7. H. Ohldag et.al. Phy. Rev. Lett., 91, 017203, 2003

July 9 (Mon)

Cristina Saenz De Pipaon 1, Javier Campo 1*, Fernando Palacio 1, Jose Alberto
Rodriguez-velamazan1, Katsuya Inoue2 and Hiroyuki Honda2
1
Materials Science Institute of Aragon (CSIC-University of Zaragoza), Spain
2
Hiroshima University, Japan

July 9 (Mon)poster Presentation

J. H. Chung1, J. M. S. Park2, K. P. Hong2, M. Matsuda3, H. Ueda4, Y. Ueda4 and S. H.
Lee5*
1
Department of Physics, Korea University, Korea
2
Korea Atomic Energy Research Institute, Korea
3
Oak Ridge National Laboratory, Korea
4
The University of Tokyo, Japan
5
University of Virginia, USA
ACr2O4 spinels (A = Zn, Cd, Hg) with antiferromagnetic Cr3+ (S = 3/2) on B sites are well known forstrong geometrical frustration preventing long-range order. The frustrations in their cubic phases are
finally lifted via spin-Peierls-like lattice distortions at low temperatures. In spite of their similarities
in the cubic phases, each of them undergo distinctive lattice distortions and exhibit unique magnetic
order. The nature of their magnetic ground states is thus of great importance in order to understandthese novel transitions. Nevertheless, the exact spin structure of CdCr2O4 has so far never beenreported. We revisited this issue by performing neutron powder diffraction measurement of isotopeenriched sample for reduced neutron absorption. We observed the cubic-to-tetragonal distortion andthe subsequent incommensurate magnetic order that are consistent with previous reports. Using
representation analysis, we found that the spins on different sublattices maintain nearly collinear
arrangements within a single tetrahedron. Whereas the obtained spin structure is different fromthe one previously conjectured based on spin wave frequencies, it is consistent with the idea thatquantum fluctuation plays an important role in the magnetic ground state of CdCr2O4.

J. Wieckowski 1*, M. U. Gutowska 1, A. Szewczyk 1, Yu. Kharchenko 2, M. F.
Kharchenko2, M. Kowalczyk3, N. Nedelko1, S. Lewinska1, A. Slawska - Waniewska1,
A. Kulka4 and J. Molenda4
1
Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
2
B.Verkin Inst. for Low Temp. Phys. and Engineering, National Academy of Sciencesof Ukraine, Kharkiv, Ukraine
3
Faculty of Materials Engineering, Warsaw University of Technology, Warsaw,
Poland4
Department of Hydrogen Energy, AGH University of Science and Technology,
Cracow, Poland
On the contrary to LiMPO4 olivines with M = Mn, Fe, Co, in LiNiPO4 two step transformation between
the paramagnetic and a uniform in space antiferromagnetic phase occurs. At first, a long-range magnetic
order develops in the form of an incommensurate antiferromagnetic phase (via a second-order transition at
21.8 K) and then a first-order transition to the antiferromagnetic phase occurs at 20.9 K. To study thermal
properties of LiNiPO4, and an influence of magnetic field, B, on the magnetic structure, specific heatmeasurements of a single crystal were carried out from 3 K to 60 K, in B=0 and in B (up to 9 T) appliedalong three main crystallographic directions. It was found that B applied along a and b directions has noeffect on the transitions, whereas B directed along c axis shifts both transitions towards lower temperatures(with the transition temperatures depending parabolically on B). To elucidate these effects, supplementarystudies of magnetic torque were performed for several B values, for B rotating within a-c and b-c planes,
for a series of fixed temperatures. This work was partly supported by the European Regional Development
Fund, through the Innovative Economy Grants: POIG.01.01.02-00-108/09 and POIG.02.02.00-00-025/09.

July 8-13, 2012 Busan, Korea

147

poster Presentation

poster Presentation

PH07

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PH13

PH16

Cr- and mo-doping effects on structural and orbital order phasetransition in spinel-type MnV2O4Resonant soft X-ray scattering studies on half-doped manganite
LaSr2Mn2O7

First-Principles Calculation of the A-Site Ordered Perovskite
CaCu3Fe4O12

Study of magnetic properties of NdCo1-xNixO3 (x = 0, 0.2, 0.4)

1

1

1

Kazuhiro Hemmi *, Ryuichiro Fukuta , Ece Uykur , Shigeki Miyasaka , Setsuko
Tajima1, Akiko Nakao2, Hironori Nakao2, Reiji Kumai2 and Youichi Murakami2
Physics, Osaka University, Japan
2
PF/CMRC, KEK, Japan

1

July 9 (Mon)

MnV2O4 has orbital degrees of freedom of t2g electrons in V3+ (3d2), and undergoes magnetic
and orbital order. In this study, we investigated the doping effects of Cr3+ (3d3) and Mo3+ (4d3),
which have no orbital degrees of freedom, for the V3+ site of MnV2O4, in order to clarify the Crand Mo-doping effect on the electronic properties in this system. In MnV2O4, the paramagnetic
to collinear ferrimagnetic phase transition and the collinear to noncollinear ferrimagnetic phasetransition occur at TN=59K and TOO=54K, respectively. The structural phase transition fromcubic to tetragonal lattices takes place at TOO concomitantly with the orbital order. From themagnetic susceptibility and powder X-ray diffraction measurements, it is clarified that the orbital
order is suppressed by Cr- and Mo-doping and disappears above x=0.12 (x=0.08) in Cr (Mo)doped samples. The resistivity and optical reflectivity measurements have clarified that the system
becomes almost metallic with increasing Mo content, while the Cr-doped samples are still Mott
insulators. These results indicate that the doped Cr and Mo with no orbital degrees of freedom
suppress the orbital order in MnV2O4. The introduced 3d electrons remain localized in the Crdoped system, while 4d electrons become nearly itinerant in the Mo-doped one.

1

1

2

3

3

4

4

J.-s. Lee *, C.-c. Kao , C.s. Nelson , H. Jang , K.-t. Ko , S.b. Kim , Y.j. Choi , S.w.
Cheong4, S. Smadici5, P. Abbamonte5 and J.-h. Park3
1
SSRL, SLAC National Accelerator Laboratory, USA
2
BNL, USA
3
POSTECH, Korea
4
Rutgers university, USA
5
UIUC, USA

1

1

1

2

Takuya Ueda , Mitsuru Kodera , Kunihiko Yamauchi and Tamio Oguchi *1
Osaka University, Japan
2
Osaka University & JST-CREST, Japan

Recently, a careful doping control study, however, reported that the La2-2xSr1+2xMn2O7
system has an exotic spin phase diagram very near the half doping with extremely
narrow antiferromagnetic (AFM) phase boundaries at x ~ 0.5 +/- 0.005: the CEtype within the boundaries but the A-type outside. To elucidate complication of thisspin phase diagram, we investigated the orbital and AFM ordering behaviors of thehalf-doped bilayer manganite LaSr2Mn2O7 by using Mn L-edges resonant soft x-ray
scattering. We confirmed the predicted CE-type AFM order for the true half-doped (x =0.5) case. Furthermore, we found that such a narrow phase boundary is due to the closecompetition of the two AFM phases via 3d Mn eg orbital instability.

R

G
UP

D

E
AD

R. Plumier and M. Sougi, Solid State Commun. 64, 53 (1987). S. Suzuki et al., Phys. Rev. Lett. 98, 127203 (2007).

We report here the magnetization studies of the NdCo1-xNixO3 (x = 0, 0.2, 0.4) samples
synthesized using conventional solid state reaction method. X-ray diffraction followedby Rietveld refinement, confirms the single phase orthorhombic structure with Pbnm
space group for all the samples. X-ray absorption spectroscopy studies revealed that both
Co and Ni exist in trivalent state. The zero field cooled and field cooled magnetization
measurements show that below room temperature the magnetization has strong influenceof paramagnetic rare earth ion inhibiting magnetic ordering of cobalt ions. Below acertain low temperature (T< 50K), samples with x = 0, 0.2, show paramagnetic to anti
ferromagnetic transition but the sample with x = 0.4 shows paramagnetic to Spin glasstransition. Isothermal magnetization hysteresis measurements revealed the similar behavior
at low temperature. The overall magnetic behavior has on the basis of various magnetic
interactions between Nd-sublattice and those of transition metal networks.

PH08

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PH14

PH17

Dopant-dependence on charge/orbital order in impurity doped layered
manganites

On the non-idle-spin behavior and the field-induced magnetictransitions of the trimer chain magnet Cu3(OH)4SO4

Soft x-ray absorption spectroscopy study of Prussian blue analogue
MCo[Fe(CN)6]H2O Nano-particles (M=Na, K, Rb)

Fluctuations of charge, orbital, and spin order in single layer
manganite Pr0.5Ca1.5MnO4Yuki Yamaki1, Hironori Nakao2, Yuichi Yamasaki2, Youichi Murakami2, Yoshio
Kaneko3 and Yoshinori Tokura4
1
Tohoku University CMRC/PF, KEK, Japan
2
CMRC/PF, KEK, Japan
3
ERATO-MF, JST CERG, RIKEN, Japan
4
ERATO-MF, JST CERG/CMRG, RIKEN University of Tokyo, Japan
A layered manganite La 0.5Sr 1.5MnO 4 shows charge/orbital order and CE-type
antiferromagnetic structure below 240 K and 110 K, respectively. We have studied how
the ordering state is changed by the substitution of Cr, Fe and Ga ions for Mn ions using aresonant x-ray scattering (RXS) technique and magnetization measurement. In trivalentions these impurity ions have no orbital degree of freedom and different spin values,in fact Cr3+ , Fe3+, and Ga3+ have S = 3/2, S = 5/2, and S = 0, respectively. As a result,the magnetization for Ga doped compound shows the same temperature dependence aspure compound, but in Cr and Fe doped compounds the magnetizations increase below
90 K and 70 K, respectively. On the other hand, in all doped compounds the RXS
intensities which reflect charge/orbital order are smaller than that in pure compound,but degrees of decrease are different according to the dopants. Namely, RXS intensityof Ga-doped compound has the same temperature dependence as pure compound,while RXS intensities of Cr- and Fe-doped compounds drastically decrease below 90
K and 70 K, respectively.

Hyun-joo Koo1, Reinhard K Kremer2 and Myung-hwan Whangbo3
1
Chemistry, Kyung Hee University, Korea
2
Max-Planck-Institut fur Festkorperforschung, Stuttgart, Germany
3
Chemistry, North Carolina State University, USA

The magnetic properties of the Cu(2)-Cu(1)-Cu(2) trimer chain magnet Cu3(OH)4SO4
were examined by evaluating the spin exchange constants, the Dzyaloshinskii-Moriya(DM) vectors, and the magnetic anisotropy energies of the Cu(1) and Cu(2) sites on
the basis of density functional calculations. Cu3(OH)4SO4 is not a idle-spin magnet,
the Cu(1) spins have a strong antiferromagnetic coupling in the Cu(1) chain, and theCu(2) spin arrangements of a Cu(2)-Cu(1)-Cu(2) trimer chain result from the presenceof two non-equivalent sets of AFM interactions between the Cu(1) and Cu(2) chains.
We propose the probable spin arrangements of a trimer chain responsible for the fieldinduced successive magnetic transition, and suggest that the nature of the magnetictransition depends on the field-direction because of the DM interactions associatedwith two strong spin exchange paths.

Eunsook Lee1, D.h. Kim1, Jihoon Hwang1, Nguyen Van Minh2, In-sang Yang3, M.
Sawada4, T. Ueno4 and J.-s. Kang1*
1
Department of Physics, The Catholic University of Korea, Bucheon 420-743, Korea
2
Department of Physics, Hanoi National Uninersity of Education, Hanoi, Viet Nam
3
Department of Physics, Ewha Womans University, Seoul 120-750, Korea
4
Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
Molecular-based magnetic materials have been studied for their possible applications as nano-magnetic devices
as well as for the understanding of the fundamental physics of their magnetic phenomena. Molecular magnetic
materials of Prussian Blue (PB) analogues, which are represented by the general formula, An[B(CN)6]m∙xH2O,
where A and B are transition-metal ions [1], show various characteristic magnetic properties depending on theirtransition metal ions. PB crystallizes in the fcc structure with space group Fm3m [2]. Of special interest is thephoto-induced spin transition. However, the origin of the photo-induced spin transition has not been understoodwell yet. In this work, we have studied the valence states of PB analogue MCo[Fe(CN)6]H2O (M=Na, K,
Rb) nano-size particles by employing synchrotron-radiation soft x-ray absorption spectroscopy (XAS). The
measured Fe and Co 2p XAS spectra of MCo[Fe(CN)6]H2O (M=Na, K, Rb) reveal the systematic changes as
the size of M ion changes, from the Fe2+-Fe3+ mixed-valent states and the nearly divalent Co2+ states to the nearly
trivalent Fe3+ states and the Co2+-Co3+ mixed-valent states. This finding suggests that the electronic structures of
PB nano-particles play an important role in determining their magnetic properties.
[1] Amit Kumar and S M Yusuf, Pramana - J. Phys., 63, 239 (2004). [2] Nguyen Van Minh, Phung
Kim Phu, Nguyen Minh Thuan, and In-Sang Yang, J. Magnetics, 13, 149 (2008).

Ismudiati Puri Handayani1*, Agung Nugroho2, Nandang Mufti3, Syarif Riyadi1, May
On Tjia2, T.t.m Palstra1 and P.h.m Van Loosdrecht1
1
Zernike Institute for Advanced Material, Netherlands
2
Bandung Institute of Technology, Indonesia
3State University of Malang, Indonesia

The magnetic and transport properties of doped manganite oxides are intimately related to thedimensionality of the MnO2 network. A three dimensional system tends to lead to metallicferromagnetic properties, whereas the two dimensional (2D) systems is dominated by chargeorbital order (COO) leading to insulating-antiferromagnetic properties. Pr0.5Ca1.5MnO4 is one of
the more interesting members of the 2D manganite family showing a charge and orbital orderingtransition above room temperature (TCOO = 320 K) with distinct changes in the magnetic,transport, and structural properties, evidencing a strong coupling between the orbital, structural,charge, and spin degrees of freedom. We study the structural, magnetic susceptibility, transport,
specific heat, and Raman spectroscopy of this material. The metal insulator transition observed
at TCOO is found to be more pronounced in comparison to the well studied isostructural
La0.5Sr1.5MnO4 compound. The same holds for the changes in the magnetic susceptibility at theantiferromagnetic transition (TN=120 K). Even though the COO is accompanied by rather abruptchanges in the physical properties, our data shows that no full ordering occurs at the transition
temperature. The system exhibits orbital fluctuations down to a temperature of about 200K, leading
to an unusual temperature dependence of the vibrational, magnetization, and transport properties.

PH09

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PH18

Magnetic and nonmagnetic impurity effect on magnetic orderings ofisosceles triangular lattice antiferromagnet CuMnO2Spin state of LaCoO3 investigated from non-magnetic-ion substitution
effect of Co sites

Long-time variation of magnetic structure in multistep metamagnets
Ca3(Co-M)2O6: Effect of disorder

Magnetic properties of spinel oxide CuCr2O4 investigated by NMR

In recent years, chemical substitution effect on magnetic and dielectric properties in frustrated magnetic
systems has been a vast field of challenging new physics. Good illustrations are the drastic and various
effects of a small level of chemical substitution upon the magnetic and dielectric properties on frustrated
magnetic systems such as CuFeO2 and MnWO4. These magnetic ground states stabilized withstrongly competing exchange interactions should be easily changed by slight chemical disturbance.
In the present study, we have investigated magnetic and nonmagnetic impurity substitution effects onmagnetic ordering of a frustrated isosceles triangular lattice antiferromagnet CuMnO2 by means of
the magnetic neutron diffraction measurements on Cu(Mn1-xCux)O2 and Cu(Mn1-yGay)O2. While themagnetic wave vector of Cu(Mn1-xCux)O2 the magnetic ground state of ``magnetically' substituted with
x=0.04 is Q=(-1/2 1/2 0)[1-3], that in the ``nonmagnetically' substituted Cu(Mn1-yGay)O2 with y=0.05,
0.15 and 0.20 is Q=(-1/2 1/2 1/2) that is identical to that of pure CuMnO2. We discuss an influence ofmagnetic or nonmagnetic impurity substitution on the magnetic ordering of CuMnO2, by comparing
the results of Cu(Mn1-yGay)O2 with Cu(Mn1-xCux)O2.

The perovskite oxide LaCoO3 is a fascinating material because of a dramatic changeof its spin state with temperature variation. In low-temperature range, LaCoO3 is nonmagnetic because the d electrons of Co3+ (3d6) fully occupy the lower t2g orbitals (LS).
On the other hand, the nature of its excited state is controversial. The spin state of thissystem is also sensitive to the chemical substitutions. Most interestingly, non-magnetic
Rh3+ (4d6: LS) substitution increases the magnetization at low temperature, which isdifferent from Ga3+ (3d10) substitution effect. We have measured the magnetization andx-ray diffraction of LaCo1-xRhxO3 [1]. We have found a weak ferromagnetic ordering
for 0.1 < x < 0.4, indicating that the Rh substitution stabilizes the magnetic state of
Co3+ at low temperatures. The effective magnetic moment of LaCo1-xRhxO3 evaluatedat room temperature is independent of x for 0 < x < 0.5, and rapidly decreases above
x = 0.5. It indicates that the excited state of Co3+ is well described as a mixture of thelow- and the high-spin Co3+ ions, and that a Rh3+ ion favors to substitute for a low-spin
Co3+ ion.

Noriki Terada1, Yoshinori Tsuchiya1, Hideaki Kitazawa1 and Naoto Metoki2
1
National Institute for Materials Science, Japan
2
Japan Atomic Research Agency, Japan[1]N. Terada, Y. Tsuchiya, H. Kitazawa, T. Osakabe, N. Metoki, N. Igawa and K. Ohoyama, Phys.
Rev. B 84 064432 (2011). [2]M. Poienar, C. Vecchini, G. Andre, A. Daoud-Aladine, I. Margiolaki,
A. Maignan, A. Lappas, L. C. Chapon, M. Hervieu, F. Damay, and C. Martin, Chem. Mater. 23, 85(2011). [3]V. O. Garlea, A. T. Savici, and R. Jin, Phys. Rev. B 83, 172407 (2011).

148

Ravi Kumar1, Vinod Kumar2, Rajesh Kumar3, Dinesh Kumar Shukla4, Sunil Kumar
Arora5 and I V Schvets6
1
Centre for Materials Science and Engineering, National Institute of Technology, Hamirpur 177005 (H.P.),
India
2
Department of physics, National Institute of Technology, Hamirpur 177005 (H.P.), India
3
Department of physics, National Institute of Technology, Hamirpur 177005 (H.P.), India, India
4
Deutshes Electronen Synchrotron DESY, 22607 Hamburg, Germany, Deutshes Electronen Synchrotron
DESY, 22607 Hamburg, Germany, Germany
5
School of Physics, Trinity College Dublin 2, 3School of Physics, Trinity College Dublin 2, Ireland
6
School of Physics, Trinity College Dublin 2, School of Physics, Trinity College Dublin 2, Ireland

The 19th International Conference on Magnetism

Shinichiro Asai*, Ryuji Okazaki, Yukio Yasui and Ichiro Terasaki
Department of Physics, Nagoya University, Japan[1]. S. Asai et al.; J. Phys. Soc. Jpn. 80 (2011) 104705.

Taketo Moyoshi*, Rui Takahashi, Yuichiro Ito, Ryotaro Irie, Tetsuto Ide, Daiki Syoji
and Kiyoichiro Motoya
Faculty of Science and Technology, Tokyo University of Science, Japan

We have reported that CeIr3Si2, Ca3Co2O6 and some other materials show long-time variationof magnetic structure [1-4]. These materials are uniform compounds including no appreciablerandomness or imperfections. All of these compounds show successive magnetic transitions
and metamagnetic transitions at low magnetic field, which indicate the presence of competing
magnetic interactions. Therefore, we think that the long-time variation of magnetic structure inthese materials is caused by the competing magnetic interactions. To ensure that randomness
or imperfections are not the main factor causing the long-time variation of magnetic structure,
we have investigated the element substitution effects. In this presentation, we show the timedependence of the magnetization in Ca3(Co1-xMx)2O6 (M=Ga, Mg, Al and Ti). The time
variations of magnetization were measured after the sample was cooled to various target
temperatures from T=30 K (T>Tc1) at B=5 mT. Characteristics of the time variation behavior
were not much modified by the disorder produced by the substitution of non-magnetic
elements. These results show that the long-time variation of the magnetic structure in Ca3Co2O6
is not caused by randomness or imperfections.

July 9 (Mon)1

Euna Jo, Soonchil Lee*, Changsoo Kim, Byeongki Kang and Sangil Kwon
Physics, KAIST, Korea

Spinel oxide CuCr2O4 is known to have non-collinear spin structure and orbital
ordering in its ground state. NMR spectrum for the magnetic ions Cr3+ and Cu2+ wasmeasured at liquid helium temperature to investigate magnetic properties of CuCr2O4.
Temperature dependence of the Cr NMR frequency shows that there exist initial energy
gap in the dispersion relation of the spin wave. This energy gap is larger than that of the
Cu ion, implying that spin-orbit coupling of the Cr ion is stronger than that of the Cu
ion. This is consistent with theory that predicts orbital order for the Cu ion in CuCr2O4.
The canting angle of the Cr3+ spin was estimated to be 80° by external magnetic fielddependence of the Cr NMR frequency. Also the line width of the Cr NMR spectrum
was measured in 7T external magnetic field. The broadening of the spectrum is inducedby the anisotropy field. The broadening of the Cu NMR spectrum is larger than that of
the Cr NMR spectrum, implying that orbital ordering, rather than anisotropy field, isthe main reason of the Cu NMR spectrum broadening.

[1]K. Motoya et al. J. Phys. Conf. Series 200 (2010) 032048 [2]T. Moyoshi et al., J. Phys. Soc. Jpn.
81 (2012) 014704 [3]T. Moyoshi and K. Motoya, J. Phys. Soc. Jpn., 80 (2011) 034701 [4]K. Motoya
et al. J. Phys. Conf. Series 273 (2011) 012124

July 8-13, 2012 Busan, Korea

149poster Presentation
PH19

PH22

PI02

PI05

Magnetic frustration effects in the new colossal magnetoresistanceoxide NaCr2O4

The patterning with a circular magnet array, its observation anddomain switching in ferromagnetic ZnCoO:H

Specific heat and magnetic properties of spinel compound FeV2O4

Structural and magnetic properties of the parent compound T'La2CuO4 of electron-doped cuprates

Today’s spintronic technologies are considered to be the most progressive solution for overcoming the typical
semiconductor electronics. Many researchers have extensively studied the effect of size, shape, structure
on single-domain magnet and its wall motion with permanent magnetic metal for high-density magnetic
memory and logic devices[1,2]. However, the fact that permanent magnetic metals could not reprogram
after the first design for logic devices is still remaining as an important issue. Thus, hydrogen-mediatedCo-doped ZnO(ZnCoO:H) having reversible room-temperature ferromagnetism has been considered asa strong candidate material for spintronic devices[3]. In this study, we observed domain switching in a
ZnCoO:H in real-space and simulate it using object-oriented micromagnetic framework(OOMMF). ZnCoO
circular patterns are fabricated by rf-sputtering and various lithography processes, and hydrogen is injectedby plasma and hot isostatic pressing(HIP) methods. The reversible magnetic single-domain behavior isactivated and deactivated by hydrogen manipulation, which are investigated with superconducting quantum
interference device(SQUID) and magnetic force microscopy(MFM) measurements, and the results arecompared with the OOMMF simulation. This reversible room-temperature magnetic switching of the oxidematerials could greatly contribute to the development of reprogrammable spin logic devices.

The spinel compound FeV2O4 has the orbital degrees of freedom at both eg (Fe2+) andt2g (V3+) orbitals. This compound shows successive structural phase transitions at
about 140 K, 110 K accompanied by ferrimagnetic ordering, 70 K and 35 K. However,the details of the phase transitions below 110 K are still not understood. In order toclarify the origin of these phase transitions, we measured magnetization and specificheat capacity for polycrystalline and single crystal of FeV2O4. We first observed threeanomalies at 140 K, 109 K and 68 K with decreasing temperature in the specific heatmeasurements using the polycrystalline sample. The λ-type anomaly at 109 K indicatesthe second order phase transition, which is related to the ferrimagnetic ordering.
Moreover, the anomaly at 68 K has a sharp peak, which conforms to the anomaly
on the temperature dependence of magnetic susceptibility. The electronic specificcoefficient γ =1.8 mJ/molK2 of FeV2O4 is smaller than that of of MnV2O4 (γ = 12 mJ/
molK2)[2] because the Jahn-Teller effect of Fe2+ for FeV2O4 may weaken the electronelectron interactions. The details of the measurements using single crystal and thecorrelation between the crystal and the magnetic structures are also discussed.

[1] S. Y. Chou, Proc. IEEE 85, 652 (1997); G. A. Prinz, Science 282, 1660 (1998) [2] E. R. Lewis et al., Nat. Mater. 9,980 (2010); J.-C.Lee et al,. Phys. Rev. Lett. 107, 067201 (2011) [3] H. J. Lee et al., Appl. Phys. Lett. 88, 062504 (2006);
S. Lee et al., Appl. Phys. Lett. 94, 212507 (2009); Y. C. Cho et al., Appl. Phys. Lett. 95, 172514 (2009); S. J. Kim et al.,Phys. Rrev. B 81, 212408 (2010); S. Lee et al., J. Appl. Phys. (accepted); J. M. Shin et al., Phys. Rev. Lett. (submitted)[1] T. Katsufuji et al., J. Phys. Soc. Jpn. 77 (2008) 053708 [2] K. M. Whun et al., Phys. Rev. B 83
(2011) 024403

PH20

PH23

PI03

PI06

Site-dependent metal-insulator transition and orbital order in quasione-dimensional V6O13

Orbitally induced molecule formations in itinerant triangularvanadates

The crossover to checkerboard charge order: Magnetic excitations ofcharge-stripe ordered of La2-xSrxNiO4Microscopic magnetic nature of the quasi-one-dimensional
antiferromagnet BaCo2V2O8

In itinerant electron systems on a geometrically frustrated lattice, the magnetic frustration isconsidered to play a crucial role for their transport properties as seen in LiV2O4 which shows theheavy fermion-like behavior [1]. Recently, a new chromium oxide NaCr2O4 with geometricallyfrustrated double chains was reported to show the unconventional colossal magnetoresistance(CMR) effect [2]. Unlike the conventional CMR materials represented by the ferromagnetic
manganites, NaCr2O4 is an antiferromagnet with the Neel temperature TN = 125 K. The originof the CMR effect in NaCr2O4 is expected to be closely related to the unconventional spin
structure generated by the magnetic frustration. In this study, we have performed 23Na NMR
measurements on NaCr2O4 to investigate the spin structure in the antiferromagnetic phase andthe magnetic correlations. We found the presence of a ferromagnetic interaction, which competes
with an antiferromagnetic one, from the temperature dependence of the nuclear spin-lattice
relaxation rate 1/T1. Below TN, 23Na NMR spectra, which change with increasing the external
magnetic field, cannot be explained by a conventional spin structure. The CMR effect may berelated to the instability of the spin structure in the external field due to the magnetic frustration.
[1]S. Kondo, et al., PRL 78, 3729 (1997). [2] H. Sakurai, et al., (unpublished).

Satoshi Aoyama1, Yasuhiro Shimizu1, Masayuki Itoh2* and Yutaka Ueda3
1
Department of Physics, Graduate School of Science, Nagoya University, Furo-cho,
Chikusa-ku, Nagoya, Japan2
Department of Physics, Graduate School of Science, Nagoya University, Japan
3
Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa,
Japan
Vanadates are prototypes of metal-insulator transitions with orbital degrees of freedom.
In a quasi-one-dimensional compound V6O13, the mixed valence gives non-uniform
spin-charge distributions on inequivalent V sites even for the metallic state. Our
sophisticated 51V NMR measurements using a single crystal distinguished the sitedependent orbital order and the local spin susceptibilities on two inequivalent chains.
One chain behaves as a metallic one with the moderately depressed susceptibility,
whereas another behaves as an insulating one with the magnetically active local
moment. The result arises from the site dependent electron correlation, giving thenet duality in the conducting and magnetic properties. A metal-insulator transition
occurring at -150 K accompanies with dramatic changes in the charge and orbital
ordering textures, as we observed in the 51V nuclear quadrupole splitting anisotropy.
Such ordering separates the metallic chain into magnetic and nonmagnetic sites, giving
a complex antiferromagnetic spin structure below -50 K.

Won-kyung Kim, Seunghun Lee, Sang-uk Cho, Yong-chan Cho, Hideomi Koinuma and Se-young Jeong*
Cogno-Mechatronics Engineering, Pusan National University, Korea

Yasuhiro Shimizu1*, Ken-ichiro Matsudaira1, Masayuki Itoh1 and Yutaka Ueda2
1
Nagoya University, Japan
2
University of Tokyo, JapanAn intriguing route that eliminates the geometrical frustration is the orbitally-induced
symmetry breaking usually described by the Kugel-Khomskii model. In itinerantsystems, however, the model for localized electrons may not be guaranteed, and thedegenerated d orbitals can be partially occupied. We show that the orbital occupation
continuously changes into a valence-bond-solid ground state in an itinerant vanadate
BaV10O15 with a triangular lattice, based on the orbital-resolved nuclear magnetic
resonance technique. Owing to the odd number of d electrons, i. e., eleven electrons
for a five-V unit, all the V sites cannot form the valence bonds. Instead, two of the five
V sites, sharing five electrons, remain magnetic with the ferro-orbital ordering [1]. In
clear contrast, no commensurate spin order and orbital order are stabilized in SrV10O15.
The result suggests fractional and incommensurate spin-orbital orders that cannot fully
remove the geometrical frustration.
[1]Y. Shimizu, K. Matsudaira, M. Itoh, T. Kajita, and T. Katsufuji, Phys. Rev. B. 84, 064421 (2011).

Shogo Kawaguchi*, Yoshiki Kubota and Hiroki Ishibashi
Department of Physical Science, Graduate School of Science, Osaka Prefecture
University, Japan

Paul G Freeman1, A. T. Boothroyd2, D. Prabhakaran2, K. Hradil3, R. A. Mole4 and S. R. Giblin51Helmholtz-Zentrum Berlin, Germany; EPFL, Lausanne, Switzerland; ILL, Grenoble, France
2
Department of Physics, Oxford University, United Kingdom
3
Technische Universitat Wien, Austria; Institut fur Physikalische Chemie, Universitat Gottingen, Germany
4
Bragg Institute, ANSTO, Australia; FRM II, Germany
5
ISIS Facility, Rutherford Appleton Laboratory, United Kingdom

Martin Mansson1*, Krunoslav Prsa1, Jun Sugiyama2, Hiroshi Nozaki2, Alex Amato3,
Shojiro Kimura4, Kumiko Omura5, Masayuki Hagiwara5 and Andrey Zheludev1
1
Lab. for Solid State Physics, ETH Zurich, Switzerland
2
Toyota Central Research and Development Labs. Inc., Japan
3
LMU, Paul Scherrer Institut, Switzerland
4
Institute for Materials Research, Tohoku University, Japan5
KYOKUGEN, Osaka University, Japan[1] M. Tranquada, et. al., Nature (London) 375, 561 (1995). [2] H. Woo et. al. Phys. Rev. B 72, 064437 (2005). [3]P. G. Freeman, et. al. Phys. Rev. B 71, 174412 (2005). [4] A. T. Boothroyd , et. el., Phys. Rev. Lett. 91 257201 (2005).

[1] S. Kimura et al. PRL 100, 057202 (2008) [2] S. Kimura et al. PRL 101, 207201 (2008) Funding
Source: Swiss National Science Foundation (Project 6, NCCR MaNEP) and Toyota CRDL.

PI07

PI01

PI04

Investigation of magnetocaloric effect in La 0.45Pr0.25Ca0.3MnO3 bydifferential scanning calorimetry and thermal analysis

Magnetic properties of low-dimensional α and γ CoV2O6

We investigated magnetocaloric effect in La0.45Pr0.25Ca0.3MnO3 by direct (changes intemperature and latent heat) and indirect methods (magnetization isotherms). This
compound undergoes a first-order paramagnetic to ferromagnetic transition with Tc= 200 K upon cooling. The paramagnetic phase becomes unstable and it transforms
into a ferromagnetic phase under the application of magnetic field, which results infield-induced metamagnetic transition (FIMT). The FIMT is accompanied by releaseof latent heat and change in temperature of the sample as evidenced from differential
scanning calorimetry and thermal analysis experiments. A large magnetic entropychange of ΔSm = -7.3 Jkg-1K-1 at Tc = 212.5 K and refrigeration capacity of 228 J/
kg are observed for a field change of ΔH = 5 T. It is suggested that the nanometer
sized ferromagnetic clusters co-exist with short-range charge-ordered clusters in theparamagnetic state, resulting in a large value of ΔSm above the Tc.

CoV2O6 is a low dimensional oxide existing in two allotropic phases, generally
called α and γ, and showing monoclinic and triclinic structures, respectively. We
synthesized this oxide by solid state reaction and performed neutrons diffraction andmagnetic measurements in order to understand the magnetic behavior in correlation
with the low dimensional structure. The magnetic properties were supported by abinitio calculations. Both phases are constituted of parallel 1D Co chains organized inplanes that are separated by vanadium oxide thin layers and are antiferromagnetic in
the ground state. The magnetization curves recorded at 5 K show a stepped variation
with sharp field-induced magnetic transitions and a magnetization plateau at one-thirdof the saturation magnetization. In α-CoV2O6, additional steps are evidenced at 1.8 K.
The magnetic moment per Co ion is larger in the α phase (4.5 μB) than in the γ phase(3 μB), although Co has the same octahedral environment in both cases. Ab initio
calculations show that α-CoV2O6 is an antiferromagnetic semiconductor with a gapof 1.1 eV in which the magnetic moment is essentially carried by Co and can reach amaximum value of about 4.2 μB for a meta-stable solution.

CoMn2O4 nanoparticles was synthesized by reverse micelle processing the mixed
precursor (consisting of Co(NO3)3 and MnCl2•4H2O). The CoMn2O4 was preparedby mixing the aqueous solution at a molar ratio of Co : Mn = 1 : 2. The synthesized
powders were calcined at 600°C for 2h. The average size and distribution ofsynthesized powders were in the range of 10-20nm and narrow, respectively. The
average size of the synthesized powders increased with increasing water to surfactant
molar ratio. The XRD diffraction patterns show that the phase of CoMn2O4 was spinel(JCPDS no.77-0471). The synthesized and calcined powders were characterized bythermo gravimetry- differential scanning calorimeter (TG-DSC), X-ray diffraction
analysis (XRD) and transmission electron microscopy (TEM). The magnetic propertyof the powder was measured by Vibrating Sample Magneto-meter (VSM) at 298K.
The effect of synthesis parameter, such as the molar ratio of water to surfactant, isdiscussed.

[1] R. Hord, H. Luetkens, et al., Phys. Rev. B 82, 180508(R) (2010). [2] G. M. Luke et al., Phys. Rev. B 42, 7981 (1990).
[3] I.W. Sumarlin, et al., Phys. Rev. B 51, 5824 (1990). [4] V.P. Plakhty et al., Phys. Lett. A 250, 201 (1998). [5] R.
Sachidanandam et. al., Phys. Rev. B 56, 260 (1997). [6] S. Katano, et al., Physica C 215, 92 (1993).

BaCo2V2O8, belongs to a wide group of quasi-1D antiferromagnets (AF). The Q1D compounds display avariety of fascinating ground states governed by the strong spin-spin coupling along the 1D direction and amuch weaker coupling along other directions. BaCo2V2O8 display a long-range AF order below TN=5 K
and possibly short-range order all the way up to 30 K. Further, a novel type of field induced magnetic orderhas been found for T<1.8 K and Hc>3.9 T [1,2]. It was determined to be an incommensurate spin structurecaused by quantum fluctuations, fitting well to theoretical predictions for a so-called Tomonaga-Luttinger
liquid (TLL). To the best of our knowledge, we present here the first μSR investigation of the microscopic
magnetic nature of single crystalline BaCo2V2O8 samples. Our data reveal several clear muon frequencies
below TN indicating the onset of a long-range order. Above 5 K, the μSR spectra are well fitted to a simple
power-exponential relaxing function. The temperature dependence of the relaxation-rate as well as thepower display a clear anomaly around T=40 K, indicating the onset of short-range 1D correllations. Finally
we also present initial and intriguing field dependent data.

Synthesis and characterization of CoMn2O4 nanopowders by a reverse
Micelle processing

Aparnadevi M, Sujit Kumar Barik and Ramanathan Mahendiran*
Department of Physics, National university of Singapore, Singapore

Recently, we found that the newly synthesized metastable T'-La2CuO4 exhibits much lower Neel temperature (TN)and increased magnetic fluctuations compared to other mother compounds of electron-doped superconductors like
Nd2CuO4 or Pr2CuO4. Muon spin rotation (μSR) reveals a gradual slowing down of dynamic magnetic fluctuations
below TN1=220K and static magnetic order below TN2=115K in contrast to T-La2CuO4 where TN2=300K. In
comparison to our T’-La2CuO4, measurements were done on T’-Pr2CuO4 to study the effect of a magnetic rareearth ion on the magnetism. Zero-Field μSR on T’-Pr2CuO4 shows oscillations at high temperatures up to 220K in
sharp contrast to the predominantly dynamic character of the depolarization in T’-La2CuO4 in the same temperature
range. This clearly demonstrates that the magnetism of T’-La2CuO4 is much more 2-dimensional than in T’-Pr2CuO4.
Interestingly, there is also an abrupt change of the internal field distribution at TN3=40K for both the T’-La2CuO4
and the T’-Pr2CuO4 compounds consistent with a reorganization of the magnetic structure at this temperature. LaNMR results for the T’-La2CuO4 also display anomalies at the abovementioned characteristic temperatures. In
addition, μSR and neutron scattering results on T’-Pr2CuO4 indicate a similar behaviour previously observed for
Nd2CuO4 pointing to, up-to-now undetected spin reorientation transitions.

Are stripes ubiquitous to the cuprates, and what is the role of stripes in high temperature superconductivity, are
two questions that have been intensively debated since the discovery of charge stripe order in the cuprates[1].
From studying the magnetism of charge-stripe ordered La2-xSrxNiO4 (LSNO) the magnetic interactions of acharge-stripe ordered phase have been quantitatively described[2], although our knowledge is incomplete[3].
For x = 1/2 the ground state order of LSNO is part stripe and part checkerboard like in character, with boththe magnetic excitations from the ordered moments and charge stripe electrons showing dramatic differencescompared to lower doping levels [2,3]. Variations of the charge-stripe periodicity, discommensurations, create
additional magnetic excitations from the ordered moments in the x = 1/2 compared to damping the excitations
at x ~ 1/3. While the magnetic excitations from the charge stripe electrons have a different wavevector
centring in the x = 1/2 [3,4]. We report a neutron scattering study of the magnetic excitations in LSNO x = 0.4
and 0.45. Between these two doping levels the magnetic excitations show a dramatic crossover in character.
We discuss this crossover behaviour with regards to charge-stripe materials with larger charge stripe spacing.

PH21
Hojung Kim and Dong Sik Bae*
Department of Convergence Materials Science and Engineering, Changwon National
Univ., Korea

Gwendolyne Pascua1, Hubertus Luetkens1, Marco Guenther2, Roland Hord3, Lukas
Keller4, Vladimir Pomjakushin4, Andreas Suter1, Hemke Maeter2, Alexander Buckow5,
Barbara Albert3, Hans-henning Klauss2 and Lambert Alff5
1
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
2
Institut fuer Festkoerperphysik, TU Dresden, DE-01069 Dresden, Germany
3
Eduard-Zintl-Institute of Inorganic and Physical Chemistry, TU Darmstadt, Petersenstr. 18, DE64287, Darmstadt, Germany
4
Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
5
Institute of Materials Science, TU Darmstadt, Petersenstr. 23, DE-64287 Darmstadt, Germany

Marc Lenertz*, Jonathan Alaria, Daniel Stoeffler, Silviu Colis and Aziz Dinia
DCMI, Institut de Physique et Chimie des Materiaux de Strasbourg, CNRS Universite de Strasbourg, France

M. Lenertz, J. Alaria, D. Stoeffler, S Colis and A. Dinia, J. Phys. Chem. C, 2011, 115, 17190-17196

July 9 (Mon)

Hikaru Takeda1*, Yasuhiro Shimizu1, Masayuki Itoh1, Hiroya Sakurai2 and Eiji
Takayama- Muromachi2
1
Department of Physics, Graduate School of Science, Nagoya University, Japan
2
National Institute for Materials Science, Japan

July 9 (Mon)poster Presentation

Detection of orbital wave in YVO3 using inelastic neutron scattering

Daichi Kawana1, Youichi Murakami1, Tetsuya Yokoo2, Shinichi Itoh2, Andrei T Savici3,
Garrett E Granroth3, Kazuhiko Ikeuchi4, Hironori Nakao1, Kazuaki Iwasa5, Ryuichiro
Fukuta6, Shigeki Miyasaka6, Setsuko Tajima6, Sumio Ishihara5 and Yoshinori Tokura7
1
Condensed Matter Research Center, Institute of Materials Structure Science, KEK, Japan2
Neutron Science Division, Institute of Materials Structure Science, KEK, Japan3
Neutron Scattering Sciences Division, Oak Ridge National Laboratory, USA
4
Comprehensive Research Organization for Science and Society, Japan
5
Department of Physics, Tohoku University, Japan
6
Department of Physics, Osaka University, Japan
7
Department of Applied Physics, University of Tokyo, Japan
We focus on an orbital excitation in YVO3, which shows the complex magnetic and orbital orderings in
the low temperatures [1]. In the phase where the G-type orbital order accompanied with the C-type spinorder (G-OO/C-SO) appears, the existence of the large orbital fluctuation is suggested [2]. Additionally, alarge dispersive orbital-wave along the c-axis, due to the strong one-dimensional spin-orbital correlation,is calculated [3]. In consideration of the neutron scattering cross-section obtained from the correlation
function for the orbital angular moment, we have attempted to detect the orbital excitation using inelastic
neutron scattering spectrometers. We observed a magnetic excitation up to 35 meV. This energy range ishigher than that reported previously [3]. On the other hand, weak excitations are observed in the range of
40-70 meV. In this Presentation, we discuss whether these are originated from orbital excitation or not.
[1] S. Miyasaka et al., Phys. Rev. B 73, 224436 (2006). [2] C. Ulrich et al., Phys. Rev. Lett. 91,
257202 (2003). [3] S. Ishihara, Phys. Rev. B 69, 075118 (2004).

150

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

151poster Presentation

poster Presentation

PI08

PI11

PI14

PI17

Orbital occupation and magnetism of tetrahedrally coordinated Fe in
CaBaFe4O7

Magnetic and calorimetric properties of Mn2GeO4 single crystals

Mössbauer studies of olivine Fe1-yMnyPO4Charge and spin ordering in Sr4Fe4O11 system

Within the framework of our research of manganese oxides the single crystals
Mn2GeO4 have been grown by the flux method using the original technique [1]. The
crystal structure, an isomorph of olivine, was determined on single crystal by X-ray
diffraction method: cell parameters, a=10.7401 A , b=6.3116 A, c=5.0766 A, andthe space group Pnma. Magnetic measurements were performed in the temperature
range from 2 to 300 K and in magnetic fields up to 50 kOe with the exact orientationof the applied magnetic field relative to the crystallographic directions of the crystal.
There are three sharp magnetic phase transition at T1=47 K, T2=17.5 K and T3=5.5
K, with phase transition at T2 depended on applied magnetic field. Also the specificheat measurements of single crystals were carried out. The heat capacity of Mn2GeO4
exhibits three sharp maxima, which exactly correlate with the magnetic phasetransition.

The olivine structured Fe1-yMnyPO4 (y = 0.1, 0.3), a possible cathode material for
lithium ion secondary battery, have been studied by x-ray diffraction and Mössbauer
spectroscopy. These Fe1-yMnyPO4 samples were prepared by chemical deintercalation
lithium from the LiFe1-yMnyPO4. The crystal structures of the Fe1-yMnyPO4 samples
were determined to be orthorhombic (space group Pnma) at 295 K by Rietveld
refinement method. The lattice constants of the Fe1-yMnyPO4 samples increased froma0 = 9.833 Å, b0 = 5.811 Å and c0 = 4.786 Å for y = 0.1 to a0 = 9.979 Å, b0 = 5.895
Å and c0 = 4.799 Å for y = 0.3 with the increasing Mn concentration. From the
Mössbauer spectra at 295 K, the electric quadrupole splitting (ΔEQ) and isomer shift(δ) values of the Fe1-yMnyPO4 were determined to be ΔEQ = 1.50 mm/s, δ = 0.31
mm/s for y = 0.1 and ΔEQ = 1.35 mm/s, δ = 0.31 mm/s for y = 0.3. The decrease in
ΔEQ of Fe1-yMnyPO4 samples can be explained by the exchange interaction due to theasymmetry in FeO6 octahedral sites depending on the Mn concentrations.

2

2

1

2

Nils Hollmann , Martin Valldor , Hua Wu , Zhiwei Hu , Navid Qureshi , Thomas
Willers2, Yi-ying Chin3, Julio Cezar4, Arata Tanaka5, Nicholas Brookes4 and Liu Hao
Tjeng3
1
Max-Planck-Institute for Chemical Physics of Solids, Dresden, Germany2
II. Institute of Physics, University of Cologne, Germany
3
Max-Planck-Institute for Chemical Physics of Solids, Germany
4
European Synchrotron Radiation Facility, Grenoble, France
5
Department of Quantum Matter, ADSM, Hiroshima University, Japan

July 9 (Mon)

CaBaFe 4O 7 is a new mixed-valent transition metal oxide from the class of
Swedenborgites [1,2] having both Fe2+ and Fe3+ ions in tetrahedral coordination situatedin a Kagome lattice. This class of materials could be an interesting starting point to study
orbital physics in tetrahedral coordination. Here we characterize its magnetic properties
by magnetization measurements and investigate its local electronic structure using
soft x-ray absorption spectroscopy at the Fe L2,3 edges, in combination with multiplet
cluster simulations and band structure calculations [3]. We found that the Fe2+ ion in theunusual tetrahedral coordination is Jahn-Teller active having a minority-spin electronwith an x2-y2 character. We deduce that there is an appreciable orbital moment caused
by multiplet interactions, thereby explaining the observed magnetic anisotropy.

Woo Jun Kwon, In Kyu Lee, Hee Seung Kim, In-bo Shim and Chul Sung Kim*
Department of Physics, Kookmin University, Korea[1] Sapronova N.V., Volkov N.V., Sablina K.A., Petrakovskii G.A., Bayukov O.A., Vorotynov A. M.,
Velikanov D.N., Bovina A.F., Vasilyev A.D., Bondarenko G.V. Phys. Stat. Sol. B., 246 (2009) 206[1] B. C. Melot, G. Rousse, J.-N. Chotard, M. Ati, J. Rodriguez-Carvajal, M. C. Kemei, and J.-M.
Tarascon, Chem. Mater. 23, 2922 (2011). [2] W. Kim, C. H. Rhee, H. J. Kim, S. J. Moon, and C. S.
Kim, Appl. Phys. Lett. 96, 242505 (2010).

PI09

PI12

PI15

Search for topological spin order in the multiferroic insulator
Cu2OSeO3

Effect of doping on the magnetic structure of YMn1-xMxO3 (M = Ga, Ti,
x ≤ 0.1)

Three- dimensional electronic structure of Na0.85CoO2[1] B. Raveau et al., Chem. Mat. 20, 6295 (2008) [2] B. Raveau et al., Z. Anorg. Allg. Chem. 635,
1869 (2009) [3] N. Hollmann et al., Phys. Rev. B 83, 180405 (2011)

M. Wagner1, T. Adams1, A. Chacon2, G. Brandl2, H. Berger3, P. Lemmens4 and C.
Pfleiderer1
1Physik-Department, Technische Universitaet Muenchen, D-85748 Garching,
Germany2
Physik-Department and Forschungsneutronenquelle Heinz-Maier Leibniz, TU
Muenchen, D-85748 Garching, Germany
3
Ecole Polytechnique Federale Lausanne, CH-1015 Lausanne, Switzerland
4
Institut fuer Physik, Technische Universitaet Braunschweig, Germany

Ordering and disordering of charge, spin, lattice and orbital degrees of freedom play an importantrole in the physics of strongly correlated electron systems. In the mixed valence (Fe3+/Fe4+)compound Sr4Fe4O11, the spin and charge ordering have recently generated a debate arisingfrom its two crystallographic (pyramidal and octahedral) sites and the distribution of Fe3+
and Fe4+ species [1-5]. Due to symmetry reasons, either the Fe4+ sublattice is frustrated while
Fe3+ ions order antiferromagnetically or the opposite. We are trying to explore this puzzle by
X-ray Absorption Spectroscopy, Photoemission Spectroscopy, muSR, Neutron, Synchrontron
X-ray diffraction and MOssbauer measurement on precisely adjusted oxygen stoichiometric
polycrystalline samples and single crystals.
1.J. P. Hodges, S. Short, J. D. Jorgensen, X. Xiong, B. Dabrowski, S. M. Mini, and C. W. Kimball. J. Solid. State. Chem.
151,190-209 (2000) 2 M Schmidt, M Hofmann and S J Campbell. J. Phys.: Condens.Matter 15, 8691-8701 (2003) 3
P Adler, A Lebon, V Damljanovic, C Ulrich, C Bernhard, AV Boris, A Maljuk, CT Lin, and B Keimer. Phys. Rev. B 73,
094451(2006) 4 R. Vidya, P. Ravindran, H. Fjellvag, and A. Kjekshus. Phys. Rev. B 74, 054422 (2006) 5 P.Adler Comment
Phys. Rev. B 77, 136401 (2008) and R. Vidya Reply Phys. Rev. B 77, 136402 (2008)

PI18

Y. Sassa1*, M. Mansson1, B. M. Wojek2, J. Chang3, M. Kobayashi4, J. Kanter1, V.
Strocov4, K. Mattenberger1 and B. Batlogg1
1
Laboratory of Solid State Physics, ETH Zurich, CH-8093 Zurich, Switzerland
2
Materials Physics, Royal Institute of Technology KTH, S-16440 Kista, Sweden
3
Laboratory for synchrotron and neutron spectroscopy, Paul Scherrer Institute, CH5234 Villigen PSI, Switzerland
4
Swiss Light Source, Paul Scherrer Institute, CH-5234 Villigen PSI, Switzerland

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Catalyst structure determination from magnetic properties

Jorge Hernandez-velasco1*, Javier Garcia-garcia2 and Angel Landa-canovas1
1
Energy, ICMM CSIC, Spain
2
CME UCM, Spain
SbVO4 series of compounds could be used as oxidation catalysts of industrial
interest yielding 20% cheaper acrylonitrile (production 8 million ton/year) by theammoxidation of propane compared to current method based on propylene asstarting reactant. SbVO4 structure was just known to be related to tetragonal rutile.
Nevertheless we have shown that actually there is a non-stoichiometric flexible series
described as Sb0.9V0.9+x□0.2-xO4 (0<x<0.2), where cation vacancies (□) are introducedin the basic rutile type-structure following the mechanism: 4V(3+)→3V(4+)+□, while
antimony remains as Sb(5+). In this sense, for the compounds synthesized in oxidizing
conditions the presence of vacancies has been confirmed, however no cation vacancies
have been observed in the reduced phase but alternating Sb/V cation order along the
crystallographic c-axis. On the other hand, our magnetic susceptibility studies could
distinguish between different phases including possible existence of magnetic order.
Using neutron diffraction we determined the magnetic structure of reduced SbVO4
coming from the ordering of vanadium magnetic moments, taking place at TN~50K,
and we studied how the substitution of V3+ (S=1) by V4+ (S = ½), while the synthesis
conditions become more oxidizing, affects the spin arrangement in SbVO4. The
structure-property relationship could be evaluated thanks to the magnetic behaviour.

We report a comprehensive study of the magnetic properties of single crystals of themultiferroic insulator Cu2OSeO3. Our study was motivated by the recent discovery of askyrmion lattice phase in the B20 transition metal Si and Ge transition metal compounds[1], which are isostructural siblings of Cu2OSeO3. For our study large high-quality single
crystals were grown by vapour transport. The magnetisation, ac susceptibility and specificheat were measured down to 2K under magnetic fields up to 9T. The magnetic properties
were studied with small angle neutron scattering. We find a paramagnetic to helimagnetictransition at T_c - 58K. The magnetic phase diagram of Cu2OSeO3 shares remarkablesimilarities with the B20 transition metal silicides, including the existence of a small phasepocket below T_c. The putative evidence for topological spin order is compared with theevidence for a skyrmion lattice in B20 transition metal Si and Ge compounds.

The effect of doping at the Mn site of multiferroic manganites, YMn1-xMxO3 (M = Ga, Ti, x≤ 0.1) have been studied by neutron powder diffraction and magnetic measurements. These
compounds have been prepared by solid state synthesis techniques. All the compounds studied
are isostructural and crystallizes with hexagonal structure in P63cm space group. We find thatboth Ga3+ (d10) and Ti4+ (d0) doping leads to significant reduction in the magnetic transition
temperature (TN) while they influence the magnetic structure of YMnO3 differently. The
magnetic structure of YMnO3 is described by the irreducible representation Γ1 (or Γ3 ) with
moment on Mn~3μB at 5K, in agreement with previously reported values on this compound[1]. We find that the representation remains the same on doping with Ga in YMnO3 albeit witha decrease in the value of the moment to 2.5μB at 6K. However, the irreducible representation
changes on doping with Ti, and this modified structure is given by the basis vectors of theirreducible representation Γ2 with moment 2.1μB at 6K. The geometrical frustration parameter,f = θp/Tn, ~ 7 and reduces with doping. These observations are different from the earlier
reported doping studies carried out in this compound [2].

[1] S. Muehlbauer et al., Science 323, 915 (2009).

[1]. J.A. Alonso et al. Phys. Rev. B 62 9498 (2000) [2] J. Park et al., Phys. Rev. B 79 064417 (2009)

PI10

PI13

PI16

PI19

Studies of neutron scattering and bulk properties of honeycomb lattice
Li2MnO3

Neutron diffraction and magnetic properties of Ba2Co2Fe12O22: Co2Y

Formation of stoichiometric of FeO synthesized under high pressure

Synthesis and characterization of the mixed perovskite Ba 1xLaxTi1/2Mn1/2O3 as a function of La-doping

Sanghyun Lee1, Sungil Choi1, Jiyeon Kim1, Choongjae Won2, Seongsu Lee3, Shin-ae
Kim3, Namjung Hur2 and Je-geun Park4*
1
Center for Strongly Correlated Materials Research, Seoul National University, Seoul
151-742, Korea
2
Department of Physics, Inha University, Incheon 402-751, Korea
3
Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305353, Korea
4
Department of Physics & Astronomy, Seoul National University, Seoul 151-742,
Korea
Li2XO3 with transition metal ions occupying the X position forms an interestinghoneycomb lattice. Among Li2XO3, Li2RuO3 was recently found to have an unusual
structural phase transition involving probably Ru dimerization. For example, it
was reported that the crystal structure changes from P21/m to C2/m near 540 K,
accompanied by a concomitant metal-insulator transition and an abrupt change inthe magnetic susceptibility. Li2MnO3 is another example having the C2/m crystal
structure with the honeycomb lattice. In order to investigate the magnetic properties ofLi2MnO3, we have successfully grown single crystal Li2MnO3 by using a flux method.
Using these single crystals, we have carried out both bulk measurements and neutron
diffraction studies with high resolution powder diffractometer (HRPD) and single
crystal diffractometer (FCD) at HANARO, Korea. We also measured the magnetizationand heat capacity of the single crystals.

152

Neetika Sharma1, Poonam Kumari2, A. Das1* and G. Ravi Kumar3
1
Solid State Physics Division, Bhabha Atomic Research Centre Mumbai, India
2
UM - DAE Centre for Excellence in Basic Sciences University of Mumbai, Mumbai,
India
3Technical Physics Division, Bhabha Atomic Research Centre Mumbai, India

Qiang Liu1,2,3, Gwendolyne Pascua4, Alexander Komarek3, Zhiwei Hu3, Nils Hollmann3, Olivier
Toulemonde2, Hubertus Luetkens4, Gwilherm Nenert5 , Alain Wattiaux2, Liu Hao Tjeng3
1
II. Physikalisches Institut, Universität zu Köln, Germany
2
Institut de Chimie de la Matière Condensée de Bordeaux, France
3
Max-Planck-Institut für chemische Physik fester Stoffe, Dresden, Germany
4
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute,CH-5232 Villigen PSI, Switzerland.
5Institut Laue-Langevin, 38042 Grenoble Cedex 9, France

The 19th International Conference on Magnetism

Chan Hyuk Rhee1, Jung Tae Lim1, Sung Wook Yoon1, Kwang Lae Cho1, Sung Baek
Kim2 and Chul Sung Kim1*
1
Department of Physics, Kookmin University, Korea
2
Advancement for College Education Center, Konyang University, Korea
Y-type hexa-ferrites with non-collinear magnetic structure have been studied formagnetoelectric effect, showing induced electric polarization under external magnetic
field. The helical magnetic structure of these ferrites depends on the temperature andmagnetic field [1]. Here, polycrystalline Y-type barium cobalt ferrite (Ba2Co2Fe12O22;
Co2Y) was synthesized by conventional ceramic method in O2 gas atmosphere to
reduce the oxygen defect. The temperature and magnetic field dependence of magnetic
structure was investigated by neutron diffraction and vibration sample magnetometer.
At temperature below TN = 615 K, the crystal structure of Co2Y was determined tobe rhombohedral with the space group R-3m. It showed soft ferrimagnetic behavior
with Hc of 145 Oe at 297 K. Most of super-lattice peaks from spin structure decreased
with increasing temperature. However, the peak at 21.1o increased with increasing
temperature at temperatures above 205 K. In addition, the slope of zero-field cooledmagnetization under low field of 0.01 T changed at 205 K. This magnetic structuretransition temperature of Co2Y is higher than that of Ba2Mg2Fe12O22 [1] due to thepresence of cobalt ion with strong magnetic anisotropy.
[1] S. Ishiwata, Y. Taguchi, H. Murakawa, Y. Onose, and Y. Tokura, Science 319, 1643 (2008).

July 9 (Mon)1

Natalia Mihashenok*, Nikita Volkov, Klara Sablina, Alexander Balaev, Maxim
Molokeev, Sergei Popkov and Dmitriy Velikanov
L.V. Kirensky Institute of Physics SB RAS, Russia

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Yasushi Kanke 1, Takuro Yoshikawa 2, Hideto Yanagihara 2, Eiji Kita2, Yorihiko
Tsunoda3, Kiiti Siratori2 and Kay Kohn3
1
National Institute of Materials Science, Japan
2
Institute of Applied Physics, University of Tsukuba, Japan3
School of Science and Engineering, Waseda University, Japan
FeO has the simplest NaCl crystalline structure and one electron exists in thedegenerated dε orbitals due to the regular octahedral ligands. Even such simple
structure, the partial quenching of the orbital angular momentum (S = 2 and L = 1)
bring the electronic structure complex.[1] Difficulty in the sample preparation, only the
samples FeXO with X ≤ 0.96 have been obtained, makes the experimental investigationof FeO hard. We have prepared the stoichiometric FeO with the high pressure synthesis
technique.[2] The starting material of the mixture of α-Fe and Fe2O3 powder wassealed in a Pt capsule and was heated up to 1000 °C and 1200 °C under 5.5GPa for 1
hour. The residual ferromagnetic parts were estimated to be less than 0.69 at%. Higher
reaction temperature may bring lower concentration of ferromagnetic components.
From Mossbauer study, it is found that the Koch-Cohen cluster does exist especiallywhen the reaction temperature is high. We present the influence of post annealing withvarious conditions for the improvement of degree of stoichiometry.
[1] J. Kanamori: Prog. Theo. Phys. 17, 177 (1957) [2] T. Katsura, B. Iwasaki, S. Kimura, S.
Akimoto : J. Chem. Phys. 47, 4559 (1967)

Raimundo Lora-serrano1*, Ulisses F Kaneko2, Eduardo Granado2, Ali F. Garciaflores2, Pablo Marques-ferreira1, Fernando A. Garcia3 and Jose G. S. Duque4
1
Instituto de Fisica, Universidade Federal de Uberlandia, 38400-902 Uberlandia-MG, Brazil
2
Instituto de Fisica 'Gleb Wataghin' UNICAMP, CP 6165, 13083-970 Campinas, SP, Brazil
3
Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
4
Nucleo de Fisica, Campus Itabaiana, UFS, 49500-000, Itabaiana, SE, Brazil

Oxides materials with perovskite structure are outstanding examples of materials used in technologicalapplications, as well as in fundamental studies in condensed matter physics due to the great number ofobserved ground states such as: multiferroicity, high-temperature superconductivity, colossal magnetoresistive
effects, multiferroicity, and many others. One possible way to work and study on the coexistence ofelectric and magnetic orders within metal oxides perovskites may be making “mixed” perovskites withd^0 and d^n ions. In this work we present the results of the synthesis and structural characterization (x-ray
powder diffraction and Raman spectroscopy analysis) within the family of transition metal oxides Ba1xLaxTi1/2Mn1/2O3 (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) as we dope the 12R-type perovskite BaTi1/2Mn1/2O3 with
the non-magnetic ion La3+. Our results show the evolution of the structure symmetry from the hexagonal
one for the non-doped (x=0) sample [1] to a tetragonal one for the highest La concentration as well as the
mixture of these two phases for intermediate doping. These results are compared with the appearance offerromagnetic and antiferromagnetic orders as a function of La-content, temperature and magnetic field.
[1] G. M. Keith, C. A. Kirk, K. Sarma et al., Chem. Mater. 16, 2007 (2004).

July 8-13, 2012 Busan, Korea

153

poster Presentation
PI20

PI23

PJ02

PJ05

Theoretical modeling of the magnetic properties and magnetocaloric
effect in La0.1Ca0.9MnO3 manganite by Monte Carlo study

The effect of cu substitution on the structural, electrical and magnetic
properties of LaMn1-xCuxO3 manganites

The new type of current and spin polarization oscillations

Parviz Kameli*, H. Vaezi, B. Aslibeiki and H. Salamati
Isfahan University of Technology, IranAlexander I Kopeliovich and Pavel V Pyshkintheoretical physics, B.Verkin Institute for Low Temperature Physics and Engineeringof the National Academy of Sciences, Ukraine

Enhancement of magnetocaloric width in La2/3Ca1/3MnO3 compoundswith remain the composition ratio between Mn3+ and Mn4+

Manganites have a special place among various materials which have a magnetocaloric
effect. This materials, first, allow varying temperature of phase transitions in wide regionof temperatures, and secondly, they are cheap and ecological. Experimental studies haveshown that the manganites are also attractive for the application in magnetic refrigeration [1].
In this work, using the Heisenberg’s Hamiltonian, we investigated by Monte Carlo method
magnetic and magnetocaloric properties of La0.1Ca0.9MnO3. In the simulation, magnetic
Mn4+ and trivalent Mn3+ ions are described by classical Heisenberg spins, while oxygen andcalcium ions are considered as non-magnetic. Mn magnetic ions are distributed on a lattice
according to the perovskite structure of the manganite. For the modelling lattice samples ofsize L3 with L=15 were used. Around 5x105 Monte Carlo steps per spin were considered
in order to compute equilibrium averages. Curie temperature obtained during the theoreticalsimulations (TC ~150 K) agrees well with theoretical result for this compound (TC ~150
K) [2]. The Curie temperature and magnetocaloric effect obtained during the theoreticalsimulations agree well with experimental data. Support by RFBR grants 10-02-96020-r-ural,
11-02-00601 and Federal Target Program № 14.740.11.1442 (03.11.2011) is acknowledged.

The hole-doped manganites, La1-xAxMnO3 (A = Sr, Ca, Ba or vacancies) with a
Perovskite structure have attracted considerable attention due to the discovery of thephenomenon of colossal magnetoresistance (CMR) and its potential application [13]. In this study, the effect of Cu substitution on structural, electrical and magnetic
properties of LaMn1-xCuxO3+δ (0≤ x ≤ 0.075) manganites are investigated by XRD,
electrical resistivity and Ac susceptibility measurements. The XRD refinement
result indicates that the samples are single phase and the lattice parameters andvolumes increase by the increase of the Cu doping level. The resistivity measurement
results show that by increasing Cu doping level, the resistivity decreases and theheavily doped samples show metal - insulator transition at low temperatures. The
paramagnetic- ferromagnetic transition temperature, Tc increases for low level doped
samples and decreases for heavily doped samples. The analysis of the frequency
dependent Ac susceptibility measurements by critical slowing down model, indicatesthat the reentrant spin glass (RSG) state exists in x=0.025, 0.05 and 0.075 samples.
The RSG state is mainly ascribed to the coexistence of ferromagnetic (FM) andantiferromagnetic (AFM) phases and increase of disorder in the FM matrix induced by
the random Cu impurity.

In our work we found new type of spin polarization and current oscillations in
conducting rings with inhomogeneous magnetic properties. In case of hydrodynamic
electron transport (when frequency of electron-electron collisions is more thanfrequency of collisions that does not conserve momentum of electrons) we obtained
spin hydrodynamics equations for non equilibrium electron spins when the electron
spectrum was spatially inhomogeneous. We showed that in case of close conductor
these equations had non zero solution in form of “spin pendulum” oscillations,i.e. oscillations of full current and spin polarization with frequency determined bycharacteristics of magnetic inhomogeneity. We found own oscillations of electron
system in conducting ring consisting of two parts with different magnetic properties.
For example it could be realized by connecting DMS and NMS conductors into a ringand placing it in magnetic field. We used equations similar to well-known two-current
model and we showed that conductance of this system as a function of external EMF
frequency had one maximum in hydrodynamic regime and this case was conform to'spin pendulum', and conductance had many maximums in a case of ballistic regime.
These maximums vanished when magnetic properties of parts of the ring wereidentical.

Large magnetic entropy in a relative narrow transition temperature in manganites has
been reported. To explore the enhancement of transition temperature width with large
magnetocaloric properties, we here designed the samples with the same composition
ratio of Mn3+ and Mn4+, and the same averaged radius at each lattice sites, which we
previously used to find the roles of the local Jahn-Teller distortion on the magnetic
properties in manganites. Here, Y and Sr are used together to replace for La and Ca in
La2/3Ca1/3MnO3 (i.e., ABO3) to remain the average radius and the average valance at
A-site. Results show that the averaged unit cell lattice parameters are unchanged. The
ferromagnetic-to-paramagnetic transition temperature Tc increases abruptly owing to
the increase of the competition between σ2 and double-exchange interaction resulting
from Mn-O-Mn bond angle. The disordered distribution of cations at A-site broaden
the phase transition temperature range (~T~10K or more) with large magnetic entropyof ΔSM=1.3 J/Kg K, which may be used as a promising candidate for magnetic
refrigerant near room temperature.

PI21

PI24

PJ03

PJ06

Pressure effects on magnetic ordering transitions of bilayer manganites
Pr(Sr1-xCax)2Mn2O7 (x=0,1) by neutron diffraction and muon spinrasonance

Investigation of the structural and magnetic peroperties of
La0.9Sr0.1MnO3 nanoparticles

Pressure-enhanced giant magnetoresistance in Fe/Cr magnetic
multilayers

Output voltage calculations in double barrier magnetic tunnel
junctions with asymmetric voltage behavior

Pressure-enhanced Giant Magnetoresistance in Fe/Cr Magnetic Multilayers G
Oomi1),S.Higashihara2),K. Suenaga2),K.Saito3),S.Mitani3) and K.Takanashi4)1)Kurume Institute of Technology,Kurume,Fukuoka,Japan 2)Department of
Physics,Kyushu University,Fukuoka,Japan,3)Institute of Materials Research,Tohoku
University,Sendai,Japan The giant magnetoresistance(GMR) of Fe/Cr magnetic
multilayers has been measured under high pressure at low temperatures. It is found that
the GMR on the second peak samples is enhanced strongly by applying pressure:themagnitude of GMR becomes twice at 2 GPa compared with the value at ambientpressure.The saturation magnetic fields of these samples decreases with increasingpressure.However the GMR of the first peak samples decreases with increasingpressure and the saturationfields increases with pressure. These sharp differences in the
behaviour against pressure will be discussed phenomenologically.

We studied the asymmetric voltage behavior of the tunnel magnetoresistance (TMR)
for single and double barrier magnetic tunnel junctions (S&DMTJ) in range of aquasi-classical tunneling model. Numerical calculations of the TMR-V curves, output
voltages and I-V characteristics for the negative and positive applied voltages werecarried out using MTJs with CoFeB/MgO interfaces. Asymmetry is explained bydifferent values of the minority and majority Fermi wave vectors for the left and rightsides of the tunnel barrier, which can arises due to different annealing regimes. Electron
tunneling in DMTJs was simulated in two ways: (I) Coherent tunneling, where the
DMTJ is modeled as one tunnel system and (II) consecutive tunneling, where the
DMTJ is modeled by two SMTJ connected in series. We found that DMTJs, in rangeof model I, the output voltage peaks will be shifted into the region of low voltages. For
the model II, we found that, in order to provide symmetric output voltage branches in
DMTJ, the conditions of equal Fermi vectors ratios have to be fulfilled for the left andright magnetic layers while ratio in the middle layer can be different.

1 Phan, Manh-Huong. 2007, Review of the magnetocaloric effect in manganite materials, J. Magn. Magn.
Mater. 308: 325-340. 2 Restrepo-Parra E. 2011, Magnetic phase diagram simulation of La1-xCaxMnO3 system
by using Monte Carlo, Metropolis algorithm and Heisenberg model, J. Magn. Magn. Mater, 323:1477-1483.

Guochu Deng1*, Denis Cheptiakov2, Ekaterina Pomjakushina3 and Kazimierz Conder3
1
Bragg Institute, Australian Nuclear Science and Technology Organization, Australia
2
Laboratory for Neutron Scattering (LNS), Laboratory for Neutron Scattering, Paul
Scherrer Institut, Switzerland
3
Laboratory for Developments and Methods, Paul Scherrer Institute, Switzerland

M. Eshraghi1*, M. Roshanmehr1, F. Khademi2, P. Kameli2 and H. Salamati2
1
Department of Physics, Payame Noor University, Iran2
Department of Physics, Isfahan University of Technology, Iran

Gendo Oomi*
Kurume Institute of Technology, Japan

Qing Ji and Xiaoshan Wu*
Physics, Nanjing University, China

July 9 (Mon)

July 9 (Mon)

Oksana Pavlukhina*, Vacily Buchelnikov and Vladimir Sokolovskiy
Chelyabinsk State University, Russia

Artur Useinov, Jurgen Kosel and Aurelien Manchon
King Abdullah University of Science and Technology, Saudi Arabia.

In recent years, magnetic nanoparticles have been the subject of intense research not
only for their fundamental scientific interest such as superparamagnetism, but also
for their potential applications in magnetic storage media, biosensor devices andmedical applications, such as targeted drug delivery and hyperthermia [1-3]. In a large
number of magnetic nanoparticles applications, it is important to know the effects ofinteraction between nanoparticles on physical properties of these systems. In this paper,
we studied the structural and magnetic properties of La0.9Sr0.1MnO3 nanoparticles.
Magnetic nanoparticles of La0.9Sr0.1MnO3 manganite with mean particle sizes of 20
nm were prepared by the Microwave synthesis method. The crystal structure of thesamples were analyzed, using X-ray diffractometer with Cu-kα ( 0.154 nm) radiation.
The morphology of the samples was characterized by a scanning electron microscope(FESEM). Magnetic dynamics of the samples was studied by the measurement of ac
magnetic susceptibility versus temperature and frequency. The XRD pattern alongwith Rietveld analysis indicates that the samples are nearly single phase. By fitting
the experimental data with Vogel-Fulcher law, the relaxation time, characteristic
temperature, magnetic anisotropy energy and effective magnetic anisotropy constant
have been estimated.

PI22

PJ01

PJ04

PJ07

Magnetization reversal and chemical pressure effect in the electron
doped manganite Ca(Mn1-xSbx)O3

Magnetotransport properties of anisotropic Co(tCo)/Au(tAu)multilayers

Spin current-induced by sound wave

Spin-current manipulation by domain wall motion in the non-local
spin valve

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Syuya Ohuchi1, Michiaki Matsukawa1*, Satoru Kobayashi1, Shigeki Nimori2 andRamanathan Suryanarayanan3
1Dep. of Materials Science and Engineering, Iwate University, Japan
2
National Institute for Materials Science, Japan
3
Universite Paris-Sud, France
In ref.1, we have demonstrated the effect of hydrostatic pressure of magnetic andtransport properties, and thermal transport properties in the electron doped manganite
Ca(Mn1-xSbx)O3. The substitution of Sb5+ ion for Mn4+ site of the parent matrix causes
one-electron doping since the X-ray photoemission spectroscopy of Sb substituted
CaMnO3 sample reveals that the valence of Sb ion is 5+. Anomalous magnetization
reversals are observed at x=0.05 and 0.08 in the field cooled magnetization while theapplication of external pressure induces a suppression of the negative magnetization.
The effect of chemical pressure on magnetization of Ca(Mn,Sb)O3 are examinedthrough the substitution of Ca ion for Sr with larger ion radius and are comparedwith the effect of external pressure on that of the same compound. We believe thatthe magnetization reversal is not caused by ferrimagnet model but is associated withthe presence of the Jahn-Teller type orbital lattice coupling between 3d eg electron
and MnO6 octahedron, giving stabilization of negative canted spin state through the
Dzyaloshinsky-Moriya interaction.
Ref.1, Y.Murano et al., Phys.Rev.B83,054437 (2011).

154

poster Presentation

The 19th International Conference on Magnetism

Conrad Rizal1, Parshu R. Gyawali2 and Ramesh K. Pokharel3
1
Electrical and Computer Engineering, University of British Columbia, Canada
2
Laboratory for Nanospintronics and Nanoelectronics, Catholic University ofAmerica, USA
3
Electrical and Communication Engineering, Kyushu University, Japan
Artificially tailored Co/Au multilayers have been the subject of intense research in search ofnovel properties for potential applications [1] [2]. Earlier, we reported various components
of giant magnetoresistance (GMR) effects and correlated them with microstructure of theisotropic multilayers [2]. In this work, we have investigated the effects of incident angle ofdeposition and magnetic annealing on GMR and magnetic properties of anisotropic Co/Au
multilayers as the layer thicknesses of Co and Au are changed. We have investigated physicalmechanisms responsible for various MR effects and correlated them with the existingmodels. The multilayers deposited at an oblique incident angle of 45 degree exhibited strong
magnetic anisotropy. The maximum MR ratio is found to be 2.1 %. The transverse MR
effect is always found to be larger than the longitudinal MR effect. These multilayers havebeen considered potential in developing biomagnetic technology.
[1] E. T. Papaioannou et al. 'Magnetic, magneto-optic and magnetotransport properties ofnanocrystalline Co/Au multilayers with ultrathin Au interlayers,' J. Nanosci. Nanotechnl, vol. 8,
pp. 4323-4327, 2008. [2] C. Rizal, 'Study of magnetic anisotropy and magnetoresistance effects inferromagnetic Co/Au multilayer films,' J. Magn. Magn. Mater., vol. 310, pp.e646-e648, 2007.

Igor Ivanovich Lyapilin
Institut Metal Physics RAS, Russia

Ryoko Sugano1, Masahiko Ichimura1, Saburo Takahashi2 and Sadamichi Maekawa3
Central Reserach Laboratory, Hitachi, Ltd., Japan
2
Institute for Materials Research, Tohoku University and CREST-JST, Japan
3
Advanced Science Research Center, Japan Atomic Energy Agency and CREST-JST,Japan
1

In recent years, increased interest in studying the effects that arise in response to spin
degrees of freedom of electrons, when the external perturbation acts on the kinetic
degrees of freedom. As rule, the external perturbation (electric field) directly affects
only the kinetic degrees of freedom of electrons and through spin-orbital interaction
is transferred to the spin subsystem. There are other ways of influencing the systemof conduction electrons, which are also reflected in the response of the spin degrees
of freedom. So, in the ferromagnetic metals temperature gradient leads to the spin
Seebeck effect. It is interesting to consider the mechanisms of interaction withexternal fields, in which the energy of the external field is transmitted simultaneously
in both electronic subsystems (kinetic and spin). An example of such interaction is
the interaction of conduction electrons with the field of sound waves. We studied theevolution of the electronic system for their interaction with the field of sound wave
analysis of the conditions of occurrence and the the responce of the spin subsystem
in a constant magnetic field. It is shown that in this case the longitudinal sound wave
propagation arises transverse spin current, which has a resonant character.

A spatially- and time-dependent magnetic spin texture exerts a spin-dependent force on conduction
electrons[1]. In particular, spin-motive force generated by a domain wall motion has been theoreticallyinvestigated and experimentally observed by detection of electric voltage[2,3]. The spin-dependent field
generated by spin-motive force is also expected to directly affect the non-equilibrium magnetizationsuch as spin accumulation. In order to study the effect of the spin motive force on the spin accumulation
in a lateral non-local spin-valve (NLSV) structure, we treat the NLSV device attached with a magnetic
wire. The device consists of spin injector F1 and detector F2 strips bridged by an non-magnetic strip N
and the magnetic wire is attached on N through the insulating layer in-between two magnetic stripes.
A domain wall is introduced into F3 and driven by external magnetic fields. The spin-dependent field
drives the pure spin current flowing in the N-channel. This effect can be detected as increase or decreasein the nonlocal spin-accumulation signals depending on the domain wall motion. We evaluated thespin-dependent field based on the LLG approach and calculate the spatial distribution of spin/charge
current of this NLSV by applying a finite element method in three-dimensions.
[1] S. Barnes and S. Maekawa, Phys. Rev. Lett. 98, 246601 (2007). [2] S. A. Yang et al., Phys. Rev.
Lett. 102, 067201 (2009). [3] P. N. Hai et al., Nature 458, 489 (2009).

July 8-13, 2012 Busan, Korea

155

poster Presentation
PJ08

PJ11

PJ14

PJ17

The study of microwave assisted magnetization reversal via spin
pumping

Magnetoresistance of CoFe/Pt nano-contacts

Domain wall configuration and magneto-transport properties in dual
spin-valve with nanoconstriction

Spin transport phenomena through MgO/CuPc hybrid barrier inmagnetic tunnel junctions

There has been a significant interest to switch high coercivity magnetic bits for the
future magnetic media by lowering the coercivity during the writing process. MAMR
is a popular method of reducing the coercivity. We present a novel method of studying
MAMR via spin pumping and the inverse spin Hall effect (ISHE). In this method, a
Pt layer was placed in contact with a ferromagnetic (Py) layer, and an rf signal wasapplied to the Py via a coplanar waveguide during loop measurements. Due to thepresence of the rf power, magnetization dynamics in the Py layer pumps spin in theadjacent nonmagnetic Py layer, which creates a measurable dc voltage across the Pt due
to the ISHE. The measured signal is of the order of several microvolts and thus does
not affect the magnetization by any significant amount. It also effectively decouples
the input rf input from the dc output. The coercivity can be easily detected by the field
at which there is a change in the polarity of the measured voltage. The coercivity as afunction of the applied rf power is studied.

Muftah Al-mahdawi* and Masashi Sahashi
Department of Electronic Engineering, Tohoku University, Japan
Using an alumina-based Nano-Oxide Layer (AlOx-NOL) between with many nanoholes between two ferromagnets [1] has gained more interest in recent years both intheir fundamental physics of spin-scattering off the confined domain-walls and intheir applicability for next-generation hard-disk-drive reading heads. Also, spin-torquedriven oscillations of the confined domain-walls has been reported [2]. Following
the report by [3] that Pt is magnetized at the interface with Co, we examined theinsertion of AlOx-NOL between the Co-rich Co90Fe10 and Pt. Film stack was (in nm):
Underlayer/Co90Fe10 3/AlOx-NOL/Pt 2/cap. It was deposited using ion-beam sputteringand dc magnetron sputtering deposition. AlOx-NOL was prepared using Ion-Assisted
Oxidation (IAO) process[1]. IAO process forms direct nano-contacts (NC) in NOL
between the CoFe and Pt (1~2 nm in diameter, with <1% areal density). One film
was pin-annealed in a 10 kOe field at 270°C for 1.5 hours and the other was left as is.
Magnetization curve was measured using VSM at room-temperature and showed only
the curve of CoFe. Current-In-Plane Tunneling (CIPT) at room-temperature showedthat CPP RA product were around 0.24 Ωμm² for both films, and MR ratio was 3% (asdepo film) and 5% (pin-annealed film). Further discussion and data will be presented.
[1] M. Takagishi et al., Journal of Applied Physics, vol. 105, no. 7, 2009. [2] H. Suzuki et al.,Journal of Applied Physics, vol. 105, no. 7, 2009. [3] M. Suzuki et al., Physical Review B, vol. 72,
no. 5, p. 054430, 2005.

In this work, we use a synthetic antiferromagnet-based dual spin-valve (SAF-DSV) structure(i.e. the SV structure is doubled symmetrically with respect to the FM) and present the effectof the direction of the applied magnetic field with respect to nanoconstriction shapes on themagneto-transport properties including domain wall (DW) configuration and reversal process.
We can tune the DW configuration and its reversal process from a vortex to a transverse typeby changing the direction of applied magnetic field respect to the nanoconstricted SAF-DSV.
When the field is applied in the perpendicular direction to the nanoconstricted SAF-DSV, theperpendicular magnetic moments are developed due to the transverse magnetization reversal
mode and result in a multistep switching process. This multi step switching process reflects thepinning and depinning of a DW at the nanoconstriction. Our results also show an asymmetricdepinning field. We demonstrate, if nanoconstriction is asymmetric along its length, i.e.
expansions from both sides of the neck into the two nanowires are not identical, and then an
asymmetric energy barrier to domain wall propagation is formed. This is due to the difference
in DW width, which leads to an asymmetry in the domain wall depinning forces.

Yu Jeong Bae1, Nyun Jong Lee1, Tae Hee Kim1*, Hyunduck Cho2, Changhee Lee2,
Luke Fleet3, Atsufumi Hirohata3, Yeong-ah Soh4 and Gabriel Aeppli4
1
Physics, EWHA Womans University, Korea
2
School of Electrical Engineering and Computer Science, Seoul National University,
Korea
3
Electronics, The University of York, United Kingdom
4
London Centre for Nanotechnology, United Kingdom
For realistic applications of organic spintronic devices, the investigation of the growthmechanism and electrical properties is of great importance to understand the spin transportphenomena in metal-organic hybrid systems. As the first step, we focused on surface
morphology, growth mode, and thermal stability of thin Cu-phthalocyanine (CuPc) organic
layers grown on metal surfaces covered with a few monolayer thick insulating films, suchas MgO(001). Recent reports of achieving spin polarized tunneling across organic-inorganic
hybrid barrier with significant magnetoresistance (MR) values at low temperature (< 10K) led us to study the organics semiconductor (OSC) thin films for substituting highly
performing inorganic barriers. Therefore, we investigated systematically the spin transportphenomena through the OSC CuPc barrier with and without MgO(001) layer as a function of
CuPc thickness. An epitaxial Fe(001)/MgO(001) layer was utilized as a spin injection layer,
while a polycrystalline Co film as a spin detector. Here, we observed, for the MgO/CuPc
hybrid barrier with a total thickness of ~ 3 nm, the high MR (> 200 %) values at 77 K and ~10 % MR at 300 K in the Si(001)/MgO/Fe/MgO(001)/CuPc/Co hybrid tunnel junctions.

PJ09

PJ12

PJ15

PJ18

Contributions of domain walls on large magnetoresistance effect inultrathin TbFeCo wires

Inversion of magenetoresistance in La1-xSrxMnO3/Nb-doped SrTiO3/
CoFe junctions

Giant magnetocaloric effect of Mn0.91Ca0.09As thin film on Al2O3 (0001)

Theoretical approach to spin-current absorption at an interface

Bang Do and Hiroyuki Awano
Toyota Technological Institute, Japan

Perpendicular anisotropy magnetic materials such as TbFeCo are expected to introduce
large effectivity of spin-transfer torque and high domain wall (DW) motion speed aswell as high magnetoresistance (MR) values. We investigated the size dependenceof MR effect in TbFeCo wires. The 80-μm-length and different widths (1 to 80 μm)
of Tb26Fe66.8Co7.2 wire-patterns were designed by using electron beam lithography
technique. The Tb26Fe66.8Co7.2 films with different thicknesses of 6, 18 nm were grownby RF sputtering. It is found that MR values are strongly depend on injection current
for all applied fields. Large MR values which up to 100% were observed at a low bias
current and depend on DW structure inside the TbFeCo wires. On the other hand, theMR values rapidly reduced at large bias currents which induce magnon and phonon
scattering effects. The introduction of DWs in a magnetic wire causes an increase in
spin-dependent scattering inside the DWs and leads to an enhancement of resistivity
expectedly. The well defined and controllable number of DWs inside magnetic nanowires will expectedly introduce a new technique to obtain high and multi-level MR
values as well as high potentials on future magnetic devices.

Kenji Ueda*, Katsunori Tozawa, Keita Sakuma, Naoto Fukatani, Tetsuya Miyawaki
and Hidefumi Asano
Graduate school of engineering, Nagoya University, Japan

Duong Anh Tuan1, Cho Sunglae1*, Dang Duc Dung2, Shin Yooleemi1 and Jeon Seung
Mok1
1
Physics, University of Ulsan, Korea
2
Physics, Depart of General Physics, School of Engineering Physics Hanoi
University of Science and Technology., Viet Nam

Understanding of the spin transport thorough ferromagnet/semiconductor interfaces is a critical issue
to realize novel spintronic devices such as spin transistors. Specially, spin transport in degenerated
semiconductors, which becomes metallic by heavy doping, is important for avoiding conductivity
mismatch problems. In this study, magnetic junctions using degenerated semiconductors, Nb-doped
SrTiO3 (Nb-STO), as intermediate layers were fabricated. XRD measurements indicate 15mol%
Nb-STO and La0.7Sr0.3MnO3 (LSMO) films were epitaxially grown on MgO substrates (MgO(001)[100]//Nb-STO(001)[100]//LSMO(001)[100]). In the hysteresis curves of the LSMO/Nb-STO/
CoFe at 4.2 K, two step magnetization correspond to the Hc of LSMO and CoFe were observed.
The junctions using the trilayers showed magnetoresistance (MR) of ~5 % at 4.2 K. The sign andthe magnitude of the MR were changed depending on the thickness of Nb-STO. Typically, positive
MR of ~2% for 10 nm and negative MR of ~1% for 15 nm were observed. The origin of the MR
is under investigation, however we consider these behaviours can be explained by regarding thetrilayers as magnetic tunnel junctions with double tunnelling barriers (FM/I/NM/I/FM), whichshow oscillation of MR [1]. The depletion layers (~2 nm) at the interface between Nb-STO andferromagnets seem to be behaved as insulative barriers in the junctions.

The MnAs compound is promising to magnetocaloric effect (MCE) application [1]. It presents thefirst order phase transition from a ferromagnetic to paramagnetic ~ 318 K, which is accompanied by astructural transition from a hexagonal NiAs-type (α-MnAs) to orthorhombic MnP-type structure (β-MnAs)[2]. Recently, the room temperature giant magnetocaloric effect was obtained by substitution of Mn by
Fe, Co, Cu or Cr in MnAs: Co-25 J/kgK at 4T, Cu-175 J/kgK at 5T, Cr and Fe-42 J/kgK at 5T [3-5].
However, there is less information about group II dopants such as Ca, Ba, and Sr in MnAs. In this work,
we report the magnetism and transport properties of epitaxial Ca0.09Mn0.91As thin film on Al2O3(001)substrate. The RHEED and XRD results indicated that film were epitaxially grown on Al2O3(0001). The
temperature dependent resistivity showed metallic and the temperature dependent magnetoresistanceat 7 kOe showed a peak around 325K. The negative anomalous Hall effect was observed in Hallmeasurement. The magnetic measurement indicates that the sample is ferromagnetic with TC was around
340K and display the giant magnetocaloric signal. The magnetization hysteresis loops exhibited thesaturation magnetization (MS) was around 300 (emu/cm3) at 10K and 180 (emu/cm3) at 300 K.

[1] S. Yuasa et al., Science 297 (2002) 234.

PJ13

PJ16

First-principles study of conductivity tensor in transition metals andalloysSpin transfer torques in antiferromagnets

Anomalous Hall effect of [Amorphous CoSiB/Pt] multilayer films

Spin-orbit interaction which is a relativistic correction to electron motion influences thetransport properties, so the resistance anisotropy and Hall effect appear in conductivity
tensor. In the present work, we calculate the conductivity tensor of transition metals
and alloys in first-principles by the Fermi-surface term of Kubo-Streda formula. To
calculate the conductivity tensor and electronic structure with spin-orbit interaction,
we employ the tight-binding linear muffin-tin orbital method based on the local
spin-density approximation [1]. The substitution disorder of alloys is treated using
the coherent potential approximation. The obtained anomalous Hall conductivity,
anisotropic magnetoresistance ratio, and also normal resistivity in ferromagnets
such as Fe-Co and Fe-Ni as a function of the alloys composition are quantitatively
consistent with the available experimental measurements in terms of their magnitude
and sign. In particular we find that the Hall resistivities reveal the nontrivial behavior
against the magnetization which can be varied by the modification of the composition
ratio. Furthermore, the intrinsic and extrinsic contribution of the Hall conductivity iscomparable in these alloys systems. Also we show the calculation results about the spin
Hall conductivity of nonmagnetic compounds obtained in similar frameworks.
[1] I. Turek, et.at., Philos. Magaz. 88, 2782 (2008); I. Turek, et.al. Phys. Rev. B 65, 125101 (2002).

The 19th International Conference on Magnetism

Hamed Ben Mohamed Saidaoui1, Aurelien Manchon2* and Xavier Waintal3
1
Physical Science and Engenering, King Abdullah University of Science And Technology KAUST, Saudi Arabia
2
Physical Science and Engineering, King Abdullah University of Science And Technology KAUST, Saudi Arabia
3
Departement de Physique, SPSMS-INAC-CEA, France
Current-driven magnetization switching through spin transfer torque [1] has been widely studied inferromagnetic (F) spin-valves [2,3]. Recently, Nunez et al. [4] theoretically showed that spin-valves basedon antiferromagnetic (AF) electrodes also display outstanding spintronics properties such magnetoresistanceand spin torque. Whereas the nature of current-driven torque has been theoretically examined in AF spinvalves [6,7], promising experimental results have been obtained on F/N/F/AF spin-valves structures (F is aferromagnet and N is a normal metal) [5]. However, the microscopic origin of the spin torque between F and
AF layers has not been addressed. In the present study, we apply non-equilibrium Green's function formalism
in the tight- binding approach to investigate the spin transport in spin-valves consisting in N/AF/N/AF/N and
N/F/N/AF/N. Whereas the spin torque calculated in the AF spin-valve is consistent with previous results [4,6,7],
it presents significant differences in the latter structure (angular dependence, spatial distribution and relative
magnitude between the in-plane and out-of-plane torque). Interestingly, we find that the AF layer exerts a
torque on the F layer. Finally, we analyze the contribution of the in-plane torque and out-of-plane torques on
the different sub-lattices of the AF layer and discuss the implications in terms of magnetization dynamics.
[1] J. C. Slonczewski, J. Magn. Magn. Mater. 159, L1 (1996) [2] E. B. Myers et al., Science 285, 867 (1999). [3] J.
A. Katine et al., Phys. Rev. Lett. 84, 3149-3152 (2000). [4] A. S. Nunez, R. A. Duine, P. Haney and A. H. MacDonald,
Phys. Rev. B 73, 214426 (2006). [5] Z. Wei, A. Sharma, et al., and M. Tsoi, Phys. Rev. Lett. 98, 116603 (2007). [6] R. A.
Duine et al., Phys. Rev. B 75, 014433 (2007) [7] Yuan Xu, Shuai Wang, and Ke Xia, Phys. Rev. Lett. 100, 226602 (2008).

Kazuhiro Tsutsui1, Kazuhiro Hosono2 and Takehito Yokoyama1*
Dept. of Physics, Tokyo Institute of Technology, Japan
2
Dept. of Physics, Tokyo Metropolitan University, Japan1

In the development of spintronic devices, techniques to detect spin currents efficiently
are indispensable as well as the generation of spin currents. In general, the spin-current
detection is demonstrated via the inverse spin Hall effect and the absorption of thespin current [1]. In this presentation, we theoretically examine the spin current induced
by an inhomogeneous spin-orbit coupling due to impurities [2]. Using the Keldysh
Green’s function formalism, we propose analytical expressions of the diffusive spincurrents under an external electric field and find a spin-current generation in thepresence of both gradient of the spin-orbit strength and that of the external field.
The resulting diffusive spin current indicates the absorption of the spin current at theinterface between materials with different spin-orbit strengths, which is exemplified
with an experimentally relevant setup.
[1] T. Kimura, Y. Otani, T. Sato, S. Takahashi, and S. Maekawa, Phys. Rev. Lett. 98, 156601 (2007).
[2] K. Hosono, A. Yamaguchi, Y. Nozaki, and G. Tatara, Phys. Rev. B 83, 144428 (2011).

[1] L. Daweritz, Pep. Prog. Phys. 69, 2581 (2006). [2] J. Mira et al, Phys. Rev. Lett. 90, 097203(2003). [3] Wang et al, Appl. Phys. Lett. 97, 042502 (2010) [4] D. L. Rocco et al, Appl. Phys. Lett.
90, 242507 (2007). [5]C. S. Mejia et al, Appl. Phys. Lett. 98, 102515 (2011).

PJ10
Yohei Kota* and Akimasa Sakuma
Department of Applied Physics, Tohoku University, Japan

156

Byong Sun Chun1, Chan Yong Hwang1, Han Chun Wu2, Mohamed Abid3, Su Jung
Noh4 and Young Keun Kim4
1
Korea Research Institute of Standards and Science, Korea
2
Trinity College Dublin, Ireland
3
Ecole Polytechnique Federale de Lausanne/IPMC, Switzerland
4
Korea University, Korea

July 9 (Mon)

Sankha Subhra Mukherjee, Siddharth Rao, Praveen Deorani, Jae Hyun Kwon,
Charanjit Singh Bhatia and Hyunsoo Yang*
ECE, National University of Singapore, Singapore

July 9 (Mon)poster Presentation

Hana Lee, Insung Park, Hyungjun Kim, Sungyong Kim, Youngkwang Kim, Hwayong
Noh and Taewan Kim*
Sejong university, Korea
We have quantitatively investigated the Anomalous Hall effect (AHE) in [CoSiB/Pt]
multilayer films. The [CoSiB/Pt] multilayers exhibited large Hall effect. In this study,
we compared with the effects of the before and after of patterning. The [amorphous
CoSiB 6A/Pt 14 A]n multilayers were deposited on SiOx substrate with a 30 A Pt
and 50 A Ta buffer layer at the room temperature using a DC magnetron sputteringsystem. Thereafter the sample was patterned into a hall bar with the line width of 10
μm. Hall effect measurements at room temperature were made up to 3 kOe with theapplied magnetic field perpendicular to the film plane. The samples for the Hall effectmeasurement were prepared with a square geometry for the easy application of the Van
der Pauw method to measure the Hall voltage of the samples. The applied current was
50μA ~ 1 mA and the measured Hall voltage was in the range of several mV.

PJ19
Magneto-transport properties of Al2O3-doped Mn-Zn ferrites

Hyo-jin Kim and Sang-im Yoo*
Department of Materials Science and Engineering, Seoul National University, Korea
We report the magneto-transport properties of Al2O3-doped Mn-Zn ferrites preparedby the conventional solid state reaction. Various amounts of Al2O3 were doped toa pure Mn-Zn ferrite to have the nominal composition of (Mn0.8, Zn0.2)1-xAlxFe2O4(x = 0.03~0.1). Field dependency of magnetization was measured with a SQUID(superconducting quantum interference device) magnetometer, and low fieldmagnetoresistance (LFMR) was also measured with the SQUID magnetometer using
an external current source and voltmeter. The X-ray diffraction analyses revealed thatall Al2O3-doped Mn-Zn ferrites of the spinel structure were a pure phase without thesecond phase. From the transport measurements of our samples in the temperature
region of 100~300 K, it was found that with the addition of the Al2O3 dopant theresistivity level of the pure Mn-Zn ferrite was abruptly dropped over four orders ofmagnitude and further the LFMR ratio was greatly improved. High LFMR ratio over
1.7% at 300 K in 0.5 kOe was achievable from 3mol% Al2O3-doped Mn-Zn ferrite
without an appreciable increase in its resistivity. Detailed effects of the Al2O3 dopant
on the microstructures, magnetic and magnetotransport properties of the Mn-Zn ferrite
will be presented for a discussion.

July 8-13, 2012 Busan, Korea

157

poster Presentation
PJ20

PJ23

PJ26

PJ29

Current induced fluctuation of switching fields in Co/Pd nanowires

Effect of pressure on magnetotransport properties in Fe/MgO granularfilms

Domain wall quantum interferometer

Spin torque in a finite two-dimensional ferromagnet with Rashba
interaction

Current induced effective magnetic fields in a thin metallic film of a ferromagnetic material
sandwiched by two nonmagnetic materials have been studied intensively due to its potential
applications for the magnetic random access memory [1, 2]. There is a controversy about
the origin of the effective field such as the Rashba effect [3] or spin torque induced by thespin Hall effect [4]. We have recently observed current induced effective fields in nanowires
made of Co/Pd multilayer [5]. The further investigation of the switching fields of nanowires
reveals fluctuation in the switching fields upon an injection of different current densities. We
have applied current pulses with a width of 2 ms and repetition of less than 1 Hz to minimize
the Joule heating effect. At low current densities (J < 10¹¹ A/m²) there is a fluctuation in theswitching field of the nanowire. For a certain value of the input current, the switching fieldof the Co/Pd nanowire increases(>6%). Furthermore, the switching fields in the positive andnegative fields are not the same. The relative angle between the sample and magnetic field
has changed and the effect of the angle on this fluctuation has been studied.

July 9 (Mon)[1] I. M. Miron, K. Garello, G. Gaudin, P. J. Zermatten, M. V. Costache, S. Auffret, S. Bandiera,
B. Rodmacq, A. Schuhl, and P. Gambardella, Nature 476, 189 (2011). [2] T. Suzuki, S. Fukami, N.
Ishiwata, M. Yamanouchi, S. Ikeda, N. Kasai, and H. Ohno, Appl. Phys. Lett. 98, 142505 (2011). [3]I. M. Miron, G. Gaudin, S. Auffret, B. Rodmacq, A. Schuhl, S. Pizzini, J. Vogel, and P. Gambardella,Nat. Mater. 9, 230 (2010). [4] http://arxiv.org/abs/1110.6846. [5] K. Narayanapillai, M. Jamali, andH. Yang, MMM conference, Arizona (2011).

A. Garcia - Garcia1, J. A. Pardo2, P. A. Algarabel1*, Z. Arnold3, J. Kamarad3 and M. R. Ibarra2
1
ICMA, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
2
INA, Universidad de Zaragoza, 50018 Zaragoza, Spain
3
Institute of Physics AS CR, 162 53 Praha 6, Czech Republic

A special example of granular thin films is the discontinuous metallic and insulator multilayers (DMIMs)
consisting of metallic layers with different degrees of discontinuity intercalated between insulating layers.
However, the studies about the effect on the magneto-transport properties of the hydrostatic pressure arescarce[1]. In this work we report the effect of hydrostatic pressure on the resistance and magnetoresistanceof a DMIM of nominal composition [Fe(t=0.7nm)/MgO(t=3 nm)]15 ,deposited on a substrate of corning
glass. The DMIM has been characterized previously showing a superparamagnetic behaviour [2]. The
resistivity has been measured at room temperatures with hydrostatic pressure (Ph) up to 7 Kbar. The
resistivity decreases linearly with pressure, indicating an increase in conduction via tunneling. The value ofthe coefficient, (1/ρ0)dρ/dPh =-3.9 10-2 kbar-1 is higher than the value obtained in other granular films. This
result implies that the electronic state of the DMIM is near the percolation threshold. Magnetoresistance (MR)
isotherms have been measured at room temperatures for Ph=1bar and Ph=7Kbar. At the maximum appliedmagnetic field (3KOe) the MR increases from 0.6% at ambient pressure to 1.1% at 7 Kbar. This result will
be explained due to the reduction of the tunnel barrier induced by the hydrostatic pressure.

John Eves, N. Grisewood and H. B. Braun
School of Physics, UCD, Ireland

Ferromagnetic nanosized toroidal rings have recently attracted much interest as
potential storage elements for conventional bit storage. Here we consider quantum
transport properties of such rings, and their dependence on the intrinsic domain
structure of the ferromagnetic materials. Considering samples with realistic anisotropies
we study the propagation of conduction electrons in the background of nontrivial
domain configurations. Due to sd-coupling, the propagating electrons experience adomain dependent phase shift due to Berry's phase. Using exact solutions for domain
configurations on a ring we use a path integral approach to determine exactly how thisphase depends on the domain configuration in the ring. We find that the transmission
through the ring can be controlled by the relative position of the domain walls, giving
rise to a novel domain wall interferometer.

Christian Ortiz, Xuhui Wang and Aurelien Manchon*
Physical Science and Engineering Division, King Abdullah University of Science andTechnology, Saudi Arabia
The interaction between a ferromagnetic exchange coupling and a Rashba spin-orbit
interaction has shown its potential in magnetization switching [1, 2]. For such a system,a coherent theoretical framework has been developed to study the coupled spincharge diffusive dynamics [3]. Using finite element method, we numerically solve,
in a two-dimensional (2D) electron system with appropriate boundary conditions,the generalized equations for the diffusive charge and spin dynamics. This numericalapproach allows for an accurate description of the spin and charge dynamics (i.e. nonequilibrium accumulation and current) for a wide range of parameters beyond thelimit of weak Rashba interaction [1,3]. The spatial profile of the spin accumulation
exhibits a strong presence of a spin precession arising from both the s-d exchange andthe effective Rashba field. Spin relaxations due to random magnetic impurities as wellas the D’yakonov-Perel mechanism are embedded in the solution. We also discuss
the diffusive dynamics and the spin torques in different regimes with respect to themagnitude of the Rashba spin-orbit interaction.
[1] A. Manchon and S. Zhang, Phys. Rev. B. 78, 212405 (2008); 79, 094422 (2009). [2] I. M. Miron,et al. Nature (London) 476, 189 (2011). [3] X. Wang and A. Manchon, arXiv:1111.1216 (to appear
on Phys. Rev. Lett.); arXiv:1111.5466.

[1] G. Oomi, Miyawaga H., Sakai T., Saito K., Takanashi K., and Fujimori Hl. Physica B 284 1245
(2000) [2] A. Garcia-Garcia, A. Vovk, J. A. Pardo, P. Strichovanec, C. Magen, E. Snoeck, P. A.
Algarabel, J. M. De Teresa, L. Morellon, and M. R. Ibarra J. Appl. Phys. 105, 063909 (2009)

PJ21

PJ24

PJ27

PJ30

Role of structural inversion asymmetry on current-induced effective
field in perpendicular magnetized trilayers

Measurement of anomalous nernst effect in [CoSiB/Pt] multilayer
films

Synthesis and magnetic properties of trilayer NiFe/Bi/NiFe films

Spin transport of Py/Au/Py spin valves with different Au channel
widths

Xuepeng Qiu, Kulothungasagaran Narayanapillai and Hyunsoo Yang*
Electrical and Computer Engineering, National University of Singapore, Singapore

The fact that a current pulse can switch the magnetic moment of a perpendicularmagnetized nanodot has attracted much attention for the next new generation spintronic
devices [1]. However, the physical origin of this effect is still under debate. Here we
report the pulse delta measurements in perpendicular magnetized substrate/2 MgO2 Pt0.8
CoFeB2 MgO (sample A) and substrate/2 MgO0.8 CoFeB2 Pt (in nm) micro-sized hallbar samples with opposite structural inversion asymmetry (SIA). For both structures,
when the magnetic field applied along the current direction tilted off-plane by 2°,
positive (negative) current induces a downward (upward) effective field with positive
magnetic fields and the effective field direction switches with negative magnetic fields.
The effective field is around 2,388 Oe per 10¹² A/m² in the sample A. For the otherstructure, the effective field shows a nonlinear correlation with the intensity of current.
With small in-plane external fields, the magnetization can be switched by pulse current
and the switching hysteresis was the same in the two structures. Our results suggest thatthe main contribution of the current induced effective field arises from the spin Hall
effect rather than the Rashba or other SIA related effects.
[1]. Ioan Mihai Miron, Kevin Garello, Gilles Gaudin, Pierre-Jean Zermatten, Marius V. Costache,
Stephane Auffret, Sebastien Bandiera, Bernard Rodmacq, Alain Schuhl and Pietro Gambardella,
Nature. 476, 189 (2011)

Ozgur Kelekci1, Ha Na Lee2, K. J. Min2, H. M. Waseem Khalil1, Tae Wan Kim2 andHwayong Noh1*
1
Physics Department and Graphene Research Institute, Sejong University, Korea
2
Department of Advanced Materials Engineering, Sejong University, Korea

Recently, a new research field taking advantage of both spintronics and thermoelectronics, called spin
caloritronics, has started to attract a great deal of attention [1]. In contrast to the Anomalous Hall Effectdriven by electrical currents, Anomalous Nernst Effect includes combination of thermal and spintransport driven by a temperature gradient in ferromagnets. We have investigated Anomalous Nernst
Effect in [CoSiB/Pt] multilayer films with perpendicular magnetic anisotropy. The layer structureof samples was SiO2Ta50APt30A(CoSiB6APt14A)n. Standard Hall bars were patterned on the samples.
Additionally, heating element was also patterned on the samples in order to apply temperature gradient.
Nernst effect measurements were made up to 1.5 kGauss with the applied magnetic field perpendicular
to the film plane. We obtained significant Nernst voltages (VN) by applying temperature gradient ∇Tto the samples. Nernst voltage exhibited similar characteristic as AHE voltage due to the spontaneous
magnetization. Samples with different number of [CoSiB/Pt] multilayers were measured and compared.
VN increased with increasing number of layers. Dependence of VN on the heating power (P) and the
distance from the heating element (d) have been investigated. We have extracted [VN] α [P] and [VN] α[1/d] dependencies from the measured samples.
[1] G. E. W. Bauer, A. H. MacDonald, S. Maekawa, Solid State Commun., 150, 459, (2010).

Konstantin Patrin1, Viktor Yakovchuk1, Gennady Patrin2 and Stanislav Yarikov2
1
Institute of Physics of Siberian Branch of Russian Academy of Sciences, Russia
2
Siberian Federal University, Russia
Earlier, it was found [1] that the bismuth spacer formation influences essentially the system
magnetization. The shape of m(H) curve is changed with bismuth spacer thickness increasing.
In particular, the test film with tBi = 0 has the narrow hysteresis loop and magnetization curveof a ferromagnetic type. For the films with tBi ≠ 0 the magnetization curves are typical for films
possessing either by <strong> intra-layer anisotropy or by antiferromagnetic interlayer coupling.
Since anisotropy is not experimentally observed, we attribute such a behavior to the presence ofinterlayer antiferromagnetic exchange. The investigations of electron magnetic resonance weremade in NiFe/Bi/NiFe films. It was established that the magnetic resonance spectrum consistsof solitary line for films with tBi = 0 nm and tBi = 15 nm, whereas for films with intermediate
value of semi metal spacer the spectrum is superposition of two lines. Theoretical treatmentof temperature dependences of resonance fields gives conclusion that the interlayer coupling
depends on both bismuth interlayer thickness and temperature. Also, the magnetoresistivity oforder of percent units and dependence of its value on thickness of bismuth spacer were found inthese films at helium temperatures [2].
[1] G.S. Patrin, V.Yu. Yakovchuk, D.A. Velikanov. Phys. Lett. A, 363, 164 (2007) [2] G. S. Patrin, V.
Yu. Yakovchuk, D.A. Velikanov, K.G. Patrin,and S.A. Yarikov. Bull. Russ. Acad. Sci. Phys., 76, 177(2012)

Jang Hae Ku1, Joonyeon Chang1*, Hyun Cheol Koo1, Jonghwa Eom2, Suk-hee Han1
and Gyutae Kim3
1
Spin Convergence Research Center, Korea Institute of Science and Technology (KIST), Korea
2
Department of Physics, Sejong University, Korea
3
Department of Electrical Engineering, Korea University, Korea

Most previous studies on spin injection and transport were dealt with one dimensional diffusive model andtwo-dimensional consideration has been neglected for simplicity [1-2]. However, all of the lateral spin valve
devices experimentally demonstrated are fabricated based on thin film technology so that it is indispensable tohave spatial distribution of spin current in a non-magnetic channel [1-2]. Actually, some of the experimental
data can’t be understood in terms of one-dimensional conduction model. Injected spin current usually produce
inhomogeneous spin accumulation which appears to a different magnitude of spin signal (ΔR) depending on
the position of voltage probes on the detector [3-4]. In the study, nonlocal spin valve (NLSV) measurements
for lateral Permalloy(Py)/Au/Py spin valve devices with different Au channel widths were carried out in two
viable voltage probe configurations. The larger channel width is at a fixed center to center channel length, thelower the magnitude of ΔR is in the NLSV, which is attributed to the increase in junction area and enhanced
spatial distribution of spin accumulation. The voltage probe configuration strongly affects the spin valve
signal owing to the non-uniform spin current distribution in lateral Au channel.
[1] M. Johnson, Phys. Rev. Lett. 70, 2142 (1993). [2] F.J. Jedema, A.T. Fillip, and B.J. van Wees,
Nature 410, 345 (2001). [3] T. Kimura, Y. Otani, and J. Hamrle, Phys. Rev. B. 73, 132405 (2006). [4]J. Ku, J. Chang, J. Eom, H. Koo, S. Han, and G. Kim, phys. stat. sol. (b) 244, No. 12, 4530 (2007).

PJ22

PJ25

PJ28

PJ31

Characterization of mechanically milled Cu-Co powder by 3D-FIB andatom probe tomography : effect of oxidation on the magnetoresistance

GMR effect in Co-Cu microwires

A study on the pulesd laser deposited metallic spin valve structures

The effect of magnetic impurities in magnetic tunnel junction

Julien Bran, Rodrigue Larde, Malick Jean and Jean-marie Le Breton*
Groupe de Physique des Materiaux - UMR 6634, CNRS - Universite de Rouen,
FranceThe Giant MagnetoResistance (GMR) effect discovered in 1988 [1] had inspired many researches onmagnetoresistive materials. The resistance of the device is reduced with the application of a magnetic
field and it is due to the spin dependent scattering effect. However, an inverse effect has been observed
after an oxide phase introduction by Khan et al. [2]. This effect appears at low magnetic field and could
be interesting for improving the sensitivity of magnetoresitive devices. In our study, a Cu80Co20 powder
was elaborated by mechanical alloying under ambient atmosphere to investigate the oxide formation andits influence on magnetoresistive properties. 3D-Focused Ion Beam tomography (3D-FIB) and Atom
Probe Tomography (ATP) [3] were used to characterize our samples. It was shown with 3D-FIB thatafter 1h30 of milling, the powder exhibits a lamellar structure with micro-sized Co rich regions. The APT
experiments have revealed that after 20h of milling 1/3 of Co atoms is oxidized leading to the formationof nano-sized CoO clusters embedded in a Cu85Co15 matrix. These results bring crucial informations
to correlate the structural properties with magnetoresistive properties of the Cu-Co-O powder and tounderstand the influence of the nano-sized oxide clusters on the inverse magnetoresistance.
[1] M. N. Baibich, J. M. Broto, A. Fert, F. Nguyen Van Dau, F. Petroff, P. Etienne, G. Creuzet, A. Friederich, and J.
Chazelas, Phys. Rev. Lett., 61(21) (1988) 2472-2475. [2] H. R. Khan, A. Granovsky, M. Prudnikova, V. Prudnikov, F.
Brouers, A. Vedyayev, A. Radkovskaya, J. Magn. Magn. Mater. 183 (1998) 379-386. [3] D. Blavette, B. Deconihout,
A. Bostel, J. M. Sarrau, M. Bouet, and A. Menand, Review of Scientific Instruments, 64(10) (1993) 2911-2919.

The 19th International Conference on Magnetism

Valentina Zhukova1*, Rastislav Varga2, Carlos Garcia3, Juanjo Del Val1, Mihail Ipatov1
and Arcady Zhukov4
1
Dpto. de Fisica de Materiales, UPV/EHU, Spain
2
Inst. Phys., Fac.Sci., UPJS, Slovakia
3
Dept Phys, Bogazici Univ, Turkey
4
Dpto. de Fisica de Materiales, UPV/EHU San Sebastian and IKERBASQUE,
Basque Foundation for Science, Bilbao, Spain
Granular materials exhibiting giant magnetoresistance (GMR) effect attracted considerable
attention. For obtaining of the granular structures, melt spinning technique allowing rapid
quenching from the melt is quite suitable. During last years considerable attention has been paid
to the studies of glass-coated microwires produced by Taylor- Ulitovski technique allowing toachieve high quenching rate and producing amorphous, nanocrystalline, microcrystalline oreven granular thin microwires. In this paper, we studied magnetic properties and GMR effectof Cox-Cu100-x (10≤x≤30 at%) microwires and observed considerable magnetoresistance (MR),ΔR/R. For Co10Cu90 microwires, ΔR/R increases when the temperature decreases, exhibiting
negative MR, tending to saturate in high magnetic fields, H. On the other hand, for Co30Cu70
samples ΔR/R(H) dependences showed non-monotonic behavior, exhibiting ΔR/R increase
with H at low H-values (up to 5 kOe) and also considerable GMR effect. X-ray diffraction(XRD) results reveal that the structure of the metallic core is granular with two phases: the mainone, fcc Cu (lattice parameter 3.61 Å) and fcc α-Co (lattice parameter 3.54 Å) which is present
in microwires with higher Co content. In the case of low Co content, XRD indicates that Co
atoms are distributed within the Cu crystals.

July 9 (Mon)

Mahdi Jamali, Xuepeng Qiu, Kulothungasagaran Narayanapillai and Hyunsoo Yang*
Electrical and Computer Engineering, National University of Singapore, Singapore

158

poster Presentation

Sayak Ghoshal1* and P. S. Anil Kumar2
1
Physics, Indian Institute of Science, India
2
Indian Institute of Science, India

It is envisaged that the conventional Spin Valve (SV) structures will be moreadvantageous over Tunneling Magneto-resistance (TMR) for the perpendicularmagnetic recording due to the suitable RA product. Here Pulsed Laser Deposited (PLD)
Spin Valve (SV) and Pseudo Spin Valve (PSV) samples are grown at room temperature
with moderately high MR values using simple NiFe/Au/Co/FeMn structure. Although
PLD is not a popular technique to grow metallic SVs because of its expected large
intermixing of the interfaces, particulate formation etc., still by suitably adjusting thedeposition parameters we could get exchange bias as well as more than 3% MR in
the Current In Plane (CIP) geometry. Different SV and PSV samples are grown to
study anisotropy effects, exchange coupling and exchange bias with anti-ferromagnet.
Angular variation of the MR is also obtained which shows that the hard layer (Co) has
a four-fold anisotropy in the NiFe/Co/Au/Co structures which becomes two-fold inpresence of anti-ferromagnet. In this presentation, properties of these PLD grown SVs
will be discussed in terms of the angular variation of MR, intermixing at the interfaces
as well as details of exchange bias.
(1) S. Yuasa et. al. J. Phys. D: Appl. Phys. 40 R337 (2007) (2) Y. Sakuraba et. al. Appl. Phys. Lett.
94, 012511 (2009)

Sungjung Joo1, K.y. Jung1, B.c. Lee2, Tae-suk Kim3, K.h. Shin4, Mung-hwa Jung5, Jinki Hong1 and K. Rhie1*
Department of Display and Semiconductor Physics, Korea University, Korea
2
Department of Physics, Inha University, Korea
3
Department of Physics, Chonnam national University, Korea
4
Spintronics Device Research Center, Korea Institue of Science and Technology, Korea
5
Department of Physics, Sogang University, Korea
1

Magnetic tunnel junctions (MTJs) have been extensively investigated for more than a decade, not only becauseof potential applications such as next generation memory devices or high frequency spin oscillators, but also
due to scientific interest. The physical properties of MTJs are very sensitive to the conditions of interface
formation and, therefore, it is essential to understand the various influencing factors to control interface quality.
The effect of oxidizing the ferromagnetic layer on tunneling magnetoresistance (TMR) is one of the mostinteresting problems in MTJs. The ferromagnetic layer in MTJs was oxidized with varying O2 concentrations
and the corresponding effect on spin-dependent transport was studied. As expected from our previous resultsfor MTJs with an over-oxidized AlOx tunnel barrier, a partially oxidized ferromagnetic layer plays an importantrole in spin-dependent transport. As the temperature is lowered, the junction resistance increases dramaticallyand the TMR is strongly suppressed. Increasing the O2 concentration enhances the increase of resistance andsuppression of TMR. This work supports our previous conclusion that oxidizing the ferromagnetic layer
generates localized magnetic moments, which act as a scattering center for spin-polarized tunneling electrons.
1. K.J. Rho, J.-S. Lee, K.B. Lee, J.-H. Park, J.Y. Kim, Y. Park, K. Kim, S. Joo, and K. Rhie, Phys. Rev. B 83,
172408 (2011). 2. K. Lee, S. Joo, J. Lee, K. Rhie, T.-S. Kim, W. Lee, K. Shin, B. Lee, P. Leclair, J.-S. Lee, andJ.-H. Park, Phys. Rev. Lett. 98, 107202 (2007). 3. T.-S. Kim and D.L. Cox, Phys. Rev. Lett. 75, 1622 (1995).

July 8-13, 2012 Busan, Korea

159

poster Presentation
PJ32

PK01

PK04

PK07

Effect of cobalt layer thickness on the magnetic and magnetoresistanceproperties of asymmetrical Co/Cu multilayers

Controlling magnetic isolation and moment reversal of FePt (001)films by Cu capping nanoislands

Magnetic reversal of Co/Pt multilayer depending on Co thickness andannealing temperature

Magnetic anisotropy in FeCo thin films

July 9 (Mon)

A series of asymmetrical multilayer thin films of Co/Cu with a systematicallyvarying cobalt layer thickness tCo= 10, 15, 20, 30, 40 and 50 A was prepared by
DC magnetron sputtering technique to study the effect of tCo on its magnetizationand magnetoresistance properties. The XRD pattern of the multilayers showed
the polycrystalline nature with texture (111). The magnetization measurements at
different temperatures of the series showed that change in tCo leads to the change inmagnetic anisotropy of the multilayers and thus change in coercive field (HC). The
magnetoresistance measurements at different temperature of the series of multilayer
showed a temperature dependent giant magnetoresistance (GMR) due to the inelastic
scattering of electrons by phonons and magnons. Moreover, an asymmetry in GMR
curves at low temperature was observed because of the asymmetrical (pseudo spin
valve) structure of the multilayer.

D. H. Wei1*, C. H. Chao1 and Y. D. Yao2
1
Institute of Manufacturing Technology and Graduate Institute of Mechanical AND
Electrical Engineerin, National Taipei University of Technology, Taiwan
2 Institute of Applied Science and Engineering, Fu Jen University, Taiwan
We aimed to control the magnetic interaction of FePt(001) films by introducing Cu
capping nanoislands for applications in magnetic recording and permanent magnets.
Fe/Pt multilayers were prepared by e-beam evaporation onto MgO substrates, and thethickness of Cu capping layers was varied from 1 to 6 nm. Out-of-plane coercivity
increases with increasing growth temperature, and the reduction of grain/domain
size and intergrain interaction of FePt can be achieved. Cu could penetrate into FePt
nanostructures along the grain boundaries and create a strain-energy modulation at theinterface due to its lower surface energy. Studies of angular dependent coercivity showa tendency of a domain-wall motion shift toward rotation of reverse-domain type with
Cu capping nanoislands. The intergrain interaction was confirmed from the KellyHenkel plot that indicated the strong exchange coupling between neighboring grains inpure FePt films, and the negative δM value was obtained while FePt films capped with
Cu nanoislands.

Seungha Yoon, Seungkyo Lee, Joonhyun Kwon, Junghyon Lee and B. K. Cho*
Materials Science and Engineering, Gwangju Institute of Science and Technology,
Korea
Magnetic reversal behaviors in ferromagnetic thin films are continuously studied toachieve high performance of technological applications. Recently, CoPt multilayers
and alloys have been an important issue in perpendicular magnetic anisotropy (PMA)
applications. However, fundamental studies of the magnetic properties were notmuch presented. In this work, we present a magnetic reversal behavior of Ta(3.0 nm)/[Co(x nm)/Pt(1.0 nm)]x3 /Ta(1 nm) multilayers, when the Co thickness varied from
0.3 nm to 2.0 nm. The multilayers were deposited using DC magnetron sputter on Si/
SiO2 substrate, and annealed with various temperature after deposition. The magnetic
and structural properties of the multilayers were measured using vibrating sample
magnetometer (VSM) and x-ray diffraction (XRD) at room temperature. In addition,
we observed the magnetic reversal behavior with magneto-optic Kerr effect (MOKE)
microscope system, capable time-resolved domain observation.

Xiaoxi Liu*, Shinsaku Isomura and Akimitsu Morisako
Department of Information Engineering, Shinshu University, Japan
Sputtered FeCo films normally show magnetic anisotropy inside the film plane. It isbelieved that the magnetic anisotropy are due to the stray field of the magnet of thetarget. However, the details of the induced magnetic anisotropy are yet to be fully
understood. In the present work, we have prepared FeCo films by both DC magnetron
sputtering system and facing targets sputtering system. The magnetic properties,
crystallographic properties, and microstructure of the films have been investigated.
Films deposited by DC magnetron sputtering show isotropic magnetic properties in thefilm plane. However, films deposited by facing targets sputtering show strong magnetic
anisotropy in the film plane. The magnetic anisotropy field increases from 40 Oe to 540
Oe with the increase of the film thickness from 10 nm to 150 nm for films depositedby facing targets sputtering system. XRD results show that the (110) lattice spacingof FeCo films increases with the increase of films thickness from 10 nm to 40 nm.
However, lattice spacing almost not changes with further increase of the film thickness.
Of particular interest is thatiInternal stress of the films increased with the decrease of
the film thickness.

July 9 (Mon)

Srikrishna Pandey, Pavel Nikolaev and Sivaram Arepalli*
Department of Energy Science, Sungkyunkwan University, Korea

PJ33

PK02

PK05

PK08

Current-induced motion of a transverse magnetic domain wall in thepresence of spin Hall effect

Perpendicular magnetic anisotropy for annealed Co/Ir(111) ultrathin
films

Annealing effect on the microstructures and magnetic properties of [Fe/Pt]16 multilayers on MgO (001) substrate

Magnetic domain wall energy of Co/Ni superlattice with perpendicularmagnetic anisotropy

Soo-man Seo1, Kyung-whan Kim2, Jisu Ryu2, Hyun-woo Lee2 and Kyung-jin Lee1*
1
Materials Science and Engineering, Korea university, Korea
2
Physics, Pohang University of Science and Technology, Korea

The electric manipulation of a domain wall (DW) in a magnetic nanowire is subject to thespin-transfer torque (STT) effect due to the coupling between local magnetic moments of the
DW and spin-polarized currents [1]. Numerous studies on this subject have been performed tounderstand its fundamental physics [2] and to extend its potential to applications such as data
storage and logic devices [3]. In this work, we study theoretically current-induced dynamics
of a transverse magnetic domain wall in bi-layer nanowires consisting of a ferromagnet on topof a nonmagnet having strong spin-orbit coupling. Domain wall dynamics is characterized by
two threshold current densities, J(WB) and J(REV), where J(WB) is a threshold for the chirality
switching of the domain wall and J(REV) is another threshold for the reversed domain wallmotion caused by spin Hall effect. The domain wall with a certain chirality may move opposite
to the electron-flow direction with high speed in the current range J(WB) < J < J(REV) for thesystem designed to satisfy the conditions J(WB) > J(REV) and α > β where α is the Gilbert
damping constant and β is the nonadiabaticity of spin torque. Micromagnetic simulations
confirm the validity of analytical results.
[1] J. C. Slonczewski, J. Magn. Mag. Mater. 159, L1 (1996); L. Berger, Phys. Rev. B 54, 9353 (1996). [2]A. Yamaguchi et al., Phys. Rev. Lett. 92, 077205 (2004); M. Yamanouchi et al., Nature (London) 428, 539(2004); M. Klaui et al., Phys. Rev. Lett. 94, 106601 (2005). [3] S. Parkin et al., Science 320, 190 (2008).

Wen-yuan Chan, Du-cheng Tsai, Cheng-hsun Chang and Jyh-shen Tsay*
National Taiwan Normal University, Taiwan

Compositions and magnetic properties of Co/Ir(111) ultrathin films thinner than 4monolayers (ML) have been investigated. As the Co thickness increases to above 2
ML, magnetic hysteresis appears in both the longitudinal and polar configurations
as revealed using surface magneto-optic Kerr effect (SMOKE) technique. Afterannealing treatments, the observations of the attenuation of Co LMM Auger signal
and chemical shifts to lower kinetic energy show that Co atoms diffuse into the Ir(111)substrate. At higher temperatures, the Kerr intensities in both the longitudinal andpolar configurations decrease due to the reduction of Co overlayer. At a temperatureinterval, magnetic hysteresis appears only in the polar configuration. This shows thatthe magnetic easy axis of Co/Ir(111) could be stabilized in the direction of the surface
normal by thermal annealing treatments. By systematical investigations for Co/Ir(111)ultrathin films thinner than 4 ML, a magnetic phase diagram has been established.
Several phases are observed, including a nonmagnetic phase, canted out-of-planeanisotropy and perpendicular magnetic anisotropy. On the top of the Co/Ir(111), theintroduction of Ag overlayer shows an oscillatory behavior of the Kerr intensities.
Possible mechanisms of the charge transferring, quantum well effects and completenessof the Ag layer are discussed.

Aimei Zhang1, Weihua Zhu2 and Xiaoshan Wu3
1
College of Science, Hohai University, China
2
College of Science, Hohai Unviersity, China
3
Physics, Nanjing University, China[Fe/Pt]16 multilayers are deposited on MgO (001) single crystal substrate by magnetic
sputtering layer by layer with varying the substrate temperature from 150-500oC to
explore the annealing effect on the microstructures and magnetic properties of thefilms. Results show that FePt alloy with L10 phase forms at about 300oC, and reaches
a completely ordered state at about 400 oC. FePt film depositing at above 300oC has(001)-preferred texture which shows that L10-FePt film has perpendicular magnetic
anisotropy. The out-of-plane coercivity increases with sample transforming from [Fe/Pt]16 multilayers to L10-FePt alloy. The out-of-plane coercivity for the morphology,
which is confirmed to have the effects on the out-of-phane coercivity, with thecontinuing surface has an order higher than that for the granular surface.

Kentaro Toyoki, Yu Shiratsuchi* and Ryoichi Nakatani
Osaka University, Japan

Co/Ni superlattice is a promising material for spintronics devices, in which the magnetic domain
walls carry information stored, owing to a perpendicular magnetic anisotropy and a highsaturation magnetization. Despite the numerous studies on the magnetic domain wall motion of
the Co/Ni superlattice, the magnetic domain wall energy density has not been reported. In thiswork, we present the experimental determination of the magnetic domain wall energy densityof the Co/Ni superlattice with perpendicular magnetic anisotropy (PMA). We confirmed thatthe epitaxial growth of Co(111)/Ni(111) superlattice on the Ag(111)-buffered Si(111) substrate.
Several parameters were determined to obtain the magnetic domain wall energy σW [1], i.e.
the saturation magnetization MS, the PMA energy, and the magnetic domain period. From thedependence of the magnetic domain period on the ferromagnetic layer thickness, the dipole
length, D0 (≡ σW/2πMS2), is estimated as 22.5±2.5 nm. Using the experimentally obtainedMS (≈660 emu/cc), the magnetic domain wall energy density is estimated as σW = 6.4±1.4
erg/cm2. The estimated σW is about three-times higher than those for L12-CrPt3[2], and about
one-third of that for L10-FePt[3]. From the obtained values, the exchange stiffness constant iscalculated as about 4.8×10-6 erg/cm, which is comparable to that of bulk-Co.
[1] C. Kooy and U. Enz, Phil. Re. Rept. 15, 7 (1960). [2] Y. Shiratsuchi, M. Yamashita, R. Nakataniand M. Yamamoto, J. Mag. Soc. Jpn, 33, 447 (2009). [3] S. Okamoto, N. Kikuchi, O. Kitakami, T.
Miyazaki, Y. Shimada and K. Fukamichi, Phys. Rev. B 66, 024413 (2002).

PJ34

PK03

PK06

PK09

Universal spin-hall effect in metallic thin films

Anomalous easy-plane magnetocrystalline anisotropy of compressive
strained (La,Ba)MnO3 films

Preparation and magnetic studies of room-temperature sputtered [Co/Pt] multilayer films on glass substrates with perpendicular magnetic
anisotropy

Anisotropic Magnetoresistance of Co/Ni multilayers

Xuhui Wang1, Jiang Xiao2, Aurelien Manchon1, and Sadamichi Maekawa3,41King Abdullah University of Science and Technology (KAUST), Physical Science and Engineering
Division, Thuwal 23955-6900, Saudi Arabia
2
Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai
200433, China
3
Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan
4
CREST, Japan Science and Technology Agency, Tokyo 102-0075, Japan
Spin-orbit interaction fills the academic and industrial pursuit for an electrical manipulation of spins.
Fabricated using the state-of-art nanotechnology, semiconductor and metallic thin films embedded between
two asymmetric interfaces in the presence of spin-orbit interaction have attracted intensive theoretical andexperimental interest in recent years. Spin Hall effect [1], voltage-controlled spin precession [2] as wellas the recently observed spin-orbit torque [3] all stem from a careful design of spin-orbit coupling in thebulk or at the interfaces. We predict a large spin-Hall conductivity due to interfacial spin-orbit interactionsin an ultrathin normal metal film that is sandwiched by two insulators. While providing a confinement,
the insulator/metal interfaces also serve as a source to the spin-orbit interaction due to inversion symmetry
breaking. More interestingly, the interfacial spin-orbit coupling gives rise to a universal spin-Hall
conductivity that is independent of microscopic details of the interfacial spin-orbit interaction and ispredicted to be much larger than that induced by bulk impurities.
[1] Y. K. Kato, et al. Science 306, 1910 (2004). [2] H. C. Koo et al., Science 325, 1515 (2009) [3] A.
Manchon and S. Zhang, Phys. Rev. B. 78, 212405 (2008); A. Chernyshov, et al. , Nature Physics 5,656 (2010);I. M. Miron, et al. Nature (London) 476, 189 (2011).

160

poster Presentation

The 19th International Conference on Magnetism

Hong Zhu*, Jinzeng Tian, Lei Yang, Qingyong Duanmu, Lin Hao and Xiaoping Wang
Department of Physics, University of Science and Technologh of China, China

Magnetic anisotropy of manganite films is sensitive to the epitaxial strain. So far, in Caand Sr-doped manganite films, many authors reported that a lattice expansion induces
easy magnetization in the corresponding direction. In this work, magnetocrystalline
anisotropy of La0.67Ba0.33MnO3 epitaxial films suffering large compressive strainon LaAlO3 substrates (LBMO/LAO) has been investigated by using ferromagnetic
resonance (FMR) technique. By mapping out the dependence of the FMR position on
the angle between the applied magnetic field and crystallographic axes of the films,
a large easy-plane anisotropy has been found in such compressive strained LBMO
films, which is in contrast to the common tendency reported before. The excellent
epitaxial crystallographic orientation gives rise to an observable fourfold symmetry of
the in-plane anisotropy. The results are discussed by taking large tolerance factor andgiant magnetostriction of Ba-doped manganites into account. In the phase diagramof temperature vs. tolerance factor for doped manganites, we noticed that LBMO
has a larger tolerance factor but a lower Curie temperature than Sr-doped manganite,meaning that shrinkage of Mn-O-Mn bond length in LBMO is in favor of spontaneous
magnetization, which in turn results in the anomalous easy-plane anisotropy in thecompressive strained LBMO films.

Chiuan-fa Huang1, Hsian-yuan Wu1, An-cheng Sun1*, Fu-te Yuan2, Jen-hwa Hsu2, S. N.
Hsiao3 and H. Y. Lee3
1
Department of Chemical Engineering & Materials Science, Yuan Ze University,
Taiwan2
Department of Physics, National Taiwan University, Taiwan
3
National Synchrotron Radiation Research Center (NSRRC), Taiwan
Multilayer [Co10/Pt7.5]n films were deposited at room temperature (RT) on glass substrates with andwithout a Pt(111) underlayer. The thicknesses of each Co and Pt layer were set at 1 and 0.75 nm
respectively. The stacking period, n, was varied from 1 to 6, leading to the total thickness of [Co10/
Pt7.5]n films from 1.75 to 10.5 nm. The results of magnetic studies indicate that the perpendicularmagnetic anisotropy (PMA) of [Co10/Pt7.5]n films is strongly influenced by inserting a Pt(111)underlayer and the number of n. Surprisingly, [Co/Pt]n films exhibit PMA behavior with a Pt(111)underlayer when n exceeds 3 even the films were deposited at room temperature. However withouta Pt(111) underlayer, the films will not exhibit PMA in all cases. The appearance of L11 phase isfound related to the appearance of PMA in [Co10/Pt7.5]n/Pt(111) films. The [Co/Pt]n film is grownalong Pt(111) resulting in the L11(222) orientation, which causes the easy axis <111> along theplane normal. In this study, the microstructure at [Co10/Pt7.5]n/Pt(111) interface is also studied andwill be presented, which is helpful for understanding the formation mechanism of PMA behavior in
multilayer [Co10/Pt7.5]n structure prepared at room temperature.

Chih_yung Chen1, James C Eckert1, Natalia Fear1, Sheena K. K. Patel1, Richard
Sayanagi1, Patricia D Sparks1, E Shipton2 and Eric E Fullerton2
1
Harvey Mudd College, USA
2
University of California, San Diego, USA
Co/Ni multilayers exhibit perpendicular magnetic anisotropy, relatively low magnetic
damping and unusual magneto-transport characteristic that make them useful for
spintronic devices. Anisotropic magnetoresistance was measured for sputtered Ni/
Co films: SiO2Ta40ÅPd40Å(Co2ÅNiY)x10Ta40Å,with Ni thicknesses from Y=2-14Å. Three
AMR configurations were studied. Two configurations, varying the applied field vs.
current angle, the applied field always in the plane of the sample, AMR1, and varying
the applied field from in plane to out of plane, AMR2, provide similar information. The%AMR1 or 2 increases monotonically as the fraction of Ni increases and shows the
expected cosθ2 dependence. Rotating the sample with the field always perpendicular
to the current, AMR3, we see anomalous angle-dependence for all samples, at all
temperatures. At the sample orientation where a peak in the AMR is expected, there
is a dip. The relative magnitudes of these contributions vary with temperature and Ni
thickness. The magnitude of the AMR3 is approximately half the AMR2. At 5K, themagnitudes of all AMRs increase with Ni thickness except the AMR3 for the sample
with 3Å of Ni is anomalously low. The temperature variations for AMR2 and AMR3
are quantitatively different but each varies by approximately a factor of 3 from 5K to
305K.

July 8-13, 2012 Busan, Korea

161

poster Presentation
PK10

PK13

PK16

PK19

Interface perpendicular magnetic anisotropy in thick amorphous
CoSiB film by Pt layer

Tunable spin configuration in [Co/Ni] adjoined NiFe exchange spring
structures

Ultrathin Co/Pt films with high thermal stability and large effective
magnetic moment

Perpendicular magnetic anisotropy and metal layer effect in MgO/
CoFeB/cap (cap = Ta, Ru, and Nb)

Recently, magnetic tunnel junctions (MTJs) with perpendicular magnetic anisotropy(PMA) have attracted a lot of research interest, because they have a potential for
spin transfer torque magnetic random access memories (MRAMs). Devices withperpendicular magnetic anisotropy have lower switching currents than devices with inplane magnetic anisotropy. We have investigated the interface perpendicular magnetic
anisotropy (IPMA) of amorphous CoSiB thin film. CoSiB/Pt exhibited perpendicularmagnetic anisotropy. The structure of samples was SiO2Ta50ÅPt30ÅCoSiBx/Pt30Å and
SiO2Ta50ÅPt30ÅCoSiBx. The thickness of CoSiB were varied in the range of from 2 to40Å. The sample without Pt capping layer exhibited perpendicular magnetic anisotropy
at tCoSiB=10Å but the sample with Pt capping layer exhibited perpendicularanisotropy at lower thickness tCoSiB=5Å. Therefore, it was expected that IPMA
properties of amorphous CoSiB on Pt layer was suitable for STT-MRAM.

Sunjae Chung1*, S. M. Mohseni1, T. N. Anh Nguyen1, N. Benatmane1, R. K. Dumas2
and Johan Akerman2
1
Materials Physics, School of ICT, KTH - Royal Institute of Technology, Electrum
229, 164 40, Kista, Sweden
2
Department of Physics, University of Gothenburg, 412 96 Gothenburg, Sweden

Prasanta Chowdhury*, Prabhanjan Dilip Kulkarni, Murali Krishnan and Harish C
Barshilia
Surface Engineering Division, National Aerospace Laboratories (CSIR), India

Future spintronic devices based on spin-transfer torque require a delicate engineeringof constituent magnetic layers. More specifically, realization of a tunable spin
configuration is expected to allow for operation in zero magnetic field, as well as
increased output efficiency and quality, e.g. linewidth, of the device.[1] Here, we reporton a tunable spin configuration in exchange coupled NiFe, with in-plane magnetic
anisotropy (IMA), to a [Co/Ni]×4 multilayer, with perpendicular magnetic anisotropy(PMA). A set of sputter deposited [Co/Ni]×4/NiFe samples (series 1) is compared withthe reverse structure, NiFe/[Co/Ni]×4 (series 2), with various NiFe thicknesses (tNiFe)
of 0.5, 1, 2 and 3 nm. Both series show the same eventual transition from dominant
PMA to IMA as tNiFe is increased. However, this transition appears for smaller tNiFein series 2, most likely due to the initially sputtered NiFe modifying the PMA of the[Co/Ni] multilayer. Most importantly, due to the competition between PMA and IMA,a tilted spin configuration can be stabilized and tuned for intermediate tNiFe.

WN
A
R

D

TH
I
W

Chih-wei Cheng, Tsung-i Cheng and G. Chern*
Department of Physics, National Chung Cheng University, Chiayi 62102, Taiwan

Perpendicular magnetic anisotropy (PMA) has been observed in MgO/CoFeB/Ta but
not in MgO/CoFeB/Ru, indicating that the metal cap layer is crucial¹-². In this report,
we extend the study to MgO/CoFeB1.2 nmNb(1 - 5 nm) by sputtering and find again that
PMA can be induced by Nb cap layer. Our experimental results also show that Nb andTa have strong interface effect but the PMA occurs in a small window (~ 1 - 3 nm)
while Ru shows much weaker effect and the induced interface anisotropy constant (Ki)
is basically not high enough to overcome the bulk anisotropy contribution.

July 9 (Mon)

Insung Park, Hana Lee, Hyung Jun Kim, Sung Yong Kim, Young Kwang Kim andTaewan Kim*
Department of Advanced Materials Engineering, Sejong Univ., Korea

July 9 (Mon)poster Presentation[1] T. N. Anh Nguyen, Y. Fang, V. Fallahi, N. Benatmane, S. M. Mohseni, R. K. Dumas,and J.
Akerman, Appl. Phys. Lett. 98, 172502 (2011).

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Perpendicular magnetic anisotropy and superparamagnetism in Ta/
CoFeB/MgO structures

Large perpendicular magnetic anisotropy in the MgO/CoFeB/Ta withthick Ta layer

Magnetic characteristics of amorphous [CoSiB/Pt]n multilayers

Dependence of perpendicular magnetic anisotropy of CoFeB thin films
on thickness of MgO overlayer

C. c. Tsai1, H. m. Chen2, Chih-wei Cheng2, C. h. Shiue2, M.c. Tsai2, J. P. Singh2, C.w. Su3 and G. Chern2*
1
Department of Engineering and Management of Advanced Technology, Chang Jung
Christian University, Tainan 71101, Taiwan
2
Department of Physics, National Chung Cheng University, ChiaYi 62102, Taiwan
3
Department of Electrophysics,, National Chiayi University, ChiaYi, 60004, Taiwan
Collapses of tunnel magnetoresistance in perpendicular magnetic tunnel junctions have been reported
recently[1-2]. These observations indicate that the coercivity of the reference layer and sensing layer
behaves differently at low temperature. We extend to study the temperature dependence of a seriesof films with SiO2 substrate/Ta5 nmCoFeBx nmMgO1 nm, 1.5<x<1.9, structures by sputtering. The
perpendicular magnetic anisotropy (PMA) is revealed as the thickness of CoFeB < 1.7 nm after a post
annealing process. In this report, we focus on the magnetic response of Ta/CoFeB1.7 nm/MgO which has acritical thickness of the transition from perpendicular to in-plane. Although the magnetic hysteresis shows
weak in-plane anisotropy at room temperature the magnetic anisotropy changes to perpendicular at low
temperature. The magnetization vs. temperature further indicates a superparamagnetic behavior withblocking temperature ~ 150K. The characteristic of a super-paparamagnetism suggests a pancake shapenanostructure with diameter ~ 40 nm exists at the interface. The present study demonstrates that small
ferromagnetic particles may exist even after a post annealing process and the temperature-dependent
coercivity is associated with an “intrinsic” structure of the interface in Ta/CoFeB/MgO structures.

Tao Zhu
Institute of Physics, Chinese Academy of Sciences, China

It is widely recognized that current-induced spin transfer torque (STT) plays animportant role in spintronic devices [1]. The magnetic tunnel junction with aperpendicular magnetic anisotropy (PMA) is a candidate for such STT devices because
the PMA enables a small critical current density for current induced magnetization
switching. The perpendicular magnetic anisotropy (PMA) in the Ta capping film,
MgO/CoFeB/Ta, has been investigated by using anomalous Hall effect. Ta capping
structures, MgO 1.1CoFeB 1.22Ta 0.55-4.4 (numbers are the nominal thicknesses innanometers, Ta=300°C), were prepared. The out-of-plane squareness increases with
the Ta cap layer thickness from 0.55 to 0.94 nm and reaches unity at Ta thickness of
0.94 nm. Different from the previous report [2], the perpendicular anisotropy of CoFeB
retains at which Ta thickness is larger than 0.94 nm. Unity squareness can be observedat the Ta cap layer thickness up to 4.4 nm. It is clear that there is no strong relationshipbetween PMA and the Ta cap layer thickness. Moreover, A large PMA in the Ta
capping film is due to the large effective anisotropy.

Woosuk Yoo1, Kyujoon Lee1, Myung-hwa Jung1*, Insung Park2, Taewan Kim2, E.h.m.
Van Der Heijden3 and H.j.m. Swagten31
Dept of Physic, Sogang University Seoul, Korea
2
Dept of Physic, Sejong University Seoul, Korea
3
Department of Applied Physics, Eindhoven University of Technology, Netherlands
The development of electronics demands an increasing effort in attaining more efficientelectronic memories. The materials with perpendicular magnetic anisotropy (PMA)
are important in applications of electronic memories. One promising new material isamorphous PMA multilayers [CoSiB/Pt]n with n the number of repeated bilayers. By
using a VSM-SQUID measurement setup, the magnetic characteristics of the [CoSiB/
Pt]n are gained. The anisotropy constants k1eff, K1, K2 are obtained by fitting thehard-axis magnetization curve with GST equation. The hysteresis loops appear slanted
increasing n. Furthermore magneto- optical Kerr effect (MOKE) imaging confirms
magnetic domain wall motion. The coercive field is first increasing with n and after amaximum, decreasing with n. This result is caused by the RKKY coupling between themagnetic layers and the balance between the domain wall energy scaling with n and themagnetostatic energy scaling with n2. In addition the reversal process is not dependingon the strength of the initial magnetization field.

[1]S. Ikeda et al., Nature Mater. 9, 721 (2010). [2]C. W. Cheng et al., J. Appl. Phys. 110, 033916(2011).

1 G. Feng, H.C. Wu, J.F. Feng, and J.M.D. Coey, Appl. Phys. Lett. 99, 042502 (2011). 2 H.D. Gan, H. Sato, M.
Yamanouchi, S. Ikeda, K. Miura, R. Koizumi, F. Matsukura, and H. Ohno, Appl. Phys. Lett. 99, 252507 (2011).

The CoFeB/MgO interface is known to favor perpendicular magnetic anisotropy (PMA) whichis already found application in the efficient magnetic tunnel junctions and electric field control themagnetization. Recently, the PMA of CoFeB/MgO structure has been achieved in both experiment[1,2] and theory [3], however the origin of PMA is still ambiguous. In this scope, the structure
Ta5nmCo10Fe70B20(0.9-2.0)nmMgO(0-6.0)nmTa5nm (unit in nm) was investigated. All samples were fabricated by
sputtering method on thermally oxidized Si substrates. We studied the dependence of the total magnetic
moment and the effective magnetic anisotropy energy of the Co10Fe70B20 layer. Magnetic anisotropy isfound to be very sensitive to MgO thickness, favouring to perpendicular direction with thin MgO film
(the maximum interface anisotropy was 1.74 erg/cm2 with the CoFeB/MgO1nm structrure. Althoughthin MgO samples have thick magnetic dead layer, resulting in the reduction of total magnetic moment,
only the existence of the magnetic dead layer cannot explain the change of the PMA. We found that the
thickness of MgO overlayer plays the very important role for the direction of magnetic anisotropy easyaxis. This work is supported by CREST, Japan Science Technology Agency, Japan.
[1] S. Yakata et al, J. Appl. Phys., 105, 07D131 (2009) [2] S. Ikeda et al, Nature Materials., 9, 721724 (2010) [3] H. X. Yang et al, Phys. Rev. B, 84, 054401 (2011)

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Observation of symmetry of wavefunction in interface controlled Co/
Pd multilayer using magnetic compton profile

Strain induced overlayer effect on perpendicular magnetic anisotropy
in Ta/CoFeB/MgO structures

Effects of phase distribution and grain size on the effective anisotropy
and coercivity of nanocomposite PtCo permanent alloy
Tao Liu1, Pei Zhao2, Zhaohui Guo1, Wei Li1, Wei Sun1 and Jingdai Wang1
1
Division of Functional Materials, Central Iron & Steel Research Institute, China
2Central Iron & Steel Research Institute, China

Dongseok Kim1, Kuyeol Jung1, Sungjung Joo1, Youngjae Jang1, Byungchan Lee2,
Jinki Hong1 and Kungwon Rhie1*
1
Display and Semiconductor Physics, Korea University, Korea
1
Department of Physics, Inha University, Korea

The perpendicular magnetic anisotropy (PMA) in ultrathin CoFeB-MgO based structure is an importantfeature for the applications on magnetic random access memory1. However, the interface structure issensitive to seed (cap) metal layer and the annealing treatment2. In this study, we fabricated a series ofstructures of Sub/Ta5 nmCoFeB1.2 nmMgO(0<x<5 nm)/Ta(0<y<5 nm) and found that the PMA not only
depends upon the thickness of MgO but also depends upon the Ta overlayer on top of MgO. In Ta/
CoFeB/MgO(0<x<5 nm)/Ta(5 nm), PMA is observed as the thickness of MgO is over 0.75 nm (~3atomic monolayer) and a maximum of Hk ~ 5 kOe at MgO thickness ~1nm is identified. In Ta/CoFeB/
MgO1 nmTa(0<y<5 nm), we found both Hk and coercivity increases from 2.5 kOe to 5 kOe and 15 Oe
to 30 Oe, respectively as the thickness of Ta varies from 1 to 5 nm. These results may conclude thatthe match of the lattice parameter between CoFe and MgO is crucial for the PMA in the CoFeB-MgO
based structure after a post anneal process. The strain induced by MgO layer and by Ta overlayer may
substantially improve the (001) texture of CoFe and thus improves the PMA in these structures.

Phase distribution and grain size are the key factors controlling the coercivity ofnanocomposite permanent magnets. Feng et al. have investigated the effective anisotropy
and coercivity of nanocomposite Nd2Fe14B/α-Fe magnets. [1] The latest research showsthat the PtCo alloy is composed of nano-structured soft and hard magnetic phases. [2] Thissystem can be used as an ideal model system for studying exchange coupling between themagnetically hard and soft phases. There exist three types of grain interfaces with different
exchange-coupling strengths in nanocomposite PtCo permanent magnets. It is necessary todescribe the proportions of the three kinds of grain interfaces for analyzing the influencesof the exchange-coupling interactions on the magnetic properties. We assume that soft andhard phases distribute randomly in nanocomposite permanent magnets and that all grains
have cubic shapes.We caculate the dependence of the coercivity Hc of a nanocomposite on
the hard-grain size Dh. For a given volume fraction vh and soft-grain size Ds, Hc shows amaximum value as a function of the hard-grain size Dh, and the maximum position shifts
to a smaller Dh with the decreasing volume fraction of the hard phase. We shows thecomparisons between the calculated coercivity Hc and experimental results.

STT-MRAM (Spin transfer torque-magnetoresistive random access memory)[1] has considered
as an outstanding candidate for the next generation memory device. Higher anisotropy constant
K and low saturation magnetization Ms are required for the perpendicular magnetic layers
to satisfy the high thermal stability and low current density for current induced magnetic
switching. The PMA(perpendicular magnetic anisotropy) have been reported in Fe-Pt alloy[2]ordered by L10, Co/Pd multi-layer[3] and CoFeB-MgO[4,5]. We report the PMA of CoFeB
based with MgO using amorphous paramagnetic FeZr buffer layer. Samples are deposited on
SiO2 substrate by RF magnetron sputtering machine at room temperature. The structures are
SiO2FeZr2nmCoFeB(tCoFeB:0.5-2)/MgO2.5nmTa1nm (in nm) and annealing for 1 hour at 400°C. Figure 1 shows Hall resistance of PMA of CoFeB after annealing. During the annealing
treatment, the lattice of CoFeB became BCC lattice structure along with crystal structure ofupper MgO. Therefore, the interface anisotropy is formed between CoFeB and MgO layers inrather thin thickness. In summary, we observed the PMA in CoFe/MgO using the FeZr buffer
layer. We obtain a high anisotropic constant K with a various conditions. This method can be an
excellent candiate for PMA- MTJ with low critical current density.

[1] W.C. Feng, W. Li, et al., J. Appl. Phys. 98, 044305(2005) [2] Xiao Q F, Bruck E, de Boer F R etal. , J. Alloys Compd., 364,64(2004)[1] Kishi, T. et al. IEDM Tech. Dig. 309 (2008) [2] Yoshikawa, M. et al. IEEE Trans. Magn. 44,25732576 (2008) [3] Mizunuma,
K. et al. APL. 95, 232516 (2009) [4] S.Yuasa. et al. Nat. Mater. 3, 868 (2004) [5] S.Ikeda. et al. Nat. Mater. 9, 721 (2010)

Kosuke Suzuki1*, Naoto Go1, Shun Emoto1, Masayoshi Itou2, Yoshiharu Sakurai2 and Hiroshi Sakurai1
1Graduate School of Engineering, Gunma University, Japan
2
JASRI/SPring-8, Japan

Co/Pd multilayers have attracted attention as a potential application in high-density magnetic recording
media because of their strong perpendicular magnetic anisotropy (PMA)[1,2]. It has been reported thatthin Co layer and thicker Pd layer enhance the PMA enegy[2,3]. In this paper two Co/Pd multilayers
which have smooth and rough interfaces, respectively, were studied. A Co1.5nmPd2.6nm multilayer withsmooth interfaces was fabricated by the MBE technique. A Co1.6nmPd4.0nm multilayer with rough interfaces
was fabricated by the sputter technique[4]. Both multilayers had almost the same PMA energy, 1.15Merg/
cc for the Co1.5nmPd2.6nm multilayer and 1.20Merg/cc for the Co1.6nmPd4.0nm multilayer, respectively. The
symmetry of the wavefunction was measured using the magnetic Compton profile measurement.
The symmetry of wavefunction of both the multilayers is almost the same. Population analysis of Co3d shows that the population of magnetic quantum number |m|=2, 1 and 0 is 50%, 36% and 14%,respectively. This suggests that the smooth interface enhances the population of |m|=2 symmetry andhence enhances the PMA energy[5-7]. In conclusion smooth interface enhances |m|=2 symmetry andhence enhances the PMA energy even if a Co/Pd multilayer has a thinner Pd layer.
[1] P. F. Carcia, A. D. Meinhaldt and A. Suna: Appl. Phys. Lett.47, 178 (1985) [2] P. F. Carcia: J. Appl.
Phys.63, 5066 (1988) [3] H. Nemoto and Y. Hosoe: J. Appl. Phys. Vol.97, 10J109 (2005) [4] M.Ota: Master’s
Thesis, Gunma University (2002), in Japanese [5] K. Kyuno, J. -G. Ha, R. Yamamoto and S. Asano: Phys. Rev.
B54, 1092 (1996) [6] H. Sakurai, M. Ota, F. Itoh, M. Itou, Y. Sakurai and A. Koizumi: Appl. Phys. Lett. Vol.88,
062507 (2006) [7]M. Ota, M. Itou, Y. Sakurai, A. Koizumi and H. Sakurai: Appl. Phys. Lett.96, 152505 (2010)

162

Duong Duc Lam1, Frederic Bonell1, Shinji Miwa1, Yoichi Shiota1, Kay Yakushiji2, Hitoshi
Kubota2, Takayuki Nozaki2, Akio Fukushima2, Shinji Yuasa2 and Yoshishige Suzuki1*
1
Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
2
National Institute of Advanced Industrial Science and Technology (AIST), Spintronics ResearchCenter, JapanThe 19th International Conference on Magnetism

C.w. Su1, H.m. Chen2, Chih-wei Cheng2, C.h. Shiue2, J. P. Singh2, C.c. Tsai3 and G.
Chern2*
1
Department of Electrophysics, National Chiayi University, Chiayi, 60004, Taiwan
2
Department of Physics, National Chung Cheng University, Chiayi 62102, Taiwan
3
Department of Engineering and Management of Advanced Technology, Chang Jung
Christian University, Tainan 71101, Taiwan

1 S. Iikeda et al., Nat. Mater. 9, 721 (2010). 2 D. C. Worledge et al., Appl. Phys. Lett. 98, 022501 (2011).

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The study of MgO based surface anisotropy of CoFeB layer

July 8-13, 2012 Busan, Korea

163

poster Presentation
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BiFeO3 thickness dependence of exchange bias in polycrystalline
BiFeO3/FeNi bilayers

Initial growth of bcc Co films on Au(001) studied by STM/BH imaging

Exchange bias effect in Ni(Zn)O film

Morphological consideration for post-annealed Cr2O3 surface andexchange bias in bilayer system

July 9 (Mon)

Due to both ferroelectric and antiferromagnetic transition temperatures above room
temperature, multiferroic BiFeO3 has attracted much attention for uses in the electricalcontrol of magnetic random assess memory. Exchange bias in ferromagnet (FM)/antiferromagnet (AFM) bilayers has also attracted much attention because of its
importance in developing magneto-electronic devices. Although there have been some
reports on the exchange bias employing BiFeO3 as antiferromagnetic layer, most ofthem the BiFeO3 layers were grown epitaxially. In this presented work, single phasepolycrystalline BiFeO3 films were successfully grown on Si substrate with LaNiO3
buffer layer. Clear exchange bias were observed at room temperature in a series of
BiFeO3(t)FeNi(3.6nm) bilayers, in which t varies from 8 nm to 240 nm. With increasing t,
both the exchange bias field and the coercivity increase sharply and approach maxima
when t is about 40 nm, which is close to one half of the spin cycloidal modulation
period (64 nm) of the bulk BiFeO3 material. Our results suggest that the cycloidal
spin structure may still exist in the polycrystalline BiFeO3 film and the interfacial
uncompensated pinned spins may be responsible for exchange bias in the BiFeO3/FeNi
bilayer films.

T. Kawagoe*, E. Wakabayashi, Y. Murasawa and T. Sakata
Osaka Kyoiku University, Japan

We have studied the surface structure and magnetism of metastable bcc Co films (>1ML) on Au(001) [1]. Here we report the initial growth of submonolayer Co films bymeans of barrier height (BH) imaging using STM, which has capability of element
discrimination. The experiments were performed in a UHV-MBE system equippedwith an STM unit. After the clean Au(001) reconstructed surface was confirmed by
STM, a submonolayer Co was deposited on it at RT. Spatially resolved BH maps,
together with the topographic images were obtained at RT using a tip-sample distancemodulation technique. We have observed numerous islands with different sizes andheights after 0.15 ML Co coverage and successfully obtained, from the BH imaging,an element-specific contrast, i.e. recognizing aggregated Au islands and Co islands, andinformation about inhomogenities of BH with proper consideration of the artifacts near
the step edges. BH of metastable bcc Co film was observed for the first time, and thatshowed a large BH value (~6 eV), whereas the observed BH of the Au(001) surface(~3.5 eV) was consistent with the previous results.
[1] T. Kawagoe et al., Surf. Sci. 602, L15 (2008).

R. Ray1*, S. Biswas1, S. Das2, S. Majumdar2 and S. Giri2
1
Department of Physics, Jadavpur University, India
2
Solid State Physics, Indian Association for the Cultivation of Science, India
Exchange bias (EB) has received significant attentions for fundamental interest andpotential applications in magnetic memory and read heads. Recently, EB is observed invarious alloys and compounds [1]. Magnetic nanoparticles have been found promisingfor significant EB effect where surface spins were found to have different magnetic
anisotropy than core spins, causing sizable EB effect. Compared to the studies of EB in
nanoparticles, these studies in film geometry having chemically single phase are rarely
investigated, which is rather promising for technological applications. Here, we report
EB in Ni1-xZnxO films where Zn substitution in NiO significantly modifies magnetic
properties and EB effect. Atomic Force Microcopy exhibits formation of granular films
of average grain size ≈25 nm. We note that EB field (HE) and coercivity (HC) decrease
considerably with Zn substitution at x = 0.3 and HE vanishes at x = 0.5. Appearance
EB in NiO film is suggested due to significant difference in anisotropy between coreand surface spins, as it has been conjectured for NiO nanoparticles. The Zn substitution
appreciably decreases the difference between core and surface anisotropy causing the
reduction of HE as well as HC.

Tomohiro Nozaki*, Naoki Shimomura, Takuya Ashida, Yuji Sato and Masashi
Sahashi
Graduate school of Electronic Engineering, Tohoku University, Japan

Magnetoelectric Cr2O3 has been received renewal of attentions as a promising material
for the low energy consumption electric controlled spintronic devices such as MERAM[1]. High exchange bias field (Hex) between ferromagnetic layer and Cr2O3 thin film
layer, and low coercivity (Hc) are essential for the applications. Previously we reported
the high Hex (~500 Oe) at the wide temperature range from 10 K to 250 K and the low
Hc (~30 Oe) at 250 K for post-annealed Cr2O3 thin film system [2]. In this study wecompared the morphology and magnetic properties of the post-annealed sample withthat of samples fabricated by other manners and examined the origin of the high Hex
and low Hc of the post-annealed sample. The post-annealed sample was identified to bepolycrystalline, which would contribute to the low Hc. From TEM and AFM images,
flat (1-102) planes (r-planes) were observed diagonally to the film surface which areformed during the post annealing by grain growth due to the low surface energy [3].
From the fact that Cr2O3 has uncompensated spin not only c-plane but also r-plane, we
conclude that the origin of the high Hex is the uncompensated r-plane.

[1] S. Giri et al. J. Phys.: Condens. Mater 23 (2011) 073201.

[1] X. Chen et al., Appl. Phys. Lett., 89 (2006) 202508. [2] T. Ashida et al., The 56th MMM
Conference, (2011) FE-05. [3] J. Sun et al., Surf. Coat. Tech., 201 (2006) 4205.

PL02

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Temperature-dependent magnetic anisotropies in epitaxial Fe/CoO/
MgO(001) system studied by the planar Hall effect

Magnetic field induced “switching” of the nanodomain state offerromagnet - antiferromagnet frustrated system

Electronic properties of transition metal oxides interface between
GdTiO3SrTiO3Magnetic properties of [NiFe/NiFeCuMo/NiFe]/FeMn¬multilayers
depending on a thickness of NiFeCuMo layer

J. Zhu1, J. Li1, W.n. Cao2, J. Zhu1 and Yizheng Wu2*
1
Physics department, Fudan university, China2physics department, Fudan university, China

The exchange coupling between ferromagnet (FM) and antiferromagnet (AFM)
has been intensively explored due to fundamental interest and its technologicalapplications. The effect of the magnetic anisotropy of the AFM layer on the exchange
coupling has not been well studied, which can only be performed in single-crystalline
FM/AFM system. In this contribution, we investigated the exchange-induced inplane magnetic anisotropies in a single-crystalline Fe/CoO/MgO(001) system in thetemperature range of 10-400K. The temperature-dependent magnetic anisotropies of
the Fe film were quantitatively measured with the torque technique utilizing the planar
Hall effect. We found the field cooling can induce a very strong uniaxial anisotropy
up to 0.196erg/cm2 in Fe film with the easy axis(EA) // CoO<110>, and also a 4-foldanisotropy with the EA//CoO<100>. Such EA of the exchange-induced anisotropy was
found insensitive to the cooling field orientation and only related to the CoO crystalline
axis. The CoO thickness dependent exchange-induced anisotropy will be discussed inthis contribution.
1.W. N. Cao, J. Li, G. Chen, J. Zhu, C. R. Hu, and Y. Z. Wu, Appl. Phys. Lett. 98, 262506 (2011)

Alexander I Morosov and Alexander S Sigov
Electronics Department, MSTU MIREA, Russia

The presence of atomic steps on the interface between the nanolayers of ferromagnet
and antiferromagnet with uncompensated atomic planes parallel to the interface causes
frustrations of the interlayer exchange interaction. If the exchange integral for the
ferromagnet is less than that one for the antiferromagnet, then, for the layers of equal
thickness, and in the case where the characteristic distance R between the neighboringedges of the steps on the interface exceeds the layer thickness, the ferromagnetic
layer appears to be broken down into 180o domains. The domain walls separatingsuch domains generated by frustrations arise at the atomic step edges and penetrate
the ferromagnetic layer, the domain wall thickness increases with increasing distancefrom the interface. An external magnetic field applied parallel to the magnetizationsof the domains, being in excess of some critical value B*, makes the monodomainstate of the ferromagnetic layer more favorable. If so, the domain walls with more
complicated structure depending on the field magnitude arise between 180o domains in
the antiferromagnet layer. The B* value can be obtained from the equality of the gainin the Zeeman energy and the difference between the energies of the domain walls in
different layers.

Sungbin Lee1* and Leon Balents2
1
University of California, Santa Barbara, USA
2
Kavli Institute for Theoretical Physics, University of California, Santa Barbara, USA
The creation of a two dimensional electron gas (2DEG) at the interface between two
insulating oxides has been a subject of great interest, and much experimental activity
has centered on the LaAlO3SrTiO3 interface. The (001) GdTiO3SrTiO3 interface has
the same naive polarization discontinuity as the former system, but unlikely it actuallyexhibits a 2DEG with the expected e/2 charge per planar unit cell.[1] Motivated byrecent experiments, which show that the 2DEG primarily lives in the SrTiO3, weconstruct a theoretical tight-binding model and discuss the electronic properties incomparison with experiment, and consider possible magnetism in this system at low
temperature.
[1] P. Moetakef et al., Appl. Phys. Lett. 99, 232116 (2011)

Jong-gu Choi1, Kwang-jun Park2, Jang-rho Rhee3 and Sangji-suk Lee2*
Eastern-Western Biomedical Engineering, Sangji University, Korea
2
Oriental Biomedical Engineering, Sangji University, Korea
3
Physics, Sookmyung Women’ University, Korea
1

Variations in the exchange bias field (HEX) and coercivity (HC) of the intermediately
super-soft magnetic NiFeCuMo layer were investigated for different thicknesses of thebottom NiFe layer. HEX of the triple pinned NiFe4 nmNiFeCuMo (tNiFeCuMo = 1 nm)/
NiFe4 nmFeMn multilayer has a maximum value that is more less than that of a single
pinned NiFe8 nmFeMn layer. If a NiFeCuMo layer is inserted between the pinned andfree NiFe layers, this multilayer system can be used as a giant magnetoresistive spinvalve (GMR-SV) device for biosensors with improved magnetic sensitivity.
[1] J. G. Choi, D. G. Hwang, S. S. Lee, J. H. Choi, K A. Lee, and J. R. Rhee, J. Kor. Magn. Soc. 19,
197 (2009). [2] J. G. Choi, D. G. Hwang, S. S. Lee, and J. R. Rhee, J. Kor. Magn. Soc. 19, 142 (2009).
[3] J. G. Choi, D. G. Hwang, J. R. Rhee, and S. S. Lee, J. Magn. Magn. Mater. 322. 2191 (2010).
[4] W. F. Egelhoff Jr., R. D. McMichael, C. L. Dennis, M. D. Stiles, F. Johnson, A. J. Shapiro. B. B.
Maranville, C. J. Popwell, Thin Solid Films 505, 90 (2006).

PL03

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Structural changes and magnetic properties of ultrathin Fe/Pt(111)films influenced by oxygen exposure

Stable structural and electronic properties of adsorption Tl on theclean Tl/Si(111) surface

Parallel ferromagnetic resonance and spin wave excitation in
exchange-biased NiFe/IrMn bilayers

Structural and magnetic properties of antiferromagnetic Heusler
Ru2MnGe epitaxial thin films

Recently, it is suggested that spin transport phenomena observed in conventional spintronics
ought to occur in systems where all FM materials are replaced by antiferromagnetic (AFM)
materials. Although various studies have investigated FM Heusler alloys, very few studies
have been made on AFM Heusler alloys in terms of spintronic applications. The AFM
transition temperatures (TN) of Heusler alloy such as Fe2VSi can be controlled by inducing
biaxial strain[1]. Thus we investigate the correlation between structural and magnetic
properties of epitaxial thin films of AFM Ru2MnGe. Structural characterization revealed
that Ru2MnGe films on MgO were subjected to compressive strain (c/a = 1.0042). The
strained Ru2MnGe exhibited markedly enhanced TN of 353 K compared to the bulk value(316 K)[2]. The in-plane Mn-Mn distance for the strained Ru2MnGe is slightly smaller thanthat of bulk Ru2MnGe, which may contribute to reducing the total J2 values, resulting in
the enhancement of TN. We also observed the exchange coupling between Heusler-type
FM half-metal Fe2CrSi and AFM metal Ru2MnGe. The present AFM Heusler alloy withrelatively high TN is useful to fabricate high-quality all Heusler-type half-metal FM/AFM
junctions and is a promising material for the emerging field of AFM spintronics.
[1] N. Fukatani, C. Shishikura, Y. Takeda, and H. Asano, Appl. Phys. Expr. 2, (2009) 053001. [2] T.
Kanomata, M. Kikuchi, and H. Yamauchi: J. Alloys Compd. 414 (2006) 1-7.

Jyh-shen Tsay1*, Hau-chun Jhang1, Ying-chen Lee1, Wei-hsiang Chen1, Yao-jungChen2 and Huei-ying Ho3
1
National Taiwan Normal University, Taiwan
2
Taipei College of Maritime Technology, Taiwan
3
National Taipei University of Education, Taiwan

Haruki Kato1*, Liang Li1, Shinya Haraguchi1, Junpei Goto1, Masahito Tsujikawa2 andTatsuki Oda3
1
Graduate School of Natural Science and Technology, Kanazawa University, Japan
2
Center for Spintronics Integrated Systems, Tohoku University, Japan
3
Institute of Science and Engineering, Kanazawa University, Japan

Marcos Sousa1*, Fernando Pelegrini1, Justiniano Marcatoma2, Willian Alayo2 andElisa Baggio-saitovitch2
1
Universidade Federal de Goias - UFG, Brazil
2
Centro Brasileiro de Pesquisas Fisicas, Brazil

Magnetic properties of Fe/Pt(111) films have received much attention in the past
decade [1-2]. In this contribution, we focus on the structures and magnetic properties
of ultrathin Fe/Pt(111) films influenced by oxygen exposure. Fe atoms in thesubmonolayer region adapt a smaller layer distance as compared to the BCC structureof a Fe layer above one monolayer (ML). At saturation conditions for absorbed oxygen
on Fe/Pt(111), the increase of oxygen in the films coincides with the Fe thickness while
the amount of adsorbed oxygen in the submonolayer range is rather small. In addition,
the amount of oxygen exposure to achieve a saturation condition increases to a
maximum value followed by a reduction for Fe/Pt(111) thicker than 1 ML. This shows
the structure related oxidation efficiency of Fe/Pt(111). The growth of Fermi edge at
620 K shows the segregation of Pt atom to the top layers. Only the Fe/Pt(111) thicker
than 3 ML shows the enhanced coercive force after thermal annealing. This could be
explained by the blocking of the formation of FePt alloy by the iron oxides.

The structural inversion asymmetry shows up surfaces or interfaces. It leads to spin split electronic
state (Rashba-Bychkov effect) in the material. In particular, heavy metals on the light elements likeSi show strong spin-orbit splitting [1] and such property in Tl/Si(111) has also been confirmed bothin simulation and experiment [2]. This surface has been observed as a clean one, indicating thestability due to the insulating property verified by the experiments and theoretical approaches [3,4].
By donating (or accepting) electrons, one can introduce carriers with spin polarization at the part ofstates, implying an interesting basis for spintronics devices. In this work, as a method of donating
electrons, Tl atom which is the same element as the top surface of Tl/Si(111) is considered within
the density functional first-principles approach of fully relativistic pseudo-potential and planewave
basis. First, the stable adsorption site has been investigated with using the √3×√3 superlattice ofTl/Si(111). It was found that one of hollow site models is most stable in the adsorption models
investigated. In the presentation, we report details of the stable structure and, for typical systems,
we also present electronic structures and spin splitting in the band dispersion relations.

Ferromagnetic Resonance (FMR) investigation of magnetron sputtered exchange-biased
Si111Ru7nmNiFetIrMn6nmRu5nm bilayers reveals that spin wave and uniform resonance modes
are excited by the microwave field. The samples studied were produced in the presence of a
400 Oe magnetic field to set the unidirectional anisotropy and the thickness t of the NiFe layer
varied in the range 55-120 nm. The FMR experiments were done at room temperature using acommercial spectrometer with swept static magnetic field and the usual detection techniques.
In-plane angular variation of resonance fields of spin wave and uniform modes reveal for bothmodes the dependence on cosθ, where θ is the field angle with respect to the anisotropy axis. The
unidirectional anisotropy field for the spin wave mode is twice larger than that for the uniform
mode; they are equal to 40 and 20 Oe, respectively, for the Si111Ru7nmNiFe65nmIrMn6nmRu5nm
sample. Spin wave resonance theory give for the NiFe layer of this sample the exchange constantof 1.2 × 10^(-6) erg/cm. The parallel FMR results at microwave frequencies of 9.45 and 34.1
GHz agree with the values given by the resonance fields of spin wave and uniform modes also
excited in perpendicular FMR at a frequency of 9.45 GHz.

[1] T.U. Nahm, et al, J. Korean Phys. Soc. 46 (2005) S125; [2] Y.J. Chen, et al, APL, 93 (2008)
012503.

[1] C. R. Ast et al., Phys. Rev. Lett. 98, 186807 (2007). [2] K. Sakamoto et al., Phys. Rev. Lett. 102, 096805 (2009). [3]J. Ibanez-Azpiroz et al., Phys. Rev. B 84, 125435 (2011). [4] S. S. Lee et al., Phys. Rev. B 66, 233312 (2002).

[1] W. Stoeklein, S. S. Parkin and J. C. Scott, Phys. Rev. B 38, 6847 (1988). [2] M. Nisenoff and R. W. Terhune, J. Appl.
Phys. 36, 733 (1964). [3] V. S. Speriosu, S. S. P. Parkin, and C. H. Wilts, IEEE Trans. Magn. 23, 2999 (1987).

The 19th International Conference on Magnetism

July 9 (Mon)

Xiaobo Xue1, Xueyong Yuan2, Wenbing Rui1, Biao You1, Qingyu Xu2 and Jun Du1*
1
National Laboratory of Solid State Microstructures and Department of Physics,
Nanjing University, China
2
Department of Physics, Southeast University, China

164

poster Presentation

Naoto Fukatani*, Hirohito Fujita, Tetsuya Miyawaki, Kenji Ueda and Hidefumi
Asano
Nagoya University, Japan

July 8-13, 2012 Busan, Korea

165

poster Presentation
PL13

PL16

PL19

PM01

Exchange-spring phenomenon of ultrathin Fe/CoPt bilayer

Structure and magnetic properties of epitaxial Fe/MgO/Si (001)heterostructures

Exchange bias effect in BiFeO3 thin films

Correlation of soft magnetic properties with free volume and medium
range ordering in metallic glasses

July 9 (Mon)A large enhancement in the polar magneto-optic Kerr signal was observed after one
monolayer (ML) of Co adatoms on Pt(111) was annealed above 600 K to form a CoPt alloy at the interface [1]. In this contribution, the composition, surface structure
and magnetic properties of ultrathin Fe films on the top of a Co-Pt(111) surface alloy
has been investigated. As the Fe coverage increases on the top of the Co-Pt alloy, thepolar Kerr rotation increases. By way of systematically changing the Fe thickness, themagnetic properties of Fe/CoPt in both the polar and longitudinal configurations areinvestigated for Fe thinner than 7 ML. At an optimal condition for both the Fe thickness
and the annealing temperature for preparing the Co-Pt alloy, the polar coercive force
remains the same as the Fe coverage increases. The Fe/CoPt system exhibits magnetic
exchange-spring behavior in the polar configuration. The interfacial conditions for the
Fe/CoPt system are demonstrated to play an important role on the exchange-spring
phenomenon and will be discussed in this contribution.
[1] C.S. Shern, J.S. Tsay, H.Y. Her, Y.E. Wu, and R.H. Chen, Surf. Sci. Lett. 429 (1999) L497.

Jeong Hong Jo1, Kyung-ho Kim2, Yoon Jae Nam3, Hyung-jun Kim2, Joonyeon Chang2
and Sang Ho Lim1*
1
Department of Materials Science and Engineering, Korea University, Seoul 136-713, Korea
2
Spin Convergence Research Center, Korea Institute of Science and Technology, Seoul 136-791,
Korea
3
Department of Nano Semiconductor Engineering, Korea University, Seoul 136-713, Korea
The ferromagnetic metal/semiconductor structures with inserting a thin MgO tunneling barrier are
expected to play a key role in spin-based electronic applications to enhance spin injection efficiency.
Recently, spin-based devices using silicon channel enable seamless integration with conventional
MOS-FET technology. However, there are only a few reports on ferromagnetic metal/MgO/Si
system due to large lattice mismatch (3.5%) between Si and MgO. The study on strain induced
microstructure of the Fe and MgO layers is essential because the lattice mismatch between Si and
MgO results in distortion in both MgO and Fe layers. In addition, the magnetic property of theferromagnetic metal with respect to its microstructure evolution is also of importance in terms ofspin injection. In this study, Fe thin films of thinner than 2 nm, were prepared on Si (001) substrates
with 4 nm thick MgO buffer layer by a molecular beam epitaxy system at room temperature and
200 °C, respectively. X-ray diffraction and reflection high-energy electron diffraction results show
epitaxial relationship of the system. In-plane four-fold magnetic anisotropy was observed byvibrating sample magnetometer, suggesting that elevated growth temperature of the Fe films leads
to the strain relaxation and the suppression of two-dimensional Fe layer formation.

Kil-dong Sung and Jonghoon Jung*
Physics, Inha University, Korea

Amit P Srivastava1*, D Srivastava1, P K Pujari1, K G Suresh2 and G K Dey1
1
Bhabha Atomic Research Centre, Mumbai, India
2
Indian Institute of Technology Bombay, Mumbai, India

We fabricated BiFeO3 thin films with Bi2O3 or γ-Fe2O3 impurities by changing oxygen
partial pressures and characterized their magnetic properties. Since Bi2O3 impurity is a
non-magnetic material, only antiferromagnetic spins of BiFeO3 will contribute to wholemagnetic properties. But γ-Fe2O3 impurity is a well known ferrimagnetic material,so there is a possibility to show exchange bias effect with antiferromagnetic spins of
BiFeO3. We measured M(H) loop at various temperatures after zero- and ±5 T-fieldcooling. Almost no but very small amount of M(H) hysteresis loop was appearedin BiFeO3 with Bi2O3 impurity. Which indicate that there is uncompensated spinsin BiFeO3 which generate exchange bias effect with γ-Fe2O3. Significant hysteresis
loop was appeared in BiFeO3 with γ-Fe2O3 impurity. Depending on the field cooling
direction, the M(H) loops also shifted to the opposite directions. But unlike otherconventional exchange bias systems, the interaction between ferrimagnetic spins of
γ-Fe2O3 and antiferromagnetic spins of BiFeO3 is not so strong as shown in the training
effect result.

The effect of cooling rate on thickness and soft magnetic properties of the metallic
glass of alloy composition Co64.5Fe3.5Si16B14Ni2 have been studied. The amorphous
structure has been characterized by positron annihilation spectroscopy (PAS) andfluctuation electron microscopy (FEM) techniques. These studies suggest that thefirst lifetime component is associated with MRO present in the amorphous structure.
Theoretical calculations showed that second component is associated with nanovoids
having free volume equivalent to that of a vacancy defect consisting of 4 and more
atom vacancy cluster. Coercivity of the samples showed small variations with wheel
speed and it was found to decrease with the decrease in effective size of the defects
present in the samples. This study reveals that, in case of amorphous metallic glass, thevariation in coercivity is mainly controlled by the defects formed during processing
rather than the small variations in MRO introduced due to different cooling rates.

July 9 (Mon)Wei-hsiang Chen1, Hsing-hsuane Wu1, Huei-ying Ho2 and Jyh-shen Tsay1*
1
Physics, National Taiwan Normal University, Taiwan
2
Physics, Department of Science Education, National Taipei University of Education,
Taiwan

PL14

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PM02

Neutron magnetic scattering study in manganite thin film system

Uncompensated magnetic moment around Mn3Ir / Fe-Co-Ni bilayerinterface

Experiment evidence to the existence of interaction between
antiferromagnetic domains in IrMn/Pt/Co/Pt multilayers

Microscopic magnetic hysteresis measurement of amorphous Tb-TM(TM=Fe and Co) thin films by magnetic Compton scattering

Exchange bias phenomenon has become an integral part of the modern magnetism, with implications
in basic research and applications in magnetoelectronic devices. In the numerous experimental andtheoretical studies, the surface layer of antiferromagnetic (AFM) material is often regarded as an
assembly of uniaxial domains, which are independence from each other. This basic assumption isreally suspect. In our presented work, experiment evidence of interaction between AFM domains has
been found. The IrMn/Pt/Co/Pt perpendicular exchange bias systems were fabricated and treated by
AC demagnetization (ACDM) parallel to the film plane at high temperature. The purpose of ACDM
is to get the pinned demagnetization state in ferromagnetic layer. In the corresponding hysteresis
loop, two minor-loops shift oppositely along the magnetic field axis and locate totally on one sideof the vertical axis. Compare the training effects of the minor-loop and full-loop, we found that one
minor-loop measurement gives influence to the other. It is reasonable that the influence is attributed
to the interaction between the IrMn surface domains. Our experiment facts can not be explained by
the past theory models, new energy item of interaction between AFM domains should be considered.

Rare earth transition metal (RE-TM) alloys have attracted considerable attention from the viewpointof fundamental research and technology. For instance, they have been studied as candidate heatassisted magnetic recording media for high-density magnetic storage. It is known that magnetic
moment of RE and TM form ferrimagnetisms and have anisotropy dispersion along magnetic
easy axes, so-called sperri-magnetism [1]. The magnetic switching process of sperri magnetism
is considered not to be simple. In this report, we have study spin, orbital and also element specificmagnetic switching process of amorphous Tb-TM (TM=Fe and Co) films by means of combinationof magnetic Compton scattering [2, 3] and conventional macroscopic magnetization measurements.
As specimen, amorphous Tb43Co57 and Tb32Fe55 (O13) thin films were fabricated by an RF sputtering
onto a thin Al foil substrates. The macroscopic magnetization curves were measured by SQUID
and VSM magnetometers. Magnetic Compton scattering measurements were carried out at ARNE1A of KEK [2] and at BL08W of SPring-8 [3], Japan. The present results suggest that magnetic
switching can be different among the spin moment, the orbital moment, and even the states ofelectrons, e.g., the Tb 4f electron, TM 3d electron, and itinerant electron.

H. Nakao1*, H. Yamada2, K. Iwasa3, J. Okamoto1, Y. Yamasaki1, Y. Murakami1 and A.
Sawa2
1
Condensed Matter Research Center and Photon Factory, IMSS, KEK, Japan
2
Electronics and Photonics Research Institute, AIST, Japan3
Department of Physics, Tohoku University, Japan
Perovskite manganites show various interesting phenomena including colossal magnetoresistance(MR) due to a close interplay among charge, orbital, spin, and lattice degrees of freedom. The
superlattice [(LaMnO3)m(SrMnO3)m]n was investigated as a stage to control the Mn valence
artificially. The physical properties were reported to strongly depend on the periodicity m, andthe interface state between LaMnO3 and SrMnO3 layer was noted.[1] The stacking structureof Mn valence state by resonant x-ray scattering technique has been studied.[2] It elucidated
that the physical properties just depend on the quality of the film. Recently, however, new large
MR effect was discovered in the high quality superlattice system.[3] To understand the MR
effect microscopically, the Mn valence state and the magnetic field effect were studied. Here themagnetism is also important, and then neutron magnetic scattering experiment was started using
the neutron spectrometer TOPAN in JRR-3. As a first step, SrMnO3 film with 80 nm thickness
has been investigated. A signal with about 2 cps at (0.5, 0.5, 0.5) corresponding G-type AFM
was certainly discovered. The temperature dependence of the signal intensity was also measured.
Consequently we have succeeded in observing magnetic scattering from thin film system.

Yohei Kota*, Hirokazu Takahashi, Masakiyo Tsunoda and Akimasa Sakuma
Graduate School of Engineering, Tohoku University, Japan

We study the microscopic origin of the uncompensated moment in Mn3Ir / Fe-Co-Ni bilayer,
which is practically utilized system due to the excellent property of exchange anisotropy, by thetheoretical and experimental approach. In order to induce exchange anisotropy, the magnetic
structure in the ferromagnetic / antiferromagnetic bilayer needs to have some asymmetry
against the field reversal, and the uncompensated moments around the interface is a candidate
for the spin asymmetry. We previously reported that there is a linear correlation between theexchange anisotropy and uncompensated moments measured by the x-ray magnetic circulardichroism (XMCD) experiment in Mn-Ir / Co-Fe bilayer [1]. Therefore, in the present work, weinvestigate the composition dependence of the uncompensated moment in Mn3Ir / Fe-Co-Ni by
performing the first-principles calculation and the XMCD measurement to clarify the origin of
the uncompensated moment. In the comparison of the calculation and experimental results, theobtained uncompensated moments are in good agreement for their sign and relative magnitude[2]. Furthermore, the calculated result reveals that the uncompensated moment originatesfrom the local magnetic correlation near the interface. So we find that the reorientation of themagnetic moments of Mn occur at the very interface with the ferromagnetic layer.

X. J. Bai1, Z. Shi2, S. M. Zhou2*, X. R. Zhao1 and C. D. Cao1
1
Key Laboratory of Space Applied Physics and Chemistry, Northwestern
Polytechnical University, Xi’an, China
2
Department of Physics, Tongji University, Shanghai 200092, China

Akane Agui1*, Tetsuya Unno2, Sayaka Matsumoto2, Kousuke Suzuki2 and Hiroshi Sakurai2
1
Japan Atomic Energy Agency, Japan
2
Dept. Production Sci & Technol., Gunma Univ., Japan[1] T. Koida et al., Phys. Rev. B 66 (2002) 14418. [2] H. Nakao et al., J. Phys. Soc. Jpn. 78 (2009)024602. [3] H. Yamada et al., Phys. Rev. B 81 (2010) 014410.

[1] M. Tsunoda, H. Takahashi, T. Nakamura, C. Mitsumata, S. Isogami, and M. Takahashi, Appl.
Phys. Lett. 97, 072501 (2010). [2] H. Takahashi, Y. Kota, M. Tsunoda, T. Nakamura, K. Kodama, A.
Sakuma, and M. Takahashi, J. Appl. Phys. 110, 123920 (2011).

[1] C. H. Lai, W. E. Bailey, R. L. White, T. C. Anthony, J. Appl. Phys. 81 4990 (1997) [2] T. Hauet, S. Mangin, J. McCord, F.
Montaigne, and E. E. Fullerton, Phys. Rev. B 76, 144423 (2007) [3] X. P. Qiu, D. Z. Yang, S. M. Zhou, R. Chantrell, K. O’Grady, U.
Nowak, J. Du, X. J. Bai, and L. Sun, Phys. Rev. Lett. 101, 147207 (2008) [4] E. Fulcomer, S. H. Charap, J. Appl. Phys. 43, 4190 (1972)

References: [1] J. M. D. Coey, J. Chappert, J. P. Rebouillat, and T. S. Wang, Phys. Rev. Lett. 36 (1976) 1061. [2] A.
Agui, H. Sakurai, T. Tamura, T. Kurachi, M. Tanaka, H. Adachi, and H. Kawata, J. Synchrotron Rad., 17 (2010) 321. [3]A. Agui, S. Matsumoto, H. Sakurai, N. Tsuji, S. Honma, Y. Sakurai, and M. Itou, APEX 4 (2011) 083002.

PL15

PL18

PL21

PM03

Direction and temperature dependences of exchange bias andcoercivity of NiFe/Cr2(1-x)Fe2xO3(x= 0.25, 0.4) bilayers

Unusual exchange bias effects in NiFe/Mn thin films induced via ionbeam bombardment

Nanoscale investigation of the Cr/Fe(001) interface grown by oxygen
assisted epitaxy

A significant reduction of hysteresis in MnFe(P,Si) compounds

Sanghoon Ki, Byeong-geon Kim and Joonghoe Dho*
Kyungpook National University, Korea

The antiferromagnets α-Fe2O3 and α-Cr2O3 have the same crystal structure but different
magnetic orderings. The AF spin structure for a-Cr2O3(TN~307 K) is represented by
the up-down-up-down spin ordering along c-axis, while that for a-Fe2O3(TN~953 K)
is done by the up-down-down-up one. As reported in previous neutron diffraction
study for the solid solution Cr2(1-x)Fe2xO3(CFO), such contradictory spin structures
may result in a new type AF structure such as spiral order or cycloidal order. Here, wereport exchange bias in NiFe/Cr2(1-x)Fe2xO3(x= 0.25, 0.4) bilayers grown on c-planeand r-plane Al2O3. The direction and temperature dependences of magnetic propertyof NiFe/CFO layer substrates were checked by a surface magneto-optical Kerr effect(SMOKE) setup. At room temperature, the M(H) loop of the NiFe layer exhibitedenhanced coercivity and exchange bias depending on the measurement direction andthe temperature. In order to see the direction dependence of magnetic property of NiFe
layer, the magnetic field was applied to two orthogonal directions within the plane.
Interestingly, the temperature dependence of M(H) loop exhibited some features ofspin reorientation of CFO layer below antiferromagnetic transition temperature.

166

poster Presentation

The 19th International Conference on Magnetism

Chi-hsin Liu1, Chin Shueh1, Yi-wen Ting1, Wen-chen Chen2, Te-ho Wu2, Johan Van Lierop3 and Ko-wei Lin1*
1
Dept of Materials Science and Engineering, National Chung Hsing University, Taiwan
2
Graduate School of Material Science, National Yunlin University of Science and Technology, Taiwan
3
Department of Physics and Astronomy, University of Manitoba, Canada

When spins at the interface between a ferromagnet (FM) and an antiferromagnet (AF) couple, aunidirectional anisotropy occurs, resulting in exchange bias [1,2]. In this study, we wish to identify thedependence of the exchange bias on the interface microstructure in NiFe/Mn thin films. A series of [NiFe/
Mn] multilayer thin films were fabricated using a dual ion-beam deposition technique [3]. Different Ar-ion
deposition voltages created striking differences in magnetic properties. The [NiFe/Mn] (VEH= 0 V, i.e. unbombarded) thin film (~ 200 nm) at 5 K when 20 kOe field-cooled (FC), exhibited an enhanced coercivity(Hc~ 935 Oe) and positive exchange bias field, Hex~ +130 Oe. By contrast, the [NiFe/Mn] (VEH= 150
V) Ar-ion bombarded thin film (~ 20 nm) at 5 K when 20 kOe field cooled showed a larger positive Hex(~ +160 Oe) with smaller Hc (~ 610 Oe) accompanied by an asymmetric hysteresis loop. The observed
enhanced positive Hex indicated that the transition from FM to AF coupling was made possible bychanging the ion-beam bombardment voltages. Further, the role of Ar ion-bombardment seems to changeboth the spin orientations in FM NiFe and AF Mn and thus gives rise to the positive enhanced Hex.
[1] T. Saerbeck, F. Klose, D. Lott, G.J. Mankey, Z. Lu, P.R. LeClair, W. Schmidt, A. Stampfl, S. Danilkin, M.
Yethiraj, A. Schreyer, Phys. Rev. B 82, 134409 (2010). [2] H. Ouyang, Y.-H. Han, S.-C. Lo, C.-H. Su, Y.-R.
Shiu, K.-W. Lin, R. D. Desautels, and J. van Lierop, Phys. Rev. B 81, 224412 (2010). [3] K.-W. Lin, V. V.
Volobuev, J.-Y. Guo, S.-H. Chung, H. Ouyang, and J. van Lierop, J. Appl. Phys. 107, 09D712 (2010).

Alberto Brambilla1*, Andrea Picone1, Guido Fratesi2, Alberto Calloni1, Michele Riva1, Gianlorenzo
Bussetti1, Alberto Ferrari1, Lamberto Duo'1, Marco Finazzi1, Mario Italo Trioni3 and Franco Ciccacci1
1
Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy2
Dipartimento di Scienza dei Materiali, Universita di Milano-Bicocca, Via Cozzi 53, 20125 Milano, Italy
3
CNR, National Research Council of Italy, ISTM, Via Golgi 19, 20133 Milano, Italy

Cr deposition on Fe(100) has been the subject of intense investigations in the past, being an excellent
model system for thin film magnetism, and also because Fe/Cr multilayers played a fundamental role in thedevelopment of giant magneto resistive devices [1]. The magnetic properties of such systems can be affectedby parameters like interfacial mixing, strain and defects. For instance, previous investigations have shown
that, within the atom distribution resulting from Cr incorporation into the Fe substrate, nearest neighbour CrCr coupling is energetically less favorable than next nearest neighbor coupling, due to magnetic frustrations[2]. Here we employ experimental and theoretical methods to highlight and characterize deviations in the
micromagnetic structure of the Cr/Fe interface due to the presence of adsorbed O, which induces a layerby-layer Cr growth at room temperature, as we recently demonstrated [3]. Scanning tunnelling microscopy(STM) is used to investigate the deposition of Cr on the Fe-p(1x1)O surface since the first stages of interface
formation. Atomic resolution STM images reveal the occurrence of different magnetic configurations,
including first-neighboring Cr atoms in the Fe matrix. The observations are discussed in the light of densityfunctional simulations with the generalized gradient approximation and plane waves basis set [4].

O. Tegus1*, Y. X. Geng1 and J. H. Huang2
1
Physics and Electronic Information College, Inner Mongolia Normal University,
Hohhot 010022, China
2
Baotou Research Institute of Rare Earths, Baotou 014030, China
The magnetocaloric effects in Mn1.3Fe0.7-xCoxP0.46Si0.54 compounds with x = 0, 0.025,
0.05 and 0.1 are studied systematically. X-ray diffraction shows that the compounds
in the range from x = 0 to 0.1 crystallize in the Fe2P-type hexagonal structure withspace group P-62m symmetry. Magnetic measurements show that the paramagneticferromagnetic transition temperatures range from 247 to 298 K. The maximum ofmagnetic entropy changes in Mn1.3Fe0.7P0.46Si0.54 compound reaches 8.3 J/kgK in afield change of 0 to 1.5 T, and the thermal hysteresis of these compounds is less than
3 K. The maximum adiabatic temperature change is 2.2 K in Mn1.3Fe0.7P0.46Si0.54 andMn1.3Fe0.65Co0.05P0.46Si0.54 compounds for a field change from 0 to 1.48 T.

[1] B. Heinrich, J.A.C. Bland (Eds.), Ultrathin Magnetic Structures, Springer Verlag, Berlin, (1994). [2] A. Davies, Joseph A.
Stroscio, D. T. Pierce, and R. J. Celotta, Phys. Rev. Lett. 76, 4175 (1996). [3] A. Calloni, A. Picone, A. Brambilla, M. Finazzi, L. Duo, F.
Ciccacci Surf. Sci. 605, 2095 (2011). [4] P. Giannozzi, N. Baroni, M. Bonini et al., J. Phys.: Condens. Matter 21, 395502 (2009).

July 8-13, 2012 Busan, Korea

167

poster Presentation
PM04

PM07

PM10

PM13

Temperature dependence of creep-induced anisotropy innanocrystalline FeCuNbSiB alloys

Ion incient energy effects on the giant magnetoimpedance
enhancement

Magnetic and magnetocaloric properties of polycrystalline Fe2P underhydrostatic pressure

Magnetocaloric effect in Fe doped La0.67Ba0.33MnO3 system

We have investigated the creep induced anisotropy in nanocrystalline
Fe75Cu1Nb3SixB21-x alloys as a function of the measuring temperature. The samples
were produced by annealing originally amorphous ribbons for about 4 s between 500°C
and 700°C with a tensile stress applied along the ribbon axis. For Si-contents equalor larger than 9 at% the annealed ribbons reveal a linear hysteresis loop indicative ofan easy magnetic plane perpendicular to the stress axis. For lower Si-contents, stressannealing results in a square loop indicative of an easy magnetic axis parallel to thestress axis. This transition from an easy plane to an easy axis as a function of the Sicontent is well-known from previous investigations and is related to the dependenceof local magnetostriction of the nanocrystals on the Si-content. However, theinvestigations so far have been only carried out at room temperature. The present work,for the first time, reveals that the Si-contents where the easy axis changes its direction
shifts to higher concentrations as the temperature increases. This is also nicely reflected
in a reversible change from a linear hysteresis loop with low remanence to a square
loop as a function of the measuring temperature.

The present experiment investigates the physical effects of ion irradiation on themagnetic properties of the amorphous ribbon. Samples were commercial amorphousribbon with sizes of 2 mm x 40 mm x 20 μm. The Ar ions were provided by an ion
implanter at various dosages from 100 keV to 200 keV at the 1.0 x1018 ion/cm2.
The GMI ratio was measured as a function of the DC magnetic field (Hmax=35 Oe)
at different driving frequencies up to 10 MHz with a 5 mA amplitude applied to thesample irradiated with different energy. The irradiated samples show a clear change
in the impedance response with applied field. When energetic ions with energies ofseveral tens of keV penetrate into a thin film, the collision cascade cause displacementsof the target atoms that induce a uniaxial anisotropy in the sample. Ion irradiationinduces uniaxial anisotropy along the transverse direction, which is accompanied by aneffective transverse susceptibility. Therefore, the increase in the GMI ratio in an ionirradiated sample is attributed to the increase in associated uniaxial anisotropy createdby ion bombardment.We found that controlling the ion energy can be one of theeffective ways of controlling the GMI property for ion

Magnetocaloric-based refrigeration presents itself as an environmentally-friendly energy-efficient technology
capable of beneficially replacing the current gas compression-based technology. Some of the most promisingmagnetocaloric working materials found to date, such as (Fe,Mn)2(P,Si), are based on the Fe2P binary
compound. Fe2P itself presents a first order magnetoelastic transition between FM and PM states at around219 K and a low magnetic entropy change spanning a large temperature range. What makes Fe2P so
unique is the coupling presented by its magnetic and crystal lattices which gives rise to the so-called mixed
magnetism[1]. We believe that the mixed magnetism is responsible for the giant magnetic entropy changepresent in Fe2P-based compounds. To further advance our understanding of this coupling we performed
magnetization experiments under hydrostatic pressures up to 8 kbar on pure Fe2P in its polycrystalline form.
Pressure is found to decrease Tc at a rate of 6 K/kbar, about twice the rate reported in literature[2]. The Tc
dependence on field is found to be non-linear and is only weakly affected by pressure. The magnetic entropychange peak is slightly decreased by increasing pressure whereas the total entropy increases by ~ 6%.

[1] E. Lee, S. Lee, W. Lee and C. E. Lee, J. Korean Phys. Soc. 56, 2108 (2010). [2] D. Pathak and R.
K. Bedi, J. Korean Phys. Soc. 57, 474 (2010).

[1] Dung, N.H. et al. Advanced Energy Materials 1, 1215 (2011). [2] Fujii, H., Hokabe, T.,
Kamigaichi, T. & Okamoto, T., J. Phys. Soc. Jpn. 43, 41-46 (1977).

PM05

PM08

PM11

PM14

Magnetocaloric properties of Ni-Co-Mn-In ribbon

Investigation of electrodeposited FeNi film prepared from tartaric acidbased bath

Influence of Er doping on magnetic and magnetocaloric properties of(NiCo)2MnGa

Study of magnetic transition and magnetic entropy changes of
La0.7Sr0.3MnO3 and La0.7Ca0.1Sr0.2MnO3FeNi films have been plated by using boric acid as pH buffer agent. However, theboric acid is needed to be replaced by another one which does not include boron,
because boron is an environmentally hazardous substance. In order to achieve boronfree electroplating of FeNi, we applied the method proposed by Luisa et al for the
CuNi electroplating [1] to that of FeNi, in which they successfully plated CuNi withgood surface morphology by using tartaric acid. We electroplated FeNi films with
Fe content of 17-45 at.% from the bath including NiSO4•6H2O, FeSO4•7H2O, NaCl,
C7H4NNaO3S•2H2O and C4H6O6 (tartaric acid). The content of Fe was controlled byvarying the amounts of tartaric acid between 0-200 g/L. The coercive force of the asdeposited films varied with the content of Fe, and showed a sharp bottom of 20 A/m ataround 22 at.% of Fe. This result is consistent with the fact that FeNi alloys have nearlyzero values of magnetocrystalline anisotropy and saturation magnetostriction at around22 at.% of Fe. From the above result, we concluded that tartaric acid based bath film is
one of hopeful plating bath for electroplating of FeNi films.

Recently, an attention has been paid to magnetocaloric properties of the Co-doped Heusler Ni2MnGa
alloys with a paramagnetic gap in martensitic phase that can be tuned by their composition [1]. The
strong influence of a rare-earth doping has been calculated and observed on the valence orbitalsof Mn that makes the main contribution to the magnetic properties of these alloys [2]. We have
prepared Co-doped Ni2MnGa alloys with a very small amount of Er. The polycrystalline sample of
Ni42.9Co7Mn31Ga19Er0.1 was checked by the EDX analysis and a segregation of Er was discovered on
grain boundaries as it was expected in [2]. Saturated magnetization M(5K,0)=2.38μB/f.u. and theCurie temperatures TCM=318 K and TCA=440 K of martensite and austenite, respectively, wereobserved in Er free sample by a SQUID magnetometer. The inverse magnetocaloric effect at vicinityof martensitic transition, TM-A=379 K, was measured by direct method with ΔT=1.2K. In the Erdoped alloy, M(5K,0)=2.83μB/f.u. and paramagnetic gap was diminished in martensitic phase.
TCA=450 K has been detected only and magnetic susceptibility obey nicely the Currie-Weis law withparamagnetic moment of mP=5.09 μB/f.u. above TCA. The effect of the Er-segregation on crystal
texture and magnetic behaviour of the Co-doped Ni2MnGa alloys will be discussed.

[1] Luisa et al, J. Appl. Electrochem, 41 (2011) 415.

[1] S. Fabbrici, J. Kamarad, Z. Arnold, F. Casoli, A. Paoluzi, F. Bolzoni, R. Cabassi, M. Solzi, G.
Porcari, C. Pernechele, F. Albertini, Acta Materialia 59 (2011) 412-419 [2] J. Wan, Y. Fei, J. Wang,
Journal of Rare Earths 24 (2006) 373-375

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Influence of bismuth substitution on the magnetocaloric properties of
Gd5Si2Ge2 compound

Electrodeposited Fe-Co film prepared from citric acid-based plating
bath

Structural and magnetic properties of FeMnAl nanocrystalline alloys

Perpendicular magnetic anisotropy of amorphous ferromagnetic
CoSiB multilayer

M. U. Gutowska1*, J. Wieckowski1, A. Szewczyk1, W. Maziarz2, N. Nedelko1, S.
Lewinska1, A. Slawska - Waniewska1, M. Kowalczyk3 and A. Kolano - Burian4
1
Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
2
Institute of Metallurgy and Materials Science, Polish Academy of Sciences, Cracow,
Poland3
Faculty of Materials Engineering, Warsaw University of Technology, Warsaw,
Poland4
Institute of Non-Ferrous Metals, Gliwice, Poland
Temperature dependences of two parameters characterizing magnetocaloric effect (isothermal change
in entropy and adiabatic change in temperature) were determined for a Ni47Co3Mn35.5In14.5 ribbon. Twoexperimental methods were used, i.e., measuring temperature dependences of a specific heat (from 3 to
380 K) in zero magnetic field and in the field B=1 T, and measuring dependences of magnetization ontemperature and on B. In the former method, both parameters were determined by analyzing the system
entropy (determined by integrating the measured specific heat). In the latter method, the Maxwell relation
was applied to get the isothermal change in entropy. The magnetocaloric effect shows two extrema of
opposite sign, one near the transition between martensitic and austenitic phases, and the other one at
the Curie temperature. The parameters characterizing the magnetocaloric effect near room temperaturein relatively low B (1 T) make this material promising for application in magnetic refrigerators. The
magnetocaloric effect was found to be highly anisotropic, being much larger for B applied in the ribbon
plane. This property is particularly useful for designs, in which the active medium rotates in the field.
This work was supported by the European Regional Development Fund, Innovative Economy Grants
POIG.01.01.02-00-108/09, POIG.01.03.01-00-058/08 and POIG.02.02.00-00-025/09.

Corneliu Bazil Cizmas1*, Rim Guetari2, Lotfi Bessais3, Najeh Thabet Mliki2 and Sorin Adam1
1
Department of Electrical Engineering and Applied Physics, Transilvania Universityof Brasov, Bd. Eroilor 29, 500036 Brasov, Romania
2
LMOP, Department of Physics, Faculty of Sciences of Tunis, Tunis El Manar
University, 2092 El Manar, Tunisia
3
ICMPE, UMR7182 CNRS, Universite Paris-Est Creteil, 2/8 rue Henri Dunant, B.P.
28 F-94320 Thiais, France

In order to study the influence of relative small Bi addition on the magnetocaloric effect of Gd5Si2Ge2, aseries of Gd5Si2-xGe2-xBi2x (2x=0; 0.02; 0.04; 0.06 and 0.08) alloys was prepared by arc melting method.
Investigations of Gd5Si2-xGe2-xBi2x properties where carried out using X-ray diffraction, thermomagnetic
analysis, magnetization isotherms measurements and differential scanning calorimetry (DSC). After a heat
treatment at 1250°C for 200 min., all the alloys have, at room temperature, a monoclinic structural phaseof Gd5Si2Ge2 type (S.G.: P112_1/a) with a small amount of hexagonal structural phase of Gd5Si3 type (S.G.:
P63/mcm). The Curie temperature is around ~ 285K (±2K). The results of the DSC measurements show
a difference of ~10K in the peak of the heating and cooling curves associated with a first order structuralphase transition. The peak slightly decreases with Bi content. This is expected to be related to theincreasing of the Si/Ge bond distance in the monoclinic phase with Bi addition. The maximum isothermal
magnetic entropy change decreases with Bi addition, however a giant magnetocaloric effect was obtained
for all alloys. As an example, the maximum magnetic entropy change for the Gd5Si1.98Ge1.98Bi0.04 wasfound to be 12.6 J/kg•K under an applied field of 5T.

The 19th International Conference on Magnetism

Hoon Song and D. g. Park*
korea atomic energy research institute, Korea

Takaya Shimokawa*, Takeshi Yanai, Ken-ichiro Takahashi, Masaki Nakano and
Hirotoshi Fukunaga
Nagasaki University, Japan

Takeshi Yanai*, Haruka Uto, Takaya Shimokawa, Ken-ichiro Takahashi, Masaki
Nakano and Hirotoshi Fukunaga
Nagasaki University, Japan
Although a lot of the electrodeposited Fe-Co films with good soft magnetic properties
were reported [1-3], boron, which is harmful and restricted by the regulation ofenvironmental protection in Japan, was included in the plating bath as boric acid forcontrolling pH. Therefore, in order to remove boron, we focused on the citric acidbased plating bath and investigated effect of citric acid for the electrodeposited Fe-Co
films. The plating bath was consisted of FeSO4•7H2O(100 g/L), CoSO4•7H2O(100 g/
L), NaCl(50 g/L), C6H8O7•H2O(0 - 270 g/L).An Fe plate as anode and a Cu plate as
cathode were used, and Fe-Co film was deposited on the Cu plate. Current density
was kept at 2 mA/mm2 and bath temperature was set at 50 °C during the deposition.
The coercivity of the deposited film was drastically reduced from 1700 to 200 A/mwith increasing content of citric acid from 0 to 100 g/L, and then slightly increased.
The Fe-Co film prepared from the bath with citric acid of 100 g/L has high saturation
magnetization of over 2.2 T and we can conclude that citric acid-based plating bathis one of hopeful plating ones to obtain good soft magnetic film with high saturation
magnetization.
[1] Qiang et al., Appl. Surf. Sci., 257 (2010) 1371. [2] Kockar et al., J. MMM, 322 (2010) 1095. [3]Teh et al., IEEE Trans. Magn., 47 (2011) 4398.

1

2

2

3

4

Luana Caron *, Viktor Hoglin , Yvonne Andersson , Per Nordblad and Ekkes Bruck
1
Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, TU Delft, Mekelweg 15,2629 JB Delft, Netherlands
2
Department of Materials Chemistry, Uppsala University, Box 538, 751 21 Uppsala, Sweden
3
Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala, Sweden
4
Fundamental Aspects of Materials and Energy, TU Delft, Mekelweg 15, 2629 JB Delft, NetherlandsJiří Kaštil1*, Jiří Kamarád2 and Zdenĕk Arnold2
1
Faculty of Mathematics and Physics, Charles University,Prague, Czech Republic
2
Institute of Physics ASCR, Prague 8, Czech Republic., Czech Republic

Kontan Tarigan, Young-yeal Song and Seong-cho Yu*
BK21 Physics Program and Department of Physics, Chungbuk National University,
Cheongju 361-763, Korea
Nanocrystalline magnetic alloys have been promising materials for magnetic device applications
requiring high saturation magnetic flux density, high permeability, and low core loss. Amongthe magnetic alloys, Fe-Mn-Al system has been one of the most interesting tenary alloys withseveral magnetic phases. The magnetic properties were studied in one particular compound inprevious works [1,2]. More systematic research of Fe-Mn-Al alloys would contribute to better
understanding with Al contens. Nanocrystalline Fe90-xMn10Alx prepared via mechanical alloying
using Fe, Mn, and Al powder with 48 hrs milling time. The structural and magnetic properties
were studied. All peaks of XRD data are broader and shifted to smaller angle with increasing Al
contents depending on the crystalline size and the lattice paramenter, respectively. All the samples
exhibit alloys behavior with an average crystallite size around 10 nm. The magnetic saturation, thecoercivity, and the permeability, obtained from measurements by vibrating sample magnetometer
showed strong dependence on the Al contents, and these dependences were related to the changes
in structure and crystallite size. In addition Mossbauer experiments confirm tha Al diffuses into
Fe bcc grains. Furthermore, these results suggest that, by adjusting the Al content, appropriate
structural transformation and appropriate magnetization values can be obtained.
[1] Kontan Tarigan, Yong-Goo Yoo, Dong-Seok Yang, J. M. Greneche, and Seong-Cho Yu, IEEE
Trans. Mag. 45, No. 6 (2009) 2492-2495. [2] E.A. Vela´squez, L.F. Duque, J. Mazo-Zuluaga, J.
Restrepo, Physica B 398 (2007) 364-368.

Hirofumi Kawanaka1*, Hiroshi Bando1 and Yoshikazu Nishihara2
1
Advanced Industrial Science and Technology, Japan
2
Ibaraki Univ., Japan

The perovskite-type oxides of La0.67Ba 0.33Mn 1-xFe xO 3 were synthesized by theconventional solid-state reaction method. The Curie temperature Tc and magnetic
entropy change (MCE) in these samples are determined and compared to those of Gddoped systems. [1,2] The Curie temperature Tc decreases from 350 K to 290 K withincreasing Fe concentration x from 0 to 0.05. The relatively large MCE with a broad
peak around Curie temperature compared with other oxides is observed in this system.
These results suggest this system is a suitable candidate as magnetic refrigerator
material working at room temperature.
[1] Z. Juan, W. Gui, J. Magn. Magn. Mater. 321 (2009) 43-46 [2] M. H. Phan, S. C. Yu, J. Magn.
Magn. Mater. 308 (2007) 325-340

July 9 (Mon)

July 9 (Mon)

Giselher Herzer*, Mie Marsilius and Christian PolakR&D Rapid Solidification Technology, Vacuumschmelze GmbH & Co. KG, Germany

168

poster Presentation

Anwar Mohammad Shafique, Shalendra Kumar, Faheem Ahmed, G. W. Kim and Bon
Heun Koo*
School of Nano & Advanced Materials Engineering, Changwon national university,
Korea
Magnetocaloric effect (MCE) and its most straightforward application, magnetic
refrigeration, are becoming fields of increasing research interest. On the one hand,
there are reasonable expectations that these subjects will give rise to energy-efficient,environmentally friendly technological applications. On the other hand, the studyof some model materials gives some more insight into the physics underlying these
phenomena. In this paper, complex magnetic materials La0.7Sr0.3MnO3, La0.7Ca0.3MnO3and La0.7Ca0.1Sr0.2MnO3, suitable for the magnetic refrigeration, has been investigated.
We have found that the substitution of the Sr with Ca leads to an important decreaseof the Curie temperature (TC) from 374 K to 345 K. The magnetocaloric study
exposes a quite large value of the magnetic entropy changes for La0.7Ca0.3MnO3and La0.7Ca0.1Sr0.2MnO3. In cooling applications, another important parameter isrelative cooling power (RCP), a good indicator of cooling efficiency of a magnetic
refrigerant. For an applied magnetic field of 2 T, the RCP value is found to be 203 J/kg for La0.7Ca0.1Sr0.2MnO3. As a result, the studied compounds could be considered as
potential material for magnetic refrigeration near and above room temperature.

Sol Jung1, H. I. Yim1*, Ahri Kim2 and Sumin Kim2
1
Physics, Sookmyung Women's University, Korea
2
Nano-Physics, Sookmyung Women's University, Korea

Perpendicular magnetic anisotropy (PMA) is worthy of notice in both fields of scienceand industry due to its high integrate. In the previous study, we used CoSiB (75:15:10,
atm%) and CoSiB/Pt multilayer showed the strong dependence on both the thicknessesof CoSiB and Pt. For the [CoSiB 3A/ Pt 14A]x5 multilayer, the maximum coercivity
was ~ 224 Oe and the maximum PMA constant was obtained as ~ 2 × 106 erg/cm31.
In addition, this film has the coercivity (Hc) and the saturation magnetization (Ms)with respect to 1.6 Oe and 407 emu/cm3. Considering this result, we suggest the newidea of CoSiB/Au/CoSiB sandwich structure and CoSiB/Pd multilayer. 1 mono-layerthick of Au and Pt are 144pm, 139pm and they are diamagnetic and ferromagnetic
materials, respectively. CoSiB/Au/CoSiB sandwich structure and CoSiB/Pd multilayer
is expected to show PMA and it can be developed to the magnetic random accessmemory (MRAM).
[1] J. Y. Hwang, S. S. Kim, and J. R. Rhee, J. Magn. Magn. 310, 1943 (2007). [2] J. S. Park, H. I.
Yim, J. Y. Hwang, S.B. Lee, T. W. Kim, J. Phys. Soc. 57, 1672 (2010). [3] S. Jeong, H. I. Yim, J. Phys.
soc. 60, 450 (2012).

July 8-13, 2012 Busan, Korea

169

poster Presentation
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Thickness dependence of magnetic induction in inhibitor-free 3%
silicon steels

Arrangement of different magnetic alloy sheets for effective magnetic
shielding

Magnetocaloric effect in Ni2.27Mn0.73Ga Heusler alloy

Ultra high speed pm type synchronous motor-generator withamorphous core for micro turbine

Cold-rolled sheets of differing thicknesses were prepared through the conventional
hot and cold rolling process. After annealing at 1200°C, final texture greatly variedwith heating rate and sheet thickness. The 0.2 mm thick samples contained no or
few {110} grains within the tested range of heating rates, yielding a poor magnetic
induction. On the contrary, the 0.15 mm thick samples consisted entirely of {110}grains, and consequently resulted in a very high magnetic induction of over 1.95 Tesla.
The 0.1 mm samples were also composed of {110} grains either at a very slow or at avery fast heating rate, but they unexpectedly exhibited a poor magnetic induction due
to the deviated <001> direction of {110} grains from rolling direction. Orientation
distribution functions of the samples taken from each cold rolling pass revealed that
initial {111}<112> texture components started to move toward {111}<110> at a
thickness of 0.13 mm. According to the nucleation and selective growth mechanism [1],primarily recrystallized texture takes after cold rolling texture, and hence the deviated
final texture was obtained. This study indicates that there exists an optimum thickness
for obtaining high magnetic induction and low iron loss.

Sang-yun Lee, Yun-seog Lim, Ho-seong Ahn, Dong-il Lee and Sang-beom Kim*
Korea Electric Power Corporation Research Institute, Korea

The purpose of this study is to provide an effective shielding method for power
frequency magnetic field emanating from a neutral ground reactor (NGR). The
0.35 mm thick commercial grade grain-oriented electrical steel (GO), non-oriented
electrical steel (NGO), and permalloy (PC) were used as shielding materials. The areaof 1200x1200 mm2 was blocked with the alloy sheets at a place 600 mm away fromthe NGR. In a weak magnetic field, PC is the best in shielding performance, whereas
GO is the best in a strong magnetic field. NGO is worse than GO, but is better than PC
in a very strong magentic field. For multi-layered shields, it was observed that GO/PC
pair (GO is close to source) was most effective, yielding a shielding factor less than
0.06 in the wide range of magentic fields. These results are explained by variation ofshielding effectiveness of a magnetic material with magnitude of magnetic field. The
inner GO sheet effectively shields a strong magnetic field first, and then the outer PC
sheet effectively shields the weakened field. Furthermore, this study demonstrates
some spacing between laminations is essential to achieve best shielding performance inthe ‘shunt’ mechanism of magnetic shielding.

Mikhail Drobosyuk, Vasiliy Buchelnikov, Sergey Taskaev and Rafael Fayzullin
Chelyabinsk state university, Russia
Drobosyuk Mikhail, Buchelnikov Vasiliy, Taskaev Sergey, Fayzullin Rafael
Chelyabinsk State University, Chelyabinsk, Russia m.syuk@mail.ru type ofpresentation: poster There are many theoretical and experimental works devoted
a possibility any magnetic materials to change its temperature after applying an
external magnetic field. This effect is called the magnetocaloric effect (MCE).
Recent experimental studies have shown that Ni-Mn-Ga Heusler alloys haveunique properties such as the shape memory effect, the large magnetostriction, thelarge magnetoresistance and other magnetic properties. In this work we present theexperimental studies of the MCE for Ni2.27Mn0.73Ga Heusler alloy. Polycrystalline
ingot was prepared by a conventional arc-melting method. Samples for measurements
were cut from the middle part of the ingot. The magnetocaloric measurements were
performed by the Magnetocaloric Measuring Setup produced by AMT&C. The resultsof measurements will be shown on the poster.

Do-kwan Hong*, Yeon-ho Jeong, Dae-suk Joo, Byung-chul Woo and Dae-hyun Koo
Electric Motor Research Center, Korea Electrotechnology Research Institute, Korea

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July 9 (Mon)

Sang-beom Kim1*, Joon-young Soh1, Sang-yun Lee1, Heejong Jung2 and Jongryoul
Kim2
1
Korea Electric Power Corporation Research Institute, Korea
2
Department of Metallurgy and Materials Science, Hanyang University, Korea

July 9 (Mon)poster Presentation[1] N. H. Heo et al., Acta Mater. 51 (2003), 4953-4964.

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Effect of M (= Ge, Y, Hf) addition on soft magnetic properties of Fe-BSi-M metallic glass alloys

Fabrication of pariculated Fe-Mg thin films by selective oxidation andtheir magnetic properties

Soft magnetic properties of Fe-6.5wt.%Si alloy sheets fabricated bypowder hot-rolling

Temperature dependence of magnetic domains in grain-oriented
silicon steel

Juho Lee1, Hwijun Kim1, Jungchan Bae1 and Dohyang Kim2*
1
Korea Institute of Industrial Technology, Korea
2Center for noncrystalline Materials, Yonsei University, Korea

Fe-based metallic glass (MG) alloys exhibit good soft magnetic properties such as
low coercivity and core loss but have the limits for industrial application because of
low saturation flux density below 1.5T. Therefore, Fe-based MG alloys with highsaturation flux density above 1.7T are very attractive soft magnetic alloy systems. In
order to investigate the effect of M(= Ge, Y, Hf) addition on soft magnetic propertiesof Fe-B-Si-M metallic glass alloys, structural variations and magnetic propertiesof Fe83-XB10Si7MX (X=1~5 at atomic percent) MG alloys were examined by X-ray
diffraction(XRD) and vibration sample magnetometer(VSM) after fabricating
Fe 83-XB 10Si 7M X MG ribbons by a single-roller melt-spinning technique underargon atmosphere. The thermal stability was measured by Differential Scanning
Calorimetry(DSC) at a heating rate of 20K/min. Fe83-XB10Si7MX MG alloys added Ge,
Y or Hf exhibited a fully amorphous structure. Saturation flux density and coercive
force of these alloys were Bs = 1.6~1.8T and Hc = 20~40 A/m, respectively. Afterannealing for 1 hr at 773K, Fe80B10Si7Ge3 MG alloy displayed excellent soft
magnetic properties such as saturation flux density of 1.8T and corecivity of 20A/m.

Pyungwoo Jang*
College of Science and Engineering, Cheongju university, Korea

It is impossible to manufacture Fe-Mg bulk alloys even in vacuum melting systembecause of very low melting temperature, high affinity with oxygen, and very highvapor pressure of Magnesium. However, it is very easy to fabricate Fe-Mg thin films
by sputtering. Becasue of big difference of enthalpy of Fe-O and MgO, Mg can beselectively oxidized in a mixture atmosphere of hydrogen and water vapor. 10 - 200
nm thick sputtered Fe-Mg films were selectively oxidized in a damp atmosphere andannealed at 800-900oC for 10 - 200 min. With increasing oxidation time, saturatio
magnetizatin of Fe-Mg films increased due to selective oxidation of Mg. Furthermore,
Initial permeability as well as the slope of magnetizatio loops of the films decreased,
which was attributed from the facts that morphology of the films were changed fromcontinuous type to pariculated type. when the films were annealed in pure hyderogen
atmosphere the rate of change is very slow. The reason for the expedited change isprobably due to energy transfer to Fe atoms during migration of Mg atoms to film
surface .

Hunju Lee1, Hwijun Kim2 and Mooyoung Huh1*
1
Department of Materials Science and Engineering, Korea University, Korea
2
Korea Institute of Industrial Technology, Korea

It is widely known that Fe-6.5 wt.% Si alloys have excellent soft magnetic properties.
In this work, Fe-6.5 wt.% Si sheets were rolled by powder hot-rolling process without
cracking and soft magnetic properties were investigated with microstructural defects.
The cylindrical preforms were prepared by inert gas atomization and subsequent spark
plasma sintering of Fe-6.5 wt.% Si powders at 1223K. The Fe-6.5 wt.% Si sheets were
fabricated by hot rolling of copper canned preforms at 1173K with total reduction of
70%, 80% and 90%, respectively. The hot rolled sheets were annealed at 1073K in an
argon atmosphere. Microstructures and magnetic properties (magnetic flux density,
coercivity and core loss) of the hot rolled and annealed Fe-6.5 wt.% Si sheets were
examined by scanning electron microscopy (SEM), vibration sample magnetometer(VSM) and B-H analyzer. The hot rolled Fe-6.5wt.% Si sheet with reduction of 90%
and subsequent annealing exhibited soft magnetic properties such as magnetic flux
density of 1.8 T and coercivity of 20 A/m. This result is due to the elimination of
microstructural defects and the increase of the average grain size and density.

H. L. Park1, R. Schaefer2, O. Y. Kwon3 and Y. H. Jeong1*
1
Physics, POSTECH, Korea
2
IFW Dresden, Institute for Metallic Materials,, Germany
3
Pohang Iron and Steel Company, Korea

Abstract: Silicon steels are essential for transformers and the reduction of loss in themis of utmost importance in this green age. Since the loss in steels are closely related
to their magnetic domain structures, the magnetic domain structures in turn are ofexceeding interest. We studied magnetic domains of 3% silicon steel single crystals
with (110) [001] texture as a function of temperature via magnetooptical Kerr effect(MOKE) microscopy. Generally, the silicon steels (110) [001] have 180° main domains
oriented along the [001] axis, and they also have complimentary Lancet domains incase of misorientation. [1, 2, 3] The MOKE images shown in Figure 1 clearly revealthat the domain patterns change as temperature is changed. The width of the 180°
main domains, for instance, decreases with increasing temperature. In order to go
one step further from mere qualitative observations, we analyzed the MOKE images
quantitatively, and, in particular, investigated temperature dependence of the 180°
domain width and the Lancet domain density. These temperature characteristics will beinterpreted from the standpoint of total energy minimization.
[1] A. Hubert, R.Schaefer, Magnetic domains(1998),Springer [2] Y. Ushigami, J. Magn. Magn.
Mater. 254-255(2003), 307-314 [3] M. Imamura, Physica Scripta. T 24 (1988)

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Effects of film composition and substrate temperature on the structure
and magnetic properties of FeCoB alloy films formed on MgO singlecrystal substrates

Optimum spacing of magnetic alloy strips in open-type magnetic
shielding

Structure and magnetic properties of nano/micro-sized Mn-Al alloy
powders produced by plasma arc-discharge and gas atomization

A tri-layer stress impedance sensor using amorphous magnetostrictive
thin film

Yugo Asai*, Mitsuru Ohtake, Tetsuroh Kawai and Masaaki Futamoto
Chuo University, Japan

Tri-layer films consisting of FeCoB and MgO layers have been investigated for MTJ applications.
Theoretical studies show that the TMR ratio of MTJ prepared using epitaxial layers is one order ofmagnitude greater than that obtainable with amorphous layers [1,2]. The structure of bulk FeCoB
alloy changes from crystalline to amorphous as the B content exceeds around 10 at. %. However
in a form of thin film, there is a possibility of crystallization for B rich compositions. In the present
study, (Fe0.7Co0.3)100-xBx (x = 0-15 at. %) films were sputter deposited on MgO substrates of (100),(110), and (111) orientations at different substrate temperatures to investigate the effects of film
composition, temperature, and substrate orientation on the structure and magnetic properties.
Epitaxial films were obtained for all compositions by adjusting substrate temperature. For example,(FeCo)95B5 and (FeCo)85B15 epitaxial films were respectively obtained at temperatures higher than
200 and 600 °C, while amorphous films were formed below these temperatures. The epitaxial
films formed on MgO (100), (110), and (111) orientations consisted of bcc(100), bcc(211), andbcc(110) crystals, respectively. The magnetocrystalline anisotropy decreased with increasing the B
content. Improved soft magnetic properties were realized in films with high B contents.
[1] W. H. Butler, X.-G. Zhang, T. C. Schulthess, and J. M. MacLaren: Phys. Rev. B., 63, 054416(2001). [2] J Mathon and A Umerski: Phys. Rev. B., 63, 220403 (2001).

170

The 19th International Conference on Magnetism

Yun-seog Lim, Sang-yun Lee, Ho-seong Ahn, Dong-il Lee and Sang-beom Kim*
Korea Electric Power Corporation Research Institute, Korea

This study suggests an effective shielding method for power frequency magnetic
field in open-type magnetic shielding, which secures the clear view of field sourcesby aligning magnetic alloy strips sparsely. A neutral ground reactor (NGR) was used
as a field source. The 0.35 mm thick commercial grade grain-oriented electrical steel(GO) and permalloy (PC) were cut into a size of 50x1200 mm2 and then placed
vertically 600 mm away from the center of the NGR. In a weak magnetic field, PC
was the best in shieldng performance, whereas GO was the best in a strong magnetic
field due to change in hierachy of material permeability with increasing magnetic fieldstrength. In case of multi-layered shields, it was observed that combination of GO/PC/
GO was more effective than the triple-layered shield of the same material. However,closely conjoined GO/PC/GO shield showed worse shielding performance than thesame layered shield seperated from each other, which demonstrates it acts as one
body regardless of presence of thin surface insulation layers. This study reports that
introducing air gap between laminations of each layered shield is important to obtain
desired shieding performances and optimum spacing between alloy strips exits in opentype magnetic shielding.

Junggoo Lee1*, Younkyoung Baek1, Hwijun Kim2 and Chuljin Choi1
1
Powder & Ceramics Division, Korea Institute of Materials Science, Korea
2
Eco-Materials and Processing Division, Korea Institute of Industrial Technology,
Korea
The τ-phase in the Mn-Al system has attracted great attention due to the remarkable magnetic properties
superior to the Alnicos and hard ferrites, low cost, as well as good machinability and corrosion resistance.
Due to these reason, several methods have been employed to produce τ-phase Mn-Al alloy powder until
now. On the other hand, plasma arc-discharge and gas-atomization method has been widely used for the
production of nano-sized and micro-sized powders, respectively. To our best knowledge, however, there isno comparison study of Mn-Al alloy powder produced by these two methods. In the present study, Mn-Al
alloy powders were prepared by the methods of plasma arc-discharge and gas-atomization and influence ofprocess parameters on composition, particle size, and magnetic properties of the powders was systematicallyinvestigated. Mn-Al powder produced by plasma arc-discharge was smaller than its single magnetic domain
and exhibited the coercivity of 5.6 kOe, which is the highest among the values reported until now. It wasalso confirmed that the magnetic properties of micro-sized powder produced by gas-atomization have been
improved by subsequent treatments such as annealing and mechanical milling Based upon these results, themagnetic properties of these two types of Mn-Al alloy powders will be discussed.
This research was supported by a grant from the Fundamental R&D Program for Core Technology ofMaterials funded by the Ministry of Knowledge Economy, Republic of Korea.

Bodong Li*, Ahmed Alfadhel and Jurgen Kosel
KAUST, Saudi Arabia

Mechanical stress sensors have a wide area of applications in strain and torquemeasurements. Thin film stress impedance (SI) sensors have several advantages overother stress sensors such as high sensitivity in small stress range, miniaturization
possibility as well as the integration capability with other devices. Stress sensors
that utilize amorphous magnetostrictive thin films have been proposed previously.
The permeability change of the magnetostrictive material upon the applied external
stress was evaluated throughout an impedance measurement. In this work, a tri-layer
thin film stress sensor is fabricated and analyzed. The sensor has a Fe40Ni38Mo4B18/
Ti/ Fe40Ni38Mo4B18 tri-layer structure with 900 nm thickness each and dimensions of
10×0.1 mm2. After the deposition, the sensor is annealed at 300 °C with a magnetic
field of 500 Oe applied in the transverse direction to induce an in-plane transverse
anisotropy. The magnetic behavior is studied with a vibrating sample magnetometerand the crystallographic structure is studied with using X-ray diffraction. The sensor
is tested by applying compressive and tensile stresses and the sensor response wasobtained from an impedance analyzer. The results show high sensitivity at strains
between 0-80 ppm with a maximum impedance change of 16% at 50 MHz.
Frommberger, M.; Glasmachers, S.; Schmutz, C.; McCord, J.; Quandt, E., IEEE Trans. Magn., vol.
41, pp.3691 - 3693, 2005

July 8-13, 2012 Busan, Korea

171

poster Presentation
PM28

PN03

PN06

PN09

Magnetoimpedance(GMI) effect in the NiFe shell/Cu core wires
fabricated by electrodeposition

Structural , compositional and magnetic study of bulk Fe doped ZnO
system and impurity phase formation

A probe into the structural, magnetic and dielectric properties ofbarium and lithium substituted pseudobrookites

Low field magnetization reversal behavior of ferromagnetic GaMnAs
film

Structural, compositional, optical, vibrational and magnetic properties have been studied for (ZnO)1x(Fe2O3)x≤0.10 series of bulk samples. The ZnO based ceramic samples with different doping percentage
of Fe2O3 were prepared by ball milling process. The phase composition of the pellets was determined via
X-ray diffraction analysis. Raman spectroscopy give information about the additional modes appear in the
ZnO spectrum having Fe doping which assures the presence of Fe in the ZnO matrix. The de-convolutionof XPS spectra of core peaks of different elements indicated the presence of different bond breakage due
to Fe substitution in ZnO lattice. The appearance of shaking satellites in XPS spectra also confirmed thepresence of different valance states of Fe ions. The red shift in energy band gap estimated from reflectanceUV-VIS spectroscopy was observed for all bulk samples. The magnetic behavior of the samples was
examined by using Vibrating Sample Magnetometer (VSM) indicating ferromagnetic behavior at room
temperature. The effective magnetic moment per Fe atom decreases with the increase in doping percentage
which indicates that ferromagnetic behavior is due to substitution of Fe ions in the ZnO lattice.

The versatile nature of the Fe-Ti oxides makes them attractive candidates inapplications in which their coupled semiconductor, magnetic and dielectric properties
can be exploited and they appear to be good candidates for emerging technologies
such as spintronics, magneto-electronics, and radar electronics. In the present work,
pure pseudobrookite Fe2TiO5 and its lithium and barium substituted varieties namely
Ba2y Fe2-x Li3xTi1-yO5 and Ba3x/2 Fe2-x Li4yTi1-yO5 (x = y = 0.05) are synthesized by thesolid-state reaction method. Powder x-ray diffraction studies show the single phaseorthorhombic structure. Substitution has reduced the crystallite size but enhanced thegrain size. A new intense plane (122) is observed in the barium-substituted sample.
Lithium intercalation is also observed. Room temperature dielectric studies haveconfirmed the Maxwell- Wagner interfacial polarization and space charge is seen tohave almost doubled with doping. The magnetic hysteresis loops show an asymmetricshift and constriction of loops. Variation of normalised susceptibility with absolutetemperature is plotted. Presence of barium and lithium have also brought about a longrange magnetic ordering in the pseudobrookite. Susceptibility measurements also
show that the Curie temperature in the barium-rich pseudobrookite approaches room
temperature making it a potential switch material.

We have investigated magnetization reversal process of a GaMnAs film by using
planar Hall effect. The angle-dependent measurements of the planar Hall resistance(PHR) showed sinusoidal behavior without hysteresis between clockwise and counterclockwise rotation with strong field. However, the magnetization reversal behavior
changes significantly by showing abrupt transition at the <110> directions as the fieldstrength reduced to 200 Oe. Furthermore, when a smaller field is used, the PHR displays
four stable values arising from the formation of four different multidomain states during
the rotation of the external field direction over 360°. Two of these states, showing
maximum and minimum values of the PHR, correspond to the sample fully magnetizedalong one of the easy axes. Other two intermediate states are multi-domain states inwhich a fraction of the domains populates one easy [100] direction, and the remaining
fraction populates an orthogonal easy [010] direction. We showed that the relative
populations of the magnetic domains corresponding to the two orthogonal easy axes
can be controlled by the value of the applied field during the process of magnetization
reversal. This phenomenon was understood by considering the differences in domainpinning fields and their distributions required for crossing the two hard axes.

PN01

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PN10

SQUID, XRD and Raman studies of Mn implanted gallium nitride atelevated temperature

Enhanced magnetization and spin injection in Co/ZnO films by Al
dopingOxygen vacancy and magnetism of a room temperature ferromagnet
Co-doped TiO2

Half-metallic antiferromagnetism in the ordered Cr1-xCaxSb alloy fromfirst-principles calculations

Microwires with NiFe shell on Cu core of 90 μm diameter were fabricated byelectrodeposition method. The thickness of NiFe shell was well controlled bydeposition time in the range of 4 μm ~18 μm. Giant magnetoimpedance(GMI) effectin the NiFe/Cu core shell wire was measured in frequency range of 10 kHz ~ 10 MHz
and in the magnetic field range of -300 Oe ~ 300 Oe. The variations GMI ratio withfrequency and NiFe shell thickness were analyzed in terms of magnetic relaxation andskin depth at ac field. We obtained maximum GMI ratio of 250 % at 300 kHz in thewire with NiFe shell of 11.5 μm thickness.

N. S. Pradhan1, Sheshmani K. Dubey2, A. D. Yadav1, B. K. Panigrahi3, K. G. M. Nair4
and M. Roy5
1
Department of Physics, University of Mumbai, Mumbai, India
2
Deparment of Physics, University of Mumbai, India
3
Materials Science Division, Indira Gandhi Centre for Atomic Research,
Kalpakkam-603 102, India
4
Materials Science Division,, Indira Gandhi Centre for Atomic Research,
Kalpakkam-603 102, India
5
Chemistry Devision, Bhabha Atomic Research Center, Mumbai - 400 005, India
The magnetic and structural properties of GaN samples implanted with 325 keV Mn2+
ions at 350 0C substrate temperature for various fluences varying from 1.75 x 1015
to 2.0 x 1016 ions cm-2 were studied using SQUID, XRD and Raman scattering
techniques. Magnetic properties were found to vary with the ion fluence.The 5 MeV
Si+ ion irradiation with fluence of 1 x 1016 ions cm-2 was performed on the sample
implanted for ion fluence 2 x 1016 cm-2.The Curie temperature estimated for asimplanted and after irradiated with 5 MeV Si++ ion samples was found to 301 and326 K respectively. XRD spectra showed GaN peak at (002) reflection, this peakshifted toward lower angle indicated the incorporation of Mn ion in GaN film.Raman
spectra of the samples showed bands at ~300 and 670 cm-1 were attributed to the local
vibration modes of gallium and nitrogen vacancies related defects respectively.

Shumaila Karamat1*, Rajdeep Singh Rawat2, Paul Lee3, Tan Tuck Lee Augustine4 and
Muhammad Ghaffari5
1
Physics, 1. NIE, Nanyang technological University, Singapore 2. COMSATSIslamabad, Pakistan
2
NSSE-NIE, Nanyang Terchnological University, Singapore
3
NSSE-NIE, Nanyang Technological Unievrsity Singapore
4
Physics, Nanyang Technological University, Singapore
5EEE, Nanyang Technological University, Singapore

Zhiyong Quan, Wei Liu and Xiaohong Xu*
School of Chemistry and Materials Science, shanxi normal university, China

An important hurdle in the development of semiconductor spintronic devices is
the inefficient injection of spin polarized currents from metallic ferromagnets
into semiconductors due to the large conductivity mismatch. Inserting a magnetic
semiconductor at the interface was regarded as an effectively route for spin injection
into semiconductors. In this work, we investigate the magnetism and electrical spin
injection into ZnO and Al-doped ZnO (Al 2at.%) matrix from Co particles in Co/
ZnO and Co/ZnAlO films, which were prepared by depositing ultrathin Co layers
and semiconductor layers at room temperature. The films consist of Co particles
dispersed in the semiconductor matrix. The graded magnetic semiconductors wereformed at the transition region between metallic Co particles and semiconductor matrix
with the substitution of Zn2+ with Co2+ ions. The increasing of magnetization of Co/
ZnAlO films compared to the corresponding Co/ZnO films is probably due to theenhanced magnetization of graded magnetic semiconductors with Al enhancing carrier
concentration. The room temperature magnetoresistance of Co/ZnAlO film with 1.0
nm of ZnAlO layer reaches -12.3% which is higher than -8.4% of the corresponding
film without Al, probably due to the large spin filter effect occurring in the gradedmagnetic semiconductors having a relative lager polarization.

Pushpinder Gupta Bhatia1* and Radha Srinivasan2
1
Physics, Department of Physics, Guru Nanak college, Mumbai-37, India
2
Physics, Department of Physics, University of Mumbai, Mumbai-98, India

Ikuo Nakai1*, Masashi Sasano1, Yingjie Li2, Ken Inui1, Tomoya Korekawa1, Hiroyuki
Ishijima1, Hisashi Katoh1 and Makio Kurisu3
1
Department of Electrical and Electronic Engineering, Graduate School ofEngineering, Tottori University, Japan
2
Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials,
Inner Mongolia Normal University, China
3
Department of Physics, Graduate School of Science and Engineering, Ehime
University, Japan
We report the magnetic and local structural study of a room temperature ferromagnetic
Co-doped TiO2 prepared by the solid state reaction. The ferromagnet with 5% Co
shows a rutile-type structure and has a saturation magnetization of 0.005 JT-1kg-1
and a coercive force of 0.02 T. We have found that it has some oxygen vacancy sitesaround a Co atom only from the extended x-ray absorption fine structure (EXAFS)
measurement. The charge compensation makes the oxygen vacancy around Co2+ and/or Co3+ substituted with Ti4+.

Yoonjung Gwon1, Hyehyeon Byeon1, Jaehyuk Won1, Hakjoon Lee1, Sanghoon Lee1*,
X. Liu2 and J. K. Furdyna2
1
Physics Department, Korea University, Korea
2
Physics Department, University of Notre Dame, USA

Guoying Gao* and Kailun Yao
School of Physics, Huazhong University of Science and Technology, China

Compared to half-metallic ferromagnets, half-metallic antiferromagnets (precisely
called half-metallic fully compensated ferrimagnets) are more promising candidates
for spintronic applications since their zero magnetization leads to lower stray fields andthus tiny energy losses. Using the first-principles calculations, we have systematicallyinvestigated the electronic and magnetic properties of the ordered Cr1-xCaxSb alloy.
It is found that Cr1-xCaxSb with x = 0.125, 0.25, 0.5 and 0.75 all are half-metals likezinc-blende CrSb and CaSb which have been fabricated experimentally or predicted
theoretically. Interestingly, Cr0.25Ca0.75Sb is a half-metallic antiferromagnet withcomplete spin polarization, and the half-metallic antiferromagnetism is robust against
the lattice compression and expansion and the choice of electronic exchange andcorrelation functional.
[1] H. Akai, M. Ogura, Phys. Rev. Lett. 97, 026401 (2006). [2] B.-G. Liu, Phys. Rev. B 67, 172411(2003). [3] M. Sieberer, et al., Phys. Rev. B 73, 024404 (2006). [4] G.Y. Gao, et al., Phys. Rev. B 75,
174442 (2007); [5] J.H. Zhao, et al., Appl. Phys. Lett. 79, 2776 (2001). [6] G. Y. Gao, J. Chen, and
K.L. Yao, Phys. Lett. A 375, 4053 (2011).

PN02

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PN11

Oxidation of monovacancies in graphene by oxygen

Structure, magnetic, and transport properties in Cu 1-x Mn x O
compounds

Effect of annealing on the magnetic anisotropy of GaMnAs film withlow Mn concentration

Translation & rotation of diamagnetic material induced by a low fieldof a permanent magnet and terminal identification of a micron-sizedparticleThaneshwor Prashad Kaloni and U. Schwingenschlögl
King Abdullah University of Science and Technology, Saudi Arabia
We study the oxidation of monovacancies in graphene by oxygen molecules using
first principles calculations. In particular, we address the local magnetic moments
which develop at monovacancies and show that they remain intact when a molecule
is adsorbed such that the dangling carbon bonds are not fully saturated. The observed
value of magnetic moment is 1.35 Bohr Magneton for monovacancy and it becomes
1.86 Bohr Magneton by oxygen adsorption on monovacancy in graphene. However,the lowest energy configuration does not maintain dangling bonds and is found to
be semiconducting. Our data can explain the experimentally observed behavior ofgraphene under exposure to an oxygen plasma.

Jinzhu Cai, Li Li, Bin Lv, Shen Wang, Wenqin Zou, Fengming Zhang* and Xiaoshan
Wu
Physics, Nanjing University, China
By annealing at air, O2, N2 atmosphere, the polycrystalline Cu1-xMnxO powders,which are prepared by sol-gel method with the concentration range of 0≤x≤0.2, aresynthesized. The phase component and atomic structure of the main phase are obtainedby X-ray diffraction (XRD) with Rietveld refinements. The bond length of Cu(Mn)-O
decreases, and the bond-angle of Cu(Mn)-O-Cu(O) increases, with increasing the
dopant. Magnetism measurements (SQUID) show that the ferromagnetic transition
temperature, Tc, and the saturation moment, Ms, increase with the doped concentrationof Mn, although all the samples show that the Tc is less than 100 K. All samples show
the well defined thermal active mechanism with the thermal active energy varying withthe annealing atmosphere. Results reveal that annealed in O2 may increase the carrier
concentration of the prepared samples while annealed in N2 the reverse.

Hyehyeon Byeon1, Yoonjung Gwon1, Jaehyuk Won1, Taehee Yoo1, Sanghoon Lee1*, X.
Liu2 and J. K. Furdyna2
1
Physics Department, Korea University, Korea
2
Physics Department, University of Notre Dame, USA
We have investigated the effect of annealing on the magnetic anisotropy of a GaMnAs
film with a low Mn composition of 2 %. Three pieces of samples were cleaved fromthe sample and two of them we are annealed at 200 and 300 °C, respectively, for
3 hours in air. In case of as-grown sample, abrupt transitions in the Hall resistanceappeared with a negative coercive field, when field strength was swept at a fixed
direction in the film plan. The phenomenon turned out to be related to the presence ofmagnetic domains with a vertical easy axis in the film, which was identified via theHall measurement that was performed with a field direction that was normal to theplane. The portion of domain with dominant out-of-plane magnetic anisotropy in the
GaMnAs film was systematically decreased with an increasing annealing temperature.
Especially, the negative coercive field disappeared in the sample annealed at 300 °C
and two abrupt positive switching fields we are observed in the field scan of the planar
Hall resistance. This indicates that the annealing significantly affects the magnetic
anisotropy of GaMnAs film by changing from out-of-plane dominant to in-plane
dominant anisotropy.

July 9 (Mon)

Dong Young Kim, Sung Jae Jeon, Jung Dong Kim and Seok Soo Yoon*
Physics, Andong National University, Korea

July 9 (Mon)poster Presentation

Keiji Hisayoshi and Chiaki Uyeda
Osaka university, Japan

It has been generally believed that field-induced motion of an ordinary diamagnetic
material can be induced only at high field above several Tesla. However, translations
were recently observed on various diamagnetic crystals in a direction of monotonously
decreasing field produced by a permanent magnet [1]; the crystals were released indiffused micro-gravity area. In a given field distribution, terminal velocity of translationis uniquely determined by intrinsic susceptibility of material; the velocity is independent
to mass of particle. Rotational oscillation, caused by diamagnetic anisotropy energy, wasalso reported for the crystals [1]. When the above motions are observable, diamagnetic
susceptibility & anisotropy of a small particle can be detected, irrespective of its size,
since the measurements are both free from interference of a sample holder and frommass measurement of sample. Material identification of particle is easily performedby comparing the obtained susceptibility (& anisotropy) with published values. A
simple and nondestructive method to identify the material of a small particle is desiredin various fields of nano-science. By introducing a compact NdFeB magnet, themeasurement was realized in an ordinary laboratory using a chamber-type drop shaft.
[1] C. Uyeda et al: Jpn. Phys. Soc. Jpn. 79, 064709 (2010). 246

172

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

173

poster Presentation
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PN15

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PN21

Magnetoresistance effect in electron-injected p-type silicon

Effect of transition metal (Co, Ni and Cu) doping on lattice volume,band gap, morphology and saturation magnetization of ZnOnanostructures

Evolution of multifunctional behavior in site specific cation substituted
Na0.5Bi0.45Gd0.05Ti0.95Mn0.05O3 ceramics

A role of mobility in hydrogen mediated ferromagnetism of ZnCoO

July 9 (Mon)

Magnetoresistance (MR) effect in silicon has gained a renewed interest in recent
years because it is large and non-saturating [1-3]. It is known that the presence of“static” inhomogeneity, like phosphorus in low-doped silicon, generates large andnon-saturating MR effect [2,4]. Inhomogeneity can also be introduced “dynamically”
by injecting electrons or holes into a low-doped silicon [1,3]. In n-type silicon (n-Si),
electron injection generates space-charge effect [1], whereas, the hole injection induces
the formation of a hole-electron (p-n) boundary [3]. These dynamic inhomogeneities
induce large MR effect even up to room temperature. Most of the silicon devices used
in inhomogeneity-induced MR effect studies are n-type, and no study has ever beenreported for p-type, so far. In this study, we investigated the MR effect in indium (In)/p-type silicon (p-Si)/In devices. Current (I)-voltage (V) characteristic of the deviceshows an Ohmic and non-Ohmic I-V regime (I is proportional to the square root ofV), which indicates electron space-charge injection into p-type silicon [5]. MR of the
In/p-Si/In device is small (10%) compared to that of In/n-Si/In device (1,000%) for
the same condition (3 T, 300 K). This suggests that the electron-hole compensation or
recombination suppress inhomogeneity formation in the silicon device.

Faheem Ahmed, Shalendra Kumar, Nishat Arshi, M S Anwar and Bon Heun Koo*
Changwon National University, Korea

1,2

1

T Karthik and Saket Asthana *1
Advanced Functional Materials Laboratory, Department of Physics,
Indian Institute of Technology Hyderabad, Andhra Pradesh - 502205, India
2
Department of Materials Science and Engineering,
Indian Institute of Technology Hyderabad, Andhra Pradesh - 502205, India

Ji Hun Park1, Seunghun Lee1, Won-kyung Kim1, Jong Moon Shin2, Yong Chan Cho1,
Chae Ryong Cho2, Hideomi Koinuma1 and Se-young Jeong1*
1
Dept. of Cogno-Mecatronics Engineering, Pusan National University, Korea
2
Dept. of Nano Fusion Technology, Pusan National University, Korea
Diluted magnetic semiconductors (DMSs) have recently been attracting much attention for
their potential as spin manipulation layers [1]. Although there have been reported several
authorized DMSs, such as Mn doped GaAs, their limited operating temperature requires new
DMS materials with high Curie temperature. Up to now, many theoretical and experimental
studies about hydrogen mediated ferromagnetism in ZnCoO have been introduced [23]; however, the interaction between such magnetic units as Co-H-Co complexes has not
yet been confirmed. Delocalized electron in ZnCoO lattice is possibly considered to playa crucial role in the correlation [4]. In this work, we investigated the correlation between
carrier mobility and ferromagnetic spin ordering in ZnCoO. Electron mobility was artificiallycontrolled with the manipulation of crystallinity and hydrogen contents. Hydrogen treatment
is carried out using hot isostatic pressing (HIP) system. The correlation between carrier
mobility and ferromagnetic spin ordering was analyzed in terms of Co-H-Co magnetic units.
Mobility-dependent ferromagnetic spin ordering is discussed in our experiment.

[1] Delmo, M.P. et al. Nature 457, 1112 (2009). [2] Porter, N.A. & Marrows, C.H., arXiv:1105.2174[cond-mat.mtrl-sci]. [3] Wan, Caihua et al. Nature 477, 304 (2011). [4] Herring, C. J. Appl. Phys.
31, 1939 (1960). [5] Roberts, G.G. Phys. Stat. Sol. 27, 209 (1968).

The interest in transition-metal (TM)-doped ZnO has increased because of promising
applications in the field of semiconductor spintronics, which seeks to extend theproperties and applications of established electronic devices by using the spin ofelectrons in addition to their charge. In this work, the effect of different TM (Co, Ni
and Cu) doping on structural, optical and magnetic properties of ZnO nanostructures
have been studied. Zn1-xTMxO (TM=Co, Ni and Cu) nanostructures were prepared by amicrowave assisted chemical route and characterized by X-ray diffraction (XRD), fieldemission scanning electron microscopy (FESEM), transmission electron microscopy(TEM), Raman spectroscopy, UV-Vis and magnetization measurements. The X-ray
diffraction (XRD) and TEM analysis showed that the TM-doped nanostructures had
single phase nature with the wurtzite structure. There is a strong correlation betweenchanges in the lattice parameters, bandgap energy, morphology and the saturation
magnetization of Zn1-xTMxO nanostrutures. Lattice volume and bandgap determinedfrom XRD and UV-Vis, respectively, were found to decrease as the atomic numberof the dopant moved away from Co. Magnetic studies showed that all the TM-doped
ZnO exhibit room temperature ferromagnetism and the decreasing trend of saturation
magnetization was observed with the increase of 3d electrons number from Co to Cu.

PN13

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PN22

First-principles investigation of the influence of adsorbed atom on thedefect and impurity substitute graphene

Functionalized graphene as a room-temperature ferromagnetic
semiconductor

Magnetic doping effect on physical properties of PbPdO2

Magnetic and magneto-optical properties of TiO2:V semiconductoroxide films with various resistivity

Kengo Nakada1 and Akira Ishii2
1
JST-CREST, Japan2
Department of Applied Mathematics and Physics, Tottori University, Japan

Graphene is well-known to be two-dimensional material made of carbon atoms.
Graphene is a substance that attracts attention not only as parts of the nanocarbons
but also for its own interesting electronic and mechanic properties. It is important
for the application that charge and magnetic are controlled by defect and impurity
in the graphene. Furthermore, influence of defect and the impurity are important in
the growth of the compound on the graphene. The technological uses of controllable
charge and magnetic carbon systems are extensive, and it is important that themechanism is known. In previous study, we investigated the adsorption energies andmagnetism in adsorption sites on graphene from atomic number 1 to 83, using the
DFT. We discussed the charge transfer and the magnetism. When several adatoms isadsorbed, the defect graphene develops magnetic. In this study, we performed atom
substitute in the graphene and atomic adsorption on the graphene with the defect. The
aim of the research is discussion about the magnetic and stability when several adatoms
adsorbed on defects and impurities substitue in graphene. In addition, we discuss thegrowth mechanism of the nitrided compounds. We used a band calculation techniquebased on the DFT calculation.

Jeongmin Hong1*, Sandip Niyogi2, Elena Bekyarova2, Mikhail E. Itkis2, Palanisamy Ramesh2,
Claire Berger3, Walt A. Deheer4, Robert C. Haddon2 and Sakhrat Khizroev5
1
Electrical and Computer Engineering, Florida International University, USA
2
Department of Chemistry, Department of Chemical Engineering, Center for Nano Scale Scienceand Eng, University of California-Riverside, USA
3
CNRS, Institut Neel, France
4
School of Physics, Georgia Institute of Technology, USA
5
Department of Electrical and Computer Engineering, Florida International University, USA

Low-temperature magneto-transport and vibrating sample magnetometry (VSM) combined with superconducting
quantum interference device (SQUID) measurements indicated that graphene, when functionalized with aryl
radicals, behaved as a room-temperature ferromagnet and therefore might form the basis for a new approach tosemiconducting ferromagnetism. After radical functionalization, epitaxially grown graphene samples became
semiconductors and at the same time displayed high-density magnetism, with a room temperature saturation
magnetization of approximately 0.1 Bohr magnetons per carbon atom. The bulk measurements with VSM andSQUID were corroborated with local studies using atomic force microscopy (AFM), electrostatic force microscopy(EFM), magnetic force microscopy (MFM), scanning tunneling microscoy (STM), and Raman Spectra
measurements. Both local and bulk measurements indicated a strong dependence on the degree of coverage of thegraphene surface with functionalized sites. The measurements showed the presence of a superparamagnetic orderin the graphene regions with a relatively low-density of functionalized sites in the entire temperature range from 2 to300 K. In contrast, the regions with a relatively high-density of functionalized sites displayed a ferromagnetic ordereven at room temperature. In summary, the measurements indicated that aryl radical functionalied multi-layered
graphene on Silicon Carbide could simultaneously be a semiconductor and a ferromagnet at room temperature.

A novel multifunctional behavior was observed by site specific cation substitution in
NBT ceramics prepared by conventional solid state reaction technique. X-ray diffraction
studies revealed the co-existence of orthorhombic reflections in co-substituted NBT
system along with the primary R3c phase. Raman spectroscopy of NBT-GM ceramics
reveals a substantial change in all phonon modes in terms of suppression and shift
indicates that the substitution affects nature of the cation displacement, octahedral tilt
and hybridization. Reduced polarization value in NBT-GM ceramics with non-saturated
hysteresis loops gives evidence for the suppression of ferroelectricity. Temperaturedependent magnetization measurements from R.T to 2.5K in NBT-GM ceramics show
the occurrence of spin-paramagnetic behavior. Susceptibility plots show some evidence
for weak interaction between Mn4+ ions at low temperatures below 30K. UV-Vis
spectroscopy measurements reveal the indirect transition allowed band gap nature forboth NBT and NBT-GM ceramics with a slight increase in band gap (Eg) value for NBTGM ceramics. Photoluminescence measurements show a strong blue emission at ~390nm(3.18 eV) in Gd-Mn substituted NBT system, which corresponds to radiative transition
from 4T1g →4A2g energy levels of Mn4+-ions.

Kyujoon Lee, Seongmin Choo and Myung-hwa Jung*
Sogang University, Korea

The exotic features of gapless semiconductors have attracted many researchers in solidstate physics. Materials such as HgCdTe have been studied as a gapless semiconductor.
Recently PbPdO2 has been theoretically proposed to be a gapless semiconductor.
In addition, by substituting Co for Pd ions the material becomes a spin gaplesssemiconductor which has full spin polarization. In this study we have experimentallyshown the changes in the physical properties of PbPdO2 by doping different magnetic
ions such as Co, Mn, and Zn. PbPdO2 shows a metal-insulator-like transition at
TMI=100 K in the resistivity vs. temperature measurements. The magnetic properties
show a diamagnetic behavior at high temperatures and a ferromagnetic behavior at
low temperatures. The TMI increases to 150 K by Co doping and the diamagnetic
behavior changes to paramagnetic behavior. By Mn doping, the TMI decreases
to 73 K and the magnetic behavior changes drastically to show antiferromagnetic
ordering at low temperatures. However no difference has been found by Zn doping.
The common feature for all materials is that the charge carrier density increases withdoping. The easily tuned properties of PbPdO2 show evidence that PbPdO2 is a gaplesssemiconductor and could be tuned to be a spin gapless semiconductor.

[1] H. Ohno, Science, 281, 951 (1998). [2] C. H. Park and D. J. Chadi, Phys. Rev. Lett. 94, 127204(2005). [3] S. Lee et al., Appl. Phys. Lett. 94, 212507 (2009); Y. C. Cho et al., Appl. Phys. Lett. 95,
172514 (2009); S. J. Kim et al., Phys. Rev. B 81, 212408 (2010). [4] Z. Lu et al., Appl. Phys. Lett.
94, 152507 (2009).

Andrey F Orlov1, Leonid A Balagurov1, Ivan V Kulemanov1, Elena A Petrova1, Nikolai Perov2*, Elena
A Gan'shina2, Leonid Yu Fetisov2, Anna S Semisalova2, Anastasia D Rubacheva2, Andrey Rogalev3,
Alevtina G Smekhova4 and Lada V Yashina2
1Institute for Rare Metals, Moscow, 119017, Russian Federation, Russia
2
Lomonosov Moscow State University, Russia
3European Synchrotron Radiation Facility, Grenoble Cedex, France
4
European Synchrotron Radiation Facility, Grenoble Cedex, France; Lomonosov Moscow State University, Russia

We present the investigation results of semiconducting films TiO2:V with 3-18%at. of vanadium, whichdevelop our previous research of doped titanium oxide [1,2]. The films have been grown by RF magnetron
sputtering on either LaAlO3 or rutile TiO2 substrates and revealed the room temperature ferromagnetic
ordering in the wide range of resistivity (10-3-106 Ω•cm). For degenerate semiconductors the values ofmagnetization were found to be lower. Magnetization of TiO2 doped with vanadium is maximum for all
semiconductor oxides doped with transition metal impurities. Maximum values of magnetization wereobserved in the films with a small content of V impurity and corresponded to 4.8 Bohr magneton per V atom.
The V impurity was found to be utterly in the oxidized state only in the films with a small V concentration.
The magneto-optical response in the 1.5-3.0 eV energy range was observed in samples with a high magnetic
moment only. The results are discussed within the model of charge-transfer ferromagnetism suggested by
Coey et al. [3,4]. Supported by RFBR and Ministry of Science and Education No.16.513.11.3088.
[1] A.F. Orlov et al., JMMM, 320, 895 (2008); [2] E.A. Gan’shina et al., JMMM, 321, 723 (2009); [3] J.M.D. Coey et al., J. Phys. D: Appl. Phys.,
41, 134012 (2008); [4] J.M.D. Coey et al., New J. Phys., 12, 053025 (2010).

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Room-temperature fabrication of highly transparent magnetic
nanocomposite systems by aerosol deposition

Tuning of the curie temperature by varying reduction potential inelectrochemically prepared thin films of Prussian blue analogue based
molecular magnets

An experimental approach using EPR and XMCD to explore hydrogen
mediated ferromagnetism

Magnetic properties and electrical conductivity on oxygen-deficient
europium monoxide

Jae-hyuk Park* and Akedo Jun
National Institute of Advanced Industrial Science and Technology (AIST), Japan

Nanocomposite systems, materials containing particles of nanometer dimensions have shown
interesting properties related to its extremely small size. Some of their optical, magnetic, electronic,
mechanical, and chemical properties are different from those exhibited by the same composition inbulk material[1]. We have proposed novel concept for materializing nanoocmposite systems using
aerosol deposition (AD) process[2-3]. Our concept can apply various sizes of nanoparticles, andachieves desirable distribution of nanoparticles in host matrix because the structure of depositedlayer is similar to that of composite powder. In this report, we developed highly transparent
magnetic nanocomposite thick films consisting of cobalt nanoparticles embedded in a host matrixof ferroelectric lead zirconate titanate (PZT) by AD process at room temperature. Transparent
thick nanocomposite cobalt/PZT films display very dense without any pores as well as any cracks.
As the wt% of nanocobalt increased, magneto-optic effect measured in the transmission mode,
especially Faraday rotation effect of nanocomposite layers gradually increases with good linearity.
The 0.1 wt% nanocobalt -containing nanocomposite film acquired the Faraday rotation angle ofapproximately 0.2 degree. These results would strongly show potential of optical multiferroics ontransparent nanocomposite systems.
[1] M. Abe, M Gomi, and F. Yokoyama, J. Appl. Phys., Vol. 57, pp. 3909-3911, 1985. [2]J. Akedo,
J. Am. Ceram. Soc., Vol. 89, pp. 1834-1839, 2006. [3] Jae-Hyuk Park, Jun Akedo and Masafumi
Nakada, Jpn. J. Appl. Phys., Vol.45, pp. 7512-7515, 2006

The 19th International Conference on Magnetism

Pramod Bhatt*, M. D. Mukadam and S. M. Yusuf
Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, India
The quest for molecular magnets with ordering temperature at or above room
temperature is highly desirable for their practical applications at ambient conditions.
In order to increase the ordering temperatures, many efforts have been devoted
to synthesizing compounds with appropriate choice of organic/inorganic ligands,
their valence modulation and spin centers, and alkali metal ion doping, etc., usingorganometallic and/or coordination chemical methods. However, we have shown
that, the magnetic ordering temperature in PBAs (Prussian blue analogues) can beenhanced by varying reduction potential in electrodeposition method. In this regard,
the electrochemically prepared films of PBAs, XjFeIIk[CrIII(CN)6]l.mH2O withvarying reduction potential are investigated using dc magnetization measurements. The
magnetization data for film deposited at lower reduction voltage shows ferromagnetic
ordering with TC (Curie temperature) of ~ 21 K, similar to previously reported
ordering temperature for this compound. However, an increase in TC up to ~50 K has
been observed for film deposited at higher reduction potential. The observed variationin TC is mainly attributed to the inclusion of potassium ion (K+) at higher reduction
potential, which changes stoichiometry of the film. The ability of tuning TC just bychanging reduction potential could be useful for designing future device applications.

July 9 (Mon)Michael P. Delmo*, Eiji Shikoh, Teruya Shinjo and Masashi Shiraishi
Graduate School of Engineering Science, Osaka University, Japan

174

poster Presentation

Seunghun Lee1, Bun-su Kim1, Yong Nam Choi2, Naoki Ishimatsu3, Masahiro Sawada3,
Won-kyung Kim1, Ji Hun Park1, Yong Chan Cho1 and Se-young Jeong1*
1
Cogno-Mechatronics Engineering, Pusan National University, Korea
2
Korea Atomic Energy Research Institute, Korea
3
Hiroshima University, Japan
Since the ferromagnetism of III-VI based DMS materials such as GaMnAs was turned out to be basedon carrier induced model, much progress has been made in developing its applicability but low operation
temperature has limited the approach to functional devices[1]. Among other materials, Co doped ZnO has
been regarded as strong candidate for room temperature DMS but the origin of ferromagnetism has been on
controversy[2]. Previously, we reported experimental results on Co-H-Co responsible for ferromagnetism
depending on hydrogen contents and position[3-5]. Here, in order to apply these phenomena for new
functional devices, more convincing experimental evidence for Co-H-Co is necessary. In this study, weshow the experimental approaches to hydrogen mediated ferromagnetic spin ordering in ZnCoO throughelectron paramagnetic resonance(EPR) and x-ray magnetic circular dichroism(XMCD). The signal intensityof ferromagnetic resonance is attributed to hydrogen contents and spin/angular magnetic moments comparedwith theoretical model of Co-H-Co are calculated from XMCD spectrum. In addition, the results ofphotoluminescence and spectrum of magnetic circular dichroism within UV-Vis range suggests the possibility
for creating and manipulating spin-polarized carrier using hydrogenated ZnCoO. Through advanced theoretical
calculation for Co-H-Co model, we are expecting to obtain the direct evidence for Co-H-Co unit.
[1] D. A. Allwood et al., Science, 309, 1688 (2005) [2] S. Lee et al., Appl. Phys. Lett. 94, 212507 (2009) [3] Y. C. Cho et al., Appl.
Phys. Lett. 95, 172504 (2009) [4] S. J. Kim et al., Phys. Rev. B 81, 212408 (2009) [5] S. Lee et al., J. Appl. Phys. (in press, 2012)

Jun-young Kim1*, Pedro M.d.s. Monteiro1, Kiyoung Lee1, Adrian Ionescu1, Stuart N Holmes2, Crispin H.w.
Barnes1, Peter J Baker3, Sean Langridge3, Zaher Salman4, Andreas Suter4 and Thomas Prokscha4
1

Department of Physics, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue,
Cambridge, CB3 0HE, United Kingdom
Toshiba Cambridge Research Laboratory, 208 Cambridge Science Park, Milton Road, Cambridge, CB4
OGZ, United Kingdom
3ISIS, Harwell Science and Innovation Campus, STFC, Oxon OX11 0QX, United Kingdom
4
Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
2

Pristine europium monoxide (EuO) is a ferromagnetic semiconductor with a Curie temperature (Tc) of 70
K. Below Tc, the conduction band is 100% spin-polarised [1] while at Tc it undergoes a metal-to-insulatortransition [2]. These properties render it a promising material for future spintronic devices such as spin injection
electrodes or filters [3]. Tunable control of magnetic properties is obtained by doping with oxygen vacancies.
We present results on co-sputtered EuO1-x films with Tc as high as 140 K. The films were characterized by
SQUID magnetometry, x-ray and polarized neutron reflectometry. The magnetic moment was found to increase
monotonically with oxygen vacancy concentration. Density-functional theory calculations of EuO1-x showthat oxygen vacancies act as n-type dopants and that the excess electrons preferentially populate the majority
spin branch of the conduction band [4]. We also present thickness-dependent magnetic properties of EuO1-x
thin films, where surface-induced changes were observed in films with below 5 nm thickness [5]. Muon
spin rotation measurements investigated microscopic magnetic behaviour and magnetic volume fraction as afunction of temperature. Electrical transport measurements in the Hall geometry will also be presented.
[1] R. P. Panguluri, T. S. Santos, E. Negusse, J. Dvorak, Y. Idzerda, J. S. Moodera, and B. Nadgorny, Phys. Rev. B 78, 125307 (2008)[2] G. Petrich, S. von Molnar, and T. Penney, Phys. Rev. Lett. 26, 885 - 888 (1971) [3] A. Schmehl et al., Nature Materials 6, 882 887 (2007) [4] M. Barbagallo et al., Phys. Rev. B 81, 235216 (2010) [5] M. Barbagallo et al., Phys. Rev. B 84, 075219 (2011)

July 8-13, 2012 Busan, Korea

175

poster Presentation
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Magnetism and optical properties of diluted magnetic semiconductor
superlattice GaGdAs/GaAs with GaGdAs nanograins

Origin of ferromagnetism in Co-doped (La,Sr)TiO3 diluted magnetic
semiconductors

MnAs nanoclusters embedded in GaAs: Magnetism and transport
properties

Production of Fe3-xZnxO4 nanoparticles for agents in hyperthermia
treatment

Miyagawa Hayato*, Yuuki Uda, Shoutaro Matsumoto, Nakaba Funaki and Shyun
Koshiba
Faculty of Engineering, Kagawa University, Japan

Xuefeng Wang1, Fengqi Song2, Yi Shi1, Rong Zhang1 and Jianbin Xu3
1School of Electronic Science and Engineering, Nanjing University, China
2
Department of Physics, Nanjing University, China
3
Department of Electronic Engineering, The Chinese University of Hong Kong,
China

Duong Van Thiet1, Dang Duc Dung2, Yooleemi Shin3 and Sunglae Cho3*
1
Department of Physics, University of Ulsan, Ulsan 680-749, Korea
2
Department of General Physics, School of Engineering Physics,Ha Noi University of
Science and Technology,1 Dai Co Viet road, Ha Noi, Viet Nam
3
Department of Physics, University of Ulsan, Ulsan 680-749,, Korea

Hiromasa Takeuchi*, Akinobu Kurokawa, Takuya Yanoh, Shinya Yano and Yuko
Ichiyanagi
Yokohama National University, Japan
Fe3-xZnxO4(x=0.2, 0.4, 0.6, 0.8, 1) nanoparticle with average diameters 12nm were
produced by our novel wet chemical method. The crystal structure and magnetic
property of the obtained particle were investigated by X-ray diffraction and SQUID
magnetometer. DC magnetization measurement showed that the coercive force Hc andsaturation magnetization Ms decreased as the composite parameter x increased. Thisphenomenon suggests that Zn2+ ions located on A-sites weaken the superexchangeinteraction between A and B sites. From the AC magnetic susceptibility, a sample withcomposition of x=0.4 is expected for heating by external field. Temperature increasedepending on the magnetic field strength and frequency supported that samples
with composition of x=0.2, 0.4 were appropriate for use as an agent in hyperthermia
treatment.

Diluted magnetic semiconductors (DMSs) are one of the important supporting materials
for the new-generation of spintronic devices. We prepared (La,Sr)TiO3 (LSTO) and Codoped LSTO DMS nanocrystals through solvothemal technique combined with postannealing process. After that, the effects of concentration of Co dopant, the annealing
atmosphere, temperature, duration and other conditions on the microstructures andmagnetic properties were investigated. When the doping concentration is lower than
5 at.%, the observed room-temperature ferromagnetism (RTFM) of our samples isof intrinsic property. Meantime, it is found that the magnetism has the close relation
with the concentration of Co dopant and the amorphous carbon which is remained
after annealing. Through controlling the annealing atmosphere and duration, we cansynthesize single-phase Co-doped LSTO nanocrystals. It is demonstrated that the RTFM
is correlated with the structural defects induced in the Ar annealing process. It is also
shown that Co-doped LSTO nanocrystals will have the CoO secondary phase when the
Co doping concentration is higher than 5 at.%. According to the interesting exchange
biasing phenomenon, the RTFM of our samples is ascribed to the collection of the CoO
nanophase or amorphous Co metallic impurities.

The fabrication of magnetic nanocluster embedded in conventional semiconductor is a research trend
because of their unique physical properties in electronics, optics and magnetism. The understanding ofmagnetic clusters effect on the transport and magnetic properties in semiconductor is timely demanded forthe spintronic device application. In this work we embedded MnAs nanoclusters in GaAs(001) by growing
MnAs/GaAs multilayer structure using molecular beam epitaxy. After growing 2000 A GaAs buffer layer
on GaAs (100) substrate, the [MnAs (20 A)/GaAs (tGaAs)]4 multi-layer configurations were grown at
400 oC, finally followed by the growth of 200 A-thickGaAs capping layer to avoid the oxidation of inner
layer. The tGaAs was selected as 100, 200 and 300 A. The reflection high energy diffraction (RHEED)
exhibited spotty patterns, indicating the island-growth of MnAs nanocluster. The result of cross-sectional
TEM measurement also showed that MnAs nanocluster are embedded in GaAs matrix successfully. The
resistance was increased rapidly with decreasing temperature, indicating that the samples demonstrate
semiconductor behavior. The magnetic properties were carried out by the superconductor quantum interface
devices (SQUID) measurement, which showed the TC above room temperature. The detail sample growth,and magnetic and transport properties of MnAs nanocluster embedded on GaAs will be discussed.

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Ferromagnetism in hydrogenated fullerene

Two dimensional growth of Nb doped SrTiO 3 thin films and its
superlatticesxHalf-metallic and ferromagnetic properties of carrier doping in Zn1CuxO

Gene delivery using polyethylenimine-coated magnetic nanoparticles
by static and oscillating magnetic field

Kyu Won Lee, Gi-wan Jeon and Cheol Eui Lee*
Physics, Korea University, Korea

We identify Stoner ferromagnetism in fcc C60Hn (n=odd) by using a local density
approximation in the framework of the density functional theory. Hydrogenchemisorption on fullerenes creates quasilocalized π-electrons on the fullerene surface,
overlapping of their wave functions giving rise to a narrow half filled impurity band in
the fcc C60Hn. The Stoner-type ferromagnetic exchange between the itinerant electrons
leads to spin-split impurity bands. The magnetic moment per C60Hn molecule is 1 μB
(for n=odd) or 0 (for n=even, including zero), only one of the hydrogens contributing
to the spin-split states. Direct overlapping of the quasilocalized π-electron orbitals isessential for the ferromagnetism.
1. T. L. Makarova, B. Sundqvist, R. Ho¨hne, P. Esquinazi, Y. Kopelevich, P. Scharff, V. A. Davydov,
L. S. Kashevarova, and A.V. Rakhmanina, Nature (London) 413, 716 (2001). 2. T. L. Makarova, B.
Sundqvist, R. Ho¨hne, P. Esquinazi, Y. Kopelevich, P. Scharff, V. Davydov, L. S. Kashevarova, and
A.V. Rakhmanina, Nature (London) 440, 707 (2006). 3. S. Okada and A. Oshiyama, Phys. Rev. B 68,
235402 (2003).

Abhijit Biswas, Yong Woo Lee, Min Hwa Jung and Yoon Hee Jeong*
Department of Physics, Pohang University of Science and Technology, Korea

Two dimensional growth modes were obtained for Nb doped SrTiO3 thin films grownon TiO2 terminated SrTiO3 (001) substrates; as monitored by in-situ reflection highenergy electron diffraction (RHEED). At low substrate temperature ordinary RHEED
oscillation was observed, indicating layer by layer growth. At high temperature,
recovery of RHEED intensity after switching off laser pulses indicated the step flow
growth mode. In both cases, films show metallic behavior with resistivity (ρ)~10-3
Ω-cm. Nb:SrTiO3/SrTiO3 (NSTOm/STOn) superlattices were also being fabricatedat low temperature containing five unit cell thick NSTO layers with various stacking
sequences. Film surfaces were characterized by atomic force microscopy (AFM),
showing high crystalline quality having steps of 3.9 A. At room temperature, resistivity
was found to be 1~2 Ω-cm. The oxide superlattice growth approach might provide a
useful way to control the charge carrier and resistivity for novel device applications.

Byung-sub Kang1, Kie-moon Song1, Yong-sik Lim1, Kyeong-sup Kim2, Young-yeal
Song2 and Seong-cho Yu2
1
Dept. of Nano science and Mechanical engineering, Konkuk University, Korea
2
Dept. of Physics and BK21 Physics Program, Chungbuk National University, Korea,
Diluted magnetic semiconductors (DMSs) have attracted a great deal of attention because of thepossibility of incorporating magnetic degrees of freedom in traditional semiconductors. However,
it is one of the primary challenges to create the ferromagnetic semiconductors due to the difficultyin the spin-injection into the semiconductors to form DMSs at room temperature or above room
temperature. Since ZnO is a direct wide-band gap semiconductor which is piezoelectric, ZnO-based
DMS would be useful for transparent thin film transistors, blue and UV light-emitting diodes andlaser diodes. The precipitates of nonmagnetic Cu dopants do not contribute to the magnetism. In
our work, the stability of ferromagnetic state in ZnO-based DMSs with a concentration of 2.77%,
5.55%, and 8.33% has been investigated by first-principles calculations. The magnetic moments
are not affected by changing the doping concentrations, while the band gap is decreased as forincreasing of Cu concentration. The band gaps in Cu-doped ZnO are 0.65, 0.22, and 0.08 eV for the
Cu concentration of 2.77%, 5.55%, and 8.33%, respectively. The half-metallic character shows at
low Cu concentration, while it is disappeared as for increasing of Cu concentration. The effects on
the electronic state by the hole (Nitrogen) doping have been investigated.

July 9 (Mon)

July 9 (Mon)We found ferromagnetic coupling in the rare earth elements Gd doped GaAs DMS,
abbreviated as GaGdAs, which was grown by molecular beam epitaxy (MBE).
However, GaGdAs is easy to have distortions or dislocations, because the atomic sizeof Gd is large compared to GaAs matrix, and also there is lattice mismatch between
GaGdAs layer and substrate. Superlattice (SL) structure of GaGdAs/GaAs, in which
GaGdAs layers are interleaved with a few ML thick GaAs layer, is considered tohave a good crystallinity. We fabricate magnetic semiconductor superlattice GaGdAs/
GaAs and mono layer GaGdAs by MBE and analyze the crystal structure by means ofTransmission Electron Microscopy (TEM) and measured the macroscopic magnetic
properties by Alternating Gradient Magnetometer (AGM). In high resolution TEM
images, there are GaGdAs grains of 2-3 nm, which has high Gd concentration andlattice-matching in GaAs Matrix. The result of magnetic measurements shows thatsuperlattice structures have larger saturated magnetization and smaller coercive field
than that of monolayers. We think that the GaGdAs grains, which are observed onlyin SL structures, possibly has main contribution to generate ferromagnetism in room
temperature. We also measured Photoluminescence of GaGdAs samples and found theenergy band gap is larger than GaAs.

Yoshiyuki Takahashi1, Satoshi Ota1, Asahi Tomitaka1, Tsutomu Yamada1, Daisuke
Kami2, Shogo Takeda3, Masatoshi Watanabe3 and Yasushi Takemura1
1
Electrical and Computer Engineering, Yokohama National University, Japan
2
Kyoto Prefectural University of Medicine, Japan
3
Materials and Chemical Engineering, Yokohama National University, Japan
Recently gene delivery without viral vectors attracts rising attention. Low transfection
efficiencies of nonviral gene vectors such as transfection reagent limit their utility in genetherapy. To overcome this disadvantage, we report a transfection method using cationicpolymer polyethylenimine(PEI)-coated magnetic nanoparticles and an external magnetic field.
It shows high transfection efficiency as well as low cytotoxicity. In this study, transfection
efficiency of plasmid DNA in complex with PEI-coated magnetic nanoparticles was studied.
HeLa cells were seeded the day before transfection. Immediately before transfection, the PEIcoated magnetic nanoparticles (γ-Fe2O3) were mixed with plasmid DNA. The complexes wereincubated and added to HeLa cells on a NdFeB magnet and a coil. After 48 hours, transfection
efficiency of plasmid DNA to HeLa cells was evaluated by the average percentage of thefluorescent cells imaged by a fluorescent microscope in triplicate. The optimal amount ofmagnetic nanoparticles was 3.0 μg/sample on a magnet for 4 h. The transfection efficiency wasincreased five-times compared without magnetic nanoparticles (only PEI). Higher transfection
efficiency was obtained by applying an ac magnetic field. Further analysis on other parametersof an applied magnetic field and endocytosis are reported.

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Enhancement of the magneto-optical effect by an addition of Co in
pseudo-quaternary II-VI magnetic semiconductor CdMnCoTe films

Anomalous hall effect in ferromagnetic nanocomposite FeGa/Fe3Ga
thin films

Synthesis and characterization of surface functionalized magnetic
polymer microspheres with multi-shell structure

Fabrication of QD-anchored magnetic nanocomposites for biomedical
applications

The anomalous Hall effect (AHE) is a central topic in the study of the ferromagnetic materials because
it exhibit one of the strong evidence for spin polarization [1]. There are three main mechanisms for AHE
including intrinsic deflection, side jump and skew scattering. The AHE in intrinsic homogeneous magnetic
material is related to spin polarize due to difference state of spin up and spin down at the Fermi energy
level and matched to the Berry phase theory [2]. In inhomogeneous magnetic material, AHE implies thepresence of spin dependent scattering mechanism. The skew scattering dominates at low temperature,
while the side jump becomes important at high temperature [3]. Recently, we reported the observation of
weak AHE in FeGa epitaxial thin film on GaAs(001) substrate where FeGa displayed the A2 structure [4].
The FeGa were recently rapidly studied because of its giant magnetostrictive characteristics [5, 6]. In thiswork, we report the observation of AHE in nanocomposite FeGa/FecGa epitaxial thin film on GaAs(001).
Unlike FeGa (A2-structure), the strong AHE were shown up to 400 K. Interestingly, the nanocomposite
FeGa/Fe3Ga film exhibited strong out-of-plane magnetization. We suggest that the origin of strong AHE
are magnetization orientation of epitaxial Fe3Ga (DO3-structure).

We synthesize magnetic polymer microspheres with amino/ carboxyl groups
on the surface. We also fabricate the microspheres by incorporating magnetite
nanoparticles(MPs) into a silica shell around preformed polystyrene(PSt)/SiO2
core/shell microspheres. Due to the silanization reaction with 3-aminopropyl
triethoxysilane(APTES), the outermost silica shell is formed and linked with aminogroup at the same time. And we use PEG diacid to obtain carboxyl functionalized
microspheres via the reaction between -NH2 and -COOH. Optical microscope andscanning electron microscopy(SEM) show that the microspheres are monodispersewith the average diameter about 2um; vibrating sample magnetometer(VSM)
indicates that the synthesized sample with amino-group on the surface exhibits
superparamagnetism with the saturation magnetization 7emu/g; thermogravimetry(TG)reveals that the microspheres are thermally stable when temperature is below 300°C
and the Fe3O4 content is 20.68%. Last, the fluorescence microscope shows that the
microspheres obtained can be successfully conjugated with biomolecular, including
streptavidin and antibody.

Masaaki Imamura* and Keisuke Ninomiya
Electrical Engineering, Fukuoka Institute of Technology, Japan

Magneto-optical properties with pseudo-quaternary magnetic semiconductor
CdMnCoTe films deposited on quartz glass substrates by using MBE equipment [1]have been studied at a visible wavelength region at room temperature. Deposition
was made at an average rate of ~1 Å/sec for 8h using a 4N Co target sputtered by anelectron gun having an emission-current of 20 mA, a 5N CdTe effusion cell heated at
490˚C and a 4N MnTe cell at 1020˚C. Using this system, ~2-μm-thick CdMnTe and
CdMnCoTe films were prepared on 0.5-mm-thick QG substrates. These films exhibitedthe preferred (111) growth and paramagnetic characteristics. The magnetization
intensity at 15 kOe at room temperature was approximately 2.5x10-4 emu for the
Cd0.65Mn0.35Te film and 2.8x10-4 emu for the Cd0.56Mn0.39Co0.05Te film, showing thevalues that were almost the same for two films. Faraday rotation measured at 620 nm
in the CdMnCoTe film was -0.32 deg/cm-G and that in the CdMnTe film was -0.10
deg/cm-G. Thus the Faraday rotation in the CdMnCoTe films was largely enhanced
compared to that in the CdMnTe films. A direct ac Faraday rotation observation under
1.27 kHz ac fields generated by a ring magnet [2] has successfully been carried out for
the CdMnCoTe films.
[1] A. Okada et al., IEEE Trans. Magn. 39, 3175 (2003). [2] A. Okada et al., J.Magn. Soc. Jpn., 31,
328 (2007).

176

poster Presentation

The 19th International Conference on Magnetism

Dang Duc Dung1, Duong Anh Tuan2, Yooleemi Shin2 and Sunglae Cho2*
1
Department of General Physics, School of Engineering Physic,Ha Noi University of
Science and Technology, 1 Dai Co Viet road, Ha Noi, Viet Nam
2
Department of Physics, University of Ulsan, Ulsan 680-749,, Korea

Zuli Liu*, Qing Li and Kailun Yao
Physics, Huazhong university of science and technology, China

Hangdeok Oh and Sang-wha Lee*
Department of Chemical and Bio Engineering, Kyungwon University, Korea

WN
A
R

D

TH
WI

[1] N. Nagaosa et al., Rev. Mod. Phys. 82, 1539 (2010). [2] M. V. Berry, Proc. Roy. Soc. of London 392, 45 (1984). [3] P.
Xiong et al.,Phys. Rev. Lett. 69, 3220 (1992). [4] D. A. Tuan et al., to be printed in JAP. [5] J. Atulasimha et al., Smart Mater.
Struct. 20, 043001 (2011). [6] O. M. J. van’t Erve et al., Appl. Phys. Lett. 91, 122515 (2007), and reference therein.

July 8-13, 2012 Busan, Korea

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poster Presentation

poster Presentation

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Determination of biomolecule interaction in magnetic particle byvoltammetry and ac impedanceMagnetic nanoemulsion as advanced drug delivery system applied tosynergic procedures in the photodynamic therapy and hyperthermia
trials using human mesenchymal stem cells as biological model

Reliability of a head movement compensation method based onminimum norm estimation for magnetoencephalographic recordings

FEM simulation of magnetic treatment of surface vessel

Fernando Lucas Primo1, Daniela Regina Jardim1, Paulo Cesar Morais2 and Antonio Claudio Tedesco1*
1

July 9 (Mon)

Magnetic biochip based immunoassay have potential in many fields, such asenvironmental immunoassay, diagnostic immunoassay, and biochemical studies
and immunosensors [1]. In the field of immunoassays, cyclic voltammetry (CV)technique have become known independently as methods suitable for the detectionof immunological reactions. CV measurements are the current signals based on theelectrochemical species consumed and/or generated during a biological and chemicalinteraction process of a biologically active substance and substrate. To apply to the realbiomarker and verify the sensitivity of CV-based sensor, we used the biomarker scheme
using the applied the real protein on the gold surface. The capture antibodies (P21mono antibody) are first immobilized on the positive gold sensor surface. The samples
with biomarkers (P21 recombination protein) to give antibody and antigen reaction
are applied on gold surface. After the non specific binding labels were successfully
removed through the washing progress, only the chemically bounded bio molecules
were remained on the Au surface. This enables to increase the sensitivity of the sensor
for the binding of biomolecules on the gold surface. The difference in the CV represents
the quantity of the antigen of interest and could be applied to the biosensor.

Chemistry, Nanotechnology and Tissue Engineering Center, FFCLRP, Sao Paulo University, Ribeirao Preto, SP, Brazil
Physical, Brasilia University - UnB, Physical Institute, Brasilia-DF, 70910-900., Brazil

Tissue engineering and nanotechnology are important research fields in the future development of biological models
useful for the understanding of wound healing processes, extracellular matrix activity and other biological skinactivities[1]. This study reports on the synthesis and characterization of advanced drug delivery system with magnetic
properties useful to Photodynamic Therapy (PDT) and Hyperthermia (HPT). Magnetic-Nanoemulsion (MNE) was
obtained from spontaneous nanoemulsification to entrapment/controlled-release of lipophilic drugs as described by
Siqueira-Moura[2]. The results demonstrated appropriated physical-chemistry stability to MNE biomaterial with size
< 200 nm, exhibited a narrow size distribution (polydispersity index < 0.1) and zeta potential with modular value> Ι40Ι mV. Biological studies were carried out on human bone mesenchymal stem cells determination of in vitro
biocompatibility after incubation with MNE which shown a safe concentration drug specific for each cellular type.
Besides, the in vitro synergic effect of PDT and HPT were evaluated after simultaneous induction of photodynamic
effects and magnetic field (40 Oe) application. These results confirmed that the use of nanotechnology associatedwith PDT and HPT procedures led to in vitro tumor inactivation by advanced protocols that can be useful to futureoncological treatment. Financial grant CNPq (D.R.J.) and FAPESP projects 2009/15363-9 and 2008/53719-4 (F.L.P.).

Non-invasive multi-channel recordings of neuronal activity of brain play an importantrole in brain research fields. Magnetoencephalography (MEG) which measuresmagnetic field generated by synchronous firing of group of neurons, has superior
spatial and temporal resolutions with quick and easy recording procedures. However,a movement of subject’s head during recordings makes significant data distortions,since the array of multi-channel sensors is not physically fixed to subject’s head.
One approach compensating these distortions is to utilize a singular-value-truncatedminimum norm estimation (MNE) method to generate virtual MEG signals at acommon reference head position. Since MNE is biased to minimize the total output
power, this approach can be applied to signals which have a number of distinct sources
generating event related fields (ERF), but not to spontaneous neuronal recordings.
In this study, we calculated compensation errors of ERF recordings and spontaneous
neuronal recordings, by comparing real sensor signals to virtually-generated signals, tosee the reliability of the method for spontaneous recordings. MEG data were recorded
using a 152-channel whole head helmet MEG system (KRISS MEG system) within amagnetically shielded room, and each channel was simulated and compared with eachtime trials.

Since most of surface vessels and submarines are constructed with ferromagnetic materials, mainly
Fe-C, Magnetic treatment (Deperm) of surface vessels and submarines is required to camouflage
them against magnetic detection from enemy marine force. We investigated whether we could
analyze practically magnetic treatment process of a surface vessel with FEM simulation. Because
a surface vessel has non-linear ferromagnetic property as well as complicated structure with verylarge dimension, it is impossible to analyze the magnetic treatment process through conventional
FEM using scalar material constants. We tried to do the FEM analysis a hysteresis model. The
magnetic property including hysteresis of the constructing material of the submarine was calculatedwith the hysteresis model, and compared with the material property measured with the ferrite yokemethod. The alternating magnetic field applied to the submarine in FEM analysis had several tens
steps, and the maximum field was 1000 A/m. The analysis results showed that overall magnetic
remanence was almost the same with that of hysteresis model. However, it was found that themagnetization in the endpiece of the vessel was changed non-linearly. The simulated results could
be analyzed with the ferromagnetic exchanging coupling of magnetic nodes in FEM model.

[1] Choi JW, Chun BS, Oh BK, Lee W, Lee WH (2005) Fabrication of DNA-protein conjugate layer
on gold-substrate and its application to immunosensor. Coll Surf B 40:173-177[1] Primo, F L.; Reis, M. B. C.; Porcionatto, M. A.; Tedesco, A. C. In vitro Evaluation of Chloroaluminum Phthalocyanine
Nanoemulsion and Low-Level Laser Therapy on Human Skin Dermal Equivalents and Bone Marrow Mesenchymal
Stem Cells. Current Medicinal Chemistry, 18, 3376-3381, 2011. [2] Siqueira-Moura, M.P.; Primo, F.L.; Peti, A.P.F.;
Tedesco, A.C. Validated spectrophotometric and spectrofluorimetric methods for determination of chloroaluminum
phthalocyanine in nanocarriers. Pharmazie, 65, 1-6. 2010.

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The effects of pulsed magnetic field stimulus on electromyographic
activity

The morphological change of red blood cells in the hand exposed to thestimulus of strong pulse magnetic field

The effect of small quantities of irradiation damage on the magnetic
properties of Steel 316.

Magnetically exchange-coupled nanoparticles as efficient heat inductor

Juyeon Seo1, Yongjin Kim1, Jaehyun Kim1, Sunghyun Kim1, Do Gwen Hwang1, Yunyeop Cha2 and Hyun Sook Lee1*
1
Department of Oriental Biomedical Engineering, Sangji University, Korea
2
Department of Oriental rehabilitation medicine, Sangji University, Korea

Pulsed magnetic fields (PMF) conducting impulses toward the deep tissues as well as transcutaneous
tissues are well known to be alternative non-invasive medical treatment for influencing humanphysiology as compared with acupuncture. In traditional Chinese medicine, acupuncture is usedclinically to relieve myalgia and many studies have attempted to elucidate its mechanism ofaction [1]. The aim of the present study was to examine the immediate effects of PMF stimulus
on the electromyographic (EMG) activity at acupoint HT2, Quingling, which is a trigger point as
hyperirritable spots in biceps brachii muscle on the arm [2]. Six healthy volunteers were asked toperform four repetitions of withstanding maximal isometric contraction with 5-kg load and an elbow
angle of 90o to cause fatigue in biceps brachii muscle on the arm. Analyzing power density spectrum
from fast Fourier transformation of EMG signal, we observed that median power frequency (MDF)
decreased and median power increased due to muscle fatigue during isometric contractions. It wasproved that PMF stimulus on acupoint was effective in relieving muscle pain by means of increased
MDF and amplitude probability distribution of RMS EMG shifted to high amplitude. Therefore, it
may be concluded that appropriate PMF stimulus affects neuromuscular function.
[1] K. Toma, R. Conatser, R. Gilders, and F. Hagerman, J. Strength & Condit. Res. 12(4), 253257(1998). [2] J. Majlesi & H. Unalan, Curr Pain Headache Rep 14,353-360(2010)

Jinyong Lee1, Hyun Sook Lee1, Jun Sang Yu2 and Do Guwn Hwang1*
1
Oriental Medical Engineering, Sangji University, Korea
2
Oriental Medical, Sangji University, Korea

The influence of magnetic field on human body has been studied to use as application oftherapeutic equipment for a long time. Some studies have carefully suggested that vascularblood flow volume can be increased by an electromagnetic field stimulus [1-3]. In thisstudy, live blood analysis (LBA) of blood collected in the hand stimulated by strong pulsed
magnetic field was used in vitro to get the morphological change of red blood cells before
and after magnetic stimulus. The LBA is a test methodology to approach the risk factors of
illness, states of immunity, nutritional states of cells, degrees of hidden lesions, or treatments
over time. The analysis can accomplish these goals functionally and preventively byobserving morphological changes of ingredients constituting blood, which is alive without
being chromated and collect through peripheral blood vessel. Our system was designed togenerate a pulsed magnetic field that had a maximum intensity variation of 0.48 T and atransition time of 0.102 msec. LBA were done in the blood collected before and after the
stimulation of 10 minutes in the hand. As a result, the hemadsorption (adhesion of red blood
cells) observed before stimulus were normally distributed after stimulus of blood.

Robert Aldus1, Jack Muir1, Greg Lumpkin2 and Paolo Imperia1*
1
bragg institute, ANSTO, Australia
2
IME, ANSTO, Australia

The Steel 300 series is often used in applications where a non-magnetic steel isrequired. The materials take the austentite FCC crystal structure as opposed to theferrite structure common in magnetic steels. It has previously been suggested thatlarge doses of radiation (approximately 1022 ions/cm2) can cause a change in thelocal crystal structure of steel-316 to the ferrite structure and thus creating a magnetic
signal [1]. We have performed x-ray absorption, x-ray dichroism and neutron scattering
using WOMBAT at ANTSO where we also commissioned the new ANSTO Oxford
Instruments cryomagnet. The samples of steel-316 were irradiated to only about 1015
ions/cm2 using He+ ions. This level of irradiation should not be enough to change thebulk crystal structure and yet we observe some magnetic signal. We present our results
and explanation for our findings.

[1] D. Roland, M. Ferder, R. Kothura, T. Faierman, and B. Strauch, Plast. Reconstr. Surg. 105, 1371
(2000). [2] H. N. Mayrovitz and P. B. Larsen, Wounds 4, 197 (1992). [3] H. N. Mayrovitz and P. B.
Larsen, Wounds 7, 90 (1995).

Seung Ho Moon, Jung-tak Jang, Seung-hyun Noh, Jae-hyun Lee and Jinwoo Cheon*
Chemistry, Yonsei University, Korea

The conversion of electromagnetic energy into heat by nanoparticles has the potential
to be a powerful, non-invasive technique for biotechnology, but poor conversion
efficiencies have hindered practical applications so far. We demonstrate a significant
increase in the efficiency of magnetic thermal induction by nanoparticles. We
take advantage of the exchange coupling between a magnetically hard core andmagnetically soft shell to tune the magnetic properties of the nanoparticle andmaximize the specific loss power (SLP), which is a gauge of the conversion efficiency.
We simulated SLP as a function of magnetocrystalline anisotropy K, diameter of thenanoparticle D, and magnetization M. The dependency on K chiefly results from theinternal magnetic spin fluctuation (Neel relaxation), and the dependency on D is due
to both Neel and Brownian relaxation. Our simulation indicates the optimal range ofK and D for nanoparticles with high SLP values. High magnetization M is beneficial,
too. The optimized core-shell magnetic nanoparticles have SLP values that are an orderof magnitude larger than conventional iron-oxide nanoparticles. We also perform an
antitumour study in mice, and find that the therapeutic efficacy of these nanoparticles issuperior to that of a common anticancer drug.
Nature Nanotech. 2011, 6(7), 418-422

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Magnetic anisotropy of CodFe3-dO4 nanoparticles for applications inmagnetic hyperthermia

An analytical comparison in electoencephalography andelectrocardiography during stimulus of pulsed magnetic field andacupuncture on acupoint PC9

Study of a hybrid magnet array for an electrodynamic maglev control

Theranostic magnetic nanoparticles

Costica Caizer*
Electricity and Magnetism, West University of Timisoara, Romania

The magnetic behaviour of the CodFe3-dO4 (d = 0 ~ 1.5) nanoparticles strongly depends on theconcentration (d) of the cobalt ions within the spinelic ferrite structure; this is a superparamagnetic
behaviour for low d, a soft magnetic behaviour for moderate d, and a hard magnetic behaviour for highd. The d parameter determines a certain value of the magnetocrystalline anisotropy [1]. The effective
magnetic anisotropy in the case of nanoparticles is a very important intrinsic parameter (besides theirdiameter) to obtain the magnetic hyperthermia (MHT), with a great influence on the specific absorption
rate (SAR), in the case of their usage in medicine to obtain tumour magnetic hyperthermia (to destroy
tumour cells) [2,3]. The purpose of this research is to determine the magnetic anisotropy of the CodFe3dO4 nanoparticles, having the diameters of 2 ~ 17 nm, to identify its origin (magnetocystalline or/
and other nature (surface anisotropy or/and shape anisotropy)), and also to establish, based on theexperimental results, the most suited nanoparticles (as anisotropy and diameter) in order to use them inintracellular MHT [4]. The obtained results are presented and discussed in detail in the paper.
Acknowledgement: This work was supported by PCCA-2012 project from the UEFISCDI-ANCS
Romania. References [1] R. Valenzuela, Magnetic Ceramics (Cambridge Univ. Press, Cambridge)(1994). [2] C.L. Ondeck, A.H. Habib, P. Ohodnicki, K. Miller, C.A. Sawyer, P. Chaudhary, M.E.
McHenry, J. Appl. Phys. 105 (2008) 07B324. [3]. C. Caizer, N. Hadaruga, D. Hadaruga, G.
Tanasie, P. Vlazan, 7th Int. Conf. on Inorganic Materials, 12 - 14 Sept. 2010, Biarritz, France. [4] J.P.
Fortin, F. Gazeau, Eur. Biophys. J. 37 (2008) 223.

178

2

Sanghyun Lim and Kiwoong Kim*
Brain and cognition measurement lab, KRISS, Korea

The 19th International Conference on Magnetism

Jinyoung Lee1, Do Guwn Hwang1, Yun-Yeop Cha2 and Hyun Sook Lee1*
1
Department of Oriental Biomedical Engineering, Sangji University, Korea
2
Department of Oriental rehabilitation medicine, Sangji University, Korea

With recent increasing attention on the pulsed magnetic field stimulus as non-invasive medical
treatment, diverse studies are being conducted to elucidate its effects on human physiology[1]. Among several bio-signals obtained from human body, electroencephalography andelectrocardiography are known to have no side effect and provide real-time information on
autonomic nervous activity with spectral analysis. The aim of the present study was to compare thechanges of EEG and ECG during the PMF and acupuncture stimulus on acupoint, which is known tosedation and tonification point. In order to compare qualitatively the effect of PMF and acupuncture
stimulus, the difference of alpha activities are calculated from EEG spectra compared with before,
during and after stimulus, and the spectrum curves of ECG were analyzed in the frequency domainof heart rate variability. The increase of alpha activities after both stimuli could be explained that theimpulse of stimulus on PC9 might pass through sensory nerve following meridian and approach the
cerebral cortex, causing the CNS to be activated for pacifying emotion and calming the mind [2].
The decrease in index of sympathovagal activity after both stimuli indicates that parasympathetic
nerves were activated and the sympathetic nerves were in constrained condition.
[1] N.M. Shupak, F.S. Prato, and A.W. Thomas, Neurosci. Lett. 363, 157 (2004). [2] H.S. Lee, S.W.
Kim, D.G. Hwang, IEEE transaction on Magn. 47(10), 3060 (2011).

July 9 (Mon)

Hoon Song and D. G. Park*
korea atomic energy research institute, Korea

Yongmin Kim1, Hwiseok Kim2, Kwan-seob Yoon3, Seon-ho Lim3, Jaewon Doh2,
Young-hak Kim4 and Kwang-ho Shin1*1Dept. of Information and Communication Engineering, Kyungsung University,
Korea
2
S/W R&D Center, Project 5 team, LIGNex1, Korea
3
S/W R&D Center, Project 4 team, LIGNex1, Korea
4
Dept. of Information and Communication Engineering, Pukyong National
University, Korea

Chan Ham1, Kurt Lin2, Younghoon Joo3 and Wonsuk Ko4*
1
Mechatronics Engineering, Southern Polytechnic State University, USA
2
Mechanical, Materials, and Aerospace, University of Central Florida, USA
3
Kunsan Nat’l University, Korea
4
Kyungwon.Univ, Korea

This paper introduces an innovative hybrid array consisted of both permanent and electro magnets
that would enable us to develop an active control mechanism for underdamped EDS Maglev
systems. The proposed scheme is based on the Halbach array configuration in order to take themajor technical advantage from the original Halbach characteristics: a strongly concentrated
magnetic field on a side of the array and a cancelled field on the opposite side. The magnetic force
produced by the proposed hybrid array can also be actively controlled. This force controllability
resulted from a variable magnetic field is instrumental to provide a dynamic damping force tocompensate the instability of EDS Maglev system caused by external perturbations and guideway
irregularities. In this study, the magnetic characteristics and capability of the proposed arraycompared to the basic Halbach concept are focused. The results show that the proposed array iscapable to produce an equivalent suspension force of the basic Halbach permanent magnet array but
in a controlled mode. The effectiveness of the proposed array confirms that this study can be used asa technical framework to develop an active control mechanism for an EDS Maglev system.
[1] Donald M. Rote and Yigang Cai, “Review of Dynamic Stability of Repulsive-Force Maglev Suspension Systems,” IEEE
Transactions On Magnetics, Vol. 38, No. 2, 1383-1390, March 2002 [2] R. F. Post and D. D. Ryutov, “The Inductrack: A
Simpler Approach to Magnetic Levitation,” IEEE Transactions on Applied Superconductivity, Vol. 10, 901-904, 2000

Seung-hyun Noh, Dongwon Yoo, Jae-hyun Lee, Jung-tak Jang, Seung Ho Moon andJinwoo Cheon*
center for evolutionary nanoparticles, Korea
The property of magnetic materials can be defined using some parameters such as
saturation magnetization(Ms), coercivity(Hc), and magnetocrystalline anisotropy(K).
Understanding the interplay of these parameters is critical for optimizing magnetic
characteristics we need for their effective use. We can control these parameters bychanging the shape, size and composition of nanoparticles. Because there are various
species of application of nanoparticles and magnetic properties needed to be optimized
in each field of application are all different flexible tuning of magnetic parameters
is very important. Important capabilities of magnetic nanoparticles are the external
controllability of magnetic heat generation and magnetic attractive forces for thetransportation and movement of biological objects. We show that these functions canbe utilized not only for therapeutic hyperthermia of cancer but also for controlled
release of drugs through the application of an external magnetic field. Additionally, theuse of magnetic nanoparticles to drive mechanical forces is demonstrated to be usefulfor molecular-level cell signaling and for controlling the ultimate fate of the cell. The
wide range of accessible features of magnetic nanoparticles underscores their potential
as the most promising platform material available for theranostics.

July 8-13, 2012 Busan, Korea

179

poster Presentation
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Ion-texturing & Dynamics in Layered Compounds: From Electric Automobiles to Frustrated Magnetism

A new definition of magneto-mechatronics and applications

Time-resolved pump-probe measurement of polarization rotation in
nano-structured chiral metamaterial

2Martin Mansson21*, Jun Sugiyama42, Kazuhiko Mukai, Yutaka Ikedo3, Hiroshi Nozaki2, Kazuya Kamazawa2,
Masashi Harada, Marisa Medarde4 , Fanni Juranyi5, Jorge 5Gavilano5, James S.8 Lord6, Isao Watanabe7,9 Ekaterina
4
Pomjakushina , Kazimierz Conder , Vladimir Pomjakushin , Tsutomu Ohzuku and Tsunehiro Takeuchi
1Lab. for Solid State Physics, ETH Zurich, Switzerland
2
Toyota Central Research and Development Labs. Inc., Japan
3
Muon Science Laboratory, KEK, Japan
4
LDM, Paul Scherrer Institut, Switzerland
5
Lab. for Neutron Scattering, Paul Scherrer Institut, Switzerland
6
ISIS, Rutherford Appleton Laboratory, United Kingdom
7Muon Science Laboratory, RIKEN, Japan
8
Department of Applied Chemistry, Osaka City University, Japan
9
Department of Applied Physics, Nagoya University, Japan

Sung Hoon Kim*, Jaewon Shin, Shuichiro Hashi and Kazushi Ishiyama
Research Institute of Electrical communication, Tohoku University, Japan
Recently, magnetic wireless sensors and actuators have been developed for use in biomedical fields. In
particular, their mechanisms depend on magnetics, such as magnetic material and physical phenomena.
However, their research boundary has not been clear. Researchers talk of magnetic micro-robots, magnetic
actuators and sensors, and so on [1-3]. Therefore, a new and correct definition is required. Magneticmechatronics is synergistic integration of magnetic engineering, mechanical engineering, and electronics/
computer engineering in the design, manufacturing, and control process. In particular, magneticmechanical mechanisms are directly controlled by external magnetic fields. Magneto-mechatronics isoffered as a new definition of magnetic sensors and actuators. In this study, we introduce and investigate
methods of magnetic field control and their suitable magnetic mechanisms. In general, the control methods
and mechanisms are determined according to the types of magnetic field: gradient, alternating, androtating magnetic fields. Because the magnetic field controls are suitable for use in the restricted spaces,
magnetic devices based on magneto-mechatronics can be widely used medical applications. In magnetomechatronics, the combination of magnetic, mechanical, and computer engineering provides physicalhardware, system modeling, and analysis, whereas the combination of magnetic, electrical, and computerengineering provides control methods and its algorithm, and an interface, and so on.

J. H. Woo1, H. -y. Shin1, M. J. Gwon1, M. Vomir2, M. Barthelemy2, D. -w. Kim1, S.
Yoon1, J.-y. Bigot2 and J. W. Wu1*
1
Department of Physics & CNRS- Ewha International, Ewha Womans University, Korea
2
CNRS-IPCMS, University of Strasbourg, France
In this study, we performed time resolved pump-probe measurement in two nano-structured
metamaterials with opposite chirality which were fabricated by e-beam lithography on 30nm thickgold film. Transient absorption was measured to investigate the temporal behavior of the polarization
rotation in metamaterial. It is well known that surface plasmonic resonances in metamaterial
are originated from its structure rather than composition [1,2]. Surface plasmonic resonances inmetamaterials which were used in this study were located in the visible spectral range with resonancepeaks at 625nm and 670nm and an optical rotatory dispersion was observed. Time resolved pumpprobe measurements were carried out with 35fs Ti:sapphire laser operating at 800nm. BBO crystal wasused to generate a 400nm pump pulses. For the probe, a sapphire crystal plate was used to generate awhite light continuum. With linearly polarized pump beam, the electron dynamics in the metamaterial
structure was studied. Also with right and left circularly polarized pump, we investigated the timedependent rotation of polarization of the probe beam in a polarization bridge configuration.

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Efficiency of Energy base deperm protocol

Yongmin Kim1, Young-hak Kim2 and Kwang-ho Shin1*1Dept. of Information and Communication Engineering, Kyungsung University,
Korea
2
Pukyong National University, Korea
Magnetic treatment of surface vessels and submarines (Deperm) is a required to
camouflage them against magnetic detection from enemy marine force. So far, deperm
has been accomplished by applying an alternating magnetic field of which amplitudedecreases linearly. However, the reduction of the residual flux density in the directionof magnetic field is not linear in the case of the linear protocol, since the ferromagnetic
material used to construct a surface vessel, mainly Fe-C, shows a nonlinear behavior inan alternating magnetic field. This is one of main reasons to make an ordinary deperm
protocol inefficient. In this paper, we propose an energy base deperm protocol whichcalculated by an algebraic hysteresis model, and present how to optimize the deperm
protocol with the minor loops of magnetic hysteresis. We found out that step number
could be reduced in the energy base deperm protocol compare with in the linear
protocol, because the larger numbers of deperm steps are dedicated in the irreversible
domain process region on the magnetic hysteresis.

[1] Y. Sassa et al., PRB 83, 140511(R) (2011) [2] W. Bao et al., arXiv:1102.3674v1 (2011) [3] T. F. Schulze et al., PRL 100, 026407 (2008) [4]
M. Weller et al., PRL 102, 056401 (2009) [5] J. Sugiyama et al., PRL 103, 147601 (2009) [6] J. Sugiyama et al., PRB 82, 224412 (2010) [7] J.
Sugiyama et al., PRB 84, 054430 (2011) Funding Source: Swiss National Science Foundation (Project 6, NCCR MaNEP) and Toyota CRDL.

[1] K. Ishiyama, M. Sendoh, A. Yamazaki, and K. I. Arai, “Swimming Micro-machine driven by Magnetic Torque,” Sens.
Actuators A, Phys. 91, 141-4, 2001. [2]L. Zhang, J. J Abbott, L. Dong , K. E. Peyer, B. E. Kratochvil, H. Zhang, C. Bergeles.
and B. J. Nelson, “Characterizing the Swimming Properties of Artificial Bacterial Flagella,” Nano Letters 9, 3663-3667,
2009. [3]S. Hashi, M. Toyoda, M. Ohya, Y. Okazaki, S. Yabukami, K. Ishiyama, and K. I. Arai, “Magnetic motion capturesystem using LC resonant magnetic marker composed of Ni-Zn ferrite core,” J. Appl. Phys. 99, 08B312, 2006.

[1] V. A. Fedotov, M. Rose, S. L. Prosvirnin, N. Papasimakis, and N. I. Zheludev, “Sharp trapped-mode resonances inplanar metamaterials with a broken structural symmetry”, Phys. Rev. Lett. 99, 147401 (2007). [2] Boyoung Kang, E.
Choi, Hyun-Hee Lee, E.S. Kim, J. H. Woo, J. Kim, Tae Y. Hong, Jae H. Kim, and J.W. Wu, “Polarization angle control
of coherent coupling in metamaterial superlattice for closed mode excitation”, Opt. Express 18, 11552 (2010).

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Large resistive switching phenomenon induced by magnetic field in
nano conduction path formed in SiO2

AC magnetic field frequency dependence of drug release characteristics
for magnetic hyperthermia based polymer-drug encapsulate systemfor cancer treatment applications

Structural and magnetic properties of glassy like carbon synthesized
by pyrolysis of sucrose

Effect of a magnetic field on mixed convection of a nanofluid in asquare cavity

Shintaro Otsuka, Tomohiro Shimizu*, Takashi Kato, Takuya Kyomi and Shoso
Shingubara
Kansai University, Japan

A large magnetoresistance (MR) exceeded 800% was observed in a nano conduction
path (NCP) formed in SiO2 layer sandwiched between Co film and Si substrate.
Applied a high voltage of 20 MV / cm between the Co film and the backside of
Si substrate, the NCP was formed by dielectric breakdown of SiO2 layer. The
Magnetoresistance of the NCP in in-plane magnetic field for NCP was measured.
Using Ni layer instead of Co, the large MR also appeared, but could not be observedin the case of using non-magnetic materials. The structure of the device was similar to
the resistive switching memory device, regarding Co layer and Si substrate as top andbottom electrode. Therefore we also measured I-V characteristic of the NCP device,and the resistive switching effect was observed. We haven’t fully understood themechanism of this large MR switching phenomenon yet. However, it is speculated thatthe atomic scale NCP consisted of Co atoms was formed due to dielectric breakdownof SiO2, and the nano gap in NCP was formed by magnetic field.
Jpn. J. Appl. Phys., 50 (2011) 06GG15.

Tejabhiram Yadavalli1, Shivaraman Ramasamy1, Gopalakrishnan Chandrasekaran1
and Ramasamy R2
1
Nanotechnology Research Centre, SRM University, India
2
School of Pharmacy, SRM University, India
Ferromagnetic nickel, cobalt and gadolinium ferrite nanomaterials with Curie
temperature values in the range of 40-50°C have been synthesized by wet chemicalroutes. These nanoparticles were then coated with Poly n-isopropyl Acrylamide
thermo-sensitive polymer and doxorubicin drug forming a drug-polymer-nanoparticle
conjugate. The conjugate was then tested for the drug release characteristics invitro by the application of alternating magnetic field to it. The study was conducted
to understand the heating rate of the nanoparticles in the conjugate system and thequantitative drug release due to the heating of the nanoparticle. The quantitative study
was conducted using a homemade magnetic hyperthermia setup and High Precision
Liquid Chromatography (HPLC) with doxorubicin standards. The study was conductedin the range of 100 to 1000 kHz with 20 W power rating. The maximum heating
rate and the drug release rate per minute was seen at around 900 kHz which was inconcurrence with the theoretical calculations done using the hysteresis loop area of thematerial. These results will later be useful for testing on animal models to analyze invivo drug release characteristics of the conjugate.

Shivaraman Ramaswamy* and C Gopalakrishnan
Nanotechnology Research Center, SRM University, India

The structure and properties of glassy carbon (GC), a technologically important andwidely used material, is still not well established. The glassy carbon samples were
produced by a low-temperature pyrolysis of sucrose. The thermal destruction occurredin five stages to minimize carbon losses. At the first stage (175 °C, 3 h) a viscous melt
was obtained due to detachment of volatile components and water. After the second
and the third stages (300 °C, 1 h and 400 °C, 0.5 h, respectively) the material becomessolid. The next stage (525 °C, 1h) and the last stage (700 °C, 1 h) are performed tocomplete removal of all volatile impurities. The samples were then characterized using
AFM and SEM to determine its structure and morphology. The magnetic properties
were studied using vibrating sample magnetometer. It was found that the glassy carbon
sample has an inherent fullerene like morphology whose concentration increases
with increased heat treatment. Further, the samples also exhibited a distinct change inmagnetic properties based on the pyrolysis. Paramagnetic and diamagnetic properties
were found in the samples. The same has been explained based on the composition of
the samples and structural properties.
[1] A.A. Ovchinnikov and V.N. Spector, “Organic ferromagnets. New results,” Synth. Met., vol. 27,
pp. 615-624, Dec. 1988. [2] H. Ohldag, et al., “Electron Ferromagnetism in Metal-Free Carbon
Probed by Soft X-Ray Dichroism”, Phys. Rev. Lett., vol. 98, May 2007.

July 9 (Mon)

July 9 (Mon)The drastic change from an antiferromagnetic to a superconducting state in cuprates exemplifies how a slight change incarrier-density strongly governs magnetic and electronic properties. In cuprates the intermediate ion-layers are thought
to only serve as 'passive' charge-reservoirs. However, it has become increasingly clear that also ion-order within theselayers is of great importance [1]. Further, it was recently demonstrated that also ion-dynamics needs to be considered. In
the Na0.8CoO2 compound it was shown that the low-T magnetic properties could be connected to Na dynamics a muchhigher temperatures [3,4]. From the context of rechargeable Li-ion batteries for electrical cars, our group has recently
presented a novel experimental method [5] to investigate microscopic ion-dynamics in lithium-transition-metal-oxides(Li-TMO). By using the μSR technique we have obtained results regarding ion-dynamics in a wide range of Li-TMO's[6-7]. We will here give an overview of the method/results as well as discuss their importance for the development ofthin-film batteries for the future. Finally, we will also present our latest results regarding Na-dynamics in magneticallyfrustrated compound NaxCoO2. With the use of μSR, neutron quasi-elastic neutron scattering and diffraction, we show
how solid state dynamics is imperative for tuning this compound's magnetic/electronic/thermoelectric properties.

G. A. Sheikhzadeh1*, S. Mazrouei Sebdani1, M. Mahmoodi2, Elham Safaeizadeh3 andSayed Ebrahim Hashemi1
1
Mechanical Engineering Department, University of Kashan, Iran2
Mechanical Engineering Department, Amirkabir University of Technology, Iran3
Department of Mathematics, Payame Noor University, Najafabad, Isfahan, Iran
The problem of mixed convection in a differentially heated lid-driven square cavity
filled with Cu-water nanofluid under effect of a magnetic field is investigatednumerically. The left and right walls of the cavity are kept at temperatures of Th and
Tc respectively while the horizontal walls are adiabatic. The top wall of the cavity
moves in own plane from left to right. The effects of some pertinent parameters such as
Richardson number (ranging from 0.1 to 10), the volume fraction of the nanoparticles(ranging 0 to 0.1) and the Hartmann number (ranging from 0 to 100) on the fluid flow
and temperature fields and the rate of heat transfer in the cavity are investigated. It
must be noted that in all calculations the Prandtl number of water as the pure fluid is
kept at 6.8, while the Grashof number is considered fixed at 104. The obtained results
show that the rate of heat transfer increases with an increase of the Rayleigh number,while but it decreases with increase in the Hartmann number. Moreover it is foundthat by increase in volume fraction of the nanoparticles the rate of heat transfer can beenhanced or deteriorated compared to the based fluid.

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Size dependence simulation of saturated field in circular permalloy

Account of the image forces in the Bi1-xSbx-insulator film structures.

Simulation of energy dispersive mode for RITA-type cold neutron
triple axis spectrometer SIKA

Magnetohydrodynamic free convection in a square cavity heated frombelow and cooled from other walls

Xinghao Hu, Byunghwa Lim, Ilgyo Jeong and Cheolgi Kim*
Department of Materials Science and Engineering, Chungnam National University,
Korea
Manipulation of magnetic beads for biomoleculars and cells separation, purification andsensing application is of great fundamental and practical interest [1]. On-chip magnetsof soft magnetic structure of permalloy is a classic manipulation systems for magnetic
beads, which utilizes external magnetic fields for control of the magnetic beads [2].
The maximum of magntic force generated by on-chip magnet in an applied field should
be obtained for transportation of magnetic beads. We present a simulation method thatis available to enable a maximum value of magnetic force under an advisable field. As
shown in simulations, when the applied field is gradually increased to 130 Oe on the
on-chip magnet of 5 um radius, the magnetization of the on-chip magnet is saturated
that means a maximum value of magnetic force is obtained. Therefore, this simulation
method can assist researchers to obtain the advisable field for maximum of magntic
force in designing variform on-chip magnets.
[1] J. Dobson, Nat. Nanotech., 2008, 3, 139. [2] K. Gunnarsson, P. E. Roy, S. Felton, J. Pihl, P.
Svedlindh, S. Berner, H. Lidbaum, and S. Oscarsson, Adv.Mater., 2005, 17, 1730.

180

poster Presentation

The 19th International Conference on Magnetism

Konstantin Nicolaevich Kashirin
The Russian State Agrarian University-Moscow Timiryasev Agricultural Academy,
Kaluga Branch, Russia
Semiconducting alloy Bi1-xSbx (x=0,11) films of the different fixed thickness with a thin layerof insulating coating (SiO2) of variable thickness are investigated. The measuring of kinetic
parameters was conducted in a superconducting solenoid gap (with magnetic induction to 9 T) andon the different temperatures (4,2÷200 K). The calculations of magnetic resistance, of the carries
mobility and the Hall coefficient was done. The resistance oscillations is observed depending on
the thickness of insulating coating for all films. The kinetic parameters oscillations was observed
as function of coating thickness at different temperature and on magnetic field. So, the following
should be noted by the results of experimental investigations: - the resistance oscillations of all
investigated bismuth-antimony alloy films is observed depending on the thickness of dielectric
coating and the period of oscillations is amounts 80-100 A average; - the magnetic resistance andthe Hall coefficient oscillate with the variation of the dielectric coating thickness in antiphasewith the analogous oscillation resistance; - the sphere of negative magnetic resistance is observed.
One of the possible mechanisms accounting for the oscillations of the kinetic parameters ofsemiconducting films with insulator coating is taking into accounts the image forces.
Semiconducting alloy Bi1-xSbx (x=0,11) films of the different fixed thickness with a thin layer of insulating coating(SiO2) of variable thickness are investigated. The measuring of kinetic parameters was conducted in a superconducting
solenoid gap and on the different temperatures. The calculations of magnetic resistance, of the carries mobility and theHall coefficient was done. The assumptions that the one of the possible mechanisms accounting for the oscillations of the
kinetic parameters of semiconducting films with dielectric coating is taking into accounts the reflection forces were done.

Guochu Deng1*, Peter Vorderwisch2, Chun-ming Wu2, Garry Mcintyre1 and Wenhsien Li2
1
Bragg Institute, Australian Nuclear Science and Technology Organization, Australia
2
Department of Physics, National Central University, Jhongli 32054, Taiwan,
Australia
SIKA is a high flux cold-neutron triple axis spectrometer in Bragg Institute. Equipped with a multiblade analyser system (13 PG(002) blade) and position sensitive detector, SIKA possesses highflexibility to efficiently run in a traditional step-by-step mode or various mapping (or dispersive)modes by changing the configuration of analysers and detectors. In this study, the energy dispersivemodes, namely the so-called E1 mode [1] at two different energy transfers is simulated using Monte
Carlo ray-trace package SIMRES. [2] The simulated results show that SIKA could effectively workon E1 mode at low and intermediate energy transfer with reasonable energy and Q resolutions. Theenergy resolution is around 0.23meV at Ei=5meV while it increases to1.8meV at Ei=15meV. This
simulation shows SIKA has the potential in operation flexibility and data-acquisition efficiency, andprovides valuable references to the future inelastic neutron scattering experiments on SIKA.
[1] Lefmann K, McMorrow D F, Ronnow H M et al. 2000 Physica B 283 343 [2] ©aroun J and
Kulda J 1997 Physica B, 234-236 1102 [3] Shirane G, Shapiro Stephen M, and Tranquada John
M, 2002, Neutron scattering with a triple-axis spectrometer, (Cambridge University Press) p 123[4] Clausen K N et al. 1998 Physica B 241-243 50 [5] Demmel F, Grach N and Ronnow H M 2004
Nuclear Instruments & Methods in Physics Research Section A 530 404

Ali Akbar Abbasian Arani*, Mostafa Mahmoodi and Saeed Mazrouei Sebdani
Mechanical Engineering, University of Kashan, IranMagnetohydrodynamic free convection fluid flow and heat transfer in a square cavity
filled with an electric conductive fluid with Prandtl number of 0.7 has been investigatednumerically. The horizontal bottom wall of the cavity was kept at Th while the sideand top walls of the cavity were maintained at a constant temperature Tc with Th>Tc.
The governing equations were solved numerically while the SIMPLER algorithm wasused. A parametric study was performed, and the effects of the Rayleigh number andthe Hartman number on the fluid flow and heat transfer were investigated. The results
showed that temperature distribution and flow pattern depended on both strength of themagnetic field and Rayleigh number. For all cases two rotating eddies were formed.
Using the longitudinal magnetic field results in a force (Lorentz force) opposite to theflow direction that tends to decrease the flow velocity. The magnetic field decreased thefree convection and flow velocity. Also it was found that for higher Rayleigh numbersa relatively stronger magnetic field was needed to decrease the heat transfer. Moreoverfor low Rayleigh numbers, by increase in the Hartman number, free convection issuppressed and heat transfer occurs through conduction mainly.

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poster Presentation

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PO32

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QA06

Interaction of a magnetic field and buoyancy force in a square cavity
filled with a fluid with low Prandtl number

Near-electrode effcets of magnetic fields in electrochemistry

Theoretical study of tuning polarization and magnetism of BiCoO3

Effects of bismuth substitution on the magnetic properties of BixCo2xMnO4

G. A. Sheikhzadeh1*, S. E. Hashemi1, S. Mazrouei Sebdani1, M. Mahmoodi2 andElham Safaeizadeh3
1
Mechanical Engineering Department, University of Kashan, Iran2
Mechanical Engineering Department, Amirkabir University of Technology, Tehran,
Iran
3
Department of Mathematics, Payame Noor University, Najafabad, Isfahan, IranIn this paper, influences of Lorentz force due to a magnetic field on buoyancy
driven heat transfer in a square cavity containing a fluid with low Prandtl number isinvestigated numerically. The left and right walls of the cavity are kept at temperaturesof Tc and Th respectively, while the horizontal walls are kept adiabatic. Effect ofexistence of an adiabatic body in the middle of the cavity is considered too.The
dimensionless governing equations associated with the boundary conditions are solved
numerically using the finite volume method. Streamlines and isotherms are shown
for Grashof number (ranging from 105 to 107), Hartman number (ranging from 0 to100) and Prandtl number (ranging from 0.005 to 0.1). The results show that variationsof magnetic field donot have noticeable effect on buoyancy force, while increasein magnetic field increases Lorentz force. Moreover buoyancy and Lorentz forces
increase by increase in Grashof number in a constant Hartman and Prandtl numbers.

Michael Coey and Peter Dunne
Physics, Trinity College dublin, IrelandYu-jun Zhao and Xing-yuan Chen
Department of Physics, South China University of Technology, China

Maria Elenice Dos Santos1, Paulo Noronha Lisboa-filho2 and Octavio Pena1
Institut des Sciences Chimiques de Rennes, Universite de Rennes 1, France
2
Laboratorio de Materiais Eletronicos, Universidade Estadual Paulista, Brazil
1

Remarkable influences of magnetic fields have been discovered on the diffusion layer
and on the electrochemical double layer. The former are mainly due to magnetic
pressure, which allows the patterning of deposits from both paramagnetic anddiamagentic ions (using a nonelectroactive paramagnetic species such as Dy3+).
The effects of small cylindrical [1] and linear magnet arrays are demonstrated. The
magnetic patterning is estimated to be effective down to about the 100 micron scale.
The essential requirement for patterning of this type are orthogonal concentration
gradients and magnetic field gradients. More surprising is the evidence we have foundfor an influence of a static magnetic field on the electrochemical double layer, a poorly
understood region about 1 nm thick at the cathode. Using a nitrobenzene model redox
system, we show that the double layer capacitance can be modified by a factor of two
at an appropriate potential. The influence of Maxwell stress on the free radicals insolution is discussed as a possible explanation. More remarkable are

WN
A
R

D

TH
I
W

[1] P. Dunne, L. Mazza and J. M. D. Coey, Phys Rev Letters 107 042501 (2011)

Coexistence of magnetism and ferroelectricity, along with coupling between them, ensures manytechnological applications of materials named multiferroics. Transition metal and/or rare earthoxides with ABO3 perovskite and AB2O4 spinel structures are good candidates due to the substitutionof magnetic and non-magnetic ions at the A and/or B sites [1]. Bi-substituted BixCo2-xMnO4
multiferroic samples, well-characterized structurally by XRD and Rietveld refinement together withSEM-EDX techniques, were synthesized by a polymeric precursors method. A gradual expansionof the lattice parameter due to the substitution of Co3+ by Bi3+ is observed for x = 0.1, 0.2 and 0.3.
Magnetic characterization was carried out by SQUID measurements. The inverse susceptibility
exhibited ferrimagnetic behaviour, as also proved by the strong antiferromagnetic and ferromagnetic
interactions shown by the ZFC and FC curves. The M(H) loops performed at various temperatures
below TC showed larger loop areas when decreasing the temperature, indicating an increasing
ferromagnetism. The inclusion of Bi in Co2MnO4 creates fluctuating valence states of both Co
and Mn ions (Co2+/Co3+, Mn2+/Mn3+/Mn4+) which occupy the tetrahedral and octahedral sites [2].
Magnetization measurements showed that TC and MS increase with increasing Bi3+ concentration
due to the redistribution of the magnetic cations, in particular the Mn3+and Mn4+ ones.

PO30

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QA04

QA07

Numerical study of magnetic field effects on flow field and heattransfer in a cavity filled with porous materials

Resonant magnetic x-ray scattering: Beamline P09 at PETRA III at
DESY

S o f t x - r a y s y n c h ro t ro n r a d i a t i o n s p e c t ro s c o p y s t u d y o f
Co0.6Fe0.9Mn1.5O4 spinel with nano-checkerboard patterns

Cross-correlation effects in multiferroic Cu3Mo2O9

Natural convection flows in a square cavity filled with a fluid-saturated porous medium
under the effect of magnetic field has been studied numerically. A square hot bodywith length W is placed in the center of the cavity (with length L). The ratio of W/L isassumed to be 0.5. Continuity, momentum and energy equations are solved using thefinite volume technique under the boundary conditions. The two vertical sides of thecavity are cooled and two horizontal bottom and top walls are adiabatic. The Prandtl
number is 0.71, the Rayleigh number changes from 104 to 106, the Darcy number
varies from 10-5 to 10-3 and the Hartmann number alters from 0 to 100. Numericalresults are presented in terms of stream functions, temperature profiles. The results
say increasing the braking effect of magnetic field as increasing the Hartman number;lead to decreases the heat transfer. Also at low Darcy number, fluid circulation is weak
due to high hydraulic resistance offered by porous medium for Darcy number down
to 10-5. Average Nusselt number increases with enhancement of Rayleigh number anddecreasing the Hartmann number.

Resonant and non-resonant magnetic scattering are complementary tools to magnetic
neutron diffraction for the investigation of magnetic properties in solids. Resonant
magnetic x-ray scattering opens the possibility to investigate magnetic order in single
crystals and layered systems element selectively. Also the interference of magnetic
order with orbital or charge order can be determined through the polarization propertiesof the x-ray and the special form of the scattering cross sections, describing thevariation of the polarization states through the scattering process. The new beamline
for Resonant Scattering and Diffraction (RSD), P09 at PETRA III, is designed
especially to address the above mentioned issues. Low temperature cryostats and highmagnetic fields of up to 14T allow the investigation of magnetic properties of materials
as function of polarization, temperature and field. Two diffractometers are available toconduct experiments using the highly brilliant synchrotron beam available at PETRA
III. The polarization of the incident x-ray beam can be varied arbitrarily through x-ray
phase-plates and the polarization of the scattered beam is analyzed by a polarization
analyzer. Examples for the performance of the beamline and experimental results onmagnetic scattering from multiferroic systems will be presented.

G. A. Sheikhzadeh*, M. Aliakbari Miyan Mahaleh, A. A. Abbasian Arani and S.
Mazrouei Sebdani
Mechanical Engineering Department, University of Kashan, IranJoerg Strempfer, Sonia Francoual, Dinesh K. Shukla and Arvid Skaugen
DESY, Germany

D.h. Kim1, Jihoon Hwang1, Eunsook Lee1, S.-w. Cheong2, B.-g. Park3, J.-y. Kim3
and J.-s. Kang1*
1
Department of Physics, The Catholic University of Korea, Korea
2
Department of Physics and Astronomy, Rutgers University, USA
3
Pohang Accelerator Laboratory, POSTECH, Korea
In the AB2O4-type spinels, transition-metal ions occupy either the tetrahedral (Td) A
site or the octahedral (Oh) B site. Recently, nano-checkerboard (CB) patterns havebeen observed in ZnMnGaO4, MgMn1.5Fe0.5O4, and Co0.6Fe0.9Mn1.5O4 [1]. When
properly annealed, these spinels show two different structures with different chemicalphases, where one is cubic and the other is tetragonal or orthorhombic. This structuraland chemical phase separation has been explained by the Jahn-Teller (JT) distortion. To
confirm this idea, it is important to determine the valence states of the transition-metal
ions that constitute these spinel oxides. In this work, we have studied the electronic
structure of checkerboard Co0.6Fe0.9Mn1.5O4 single crystal by employing soft x-ray
absorption spectroscopy (XAS) and soft x-ray magnetic circular dichroism (XMCD).
The measured T 2p XAS spectra (T=Co, Fe, Mn) of Co0.6Fe0.9Mn1.5O4 reveal that thevalence states of Co, Fe, and Mn ions are nearly divalent (Co2+), trivalent (Fe3+), andmixed-valent (Mn2+-Mn3+), respectively. Very weak XMCD signals are observed incheckerboard Co0.6Fe0.9Mn1.5O4. *Corresponding Author : kangjs@catholic.ac.kr

July 10 (Tue)July 10 (Tue)[1] P. Barahona, et. al. J. Chil. Chem. Soc. 50. N 2 (2005) 495. [2] N. E. Rajeevan, et. al. Mater. Sci.
Eng. B 163(2009) 48.

Ryusuke Itoh1*, Tomohiro Hosaka1, Takuya Hasegawa1, Haruhiko Kuroe1, Tomoyuki
Sekine1, Masashi Hase2, Kunihiko Oka3, Toshimitsu Ito3 and Hiroshi Eisaki3
1
Sophia University, Japan
2
National Institute for Materials Science (NIMS), Japan
3
National Institute of Advanced Industrial Science and Technology (AIST), Japan
We present the cross correlation effects in a multiferroic material Cu3Mo2O9. This
material contains spin tetrahedra made from the Cu2+ ions which form a edge
sharing spin chain. The quasi-one dimensional magnon dispersion curve, theferroelectric properties caused by the geometrical magnetic frustration, and a strong
magnetocapacitance effect have been reported [H. Kuroe et al., Phys. Rev. B 83
(2011) 184423, H. Kuroe et al., J. Phys. Soc. Jpn. 80 (2011) 083705]. In this study, we
focus on the change of the longitudinal magnetization under the electric field. Usinga SQUID magnetometor which has two electric leads, we measured the longitudicalmagnetization Ma along the a axis and the electric polarization Pc along the c axis ofa plate-like single crystal of Cu3Mo2O9 simultaneously. We measured the longitudinalmagnetization along the a axis (Ma-Ha loop) under the static electric field Ec along thec axis, and the Ma-Ec loop under the static Ha. The details of our results including thechange of the Ma-Ha loop under the static electric field and butterfly-loop in the Ma-Ec
loop will be presented in this study.

[1] C.L. Zhang, et al., Appl. Phys. Lett. 91, 233110 (2007).

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QA08

Numerical simulation of magnetohydrodynamic Benard convection ina shallow enclosure

Magnetic and dielectric properties of FeTiO3

Zn-substitution effects in multiferroic Cu3Mo2O9

Nonlinear current-voltage characteristics of (La0.5Eu0.5)0.7Pb0.3MnO3Single crystals: Possible manifestation of the internal heating of charge
carriers

G. A. Sheikhzadeh*, M. Mahmoodi and S. Mazrouei Sebdani
Mechanical Engineering Department, University of Kashan, IranIn this paper the problem of magnetohydrodynamic Benard convection in a shallow
rectangular enclosure with aspect ratio of 10 (width to height ratio) has been
investigated numerically. The enclosure is filled with an electric conductive fluid with
Prandtl number of 1. The bottom and the top walls of the cavity are maintained at aconstant temperature Th and Tc respectively, with Th > Tc, while; the side walls of thecavity are kept insulated. The governing equations written in terms of the primitive
variables are solved numerically using the finite volume method and the SIMPLER
algorithm is employed to couple velocity and pressure fields. Using the developed
code, a parametric study is performed, and the effects of the Rayleigh number andthe Hartman number on the fluid flow and heat transfer inside the enclosure areinvestigated. The results show that temperature distribution and flow pattern inside
the enclosure depend on both the strength of the magnetic field and Rayleigh number.
Moreover it was found that at low Rayleigh number with increase in Hartman number
the flow intensity decreases and fluid becomes stagnant. At high Rayleigh numbers
number of the Benard cell decreases by increase in Hartman number.

182

The 19th International Conference on Magnetism

Takayasu Kiyokawa1*, Shigeki Yamada1 and Takatsugu Masuda2
1
Nanosystem Science, Yokohama City University, Japan
2
Institute for Solid State Physics, University of Tokyo, JapanThe magnetic and dielectric properties of single crystal iron ilmenite FeTiO3 have been
investigated. The temperature dependence of the magnetization for H parallel to the caxis (M//c) has a sharp peak at 58 K (TN) and abruptly decreases below TN, while themagnetization for H perpendicular to the c axis (M┴c) is almost independent of thetemperature. These features indicate that the ground state is Neel state with the easy
axis in the c direction. Above TN the value of M//c is larger than that of M┴c due to themagnetic anisotropy. These results are consistent with previous report by Kato et al..
The temperature dependence of the dielectric constant for E parallel to the c axis also
shows a kink at TN. Furthremore the dielectric polarization for E parallel to the c axis
abruptly increases at TN. Hence this kink is ascribed to ferroelectric phase transition.
These results indicate that FeTiO3 is a strong candidate for a new type of multiferroic
materials.

Haruhiko Kuroe 1*, Kento Aoki 1, Ryusuke Itoh 1, Tomohiro Hosaka 1, Takuya
Hasegawa1, Suguru Hachiuma1, Mitsuru Akaki1, Hideki Kuwahara1, Tomoyuki
Sekine1, Masashi Hase2, Kunihiko Oka3, Toshimitsu Ito3 and Hiroshi Eisaki3
1 Department of Physics, Sophia University, Japan
2 National Institute for Material Science (NIMS), Japan
3 National Institute of Advanced Industrial Science and Technology (AIST), Japan
We present the Zn substitution effects on the quasi-one dimensional frustrating spin
system Cu3Mo2O9. This material has S = 1/2 distorted tetrahedral spin chains andundergoes the multiferroic phase below 7.9 K without magnetic field [T. Hamasaki
et al., Phys. Rev. B 77 (2008) 134419, H. Kuroe et al., J. Phys. Soc. Jpn. 80 (2011)083705]. The S = 0 Zn2+ ions substitute for the S = 1/2 Cu2+ ions at the three
crystallographically different sites, namely Cu1, Cu2, and Cu3. The spins at the Cu2 andCu3 sites form nearly spin-singlet spin dimers at the bisectors of the nearest neighborCu1 sites in the quasi-one dimensional spin chain [H. Kuroe et al., J. Phys.: Conf. Ser.
200 (2010) 022028, H. Kuroe et al., Phys. Rev. B 83 (2011) 184423]. In this study,
we focus on the magnetic, electric, and thermodynamical properties of the single
crystal of (Cu,Zn)3Mo2O9. Comparing our previous results in polycrystalline samples[M. Hase et al., J. Phys. Soc. Jpn. 77 (2008) 034706], we discuss the reduction of theantiferromagnetic correlation and the singlet-pair breaking effect on the Cu2-Cu3 spin
dimers. The dielectric constant and the specific heat in (Cu,Zn)3Mo2O9 will also be
discussed in this study.

Kirill Shaykhutdinov*
Kirensky Institute of Physics, Russia

Current--voltage characteristics of the polycrystalline substituted lanthanum manganite
La0.7Ca0.3MnO3 were experimentally studied at Т = 77.4 K in magnetic fields up to 13
kOe. In these characteristics, a portion of negative differential resistivity was observed
above a certain threshold value of critical current density j caused, in our opinion,
by nonequilibrium heating of the electron gas due to low thermal conductivity of themanganite material. Because of the nonlinearity of the current--voltage characteristics,
the field dependences of resistivity ρ(H) appear extremely sensitive to the value of atransport current. In this case, the ρ(H) dependences reveal both ordinary negative andpositive magnetoresistance.

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QA12

QA15

High field phase diagram in multiferroic Cu3Mo2O9

Study of magnetic and magnetodielectric properties of perovskite
YbCrO3Controlling the superparamagnetic limit using the magnetoelectriceffectJuly 10 (Tue)We present the multiferroic behavior in the quasi-one dimensional antiferromagnet Cu3Mo2O9.
This material has spin chains of the distorted spin tetrahedra made from S = 1/2 Cu2+ ions.
In ICM2009, we have presented that the magnon dispersion relation in Cu3Mo2O9, which iswell explained by the hybridization effects between a magnon excitation from the quasi-one
dimensional spin system and that from the isolated spin dimers [H. Kuroe et al., J. Phys.: Conf.
Ser. 200 (2010) 022028, H. Kuroe et al., Phys. Rev. B 83 (2011) 184423]. Recently, we foundthat this material shows a multiferroic behavior [H. Kuroe et al., J. Phys. Soc. Jpn. 80 (2011)083705]. We proposed that the origin of the multiferroic behaviors in Cu3Mo2O9 is the charge
redistribution effect in a frustrated Mott insulator studied by Bulaevskii et al.[L. N. Bulaevskii
et al., PRB 78 (2008) 024402.], which is presented by Khomskii as an invited talk in ICM2009[D. I. Khomskii, J. Phys.: Condens. Matter 22 (2010) 164209]. In this study, we present
the magnetic-field-temperature phase diagram up to 55 T obtained from the temperatureand magnetic-field dependences of the magnetization, the dielectric constants, the electric
polarization, the pyroelectric current, and the specific heat.

Jong-suck Jung, Ayato Iyama*, Hiroyuki Nakamura, Yusuke Wakabayashi andTsuyoshi Kimura
Division of Materials Physics, Osaka University, Japan

Perovskite YbCrO3 shows the G-type antiferromagnetic ground state for Cr3+ moments(TN ~ 118 K). Because of the Dzyaloshinskii-Moriya interaction, the G-type structure
becomes canted, and then YbCrO3 exhibits weak ferromagnetism. When weakmagnetic fields are applied (B ≤ 0.3 T), temperature-induced magnetization reversal isobserved. The magnetization reversal is probably associated with a keen competition
between antiferromagnetically coupled Cr3+ - Yb3+ moments. Recently, a distinct
magnetodielectric effect was observed in another perovskite SmMnO3 which also
shows temperature-induced magnetization reversal due to the competition between
antiferromagnetically coupled Mn3+ - Sm3+ moments [1]. Thus, it is intriguing to study
magnetodielectric properties of YbCrO3. In this study, we investigated magnetic andmagnetodielectric properties for single crystals of YbCrO3 grown by the flux method.
The comparison of magnetodielectric properties between YbCrO3 and SmMnO3
provides useful information to understand the distinct magnetodielectric effectobserved in SmMnO3.
[1] J.-S. Jung et al. Phys. Rev. B 82, 212403 (2010)

Hyungsuk K. D. Kim1, Laura Schelhas2, Sarah Tolbert2 and Gregory P. Carman3*
1
Department of Materials Science and Engineering, UCLA, USA
2
Department of Chemistry and Biochemistry, UCLA, USA
3
Department of Mechanical and Aerospace Engineering, UCLA, USA

MRAM (Magnetic Random Access Memory) is attracting considerable attention as a possible candidate
for next generation of non-volatile memory devices. Major challenges facing scientists today are
overcoming thermal instability and reducing the writing energy. As bit density increases, this requires
smaller magnetic regions to be written magnetically at small scales and external energies become
a dominant feature. For example in the small scale, thermal energy becomes larger than magnetic
anisotropy, resulting in superparamagnetic behavior. For a given small scale size, the temperature
above which superparamagnetism begins is referred to as the blocking temperature. Superparamagnetic
behavior is undesirable due to limits it places on the size of a bit of information. Recently, researchers
have begun to study magnetoelectric (ME) memory related to some issues with memory. Their focus
has been on writing processes using electric field-induced strain rather than addressing the morechallenging topic of controlling superparamagnetism. Here we report experimental results showing the
introduction of a magnetoelectric anisotropy energy to alter the blocking temperature and thus control thesuperparamagnetic behavior. This is achieved via an electric field-induced strain in a ME composite. Our
results show 50 K increase of the blocking temperature with the application of an electric field.

QA18
Impedance spectroscopy of ferromagnetic oxide: Pr0.6Sr0.4MnO3

D V Maheswar Repaka1 and Mahendiran Ramanathan2
1
PHYSICS, National University of Singapore, Singapore
2
Physics, National University of Singapore, Singapore

In recent years, coupling between electrical and magnetic polarizations in multiferroicmagnetoelectrics have become a topic of considerable interest due to novel applications andfundamental physics involved [1]. Impedance spectroscopy has been extensively used toinvestigate cross coupling between magnetic and electrical dipole ordering. Anomalies in lowfrequency (f = 1-10 kHz) dielectric constant at magnetic transition have been reported in YMnO3[2], BiMnO3 [3] etc. However, measurement in MHz range has been hardly reported. In this work,
we report temperature, frequency and magnetic field dependence of impedance in Pr0.6Sr0.4MnO3
which shows ferromagnetic transition near room temperature (TC= 303 K). It is found that withincreasing frequency of the ac current, an anomaly in the form of a sharp peak appears at theCurie temperature. A second anomaly in the form of an abrupt decrease occurs at T= 100 K much
below the Curie temperature. These anomalies are suppressed under external magnetic field. It issuggested that the observed anomalies are not necessarily caused by ordering of electrical dipoles.
The observed features in impedance closely correlate with the magnetization. We suggest that
impedance spectroscopy in these materials can probe magnetization dynamics, which is often
neglected in studies of magnetocapacitance effect in multiferroic materials.

1. Y. Jun, J. Seo, J. Cheon, Accounts of chemical research 41, 179 (2008). 2. F. Zavaliche et al., Nano letters 7, 1586 (2007).
3. T. Wu et al., Applied Physics Letters 98, 012504 (2011). 4. M. Bibes, A. Barthelemy, Nature Materials 7, 425 (2008).

[1] S.W. Cheong and M. Mostovoy, Nat.Mater. 6 (2007) 13. [2] S. Lee, A. Pirogov, M. Kang, K.H.
Jang, M. Yonemura, T. Kamiyama, S.W. Cheong, F. Gozzo, N. Shin, H. Kimura, Y. Noda, and J.G. Park,
Nature (London) 451, (2008) 451. [3] R. Seshadri and N. A. Hill, Chem.Mater. 13, (2001) 2892.

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QA19

Magnetoelectric effect in Ca2FeAlO5

Interplay among spin, orbital, and lattice degrees of freedom in afrustrated spinel Mn3O4

Magneto-Capacitance Effect and Electric Polarization in Spinel
Co2MnO4

Structures and magnetic properties of Tm1-yYyMn1-xCoxO3

Nobuyuki Abe1*, Khanh Duy Nguyen2, Yoichi Nii2, Yutaro Kitagawa3 and Taka-hisa
Arima1
1
Department of Advanced Materials Science, The University of Tokyo, Japan2
Department of Physics, Tohoku University, Japan3
Department of Applied Physics, The University of Tokyo, Japan

Yoichi Nii1*, Hiroshi Umetsu1, Hajime Sagayama2, Nobuyuki Abe2, Kouji Taniguchi2
and Taka-hisa Arima2
1
Dept. of Phys., Tohoku University, Japan
2
Dept. of Advanced Mater. Sci., The University of Tokyo, Japan

Ca2FeAlO5 has the same crystal structure as mineral Brownmillerite. The oxygen deficientperovskite type structure is constructed by the alternate stacking of (Fe,Al)O6 octahedra and(Fe,Al)O4 tetrahedra. An early structure analysis showed that Ca2FeAlO5 belongs to a noncentrosymmetric space group Ibm2 [1], which originats from the in-phase stacking of (Fe,Al)O4 tetrahedra. This compound shows antiferromagnetic order below 350 K. Mossbauer
spectroscopy measurements conclude that the magnetic moments of Fe3+ align along thea-axis[2]. Because the crystal structure lacks the inversion symmetry, Ca2FeAlO5 is acandidate material which has a magnetoelectric coupling. Here we show the measurementsof magnetoelectric effect in single crystalline Ca2FeAlO5. The field dependence of themagnetization along the a-axis shows a metamagnetic transition caused by the spin flop of
Fe3+ moments. Moreover, the dielectric constant and electric polarization show an anomaly
at around the phase transition. These results indicate that Ca2FeAlO5 shows magnetoelectriceffect in a magnetic field induced spin flop phase, which is one example of a new route torealize a magnetoelectric coupling above the room temperature.

Spinel oxides, AB2O4, are one of the typical systems for studying the effects of geometricalfrustration and the possible coupling among spin, orbital and lattice degrees of freedom. Mn3O4
exhibits the cooperative Jahn-Teller (JT) transition from cubic to tetragonal structure at 1443 K withthe 3z2-r2 ferro-orbital order at B-site Mn3+. The gigantic JT distortion (~16 %) would encourage
the formation of one-dimensional (1D) antiferromagnetic spin chains at B-site Mn3+ normal to thec-axis. A macroscopic degeneracy of the arrangements of 1D-spin-chains still remains, even if one
considers the magnetic interaction between the nearest neighbor 1D-chains. It was reported that
Mn3O4 exhibits successive magnetic phase transitions from paramagnetic to Yafet-Kittel (43 K),
incommensurate (IC) (40 K) and commensurate (C) phase (34 K)[1], which is an indicative of thesurviving magnetic frustration. Another phase transition is induced by applying magnetic field in the
low-temperature C phase [2]. In order to elucidate the magnetic-field induced phase transition, we
have measured synchrotron x-ray diffraction and neutron scattering in a magnetic field along [100]c. We propose a scenario of the magnetic-field induced phase transition, where the rearrangement of
1D-spin-chains is triggered by orbital hybridization at B-site Mn3+ through the spin-orbit coupling.

[1] A. A. Colville and S. Geller, Acta Cryst, B27, 2311(1971) [2] R. W. Grant et.al. , J. Appl. Phys.
39, 1122 (1968)[1] R. Tackett et al., Phys. Rev. B 76, 024409 (2007). [2] T. Suzuki et al., Phys. Rev. B 77, 220402(R) (2008)

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Electronic and magnetic phase separation in the semimetallic
ferromagnet EuB6

Structural and dielectric study of hexagonal Y0.8Sr0.2MnO3 Compound

Magnetically induced polarization in copper metaborate CuB2O4

Pintu Das1, Adham Amyan1, Jens Brandenburg1, Jens Mueller1*, Peng Xiong2,
Stephan Von Molnar2 and Zachary Fisk3
1
Institute of Physics, Goethe University Frankfurt, Germany
2
Dept. of Physics, Florida State University, Tallahassee, USA
3
Dept. of Physics, University of California, Irvine, USA

EuB6 is a low-carrier semimetal, which undergoes a unique paramagnetic to ferromagnetictransition displaying two consecutive features at Tc1= 15.5 K and Tc2 = 12.6 K in electricaltransport, magnetization and specific heat. Its structural and electronic simplicity makes EuB6
an ideal model system for studying the effect the magnetic state of a system has on its electronictransport properties. In particular, the fundamentals of intrinsic electronic and magnetic phaseseparation can be studied, which play a critical role for the colossal magnetoresistance (CMR)in magnetic semiconductors and manganites. In explaining CMR in EuB6, being largest at
Tc1, the concept of magnetic polaron (MP) percolation has been invoked. We report resistancenoise and weakly nonlinear transport measurements, being sensitive to the microgeometry of
the electronic system. We find direct evidence for electronic phase separation when coolingthrough Tc1 and a diverging noise level at Tc2, which we interpret as magnetically-driven
percolation resulting from the overlap of spatial inhomogeneities in conductivity producedby MP. Interestingly, MP percolation can be induced also by applying magnetic fields in theparamagnetic region. We find that the density of MP can be described by a universal scaling
function, being related to a single critical magnetization.

The 19th International Conference on Magnetism

Sun Hee Kang1, San Youn Park2, Ill Won Kim1, Yoon Hee Jeong3 and Tae Yeong
Koo4*
1
Physics Department, Ulsan University, Korea
2
Physics Department, Pohang Univsersity of Science and Technology, Korea
3
Physics Department, Pohang University of Science and Technology, Korea
4
Pohang Accelerator Laboratory, Korea
Structural phase diagram of spinel Co3-xMnxO4 (1.0 ≤ x≤ 2.0) was reexamined at theroom temperature with a focus on the cubic-tetragonal phase boundary. A specificcomposition of Co2MnO4 (x=1.0) was selected from the phase diagram study under
the requirement of both high ferrimagnetic transition temperature (Tc) and non-mixed
structural phase condition. Experimental result of magnetization measurements andlocal distortions due to the Jahn-Teller Mn3+ ions support the stabilization of YafetKittel type magnetic configuration in the cubic inverse spinel Co2MnO4. Correlation
between the observed forced magnetization - a continual increment of magnetization
above the saturation field - and magneto-capacitance effect (MCE) was clarified. MCEof up to 7 % at 8 T around Tc was observed without an appreciable hysteresis andnonlinearity in the field variation. Diffraction-spectroscopy techniques were also used
to identify the local chemical and structural environments of both Co and Mn ions at
two crystallographic sites of the spinel structure.

Rajesh K. Thakur1*, Rasna Thakur2, A. Bharathi3 and N.k. Gaur2
1
Department of Physics, Barkatullah University, Bhopal, India
2
Department of Physics, Barkatullah University, Bhopal, India
3
Condensed Matter Physics Division, Materials Science Group, Indira Gandhi Centre
for Atomic Research, Kalpakkam, India

Khanh Duy Nguyen1, Nobuyuki Abe2, Masashi Tokunaga3, Mitsuru Saito1 and Takahisa Arima2*
1
Deparment of Physics, Tohoku University, Japan2
Department of Advanced Materials Science, The University of Tokyo, Japan
3
Institute for Solid State Physics, The University of Tokyo, Japan

Strontium doped YMnO3 compound have been prepared in single-phase form byusing high temperature solid sate reaction method. The structural and dielectric
properties of the prepared sample have been carried out in the wide range oftemperature and frequency. Temperature and frequency variations of dielectric
permittivity measurements show that the present hole doped YMnO3 compound
exhibits a competing interaction in between the ferromagnetic double - exchange
and antiferromagnetic super-exchange interactions, further a weak signature offerromagnetic ordering at lower temperature has been witnessed. Our resistivity
measurement reveals that the material is highly insulating at lower temperature justbelow the reported AFM transition in this class of materials.

Intriguing electro-magneto optic effect of non-centrosymmetric magnet copper metaborate has
attracted huge consideration during last time [1]. In here we report the magneto-electric behavior of
CuB2O4 under external magnetic field. It is well known that CuB2O4 undergoes a phase transition
from paramagnetic state to canted-antiferromagnet at 21 K, then followed by a second transition
to spiral order around 10 K. Although the magnetic structure at low temperature below 10 K has
not completely been made clear yet, some evidences of incommensurate helical order in thisrange of temperature have been observed [2]. Result of magnetization measurement points out
the existence of an anomaly around 1, 3 T at 2 K, then disappeared when increasing temperature
above 10 K, which may be attributed to the transition from commensurate to incommensurate
phase. Furthermore, electric polarization was also observed by applying a magnetic field along the[110] and [1-10] axes without poling electric field in low temperature regime. The magnitude ofpolarization in static field was found to be compatible with the measurement in pulse magnetic field.
Besides novel optical characteristic, these results show the ability of generation and control electric
polarization by magnetic field in CuB2O4 as well as application to opto-electronic devices.
[1] M. Saito, K. Ishikawa, S. Konno, K. Taniguchi and T. Arima, Nature Mater. 8, 634 (2009) [2] M.Boehm, B. Roessli, J.
Schefer, A. S. Wills, B. Ouladdiaf, E. Lelievre-Berna, U. Staub and G. A. Petrakovskii, Phys. Rev. B 68, 024405 (2003)

July 10 (Tue)QA09Haruhiko Kuroe1*, Ryo Kino1, Ryusuke Itoh1, Tomohiro Hosaka1, Takuya Hasegawa1,
Tomoyuki Sekine1, Takumi Kihara2, Masashi Tokunaga2, Masashi Hase3, Kanji
Takehana3, Hideaki Kitazawa3, Kunihiko Oka4, Toshimitsu Ito4 and Hiroshi Eisaki4
1
Department of Physics, Sophia University, Japan
2
The Institute for Solid State Physics, The University of Tokyo, Japan
3
National Institute for Materials Science (NIMS), Japan
4
National Institute of Advanced Industrial Science and Technology (AIST), Japan

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poster Presentation

Toshiyuki Tanaka, Yusuke Amakai, Naoki Momono, Shigeyuki Murayama and
Hideaki Takano*Department of Applied Sciences, Muroran Institute of Technology, JapanThe structure and magnetic properties of Tm1-yYyMn1-xCoxO3 with 0≤x≤0.5 and0≤y≤0.3 were investigated by X-ray diffraction, specific heat and magnetization
measurements. A thulium manganite TmMnO3 prepared by the solid state synthesis
method in ambient pressure is hexagonal and antiferromagnetic with Neel temperature
TN=86 K. The substitution of Y for Tm in TmMnO3 does not largely affect thefundamental hexagonal structure. We can roughly understand the results of themagnetization and the specific heat of Tm1-yYyMnO3 in terms of a dilution effect of
Tm by Y. On the other hand, the structure of TmMn1-xCoxO3 gradually changes fromhexagonal to orthorhombic with the substitution of Co for Mn and hexagonal andorthorhombic phases coexist in samples for x≤0.3, and TmMn0.6Co0.4O3 become almost
orthorhombic single phase. The magnetization of TmMn0.6Co0.4O3 in a field of 250
Oe increases rapidly below about 60 K with decreasing temperature. The discrepancyof the zero-field-cooled (ZFC) and the field-cooled (FC) magnetization remarkablely
expands below about 60 K. Moreover, temperature dependence of ZFC and FC
magnetization show peaks at 40 K and 27 K, respectively. TmMn1-xCoxO3 we obtainedshows complicated magnetic properties.

QA20
Complex magnetic and electric orders in multiferroic Co3TeO6

Chin-wei Wang1, Chih-jen Wang1, Wen-hsien Li1*, Chih-chieh Chou2, Hung-duen Yang2, Yang
Zhao3, Sung Chang3, Jeffrey W. Lynn3 and Helmuth Berger4
1 Department of Physics and Center for Neutron Beam Applications, National Central University, Taiwan
2 Department of Physics and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen
University, Taiwan
3 NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, USA
4 Institute of Physics of Complex Matter, EPFL, Lausanne, Switzerland

Multiferroics, where both ferroelectric and magnetic order coexist, are quite uncommon, but
are of particular interest both to understand the fundamental interactions between the two
types of order as well as for the potential for practical applications. The novel metal tellurates
M3TeO6, where M is a first-row transition metal, have been shown to be rich in crystalline
chemistry. Ferroelectricity and magnetic-field-driven polarization have been observed. Here, wereport on the results of neutron diffraction, magnetic susceptibility, specific heat, and dielectric
constant measurements made on a single crystal Co3TeO6 to study the interplay between
the ferroelectricity and magnetic order. A strong interplay between the order parameters offerroelectricity and both commensurate and incommensurate magnetic order are observed. Long
range incommensurate magnetic order develops below TM1=26 K, which is followed by three
additional zero-field phase transitions at TM2=19.5 K, TM3=18 K, and TM4=16 K where theincommensurate order changes and commensurate order develops. In magnetic fields up to 14 T
we find that the magnetic intensities and incommensurate wave vector are dramatically alteredas ferroelectricity develops, with a fifth abrupt transition around 10 T. The overall behavior
characterizes Co3TeO6 as a type-II multiferroic.

July 8-13, 2012 Busan, Korea

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poster Presentation

poster Presentation

QA21

QA24

QA27

QB03

Annealing induced colossal magnetocapacitance and colossal
magnetoresistance in in-doped CdCr2S4

Anomalous magnetodielectric and magnetostrictive effect via spin
reorientation in terbium iron garnet

Tuning magnetic order, electromagnons and exchange bias by epitaxial
strain in BiFeO3 thin filmsxZhaorong Yang*
Institute of Solid State Physics, Chinese Academy of Sciences, China

Colossal magnetocapacitance (CMC) and colossal magnetoresistance (CMR) induced
by annealing polycrystalline Cd0.97In0.03Cr2S4 are reported. In agreement with theappearance of CMR near the Curie temperature Tc, a insulator-metal transition isobserved with decreasing temperature at zero magnetic field. On the contrary, after
the same annealing treatment, CdCr2S4 displays typical semiconductor behavior anddoes not show magnetic field dependent dielectric and electric transport properties.
Accordingly, the simultaneous occurrence of CMC and CMR effects implies that the
CMC in the annealed Cd.97In0.03Cr2S4 could be explained qualitatively by a combinationof CMR and Maxwell-Wagner effect.

Ki-myung Song1, Seongsu Lee2 and Namjung Hur1*
1
Dept. of physics, Inha univ., Korea
2
Neutron Science Division, Korea Atomic Energy Research Institute, Korea

We have investigated the relationship among the magnetic, dielectric andmagnetostrictive properties of terbium iron garnet (TbIG). In this presentation, we
report experimental observations which are extraordinary magnetostriction andmagnetodielectric effects in TbIG with a non-collinear spin structure in a single
unit cell. The distinct effects of magnetism on the lattice are also demonstrated by
the unprecedented magnetostriction with a negative poisson ratio. We attribute theobserved magnetodielectric effects and the huge magnetostriction to the magnetic field
induced spin reorientation from non-collinear to collinear. In this study, we analyzed
crystallographic and spin structure of TbIG in various temperatures by the Fullprof
program. We investigated the effect of the non-collinear spin structure on the crystal
structure of TbIG to elucidate the relation between them through analyzing neutron
diffraction data.

Manuel Bibes1*, Daniel Sando1, Arsene Agbelele2, Maximilien Cazayous3, Ingrid Infante4, Wei
Ren5, Sergey Lisenkov6, Cecile Carretero1, Agnes Barthelemy1, Laurent Bellaiche5, Jean Juraszek2
and Brahim Dkhil4
1
Unite Mixte de Physique CNRS/Thales, France
2
Universite de Rouen, France
3
Universite Paris Diderot, France
4
Ecole Centrale Paris, France
5
University of Arkansas, USA
6
Universiy of South Florida, USA

With a ferroelectric Curie temperature of 1100 K and a Neel temperature of 640K, BiFeO3 is one
the very few room-temperature multiferroics [1]. Its ferroelectric polarization is as high as 100 μC/
cm² and in the bulk it is a G-type antiferromagnet, with a superimposed cycloidal modulation. In
addition to showing magnetoelectric coupling between its ferroic orders, BiFeO3 also exhibits coupling
between dynamic lattice and spin excitations (electromagnons), enabling an electrical control of spinwaves [2]. We have explored the influence of epitaxial strain [3] on the antiferromagnetic properties
of BiFeO3 thin films. Combining Mossbauer spectroscopy and Raman scattering, we have found thatthe harmonic cycloidal order is stable at low strain but is replaced at higher strain by conventional
antiferromagnetism. This is accompanied by strong changes in the electromagnon spectra and on theirdependence on external stimuli. In addition, the mean antiferromagnetic vector progressively rotates as
strain varies, offering novel strategies to control exchange bias with ferromagnetic overlayers.

Raman scattering study of the lattice dynamics in LiFeAs and Fe1+yTe1Sex

Youngje Um
Max-Planck institute, Stuttgart, Germany

Following the recent discovery of superconductivity in F doped LaFeAsO with Tc of
26 K, numerous families of the Fe-based superconductors such as REFeAs(O1-xFx)(RE = rare earth), MFe2As2 (M = Ba, Ca, Sr, K, ...), LiFeAs/NaFeAs and Fe1+yTe1xSex have been found and investigated. Most of these compounds have closely related
phase diagrams and present an antiferromagnetic parent compound at low temperature,
which turns superconductor upon doping. A noticeable exception is LiFeAs, in which
superconductivity is observed already in the parent compound. Recent ARPES results
suggest strong electron-phonon coupling in LiFeAs, but so far no experimental studyof its lattice dynamics is available. Here, we present first Raman light scattering
investigations of lattice dynamics on superconducting LiFeAs. Five of the six expectedphonon modes are observed, and show a conventional anharmonic behavior. No clear
evidence for coupling of electron with zone center phonon is observed. Then, we
present a systematic study of the lattice dynamics in Fe1+yTe1-xSex as a function of Se
and excess Fe contents, with special emphasis on the Fe phonon. A peculiar doping
dependence of the mode is observed, which suggests an original coupling of thisphonon to the low energy spin excitations induced by excess iron.

QA22

QA25

QB01

Critical dynamics in LiCuVO4

Template based synthesis of multiferroic BiMnO3 nanotubes and shapedependent study of its magnetic properties

Magnetic-enhanced electron-phonon coupling and vacancy effect in'111' type iron pnictides from first-principles calculations

The synthesis of Bismuth manganite nanotubes was done by templating precursors ofbismuth and manganese on titanium dioxide nanotubes. The yield was post treated toremove the template material and sintered at 400C. The resulting powders were studied using
X-ray Diffractometer and Scanning Electron Microscope, which revealed the formation of
perovskite nanotubes . The BiMnO3 nanotubes were characterized for its magnetic properties
by Vibrating sample magnetometer that revealed the intrinsic ferromagnetic nature withincrease in its magnetic saturation that could have been due to the shape anisotropy of thenanotubes. The magnetization under field cooled and zero-field cooled was also found todiffer significantly with applied magnetic field. These results indicate the co-existence of
antiferromagnetic behavior at higher temperatures along with its intrinsic ferromagnetic nature
which deviate from its bulk counterpart that only exhibits ferromagnetic nature.

We investigate the lattice dynamics in both nonmagnetic and striped antiferromagnetic
states of '111' type iron pnictides using the density-functional perturbation theory.
The anisotropic spin-phonon effects lead to the softening of phonon frequencies
and the renormalization of electron-phonon matrix elements, so as to increase theelectron-phonon couplings by 68%, 65%, and 0.9% for LiFeAs, NaFeAs, and LiFeP,
respectively. Taking into account the vacancy effects in the three iron pnictides, wefind that the electron-phonon couplings are further enhanced by hole doping, yielding
superconducting transition temperatures close to their experimental values.

The recent discovery of superconductivity in AxFe2-ySe2 (A = alkali metal), withtransition temperatures up to Tc ~ 32 K, has led to a renewed interest for iron based
chalcogenide systems. A remarkable observation is that, beside the superconducting
state, a strong antiferromagnetic (AFM) state with magnetic moments up to 3.3μB
per Fe ion is observed below TN~550 K. The key issue in AxFe2-ySe2 is whether AFM
order and superconductivity cohabit due to phase separation or share a microscopic
coexistence. We have performed muon spin relaxation/rotation measurements insingle crystalline samples of superconducting (SC) Rb0.8Fe1.6Se2 (Tc = 29 K) and nonSC Rb0.8Fe1.6Se2, which doesn’t show superconductivity, in order to elucidate whether
there is difference of magnetic state between SC and non-SC samples. In SC sample,
we found that SC volume fraction is only ~6% and the rest of amount is AFM orderedphase, suggesting SC and AFM ordered phases are separated. We found that muon
spin depolarization increases with decreasing temperature in non-SC sample, while nochange was observed in SC sample. It suggests the appearance of new magnetic state
below 40 K in non-SC sample.

Christoph Grams1*, Maximilian Schalenbach1, Daniel Niermann1, Petra Becker2 andJoachim Hemberger1
1
II. Physikalisches Institut, University of Cologne, Germany
2
Institut fur Kristallographie, University of Cologne, Germany

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Geo George Phillip, Anuraj Sundar, Mahdiyar Bagheri, Helen Annal Therese* andGopalakrishnan Chandrasekaran
Nanotechnology Research Centre, SRM University, India

Mei Liu1 and Bin Li2
1
Dept. of Physics, Southeast University, China
2
Department of Physics, Southeast University, China

1. Srikala, D., Singh, V.N., Banerjee, A., Mehta, B.R.Effect of induced shape anisotropy on magnetic properties offerromagnetic cobalt nanocubes (2010) Journal of Nanoscience and Nanotechnology, 10 (12), pp. 8088-8094. 2.
Tajiri, T., Harazono, M., Deguchi, H., Mito, M., Kohno, A., Kohiki, S. Synthesis and magnetic property of multiferroic
BiMnO3 nanoparticles in the pores of mesoporous silica (2010) Japanese Journal of Applied Physics, 49 (6 PART 2),
pp. 06GH041-06GH044. 3. Xu, E., Qian, T., Zhang, G., Zhang, T., Li, G., Wang, W., Li, X. Fabrication and magnetic
properties of multiferroic BiFeO3 nanotube arrays (2007) Chemistry Letters, 36 (1), pp. 112-113.

Magnetism and Superconductivity in RbxFe2-ySe2

Kazuki Ohishi1*, Shouhei Kototani2, Shunsuke Saiki2, Yoshiaki Kobayashi2, Masayuki
Itoh2 and Masatoshi Sato1
1
Research Center for Neutron Science and Technology, CROSS, Japan2
Department of Physics, Nagoya University, Japan

QA26

QB02

QB05

High quality crystal growth and Low temperature diffuse scatteringstudies

Solitary reentrant superconductivity prediction in asymmetrical
ferromagnet-superconductor-ferromagnet trilayer

Penetration depth and knight shift in iron-based superconductor Ba1xKxFe2As2

Magnetic Resonant mode in the Spin-Excitation Spectrum ofSuperconducting Rb2Fe4Se5 Single Crystals

The 120 K Verwey-transition [1] in magnetite Fe3O4 is the classical example for chargeor- dering, but the complex low-temperature structure was unresolved during decades.
Early experimental studies and recent calculations suggest ferroelectricity (FE) due
to charge ordering, which would be significant if confirmed. Very recent structuralrefinement [2] supports the necessary polar structure. Recently, signatures of relaxor
FE were observed below 40 K [3] . Specific diffuse scattering would be expected insuch a case [4], best re- solved on high quality single crystals. The Verwey transition
depends sensitively oxygen stoichiometry [5] and the high quality crystals are obtainedby the direct synthesis in an appropriate CO/CO2 flow [6].We have grown high quality
single crystals of magnetite under the tailored growth conditions by optical floatingzone method and characterized them primarily by specific heat measurement. We
present the results of high energy x-rays and neutrons diffuse scattering experiments,
performed to test the proposed relaxor FE. The presence of weak diffuse scattering atvery low temperature is observed only by neutron scattering, and thus likely magnetic,
not supporting relaxor FE. Proof of the latter would require time resolved scattering.
1.E.J.W.Verwey, Nature 144, 327 (1939). 2.Mark S.Senn et al, Nature Letter (2011). 3.F.Schrettle etal, Phys. Rev. B. 83 195109 (2011). 4.Grace Yong et al , Phys. Rev. B. 62, 14763 (2000). 5.P.Shepherd
et al., Phys. Rev. B 43, 8461 (1991). 6.R.Aragon et al., J. crystal growth, 61, 221 (1983)

186

QB04

QA23
Shilpa Adiga*, Yixi Su, Jrg Persson and Manuel Angst
PGI-4, Forschungszentrum Juelich, Germany

The 19th International Conference on Magnetism

Yurii N. Proshin*, Marat M. Khusainov, Arthur Minnullin and Mansur G. Khusainov
Theoretical Physics Department, Kazan Federal University, Russia

The theory of proximity effect for thin bilayer FS, trilayer FSF and fourlayered system
FSFS, where F is a ferromagnetic metal, and S is superconductor, is proposed on thebase of new boundary-value problem for the Eilenberger function. For all systems thedependencies of critical temperature on an exchange field of the F metal, electronic
correlations in the S and F metals, and thicknesses of layers F and S are derived. It
is shown that the possibility of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state
observation is especially increased in the asymmetrical systems (FSF' and FSF'S') for
which solitary reentrant superconductivity is predicted. On the basis of a proximity
effect we propose new method of probe of electronic parameters of contacting
materials. If well known BCS superconductor S is used as a probe, one can determine
the exchange field, the electron-electron constant in various magnetics F for the FS
structures. It allows us to predict the sign and value of the constant of electron-electroninteraction in gadolinium and to explain a surprisingly high critical temperature Tc ~5K in the short-periodic Gd/La superlattice [1].
P.P. Deen, et al. J. Phys.: Cond. Matt. 17, 3305 (2005).

Kazuki Ohishi1*, Yasuyuki Ishii2, Isao Watanabe3, Taku Saito4, Hideto Fukazawa4,
Yoh Kohori4, Kunihiro Kihou5, Chul-ho Lee5, Hijiri Kito5, Akira Iyo5 and Hiroshi
Eisaki5
1
Research Center for Neutron Science and Technology, CROSS, Japan2
Department of Physics, Tokyo Medical University, Japan
3
Advanced Meson Science Laboratory, RIKEN, Japan
4
Department of Physics, Chiba University, Japan
5
AIST, Japan
We have observed temperature and magnetic field dependence of penetration depth λin single crystalline samples of Ba1-xKxFe2As2 (x = 0.27, 0.64, 0.7, 0.8, 0.94 and 1.0) in
order to clarify the superconducting gap mechanism. We have found that T dependenceof 1/λ^2 in KFe2As2 with H//c and H┴c are completely different. While the T
dependence of 1/λ^2 observed with H//c is well fitted by a two-full-gap model, T-linear
behavior is clearly observed below ~T_c/2 with H┴c, suggesting the existence of line
node. These results are well interpreted when we take into account the horizontal line
node (line node in ab-plane) in KFe2As2. At the presentation, we will also report the T
and H dependence of λ and Knight shift over a wide x region of Ba1-xKxFe2As2.

July 10 (Tue)July 10 (Tue)[1] G. Catalan et al, Adv. Mater. 21, 2463 (2009) ; [2] P. Rovillain et al, Nature Mater. 9 975 (2010) ;[3] I.C. Infante etal, Phys. Rev. Lett. 105, 057601 (2010)

Jitae Park
Max-Planck-Institute for Solid State Research, Germany

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187

poster Presentation
QB09

QB12

Magnetic field-induced superconductivity in the canted
antiferromagnet Eu(Fe0.81Co0.19)2As2

Angular dependence of the resistive upper critical field of an ironbased superconductor Fe(Te,Se) in high magnetic fields

Interplay between 3d- and 4f-electrons in ReFe1-xCoxAsO (Re = Ce,Gd)

July 10 (Tue)We present results of ac-magnetic susceptibility, dc-magnetization, specific heat andmagnetotransport measurements on a single crystal of magnetic Eu(Fe0.81Co0.19)2As2
superconductor. The compound undergoes multiple phase transitions; fromparamagnetic to a spin-density-wave (SDW) at TSDW = 80 K, to canted
antiferromagnetic (C-AF) state at TN = 16.5 K and superconducting (SC) state at Tc= 5.15 K at zero field. Upon applying fields both the C-AF and SC states evolve in an
unconventional manner. Magnetic field distinctly affects the spin canting, resulting inseparation of the C-AF into two a new C-AF and ferromagnetic phases. The unusual
behavior of the SC state deserves the observation that Tc can be increased up to 6.5 K
with magnetic fields applied parallel to the ab-plane of crystals. The observed fieldinduced superconductivity is interpreted as a result of a weakening of the orbital pairbreaking effect. From the experimental data we propose the field-temperature phase
diagrams for Eu(Fe0.81Co0.19)2As2.

Takanori Kida1, Yoshikazu Mizuguchi2, Yoshihiko Takano3 and Masayuki Hagiwara1
1
KYOKUGEN, Osaka university, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
2
Grad. Sch. Sci. Eng., Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Japan
3
National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, JapanThe 11-system FeCh (Ch=S, Se, Te) superconductors are of great importance inunderstanding the mechanism of superconductivity in iron-based superconductors owing
to their simple structures. Previously, we have reported the temperature dependence of theresistive upper critical field (Hc2) on Fe1.05Te0.85Se0.15, which exhibits superconductivity
at T = 14 K [1,2]. The Hc2 of this compound at low temperature is considerably smaller
than that expected from the Werthamer-Helfand-Hohenberg model, manifesting the Paulilimiting behavior. It suggests that this compound shows the spin-singlet pairing in the
superconducting state. The anisotropy coefficient of Hc2 decreases from 2.4 near Tc to~1 (nearly isotropic) at low temperatures. In this study, we have investigated an angulardependence of Hc2 of a single crystal of Fe1.05Te0.85Se0.15 in pulsed high magnetic fields up
to 52 T. At T = 10 K, the Hc2 increases with increasing Θ, which is the angle between thec-axis and applied magnetic fields direction. We have found that the angular dependence of
Hc2 is well agreement with the Gintzbrug-Landau effective-mass prediction.
[1] T. Kida et al., J. Phys. Soc. Jpn. Vol.78 (2009) 113701. [2] T. Kida et al., J. Phys. Soc. Jpn.
Vol.79 (2010) 074706.

QB15

T. Shang1, L. Yang1, Y. Chen1, L. Jiao1, J. L. Zhang1, J. Chen1, H. Q. Yuan1*, N.
Cornell2, A. Howard2, A. Zakhidov2, M. B. Salamom2, F. Ronning3, E. D. Bauer3 and J.
D. Thompson3
1
Department of Physics and Center for Correlated Matter, Zhejiang University, China
2
UTD-NanoTech Institute, The University of Texas at Dallas, USA
3
Los Alamos National Laboratory, USA
In order to study the evolution from a high Tc superconductor to a strongly correlated systemwith largely enhanced effective mass in iron pnictides, we have synthesized a series of ReFe1xCoxAsO (x=0-1) polycrystalline samples and characterized their physical properties bymeans of electrical resistivity, magnetization and specific heat. It is shown that, for CeFe1xCoxAsO, the SDW transition of the 3d-electrons is quickly suppressed upon substituting Fewith Co and superconductivity appears in a narrow doping range of 0.05<x<0.20. On theother hand, the 4f-electrons of Ce is antiferromagnetically ordered with a nearly unchanged
TN~4K over a wide doping concentration (0≤x≤0.8). Remarkably, the 3d- and 4f-electrons
become ferromagnetically ordered above x~0.75 and x~0.80, respectively. Similar results
are derived for the GdFe1-xCoxAsO upon partially substituting Fe with Co. However, the
4f-electrons are antiferromagnetically ordered over the entire doping concentration andlikely undergo a spin reorientation above x~0.6. On the Co-side (x<0.8), the 3d-electrons
undergo a FM transition, followed by an AFM transition upon decreasing temperature. These
results suggest that the interplay of 3d- and 4f-electrons may play an important role in ReFe1xCoxAsO, giving rise to rich physical properties attributed to the the Kondo scattering and thepolarization between the 3d-and 4f-electrons.

75As NMR/NQR study of hole-doped superconductor Ba1-xKxFe2As2

Masanori Hirano1, Yuji Yamada1, Taku Saito1, Ryo Nagashima1, Hideto Fukazawa1,
Yoh Kohori1*, Yuji Furukawa2, Kunihiro Kihou3, Chul-ho Lee3, Akira Iyo3 andHiroshi Eisaki3
1
Department of Physics, Chiba University, Japan
2
Ames Laboratory and Department of Physics and Astronomy, Iowa State University,
USA
3
National Institute of Advanced Industrial Science and Technology, Japan
We have performed 75As NMR and NQR on single crystalline Ba1-xKxFe2As2 for
x = 0.27-1. The Knight shift K in normal state shows Pauli paramagnetic behavior
with slight temperature T dependence. The value of K increases gradually withincreasing x. By contrast, nuclear spin- lattice relaxation rate 1/T1T in normal state
has a large T-dependence, which indicates existence of large antiferomagnetic (AF)spin fluctuations for all x. The T-dependence of 1/T1T shows a gap-like behavior
below approximately 100 K for 0.6 < x < 0.9. These behaviors are well explained by
the change of band structure with expansion of hole Fermi surfaces and shrink anddisappearance of electron Fermi surfaces at Brillouin zone (BZ) with increasing x. The
T dependence of 1/T1 in SC state indicates multiple-SC-gap feature. A simple two gap
model analysis shows that the larger superconducting gap gradually decreases withincreasing x from 0.27 to 1 and smaller gap decreases rapidly and nearly vanishes for x> 0.6 where the electron pockets in BZ disappear.

QB07

QB10

QB13

QB16

Superconductivity and spin fluctuations in Ca 1-x Pr x Fe 2 As 2
superconductors studied by 75As NMR

Ab initio evidence of strong correlation and large Mott proximity iniron-based superconductors

Anisotropic Hc2 curves determined up to 92 T and two-band
superconductivity in Ca10(Pt4As8)((Fe1-xPtx)2As2)5 superconductor

Homogeneous coexistence and phase segregation in the 1111 iron-based
pnictides studied via NMRLong Ma1*, Gaofeng Ji1, Jia Dai1, S. R. Saha2, J. Paglione2 and Weiqiang Yu1
1
Department of Physics, Renmin University of China, China
2Center for Nanophysics and Advanced Materials, Department of Physics, Universityof Maryland, USA

The observation of superconductivity in the rare earth doped CaFe2As2 with Tc ashigh as 47 K is still not understood. Here we report the first NMR study on the newly
discovered Ca1-xPrxFe2As2 (x=0.075, 0.15) single crystals. The magnetization shows
superconductivity at ~25 K with a small volume ratio for both samples. A first order
structural transition from the tetragonal to the collapsed tetragonal phase in both
crystals is shown by 75As spectra. Residual tetragonal phase is seen in the x = 0.075
sample with a finite volume, but not seen in the x = 0.15 sample. We also observed
a sharp drop of Knight shift below Ts in both samples, suggesting a suppression of
local moments in the collapsed phase. However, the 1/75T1 is enhanced below 50
K and shows a prominent peak at about 25 K. Such behaviors indicate strong lowenergy antiferromagnetic spin fluctuations, with static or quasi-static magnetic ordering
at low temperatures, which is probably caused by Pr3+ doping. The absence of theresidual tetragonal phase and the observation of antiferromagnetic spin fluctuations in
the x=0.15 sample suggest that superconductivity in Ca1-xPrxFe2As2 is not tied to thetetragonal phase and may have a magnetic origin.

Takahiro Misawa, Kazuma Nakamura and Masatoshi Imada
Dept. Appied Physics, Univ. of Tokyo, Japan

Recently discovered iron-based superconductors have attracted much interest in theirhigh superconducting critical temperatures (Tc). Although it is believed that electron
correlations mediate the unconventional high-Tc superconductivity, their roles are
not fully understood yet. To clarify electron correlation effects from a microscopic
point of view, we study the ab initio low-energy effective model for iron-based
superconductors by using multi-variable variational Monte Carlo method. From
this ab initio calculations, we show that iron-based superconductors discovered neard6 configuration (5 Fe 3d orbitals filled by 6 electrons) is located on the foot of an
unexpectedly large dome of correlated electron matter centered at the Mott insulator
at d5 (namely, half filling). The d5 Mott proximity extends to subsequent emergenceof incoherent metals, orbital differentiations due to the Mott physics and Hund’s-rule
coupling, followed by antiferromagnetic quantum criticality, in quantitative accordancewith available experiments.

Eundeok Mun1, Ni Ni2, Jared M Allred2, Robert J Cava2, Oscar Ayala1, Ross D
Mcdonald1, Neil Harrison1 and Vivien S Zapf1
1
Nationa High Magnetic Field Lab, Los Alamos National Lab, USA
2
Department of Chemistry, Princeton University, USA
The upper critical fields, Hc2(T), of single crystals of the novel superconductor
Ca 10(Pt 4As 8)((Fe 1-xPt x) 2As 2) 5 with x=0.02 were determined over a wide rangeof temperatures down to T = 1.42 K and magnetic fields up to H = 92 T. The
measurements of anisotropic Hc2(T) curves are performed in pulsed magnetic fields
using radio-frequency contactless penetration depth measurements for magnetic field
applied both parallel and perpendicular to the ab-plane. The high magnetic fields
up to 92 T and temperatures down to 1.42 K, used in this study, enable access tothe complete evolution of the Hc2(T) curves. Whereas a clear upward curvature in
Hc2c(T) along H||c is observed with decreasing temperature, the Hc2ab(T) along H||abshows a flattening at low temperatures. The rapid increase of the Hc2c(T) suggeststhat the superconductivity can be described by two dominating bands. The anisotropy
parameter, Hc2ab(T) / Hc2c(T) , is ~7 close to Tc and decreases considerably to ~1
with decreasing temperature, showing rather weak anisotropy at low temperatures.

Naoki Fujiwara1*, Satoru Matsuishi2, Yoichi Kamihara3 and Hideo Hosono2
Gradutate School of Human & Environmental Studies, Kyoto University, Japan
2
Frontier Research Center (FRC), Tokyo Institute of Technology, Japan
3
Faculty of Science & Technology, Keio University, Japan
1

In iron-based pnictides, one of the interesting topics is homogeneous coexistence or phasesegregation between antiferromagnetic (AF) and superconducting (SC) states, because these
phenomena are deeply related to the pairing symmetry. We addressed this problem on a
microscopic level by means of 75As NMR measurements in LaFeAsO1-xFx ( La1111 series ),and CaFe1-xCoxAsF ( Ca1111 series ) having an intermediate electronic phase diagram between
Ba(Fe1-xCox)2As2 and the La1111 series [1]. The spectra for 6%-Co Ca1111 samples exhibited
75As signals similar to the undoped samples even below Tc [1], whereas those for 2.6%-F
La1111 samples exhibited signals arising from both AF and SC phases at 3.0 GPa. At ambientpressure, we observed signals arising from AF and paramagnetic metallic (PM) states. These
results indicate that homogeneous coexistence between AF and SC states is realized in the Ca1111
series, whereas SC or PM domains are formed other than AF domains in the La1111 series. The
separation of two phases at ambient pressure indicates that the SC phase is not directly related to
the AF phase and some pairing mechanism other than spin fluctuation would be important.
[1] T. Nakano, S. Tsutsumi, N. Fujiwara, S. Matsuishi, and H. Hosono, Homogeneous coexistenceof superconducting and spin-density-wave states in CaFe1-xCoxAsF as seen via nuclear magnetic
resonance, Phys. Rev. B 83 (2011) 180508(R)

QB08

QB11

QB14

QB17

Importance and details of the spin excitation spectra in high-Tc
pnictide superconductors

As-NQR study of LaFeAsO1-xFx

Effect of Ni-doping on superconductivity and magnetism in
Eu0.5K0.5Fe2As2

NMR study of Fe-based superconductors KxFe2-ySe2

Tanmoy Das and A. V. Balatsky
Theoretical Division, Los Alamos National Laboratory, USA

One common feature that underlies all high-Tc superconductor families is the developmentof a magnetic resonance peak at or around the antiferromagnetic ‘hot-spot’ vector. Thisfeature has proven to give valuable information about the pairing symmetry, and bulk
Fermi surface properties. We provide a random-phase approximation (RPA) based BCS
susceptibility calculation using material specific band structure for 122 family of ironpnictide and layered iron selenide superconductors. (i) In iron-pnictide, we show thatwhen two hole-pockets at Gamma point and the electron pockets at M point are present
on the Fermi surface, the spin-excitation spectra split into two distinct resonance branches.
[1] The energy separation between the two resonances is related to the differences in the
superconducting gaps on two hole-pockets. Again, the momentum resolution between thetwo modes comes from the differences in Fermi surface areas of the two hole-pockets. (ii)We also show that when one hole-pocket disappears, one of the resonances disappears.
Furthermore, when both hole pockets vanish, the magnetic scattering between theremaining electron-pockets lead to a change in the gap symmetry from s± to d-wave. The
latter is observed in the newly discovered iron-selenide superconductors. [2] Finally, we
will present the resulting spin-excitation spectra for both materials.
[1] T. Das, and A. V. Balatsky, Phys. Rev. Lett. 106, 157004 (2011). [2] T. Das, and A. V. Balatsky,
Phys. Rev. B 84, 014521 (2011).

The 19th International Conference on Magnetism

July 10 (Tue)QB06
Vinh Hung Tran1*, T A Zaleski2, Z Bukowski1, L M Tran1 and A J Zaleski1
1Institute of Low Temperature and Structure Research, Polish Academy of Sciences,
50-950 Wroclaw, Poland
2
Institute of Low Temperature and Structure Research, Polish Academy of Sciences,
50-950, Poland

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poster Presentation

Toshihide Oka1*, Z Li2, S Kawasaki1, G F Chen2, N L Wang2 and G -q Zheng1
1
Department of Physics, Okayama uiversity, Japan2
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics,
Chinese Academy of Science, China
The discovery of superconductivity in LaFeAsO1-xFx at superconducting transition
temperature Tc=26K, followed by that in ReFeAsO 1-xFx(Re:Ce,Pr,Nd,Sm) withTc as high as 55K, has gained much attention. We have performed systematic Asnuclear quadrupole resonance(NQR) measurements on LaFeAsO1-xFx to elucidate
its superconducting gap structure and mechanism of the Cooper pair formation.
For x=0.03, we find the spin-lattice relaxation rate(1/T1) exhibits a small upturn at
TN=58K, below which the spectra become broadened due to the internal magnetic
field attributed to an antiferromagnetic ordering. Above TN, 1/T1T increases withdecreasing T due to the antiferromagnetic spin fluctuation(AFSF), which persists inthe x=0.04,0.06, and 0.08 compounds. A dome-shaped x dependence of Tc is found,with the highest Tc=27 K at x=0.06, which is realized under significant AFSF. With
increasing x further, AFSF decreases, and so does Tc. These features resemble thecuprates La2-xSrxCuO4, which suggests that AFSF is also important in producing highTc superconductivity in LaFeAsO1-xFx . In the superconducting state, we find that 1/T1
decreases exponentially below Tc down to 0.13Tc for x=0.06, which suggests that theenergy gaps are fully opened. Meanwhile, 1/T1 below Tc decreases nonexponentiallyfor x either smaller or larger than 0.06, which is accounted for by impurity scattering.

Anupam Guleria1, Vivek Kumar Anand2, P.l. Paulose2, S. Ramakrishnan2, C. Geibel3
and Z. Hossain1*
1
Department of Physics, Indian Institute of Technology, Kanpur, India
2
DCMP&MS, Tata Institute of Fundamental Research, Homi Bhabha Road,
Mumbai-400 005, India
3
Max-Planck Institute for Chemical Physics of Solids 01187 Dresden, Germany

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Yuusuke Tomita1, Hisashi Koteawa1*, Hideki Tou1, Yoshikazu Mizuguchi2, Hiroyuki
Takeya2 and Yoshihiko Takano2
1
Department of physics, Kobe University, Japan
2
NIMS, JapanKxFe2-ySe2 with a transition temperature Tc of 32K is an unique example among
Fe-based superconductors.[1] Angle-resolved photoemission spectroscopy studies
suggest that the electronic structure is distinct from other Fe based superconductorin the absence of hole-like Fermi surface around Γ point. [2]On the other hand, thediffraction studies suggest a phase separation of an antiferromagnetic (AF) phase anda superconducting phase.[3] We measured nuclear spin-lattice relaxation time T1 andKnight shift using 77Se-NMR in a single crystal KxFe2-ySe2. Their anisotropy for H//
ab and H//c including the field dependence were measured in a wide temperature
range down to the SC state. In the SC state, the field dependence of 1/T1 was weak,suggesting that the relaxation is dominated by the SC quasiparticle and the contribution
from the AF phase and the phase boundary is weak. Knight shift in the normal
state is almost isotropic, but it consists of the spin part and the orbital part. From ameasurement at low temperatures, we found that the orbital part is anisotropic, andhence the anisotropic spin part. We will discuss the SC gap symmetry and the characterof spin fluctuations in KxFe2-ySe2.
[1] J. Gio et al. Phys. Rev. B 82, 180520(R) (2010) [2] I.I.Marzin et,al Phys. Rev. B 84, 024529 [3]W.Bao et.al Chinese Phys. Lett. 28, 086104

July 8-13, 2012 Busan, Korea

189

poster Presentation
QB18

QB21

QB24

QB27

Spectroscopy and anisotropies in the magnetic state of iron pnictides

High-pressure resonant x-ray emission study of Fe 1.01 Se
superconductors

Multi-frequency ESR in EuFe2As2

Vortex tunneling spectra of iron-pnictide superconductors

One kind of the iron based superconductors is called ‘122’ system. Most parent
materials of the ‘122’ system exhibit a spin-density wave (SDW) transition thatis accompanied by a structural phase transition [1]. EuFe2As2 shows the SDWtransition at TSDW=190 K, and the large local moment Eu2+ (S =7/2, L =0) orders
antiferomagnetically below TN=19 K. Above TSDW, it is believed that Eu2+ localized
magnetic moments interact with itinerant electrons. Below TSDW, the interlayerinteraction turns to be weak and the system becomes anisotropic [2]. To study theabove natures of EuFe2As2 in more details, we have performed multi-frequency (2035 GHz) electron spin resonance (ESR) measurements. Above TN, the resonancesignal can be fitted with the Dysonian function, and the temperature dependence of thelinewidth obtained by this fitting obeys the Korringa relation above TSDW as observedat X-band ESR [2]. From this relation, we will discuss the exchange interaction
between Eu2+ moments and conduction electron spins.

Symmetry and structure of the superconducting gap functions in iron-pnictides havebeen still under spirited debate. Quasi-particle states around surfaces/interfaces or
impurities have played a crucial role for identifying the gap functions in several
unconventional superconductors such as cuprates or Sr2RuO4. However, the gap
symmetry of iron-pnictide is believed to be s-wave, and the point at issue is to identify
whether the gap structure has inter-band sign reversal (s+-) or not (s++). Thus, itwill be difficult to distinguish these gap structures based on surfaces/interfaces
information. There exist several studies on impurity-induced states in iron-pnictides.
However, because of the complex band-structures of such systems, theoreticalmodeling of impurities in iron-pnictide is not free of ambiguity. Vortex core states canbe another “probe” to identify the gap symmetries and structures in unconventional
superconductors. Since a vortex core is not a chemical substance, there are no
ambiguities in theoretical modeling. Thus, in this work, we theoretically study thequasi-particle states induced around a vortex core in iron-pnictides using two- or fiveband effective two-dimensional lattice models [1][2] within the Bogoliubov-de Gennes
theory. We will also examine the impurity-induced quasi-particle states, and discuss therelation between present results and recent STM/S experimental results.

[1]Y. Xiao et al., Phys. Rev. B 80 (2009) 174424. [2]E. Dengler et al., Phys. Rev. B 81 (2010)
024406.

[1]T. Kariyado and M. Ogata, J. Phys. Soc. Jpn. 79, 083704 (2010). [2]S. Raghu et al., Phys. Rev. B
77, 220503 (2010).

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Jin-ming Chen, S. C. Haw, J. M. Lee, S. A. Chen, K. T. Lu, N. Hiraoka, H. Ishii and K.
D. Tsuei
National Synchrotron Radiation Research Center, Taiwan
The Fe 3d valence states, electron structures and spin states of iron-chalcogenide
Fe1.01Se superconductors under pressure up to 45 GPa were probed by resonant
x-ray emission spectroscopy (RXES) and and x-ray absorption spectra. The Fe 1s3pRXES spectra of Fe1.01Se at ambient pressure, 6 GPa and 45 GPa were measured todeduce the variation of Fe 3d valence states. The 1s3p-RXES data obtained at the Fe
K edge clearly reveal that unoccupied Fe 3d states exhibit a relatively delocalized
character, stemming from hybridization of the Fe 3d states with the Fe 4p orbitals.
The pronounced pre-edge peak at ~7112.7 eV in Fe K-edge x-ray absorption spectraof Fe1.01Se predominantly originates from the dipole transition of a Fe 1s electron tounoccupied Fe 3d-Se 4p hybrid bands. The larger compression accompanied with asignificant distortion around the Fe atoms along the c axis in Fe1.01Se upon applying
pressure suppresses the Fe 3d-Se 4p and Fe 4p-Se 4d hybridization. The appliedpressure suppresses the nearest-neighbor ferromagnetic superexchange interactionand enhances spin fluctuations on the Fe sites in Fe1.01Se. Fe1.01Se shows a small net
magnetic moment of Fe2+ at ambient pressure.

Masami Ikeda1, Tatsuya Kobayashi2, Wataru Hirata2, Shigeki Miyasaka2, Setsuko
Tajima2 and Masayuki Hagiwara1
1
KYOKUGEN, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531,
Japan2
Dep. of Phys., Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka,
Osaka 560-0043, Japan

QB19

QB22

QB25

QB28

Magnetic interactions in iron pnictides

Microscopic coexistence and competition of magnetism andsuperconductivity in Ba1-xKxFe2As2 : A structural, magnetic, andsuperconducting phase diagram

Analysis of the critical current density and flux pinning properties iniron-based Ba0.55K0.45Fe2As2 high Tc superconductor

Direct observation of superconducting gaps and their anisotropies in
Ba1-xKxFe2As2

Maria Jose Calderon, Gladys Leon, Belen Valenzuela and Elena . Bascones*
Theory and Simulations of Materials, Instituto de Ciencia de Materiales de Madrid,
Spain

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Gwendolyne Pascua1, Hubertus Luetkens1, Erwin Wiesenmayer2, Zurab Shermadini1,
Rustem Khasanov1, Alex Amato1, Hans-henning Klauss3 and Dirk Johrendt2
1
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
2
Department Chemie,, Ludwig-Maximilians-Universitaet Muenchen, D-81377 Muenchen,, Germany
3Institut fuer Festkoerperphysik,, TU Dresden, DE-01069 Dresden, Germany

It is widely believed that in contrast to its electron-doped counterparts, the hole-doped
compound Ba1-xKxFe2As2 exhibits a mesoscopic phase separation of magnetism andsuperconductivity in the underdoped region of the phase diagram. Here, we report a combined
high-resolution X-ray powder diffraction and volume-sensitive muon spin rotation (μSR)
study of Ba1-xKxFe2As2 showing that this paradigm does not hold true in the underdoped
region of the phase diagram (0 ≤ x ≤ 0.25). Instead, we find a microscopic coexistenceof the two forms of order. A competition of magnetism and superconductivity is evident
from a significant reduction of the magnetic moment and a concomitant decrease of themagnetoelastically coupled orthorhombic lattice distortion below the superconducting phasetransition. The doping dependence of structural, magnetic, and superconducting properties iscompleted in a phase diagram (0≤ x ≤ 1) herein presented and discussed.

Dawood Ahmad1, I S Park1, G C Kim1, Rock Kil Ko1,2, J H Lee1, and Y C Kim1
Department of Physics, Pusan National University, Korea
2
Korea Electrotechnology Research Institute, Changwon 641-120, Korea

1

The critical current density and flux pinning properties of the Ba0.55K0.45Fe2As2 highTc superconductor with Tc = 37K are studied using field and time dependence ofthe magnetization. The temperature dependence of the critical current density Jc(T)have been found to follow the form Jc ∝ (1-T/Tc )n and is consistent with δ Tc typepinning due to the randomly distributed defects larger than the coherence length ξ.
The temperature dependence of the magnetic relaxation rate S exhibits a peak atmuch lower temperature which corresponds to the smaller pinning energy in theBa0.55K0.45Fe2As2 superconductor. Moreover, the effective pinning potential Uo increases
with the increase in temperature this behavior is in agreement with those of high Tc
cuprate superconductors.

[1] E. Wiesenmayer, H. Luetkens et al., Phys. Rev. Lett. 107, 237001 (2011). [2] M. Rotter et al., Nature Physics 5, 141(2009). [3] A. A. Aczel et al., Phys. Rev. B 78, 214503 (2008). [4] T. Goko et al., Phys. Rev. B 80, 024508 (2009).

Y. Ota1*, K. Okazaki2, Y. Kotani2, T. Shimojima3, T. Kiss4, C. - T. Chen5, S. Watanabe6, K. Kihou7, C. H. Lee7, A.
Iyo7, H. Eisaki7, T. Saito8, H. Fukazawa9, Y Kohori9 and S. Shin10
ISSP, Japan
2
ISSP, JST-CREST, Japan3
Univ. of Tokyo, Japan
4
Osaka Univ., Japan
5
CAS, China
6
Tokyo Univ. of Sci., Japan
7
AIST, JST-TRIP, Japan
8
Chiba Univ., Japan
9
JST-TRIP, Chiba Univ., Japan
10
ISSP, JST-CREST, JST-TRIP, RIKEN, Japan
1

Among the iron-pnictides, (Ba,K)Fe2As2 (BaK122) system is the most interesting: while theoptimally-doped BaK122 has a full gap (no node in the superconducting(SC) gap), the extremely
hole-doped KFe2As2 (K122), which has no electron pocket, has been suggested to have SCgap nodes from several experiments. From the previous studies of laser-excited angle-resolved
photoemission spectroscopy (laser ARPES), the optimally doped BaK122 has no anisotropy andFermi surface (FS) sheet dependence in SC-gap sizes on the three hole FS around the Brillouinzone center. On the other hand, we found that K122 has clear anisotropies and sheet dependence.
In addition, we found that the middle hole FS has eight nodes and identified their Fermi momenta.
It should be important to investigate doping dependence of anisotropies and FS-sheet dependenceof SC-gap sizes, and node existence to clarify the paring mechanism at each doping level. We havedirectly observed superconducting gaps and their anisotropies in the overdoped BaK122 utilizing
laser ARPES. We will discuss these results and contrast them with other experimental and theoreticalresults available in literature.

QB20

QB23

QB26

QB29

Te-doped K0.80Fe1.81Se2-xTex single crystals

Anomalous superconducting phase in LaFeAsO1-xHx studied via 75As
NMR

In-plane anisotropy of magnetic and electric properties of the Fe
pnictide Ba(Fe1-xCox)2As2

Contrasting superconducting property in Fe-based superconductors(Ca4Al2O6-y)(Fe2Pn2)[Pn=As and P]

LaFeAsO1-xFx ( La1111 series ) is a prototype of high-Tc pnictides and has been
investigated extensively by means of various experimental techniques. The
electronic phase diagram is unique compared to other high-Tc pinctides in that theantiferromagnetic ( AF ) phase hardly overlaps the superconducting ( SC ) phase,and the optimal doping level is located away from the AF phase boundary. The latterfeature is common to the R1111 series ( R = Ce, Nd, etc. ). Recently, an exotic phase
diagram has been obtained in LaFeAsO1-xHx in which a high Tc is maintained evenin an overdoping regime, and the second SC dome emerges upon excess H doping.
To investigate the exotic electronic state on a microscopic level, we performed 75As
NMR measurements for 20% and 40% doped samples. The former doping level
corresponds to the boundary between two SC domes, and the latter corresponds to the
optimal doping level of the second dome. The relaxation rates for 20% doped samples
are comparable with those of LaFeAsO1-xFx (x = 14%) , however rates for 40% doped
samples enhanced at a fixed temperature implying that some spin fluctuations returnand some magnetic ordering would occur upon excess H doping.

The anisotropy of electronic and magnetic properties within FeAs-planes of Co(2%)doped BaFe2As2 was investigated by 75As-NMR measurements of the As sites As0
with all four nearest neighbor sites occupied by Fe. Interestingly, even in the tetragonalphase (T >100 K), two sets of NMR spectra with two fold symmetry of in-plane
Knight shifts and electronic nuclear quadrupole frequencies were observed. They
originate from the existence of two domains with their symmetry axes lying at rightangles to each other. The anisotropy of the electronic and magnetic properties become
pronounced on cooling at ~140 K, below which the in-plane anisotropy was reported toappear for the electrical resistivity under the pressure along one of Fe-Fe directions [1].
75As-NMR was also carried out at the As site As1 surrounded by one Co and three Fe.
From the data, we can see that the spin susceptibility at As1 is ~1/3 of the value at As0
and that the antiferromagnetic spin fluctuation at As1 is fairly suppressed as comparedwith the value at As0. We discuss these behaviors of the FeAs layer in connection with
the impurity-induced local orbital ordering suggested by the theoretical studies.

C T Lin*
Crystal Growth, Max Planck Institute for Solid State Research, Germany
We report the growth a serious of Te-substituted K0.80Fe1.81Se2-xTex (x~0, 0.09, 0.16, 0.34
and 0.55) single crystals using optical floating-zone technique under application of 8
bar of argon pressure. Study of XRD indicated that the undoped single crystals containa significant intergrowth of two sets of the c-axis characterized by slightly different
lattice constants, i.e., the phase separation phenomenon. Our results demonstrate thatthe partial substitution of Se by Te atoms can lead to the expansion of the c-lattice
constant, whereas the phase separation phenomenon is suppressed continuously with
the increase of substitution level and vanished at x~0.55. The magnetization data show
the superconducting transition temperature is gradually depressed for Tc ~32, 27, 25,
15, and 0 K with the substitution level x~0, 0.09, 0.16, 0.34 and 0.55, respectively.

N. Fujiwara1*, S. Tsutsumi1, S. Iimura2, S. Matsuishi2 and H. Hosono2
1
Gradutate School of Human & Environmental Studies, Kyoto University, Japan
2
Frontier Research Center (FRC), Tokyo Institute of Technology, Japan

Yoshiaki Kobayashi1*, Akihiro Ichikawa1, Masayuki Itoh1 and Masatoshi Sato2
1
Department of Physics, Graduate School of Science, Nagoya University, Japan
2
Research Center For Neutron Science And Technology, CROSS, Japan[1] J.-H. Chu, J. G. Analytis, K. D. Greve, P. L. McMahon, Z. Islam, Y. Yamamoto and I. R. Fisher:Science 329 (2010) 824.

190

Yuhei Kikuchi* and Hiroki Tsuchiura
Applied Physics, Tohoku University, JapanThe 19th International Conference on Magnetism

July 10 (Tue)Belen Valenzuela, Maria Jose Calderon, Gladys Leon, Noel A. Garcia and Elena
Bascones*
Theory and Simulations of Materials, Instituto de Ciencia de Materiales de Madrid,
Spain

July 10 (Tue)poster Presentation

Hiroaki Kinouchi1, Hidekazu Mukuda1, Mitsuharu Yashima1, Yoshio Kitaoka1, Chulho Lee2, Parasharam M. Shirage2, Hiroshi Eisaki2 and Akira Iyo2
1
Department of Materials Engineering Science, Graduate School of Engineering
Science, Osaka University, Japan
2
National Institute of Advanced Industrial Science and Technology (AIST), Japan
We report As-nuclear quadrupole resonance (NQR) study on (Ca4Al2O6-y)(Fe2As2) with
Tc=27K, and P-nuclear magnetic resonance (NMR) study on (Ca4Al2O6-y)(Fe2As2) with
Tc=17K. (Ca4Al2O6-y)(Fe2As2) possesses the characteristic structural parameters such as shorta-axis length, high pnictgen height, narrow As-Fe-As angle, and thick perovskite-type blocking
layer. A measurement of the nuclear spin relaxation rate 1/T1 revealed a significant evolution of
antiferromagnetic (AFM) spin fluctuations in normal state, which originates from the possible
well nested hole and electron Fermi surfaces. Below Tc, the 1/T1 decreases steeply upon coolingwithout any trace of Hebel-Slichter peak, which is consistently accounted for within the frameworkof nodeless s(+-)-wave multiple gap model. On the other hands, (Ca4Al2O6-y)(Fe2As2) ischaracterized by lower pnictgen height and wider As-Fe-As angle than that of (Ca4Al2O6-y)(Fe2As2),
where FeP_4 forms nearly regular tetrahedron. The P-NMR- 1/T1 measurement revealed thepresence of AFM spin fluctuations in normal state and gapless SC state. These facts indicate theclose relationship between the local structural characters of FePn_4 and the SC properties.
H. Kinouchi, H. Mukuda, M. Yashima, Y. Kitaoka, P. M. Shirage, C-H. Lee, H. Eisaki, and A. Iyo

July 8-13, 2012 Busan, Korea

191

poster Presentation
QB30

QC02

QC05

QC08

Superconducting properties of FeTe1-xSex single crystals: impact ofdisorder and hydrostatic pressure

Theoretical studies of the superconductivity and antiferromagnetism
coexistence and the divergence of effective electron mass near quantum
critical point in CeRhIn5

Sb NQR study of filled skutterudite CeFe4Sb12 synthesized under highpressure

Ru doping evolution of magnetic properties in Ce(Fe1-xRux)PO studied
by 31P-NMR

July 10 (Tue)It was found that chemical and structural disorder in superconducting single crystalsof Fe(Te,Se), originating from kinetics of crystal growth process, strongly influences
superconducting properties. The sharpness of a transition to the superconducting state isevidently inversely correlated with crystallographic quality. Ions inhomogeneous spatial
distribution seems to enhance the superconductivity and inhomogeneous distribution ofhost atoms might be an intrinsic feature of superconducting chalcogenides. Small disorderintroduced into magnetic sublattice, by partial replacement of Fe ions by slight amountof nonmagnetic ions of Cu or by magnetic ions of Ni and Co with spin value different
than that of Fe ion, completely suppresses superconductivity. Even if superconductivity isobserved in the system containing magnetic ions it can not survive when the disorder inmagnetic ions sublattice is introduced. We have found pressure-induced enhancement of
all of the superconducting state properties of FeTe0.5Se0.5 single crystals, which entails a
growth of the density of superconducting carriers. We noticed more pronounced increasein superconducting carrier density under pressure than that in the critical temperature what
may indicate an appearance of a mechanism limiting the increase of Tc with pressure. The
critical current density increases under pressure by at least one order of magnitude.

Valery V. Val'kov and Anton O. Zlotnikov
Laboratory of Theoretical Physics, L.V. Kirensky Institute of Physics, Russia

Competition and coexistence of superconductivity and antiferromagnetism have been studied in the frameworkof the periodic Anderson model taking into account the superexchange interaction between localized 4f
electrons. It has been shown that pressure-induced energy change of the localized states leads to modifying
antiferromagnetic and superconducting order parameters. This modification of the order parameters develops
in such way that a strong competition is suggested between antiferromagnetism and superconductivity. It has
been proposed that the energy increase is caused by pressure growth. In spite of the competition mentioned
above, conditions have been found for the coexistence of superconductivity and antiferromagnetism in themodel. Theoretical results of the pressure effects on the ground state character of the heavy-fermion systems
are in good agreement with specific heat data for CeRhIn5 [1, 2]. In the coexistence phase there occur two
types of Cooper pairing due to the antiferromagnetic exchange field. The divergence of the effective electronmass produced by suppressing antiferromagnetic order has also been analyzed in the same framework. Further
it has been shown that at quantum critical point there occurs the transition from small to large Fermi surface.
Such features have been found in the de Haas-van Alphen experiments for CeRhIn5 [3].

Ko-ichi Magishi1*, Hitoshi Sugawara2, Masahiro Takahashi1, Takahito Saito1,
Kuniyuki Koyama1, Takashi Saito3, Sho Tatsuoka3, Kenya Tanaka3 and Hideyuki Sato3
1
Institute for Socio-Arts and Sciences, The University of Tokushima, Japan
2
Graduate School of Science, Kobe University, Japan
3
Graduate School of Science, Tokyo Metropolitan University, Japan

Shunsaku Kitagawa1*, Yusuke Nakai2, Kenji Ishida1, Hiroaki Ikeda3, Kensuke Iritani4,
Masanori Matoba4, Youichi Kamihara4, Masahiro Hirano5 and Hideo Hosono6
1
Department of Physics, Kyoto University JST-TRIP, Japan2
Department of Physics, Kyoto University JST-TRIP *present address Graduate School of Science,
Tokyo Metropolitan Univers, Japan3
Department of Physics, Kyoto University, Japan
4
Departments of Applied Physics and Physico-Informatics, Keio University, Japan
5
Frontier Research Center, Tokyo Institute of Technology, Japan
6
Frontier Research Center, Materials and Structures Laboratory, Tokyo Institute of Technology, Japan

1. H. Hegger, C. Petrovich, E.G. Moshopoulou, M.F. Hundley, J.L. Sarrao, Z. Fisk, J.D. Thompson,
Phys. Rev. Lett. 84, 4986 (2000). 2. T. Park, J.D. Thompson, New Journal of Physics 11, 055062(2009). 3. H. Shishido, R. Settai, H. Harima, Y. Onuki, J. Phys. Soc. Jap. 74, 1103 (2005).

Among filled skutterudites, the influence of the filling fraction of R ion on thephysical properties has been argued, especially in Sb-based filled skutterudites witha large pnictogen cage. On RFe4Sb12 system, the drastic effect of the R-site vacancy
on the basic properties has been pointed out. Recently, it has been reported that
CeFe4Sb12synthesized under high pressure (HP) in order to increase the Ce-site filling
fraction shows the semiconducting transport property at low temperatures, in contrast
that the sample synthesized under ambient pressure (AP) shows the metallic behavior.
At the presentation, we report on the result of the Sb NQR measurements for the HP
sample of CeFe4Sb12, and compare with that for the AP sample in order to understandthe influence of the Ce-site filling fraction. In the high temperature range, the nuclear
spin-lattice relaxation rate for the HP sample decreases on cooling, and follows the
exponential decrease above 100 K with the energy gap of 270 K. The value of thegap for the HP sample is larger than that for the AP sample, which suggests that the
hybridization is enhanced by increasing the Ce-site filling fraction. More detailed
results and analyses will be presented at the conference.

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The influence of superconductivity with magnetism in superconductor/
magnetic heterostructures

Josephson effect between UPt3 and Nb under pressure

High-mobility magnetotransport of the narrow-gap semiconductor
FeSb2

Determining the orientation of the 4f ground state orbital in CeCu2Si2
with vector q dependent non-resonant inelastic X-ray scattering (NRIXS).

Jeehoon Kim*, R. Baumbach, N. Haberkorn, J. Lee, L. Civale, Q. Jia, A. J. Taylor, E.
Bauer, J. D. Thompson and R. Movshovich
Los Alamos National Laboratory, USA

Akihiko Sumiyama1*, Jun Gouchi1, Gaku Motoyama1, Akira Yamaguchi1, Noriaki
Kimura2, Etsuji Yamamoto3, Yoshinori Haga3 and Yoshichika Onuki4
1
Univ. of Hyogo, Japan
2
Tohoku Univ., Japan
3
JAEA, Japan
4
Osaka Univ., Japan

Hidefumi Takahashi*, Ryuji Okazaki, Yukio Yasui and Ichiro Terasaki
Department of Physics, Nagoya University, Japan

CeFePO and CeRuPO have the same layered crystal structure as iron pnictide superconductors RFeAs(O1-xFx) (R:rare earth). CeFePO is a paramagnetic down to 80 mK and possesses a large Sommerfeld coefficient gamma ~700 mJ/mol K2 at low temperatures, indicating that CeFePO is a heavy fermion compounds originated from Ce
4f electrons[1]. On the other hand, CeRuPO is a ferromagnetic Kondo lattice system with TCurie = 15 K andcoherent temperature TK ~ 10 K[2]. We have performed 31P-NMR on Ce(Fe1-xRux)PO system to investigate
the evolution of magnetic properties at low temperatures. Knight shift and spin-lattice relaxation rate 1/T1
shows extremely large anisotropy. In CeFePO, we found a metamagnetic transition at around mu0H = 4 T and
below 5 K characterized by the sudden increase in Knight shift when fields are applied perpendicular to the caxis[3]. As far as we know, this is the first example of the metamagnetic behavior in a heavy fermion observedwith XY spin anisotropy. Moreover, Ce(Fe0.75Ru0.25)PO shows ferromagnetic ordering at ~ 3 K with strong two
dimensional ferromagnetic fluctuations. We will show the phase diagram in Ce(Fe1-xRux)PO and discuss how
two dimensional ferromagnetic fluctuations are changed with the Ru doping.
[1] E. M. Bruning et al., Phys. Rev. Lett. 101, 117206 (2008). [2] C. Krellner et al. J. Cryst. Growth
310, 1875 (2008). [3]S.Kitagawa et al., Phys. Rev. Lett. 107, 277002 (2011).

Thomas Willers1*, Fabio Strigari1, Yong Cai2, Nozomu Hiraoka3, Ku-ding Tsuei3, Yen-fa Liao3, Maurits Wim
Haverkort4, Silvia Seiro5, Christoph Geibel5, Frank Steglich5, Liu Hao Tjeng5 and Andrea Severing1
1

Institute of Physics II, University of Cologne, Germany
Brookhaven National Laboratory, USA
National Synchrotron Radiation Research Center, Hsinchu, Taiwan
4
Max Planck Institute for Solid State Research, Stuttgart, Germany
5
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
2

The heavy-fermion compound UPt3 is an odd-parity superconductor and possesses a complex
field-temperature (H-T) phase diagram with three phases: A (low H and high T), B (low H and
low T) and C (high H and high T) phases. We have investigated the Josephson effect between UPt3
and Nb and observed an anisotropic temperature dependence of Josephson critical current Ic at
the transition from A to B phases[1]. However, the Josephson effect, which is easily destroyed bya small magnetic field, has not been measured in C phase. Considering that C phase appears evenin zero field by applying pressure[2], we have investigated the pressure dependence of Josephson
effect together with resistance and Meissner effect of UPt3. The superconducting transition occurs
at lower temperature and becomes broader by applying pressure. As the pressure is increased, theJosephson effect appears at lower temperature than the zero-resistivity temperature of UPt3, while
Ic increases more rapidly; the increasing rate -dIc/dT is a linear function of pressure. Although
the Josephson effect in C phase has been observed for the first time, an abrupt change in thetemperature dependence of Ic caused by the transition to C phase has not been found yet.

Recently, a huge Seebeck coefficient S (-45 mV/K at 10 K) was reported for singlecrystalline FeSb2 samples. Such a huge value seems beyond conventional semiconductor
physics, indicating a novel mechanism to enhance the Seebeck coefficient such as a strong
electron correlation expected in so-called 'Kondo insulators'. We study the magnetotransport
properties of FeSb2 single crystals to investigate its electronic state at low temperatures[1].
The conductivity tensor is well analyzed using a two-carrier model, leading to proper
evaluation of the mobility and carrier concentration. The mobility significantly increases
with decreasing temperature and reaches 28000 cm2/Vs at 4 K. The carrier concentration
decreases from 1 down to 10-4 ppm/unit cell with decreasing temperature from 30 down
to 4 K, which is well described by thermal activation with a small gap of 6 meV. We alsofind that the magnetoresistive behavior dramatically changes from positive to negative
at lower temperatures. The negative magnetoresistance is generally observed in doped
semiconductors and derives from a weak localization of carriers, indicating a considerable
impurity level in the electronic structure. Our magnetotransport measurements, as well as
the impurity-effect study[2], strongly suggest that the low-temperature transport is wellunderstood within an extrinsic semiconductor picture with ppm-level impurity.

[1] A. Sumiyama et al.: Phys. Rev. Lett. 81 (1998) 5213; A. Sumiyama et al.: Jpn. J. Appl. Phys.
Series 11 (1999) 47. [2] M. Boukhny et al. : Phys. Rev. Lett. 73 (1994) 1707.

[1] H. Takahashi et al. Phys. Rev. B 84, 205215 (2011). [2] H. Takahashi et al. J. Phys. Soc. Jpn. 80,
054708 (2011).

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The influence of the magnetic moment on the atomic distance inamorphous CexRu100-x

Hidden order in URu2Si2 --- Analysis based on the first-principles
approach

A possible ferromagnetic quantum critical point in CeFe1-x RuxPO

Possible superconducting fluctuation in pressure-induced heavyfermion superconductor CeRhSi3

Interplay between superconductivity and magnetism continues to be one of thecentral themes in Condensed Matter Physics. We have investigated a variety ofsuperconductor/ferromagnetic heterostructures, such as YBCO/LSMO, Nb/GCMO,
and Nb/CeRu2Al2B using low temperature magnetic force microscopy, addressing
mainly magnetic pinning and domain wall superconductivity. In YBCO/LSMO, we
focused on the critical state and observed effects of magnetism on superconductivity.
In Nb/GCMO, we found that magnetic domains provide weak pinning centers, andact as magnetic templates. A recently discovered CeRu2Al2B system shows a variety
of magnetic phases such as antiferromagnetic, ferromagnetic, and ferrimagnetic
domains in the field/ temperature plane. We will discuss how we can manipulate
superconducting domains in superconducting film (Nb) via these magnetic phases inclose proximity.

Yingjie Li1, Nakai Ikuo2*, Amakai Yusuke3 and Shigeyuki Murayama3
1
1Inner Mongolia Key Laboratory for Physics and Chemistry of Functional
Materials, Physics and Electronic Information College, Inner Mongolia Normal
University, Hohhot 010022, China
2
Department of Electrical and Electronic Engineering, Graduate School ofEngineering, Tottori University,Tottori 680-8552, Japan3
Department of Materials Science and Engineering, Muroran Institute of Technology,
Hokkaido 050-8585, JapanThe extended x-ray absorption fine structure (EXAFS) measurement was performedin amorphous alloys CexRu100-x (x=9, 43 and 80). We found that the Ce-Ce interatomic
distance increases with increasing the Ce content while those of Ce-Ru and Ru-Ru
pairs are unchanged and that the Ce-Ce interatomic distance is exactly proportional
to the Ce effective magnetic moment. We discuss the relation between the Ce-Ce
atomic distance and the effective magnetic moment 1) from the point of view of themagnetovolume effect.
1) Y. Amakai et al., J. Phys. : Conf. Ser. 150 (2009) 042004.

The 19th International Conference on Magnetism

Hiroaki Ikeda1*, Michi-to Suzuki2, Ryotaro Arita3, Tetsuya Takimoto4, Takasada
Shibauchi1 and Yuji Matsuda1
1
Department of Physics, Kyoto university, Japan
2
CCSE, Japan Atomic Energy Agency, Japan3
Department of Appliced Physics, University of Tokyo, Japan
4
Asia Pacific Center for Theoretical Physics, POSTECH, Korea
The so-called 'hidden-order' phase transition at $T_{HO}=17.5$K in the heavy-electron metal
URu2Si2, specified by a clear jump in the specific heat measurement, is a long-standing mysteryin the condensed-matter physics since the discovery in 1985. In spite of every effort, it remains
still dark what kind of symmetry is broken below $T_{HO}$. So far, there are no evidence
for magnetic/structural and any low-rank multipole orders. Recent advanced angle-resolved
photo-emission spectroscopy indicates that $5f$ electrons appears to be itinerant rather thanlocalized. Thus, the detailed analysis of the complicated band structures including the spinorbit coupling has been strongly desired. We show here the first report of the complete set ofitinerant multipole correlations up to the fifth rank within the random-phase approximation andbeyond. The itinerant Hamiltonian is obtained by the advanced Wannier method from the firstprinciples calculations. From the most divergent correlations, we obtain nearly degenerate twostaggered-ordered states of rank-1 dipole with $A_2^-$ and rank-5 dotriacontapole with $E^$; the former corresponds to the antiferromagnetic state realized under high pressures, and thelatter the hidden-order state. This novel high-rank electronic state provides natural explanationsof the key features for the hidden order including spontaneous fourfold symmetry breaking.

Tetsuro Nakmura1, Takashi Yamamoto2, Masanori Matoba1, Yasuaki Einaga2 andYoichi Kamihara1
1
Department of Applied Physics and Physico-Informatics, Keio University., Japan2
Department of Chemistry, Keio University., Japan
Many materials have their own magnetic transition temperature, and it is controllable by the applicationof a pressure, field or through chemical substitution. In particular, phase transitions which take place atabsolute zero are called quantum phase transitions, and the transition point is called a quantum criticalpoint. Quantum critical points have attracted much attention since some materials exhibit superconductivity
in proximity to a magnetic quantum critical point. [1] Both CeFePO and CeRuPO are heavy-fermion
materials containing Ce 4f-electron’s sublattice inducing Kondo effects. Although CeFePO exhibits nomagnetic transition down to 0.4 K, CeRuPO is one of rare examples of a ferromagnetic Kondo lattice,whose transition temperature is 15 K [2]-[5]. In this study, we synthesized CeFe1-xRuxPO by a solid
reaction to quantify a chemical composition which is a boundary between ferromagnetic phase andparamagnetic phase indicating the quantum critical point. Electrical resistivity and magnetic susceptibility
are measured at temperatures from 4 K to 300 K. Furthermore, 57Fe Mossbauer spectroscopy was applied
to CeFe1-xRuxPO to confirm the ordering of the magnetic sublattice. Our results tentatively indicate that
CeFe1-xRuxPO is heavy-fermion metal, and the magnetic quantum critical point exists at x~0.15.

July 10 (Tue)Roman Puzniak*, Dariusz J. Gawryluk, Marek Berkowski, Piotr Dluzewski, Jaroslaw
Pietosa, Aleksander Wittlin and Andrzej Wisniewski
Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02-668
Warsaw, Poland

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Noriaki Kimura*, Tetsuya Sugawara, Hiroki Iida and Haruyoshi Aoki
Department of Physics, Tohoku University, Japan

CeRhSi3 is a heavy fermion antiferromagnet whose transition temperature is 1.6K.
The itinerant f electron is thought to be responsible for the magnetism in this material.
Application of pressure suppresses the magnetism and simultaneously induces
the superconductivity. At pressures from 0.2GPa to 2.4GPa, the superconductivity
coexists with the antiferromagnetism. In this pressure region, a broad drop of theelectrical resistivity and weak shielding in the ac-susceptibility are observed at thesuperconducting transition temperature. We argue a possibility of the superconducting
fluctuation realized in the coexisting region of the superconductivity andantiferromagnetism.

1) A. J. Millis: Phys. Rev. B 48 7183 (1993). 2) E. M. Bruning, C. Krellner, M. Baenitz, A. Jesche, F. Steglich,
and C. Geibel: Phys. Rev. Lett. 101 117206 (2008). 3) S. Kitagawa, H. Ikeda, Y. Nakai, T. Hattori, K. Ishida, Y.
Kamihara, M. Hirano, and H. Hosono: Phys. Rev. Lett. 107 277002 (2011). 4) Y. Kamihara, H. Hiramatsu, M.
Hirano, H. Yanagi, T. Kamiya and H. Hosono: J. Phys. Chem. Solids. 69 2916 (2008). 5) C. Krellner, N. S. Kini, E.
M. Bruning, K. Koch, H, Rosner, M. Nicklas, M.Baenitz, and C.Geibel: Phys. Rev. B 76 104418 (2007).

July 8-13, 2012 Busan, Korea

193

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poster Presentation

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Thermoelectric power in a single-crystalline CeRhSi3

Electronic structures of plutonium compounds with the NaCl-type
monochalcogenides structure

Crystal growth and low temperature properties of non-centrosymetricheavy-fermion comound CeTAl3 (T = Cu, Ag, Au)

Magnetization of Tm1-xYbxB12 in strong pulsed and steady magnetic
fields3

CeRhSi is a non-centrosymmetric heavy fermion superconductor.[1] The a- and c-axis
thermoelectric power S_a and S_c of a single-crystalline CeRhSi3 were measured underpressure up to around 2.7 GPa in the temperature range from 1.5 K to 300 K. Both S_a
and S_c exhibit a large positive value up to around 60 μV/K, which is characteristic ofheavy-fermion systems. S_a and S_c show a maximum in its temperature dependence
due to the Kondo effect and its maximum temperature T_Smax gradually moves tohigher temperatures from about 90 K (at ambient pressure) to about 130 K (at 2.7
GPa) by applying the pressure. In both directions, such behaviors of thermoelectric
power are very similar to those in the CeIrSi3.[2] In the conference, we will discuss
the anisotropy of the thermoelectric power in connection with the superconductivity in
CeRhSi3.
[1] N.Kimura et al., Phys. Rev. Lett. 95 (2005) 247004. [2] Y.Takaesu et al., J. Phys. Soc. Jpn. 80(2011) SA068.

Takahiro Maehira1*, Yasutomi Tatetsu2 and Eijiro Sakai1
1Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
2
Graduate school of Engineering and Science, University of the Ryukyus , Nishihara,
Okinawa 903-0213, Japan
Some of the uranium and the transuranium compounds are characterized as strongly
correlated f electron systems and have attracted particular interest because of richvariety of anomalous physical phenomena such as the valence fluctuation, the Kondo
lattice, exotic magnetism, unconventional superconductivity, etc. Among suchcompounds, the plutonium monochalcogenides display a variety of anomalous physicalproperties. For PuX (X=S, Se, Te) have been studied intensively both theoreticallyand experimentally[1,2]. To understand the electronic properties of these materials,
the features of the ground state should be first clarified. The calculations for the energy
band structure have been done by using the relativistic linear augmented-plane-wave(RLAPW) method. Note here that relativity should be taken into account, because oflarge atomic numbers of the constituent atoms. In the presentation, we try to understandwhat the key issues are to construct the energy band structures around the Fermi energy
for PuS, PuSe and PuTe.

Christian Franz, Alexander Regnat, Andreas Bauer and Christian Pleiderer
Department fur Physik, Technische Universitat Munchen, Germany

For a long time full inversion symmetry was thought to be a precondition for heavyfermion superconductivity. The discovery of heavy-fermion superconductivity inthe antiferromagnetic state of CePt3Si at ambient pressure and CeRhSi3, CeIrSi3 andCeCoGe3 at high pressure contradicted these paradigms. All compounds in this classcrystallize in a P4mm or subclass crystal structure. Here we report on the single crystal
growth of CeTAl3 (T = Cu, Ag, Au) with crystal structure I4mm, being isostructural
to CeRhSi3 and CeIrSi3. High purity elements (>5N) have been used as starting
materials. A special build image furnace was used for crystal growth. Crystal quality
was determined by Laue x-ray scattering, x-ray powder diffraction and edx. Low
temperature properties have been investigated by measurements of bulk properties
including magnetisation, heat capacity and electrical resistivity.

July 10 (Tue)[1] A. Hasegawa, and H. Yamagami, J. Magn. Magn. Mater. 104-107, 65 (1992). [2] P. M.
Oppeneer, T. Kraft, and M. S. S. Brooks, Phys. Rev. B61, 12825 (2000).

The magnetization of solid solutions Tm1-xYbxB12 (0<x\leq 0.8) crossing metal-insulatortransition point at x_{c}~0.3 have been studied at low temperatures 1.8-40 K in strong steady(up to 11T) and pulsed (up to 50T, pulse duration ~20-100 ms) magnetic fields. The analysisof the magnetization data allows extracting three contributions to the paramagnetic response.
Itinerant electron components are attributed to heavy fermion and ferron type manybody
states at EF with densities of states N(EF)= 1\div 4?1022 cm-3meV-1 and 3\div 4?1021 cm3
meV-1, correspondingly. The third contribution may be identified as the response from thelocalized magnetic moments of the rare earth ions (~0.8-3.7 μB per unit cell) which saturates
at helium temperatures in strong magnetic fields. The reduced intensity of the manybody
resonance at EF is shown to increase with Yb concentration reaching 2 electrons per unit cellfor x>0.7. Comparison between the steady and pulsed field magnetization behavior provides
additional arguments in favor of magnetic nanoclusters formation, short range ordering andelectron phase separation effects in Tm1-xYbxB12.

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Valence of CeM2Al10 (M=Ru, Os, and Fe) determined with hard X-ray
photo emission spectroscopy (HAXPES).

Electronic property of ThSn 3 in comparison with uranium andtransuranium compounds

Enhancement of the hall coefficient under pressure in CeCu2Si2

Stabilization of ferromagnetism and existence of ferromagnetic
quantum criticality in UCo1-xRuxGe system

Fabio Strigari1, Thomas Willers1, Ku Ding Tsuei2, Yen Fa Liao2, Arata Tanaka3, K.
Yutani3, Y. Muro3, Toshiro Takabatake3, Liu Hao Tjeng4 and Andrea Severing1*
1
University of Cologne, Germany
2
National Synchrotron Radiation Research Center, Taiwan
3
ADSM, Hiroshima University, Japan
4
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

Yasutomi Tatetsu1*, Takahiro Maehira2 and Eijiro Sakai2
1
Graduate school of Engineering and Science, University of the Ryukyus, Japan
2
Faculty of Science, University of the Ryukyus, Japan

Shingo Araki1*, Naoto Nishiumi1, Minami Hayashida1, Takafumi Shinohara1, Yoichi
Ikeda1, Tatsuo C. Kobayashi1, Silvia Seiro2, Christoph Geibel2 and Frank Steglich2
1
Department of Physics, Okayama University, Japan
2
Max Planck Institute for Chemical Physics of Solids, Germany

Michal Valiska*, Jiri Pospisil, Martin Divis, Jan Prokleska and Vladimir Sechovsky
DCMP, Charles University, Ke Karlovu 5, 121 16, Prague, Czech Republic

We have prepared polycrystalline samples of UCoGe doped by Ru on the Co-site about
nominal stoichiometry UCo1-xRuxGe where x = 0.01-0.35 with step 0.01 to studied
the magnetic state and ferromagnetic instability in UCoGe. The whole series of doped
materials keeps the orthorhombic TiNiSi-type structure. The evolution of the lattice
parameters well follows Vegard’s law respecting the pure parent UCoGe and URuGe.
While the UCoGe is well known ferromagnetic superconductor (TC = 2.5 K, TSC =0.6 K) the URuGe is paramagnetic down the lowest temperatures. Nevertheless theruthenium doping of UCoGe leads to surprising stabilization of the ferromagnetic
state when the maximum TC = 8.5 K has been found in 12 % Ru doped sample. The
further increase of the Ru content destabilizes previous ferromagnetic state and it isterminated by ferromagnetic quantum critical point at concentration of 30 % of Ru. We
have prepared single crystal of the UCo0.88Ru0.12Ge and UCo0.70Ru0.30Ge for detail studyof the ferromagnetic state, individual contributions of the U, Co and Ru components tototal magnetic moment, magnetic anisotropy and destabilization of the ferromagnetismin UCoGe in relation to superconductivity. The results are discussed on the basis of thechange of electronic structure.

Recent rapid expansion of the research frontier of condensed matter physics fromuranium to transuranium compounds has stimulated renewed attention and muchinterest on exotic properties of actinides and related compounds. It is a challenge tomodern electronic-structure theory to understand the appearance of a large numberof exceptionally complicated crystal structures of actinide metal. It is important toclarify electronic structure of actinide compounds which exhibit exotic magnetismand unconventional superconductivity. By using a relativistic linear augmentedplane-wave (RLAPW) method with the one-electron potential in the local-density
approximation, we investigate energy band structures and the Fermi surfaces oftransuranium compounds ThSn3, USn3, NpSn3 and PuSn3. It is found in common
that the energy bands in the vicinity of the Fermi level are mainly due to the large
hybridization between 5f and Sn 5p electrons. Thorium contains no occupied 5f states,
thorium compounds provide good comparative systems for investigating the role of 5f
electrons. In the presentation, we try to understand what the key issues are to construct
the energy band structures around the Fermi energy for ThSn3, USn3, NpSn3 and PuSn3,
we attempt to unveil 5f electron properties purely originating from actinide atoms.

CeCu2Si2 is the heavy fermion superconductor discovered in 1979. The unconventional
superconductivity with Tc ~ 0.6 K at ambient pressure is believed to be mediatedby antiferromagnetic spin fluctuation around the AFM quantum critical point.
With increasing pressure, Tc increases to reach the maximum at 4.2 GPa, although
antiferromagnetic spin fluctuation decreases. The existence of the critical valencefluctuation around the critical valence transition is proposed to explain the enhancementof Tc under pressure [1]. However, there is no direct evidence to reveal the existence ofthe valence fluctuation. In this study, we investigated the Hall effect on single crystalof CeCu2Si2 under high pressure. The temperature dependence of the Hall coefficient at
ambient pressure shows a peak at TmL = 4 K for H // [001] and [100]. In addition, theHall coefficient shows the other peak at T1max for H // [100]. The magnitude of theHall coefficient at TmL increases with increasing pressure and reaches the maximum
at around 4 GPa, coincident with the enhancement of Tc. We will discuss the relation
between the enhancement of the Hall coefficient and Tc.

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Studies on novel tetragonal Ce2RhGa12 heavy fermion compound

Multipolar phase transition of the 4f2 nonmagnetic doublet in a caged
compound PrRh2Zn20

Saturation moment in the ferromagnetic state of EuB6

Thermal properties of RB6 (R-La, Ce, Pr, Nd)

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Ramamoorthi Nagalakshmi1*, Sengodan Nallamuthu1, Varadharajan Krishnakumar2,
Celine Besnard3, Hans Hagemann4 and Marian Reiffers5
1
Physics, National Institute of Technology, Tiruchirappalli, India
2
Physics, Periyar University, Salem, India
3
Laboratory of Crystallography, Laboratory of Crystallography, University of Geneva, 24 Quai
Ernest-Ansermet, CH-1211 Geneva 4, Swit, Switzerland
4
Physical Chemistry, University of Geneva, Geneva, Switzerland, Switzerland
5
Physics, Institute of Experimental Physics, Slovakia Academy of Sciences, Kosice, Slovakia
Single crystals of Ce2RhGa12 have been synthesized using Ga flux and their structure was determined bysingle-crystal X-ray diffraction. The Ce2RhGa12 crystallizes in the tetragonal P4/nbm space group (No.
125), which is isostructural to Ce2PdGa12, with Z = 2 and lattice parameters a 6.0405 A and c= 15.706 A.
Data were collected at the Swiss Norwegian Beam Line at the European Synchrotron Facility, Grenoble
France. Also the Laue diffraction was carried out to confirm the single crystal quality possessing
tetragonal symmetry. The tetragonal structure of Ce2RhGa12 is composed of Ce-Ga and PdGa8/2 layers
similar to CePdGa6 [1] . The structure is isomorphous to Ce2MGa12 M=(Ni, Cu[2], Pd). Along the c axis
slabs of edge-sharing rectangular prism of RhGa8 alternates with Ga rich areas in which Ce atoms occupy
cavities made of Ga atoms. The bulk anti ferromagnetic transition of Ce2RhGa12 at 3.5 K is exhibitedby a big jump up to12 J/mol K. The value of γ above magnetic transition in specific heat measurementssuggests that it is a heavy-fermion system with γ = 420 mJ mol-1 K-2. The magnetic measurements are in
progress to confirm the consistency of the ordering temperature and the further studies are in progress.
1. Robin T. Macaluso, S. Nakatsuji, H. Lee, Z. Fisk, M. Moldovan, D.P. Young, and Julia Y. Chana
Journal of Solid State Chemistry 174, 296-301(2003) 2. J.Y. Cho, J.N. Millican, C. Capan, D.A. Solokov, M.
Moldovan, A.B. Karki, D.P.Young, M.C. Aronson, J.Y. Chan, Chem. Mater. 20, 6116-6123(2008)

194

Alexey Bogach1*, Nickolay Sluchanko1, Vladimir Glushkov1, Sergey Demishev1,
Andrey Azarevich1, Vladimir Filipov2, Natalia Shitsevalova2, Slavomir Gabani3, Karol
Flachbart3, Johan Vanacken4 and Victor Moshchalkov4
1
Low temperature and cryogenic engineering, A.M.Prokhorov General Physics
Institute RAS, Russia
2
Institute for Problems of Materials Science NASU, Ukraine
3
Institute of Experimental Physics, Slovakia Academy of Sciences, Slovakia
4
Institute for Nanoscale Physics and Chemistry of KUL, Belgium

The 19th International Conference on Magnetism

Nagasawa Naohiro1, Matsumoto T Keisuke1, Wakiya Kazuhei1, Onimaru Takahiro1,
Umeo Kazunori1, Kittaka Shunichiro2, Sakakibara Toshiro2 and Takabatake Toshiro1
1
Hiroshima University, Japan
2
The University of Tokyo, JapanThe caged compound PrIr2Zn20 with the Pr3+ ion in the Γ3 doublet ground state exhibits asuperconducting transition at TSC=0.05K in the presence of an antiferroquadrupolar (AFQ)order below TQ=0.11K [1, 2]. The entropy release up to TQ is only 20% of Rln2 whichis expected for the Γ3 doublet with the quadrupolar degrees of freedom. It suggests that
quadrupolar degrees of freedom remain active even below TQ and quadrupole fluctuations
play an important role in forming the Cooper pair in the superconducting state. In thepresent work, we have focused an isostructural and isoelectronic compound PrRh2Zn20. The
electrical resistivity shows a hysteretic behavior between 140K and 470K, suggesting a firstorder structural transition. In spite of the possible structural transition, a Schottky-like peakat around 10K in the specific heat and anisotropic behavior of the isothermal magnetization
at 1.8K indicate the crystalline electric field ground state to be the Γ3 doublet. The specificheat exhibits a peak at TQ=0.06K, where the entropy release is evaluated to be only 6% of
Rln2. Because of the increment of TQ in the magnetic fields and the anisotropic B-T phase
diagram, the phase transition at TQ should be an AFQ order.
[1] T. Onimaru et al., J. Phys. Soc. Jpn. 79 033704 (2010). [2] T. Onimaru et al., Phys. Rev. Lett.
106 177001 (2011).

[1] K. Miyake et al.: J. Phys.: Condens. Matter 19 (2007) 125201.

Vladimir V. Glushkov1*, Alexey V. Bogach1, Alexey V. Semeno1, Sergey V. Demishev1, Vsevolod Yu.
Ivanov1, Nickolay E. Sluchanko1, Alexey V. Kuznetsov2, Sergey Yu. Gavrilkin3, Kirill V. Mitsen3, Natalja Yu.
Shitsevalova4, Vladimir B. Filipov4, Johan Vanacken5 and Victor Moshchalkov5
1
Low Temperatures and Cryogenic Engineering Dept., A.M.Prokhorov General Physics Institute of
RAS, Russia
2
National Research Nuclear University MEPhI, Russia
3
P.N.Lebedev Physical Institute of RAS, Russia
4
I. Frantsevich Institute for Problems of Materials Science NASU, Ukraine
5
Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Belgium

Two consequtive phase transitions featuring the onset of ferromagnetism in europium hexaboride [1-4] arecommonly associated with percolation in the system of linked magnetic polarons at T_M~15.6 K and withlong range magnetic ordering below T_C=12.6-13.9 K [1]. However, the recent study of high frequency
electron spin resonance [5] showed neither magnetic phase separation nor MP formation features in thesystem of localized magnetic moments of Eu2+. To shed more light on the nature of ferromagnetism westudied the magnetic and thermal properties of the EuB6 single crystals in pulsed (up to 40 T) and steady(up to 9 T) magnetic fields at temperatures 2-40 К. The estimated saturation moment M_{sat}~7.4μ_B isfound to exceed noticeably the magnetic moment of Eu2+ ion. The difference is shown to be induced byan additional contribution to magnetization due to the formation of intermediate magnetic phase below T_
M. The observed renormalization of M_{sat} is discussed in terms of the effects of the spin polarizationin 5d-band and the short range magnetic ordering in the system of Eu2+ ions. Support from RFBR 11-0200623 project, Federal Programme “Scientific and Educational Human Resources of Innovative Russia”
and the Methusalem Funding by the Flemish Government is acknowledged.
[1] U.Yu, B.I.Min, Phys. Rev. B, v.74, p.094413 (2006). [2] S.Sullow et al., Phys. Rev. B, v.57, p.5860(1998). [3] V.V.Glushkov et al., JETP v.105, p.32 (2007). [4] J.Kim et al., Phys Rev B, v.78, p.165120(2008). [5] A.V.Semeno et al., Phys Rev B, v.79, p.014423 (2009).

July 10 (Tue)

Hidekazu Tanaka1*, Naofumi Aso2, Yoshinao Takaesu1, Masato Hedo2, Takao
Nakama2, Hiroki Iida3, Noriaki Kimura3 and Haruyoshi Aoki3
1
Graduate School of Engineering and Science, University of the Ryukyus, Japan
2
Faculty of Science, University of the Ryukyus, Japan
3
Graduate School of Science, Tohoku University, Japan

M. A. Anisimov1*, A. V. Bogach1, V. V. Glushkov1, S. V. Demishev1, N. A. Samarin1, S. Gavrilkin2, N.
Yu. Shitsevalova3, A. V. Levchenko3, V. B. Filipov3, S. Gabani4, K. Flachbart4 and N. E. Sluchanko1
1 Low Temperatures and Cryogenic Engineering Dept., A.M.Prokhorov General Physics Institute of RAS, Russia
2 P.N.Lebedev Physical Institute of RAS, Russia
3 Institute for Problems of Materials Science NAS, Ukraine
4 Institute of Experimental Physics of SAS, Slovakia
Rare earth (RE) hexaborides RB_6 represent a class of compounds with variety of magnetic properties including
antiferromagnetic (R-Ce, Pr, Nd, Gd, Dy, Tb, Ho), ferromagnetic (EuB_6), intermediate valence (SmB_6)
and heavy fermion behavior (CeB_6). Here we investigate the heat capacity C_P(T) on the high quality single
crystals of light hexaborides (R-La, Ce, Pr, Nd) in the wide range of temperatures 2-300K. The data obtained
allow to estimate correctly (i) the electronic component with γ(LaB_6)~2.4mJ/(mol•K), (ii) contribution fromquasilocal vibrational mode of R^{3+} ion with Θ_E~119 - 152K, (iii) the Debye-type term from rigid boron
cage with Θ_D~1160K. Our data also suggest the additional (iv) defect mode component which is provided by
the contribution of the boron vacancies. The estimated values of residual concentration N_{vac}~1-4% agrees
with the results of X-ray studies of RB_6 [1], [2]. The analysis of magnetic contribution shows that magnetic
entropy S=∫ΔC_{mag}/TdT reaches the value corresponding to the ground state of 4f-multiplet in the range
2-4T_N. Taking into account the results of previous thermal investigations [3] we conclude in favour of the spinpolaron formation (see [4], [5] for details) in the paramagnetic vicinity of Neel temperature.
[1] V.A.Trunov, A.L.Malyshev et al., J. Phys.: Cond. Mat. v. 5, p. 2479 (1993). [2] M.M.Korsukova, V.N.Gurin et al., J. LessCommon. Met. v. 117, p. 73 (1986). [3] M.Sera, S.Kobayashi et al., Phys. Rev. B v. 54, p. R5207 (1996). [4] N.E.Sluchanko,
A.V.Bogach et al., JETP v. 104, p. 120 (2007). [5] M.A.Anisimov, A.V.Bogach, V.V.Glushkov et al., JETP v. 109, p. 815 (2009).

July 8-13, 2012 Busan, Korea

195

poster Presentation
QD01

QD04

Magnetic penetration depth and skin depth study of superconductivity
and quantum criticality in Ce1-xRxCoIn5 (R=La and Nd)

Fe doping and magnetic field effect in the valence fluctuating heavy
fermion system α-YbAlB4

Investigation of crystal structure, magnetism and transport properties
of SrFe1-xTixO3-δ systems

A heavy fermion superconductor CeCoIn5 shows different responses to Nd- or Lasubstitutions for Ce, with the former inducing long range magnetic order coexistingwith superconductivity. To understand the origin of the differences, we studied thetemperature and field dependent in-plane magnetic penetration depth, $\lambda(T)$,in single crystals of (Ce,R)CoIn5 (R=La, Nd). Measurements were performed with atunnel diode resonator down to 50~mK in a dilution refrigerator, in magnetic field up
to 14 T parallel to the $c$-axis. These low-temperature and high field measurementsallowed for the exploration for the full domain of superconductivity and quantum
criticality in the TH phase diagram. Some previously unreported features were observed
and will be discussed from the point of view of measured differential magnetic
susceptibility. These measurements bring new insight into the interplay between
superconductivity and magnetism as well as field-tuned quantum critical behavior of
doped 115 systems.

The Yb-based heavy fermion system, α-YbAlB 4, has a noncentrosymmetriccrystal structure, while the structure of the isostoichiometric system, β-YbAlB4 iscentrosymmetric [1]. β-YbAlB4 is a unique example of the Yb based heavy fermion
systems that shows pronounced non Fermi liquid behaviors and a superconducting
transition at 80 mK under ambient pressure and field [2,3,4]. On the other hand,
α-YbAlB4 at low temperatures is well fit to a Fermi liquid type description. Both α andβ-YbAlB4 are valence fluctuating systems with the Yb valence of 2.73 for α-YbAlB4
and 2.75 for β-YbAlB4 [5]. We succeeded in substituting Fe for Al in α-YbAlB4,
and found an antiferromagnetic order at 10 K. By a small substitution to α-YbAlB4,
we also succeeded in inducing non-Fermi liquid behaviors. The antiferromagnetic
ordering temperature is suppressed by magnetic field and non-Fermi liquid behaviors
are induced where the Neel temperature vanishes. In this presentation, we will discuss
the difference of the two non-Fermi liquid behaviors in Fe doped α-YbAlB4 showing
thermodynamic and transport properties.

SrFeO3 has attracted lot of attention in the recent past due to the exciting electric and magnetic properties
that can be achieved by varying oxygen stoichiometry. In this investigation, partial replacement of Fe4+
with a non-magnetic ion of Ti4+ in SrFeO3-δ is carried out to reduce the magnetic complexity of the helicalstructure and determine the resulting chemical and magnetic structure using neutron powder diffraction
and Mossbauer spectroscopy. Rietveld refinement of the neutron data indicated the presence oftetragonal symmetry with I4/mmm space group in δ~0.125. Our neutron and Mossabauer measurements
confirm that Fe exists in three different sites both crystallographically as well as magnetically in all four
compositions. oxygen deficient SrFe1-xTixO3-δ (x = 0 to 0.3) show an insulating behavior with a canted
antiferromagnetic spin ordering, in comparison to a metallic, helical spin arrangement of x=0. Resistivityof x = 0 to 0.3 follows the Mott’s 2-dimensional variable range hopping (VRH), ρ= ρ0 exp(T0/T)1/3. The composition dependence of ac conductivity is carried out in the frequency range 40 Hz to 1
MHz and the cole-cole plots show a single semicircular arc representing the grain contribution. The
temperature coefficient of resistance (TCR) changes from negative to positive (PTCR) for x = 0.2.

July 10 (Tue)

Kentaro Kuga, Keita Sone, Yosuke Matsumoto, Eoin Conor O'farrell and Satoru
NakatsujiInstitute for Solid State Physics, Japan

QD07
1

2

3

4

1

Sendilkumar A , Babu P. D. , Manivelraja M , R. Reddy V. and Srinath S *1School of Physics, University of Hyderabad, India
2
UGC-DAE Consortium for Scientific Research, R-5 Shed, B.A.R.C,Mumbai, 400 085, India
3
School of Physics, Advanced Magnetics Group , DMRL, Hyderabad, 500 046 , A.P , India
4
4UGC-DAEF ,Khandwa Road, Indore, 425017, M.P, India

Fermi surface and electronic correlations in a valence fluctuating Eusystem: an experimental and theoretical study of EuIr2Si2

Silvia Seiro1, Oleg Ignatchik2, Violeta Guritanu1, Vivien Petzold1, Takuya Iizuka3,Kathrin Gotze2, Jorg Sichelschmidt1, Shin-ichi Kimura3, Horst Borrmann1, Jochen
Wosnitza2, Helge Rosner1 and Christoph Geibel1*
1
Max Planck Institute for Chemical Physics of Solids, Germany
2
High Magnetic Field Laboratory Dresden, Helmholtz Center Dresden-Rossendorf, Germany
3Institute for Molecular Science, UVSOR Facility, Okazaki 444-8585, Japan

Electronic correlations can induce strong changes in electronic states, especially those at the Fermi level. These
effects are presently the subject of intense theoretical and experimental investigations, especially on Ce- andU-based heavy fermion systems as well as on High Tc cuprates. In contrast valence fluctuating Eu-systems
have yet not been investigated in this respect, although the valence fluctuations of Eu should have a strong
impact. We have recently grown high quality single crystals of the valence fluctuating compound EuIr2Si2 andstarted a thorough investigation of its electronic properties. From previous Moessbauer studies the valencev of Eu in EuIr2Si2 was reported to decrease continuously with temperature, from v = 2.3 at 300 K to v =2.8 below 20 K [1, 2]. Our T-dependent XRD, susceptibility, resistivity, and specific heat measurements onthese single crystals confirm such a strong evolution of the valence and give insight into global effects of thestrong correlations. These single crystals allowed the first observation of de Haas-van Alphen oscillations in avalence fluctuating Eu-system, as well as the first determination of the optical conductivity in such a system.
Comparing these results with DFT-based calculations give a deeper insight into the correlation effects.

[1] R. T. Macaluso et al, Chemistry of Materials 19, 1918 (2007). [2] S. Nakatsuji et al, Nature Physics 4,603 (2008). [3] K. Kuga et al, Physical Review Letters 101, 137004 (2008). [4] Y. Matsumoto et al,
Science 21, 316 (2011). [5] M. Okawa et al, Physical Review Letters 104, 247201 (2010).

[1] J.P.Hodges , S.Short, J.D.Jorgensen, X.Xiong,B.Dabrowski, S.M.Mini and C.W.Kimball Journal of Solid State Chemistry 151,(2000)
190-209. [2] P.K.Gallagher ,J.B.Mac Chesney and D.N.E.Buchanan, The Journal of Chemical Physics 41, 8(1964) 2429. [3] Y.Takeda,
K.Kanno ,T.Takada, O.Yamamoto, M.Takano, N.Nakayama and Y.Bandol J.Solid State Chemistry 63,(1986) 237-249. [4] M.Takano, T.Okita,
N.Nakayama, Y.Bando, Y.Takeda, O.Yamamoto and J.B.Goodenough J.Solid State Chemistry 73,(1988) 140-150. [5]A.Lebon, P.Alder,
C.Bernhard, A.V.Boris, A.V.Pimenov, A.Maljuk, C.T.Lin, C.Ulrich and B.Keimer Phy.Rev.Lett. 92,3(2004) 037202 [6]Peter Alder and Sten
Eriksson , Z.Anorg. Allg. Chem. 626 (2000) 118-214. [7] S. Srinath, M. Mahesh Kumar, M. L. Post, and H. Srikanth, Phys. Rev. B 72 (2005)

QC24

QD02

QD05

QD08

Low energy spin excitations in single-crystalline CeCu2Ge2 in magnetic
fields up to 10T

Magnetic and electric properties of single crystal SmBaMn2O6

Evolution from a localized to an intermediate valence regime in
Ce2Cu2-xNixIn

Heat capacity and electrical resistivity of CeNi5-xGex

Astrid Schneidewind 1*, Michael Loewenhaupt 2, Oliver Stockert 3 and Enrico
Faulhaber1
1Helmholtz-Zentrum Berlin fur Materialien und Energie, Germany
2
IFP, TU Dresden, Germany
3
MPI-CPfS Dresden, Germany
CeCu2Ge2 is Kondo lattice with a moderately enhanced Sommerfeld coefficient of thespecific heat γ =140 mJ/molK2. It exhibits antiferromagnetic order below TN = 4.1 K.
The incommensurate magnetic structure can be explained by the nesting properties of
the calculated Fermi surface when taking into account an itinerant component of theCe 4f-moments in addition to their local character. We performed low-energy inelastic
neutron scattering experiments on a 2g single crystal of CeCu2Ge2 using the cold threeaxes spectrometer PANDA at FRM II. Data were taken at 1.5 K and in magnetic fields
up to 10T applied perpendicular to the (110/001) scattering plane. At zero field thespin excitations show an energy gap of 0.5 meV at the magnetic zone center. Awaythe magnetic excitations become dispersive merging into a band of excitations around
1 meV. For increasing magnetic fields, the gap energy is lowered indicating opposite
action of external and internal fields. The results will be discussed in the framework of
local, crystal-field related, and non-local, spin-wave-like, magnetic excitations.

Youichi Maeda1*, Shigeki Yamada1 and Takahisa Arima2
1
Yokohama city univercity, Japan
2
Univercity of Tokyo, Japan

We have succeeded in growth of single crystals of an A-site ordered perovskite
manganese oxide, SmBaMn2O6, and investigated the magnetic and electric properties.
Since Sm and Ba ions alternately occupy the perovskite A-site, it is expected thatthe magnetic and electric properties should be anisotropic. Moreover, the anisotropy
may be modified with the charge orbital ordering. We also found that a peak inmagnetic susceptibility of polycrystals at about 250 K. The magnetic susceptibilityof a single crystal shows an anomaly which is accompanied by a hysteresis between
170 K and 210 K. This anomaly is caused by a rearrangement of charge orbital
ordering. A clear magnetic anisotropy is observed below this temperature indicatingthat this rearrangement of charge orbital ordering accompanies the simultaneous
antiferromagnetic spin ordering. Temperature dependence of the dielectric constantalong the c axis also shows an anomaly at the rearrangement temperature, while noclear anomaly is observed for E perpendicular to the c axis. This result is consistent
with the rearrangement of the stacking of the charge- and orbital-ordered sheets along
the c axis.

Adam Pikul* and Dariusz Kaczorowski
Institute of Low Temperature and Structure Research, Polish Academy of Sciences,
PolandCe2Cu2In and Ce2Ni2In crystallize in a primitive tetragonal structure of the Mo2FeB2
type. The former compound orders antiferromagnetically at the Neel temperature of
5.5 K, while the latter one is a system with fluctuating valence [1]. Here we reporton low temperature physical properties of the solid solution Ce2Cu2-xNixIn studied bymeans of x-ray powder diffraction, magnetic susceptibility and electrical resistivity
measurements, using polycrystalline specimens. We show that partial substitutionof Cu by Ni results in a quasi-linear decrease of the lattice parameters and unit cellvolume of the system. The lattice compression leads to an increase in the exchange
integral and yields a reversal in the order of the magnetic 4f1 and nonmagnetic 4f0
states, being in line with the Doniach phase diagram. In the localized regime, where aninterplay of the Kondo scattering and the crystalline electric field effect occurs, the risein the hybridization strength is accompanied by a relative reduction in the scattering
conduction electrons on excited crystal field levels.
[1] D. Kaczorowski, P. Rogl and K. Hiebl, Phys. Rev. B 54 (1996) 9891.

[1] B. Chevalier, J.M.D Coey, B. Lloret, and J. Etourneau; J. Phys. C: Solid State Phys. 19 (1986) 4521. [2] S.
Patil, R. Nagarajan, L.C. Gupta, R. Vijayaraghavan, and B.D. Padalia; Solid State Comm. 63 (1987) 955

Mariana Zapotokova1, Ivan Curlik2, Marian Reiffers3 and Mauro Giovannini4
1
Institute of Experimental physics, Watsonova 47, SK 043 53 Kosice, Slovakia
2
Centre od Low Temperature Physics, Institute of Experimental Physics, Watsonova
47, SK 043 53 Kosice, Slovakiaia, Slovakia
3
Centre od Low Temperature Physics, Institute of Experimental Physics, Slovakia
Academy of Sciences, Kosice, Slovakiaia, Slovakia
4
CNR-SPIN and Department of Chemistry, CNR-SPIN and Department of Chemistry,
University of Genova I-16146 Genova, Italy
Metallic Ce compounds are of great interest for the intriguing physical properties
associated with the 4f electrons. One notable example of compound intensively studied
for many years is CeNi5 crystallizing in the hexagonal CaCu5 type, which results tobe a Stoner enhanced paramagnet characterized by a spin fluctuation contribution on
its transport properties. Here the effect of the Ni/Ge substitution on the ground stateof CeNi5 is presented. Several ternary germanides CeNi5-x Gex (x=0.1, 0.2, 0.5, 0.8)
were prepared by arc melting method. All the alloys crystallize in the CaCu5 structure.
Single phase of the polycrystalline samples was confirmed by X ray diffraction. The
measurements of resistivity between 2-300 K and heat capacity between 0.4-300 K
were provided and the results are presented. The resistivity measurements show typicalmetallic behaviour. No phase transition was observed in resistivity and heat capacity
measurements.

QC25

QD03

QD06

QD09

Magnetization measurements under high pressure on incommensuratecommensurate phase transitions on UPd2Si2

Phase diagram and Eu valence state in EuPtP1-xAsx

Substitution effect in CeFe2Al10

Antiferromagnetic order in Yb5Rh4Ge10

Hiroyuki Hidaka, Hideki Igarashi, Yusei Shimizu, Chihiro Tabata, Tatsuya
Yanagisawa and Hiroshi Amitsuka
Graduate School of Science, Hokkaido University, Japan

UPd2Si2 has the ThCr2Si2-type body-centered tetragonal structure. This compoundshows an incommensurate-antiferromagnetic (IC-AFM) ordering with a propagation
vector Q = 0.73c* at 135 K (= TNh), and successively undergoes a simple
commensurate (C) type-I AFM ordering at 108 K (=TNl). It is known that the phasetransitions are of second order at TNh and of first order at TNl. In addition, an antiphase ordering state (Q = 2/3c*) becomes stable in high magnetic field applied along
the c-axis. The magnetism of UPd2Si2 is phenomenologically well explained in termsof the one-dimensional Ising model assuming localized 5f spins, whereas Fermi liquidbehavior with a moderately large electric-specific-heat coefficient ~ 30 mJ/molK2 isalso seen at low temperature [1]. In the present study, we have measured magnetizationof UPd2Si2 under high pressure up to 5.5 GPa and high magnetic field up to 7 T inorder to investigate the duality between the localized and the itinerant features of
the 5f-electronic states in U compounds. From the results of the magnetization andprevious resistivity measurements under high pressure [2], we will discuss about the
5f-electronic states of the compound.
[1] H. Honma et al., J. Phys. Soc. Jpn. 67 (1998) 1017. [2] H. Hidaka et al, J. Phys.: Conf. Ser. 273(2011) 012032.

The 19th International Conference on Magnetism

Masaki Sugishima1, Akihiro Mitsuda1, Hirofumi Wada1*, Masahiko Isobe2 and Yutaka
Ueda2
1
Department of Physics, Kyushu University, Japan
2
Institute for Solid State Physics, University of Tokyo, Japan

Takashi Nishioka 1, Yuta Oogane 1, Daishi Hirai 1, Harukazu Kato 1, Masahiro
Matsumura1, Yukihiro Kawamura2 and Chihiro Sekine2
1
Physics, Kochi University, Japan2
Physics, Muroran Institute of Technology, Japan

EuPtP is known to exhibit two valence order transitions at T1 = 235 K and T2 = 190 K[1]. At T > T1, the Eu ions have a single valence state with the mean valence of 2.16. At
T2 < T < T1, the Eu valence state is ordered with the sequence of -Eu2+-Eu2+-Eu3+-Eu2+Eu2+-Eu3+- along the c-axis. Moreover, the stacking is replaced by another sequencewith -Eu2+-Eu3+-Eu2+-Eu3+- below T2 [2]. Consequently, the successive valence ordertransitions are accompanied by increase in the Eu mean valence upon cooling. The
substitution of As for P expands the lattice and decreases both T1 and T2 [3]. In thisstudy, we report a phase diagram and the Eu valence state in EuPtP1-xAsx. For 0 <x < 0.4,
the resistivity, ρ, decreases with decreasing temperature, and shows an abrupt increaseat T1, followed by a sharp drop below T2. For x = 0.55 and 0.6, only a sharp increasein ρ was observed with decreasing temperature, suggesting a single valence ordertransition at T1. For x = 0.7, a slight upturn was observed in the ρ - T curve. Based onthese results, we will present a phase diagram of EuPtP1-xAsx.

CeFe 2Al 10 is an important reference material as CeRu 2Al 10 which indicates amysterious phase transition. We have performed the electrical resistivity and magnetic
susceptibility of substiututed systems, i.e., (Ce,La)Fe2Al10 and Ce(Fe,Co)Ru2Al10.
The former system reveals the effect of periodicity and the latter one reveals that ofelectron number. A broad peak, which is attributed to Kondo effect, monotonicallyshifts to higher and lower temperatures with La- and Co-substitution, respectively.
The electrical resistivity of CeFe2Al10 shows a broad peak at 60 K and sharp increase
below 15 K. A slight substitution of Ce by La and Fe by Co site remove the broad peak
and the increase at low temperatures. These results indicate the broad peak is due tocoherence effect and the increase is due to a semiconducting gap.

[1] N. Lossau et al. Z. Phys. B 74 (1989) 227. [2] T. Inami et al. Phys. Rev. B 82 (2010) 195133. [3]A. Mitsuda et al. To be published in EPJB.

July 10 (Tue)QC23
H. Kim1, M. A. Tanatar1, K. Cho1, J. Murphy1, R. Hu2, C. Petrovic2 and R. Prozorov1*
1
The Ames Laboratory, USA
2
Brookhaven National Laboratory, USA

196

poster Presentation

Kazunori Umeo1*, Kenichi Katoh2 and Toshiro Takabatake3
1
N-BARD, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526,
Japan
2
Department of Applied Physics, National Defense Academy, Yokosuka 239-8686,
Japan
3
AdSM and IAMR, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima
739-8530, JapanThe titled compound has three Yb sites in the tetragonal Sc5Co4Si10-type structure.
The magnetization process shows strong anisotropy [1]. At 2 K, M (B//a) is saturated
to 4.5 μB/f.u. in 5 T, whereas M (B//c) increases linearly up to 0.9 μB/f.u. at 5 T. The
effective magnetic moment for B//a is 4.25 μB/Yb, which is close to the value of 4.53
μB/Yb expected for the Yb3+ free-ion [1]. The continuous increase in the specific heat
down to the lowest measured temperature 2 K suggests a magnetic order below 2 K[1]. Therefore, we have measured the temperature dependence of the magnetizationM, specific heat C and resistivity down to 0.3 K. A cusp in M (B//a) and sharp peakin C(T) were observed at 0.5 K, both of which were suppressed by applying magnetic
fields up to 0.8 T. These findings indicate an antiferromagnetic order at TN = 0.5 K.
However, the magnetic entropy Sm at TN is only 60 % of Rln2. This observationsuggests a heterogeneous mixed valence state where three of five Yb ions in formula
unit are in trivalent state and the rest two are in divalent state.
[1] K. Katoh et al., Physica B 373 (2006) 111.

July 8-13, 2012 Busan, Korea

197

poster Presentation

poster Presentation

QD10

QD13

QD16

QE01

Magnetic field dependence of the resistivity minimum of nanosized YbAl3

Magnetic properties of ytterbium fluoride sulfide Yb3F4S2Magnetic behavior of polycrystalline Eu5Si3 compound

Critical behavior of a spin-1 triangular lattice Ising antiferromagnet

The ternary ytterbium fluoride sulfide Yb3F4S2 crystallizes in the tetragonal structurewith space group I4/mmm. This structure can be described as an alternative stack of
one layer of YbF2 and two layers of YbFS along the c-axis. In a previous paper, it wassuggested that there are two different ytterbium cations (Yb2+)(Yb3+)2(F-)4(S2-)2 present[1]. An anomaly with the long-range magnetic order has not been observed down to 0.4
K by magnetization measurements, and the magnetic susceptibility exhibits a CurieWeiss behavior above 50 K. However, it has become clear that the estimated value ofthe effective magnetic moment cannot be explained by a model which assumes thatYb2+ and Yb3+ occupy the two different crystallographic sites. A Schottky anomaly isfound in the temperature dependence of the specific heat around 1.0 K at zero magnetic
field. This anomaly is shifted towards higher temperatures with increasing appliedmagnetic field, and a release of the residual entropy is observed simultaneously.

The series R5X3 (R= light rare earth and X = Ga,Si,Ge,Sn,Sb), form in Cr5B3-type
tetragonal structure. There are two inequivalent ‘R’ sites in this structure, one of themshowing a very short distance between rare-earth atoms. Single crystal studies of Ce5Si3
show that metamagnetic transition temperature is different along ‘a’ axis and ‘c’ axis,
which was attributed to the two inequivalent sites of Ce atoms. Studies of R5X3 havebeen extensively reported for different rare earths with exception of Eu5Si3. Rietveld
analysis of x-ray diffraction shows the formation Eu5Si3 in the Cr5Br3-type tetragonal
structure (space group I4/mcm). Magnetization display a prominent cusp around32K corresponding to antiferromagnetic ordering. Zero field cooled and field cooledmagnetization is different below 30K, thereby showing a complex magnetic structure.
Magnetization for applied magnetic fields up to 12 T shows that this sample does notundergo metamagnetic transition like that in Ce5Si3. Heat capacity shows a peak below
32K which shifts to lower temperatures upon application of magnetic fields, like in a
typical antiferromagnet. Specific heat also shows a strong magnetic field dependence
below 20K, revealing the complex nature of magnetic ordering.

We employ Monte Carlo simulations in order to investigate critical behavior of afrustrated spin-1 Ising antiferromagnet on a triangular lattice in the presence of asingle-ion anisotropy. It has been previously found that no long-range order can exist
in the system with spin 1/2 [1] but it can occur if the spin is larger than some criticalvalue estimated as 11/2 [2]. We demonstrate that even small amount of the singleion anisotropy can change this scenario. More specifically, we show that long-rangeorder can exist in the low-temperature region even below this critical value, namely
for spin 1, within a certain range of the single-ion anisotropy strength. At higher
temperatures we identify another phase of the Berezinsky-Kosterlitz-Thouless typecharacterized by a power-law decay of the spin correlation function. We perform finitesize scaling analyses to calculate the correlation decay exponent. Subsequently, we
estimate the critical boundaries of both phases and plot the phase diagram as a functionof the single-ion anisotropy strength. This work was supported by the Scientific Grant
Agency of Ministry of Education of Slovakia Republic (Grant No. 1/0234/12).

Yb-based alloys follow the Doniach phase diagram where the competition between RKKY and Kondointeraction plays a predominant role. Among them, a simple cubic compound (Pm-3m) YbAl3 is a fine example
of strong electron correlations leading to intermediate valence behavior [1]. Recently, we have investigatedthe effect of crystallite size on the electronic and magnetic properties of the nanometric samples of thisalloy, prepared by high-energy milling of arc-melted ingots. Milling yields massive quantities of 4f-alloys in
nanocrystalline (nc-) form with a relatively narrow size distribution [2]. In nc-YbAl3, the variation of valence isdue to a modification of the fraction of surface atoms compared to the total number of particles. This affects both
specific heat and susceptibility data [3]. Here, we present a magnetic field (H)-dependent study of the electricalresistivity, ρ, of annealed and pressed pellets of nc-YbAl3. The XRD Rietveld refinements yield particle sizesof maximum ~10 nm whereas slightly smaller values are detected by HRTEM. The results are striking in thatthe physical properties change drastically compared to the bulk [4] and an unexpected minimum in ρ(T) occurs
around 15 K. With increasing H, the minimum becomes more pronounced and shifts to higher temperatures.

Masashi Kosaka1, Takuya Kobiyama1, Hiroko Aruga Katori2 and Naoki Shirakawa3
1
Graduate School of Science and Engineering, Saitama University, Japan
2
Division of Advanced Frontier Applied Physics, Tokyo University of Agriculture andTechnology, Japan
3
Nanosystem Research Institute, National Institute of Advanced Industrial Scienceand Technology, Japan

July 10 (Tue)Milan Zukovic* and Andrej Bobak
Department of Theoretical Physics and Astrophysics, Faculty of Science, P. J. Safarik
University, Slovakiaia[1] G.H. Wannier, Phys. Rev. 79 (1950) 357. [2] Y. Yamada et.al., J. Magn. Magn. Mater. 140-144(1995) 1749.

[1] T. Schleid et al., Z. Anorg. Allg. Chem. 626 (2000) 2429.

1. R. Pottgen et. al.Z. Anorganische und allgemeine Chemie, 624, 1998, 945. 2. Y. Ushida, M.
Kontani, Physica B, 281-282, (2000), 86-87. 3. Y. Ushida et. al. J. Phys. Soc. Japan, 70, (2001) 513.
4. F. Canepa et al J. Alloys and Comp. 203, (1994) L11.

QD11

QD14

QD17

QE02

Electronic states of Eu4As3 under high pressure

Physical properties of the layered oxypnictides (CeO)MnPn; Pn=As,
Sb

Valence fluctuation study by using X-ray absorption and emission
spectroscopies at Yb L3-edge in YbNi3X9 (X=Al and Ga)

Selectively diluted triangular lattice Ising antiferromagnet in an
external magnetic field

Quantum criticality of Ce- and Yb-based heavy fermion system has been recently
discussed from a viewpoint of valence fluctuation [1], thus the estimation of valence
guides in the solution for several anomalies observed near the quantum critical point(QCP). Recently, high-quality YbNi3X9 (X = Al and Ga) is newly synthesized [2,3] and isdesired to investigate the electronic states including the valence state as a heavy fermion
system. In order to clarify the Yb valence state in YbNi3X9, X-ray absorption and emission
spectroscopies at the Yb L3-edge have been performed at BL39XU of SPring-8. For
YbNi3Ga9, the Yb valence of 2.71 at room temperature almost linearly decreases to 2.60 at
55 K with decreasing temperature, and then the valence maintains a constant value at 2-55
K, while the valence of YbNi3Al9 is almost trivalent in a temperature range of 2-300 K.
Moreover, the XES spectra for YbNi3X9 give us detail information of Yb electronic statesby comparison with the result in several Yb-based compounds.

It is well known that the pure Ising model with nearest-neighbor antiferromagnetic
interactions on a triangular lattice shows no long-range ordering due to a high degreeof frustration. Dilution of one out of three sublattices with nonmagnetic impurities
can relieve the geometrical frustration globally and, above a certain dilution threshold,the system starts showing long-range magnetic ordering characterized by the secondorder phase transitions [1]. Within the effective-field theory with correlations wedemonstrate that the presence of a finite external field in the selectively diluted system
can dramatically change its critical behavior. In particular, above a certain field value
the system starts displaying tricritical behavior, i.e., as the dilution increases the phasetransition becomes initially of first order and only upon further dilution changes tothe second order. We confirm the existence of the first-order transition in the regionof moderate dilution and relatively high fields by Monte Carlo simulations. An Ising
antiferromagnet on a honeycomb lattice is treated as a special case when one sublattice
is completely removed by dilution. This work was supported by the Grant VEGA No.
1/0234/12.

[1] E. Bauer et al., Phys. Rev. B 52, 4327 (1995). [2] D. P. Rojas et al., J. Phys: Cond. Matter 19, 186214 (2007). [3]D. P. Rojas et al., Phys. Rev B 78, 094412 (2008). [4] D. M. Rowe et al., J. Phys. D: Appl. Phys. 35, 2183 (2002).

Hisao Kobayashi1*, Yoshitaka Yoda2 and Akira Ochai3
1
Graduate School of Material Science, University of Hyogo, Japan
2
Japan Synchrotron Radiation Institute, Japan3
Department of Physics, Tohoku University, JapanThe mixed valence Eu4As3 compound with an anti-Th3P4 structure shows the charge ordering
at 345 K and ambient pressure accompanied by trigonal distortion, which is similar to those in
Yb4As3 and Sm4Bi3 [1-3]. The hybridization of a narrow 4f band with broad conduction bands
is one of the important parameters in these charge-ordering compounds, which is possible to becontrolled by hydrostatic pressure. We observed the melting of the static charge order at about
10 GPa and room temperature without structural change using high-pressure X-ray diffraction[4]. We have carried out 151Eu nuclear forward scattering (NFS) measurements usingsynchrotron radiation under high pressures at low temperatures to investigate the magnetic
properties of Eu4As3. Clear quantum beats due to magnetic hyperfine field were observedin 151Eu NFS spectra at 6 K under pressure up to 14.5 GPa. The results of temperaturedependences of 151Eu NFS spectra reveal that a magnetic ordering temperature increases
linearly with pressure up to 10 GPa. Above 10 GPa, the magnetic ordering temperature
decreases gradually with pressure. Consequently, the pressure dependence of the magnetic
ordering temperature is related to the melting of the static charge order.

Morosawa Yasuhiro1, Takase Koichi1*, Onizawa Manami1, Moriyoshi Chikako2,
Kuroiwa Yoshihiro1, Watanabe Tadataka1 and Takano Yoshiki1
1
Nihon University, Japan
2
Hiroshima University, Japan

Recently, the layered iron oxypnictides (LaO)FePn ; Pn = P, As, Sb, which belong to the tetragonal system,
have attracted much attention due to the discovery of the superconductors (LaO)FeP [1] and (LaO)FeAs [2].
Many efforts have been dedicated to explore the superconductor with the highest transition temperature.
In this tidal stream, many new materials with different physical properties have been found. In case of
selection of the cerium atom as a rare earth element, these materials of (CeO)FeP [3], (CeO)FeAs [4],(CeO)CoP [5], (CeO)CoAs [6] show the typical metallic properties and the Fermi liquid behaviors at
low temperature. In these systems, the 3d electrons of the iron and cobalt have finite density of state at
the Fermi energy, and the cerium atom provides the f electrons as carriers at the same time. Namely, it isdifficult to know which effects are dominant. In our group, the semiconductor based materials (LaO)MnPn
have been focused and the substitution effects of the rare earth elements on the physical properties havebeen investigated. (CeO)MnAs and (CeO)MnSb indicate metallic character and the Fermi liquid behaviors
below 30K and 8 K, respectively due to the valence fluctuation of the Ce f electrons.

[1] A. Ochiai, et al., J. Phys. Soc. Jpn. 72, 3174 (2003). [2] A. Ochiai, et al., J. Phys. Soc. Jpn. 59,
4129 (1990). [3] A. Ochiai, et al., J. Magn. Magn. Mater. 52, 13 (1985). [4] H. Kobayashi, et al., J.
Phys.: Condens. Matter 20 415217 (2008).

[1] Y.Kamihara et al., PHYSICAL REVIEW B 77, 214515 (2008). [2] Y.kamihara et al., J. AM. CHEM. SOC.
130, NO. 11, 3296-3297 (2008). [3] Y.Kamihara et al., Journal of Physics and Chemistry of Solids 69 29162918 (2008). [4] G. F. Chen et al., PHYSICAL REVIEW LETTERS 100, 247002 (2008). [5] C. Krellner et al.,PHYSICAL REVIEW B 404, 3206-3209 (2009). [6] Rajib Sarkar et al., Phys. Rev. B 82, 054423 (2010).

QD12
Pressure effect on intermediate valence semiconductor SmB 6 :11B-NMR

Kouhei Nishiyama1, Gabriel Pristas2, Takeshi Mito1, Takao Kohara1, Slavomir
Gabani2, Marian Reiffers2, Yasuhiro Komaki3, Mitutane Kokubu3, Hideto Fukazawa3,
Yoh Kohori3, Nao Takeshita4 and Natalia Shitsevalova5
1
Graduate school of Material Science, University of Hyogo, Japan
2
Institute of Experimental Physics, Slovakia Academy of science, Slovakia
3
Graduate School of Science, Chiba University, Japan
4
Nanoelectronics Research Institute, National Institute of Advanced Industrial
Science and Technology, Japan
5
Institute for Problems of Material Science, National Academy of science of Ukraine,
UkraineThe intermetallic compound SmB6 is one of the most famous compounds in terms of the physics ofintermediated valence state, heavy Fermion systems and Kondo insulators. Recent high pressure measurementsof 149Sm nuclear forward scattering and resistivity revealed that a pressure-induced insulator-metal transitionof SmB6 is intimately connected with a long-range magnetic order, which has renewed interest in thiscompound. In order to investigate variations of the ground state and magnetic properties in SmB6, we havecarried out 11B-NMR measurement under pressure. While our group had reported the results of 11B-NMR
measurements up to 2.6 GPa with a piston-cylinder type pressure cell, the use of a Bridgman Anvil Cell has
recently enabled us to perform NMR measurements at higher pressures than 4.5 GPa. Spin-lattice relaxation
rate 1/T1 above 20 K roughly follows an exponential function of temperature, Exp(-Eg/2kBT), consistent withprevious reports. 1/T1 between 20 and 100 K increases with increasing pressure, indicating a reduction of theinsulating gap. We will discuss detailed pressure dependences of the energy gap and the Sm valence.

198

Sujata M. Patil1*, P. L. Paulose2 and E. V. Sampathkumaran2
1
Wilson College, Mumbai 400007, India
2
Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India

The 19th International Conference on Magnetism

Naomi Kawamura1, Masaichiro Mizumaki1, Hisashi Hayashi2, Noriko Kanai2,
Kazuyuki Matsubayashi3, Yoshiya Uwatoko3, Tetsuro Yamashita4 and Shigeo Ohara4
1
Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Japan2
Department of Chemical and Biological Science, Japan Women's University, Japan
3
Institute for Solid State Physics, University of Tokyo, Japan
4
Department of Engineering Physics, Nagoya Institute of Technology, Japan

Andrej Bobak*, Michal Borovsky and Milan Zukovic
Department of Theoretical Physics and Astrophysics, Faculty of Science, P.J. Safarik
University, Slovakiaia[1] S. Watanabe, et al., Phys. Rev. Lett. 105, 186403 (2010). [2] S. Ohara, et al., J. Phys.: Conf. Ser.
273, 012048 (2011). [3] T, Yamashita, et al., J. Phys. Soc. Jpn. 81, 034705 (2012).

[1] H. Kaya, A.N. Berker, Phys. Rev. E 62 (2000) R1469.

QD15

QD18

QE03

31P-NMR study of valence fluctuating compound EuPtP

Angle-resolved photoemission spectroscopy of mixed-valence Sm1-xYxS

Possible magnetic transition observed in S=1/2 kagome
antiferromagnet volborthite by high field ESR

Takeshi Mito1, Koji Nishitani1, Takehide Koyama1, Koichi Ueda1, Takao Kohara1,
Akihiro Mitsuda2, Masaki Sugishima2 and Hirofumi Wada2
1
University of Hyogo, Japan
2
Kyushu University, Japan
We report the results of the first 31P-NMR measurements on the hexagonal layered
compound EuPtP. This compound exhibits two valence transitions at T1= 235 K
and T2= 190 K. Various experiments, including magnetization, Eu Mossbauer, andx-ray diffraction measurements [1-5], have been carried out in order to investigate thevalence transitions so far, however the ordered structures below T1 and T2 have notbeen fully clarified. We observed 31P-NMR signals in all three phases. They show
anomalies at T1 and T2, and the Knight shift of the 31P-NMR lines reach ~ 20 % at
low temperatures due to large effective moments of magnetic Eu2+ ions. Below T2,
three resonance lines of 31P-NMR were observed, which should reflect local symmetryat the P-site. Based on these information obtained from the NMR measurements(spectrum and spin lattice relaxation time T1, and so on), we discuss possible orderedstructures at low temperatures of EuPtP.
[1] N. Lossau et al., Z. Phys. B 74, 227 (1989). [2] N. Lossau et al., Z. Phys. B 77, 393 (1989). [3] G.
Michels et al., Z. Phys. B 98, 75(1989). [4] A. Mitsuda et al., J. Phys: Condens. Matter 22, 226003(2010). [5] T. Inami et al., Phys. Rev. B 82, 195133 (2010).

Keiichiro Imura1*, Tetsuya Hajiri2, Masaki Kaneko2, Yusuke Nishi2, Hiroyuki S.
Suzuki3, Noriaki K. Sato2, Takahiro Ito2, Masaharu Matsunami1 and Shin-ichi Kimura1
1
UVSOR Facility, Institute for Molecular Science, Japan
2
Nagoya University, Japan
3
National Institute for Materials Science, Japan
It is known that samarium mono-sulfide (SmS) exhibits an insulator-to-metal transition,so called Black-to-Golden phase transition, by the application of pressure or by thesubstitution of Sm ions [1,2]. Although extensive studies to investigate the mechanismof this transition as well as the ground state of golden phase have been made, the phasetransition has net been perfectly clarified yet. In this study, we focus on Sm1-xYxS
system in order to investigate the electronic structure of these two phases by an angleresolved photoemission spectroscopy (ARPES). Single crystals of Sm1-xYxS (x = 0, 0.17,0.33) were grown by the Bridgman technique using a high-frequency induction furnace
installed in NIMS. Photoemission spectroscopy measurement on these crystals was
performed at UVSOR-II BL5U end station. The obtained ARPES spectrum of pure
SmS (x = 0) has an energy gap of about 0.4 eV which is consistent with a previous
report [3]. This energy gap decreases with increasing x, and the top of the Sm2+ 4f band
touches the Fermi level in x = 0.33. This result suggests that the Golden phase inducedby the yttrium substitution is a mixed-valence state.
[1] A. Jayaraman, et al., Phys. Rev. Lett. 25 (1970) 1430. [2] L. J. Tao and F. Holtzberg Phys. Rev.
B 15 (1975) 3842. [3] T. Ito, et al., Phys. Rev. B 65 (2002) 155202.

July 10 (Tue)C. Echevarria-Bonet1*, D. P. Rojas2, L. Fernandez Barquin1, J. C. Gomez Sal1, S. N.
Kaul3, B. Coqblin4, S. G. Magalhaes5 and E. Bauer6
1
CITIMAC, Universidad de Cantabria, Spain
2
Departamento de Fisica, Universidad Carlos III de Madrid, Spain
3
School of Physics and Centre for Nanotechnology, University of Hyderabad, India
4
Laboratoire de Physique des Solides, CNRS-Universite Paris-Sud, France
5
Instituto de Fisica, Universidade Federal Fluminense, Brazil
6
Institute of Solid State Physics, TU Wien, Austria

Hitoshi Ohta1*, Wei-min Zhang1, Susumu Okubo1, Takahiro Sakurai2, Yoshihiko
Okamoto3, Hiroyuki Yoshida4 and Zenji Hiroi3
1
Molecular Photoscience Research Center, Kobe University, Japan
2
Center for Supports to Research and Education Activities, Kobe University, Japan
3
Institute for Solid State Physics, University of Tokyo, Japan
4
National Institute for Materials Science (NIMS), JapanDue to the recent discovery of model substances, such as ZnCu 3 (OH) 6 C l2
(herbertsmithite), Cu3V2O7(OH)2∙2H2O(volborthite) and BaCu3V2O8(OH)2(vesignieite),
S=1/2 kagome antiferromanet has attracted much interest experimentally, and wesuggested a gapless spin liquid state in vesignieite [W. Zhang et al, J, Phys. Soc. Jpn.
79 (2010) 023708.]. In this paper we will report on high field ESR results of volborthite
powder sample. For the spin dynamics volborthite shows the g-shift below around 20 K
similar to vesignieite [H. Ohta et al., Phys. Status Solidi B 247(2010) 679.]. However,it shows two modes at 1.8 K, mode A with a very small gap of about 40 GHz (1.9 K)
and mode B with no gap. Existence of mode B may suggest the spin liquid state withno spin gap at 1.8 K. Moreover, two modes cross at around 4.5 T, which corresponds
to magnetization anomaly at 4.3 T. Detailed frequency dependence measurement up to
30 T at 1.8 K shows also new anomaly at 14 T. Possible magnetic transitions at 4.3 and
14 T will be discussed in connection with recent NMR result on volborthite powder.
Finally very recent high-filed ESR result using single crystal of volborthite will be alsopresented.

July 8-13, 2012 Busan, Korea

199

poster Presentation
QE04

QE07

QE10

QE13

Field-induced staggered moment stabilization in frustrated quantum
magnets

Gapless spin excitation of the triangular-lattice antiferromagnet

Origin of field induced magnetic ordering in frustrated honeycomb
lattice antiferromagnet

Kasteleyn transitions in the spin ice Dy2Ti2O7

For low-dimensional frustrated magnets, the dependence of the staggered moment
on a magnetic field is nonmonotonic: For small and intermediate fields, quantum
fluctuations are gradually suppressed, leading to an increase of the staggered moment
as function of the field strength. For large applied magnetic fields, the classically
expected field dependence is recovered, namely a monotonous decrease with increasing
field strength. The staggered moment is eventually suppressed when reaching thefully polarized state at saturation. The quantitative analysis of this behavior is an
excellent tool to determine the frustration parameter of magnetic compounds. We havedeveloped a general finite-size scaling scheme for numerical exact-diagonalization
data of low-dimensional frustrated magnets, which we apply to the recently measured
field dependence of the magnetic neutron scattering intensity of Cu(pz)2(ClO4)2 in
the framework of the S=1/2 two-dimensional J_1-J2 Heisenberg model. We also apply
linear spin-wave theory to complement our numerical findings. Our results showthat Cu(pz)2(ClO4)2 is a quasi-2D antiferromagnet with intermediate frustration J_2/
J_1=0.2. A self-consistent RPA theory for the magnetic ordering temperature showsthat with this ratio the observed reentrant behavior of the latter as function of theapplied magnetic field can be understood as a consequence of the reduced quantum
fluctuations as well.

Two-dimensional frustrated magets including the triangular-lattice antiferromagnet(TLA) have attracted much attention. However, a useful method among unbaised
computational methods is limited to being the numerical-diagonalization method that
can treat only small systems. In spite of such situation, great efforts have been done forstudies of the TLA; it is widely believed that the ground state of TLA has a long-rangeorder of 120-degree structure. The existence of this order indicates that spin excitation
is gapless; however, the system size (N) dependence of the singlet-triplet energy
difference of finite-size clusters shows a peculiarity that a nonzero spin gap seems tosurvive in the extrapolation with respect to N[1]. Under circumstances, we calculate thesinglet-triplet energy difference of possible all the finite-size clusters up to 39 sites by
our MPI-parallelized code of the numerical-diagonalization method. The analysis usedin the study of the spin-gap issue of the kagome-lattice antiferromagnet[2] is applied
to the TLA. The present examination successfully confirms a gapless spin excitation,
which is consistent with the existence of the long-range order.

QE05

QE08

QE11

QE14

Structural and magnetic properties of single crystals of volborthitecomprising a distorted spin-1/2 kagome lattice

Magnetic properties of the spin-1/2 kagome antiferromagnets:
vesignieite BaCu3V2O8(OH)2 and CdCu3(OH)6Br2

Semi-classical spin-liquid state as a low-energy excited state in
frustrated quantum spin systems on triangle-based lattice system

Novel frustrated quantum antiferromagnets in the solid-solution
Cs2CuCl4-xBrx through site-selective halide substitution

Hiroki Nakano1* and Toru Sakai2
1
University of Hyogo, Japan
2
JAEA, SPring8, Japan[1] J. Richter et al.: Phys. Rev. B 70 (2004) 174454. [2] H. Nakano and T. Sakai: J. Phys. Soc. Jpn.
80 (2011) 053704.

Hajime Ishikawa1*, Yoshihiko Okamoto1, Junichi Yamaura1, Hiroyuki Yoshida2,
Gøran J. Nilsen1 and Zenji Hiroi1
1
ISSP, the University of Tokyo, Japan
2
NIMS, Japan

Yoshihiko Okamoto1*, Makoto Yoshida1, Hajime Ishikawa1, Gøran J. Nilsen1,
Hiroyuki Yoshida2, Masashi Takigawa1 and Zenji Hiroi1
1
Institute for Solid State Physics, Univ. of Tokyo, Japan
2
National Institute for Materials Science, Japan

In geometrically frustrated magnets, exotic ground states such as a spin liquid
are expected to realize as a result of competing magnetic interaction. Volborthite
Cu3V2O7(OH)2∙2H2O has drawn attention as a model compound for the distorted spin1/2 kagome antiferromagnet. Previous studies using powder samples showed a peculiar
magnetic transition at 1 K. Recently, H. Yoshida et al. synthesized a small single
crystal, and found a structural phase transition at 310 K and two magnetic transitions ataround 1 K, which have not been observed in powder samples. To clarify the physicalproperties of volborthite at low temperatures, we tried to synthesize a large and highquality single crystal and obtained large single crystals of 2.5×1.5×0.1 mm in size as aresult of improving synthesis conditions. By means of single crystal XRD, we founda new crystal polymorph at room temperature which crystallizes in space group C2/
c, not in C2/m as reported before. There is a phase transition upon cooling at around
290 K to an I2/a phase, similar as in the C2/m phase. In this presentation, we show thedifferences of structure and magnetic properties between various polymorphs.

An ideal model system for the spin-1/2 kagome antiferromagnet has not yet beenobtained and the search for that is still going on. Here we report the magnetic
properties of two Cu minerals, vesignieite BaCu3V2O8(OH)2 and CdCu3(OH)6Br2, bothof which comprise spin-1/2 kagome lattices. Vesignieite has a nearly isotropic kagome
lattice and was found to show neither Neel order nor a spin-glass transition above 2
K [1]. However, the intrinsic ground state has remained unsolved, because previous
samples contained many impurity spins caused by the low crystallinity. Recently, we
succeeded in improving the sample quality by optimizing preparation parameters underhydrothermal conditions. The magnetic susceptibility of the new sample increases
steeply below 15 K, followed by a sharp peak at 9 K that is indicative of long-range
antiferromagnetic order. CdCu3(OH)6Br2 has an isotropic kagome lattice made of Cu2+
ions. The compound is an antiferromagnet with a Weiss temperature of -48 K andshows long-range antiferromagnetic order at 7 K. Thus, both the compounds show
long-range order at rather high temperatures, which may be due to significantly large
interlayer magnetic interactions.

2

3

4

1

Susumu Okubo *, Tomonari Ueda , Wei-min Zhang , Takahiro Sakurai , Masashi Fujisawa , Hitoshi
Ohta1, Nozomi Ohnishi5, Masaki Azuma6, Yuichi Shimakawa5 and Nobuhiro Kumada7
1
Molecular Photoscience Research Center, Kobe University, Japan
2
Graduate School of Science, Kobe University, Japan
3
Center for Collaborative Research and Technology Development, Kobe University, Japan
4
Center for Supports to Research and Education Activities, Kobe University, Japan
5
Institute for Chemical Research, Kyoto University, Japan
6
Materials and Structures Laboratory, Tokyo Institute of Technology, Japan
7
Graduate School of Medicine and Engineering, University of Yamanashi, JapanThe ground state of honeycomb lattice antiferromagnet (HLAF) have been considered theoreticallyto be the Neel state similar to the square lattice antiferromagnet because both antiferromagnets
are bipartite lattices. However, the honeycomb lattice has smaller coordination number 3 than
the square lattice of 4 and it is close to the one dimensional chain. Therefore, the stronger spin
fluctuation is expected in the HLAF. Actually, anomalous spin dynamics are reported in S=1/2
HLAF InCu3/2V1/3O3 [1]. On the other hand, the spin liquid state is expected in S=3/2 HLAF
Bi3Mn4O12(NO3) due to no long range order down to 0.4K despite of the large Weiss temperature.
Although no spin gap has been observed in the magnetic susceptibility of Bi3Mn4O12(NO3),
it shows the field-induced magnetic ordering (FIMO) above around 6 T. Neutron diffraction
measurements confirmed FIMO state and suggested that Dzyaloshinski-Moriya (DM) interaction
plays an important role in the FIMO state. In order to estimate the DM interaction, high-field ESR
measurements have been performed. The D-term of DM interaction is estimated to be 1.3K fromthe analysis of observed antiferromagnetic resonance mode. Origin of FIMO will be discussed inconnection with the DM interaction and the other magnetic anisotropy.
[1] S. Okubo et al, J. Phys. Soc. Jpn. 80 (2011) 023705

Makoto Isoda1, Hiroki Nakano2 and T^oru Sakai3
1
Kagawa University, Japan
2
University of Hyogo, Japan
3
JAEA SPring-8, JapanThe magnetic and the thermal properties of the spin-1/2 Heisenberg antiferromagnets on the trianglebased lattice are summarized , focusing on the realization of the semi-classical spin-liquid state of
the resonating doublet trimers formed on triangles, through the calculations for various systems
such as the triangular , the kagome, the triangulated-kagome1), the Sierpinski-gasket like2) and thespatially anisotropic triangular lattices, which interpolates the triangular and the kagome lattices.
The calculations have been performed by the numerical diagonalization method. On these systems,
the peculiar behaviors have been found in the Heisenberg3,4) and the Ising5) models for spin1/2 on those triangle-based lattices with nearest neighbor (nn) antiferromagnetic interaction. The
peculiarities are the bending of the magnetic susceptibility as a function of temperature, the more than
two peaks structure on the specific heat and the 1/3 magnetization plateau under magnetic field. Eachof these peculiarities appears at the characteristic temperature or magnetic field corresponding to themagnitude of nn interaction, suggesting the predominance of the doublet trimer low energy excitedstate. The peculiarities reveal as an intrinsic character of the systems with the nn antiferromagnetic
interaction depending on whether the lattice is formed by the equilateral triangle as a unit cell or not.

Hiroaki Kadowaki1*, Naohiro Doi1, Hiroshi Takatsu1, Ryuji Higasginaka1, Yuji Muro2, Kiyoichiro
Motoya3, Rei Morinaga4, Taku J Sato4, Takashi Tayama5, Toshiro Sakakibara4, Kazuyuki Matsuhira6
and Zenji Hiroi4
1
Department of Physics, Tokyo Metropolitan University, Japan
2
Toyama Prefectural University, Japan3
Department of Physics, Tokyo University of Science, Japan
4
Institute for Solid State Physics, University of Tokyo, Japan
5
Department of Physics, University of Toyama, Japan
6
Department of Electronics, Kyushu Institute of Technology, JapanThe spin ice model in the pyrochlore lattice, e.g. Dy2Ti2O7, consisting of corner sharing tetrahedra
has attracted much attention because of its intriguing frustration mechanism. The ground states of thissystem are macroscopically degenerate with the finite zero-temperature entropy, and the spins freeze
in this manifold at low temperatures. The macroscopic degeneracy of the ground states is partly lifted
under magnetic fields, where degrees of the degeneracy depend on direction and strength of the field.
Interesting theoretical predictions, which have not been seriously investigated to date by experiments,
are Kasteleyn transitions [1] in three and two space dimensions, which may occur under magnetic
fields along a [100] direction [2] and fields tilted slightly from a [111] direction [3]. These transitions
are classified into topological phase transitions which are characterized by line (string) defects. We
have investigated these possibilities in the spin ice compound Dy2Ti2O7 using magnetization andspecific heat measurements.
[1] P. W. Kasteleyn, J. Math. Phys. 4, 287 (1963). [2] L. D. C. Jaubert et al. Phys. Rev. Lett. 100,067207 (2008). [3] R. Moessner, S. L. Sondhi, Phys. Rev. B 68, 064411 (2003).

Bernd Wolf*, Pham Thanh Cong, Natalia Kruger, Franz Ritter, Wolf Assmus andMichael Lang
Physics Institute, Goethe-University Frankfurt (M), SFB/TR 49, D-60438 Frankfurt(M), Germany
We report on the magnetic properties of tetragonal and orthorhombic single crystals of the solid
solution Cs2CuCl4-xBrx (0 ≤ x ≤ 4). Two phase regions, namely an A-type orthorhombic and a
B-type tetragonal structure, were detected in this system depending on the growing conditions.
The two known orthorhombic end-member compounds Cs2CuCl4 and Cs2CuBr4 are classified
as quasi-two-dimensional quantum antiferromagnets with different degrees of magnetic
frustration. By measurements of the magnetic susceptibility χ(T) on orthorhombic single
crystals with different Br concentrations, we found that the in-plane and out-of-plane magnetic
correlations, probed by the position and height of a maximum in χ(T), respectively, do not show
a smooth variation with x. Instead three distinct concentration regimes can be identified, which
are separated by critical concentrations xc1 = 1 and xc2 = 2. This unusual magnetic behaviour
can be explained by considering the structural peculiarities of the materials, which support asite-selective replacement of Cl- by Br- ions [1]. Consequently, the critical concentrations xc1(xc2) mark particularly interesting systems, where one (two) halide-sublattice positions are fully
occupied. The magnetic properties of the tetragonal phase of Cs2CuCl4-xBrx differ strongly fromthose of the orthorhombic variants, reflecting changes in the Cu-coordination.

[1] Y. Okamoto et al., J. Phys. Soc. Jpn. 78, 033701 (2009).

1) M.Gonzalez et al., Mol. Cry. Liq. Cry. 233 (1993) 317. 2) T. Stosic et al., Phys. Rev. E 49 (1994) 1009. 3) M.Isoda,
H.Nakano and T.Sakai, Mod. Phys. Lett. B 25 (2011) 909. 4) M.Isoda, H.Nakano and T.Sakai, J. Phys. Soc. Jpn. 80 (2011)084704. 5) M.Isoda, J. Phys.: Condens. Matter 20 (2008) 315202.

QE06

QE09

QE12

QE15

High-field study of multiferroic Ni3V2O8Spin dynamics of triangular spin tubes

High pressure and low-temperature 31P NMR study of the twodimensional frustrated square lattice compound BaCdVO(PO4)2

Strong geometrical frustration in Fe oxychalcogenide

Junfeng Wang1, Masashi Tokunaga2, Zhangzhen He3 and Koichi Kindo2
1
Wuhan National High Magnetic Field Center, China
2
The Institute for Solid State Physics (ISSP), The University of Tokyo, Japan3
Fujian Institute of Research on the Structure of Matter, Chinese Academy of
Sciences, China

WN
A
R

D

TH
I
W

Hirotaka Manaka1* and Yoko Miura2
1
Graduate School of Science and Engineering, Kagoshima University, Japan
2
Suzuka National College of Technology, Japan
Triangular spin tubes belong to a new category of one-dimensional Heisenberg
antiferromagnets along the tubes coexisting with geometrically frustrated spin systems
in the triangular plane. Recently, we discovered that chromium fluoride CsCrF4 forms
ideal equilateral triangular spin tubes with S=3/2[1]. All Cr ions are at equivalent sites,and each angle of Cr-Cr-Cr in the triangular plane is 60 deg.[2] Because superexchangeinteractions through the three Cr-F-Cr paths in each equilateral triangle may be kept
in equilibrium at 0 K, we propose resonating spin-singlet pairs in each equilateraltriangle. From DC magnetic susceptibility and adiabatic heat capacity data above 1.5 K,
we concluded that there is no magnetic phase transition. Therefore, CsCrF4 consists ofa gapless spin-liquid ground state encompassing resonating spin-singlet pairs not onlyin each equilateral triangle but also along the tubes[2]. To clarify spin dynamics of thespin-liquid ground state, we performed linear and nonlinear AC magnetic susceptibility
measurements on CsCrF4. As a result, temperature dependence of a linear susceptibility
exhibits a positive peak at around 4 K, while a nonlinear susceptibility exhibits a broadand negative peak at around 3.5 K. We found that a spin-glass like state was realized
below 4 K.
[1] H. Manaka et al., J. Phys. Soc. Jpn. 78, 093701 (2009). [2] H. Manaka et al., J. Phys. Soc. Jpn.
80, 084714 (2011).

200

1

The 19th International Conference on Magnetism

Yuji Furukawa1, Beas Roy1, Ramesh Nath2, David C Johnston1, Yasuhiro Komaki3,
Hideto Fukazawa3 and Yoh Kohori3
1
Department of Physics and Astronomy, Iowa State University / Ames Laboratory,USA
2
Indian Institute of Science Education and Research, India
3
Department of Physics, Chiba University, Japan
We report first NMR study under pressures on BaCdVO(PO4)2, a S = 1/2 frustrated
square-lattice (FSL) compound with a nearest neighbor exchange coupling J1 ~ - 3.36
K and a next-nearest neighbor exchange coupling J2 ~ 3.53 K bearing J2/ J1 ~ 1.05.
Based on the J2/J1 ratio, the system is known to be located close to the disorderedground state (known as 'nematic state') regime of the phase diagram. We havecarried out 31P-NMR measurements under high pressure (up to ~ 2 GPa) and at low
temperatures (down to ~0.1 K) using a dilution refrigerator to investigate the pressure
effects on the magnetic properties of the system from microscopic point of view. Under
ambient pressure, we observed a sharp peak in 31P spin lattice relaxation rate (1/T1)
at TN ~ 1.05 K at H = 2.67 T, which corresponds to the antiferromagnetic ordering
temperature. With increasing pressure, the peak position of 1/T1 shifts to lower
temperature. This indicates that TN decreases with the application of pressure. We will
discuss pressure effects on magnetic state based on the temperature dependence of the
NMR spectra and of the 1/T1 under different magnetic fields and pressures.

July 10 (Tue)Burkhard Schmidt*, Mohammad Siahatgar and Peter Thalmeier
Max-Planck-Institut fur Chemische Physik fester Stoffe, Germany

July 10 (Tue)poster Presentation[1] P. T. Cong et al., PRB 83, 064425, (2011)

Sungdae Ji1, K. Horigane2 and K. Yamada3
1
CROSS, Japan
2
University of Virginia, USA
3
Tohoku University, Japan

After Fe-based superconductors have emerged, it has generated a lot of controversies
regarding to low ordered moments in parent compounds which have been explainedby itinerant magnetism with Fermi surface nesting vs. magnetic frustration and/or fluctuation effects in a large-local-moment system [1]. Very recently, Feoxychalcogenide has drawn attention, because it has been identified as a layered
insulating antiferromagnet with the geometrically frustrated, so-called, “double
diagonal stripe” spin structure which is realized only in Iron telluride among thefamily of Fe-based superconductors [2,3]. Here, we report elastic and inelastic neutron
scattering study on La2O2Fe2OSe2. Our elastic neutron measurement at 5 K shows thatmagnetic Bragg peaks are diffusive and a obtained magnetic moment is 2.2 μ_B, whichis smaller than a localized spin, S=5/2. Inelastic neutron scattering measurement showsthat a strong magnetic fluctuation survives even at 300 K far above magnetic transition
temperature, T_N = 90 K. Moreover, observed dispersive excitation reveals that the
3rd nearest neighbor interaction is the key to explain a magnetic ground state on thegeometrically frustrated lattice.
[1]. David C. Johnston, Adv. in Phys. 59, 803 (2010). [2]. Jian-Xin Zhu et al., Phys. Rev. Lett. 104,
216405 (2010). [3]. David G. Free and John S. O. Evans, Phys. Rev. B 81, 214433 (2010).

July 8-13, 2012 Busan, Korea

201

poster Presentation
QE16

QE19

QE22

QE25

Magnetic properties of the frustrated magnet Cu5(PO4)3(OH)4 on apeculiar spin network composed of pentagons and triangles

Order and excitations in the frustrated quantum spin ladder BiCu2PO6

Field-induced staggered moments in the spin-gapped antiferromagnet
on a deformed kagome lattice, Rb2Cu3SnF12First-principles study of S=1/2 Kagome antiferromagnet

P. Merchant1, S. Wang2, O. Zaharko3, Ch. Niedermayer3, L. P. Regnault4, M. Boehm4,
M. Kenzelmann2 and Ch. Ruegg3
1
London Centre for Nanotechnology, University College London, United Kingdom
2
Laboratory for Developments and Methods, Paul Scherrer Institute, Switzerland
3
Laboratory for Neutron Scattering, Paul Scherrer Institute, Switzerland
4
Institut Laue-Langevin, France

Chung-yuan Ren*
National Kaohsiung Normal University, Taiwan

3-D systems with interacting spins usually develop static long-range order when they
are cooled. However, quantum fluctuations are enhanced in low dimensionality systemwith low spin value and lead to suppress the long-range ordering, and can show someextremely subtle, complex, and sometimes even useful magnetic behavior in solids.
Here, using first-principles calculations, we investigated the atomic structural andmagnetic properties of S=1/2 Kagome antiferromagnet AxCu4-x(OH)6Cl2 (A=Zn, alkali
metal ion). Cu ions are indeed found to locate at the tetragonally elongated intralayersite and Zn ions favorably rest on the higher symmetry interlayer site, in support ofexperimental contention. The intra- and inter-layer exchange interactions are studied
in details. The effect of Dzyaloshinskii-Moriya interaction on the magnetic structure isalso discussed.

Quantum spin ladders are exceptional model systems showing non-trivial phenomena
ranging from complex spin correlations in the ground state to rich phase diagrams withseveral quantum critical points. A fully quantitative understanding of their magnetic
and thermodynamic properties may be achieved e.g. by powerful computational
methods (DMRG, ED, bond operators) [1, 2] and comparison with high-precisionexperimental data, which may only be possible in such model systems [3]. BiCu2PO6
is a new prototypical model material in which the spin ladders are frustrated by nextnearest neighbour exchange along the ladder legs, furthermore it can be doped with
non-magnetic Zn2+ impurities. The results of comprehensive neutron scattering studies
on single crystals are presented of the elementary excitations and spin Hamiltonian of
this frustrated ladder compound, as well as of the Zn-induced magnetic order and phase
diagrams. The physics in this system is dominated by incommensurate correlations on
all energy scales.

Rb2Cu3SnF12 is a kagome lattice antiferromagnet in which Cu2+ ions with spin 1/2 interact with four
exchange interactions, J1~200K>J2>J3>J4~100K. The ground state of this compound is a valence bondsolid owing to the quantum and frustration effects, so that no magnetic ordering occurs [1,2]. We have
performed 19F-NMR experiments on a single crystal of Rb2Cu3SnF12 in order to clarify the microscopic
property of the ground state. One sharp 19F-NMR spectrum at high temperature splits to several peaks at
low temperatures due to different magnetic sites of 19F. The shifts of these peaks increase steeply below
around 70K, whereas the static susceptibility decreases exponentially below this temperature owing to
the singlet ground state with the spin-gap. The shifts are proportional to the applied field. These results
strongly suggest that the local fields are produced by the staggered moments induced by the external field
through Dzyaloshinsky-Moriya interaction. The staggered moments become dominant below 70K, while
the parallel moments are remarkably small because of the large exchange interaction. This characteristic
temperature differs from the spin-gap of 20K obtained from the susceptibility, because the large density ofstate in the dispersion curve around 70K contributes to the generation of the staggered moments [3].

[1] P. Bouillot et al., Phys. Rev. B 83, 054407 (2011). [2] B. Normand and Ch. Ruegg, Phys. Rev. B
83, 054415 (2011). [3] e.g. see B. Thielemann et al., Phys. Rev. Lett. 102, 107204 (2009).

[1] K. Morita, M. Yano, T. Ono, H. Tanaka, K. Fujii, H. Uekusa, Y. Narumi, and K. Kindo, J. Phys. Soc. Jpn. 77, 043707 (2008). [2]K. Matan, T. Ono, Y. Fukumoto, T. J. Sato, J. Yamaura, M. Yano, K. Morita, and H. Tanaka, Nature Phys. 6, 865-869 (2010). [3] H.
Tashiro, M. Nishiyama, A. Oyamada, T. Itou, S. Maegawa, M. Yano, T. Ono, and H. Tanaka, J. Phys.: Conf. Ser. 320, 012052 (2011).

QE17

QE20

QE23

QE26

Single crystal growth and magnetic properties of novel kagome
compound KMn3Ge2O9

Melting of the spin ice state in Dy2(Ti1-xZrx)2O7 without dilution of rareearth ion

Magnetic order in finite size domains of the honeycomb latticecompound InCu2/3V1/3O3

Exotic phases in the frustrated hexagonal lattice

Orthorombic Cu5(PO4)2(OH)4 (pseudomalachite) is a layered compound. Each Cu-O
layer in this compound is well separated by PO4 tetrahedrons. Spin network in bcplane of pseudomlachite is composed of triangles and pentagons, which will induce thespin frustration effect. This network can be a new type of geometrically frustrated spinlattice. Magnetic susceptibility, specific heat, high field magnetization are measured to
study magnetic properties of Cu5(PO4)2(OH)4 using natural mineral samples. Magnetic
ordering is observed at around 4.2 K. Spin entropy change at the transition temperature
is about one fifth times smaller than that expected for a usual long range order. 1/5
magnetization plateau is observed in the high field magnetization curve. The plateau
can be explained based on the simple model in which the spin network is assumed tobe composed of chain, dimer and monomer units.

Shigeo Hara* and Hirohiko Sato
Department of Physics, Chuo-univ, Japan

We have succeeded in synthesizing single crystals of a novel manganese oxide
KMn3Ge2O9 by a hydrothermal method. This compound has a hexagonal unit cellwith lattice constants a = 11.77 Å and c = 13.77 Å. In this structure, edge-shared
MnO6 octahedra form layers separated by GeO4 tetrahedra. In each layer, Mn ionswith S = 2 spin form a rippled kagome lattice. Therefore, we can expect a frustrated
magnetism. We measured temperature dependence of the magnetic susceptibility on asingle crystal. The result suggests the existence of a strong magnetic frustration. The
Curie constant and Weiss temperature are estimated at 3.4 emu K/mol Mn and - 84
K, respectively. The negative Weiss temperature indicates that the nearest-neighborexchange interaction among Mn ions is antiferromagnetic. At low temperatures, thesusceptibility suggests the existence of multiple magnetic phases. For example, thesusceptibility shows an antiferromagnetic like transition at 40 K and a spin-glass liketransition at 20 K under 0.5 T of magnetic field perpendicular to the kagome lattice.
The successive transitions are also observed in other conditions of magnetic field. We
consider that these behaviors are driven from the strong magnetic frustration of the
kagome lattice.

Yuta Kodama, Kousuke Tsuruta, Daisuke Akahoshi and Toshiaki Saito*
Department of Physics, Faculty of Science, Toho University, Funabashi City, Chiba
274-8510, Japan

The pyrochlore Dy2Ti2O7 is a spin ice material, in which the spins reside on the lattice ofcorner-sharing tetrahedra with single-ion anisotropy along each local <111> axis. The effective
ferromagnetic interaction between spins leads to a highly degenerate ground state. Earlier
researches [1][2] reported that the magnetic relaxation shows three successive processes;
thermally activated Arrhenius process above 13 K, quantum tunneling process between 4 K~ 13 K, and process with strong spin correlation below 4 K. The relaxation in the medium
temperature regime is the Davidson-Cole type [3] characterized by a wide distributionof relaxation time τ with a cut-off τ. The dilution of Dy causes disappearance of the ac
susceptibility 15 K peak [1] due to a speeding up of relaxation [2]. In this talk, we examined themagnetic relaxation of Dy2(Ti1-xZrx)2O7 through ac magnetic susceptibility measurements inorder to study B-site disorder effect. We found, for x above about 0.01, disappearance of the 15
K peak, small frequency dependence, and substantial change of the magnetic relaxation fromthe Davidson-Cole type into the Cole-Cole one having no cut-off τ, indicating a major effect ofB-site disorder on the spin ice state toward melting without dilution of Dy ion.
[1] J. Snyder et al., Phys. Rev. B 70 (2004) 184431. [2] G. Ehlers et al., J. Phys. Condens. Matter 15(2003) L9. [3] K. Matsuhira et al., J. Phys. Condens. Matter 13 (2001) L737. [4] L.D.Jaubert and
P.C.Holdsworth, J. Phys. Condens. Matter 23 (2011) 164222.

E. Vavilova1*, M. Yakovleva1, M. Yehia2, R. Klingeler3, V. Kataev2, T. Taetz4, U. Loew5, A. Moeller6
and B. Buechner2
1
Zavoisky Physical Technical Institute, RAS, Kazan, Russia
2
IFW Dresden, Dresden, Germany
3
Heidelberg University, Heidelberg,, Germany
4
Institut fur Anorganische Chemie, Universitaat zu Koln, Germany
5
Technische Universitaat Dortmund, Germany
6
University of Houston, Department of Chemistry and Texas Center for Superconductivity, USA

The results of high field electron spin resonance, nuclear magnetic resonance, nuclear
quadrupole resonance and magnetization studies addressing the ground state of thequasi two-dimensional spin-1/2 honeycomb lattice compound InCu2/3V1/3O3 arereported. Uncorrelated finite size structural domains occurring in the honeycomb planes
are expected to inhibit long range magnetic order. Surprisingly, magnetic resonancedata show the development of two collinear antiferromagnetic (AFM) sublattices below
35K and the presence of the staggered internal field. Magnetization data evidence a
spin reorientation transition at 5.7T. Quantum Monte-Carlo calculations show thatswitching on the coupling between the honeycomb spin planes in a finite size cluster
yields a Neel-like AFM spin structure with a substantial staggered magnetization at
finite temperatures. ESR, NMR and NQR data allow to retrace the development ofstaggered magnetization during the crossover to ordered ground state.

QE21

QE24

Specific heat study of geometrically frustrated magnet botallackite
Cu2(OH)3Cl

Unusual magnetic ordering of kagome lattice magnet[Cu3(CO3)2(bpe)3]•2ClO4

Z_2 vortices in frustrated background of cuprates

Specific heat measurements have been performed in the geometrically frustrated
magnets botallackite, Cu2(OH)3Cl with the triangular structure of the Cu2+ ions. Thisis a different polymorphic form of clinoatacamite with the corner-sharing tetrahedral
structure, which exhibits the coexistence of spin fluctuation and long range ordering
below 6.2 K[1]. The specific heat of botallackite shows a sharp peak at TN=7.0K andapproximately exhibits T3-dependence with lowering temperature in zero magnetic
field. When a magnetic field is applied, TN shifts to lower temperatures and the peaks
disappears at H=8 T. Moreover, no residual entropy is observed at lower temperatures.
[1] X.G. Zheng, et. al., Phys. Rev. Lett. 95 057201 (2005).

Hikomitsu Kikuchi1, Hayato Nakata1, Yutaka Fujii2 and Toshifumi Taniguchi3
1
Department of Applied Physics, University of Fukui, Japan
2
Research Center for Development of Far-Infrared Region, University of Fukui,Japan
3
Graduate School of Science, Osaka University, Japan

Cu2+ ions in a hexagonal compound [Cu3(CO3)2(bpe)3]•2ClO4 (space group; P-6)
form slightly distorted kagome lattice in its c-plane. Former study1) reported that themagnetic susceptibility increased rapidly below about 7 K indicating an occurrenceof the ferromagnetic transition. Surprisingly, however, no anomaly in the specific heat
was observed at the transition temperature in this compound. In order to scrutinize
the magnetic properties, we measure the specific heat of this compound using single
crystals under an applied magnetic field up to 7 T. 1H-NMR measurement is also
carried out. NMR spectra-broadening and a divergent behavior of the spin-lattice
relaxation rate are observed at around 7 K. Slight anomaly in the specific heat isobserved and the anomaly temperature is found to depend on the magnetic field. These
results suggest that entropy change associated with the magnetic ordering of thiscompound is vanishingly small.
1) P. Kanoo et al. Dalton Trans. 2009, 5062.

The 19th International Conference on Magnetism[1] M. P. Shores, E. A. Nytko, B. M. Bartlett, and D. G. Nocera, J. Am. Chem. Soc 127, 13462, (2005)[2] S. Chu, T.M McQueen, R. Chisnell, D.E. Freedman, P. Muller, Y.S. Lee, and D.G. Nocera, J. Am.
Chem. Soc. (2010).

Daniel C. Cabra*
Physics Department, National University of La Plata, Argentina
We study the phase diagram of the Heisenberg model on the Honeycomb lattice with
antiferromagnetic interactions up to third neighbors along the line J2=J3, close to thepoint where it has macroscopic degeneracy at the classical level. Using the Schwinger
boson technique followed by a mean field decoupling and exact diagonalization
for small systems we find an intermediate phase with a spin gap and short range
Neel correlations even in the strong quantum limit 1/2. We have also studied themagnetization curve for J3=0, close to J2/J1 = 1/2 where the classical ground state isalso highly degenerate. The properties of the magnetization curve and phase transitions
are studied by means of Montecarlo, which shows many interesting transitions.

A. Yehia, et al., Phys. Rev. B 81, 060414 (2010)

QE18
Hiroki Morodomi1, Yuji Inagaki1, Tatsuya Kawae1, Masato Hagihala2 and X.g. Zhen2
1
Department of Applied Quantum Physics, Kyushu University, Japan2
Department of Physics, Saga University, Japan

202

Hiroshi Tashiro1*, Masahide Nishiyama1, Akira Oyamada1, Tetsuaki Itou1, Satoru
Maegawa1, Midori Yano2, Toshio Ono3 and Hidekazu Tanaka2
1
Graduate School of Human and Environmental Studies, Kyoto University, Japan2
Department of Physics, Tokyo Institute of Technology, Japan3
Department of Physical Science, Osaka Prefecture University, Japan

July 10 (Tue)Hikomitsu Kikuchi1, Nguyen Thi Tinh Y1, Yutaka Fujii2, Masashi Fujisawa3, Akira
Matsuo4 and Koichi Kindo4
1
Department of Applied Physics, University of Fukui, Japan
2
Research Center for Development of Far-Infrared Region, University of Fukui,Japan
3
Research Center for Low Temperature Physics, Tokyo Tech, Japan
4
ISSP, The University of Tokyo, Japan

July 10 (Tue)poster Presentation

Maciej Fidrysiak and Paweł Rusek*
Wroclaw University of Technology, Poland

La2-xSrxCuO4 (LSCO) in the underdoped regime (x=0.02 - 0.05) is a non-collinear
quantum antiferromagnet. The relevant order parameter is a triad of orthonormal
vectors. The topology of the order parameter space allows the existence of Z_2
vortices. Randomly distributed Sr dopants introduce holes into the Cu-O planes which
are the source of fluctuating dipolar fields resulting in frustrated spin background. We
study Z_2 vortices in the system in the framework of non-linear sigma-model coupled
to SO(3) gauge fields which represent fluctuating frustrated background. In this model
we describe explicitly not only spin degrees of freedom, but also the distribution of
frustrations as opposed to pure spin systems. We have found explicitly a finite energy
Z_2 vortex solution. Frustrations are concentrated in the soft core of Z_2 vortices andexponentially decrease at large distances. The chirality of spin system changes its signin the vortex core as expected. Our vortex seems to be more relevant to the study offrustrated Heisenberg spin systems and the charge transport by vortices in cuprates than
Z_2 vortices in pure spin degrees of freedom.

QE27
Light scattering in spin liquid systems

Dirk Wulferding1*, Peter Lemmens1, Vladimir Gnezdilov2, Tianheng Han3, Young S.
Lee3, Hiroyuki Yoshida4, Yoshihiko Okamoto5 and Olga Volkova61
IPKM, TU-BS, Braunschweig, Germany
2
ILTPE NAS, Ukraine
3
MIT, Massachusetts, USA
4
NIMS, Tsukuba, Japan
5
ISSP, Tokyo, Japan
6
MSU, Moscow, Russia
When quantum spin systems are restricted in dimensionality and coordination theyrealize spin liquid states with enhanced quantum fluctuations and exotic correlation
functions. We compare the experimentally determined excitation spectra of different
spin liquid candidates such as the s=1/2 Heisenberg antiferromagnet on a kagome
lattice and weakly coupled spin chain system in Herbertsmithite and (NO)Cu(NO3)3
using Raman scattering. This technique is sensitive to fractional spinon excitations. The
effect of the crystal’s lattice structure and defects on the spin dynamics is investigated.
The data is also compared with recent theoretical modelling. Work supported by DFG,
B-IGSM and NTH School for Contacts in Nanosystems.
D. Wulferding, et al., Phys. Rev. B 82, 144412 (2010) V. Gnezdilov, et al., arXiv:1203.2818 (2012) D.
Wulferding, et al., arXiv :1111.2167 (2012)

July 8-13, 2012 Busan, Korea

203

poster Presentation
QF01

QF04

QF07

QF10

Molecular nanomagnets as quantum simulators

Non-magnetic impurity effect of S=1/2 spin ladder system (pipdH)2Cu1xZnxBr4

Thermal conductivity and magnetic susceptibility of the 4-leg spinladder system (La1-xYx)2Cu2O5 and the 5-leg spin-ladder system (La1XEux)8Cu7O19

Thermal conductivity due to magnons in high-quality single crystals of
the two-leg spin ladder system (Ca,Sr,La)14Cu24O41

Quantum simulators (QSs) are controllable quantum systems that can be used tosimulate other quantum systems. QSs can tackle problems intractable on classicalcomputers. Here we focus on the dynamics of qubits encoded in chains of molecular
nanomagnets. For istance, we have shown that Cr7Ni rings are good candidates qubits
and can be linked to each other either directly or through magnetic complexes [1,2].
We theoretically show that the dynamics of such chains can be controlled by means of
uniform magnetic pulsed fields and used to mimic the coherent time evolution of otherquantum systems (e.g., spin-one chains) [3]. We propose two significant proof-ofprinciple experiments [3].
[1] G.A. Timco et al., Nature Nanotechnology 4, 173 (2009) [2] A. Candini et al., Phys. Rev. Lett.
104, 037203 (2010) [3] P. Santini, S. Carretta, F. Troiani, G. Amoretti, Phys. Rev. Lett. 107, 230502(2011)

Chiori Yokoyama1, Weimin Zhang2, Takahiro Sakurai3, Susumu Okubo4*, Hitoshi Ohta5, Eiichi
Matsuoka6, Hitoshi Sugawara7 and Hikomitsu Kikuchi8
1
Kobe University, Japan
2
Center for Collaborative Research and Technology Development, Kobe University, Japan
3
Center for Supports to Research and Education Activities, Kobe University, Japan
4
Molecular Photoscience Research Center, Kobe University, Japan
5
Molecular Photoscience Research, Kobe University, Japan
6
1Graduate School of Science, Kobe University, Japan
7
Graduate School of Science, Kobe University, Japan
8
Department of Applied Physics, University of Fukui, JapanLow dimensional spin system shows fruitful magnetic properties such as the Bose-Einstein condensationof magnon or the spin liquid state. Non-magnetic impurity effect in a quantum spin chain, which arises
as an appearance of magnetic moment with spin correlation at around the impurity, is one of typicalquantum effects of correlated spins. (pipdH)2CuBr4 is known as a model substance of weakly coupledspin 1/2 Heisenberg antiferromagnetic ladder system. Recently, we succeeded in synthesizing Zn-doped(pipdH)2Cu1-xZn1-xBr4 single crystal. Samples were confirmed to be in a single phase and have the same
crystal structure as the pure system (pipdH)2CuBr4 by X-ray diffraction measurements. To check magnetic
properties, the magnetic susceptibility and the magnetization measurements are performed by the SQUID
magnetometer. The magnetic susceptibility shows a maximum related to the spin ladder and the Curie
increase at low temperature related to the doping of Zn. The Curie term increases as the Zn concentration
increase. Observed non-magnetic impurity effect of S=1/2 spin ladder system will be discussed inconnection with AKLT model.

Takayuki Kawamata*, Takashi Noji and Yoji Koike
Department of Applied Physics, Tohoku University, Japan

We have measured the thermal conductivity and magnetic susceptibility of the 4-leg spin-laddersystem (La1-xYx)2Cu2O5 (x = 0.01) and the 5-leg spin-ladder system (La1-xEux)8Cu7O19 (x = 0,0.01). It has been found that the temperature dependence of the thermal conductivity along
the spin-ladders of (La0.99Y0.01)2Cu2O5, La8Cu7O19 and (La0.99Eu0.01)8Cu7O19 shows only one
peak originating from the thermal conductivity due to phonons at ~15K. That is, the thermal
conductivity due to spins, κspin, has not been observed in these compounds, though κspin
was expected to be large owing to the exchange interaction along the spin-ladders as large as~1000K. Since the antiferromagnetic transition temperature, TN, is as large as 137K and 103K
in La2Cu2O5 [1] and La8Cu7O19 [2], respectively, it has been concluded that the comparatively
large exchange interaction between spin-ladders disturbs the thermal conduction due tospins along the spin-ladders. Moreover, it has been found that the temperature dependenceof the magnetic susceptibility below TN is clearly different between (La0.99Y0.01)2Cu2O5 and(La0.99Eu0.01)8Cu7O19, which may be related to the difference of the ground state between theodd- and even-leg spin-ladder systems.

[1] K. Kudo, S. Ishikawa, T. Noji, T. adachi, Y. Koike, K. Maki, S. Tsuji, and K. Kumagai: J. Phys.
Soc. Jpn. 70, 437 (2001). [2] C. Hess C. Baumann, U. Ammerahl, B. Buchner, F. Heidrich-Meisner, W.
Brenig, and A. Revcolevschi: Phys. Rev. B 64, 184305 (2001).

QF11

QF05

QF08

ESR signature of the next-nearest-neighbor interactions in the S = 1/2
chain compound (6MAP)CuCl3.

H i g h - f i e l d m u l t i - f re q u e n c y E S R i n t h e S = 2 H e i s e n b e r g
antiferromagnetic chain compound MnCl3(bpy)Magnetic susceptibility of the quasi one-dimensional spin system
Sr2V3O9

Masayuki Hagiwara1*, Shojiro Kimura2, Yuichi Idutsu1 and Zentaro Honda3
1
KYOKUGEN, Osaka University, Japan
2
IMR, Tohoku University, Japan
3
Graduate School of Science and Engineering, Saitama University, Japan

D

E
OV

Electron spin resonance (ESR) studies of the S = 1/2 chain material (6MAP)CuCl3[6MAP = C6H9N2] are presented. Two modes with asymmetric with respect to asimple gapless Zeeman splitting resonance positions have been observed in the
low-temperature ESR spectrum. This shows that the simple S = 1/2 Heisenberg
antiferromagnet chain model, employed so far, is not sufficient for a complete
description. The frequency-field diagram of magnetic excitations is interpreted in
the frame of the recently developed theory for S = 1/2 chains with nearest- and nextnearest-neighbor interactions [A.A. Zvyagin, Phys. Rev. B 79, 064422 (2009)]. A goodqualitative agreement with experiment has been achieved. The work was supported inpart by DFG and EuroMagNET II (EU Contract No. 228043).

M

In order to enhance the thermal conductivity due to magnons, κmagnon, in the two-leg spinladder system (Ca,Sr,La)14Cu24O41, we have grown single crystals using high-purity raw materials,
improved the quality of the single crystals by annealing in O2 and measured the thermal
conductivity along the spin ladders. In both Ca9La5Cu24O41 and Sr9La5Cu24O41, the thermal
conductivity shows a very large peak around 150K owing to the contribution of κmagnon along
the spin ladders[1,2]. However, no enhancement of κmagnon has been observed in spite of theincrease of the purity of the raw materials and the O2-annealing. In Sr14Cu24O41, on the other hand,a large enhancement of κmagnon has been observed through the O2-annealing. These results
indicate that the mean free path of magnons, lmagnon, has already limited by the disorder of theatomic arrangement due to the substitution of Ca and La for Sr in Ca9La5Cu24O41 and Sr9La5Cu24O41,
while lmagnon is enhanced owing to the decrease of spin defects through the O2-annealing in nonsubstituted Sr14Cu24O41. Accoringly, it is necessary for the enhancement of κmagnon to remove thedisorder of the atomic arrangement in the spin ladders in (Ca,Sr,La)14Cu24O41.

[1] K. Kudo et al., J. Phys. Soc. Jpn. 72 (2003) 2551. [2] I. A. Zobkalo et al., Physica B 234-236(1997) 734.

QF02
M. Ozerov1, A. A. Zvyagin2, E. Cizmar3, F. Xiao4, C. P. Landee4, J. Wosnitza1 and S. A.
Zvyagin1
1
Dresden High Magnetic Field Laboratory, Helmholtz-Zentrum Dresden-Rossendorf,
Dresden, Germany
2
Institut fur Festkorperphysik, Technische Universitat Dresden, Dresden, Germany
3
Centre of Low Temperature Physics, P.J. Safarik University, Kosice, Slovakia
4
Department of Physics and Carlson School of Chemistry, Clark University,
Worcester, Massachusetts, USA

Koki Naruse1*, Takayuki Kawamata1, Mitsuhide Sato1, Masumi Ohno1, Kazutaka Kudo2, Norio
Kobayashi3 and Yoji Koike1
1
Department of Applied Physics, Tohoku University, Japan2
Department of Physics, Okayama University, Japan
3
Institute for Materials Research, Tohoku University, Japan

Takayuki Kawamata*, Masanori Uesaka, Mitsuhide Sato and Yoji Koike
Department of Applied Physics, Tohoku University, Japan

According to the magnetic susceptibility of polycrystalline samples of the quasi onedimensional spin system Sr2V3O9, this compound undergoes a weak ferromagnetictransition due to the Dzyaloshinsky-Moriya (DM) interaction at TN ~ 5K [1]. We havegrown single crystals of Sr2V3O9 [2] and measured the magnetic susceptibility along
the [101] direction, χ[101], along the [10-1] direction, χ[10-1], and along the b-axis,
χb. It has been found that temperature dependences of χ[101], χ[10-1] and χb show
Bonner-Fisher-type behavior and that the anisotropy is very small at high temperatures
above TN, indicating that Sr2V3O9 is regarded as an isotropic one-dimensional
Heisenberg spin system. At low temperatures below TN, however, both χ[10-1] andχb increase with decreasing temperature, while χ[101] decreases. This anisotropic
behavior is consistent with the canted spin state proposed from the ESR measurements[3].
[1] E. E. Kaul et al., Phys. Rev. B 67 (2003) 174417. [2] M. Uesaka et al., J. Phys.: Conf. Ser. 200(2010) 022068. [3] V. A. Ivanshin et al., Phys. Rev. B 68 (2003) 064404.

July 10 (Tue)Paolo Santini
University of Parma. Italy

July 10 (Tue)poster Presentation

Magnetic property of Ni2+ antiferromagnetic perfect triangle cluster

Emika Takata1,2*, Minoru Sanda1, Katsutaka Kubo2, Takayuki Asano2, Akira Matsuo1,
Koichi Kindo1 and Masaki Oshikawa1
1
Institute for Solid State Physics, University of Tokyo, Japan2
Department of Physics, Kyushu University, JapanThe magnetic properties of spin systems with frustration have attracted much attention
for a long time. The fundamental structure causing the frustration is “triangle”. The
magnetic properties of the antiferromagnetic perfect triangular cluster (APTC) withhalf-integer spins have been already studied well. [1] By contrast, there are little
experimental data on the APTC with integer spins. Such an APTC is expected topossess a non-magnetic, singlet ground state. Recently, Liu et al. have investigatedmagnetic properties of S=1 APTC, [Ni 3(μ1,3-N3)3(2,2'-bpy)3](ClO4)3•3H2O. It isbelieved as one of model materials for the S=1 APTC. [2] We synthesized it andmeasured the magnetization process (M(H)) and the temperature dependence of themagnetic susceptibility (χ(T)) of the material. We calculated M(H) and χ(T) in thesimple ISOTROPIC S=1 APTC. However, the experimental results clearly cannot
be accounted for by the calculated results. When the spin is greater than or equal to1, generally a single ion anisotropy D can present. Thus we consider an anisotropic
model Hamiltonian by including D. We will discuss the experimental data based on
calculations using the new Hamiltonian with D.
[1] for example T. Yosida et al., J. Phys. Soc. Jpn. 57 (1988) 1428. [2]J.L. Liu et al., Aust. J. Chem.
63 (2010) 1111.

QF03

QF06

QF09

QF12

Electron spin resonance in the spin-ladder compound BPCBHigh field magnetization of bimetallic chain with alternating ising andHeisenberg spins

Magnetic property of a single crystal of spin-1/2 triple-chain magnet
Cu3(OH)4SO4

Thermal conductivity of anisotropic spin ladder

S. Zvyagin1, E. Cizmar2, M. Ozerov1 and J. Wosnitza1
1
Dresden High Magnetic Field Laboratory (HLD) Helmholtz-Zentrum DresdenRossendorf, Dresden, Germany
2
Centre of Low Temperature Physics, P.J. Safarik University, Kosice, Slovakia
Magnetic excitations in the spin-ladder material (C52H12N2)CuBr4 (known as BPCB)
are probed by means of electron spin resonance (ESR) spectroscopy in magnetic
fields up to 16 T. The gap between the ground state and the first excited state, 16.5
K (or 1.42 meV), is detected directly. In addition, our experiments provide clear
evidence for a pronounced anisotropy (~ 5% of the dominant exchange interaction),
responsible for a shift of the observed ESR line and a specific angular dependence ofresonance absorptions. The results are explained in frame of the recently developed
theory for ESR in spin-ladders (Furuya et al., arXiv: 1107.5965). The work was donein collaboration with B. Thielemann, K. W. Kramer, Ch. Ruegg, O. Piovesana, M.
Klanjsek, M. Horvatic, and C. Berthier. The work was supported in part by DFG andEuroMagNET II (EU Contract No. 228043).

204

The 19th International Conference on Magnetism

Yibo Han1, Jozef Strecka2, Takanori Kida1, Zentaro Honda3, Masami Ikeda1 and Masayuki
Hagiwara1*
1
KYOKUGEN, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan2
Department of Physics, Faculty of Science, P. J. Safarik University, Park Angelinum 9,040 01
Kosice, Slovakiaia, Slovakia
3
Department of Functional Materials Science, Graduate School of Science and Engineering,
Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan

3d-4f bimetallic chain [Dy(NO3)(DMSO)2Cu(opba)(DMSO)2] built from alternating
dysprosium(3+) and copper(2+) ions has been synthesized and magnetically studied.
Magnetic susceptibility as well as high-field magnetization of the polycrystalline sample
was measured under the temperature down to 1.3 K and the magnetic field up to 52 T. After
performing correction for the temperature independent paramagnetism, the magnetization
curve recorded at 1.3 K shows a rapid increase with the magnetic field in the low-field
range 0-3 T, followed up with a less steep increase in the field range 5-34 T before tending
towards its saturation value at 34 T. The observed magnetization process can be interpreted
in terms of the spin-1/2 chain model with alternating Ising and Heisenberg spins, which
accounts for both parallel and perpendicular Zeeman's energy of Dy and Cu ions. The goodfitting of the experimental data by using the above theoretical model suggest the effective
antiferromagnetic exchange constant J/kB= -26 K, the highly anisotropic g-factor of Dy
ions and almost isotropic g-factor of Cu ions. It was concluded that a new type of onedimensional Ising-Heisenberg spin chain was found.

Yutaka Fujii1*, Yuya Ishikawa2, Hikomitsu Kikuchi2, Yasuo Narumi3, Hiroyuki
Nojiri3, Shigeo Hara4 and Hirohiko Sato4
1
Research Center for Development of Far-Infrared Region, University of Fukui,Japan
2
Department of Applied Physics, University of Fukui, Japan
3
Institute for Materials Research, Tohoku University, Japan
4
Department of Physics, Chuo University, Japan
A spin-1/2 triple-chain magnet Cu3(OH)4SO4 (antlerite) is a candidate 'idle-spin' system inwhich magnetic moments on central spin chain seem to disappear, while the rest exhibit
a long-range order below TN=5.5 K [1]. Our previous proton NMR study with a powder
sample almost supported this scenario, although it was difficult to determine the spin
structure [2]. Recently, successive phase transitions and anisotropy of phase diagram were
found from the results of magnetization measurements with high-quality single crystalsof Cu3(OH)4SO4 [3]. In order to study phase transitions in the present compound in detail,we have performed specific heat measurements under magnetic fields up to 7 T and in thetemperature range down to 2 K and proton NMR experiments at several frequencies withsingle crystals. We found at least three successive phase transitions at zero field around
TN. Complicated phase diagrams involving changes of spin structures were suggested.

Hamed Rezania*
Razi university, Iran

We have studied the thermal conductivity of anisotropic spin ladder model with
antiferromagnetic coupling constants between spins on the both rung and ladderdirections. Kubo formalism has been applied to study temperature dependency ofthermal conductivity of this model hamilltonian. The bond operator formalism isused to transform the spin model to a hard core bosonic gas. We have used the green's
function approach to obtain the temperature dependence of spin excitation spectrum.
We have found the temperature dependence of the thermal conductivity for various
exchange coupling constants and anisotropies in both coupling strengths. We haveobtained the increase of coupling constant along ladder direction leads to decreaseof thermal conductivity. Furthermore the effect of local anisotropy anisotropy on thethermal conductivity has more significant in comparison with other one.
1)E. Dagootto and T. M. Rice, Science 271, 618 (1996) 2)A. Klumper and D. C. Johnston, Phys.
Rev. Lett, 84, 4701 (2000) 3)A. V. Sologubenko and K. Gianno, H. R. Ott, U. Ammerahl and A.
Revolevschi, Phys. Rev. Lett, 84, 2714(2000) 4)X. Zotos, F. Naef, P. Prelovse, Phys. Rev. B, 55,
11029 (1997) 5)K. Louis, P. Prelovse and X. Zotos, Phys . Rev. B 74, 235118(2006)[1] S. Vilminot et al., J. Solid State Chem., 170, (2003) 255. [2] Y. Fujii et al., J. Phys.: Conf. Ser.,145, (2009) 012061. [3] S. Hara et al., J. Phys. Soc. Jpn., 80, (2011) 043701.

July 8-13, 2012 Busan, Korea

205

poster Presentation

poster Presentation

QF13

QF16

QF19

The magnetic properties of the newly synthesized trinuclear copper
complex

Ligand-driven geometric and electronic structures of FeII spincrossover molecules

Spectral signatures of magnetic Bloch oscillations in 1D ferromagnets

A. N. Ponomaryov1*, K. Y. Choi1, N. Kim2, S. Yoon2, B. J. Suh3 and Z. H. Jang4
1
Department of Physics, Chung-Ang University, Seoul, Korea
2
Department of Chemistry, Kookmin University, Seoul, Korea
3
Department of Physics, The Catholic University of Korea, Bucheon, Korea
4
Department of Physics, Kookmin University, Seoul, Korea

We present magnetic properties of a newly synthesized single molecule magnet (SMM)
Cu3(μ3-OMe)(μ-OMe)(μ-O2CAr4F-Ph)2(O2CAr4F-Ph)2(HOMe)3. In this compound, threecopper ions with s=1/2, connected by one μ3-bridged methoxide, form a spin triangle,
whereby two Cu2+ ions are 5 coordinated and the other Cu2+ ion is 4 coordinated. Bymeans of SQUID magnetometer, temperature dependence of magnetic susceptibility
χ(T) was measured in the range from 2 K to 300 K at the external field of 100 Oe
and field dependence of magnetization M(H) was measured at 2 K and 300 K in therange from 0 to 7 T. From an analysis of the magnetization data of the polycrystalline
powder sample using ITO (Irreducible Tensor Operator) method, we obtain theantiferromagnetic exchange coupling constants of J1 = -143.65 K, J2 = -143.78 K, J3 =-143.61 K and the g-factor of g = 2.66. A further analysis with a model Hamiltonian
including anisotropic exchange interactions is on-going.

Van Thanh Nguyen and Anh Tuan Nguyen*
Faculty of Physics, Hanoi University of Science, Viet Nam

Transition-metal complexes that exhibit spin-crossover (SCO) between low-spin (LS)state and high-spin (HS) state are now potential candidates for many applications suchas display and memory devices. In these applications, thermal hysteresis in SCO oftransition-metal complexes is required. Our previous study demonstrated that there is acorrelation between thermal hysteresis in SCO and the electrostatic-energy difference(ΔU) of transition-metal complexes [1]. In this work, in order to explore more about
the role of ligands in tailoring SCO behavior of transition-metal complexes, we study
SCO of a series of FeII molecules with different ligand configurations [2-4]. Our
results showed that the ΔU of transition-metal complexes can be determined by pKa
constant of ligands. These results should be helpful for designing new SCO complexes.
[1]. Nguyen Anh Tuan, Geometric Structure, Electronic Structure and Spin Transition of Several
FeII Spin-crossover Molecules, to be published on Journal of Applied Physics, 111, No. 7, (2012),
DOI: 10.1063/1.3670044. [2]. Birgit Weber, et.al., Eur. J. Inorg. Chem. No. 10, 1589 (2008). [3].
Birgit Weber, et.al., Eur. J. Inorg. Chem. No. 31, 4891 (2008). [4]. Birgit Weber, et.al., Eur. J. Inorg.
Chem. No. 21, 3193 (2011).

Sergey Shinkevich and Olav F. Syljuasen
Department of Physics, University of Oslo, Norway

Domain walls in a one-dimensional gapped easy-axis ferromagnet can exhibit Blochoscillations in an applied magnetic field. We investigate how exchange couplings
modify this behavior within an approximation based on non-interacting domainwall bound states. In particular we obtain analytical results for the spectrum and the
dynamic structure factor, and show where in momentum space to expect equidistantenergy levels, the Wannier-Zeeman ladder, which is the spectral signature of magnetic
Bloch oscillations. We compare our results to previous calculations employing a single
domain-wall-approximation, and make predictions relevant for the material cobalt
chloride dihydrate (CoCl2•2H2O).
1) Jordan Kyriakidis and Daniel Loss, Phys. Rev. B 58, 5568 (1998). 2) W. Montfrooij, G. E.
Granroth, D. G. Mandrus, and S. E. Nagler, Phys. Rev. B 64, 134426 (2001). 3) N.B. Christensen, K.
Lefmann, I. Johannsen, and O. Jørgensen, Physica B 276, 784 (2000).

QF22
Magnetic properties of the novel low-dimensional spin-1/2 magnet α-Cu2As2O7

V. Kataev1*, Y. C. Arango1, E. Vavilova2, M. Abdel - Hafiez1, O. Janson3, A. Tsirlin3, H. Rosner3, S.-l.
Drechsler1, M. Weil4, G. Nenert5, R. Klingeler6, O. Volkova7, A. Vasiliev7 and B. Buechner11Leibniz Institute for Solid State and Materials Research IFW Dresden, Germany
2
Zavoisky Physical Technical Institute of the Russian Academy of Sciences, 420029, Kazan, Russia
3
Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
4
Institute for Chemical Technologies and Analytics, Vienna University of Technology, A-1060 Vienna, Austria
5Institut Laue-Langevin, Boıte Postale 156, 38042 Grenoble Cedex 9, France
6
Kirchhoff Institute for Physics, University of Heidelberg, D-69120 Heidelberg, Germany
7
Low Temperature Physics Department, Moscow State University, Moscow 119991, Russia

In copper pyroarsenate α-Cu2As2O7, the quantum spins S = 1/2 localised at the Cu sites in the
structurally well defined dimer chains interact predominantly in one spatial dimension (onedimensional spin systems). Magnetic properties of this new material have been thoroughly
investigated by means of magnetization, heat capacity, electron spin resonance, and nuclear magnetic
resonance techniques, as well as by density functional theory (DFT) calculations and quantum Monte
Carlo (QMC) simulations. The data reveal that the magnetic Cu-O chains in the crystal structure
represent a realization of a quasi-one-dimensional (1-D) coupled alternating spin-1/2 Heisenberg
chain model with relevant pathways through nonmagnetic AsO4 tetrahedra. Owing to residual 3-D
interactions, antiferromagnetic long range ordering at TN ~10 K takes place. The experimental datasuggest that substantial quantum spin fluctuations take place at low magnetic fields in the orderedstate. DFT calculations and QMC fits enable quantitative evaluation of the exchange couplings. We
conclude that the electronic state of the central ion in the nonmagnetic AsO4 side groups plays acrucial role for determining the relevant interchain pathways which makes α-Cu2As2O7 distinct in its
magnetic properties from other representatives of this class of compounds [1].

QF14

QF17

QF20

QF23

Magnetization process of S=1/2 diamond chain compound
Na2Cu3Ge4O12

Magnetic properties of S=1/2 zigzag antiferromagetic chain
compounds, VO(XO4)(2,2'-bpy) (X=S, Mo; bpy = bipyradine)

Quasi-one-dimensional magnetic phase as a competing ground state ina frustrated magnet

Low temperature magnetic properties of the dilutable frustrated spinladder Bi(Cu1-xZnx)2PO6

Minoru Sanda1*, Keisuke Matsuura1, Takayuki Asano1, Junfeng Wang2, Akira Matsuo2, Koichi
Kindo2, Hiroki Morodomi3, Yuji Inagaki3 and Tatsuya Kawae3
1
Department of Physics, Kyushu University, Japan
2
Institute for Solid State Physics, University of Tokyo, Japan3
Department of Applied Physics, Kyushu University, Japan

Frustrated magnetism is one of the most fascinating systems because these systems have a great variety ofquantum phenomena, and a lot of research activities are going on. Diamond chain in which spins exist on
the Diamond-shaped lattice is one of examples of 1D-frustrated magnet. In this system, it is theoretically
expected that not only the frustration but also low-dimensionality induces the quantum phenomena.
Experimentally, Cu3(CO3)(OH)2 was reported as an S=1/2 Diamond chain compound, and its magnetic
properties are studied actively [1]. Recently, Mo et al. reported the crystal structure of Na2Cu3Ge4O12,
which has magnetic ions Cu2+ (3d9:S=1/2) arranging in Diamond chain [2]. This compound has a shortrange order at T(SLO)~10K and a long-range order at T(N)=2K by means of magnetic susceptibility andheat capacity measurements [2][3]. We performed high field magnetization measurement using pulse
magnetic field up to 55T at T(N)<T<T(SLO). The magnetization curve increase convex downward up
to one-third of saturation value, and clearly exhibit a plateau behavior with increasing magnetic field
more than 30T. The convex downward curve indicates the components of S=1/2 1D antiferromagnetic
phenomena with a spin reduction. More detailed results will be discussed in the conference.

Akira Matsuo1*, Yuya Ishikawa2, Yutaka Fujii3, Hikomistu Kikuchi2 and Koichi
Kindo1
1
The Institute for Solid State Physics, The University of Tokyo, Japan2
Department of Applied Physics, University of Fukui, Japan
3
Research Center for Development of Far-Infrared Region, University of Fukui,Japan
One dimensional Heisenberg antferromagnets (1D HAF) with the nearest J1 andsecond-nearest J2 interactions (zigzag chain) are the simplest frustrated magets. We
measured magnetic susceptibility, specific heat and high field magnetization up to
about 60 T of VO(XO4)(2,2'-bpy) (X=S, Mo; bpy = bipyradine), model compoundsof the zigzag chain. V4+ ions carry S =1/2 in these compounds. No magnetic longrange order is observed in both compounds, assuring low dimensionality of the present
compounds. The exchange interactions are determined by comparing the experimental
data with calculated results based on the exact diagonalization to the finite spin chain
up to N=12. For VO(SO4)(2,2'-bpy), data agree well with the theoretical curve for thesimple 1D HAF, thus J2 is found to be zero. On the other hand, for VO(MoO4)(2,2'-bpy),
a ratio of J2 to J1 is estimated to be 0.2-0.3.

[1] H. Kikuchi et al., Phys. Rev. Lett. 94 (2005) 227201. [2] X. Mo et al. : Inorg. Chem. 45 (2006) 3478. [3] M. Sato etal. : Solid State Science (2009) 1.

Low-dimensional physics is interesting because it is driven by fluctuations and it may result in exotic
phenomena, like the fractionalization of quantum numbers and spinons in magnetic chains. In magnetic
systems, the reduction of dimensionality occurs due to anisotropic short-ranged interactions. Generally,transition metal oxides order at low temperatures. Here, in geometrically frustrated Ca3Co2O6, weshow that by geometric frustration a stable quasi--one--dimensional (Q1D) magnetic phase emerges
from a competition of degenerate ground states. This phase coexists and competes with the 3D
antiferromagnetism in a large range below the 3D ordering temperature. We show that (i) constituent
entities of this Q1D phase are shaped as rods in real space with alternating up and down magnetized
sections (d=15A, l=320A at 15 K) along the chain axis where (ii) the sections belong to a degenerate
ferrimagnetic class of ground states, (iii) these magnetic rods are arranged randomly in the frustrated
triangular plane, (iv) they occupy a significant volume fraction (estimated 25% of moments at 15K) and(v) they are correlated with the magnetic response of this material. These results provide a new general
possibility of a frustration--stabilized one--dimensional phase in physics.

Shuang Wang1, Krunoslav Prsa2, Neda Nikseresht2, Christian Ruegg3, E. Pomjakushina4, Kazimierz
Conder4 and Henrik M Ronnow2
1
Laboratory for Quantum Magnetism/Laboratory for Developments and Methods, Ecole Polytechnique
Federale de Lausanne, 1015 Lausanne Paul Scherrer Institut, 5232 Villigen, Switzerland
2
Laboratory for Quantum Magnetism, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne,
Switzerland
3
Laboratory for Neutron Scattering, Paul Scherrer Institut,5232 Villigen, Switzerland
4
Laboratory for Developments and Methods, Paul Scherrer Institut,5232 Villigen, Switzerland

Quantum antiferromagnets with a spin-ladder magnetic network show an energy gap in the spin excitation
spectrum and may possess an intrinsically disordered (spin liquid) ground state. BiCu2PO6 (BCPO)
shows a structure where Cu2+ magnetic ions (S=1/2) form two-leg zigzag ladders along the b-axis, whichclosely corresponds to theoretical quasi-1D AF spin ladder model. We can reveal quantum nature of low
temperature behavior by studying the effect of non-magnetic impurities (e.g. Zn2+, Ni+) introduced atmagnetic Cu-sites. Recently, single crystals of Bi(Cu1-xZnx)2PO6 (0≤x≤0.05) were successfully synthesized
and studied by NMR for the first time [1,2]. We present here the specific heat Cp (H,T), ac susceptibility(f,T) and dc magnetization M(H,T) on single crystal sample of the undoped BCPO and 5% Zn-doped
BCPO (Zn005BCPO) with field applied along main crystallographic axes focusing on low temperatures
T < 10 K. We argue that the ground state of the Zn doped compound (Zn005BCPO) has features of bothspin-glass and long range magnetic order, and that glassiness is lost under application of higher magnetic
fields. We show the H-T magnetic phase diagram.
[1] S.Wang., E. Pomjakushina, T. Shiroka, G. Deng, N. Nikseresht, Ch. Ruegg, H.M. Rønnow, and K. Conder. J.Crystal.Growth.313,
51-55 (2010) [2 ]F. Casola, T. Shiroka, S. Wang, K. Conder, E. Pomjakushina, J. Mesot and H.-R. Ott, Phys. Rev. Lett. 105, 067203(2010)

QF15

QF18

QF21

QF24

Quantum criticality in a frustrated ising chain columbite

Inter-chain coupling and anisotropy in the frustrated chain cuprate
Li2CuO2

Crossover of magnetic relaxation from 2D-spin ice like state to orderedstate in layered single molecular magnet networks

51V-NMR study of the quasi-one-dimensional antiferromagnet
BaCo2V2O8

Kazuhiro Igarashi, Yasuhiro Shimizu* and Masayuki Itoh
Nagoya University, JapanA ferromagnetic Ising model in transverse magnetic field is a textbook example of thequantum phase transition. Nevertheless, few experiments have been accessible to thequantum criticality. CoNb2O6 with a triangular lattice of ferromagnetic Ising chains is
the highlight compound that has been recently found to exhibit the emergent symmetry
in the excitation spectrum. Here we present the NMR observation of the low-energy
quantum critical behavior in CoNb2O6. We find that the dynamical critical exponent
toward the quantum critical point exhibits close to that of quantum antiferromagnets.
Namely, the nuclear spin-lattice relaxation rate is independent of temperature at thecritical transverse magnetic field of 5.4 T. The strong field dependence is manifested
only in the dynamical susceptibility, whereas the uniform part is almost independentof magnetic field. Our results can be served as the ideal Ising spin dynamics on thequantum phase transition.

206

Krunoslav Prsa1, Mark Laver2, Martin Mansson1, Ivica Zivkovic3, Peter Derlet4, Sebastian Guerrero4,
Christopher Mudry4, Oksana Zaharko2, Sang-wook Cheong5, Hee-taek Yi5, Jorge Gavilano2, Joachim
Kohlbrecher2, Michel Kenzelmann6 and Joel Mesot2
1
Laboratory for Solid State Physics, ETH Zurich, Switzerland
2
Laboratory for Neutron Scattering, Paul Scherrer Institute, Switzerland
3
Institute of Physics, Croatia
4
Condensed Matter Theory, Paul Scherrer Institute, Switzerland
5
Department of Physics and Astronomy, Rutgers University, USA
6
Laboratory for Developments and Methods, Paul Scherrer Institute, Switzerland

The 19th International Conference on Magnetism

W. E. A. Lorenz1*, S.-l. Drechsler2, R. O. Kuzian3, S. Petit4, Y. Skourki5, R. Klingeler6 and B.
Buchner2
1
Neutron Scattering and Magnetism Group, Laboratory for Solid State Physics, ETH Zurich,
Switzerland
2
Leibniz Institute for Solid State and Materials Research Dresden, Germany
3Institute for Problems of Materials Science, Kiev, Ukraine
4
Laboratoire Leon Brillouin, Saclay, France
5
Dresden High Magnetic Field Laboratory, FZ-Dresden-Rossendorf, Dresden, Germany
6
Kirchhoff Institute for Physics, University of Heidelberg, Germany

Frustrated spin-chains with nearest neighbor ferromagnetic and next-nearest neighbor
antiferromagnetic interactions have recently attracted lots of interest. In this class ofmaterials, Li2CuO2 represents a reference system with a particularly simple structure.
Here we present a detailed experimental study of this quasi-one-dimensional magnet
with focus on the properties at low temperature where long range order sets in due tothe present inter-chain interactions. We discuss the magnetic phase diagram as obtained
from magnetization, specific heat and lattice expansion measurements. Using inelastic
neutron scattering we have further examined the magnetic excitations throughout avast part of the Brillouin zone and in great detail, revealing an exceptional spectrum.
In conclusion, we demonstrate that the low temperature dynamics of this S=1/2 chainmaterial is well described within spin-wave theory and that the observed ground stateis largely due to the exchange anisotropy.

Yuta Kodama1, Rikako Ishii2, Chihiro Kachi-terajima2, Hitoshi Miyasaka3, Daisuke
Akahoshi1 and Toshiaki Saito1*
1
Dept. of Phys., Fac. of Sci., Toho Univ., Funabashi , Chiba 274-8510, Japan
2
Dept. of Chem., Fac. of Sci., Toho Univ., Funabashi , Chiba 274-8510, Japan
3
Dept.of Chem., Div. of Mat. Sci., Grad. Sch. of Nat. Sci. and Tech., Kanazawa Univ.,
Ishikawa 920-1192, Japan

Layered 2D single molecular magnet (SMM) network [Mn(saltmen)]4[M(CN)6]ClO4•nH2O (M=Mn,
Fe[1]) is a strongly frustrated system. The each SMM unit [Mn(saltmen) ] (ST =4) is ferromagneticallyconnected through the [M(CN)6] unit (S=1 for Mn, and S=1/2 for Fe) within a layer. The origin of
the frustration [2] is a competition between the orthogonally oriented two uniaxial axes of the SMM
unit and the ferromagnetic interaction, leading to a macroscopically degenerated ground state as the
pyroclore 3D-spin ice. Our previous work [2] for M=Mn showed no transition down to 2 K throughthe Weiss temperature Θ= 8.3 K and Davidson-Cole (DC) type magnetic relaxation as 3D-spin ice[3]. However, for M=Fe, a distinct anomaly of relaxation time is observed at 2.6 K (Θ = 7.5 K), andthe relaxation is the Cole-Cole (CC) type, suggesting a magnetic order. In this work, we measured
ac susceptibility of M = Mn1-xFex (x = 0 ~ 1.0). We found that the relaxation is not the DC type for
x=0.1, and changes into CC type for x > 0.3 accompanying the distinct anomaly of relaxation time. The
results suggest that 2D-spin ice-like state is ordered into a randomly frozen state above x ~ 0.1.
[1] H. Miyasaka et al., J. Am. Chem. Soc. 118 (1996) 981. [2] T. Saito et al. (2012), in preparation(partly presented in ICM 2009). [3] K. Matsuhira et al., J. Phys. Condens. Matter 13 (2001) L737.

July 10 (Tue)July 10 (Tue)[1] Y.C. Arango, E. Vavilova, M. Abdel-Hafiez et al., Phys. Rev. B 84, 134430 (2011)

Yukiichi Ideta1, Yu Kawasaki1, Yutaka Kishimoto1, Takashi Ohno1, Yoshitaka
Michihiro1, Zhangzhen He2, Yutaka Ueda3 and Mitsuru Itoh4
1
Institute of Technology and Science, The University of Tokushima, Japan2
Fujian Institute of Research on the Structure of Matter, Chinese Academy of
Sciences, China
3
Institute for Solid State Physics, University of Tokyo, Japan
4
Materials and Structures Laboratory, Tokyo Institute of Technology, JapanThe double rectangle-like powder pattern has been observed in the 51V-NMR
spectrum for the quasi-one dimensional antiferromagnet BaCo2V2O8 below TN = 5.4
K. The powder pattern indicates the existence of two V sites with different internal
field, 2.1 and 3.8 kOe, although V atoms occupy only one magnetically symmetric sitewhere the scalar type transferred field from the surrounding Co2+ magnetic moments iszero. The internal field at V site is explained by taking into account of the classical andthe pseudo-dipolar fields from Co2+ magnetic moments. In the paramagnetic state, thenuclear spin-lattice relaxation is dominated by the antiferromagnetic spin fluctuation
via the dipolar field, which is proved by the linear relation between the nuclear spinlattice relaxation rate divided by temperature 1/T1T and the magnetic susceptibility.
The change in the slope of 1/T1T against the magnetic susceptibility around 150 K
suggests the change in the antiferromagnetic spin fluctuation spectrum. Below 60 K, 1/
T1 shows the thermal activation-type temperature dependence signaling the formationof spin gap.

July 8-13, 2012 Busan, Korea

207

poster Presentation
QF25

QG02

QG05

QG08

Magnetic properties of one-dimensional chain of O2 confined innanospaces of MFI-zeolite

Incommensurate-commensurate phase transition in TbNi5 induced byexternal magnetic field

X

Magnetic and thermoelectric properties of the solid solutions Mn1NiXS

Study of the metamagnetic behavior of Ni-Co-Mn-Sb alloy in highmagnetic fields

We have studied the molecular arrangement and the magnetic properties in O2 adsorbed in nanoporouscompounds [1-3]. We found that the O2 adsorbed in MFI zeolite form a one-dimensional chain. The O2
adsorption isotherm shows a plateau and the step, indicating a phase transition. It is found by means of the
x-ray diffraction measurements that the zeolite deforms from monoclinic to orthorhombic corresponding
to the step of adsorption isotherm.In the low-adsorption case, the adsorbed O2 aligns linearly in the straightand sinusoidal channels in MFI zeolite. In the high-field magnetization measurements, the magnetization
process does not show the linear field dependence characteristic to one-dimensional Heisenberg
antiferromagnet and presents the metamagnetic transition similar to the case of O2-O2 dimer reported
previously [1, 2]. This result may suggest that the singlet ground state is realized at low fields and the fieldinduced orientational change of molecular axis occurs. In the high-adsorption case, the adsorbed O2 seems
to align in rows of two. The temperature dependence of susceptibility shows the first-order transition withlarge hysteresis. By XRD measurement, the structural phase transition from orthorhombic to monoclinicwith decreasing temperature was found, which is not observed in N2 adsorbed compound.

The rare earth intermetallic RNi5 compounds are attractive subjects for the study ofthe exchange and crystal field interactions due to their simple crystal and magnetic
structures. The magnetic ordering in TbNi5 compound has been interpreted in termsof FAN-like incommensurate structure at temperatures between 23 K and 10 K. On
cooling sample down to T = 10 K order-order type magnetic phase transition from theincommensurate phase to a “lock-in' phase takes place. In the present work we report
the results of neutron diffraction experiment on TbNi5 single crystal sample in external
magnetic field up to μ0H = 1T. Abrupt change of the intensity of (001) Bragg peak andsatellites (001)± occurs within temperature interval 7 K -10 K due to magnetic phasetransition from the incommensurate phase to a “lock-in' phase. It has been found thatthe application of external magnetic field up to μ0H = 0.1T at the temperature T = 11K
along [100]-axis of TbNi5 single crystal recovers zero-field low temperature 'lockin' magnetic structure. The external magnetic field increase up to μ0H = 0.4T leads totransformation of the modulated magnetic structure to a ferromagnetic structure.

[1] T. C. Kobayashi et al., Prog. Theor. Phys. Suppl. 159 (2005) 271. [2] A. Hori et al., J. Phys. 200 (2010) 0022018. [3]
A. Hori et al., J. Low. Temp. Phys. 159 (2010) 122.

Elena Sherstobitova1*, Alexander Pirogov1, Vadim Sikolenko2, Savva Bogdanov1 andRoland Schedler3
1
Institute of Metal Physics of UD of RAS, Russia
2
Joint Institute for Nuclear Research, Dubna, Russia
3
Hahn-Meitner Institute, Berlin, Germany

Sergey Aplesnin1, Oksana Romanova1, Ludmila Ryabinkina1, Olga Demidenko2,
Anatoly Galyas2 and Kazimir Yanushkevich2
1
L.V. Kirensky Institute of Physics, Russia
2
Scientific-Practical Materials Research Centre NAS of Belarus, Belarus

In connection with intensive development of a microelectronics and spintronics, interestof researchers to the magnetic semiconductor materials showing magnetoresistivity
effect and metal-insulator transition has increased. New sulphide solid solutions
Mn1-XNiXS (0<Х≤0.1) are synthesized. The structural, magnetic and thermoelectric
properties of the obtained materials have been studied at the temperatures 77-1000
К in magnetic fields up to 10 kOe. The X-ray diffraction analysis has shown that the
samples synthesized Mn1-XNiXS have a NaCl-type FCC lattice and are observed fourreflexes of a weak intensity, associated with γ - modifications of MnS. Solid solutions
Mn1-XNiXS are antiferromagnetic with the Neel temperature (TN = 180 K for Х=0,05
and TN= 200 K for Х=0,1). The temperature dependence of magnetization is describedby the Curie-Weiss law at T> TN. The effective magnetic moment are found to be μef.
f=5,04 μВ for Х=0,05 and μeff.=5,16 μВ for Х=0,1. Change in the conductivity typefrom the hole to the electronic at Х=0,05 is revealed on the basis of measurements ofthermoelectric power.

Rie Y Umetsu1*, Xiao Xu2, Wataru Ito3, Takumi Kihara4, Masashi Tokunaga4, Kohki
Takahashi1 and Ryosuke Kainuma2
1
Institute for Materials Research, Tohoku University, Japan2
Department of Materials Science, Graduate School of Engineering, Tohoku University, Japan3
Department of Materials and Environmental Engineering, Sendai National College of Technology, Japan
4
International MegaGauss Science Laboratory, Institute for Solid State Physics, The University of Tokyo,
Japan

In order to investigate metamagnetic behavior and temperature dependence of equilibrium magnetic fieldof the martensitic transformation for Ni-Co-Mn-Sb, magnetization experiments up to 18 T static magnetic
field and up to 40 T pulsed magnetic field were performed. Polycrystalline specimen of Ni41Co9Mn39Sb11
was prepared by induction melting, and annealed at 1173 K for 1 day. Transformation temperatures, TM, andentropy change, ΔS, between the martensite phase and parent phase were examined with DSC. Magnetic
measurements were performed with using a SQUID magentometer up to 5 T, by extracting method up
to 18 T static magnetic fields, and also by induction method up to 40 T pulsed magnetic fields. In thethermomagnetization curves, it was observed that TM decreased with increasing the applying magnetic field,
H, with a rate of dTM/dH = 3.8 K/T. An estimated value of ΔS from the Clausius-Clapeyron relation, is about
15.8 J/K-kg, being in good agreement with the value obtained by the DSC. For the isothermal magnetization
curves, metamagnetic behavior associated with the magnetic field induced martensitic reverse transformation
was observed. Arresting behavior of the martensitic transformation was confirmed in lower temperature, as
similar to the Ni(Co)-Mn-Z (Z = In, Sn, Ga) alloys.

QF26

QG03

QG06

QG09

Quantum spin transport in a Heisenberg spin chain

First-principles dynamical CPA study of ferro- and antiferromagnetismof transition metals

Field induced anisotropy in NiMn and NiMnPt alloys

Magnetic Transition and Thermal Expansion in LaFe13-x-yCoySix

Quantitative explanation of the finite-temperature properties of 3d transition metals andalloys has been a long standing problem in metallic magnetism because their Coulombinteractions are comparable to the band widths and simple perturbation approach is
not applicable to such systems. We present here the first-principles dynamical CPA
combined with the LDA+U Hamiltonian toward quantitative calculations of magnetic
properties at finite temperatures and explain quantitatively or semi-quantitatively thefinite-temperature magnetism of 3d transition metals from V to Ni. We obtained theCurie-Weiss spin susceptibility with meff=1.8 muB (Expt. 2.1 muB) in V, the Pauliparamagnetic susceptibility in Cr being in agreement with the experimental data, as
well as the Curie-Weiss susceptibilities in Fe, Co, and Ni whose meff quantitatively
agree with the experimental data (3.2, 3.2, and 1.6 muB). Calculated ground-statemagnetizations are 2.58, 1.72, and 0.64 muB for Fe, Co, and Ni, being in good
agreement with the experimental data (2.2, 1.74, and 0.62 muB). On the other hand we
obtained the Curie temperatures 1900K, 2100K, and 620K for Fe, Co, and Ni which
are somewhat overestimated because of the single-site approximation. We also clarify
the systematic change of the single-particle DOS in these systems.

We report the detailed characterization of the magnetic properties of polycrystalline
disks of Ni72Mn28 and Ni72-xMn28Ptx (x=1.0, 4.0, and 10.0) at 4.2 K induced by fieldcooling (FC). It is found that the FC-induced anisotropy field ,HK and coercivity , HC
are strongly enhanced by the addition of nonmagnetic Pt impurities. The remanent
magnetization in the direction of the initial applied field (in the disk plane) for eachsamples can be rotated from 0° to 1800 and back to 0° in various stationary fields aboveand below HK and the parallel component of the rotated remanents are measured.
From the analysis of the angular dependence of ML, we show that these results can be
accounted for by the coexistence of Mn(Ni)-rich and /or Mn(Ni)-deficient nano scaleregions coupled antiferromagnetically. It is found that the unidirectional anisotropy
originates from interfacial exchange interactions between these regions. Up to somecritical angle rotation (θC) relative to H, the unidirectional anisotropy field turns
rigidly with the sample, while above θC, the coupled regions become unstable andmagnetically rearrange such that a unidirectional anisotropy is induced along H .

Nan-hong Kuo1, Sujit Sarkar2 and Chong Der Hu1*
1
Physics, NationalTaiwan University, Taiwan
2
PoornaPrajna Institute of Scientific Research, India

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Yoshiro Kakehashi* and Sumal Chandra
Department of Physics, University of the Ryukyus, Japan

Yildirhan Oner
Department of Physics, Istanbul Technical University, Dept. of Physics, 34469,
Istanbul, Turkey

July 10 (Tue)Akihiro Hori1, Kanako Kuwana2, Tatsuo C Kobayashi2, Yasushi Wanikawa3, Yoshiki Kubota3,
Kenichi Kato1, Masaki Takata1, Ryotaro Matsuda4 and Susumu Kitagawa1
1
RIKEN SPring-8 Center, Japan
2
Okayama University, Japan
3
Osaka Prefecture University, Japan
4
Exploratory Research for Advanced Technology (ERATO), Japan

July 10 (Tue)poster Presentation

Jianli Wang1, Stewart James Campbell2*, Shane J Kennedy3, Precious Shamba4, Rong
Zeng4, Shixue Dou4 and Guang Heng Wu5
1
Institute for Superconducting & Electronic Materials, The university of Wollongong, Australia
2
School of PEMS, The University of New South Wales, Canberra, Australia
3
Bragg Institute, ANSTO, Australia
4
Institute for Superconductivity and Electronic Materials, The University of Wollongong, Australia
5
National Laboratory for Condensed Matter Physics, Institute of Physics,, Chinese Academy of
Sciences, China
Materials with a large magnetocaloric effect (MCE) continue to attract significant attention for coolingapplications with particular interest in the isothermal entropy changes at first-order magnetic transitions [1].
The large entropy change in LaFe13-xSix is associated with negative lattice expansion and metamagnetictransition behaviour [2]. We have investigated LaFe13-x-yCoySix to clarify the influence of magneto-structural
coupling on the MCE. The Curie temperatures of LaFe13-xSix increase with Si content from TC=219 K for
x=1.6 to TC=250 K for x=2.6 with further enhancement to TC=281 K on substitution of Co to LaFe9.4CoSi2.6.
A pronounced positive spontaneous volume magnetostriction has been observed below TC and the anomalous
thermal expansion attributed to the volume dependence of the magnetic energy. Our results show that themagnetic transition changes from first order for LaFe11.4Si1.6 to second order for LaFe10.4Si2.6 and LaFe9.4CoSi2.6.
The different natures of the magnetic transitions in LaFe13-x-yCoySix have been discussed in terms of theclassical model for itinerant ferromagnets and the volume dependence of the magnetic energy.
[1] KA Gschneidner, Jr., VK Pecharsky and AO Tsoko, Rep. Prog. Phys. 68, 1479 (2005) [2] FX Hu,
BG Shen, JR Sun, ZH Cheng, GH Rao, X Zhang, Appl. Phys. Lett. 78, 3675 (2001)

QG01

QG04

QG07

QG10

Magnetic transition of plastic deformed Si-doped Ni3Mn alloy

High-coercive metastable ferromagnetic state induced in the Ising
antiferromagnet Fe0.5TiS2

X-ray-absorption near-edge structure and X-ray magnetic circulardichroism studies of a Lu2Fe16.5Ru0.5 single crystal

The magnetovolume effect of Y2Fe17-xGax

Kowan-young Ko1*, Sung-won Ko2 and John Graham Booth3
1
Faculty of mechanical engineering, Ulsan College University, Korea
2
Department of biological science, Sungkyunkwan University, Korea
3
School of computing, science and engineering, Salford University, United Kingdom
Structural and magnetic properties of plastic deformed Si-doped Ni3Mn alloy werestudied and compared with those of undeformed specimen investigated by powder
neutron diffraction and diffuse purely magnetic scattering measurements in which
coexistences of ferromagnetic and antiferromagnetic interactions were still existingeven far above Neel temperature. Two specimens showed spin glass properties anddisordered face-centered cubic structure but lattice parameters were a little different
value of 3.5961 Å and 3.5890 Å. Magnetic properties showed very different Neeltemperatures of 87.5 K and 62.5 K respectively. The paramagnetic Curie temperatureappeared by -325 K and 125 K and therefore effective magnetic moments were
calculated by 3.51 μB and 0.41 μB respectively. The reasons for different magnetictransition could be introduced by the elongation of ferromagnetic clusters and changeof atomic environments effect after plastic deformation. This report shows two kinds ofmagnetic properties by plastic deformation.

Nikolay Baranov1*, Elizaveta Sherokalova2, Alexey Volegov2, Alexey Proshkin3,
Nadezshda Selezneva2, Andrey Gubkin4 and Ekaterina Proskurina2
1
Micromagnetic laboratory, Institute of Metal Physics, Russia
2
Institute of Natural Sciences, Ural Federal University, Russia
3
Laboratory of ferromagnetic alloys, Institute of Metal Physics, Russia
4
Laboratoty of neutron studies of matter, Institute of Metal Physics, Russia
The transition metal (T) dichalcogenides TX2 (X = S, Se, Te) with a layer crystal structure being
intercalated with 3d-transition (M) metals demonstrate different magnetic states depending on thetype and concentration of M-atoms as well as on the parent TX2 matrix [1]. In the present work, themagnetic susceptibility, magnetization, electrical resistivity, magnetoresistance and powder neutron
diffraction measurements have been performed for the Fe intercalated compound Fe0.5TiS2. It has beenshown that this compound exhibits an antiferromagnetic (AF) ground state below the Neel temperature
TN = 140 K. Application of the magnetic field at T < TN induces a metamagnetic phase transition to
the ferromagnetic (F) state, which is accompanied by the large magnetoresistance effect (~ -27 %).
The field-induced AF-F transition is found to be irreversible below 100 K. At low temperatures, themagnetization reversal in the metastable F state is accompanied by substantial hysteresis (up to 100kOe) which is associated with the Ising character of Fe ions. This work was supported by the RFBR
(project 12-02-00778) and by the program of the Ural Branch of RAS (project № 12-T-1012).
[1] Baranov N. V. et al. J. Phys. Condens. Matter. 17 (2005) 5255

208

The 19th International Conference on Magnetism

E. A. Tereshina1, A. Smekhova2, O. Isnard3, A. V. Andreev4 and A. Rogalev51Institute of Physics, Academy of Sciences, 18221 Prague, Czech Republic
2
Faculty of Physics, Moscow State University, 119991 Moscow, Russia
3
Universite Joseph Fourier/Institut Neel (CNRS), 38042 Grenoble Cedex, France
4
Institute of Physics, Academy of Sciences, Czech Republic
5
European Synchrotron Radiation Facility (ESRF), 38043 Grenoble Cedex, France

The magnetism of R2Fe17 with the smallest rare-earth R=Lu (hexagonal Th2Ni17 structure type) is essentiallyassociated with its Fe sublattice behavior. Strong contribution of the local antiferromagnetic (AF) Fe-Fe
interactions in the overall ferromagnetic (F) exchange considerably lowers the ordering temperature (TN=274
K) and balances the non-collinear antiferromagnetic phase above the Curie temperature TC=130 K. Generally,various doping elements (M) in Lu2Fe17- xMx suppress fully the AF states by strengthening the ferromagnetic ones
accompanied by a dramatic TC increase. However, recently a unique case of antiferromagnetism stabilization in
the whole range of magnetic ordering in Lu2Fe17- xRu1x was reported [1], and this work is dealing with the local
studies of intrinsic magnetic properties of Lu2Fe16.5Ru0.5. A single-crystalline sample of Lu2Fe16.5Ru0.5 has been
investigated by X-ray-absorption (XANES) and X-ray magnetic circular dichroism (XMCD) techniques in theapplied magnetic field up to ±3 T at 7 K. By probing the lutetium L2,3-, iron K- and ruthenium L2 absorption
edges, information on magnetic states of the constituents of Lu2Fe16.5Ru0.5 is obtained. Small but noticeable
induced magnetic moments with an antiparallel orientation to Fe moments have been registered on Lu and Rusites.

Daiki Haruna and Tatsuo Kamimori
Ehime University, JapanThe unit cell volume and the Curie temperature of Y2Fe17 increases by substitution of
Ga for Fe. This phenomenon is understood as a property of Invar materials, dTc/dV >0, because the compounds R2Fe17 have Invar properties. However, in the substitutionof Si for Fe, dTc/dV is negative. Kamimori et. al. proposed damping of the Invar
properties by these substitutions. In this work, the magnetovolume effect of Y2Fe17xGax was investigated by measuring temperature dependence of unit cell volume
and forced volume magnetostriction. X-ray diffraction was used to measure unit cellvolume at under R.T. and thermal expansion meter at above R.T.. The forced volume
magnetostriction was measured by three terminals capacitacne method under magnetic
field up to 1.5T. The forced volume magnetostriction at R.T. is positive. This shows
Y2Fe17-xGax compounds have Invar property. However, the magnitude of the forced
volume magnetostriction decreases violently by the substitution of Ga for Fe. This
tells us the substitution of Ga for Fe in R2Fe17 decreases magnetovolume effect andattenuates Invar characters of the compounds.

[1] E.A. Tereshina et al., J. Appl. Phys. 105 (2009) Art. No. 07A747.

July 8-13, 2012 Busan, Korea

209

poster Presentation
QG11

QG14

QG17

QG20

Pressure effect on the electrical resistivity of La 1.09(Fe0.845Si0.155)13
compoundMagnetic structure and excitations of the one-dimensional quantum
antiferromagnet RbCoCl3

Design strategy for strongly coupled diradicals: Systematic Approaches
of intramolecular magnetic interactions

Fundamental Magnetism of Fe-P Alloys and Fe3P Compounds: A
density functional study

RbCoCl3 is a hexagonal perovskite in which the Co2+ ions have an effective spin S = 1/2 and form onedimensional (1D) chains perpendicular to the basal plane. Measurements of the magnetic susceptibility
confirm its antiferromagnetic behaviour; the difference between the maximum of the susceptibility and theNeel temperature indicates 1D magnetic correlation. Isostructural materials, such as CsCoCl3 and TlCoCl3, arequasi-1D Ising-like spin systems[1][2]. The lowest-lying magnetic modes in their spectrum consist of pairsof domain-wall excitations and are described by a strongly anisotropic Heisenberg Hamiltonian[3]. Here we
report the first results of a comprehensive neutron scattering study of the magnetic structure and excitations in
RbCoCl3. A neutron diffraction experiment on HRPT (SINQ,PSI,Switzerland) revealed the existence of twophase transitions at TN1=28K and TN2=14K. At TN1 there is a paramagnetic-to-antiferromagnetic transition,
while at TN2 a low-temperature phase with a new propagation vector develops. Inelastic neutron scatteringexperiments were performed on LET (ISIS,RAL,UK) and IN22 (ILL,Grenoble,FR). Between TN1 and TN2,
as well as above TN1, excitations characteristic for an Ising magnet are observed. Below TN2 an additional
splitting of the modes is discovered. Results and analysis of the data from LET will be presented and discussed.

A new series of neutral radicals (DP1-DP6) based on diazaphenalenyl were designed
via heteroatomic modifications. As spin sources, the designed radicals were
implemented in four different diradical model systems (Model I, II, III, and IV)
by changing the reference radical and the linkage, and their magnetic interactions
between the designed radicals and the reference radical were investigated by using
density functional theory calculations. The trend in strength of magnetic interactionsof radicals was found to be identical in different model systems. In particular, as a new
family of spin source radical, DP3 could be a potential candidate in designing neworganic magnetic materials due to its strong magnetic coupling and high stability indiradical systems.(1) We divided 8 monoradicals into α-group and β-group according
to Mulliken spin density values of the connected atoms. The overall trends in thestrength of magnetic interactions of diradicals were found to be identical in threedifferent model systems (Model I, II and V). NN-ethylene-PO was calculated to havethe strongest magnetic coupling constant with ferromagnetism, and even stronger (morethan twice) than NN-ethylene-NN which was reported to have strong antiferromagnetic
interactions in a previous experiment.

Phosphorus (P) is quite harmful on the mechanical properties of steel. For instance,
the decrease of the strength and plastic properties of G13L steel is nearly half when it
contains 0.065 wt.% P compared to the case of 0.028 wt.% P steel. On the contrary, P
is an important component in the making phosphor bronze which enhances wear andwater corrosion resistant. On the purpose of solid solution strengthening, P containing
interstitial free steel is very important in the automotive industry due to their excellent
deep drawability. However, there is no systematic first-principles study done forunderstanding the Fe-P alloys and Fe3P compounds. Thus, we investigated fundamental
magnetic and thermodynamic properties of ferrites with the various P concentrations(Fe1-xPx alloys, x = 0.037, 0.0625, and 0.125) and (L12, D03, and I-4 structured) Fe3P
compounds using the highly precise all-electron full-potential linealized augmented
plane wave method. As a result, the ferromagnetic state for I-4 structured Fe3P
compound is more stable than the nonmangetic one by energy difference of about
809 meV. The calculated magnetic moments are rather overestimated compared to theneutron diffraction study. Detailed discussion on the magnetic and thermodynamic
properties of Fe1-xPx alloys and Fe3P compounds will be given.

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Mattia Mena1*, Eva Hirtenlechner2, Nora Haenni3, Simon Ward4, Karl Kraemer3,
Christian Ruegg4 and Des Mcmorrow1
1
London Center for Nanotechnology, UCL, United Kingdom
2
Institut Laue-Langevin, France
3
University of Bern, Switzerland
4
Paul Scherrer Institut PSI, Switzerland

Kyoung Chul Ko, Daeheum Cho and Jin Yong Lee*
Department of Chemistry, SungKyunKwan University, Korea

Won Seok Yun, Jee Yong Lee and In Gee Kim*
Graduate Institute of Ferrous Technology, POSTECH, Korea[1] J. P. Goff, D. A. Tennant and S. E. Nagler, Phys.Rev. B 52, 15992 (1995). [2] A. Oosawa, Y. Nishiwaki, T. Katoand K. Kakurai, J. Phys. Soc. Jpn. 75, 15002 (2006). [3] N. Ishimura and H. Shiba, Progr. Theor. Phys. 63, 743 (1980).

(1) Ko, K. C.; Son, S. U.; Lee, S.; Lee, J. Y. J. Phys. Chem. B 2011, 115, 8401.

QG12

QG15

QG18

QG21

One- and two-magnon and exciton raman scattering in
antiferromagnetic CoF2: Experiment and theory

Antiferromagnetic transition in Ru2CrSi in magnetic fields

Single crystal growth and physical properties of metalic
antiferromagnet (Mn,Fe)3Si

Analysis of spin-polaron formation in Hund lattices

Eric Meloche1, Michael Cottam1 and David Lockwood2
1
Department of Physics and Astronomy, University of Western Ontario, Canada
2Institute for Microstructural Sciences, National Research Council, Canada

Masahiko Hiroi1*, Kaori Uchida1, Iduru Shigeta1, Masakazu Ito1, Keiichi Koyama1,
Shojiro Kimura2 and Kazuo Watanabe2
1
Department of Physics and Astronomy, Kagoshima University, Japan
2
Institute for Materials Research, Tohoku University, JapanSo Nara1, Sun Chang Che1, Haruhiro Hiraka2, Kenji Ohoyama2, Yasuo Yamaguchi2,
Hiroyuki Miki3 and Kazuyoshi Yamada4
1
Dept. of Physics, Tohoku University, Japan
2
IMR,Tohoku University, Japan
3
IFS,Tohoku University, Japan
4
WPI,Tohoku University, Japan

Yesenia Arredondo1*, Emmanuel Vallejo2, Oracio Navarro1 and Michel Avignon3
Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Mexico
2
Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Coahuila, Mexico
3
Institut Neel, CNRS and Universite Joseph Fourier, France
1

Experimental data are reported for the temperature and polarization dependence of theone- and two-magnon Raman light scattering in the rutile-structure antiferromagnet
CoF2 (Neel temperature = 38 K). A detailed analysis of the one-magnon Stokes andanti-Stokes Raman spectra is presented resulting in comprehensive experimental data
for the temperature variation of the one-magnon frequency, line width, and integrated
intensity. A similar analysis was carried out for the two-magnon scattering. The lowlying excitons were also investigated at low temperatures and comparisons are madewith results from earlier Raman, infrared, and neutron scattering work. The Green’s
function equation of motion method was employed to derive the excitation energies
and spectral intensities over a broad range of temperatures for the magnetic excitations
in a spin S = 3/2 anisotropic antiferromagnet with strong spin-orbit coupling. Results
were obtained using RPA for the product of operators at different sites while the singleion anisotropy terms were treated exactly by generating a closed set of coupled Green’s
function equations. The numerical results are in good agreement with one-magnon
Raman light scattering data. Results were deduced for some exchange and anisotropy
parameters and the relative magnitudes of the magneto-optical coefficients in theinteraction Hamiltonian.

Heusler compounds Ru2-xFexCrSi for Fe-rich region were recently found to beferromagnetic and to be candidates for a half-metal, where conduction electrons are
fully spin-polarized.[1] In the Heusler compound Ru2CrSi, on the other hand, anantiferromagnetic (AF) transition at TN =14 K was revealed by specific heat andmagnetization measurements.[2] In this study electrical resistivity is measured inmagnetic fields up to 14.5 T and the AF transition in magnetic fields is investigated. In
the temperature dependence of the resistivity at zero field a clear kink is observed at
TN =14 K. With decreasing temperature the resistivity turns upward from the kink at
TN. This kink can be regarded as an indication of the AF transition. With increasing
magnetic field the resistivity only slightly changes and even at 14.5 T the clear kink isobserved. From the kink TN is found to decrease just a little in high magnetic fields.
TN at 14.5 T is lower than TN at zero field by 0.5 K. These results demonstrate that the
AF state in Ru2CrSi is unusually unaffected by strong magnetic field.

QG13

QG16

QG19

QG22

Thermodynamic and transport properties of Ru2-xFexCrSi (1.3 ≤ x ≤1.8)

Assessment of Curie temperature by magnetization vs. temperature(M-T) scans in a granular magnetic Cu-Fe-Ni alloy

AC magnetic measurement of LiFeAs at pressures up to 5.2 GPa:
Verification of the relation between Tc and structural parameters

Chiral magnetic orders in chiral helimagnet Cr1/3NbS2

Masakazu Ito*, Toru Hisamatsu, Tsugumi Rokkaku, Iduru Shigeta and Masahiko
Hiroi
Department of Physics and Astronomy, Graduate School of Science and Engineering,Kagoshima University, Japan
Full-Heusler compounds with the generic chemical formula X2YZ (X and Y aretransition elements, Z is sp element) attract much interests because this system shows anumber of physical properties and some of them have a potential for the technologicalapplications. The ferromagnetic Heusler compound Ru2-xFexCrSi is one of candidate
materials expected a half metallicity1] and this system has relatively high Curie
temperature TC~500 K for x > 1.4 2]. We have carried out electric resistivity ρ(T) andspecific heat Cp(T) measurement of Fe-rich Ru2-xFexCrSi ( x = 1.3, 1.6, and 1.8 ). For
all samples, ρ(T) shows metallic behavior ( ∂ρ/∂T ) in 20 < T < 300 K, and upturn
at around 20 K. In low-temperature range, Cp(T) can be described by Debye’s law.
Although a coefficient of lattice specific heat β is insensitive for Fe concentration x, aelectronic specific heat part γ decreases slightly with increasing x. For each x sample,
we estimated total density of states (DOS) at the Fermi level D(EF) from γ.
1]S. Mizutani et al., Mater. Trans. 47, 25 (2006). 2]M. Hiroi et al., Phys. Rev. B 79, 224423 (2009)

The 19th International Conference on Magnetism[1] M. Hiroi et al., Phys. Rev. B 76, 132401 (2007). [2] M. Hiroi et al., to be published in J. Phys.:Conf. Series.

Heusler alloys Mn3-x Fex Si(x=0~3) have a face centered cubic (DO3 type) structure in the wholex-region from the antiferromagnet Mn3 Si(TN~23K) to the ferromagnet Fe3 Si(TC~850K). As acharacteristic point, Mn3Si shows anomalous magnetic excitations so-called “chimney-type” ones,
which is difficult to understood by normal spin waves, while Fe3Si shows typical ferromagnetic
spin wave excitations. Our final goal is to clarify how the spin dynamics qualitatively changes from
antiferromagnet to ferromagnet in this (Mn,Fe)3Si system, so that a deep insight into the originof magnetism would be gained. The purpose of current work is to grow high quality large single
crystals of Mn3-x Fex Si for inelastic neuron scattering experiments, which can reveal generalized
magnetic susceptibility directly. Besides, for accurate measurement of bulk properties, such as
electric resistivity ρ(T) and magnetic susceptibility χ(T) , minimizing amount of impurities isimportant. So far, we have succeeded in growing large single crystals of x=0, 0.2, 0.6, 1.0, and1.5 by the Bridgman method. At present, an impurity phase (several-% order) is still observablein X-ray powder diffraction patterns. In this work, we report the details of single crystal growth of
Mn3-x Fex Si, assignment of impurity phase,and resultant χ(T), and ρ(T).

Sung Kang1, Atsuki Takano2, Dong-hae Lee2, Mahoto Takeda2*, Zenji Hiroi3 andMasaki Takeguchi4
1
Research Institute of Industrial Science & Technology (RIST), Korea
2
Yokohama National University, Japan
3
University of Tokyo, Japan
4
National Institute for Materials Science (NIMS), Japan

Shuhei Yamaguchi1, Nobuhiro Yamaguchi1, Masaki Mito1, Hiroyuki Deguchi1,
Michael. J. Pitcher2, Peter. J. Baker3, Stephen. J. Blundell3, Dinah. R. Parker2 andSimon. J. Clarke2
1
Fac. of Eng, Kyushu Inst. of Tech, Japan2
Dep. of Chem, Univ. of Oxford, United Kingdom
3Dep. of Phys, Univ. of Oxford, United Kingdom

The present study has investigated the Curie temperature of Cu-Fe-Ni ternary alloy which is known as a
granular giant magneto-resistance (GMR) material with a high magneto-resistance (MR) ratio. At first, wesurveyed the relationship between the microstructure and the aging temperature of precipitates formed in CuFe-Ni alloys isothermally annealed at 873K and 1073K for various aging times, using a transmission electron
microscopy (TEM). According to TEM observations, we have revealed that two or more nano-scale particles
with a cubic shape and rod shape precipitates were formed at 873K and 1073K, respectively. The criticaltemperature of the drastic change of the microstructure coincides with the Curie temperature of magnetismof the alloy. And, the Curie temperature has been determined by the magnetization (M) vs. temperature (T)scans, using the SQUID magnetometer. The experimentally determined temperature of 1028K was as high as
a bulk Fe-Ni alloy, even though nano-scale ferromagnetic particles are finely distributed in copper matrices.
The high Curie temperature has, however, well explained the temporal evolutions in both microstructure andmagnetic properties occurring during isothermal annealing.

We have already conducted AC susceptibility measurements at pressures up to 1.5
GPa and X-ray diffraction experiment up to 20 GPa for a 111 type of iron-based
superconductor, LiFeAs[1]. Now, we have enlarged the pressure range of the ACsusceptibility measurement for the same sample up to 5.2 GPa. The superconducting
transition temperature Tc decreased from 17 K at 0 GPa to 10 K at 5.2 GPa. Tc has
been related to two structural parameters, an As-Fe-As bond angle α and the height ofAs from the Fe layers (hAs): Lee et al. have suggested that Tc has the highest value
at the optimal α of 109.47°[2]. Kuroki et al. have suggested that Tc increases withincreasing hAs[3]. According to our previous study, α changes from 101.5° at 0 GPa to
97.8° at 17 GPa, and hAs changes from 0.154 nm at 0 GPa to 0.156 nm at 17 GPa. The
present pressure-induced decrease in Tc is not explained by the change in hAs, but isqualitatively consistent with the change in α.

[1] S. Kang, M. Takeda, Z. Hiroi, G. W. Kim, C. G. Lee, and B. H. Koo, J. Phys. D: Appl. Phys. 43,415001 (2010) [2] S. Kang, M. Takeda, M. Takeguchi, and D. S. Bae, J. Alloy. Compds. 496, 196 (2010)[1] M. Mito et al., J. Am. Chem. Soc., 131 (2009) 2986. [2] C.H. Lee et al., J. Phys. Soc. Jpn. 77(2008) 083704. [3] K. Kuroki et al., Phys.Rev.B 79 (2009) 224511.

July 10 (Tue)Makio Kurisu1*, D. T. K. Anh2 and Go Nakamoto3
1
Department of Physics, Ehime University, Japan
2
School of Materials Science, Japan Advanced Institute of Science and Technology,
Japan
3
School of Materials Science, Japan Advansed Institute of Science and Technology,
Japan

210

poster Presentation

The ferromagnetic Kondo lattice model, also known as Hund lattice model, is a well-established model tostudy the interplay between charge and spin degrees of freedom in strongly correlated fermionic systems
such as transition-metal oxides. Their electronic, magnetic and transport properties have displayed interesting
physics such as the phenomenon of magnetoresistance [1]. Their properties depend as well strongly on thedoping of the materials, which leads to formation of magnetically ordered regimes [2]. In our work, we study
numerically the formation of spin-polarons in one-dimensional systems. We consider a Hund lattice model
where a conducting band is coupled to a background of localized spins interacting antiferromagnetically withcoupling constant J. Even though the zero-temperature of such lattice model has been intensively studied [3,4], the physics of its phase diagram is still not exhausted. We investigated the ground state phase diagram
as a function of the exchange coupling J and as a function of the band filling and found different evolving
magnetic orderings. We report measurements of static properties such as spin structure factor. We study thequasi-particle formation and phase separation using the density-matrix renormalization group method, which
is a highly efficient method to investigate quasi-one-dimensional strongly correlated systems[5].
1. D. D. Sarma, P. Mahadevan, T. Saha-Dasgupta, S. Ray, A. Kumar, Phys. Rev. Lett. 85, 2549(2000). 2. T.
Kumar, M. Greenblatt. In Functional Oxides, John Wiley & Sons, 2010. 3. E. Vallejo, F. Lopez-Urias, O.
Navarro, M. Avignon, Solid State Commun. 149, 126(2009). 4. D. J. Garcia, K. Hallberg, B. Alascio, M.
Avignon, Phys. Rev. Lett. 93, 177204(2004). 5. U. Schollwock, Rev. Mod. Phys. 77, 259(2005).

Yoshihiko Togawa 1*, Tsukasa Koyama 2, Shigeo Mori2, Yusuke Kousaka3, Jun
Akimitsu3, Sadafumi Nishihara4, Katsuya Inoue4, Alexander Sasha Ovchinnikov5 andJun-ichiro Kishine6
1
Nanoscience and Nanotechnology Research Center (N2RC), Osaka Prefecture
University, Japan2
Department of Materials Science, Osaka Prefecture University, Japan3
Department of Physics, Aoyama Gakuin University, Japan
4
Department of Chemistry, Hiroshima University, Japan
5
Department of Physics, Ural Federal University, Russia
6
Graduate School of Arts and Sciences, The Open University of Japan, Japan
We directly present that chiral magnetic orders emerge in chiral helimagnet Cr1/3NbS2 in small magnetic fields
by means of low-temperature Lorenz transmission electron microscopy and small-angle electron diffraction
technique. Based on precise analyses in both real and reciprocal space, we undoubtedly demonstrate that chiralmagnetic soliton lattice (CSL) develops from chiral helimagnetic structure (CHM) with increasing the spatial
period from 48 nm toward infinity in rising magnetic fields perpendicular to the helical axis. CSL and CHM do
not exhibit any structural dislocation, indicating their high stability and robustness. This is because chiral magnetic
orders are macroscopically induced by the uniaxial Dzyaloshinkii-Moriya (DM) exchange interactions that isallowed in Cr1/3NbS2 hexagonal crystals belonging to noncentrosymmetric chiral space group. Theoretical sidesof this talk will be given in this topic category by Prof. Jun-ichiro Kishine from the Open University of Japan.
[1] Y. Togawa, T. Koyama, K. Takayanagi, S. Mori, Y. Kousaka, J. Akimitsu, S. Nishihara, K. Inoue, A.
S. Ovchinnikov, and J. Kishine, to appear in Phys. Rev. Lett.

July 8-13, 2012 Busan, Korea

211

poster Presentation
QG23

QG26

QH01

QH04

ESR study of AFM - Ordering in the orthorhombic CuMnAs

Mn-Sublattice of YbMn2Si2

Structural and magnetic properties of Fe2Mn0.5Cu0.5Al Nanocrystalline
AlloysMossbauer study on Fe (Si,Ge) alloys

At the present time the Mn based compounds with elements of I or V group werestudied intensively as advances materials for spintronic. One from such compounds
is CuMnAs. CuMnAs is ordered antiferromagneticaly above room temperature. We
have studied electronic spin resonance (X-band) in this compound at temperature
range 10 - 400 K At all temperature we observed symmetric Lorentz’s shape resonancelines from Mn2+ ions with g - factor 2.00. The lineswidth increase in 2 times attemperature decreasing to 10 K. The second line with a g-factor of 2.55 has appearedin the spectrum at temperatures below 60 K Non resonant absorption was observedfor powder samples. We interpreted our results in terms Mn-Cu-Mn and Mn-AsMn indirect superexchange interaction. Work was supported by Grants of RFBR and
Presidium of the RAS.

July 10 (Tue)[1] F. Maca, J. Masek,O. Stelmakhovych, et al., ArXiv: 1102.5373v1 [cond-mat. matrl-sci] 25
Feb 2011 [2] T. Jeong, Ruben Weht,W. E. Pickett, Phys.Rev. B 71, 184103 (2005) [3] J. Boeuf, C.
Pfleiderer, A. Faißt, Phys.Rev. B 74, 024428 (2006) [4] T. Jungwirth, V. Novak, X. Martı, M. Cukr, etal., Phys.Rev. B 83, 035321 (2011)

Stewart J Campbell1*, Michael Hofmann2, Richard A Mole3, Karel Prokes4, Jianli Wang5 and Dirk Wallacher6
1
School of Physical, Environmental and Mathematical Sciences,ADFA, The University of New South
Wales, Australia
2
Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universitat Munchen, Germany
3
Bragg Institute, ANSTO, Australia
4Helmholz Zentrum Berlin, Lise Meitner Campus, Germany
5
Institute for Superconducting & Electronic Materia, University of Wollongong, Australia
6Helmholz Zentrum Berlin,, Lise Meitner Campus, Germany
2+

The instability of the f shell in Yb and the small energy difference between the Yb divalent andYb3+trivalent states, has led to the wide range of physical and magnetic properties exhibited by ytterbiumbased intermetallic compounds. The ranges of effects are linked with many physical states such as: mixed
valence, Kondo effect, heavy fermions, spin wave excitations, superconductivity and magnetic quantum
critical point [e.g. 1]. Trivalent YbMn2Si2 exhibits a collinear antiferromagnetic AFil structure below TN1 =526(4) K with a doubling of the magnetic c-lattice below TN2 = 30(5) K; this structure of the Mn-sublatticewould therefore be expected to result in different environments for Yb atoms in the doubled unit cell [2].
However 170Yb Mossbauer studies led to the conclusion that the observed spectra are inconsistent with thecell-doubling [3]. To clarify this discrepancy, we have re-investigated the magnetic behaviour of YbMn2Si2over the temperature range ~0.4-50 K using the E6 neutron diffractometer, HZB. The high density ofdiffraction patterns confirm the cell doubled magnetic behaviour of the Mn-sublattice below 27.3(2) K withthe onset of the satellite reflections (propagation vector k = 00½) described well by a power law.

Dwi Nanto1, Dong-seok Yang2, Suhk-kun Oh1 and Seong-cho Yu1*
1
Dept. of Physics, BK 21 Physics Program and Dept. of Physics, Chungbuk National
University, Cheongju, 361-763, Korea
2
Dept. of Physics Education, Physics Division, Chungbuk National University,
Cheongju, 361-763, Korea
We synthesized Fe2Mn0.5Cu0.5Al nanocrystalline alloys by mechanical alloying
technique and studied as a function of milling time. The milling times were 1, 3, 6, 9,
and 24 hrs. The effect of milling time on structure formation was investigated by X-ray
Diffraction (XRD), and magnetic properties was investigated using vibration sample
magnetometer (VSM). Alloy nature of Fe2Mn0.5Cu0.5Al was confirmed after 24 hrs. The
crystallite size after 24 hrs of milling time was estimated using Scherer formula, andthe value was 24 nm. Magnetic saturation was decreased with increased milling time,
which seemed be due to co-existence of Mn and Cu atoms. The magnetic saturation
was 86.19 (emu/gr) and the coercivity was 376.59 Oe after 24 hrs of milling time. The
coercivity (Hc) was increased with milling time presumably due to magnetic domain
growth towards stable structure. Keywords: Heusler compound, nanocrytalline

Yasushi Amako, Yusuke Taniguchi and Miho Nakashima
Faculty of Science, Shinshu University, Japan
Calculations of electronic structures in FeSi1-xGex with a cubic B20-type structure
found that they were narrow-gap semiconductors in the non-magnetic state for x<0.5,
however, the metallic state with the magnetic moment of about 1μB per Fe was shown
to be more stable for x≥0.5 [1]. In this paper, we report the results of the magnetization
measurements and 57Fe Mossbauer effect measurements on FeSi1-xGex compounds.
The 57Fe hyperfine fields for x=0.6 and 0.8 estimated by fitting of Mossbauer spectra
at 80K were 6.0T and 8.0T, respectively, while they were almost zero for 0≤x≤0.5. The
Curie temperature and spontaneous magnetization at 4K were found to be 124K and
0.66μB/f.u. for x = 0.6 and 171K and 0.71μB/f.u. for x = 0.7, respectively.
[1] H.Yamada, K.Terao and T.Goto, Physica B 344 (2004) 451.

[1] C. Klingner, C. Krellner, M. Brando, C. Geibel, F. Steglich, D. V. Vyalikh, K. Kummer, S. Danzenbacher, S. L. Molodtsov, and C.
Laubschat, T. Kinoshita, Y. Kato, and T. Muro, Phys. Rev. B 83, 144405 (2011). [2] M. Hofmann, S.J. Campbell, A.V.J. Edge and A.J. Studer, J.
Phys.: Condens. Matter 13, 9773 (2001). [3] D. H. Ryan, J. M. Cadogan, and A.V.J. Edge, J. Phys.: Condens. Matter 16, 6129 (2004)

References: [1] Tanja Graf, Claudia Felser, Stuart S.P. Parkin, Progress in Solid State Chemistry39 (2011) 1-50 [2] Shane Stadler1, Mahmud Khan1, Joseph Mitchell1, Naushad Ali1, Angelo M.
Gomes2, Igor Dubenko3, Armando Y. Takeuchi3, and Alberto P. Guimaraes3 Appl. Phys. Lett. 88,
192511 (2006)

QG24

QG27

QH02

QH05

Elastic properties and stability of Heusler compounds

Electronic structures and magnetic properties of full and half Fe-MnGa Heusler alloys

Antiferromagnetic resonance in the one-dimensional magnet
IPACu(Cl1-xBrx)3 (x=0.83)

Ab initio and Monte Carlo investigations of the magnetic exchange
and curie temperature of Ni2Mn1+xSn1-x alloys

S.-c. Wu*, S. S. Naghavi, G. H. Fecher and C. Felser
Max Planck Inst. for Chem. Phys. of Solids; Inst. for Inorg. and Analy. Chem., Uni.
Mainz, Germany
The physical properties of Heusler compounds which are promising materials for
spintronics are important. Various Heusler compounds are investigated with respect
to their malleability and stability. The elastic constants are calculated by applying
isotropic strain in different ways to the cubic crystal. We used FP-LAPW implemented
in Wien2K to calculate the elastic constants as well as further physical properties(bonding, hardness, velocity of sound, Debye temperature, etc.) that can be derived
from the elastic constants. The result of the cubic elastic anisotropy can be used todecide the structural stability. Zener's ratios of the most stable compounds are in therange of 1.0 < Ae < 2.5. Ae < 0 is not stable and Ae = 0 is isotropic. We observed phasetransitions in some of Heusler compounds with Ae < 0. It is shown that calculating
elastic constants provides an estimate for studying phase transitions.

Y. V. Kudryavtsev1, N.v. Uvarov1, J. Dubowik2, I.n. Glavatskyy3, Y. J. Yoo4 and Y. P. Lee4*
1
G.V.Kurdumov Institute of Metal Physics NAS of Ukraine, Ukraine
2
Institute of Molecular Physics, PAS, Poland
3
Helmholtz Centre Berlin for Materials and Energy, Germany
4
Dept. of Physics, Hanyang University, Korea

Electronic and magnetic structures of bulk and film Fe2MnGa and FeMnGa alloys near 2:1:1 and 1:1:1
stoichiometric compositions have been investigated theoretically and experimentally. It was experimentallyfound that unlike most of full stoichiometric Heusler compounds, bulk Fe50,4Mn24,2Ga25,4 alloy with
the Curie temperature of 800 K and saturation magnetization of 4.86 μB/f.u. crystallizes in the facecentered-cubic (FCC) ordered lattice of L12 (Cu3Au)-type with small admixture of B2-phase. According
to results of our first-principle calculations of full electron energy ferromagnetic metallic FCC phase(μFCC=6.11 μB/f.u.) is energetically more preferable than ferrimagnetic half-metallic phase with L21 typeof structure (μL21=2.04 μB/f.u.) or ferrimagnetic metallic FCC phase (μFCC=0.48 μB/f.u.). Metamagnetictransition in Fe50,4Mn24,2Ga25,4 alloy from antiferromagnetic to ferromagnetic phase was observed at low
temperatures. Bulk Fe33.5Mn32.0Ga34.5 alloy has hexagonal structure and saturation magnetization at T=15
K of μ=3.00 μB/f.u. and the Curie temperature of 453 K. Magnetic properties of Fe33.6Mn32.9Ga32.8 alloy
films strongly depend on their structure. Atomic disorder in amorphous state significantly reduces the film
magnetization nearly to zero at room temperature. Depending on deposition conditions, unlike the bulk
alloy, crystalline Fe33.6Mn32.9Ga32.8 alloy films exhibit BCC- or FCC-ordering that result in anomalous
temperature dependencies of magnetization in low-temperature region.

Takahito Fujita1, Masayuki Hagiwara1 and Hirotaka Manaka2
1
KYOKUGEN, Osaka university, KYOKUGEN, Osaka university, 1-3
Machikaneyama, Toyonaka, Osaka 560-8531, Japan
2
Graduate School of Science and Engineering, Kagoshima University, Graduate
School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto,Kagoshima 890-00, Japan
Low-dimensional antiferromagnets with a small spin value exhibit various fascinating
properties. IPACuCl3 and IPACuBr3 (IPA: isopropyl-amine) having magnetic Cu2+ (spin
S=1/2) ions form the ladder chain in the b plane. The ground states of IPACuCl3 andIPACuBr3 are considered to be the Haldane state [1] and the singlet dimer state [2]. It
was reported that IPACu(ClxBr1-x)3 (0.44 < x<0.87) undergo an antiferromagnetic longrang order (AFLRO) at low temperatures. However, the details of the AFLRO phasehave not been clarified yet [3]. Therefore, we have performed electron spin resonance(ESR) measurement on single crystals of IPACu(ClxBr1-x)3 (x=0.83) in magnetic
fields of up to 14 T. We have observed the typical antiferromagnetic resonance(AFMR) signals, and successfully explained all the observed resonance modes by theconventional AFMR modes with orthorhombic anisotropy.

Vasiliy Buchelnikov1*, Vladimir Sokolovskiy1, Mikhail Zagrebin1, Peter Entel2 andSergey Taskaev1
1
Chelyabinsk State University, Russia
2
University of Duisburg-Essen, Germany

The ab initio and Monte Carlo calculations of magnetic exchange constants, magnetic
moment and the Curie temperatures of stoichiometric and non-stoichiometric Heusler
Ni50Mn25+xSn25-x alloys have been performed. For the ab initio calculations of magnetic
exchange constants and magnetic moment the Munich SPR KKR package was used [1]. The
calculations were made for order and disorder structures. We consider two types of disorder.
First is a disorder between Ni and Mn atoms and second is a disorder between Mn and
Sn atoms. The Curie temperatures have been calculated by mean field approximation andMonte Carlo method using the Heisenberg model. It is shown that the experimental Curie
temperature of non-stoichiometric alloys can be explained theoretically by the assumptionthat in alloys the disorder between Mn and Sn atoms exists. Our calculations have shownthat the magnetic moment and Curie temperatures for Ni-Mn-Sn alloys are in qualitative
agreement with experimental magnetic moment and transition temperatures [2].

[1] T. Masuda et al., Phys, Rev. Lett. 96 (2006) 047210. [2] H. Manaka and I. Yamada, J. Phys. Soc.
Jpn. 66 (1997) 1908. [3] H. Manaka et al., Phys, Rev. B 64 (2001) 104408.

1. H. Ebert, Electronic Structure and Physical Properties of Solids, ed. H. Dreysse, Springer,
Lecture Notes in Physics, Berlin, 1999, Vol. 535, p. 191. 2. T. Kanomata, et al., Magnetic andcrystallographic properties of shape-memory alloys Ni2Mn1+xSn1-x, Materials Science Forum 583(2008) 119.

QG25

QG28

QH03

QH06

Electronic and magnetic properties of ferromagnet/dilute-magnetic
semiconductor interfaces

Microscopic analysis of magnetic orders in MnP single crystals

Magnetization steps in Yb2Pt2Pb with the Shastry-Sutherland lattice

Structural, magnetic, magnetocaloric and magneto-transport
properties in Ge doped Ni-Mn-Sb Heusler Alloys

Alessandra Continenza* and Gianni Profeta
Physics, Universita' degli studi dell'Aquila, Italy

A. Continenza and G. Profeta Experimental findings [1-4] report exchange-bias effects
at the Fe/GaMnAs together with interesting possible magnetic prossimity effects at theinterface between the ferromagnetic (FM) material and the dilute semiconductor (DMS).
In this work we perform ab-initio calculations of different FM/DMS geometries(superlattice systems and periodic slab) for Fe/Ge:Mn and Fe/GaAs:Mn interfaces. We
examine different interfaces to assess the most stable structures, the magnetic coupling
between the magnetic overlayer and the Mn dopant atoms and how the ferromagnetic
overlayer affects the interaction between two Mn atoms dispersed in the semiconductor
matrix. An antiferromagnetic coupling between the overlayer Fe and the Mn is foundfor Mn close to the interface layers, fading away with the distance of the Mn atomfrom the interface. A study of how the magnetic coupling between overlayer and dilute
Mn and between dilute Mn's at different locations is performed and discussed. We finda rather large magnetic coupling enhancement in the case of Ge while the situation for
GaAs looks to be much more complex due to chemical effects at the GaA/Fe interface.
Results are discussed in terms of local densities of states, magnetic moments and totalenergies.
[1] Phys. Rev. Lett. 101, 267201 (2008) [2] Phys. Rev. B 81, 104402 (2010) [3] Phys. Rev. B
81.035211 (2011) [4] J. Appl. Phys. 109, 07C505 (2011)

The 19th International Conference on Magnetism

Tsukasa Koyama1, Shin-ichiro Yano2, Yoshihiko Togawa3, Yusuke Kousaka2, Shigeo
Mori1, Jun-ichiro Kishine4 and Jun Akimitsu2
1
Department of Materials Science, Osaka Prefecture University, Japan2
Department of Physics, Aoyama Gakuin University, Japan
3
Nanoscience and Nanotechnology Research Center, Osaka Prefecture University,
Japan
4
Graduate School of Arts and Sciences, The Open University of Japan, Japan

Yasuyuki Shimura1*, Toshiro Sakakibara1, Ken Iwakawa2, Kiyohiro Sugiyama2 andYoshichika Onuki2
1
Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581,
Japan
2
Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan

Manganese phosphide (MnP) has been extensively studied because of its richness of magneticallyordered phases in the magnetic phase diagram. In this study, as a first step to understand the mechanismof the magnetic phase transition from the ferromagnetic (FM) phase to the proper screw spiral phaseor FAN phase, we have studied FM structures in the FM phase of MnP single crystals by means of
low-temperature Lorentz transmission electron microscopy and small-angle electron diffraction[1].
In Lorentz Fresnel micrographs, striped FM domain structures were observed in external magnetic
field less than 10 Oe in the specimens with the ab-plane in the plane of the specimen. From real- andreciprocal-space analyses, it was undoubtedly identified that striped FM domains oriented to the c-axis
appear with Bloch-type domain walls in the b direction and arrange regularly along the a-axis with 64
nm separation. Moreover, the magnetic chirality reverses in alternate FM domain walls. These specificspin configuration of striped FM domains will affect the magnetic phase transition from the FM phaseto the proper screw spiral phase at the low temperature or the FAN phase in the magnetic field in MnP.

In the tetragonal compound Yb2Pt2Pb, Yb3+ ions form the Shastry-Sutherland lattice[1]. The Yb moment shows a strong Ising type anisotropy with the easy axis lying
along either [110] or [1-10] directions, and exhibit an antiferromagnetic long rangeorder at TN=2.1 K [1]. Surprisingly, the recent H-T phase diagram investigation [2]has revealed that when a sufficiently strong magnetic field is applied along the [110]direction, the system exhibits a partially disordered state below TN; half of the Ybsites remain antiferromagnetically ordered whereas the rest become paramagnetic.
This unusual behavior has been interpreted by a decoupling of two Yb sublattices in a[110] magnetic field due to the characteristic crystal structure and the competing Ising
anisotropy [2]. In this paper, we measured the DC magnetization of Yb2Pt2Pb at very
low temperatures down to 0.08 K for H//[100] and [110] in order to further explore its
unusual phase diagrams. For both directions, a sequence of sharp magnetization steps
is observed at T<0.5 K. Comparison of the differential susceptibility data for the two
directions indicates the presence of an intersublattice coupling for H//[100].

[1] T. Koyama, S. Yano, Y. Togawa, Y. Kousaka, S. Mori, K. Inoue, J. Kishine, and J. Akimitsu,
submitted.

[1] M.S. Kim et al., Phys. Rev. B 77 144425 (2008). [2] A. Ochiai et al., J. Phys. Soc. Jpn. 80
123705 (2011).

July 10 (Tue)Yuriy Vladimirovich Goryunov1* and Alexandr Nikolaevich Nateprov2
1
Russian Academy of Sciences, Kazan Physical-Technical Institute of the Russian
Academy of Sciences, Russia
2
Academy of Sciences of Moldova, Institute of Applied Physics, Moldova

212

poster Presentation

A. K. Nigam1, Roshnee Sahoo2 and K. G. Suresh2*
Physics, TIFR, Mumbai, India
2
Physics, IIT Bombay, India
1

A. K. Nigama, Roshnee Sahoob and K. G. Sureshb* aTata Institute of Fundamental
Research, Homi Bhabha Road, Mumbai-400005, India bDepartment of Physics,
Indian Institute of Technology Bombay, Mumbai-400076, India Abstract The
effect of Ge substitution on the magnetic, magnetocaloric and transport properties
of Ni 45Co 5Mn 38Sb 12-xGe x (x=0-3) has been investigated. The decrease in theexchange interaction brought by Ge substitution can be seen from the reduction in
the magnetization of austenite phase and the increase in the martensitic transition
temperature. The hysteresis observed for x=0 between the heating and the coolingcurves in the magnetization data decreases considerably for x=3. The reduction in
the sharpness of the metamagnetic transition is also observed with Ge doping. From
the resistivity data it is found that the disorder in the martensite phase increases withincrease in the Ge concentration. It is also found that the martensitic transition can betuned over a large temperature interval with a small change in Sb/Ge ratio, giving rise
to a large MCE and a large MR value over a broad temperature interval. This makes
the system as a potential material system for various applications.

July 8-13, 2012 Busan, Korea

213

poster Presentation

poster Presentation

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QH10

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Effect of doped Mn ions in thermoelectric material of Mg3Sb2

First-principles-calculations of the magnetic anisotropy energy of
FeCo and FeNi alloys

Magnetovolume effect in the itinerant-electron frustrated magnet
Fe3Mo3N

Magnetic study of mechanically deformed FeAlSi alloys

Spin caloritronics is about the physics that control of heat, charge and spin currents instructures, devices, and materials. Here we focus on the spin-related thermoelectric
properties and study the effect of magnetic ion doping on the thermoelectric materialof Mg3Sb2. We have synthesized single crystals of Mg3Sb2 and Mn-doped Mg3Sb2 byusing Bridgeman method. The X-ray diffraction data show that the crystals are singlephased and c-axis oriented. In order to illustrate the thermoelectric performance, wehave measured the seebeck coefficient (S), electrical conductivity (σ), and thermal
conductivity (κ) as a function of temperature. The efficiency of thermoelectricperformance is dominated by the figure of merit, ZT=S2∙σ∙T/κ. The obtained S, σ,and κ values at 300K are 600 μV/K, 16 S/m, and 3.5 W/mK, respectively for Mg3Sb2.
Because of the lower σ, the ZT value is estimated to be small. However, by doping
Mn ions into Mg3Sb2, we find the electrical properties to be improved. We will
discuss more about the optimal condition of Mn doping rate in Mg3Sb2 to promote thethermoelectric performance.

1

2

3

Masanori Enoki , Satoshi Iikubo and Hiroshi Ohtani
1
Graduate School of Engineering, Kyushu Institute of Technology, Japan Science andTechnology CREST, Japan
2
Graduate School of Life Science and Systems Engineering, Kyushu Institute ofTechnology, Japan Science and Technology CREST, Japan3
Department of Materials Science, Kyushu Institute of Technology, Japan Scienceand Technology CREST, JapanThe calculations of T.Burkert et at. predict an unusually large magnetic anisotropy energy (MAE)of ~700 μeV/atom for the Fe0.4Co0.6 random alloy at a ratio of 'c/a'[1]. This result suggests that othertransition metal alloys are also candidate for emerging a high MAE with altering the 'c/a'. In order
to seek new design of materials, we research MAE and electronic structures for Fe-Co and Fe-Ni
alloys with using the first-principles-calculations. The calculations were carried out using the VASP
code. At first, we optimized the length of lattice constant 'a' against the fixed 'c/a' at range of 1.101.35. The MAE were evaluated by subtracting the energy with polarized spin direction parallel to[100] from that to [001]. For the Fe-Co alloy, the estimated MAE has maximum at c/a~1.25 andFe0.5Co0.5, which is roughly consistent with the previous result of Burkert et al. On the other hand,
Fe-Ni system has the high MAE (~300 μeV/atom) is found at the Fe0.75Ni0.25. We will present theorigin of the large MAE from the electronic structures in these systems.

1

1

1

1

Yoshikazu Tabata *, Masaki Yamamoto1 Shinsuke Terazawa , Takeshi Waki , Kenji
Ishida2 and Hiroyuki Nakamura1
1
Department of Materials Science and Engineering, Kyoto University, Japan2
Department of Physics, Kyoto University, JapanThe η-carbide-type compound Fe3Mo3N, including the frustrated stella-quadrangula
Fe-sublattice, is a novel itinerant-electron frustrated magnet and exhibits intriguingfeatures such as non-Fermi-liquid behavior without parameter-tuning and sharp
metamagnetic transition [1]. We performed thermal expansion and magnetostriction
measurements of Fe3Mo3N up to 15 T. A large volume expansion is found at themetamagnetic transition field and the magnetovolume coupling constant is estimatedas about 4 × 10-3 μB-2, being the same of magnitude of those of Co Laves phasecompounds [2]. It indicates that the metamagnetic transition of Fe3Mo3N is a typicalmoment-induced-type in nonmagnetic itinerant electron systems. The nonmagnetic
ground state of Fe3Mo3N at zero field is emergent due to the frustration effect built into
the stella quadrangula lattice.
[1] T. Waki et al., J. Phys. Soc. Jpn. 79, 043701 (2010).; T. Waki et al., Europhys. Lett. 94, 37004(2011). [2] Y. Muraoka et al., J. Phys. Soc. Jpn. 53, 331 (1984).

July 10 (Tue)[1]T. Burkert et al. Phys. Rev. Lett. 93 027203 (2004)

The mechanical deformation of Fe-Al alloys produces order-disorder transition that induces an enlargementof the magnetism of the alloys. It has been demonstrated that this enlargement is related to atomic disorder andcell volume increase [1]. The behaviour of the saturation magnetization with milling and Si content in Fe75Al25xSix anf Fe70Al30-xSix alloys is similar to the behaviour shown by the mean magnetic hyperfine field. Theirvalues increase with disordering in alloys with low Si content, but decrease in alloys with higher Si content.
The behaviour observed indicates clearly that the introduction of Si in the binary Fe75Al25 and Fe70Al30 alloys
opposes the magnetic behaviour induced by Al in the magnetism of Fe. These opposite behaviours are related to
the lower increase of the lattice parameter with disorder for FeSi alloys. Besides, when plotting the normalized
variation of lattice parameter produced by the disorder versus the normalized variation of magnetization we
observe a linear relationship, showing that lattice parameter and magnetic properties are related. The study ofthe hyperfine fields also indicates that there is a redistribution of non-ferrous atoms around Fe atoms with thedisordering, indeed, there is an inversion of the behaviour of the hyperfine fields.
[1] A. Hernando, X. Amils, J. Nogues, S. Surinach, M. D. Baro, and M. R. Ibarra, Phys. Rev. B 58 11864 (1998).

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QH11

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QH17

X-ray diffraction study on crystal structure of Mn1.8Co0.2Sb under highmagnetic fields

Tuning the magnetic properties of amorphous FeZr thin by hydrogen
implantation

NMR studies of magnetic properties in the spinel-type Cu(Cr1-xHfx)2S4

The propagation of electromagnetic waves in magnetic withferromagnetic spiral

Hiroki Orihashi1*, Daisuke Mitsunaga1, Masahiko Hiroi1, Yoshifuru Mitsui2, Kohki
Takahashi2, Kazuo Watanabe2 and Keiichi Koyama1
1
Graduate School of Science Engineering, Kagoshima University, Japan
2
HFLSM, IMR, Tohoku University, Japan

Measurements of magnetization, electrical resistivity and high field X-ray powder
diffraction (XRD) were carried out for polycrystalline Mn1.8Co0.2Sb in magnetic
fields up to 5 T in 4.2-300 K temperature range, in order to investigate the structuralproperties affected by magnetic fields. In a zero field, the compound shows the firstorder magnetic transition from the ferrimagntetic (FRI) to antiferromagnetic (AFM)
states at Tt = 145 K with decreasing temperature. By applying magnetic fields of 5 T,
Tt decreased to 60 K with thermal hysteresis of 35 K. From the XRD measurements,
not only the AFM phase but also the residual FRI phase was confirmed even at 10 K
in cooling process under 5 T. Results obtained indicate that the residual FRI phase iskinetically arrested [1].
[1] H. Orihashi et al. Mater. Trans. [Selected Papers from JIM Fall Meeting(2011)] 76 (2011) inpress

Atieh Zamani1*, Anders Hall2, Per Nordblad3, Bjorgvin Hjorvarsson1 and Petra
Jonsson1
1
Physics and Astronomy,Material Physics, Uppsala University, Sweden
2
School of Information and Communication Technology (ICT), KTH, Sweden
3
Department of Engineering Sciences, Uppsala University, Sweden

Amorphous FeZr alloys order ferromagnetically, with a maximum in the ferromagnetictransition temperature near 240K for Zr contents between 10-20 at.% . Interestingly,hydrogen can be introduced into the alloy, enhancing its Curie temperature, magnetic
moment and soft magnetic properties. In order to understand the magnetism of theFe(Zr) binary system, and the e ect of hydrogen on the magnetic interaction, we haveinvestigated in details the magnetic properties of amorphous thin lms of Fe(Zr). Fe1
xZrx lms with compositions x=7.5, 9.5, 11.5, 12.5 and 13.5 at.% were grown by cosputtering on Si substrate in ultra high vacuum (UHV) conditions. The compositions,structural and magnetic properties of the lms were investigated by Rutherford
Backscattering spectrometry (RBS), X-ray di raction, and SQUID magnetometeryrespectively before and after hydrogenation. The hydrogen implanted samples show
an increased value of the Curie temperature with increasing hydrogen content. The
magnetization curves at low temperature show a continuous increase with increasing
eld also at quite high temperature con rming the presence of random anisotropy. Thisanisotropy is heavily suppressed by hydrogen implantation. Keywords: Amorphous
Fe(Zr), Magnetization, H-implantation

Haruo Niki1*, Morihito Oshiro1, Saori Nakamura1, Ayaka Uechi1, Mamoru Yogi1,
Shuji Ebisu2 and Shoichi Nagata2
1
Department of Physics, Faculty of Science, University of the Ryukyus, Japan2
Muroran Institute of Materials Research, Japan
A chalcogenide tiospinel CuCr2S4 is a metallic ferromagnet with Tc = 380 K. The
increase of x for the mixed spinel Cu(Cr1-xHfx)2S4 shows a successive change froma ferromagnetic, a re-entrant spin-glass, a spin-glass, and finally to a paramagnetic
state. A step-like anomaly in magnetization is also found around 160 K in the rangeof 0.50 ≤ x ≤ 0.70 due to a spin crossover phenomenon [1]. In order to investigate
the magnetic properties of Hf rich side in Cu(Cr1-xHfx)2S4 from a microscopic pointof view, 63Cu NMR have been carried out between 4.2 and 300 K. Temperaturedependences of resonance line-width, Knight shift and spin-lattice relaxation time (T1)have been measured. Knight shift in the range of 0.50 ≤ x ≤ 0.70 gradually shifts tonegative side down to 130 K, but rapidly shifts to negative side below 130 K due tothe core polarization of d conduction electrons. Temperature dependence of 1/T1T in
the range of 0.50 ≤ x ≤ 0.70 obeys the Korringa relation (T1T = constant) down to 130
K, as expected in a Pauli-paramagnetic metallic state. However, the values of 1/T1T=constant abruptly change between 130 and 90 K, and keep constant below 90 K.

Igor Valer'evich Bychkov1, Vasily Dmitrievich Buchelnikov1, Dmitry Aleksandrovich
Kuzmin1 and Vladimir Grigor'evich Shavrov2
1
Cheliabinsk State University, Russia
2
The Institute of Radioengineering and Electronics of RAS, Russia[1] F. Kariya, K. Ebina, K. Hasegawa, K. Koshimizu, B. Wuritunasitu, K. Hondou, S. Ebisu and S.
Nagata, J. Solid State Chem. 182 (2009) 2018.

Recently, spiral magnetic materials have attracted researchers' attention for their
unusual physical properties. However, the spectrum and dynamic properties of magnets
in a phase <<ferromagnetic spiral>> are not studied enough. In the present work thespectrum of the coupled spin and electromagnetic waves in spiral magnetic structure oftype <<ferromagnetic spiral>> is investigated. Also the reflection of electromagnetic
waves from a layer of magnetic having the ferromagnetic spiral and the Faradey effectare considered. We use approach L >> a, where L - the spiral period, a - the lattice
constant. Studies showed that the spectrum of the coupled waves has band structure.
The band gap depends on the angle of the ferromagnetic spiral, and hence on theexternal magnetic field. The frequency dependence of the reflection coefficient ofelectromagnetic waves from the plate of the magnetic with a ferromagnetic spiral atdifferent angles of the helix has been calculated. As the angle increases the opacity
region broadens and shifts to higher frequencies. Thickening of the plate also leads tobroadening of the opacity region. The Faraday effect has been observed for different
frequencies. The angle of plate-of-polarization rotation increases near the band gap.
The Verdet constant has been calculated.

QH09

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QH18

Emergence of Ferromagnetism under pressure in (Mn1-xFex)3GaN

Normal and intrinsic anomalous Hall effect in NbFe2

Relationship between microstructure and magnetic properties of nanoscale magnetic particles formed in a Cu-Ni-Co alloy

Magnetism of sigma-phase Fe-Mo and Fe-Re systems

S. Iikubo1,6, T. Inagaki2, K. Takenaka2, K. Matsubayashi3, Y. Uwatoko3, H. Takagi4,and H. Ohtani5,61
Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Japan2
Department of Crystalline Materials Science, Nagoya University, Japan
3
Institute for Solid State Physics University of Tokyo, Japan
4
RIKEN (The Institute of Physical and Chemical Research), Japan
5
Department of Materials Science and Engineering, Kyushu Institute of Technology, Japan
6
JST, CREST, JapanThe recent development of “metallic” antiperovskite nitrides Mn3AN, where A is a metal or asemiconducting element, has promoted research toward practical use. We found an intimate
relationship between the large magneto-volume effect (MVE) in cubic Mn3AN and the Γ5g-type
antiferromagnetic (AF) ordering. As a tunable thermodynamic parameter, the external pressure
may play an important role in this system, because it can affect not only the crystal structure but
also the magnetic structure. We report the pressure effect on the stability of magnetic structure of(Mn1-xFex)3GaN.
In this system, it was reported that a few percent of Fe dopants at the Mn sites alters the AF spin
structure of Mn3GaN and induces a first-order antiferromag-netic-ferromagnetic phase transition.
We have measured the magnetization of (Mn1-xFex)3GaN with x=0, 0.05 and 0.07 and Mn3Ga(N1yCy) with y=0, 0.05 and 0.1 under pressure up to 1.3 GPa. A magnetic transition from an AF to an
ferromagnetic (FM) state with spontaneous magnetization is observed under pressure. Especially,a spontaneous magnetization in Mn3GaN is 0.24 μB per Mn under pressure. The application ofpressure increases the magnetization in the FM phase for all these compounds.

214

Estibaliz Legarra1, Estibaliz Apinaniz2, Damian Martin-rodriguez3, Jose Javier
Garitaonandia4 and Fernando Plazaola1
1
Department of Electricity and Electronics, Basque Country University, UPV/EHU, p. c. 644, 48080,
Bilbao, Spain
2
Department of Applied Physics I, Basque Country University, UPV/EHU, Alameda Urquijo s/n, 48013,
Bilbao, Spain
3
Julich Centre for Neutron Science and Institute for Complex Systems, Forschungszentrum Julich GmbH,52425 Julich, Germany
4
Department of Applied Plysics II, Basque Country University, UPV/EHU, p. c. 644, 48080, Bilbao, Spain

The 19th International Conference on Magnetism

Sven Friedemann1*, William J Duncan2, Andreas Neubauer3, Manuel Brando4,
Christian Pfleiderer3 and F Malte Grosche1
1Cavendish Laboratory, University of Cambridge, United Kingdom
2
Department of Physics, Royal Holloway University of London, United Kingdom
3
Physik Department E21, Technical University Munich, Germany
4
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
Hall effect studies are a powerful probe of the Fermi surface of metals via the normal
contribution whilst the anomalous contribution may give substantial insight into spinorbit interactions. Here, we present Hall effect measurements on selected samples ofthe band magnet system NbFe2. In the dilution series Nb1-yFe2+y composition tuning
allows to access various magnetic ground states including a complete suppression ata quantum critical point. We observe normal and anomalous contributions in the Hall
effect. Consistent analysis of the anomalous contribution, however, is only possible
for Fe-rich Nb0.985Fe2.015 featuring a ferromagnetic ground state. Here, a positive
normal Hall coefficient is found at all temperatures with a moderate maximum at the
spin-density-wave transition. The anomalous Hall effect is covered by an intrinsic(Berry-phase) contribution which is constant below the ordering temperature TC andcontinuously vanishes above TC. For samples with antiferromagnetic ground state, i.e.,
stoichiometric NbFe2 and Nb-rich Nb1.01Fe1.99, an additional contribution to the Hall
resistivity impedes a complete analysis and indicates the need for more sophisticatedmodels of the anomalous Hall effect in itinerant antiferromagnets.

July 10 (Tue)Soo Hyun Kim1, Chung Man Kim1, Junpei Kajino2, Toshiro Takabatake2 and Myunghwa Jung1*
1
Physics, Sogang university, Korea
2
Physics, Hiroshima University, Japan

Donghae Lee1, Mahoto Takeda1*, Sung Kang2 and Takahiro Moriki1
1
Department of materials engineering,Yokohama national university, Japan
2
Research Institute of Industrial Science & Technology(RIST), Korea

Jakub Cieslak1*, Stanislaw M Dubiel1, Michael Reissner2 and Janusz Tobola1
1
Academy of Mining and Metallurgy, AGH al. Mickiewicza 30, 30-059 Krakow,
Poland2
Institute of Solid State Physics, Vienna University of Technology, A-1040 Wien,
Austria

The discovery of Giant Magnetic Resistance (GMR) has invoked strong interest to relationshipbetween microstructure and magnetic properties of nano-scale particles. The magnetic
properties of nano-scale particles are strongly dependent on their structures, particle sizes,
shapes, and interparticle distances particularly in granular magnets. The present study aimed
to investigate the relationship between the microstructure and the magnetic properties of
granular Cu-Ni-Co alloys, using transmission electron microscope (TEM), a superconducting
quantum interference device (SQUID) magnetometer and thermo gravimetric-differential
thermal analysis (TG-DTA). The present TEM observations revealed a specific feature thatspherical ferromagnetic precipitates are transformed into cubic ones, and subsequently two
or more cubic precipitates are aligned along the <100> orientation of a Cu matrix, whichfeature was significantly different from previous recognition to conventional precipitation.
SQUID measurements shows that the magnetic property of the specimen changes from superparamagnetism to ferromagnetic in character with increasing isothermal annealing period
from M-T curves. The present TG/DTA curves showed that a ferromagnetic to paramagnetictransition occurred at low temperatures (~950K) but paramagnetic to ferromagnetic transition
at high temperatures(600~700K). This suggests that the coalescence of magnetic atoms andaccordingly the Curie point are sensitive to annealing temperature.

Sigma phase exists in five binary systems of the Fe-X type viz. for X = Cr, V, Mo,
Re and Tc. It is characterized by a lack of chemical order on all five sublattices of thetetrahedral unit cell. Until now, the magnetic properties have been known only forsigma-FeCr and sigma-FeV systems. The newly discovered low temperature magnetic
properties of sigma-FeMo and sigma-FeRe phases will be presented and analyzed indetail in the whole concentration range in which this phase occurs. In particular, in bothcases, the observed increase in an average magnetic moment and magnetic ordering
temperature with increasing of Fe content is evident. Differences in Zero-Field Coolingand Field Cooling magnetization measurements suggest the magnetic ordering of
spin-glass type or a large magnetic anisotropy in the measured samples. Electronic
structure calculations using the KKR method were carried out for more than a dozen
semi-ordered unit cells. The results of these calculations show a linear dependence ofmagnetic moments and hyperfine fields of Fe atoms at different sites versus the numberof Fe atoms being their nearest neighbors. They also suggest a noncollinear magnetic
structure in some sublattices.

July 8-13, 2012 Busan, Korea

215

poster Presentation
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Second order magnetization effects in bcc Fe

Structural and magnetic properties of (Co, Fe, Ni), (Fe, Mg, Zn) and(Fe, Mn, Zn) alloys deposited onto Al2O3 and SiO2

Magnetic orderings in Fe-intercalated TiX2 (X=S, Se)

Magnetoresistance effect of Heusler-type Fe2VAl single crystal

Second order effect in magnetization are becoming an important way ofcharacterization of the magnetic samples. One of the examples of second order effectin magnetization are anisotropic magnetoresistance (AMR), Voigt effect, quadraticmagneto-optical Kerr effect (QMOKE) or X-ray magnetic linear dichroism (XMLD).
All those effects are originating from conductivity (or permittivity) tensor, whichelements are varying with direction of the sample magnetization. This dependence
is determined by symmetry arguments describing break of the symmetry bymagnetization in the crystal. From first principles we have calculated the complete
angular dependence of all elements of the permittivity tensor with respect to the changeof magnetization axis in a wide spectral range (from dc to ultraviolet) for a bodycentered cubic Fe. The correctness of calculations are verified by careful comparison
with expected dependences provided by symmetry arguments. The calculations are
based on density functional theorem utilizing one of the most accurate full potnetial
augmented plane-wave code. The effect of the spin-orbit interaction for valence andsemicore states is included as well.

1

2

3

1

Lonzeche Jean Augustin Lodya *, Adli Beck , Rudelle White , Bongani Xaba ,Siyanda Lubhelwane1, Khuselwa Vundisa1 and Jeanette Ngubane1
1
Research & Development, Sasol Technology, South Africa
2
Chemistry Department, University of Stellenbosch, South Africa
3
Chemistry Department, North-West University, South Africa
Structural and magnetic properties of (Co, Fe, Ni), (Fe, Mg, Zn) and (Fe, Mn, Zn) alloys
deposited onto Al2O3 and SiO2 supports are reported. The samples were synthesised by ball
milling and characterised using magnetic measurements (MM), Mossbauer spectroscopy (MS),XRD, SEM, TPR and (BET). Granular and irregular shaped particles were formed. MM, MS
measurements and XRD data revealed the formation of peculiar solid solutions some of themhaving spinel structures. In all the samples small crystallites in a superparamagnetic (SPM)
state at room temperature were found to coexist with larger ones, their fractions depending on
the energy imparted during the ball milling process. That is, crystallites were predominantly ina SPM state at a relatively high ball-to-powder ratio while larger crystallites were prevalent at
a relatively low ball-to-powder ratio. The ball milling process resulted also in low surface areasand collapse of pores. Further, the existence of strong metal support interactions (SMSI) was
inferred in all the samples; this rendered reduction difficult and/or led to incomplete reduction.
Fittings of the Curie-Weiss model to the experimental temperature dependences of AC
magnetic susceptibility were used to determine the effective magnetic moments associated withmagnetic cations and the nature of their interactions.

Seung Ill Hyun and J.h. Shim*
Chemistry, POSTECH, Korea

Titanium dichalcogenides shares the same layered structure, except TiO2. Their
physical properties, however, are different from each other. TiSe2, for example, is the
only compound that bears an unconventional charge-density wave (CDW) transition
under 200K, whereas the others show no distinct structural distortion.[1] Furthermore,
Iron-intercalated TiS2 and TiSe2 exhibit different types of magnetism. Fe0.5TiS2 displays
a ferromagnetic ordering under 80K, Fe0.5TiSe2 shows an antiferromagnetic ordering
under 135K.[2,3] In order to describe the magnetic interactions between Fe atoms, weapply the first principle calculation on Fe0.5TiX2 (X=S, Se) and explain the experimental
observations correctly. We also discuss the origin of different magnetic behaviors basedon the structural & elemental effect.
[1] K. C. Woo, F. C. Brown, W. L. McMillan, R. J. Miller, M. J. Schaffman, and M. P. Sears, Phys.
Rev. B 14, 3242 (1976) [2] N. V. Selezneva, N. V. Baranov, V. G. Pleshchev, N. V. Mushinikov, andV. I. Maksimov, Phys. Solid State 53 (2), 329 (2011) [3] N. V. Baranov, V. G. Pleshchev, E. M.
Sherokalova, N. V. Selezneva and A. S. Volegov, Phys. Solid State 53 (4), 701 (2011)

The Heusler-type intermetallic compound Fe2VAl has attracted strong attention becauseof a semiconducting behavior of ρ and a large electronic specific heat coefficient γ,
14 mJ/(K2mol). The band calculation revealed that the Fe2VAl was a semimetal andnonmagnetic with a pseudogap around the Fermi level [2]. Endo et al. discovered
the giant magnetoresistance (GMR) effect in the Heusler type alloys Fe2+xV1-xAl poly
crystal of about 30 % for Fe2.1V0.9Al at 4.2 K in the field of 55 kOe [3]. Recently wehave succeeded in fabricating single crystals of Fe2.1V0.9Al using Czochralski method
and investigated their electric and magnetic properties. The temperature dependence of
GMR is negative below the Curie temperature (TC). The maximum value of GMR isabout 35 % around the TC. The value of GMR in Fe2.1V0.9Al single crystal is similar inthat of poly crystal.
[1] Y. Nishino et al., Phys. Rev. Lett. 79, 1909 (1997). [2] G. Y. Guo, G. A. Bottom and Y. Nishino,
J. Phys.: Condens. Matter 10 L119 (1998). [3] K. Endo et al., J. Magn. Magn. Mater. 177-181 1437
(1998).

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Magnetic structure of nearly equiatomic MnRh alloy

Structure disorder effect of L10 FePt within supercell method

Non-Stoner Itinerant Ferromagnetism of a Transition Metal Monomer

Electronic structures and magnetic properties of antiferromagnetic
BaFe2As2

Yuki Matsuoka1 and Aya Takasaki2
1
Nara Women's University, Japan
2
Graduate School of Humanities and Sciences, Nara Women's University, Japan
MnRh shows various kind of magnetic state. The magnetic structure and the transition
temperature of MnRh are expected to be very sensitive to the atomic composition.
At the equiatomic composition, this alloy shows antiferromagnetic - paramagnetictransition. By increasing Mn ratio, this alloy shows complicated magnetic property,
ferromagnetic - weak ferromagnetic transition.[1] Yamada et.al. reported that
antiferromagnetic structure is most stable in this alloy.[2] To determine the magnetic
structure, we performed neutron diffraction measurements and observed some magnetic
scattering peaks. The intensities of magnetic scattering peaks were almost same evenjust below the phase transition temperature. On the other hand, magnetization curve ofsame component alloy suggests magnetic phase transition. We attempt to determine themagnetic structure and to make magnetic phase diagram of nearly equiatomic MnRh.
[1] Matsuoka Y, 1995 MA Thesis [2] Yamada H, Shimizu H, Yamamoto K, Uebayashi K, 2006 J.Alloys
Comp. 415 31

Kazuhiko Uebayashi
Section of Natural Science, Akita National College of Technology, Japan

L10 FePt alloy is famous for a good candidate of high density magnetic recording
media. In my previous work[1], I have performed energy-band calculations for theL10 bulk alloy FePt by using the linear muffin-tin orbital method with atomic sphereapproximations. This previous calculated study shows that the calculated lattice
constants and magnetic moments are good agreement with observed ones. The
experimental stable-magnetic state is ferro magnetic, but in the calculation one of
the anti-ferro magnetic state is most stable, and the second is ferro magnetic above 1
mRy/ f.u. The difference between the experimental and calculated result for L10FePt
is known by another work[2]. To improve the difference, I carry out structure-disorderband calculation for FePt with supercell method. I assumed that the supercell is as 8times large as a formula unit. In the supercell with only one substitution Fe and Pt,
the most stable state becomes ferro and the difference between ferro and anti-ferro
magnetic state is about 102mRy. The result indicate that the structure disorder of L10
FePt in the supercell makes ferro magnetic stable with observed lattice constants.

Hanhim Kang, Geunsik Lee, P. Dua, Ji-hoon Shim and Kwang S Kim*
Department of Chemistry, POSTECH, Korea

We investigated the one-dimensional monomer chain of 3d transition metals ( Fe, Co,
and Ni ) by ab-initio band structure calculation with quasiparticle GW method [1].
We also studied the role of pair hopping interaction on the magnetic properties using
the extended Hubbard model [2][3]. GW calculation of transition metal monomer
shows the spin-dependent band width changes as well as spin-dependent transport
properties in ferromagnetic phase. Such behavior is well described by the extended
Hubbard model, where the pair hopping enhances the metallic ferromagnetism in onedimension. We suggest that the electron correlation effect such as pair hopping usually
has important role in the metallic ferromagnetism of low dimensional system.
[1] T. Kotani, M. van Schilfgaarde, and S. Faleev, Phys. Rev. B, 76 (2007). [2] J. Hirsch, Phys. Rev. B.
59, 6256 (1999) [3] J. Hirsch, Phys. Rev. B. 43, 701 (1991)[1] K. Uebayashi, JOURNAL OF APPLIED PHYSICS 107, 09A733 (2010) [2] G. Brown,
PHYSICAL REVIEW B 68, 052405 (2003)

Jae Kyung Chang, Ju Young Kim, Chang Hyun Yi and Joo Yull Rhee*
Department of physics, Sungkyunkwan university, Korea

In low dimensional metals the electrons can be organized into regular patterns,
which is known to be the charge-density wave(CDW) or spin-density wave(SDW).
The parent compound of iron-based superconductors, BaFe2As2, undergoes both
structural and magnetic phase transitions. The crystal structure changes from tetragonal
to orthorhombic, and the magnetic ground state changes from paramagnetic to
antiferromagnetic at ~140 K and neutron scattering measurements show the magnetic
moment of 0.87μB per Fe in antiferromagnetic state. SDW anomaly at 140 K, which
is believed to be an important prerequisite for high-Tc superconductivity in ironbased superconductors, was also observed. We performed the electronic-structure
calculation for the BaFe2As2 compound in various antiferromagnetic states, and theelectronic structures and Fermi surfaces are carefully investigated. While there havebeen considerable debates as to whether the antiferromagnetism is due to the Fermisurface nesting or the second-neighbor superexchange, via comparing our results withexperimental and hypothetical cases, we can deduce the correlation between the SDW
and the Fermi-surface nesting.

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QI01

Magnetic and transport properties of Pd2Mn1+xIn1-x Heusler alloys

Itinerant antiferromagnetism in high-quality single crystal CrB2

Magnetic structure variation with structural phase transition in
SrMnSb2

Development of magnetic order in the TbNi(Al,In) series andmagnetocrystalline anisotropy in TbTX compounds

Hironari Okada1*, Yohei Yamazaki2, Takashi Yasuda1 and Takeshi Kanomata1
1
Faculty of Engineering, Tohoku Gakuin University, Japan
2
Division of Engineering, Graduate School of Tohoku Gakuin University, Japan
Recently, it was reported that Ni-Mn-In and Ni-Mn-Sn Heusler alloys having aferromangetically ordered L21 type structure show a magnetic-field-induced reverse
martensitic transformation associated with a metamagnetic transition [1]. The interplay
between the martensitic transformation and the magnetic transition gives rise to amagnetic-field-induced shape recovery effect and a magnetoresistance effect. Pd2MnIn
has an antiferromagnetically ordered L21 type Heusler structure [2], which is different
from the magnetic ordered state of Ni2MnIn. In this work, in order to investigate
the magnetic and transport properties of the antiferromagnetic Heusler alloys, we
performed magnetization and electrical resistivity measurements for Pd2Mn1+xIn1-x.
In Pd2Mn1+xIn1-x with x > 0.2, a sudden increase of the resistivity was observed.
The temperature at which the anomaly of the resistivity appears shifts to the higher
temperature with increasing Mn content, and no anomaly was detected for the Mncontent with x = 0.55. The results of powder X-ray diffraction experiment indicatethat a martensitic phase appears for the Mn content with x = 0.55 at room temperature.
Therefore, it is considered that the anomalous behavior of the resistivity results fromthe martensitic transformation.
[1] R. Kaimuma et al, Nature 439 (2006) 957. [2] P. J. Webster and R. S. Tebble, Phil. Mag. 16 (1967)
347.

216

Rika Hamada1, Hidetoshi Miyazaki2* and Yoichi Nishino1
Department of Frontier Materials, Nagoya Institute of Technology, Japan
2
Center for Fostering Young and Innovative Researchers, Nagoya Institute ofTechnology, Japan1

The 19th International Conference on Magnetism

Andreas Bauer1*, Alexander Regnat1, Christian Blum2, Saskia Gottlieb-schoenmeyer1,
Bjoern Pedersen3, Sabine Wurmehl2, Bernd Buechner2 and Christian Pfleiderer1
1Physik-Department E21, Technische Universitaet Muenchen, D-85748 Garching,
Germany
2
Leibniz Institute for Solid State and Materials Research IFW, D-01171 Dresden,
Germany
3
Forschungsneutronenquelle Heinz-Maier Leibniz, Technische Universitaet
Muenchen, D-85748 Garching, Germany
Transition metal and rare earth diborides with the hexagonal AlB2 structure form a seriesof compounds with a remarkably wide range of different electronic ground states. We
report the properties of isotopically enriched high-purity single crystals of CrB2 grown by
optical float-zoning. The temperature dependence of the electric resistivity and specificheat provide unambiguous evidence of spin density wave type order with a slightly
anisotropic charge gap Δ(001) = 230 K and Δ(100) = 212 K, respectively. We also findthat the Neel temperature of 88.5 K remains unchanged under magnetic fields up to 14
T, the highest field studied. A detailed neutron scattering study, made possible throughthe use of 99% isotopically enriched 11B, provides for the first time unambiguous
evidence of antiferromagnetic order, and identifies CrB2 as a textbook example of itinerant
antiferromagnetism. In comparison to the properties of other high-quality single crystal
transition metal and rare earth diborides we have prepared, our studies of CrB2 shed an
unexpected new light on the properties of this exciting series of compounds.

M. Arshad Farhan, Geunsik Lee and Ji Hoon Shim*
Chemistry, POSTECH, Korea

RMnSb2 system (R = Alkali Earth Metal) is analyzed by first principle DFT calculation
using full potential linearized augmented plane wave method while PBE-GGA is used
to account for the Exchange-Correlation potential. SrMnSb2 has zig-zag chains of Sbions while BaMnSb2 has square planes of it. The application of pressure on SrMnSb2
leads to a phase transformation from chain like semi-metal phase to BaMnSb2 like
Square planner structure showing metallic properties. The density of states for AFM
SrMnSb2 changes with the structural phase change indicating a magnetic transition.
While for a similar chain to square transition in BaMnSb2 accompanying an Insulator
to Metal transition, no such variation in magnetic structure is observed.

July 10 (Tue)Dominik Legut*, Jaroslav Hamrle and Jaromir Pistora
Nanotechnology Centre, VSB-Technical University of Ostrava, Czech Republic, Czech
Republic

July 10 (Tue)poster Presentation

Milan Klicpera1*, Pavel Javorsky1, Ines Puente Orench2, Eva Santava3 and Stanislav
Danis1
1
Department of Condensed Matter Physics, Charles University in Prague, Faculty ofMathematics and Physics, Czech Republic
2
Institut Laue-Langevin, Grenoble, France
3
The Academy of Sciences of the Czech Republic, Czech Republic
We present recent study of magnetocrystalline anisotropy in TbNi(Al,In) series, crystallizing in hexagonal
ZrNiAl structure. The properties of this series were investigated by magnetic measurements, lowtemperature x-ray diffraction in magnetic field and mainly by powder neutron diffraction. Parent compoundsof our series were previously studied. TbNiAl orders antiferromagnetically with propagation (1/2,0,1/2) andat lower temperatures undegoes another magnetic phase transition when one third of magnetic moments is
reduced to almost zero. TbNiIn shows complex magnetic ordering with propagation vector (0,0,0) and otherpropagation (1/2,0,1/2) occurs at lower temperatures. Our data reveal suppression of the antiferromagnetic
structure of TbNiAl with substitution of 10% Al by In. Instead, dominant ferromagnetic order appears,
while the direction of Tb magnetic moments along the c-axis is retained. Additional weak antiferromagnetic
components arranged within the basal plane and described by k=(1/2,0,1/2) appear at low temperatures.
This antiferromagnetic component is presented in the whole rest of series. Dominant component describedby (0,0,0) propagation then undergoes change from c-axis ferromagnetic order to a more complex basalplane structure around 40% of In. Anisotropy change in this series is related to strong change of the c/a ratioof lattice parameters. This behaviour can be generalized for other hexagonal Tb-based compounds.

July 8-13, 2012 Busan, Korea

217

poster Presentation
QI02

QI05

QI08

QI11

Magnetic properties of Ho1-xLuxB12 solid solutions

Magntization curves in high magnetic fields of TbZn2

Giant magnetoresistance and field-induced phase transitions in Tb7Rh3
single crystal

Effect of temperature and magnetic field history on magnetization
behavior of NdVO3 polycrystalline

Takanori Tsutaoka1*, Koji Shimomura1, Nikolay V. Baranov2, Alexey V. Proshkin2,
Evgeny G. Gerasimov3 and Pavel B. Terentev3
1
Graduate School of Education, Hiroshima University, Japan
2
Institute of Natural Sciences, Ural Federal University, Russia
3
Institute of Metal Physics, Ural Branch of RAS, Russia

Zhengcai Xia*
wuhan national high magnetic field center, huazhong university of science andtechnology, China
The magnetic properties of NdVO 3 polycrystalline have been studied in thetemperature range from 300 to 1.8K and in magnetic fields up to 16 T. It is foundthat in an applied field less than 1 T remarkable magnetization reversals occurredin field cooling mode: a diamagnetic behavior was observed below a compensation
temperature Tcomp. Most interestingly, the diamagnetic behavior was dependent toboth the temperature and applied magnetic field, where the temperature window is 50100K, and magnetic field below 1T. Beyond the temperature window and above themagnetic field, the diamagnetic behavior disappeared. That is the magnetization always
switches to the opposite direction if the sample is cooled through the temperature
window in a field less than 1 T. However, the temperature dependence of the resistancehas an almost independent to the applied magnetic field in the range from 0 to 16T. A
possible mechanismbased on the competition of the single-ion magnetic anisotropy
and the antisymmetric Dzyaloshinsky-Moriya interaction accompanied by a change oforbital ordering is discussed.

Rare earth Zinc compounds RZn2 (R=Gd, Tb, Dy, Ho, Er) crystallize in CeCu2-type
structure. In the case of GdZn2, its magnetism is ferromagnetic, in the other cases,
antiferromagnetic. Debray et al. [1] was reported that TbZn2 is the antiferromagnet
with two antiferromagnetic phases which are the high temperature phase AF(a)and the low one AF(b). Two transition points TN(a) = 75 K and TN(b) = 60 K are
corresponding to those phases. The magnetic structure of AF(b) is a collinear type
and AF(a) is a sinusoidal transverse wave type. The magnetic measurements were
performed with a single crystalline sample by Kitai [2]. Two transition points TN and
Tt were observed corresponding to TN(a) and TN(b). We performed the measurementsof the magnetization curves in high magnetic fields with the single crystalline sample
of TbZn2. The metamagnetic transitions were observed in the directions of all axes.
Especially in the direction of c-axis, the metamagnetic behaviors were observed above
TN. In this paper, we will discuss the origin of the metamagnetic transitions for TbZn2.

The rare earth intermetallic compound Tb7Rh3 crystallizes in the Th7Fe3 type hexagonal
structure with the space group P63mc in which Tb occupies three non-equivalent sites.
Tb7Rh3 enters an antiferromagnetic (AF) state below TN = 91 K and shows further magnetictransformations with decreasing temperature below ~ 73 K [1]. Unusual negative temperature
coefficient of the resistivity in a wide temperature range above TN [1] and the large
magnetoresistance even in paramagnetic state [2] were observed for this compound. In thisstudy, we have performed high field magnetization (up to 350 kOe) and magnetoresistance(up to 120 kOe) measurements on a Tb7Rh3 single crystal. The metamagnetic transition along
the b-axis is observed to be accompanied by the giant magnetoresistance effect (~ 65 %) in thefield interval (70 -110) kOe. The magnetization measurements along the c-axis have revealed
multiple phase transitions at fields above 200 kOe. The magnetization curves measured in
the paramagnetic state along the c-axis show an inflection point up to 140 K, which may be
indicative of the persistence of antiferromagnetic short-range magnetic order in the c-plane.

[1] D. Debray et al.: J. Chem. Phys., 56 (1972) 4325. [2] T. Kitai: J. Phys. Soc. Jpn., 64 (1995)
3403.

[1] Y. Nakamori et al. Physica B, 304 (2001) 1. [2] K. Sengupta et al. Solid State Comm., 39 (2006)
351

QI03

QI06

QI09

QI12

High-field magnetization of Tm2Fe17 and its deuteride

Deuteration induced ferromagnetic metallic properties in R7Rh3Dx (R= Tb, Dy)

Magnetic properties of a GdFe5Al7 single crystal

Phase diagram and transport properties of Y1-xNdxCo2 pseudo-binary
alloysRare earth dodecaborides (REB12) have attracted considerable attention in recent
years, above all due to the wide variety of their physical properties. In our contribution
we present the magnetic properties of the geometrically frustrated antiferromagnet
HoB12 (with ordering temperature T_N = 7.4 K) modified by substitution of magnetic
Ho atoms through nonmagnetic Lu ones. In this case, in the so-called solid solution
Ho1-xLuxB12, both chemical pressure (as Lu3+ ions and Ho3+ ions have different radii)
and magnetic dilution take place with the increasing content of Lu that change theproperties of the system. The received results show strong indication for the existenceof a quantum critical point close to x = 0.9. This critical point separates the region ofmagnetic order (starting with HoB12 for x = 0) and the nonmagnetic region (ending
with superconducting LuB12 for x = 1). The work was supported by the Slovakia
Scientific Agency VEGA (0148-10), the Slovakia Research and Development Agency
APVV, and by the Center of Excellence of the Slovakia Academy of Sciences.

July 10 (Tue)Yoshiya Adachi1, Tetsuo Kitai2, Keiichi Koyama3, Hajime Yoshida4 and Takejiro
Kaneko4
1
Graduate School of Science and Engineering, Yamagata University, Japan
2
Faculty of Engineering, Kyushu Institute of Technology, Japan
3
Graduate School of Science and Engineering, Kagoshima University, Japan
4
IMR, Tohoku University, Japan

A. V. Andreev1*, O. Isnard2, M. D. Kuz'min3, Y. Skourski4, D. I. Gorbunov1, J.
Wosnitza4, N. V. Kudrevatykh5, A. Iwasa6, A. Kondo6, A. Matsuo6 and K. Kindo6
1
Institute of Physics ASCR, 18221 Prague, Czech Republic
2
Institut Neel CNRS and Universite Joseph Fourier, BP166X, Grenoble, France
3
IFW, 01171 Dresden, Germany
4
High Magnetic Field Laboratory, 01314 Dresden, Germany
5
Ural Federal University, 620083 Ekaterinburg, Russia
6
ISSP, Tokyo University, 277-8581 Kashiwa, Japan
A magnetization study of a Tm2Fe17 single crystal and aligned powder of the deuteride
Tm2Fe17D3 has been carried out in steady (14 T) and pulsed (60 T) magnetic fields at 1.5300 K. Tm2Fe17 is a ferrimagnet with TC=295 K and a spontaneous moment of 21 μB/f.u.
Due to competing magnetic anisotropy of the Tm and Fe sublattices, a spin-reorientation
occurs at 70-100 K, from the easy-axis to the easy-plane type via a cone of easy axes.
Two metamagnetic transitions, at 41 and 53.5 T, are observed at 2 K in fields appliedalong the c axis. At 60 T the magnetization reaches 43 μB/f.u., i.e. the sublattices are not
yet parallel (MFe+MTm= 49 μB). In the basal plane a wide S-shape magnetization curve isobserved. The high-field behavior of Tm2Fe17 is compared with that of two other easyaxis R2T17 compounds, Tm2Co17 and Er2Co17. Hydrogenation (deuteration) stabilizes easyplane anisotropy in Tm2Fe17D3 over whole ferrimagnetic range (up to TC=465 K). Despite
different types of magnetic anisotropy, the high-field behavior of the deuteride and theparent compound is qualitatively similar. The transitions along the c axis occur in the same
fields, being less pronounced in the deuteride.

Koji Shimomura1*, Takanori Tsutaoka1 and Stanislaw M. Filipek2
1
Graduate School of Education, Hiroshima University, Japan
2
Institute of Physical Chemistry, Polish Academy of Sciences, Poland

Heavy rare earth compounds R7Rh3 (R = Gd to Er) show the antiferromagnetic
character at low temperature and semimetallic behavior in which the temperature
coefficient of electrical resistivity is negative in high temperature region [1]. We
studied the magnetic properties of Tb7Rh3 and Dy7Rh3 hydrides and reported thehydrogenation induced ferromagnetic states in these compounds [2]. At this time, wehave investigated the magnetic and electrical properties of the R7Rh3Dx deuterides andfound the ferromagnetic metallic state in these compounds. Deuteration of Tb7Rh3 andDy7Rh3 were carried out using the high pressure apparatus in the pressure range up to
1 GPa at 100 °C for 24 hours and Tb7Rh3D27 and Dy7Rh3D28 were obtained. Dy7Rh3
has an antiferromagnetic phase below TN = 59 K and a semimetallic properties. On theother hand, Dy7Rh3D28 shows a ferromagnetic state below TC = 11.5 K and a metallic
property below 300 K. In Tb7Rh3D27, almost the same changes in magnetic andelectrical properties were observed.

D. I. Gorbunov1*, A. V. Andreev1 and M. D. Kuz'min2
1
Institute of Physics ASCR, 18221 Prague, Czech Republic
2
IFW, 01171 Dresden, Germany
A magnetization study of a GdFe5Al7 single crystal has been carried out in static
magnetic fields up to 14 T at temperatures between 2 and 300 K. The compound isfound to order ferrimagnetically at TC = 266 K. The spontaneous magnetic momentis 0.56 μB at 2 K. There is no compensation point in GdFe5Al7, as distinct fromisomorphic compounds DyFe5Al7 and HoFe5Al7. GdFe5Al7 is endowed with anappreciable magnetic anisotropy, the 4-fold axis being a hard magnetization direction.
The easy direction is [110] and the anisotropy within the basal plane is also rather
strong. The latter is quite remarkable for a system devoid of significant orbital
moments. The possible cause of the in-plane anisotropy in GdFe5Al7 could be theunusually large crystal field parameter B44, as observed in other compounds with theThMn12-type structure, e.g., in DyFe11Ti. The crystal field effect could be mediatedby a small admixture of the 4f8 configuration to the ground state 4f7. The exchange
field on the Gd sublattice is determined from the high-field slope of the basal-planemagnetization curves to equal 62 T.

[1] T. Tsutaoka, Y. Nakamori, T. Tokunaga, T. Itoh, J. Phys. Soc. Jpn., 70 (2001) 199. [2] R. Sato, T.
Tsutaoka, S. M. Filipel, J. Alloys Comp., 446-447 (2007) 610.

Alexander T Burkov 1, Masataka Takeda2, Ai Nakamura 2, Yoshinao Takaesu2,
Kiyoharu Uchima3, Masato Hedo2, Takao Nakama2*, Katsuma Yagasaki2 and Yoshiya
Uwatoko4
1
A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, Russia
2
Department of Physics and Earth Sciences, Faculty of Science, University of the
Ryukyus, Japan
3
General Education, Okinawa Christian Junior College, Japan
4
Institute for Solid State Physics, University of Tokyo, Japan
Electrical resistivity ρ and thermopower S of pseudo-binary Y1-xNdxCo2 alloys have been measured attemperatures from 2 K to 300 K, under pressures up to 3.5 GPa. NdCo2 is a ferromagnet with Curie
temperature TC of 99 K. In ferromagnetic phase it undergoes 4f spin-reorientation transition at TR = 40 K.
At this transition the easy direction of 4f magnetization is changed from [100] above TR to [110] below
TR. The system phase diagram TC(x,P) and TR(x,P) is inferred from the temperature dependencies of theelectrical resistivity and thermopower. The Curie temperature of the alloys, TC decreases with decreasing
Nd concentration x and vanishes around xc=0.3. Above xc the Curie temperature decreases with pressure.
The spin-reorientation temperature is weakly dependent on composition and on pressure until it merges
with TC. There is a large region of the phase diagram, partly overlapping with the ferromagnetic phase,where cobalt 3d electron system is non-uniformly magnetized due to spatial fluctuations of the 4f-3d
exchange field, related to random distribution of Nd 4f magnetic moments over R-sublattice. In this region,
spanning the range 0 < x < xm, large static 3d magnetic fluctuations govern the electronic transport.

QI04

QI07

QI10

QI13

RKKY interaction and magnetic properties in (Y-Gd)Ni compounds

Magnetic properties of Nd7Pd3 single crystal

Study of multipole ordering in CePd3S4 by resonant X-ray diffraction
with full polarization analysis

Effect of partial magnetic order on resistivity and thermopower ofHo(Co1-xAlx)2 alloys

Kazuo Yano1*, Katsuhiko Nishimura2, Eiji Kita3, Tsuyoshi Ohta4 and Kiyoo Sato5
1
College of Science and Technology, Nihon University, Japan
2
Graduate Scool of Science and Engineering for Research, University of Toyama,Japan
3
Applied Physics, University of Tsukuba, Japan
4
Quatum Desighn Japan, Japan
5
Faculty of Engineering, Yokohama National University, Japan
CeNi is well known as one of the most famous heavy fermion compounds and showsa peculiar behavior as an enhanced Pauli-paramagnet. That is, both Ce and Ni seem tobe non-magntetic in CeNi. On the other hand, GdNi, which has the same structure asthat of CeNi, is a ferri-magnet and not only Gd but also Ni are magnetic. It follows thatthe result that Ni is non-magnetic in CeNi becomes not self-evident and the mechanismof disappearance of Ni magnetic moment is important and interesting problem. Basedon such scenario, we have been investigating a (Ce-Gd)Ni compound system. One of
the results obtained is a linear relationship in M(T) in Gd-poor content (Gd<20 at%)and it is found that this result reflects the collapse-like decrease of Gd-Gd exchangeinteraction. In order to examine this collapse-like decrease of RKKY interaction, we
have investigated the (Y-Gd)Ni compound sysytem where Ce is replaced by Y. In thissystem, the exchange interaction between Gd and Gd does not collapse-likely decreseand seems to revive even in Y=15 at%. Furthermore, YNi (Gd=0) seems to be itinerant,
however, the substitution of Y by Gd causes localization and Curie-Weise law becomesvalid.
The 19th International Conference on Magnetism

Takuya Matsushita, Koji Shimomura and Takanori Tsutaoka*
Graduate School of Education, Hiroshima University, Japan
Rare earth intermetallic compound Nd 7Pd 3 shows relatively large magnetocaloric property and magnetoresistance [1]. This time, we have succeeded to makesingle crystals of Nd7Pd3 and investigated the magnetic properties by measuring
magnetization and magnetic susceptibility. Single crystals were grown by the
Czochralski method from single-phase polycrystalline samples, which were made byarc-melting the constituting 99.9%-pure Nd and 99.95%-pure Pd elements, under highpurity argon atmosphere. The crystal orientation was determined by the back-reflection
Laue method. Magnetization curve at 2 K indicates ferromagnetic property for botha- and c-axes; the easy magnetization axis locates in the c-plane. Metamagnetictransitions indicating an antiferromagnetic state were observed above TC = 34 K in themagnetization curves, which were reported so far. A first order magnetic transition fromferromagnetic to antiferromagnetic was observed at TC in the temperature dependenceof magnetic susceptibility in both a- and c-axes. Magnetic susceptibility curves for bothaxes also indicate a small cusp at around TN = 40 K indicating the antiferromagnetic toparamagnetic transition.
[1] N. K. Singh, P. Kumar, Z. Mao, D. Paudyal, V. Neu, K. G. Suresh, V. K. Pecharsky, K. A.
Gschneidner Jr., J. Phys. Cond. Mat., 21 (2009) 456004.

Sinji Michimura1*, Toshiya Inami1, Toru Otsubo2, Takeshi Matsumura2, Hiroshi
Tanida2, Masafumi Sera2, Eiichi Matsuoka3, Masanori Watahiki4, Katsumi Tanigaki4
and Hideya Onodera4
1
Condensed Matter Science Division, Japan Atomic Energy Agency, Japan
2
AdSM, Hiroshima University, Japan3
Department of Physics, Kobe University, Japan
4
Department of Physics, Tohoku University, Japan

Takao Nakama 1*, Chojun Zukeran 1, Ai Nakamura 1, Atsushi Teruya 1, Sentaro
Hirakawa1, Shintaro Watanabe1, Masataka Takeda1, Yoshinao Takaesu1, Kiyoharu
Uchima2, Masato Hedo1, Katsuma Yagasaki1 and Alexander T Burkov3
1
Department of Physics and Earth Sciences, Faculty of Science, University of the
Ryukyus, Japan
2
General Education, Okinawa Christian Junior College, Japan
3
A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, Russia

In rare-earth palladium bronzes RPd3S4 (R = La-Yb) compounds with a cubic structure, it is expected thatthe multipole interactions dominate the low temperature properties because the degeneracy of the orbital
degree of freedom remains in the crystalline electric field ground states of R3+ in RPd3S4 except for R =Tm.[1] CePd3S4 orders ferromagnetically below the transition temperature TC = 6.3 K.[2] Recently werevealed that the O20-type quadrupole moments order below TC, and infered that the magnetic structure
is a ferrimagnetic structure by resonant x-ray diffraction (RXD) experiments.[3] Since the symmetry of themagnetic and O20-type quadrupole moments differs from each other, simultaneous order of them below
TC suggests the involvement of the octupole interaction. We performed full polarization analysis of RXD
experiments in magnetic fields to study the contribution of an octupole interaction. The experiments were
performed at the Ce-L3 absorption edge using a single crystal at BL22XU in SPring-8. In our presentation,
we will discuss the contribution of multipole interactions for the low temperature properties in detail.

The electrical resistivity ρ and thermopower S of Ho(Co1-xAlx)2 alloys (x = 0, 0.15 and0.2) were measured from 2 K to 300 K in magnetic fields up to 10 T and under pressures
up to 3 GPa. While ρ(T) and S(T) of the pure HoCo2 reveal abrupt changes at themagnetic ordering temperature TC, indicating the first order transition, the temperature
variation of both properties across the ordering temperature in Ho(Co1-xAlx)2 alloys
clearly show that the type of the magnetic transition changes under substitution of Al for
Co from the first order to the second order. ρ(T ) of the Al substituted samples (x = 0.15
and 0.2) has a very unusual variation below TC. Usually, the resistivity of an itinerant
ferromagnet decreases below TC with decreasing temperature at higher rate than above
TC, its temperature derivative having positive “lambda” anomaly at the ordering point.
In contrast, ρ(T ) of Ho(Co1-xAlx)2 alloys (x=0.15 and x=0.2) increases below TC.
Moreover, the magnetoresistance of these alloys is positive around TC, this is also in a
sharp contrast to usually observed negative magnetoresistance.

[1] K. abe et al.: Phys. Rev. Lett. 76 (1999) 5366. [2] E. Matsuoka et al.: J. Phys. Soc. Jpn. 77 (2008)
114706. [3] S. Michimura et al., submitted to J. Phys. Soc. Jpn.

July 10 (Tue)Slavomir Gabani1, Emil Gazo1, Gabriel Pristas1, Marian Reiffers1, Iveta Takacova1,
Natasha Shitsevalova2, Konrad Siemensmeyer3, Nickolay Sluchanko4 and KaroFlachbartl*
1
Institute of Experimental Physics of Slovakia Academy of Sciences, Kosice, Slovakia
2
Institute for Problems of Materials Sciences, NASU, Kiev, Ukraine
3
Helmholtz Zentrum Berlin, Berlin, Germany
4
General Physics Institute, RAS, Moscow, Russia

218

poster Presentation

July 8-13, 2012 Busan, Korea

219

poster Presentation
QI14

QI17

QJ01

Breakdown of Hund’s third rule for intrinsic magnetic moments

Antiferromagnetism of TbPd2Ge2 Single Crystals

Successive magnetic transitions of PrRh2Ge2 single crystal

July 10 (Tue)Hund’s rules were originally developed in an atomistic picture, and it is therefore
surprising that they also hold, almost universally, for molecules and solids. Here we
report the first experimental example of a breakdown of Hund’s third rule in an intrinsic
magnetic moment: the Co 3d moment of the unorthodox ferrimagnet ErCo2. The
application of magneto-optical sum rules to X-ray magnetic circular dichroic spectra
allows for the determination of the Co orbital and spin magnetic moments both in theferrimagnetic and paramagnetic phases of ErCo2. In agreement with the predictionsof Hund’s third rule, Co orbital and spin moments are parallel throughout the overalltemperature range, except in a narrow temperature window within the paramagnetic
phase, in which they are overall coupled antiparallel. A qualitative consideration of
the balance between the interatomic and intra-atomic interactions acting on the cobalt
atoms explains the phenomenon. This situation also leads to the observation of otherexotic forms of magnetism in solids, such as a “pure” spin or a “pure” orbital momenton the same compound at selected temperature and fields.

Takahiro Hasegawa 1*, Fujiwara Tetsuya 1, Matsubayashi Kazuyuki 2, Uwatoko
Yoshiya2 and Shigeoka Toru1
1
Grad. Sch. Sci. and Eng. Yamagnchi Univ., Japan
2
ISSP. Univ. Tokyo., JapanThe compound TbPd2Ge2, having the tetragonal ThCr2Si2-type crystal structure,
exhibits an antiferromagnetic order below TN=4 K [1]. The details are not clear. In
order to clarify magnetic behavior, we have grown TbPd2Ge2 single crystals, andcarried out magnetic and specific heat measurements using the single crystals. The
magnetic susceptibility shows an anomaly at 13 K in susceptibility vs. T curves,indicating an antiferromagnetic order. The appearance of anomaly at 13K is confirmedin specific heat. This transition temperature is fairly higher than one reported previously[1]. The easy magnetization direction is the [100] direction in the basal plane within
this experimental magnetic field up to 7 T. Three metamagnetic transitions appear in
the process at low temperatures. In the [110] magnetization process, two metamagnetictransitions are observed. In magnetization curves along the all directions, downward
curvatures can be seen, suggesting a precursor of further transition. From these results,
the magnetic behavior of this compound is discussed in detail.
[1] A.Szytula et al., Solid State Commun.66 (1988) 309.

Okawara Yuu1*, Cui Jingwei1, Fujiwara Tetsuya1, Matsubayashi Kazuyuki2, Uwatoko
Yoshiya2, Kimura Shoji3, Watanabe Kazuo3 and Shigeoka Toru1
1
Grad. Sch. Sci. and Eng. Yamagnchi Univ., Japan
2
ISSP. Univ. Tokyo., Japan
3
IMR. Tohoku Univ., JapanThe ternary compound PrRh2Ge2, having the tetragonal ThCr2Si2-type crystal structure,shows an interesting magnetic behavior; it orders antiferromagnetically below TN=45
K and exhibits an additional magnetic transition at Tt=30 K [1]. The details have been,
however, unknown yet. In order to elucidate its magnetic behavior, measurements ofmagnetization and specific heat have been performed on a PrRh2Ge2 single crystal. A muchlarge magnetic anisotropy with the easy magnetization direction of c-axis is observed.
Four anomalies appear in the temperature dependence of magnetic susceptibility along thec-axis; a cusp at TN=52 K, a high peak at T3=38 K, a shoulder at T2=33 K and a small
peak at T1=4 K are observed. Specific heat also shows four anomalies at corresponding
temperatures where magnetic anomalies appear, confirming an occurrence of successive
magnetic transitions. A clear two-step metamagnetic process appears along the easymagnetization direction of the c-axis at low temperatures. The magnetization in the firststep is almost flat and is corresponding to (1/5) Ms, indicating this field-induce phase has along period magnetic structure. This behavior is discussed as one of characteristic features
for Ising-like system with competing exchange interactions.

QJ04
Magnetic properties of C15 laves phase compound SmRu2

Yusuke Amakai*, Mototsugu Sato, Naoki Momono, Hideaki Takano and Shigeyuki
Murayama
Graduate School of Engineering, Muroran Institute of Technology, Japan
We report the magnetic properties of polycrystalline C15 laves phase rare-earth
compound SmRu2. The sample of SmRu2 was made by an arc-melt method and wasannealed at 500 °C in vacuumed quartz tube for 50 hours. The susceptibility χ of
SmRu2 follows a typical Curie-Weiss law above 80 K. The effective magnetic moment
peff is 1.39 μB/Sm-atom, and the Weiss temperature θ is a positive value of 42 K. The
low-temperature χ for T < 70 K increases rapidly with decreasing temperature. In theresistivity ρ and the specific heat Cp, we found a small anomaly and a jump at about
55 K. Furthermore, we observed a hysteresis in the magnetic field dependence ofmagnetization at 2 K. These experimental results suggest that C15 laves phase SmRu2
is ferromagnetic material on Tc ~ 55 K. Detailed discussion will be presented at theconference.

[1] A. Szytula et al., Intermetallics 18 (2010) 1766.

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Magnetic properties of Y substituted TbB4

Multi-step metamagnetic processes in PrPd2Si2 single crystal

Phase diagram of the magnetically frustrated system SmPd2Al3 studied
by neutron diffraction

Pressure effect on the electrical resistivity of a ferromagnetic clathrate
Eu8Ga16Ge30

SmPd2Al3 represents a distinctive example of Sm magnetism exhibiting a complex magnetic behavior [1].
The complexity of magnetism is caused by specific features of the Sm3+ ion, namely by nearness of theground-state multiplet J = 5/2 and the first excited multiplet J = 7/2 in conjunction with strong crystal field. We
have established a magnetic phase diagram based on magnetization data. Detailed information regarding themagnetic structure of each magnetic phase was lacking and neutron diffraction was highly desirable. To reduce
the neutron absorption by the Sm we have performed an experiment at the ILL Grenoble D9 diffractometer withthe short wavelength neutrons which are much less absorbed by the natural Sm. The four successive magnetic
phases have been detected within the neutron diffraction experiment providing the values of the criticaltemperatures 3.5, 4, 4.5 and 12.4. Despite the still strong Sm neutron absorption and the low effective magnetic
moment we have determined the magnetic k-vector (1/3 1/3 0) of the phase existing in the temperature interval
12.4-4.5 K which classifies the SmPd2Al3 to the unique group of magnetically frustrated systems. Discussion
will be drawn in the context of recent theoretical approaches to geometrically frustrated magnetic systems.

Eu8Ga16Ge30 is a unique intermetallic clathrate in which the guest sites are fully
occupied by a rare-earth element. The Eu2+ ions in the tetrakaidecahedral cages in thetype-I structure are rattling among off-center positions [1]. This compound exhibits aferromagnetic transition at Tc=36K. Both the electrical resistivity ρ and the temperaturedeviative of magnetization exhibit peaks at Tc and T*. Upon applying pressure of
6GPa at 290K, the off-center rattling state of Eu ions changes to the on-centered state.
Furthermore, at Ps=14GPa, a structural transition occurs with the volume reductionof about 4% [2]. In order to examine the pressure dependence of Tc and T*, we havemeasured the temperature dependence of ρ under various pressures up to 15GPa, byusing a Bridgman anvil cell made of sintered diamond. With increasing pressure, Tc
shifts to higher temperatures. Broading of the peak at T* for P≥4GPa is attributed tothe change from the off-center to on-center state. At 290K, ρ(P) jumps at 13GPa, whichmust be the manifestation of the structural transition.

Boyoun Kang1, Sungsu Lee1, Juyoung Kim2 and B. K. Cho1*
1
School of Materials Science & Engineering, Gwangju Institute of Science andTechnology, Korea
2
Advanced matallic materials research department, Research Institute of Industrial
Science & Technology, Korea

Toru Shigeoka1*, Tetsuya Fujiwara1, Kazuyuki Matsubayashi2, Yoshiya Uwatoko2,
Shoji Kimura3 and Kazuo Watanabe3
1
Yamaguchi University, Japan
2
ISSP., University of Tokyo, Japan
3
IMR., Tohoku University, Japan

We synthesized the single crystals of Tb1-xYxB4 (x=0.0, 0.1, 0.2, 0.3, 0.35, 0.4, 0.5,
and 0.6)using metallic flux method. The lattice parameters of these crystals are
confirmed by powder x-ray diffraction using Fullprof program. The lattice parameters
are decreased with increasing substituted Y ratio, according to Vegard’s law. The
measurements of temperature-dependent magnetization M(T) is carried out for the
single crystals of Tb1-xYxB4 (x=0.0, 0.1, 0.2, 0.3, 0.35, 0.4, 0.5, and 0.6) in 1 Tesla.
The compounds reveal antiferromagnetic ordering and its Neel temperatures are
decreased with increasing Y ratio. We confirm the spin direction of antiferromagnetic
contribution in Tb0.65Y0.35B4 using single crystal neutron scattering. The direction of Tb
spin magnetic moment is tilted from a axis.

Magnetic studies have been performed in detail on a PrPr2Si2 single crystal which is
crystallized in the tetragonal ThCr2Si2-type structure. The temperature dependenceof magnetic susceptibility indicate the compound orders antiferromagneticallybelow TN=3.0 K. The transition has been confirmed by specific heat. Magnetization
measurements up to 18 T have been performed and obtained following results. The easymagnetization direction is the [100] direction in the basal plane. In the magnetization
process, four metamagnetic transitions appear; it is a four-step metamagnetic one. The[110] magnetization process is a three-step one. A strong magnetic anisotropy between
the [100] and [110] directions is observed within the basal plane in high magnetic
fields. Along the hard magnetization direction of the c-axis, a metamagnetic transition
appears. A magnetic anisotropy between the [100] and [001] directions is also strong.
These behaviors are discussed from an analysis of crystal field effects.

Jiri Pospisil1*, Gwilherm Nenert2, Hideaki Kitazawa3, Martin Divis1, Jan Prokleska1
and Vladimir Sechovsky1
1
DCMP, Charles University, Ke Karlovu 5, 121 16, Prague, Czech Republic
2
Institut Laue Langevin, 6 rue Jules Horowitz, BP 156, F-38042 Grenoble Cedex 9,France3
National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, JapanT Iizuka1, K Umeo2*, M A Avila3 and T Takabatake1
1
AdSM, Hiroshima Univ., Kagamiyama 1-3-1, Higashi-Hiroshima 739-8530, Japan
2
N-BARD, Hiroshima Univ., Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526,
Japan
3
Federal University of ABC, Santo Andre, SP, 09210-170, Brazil[1] J. Pospisil, M. Kratochvilova, J. Prokleska, M. Divis, V. Sechovsky; Phys. Rev. B 81, 024413(2010)[1] B. C. Sales, et al., Phys. Rev. B 63, 245113 (2001). [2] T. Kume et al., unpublished.

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High pressure effects on antiferroquadrupolar orders in RB2C2 (R =Dy and Ho)

Anisotropic properties of Tb2Pd2In single crystal

Interplay of rare-earth and iron sublattices in NdFeAsO

Magnetic transitions under pressure in GdCo2B2

Hiroki Yamauchi1*, Toyotaka Osakabe1, Masashi Kosaka2, Eiichi Matsuoka3 andHideya Onodera4
1
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Japan
2
Graduate School of Science and Engineering, Saitama University, Japan3
Department of Physics, Graduate School of Science, Kobe University, Japan
4
Department of Physics, Graduate School of Science, Tohoku University, Japan

Single-crystal neutron diffraction experiments under 10 GPa class pressure were performedon tetragonal DyB2C2 and HoB2C2 compounds showing antiferroquadrupolar (AFQ) andantiferromagnetic (AFM) orders. Both magnetic structures in the ground state phases arebasically same and described mainly by the propagation vectors k1 = (1, 0, 0) and k2 = (0, 1,
1/2) for an AFM alignment in the c-plane and an orthogonal arrangement along the c-axis. This
characteristic zigzag structure is attributed to the competitive coexistence of the underlying
AFQ order with the AFM order. Our purpose is to investigate pressure effects on the AFQ and
AFM orders through the alteration of the magnetic structures with k1 and k2. The high pressure
experiments revealed that applying pressure enhanced the AFM interactions and simultaneously
suppressed the AFQ orders in the both compounds. In addition, we found that applying pressure
shranks the crystal volumes more greatly in the direction of the c-axis even under hydrostaticpressure. Therefore, we presume that the volume shrinkage by applying pressure constrains the
buckling accompanied by the AFQ orders, which means a local atomic displacement of (B-C)
layers along the c-axis, and leads to the suppression of the AFQ orders in the both compounds.

The 19th International Conference on Magnetism

Silvie Maskova1, Ladislav Havela1, Olexander Kolomiets2, Alexander V. Andreev3 andPavel Svoboda1*
1
Department of Condensed Matter Physics, Charles University, Czech Republic2
Department of Physics, Lviv Polytechnic National University, Ukraine
3
Institute of Physics, ASCR, Czech Republic
Tb2Pd2In (tetragonal Mo2FeB2 structure type) was reported to be an antiferromagnet
with the Neel temperature TN = 32 K and metamagnetic transition at μ0Hc = 4 T [1].
On the contrary, our magnetization measurements on polycrystalline sample indicatethat the magnetization curve of Tb2Pd2In has 4 metamagnetic features in the field range
to 14 T. We have succeeded to prepare singe-crystalline sample of Tb2Pd2In using
Czochralski method. The magnetic susceptibility measured on single-crystal in various
crystallographic directions shows that magnetic properties of Tb2Pd2In are highly
anisotropic. c-axis was found to be an easy magnetization direction. The magnetization
curve along the c-direction at T = 2 K shows two metamagnetic transitions (μ0Hc= 5 and 8 T). The magnetization is completely saturated at 14 T (Ms = 19.1 μB/
f.u.). We have also observed another metamagnetic transition along the a-direction.
The magnetization in the a-direction does not show any tendency to saturation in thehighest available fields.
[1] M. Giovannini et al., J. Alloys Compd. 280, 26 (1998).

Gwendolyne Pascua1, Hubertus Luetkens1, Yurii G. Pashkevich2, Hemke Maeter3 andHans-henning Klauss3
1
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen
PSI, Switzerland
2
A.A. Galkin Donetsk Phystek, NASU, 83114 Donetsk, Ukraine
3
Institut fur Festkorperphysik, TU Dresden, DE-01069 Dresden, Germany
We report zero-field (ZF) muon spin relaxation (μSR) measurements on NdFeAsO
polycrystalline samples. We investigate the interaction of the Fe magnetic sublattice with
the RE (rare-earth) paramagnetic moment in the nonsuperconducting magnetically ordered
Nd oxypnictide by a detailed analysis of the hyperfine fields at the muon site. At hightemperatures, the fluctuations of the Nd moments are evident from the observed exponential
depolarization of the μSR signal. Microscopic evidence of static commensurate magnetic
order of Fe moments is revealed by μSR at temperatures below TΝ(Fe) = 136K. Drastic
slowing down of RE moment fluctuations is observed only below TΝ(RE) = 2K. In theintermediate temperature range, a Schottky-like polarization of the Nd magnetic sublattice by
the ordered Fe system is observed. In the Fe system, a transition between a high- and a lowtemperature magnetic structures is proposed on the basis of a detailed symmetry analysis andmagnetic dipole-field calculations at the muon site. The observed behavior resembles the oneof the spin reorientation in the structurally-related Nd2CuO4.
[1] H. Maeter, H. Luetkens, Y. Pashkevich, et.al. Phys. Rev. B. 80 094524 (2009). [2] W. Tian, et.al.
Phys. Rev. B. 82, 060514 (2010). [3] Y. Qiu, et.al. Phys. Rev. Lett. 101, 257002 (2008).

July 10 (Tue)Julia Herrero-albillos1*, Fernando Bartolome2, Luis Miguel Garcia2 and A. T. Young3
1
CUD, Centro Universitario de la Defensa, Ctra. de Huesca s/n, E-50090 Zaragoza,
Spain, Spain
2
ICMA, ICMA and Dpto. de Fisica de la Mat. Cond. CSIC - Universidad deZaragoza, Pedro Cerbuna 12, Spain
3
Advanced Light Source, Lawrence Berkeley National Laboratory, University ofCalifornia Berkeley, CA, USA

220

poster Presentation

Guanghui Hu1*, Izuru Umehara1, Lingwei Li2 and Katsuhiko Nishimura3
1
Department of Physics, Yokohama National University, Japan
2
Institute of Materials Physics, Hangzhou Dianzi University, China
3
Graduate School of Science and Engineering, University of Toyama, Japan

The pressure effect on magnetic transitions of GdCo2B2 compound was studied by dc susceptibility and ac
heat capacity in the temperature range 2 K ~ 300 K. The temperature dependence of dc susceptibility for
GdCo2B2 under various pressure in 0.1 T magnetic field show two information. First, the Antiferromagnetictransition temperature TN decrease with pressure increasing from 12.5 K in 0GPa decrease to 6.3 K in 1.07
GPa and disappeared near to 1.30 GPa with a slope of dTN/dP about -5.8 K/Gpa. Second, ferromagnetictransition TC increases alightly with pressure increasing from 20.4 K in 0 GPa to 22.1 in 1.27 GPa witha slope of dTC/dP about 1.5 K/Gpa. They were also found in ac heat capacity measurements. It can beunderstand that there is a strong interaction in the ferromagnetic state and a very weak interaction in
antiferromagnetic state which can easily be destroyed by pressure and magnetic field. The transitions
are proved to be the second-order transition. In addition, a transition temperature TM which comes fromdomains of ferromagnetism in heat capacity measurements was found increase from 17.5 K under 0 GPa
to 22.0 K under 2.36 GPa with a ratio dTM/dP about 2.2 K/GPa.
[1] L. Li, K. Nishimura, and H. Yamane, Appl. Phys. Lett. 94 (2009) 102509 [2] L. Li, D. Huo, Z.
Qian, and K. Nishimura, J. Phys.: Conf. Ser. 263 (2011) 012017 [3] I. Felner, Sol. Sta. Comm. 52(1984) 191-195 [4] V. K. Pecharsky, and K. A. Gschneidner, Jr., Int. J. Refrig, 29 (2006) 1239 [5]I. Umehara, F. Tomioka, A. Tsuboi, T. Ono, M. Hedo, Y. Uwatoko, J. Magn. Magn. Mater. 272-276(2004) 2301-2302.

July 8-13, 2012 Busan, Korea

221

poster Presentation

poster Presentation

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New ferromagnetic compounds with noncentrosymmetric crystal
structures

Competition between magnetic ordering and random spin freezing in
Dy2PtSi3

Influence of weak-magnetic, non-magnetic and disoriented grains on
remagnetization processes of Nd-Fe-B alloys

Resonance, magnetic and neutron investigations of magnetic structuresin Pr1-xYxFe3(BO3)4 system

Recently, physical properties in noncentrosymmetric crystal structures have attracted
considerable attentions. The broken inversion symmetry in the crystal causes finite
antisymmetric spin orbit coupling (ASOC). A spin-polarized electrons that originatesfrom the ASOC effect is formed even for nonmagnetic materials. Generally, theelectronic states of opposite spin orientation are considered to be degenerate innonmagnetic materials due to the presence of both time-reversal and space-inversion
symmetries. However, this degeneracy will be solved by the ASOC in broken spaceinversion symmetries with noncentrosymmetric crystal structures. A pair of split bands
is produced in the k-space. Ferromagnetic compounds with noncentrosymmetriccrystal structures are interesting materials, because the time-reversal symmetries
also broken. We discovered new ferromagnetic compouds, Pr4Bi3 and Nd4Bi3, withnoncentrosymmetric crystal structures. They are crystalized in anti-Th3P4 structure(space group I-43d), which has no inversion center. Curie temperature T_C are 48K
and 94K, respectively. Large ASOC is expected caused by heavy material of Bi. We
will report further results in detail.

We have been paying special attention to a new family of the ternary intermetallic compounds
R2PtSi3. The spin-glass or cluster-glass-like effect can be observed in some R2PtSi3 compoundswith heavy rare earth element, which have been confirmed to crystallize in the ordered hexagonal
structure [1]. The mechanisms of the anomalous magnetic behaviors are very interesting inphysics. Recently, we prepared a polycrystalline Dy2PtSi3 sample and systematically measured
its magnetic properties including ac susceptibility (Χac), FC and ZFC magnetization, magnetic
relaxation, electrical resistivity and specific heat. The most important observation is the evident
peak in Χac(T) curve near Tc~6 K, which shifts to high temperature with increasing frequency
suggesting the presence of random spin freezing effect. The observed long-time magnetic
relaxation and the low temperature irreversible magnetism give further evidence for thisconclusion. However, specific heat measurement shows an evident peak at Tc and the electricalresistivity drops rapidly as decreasing the temperature just below Tc. In this sense, the long-range
magnetic exchange interactions have also important influence on the magnetic behavior. Thus it
seems to be appropriate to classify the Dy2PtSi3 sample as a large magnetic cluster system withcompetition between magnetic ordering and random spin freezing.

The uniaxial high-anisotropic materials, in which magnetostatic interaction between
volumes have a significant influence were investigated. The analysis of domain
structure formation during magnetization reversal these materials in the presence of
weak-magnetic, non-magnetic and disoriented grains was carried out. The modelingensemble simulating magnetic properties of sintered alloy neodymium- iron - boron(Nd15Fe77B8) was selected. Research of influence of inclusions was conducted on thebasis of model experiments with the received ensemble. The program, devised foruniaxial high-anisotropic ferromagnetics, in which the sample is presented by ensemble
from 1000 particles having transitive domain structure and following individual
characteristics was used. After selection of all parameters of the ensemble simulating
this material, for researching the influence of inclusions on magnetic reversal processes,
key parameters of some microvolumes (Мs, Номах, Нs, Angle) were changed. It was
concluded that magnetic reversal is realized by the channels formed at the expenseof directed magnetostatic interaction. Weak-magnetic, non-magnetic and disoriented
grains are the magnetic reversal centers, i.e. they are the beginning of formation of thechannel of magnetic reversal.

D. X. Li1*, T. Yamamura1, S. Nimori2 and T. Shikama1
1
Institute for Materials Research, Tohoku University, Japan
2
Tsukuba Magnet Laboratory, National Research Institute for Metals, Japan

Anna Starikova*, Alexey Lileev and Olga Arinicheva
National University of Science and Technology 'MISIS' (MISIS), Russia

July 10 (Tue)[1] D. X. Li , S. Nimori, Y. Homma and Y. Shiokawa, J. Phys. Soc. Jpn., 71 (2002) Suppl. 211.

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Singlet-triplet crossover in the two-dimensional dimer spin system
YbAl3C3

Dilatometric investigations on the semimetallic ferromagnet EuB6

Cobalt magnetism in HoCo2 under pressure

Shunichiro Kittaka 1 *, Tomoyoshi Sugiyama 1 , Yasuyuki Shimura 1 , Toshiro
Sakakibara1, Saori Matsuda2 and Akira Ochiai2
1Institute for Solid State Physics, University of Tokyo, Japan2
Department of Physics, Tohoku University, Japan
YbAl3C3 has the hexagonal ScAl3C3 type structure in which magnetic Yb3+ ions form a
two-dimensional triangular lattice. At 80 K, it exhibits a structural phase transition to an
orthorhombic structure with a slight displacement of the Yb atoms [1]. Interestingly, a
dimer ground state with the singlet-triplet energy gap of about 15 K has been suggested
from the magnetic susceptibility and the specific heat at low temperatures [2]. Indeed, adirect observation of the singlet-triplet excitations has been reported from the inelastic
neutron experiments [3]. To investigate the variation of the ground states in magnetic
fields, we measured magnetization of a single crystal of YbAl3C3 down to 0.07 K andin fields up to 14.5 T. At low temperatures below 0.8 K, several magnetization steps
were clearly observed for H||c in 6 T < μ0H < 9 T, whereas only two transitions wereobserved at 4.7 and 6.6 T for H||ab. At fields above 9 T, the magnetization becomesalmost saturated for both H||c and H||ab. Our results indicate that the singlet-triplet
crossover occurs in a relatively narrow field range, suggesting a rather weak interdimer
interaction in spite of the nearly triangular lattice of Yb ions.

The rare earth borates RFe3(BO3)4 with the structure of the huntite mineral are interesting as materials withtwo magnetic subsystems with competing anisotropy. In this work we present data on antiferromagnetic
resonance (AFMR), magnetic properties and neutron investigation of Pr1-xYxFe3(BO3)4 system. Our AFMRand neutron investigations [1-3] show that the last points of the system, YFe3(BO3)4 and PrFe3(BO3)4,are easy-plane (EP) and easy-axis (EA) antiferromagnets, respectively, confirming the magnetic data
for R=Pr [4]. A dilution of the Pr3+ subsystem by diamagnetic yttrium reduces the magnetic anisotropyof the Pr subsystem and can lead to a transition from EA to EP state at some yttrium content. The single
crystals Pr1-xYxFe3(BO3)4 with x=0.25, 0.325, 0.5 and x=0.75 were grown. Magnetic and resonanceinvestigations show that the crystals with x = 0.25 and 0.325 are EA antiferromagnets with the energy gap
at T=4.2 K close to 75 and 60 GHz, respectively, but the crystals with x=0.5 and 0.75 are EP ones. Neutron
investigations showed that the concentration transition from EP to EA state occurs via an inclined magnetic
structure which was found for x=0.325.The concentration dependency of AFMR energy gap is studied at
T=4.2 K. This work was supported by RFBR grant #10-02-00765.
[1] A.I. Pankrats, G.A. Petrakovskii, L.N. Bezmaternykh, V.L. Temerov, Physics of Solid State, 2008,
Vol. 50, p. 79. [2] Ritter C., Vorotynov A., Pankrats A., et al., J. Phys.: Cond. Matter., 2008, V. 20,
p. 365209. [3] Ritter C., Vorotynov A., Pankrats A., et al., J. Phys.: Cond. Matter, 2010, V. 22, p.
206002. [4] A. M. Kadomtseva, Yu. F. Popov, G. P. Vorob’ev et al, JETP Lett., 2008, V. 87, p. 45.

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Anisotropic transport and magnetic properties of PrGe single crystal

Jaroslav Valenta, Jiri Prchal*, Marie Kratochvilova, Martin Misek and Vladimir
Sechovsky
Department of Condensed Matter Physics, Charles University in Prague, Czech
Republic

Pranab Kumar Das, Neeraj Goyal, Ruta Kulkarni, Arumugam Thamizhavel andSudesh Kumar Dhar
Department of Condensed Matter Physics and Materials Science, Tata Institute ofFundamental Research, Mumbai, India

HoCo2 belongs to a group of RCo2 (R = rare earth metal) compounds forming in the
cubic Laves phase structure. The Ho localized 4f-electron magnetic moments coexist
together with the itinerant Co 3d moments, which appear on the verge of magnetism,
similar to the ErCo2 system [1]. Below TC, the large exchange field due to theferromagnetically ordered Ho moments polarizes the Co 3d-electron states and theemerged moments in the Co sublattice orient antiparallel to the Ho sublattice. Weak
Co moments survive rather far above TC (= 79,5 K) in Co magnetic clusters remaining
coupled antiparallel to paramagnetic Ho moments forming a parimagnetic phase. This
causes a susceptibility anomaly at the parimagnetic transition temperature Tf (= 125 K).
At low temperatures the easy magnetization direction changes at the spin-reorientation
temperature TR = (16,4 ± 0,5) K. We will present variations of the three transition
temperatures with applying hydrostatic pressure up to 3 GPa. TC and TR coincidently
decrease with increasing pressure whereas TR increases. The results will be discussed
in term of suppressing the Co magnetic moments and varying the exchange and crystalfield interactions with applying the hydrostatic pressure.

The compounds RGe (R = La, Ce, Pr and Nd) crystallize in the two closely related CrB and
FeB-type orthorhombic crystal structures, depending upon R and heat treatment. We haverecently reported the anisotropic magnetic properties of CeGe in detail which crystallizes
in the FeB-type crystal structure [1]. In continuation of our studies on RGe compounds,
we report here the anisotropic properties of a single crystal of PrGe grown by Czochralski
method. PrGe exhibits dimorphism in which the high temperature FeB-type structuretransforms into CrB-type structure at lower temperatures [2]. From the powder X-ray
diffraction we have confirmed that the grown single crystal of PrGe possesses CrB-type
crystal structure with the space group Cmcm(#63). The anisotropic magnetic properties
have been studied along the three principal crystallographic directions. From the magnetic
and transport properties we find that PrGe exhibits two magnetic transitions at 44 K and
41.6 K along [100] and [010] directions, whereas along [001] direction only a ferromagnetic
ordering at 44 K is observed. The susceptibility data clearly indicate that the high temperatureordering is antiferromagnetic and the low temperature one is ferromagnetic. The specific heat
capacity data also confirm the two magnetic transitions in PrGe.

[1] J. Herrero-Albillos et al., Phys.Rev.B 76 (2007) 094409.

[1] Pranab Kumar Das, Neeraj Kumar, Ruta Kulkarni, S.K. Dhar and A. Thamizhavel, arXiv:
1108.1291 [2] D. Hohnke and E. Parthe, Acta Crys. 20 (1966) 572.

[1] T. Matsumura et al., J. Phys. Soc. Jpn. 77, 103601 (2008). [2] A. Ochiai et al., J. Phys. Soc. Jpn.
76, 123703 (2007). [3] Y. Kato et al., J. Phys. Soc. Jpn. 77, 053701 (2008).

EuB 6 is a semimetallic correlated electron system, which exhibits a complex
sequence of electronic and magnetic phase transitions at ~ 15.5 K (Tc1) and 12.5 K(Tc2). The material also shows a colossal magnetoresistance effect which is largest
at Tc1. A percolative transition of magnetic polarons, i.e., clusters of ordered Eu2+
moments polarized by the spins of localized charge carriers (holes), is involved in theparamagnetic to ferromagnetic transition. Thermal expansion and magnetostriction
measurements have been performed on this material to explore to which extent lattice
degrees of freedom are involved in these phase transitions. We find two corresponding
anomalies in the thermal expansion, the one occurring at Tc2 being much larger thanthat at Tc1. By applying a small magnetic field of less than 50 mT, the anomaly at
Tc1 is fully suppressed, while the lower-temperature anomaly at Tc2 shifts to higher
temperature as the field is increased and finally fades out at a field B > 5 T. These
measurements are complemented by magnetostriction measurements for a set oftemperatures from below Tc2 to above Tc1, highlighting the extraordinarily large
magnetoelastic effects in this material.

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Magnetic structure transition in PrPd3

The magnetic anisotropy and magnetostriction of RAl2 (R= rare earth)compounds

High-field magnetization study of ErCo2

Theoretical investigation of the phase transition and the spin-gap
behavior of the triangular antiferromagnet YbAl3C3

Hiroyuki S. Suzuki1*, Noriki Terada1, Akiko Kikkawa1, Koji Kaneko2 and Naoto
Metoki2
1
National Institute for Materials Science, Japan
2
Japan Atomic Energy Agency, Japan
A complex magnetic phase diagram of PrPd3 with AuCu3-type structure was reported[1]. The specific heat shows double peaks at TN = 0. 88 K and 0.77 K, which are
relatively low compared with the Curie-Weiss temperature Θp ~ 17 K. The temperatureof the peak at higher temperature is increased but another decreased with the magnetic
field. A large tail above TN in the specific heat is also observed. Considering nogeometric frustrations in the simple cubic structure of the Pr site, these behavior suggest
a competition of inter-site interactions. The magnetic field dependence of the peak athigher temperature, which is typical in the quadrupole ordering system, also suggests
an importance of the multipole effect arising from the crystalline electric field groundstate. We have investigated the multipole effect using the single crystal by specific heat,magnetic susceptibility, ultra-sonic and also neutron scattering measurements. In thisreport, we focus on the magnetic structure and its transition. We have found first the
1st transition of the magnetic phase at 0.5 K. The propagation vector observed in theneutron scattering is changed from the incommensurate to commensurate one. We will
discuss the complex magnetic phase based of the multipole effect.
[1] S. Zhang, et al., Journal of Physics : Conference Series, 15 (2009) 042074

222

Rudra Sekhar Manna1, Frank Schnelle1, Mariano De Souza1, Michael Lang1, Pintu
Das1, Adham Amyan1, Jens Mueller1, Stephan Von Molnar2, Peng Xiong2 and Zachary
Fisk3
1
Physics Institute, Goethe-University Frankfurt (M), SFB/TR 49, D-60438 Frankfurt(M), Germany
2
Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
3
Department of Physics, University of California, Irvine, California 92697, USA

A Pankrats1, V Tugarinov1*, C Ritter2, D Velikanov1, I Gudim1 and V Temerov1
1
Kirensky Institute of Physics SB RAS, Krasnoyarsk, Russia
2
Institute Laue-Langevin, Grenoble, France

The 19th International Conference on Magnetism

Masashi Ohashi, Yusuke Araki and Kazuma Sawami
Kanazawa University, JapanThe RAl2 (R : rare earth element) intermetallic compounds crystallize in the MgCu2
cubic Laves phase structure. In most of these compounds the R ions are trivalent
3+ and ferromagnetic ordering has been observed with Curie temperature TC up
to 170 K. It is expected that some of structural transition occurs due to magnetic
symmetry braking below TC. In the present work, spontaneous magnetostriction offerromagnetic RAl2 compounds are studied from the X-ray diffraction measurement at
low temperature and the thermal expansion of the single crystal. The X-ray diffraction
pattern shows the d-spilliting at several peaks of TbAl2 and DyAl2 due to the large
magnetic anisotropy below TC. From these results, the crystal structures are estimatedat ferromagnetic phase of TbAl2 and DyAl2. The anisotropic magnetoelastic constants
have been calculated by using the results of the magnetization and the magnetostriction
at the ferromagnetic phase and at the magnetic field up to 2 T.

Maurice Guillot1 and Yildirhan Oner2*
1
1. Grenoble High Magnetic Field Laboratory, CNRS, BP166, 38042 Grenoble
Cedex 9, France, France
2
Department of Physics, Istanbul Technical University, Turkey
In this work are presented new results on the magnetic properties of the ErCo 2
compound in which three magnetic phases (ferrimagnetic, parimagnetic andparamagnetic) were proposed very recently. This study is based on the investigationof the magnetization under continuous high magnetic fields (up to 330 kOe at 4.2K
and up to 230 kOe in the 4.2-300K respectively). At low temperatures the stability of
the ferrimagnetic structure is shown although the saturation was never found. Special
attention was paid to the 35-100K temperature range where the transitions between
the different magnetic phases occur confirming of the parimagnetic” orderings.
The transition temperature Tc from the ferrimagnetic to the parimagnetic phaseincreases from ? 34 to 62 K with the applied field. For the values of H smaller than
100 kOe. At H values greater than this Tc remains constant at (62 ±5) K. The atomic
magnetic moment of Co is independent of the magnetic structure is and in the order of
1μBatom-1.

July 10 (Tue)Yoshihiko Inada1*, Guizhi Bao2 and Akiko Ono1
1
Graduate School of Education, Okayama University, Japan2
Department of Physics, Okayama University, Japan

Changhoon Lee1*, Myung-hwan Whangbo2, Juergen Koehler3 and Ji-hoon Shim1
1
Chemistry, Postech, Korea
2
Chemistry, North Carolina State University, USA3
MPI for Solid State Research, Stuttgart, Germany

Ytterbium aluminum carbide YbAl3C3, first reported in 1992,[1] has recently attracted much attention
concerning the nature of its phase transition at T* = 77 K.[2-4] YbAl3C3 containing triangular sheets ofmagnetic ions Yb3+ (f13) undergoes a phase transition at T* = 77 K and exhibits a spin-gap behavior.
The two model structures of YbAl3C3, proposed to explain these observations, give unreasonably
short C-Al distances. These model structures were optimized by density functional calculations tofind that the Model 2 structure is more stable than the Model 1 structure, with chemically reasonable
C-Al distances, and that the phase transition at T* is a cooperative second-order Jahn-Teller distortion
involving the layers of corner-sharing CAl5 trigonal bipyramids. The spin exchanges between nearestneighbor Yb3+ ions, evaluated by density functional calculations for the optimized Model 2 structure,
show that YbAl3C3 has a two-dimensional spin lattice described by three antiferromagnetic exchanges,
but exhibits a spin-gap behavior because one exchange is substantially stronger than the other two.
(1) Gesing, T. M.; Pottgen, R.; Jeitschko W.; Wortmann, U. J. Alloys Compd. 1992, 186, 321. (2) Kosaka,M.; Kato, Y.; Araki, C.; Mori, N.; Nakanishi, Y.; Yoshizawa, M.; Ohoyama, K.; Martin C.; Tozer, S. W. J.
Phys. Soc. Jpn. 2005, 74, 2413. (3) Ochiai, A.; Inukai, T.; Matsumura, T.; Oyamada A.; Katoh, K. J. Phys.
Soc. Jpn. 2007, 76, 123703. (4) Kato, Y.; Kosaka, M.; Nowatari, H.; Saiga, Y.; Yamada, A.; Kobiyama, T.;
Katano, S.; Ohoyama, K.; Suzuki, H. S.; Aso N.; Iwasa, K. J. Phys. Soc. Jpn. 2008, 77, 053701.

July 8-13, 2012 Busan, Korea

223

poster Presentation
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First Principle Analysis for Pressure Effect on Charge Density Wave
Phases of SmNiC2

GMR properties on flexible polymer film with bending stressSpin valve effect of NiFe/graphene/NiFe junctions

Simulation of spin-dependent transport in GaAs: Effect of electronelectron interactions

Using a first principles calculation, we have investigated pressure effect on the electronic
structure anisotropies, Fermi surface properties, and transport properties of SmNiC2 tocheck their effects on the charge density wave instabilities. Both band structure and electric
conductivity results show that SmNiC2 has quasi 1D electronic structure by Ni 1D chain
along a axis. However hybridization between nearest Sm 1D chain makes its charge density
wave (CDW) properties 2D like with CDW vector q1=(0.5, 0.5, 0) and another weak CDW
vector qR=(0.5, 0.5, 0.5) at -6 GPa. With increasing pressure, highly anisotropic changeof lattice induces these CDW vector to become incommensurate with flattening Fermi
surface (FS) in the [110] plane and suppressing FS in [111] plane. The FS nesting vector
q1 is gradually shifted from q1=(0.5, 0.50, 0) at -6 GPa to q1=(0.5, 0.56, 0) at 14 GPa, whileq1=(0.5, 0.52, 0) at 0 GPa, coincide with experimental results. Also, qR=(0.5, 0.5, 0.5), which
is significant local maximum at -6GPa, becomes almost saddle point like with its nesting
vector shifting another points. We conclude that CDW strength along q1 vector become
stronger with flattening (more 1D like) FS, but CDW strength along qR vector become weakwith highly anisotropic change of lattice.
[1] S. Shimomura, C. Hayashi, G. Asaka, N. Wakabayashi, M. Mizumaki, and H. Onodera, Phys. Rev. Lett. 102, 076404(2009). [2] Alexander Wolfel, Liang Li, Susumu Shimomura, Hideya Onodera, and Sander van Smaalen, Phys. Rev. B 82,
054120 (2010). [3] J. Laverock, T. D. Haynes, C. Utfeld, and S. B. Dugdale, Phys. Rev. B 80, 125111 (2009).

Joonhyun Kwon, Seungha Yoon, Seungkyo Lee, Jeonghyeon Lee and B. K. Cho*
School of Materials Science and Engineering, Gwangju Institute of Science andTechnology (GIST), Korea
Recently, demands and researches about variable flexible devices have been
constant. In other to satisfy such demands, researches about magnetic properties inflexible environment also have been continued. In these researches, the simple giant
magnetoresistance (GMR) spin valve structure was deposited on flexible polymer films,
then was induced by external tensile stress from repetitive bending fatigue. As bending
samples, bending directions were decided whether parallel or transverse directions toeasy axis directions of GMR structure. As a result, when increasing parallel bendingtimes, switching field interval range of free layer also increased, inversely as increasingtransverse bending times, coercivity of free layer also increased. Such tendency had
opposite properties to inverse magnetostriction effect theory from the view of bending
direction, because flexible films had larger elastic recovery forces than tensile forces
after bending. Therefore we anticipate that such elastic recovery forces was the reasonof opposite tendency from the aspect of direction. Based on these results, we clarified
possibilities that the coercivity could be controlled without curvature, moreover axis
behavior, e.g., easy axis or hard axis, also could be controlled without curvature andextra annealing processes.

Novel linear dispersion in graphene makes unique electronic properties such as
ambipolar transport and Dirac particle quantum Hall effect. Although graphene waspreviously considered to be a physically unstable form until it was shown to exist
on the Si substrate, various methods to synthesize graphene have been developed.
Exploiting such superior electronic properties combined with recently developed large
scale growth of graphene by chemical vapor deposition (CVD), has led to field effectdevices integrated on a wafer scale showing promise for future electronic applications.
In this paper, CVD-grown graphene is used as intervened spacer between two
ferromagnetic electrodes. The device is composed of 55 nm thick NiFe film, graphene
and 75 nm thick NiFe film. The current-to-perpendicular-to-plane magnetoresistance(MR) shows the spin valve effect. The increased resistance in the antiparallel
configurations of magnetizations is due to the spin dependent scattering inside themagnetic films or at interfaces. A positive MR ratio of the order of 0.045% has been
observed at 300 K and this signal grows up to 0.14 % at 10 K. The junction resistanceis found to be monotonically increasing with temperature. Graphene functions as not atunnel barrier but a resistive thin film between two NiFe electrodes.

Matthew Hodgson, Gionni Marchetti, Roy W. Chantrell and Irene D'amico
Physics, University of York, United Kingdom

We investigate the effect of electron-electron interaction on electronic spin transport inbulk GaAs. We use Ensemble Monte Carlo (EMC) techniques to simulate the electron
and spin dynamics. EMC has been successfully used in the study of charge transportand more recently in spin transport. However electron-electron interactions are often
neglected, also due to computational costs. Here, in addition to electron-electron
scattering we include scattering from optical and acoustic phonon, and charged defectscattering. Spin decoherence occurs due to the spin-orbit interaction (Dresselhausterm), which arises from the lack of inversion symmetry in GaAs. The electron-electroninteraction is described by the screened Coulomb potential. At variance with previous
simulations, we implement both spin dependent (Mott) and spinless (Rutherford)
scattering. We also propose a new, more realistic, method for choosing partners
undergoing electron-electron collisions which properly accounts for the dependence on
the distance between electrons. We show that, in EMC simulations, electron-electroninteractions should not be discarded, as doing so may result in an anomalous drop in
the spin relaxation time at temperatures as high as 100K.

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The magnetoresistance of sandwich-structure organic spin-valve

Giant magnetoresistance in graphene nanoribbons: Geometry,interface and dephasing effects

Giant magnetoimpedance and photoinduced magnetoresistance effects
in ferromagnet/SiO2/p-Si hybrid structures

Electrical detection of spin-polarized current in InAs quantum point
contacts

Feng Li*, Fapei Zhang and Yu Xiao
High Magnetic Field Laboratory, Chinese Academy of Science, China

We studied the magnetoresistance (MR) effect in an organic spin-valve structureof ferromagnetic/organic semiconductor/ferromagnetic system theoretically using
the spin-diffusion theory and Ohm’s law. Spin polarons and spinless bipolarons are
assumed to be the main carriers in organic semiconductors. From the calculation, it
is obtained that MR value increases with the increase of the polaron proportion andrapidly decreases with the increase of the thickness of organic layer. MR ratio canbe enhanced remarkably when the interfacial resistances are spin related. We also
investigated MR value dependence of the effects of the matching conductivity and thespin-polarization of ferromagnetic layer.

Stefan Krompiewski*
Institute of Molecular Physics, Polish Academy of Sciences, Poznan, Poland

Motivated by the ongoing debate on the role of external contacts on electronic transport
through carbon nanostructures [1-3], we theoretically estimate the combined effects- due to (i) geometry, (ii) the way the external contacts are attached and (iii) possibledephasing processes - in graphene nanoribbon (GNR). The method is based on thetight binding model, the Green function technique and the Landauer-type formalism.
It is shown that giant magnetoresistance in GNRs depends strongly not only on the
aspect ratio of the sample and the current direction, but also on whether ferromagnetic
electrodes are attached in the end- or side-contacted manner. Typically the former
attachment is favorable for conductivity. However the observed tendency is that thehigher conductive systems reveal the lower giant magnetoresistive effect, and viceversa. Accordingly, the dephasing usually decreases conductivity, thereby increasing
the GMR.
[1] X. Song et al, Nanotechnology 20 195202 (2009). [2] Y. Matsuda et al, J. Phys. Chem. C, 114,
17845 (2010). [3] S. Krompiewski, Nanotechnology, 22, 445201 (2011). Acknowledgment This work
was supported by the Polish Ministry of Science and Higher Education as a research project No. N
N202 199239 for 2010-2013.

N. V. Volkov*, A. S. Tarasov, E. V. Eremin, A. V. Eremin, S. N. Varnakov and S. G.
Ovchinnikov
L.V. Kirensky Institute of Physics SB RAS, Russia

We report the electron transport properties in the Fe/SiO2/p-Si hybrid structure. The
results of dc studies show that the features of the transport properties of the structure
are caused by a metal/insulator/semiconductor transition with a Schottky barrier
formed at the SiO2/p-Si in-terface [1]. The magnetoresistance effect is determined bycontributions of the processes occurring in the volume of a semiconductor and in a
inversion layer near the SiO2/p-Si inter-face. Study of the impedance Z = R + iX andmagnetoimpedance allows separating the dynamic contributions determined by charge
and spin transport in different regions of the hybrid structure. The strongest effect of amagnetic field on R and X is caused by the presence of magnetic impurity centers inthe semiconductor near the SiO2/p-Si interface. Magnetoimpedance originates fromspin-dependent tunneling between a ferromagnetic electrode and magnetic impurity
centers via a potential barrier (SiO2). The magnetic impurity centers determine also
the change in photoconductivity in a magnetic field. The structure, as a matter of fact,
exhibits giant magnetoresistance induced by optical radiation. As a mechanism of
this effect, we consider the spin-dependent tunnel photocurrent, i. e., the current ofphotoexcited electrons, from p-Si to Fe via the SiO2 barrier.

Taeyueb Kim1, 2, Sungjung Joo1, Jinki Hong1*, Kungwon Rhie1, Hyuncheol Koo2*,
Jindong Song3, Joonyeon Chang 2, Sukhee Han 2, Kyungho Shin 2
1
Department of Applied Physics, Korea University, Chochiwon, Korea
2
Spin device research center, Korea Institute of Science and Technology, Seoul 136-791, Korea
3
Nano Photonics research center, Korea Institute of Science and Technology, Seoul 136-791, Korea

The controlled generation, manipulation and detection of spin-polarized currents in semiconductor
is an important issue in spintronic devices [1]. The Rashba spin-orbit interaction has been focused tomanipulate spin currents. Furthermore, the quantum point contact (QPC) having the Rashba interaction
was recently proposed as a spin-current generator. [2], [3] In this work QPCs were fabricated from InAs
quantum well. Gates were installed on the sides of the quantum well, and narrow conducting channels, i.e.
QPC, were formed by application of voltages on theses gates. Two QPCs were connected in series and the
distance between them was less than 1.6 micro-meter. An external magnetic field was applied in parallelwith the line connecting the two QPCs. Oscillations of resistance according to the magnetic field havebeen observed in this device at 1.8K. We believe that these data can be an evidence for our QPCs to work
as a spin polarizer with a following scenario; the first QPC works as a spin-polarizer, and the second does
as a detector. The spin-current produced by the first QPC precesses by the external magnetic field, whichmakes the oscillatory resistance as the magnetic field changes.

1. N.V. Volkov, A.S. Tarasov, E.V. Eremin, et al., J. Appl. Phys. 109, 123924 (2011).

[1] Mikio Eto, Tetsuya Hayashi and Yuji Kurotani, J. Phys. Soc. Jpn. 74, 7, 193(2005) [2] P. Debray, S. M. S.
Rahman, J. Wan, R. S. Newrock, M. Cahay, A. T. Ngo, S. E. Ulloa, S. T. Herbert, M. Muhammad and M. Johnson,
Nature Nanotech. 4, 759 (2009) [3] A. Reynoso, Gonzalo Usaj, and C. A. Balseiro , Phys. Rev. B. 75, 085321 (2007)

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First-principles calculations investigation of interfacial roles in spindependent transport properties in OMTJs

Negative magnetoresistance in ferromagnet/semiconductor/
ferromagnet structures with cubic dresselhaus spin-orbit-interaction

Charge imbalance with the same decaying length as spin accumulation

Gate dependence of spin-orbit interaction in a two-dimensional holegas structure

Shiheng Liang1, Dongping Liu1, Lingling Tao1, Hong Guo2 and Xiufeng Han1*
1
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics,
Chinese Academy of Sciences, China
2
Department of Physics and Center for the Physics of Materials, McGill University,
Montreal, Quebec, Canada
Organic spin valves and organic magnetic tunnel junctions (OMTJs) are new and promisingresearch fields and show advantages for spin-dependent transport due to relatively weak
spin-orbital coupling and hyperfine interaction. Long-chain alkanoic acids usually form
close-packed monolayer films with alkyl chains highly oriented on substrates. The
characterization of stearic acid adsorbed on Ni(111) surface has been studied. Our results
suggest that the stearic acid is chemically adsorbed on the Ni surface via a bidentate
interaction with a distance of about 1.8 A. We also investigated spin-dependent transportcharacterization through two kinds of organic magnetic tunneling junctions (OMTJs), as
Ni/1-stearic acid radical (1-SAR)/Ni and Ni/1,18-stearic diacid radical (1,18-SDR)/Ni. We
found magnetoresistance (MR) of Ni/1-SAR/Ni is -19.6%, and it is 13.7% for Ni/1,18SDR/Ni OMTJ. There is a magnetic proximity effect in the interface, and the magnetic
decay rate is dissimilar in different interfaces. Due to interaction at hybrid organic/magnetic
interface, the electronic properties of interfacial atoms are modified. These effects influence
the spin-dependent transport properties, and there appears positive or negative tunnelingmagnetoresistance (TMR) due to different interface. Our results suggest, the interface
between organic barrier and FM electrode play an important role in the transport behavior.

224

Muhammad Zahir Iqbal, Muhammad Waqas Iqbal and Jonghwa Eom*
Department of Physics & Graphene Research Institute, Sejong University, Korea

The 19th International Conference on Magnetism

Kenji Kondo*
Laboratory of Quantum Electronics, Research Institute for Electronic Science, Japan

We have investigated the spin transport in Ferromagnet (FM)/Semiconductor (SC)/
Ferromagnet (FM) structures with a central SC barrier exhibiting cubic Dresselhaus
spin-orbit-interaction (SOI). The energy profile of the barrier is assumed to be a squarewith height V and thickness d along z-direction. The magnetoresistance (MR) ratio has
been calculated for three different barriers, GaAs, GaSb, and GaAs without SOI as afunction of barrier thickness. Both ferromagnets are assumed to be Fe. Intriguingly,
MR ratios exhibit negative values for two different barriers in some range of thickness.
For GaAs, the MR ratio is negative when the thickness is larger than 0.03 nm. For
GaSb, the MR ratio is negative in the range of 0.02 to 0.9 nm, changing the sign
gradually from negative to positive at a thickness of about 0.9 nm. Afterwards, its value
increases monotonically and reaches a constant value at a thickness of 2.5 nm. We canattribute these phenomena to spin filtering effects caused by both the spin precession
and the energy-splitting in the central SC region. Without SOI, the MR ratio shows
positive value in all the range since the spin does not rotate in the barrier.

Yao-hui Zhu*
Physics Department, Beijing Technology and Business University, China

Starting from the Valet-Fert theory of the current-perpendicular-to-plane giant
magnetoresistance, we study the charge imbalance in ferromagnetic metals bysolving Poisson's equation. Our results show that, in ferromagnetic layers, the charge
imbalance has two exponential terms with different decaying lengths: the ThomasFermi screening length (on the order of angstrom) and the spin diffusion length (tensof nm in 3d ferromagnetic metals). The charge imbalance on the scale of the screening
length has been well studied and it is also present in spin-unpolarized transport innonmagnetic multilayers. However, the charge imbalance on the scale of the spin
diffusion length has never been studied before and it shows up only in ferromagnetic
layers with spin accumulation, which also decays on the scale of the spin diffusion
length. This charge imbalance is essential to the giant magnetoresistance effect andthus one should be cautious when using quasi-neutrality condition, which neglects the
charge imbalance.
[1] T. Valet and A. Fert, Phys. Rev. B 48, 7099 (1993). [2] Y.-H. Zhu, B. Hillebrands, and H. C.
Schneider, Phys. Rev. B 78, 054429 (2008). [3] S. Zhang, Phys. Rev. Lett. 83, 640 (1999).

July 10 (Tue)Jae Nyeong Kim and Ji-hoon Shim*chemistry, POSTECH, Korea

July 10 (Tue)poster Presentation

Youn Ho Park1, Hyun Cheol Koo1*, Sang-hoon Shin1, Jin Dong Song1, Hyung-jun
Kim1, Joonyeon Chang1, Suk Hee Han1 and Heon-jin Choi2
1
Spin Device Research Center, Korea Institute of Science and Technology, Korea
2
Department of Materials Science and Engineering, Yonsei University, Korea

In order to implement spin-Field Effect Transistor (spin-FET), gate control of spinorbit interaction parameter (α) is a key factor in a quantum well structure because spin
precession is influenced by strength of the α [1]. Many papers utilized n-type channel
for the spin transport, however, for the complementary logic device p-type channel
should be also necessary. We have investigated the spin-orbit interaction parameterand the effective mass using the Shubnikov-de Haas (SdH) oscillation measurement
in a GaSb two-dimensional hole gas (2DHG) structure. The α of 1.71 × 10^11eVm
and effective mass of 0.98m0 are obtained at T = 1.8 K, respectively. We also foundthe gate dependence of the α and the hole concentration at 1.8 K. As increasing thegate voltage both the α and the hole concentration are reduced, which indicates the α
increases with the carrier concentration in p-type channel. On the order hand, n-typechannel shows opposite gate dependence [1, 2]. Therefore, the combined device of pand n-type channel spin transistor would be a good candidate for the complimentary
logic device.
[1] H. C. Koo, J. H. Kwon, J. Eom, J. Chang, S. H. Han, and M. Johnson, Science, 325, 1515 (2009).
[2] J. Nitta, T. Akazaki, and H. Takayanagi, Phys. Rev. Lett. 78, 1335 (1997).

July 8-13, 2012 Busan, Korea

225

poster Presentation
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Perpendicular spin transport in ferromagnet/MgO/GaAs structures

Spin signal in metallic lateral spin valves made by a shadow
evaporation technique

Perfect spin filter and highly spin-polarized current induced by fanoantiresonance effect in the multiple-quantum-dot nanodevices

The Rashba-type Spin splitting in Pb monolayer on Si and Ge
surfaces: a First-principles study

Piotr Laczkowski, Laurent Vila, Williams Savero-torres, Van Dai Nguyen, Juan Carlos
Rojas-sanchez, Murat Cubukcu, Alain Marty, Lucien Notin, Cyrille Beigne and Jeanphilippe Attane
Universite Joseph Fourier, BP 53, 38041, Grenoble and INAC/ CEA Grenoble,
FranceHua-hua Fu1, Kai-lun Yao2* and Zu-li Liu2
1
Department of Physics, Huazhong University of Science and Technology, Wuhan
430074, China
2
Physics Department, Huazhong University of Science and Technology, Wuhan
430074, China

Amidst the large variety of proposed spin structures, Lateral Spin Valves (LSV) devices attracted
recently an increasing attention. These lateral devices consist in two ferromagnetic electrodesconnected by a non-magnetic metallic wire allowing to tune the transport properties according to therespective magnetic states of the two ferromagnetic electrodes. They allow realizing non-local transportmeasurements, by separating the spin current from the charge current using a four probe connections
to an interface. We are developing non-local spin injection and detection technique in lateral spin valve
structure made by electron beam lithography and angle evaporation techniques with a special emphasison the study of the spin Hall effect. The spin signal depends mainly on the geometry of the LSV, on thequality of the interfaces, and on the choice of the used materials. We present a method used to optimize
the spin signal of lateral spin valves using a technique to form and connect nanowires in a single stepin vacuum, avoiding interface contamination and oxidation. By using different evaporation angles ofmaterials through a resist mask and by reducing the devices geometry, we succeeded in obtaining spinsignals close to 25 mΩ at 77K in devices with transparent interfaces.

To realize perfect spin filter or to generate highly spin-polarized current is one of the fundamental
requirements of any applications on spintronics, and in what material or model structure to achieve thisgoal effectively is still one of the central issues in spintronics. To realize these aims, multiple-quantumdot system which can be man-made in a controllable way have been attracted much attention. In thisreport, we propose a practical design to realize perfect spin filter in a periodic diamondlike network
composed of multiple quantum dots (QDs). In our design, by producing an energy difference between
the site energy between the upper and down QDs in the network, the conductance spectra show
a valley structure with a zero point due to the Fano antiresonance effect. As the energy difference
increases or the network size increases to a not very large value, the antiresonance valley changes to awell-defined insulating band. Moreover, the conditions for the occurrence of the Fano antiresonanceand its relation with the formation of the well-defined insulating band are determined. By a Zeeman
effect, the spin-splitting conductance spectra show several highly to 100% spin-polarized windows,
strongly proposing that this network can be applied as a perfect spin filter.

P. Łaczkowski et al., Applied Physics Express, Volume 4, Issue 6, pp. 063007-063007-3 (2011)

1. H. H. Fu, K. L. Yao, Appl. Phys. Lett. 110, 013502, 2012. 2. H. H. Fu, K. L. Yao, J. Chem. Phys.
134, 054903 (2011). 3. H. H. Fu, K. L. Yao, J. Appl. Phys. 108, 084510 (2010); 110, 094502 (2011).

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Spin hall effect in 2DEG in the presence of Rashba spin-orbit
interation

Hanle effect with in-plane magnetic fields in metallic lateral spin valves

Transmission of spin polarized photoelectrons across ferromagnet/
semiconductor interfaces using oblique Hanle effect

Geometry effect on quasi-twodimensional electron system

July 10 (Tue)The electrical spin transport from TbFeCo/CoFeB into GaAs using MgO tunnel barrier
is investigated. The 20 nm thick TbFeCo layer produces perpendicular magnetizationand the 0.8 nm thick CoFeB layer, which contacts the MgO/GaAs layer, enhances thespin polarization of the injector. The MgO layer has a role of spin filter for efficient
spin injection. In order to reduce the contact resistance, the heavily doped GaAs
layer is inserted between TbFeCo/CoFeB/MgO and GaAs substrate. We measured
spin accumulation and spin lifetime using three-terminal Hanle measurements withtemperature range from 1.8 K to 300 K. In this geometry, the bias current is applied
from the top TbFeCo layer to the GaAs channel and the voltage is measured at theinterface. The perpendicular spin is injected so the in-plane magnetic field is swept toobserve the spin relaxation at the interface. For a bias current of 1.5 mA, the spin signalof 0.12 mV and 0.03 mV are obtained at T = 1.8 K and 300 K, respectively. From theanalysis of the Hanle curve, a spin life time of 0.4 ns is extracted at 300 K.

Won Young Choi, Hyung-jun Kim, Joonyeon Chang, Suk Hee Han and Hyun Cheol
Koo*
Korea Institute of science and technology, Korea
Spin Hall effect using an InAs-based 2DEG system with a strong Rasba effect isresearched. To make all electric devices, permalloy is used as spin injector on Hall
bar geometry. Two kinds of equivalent measurement, inverse and direct spin Hall, areperformed. Inverse and direct spin Hall are the conversion of spin to charge and charge
to spin, respectively. Also to confirm the effect of precession, dependences of channel
length and magnetization direction are systematically investigated. The bias current
between ferromagnet and neutral region of channel induces the injection of in-plane
spin. Inside the channel, spin precession occurs and then spin orientation is changed tothe perpendicular direction at the Hall cross. The spin signal as a function of channel
length shows oscillation behavior which is also evidence of spin precession. At 1.8K, aspin Hall voltage of 4 μV is detected for a bias current 0.1 mA and a channel length of
0.64 μm. From this experiment, we confirm the spin Hall effect and spin precession at
the same time.

Juan-carlos Rojas Sanchez, Laurent Vila, Matthieu Jamet, Piotr Laczkowski, Murat
Cubukcu, Williams Savero-torres, Van Dai Nguyen, Alain Marty, Cyrille Beigne andJean-philippe Attane
Universite Joseph Fourier, BP 53, 38041, Grenoble and INAC/ CEA Grenoble,
FranceWhen a charge current crosses the interface between a ferromagnetic (FM) and a nonmagnetic (NM) material, a spin current appears that occurs on the length scale of thespin diffusion. It is possible to detect this spin accumulation by measuring the voltage
between the NM wire and the other FM wire. We show that the spin signal amplitude
can be enhanced by inserting a natural Al oxide between the interface of Py and Al,
achieving spin signals above 150 mOhms at 77 K (instead of 24mOhms with transparent
contacts) and 38 mOhms at RT. When the magnetic field is applied perpendicularly to
the LSV plane, the injected spins in the normal channel precess around an axe parallelto H. The decoherence and/or the precession induced by the magnetic field can lead tooscillations and disappearance of the spin signal (Hanle effect). Hanle measurements
are usually performed by applying H perpendicular to the sample plane [1], the spin
precessing in plane. Here we show that it is possible to carry out Hanle measurements
by applying H in the sample plane, generating out-of-plane spin precession, and thus
gaining a degree of freedom for the control of the spin current.

Yasuhiro Shirahata1, Toshiyuki Isozaki1, Ippei Suzuki1, Eiji Wada1, Mitsuru Itoh1,
Masahito Yamaguchi2 and Tomoyasu Taniyama1
1
Materials and Structures Laboratory, Tokyo Institute of Technology, Japan2
Department of Electrical Engineering and Computer Science, Nagoya University,
Japan

Hyungjun Lee and Hyoung Joon Choi*
Department of Physics, Yonsei University, Korea

Rashba spin-orbit splitting of the surface states due to structural inversion asymmetry
is a rapidly growing field of research. Specifically, owing to a technological importancein spin-dependent electronics, spin-polarized metallic surface states on semiconductor
surfaces would be highly interesting. Along this line, we have performed first-principles
calculations of electronic structures of monolayer of heavy element deposited on
semiconductor surfaces, Pb/Si(111) and Ge(111)-√3×√3 surfaces, by including thespin-orbit coupling in the form of additional nonlocal pseudopotential projectors.
We investigate and compare energy band dispersions and spin polarizations of thesesystems and simulate angle-resolved photoemission spectra for direct comparison
with experimental results. We also discuss our results focusing on the difference fromthe Rashba splitting in the Shockley surface states on Au(111) surface. This work
was supported by the NRF of Korea (Grant No. 2011-0018306), and computational
resources have been provided by KISTI Supercomputing Center (Project No. KSC2011-C3-06).

Kuo-chin Chen, Hsin-han Lee and Ching-ray Chang*
National Taiwan University, Taiwan

We calculate the local charge density and local spin density in a deformed square latticesystem with Rashba spin orbital interaction. Use nonequilibrium Keldysh Green’s
function formalism, within the tight-binding framework. The system consists of normal
metal lead and deformed central part. We treat the deformed system as adding effective
magnetic field that introduces Zeeman effect. We also present the charge and spincurrent. The deformation we adopt is hemispherical shape and Gaussian shape. We willcompare the result with the case that deformation vanished.

[1] “Electrical detection of spin precession in a metallic mesoscopic spin valve” F.J. Jedema, H.B.
Heersche, A.T. Filip, J.J.A. Baselmans and J. van Wees, Nature 416, 713 (2002).

We demonstrate spin-dependent transmission of photoelectrons from a GaAs quantum
well (QW) into a ferromagnetic FeGa layer under optical spin orientation in a small
oblique magnetic field. The application of the oblique magnetic field enables us tomeasure the spin-dependent electron transmission across the interface due to the inplane spin component of photoelectrons caused by the Larmor precession of electron
spins about the magnetic field. A clear field dependence of the spin-dependent
photocurrent is observed for a 20-nm-thick FeGa/GaAs QW sample, showing thatthe filtering of in-plane polarized electron spins which are generated by the Larmor
precession occurs at the interface. To get concrete evidence for the spin filtering effect,
we measure the magnetic field dependence of the phase shift between the circularpolarization of light irradiated and the spin-dependent photocurrent. The phase shiftexhibits a hysteresis behavior as a function of magnetic field, in compatible with the inplane magnetization process of the FeGa layer. These results clearly demonstrate thata very efficient spin filtering effect occurs at the FeGa/GaAs interface even at a low
magnetic field, providing a promising basis for designing spin detection technology
based on spin filtering effect.

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Spin transport and spin injection into turbostratic graphene

Detecting the magnetization switching of a ferromagnetic dot using
non local spin injection by means of lateral spin valve structures

Electric field tunning and spin coulomb drag in spin field effecttransistors (spin-FETs)

Electrical measurement of spin accumulation and transport in Fe/
AlGaAs heterostructures[1] J. Wunderlich, B. G. Park, and A. C. Irvine et al, Science 330, 1801 (2010) [2] L. Sheng, D. N.
Sheng, and C. S. Ting, PRL 94, 016602 (2005) [3] H. C. Koo, J. H. Kwon, J. Eom, J. Chang, S. H.
Han, and M. Johnson, Science 325, 1515 (2009).

June Seo Kim1, Sebastian Schweitzer2, Ajit K Patra2, Yenny Hernandez3, Klaus
Muellen3, Xinliang Feng3 and Mathias Klaeui1*1Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz, Germany
2
Fachbereich Physik, Universitaet Konstanz, Germany
3
Max Planck Institute for Polymer Research, Germany
The remarkable physical properties of graphene, a monolayer of carbon atoms packed into a twodimensional hexagonal lattice, make it a promising material for applications, In particular, the highelectron mobility [1] and the relatively long spin lifetime (weak interaction of the electrons spinand orbital degree of freedom [2]) resulting in long spin diffusion lengths λ up to 2 μm [3], makeit an interesting candidate for spintronics. However, λ is currently limited by the strong interaction
between graphene and the underlying substrate and by the intrinsic corrugation of mechanicallyexfoliated graphene sheets. This can be overcome by using turbostratic graphene (TG), a multilayer
graphene stack consisting of tens of electronically decoupled layers. TG combines the exciting
properties of graphene with the higher robustness to environmental influences and the absence of
inner corrugations of a microstructured material [4]. In this study, we have successfully performed
spin injection from ferromagnetic electrodes into TG discs and detected the spin transport using a
non-local spin valve configuration [3]. Moreover we can also investigate the correlation between
the charge carrier transport properties and the spin injection efficiency.
[1] A. K. Geim et al., Nature Materials 6, 183 (2007), Science 324, 1530 (2009). [2] Hernando etal., Phys. Rev. B 74, 155426 (2006). [3] N. Tombros et al., Nature 448, 571 (2007). [4] M. Orlita etal., Phys. Rev. Lett. 101, 267601 (2008).

The 19th International Conference on Magnetism

Williams Savero-torres, Laurent Vila, Alain Marty, Piotr Laczkowski, Van Dai
Nguyen, Murat Cubukcu, Juan-carlos Rojas Sanchez, Lucien Notin and Jean-philippe
AttaneUniversite Joseph Fourier, BP 53, 38041, Grenoble and INAC/ CEA Grenoble,
FranceIn most researches on Spin Torque, the charge and spin currents cannot be separated. To solve
this problem, spin injection using lateral spin-valves, made of magnetic and non magnetic
materials, have been proposed [1]. In this context, we study the spin torque generated by purespin current on a ferromagnetic dot, using lateral spin-valve structures. The nanostructure
is composed of two parallel ferromagnetic electrodes, one transversal metallic channel, andone ferromagnetic dot at the middle of the structure. The width of wires and dots is 50 nm.
To detect the dot magnetization switching, non-local measurements are performed. The spinpolarised current is injected on one side using a ferromagnetic electrode. The spin accumulation
produces the splitting of the electrochemical potential, enabling the diffusion of the pure spincurrent along the channel. The pure-spin current is found to be adsorbed by the ferromagnetic
dot, decreasing the spin signal amplitude, which is detected using the second ferromagnetic
electrode. The non local geometry enables the spin current and the charge current separation,
giving the possibility to test the magnetization switching induced by a pure spin current.
[1] T. Yang, T. Kimura, and Y. Otani, Giant spin-accumulation signal and pure spin-current-induced
reversible magnetization switching, Nat. Phys. 4, 851 (2008).

George Alexandru Nemnes, Lucian Ion and Stefan Antohe
University of Bucharest, Faculty of Physics, Romania

The quasi-bound states which appear as a consequence of the Rashba spin-orbit (SO) coupling,
introduce a strongly irregular behavior of the spin-FET conductance at large Rashba parameter[1]. However, by introducing stray electric fields in addition to the SO couplings, the effectof the SO induced quasi-bound states can be tuned. The oscillations of the spin-resolved
conductance become smoother, resulting the possibility to control the spin-FET characteristics[2]. Besides these effects, the Coulomb interaction gives rise to new and interesting manybody phenomena. D'Amico et al. discussed recently the physical origin of spin Coulomb drageffect (SCD) in rather general three-, two- and one dimensional systems. Here, a step closer toa realistic device is made: the SCD effect will be investigated in a nanowire spin-FET structure
within the framework of self-consistent calculations for the open quantum system [3]. The spin
drag trans-resistivity as a measure for SCD effect will be obtained, in the context of adjusting
the spin injection efficiency from the contacts. In addition, the SCD effect in the presence ofRashba spin-orbit coupling will be analyzed. The Coulomb interaction will also be introduced
in an exact manner for a few electron system, using the exact diagonalization method [4].
[1] M. M. Gelabert et al., Phys. Rev. B 81, 165317 (2010). [2] G. A. Nemnes, A. Manolescu, V.
Gudmundsson, IOP - JPCS (to be published, 2012). [3] G. A. Nemnes, L. Ion, and S. Antohe, J.
Appl. Phys. 106, 113714 (2009). [4] C. Yannouleas and U. Landman, Rep. Prog. Phys. 70, 2067
(2007).

July 10 (Tue)Joohyung Bae1, Kyung-ho Kim1, Hyun Cheol Koo1*, Hyung-jun Kim1, Joonyeon
Chang1, Suk Hee Han1 and Sang Ho Lim2
1
Spin Device Research Center, Korea Institute of Science and Technology, Korea
2
Department of Materials Science and Engineering, Korea University, Korea

226

poster Presentation

Joon-il Kim1*, Jennifer Misuraca1, Kangkang Meng2, Jun Lu2, Lin Chen2, Jianhua
Zhao2, Stephan Von Molnar1 and Peng Xiong1
1
Physics, Department of Physics, Florida State University, Tallahassee, Florida, USA
2
Physics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China
Utilizing the persistent photoconductivity effect, we report on spin accumulation and transportin AlGaAs at different carrier densities under the same experimental conditions without thenecessity for making replicas to access different doping levels. We conducted non-local 3
and 4 terminal Hanle effect measurements in AlGaAs to measure spin accumulation andspin transport respectively at different carrier densities. We will present our recent results,
especially the carrier density dependence of the spin lifetime derived from our non-local spinmeasurements. We also report the bias current dependence of the spin lifetime. From opticalstudies, the spin life-time at zero bias and at low temperature was reported to be larger than 100
ns in n-GaAs on the insulating side and ~80 ns on the metallic side [1]. Based on our non-local
3 terminal measurement in Si:Al0.3Ga0.3As, the extrapolated spin life-time at zero bias and at 5
K was found to be as large as ~2 ns on the insulating side and decreased with increasing bias
current. This work was supported by NSF DMR-0908625 and NSFC 10920101071.
[1] M. Furis, D.L. Smith, and S.A. Crooker and J.L. Reno, Appl. Phys. Lett. 89, 102102 (2006).

July 8-13, 2012 Busan, Korea

227

poster Presentation
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Pure spin current injection into a Gd wire

The magnetic and dielectric properties of multiferroic Bi1-xGdxFeO3Magnetism and electronic transport of MnAs single nanostructures

Magnetic properties of hydrothermally synthesized ZnOnanostructures

July 10 (Tue)In magnetocaloric effects, the spin entropy is transformed to the thermal entropy
because of an interaction between spin and heat. Since the spin entropy can becontrolled by the external magnetic field, the environment temperature also canbe tuned by the external magnetic field. Although such methods can be operated
efficiently, it is difficult to reduce the size of the entire system. An effective magnetic
field can be produced also by injecting spin currents via the interaction between the
conduction electrons and localized magnetic moments. Therefore, when a pure spincurrent is injected into the magnetocaloric material, we may control the spin entropy
because of the spin transfer torque and/or spin accumulation. Such a cooling effect has
a possibility for a highly efficient nanosized refrigeration device. To demonstrate thiseffect, we prepared a lateral spin valve with the Gd middle wire, which is a magnetocaloric material. We observed the reduction of nonlocal spin signal by inserting the
middle Gd wire, meaning the pure spin current was injected into the Gd wire. We
also found that the background resistance decreases with increasing DC current. Thisimplies that the device was cooled by the pure spin current injection into the Gd wire.

Takuya Yanoh*, Naoki Sakai, Liming Zhu, Akinobu Kurokawa, Hiromasa Takeuchi,
Shinya Yano, Kazuki Onuma, Takaya Kondo, Kazunari Miike, Toshiki Miyasaka andYuko Ichiyanagi
Physics, Yokohama National University, Japan
BiFeO3 is known as multiferroic material with antiferromagnetic and ferroelectric
properties. Especially, ferroelectricity at room temperature is remarkable and BiFeO3 is
expected for new device materials. However, BiFeO3 has antiferromagnetic ordering,as the result, magnetic values such as remanent magnetization Mr and coercive force
HC are rather small for further application. In this study, in order to improve magnetic
property and to evaluate dielectric property, we tried to synthesize Bi1-xGdxFeO3particles where x = 0 to 1.0 by our original wet chemical method. The structural,magnetic and dielectric properties of prepared samples were investigated. Crystal
structure change from rhombohedral to orthorhombic was found around x = 0.2 fromthe X-ray diffraction (XRD) measurement. Lattice constants a and c estimated by XRD
decreased as Gd ion increased, supporting that Gd ions were doped exactly in BiFeO3.
The magnetic properties of Bi0.9Gd0.1FeO3 which has rhombohedral (BiFeO3 type)structure exhibited canted antiferromagnetism at 5 K. Both remanent magnetization
Mr and coercive force HC significantly increased as Gd ion increased compared with
BiFeO3. The dielectric properties of Bi0.9Gd0.1FeO3 showed that dielectric loss (tanδ)has been drastically improved compared with that of BiFeO3 for about 90%, while realdielectric constant ε’ decreased about 15%.

Federico Fernandez Baldis1, Marina Tortarolo2, Martin Sirena1, Laura Steren3, Victor
Etgens2 and Mahmoud Eddrief2
1
Centro Atomico Bariloche, Argentina
2Institut des NanoSciences de Paris, France
3
Centro Atomico Constituyentes, Argentina
The magneto-structural properties of MnAs thin films grown onto GaAs have recently
drawn much attention due to its potential application in spintronics devices. The MnAs
thin films exhibit a coexistence of a low-temperature ferromagnetic hexagonal phase (α)
and a paramagnetic orthorhombic (β) one in a finite temperature range below the Curie
temperature. When MnAs is grown onto GaAs[100], both phases are self-organized in a
regular stripes array. This pattern is affected when the MnAs films are confined laterally
to micrometric sizes and depends on the direction of the confinement. In this work,
we present an investigation of the temperature dependence of the magnetic domain
structure and magneto-transport properties of MnAs nanoribbons in order to determine
the anisotropic response of the system, regarding both the magnetism and electronictransport. The confinement effects were examined at the low-temperature pure
ferromagnetic phase and at the α-β phase-coexistence regime. Nanoribbons confinedalong the (I) α-MnAs[1120] and (II) α-MnAs[0001] directions were fabricated bye-beam lithography combined with optical lithography. The magnetic domain imaging
was performed with a MFM, home-adapted for variable temperature measurements
between 284K and 320K. The magneto-resistance and Hall effect measurements weremade between 50K and 320K using a 9 Tesla superconducting magnet.

H Hadiyawarman, Kadek J. Parwanta, Bowha Lee and Chunli Liu*
Department of Physics, Hankuk University of Foreign Studies, Korea

We report the study on the ferromagnetism in ZnO nanostructures fabricated byhydrothermal method at low temperature and with three different pH values. No posttreatment was applied to all samples. X-ray diffraction shows that the samples possess
typical wurtzite structure and have no other impurity phases. Magnetization properties
of ZnO samples were measured. With the defect analysis based on low temperature
photoluminescence spectroscopy, the effective defects contributed to the magnetic
properties were investigated. The result suggests that oxygen defects and synthesis
conditions play an important role in mediating the magnetic property in the undopped
ZnO nanostructures.

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QL10

Synthesis and characterization of Ba3Co2Fe24O41 by the proteic sol-gel
process

Double-exchange interaction in heavily Mn-doped CuO thin films

The generated antiferromagnetic and ferromagnetic states innanocrystalline Cu-Cu 2O system and the consequences for spinchemistry

Electrical, magnetic and magnetoimpedance studies of LSMO thinfilm prepared by sol gel method

Bruna Andrade, Petrucio Silva and Marcelo Macedo*
Physics, Federal University of Sergipe, Brazil

In this work, we show the production of hexagonal Z-type barium ferrite (Ba3Co2Fe24O41) prepared via the proteic sol-gel process as well as their structuralcharacterization and magnetic properties. The precursor materials were iron nitrate,
cobalt nitrate and barium carbonate which formed a sol after being stoichiometricallydissolved in coconut water. We carried out a heat treatment at 100°C/24 h for theformation of an amorphous xerogel and a calcination at 1000°C/1 h for phase formationof Z-type barium ferrite. The material exhibited a magnetization curve as a function oftemperature characteristic of ferrimagnetic material with Tc > 300 K and a hysteresis
at room temperature with low coercive field (142 Oe) and saturation magnetization
around 48 emu/g for a field of 7 T. Our results indicate that the proteic sol-gel process
may be a route of great potential for obtaining Z-type ferrites.

Li Li, Bin Lv, Shen Wang, Jinzhu Cai, Wenqin Zou, Fengming Zhang* and Xiaoshan
Wu
Physics, Nanjing University, China
RKKY exchange, double-exchange interactions are two main mechanisms which areproposed to explain the origin of ferromagnetism of Mn-doped CuO films. Consider
that double-exchange interactions cannot produce long-range magnetic order atconcentrations of magnetic cations of low percent, Heavily Mn-doped CuO films havebeen prepared by PEVCD in air and in O2. The M-T and M-H curves show that the
average magnetic moment of the films prepared in O2 is larger than those preparedin air, which may attribute to the variation of Mn chemical valence state. Doubleexchange between Mn2+ and Mn3+ can be used to understand the ferromagnetism ofCuO under heavily Mn-doping.. The Curie temperature varies slightly with the growth
atmosphere. The structure and magnetic properties vary with the annealing parameters
obviously, which may indicate that the strain and carriers may play roles on the double
exchange.

Anatoly Yermakov1*, Michael Uimin1, Alexandre Korolyov1, Ilya Byzov1, Alexey
Mysik1, Vladislav Maikov1 and Mamoru Senna2
1
Institute of Metal Physics, Ural Branch of RAS, Russia
2
Faculty of Science and Technology, Keio University, Japan

Under investigations of nanocrystalline Cu-Cu2O oxides it has been established that they
actually possess heterogeneous magnetic states in nanoscale range. In nano-structured Cu-Cu2O
oxides, ferromagnetic (FE) and anti-ferromagnetic (AF) states are coexisting at above room
temperature. The new idea based on the magnetic phase transformation from AF to FE stateat an external field was suggested as a hypothesis to understand the variation of chemical ratetransformations. The point is that a metamagnetic phase transition is accompanied by a variationof an electronic state of carrier from localized to delocalized one which can result in a variationof nanoreagents reactivity. In fact, the influence of magnetic field on the rate of chemicaltransformations, e.g. Cu ammonium complex formation using Cu-Cu2O nanomaterials, as
magneto-controlled reagents, has been reliably observed. Thus, the nanocrystalline copperoxides having a liquid-like potential are a remarkable example of energy-wise degenerated
different magnetic states that can be operated by fairly weak external magnetic fields to control
a rate of chemical transformations and other properties. We think the principle we here propose
could be extended to other transition metal oxide nanoparticles with a similar electronic states.
Thanks to RFBR Grants # 10-02-00323 and # 10-02-546 for support.

Pawan Kumar and Ramanathan MahendiranPhysics, NUS, Singapore

In this work, we have prepared La0.7Sr0.3MnO3 by sol-gel method using Si (100)substrate and characterized the sample by XRD,dc magnetization, dc magnetoresistance,
and atomic force microscopy. The sample is found to be ferromagnetic below 367 K
from the magnetic measurement. Impedance spectroscopy study has been reported
on the thin film for the first time. We have studied the ac electrical impedance (Z) in
LSMO thin film as function of Temperature (T) and magnetic field in response to radio
frequency (f=0.1-5MHz) ac current flowing directly through the sample. DC resistivity
and Z (T) shows transition around 365K which is correspond to Tc of LSMO thin film.
In Z (T) peaks around Tc decreases in magnitude with applied field (1KOe), which
is not affected much in DC resistivity. Magnetoimpedance ΔZ/Z= -30% is observedin MHz frequency range. It is suggested that observed magnetoimpedance resultsfrom suppression of the high frequency transverse permeability by an external field.
Our study suggests that magnetoimpedance in manganite thin films might find new
application in radio frequency regime.
References: (1). Gang Zou , Xian You, Pingsheng He, Materials Letters 62 (2008) 1785-1788.

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Ferromagnetism in vanadium doped ZnO thin films grown by pulsed
laser deposition

Magnetic properties of Cu-doped GaN films grown by MBE

Unidirectional anisotropy observed in Fe film grown on GaAs at low
temperature

Differential conductance measurements in Ni nanoscale contact
fabricated by electromigration

Shumaila Karamat1*, Rajdeep Singh Rawat2, Paul Lee3, Tan Lee Augustine4, Raju V
Ramanujan5 and H.d Sun6
1
Physics, 1. NIE, Nanyang Technological University, Singapore 2. COMSATS,Islamabad, Pakistan
2
Physics, National Institute of Education, Nanyang Technological University, Singapore
3
Physics, NIE-NTU, Singapore
4
Physics, NIE-NTU Singapore
5
Material Science, MSE-NTU Singapore
6
SPMS, SPMS-NTU, Singapore
This paper investigates the structural, compositional and magnetic properties of vanadium doped ZnO films((ZnO)1-x(V2O5)x where x = 0.02, 0.03 and 0.05) deposited by pulsed laser technique (PLD). Thin films were
deposited for a constant duration of 1 hr at 2×10-2 mbar O2 ambient gas pressure by using frequency doubled
Nd:YAG laser at 750 °C substrate temperature. The preferred orientation in thin films is along the (002) plane of
ZnO. The lattice parameter c derived from the (002) diffraction peak increases as vanadium content increases,suggesting that vanadium substitutes for Zn in ZnO lattice. The PL measurement at low temperature showsthe emission peak at 3.30 eV which is usually caused by acceptor-related transitions such as free electron toneutral acceptor (FA) and donor-acceptor-pair (DAP). The XPS results show that vanadium exist in V2+ andV4+ valence state which is in agreement with the XRD and PL results and points to the fact that the ZnVO
phase, desirable in DMS, is formed in thin film samples. Furthermore, the hysteresis curves exhibiting theferromagnetism for all thin films samples further support the formation of ZnVO phase in thin films samples.

The 19th International Conference on Magnetism

Philipp R. Ganz1, Christoph Suergers2*, Gerda Fischer3 and Daniel M. Schaadt4
1
Institut fur Angewandte Physik and DFG-Center for Functional Nanostructures,
Karlsruhe Institute of Technology (KIT), Germany
2
Physikalisches Institut and DFG Center for Functional Nanostructures, Karlsruhe
Institute of Technology (KIT), Germany
3
Physikalisches Institut, Karlsruhe Institute of Technology (KIT), Germany
4
Institute for Energy Research and Physical Technologies, Clausthal University ofTechnology, Germany
The magnetic properties of Cu-doped GaN films have been investigated in dependenceof Cu doping level and film thickness. The films were epitaxially grown at different Cuto-Ga beam-equivalent-pressure ratios (BEPR) by molecular beam epitaxy on sapphire
substrates with an AlN buffer and were characterized by scanning electron microscopy,
energy dispersive x-ray spectroscopy, and x-ray diffraction. Within a narrow range of
BEPR around 1 %, a ferromagnetic behavior with a Curie temperature higher than 400
K is observed. For BEPR > 1 %, nonferromagnetic Cu-Ga islands are predominantly
formed at the surface. The saturation magnetization of ferromagnetic films with BEPR
= 1 % decreases with increasing film thickness. This suggests that the ferromagnetic
behavior is due to defects created during the growth process and by the incorporationof Cu into GaN for BEPR ≤ 1 % leading to a long-range magnetic polarization.

Seonghoon Choi1, Taehee Yoo1, S. Khym1, Sanghoon Lee1*, X. Liu2 and J. K.
Furdyna2
1
Physics Department, Korea University, Korea
2
Physics Department, University of Notre Dame, USA
The magnetic anisotropy properties of Fe films have been investigated by planar
Hall effect (PHE) measurements. A 4 nm thick Fe film was grown on a (001) GaAs
substrate by MBE technique at room temperature. The field scans of the planar Hall
resistance (PHR) at room temperature show an abrupt transition with hysteresis
centered at zero field during the magnetization reversal, indicating the presence ofsymmetric magnetic easy axes in the film plane. However, the hysteresis in the PHR
appeared to be shifted toward one field direction when the temperature decreased to 3
K. This asymmetry in the magnetization reversal process at 3 K can be understood byintroducing an unidirectional anisotropy field Hud. Interestingly, the direction of the Huddirectly follows the direction of the cooling field. This indicates that the direction of the
Hud is not fixed but can be changed by the cooling field. For the case of the cooling fieldalong the [-1-10] direction, we obtained the values of cubic, uniaxial and unidirectional
anisotropy fields by analyzing angular dependence of PHR. The magnitude of Hudwas one order of magnitude smaller than other anisotropy fields although it caused asignificant asymmetry in the PHR hysteresis.

July 10 (Tue)

Seiji Nonoguchi, Tatsuya Nomura and Takashi Kimura*
Kyushu University, Japan228

poster Presentation

Junya Sakai1*, Koichiro Ienaga1, Yuji Inagaki1, Hiroyuki Tsujii2, Ryuya Nomura3,
Seiji Nonoguchi3, Takashi Kimura4 and Tatsuya Kawae5
1
Department of Applied Quantum Physics, kyushu university, Japan
2
Faculty of Education, Kanazawa university, Japan
3
INAMORI Frontier Research Center, Kyushu University, Japan
4
INAMORI Frontier Research Center, Kyushu University, Japan
5
Department of Applied Quantum Physics, Kyushu University, JapanA zero-bias anomaly in differential conductance has been reported in atomic-size
contacts fabricated from the ferromagnets, Fe, Co and Ni, which is considered to comefrom the Kondo effect [1]. This is interesting because the Kondo effect usually requires
two species of atom and is thought to be incompatible with ferromagnetic interaction.
In order to clarify the origin of Kondo effect in atomic ferromagnetic contact, we havestudied the size dependence of the zero-bais anomaly in Ni nanoscale contacts bymechanical controllable break junction technique and observe the anomaly in a large
size where the ferromagnetism appears[2]. In this presentation, we study differential
conductance in Ni nanoscale contacts with decreasing the size by electromigration.
In large size contacts, zero-bias anomaly is not observed. When the conductance issmaller than 200G0 (G0=2e2/h), the anomaly is clearly observed.
[1]M. Reyes-Calvo et al., Nature 458, 1150 (2009) [2]K. Ienaga et al., to be published.

July 8-13, 2012 Busan, Korea

229

poster Presentation

poster Presentation

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Magnetoresistance measurements in Pd atomic-scale contact at 4.2K

Bias-voltage dependence of magnetotransport properties in codeposited Co-C granular thin films

Magnetic control of the hydrogen storage of hydrogen-injected ZnCoO

Room temperature ferromagnetism in Zn1-xNixS diluted magnetic
semiconducting nanocrystalline thin films

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Jun-goo Kang1*, Masaki Mizuguchi1, Shiro Entani2, Seiji Sakai2 and Koki Takanashi1
1
Institute for Materials Research, Tohoku University, Japan
2
Advanced Science Research Center, Japan Atomic Energy Agency, Japan

Granular systems consisting of ferromagnetic nanoparticles dispersed in a nonmagnetic
matrix exhibit giant magnetoresistance (MR) due to spin dependent transport. Carbon-based
nanocomposite thin films have large application potential as spin transport materials because
long spin relaxation time is expected due to its weak spin-orbit interaction [1]. We have foundthat co-deposited Co-C films exhibit a large negative magnetoresistance (MR: 27.6% at 2 K)
[2]. It is expected that the bias voltage dependence of MR includes significant information on
the mechanism of the MR. In this study, the bias-voltage dependence of magneto-transport
properties for Co-C granular thin films has been investigated. Co-C granular thin films were
fabricated by a co-sputtering technique. The current (I)- bias-voltage (V) characteristics and the
MR behavior of the Co-C films were measured at temperatures of 2-30 K in a two-terminal
geometry with the electrical current and magnetic fields (up to 70 kOe) in the in-plane direction.
It was found that the magnitude of the MR ratio changed remarkably with bias voltage. A clear
increase in the MR ratio with bias voltage was observed, and it reached 66.6 % for V= 25 V.

July 10 (Tue)[1] S. Sakai, K. Yakushiji, S. Mitani, K. Takanashi, H. Naramoto, P. V. Avramov, K. Narumi, V.
Lavrentiev, and Y. Maeda, Appl. Phys. Lett. 89, 113118 (2006). [2] R. Tang, M. Mizuguchi, H. Wang,
R. Yu, and K. Takanashi, IEEE Trans. Magn. 46, 2144 (2010).

Many researchers have tried to apply ZnO for hydrogen storage through additional doping and nanostructure
which increase hydrogen capability[1]. It has been regarded for Zn-O bond center and oxygen vacancy
as practicable position for hydrogen storage. Co-Co dimer in ZnCoO has been suggested as appropriate
position for its reversibility, and hydrogen placed in Co-Co dimer mediates ferromagnetic spin ordering by
Co-H-Co complex[2,3]. In our recent research, we have reported the correlation between hydrogen content
and ferromagnetism in Co doped ZnO (ZnCoO) and suggested that ZnCoO can be exploited for hydrogenstorage and the tools for the measurement of hydrogen[4]. In this study, ZnCoO powder was fabricated bysol-gel method and annealing process was performed at 300 °C and subsequently 800 °C for removing
organic compound. Pt was coated on ZnCoO powder as hydrogen catalyst. The hydrogen absorption andchange in structure are characterized by the press composition and temperature (PCT) system and neutron
diffraction, in-situ. We investigate the correlation between hydrogen contents and magnetism in ZnCoO anddiscuss its applicability for hydrogen storage. We also show the hydrogen contents in ZnCoO depending on
the Pt layer and the spillover effect between Pt layer and ZnCoO nanocrystal.
[1] Q. Wan et al., Appl. Phys. Lett. 84, 124 (2004). [2] S. Lee et al., Appl. Phys. Lett. 94, 212507(2009). [3] Y. C. Cho et al., Appl. Phys. Lett. 95, 172514 (2009). [4] S. Lee et al., J. Appl. Phys. (inpress, 2012).

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Differential conductance measurements in Cu-Mn atomic-scale
contacts

Switchable voltage control of the magnetic anisotropy inheterostructured nanocomposites of CoFe/NiFe/PZT

Ferromagnetism in Co-doped TiO2 films probed by low-energy muon
spin rotation

Koichiro Ienaga1, Naoya Nakashima1, Yuji Inagaki1, Hiroyuki Tsujii2 and Tatsuya
Kawae1*
1 Dapartment of Applied Quantum Physics, Kyushu University, Japan
2 Faculty of Education, Kanazawa University, Japan

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Thang D. Pham1*, Hong T. M. Nguyen2, Dong H. Kim3, Tiep H. Nguyen2 and Cuong V.
Le2
1
Faculty of Engineering Physics and Nanotechnology, University of Engineering andTechnology, Vietnam National University, Hanoi, Viet Nam
2
Laboratory for Micro and Nanotechnology, University of Engineering andTechnology, Vietnam National University, Hanoi, Viet Nam
3
Department of Physics, Chungbuk National University, Korea
Heterostructures of nanostructured ferromagnetic (FM) and ferroelectric (FE) layers areof increasing interest due to the coupling between the magnetic moment and electric
polarizations. In particular electric voltage, rather than the conventional magnetic field, canbe directly used to control the magnetic properties of the magnetic layers. This magneticelectric coupling may open promising applications towards novel spin electronic devices
with low power consumption and high-speed data access. In this article, we study on the
crystallographic structure and magnetic properties of CoFe/NiFe/PZT heterostructures. In
these nanocomposites, the magnetic behaviors, such as magnetization significantly changes
in the presence of an applied voltage. The change also depends on the FM layer thickness,the magnetic field direction and it can reaches up to more than 100%. Furthermore weobserved the switching in magnetization at suitable applied voltage. Besides, we presenta phenomenological approach to investigate stress-induced magnetic anisotropy, which
originated from magnetoelectric coupling between two FM and FE phases.

Hassan Saadaoui1*, Jiabao Yi2, Zaher Salman1, Thomas Prokscha1 and Elvezio
Morenzoni1
1
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, 5232 Villigen PSI,
Switzerland
2
School of Materials Science and Engineering, University of New South Wales,
Kensington, NSW, 2052, Australia

M A El-hagary1*, Soltan Soltan2, M Emam-ismail1 and S Althoyaib1
1
Physics Department, Qassim University, Saudi Arabia
2
Physics Department, Helwan University, Helwan, Cairo, Egypt

We have investigated the magnetic properties of Ni doped Zn1-xNixS diluted magnetic
semiconducting nanocrystalline thin films for different doping concentrations (0.005≤ x ≤ 0.2) synthesized by electron beam evaporation technique. X-ray diffraction
patterns confirm the existence of single phase nature in all the Ni doped Zn1-xNixS
samples with cubic zinc blend type structure. Evidence of nanocrystalline nature of
the films was observed from the investigation of surface morphology using scanningelectron microscopy and atomic force microscopy. Magnetic domains were observedby using magnetic force microscopy at room temperature indicating the existenceof ferromagnetism over the film surface. The temperature and field dependent
magnetization measurements by using superconducting quantum interface device
showed ferromagnetic behavior between room and low temperatures (5 K) with a Tc
at or above room temperature for the nanostructure samples with 0.1 ≤ x ≤ 0.2. The
saturation magnetization for Zn1-xNixS system is found to increase with the dopant
concentration (x). The exchange interaction between local spin polarized electrons (Niions) and conductive electrons according to RKKY mechanism, rather than from theNi oxide impurities, is proposed to be the possible mechanism for ferromagnetism.

QM01
Extraordinary hall measurements of Co/Ni multilayers

Chih-yung Chen1, James C Eckert1, Natalia Fear1, Sheena K. K. Patel1, Richard
Sayanagi1, Patricia D Sparks1, E Shipton2 and Eric E Fullerton2
1
Physics, Harvey Mudd College, USA
2
University of California, San Diego, USA

Ferromagnetic semiconductors have been widely studied recently for potential
applications in spintronics. In this experiment, we probe the magnetism in Co-doped
TiO2 ferromagnetic semiconducting films using Low-energy muon spin rotation (LEμSR). This technique is very powerful to probe the magnetic properties of thin films
and interfaces on a nanometer length scale. We investigated Co-doped (5%) TiO2-δ
films grown in different oxygen pressures. We find the internal magnetism in thesefilms to be strongly dependent on the oxygen pressure during growth. The oxygen
vacancies, modified by pressure, act as electron donors and alter the electron density.
As the pressure increases, the magnetic volume fraction is strongly reduced. In thiswork, we present the temperature, magnetic field and depth dependence of the internal
magnetism, and discuss its origin.

Interest in Co/Ni multilayers is driven by their unusual magnetic properties. They
exhibit perpendicular magnetic anisotropy, relatively low magnetic damping andunusual magneto-transport characteristics making them well suited for spintronic
devices. To understand their magnetic and magneto-transport properties we measured
the temperature dependence of the Hall effect for a series of sputtered Ni/Co films:
SiO2/Ta(40A)/Pd(40A)/[Co(2A)/Ni(Y)]x10/Ta(40A)), with Ni thicknesses from Y=214 A. Because the signs, and the temperature dependence, of the extraordinary Hall
effects (EHE) differ for Co and Ni, the behavior for the multilayers is complex. At
room temperature the sign of the EHE changes as the Ni thickness increases from 4 to
5A. For Y=4A, the sign of the EHE is temperature dependent, going to zero near 220K
and changing sign for lower temperatures. The magnitude of the EHE increases withincreasing temperature for Y<5A, decreases for Y=5 and 6A and then increases for
Y>6A. We used the EHE to measure the magnetization properties finding a decreasein the coercive field for increasing Y. For Y<4A, a complicated EHE response does
not reflect the average magnetization. We discuss this research in term of competing
EHE properties of Co and Ni. Work at UCSD supported by DOE-BES Award # DESC0003678.

QL14

QL17

QL20

QM02

Tuning the magnetic interaction in carbon nanotube/NiO
nanocomposite system

Origin of the ferromagnetism in scandium-doped ZnO thin films

Structural and magnetic changes induced by high energy ball millingof CdFe2O4 oxide

Magnetic Spin Structure of Fe50Pt50-xRhx Films

S Chattopadhyay, S Giri and S Majumdar*
Department of Solid State Physics, Indian Association for the Cultivation of Science,
India
We have prepared a series of nanocomposite materials with multi-walled CNTs andNiO nanoparticles by varying the concentration of nickel nitrate solution. Transmission
electron microscopy shows that the average size of the nanoparticles is about 10 nm
and they are predominantly embedded either on the inner or the outer wall of themulti-walled CNTs forming a quasi one dimensional arrangement. It is also observedthat the particles are well separated and density of the product NiO nanoparticles
increases systematically with increasing concentration of the nickel nitratesolution. DC magnetization measurement shows the presence of thermomagnetic
irreversibility in the temperature variation of the magnetization data. In contrary to theantiferromagnetic bulk NiO, field dependence of magnetization reveals the presenceof strong ferromagnetic interaction along with prominent exchange bias effect. Thesematerials also show magnetization relaxation which is an indication of non-ergodicity
in the magnetic ground state. This system provides a rare opportunity to externallyfabricate the degree of isolation among the particles and to tune the interparticle
magnetic interactions as well for performing a systematic investigation on the evolutionof the magnetic ground state with the variation of the interaction strength.

230

Bum-su Kim1, Seunghun Lee1 Jong Moon Shin2, Yong-chan Cho1, Yong Nam Choi3,
Hee-ju Lee3, Chae Ryong Cho2, Hideomi Koinuma1 and Se-young Jeong1*
1
Cogno-Mechatronics Engineering, Pusan National University, Korea
2
Nano fusion technology, Pusan National University, Korea
3
Korea Atomic Energy Research Institute, Korea

The 19th International Conference on Magnetism

Mohammed Benali Kanoun*, Souraya Goumri-said, Udo Schwingenschlogl andAurelien Manchon
1
King Abdullah University of Science and Technology(KAUST), Saudi Arabia
In recent years, there have been more startling discoveries in diluted magnetic semiconductors [1]achieving possible room-temperature ferromagnetism in undoped (ZnO [2]) and non-transition metaldoped (ZnO:C [3]) systems. ZnO--based materials serve as model systems for the dilute magnetic
oxides and are among the most intensely studied systems so far [4]. Interestingly, Venkatesan et al [5]have shown that room temperature ferromagnetism is observed in Sc-doped ZnO films. We note thatin the bulk phase Sc has different crystal structures and nonmagnetic properties. How different are theirmagnetic properties when doped in ZnO thin films? Why do experimental results differ so much? Toanswer these questions, we have carried out comprehensive first-principles theoretical investigationsof energetics, electronic structure, and magnetic properties of Sc-doped ZnO (11-20) thin films. In thiswork, the ZnO thin film was modeled by a (1×2) seven-layer slab supercell having a wurtzite structure
along the [11-20] surface orientation. Each slab was separated from the other by a vacuum region of 10
A along the [11-20] direction. Even though Sc is not magnetic in its natural phase, we found that it islikely to order ferromagnetically in ZnO thin film, in agreement with experiment [5].
[1] T. Dietl et al., Science 287, 1019 (2000). [2] Q. Xu et al., Appl. Phys. Lett. 92, 082508 (2008).
[3] C. Liu et al., J. Mater. Sci. 16, 555 (2005). [4] Q. Ma, D. B. Buchholz, and R. P. H. Chang, Phys.
Rev. B 78, 214429 (2008). [5] M. Venkatesan, C. B. Fitzgerald, J. G. Lunney, and J. M. D. Coey,
Phys. Rev. Lett. 93, 177206 (2004).

Justice Msomi and Ta Nhlapo
School of Chemistry and Physics, University of KwaZulu-Natal, South Africa

Bulk CdFe2O4 ferrite nanoparticles have been synthesized by solid state reaction.
The fine powders of CdFe2O4 oxide were produced by high energy ball milling. The
structural and magnetic changes induced by high energy ball milling are investigated.
The oxides have been characterised by XRD, Mossbauer spectroscopy and VSM
measurements. A general decrease in lattice constant with increasing milling time isobserved. The Mossbauer spectra indicate paramagnetic spin state in all the samples.
Magnetization increases with reduction in particle size. This can be explained by theredistribution of Cd ions in both tetrahedral (A) and octahedral (B) sites. The coercive
field of the milled CdFe2O4 oxide are highly sensitive to temperature compared to thatof the bulk compound. An increase in coercive field for 50 hours milled oxide fromabout 9 Oe at 300 K to 520 Oe at 10 K has been observed. A smaller increase from
9 Oe at 300 K to 200 Oe at 10 K occurs in the coercive field of the bulk oxide. The
variation of magnetization as a function of measuring temperature is also presented.
An anomalous variation of field cooled magnetization as a function of temperature has
been observed.

July 10 (Tue)Koichiro Ienaga1*, Naoya Nakashima1, Yuji Inagaki1, Hiroyuki Tsujii2 and Tatsuya
Kawae1
1
Department of Applied Quantum Physics, Kyushu University, Japan
2
Faculty of Education, Kanazawa University, Japan

Jochen Fenske1, Dieter Lott1, Gary J. Mankey2, Wolfgang Schmidt3, Karin Schmalzl3,
Elena V. Tartakovskaya4 and Andreas Schreyer11Helmholtz-Zentrum Geesthacht, Germany
2
MINT Center, University of Alabama, USA
3
Juelich Centre for Neutron Science, Germany
4
Institute for Magnetism, National Ukrainian Academy of Science, Ukraine
Ordered FePt alloys with L10 structure are known as materials with FM order anda high magnetic moment of Fe providing a large magnetization. The large atomic
number of Pt on the other hand results in a high magnetic anisotropy. If grown in thinfilms, the high anisotropy often results in perpendicular magnetization which is thepreferred orientation for current magnetic recording media. One way to control themagnetic properties in these materials is through the introduction of a third element
into the crystal matrix e.g. Rh. When Rh is added to replace Pt in the equiatomic alloy,
new magnetic phases emerge. Bulk samples of Fe50Pt50-xRhx studied by magnetization
measurements refer to an AF-FM transition with decreasing Rh content. An additionaltemperature driven AF-FM transition was observed in the Fe50Pt40Rh10 film. It is also
well known that the magnetic properties of a thin film can differ drastically from thebulk behavior due to dimensionality effects. Here we present neutron diffraction studies
on the magnetic properties of different 200nm thick Fe50Pt50-xRhx films in dependenceof temperature and external magnetic fields. The polarized and unpolarized neutron
diffraction data allowed us to develop a detailed model of the magnetic structure of thefilms.

July 8-13, 2012 Busan, Korea

231

poster Presentation
QM03

QM06

QM09

QM12

Cross over from anisotropic magnetoresistance to magnon
magnetoresistance in PLD grown permalloy nanowires

Non-linear susceptibility of nanogranular FeAg films at the verge ofsuperferromagnetism

Magnetic properties and structure of electrodeposited nickel on thinniobium film

Magnetic circular dichroism in near-threshold two-photon
photoemission

A detailed magnetization study of FexAg100-x films, comprising nanoparticles (3 nm) of Fe embedded in a Ag
matrix, has recently revealed [1] a crossover from superspin glass state to superferromagnetic state at x?30. Thischangeover is presumably caused by an interplay between the direct exchange, dipolar and RKKY interactions
operating between the particle magnetic moments. In order to gain further insight into the nature of inter-particle
interactions and their role, first five harmonics χ1- χ5 of the ac magnetic response were measured at several
frequencies and magnetic fields over the temperature range 5-300 K on DC-sputtered FexAg100-x (x = 25, 35,
below and above the percolation threshold, respectively) 100 nm thick films. Susceptibilities χ1- χ5 measured
in the absence of the superposed dc magnetic field, Hdc, exhibit features that are characteristic of a spin glass
and a ferromagnet in x = 25, 35. The ferromagnetic fingerprints in the temperature variations of the linear andnonlinear susceptibilities become all the more apparent when Hdc is applied. The data are analyzed on the samelines as those in the previous works on magnetically disordered CMR manganites [2, 3] and LiNiO insulators [4].

Cyclic voltammetry, chronopotentiometry, atomic force microscope, magneto-optical
Kerr effect, and X-ray diffraction were used to investigate the magnetic property andstructure of thin Ni films electrodepositing onto a 100 nm Nb. Constant-current method
was used to grow the Ni films in this study. During the reduction process of Ni, a small
amount of β-Ni(OH)2 is formed; it becomes intense when the applied potential is morecathodic. The average size of the Ni grains grows and the coercivity of the Ni film
decreases during the steady-state depositing process. The preferred orientations of theelectrodeposited Ni film are fcc-(111) and fcc-(200), the easy axis of the magnetizationof it is in the in-plane direction, however. This may due to the formation of theβ-Ni(OH)2. The effects of current density on the magnetism and structure were alsostudied. The high current density does not make any significant change in the magnetic
property if the current density is higher than 5.2 mA/cm2. This may due to the intensehydrogen evolution reaction during the high current density deposition. These results
could be the foundation of further research in the hydrogen energy area.

July 10 (Tue)We are able to observe and distinguish Anisotropic-Magnetoresistance(AMR) andMagnon Magnetoresistance(MMR) [1] contributions clearly in Permalloy nanowires byvarying their width thereby tuning their shape anisotropy. Nanowires of thickness 20nm
and varying widths down to 160nm were prepared by e-beam lithography and Pulsed
Laser Deposition. A linear non-saturating longitudinal MR observed in high field regime
for NiFe nanowires could never be explained using AMR but only MMR can accountfor it. MMR follows as ρ=α(M/Ms)B, where M is magnetization along the easy axis,
Ms saturation magnetization, B magnetic field applied along the easy axis, α=(dρ/dB) is
the slope of ρ(B) at magnetic saturation. A cross over in magnetoresistance at low fieldfrom AMR-dominant to MMR-dominant one was observed as wire width reduces since
the AMR value is getting reduced from 1.2% for 650nm wide wire to 0.26% for 160nm,
however the contributions from the electron-magnon interactions still persist. At 280nm
itself the AMR contribution to the longitudinal MR has substantially reduced so that
only magnon effect is visible. The MMR proves to be an excellent way of determining
M/Ms, understanding the magnetization reversal mechanisms in nanostructures, domain
wall dynamics and also fundamental problems like electron magnon interactions.

D. Alba Venero1, L. Fernandez Barquin1*, S. N. Kaul2, J Alonso3 and M. L. Fdezgubieda3
1
CITIMAC, Universidad de Cantabria, Santander 39005, Spain
2
School of Physics and Centre for Nanotechnology, University of Hyderabad,
Hyderabad - 500046, India
3
Electricidad y Electronica, Universidad del Pais Vasco, Bilbao 48080, Spain

Huei-ying Ho1*, Wei-yan Lin1, Shih-jia Chen1, Hong-wen Cheng1 and Yung Liou2
1
Department of Science Education, National Taipei University of Education, Taiwan
2
Institute of Physics, Academia Sinica, Taiwan

K Hild1, S A Nepijko1, G Schoenhense1, H J Elmers1*, T Nakagawa2, T Yokoyama2, K
Tarafder3 and P M Oppeneer3
1
Institute of Physics, University of Mainz, Germany
2
Institute for Molecular Science, The Graduate University for Advanced Studies (Sokendai), Japan3
Department of Physics and Astronomy, Uppsala University, Sweden
Magnetic circular dichroism in near-threshold photoemission (TPMCD) results in large asymmetries
similar to values observed in the regime of x-ray magnetic circular dichroism (XMCD). Hence, TPMCD
facilitates new routes for microscopy and time-resolved experiments. Here we investigate the microscopic
origin of the TPMCD for ultrathin Co films [1]. TPMCD is measured for perpendicularly magnetized Cs/
Co/Pt(111) films with work function adjusted by Cs adsorption. For one-photon photoemission (1PPE)TPMCD at a fixed photon energy of hν = 3.06 eV and varying work function results in an almost constantvalue of 6.2 %. TPMCD in two-photon photoemission (2PPE) with the same photon energy results in 8.4% demonstrating that for 2PPE the first excitation step is the dominant asymmetry-generating process.
For 2PPE with reduced work function TPMCD yields an asymmetry of 17 % in the photon energy rangehν = 1.53-1.66 eV, thus revealing the importance of a real intermediate state. The experimental results are
in reasonable agreement with ab initio calculations considering energy conservation and all directions of
excitation instead of only those conserving parallel momentum. Funded by DFG (EL175/15, EL175/16),
Carl-Zeiss-Stiftung and the MAINZ Graduate School of Excellence.

1. A. P. Mihai et al Phy. Rev. B 77, 060401 (2008).

[1] J. Alonso et al., Phys. Rev. B 82, 54406 (2010). [2] Y. Bitla and S. N. Kaul, EuroPhys. Lett. 96,
37012 (2011). [3] L. Fernandez Barquin and R. Garcia Calderon, J. Phys.: Conf. Ser. 17, 87 (2005).
[4] A. Bajpai and A. Banerjee, Phys. Rev. B 62, 8996 (2000).

QM04

QM07

QM10

QM13

Investigation of magnetic anisotropy of ferromagnetic GaMnAs filmby planar Hall effect

Dynamics of Ni-Fe elliptical dot arrays based on CPW-FMR
measurements

Characterization of epitaxial EuS(111) thin films on BaF2(111) andSrF2(111) substrates grown by molecular beam epitaxy

Structural and magnetic properties of pseudocubic BaFeO3-d thin films

Jaehyuk Won1, Jinsik Shin1, Yoonjung Gwon1, Hyehyeon Byeon1, Sangyeop Lee1,
Sanghoon Lee1*, X. Liu2 and J. K. Furdyna2
1
Physics Department, Korea University, Korea
2
Physics Department, University of Notre Dame, USA
Magnetic anisotropy properties of the GaMnAs ferromagnetic film have been
investigated by using planar Hall effect measurements. The field scan of the planar
Hall resistance (PHR) showed a two-step switching behavior indicating a strong cubic
anisotropy along the <100> directions. The difference in the behavior of the PHR for thetwo applied field directions between the [11‌0] and the [110] was understood via wellknown uniaxial anisotropy along the [110] direction. In addition to such known effects,
we also found the presence of asymmetry for the field directions between the [010] andthe [100] directions. This new asymmetry phenomenon was explained by introducing an
additional uniaxial anisotropy field HU2 along the [100] and the [100] directions, whichcoincides with the two directions of cubic anisotropy. The values of the anisotropy fields,
cubic (Hc), first uniaxial (HU1), and second uniaxial (HU2), were obtained by analyzing
the angle dependence of the PHR. Although the value of is small, its effect is clearlyobserved at high temperature above 25 K, where the transition of magnetization occurred
before the field direction is reversed during the magnetization reversal process.
PACS number: 73.50.-h; 75.50.Pp; 75.30.Gw
Keywords: Ferromagnetic semiconductor, Magnetic anisotropy, Planar Hall effectYasushi Endo, Naomi Skashita*, Yutaka Shimada and Masahiro Yamaguchi
Graduate School of Engineering, Tohoku University, JapanThe dynamics of nanomagnets have been studied intensively for high-frequency
applications in spintronic devices. The dynamics closely correlate with the damping
constant α which determines the strength of damping torque in nanomagnets. α has
been evaluated by exciting ferromagnetic resonance (FMR) in nanomagnets using
microwave cavities and coplanar waveguides (CPWs). Advantages of CPW-FMR
measurements are a wide range of radio frequencies and external field intensity andmicron-scale samples. Herein to clarify the dynamics of nanomagnets, we employed
FMR measurements with CPW to evaluate α in 50-nm-thick Ni-Fe elliptical dot
arrays. Effective in-plane anisotropy field Hk,eff increases markedly as the dot size
decreases, which may be attributed to enhanced magnetostatic energy. Eeffective
saturation magnetization 4πMs,eff decreases slightly as the dot size decreases because
the demagnetization field coefficient changes as the dot size decreases. Additionally, αincreases monotonically from 0.01 to 0.02 as the dot size decreases in a 500 Oe external
magnetic field applied in the longitudinal axial direction of the dots. Their values arehigher than that of the Ni-Fe film (α= 0.009) likely because the inhomogeneity of thedemagnetization field distribution near dot edges. Therefore, these results propose that
CPW-FMR measurements can evaluate the dynamics of nanomagnets in detail.

[1] K. Hild, G. Schoenhense, H. J. Elmers, T. Nakagawa, T. Yokoyama, K. Tarafder and P. M.
Oppeneer, Phys. Rev. B 85, 014426 (2012).

Shinya Senba1*, Naoki Matsumoto2, Mitsuhiro Jomura2, Hironori Asada2, Yasuhiro
Fukuma3, Tsuyoshi Koyanagi2 and Kengo Kishimoto2
1
Ube National College of Technology, Japan
2
Graduate School of Science and Engineering, Yamaguchi University, Japan
3
Faculty of Computer Science and Systems Engineering, Kyushu Institute ofTechnology, JapanA ferromagnetic insulating EuS thin film has received considerable attentions in fundamental studies of spin
injection devices because of its very high spin filter efficiency[1]. It has been reported that EuS thin films
on Si(100) and GaAs(100) substrates become insulating at a growth temperature(Ts) of 300°C and above,and the resistivity of that decreases with decreasing Ts due to the sulfur deficiency[2]. In this study, we havesuccessfully grown EuS(111) epitaxial films on BaF2(111) and SrF2(111) substrates using molecular beam
epitaxy at Ts=100~500°C. Pole figures of x-ray diffraction indicate a high degree of in-plane orientation, andall of the samples show very high resistivity. The arithmetic mean deviation of the surface for 10 nm-thick
EuS films on BaF2(111) and SrF2(111) substrates measured by AFM are 0.122 and 0.092 nm, respectively.
The Curie temperature of EuS films increases up to ~16 K with increasing Ts. In order to achieve an antiparallel state between two ferromagnetic layers in spin injection devices, we try to manipulate the coercive
force by Te doping. The obtained coercive force of Te-doped film (110 Oe) is large compared with that ofundoped one (20 Oe).Optical properties such as a magnetic circular dichroism are also presented.

B. Ribeiro1*, R. P. Borges1, R. C. Da Silva2, N. Franco2, P. Ferreira3, T. P. Gasche4, E. Alves2 and M. Godinho1
1
CFMC /Dep. Fisica, Faculdade de Ciencias, Universidade de Lisboa, Campo Grande, 1749-016
Lisboa, Portugal
2
Unidade de Fisica e Aceleradores, Instituto Tecnologico e Nuclear, E.N. 10, 2686-953, Portugal
3
Departamento de Engenharia Ceramica e do Vidro, CICECO, Universidade de Aveiro, Portugal
4
CINAMIL, Laboratorio de Fisica da Academia Militar, Lisboa, Portugal
Bulk BaFeO3-d is known to assume different crystal structures (hexagonal, cubic, tetragonal, orthorhombic,
monoclinic) depending on the oxygen stoichiometry. For d < 0.35[1] the compound has a hexagonal
structure and is antiferromagnetic below160 K[2], while for higher values of d it assumes a distorted cubic
structure and is a magnetically ordered insulator at room temperature that has been considered a potential
multiferroic[3]. In order to explore their structural and magnetic properties, thin films of BaFeO3-d weregrown by Pulsed-Injection Metal Organic Chemical Vapour Deposition (PI-MOCVD) on cubic SrTiO3 single
crystal substrates using different deposition conditions. The films were characterized using X-Ray diffraction,
atomic force microscopy (AFM), SQUID magnetometry and Rutherford Backscatering Spectroscopy (RBS).
By tuning the deposition conditions, namely the substrate temperature and the relative concentrations of Ba
and Fe precursors, it was possible to obtain films that have a pseudocubic structure, are insulating and show
antiferromagnetic properties at room temperature. The results obtained from the experimental characterizationof the pseudocubic BaFeO3-d thin films are discussed and compared with the results obtained using density
functional theory (DFT) using local spin density approximation (LSDA) and LSDA+U.
[1] J. C. Grenier, et al, J. Solid State Chem., 80, 6 (1989) [2] J. B. MacChesney, et al, J. Chem.
Phys. 43, 3317, 1965 [3] T. Matsui, et al, Appl. Phys. Lett. 81, 2764 (2002)[1] P. LeClair et al., Appl. Phys. Lett. 80, 625 (2002). [2] I. J. Guilaran et al., Phys. Rev. B 68,
144424 (2003).

QM05

QM08

QM11

QM14

A crossover between magnetic vortex state and strip domains inelectrodeposited nanogranular nickel films

Structure and magnetic properties of SiO2(Co) granular film on GaAs substrate.

The cation distribution and electrical hopping in Fe3-xCoxO4 (0<x<1.65)
ferrite films on MgO substrate grown by molecular beam epitaxy

Exchange anisotropy and antiferromagnetic coupling in NiFe/FeMn/
Co trilayers

Alexander Sergeevich Samardak1*, Ekaterina Sukovatitsina1, Alexey Ognev1, Ludmila
Chebotkevich1, S. M. Janjan2 and Farzad Nasirpouri2
1
School of Natural Sciences, Far Eastern Federal University, Institute of Automation
and Control Processes FEBRAS, Russia
2
Department of Materials Engineering, Sahand University of Technology, Iran

We have investigated the change of magnetization mode of nanogranular nickel films
electrodeposited on silicon. The electrodeposition of nickel at a distinct potential starts with theformation of isolated nanogranules with size of 130÷190 nm which subsequently tend to coalesce
forming a continuous nanogranular film. Assuming nickel nanogranules as oblate spheroids
and calculating the critical size for single domain state, we find that the nickel nanogranules aremagnetized under vortex ground state. Micromagnetic simulations calculated for this isolated
nanogranules and MFM images confirm the magnetic vortex states for electrodeposited nickel
nanogranules. Upon the nanogranules joining each other, coercivity increases due to the reductionof intergranular space and strengthening of magnetostatic interaction. Further growth leads to theformation of continuous nanogranular film which is associated with decrease in coercivity androtation of the easy axis of magnetization to in- plane mode which is characterized by the domain
wall displacement and strip-like multidomain pattern. The crossover between vortex ground stateand multidomain magnetic pattern leads to the significant decrease in coercive force. Continuous
nickel films electrodeposited on silicon have anisotropic magnetoresistance the value of which
increases as the thickness and, appropriately, uniformity of film is increased.

The 19th International Conference on Magnetism

Victor Ukleev1*, Natalya Grigoryeva2, Ekaterina Dyadkina1, Alexei Vorobiev3, Dieter Lott4,
Leonid Lutsev5, Alexandr Stognij6, Dirk Menzel7, Nicolay Novitskiy6 and Sergei Grigoriev1
1
Petersburg Nuclear Physics Institute, Russia
2Saint-Petersburg State University, Russia
3European Synchrotron Radiation Facility, France
4
Helmholtz-Zentrum Geesthacht, Germany
5
Ioffe Physical-Technical Institute, Russia
6
Scientific and Practical Materials Research Centre of NAS of Belarus, Belarus
7
Institut fur Physik der Kondensierten Materie, TU Braunschweig, Germany
The effect of giant injection magnetoresistance (GIMR) was recently observed in a granular SiO2/(54 - 75 at.% Co) film on a semiconductor GaAs substrate in a temperature range near T = 300 K. The
magnetoresistance reaches the value of 10000% in the magnetic field of 1.9 T and at the voltage of 90
V [1]. The grazing-incidence small-angle X-ray scattering (GISAXS) data indicated the layer of lower
concentration of cobalt particles at the granular film/semiconducter interface if compared to the SiO2(Co)granular film itself. The thickness of this interface layer is about 70 A [2]. The polarized neutron reflectometry
confirms the existence of the additional layer on the granular film/substrate interface. The temperaturedependence of the magnetization M(T) shows the presence of two types of magnetic nanoparticles withdifferent blocking temperatures and magnetization dynamics. The hysteresis curve of the magnetization
demonstrates two-loop structure in region of the fields 0 - 80 mT and 80 - 200 mT. Data obtained bypolarized neutron reflectometry, GISAXS and SQUID measurements are well correlated with each otherand give the possibility to develop the GIMR effect theory paying attention to the interface features.
[1] L.V. Lutsev, A.I. Stognij, and N.N. Novitskii, Phys. Rev. B, 184423 (2009). [2] N. Grigor'eva, A. Vorob'ev, V.
Ukleev, E. Dyad'kina, L. Lutsev, A. Stognij, N. Novitskii, and S. Grigor'ev, JETP Letters, 92:767 - 773, 2010.

July 10 (Tue)Vineeth Mohanan Parakkat and Anil P. S Kumar
Physics, Indian Institute of Science, India

232

poster Presentation

Der-sheng Lee1 and Gung Chern2*
1Electrical Engineering Department, DA-YEH University,Chunghua, Taiwan
2 Physics Department and SPIN Research Center, National Chung Cheng University,
Chia-Yi, Taiwan

TH
WI

D

WN
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Fernando Pelegrini1*, Marcos Antonio De Sousa2, Willian Alayo3 and Elisa Baggiosaitovitch3
1
Universidade Federal de Goias - Instituto de Fisica, Brazil
2
Universidade Federal de Goias, Brazil
3
Centro Brasileiro de Pesquisas Fisicas, Brazil
Ferromagnetic Resonance (FMR) study of the exchange anisotropy of magnetron sputtered Si100Cu20nmN
iFe5nmFeMn10nmCotCu5nm trilayers reveals the existence of antiferromagnetic coupling between NiFe andCo layers. The samples studied were produced in the presence of a magnetic field of 400 Oe to set theunidirectional anisotropy and the thickness of the Co layer varied from 3 to 5 nm. The FMR experiments
were done at room temperature using a commercial spectrometer operating with microwave frequenciesof 9.79 and 34.1 GHz, swept static magnetic field and the usual detection techniques. The FMR spectra
display two resonance modes due to Co and NiFe layers with very distinct effective magnetizations. The
in-plane angular dependence of the resonance field of the Co layer displays the characteristic bell shape
curve due to an exchange-biased bilayer with unidirectional anisotropy larger than the magnetocrystalline
anisotropy. At the FeMn/Co interface of the sample with 5 nm thick Co layer, the exchange bias field is
160 Oe. At the NiFe/FeMn interface it is about only 10 Oe and the angular dependence of the resonancefield exhibits an asymmetry due to the presence also of uniaxial anisotropy. This additional anisotropy
results from an antiferromagnetic coupling between NiFe and Co layers.
[1] Z. Zhang, L. Zhou, and P. E. Wigen, Phys. Rev. B 50, 6094 (1994). [2] W. Alayo, M. A. Sousa, F.
Pelegrini and E. Baggio-Saitovitch, J. Appl. Phys. 109, 083917 (2011).

July 8-13, 2012 Busan, Korea

233

poster Presentation

poster Presentation

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QM18

QM21

QM24

Parallel spin wave resonance in exchange-biased NiFe/FeMn/NiFe
trilayers

Depth dependent chemical and magnetic information of CoFeB/
MgO multilayered thin films studied by x-ray and polarized neutronreflectometry

Uniaxial magnetic anisotropy of La0.7Sr0.3MnO3 film grown on stepterrace surface SrTiO3 (100) substrate

Interlayer interaction In ReCoPO (La, Nd and Sm): 31P NMR Study22Fernando Pelegrini *, Valberto Pedruzi Nascimento , Armando Biondo , Edson
Caetano Passamani2 and Elisa Baggio-saitovitch3
1
Instituto de Fisica, Universidade Federal de Goias, Brazil
2
Departamento de Fisica, Universidade Federal do Espirito Santo, Brazil
3
Centro Brasileiro de Pesquisas Fisicas, Brazil

July 10 (Tue)The Ferromagnetic Resonance (FMR) technique was used to study the magnetic properties of asymmetrical
NiFe30nmFeMn15nmNiFe10nm trilayers magnetron sputtered under working pressures of 2, 5 and 10 mTorr, in thepresence of a 460 Oe magnetic field to set the unidirectional anisotropy. The FMR experiments were done atroom temperature using a commercial spectrometer operating with microwave frequencies of 9.79 and 34.0
GHz, swept static magnetic field and the usual detection techniques. At a microwave frequency of 34.0 GHz,
the parallel FMR spectra reveal that spin wave and uniform resonance modes are excited by the microwave
field. The study of the in-plane angular dependences of the resonance fields reveals for both modes the effectof the unidirectional anisotropy. The dependences of the absorption fields on cosθ, where θ is the field angle
with respect to the anisotropy axis, give for the spin wave and uniform modes of the sample produced under
the pressure of 2 mTorr the anisotropy fields of 66 and 37 Oe, respectively. The parallel FMR results and spinwave resonance theory imply for this sample the exchange constant of 0.92 x 10-6 erg/cm. This result agrees
with perpendicular FMR measurements at a microwave frequency of 9.79 GHz.

Ki Yeon Kim1*, Il Jae Shin2, Byoung Chul Min2, Hyeok Cheol Choi3, Chun Yeol
You3, Jeong Soo Lee1, Surendra Singh4, M. R. Fitzsimmons4 and Sungkyun Park5
1
Neutron Science Division, Korea Atomic Energy Research Institute, Korea
2Center for Spintronics Research, Korea Institute of Science and Technology, Korea
3
Department of Physics, Inha University, Korea
4
Los Alamos National Laboratory, USA
5
Department of Physics, Pusan National Laboratory, Korea
Magnetic Tunnel Junctions (MTJs), consisting of a crystalline MgO barrier sandwiched by amorphous CoFeB
layers, have received much attention owing to novel magnetic and transport properties such as perpendicularmagnetic anisotropy and large tunneling magneto-resistance at room temperature [1-2]. With a combined studyof x-ray (XRR) and polarized neutron reflectometry (PNR), depth-dependent chemical and magnetic profiles
in Co40Fe40B20/MgO multilayered thin films were investigated. The annealing was done at 400°C for half anhour in an applied field of 4 kOe after sample growth. In addition to XRR and PNR, structure characterization
was also conducted using high-angle theta/2theta x-ray diffraction, and high resolution tunneling electron
microscopy (HR-XTEM); the magnetic property was studied using vibrating sample magnetometer. The
boron diffusion and magnetic moment around both CoFeB/MgO interfaces will be discussed in detail.

Byeong-geon Kim, Sanghoon Ki and Joonghoe Dho*
Kyungpook National University, Korea

In this work, we used the step-terrace surface STO (100) substrates to control the spin
direction of the La0.7Sr0.3MnO3 (LSMO) film in the atomic level. The shape magnetic
anisotropy in the nano scale was induced by using step-terrace surface STO (100)substrates with small vicinal angle of 0.1 degree. Atomically flat STO substrate wasprepared by annealing after etching by HCL (hydrochloric acid), and the surface
morphology of the STO substrate with molecular step-and-terrace was observed byatomic force microscopy. Here, we simultaneously deposited two La0.7Sr0.3MnO3 films
on the processed and unprocessed STO substrates by using pulsed laser deposition.
The direction dependence of magnetic hysteresis within the film plane was investigatedby using SMOKE (Surface Magneto-Optical Kerr Effect) system. The magnetic
hysteresis loops of the LSMO film on the unprocessed STO substrate showed weak
direction dependence within the plane, while those on the step-terrace surface STO dida significant uniaxial magnetic anisotropy along the longitudinal direction of the stepterrace of the STO substrate.

M Majumder1, K Ghoshray1*, A Ghoshray1, A Pal2 and V. P. S Awana2
1
ECMP Division, Saha Institute of Nuclear Physics, Kolkata, India
2
QPA Division, National Physical Laboratory (CSIR) Dr. K.S. Krishnan Marg, New
Delhi-110012, India
31P NMR result is presented in Co based non-superconducting members of pnictides
family revealing the importance of the interlayer interaction, a key factor that
determines the ground state. In ReCoPO (Re = rare earth) series, La and Ce show
only PM → FM transition, whereas Nd and Sm show successive PM → FM → AFM
transition with varying degree of TC and TN. 31P NMR spectrum in polycrystalline
La, Nd and SmCoPO respectively corresponds to a powder pattern for a spin 1/2
nucleus with axially symmetric local magnetic field showing varying degree of shiftparameters. In particular, Nd and Sm compound show large temperature dependent
shift anisotropy with similar magnitude of Kiso and Kax. However, relaxation rate (1/T1T) in Sm is atleast two orders of magnitude higher than that observed in other two
compounds. Our earlier 31P and 139La NMR [1] measurements in LaCoPO (quasi 2DFermi surface) reveal dominant 2D spin fluctuation of 3d electrons in PM state with
non negligible 3D part and in the FM state spin fluctuation is 3D in nature. Whereas,in SmCoPO the present result is able to distinguish the FM in plane spin-correlations
from the AFM type out of plane spin-correlations.

[1] V. P. Nascimento, E. Baggio-Saitovitch, F. Pelegrini, L. C. Figueiredo, A. Biondo and E. C.
Passamani, J. Appl. Phys. 99 (2006) 08C108. [2] W. Stoeklein, S. S. Parkin and J. C. Scott, Phys.
Rev. B 38 (1988) 6847. [3] M. Nisenoff and R. W. Terhune, J. Appl. Phys. 36 (1964) 733.

[1] S. Ikeda, K. Miura, H. Yamamoto, K. Mizunuma, H. D. Gan, M. Endo, S. Kanai, H. Hasegawa, J. Hayakawa,
F. Matsukura, and H. Ohno, Nature Mater. 9, 721 (2010). [2] D. D. Djayaprawira, K. Tsunekawa, M. Nagai, H.
Maehara, S. Yamagata, N. Watanabe, S. Yuasa, Y. Suzuki, and K. Ando, Appl. Phys. Lett. 86, 092502 (2005).

QM16

QM19

QM22

QM25

Studies on local structures and magnetism at buried Fe/ Fe 3O 4interfaces using synchrotron-radiation Mössbauer spectroscopy

Depth-resolved rotational hysteresis of exchange-coupled Fe/Cr
multilayers

The effect of compositional ratio on the magnetocaloric effectJahn-teller distortion and enhancement of curie temperature of Mn3xNixO4 films on MgO (001) by molecular beam epitaxy

Ko Mibu1*, Hideto Yanagihara2, Takaya Mitsui3, Ryo Masuda3, Shiori Hori1, Atsushi
Murata1, Masaaki Tanaka1, Kazuya Suzuki2, Eiji Kita2 and Makoto Seto4
1
Graduate School of Engineering, Nagoya Institute of Technology, Japan
2
Institute of Applied Physics, University of Tsukuba, Japan
3
Japan Atomic Energy Agency, Japan
4
Research Reactor Institute, Kyoto University, Japan

Tatyana Guryeva, Kai Schlage, Hans-christian Wille and Ralf Roehlsberger
HASYLAB, Deutsches Elektronen-Synchrotron (DESY), Germany

Strong antiparallel magnetic coupling was found recently in Fe/ Fe3O4 bilayers [1],and attention has been paid as a new and noble-metal-free “synthetic antiferromagnet”
for magnetic recording devices. In order to clarify the mechanism of this interfacial
magnetic coupling, it is important to elucidate the local crystallographic structure
and magnetism at the buried interface experimentally. Mössbauer spectroscopy is a
useful method to obtain such information through absorption spectra of gamma-rays(or X-rays) by the constituent Fe nuclei. In this presentation, we report the results
we have obtained using recently developed synchrotron-radiation-based Mössbauer
spectroscopy with a nuclear Bragg monochromator at BL11XU, SPring-8 [2]. The
structures and magnetism at the buried Fe/ Fe3O4 interface are discussed on the basis of
the obtained spectra.

WN
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D

TH
I
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[1] H. Yanagihara et al., Appl. Phys. Express 1 (2008) 111303. [2] T. Mitsui et al., J. Synchrotron
Radiation 19 (2012), in press.

1. M. Majumder, K. Ghoshray, A. Ghoshray, B. Bandyopadhyay, M. Ghosh , Phys. Rev. B 82, 054422(2010).

Ho-sup Kim1, Sang-soo Oh1, Kiran Shinde1, Seung-kyu Baik1, Kook-chae Chung2 andBhavesh Bharat Sinha2
1
Korea Electrotechnology Research Institute, Korea
2
Korea Institute of Materials Science, Korea
Film type Ni-Mn-Ga alloys were prepared using co-evaporation method in order toinvestigate the effect of compositional ratio on magnetocaloric effect (MCE). In thedeposition process on the metal substrate, Ni was evaporated by an induction heating,and Mn and Ga were evaporated by a resistive heating. The deposition rate of eachelement was measured by Quartz Crystal Microbalance and the rate was controlled
up to 0.1 mm / hour to get a thick Ni-Mn-Ga film. Three crucibles of Ni, Mn, and Ga
were arranged triangularly to form the composition gradient of Ni-Mn-Ga film on thesurface of whole substrate. Long tape samples with different composition of Ni, Mn,
and Ga along the length were prepared. The magnetic property of prepared sample ataround transition temperature was continuously evaluated by a reel to reel Hall probe
measurement system with a temperature controller. The Hall probe signal is related to
the relative value of MCE so that the optimal composition ratio could be obtained byanalyzing it. The section which exhibited the highest value in Hall probe measurement
was cut and analyzed by XRD and followed by MCE measurement using PPMS
equipment. Detailed experimental results will be reported in the presentation.

Der-sheng Lee1, K. M. Kuo2 and Gung Chern2*
1Electrical Engineering Department, DA-YEH University , Chunghua, Taiwan
2
Physics Department and SPIN Research Center, National Chung Cheng
University,Chia-Yi, Taiwan

We report on x-ray diffraction, scanning electron micrograph, and magnetization
measurements vs. external field and temperature of Mn3-xNixO4 (x=0, 0.25, 0.5,
0.75, 1) films grown on MgO (001) and (011) substrates by molecular beam
epitaxy. Magnetization vs. temperature measurements reveal that Curie temperature
increases from 43 K to 103 K as the Ni composition increasing. This increase of Tc
is qualitatively understood as a result of the decrease of the exchange coupling of thecations between B site and B site (JBB). The Jahn-Teller distortion also reduces as the
Ni composition increasing and the cubic structure is estimated to be recovered as x
approaches ~ 1.2. The cation distribution in the present films is different from the bulk
and can be described as [Mn²+1-xMn³+2x/3Ni²+x/3]A[Ni²+2x/3Mn³+2-2x/3]BO4.

1. V. Recarte et al.,Appl. Phys. Lett., 95, 141908, 2009. 2. Yuepeng Zhang et al.,Smart Mater. Struct.,18 , 025019, 2009. 3. V A Chernenko et al.,J. Phys.: Condens. Matter ,17,5215-5224, 2005.

QM17

QM20

QM23

QM26

Dependence of in-plane magnetic anisotropy of Au/Co/Au
heterostructures on thickness of Co-component layer: An FMR study

Magnetization reversal behavior in exchange-coupled NiFe/FeMn/
CoFe trilayers: vectorial MOKE & PNR study

Magnetocaloric effect in Ni doped Zn ferrite nanoparticles grown by
the combustion method

Anomalous switching of in-plane magnetic anisotropy of Fe and Co
thin films grown on curved Pt(001) surface

Leszek Gladczuk, Pavlo Aleshkevych and Piotr Przysłupski
Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL02-668
Warsaw, Poland

Recently, there was a lot of interest in magnetic tunnel junctions built from electrodes
characterized by in-plane magnetic anisotropy. In the present study; ultrathin Mo/Au/
Co/Au heterostructures where the cobalt layer is of the wedge shape (i.e. with thickness
gradually changing along the sample) were grown on a sapphire substrate by molecularbeam epitaxy. Room temperature ferromagnetic resonance (FMR) measurements
were used to evaluate the resonance field as a function of (i) the in-plane and the outof-plane orientation of external magnetic field and of (ii) the cobalt layer thickness.
The experiments demonstrates an interesting effect of enhancement of the in-planeanisotropy for heterostructures with wedge-shaped Co layer. This finding provides amethod to modify the magnetic anisotropy, which can be of a great importance for theapplication in magnetic tunneling junctions. A comparison of the obtained results withearlier data on Co anisotropy will be presented.

July 10 (Tue)1

Ki Yeon Kim1*, Ji Wan Kim2, Hyeok Cheol Choi3, Anke Teichert4, Chun Yeol You3,
Sungkyun Park5, Sung Chul Shin2 and Jeong Soo Lee1
1
Neutron Science Division, Korea Atomic Energy Research Institute, Korea
2
Department of Physics and Center for Nanospinics of Spintronic Materials, Korea
Advanced Institute of Science and Technology, Korea
3
Department of Physics, Inha University, Korea
4
Helmholtz Zentrum Berlin fur Materialien und Energie, Germany
5
Department of Physics, Pusan National Laboratory, Korea

With a combination of vector magneto-optic Kerr effect (MOKE) magnetometry and polarized neutronreflectometry(PNR), the detailed magnetization reversal mechanism of the exchange-biased Py(30-nm)/
FeMn[t_AF=0-30nm]/CoFe(30-nm) trilayers was studied.[1] We found that Py/FeMn(15-nm) and FeMn/
CoFe bilayers show completely different magnetization reversal modes, whereas they become very similar
to each other in the corresponding Py/FeMn/CoFe trilayers. This is convincing evidence that the 15nm FeMn layer mediates the magnetization reversal behaviors of Py and CoFe layers through interlayer
exchange bias coupling. Furthermore, magnetization reversal of Py and CoFe layers are decoupled for t_
AF=30 nm, indicating that both Py and CoFe layers separated by an intermediate FeMn layer are exchangecoupled within 30 nm distance. This is in reasonable agreement with the theoretically predicted domain-wall
width such as 28 nm for the polycrystalline FeMn/Co bilayers and 50 nm for the perfect Fe50Mn50 crystal.

Kyungdong Lee, Rahul Chandrakant Kambale and Namjung Hur*
Department of Physics, Inha university, Korea

We studied the magnetocaloric effect (MCE) in two different compositions of NiZn ferrite nanoparticles (NixZn1-xFe2O4, x=0.2 and 0.3) which were prepared by
the combustion method. From the temperature and the magnetic field dependent
magnetization curves, the magnetic entropy changes (ΔS) and the adiabatic temperaturechanges (ΔT) were evaluated. Magnetocaloric effect in these nanoparticles is comparedto that in bulk system with the same compositions to study the effects of grain size.
Although the values of ΔS and ΔT at 2 T magnetic fields in these nanoparticles arelower than the values in the bulk one, wider effect transition windows were observedin nanoparticle systems. As the domain size of Ni-Zn ferrite nanoparticles affects thetemperature and magnetic field dependence of magnetization, the maximum ΔS and ΔT
are also influenced by the grain size around the magnetic transition temperature (TC).
Therefore, the field dependence of ΔT at TC, which can be analyzed by the mean fieldapproximation denoted by the exponential p, was found to be different from the typicalone.

Wondong Kim1*, Chanyong Hwang1 and Z.-q. Qiu2
1
Korea Research Institute of Standards and Science, Korea
2
Physics Department, University of California at Berkeley, USA

We investigated the step-induced magnetic anisotropy of Fe and Co thin films grownon the curved Pt(001) surface using Surface Magneto-Optical Kerr Effect(SMOKE)
and Scanning Tunneling Microscopy(STM). The continuous variation of step densityof the curved Pt(001 surface are confirmed by STM experiment. From SMOKE
measurements on both of Fe and Co thin films, we observed the switching of themagnetic easy axis from the parallel-to-step direction to the step-normal direction withincrease of the step-density. We attributed The origin of this anomalous transition to theabrupt change in the step structure at high-step density position, which was revealed by
STM measurements.

[1]Ki-Yeon Kim, Ji-Wan Kim, Hyeok-Cheol Choi, A. Teichert, Chun-Yeol You, Sungkyun Park, SungChul Shin, and Jeong-Soo Lee, Phys. Rev. B. 84,144410 (2011).

234

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

235

poster Presentation
QM27

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QN04

QN07

Magnetic-field and temperature-dependent relaxation in ferrofluids
characterized with a high-Tc SQUID-based nuclear magnetic
resonance spectrometer

Antiferromagnetic order and domains in Sr3Ir2O7

Hysteresis analysis: A study on the demanetization by using M-B
preisach model for improved stability of numerical analysis

On real-time hysteresis compensation for magentostirictive soundtransducers

It is necessary to describe the hysteresis characteristic of magnetic material precisely
for the analysis of design of system with ferromagnetic materials. Although
Preisach model is regarded as the most accurate method to describe the hysteresis
characteristics, it is not applied widely to the real systems because of some difficulties.
The conventional Preisach model shows the numerical instabilities during the iterative
computations because the density distribution obtained from the sets of M-H curves
are strongly localized. To remove such numerical instabilities, if we use a M-B variable
instead of M-H variable would be better the results. In this paper, we suggest method
for a M-H variable to change a M-B variable, and also, from the computed results ofused normal Preisach, M-H cure method and M-B curve method, we shows better than
numerical stabilities by using two dimensional finite element method.

Magnetostrictive actuators show inherent hysteresis, and it hinders wide applications.
To solve this problem, in the literature, ‘Jiles-Atherton model’ and ‘Preisach model’
have been used mostly. But the methods require huge CPU time, or need complex
mathematics. Thus, for real-time, ability of hysteresis compensation using capacitor
is proposed by park et al [1]. In this paper, class-D amplifier containing capacitor as
hysteresis compensator is proposed. The Class-D amplifier consists of comparator,
current supplier and R-C circuit. Hysteresis compensator is implemented by a
R-C circuit, because the output voltage of capacitor has similarity to a hysteresis
compensated input, and the process of development is as follows: 1. Generation ofHysteresis compensated input by Preisach model; 2. Comparison between hysteresis
compensated input and R-C circuit model by non-linear regression; 3. Application
found capacitance to the class-D amplifier. Experimental setup is consisted of acapacitance displacement sensor, a digital oscilloscope and a function generator.
Hysteresis loss observed about 19 percent before application of hysteresis compensator,and hysteresis loss observed less than 13 percent after application of hysteresis
compensator at 10 Hz by using the 3 uF of capacitor.

S. Boseggia1, R. Springell1, H. C. Walker2, A. T. Boothroyd3, D. Prabhakaran3, D.
Wermeille4, L. Bouchenoire4, S. P. Collins5 and D. F. Mcmorrow1
1
Physics and Astronomy, London Centre for Nanotechnology, UCL, United Kingdom
2
European Synchrotron Radiation Facility, France
3
Clarendon Laboratory, University of Oxford, United Kingdom
4
5XMaS, UK-CRG, European Synchrotron Radiation Facility, France
5
Diamond Light Source, Didcot, Oxfordshire, United Kingdom

Hyuk Won and Gwan Soo Park*
School of Electrical Engineering, Pusan National University, Korea

Hae Jung Park and Young-woo Park*
Department of Mechatronics Engineering, Chungnam National Univers, Korea

In this work the magnetic-field and temperature dependent spin-lattice relaxation
rate, 1/T1, and spin-spin relaxation rate, 1/T2, of ferrofluids are characterized using ahigh-Tc SQUID-based magnetometer as the detector. The ferrofluids are consisted ofdetrain-coated Fe3O4 dispersed in phosphate buffer saline solution. It was found that 1/
T1 measured in a magnetic field of 56.8 mT is significantly higher than 1/T2 measured
in a magnetic field of 102 μT. We attribute this to the magnetic-field gradients frommagnetic nanoparticles that accelerate the T1-relaxation more in a high strength ofmagnetic fields than they are in a low strength of magnetic fields. Furthermore, 1/T1
and 1/T2 decrease when temperature increases. We attribute this to the improved fieldhomogeneity seen by protons’ spins under the influence of enhanced Brownian motionof magnetic nanoparticles at high temperatures than they are at low temperatures.
Characterizing the relaxation rates of ferrofluids in low concentration regimes will be
helpful for their future applications such as the low field MR imaging.

Resonant scattering at the Ir L2, 3 edge has been used to determine that Sr3Ir2O7 is along-range ordered antiferromagnet below TN~230 K with an ordering wavevector,
q = (½, ½, 0). The energy resonance at the L3 edge was found to be a factor of ~30
times larger than that at the L2. This remarkable effect has been seen in the single
layer compound Sr2IrO4 and has been linked to the observation of a Jeff= 1/2 spin-orbit
insulator. Our result shows that despite the modified electronic structure of the bilayercompound, caused by the larger bandwidth, the effect of strong spin-orbit couplingon the resonant magnetic scattering persists. Using the programme SARAh, we havedetermined that the magnetic order consists of two domains with propagation vectors
k1 = (½, ½, 0) and k2 = (½,-½, 0), respectively. A raster measurement of a focussed
x-ray beam across the surface of the sample yielded images of domains of the orderof 100 μm size, with odd and even l components, respectively. Fully relativistic,
monoelectronic calculations (FDMNES) have been employed to calculate the relative
intensities of the L2, 3 edge resonances, comparing the effects of including spin-orbit
coupling and the Hubbard, U, term.

QM28

QN02

QN05

QN08

Influence of metal precursor on synthesis and magnetic properties ofnanocrystalline strontium hexaferrite thin films

High frequency permeability of Fe-Co and Co granular composite
materials

A study on the design of transmitting coils and receiving coils on active
magnetic snesor using finite element method

The investigation on structural and magnetic properties of Ni-Cu-ZnMn-Mg-Li ferrites

Proximity magnetic sensor is able to detect the object target accurately in close range
and it has been widely used in the underwater guided weapon system because there
is no countermeasures from the target. In order to increase the damage of target byshock wave due to explosion of the underwater guided weapon system, the maximum
detection range of the proximity magnetic sensor needs to be increased. In this paper,
we describe the techniques of the optimum transmitting and receiving coils designusing the Finite Element Method for the output power enhancement of the transmitterand the sensitivity improvement of the receiver. Finally, the proposed design techniquesof the transmitter and the receiver were verified using a experimental setup and a
prototype.

In this work, addition of seven raw materials inclusive of nickel oxide, copper oxide,
zinc oxide, manganese oxide, magnesium oxide, lithium oxide, and iron oxide to forma new multi-component ferrite system. The Ni-Cu-Zn-Mn-Mg-Li substituted ferrites
were prepared by conventional solid-state-reaction process and sintered at 1100°C
for 2 h in air atmosphere. The influences of Ni-Cu-Zn-Mn-Mg-Li substitution on
structural and magnetic properties were investigated by scanning electron microscopy,
RF impedance/material analyzer, B-H curve loop tracer, and vibrating sample
magnetometer. The experimental results show that the additives with low melting point
form precipitates at the grain boundaries.[1] The average grain size of sintered ferrites
decreases with a decrease of Ni/Mn ratio. The sintered ferrites, Ni/Mn=0.79, showedlargest initial permeability (μi=85), largest saturation magnetism (Bs=3930 gauss), andbetter saturation magnetization (Ms=74.91 emug-1).

S. M. Masoudpanah, S. A. Seyyed Ebrahimi* and M. Khodaei
Center of Excellence for Magnetic Materials, University of Tehran, Iran

The effects of starting metal salts on the structure and magnetic properties of strontium
hexaferrite thin films synthesized by sol gel process have been investigated. Fouriertransform infrared and thermal analyses were conducted to determine the chelated
species and thermal decomposition of the gels, respectively. X-ray diffraction,scanning electron microscopy and vibrating sample magnetometery techniques werealso applied to evaluate the microstructure, composition, crystallite size and magnetic
properties of the thin films. The results showed the film prepared from nitrate precursor
offered a single phase strontium hexaferrite with nanocrystalline structure and higher
saturation magnetization after calcination. However, the films obtained from hydroxide
and chloride precursors had higher coercivity due to smaller crystallite size.

Teruhiro Kasagi1*, Aiko Tsurunaga2, Takanori Tsutaoka2 and Kenichi Hatakeyama3
1
Tokuyama College of Technology, Japan
2
Graduate School of Education, Hiroshima University, Japan
3
Graduate School of Engineering, University of Hyogo, Japan

Relative complex permeability and permittivity spectra of Fe50Co50 (Permendur)and Co granular composite materials have been studied in the microwave frequency
range up to 18 GHz. Particles were heat-treated in air using an electric furnace
in order to suppress the eddy current effect in the composite structure containing
percolated particles. Composite materials were prepared by mixing these particles
with Polyphenylene sulfide resin. The 78 vol.% Fe50Co50 granular composite has
the larger relative permeability value than that of the 79 vol.% Co composite at 100
MHz. The negative frequency dispersion of permeability was observed above 7 and
8 GHz for Fe50Co50 and Co composites, respectively. The dc magnetic field effect on
the permeability spectra revealed that the permeability dispersion of Co composites in
the microwave range is mainly attributed to the gyromagnetic resonance. The relative
permittivity spectra of 78 vol.% Fe50Co50 and 79 vol.% Co composites show theinsulating property up to several GHz; the permittivity value increases with increasing
particle content in both composites.

[1] Ki-Hyun Ji, Hae-Jung Park, and Young-Woo Park, “Semiempirical Approach to Compensate
Hysteresis in Magnetostrictive Actuator”, IEEE International Magnetics Conference 2011, 2011

Hye Sun Ju and Gwan Soo Park*
Pusan National University, Korea

Chih-wen Chen*, Mean-June Tung and Shi-Yuan Tong
Industrial Technology Research Institute, Taiwan[1]Guiqing Wang, Xiufang Bian, Weimin Wang, Junyan Zhang,Mater. Lett., 57 (2003) 4083-4087.

QM29

QN03

QN06

QN09

Planar Hall effects measurements of sensitive magnetization responsein epitaxial Fe thin films

Magnetic carbonyl iron suspension with nanoclay additive and its
magnetorheological properties

What can we learn from isothermal remanent magnetization curves on
diluted nanoparticle assemblies?

Magnetorheology of xanthan gum coated soft magnetic carbonyl ironmicrospheres and their polishing characteristics

Soft magnetic carbonyl iron (CI) based magnetorheological (MR) fluids with different
loadings of nanoclay were prepared, in which the MR fluid is a complex colloidal
suspension consisting of magnetic particles dispersed in a liquid, showing its rapid,
reversible and tunable change between a liquid-like and solid-like state with an appliedexternal magnetic field. The MR characteristics were measured via rotational tests, inwhich the flow curves exhibited a non-Newtonian behavior for all investigated samples
under applied magnetic fields. Flow curves showed not only the dynamic yield stresschange measured as a function of magnetic field strength using a power law fit but also
the existence of a solid-like character. Sedimentation of the MR fluid with and without
an additive was also examined.

Isothermal remanent magnetization (IRM) and direct-current demagnetization (DcD)
curves are mainly used to characterize interactions in a granular magnetic media and to
determine the switching field distribution. These curves are only sensitive to irreversible
changes, i.e. to the particle magnetization switching for samples made of clusters
embedded in a matrix. Moreover, at remanence there is no unsuitable contribution(superparamagnetic, diamagnetic or paramagnetic) to the signal. This makes IRM/DcD
curves of great interest in the investigation of the intrinsic properties of nanoparticles. The
underlying process, i.e. macrospin switching by applying a field, is complementary to thethermal switching observed with ZFC/FC curves where the particle size distribution has acritical influence. Interestingly, IRM curves have a high sensitivity to other characteristics
such as an anisotropy constant distribution, non-uniaxial terms of the anisotropy, and ofcourse inter-particle interactions. We show how IRM/DcD curves can be modelled for an
assembly of randomly oriented and non-interacting macrospins, thus allowing efficientand realistic simulations of experimental curves (taking into account the size distribution,
temperature, etc). This modelling is then confronted to a series of measurements on diluted
Co nanoparticle samples prepared by low-energy cluster-beam deposition. Experiment/
theory comparison can provide new insights on their magnetic properties.

Anis Faridah Md Nor1*, Tatsuya Matsumoto2, Teppei Takashima2, Terumitsu Tanaka2
and Kimihide Matsuyama2
1
Physics Department, University of Malaya, Malaysia
2
Department of Electronics, ISEE, University of Kyushu, JapanThe Fe thin film is a promising candidate for future magnetic microwave devices, owing to
the high ferromagnetic resonance frequency with an order of 10 GHz [1-2]. A high sensitive
magnetization response is crucial for the low power device operation. In the present study, we
prepared Fe(100) thin films deposited on MgO(100) substrates using magnetron sputteringsystem and investigate the magnetization process using the planar Hall effect (PHE).The
PHE measurements were carried out with several Fe thicknesses and temperatures. In the
PHE measurements, alternating external magnetic fields along vertical easy axis were appliedwith various amplitudes and the sense current was applied along the horizontal easy axis.
With increase of alternating magnetic field, the PHE voltage increased due to the dispositionof Fe magnetization from easy axis. When the alternating magnetic field exceed a thresholdvalue, the PHE voltage decreased rapidly. The threshold value depend on the thickness of Fe
film and the PHE voltage decreased with decreasing temperature. These results suggest thatthe magnetization rotates exceeding the hard axis direction and reversible susceptibility canbe realized. The stochastic aspect of the magnetization process also appears at 10 K.
[1] E. Schloeman et al., J. Appl. Phys., 63, 3140 (1988). [2] N. Cramer et al., J. Appl. Phys., 87,
6911 (2000).

The 19th International Conference on Magnetism

Cheng Hai Hong, Ying Dan Liu and Hyoung Jin Choi*
Department of Polymer Science and Engineering, Inha University, Korea

July 10 (Tue)July 10 (Tue)Hong-chang Yang1*, Chieh-wen Liu1, Shu-hsien Liao2, M.j. Chen1, K.I. Chen1, Hsinhsien Chen2, Herng-er Horng3, L.m. Wang1 and S.Y. Yang2
1
Department of physics, National Taiwan University, Taiwan
2
Institute of Electro-Optical Science and Technology, National Taiwan Normal
University, Taiwan

236

poster Presentation

Florent Tournus*, Arnaud Hillion, Alexandre Tamion and Veronique Dupuis
LPMCN, CNRS & Univ. Lyon 1, France

Seung Hyuk Kwon1, Hyoung Jin Choi1*, Jung Won Lee2, Kwang Pyo Hong2 andMyeong Woo Cho2
1
Department of Polymer Science and Engineering, Inha University, Korea
2
Department of Mechanical Engineering, Inha University, Korea
Magnetorheological fluids, complex colloidal suspensions consisting of magnetic particles
dispersed in a liquid, showing their rapid, reversible change between a liquid-like and solidlike state with an applied magnetic field. Among these applications, MR polishing arrests
a lot of attention due to its smart controlling polishing characteristics for dedicated MEMS
applications. In order to improve polishing characteristics of MR fluids, in this study,
carbonyl iron (CI) microspheres coated with xanthan gum (XG) were fabricated via solvent
casting method. The morphologies and densities of both pure CI and CI/XG particles werecharacterized via SEM and pycnometer, respectively. In addition, rheological characteristicsof the MR fluids under applied magnetic field strengths were examined via a rotationalrheometer, in which shear viscosity, storage modulus, normal force the variation in MR
performance under applied magnetic fields. Especially, the normal force was measured
for different gap distances to simulate the work condition of MR polishing. MR polishing
characteristics were conducted using an MR polishing machine to investigate the surface
roughness from the MR polishing with nano ceria slurry abrasives. A series of experiments
were performed for fused silica glass using prepared slurry by changing the processing
parameters such as a rotating wheel speed and polishing time.

July 8-13, 2012 Busan, Korea

237

poster Presentation

poster Presentation

QN10

QN13

QN16

QN19

Cluster-glass-like magnetic state in rare-earth intermetallic compound
Tb5Pd2Magnetic Properties of Co2Z Ferrite Densified through High BET
Powders

Characteristics of composite materials Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15O19/
La0.7Ba0.3MnO3 as a microwave absorber

Structural and magnetic properties of Mn2Rh1-xCoxSn Heusler alloys

21Andrey F. Gubkin *, Pavel E. Terent'ev , Elena A. Sherstobitova and Nikolai V.
Baranov3
1
Laboratory of neutron scattering, Institute of Metal Physics, Russia
2
Laboratory of ferromagnetic alloys, Institute of Metal Physics, Russia
3
Laboratory of micromagnetic materials, Institute of Metal Physics, Ural Federal University, Russia

The rare-earth intermetallic Tb5Pd2 compound crystallizes in a cubic crystal structure with site disorderand magnetic frustrations due to triangle-like arrangement of Tb atoms [1]. In this work the DC and AC
magnetic susceptibility measurements together with powder neutron diffraction have been performed
in order to study the Tb5Pd2 magnetic state. The susceptibility measurements on a polycrystalline
Tb5Pd2sample have revealed a complex highly irreversible behaviour below 58 K, which can be associatedwith the existence of a spin-glass-like magnetic state. According to our neutron diffraction data the Tb5Pd2
compound doesn’t exhibit a long-range magnetic down to 5 K. However below and above the freezing
temperature TG ? 58 K, the appearance of the broad diffuse maxima of magnetic origin has been detectedin the low angle region. The second anomaly of the susceptibility was observed at TB ? 25 K, which canbe ascribed to the blocking process of uncompensated magnetic moments of antiferromagnetically shortrange correlated regions. The results obtained allow us to suggest that the Tb5Pd2 compound exhibits acomplex non-ergodic magnetic state of a cluster-glass type associated with frustrations of the RKKY-typeexchange interaction. This work was supported by the program of RAS (Projects RAS UB 11-2-НП-265).

Ji Yeon Song and Young Ho Han*
Materials Engineering, Sungkyunkwan University, Korea

V. Vekky R. Repi* and Azwar Manaf
Graduate Program of Materials Science Study, Universitas Indonesia, Indonesia

Co2Z is a planar hexagonal ferrite that exhibits high permeability (μi) and highresonance frequency (fr) up to the GHz region. Z-type Ba3Co2Fe24O41 hexagonal
ferrite was prepared by two-step calcinations [1]. Single phase Co2Z ferrite powders
were possible after post-calcination at 1300°C. Various sintering aids improved
densification of ceramic bodies, but lowered magnetic permeability due to nonmagnetic characteristics of sintering additives. In order to increase permeability, Co2Z
specimen was sintered without sintering aids. The densities of sintered bodies increased
with increasing specific surface area (BET) of calcined powders, and Co2Z with BET
7.80m2/g led to significantly high densification(5.23g/cm3, 97% theoretical density).
Permeability of Co2Z gradually increased with increasing density, whereas theirresonance frequencies decreased with increasing permeability, where the product of μi
x fr was estimated to be ~10.3GHz. It was thus confirmed that the calcined powders
with high BET could enhance sintering kinetics of Co2Z hexagonal ferrites without
sintering additives and significantly increase magnetic permeability.

WN
A
R

D

TH
I
W

July 10 (Tue)Microwave absorption properties of polymer composites withamorphous Fe-B and Ni-Zn-Co ferrite nanoparticles
Kazuaki Shimba*, Shozo Yuki, Nobuki Tezuka and Satoshi Sugimoto
Materials Science, Tohoku University, Japan

Recently, many communication devices use GHz-range microwave. It causes serious
issue, such as electromagnetic interference and multipath interference. To prevent these
problem, microwave absorbers (MA) consisting of polymer composites of magnetic
powders are paid attention. With the current trend being to miniaturize devices, thinner
MA are now required. We reported that polymer composites with amorphous Fe-B
particles (AFBP) and Ni-Zn ferrite nanoparticles showed high permeability of μ'r =9.5 at 1.0 GHz and good microwave absorption properties at 0.6-1.1 GHz and resulted
in thinner MA than reported MA [1]. However, they cannot used as MA over 1.1
GHz, because of their low resonant frequency (fr = 1.2 GHz). In this study, Ni-Zn-Co
ferrite nanoparticles (NZCFN) were mixed with AFBP for increasing fr in polymer
composites. XRD analyses show that NZCFN exhibit typical spinel structure. The fr
of NZCFN increases from 0.7 to 3.6 GHz with increasing Co contents. It indicatesthat the magnetocrystalline anisotropy of NZCFN is increased by Co addition. The frof polymer composites with AFBP and NZCFN can be increased to 2.6 GHz. They
exhibites good microwave absorption properties at 0.8-1.4 GHz with thicknesses of
2.4-3.9 mm and resulted in thin MA at 1-1.4 GHz.

QN14
3+

Magnetic properties of Cr substituted Mg-Cd ferrites
S A Masti1*, A. K Sharma2 and P. N. Vasambekar3
1Physics, Dr. Ghali College, Gadhinglaj, India
2
Physics, Shivaji University, Kolhapur, India
3
Electronics, Shivaji University, Kolhapur, India

Magnetization and susceptibility of polycrystalline ferrites with general formula Cdx
Mg1-x Fe2-y Cry O4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; y = 0, 0.05 and 0.10) were studied.
Study of saturation magnetization reveals that the Neels two sublattice model exists
up to x = 0.4, for y = 0, 0.05 and 0.1 and a three sublattice model (YK-model) is
predominant for x > 0.4, y = 0, 0.05 and 0.10. The saturation magnetization andmagnetic moment were found to decrease with the increase of Cr3+ contents, which is
attributed to the dilution of B-B site interaction. Temperature dependence normalized
AC susceptibility study reveals that MgFe2O4 exibits single domain(SD) structure. On
substitution of Cd2+ , single to multi domain transition takes place. Curie temperature
decreases with Cd2+,was attributed to decrease in A-B intraction. On substitution of
Cr3+ , peak obtained in MgFe2O4 was supressed which is attributed to decrease in grain
size and further decrease

Mn2-based Heusler compounds are promising candidates for spintronic applications as they are
known to crystallize with cubic and tetragonal structures or exhibit cubic-tetragonal phase transitions.
Sn-containing compounds have only a small lattice mismatch with MgO thus providing higher
symmetry correlation between magnetic film and tunneling barrier. Quaternary Mn2Rh1-xCoxSn
and Mn2+xRh1-xSn Heusler alloys have been synthesized with a step of x = 0,1 and their magnetic
properties were experimentally investigated. In the present work the structural and magnetic propertiesare discussed depending on the Rh and Co content. The frst series undergoes a cubic-tetragonaltransition at x = 0,5, while the latter one experiences a hexagonal-tetragonal change of structure. The
presence of Co increases the Curie temperature keeping the magnetic moment unchanged. This work
is supported by the Graduate School of Excellence Materials Science in Mainz (MAINZ).
[1] Simple Rules for the Understanding of Heusler Compounds, Tanja Graf, Stuart S. P. Parkin, and Claudia Felser,
Progress in Solid State Chemistry 39 (2011) 1-50, invited review. doi:10.1016/j.progsolidstchem.2011.02.001. [2]Electronic, magnetic, and structural properties of the ferrimagnet Mn2CoSn, Jurgen Winterlik, Gerhard H. Fecher,
Benjamin Balke, Tanja Graf, Vajiheh Alijani, Vadim Ksenofontov, Catherine A. Jenkins, Olga Meshcheriakova, andClaudia Felser 83 (2011) 174448. [3] Quaternary half-metallic Heusler ferromagnets for spintronics applications,
V Alijani, J. Winterlik, G. H. Fecher, S. S. Naghavi, C. Felser, Phys. Rev. B 83 (2011) 184428[1] J. Jeong, K.W. Cho, D.W. Hahn, B.C. Moon, Y.H. Han, Mater. Lett. 59 (2005) 3959-62

1. M. L. Fornasini, A. Palenzon, J. Less-Common Metals, 38, (1974) 77-82.

QN11

Olga Meshcheriakova1, Jurgen Winterlik1, Gerhard H. Fecher2, Benjamin Balke1 and Claudia Felser3
1
Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University Mainz, Germany
2
Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University Mainz, Max
Planck Institute for Chemical Physics of Solids, Dresden, Germany
3Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University Mainz, Max
Planck Institute for Chemical Physics of Solids, Dresden, Germany

QN17

QN20

The effect of shape anisotropy to acoustical performance ofmagnetostrictive sound transducer

Magnetic properties of Mn2Sb1-xGex (0.05 ≤ x ≤ 0.2) in high magnetic
fieldsHae Jung Park, Young Woo Park* and Ok Kyun Oh
Department of Mechatronics Engineering, Chungnam National Univers, Korea

This paper presents the experimental approach to investigate the effect of the
shape anisotropy of magnetostrictive material (MM) to acoustical performance ofmagnetostrictive sound transducer. The assumption is that the volume of MM is kept
constant. In the experiments, four MM samples are used with a volume of 295 mm^3
and input currents are swept from 20 Hz to 20 kHz. The diameters of MM samples
are 4, 5, 6 and 10 mm and the lengths are 23.5, 15, 10.5 and 3.5 mm, respectively. The
displacements are measured from 2.1 to 0.8 um at 20 Hz. Forces are measured from81 to 120 N at 20 Hz. Among the samples, the MM sample of 23.5mm length shows
the largest displacement and force. SPL is obtained from forces of MM and a areaof vibration panel. The largest SPL is observed at 20 Hz and the SPL is measured to
115dB. Also, the SPL of the samples show the level from 103 dB at 1 kHz to 81 dB at
20 kHz. The displacement and force are measured from 0.36 um and 29N at 1 kHz to
15.3 nm and 2.5 N at 20 kHz.

[1] K. Shimba, N. Tezuka, S. Sugimoto; Materials Science and Engineering B 177 (2012) 251-256

Daisuke Shimada1*, Hiroki Orihashi1, Daisuke Mitsunaga1, Kohki Takahashi2,
Masahiko Hiroi1, Masakazu Ito1, Kazuyuki Matsubayashi3, Yoshiya Uwatoko3 andKeiichi Koyama1
1
Kagoshima University, Japan
2
Tohoku University, Japan
3
Tokyo University, JapanThe Mn2Sb compound with a Cu2Sb-type tetragonal structure is ferromagnetic (FRI) below TC ~550 K. The substitution of various elements (V, Cr, Co, Cu and Zn) for Mn as well as (As, Ge andSn) for Sb results in a first-order magnetic (FOM) transition from the ferromagnetic (FRI) to an
antiferromagnetic (AFM) states with decreasing temperature [1]. Mn2-xCoSb, it has been reported
that the FOM transition occurs accompanied with large change in unit cell volume, resistivity andmagnetization etc. However, detailed results on Mn2Sb1-xGex have not been reported yet. In thisstudy, magnetization and electrical resistivity measurements were carried out for polycrystalline
Mn2Sb1-xGex (0.05 ≤ x ≤ 0.2) in magnetic fields up to 16 T in 4.2-600 K temperature range, in order
to investigate the magnetic and electrical properties affected by magnetic fields. Mn2Sb0.92Ge0.08
showed the Curie temperature Tc of 532 K and the FOM transition at Tt = 230 K in a zero magnetic
field. With increasing x, Tc decreased and Tt increased. For Mn2Sb0.92Ge0.08, we observed amatamagnetic transition from the AFM to FRI with a hysteresis of 0.5 T at 200 K.
[1] O. Beckman and L. Lundgren: Handbook of Magnetic Materials vol 6, ed K H J Buschow(Amsterdam: Elsevier) chapter 3, (1991) p 181-287

QN12

QN15

QN18

QN21

Magnetostrictive properties of Mn substituted sintered cobalt ferrite
derived from nanocrystalline materials

Docking Speaker Based on Magnetostrictive Sound Transducer

Size effects on magnetic properties of nanocrystalline Sr2CuCo2Fe24O41
prepared by Co-precipitation method

Microwave magnetic properties of FeNi films prepared byelectrodeposition

Khaja Mohaideen Kamal and P A Joy*
Materials chemistry division, National Chemical Laboratory, India

Magnetostrictive smart materials are of great importance for sensor applications. Cobalt
ferrite is well known for its highest magnetostrictive strain at room temperature among
the oxide based magnetostrictive materials. The substitution of manganese for iron incobalt ferrite, CoFe2O4, increases the strain derivative even though the magnetostriction
value is decreased for the material synthesized through the conventional ceramic route[1,2]. In the present study we have investigated the influence of the initial particle
size of the powders of manganese substituted cobalt ferrite on the magnetostrictive
coefficient of the sintered ferrite samples with compositions 0≤x≤0.3 in CoFe2xMnxO4. Nanoparticles of CoFe2-xMnxO4 of size less than 10 nm were synthesized byan autocombustion method and the resulting powders were sintered in air at 1300° C.
Magnetic characteristics of the nanocrystalline powders and sintered products havebeen studied. Magnetostriction measurements were performed on the sintered samples
to determine the influence of initial particle size of the starting powders. Higher
magnetostriction at low fields is obtained along with enhanced strain derivative for thesintered Mn substituted cobalt ferrite derived from nanocrystalline materials comparedto the bulk counterparts.

July 10 (Tue)1

Han Sam Kang, Jin Hong Min and Young Woo Park*
Department of Mechatronics Engineering, Chungnam National University, Korea
All docking speakers available in the market are equipped with iDevice cradle andwith cone-type sound unit. This paper presents a novel docking speaker without them.
It is based on the magnetostrictive sound transducer (MST), which transforms any flat
surface into speaker. The docking speaker consists of one MST, two circuit boards, andaluminum housing. One circuit board contains a Bluetooth module, a power amplifier
module, Aux, and a recharge adapter. The other board is called a control board, which
ATmega128 is used to control a digital clock, a LCD module, four control switches,
and a power amplifier module. The reluctance concept is utilized to the magnetic circuit
for the MST. Allowable current and number of coil turns are determined through thisprocedure. The result is compared with the simulation result. Then, circuit board andhousing are designed. The assembled docking speaker is subjected to the experiments.
For the experiments, the MST is placed and bolted between the wood and glass panels.
An accelerometer sensor, ADXL001, is firstly located beneath the center of the MST.
Then, the location is placed away by 50 mm from the center of the MST. It is provedthat the developed docking speaker works well.

K Praveena and K Sadhana
Materials Research Centre, Indian Institute of Science, India

The nanocrystalline z-type hexaferrite powders were synthesized by Co-precipitation
method using aqueous solutions of strontium, copper, cobalt iron and nitrates. The
as synthesized powders were characterized using XRD, TEM and TG/DTA. The
average particle size of the powders was found to be 48nm.The effect of calcinations
temperature on crystallinity, morphology and magnetic properties have been
investigated. The sintered samples were characterized using XRD, FE-SEM and EDS.
The hexagonal ferrite formation was observed around 900°C which is confirmed with
the TG/DTA curves. The plate shape grains were observed in FE-SEM at 950°C. The
grain sizes of sintered hexaferrites are in the range of 220nm to 850nm. The value of
Ms= 70 emu/g and Hc=540 Oe was obtained at 900°C/5h.

Dong Zhou1, Wei Li1, Minggang Zhu1*, Yanfeng Li1, Wei Sun1 and Fashen Li2
1
Central Iron & Steel Research Institute, China
2
Lanzhou University, China

With the development of computers and communication devices using theelectromagnetic wave of GHz range, the serious electromagnetic interference (EMI)have been emerged. The electromagneic wave absorbers have been widely investigatedto eliminate the EMI problems. Electrodeposition is one of the simplest, mostflexible, and cheapest processes available for the fabrication of single component andmultilayered thin films. In this study, FeNi alloys thin films have been successfully
electrodeposited on Ag films. The morphology, structure, composition, and magnetic
property of the FeCo films were characterized by scanning electron microscopy,
x-ray diffraction, energy dispersive spectrometer, vibrating sample magnetometer andnetwork analyzer. With the increase of depostion time, the coercivity of deposited
FeNi films reduce until getting a minimum value and the the real part of permeability
increase. At the same time, the increase of the thickness leads to the decrease ofresonance frequency. We also study the effect of the compostion on the coercivity andmicrowave magnetic properties. By changing the compositon of FeNi alloy films, theeffective permeability and the resonance frequency can be adjusted.

1. J.A. Paulson et al. J. Appl. Phys., 97, 44502 (2005). 2. S.D. Bhame and P.A. Joy, J. Appl. Phys.,
100, 113911 (2006).

238

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

239

poster Presentation

poster Presentation

QN22

QN25

QO02

QO05

Preparation and characterization of ferromagnetic fluid and magnetorheological fluid

A novel low-temperature-fired multifunctional varistor-magnetic
NiCuZn ferrites

Optimized Halbach array based magnet systems for Lorentz force
velocimetry purposes

Magnonic meta- and meta-meta-materials

2

3

1

Tae Min Hong , Jong Hee Kim , Cheolgi Kim and Seung Goo Lee *1
Advanced Organic Materials & Textile System Engineering, Chungnam National
University, Korea
2
Research Center for Advanced Magnetic Material, Chungnam National University,
Korea
3
Materials Science & Engineering, Chungnam National University, Korea

July 10 (Tue)Ferromagnetic fluid and magneto-rheological fluid are liquids that nanometer-sizedparticles of iron dispersed in the medium. PEG(polyethylene glycol) and silicon
oil were used as the fluidic media. Fluids are flexible dispersion state under a nonmagnetic field. But, under a magnetic field, particles are oriented in the direction of themagnetic field and the fluid shows the solid-like behavior. In this study, we studied toknow how the magnetic field impacts the yield stress of ferromagnetic and magnetorheological fluids. Yield stress of the fluid is evaluated by the viscosity measurement.
Viscosity behaviors of ferromagnetic and magneto-rheological fluids are measured
with a magneto-rheological viscometer (MCR 301, Anton paar, Austria) with applying
magnetic field from the plate. Two types of experiment were conducted. One is a static
test in which the viscosity of fluids is measured with increasing shear rate while theapplied magnetic field is fixed. The other one is a dynamic test in which the viscosityof fluids is measured with increasing magnetic field while shear rate is fixed. As theresults, viscosity of ferromagnetic fluid and magneto-rheological fluid increased largely
by applying magnetic field in all conditions.

Wei-hung Hsu, Hsing-i Hsiang* and Li-then Mei
Resources Engineering, National Cheng Kung University, Taiwan

A novel low temperature-fired(950°C) multifunctional varistor-magnetic ferrite
materials can be obtained by adding Bi2O3 into Zn0.5Ni0.3Cu0.19Nb0.01Fe2.02O4 ferrites.
The relationship between the microstructure and varistor properties were investigatedusing scanning electron microscopy (SEM), X-ray Diffraction (XRD), and impedance
analysis. For Zn 0.5Ni 0.3Cu 0.19Nb 0.01Fe 2.02O 4 ferrites with 2.5wt% Bi 2O 3 content
sintered at 950°C for 2h, the nonlinearity exponent (α) can reach 5.1 and the initial
permeability(μ) is about 200 to 250. Moreover, the αvalue can be promoted to 67.8 for
the Zn0.5Ni0.3Cu0.19Nb0.01Fe2.02O4 ferrites added with 9Bi2O3-CuO sintered at 950°C for
2h.

1

2

Michael Werner * and Bernd Halbedel
1
University of Technology Ilmenau, Germany
2
Department of Inorganic-Nonmetallic Materials, University of Technology Ilmenau,
Germany
Lorentz Force Velocimetry (LFV) is in research since 2003. The Lorentz force acting
on a source magnet system is providing a velocity dependent signal. The efficiency ofthe magnet system (ratio of generated Lorentz forces to the mass of the system) is an
essential parameter for sufficient resolutions of the whole LFV sensor device. The fullarticle will propose a very efficient combination of permanent magnet arrays, where
the particular permanent magnets have different magnetization directions. Here aniron yoke is not necessary, respectively ineffective, and so the arrays can be assembled
with a very light carbon fiber composite fixture in order to reduce the overall mass
further. The underlying principle of this array combination will be presented and thegeometric optimization with commercial software, as well as the assembling method,
will be explained. On an experimental test channel for LFV on electrolyte flows themagnet system is tested and compared to another simple standard magnet system withsingle permanent magnet blocks instead of the arrays. From previous finite element
simulations an increase of a factor of three in efficiency is estimated and will be provenin the experiment. Further improvement using cladding technique will be introducedtoo.

We report on magnonic metamaterials represented by a system of magnetic layers
separated by those of a dielectric non-magnetic material. In such a metamaterial, theconstituent elements are made from a magnetic material that provides an easy way
to control its electromagnetic response by tuning the bias magnetic field. Firstly, we
report a theory of the effective permeability of planar multilayered metamaterials
containing thin ferromagnetic layers with magnetization pinned on either one or both
surfaces. The pinning of the magnonic modes at film surfaces facilitates their coupling
to the uniform magnetic field of the incident electromagnetic wave. We demonstratethat such structures, for magnetic parameters characteristic for conventional transition
metal alloys, exhibit a negative refractive index at sub-THz frequencies. Furthermore,
we show how the constituent magnetic layers of such systems could themselves benanostructured into planar magnonic crystals, with the whole structure therefore
representing a meta-metamaterial. Due to the additional nanostructuring, the negative
permeability at sub-THz frequencies can be achieved as a result of a small lattice
constant and lateral quantization of spin waves. Finally, we discuss the prospects forfabrication of such metamaterials and their experimental studies.

QN23

QN26

QO03

QO06

Microwave magnetic and absorbing properties of the planaranisotropy Ce2Fe17N3-δ powder composite

Synthesis and magnetic properties of transition metal ferrite
nanoparticles

Growth and characterization of SmFe6Ge6 single crystals

Understanding the nature of magnetic phase transition in relevance tomagnetic refrigeration

Jianqiang Wei, Wenliang Zuo, Tao Wang and Fashen Li*
Key Laboratory of Magnetism and Magnetic Materials of Ministry of Education,
Lanzhou University, China

Ce2Fe17N3-δ powders were prepared by arc-melting, milling and nitrogenation. The microstructureand static magnetic properties of the powders were analyzed by x-ray diffraction (XRD) andvibrating sample magnetometer (VSM), respectively. The c-plane alignment of Ce2Fe17N3-δ wasevaluated with the XRD data of an aligned composite sample. The effective complex permeabilityof Ce2Fe17N3-δ powders/epoxy resin composite was measured in the frequency range of 0.1-15 GHz.
The intrinsic static permeability of Ce2Fe17N3-δ powder was calculated by Bruggerman (BG) effective
medium theory. The natural resonance frequency of Ce2Fe17N3-δ was obtained using Landua-LifshitzGilbert (LLG) equation. The Snoek's product of the effective static susceptibility and the resonancefrequency is much larger than the Snoek's limit of the composite. The reflection loss of the composite
sample was determined by simulation and by measuring the S11 parameters after rear face ofsample was terminated by metal. The minimum reflection loss was found moving towards the lower
frequency region with increasing the sample thickness. Quantitatively analysis reveals that the peakfrequencies (fp) of the dips (minimum reflection loss), the μ(fp), the ε(fp) and the sample thickness
obey the quarter-wavelength (λ/4) formula. Accordingly, the quarter-wavelength formula have beensuccessfully applied to explain and predict the microwave absorbing properties.

Tejabhiram Yadavalli1, Shivaraman Ramaswamy1, Gopalakrishnan Chandrasekaran1
and Ramasamy R2
1
Nanotechnology Research Centre, SRM University, India
2
School of Pharmacy, SRM University, India
The use of ferromagnetic metal ferrite particles for magnetic hyperthermia application
has been extensively studied by many scientists. The use of ferromagnetic particles withlow curie temperatures result in the formation of self regulated magnetic hyperthermia.
In this context, multiple experiments on synthesizing ferrite nanoparticles with varying
cobalt and nickel oxide concentrations have been done. The products were analyzed
using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction
and vibrating sample magnetometer. The microscope images indicated the formationof nanoparticles while the spectroscopy and diffraction patterns indicated the formationof nickel and cobalt ferrite nanoparticles along with additional nickel oxide and cobalt
oxide. Magnetometer analysis conducted on the samples indicated a reduced magnetic
saturation and hysteresis. Hysteresis loss energy was determined by calculating the area
under the hysteresis loop, frequency of the magnetic field and the curie temperature of
the material. The results indicated a two-fold decrease in the hysteresis energy giving ahint for their use in controlled magnetic hyperthermia treatment.

Rodrigo S. Monteiro, Lucas K. Piquini, E. Thizay Magnavita, Raquel A. Ribeiro andMarcos A. Avila*
Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Brazil
Hexagonal single crystal plates of SmFe6Ge6 have been grown by the flux method
using a 4th flux element (Sn), extending the range of members in the RFe6Ge6 familyof magnetic compounds, whose physical properties have so far been described
only for rare earths R = Gd-Lu [1]. This family exhibits antiferromagnetic (AF II)
ordering at 450 K of the layered Fe honeycomb sublattice, and independent ordering(or no ordering) of the R sublattice moments below 30 K. Here we present a basic
characterization of the structural, magnetic and transport properties of the SmFe6Ge6
crystals and compare the general anisotropic behavior with other members of thefamily. We thank the support of Brazilian agencies FAPESP and CNPq.
[1] G. Venturini, R. Welter and B. Malaman, J. Alloys Comp. 185 (1992) 99-107.

S M Yusuf*
Solid state physics division, bhabha atomic research centre, mumbai 400085, India

It is important to understand the nature of magnetic phase transition for a material suitable for magnetic
refrigeration. With this aim, we have studied a wide class of intermetallic compounds with diversity in their natureof magnetic ordering and phase transition, such as ferromagnetic ordering, ferrimagnetic ordering, coexistenceof ferromagnetic and antiferromagnetic ordering, metamagnetic transition, and magnetostructural transition. The
dependences of the nature of magnetic phase transition on temperature, magnetic field and chemical substitutions
have been investigated. The role of the nature of exchange interaction and universality class in determining
magnetocatoric effect (MCE) has been brought out by investigating the intermetallic compounds TbCo2-xFex and
Mn4FeGe3-xSix. A phase coexistence of ferromagnetic and antiferromagnetic phases has been observed in Cu1xNixMnSb semi-Heusler alloys around x = 0.15 where a large MCE is found as a low applied magnetic field
causes an AFM to FM phase transformation. A broad operating temperature range due to coexistence of AFM
and FM phases, and quenched disorder has also been obtained. The role of other interesting phenomena, such as
metamagnetic transitions and domain wall pinning in obtaining a large MCE and an inverse MCE, respectively,
has been brought out through the investigation of the intermetallic compounds NdMn2-xCoxSi2.
[1] M. Halder, S. M. Yusuf, M. D. Mukadam, and K. Shashikala, Phys. Rev. B 81, 174402 (2010). [2] M.
Halder, S. M. Yusuf, A. Kumar, A. K. Nigam and L. Keller, Phys. Rev. B 84, 094435 (2011). [3] M. Halder, S.
M. Yusuf and A. K. Nigam, J. Appl. Phys. 110, 113915 (2011). [4] M.D. Mukadam, and S.M. Yusuf, Physica B:
Cond. Matter 405, 686 (2010). [5] M. D. Mukadam and S. M. Yusuf, J. Appl. Phys. 105, 063910 (2009).

This work is supported by the National Basic Research Program of China (Grant No.
2012CB933101) and the National Natural Science Foundation of China (Grant No. 11144008).

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QO07

Co2Y-NiCuZn ferrite composites for high frequency applications

High room temperature power factor (Z) in KxRhO2

Anomalous magnetic and related properties of Nd5Ge3

Specific heat study on successive magnetic transitions in α-Dy2S3 single
crystal under magnetic fields

The most commonly used materials in inductors for high-frequency applications are
NiCuZn ferrites, or non-magnetic materials such as low-temperature cofired ceramics.
The non-magnetic materials are used for high-frequency applications because NiCuZnferrites (ferroxcube) typically exhibit severe property changes above 200MHz due tothe Snoek limit. The maximum quality factor frequency in chip inductors made of nonmagnetic material is over 500 MHz. However, the quality factors at frequencies around200-300MHz are much lower than those at higher frequencies. Because chip inductors
are prepared by winding a wire around a non-magnetic material core it is necessary
to have a larger number of coil winding turns to obtain the desired inductance; thus
limiting miniaturization. Therefore, it is desirable to develop a magnetic material thathas a higher initial permeability and quality factor than non-magnetic materials at 200300 MHz, for use in making high frequency inductors. In this study, a Co2Y-NiCuZnferrite composite with high permeability was prepared by coating NiCuZn ferrites onto
the surface of Co2Y ferrites using heterogeneous nucleation process. The effects of
NiCuZn ferrites addition on the densification behavior, micro-structure and magnetic
property of Co2Y-NiCuZn ferrite composites were investigated.

We discuss the thermoelectric and optical properties of layered KxRhO2 by means of
the electronic structure determined by first principles calculations as well as Boltzmanntransport theory. The main contribution to the optical spectra are due to intra and interband transitions between the Rh 4d and O 2p states. Our results of transport perproties
of KxRhO2 at room temperature show highest value among hole-type materials.
Specially at 100 K, the Z value of KxRhO2 is 3x10-3 K-1. Our results show that theelectronic and optical properties of KxRhO2 are similar to NaxCoO2 with an enhanced
transport properties.

Ruei-lin Lin and Hsing-i Hsiang*
Resources Engineering, National Cheng Kung University, Taiwan

240

Rostislav V. Mikhaylovskiy 1*, Michal Mruczkiewicz 2, Maciej Krawczyk 2 andVolodymyr V. Kruglyak1
1School of Physics, University of Exeter, United Kingdom
2
Faculty of Physics, Adam Mickiewicz University, Poznan, Poland

The 19th International Conference on Magnetism

Nirpendra Singh, Yasir Saeed and Udo Schwingenschlogl*
King Abdullah University Science and Technology Thuwal, Saudi Arabia

July 10 (Tue)1

Bibekananda Maji1*, K G Suresh1 and A K Nigam2
1
Physics, Indian Institute of Technology Bombay, Mumbai- 400076, India
2
Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai- 400005,
India
We have observed that the stoichiometric intermetallic compound Nd5Ge3 shows many
anomalies in the magnetization, resistivity and heat capacity data. This compound
undergoes an antiferromagnetic (AFM) transition at 46 K and another one at 30 K on
cooling. It is found that the strengths of these two antiferromagnetic states are different.
Ultra-sharp jumps are seen in the low temperature isotherms of magnetization, heat
capacity and electrical resistivity. Another important anomaly is the field-induced
irreversibility in all these three properties, which suggests that the spin, electronic andlattices states are strongly coupled in this compound. The memory effect seen here isquite remarkable and is consistently seen in various measurements. Another striking
observation is the spontaneous evolution of the ferromagnetic (FM) phase as a functionof time, at a fixed temperature and at the critical field. Sweep rate and cooling fielddependencies point towards the role of martensitic strains in the anomalous behavior.
The compound appears to show the coexistence of FM and AFM components at low
temperatures. The features seen in this compound indicate the presence of disorder in
influencing the magnetic and related properties considerably. The correlation of various
properties as seen from the martensitic scenario will be presented.

Shuji Ebisu*, Yuji Ushiki and Shin Takahashi
Division of Applied Sciences, Muroran Institute of Technology, Japan

Specific heat measurements in magnetic fields have been performed on α-Dy2S3 single
crystal which shows successive magnetic transitions at TN1 = 11.5 K and TN2 = 6.4
K¹. The specific heat in no magnetic field exhibits sharp peaks at both temperaturesof TN1 and TN2. The change of magnetic entropy at each transition is estimated as
N0kBln2 per mole of Dy2S3, which suggests Dy moments on only one site between two
crystallographically inequivalent Dy sites order at each transition temperature. Whenthe magnetic field is applied along the b-axis of the orthorhombic system, two peaks ofthe specific heat shift toward lower temperatures. On the other hand, the magnetic field
perpendicular to the b-axis shifts the peaks toward higher temperatures. The transition
temperature TN1 shifts to 9.6 K (H//b) and 12.5 K (H┴b) with keeping sharpness ofthe peak under the magnetic field of μ0H=2 T. The peak of TN2 broadens graduallywith increasing the magnetic field for each direction, and the peak is consequently
obscure under the field of 2 T.
¹ S. Ebisu, M. Narumi, M. Gorai and S. Nagata, J. Magn. Magn. Mater. 310, 1741 (2007).

July 8-13, 2012 Busan, Korea

241

poster Presentation
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QO17

Magneto-inductive wave in periodic chains of ferrite cores and chipcapacitors

Reconstruction of cubic rs-ZnO on MgO (200) substrate through 100
plane of w-Zn for transparent electronic application

Investigation of magnetic-field tunable properties ofmagnetorheological elastomers

Enhancement of the refrigerant capacity in Gd65Fe20Al10B5 alloys bypartial crystallization of melt-spun amorphous ribbons

In this paper, we present a new magneto-inductive wave generated in a chain ofresonators fabricated with ferrite cores and chip capacitors. RF signal propagates toneighbor resonator one by one as a consequence of the magnetical coupling between
two resonators in our device. The magnetical coupling is due to the mutual inductancesalong chains of resonators. So, the signal amplitude (? coupling intensity) is inversely
proportional to the distance between two elements. In order to design the device, someelectromagnetic simulations and experiments have been carried out systemically.
The transmission characteristics of a magneto-inductive wave could be controlled byapplied external magnetic field. For, the device composed of 5 resonance elements,
the center frequencies were estimated to be 41.1 MHz and 34.8 MHz with the external
magnetic flux density of 750.72 G and 2680 G, respectability. The reported result
opens a promising way to a high variety of applications in one- and two-dimensional
functional devices, such as transducers, delay lines, power dividers and couplers.

Chungman Kim1, Santosh M Bobade1, Seong-min Choo1, Suhyun Kim1, Kyung Ho
Shin2 and Myung-haw Jung1*
1
Sogang University, Korea
2
Korea Institute of Science and Technology, Seoul, Korea
ZnO crystallizes in various crystallographic forms. However, wurtzite (w) ZnO isgenerally observed structure while the rock salt (rs) structure of ZnO appear at highpressure. We present rs-ZnO structure grown on MgO (200) substrate at certain
growth environments, not high pressure. The lattice constant of MgO. The possible
configurational path for transformation is proposed, so that the compression of w-ZnO
along c-axis and movement of Zn or O sublattice along (110) direction and (110)plane.
These results are confirmed by X-ray diffraction and X-ray photoemission spectrum
experiments. It has also been observed that rs-ZnO on MgO substrate is stable forcertain minimum thickness (in this case, it is 150nm) and possible be stabilize at lower
temperature for few nm thickness

Jozef Marcin1, Zbigniew Sniadecki2, Jozef Kovac1, Peter Svec3, Bogdan Idzikowski2
and Ivan Skorvanek1*
1
Institute of Experimental Physics SAS, Kosice, Slovakia
2
Institute of Molecular Physics PAS, Poznan, Poland
3
Institute of Physics SAS, Bratislava, Slovakia

In this work we present the results of investigation of magnetic field influence on thevalue of dielectric permittivity and magnetic susceptibility in magnetorheologicalelastomers (MRE) based on the powders with various magnetic properties - Fe, FeNdB
and Fe3O4. Both magnetic susceptibility and dielectric permittivity have been found to
be considerably changed under magnetic field, the changing of permittivity value up to
150% has been observed. The field dependence of the dynamic dielectric permittivity
was significantly non-linear. The anisotropy of field influence on the permittivity andsusceptibility was observed as well. The saturation magnetization and coercivity of themagnetic fillers have been shown to be the most important factors affecting the fielddependence of permittivity. In addition, the size and concentration of particles as well as
conductivity of magnetic material have significant influence on the type of field effect.
The influence of named parameters on the permittivity and susceptibility changing is
discussing; we consider the mechanisms determining the features of magnetic field
influence on studied physical properties in detail. It is shown that MRE based on various
magnetic particles can be considered as promising materials with magnetic-field tunableproperties. Supported by Russian Foundation for Basic Research.

The magnetocaloric effect (MCE) is attracting a great deal of scientific interest because it is a basis of theenvironmentally friendly magnetic refrigeration technology. Among the recently developed magnetic
refrigerant materials, the Gd(Fe,Mn)Al-based glassy alloys combine good magnetic entropy characteristics
with sufficiently high effective magnetic moment per volume, which makes them promising candidates
for magnetic refrigeration in the operating temperatures around 150 K [1,2]. In this work, we report on thebeneficial effect of partial crystallization on magnetocaloric properties of melt-spun Gd65Fe20Al10B5 alloys. The
magnetic entropy changes, ΔSm, were calculated from the magnetization versus applied field dependences
measured in the temperature range from 5 to 390 K. The value of the maximum magnetic entropy change
under 50 kOe for the Gd65Fe20Al10B5 ribbon reached 5.01 J/kg K at 185 K. The corresponding value of therefrigeration capacity, RC, determined as the area below the ΔSm peak with the integration limits at its half
maximum is 647 J/kg. We have found that this value can be further enhanced by suitable heat treatmentof melt-spun ribbons leading to a formation of hexagonal Gd particles with higher Curie temperature. The
observed improvement is discussed in relation with two-phase character of partially crystallized samples.
[1] S. Gorsse, B. Chevalier, G. Orveillon, Appl. Phys. Lett. 92 (2008) 122501 [2] Y.K. Fang, C.H.
Lai, C.C. Hsieh, X.G. Zhao, H. W. Chang, W.C. Chang W.Li, J. Appl. Phys. 107 (2010) 09A901

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Large refrigerant capacity in Ni2.9Co0.1MnIn type-Heusler alloy

Magnetic cooling machine prototype based on cold rolled Gd foil

Disagreement between modification methods for magnetism-absorbing
agent

Chemical pressure effects on half-metallic properties in single crystalsof A2FeMoO6 (A = Ca, Sr, and Ba)

Two methods are widely used to improve absorbing properties of the microwave
magnetism-absorbing agent: mixing with the other material such as resistancecarbon fiber absorbent, or wrapping the microwave magnetism-absorbing agent
in that material. However, do these two methods coincide with each other? If not,which method should be used as better way to represent the absorbing properties ofmagnetism-absorbing agents? To answer these questions, both methods are carried out
on the same magnetism-absorbing agents, of which the results are compared. Distinct
difference between these measured results is found, and the possible reasons for thedifference are also discussed.

An ordered double perovskite oxide Sr2FeMoO6 has been predicted and widely studied
as a half-metal, in which electrons with only one spin direction present at the Fermi
level (100% spin polarization), above room temperature. In this study, in order toimprove the half-metallic properties, the chemical pressure effects, through A-site
substitution, on the magnetic and electronic properties have been examined using single
crystalline samples of A2FeMoO6 (A = Ca, Sr, and Ba) grown by the floating zone
method. In the A = Ca crystal, every property related to the half-metallic performance
was found to be degraded as compared with the A = Sr and Ba crystals: the saturation
magnetization and the Curie temperature were significantly decreased, metallic
conductivity became more than twice larger, and the spin polarization (evaluated byAndreev reflection spectroscopy) was reduced below 50%. From the results in the
A = Sr and Ba crystals, it is suggested that the optimized half-metallic performance
will be obtained in between these two compositions. Optical measurements were also
performed to gain insight into the change of electronic structures with respect to the
A-site substitution.

QO19

Catalina Salazar Mejia 1, Angelo M Gomes 1, Ana Lima Sharma 2 and Fivos R
Drymiotis3
1
Instituto de Fisica, Universidade Federal do Rio de Janeiro, Brazil
2
Materials Physics Department, Sandia National Laboratory, Livermore, CA, USA
3
Department of Physics and Astronomy, Clemson University, Clemson, SC, USA
Magnetic refrigeration (MR) is a cooling method that is based on the magnetocaloric effect (MCE). Our
research effort focuses on identifying magnetic structures that may have improved efficiency with suitablecharacteristics for MR i.e. good magnetocaloric properties with small or zero thermal and magnetic
hysteresis. Some Heusler alloys may meet these criteria. The Ni2MnIn full-Heusler alloy exhibits a secondorder paramagnetic to ferromagnetic transition at 300 K, but its MCE is small [1,2]. However, we observea large improvement in the refrigerant capacity (RC) value when the Ni2MnIn is Co and Ni-doped. In thispaper, we present the study of the magnetic, structural and magnetocaloric properties of the Ni2.9Co0.1MnIn
Heusler-type alloy. The samples crystallizes in a cubic structure. Magnetization measurements show aferromagnetic transition at 207 K. The transition is almost 40 K wide, and thermal hysteresis is negligible.
The magnetic entropy change, ΔSM, for ΔH=5T, was calculated from heat capacity data and the maximum
value found is -2.75 J/kg K, with broad temperature range which leads to RC=261.3 J/kg. The large RC
value found and the absence of thermal hysteresis makes this material a good candidate for magnetic
refrigeration applications. C.S.M. and A.M.G. would like to thank CNPq and FAPERJ.

Sergey V. Taskaev*, Vasiliy D. Buchelnikov, Victor V. Nikolenko, Ivan A. Chernets
and Andrey N. Denisovsky
Physics department, Chelyabinsk State University, Russia
With the discovery of the “giant magnetocaloric effect“ (Pecharsky and Gschneidner, 1997)
the development of magnetic refrigeration gained increased momentum [1]. One of theways of engineering MCE materials is tightly connected with preparing very thin (a few
microns) ribbons of high value MCE alloys with good mechanical properties. At present rapid
solidification is the main technique for producing this kind of materials [2]. In our work we
present magnetic cooling device which is used Gd cold rolled samples of different thickness asa working body. Magnetocaloric, mechanical and other properties of this material are discussed
Morphology of the surface was investigated by AFM methods. Magnetocaloric effect wasmeasured by direct method on AMT&C setup. Mechanical properties was investigated on
Netzsch DMA 242C. Magnetic properties was measured on SQUID magnetometer. X-ray
analysis was performed on Brucker D8 Advance difractometer. Several axial magnetic systems
are proposed as the source of high gradient magnetic field. Depending on the air gap ofmagnetic system the residual magnetic induction is in 600 mT..1900 mT range. It is shown, thatcold rolling technique is the alternative way for producing thin ribbons of MCE materials withgood mechanical properties for magnetocaloric application.

Wu Chao, Lv Xuliang*, Zeng Zhaoyang, Wen Xiaodi and Wen Liuqiang
PLA University of Science and Technology, China[1] T. Krenke, et al., Phys. Rev. B 73, 174413 (2006). [2] C. Salazar Mejia, et al., unpublished.

1.Gschneidner K.A. Jr. et al. Thirty years of near room temperature magnetic cooling: Where we aretoday and future prospects, Int. J. Refrig, 31, 945 (2008). 2.P. M. Shan et al. Magnetic behavior ofmelt-spun gadolinium, Phys. Rev. B. 77, 184415 (2008).

QO10

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Reduction of weak localization strength on controlling oxygen defects
by ex-situ annealing

Research on the orbital state of IrO2 with resonant x-ray scattering
methodOrdered magnetic arrays of cobalt SMM: properties and therelationship with crystal symmetry and SMM environment

Seong-min Choo1, Kyujoon Lee1, Sungmin Park1, Gwang-seo Park1, Jungwon Jang2,
Jinhee Kim2 and Myung-hwa Jung1*
1
Department of Physics, Sogang university, Korea
2
Korea Research Institute Standard Science, Korea
We have studied Pb-based gapless semiconductors, which are very sensitive to externalparameters such as temperature, pressure, magnetic field, electric field, etc [1]. Basedon the theoretical paper, this material has a strong spin-orbit interaction. So, we havefabricated pure PbPdO2, Co- and Mn-doped PbPdO2 thin films. Because a Pb is aneasily vaporized element when we grow the films, the films have a lot of oxygen
vacancies. It may induce other problems. For example, Pd is unstable state as Pd+1
and the oxygen vacancies act as additional hole carriers. To study intrinsic propertiesof doped PbPdO2 thin films, we tried to various methods to enhance the films quality.
Because Pb is hard to handle in growth process, we have annealed thin films withdifferent annealing time, temperature, and environments after deposition. The carrier
densities for all the samples are deceased with annealing time while the electric
resistivities are changed in different way. More importantly, weak localization strength
is most likely to be reduced by ex-situ annealing. Furthermore, magnetoresistance ratio
is also reduced by increasing ex-situ annealing time.

Yasuyuki Hirata1, Kenya Ohgushi1, Junich Yamaura1, Hiroyuki Ohsumi2, Soshi
Takeshita2 and Takahisa Arima3
1
Institute for Solid State Physics, University of Tokyo, Japan
2
RIKEN SPring-8, Japan3
Department of Advanced Materials Science, University of Tokyo, Japan

In the 5d electron systems of iridium oxides, the crystal fields, the Coulomb repulsion, andthe spin-orbit interaction compete with each other, which results in various exotic physicalproperties. For example, magnetic iridium oxides Sr2IrO4 and CaIrO3 are known to bespin-orbit-induced Mott insulators: the reported resonant x-ray scattering experiments
showed that 5d t2g orbitals of Ir are reconstructed by the spin-orbit interaction and realize
the complex Jeff=1/2 orbital states, which form a narrow band and enhance the electron
correlation.[1] On the other hand, the orbital states of metallic iridium oxides like IrO2,
which is attracting attention for a gigantic spin-Hall effect, are yet to be investigated. We
performed a resonant X-ray scattering measurement for metallic iridium oxide IrO2 which
has a rutile-type structure, and observed the 0 0 3 reflection coming from the anisotropic
tensor of susceptibility (ATS). In the energy spectrum the peak corresponding to theexcitation to 5d t2g orbitals appeared around the L3 absorption edge, but did not appear
around the L2 absorption edge. These results indicate that the complex Jeff=1/2 states of
5d t2g orbitals are realized even in metallic iridium oxides IrO2.
[1] B. J. Kim et al., Science 323, 1329 (2009).

242

Nikolai Perov1*, Anna Semisalova1, Elena Yu Kramarenko1, Alexey R Khokhlov1 andGennady V Stepanov2
1
Lomonosov Moscow State University, Russia
2State Research Institute for Chemistry and Technology of Organoelement
Compounds, Moscow, Russia

The 19th International Conference on Magnetism

Milagros Tomas1, Cristina Saenz De Pipaon2, Elena Forcen-vazquez2, Isabel Mayoral2,
Larry Falvello3, Javier Campo2 and Fernando Palacio4*
1Instituto de Sintesis Quimica y Catalisis Homogenea (ISQCH), Consejo Superior deInvestigaciones Cientificas and University of Zaragoza, Spain
2
Instituto de Ciencia de Materiales de Aragon, Consejo Superior de Investigaciones
Cientificas and University of Zaragoza, Spain
3
Departamento de Quimica Inorganica and Instituto de Ciencia de Materiales de Aragon,
Consejo Superior de Investigaciones Cientificas and University of Zaragoza, Spain
4
Instituto de Ciencia de Materiales de Aragon (ICMA), Consejo Superior deInvestigaciones Cientificas and University of Zaragoza, Spain

The modulation of the magnetic properties of SMMs and their organization in extended magnetic arrays
are, at the present, some of the top areas in the field of molecular magnetism for the implication in the
improvement of the physical properties of the SMM and the potential use in devices such as for data
storage. Few polymers of SMM have been structurally characterized in spite of the number of known
SMM. [Co4citrate4]8- cubanes can behave as SMM.(1) We have reported recently(2) the union ofthese cubanes through “Co(H2O)2ETG” (ETG=ethylene glycol) bridges and the formation of anionic
2D layers. These layers crystallize in the tetragonal system, P-421c space group, with counterions (Cs+or Rb+), water and ETG molecules connecting the layers though electrostatic interactions and hydrogenbridges. The magnetic studies show the co-existence of two magnetic nets: the SMM net and the one
formed by the bridged cobalt atoms and also shows the influence of the counterions in the layer magnetic
properties. Two intriguing relaxation processes with different characteristics timescales are observed.
Moreover, [Co4citrate4]8- cubanes can also organize in 3D, diamond-like structural arrays showing
SMM magnetic behaviour below 6K with an energy barrier of 54K and magnetic ordering below 2.7K.

July 10 (Tue)Yongmin Kim and Kwang-ho Shin*
Dept. of Information and Communication Engineering, Kyungsung University, Korea

July 10 (Tue)poster Presentation

Akira Isayama* and Takao Sasagawa
Materials and Structures Laboratory, Tokyo Institute of Technology, Japan

Magnetic label field collector of biochip sensor

Sunjong Oh, Brajalal Sinha, Jaein Lim and Chelgi Kim*
Department of Materials Science and Engineering, Center for NanoBioengineeringand Spintronics, Chungnam National University, Korea
We have proposed a new method called stray field collector (SFC) of magnetic labels
for signal enhancement in the magnetoresistive biosensors. The proposed design related
to qualitative as well as quantitative detection of magnetic beads. The integration of
SFC in magnetic sensor will increase the amount of stray field via the increase of active
surface area. Therefore, this SFC may have great potential to improve the performanceof magnetic biosensor.
[1] Adarsh Sandhu, et al, “High efficiency Hall effect micro-biosensor platform for detectionof magnetically labeled biomolecules,” Biosensors and Bioelectronics, 22, 2115-2120, 2007.
[2] Guanxiong Li, et al, “Spin valve sensors for ultrasensitive detection of superparamagnetic
nanoparticles for biological applications,” Sens Actuators A Phys., 126(1), 98-106, 2006. [3] W.
Clark Griffith, et al, “Miniature atomic magnetometer integrated with flux concentrators,” Applied
Physics Letters, 94, 023502, 2009.

1- M. Murrie, Chem. Soc. Rev. 2010, 39, 1986 -1995. 2- E. Burzuri, J. Campo, L. Falvello, E. Forcen-Vazquez, F.
Luis, I. Mayoral, F. Palacio, Cristina Saenz de Pipaon, M. Tomas. Chem. Eur. J. 2011, 17, 2818-2822.

July 8-13, 2012 Busan, Korea

243

poster Presentation

poster Presentation

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QO26

QP01

Cogging torque cancellation technique for dual rotor type motor using
adjustment between outer and inner rotor magnet angle

Magnetism and transport properties of epitaxial Mn5Ge3 thin films on
GaAs(001) and GaSb(001)Theoretical and experimental studies of valence states in Fe-Mo
compounds

Magnetic coupling at the CoO/Ni interface

Dang Duc Dung1, Doji Odkhuu2 and Sunglae Cho2*
1
Department of General Physics, School of Engineering Physics, Ha Noi Universityof Science and Technology,1 Dai Co Viet road,Ha Noi, Viet Nam
2
Department of Physics, University of Ulsan, Ulsan 680-749, Korea

In this paper, we design the IPM motor and discuss the design method of double rotor permanent
magnet motor for cancelling the cogging torque. According to downsizing the electric motor, high torqueand power density are the most serious requirements for electric machines. Double rotor permanent
magnet motor is proposed to solve the problem. But it has a large cogging torque that generates thelarge acoustic noise. A variety of techniques exist for reducing the cogging torque of conventional radial
flux IPM machines. This paper introduces a new cogging torque minimization technique for radial flux
multiple IPM motors. Optimization of the adjustment magnet angle between outer rotor and inner rotor
which results in offset cogging torque and assessment of the effect on the maximum available torqueusing Finite Element Analysis (FEA) is investigated. In our experiments, Prototype dual rotor typemotor has achieved the outer rotor and inner rotor cancellation of cogging torque by 70 percent.

The epitaxially ferromagnetic Mn5Ge3 thin films were grown on GaSb(001) andGaAs(001) substrates using molecular beam epitaxy. Our result revealed that thesubstrate facilitates to modify magnetic and electrical properties due to tensile strain
effect. The Curie temperature was remained above 350 K for samples grown on
GaAs(001), while was about 320 K for samples grown on GaSb(001). The anomalous
Hall effect were observed up to 370 K and 320 K for films grown on GaAs(001)and GaSb(001), respectively, which are strong evidence for spin polarization. Ourelectronic calculation indicated that the difference in Mn-Mn bond length in Mn5Ge3
modified the magnetization and spin polarization. The strains are promised to control
both magnetic properties and spin polarization.

July 10 (Tue)[1] R. Qu and T. A. Lipo, 'Dual-rotor, radial-flux, toroidally wound, permanent-magnet machines',
IEEE Transactions on Industry Applications, Vol. 39, No.6, Nov/Dec 2003, pp.1655-1673. [2] R.
Qu, and T. A. Lipo, 'Design and parameter effect analysis of dualrotor, radial-flux, toroidally wound,permanent-magnet machines', IEEE Transactions on Industry Applications, Vol. 40, No.3, May/
June 2004, pp.771-779 [3] R. Qu and T. A. Lipo, 'Sizing Equations and Power Density Evaluationof Dual-Rotor, Radial-Flux, Toroidally Wound, Permanent-Magnet Machines,' XVI International
Conference on Electrical Machines, ICEM 200r, Cracow, Poland, Sept 2004.

Francisco Estrada1*, Reginaldo Mondragon1, Humberto Noverola2, Jaime Raul
Suarez3, Martha Teresita Ochoa1, Francisco Espinosa1, Lorena Alvarez1, Ricardo
Morales4, Jose Lemus4, Oracio Navarro2 and Michel Avignon3
1
Centro de Investigacion en Materiales Avanzados, S. C, Mexico
2
Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de
Mexico, Mexico
3
Institut Neel, CNRS and Universite Joseph Fourier, France
4
Instituto de Investigaciones Metalurgicas, UMSNH, Mexico

The half-metallic ferromagnetic double perovskite compound Sr2FeMoO6 is considered as animportant material in view of its potential spintronic applications. It appears to be fundamental tounderstand the role of electronic parameters controlling the half-metallic ground state. In particular,
half-metallic ferromagnetic compounds have been searched as a source of spin polarized currents. In
this work, we study the valence states of cations in Fe-Mo based double perovskites from theoreticaland experimental point of view. In the experimental case, we apply the electron energy-loss
spectroscopy (EELS) technique. For transition metals, L2,3 edges of EELS are characterized by two
sharp peaks, known as white lines. EELS experiments have shown that the change in valence statesof cations introduces significant modification in the energy and shape of the white lines, leading to thepossibility of identifying cation valence states. These results are compared with those coming fromtheoretical calculation using the Green functions and the renormalization perturbation expansion
method. The theoretical model is based on a correlated electron picture with localized Fe-spins andconduction electrons interacting with the local spins via a double-exchange-type mechanism.

Sergiy Grytsyuk*, Fabrizio Cossu and Udo Schwingenschlog
Physical Sciences and Engineering, King Abdullah University of Science &Technology, Saudi Arabia
We study the CoO/Ni interface. Since the lattice mismatch between Ni and CoO is21%, we use a large supercell for our first principles calculations which reduces thelattice mismatch to 0.8%. We investigate the structural, electronic, and magnetic
properties of two interface configurations: (1) An O layer mediates the coupling
between Ni and Co and (2) a direct Ni-Co contact. Our results indicate that themagnetization is reduced by 19% in the first case, while in the second case it increases
by 100% as compared to bulk Ni. The magnetic moments obtained at the interfaces
can be explained by the local environment of the interface atoms. In addition, we findeffects of charge transfer between the interface atoms.

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QP02

A broadband circuit analog absorber based on printed dipole antenna

Current-driven domain wall motion in artificial magnetic domain structures

Structural modifications in magnetic MWCNT by 100 MeV SHI
irradiations

Electronic, structural, and magnetic properties of O and Py deficient
CoO/Py interfaces.

Li Xiaopeng1, Cui Chuan'an1, Lv Xuliang1* and Lin Shaofeng2
1
Engineering Institute of Corps of Engineers,PLA University of Science andTechnology, China
2
Xi'an Communication Institute, China
Based on the equivalent transmission line theory, a composite absorber with broadband
planar array antenna is designed. The first layer is an array antenna, which uses
printed dipole with balun feed as basic unit. The second layer a PIN diode array,
which corresponded with antenna feeding units. The impedance match characteristicof the absorber can be adjusted by setting the microstrip balun. And the reflection
characteristic of the absorber can be adjusted by adjusting the bias voltage of the PIN
diode array. Simulated by electromagnetic simulation software HFSS, the results showthat the absorber reflection coefficient is below -10dB at 3.5-15GHz.The experimental
result, which replace PIN diodes with surface mount device resistors, is in good
agreement with simulation data.

Ke Wang1, Murali Krishnan Hari1*, Simon Bending1, Erhan Arac2, Del Atkinson2,
Serban Lepadatu3, J S Claydon3 and Chris Marrows3
1
Department of Physics, University of Bath, United Kingdom
2
Department of Physics, University of Durham, United Kingdom
3
School of Physics and Astronomy, University of Leeds, United Kingdom
We report progress towards optimisation of artificial magnetic domain structures for efficient spin transfer torquedomain wall (DW) motion [1]. Co/Pt multilayer samples have been sputtered on (100) Si/SiO2 substrates andperpendicular magnetic anisotropy confirmed using polar magneto-optical Kerr effect (MOKE) measurements.
The influence of the thickness of Co and Pt layers on the coercivity and switching behaviour was systematicallyinvestigated and the conditions established for realising well-suited structures with medium coercivity (~100Oe) and sharp switching fields [2]. Optimised Co/Pt multilayer films were lithographically patterned into
nanowire devices for time-resolved extraordinary Hall effect (EHE) measurements. Our devices are based on
50 W coplanar waveguides incorporating single and double Hall cross structures. The coercivity of the region
surrounding the Co/Pt Hall crosses was reduced by local focussed ion beam (FIB) irradiation [3] allowing
the controlled nucleation of domain walls at the edges of these regions by application of an appropriate field
sequence. We describe polar MOKE experiments that show how DC currents lead to asymmetric switching ofthese artificial domains due to current-assisted DW motion across them. We will also present preliminary resultsof time-resolved EHE and MOKE measurements of current-driven DW motion in these structures.
[1] O. Boulle et.al, Phys. Rev. Lett. 101, 216601 (2008); I.M. Miron, P.-J. Zermatten, G. Gaudin, S. Auffret, B.
Rodmacq, and A. Schuhl, Phys. Rev. Lett. 102, 137202 (2009); L. San Emeterio Alvarez, K.Y. Wang, S. Lepadatu, S.
Landi, S. J. Bending, and C. H. Marrows, Phys. Rev. Lett. 104, 137205 (2010) [2] K. Wang, M-C. Wu, S. Lepadatu, J. S.
Claydon, C.H. Marrows, and S. J. Bending, J. Appl. Phys. 110, 083913 (2011). [3] A. Aziz et.al, J. Appl. Phys. 98,

Sanjeev Gautam1, Keun Hwa Chae1, Jong Han Song1, Saji Augstine2, J.k. Kang2 and K.
Asokan31
Advanced Analysis Center, Korea Institute of Science and Technology (KIST), Korea
2
Material Science and Engineering, Korea Advanced Institute of Science andTechnology (KAIST), Korea
3
Material Science Center, Inter-University Accelerator Center, New Delhi, India
Carbon nanotubes (CNTs) possess unique mechanical and electronic properties suitable forfabricating the nano-scale building blocks of nanodevices [1]. One of the requirements forapplications is to cut the CNT in small dimensions in the order of few nanometers. To thisrespect, we investigate the effect of heavy ion beams, namely, 100 MeV of O and Ni ion beamon CNT synthesized by chemical vapor deposition (CVD) technique[2]. The ion fluence
selected for this study was 1e13 ions per cm2. High energy heavy ion irradiation was carried out
at Inter-University Accelerator Centre, New Delhi, India. This paper reports the experimental
results obtained from X-ray diffraction pattern and images of scanning electron microscopy(SEM) and transmission electron microscope (TEM) measured at Nano Materials Analysis
Center, KIST, Korea. These results show that heavy ions can induce damage or cut in anordered periodicity of few nanometers. Apart from above studies, we also carried out near-edge
x-ray absorption spectroscopy investigations for electronic structure modifications.

Sergiy Grytsyuk* and Udo Schwingenschlogl
Physical Sciences and Engineering, King Abdullah University of Science &Technology, Saudi Arabia

The development of magnetic devices, which are based on coupling between
ferromagnet and antiferromagnet (such as spin-valves), depends strongly on theinterfacial magnetic structure. Since vacancies at the interface are expected to beimportant in determining the macroscopic properties of such systems, a quantitative
determination of their influence on the interfacial magnetization is essential. We
therefore investigate the CoO/Py interface (Py = Ni80Fe20, Permalloy). Py has a highpermeability, low magnetostriction, and high anisotropic magnetoresistance. It is agood conductor for spin-majority electrons and poor conductor for spin-minority
electrons. At the same time the Neel temperature of CoO is approximately room
temperature and its magnetocrystalline anisotropy is high. Since the lattice mismatch
between Py and CoO is about 20%, we use a large supercell for our first principles
calculations which reduces the lattice mismatch to less than 0.1%. We describe thedependence of the interface magnetization on the amount of O and Py vacancies andaddress the exchange bias.

[1] E. Wohlfarth, in: G. Rado, H. Suhl (Eds.), Magnetism,Vol. 3 (Acad Press, New York, 1963). [2]Gautam S, Thakur P, Augustine S, Kang JK, Kim JY, et al. arXiv: 1111.5416v1 (Nov. 23 2011).

QO22

QO25

QO28

QP03

Effect of oxygen pressure to magnetism and transport properties of
epitaxial Fe3O4 grown by molecular beam epitaxy

The cellular uptake mechanism of SPIONs: an in-vitro study

Magnetic and magneto-transport properties of (Mn0.8, Zn0.2)1-xGaxFe2O4
ferrites

Effect of the external fields on SpinRAM switching time

Dang Duc Dung1, Wuwei Feng2, Duong Van Thiet3, Duong Anh Tuan3 and Sunglae
Cho3*1
Department of General Physics, School of Engineering Physics,Ha Noi University of
Science and Technology,1 Dai Co Viet road, Ha Noi, Viet Nam
2
Department of Physics, University of Ulsan, Ulsan 680-749,, Korea
3
Department of Physics, University of Ulsan, Ulsan 680-749, Korea
Fe3O4 is predicted to possess as half-metallic nature, ~ 100% spin polarization, and has a high Curie temperature
and an ultrahigh room temperature magnetoresistance (MR) for tunneling magnetoresistance (TMR) junctions
with Fe3O4 electrodes [1]. However, for the TMR junction, a highly conductive under layer and the sharp between
interfaces are required because the poor conductivity and roughness of films may lead to a non-uniform current
distribution [2]. In addition, the Verwey transition (TV, a first order metal-insulator transition) of 120 K in bulk
Fe3O4 is still under controversy because many parameters such as orientation of substrate, buffer layer, thickness,pressure, and thermo-chemical treatment affect the TV [3, 4]. Epitaxial Fe3O4 films were grown on MgO(001)substrates via molecular beam epitaxy. The growth modes, magnetism, and transport properties of the thin films
were strongly dependent on the oxygen pressure during film growth. The average roughness decreased from 1.021
to 0.263 nm when the oxygen pressure was increased from 2.3x10-7 to 8.2x10-6 Torr, respectively. In addition,
the saturation magnetic moment reduced as increasing the oxygen pressure during grown. Moreover, the Verweytransition in the Fe3O4 disappeared for a sample grown at a high oxygen pressure.

Yasmin Khan1 and Radha Srinivasan2*
1
Department of Life Sciences, Sophia College, Mumbai, India
2
Department of Physics, University of Mumbai, India

The Superparamagnetic Iron Oxide Nanoparticles of sizes ranging from 10-50 nm
are being used in a large number of biological studies because of their peculiar
characteristics of inducing local hyperthermia, MR imaging, specific targeting anddrug delivery. An in-vitro study of the cytotoxicity and an understanding of the specificpathway of cellular uptake will enable manipulation of conditions for optimal cellular
uptake of SPIONs for targeted therapy. The objective of the present study was to
identify the endocytotic pathway through which the SPIONs are taken up by C6 glioma
cells. The cells were pre-incubated with different concentrations of pharmacologicalinhibitors and then exposed to SPIONs for a few hours. The endocytosed particles werelocalized and quantitatively estimated using Perl's or Prussian Blue reaction. Therewas significant reduction in the uptake of SPIONs when incubated with the inhibitor
indicating the uptake of nanoparticles is being inhibited.This reduction in SPION
uptake was found to be dependent on the concentration of the inhibitors and also thenature of the inhibitors. By a systematic study of choosing various inhibitors, the data
can be narrowed down to the final pathway that may be involved in the SPION uptake.

July 10 (Tue)Tae Won Jeong1, Hyun Rok Cha1*, Dae Yeong Im1, Kwang Heon Kim2 and Hyoung
Uk Nam1
1
Automotive components R&D group, korea institute of industrial technology, Korea
2
Department of Electrical Engineering University of the Chonnam, Korea

Hyo-jin Kim and Sang-im Yoo*
Department of Materials Science and Engineering, Seoul National University, Korea

A significant enhancement of low-field magnetoresistance (LFMR) could be achieved
from polycrystalline samples of Ga2O3-doped Mn-Zn ferrites. For this study, themagnetic and magnetotransport properties of samples with two different nominal
compositions of (Mn0.8, Zn0.2)1-xGaxFe2O4 (x = 0.05, 0.1) were carefully investigated.
The X-ray diffraction analyses revealed that all Ga2O3-doped Mn-Zn ferrites of thespinel structure were a pure phase without the second phase. By doping Ga2O3 to thepure Mn-Zn ferrite, the resistivity level was abruptly decreased over four orders ofmagnitude. The 5 mol% Ga2O3-doped Mn-Zn ferrite sample exhibited the LFMR ratio
over 1.7 % at 300 K in 0.5 k Oe without appreciable increase in its resistivity. Detailed
doping effects of Ga2O3 on the magnetic and maneto-transport properties of the Mn-Zn
ferrite will be presented and discussed in this paper.

Mitsuhiro Shiomi* and Yoshinobu Nakatani
Univ. of Electro- Communications, Japan

Spin current driven magneto resistive random access memory (SpinRAM) is one of thecandidates for the next generation non volatile memory. There are still many problems
to realize it. One of the problems is the switching speed. The method for fast switchingwith lower current is required. Field assist switching is one way. In this paper, theeffect of the DC and AC external field on the switching time of the SpinRAM withperpendicular anisotropy is investigated by simulation. The effect of the thermal noiseis also investigated. From the results without thermal noise, the switching time wasdecreased by both of the DC and AC field. However, AC field is effective for fastswitching compared with DC field. From the results with thermal noise, the switchingtime was not decreased by weak DC field and more strong DC field was required toreduce the switching time. On the other hand, the switching time was decreased byweak AC field. From these results, it was found that AC field is more effective thanDC field to reduce the switching time. This study was supported by New Energy andIndustrial Technology Development organization (NEDO) partly.

[1] Z. Zhang et al., Phys. Rev. B 44, 13319 (1991). [2] P. H. Huang et al., J. Appl. Phys. 97, 10C311 (2005). [3] E. J. W.
Verwey et al., Physica 8, 979 (1941). [4] A. R. Muxworthy et al., Geophys. J. Int. 140, 101 (2000), and reference therein.

244

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

245

poster Presentation
QP04

QP07

QP10

QP13

A study on the perpendicular toggle-MRAM system by using new
combined hysteresis method for high Gb/Chip

Concomitant memory effect in CrO2/Cr2O3 core-shell nanorods

Thermal effect in microwave assisted magnetization reversal

Controlling nanostructure in FePt films: Co-sputtering of FePt and C
or SiO2

July 10 (Tue)Conventional (toggle) MRAM has unlimited read/write endurance but has a low
capacity than flash technology. A lot of work has been done for the commercializationof submicrometer MRAM in recent years. A low-power 1Mb MRAM with copper
interconnects and cladding layer, and about 35 ns access and cycle times tested in theprevious work show the potential of this technology. A new multibit MRAM cell of
toggle switching type has been reported and also, a heat interaction investigation inthermally assisted MRAM has been reported. In this paper we presents a new designthat has advantages conventional MRAM on injected current and cell size. It is poletype perpendicular MRAM (PTP MRAM). PTP MRAM uses perpendicular magnetic
field in order to change the state of the free layer in a perpendicular magnetic tunnel
junction (pMTJ). In this paper, new efficient algorithm to combine two models arepresented and tested. This approach reduces computing time and gives more precise
results because the result of 2 dimensional Preisach model becomes an initial values of
3 dimensional micromagnetics.

Ashish Chhaganlal Gandhi and Sheng Yun Wu*
Department of Physics, National Dong Hwa University, Taiwan

The concomitant memory effects are intensively studied in last few decades and are mostly observed inspin-glass and superparamagnetic systems [1-3]. The memory effects were observed in the interacting
permalloy nanoparticles [4] and isolated nanoparticles [5], providing us interesting information
about the investigation of nature of the low temperature phase. In the present work, we succeededin preparing CrO2/Cr2O3 core-shell nanorods using the chemical vapor deposition method. The
magnetic properties of CrO2/Cr2O3 core-shell nanoparticles can be treated as a ferromagnetic-CrO2core and antiferromagnetic-Cr2O3O-shell compound coupled by an exchange interface coupling andraised magnetic anisotropy energy between them. The evolution of core shell magnetization triggeredby an applied magnetic field at 1.8 K was observed, and a core-shell anisotropic energy model wasapplied to simulate the competition between the surface magnetic anisotropy and exchange interface
coupling. Memory and aging effects were observed and overcame the superparamagnetic limit [3] up
to sufficiently high temperature which makes it an important candidate in magnetic data storage, as
an application. Acknowledgments: This research was supported by a grant from the National Science
Council of Taiwan, the Republic of China, under Grant Number NSC-100-2112-M-259-003-MY3.
[1] M. Sasaki, P. E. Jonsson, H. Takayama, and H. Mamiya; Phys. Rev. B 71, 104405 (2005). [2]Malay Bandyopadhyay and Sushanta Dattagupta; Phys. Rev. B 74, 214410 (2006). [3] V. Skumryev,
S. Stoyanov, Y. Zhang, G. Hadjipanayis, D. Givord and J. Nogues Nature 423, 850 (2003). [4]Young Sun, M. B. Salamon, K. Garnier and R. S. Averback; Phys. Rev. Lett. 91, 167206 (2003). [5]M.
Sasaki, P. E. Jonsson, H. Takayama, and P. Norblad, Phys. Rev. Lett. 24, 139701 (2004).

Yoshitoki Furomoto, Yuto Otsuka, Terumitsu Tanaka* and Kimihide Matsuyama
ISEE, Kyushu University, Japan
Microwave assisted magnetization reversal (MAMR)[1] has potential applicationin future magnetic recording. The critical curves for MAMR in a single-domain
particle is theoretically estimated by Bertotti et al.[2, 3], which well explains steadystate magnetization switching at 0 K and the equations allow three solutions “stable”,“unstable” and “saddle”. In this study, MAMR properties in a single-domain particle
were simulated solving the Landau-Lifshitz-Gilbert equation taking account of
temperature elevation due to ferro-magnetic resonance. Magnetization switchingprobability at 400 K widely distributes in HMW in unstable region. The critical valuesof HMW are greater than that at 0 K nevertheless thermal activation decreases energy
barrier height. This implies stochastic thermal fields reduce efficiency in MAMR in
the region. On the other hand, thermal activation gives 25-35 % of reduction in criticalvalue of HMW in stable region, which is achievable for recording head of recent harddisk drive.
[1] J. O. Artman, S. H. Charap, and D. J. Seagle, IEEE Trans. Magn. MAG-19, 1814 (1983). [2] G.
Bertotti, C. Serpico, and I. Mayergoyz, Phys. Rev. Lett. 86, 724 (2001). [3] S. Batra and W. Scholz,IEEE Trans. Magn. 44, 3392 (2008).

George Giannopoulos*, Thanassis Speliotis and Dimitris G Niarchos
Institute of Materials Science, NCSR DEMOKRITOS, Greece

Achieving magnetic recording densities in excess of 1Tbit/in2 requires not only
perpendicular media with anisotropy larger than 7 MJ/m3, which makes the FePt alloy
as the best choice , but also narrow distribution and small sizes below 10 nm for a
reduced S/N ratio along with high thermal stability. Previous work has shown that the
L10 FePt grain size can be controlled by alloying FePt with materials such as C, Ag,
and insulator like AlOx, MgO act to segregate and magnetically decouple the FePt
grains. Better results were obtained with C with respect to the uniformity of grains and
SiO2 with respect to the shape, but far from optimization. We present our results by cosputtering FePt with C or SiO2 (up to 30 vol % ) on MgO (001) single crystal substrates
at 350 and 500 0C. With C or SiO2 addition we achieved the grain size reduction, theshape control and isolated structure formation, by producing continuous films withhigh uniformity and narrow main size distribution down to 10 nm. This also reflectedin the variation of coercivity as a function of the additional phase, thus giving us a
possibility to simultaneously control the coercivity and the S/N ratio.

QP05

QP08

QP11

QP14

Room temperature exchange bias in the multiferroic BiFe0.8Mn0.2O3
nanoparticles with a core-shell structureHigh resolution probes for magnetic force microscope

Stable magnetization switching with microwave assistance forexchange coupled composite grain

Retention time under currents and magnetic fields in a CoFeB/MgO
perpendicular magnetic tunnel junction

S M Yusuf* and P K Manna
Solid state physics division, bhabha atomic research centre, mumbai 400085, India

The compound BiFeO3 shows a multiferroic character. We have shown that the
BiFeO3-based compound viz. BiFe0.8Mn0.2O3 nanoparticle system exhibits otherimportant multifunctional behaviour as well. We have observed the exchange
bias effect, in the form of a shift in the field-cooled hysteresis loop, and a training
effect in a dc magnetization study. From transmission electron microscopy, neutron
diffraction, thermoremanent magnetization, and isothermoremanent magnetization
measurements, the nanoparticles are found to be core-shell in nature, consisting ofan antiferromagnetic (AFM) core, and a two-dimensional diluted AFM (DAFF) shellwith a net magnetization under a field. Our calculation using the Binek’s model on the
training effect yields a theoretical understanding of the observed loop shift which arises
entirely due to an interface exchange coupling between core and shell. The intrinsic
contribution of the DAFF shell to the total loop shift is zero. The present study is usefulto understand the origin of exchange bias in other DAFF-based systems as well. The
significantly high value of the exchange bias field (~ 0.16 kOe), observed at room
temperature, in the present nanoparticle system has made it a blue-eyed candidate forthe next generation advanced nano-technological applications in the area of magnetic
storage devices.

Xiaoxi Liu*, Shinsaku Isomura and Akimitsu Morisako
Department of Information Engineering, Shinshu University, Japan
Magnetic force microscopy is a convenient and efficient method to detect magnetic
domain structures in magnetic recording media or nano-magnet. In this work, we
present a simple process to fabricate probes for magnetic force microscopy with
sub-ten nanometer resolution. A thin layer of FeCo is deposited onto commerciallyavailable silicon probes by a facing targets sputtering system. We choose facing targets
sputtering because this kind of system can minimize the damage of the films from highenergy particle bombardment. The radius of the curvature of the probes is depended on
the FeCo film thickness. High resolution scanning microscope image show the radiusof the curvature is less than 20 nm for a 20 nm thick FeCo coating. Magnetic force
microscopy images show our probes have resolution better than 10 nm. Due to the highmagnetic moment of FeCo, we can get magnetic contrast for FeCo coating as thin as
10 nm. Micromagnetic simulations indicate than the formation of a magnetic vortex at
the apex of the probe is crucial for the high resolution.

Terumitsu Tanaka*, Yoshitoki Furomoto, Yuto Otsuka and Kimihide Matsuyama
ISEE, Kyushu University, Japan

Microwave assisted magnetization reversal (MAMR)[1] is a promising candidate for
future magnetic recording. Li et al. proposed ECC medium for solving the potential
problems in microwave power and frequency for MAMR[2]. Bertotti et al. theoreticallyanalyzed MAMR process taking a single spin for example[3], which showed the LLG
equation can be written in the other forms[4]. The equation allows three solutions“stable”, “unstable” and “saddle”. However, the theory cannot be applied to exchange
coupled composite (ECC) structured grain. In this study, distributions of the regions
defined by the three solutions were estimated for an ECC grain. In the ECC grain,stable switching region, in which magnetization reversal modes are hardly affected by
disturbance such as thermal fluctuation, distributes at lower fields region comparing
to that for the single spin particle. This result means that stable magnetization reversal
occurs with relatively weak magnetic fields even for ultra high Hk materials assigned
to future high density recording.
[1] J. -G. Zhu, X. Zhu and Y. Tang, IEEE Trans. Magn. 44, 125 (2008). [2] S. Li, B. Livshitz, H. N.
Bertam, M. Schabes, T. Schrefl, E. E. Fullerton and V. Lomakin, Appl. Phys. Lett. 94, 202509 (2009).
[3]Giorgio Bertotti , Claudio Serpico , and Isaak D. Mayergoyz , Phys. Rev. Lett. 86, 724 (2001) [4]Werner Scholz and Sharat Batra , J. Appl. Phys.103, 07F539 (2008)

Michihiko Yamanouchi*, Hideo Sato, Katsuya Miura, Shoji Ikeda, Fumihiro
Matsukura and Hideo Ohno
Center for Spintronics Integrated Systems, Tohoku University, Japan

CoFeB/MgO based magnetic tunnel junctions with perpendicular anisotropy (p-MTJs)[1,2] have been investigated extensively because of their potential for realizationof nonvolatile logic circuits and random access memories [3-6]. For ensuring theirnonvolatility, effects of current (I) and magnetic field (H) on cumulative distribution ofretention time (tr) of magnetization direction in the recording layer should be clarified.
Theoretical expression for the distribution under I and H has been proposed [7]. However
it has not been compared with experimental results in CoFeB/MgO p-MTJs. In this work,
we investigated tr under I and perpendicular H in the same CoFeB/MgO p-MTJ with 40
nm in diameter and compared it with the theoretical expression [7]. It was found that the
cumulative distribution of tr under I (H) can be fitted well with the theoretical expression
in the range of tr = 30 μs - 100 s (5 - 960 s). From tr under I (H), thermal stability factor
is evaluated to be 44 (39), which agrees well with previous results in similar MTJs [1,4].
This work was supported by the FIRST program from JSPS.
[1] M. Endo et al., Appl. Phys. Lett. 96, 212503 (2010). [2] S. Ikeda et al., Nature Mater. 9, 721(2010). [3] D. C. Worledge et al., Appl. Phys. Lett. 98, 022501 (2011). [4] H. Sato et al., Appl. Phys.
Lett. 99, 042501 (2011). [5] H. D. Gan et al., Appl. Phys. Lett. 99, 252507 (2011). [6] J. J. Nowak etal., IEEE Magn. Lett. 2, 3000204 (2011). [7] Z. Li et al., Phys. Rev. B 69, 134416 (2004).

QP06

QP09

QP12

QP15

Magnetic and Transport Properties of Mn 3-xGa/MgO/Mn 3-xGa
Magnetic Tunnel Junctions: A First-Principles Study

Selective magnetization switching by microwave assistance for layered
magnetic pillar

Low-temperature epitaxial growth of FePt on glass substrates forultrahigh magnetic recording densities

Thermal diffusion in magneto-optic collinear volumetric hologram
memoryMicrowave assisted magnetization reversal (MAMR)[1] is a promising candidate for
future magnetic recording technology. In MAMR, magnetization switches only when DC
and microwave fields are applied to magnetic material at particular microwave frequency.
Utilizing such a feature, possibility of selective switching of magnetizations was estimated by
micromagnetic calculation for realizing 3-dimensional magnetic recording. In the calculation, amagnetic pillar composed of 3 layered materials was considered. Pillar diameter is 11 nm, andthickness of the 1st, 2nd, and 3rd layers are 5, 13, and 14 nm, respectively. Hk1 (= 24kOe), Ms1(= 600 emu/cc), Hk2 (= 13kOe), Ms2 (= 400 emu/cc), and Hk3 (= 6 kOe), Ms3 (= 800 emu/cc)
represent anisotropy fields and saturation magnetizations of 1st, 2nd, and 3rd layers. These values
give sufficient thermal stability indices (greater than 60 at 300 K) for every layer. Magnetization
switching probabilities equal to 1 were obtained at particular microwave frequencies for every
layer; selective switching occurs at 1st, 2nd, and 3rd layer when microwave frequency is 8,
18, and 28 GHz, respectively. In this calculation, the single pillar has shown to store 3 bits
information. These results imply MAMR has a potential in 3-dimensional magnetic recording.

Magnetic FePt alloy thin film with ordered L10 structure is a promising material
for perpendicular magnetic recording (PMR) application, duo to its huge uniaxial
magnetocrystalline anisotropy (Ku), high saturation magnetization (Ms), high coercivity (Hc)and outstanding corrosive resistance. Ku value of L10 FePt is about 7 MJ/m3 which sets thesuperparamagnetic limit of L10 FePt as small as 2.8 nm. In PMR application the preferredorientation has to be transformed into (001) that makes the [001]-axis perpendicular to thefilm. Accordingly, developing an effective way to prepare L10 FePt (001) thin film withperpendicular magnetic anisotropy at low order-disorder transformation temperature is theconcern of first priority.Although excellent properties can be obtained in sputtered FePt on
single crystal MgO (001) much effort is needed to obtain PMR properties of sputtered FePt
films on glass substrates. A number of underlayers have been used to induce texture such
as CrRu, MgO and very recently TiN. Here we report a systematic study of the system {Hoya glass/CrRu/MgO/FePt/Ta} and through optimization of layer thickness, deposition
temperature and sputtering power , we achieved perpendicular anisotropy, coercivity inexcess of 1 T and deposition temperatures around 400 0C.

[1] J. -G. Zhu, X. Zhu and Y. Tang, IEEE Trans. Magn. 44, 125 (2008)

Supported by the project TERAMAGSTOR of the EU

Zhaoqiang Bai, Yongqing Cai, Lei Shen, Guchang Han and Yuanping Feng*
Physics, National University of Singapore, Singapore

Magnetic and transport properties of Mn3-xGa/MgO/Mn3-xGa (0≤x≤1) magnetic tunnel
junctions are studied using first-principles approach based on density functional theory
and non-equilibrium Green's function. Perpendicular magnetization, of which themagnetic anisotropy energy reaches more than 1 meV/unit-cell, is confirmed to beenergetically favoured by both Mn2Ga and Mn3Ga thin films. Furthermore, despitehigh spin-polarization at Fermi energy for both these compounds as reported, ourtransport calculation shows considerable disparity in the transmission behaviour
between Mn2Ga/MgO/Mn2Ga(001) and Mn3Ga/MgO/Mn3Ga(001) magnetic tunnel
juctions: huge optimistic tunneling magnetoresistance ratio ~ 1000% for the former,
and nevertheless, no tunneling magnetoresistance effect absolutely for the latter. Thisphenomenon is attributed to the spin symmetry filtering effect of the MgO spacer.
On this premise, Mn3-xGa compounds with low Mn concentration are predicted to bepromising candidate materials to serve as the electrodes of spin-transfer toque devices
inThe 19th International Conference on Magnetism

Terumitsu Tanaka1*, Yuto Otsuka1, Yoshitoki Furomoto1, Kimihide Matsuyama1 andYukio Nozaki2
1
ISEE, Kyushu University, Japan2
Department of Physics, Keio University, Japan

Thanassis Speliotis1*, George Giannopoulos1 and Dimitris G Niarchos2
1
Institute of Materials Science, NCSR DEMOKRITOS, Greece
2
Institute of Materials Science, NCSR Demokritos, Greece

July 10 (Tue)Hyuk Won and Gwan Soo Park*
School of Electrical Engineering, Pusan National University, Korea

246

poster Presentation

Seungmin Baek, Hiroyuki Sakurai, Pang Boey Lim and Mitsuteru Inoue
Toyohashi University of Technology, Japan

Collinear holography memory is a good candidate of the next generation of opticalmemory. Recently we have investigated the magneto-optical recording with thickpolycrystalline magnetic garnet films by collinear holography. Rewritable properties
and shift multiplexing of the magnetic holograms were confirmed experimentally.
However, it has still high noise level in the retrieved image. We investigated the
suppression method of thermal diffusion in magnetic hologram recording numericallyand experimentally. The recording principles of the magnetic holography arebasically similar with thermomagnetic recording. The interference patterns withsignal information are recorded as magnetization patterns. Due to thermal diffusion
in recording process, the interference patterns were in disorder. It could be shown inresults of the low diffraction efficiency and high noise level. Numerical simulation
result shows the influence of thermal diffusion was suppressed with below 10-9 secondof laser pulse width. Experimental result with two-beam interferometer also showsover 200 % higher diffraction efficiency recorded by 50 ps pulse width laser than 25 ns
one in high spatial frequency range.

July 8-13, 2012 Busan, Korea

247

poster Presentation
QP16

QP19

QP22

RA01

Resolution of magnetic garnet films for magneto-optic collinear
volumetric hologram memory

Nanoscale ion beam etching process for reducing damage and leakage
path of magnetic tunnel junction

The effect of capped layer thickness on switching behavior in coupled
granular/continuous media

Magnetic resonance and ferroelectricity of BaTi1-xFexO3

July 10 (Tue)Collinear holography memory is promising optical memory of the next generation.
The photopolymer materials have received much attention because of high sensitivity,
high dynamic range and low costs as recording materials. On the other hands,
magnetic garnet films have the advantage of rewritable, no necessity of shading, andno shrinkage, as compared to photopolymer which has write-once property. In thisstudy, we fabricated the different grain sizes of magnetic garnet films by annealing
time. The fundamental properties of samples and the SNR of the retrieved images withsingle hologram were investigated. Bi-substituted iron garnet films (3.3 μm thick) were
fabricated by RF magnetron sputtering on SGGG substrates. Samples were annealed
at 750 °C in air for several annealing time. The retrieved images were evaluated bycollinear holographic system. The resolution of magnetic recording media was relatedwith the grain size of magnetic recording media. The results show SNR of the retrieved
image was improved by reduction of the grain size.

1

1

1

1

1

Daehong Kim , Bongho Kim , Sungwoo Chun , Hyungyu Kim , Seonjun Choi and
Seung-beck Lee2*
1
Department of Electronic Engineering, Hanyang University, Seoul, Korea
2
Institute of Nano Science and Technology, Hanyang University, Seoul, Korea

To integrate ultrahigh density spin-transfer torque magnetic random access memory (STT-MRAM),a stable process to pattern metallic magnetic tunnel junctions (MTJs) is required. [1] We investigated
the ion milling process to fabricate the MTJ cells for perpendicular STT-MRAM application withminimized redeposition layer by a gradational stage tilting process and low damage of MTJ by
reduced beam supply voltage. The hard mask used a 30nm diameter negative electron-beam resist
patterned by electron beam lithography. Thereafter, ion milling process was conducted throughregulation of beam/accelerate supply voltage and stage tilting angle. We found that the highest
MTJ slope angle was attained at the stage tilt angle of 80° which was the angle of the incident ion
flux to the stage surface. However, high angle etching resulted in a thick redeposition layer. For
reducing redeposited layers, we have utilized variable-angle multi-step ion milling process. Also
for reduced MTJ sidewall damage by high beam supply voltage, reduced the beam supply voltage.
Consequently, sidewall damage of MTJ layer was minimized. The TMR ratio and the resistance ofthe fabricated MTJ cells were 13% and 1kΩ respectively. Our results showed the potential of using
optimized ion milling for fabricating nanoscale MTJs for ultrahigh density STT-MRAMs.

1

1

2

Weimin Li , Jun Ding * and Jianzhong Shi
1
Department of materials science and engineering, National University of Singapore,
Singapore
2
Data Storage Institute, Agency for Science, Technology and Research (A*STAR),
Singapore

Coupled granular/continuous (CGC) media (a CoPtCrB continuous layer exchange coupled to a granularoxide CoPtCr: SiO2TiO2Ta2O5 layer) exhibited improvement of SNR, thermal stability and switching
field distribution (SFD)[1, 2]. TEM images together with intrinsic SFD for capped structure are studied toinvestigate the mechanism of the SFD reduction in CGC media. We find out that in the bottom part, CoPtCr
magnetic grains are separated by nonmagnetic oxide grain boundaries. The amorphous grain boundary
phase in the granular layer propagates to the top surface of the capped layer. The grain size increases withcapped layers thickness. A critical capped thickness exists. At thinner capped thickness, capped layer inherits
structural irregularity from the granular layer, while at thicker layer, the upper portion of capped layer is lessinfluenced by the granular layer. ReportedΔH (M, ΔM) method[3] is used to calculate intrinsic SFD. Bothintrinsic and macroscopic SFD decrease linearly with capped layer thickness. As we know, the intrinsic
SFD is due to the local variations of the grains properties. The reduction of macroscopic SFD is caused byhomogenous grains and uniform exchange coupling at thicker capped layer.

Dianta Ginting1, N. V. Dang2, V. D. Lam2, S. C. Yu1 and T. L. Phan1*
1Phyisch, Bk 21, chungbuk national university, Korea
2
Institute of Materials Science, Vietnamese Academy of Science and Technology,
Hanoi, Viet Nam
BaTiO3 is known as an excellent candidate for multiferroics. In this work, we present magneticresonant and ferroelectric properties of polycrystalline BaTi1-xFexO3 ceramics (0 ≤ x ≤0.12) preparedby conventional solid-state reaction. Measurements have been based on an X-ray diffractometer,
electron spin resonance (ESR) spectroscopy, and Precision Premier-Radiant. X-ray diffraction
patterns reveal the tetragonal-hexagonal phase transformation as increasing Fe-doping content. ESR
spectra prove that many samples to be ferromagnetic, excepting for the x = 0.02-0.06 samples, which
are paramagnetic. Such the results are in good agreement with the previously report on the magnetic
behavior. Room-temperature P-E hysteresis loops of BaTi1-xFexO3 reveal that with increasing Fe
concentration, the feature of ferroelectric P-E loops changes in the shape to the paraelectric regime,
indicating the decrease in ferroelectricity. Consequently, the values of the remnant polarization Pr andthe coercive field Ec gradually are also decreased. Keywords: Fe-doped BaTiO3; Magnetic phaseseparation; Ferroelectricity *Electronic mail: ptlong2512@yahoo.com Phone:[1] M. Hosomi, H. Yamagishi, T. Yamamoto, K. Bessho, Y. Higo, K. Yamane, H. Yamada, M. Shoji, H.
Hachino, C. Fukumoto, H. Nagao,and H. Kano: IEDM Tech. Dig., 2005, p. 459.

1. H. S. Jung, E. M. T. Velu, S. S. Malhotra, U. Kwon, D. Suess and G. Bertero, Magnetics, IEEE Transactions on 43 (6), 20882090 (2007). 2. H. Nemoto, I. Takekuma, H. Nakagawa, T. Ichihara, R. Araki and Y. Hosoe, Journal of Magnetism and Magnetic
Materials 320 (22), 3144-3150 (2008). 3. A. Berger, B. Lengsfield and Y. Ikeda, Journal of Applied Physics 99 (8), 08E705-706 (2006).

Daniel Khomskii, Physics,2.20 (2009) W. Eerenstein, N.D. Mathur & J.F. Scott, Nature 442(17) (2006) N.V Dang,
Thanh, L.V.Hong, V.D Lam, The-Long Phan, Applied Physics 110, 043914, (2011). QIU Shen-Yu, LI Wang, LIU
YU, LIU GUi Hua, WU Yi-Qiang, Chen Nan, Trans. Nonferrous Met.Sos. China 20,1911-1915(2010). ManfredFiebig, J. Phys. D: Apply.Phys.38, R123-R152. S.Angappane, G Rangarajan, and K.Sethupathi, J. Apply.
Phys.93,8334 (2003).F. Lin, D. Jiang, X. Ma, and W. Shi, Physica B 403, 2525 (2008). S. Ray, P. Mahadevan, S.
Mandal, S. R. Krishnakumar, C. S. Kuroda, T. Sasaki, T. Taniyama, and M. Itoh, Phys. Rev. B 77, 104416 (2008).

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Room temperature ordering perpendicular magnetic anisotropy L11
CoPtCu thin film on glass substrate

A new planer patterned media with anti-ferro / ferro transformation

The effect of magnetic field on FePt nanoparticles during annealing
process

Growth of high pure BiFeO3 single crystals

Chiuan-fa Huang1, Long-jie Li1, An-cheng Sun1*, Fu-te Yuan2, Jen-hwa Hsu2, S. N.
Hsiao3 and H. Y. Lee3
1
Department of Chemical Engineering & Materials Science, Yuan-Ze University, Taiwan
2
Department of Physics, National Taiwan University, Taiwan
3
National Synchrotron Radiation Research Center (NSRRC), Taiwan

Rhombohedral unit cell of L11 CoPt films have attracted a lot of attention due to their large magnetocrystalline
anisotropy (Ku ~ 107 erg/cm3) as well as relatively low ordering temperature (~ 200 oC) [1,2]. The addition of
Cu significantly improves the alignment of c-axis, chemical ordering and enhances perpendicular coercivity (Hc┴)
of L11 CoPtCu phase deposited at 350 oC [3-5]. In this study, Co27Pt50Cu23 films with a Pt underlayer were
deposited on glass substrates at room temperature (RT) to 500 oC by sputtering. The thickness of the film was 5
nm. Interestingly, the high perpendicular magnetic anisotropy (PMA) was observed when the film was deposited
at RT. Furthermore, PMA was maintained until the substrate temperature (Ts) exceeded 450 oC. Hc was largely
enhanced from 0.25 to 2.6 kOe when Ts was increased from RT to 350 oC. Beyond 350 oC Hc started to decline.
The appearance of high PMA suggests that the ordered L11 structure is formed in CoPtCu film even prepared atroom temperature. This finding promotes the applications of L11 CoPtCu films in future perpendicular magnetic
recording and spintronic device. The variation of phase structure and microstructure with Ts will be presented.
[1] S. Iwata, S. Yamashita, S. Tsunashima, IEEE Trans. Magn. 33 (1997) 3670. [2] F.T. Yuan, A.C. Sun, J.H. Hsu, Scripta Materialia
62 (2010) 762. [3] F-T. Yuan, A-C. Sun, J-H. Hsu, C.S. Tan, P.C. Kuo, W.M. Liao, H.Y. Lee J. Appl. Phys. 108 (2010) 113909. [4]F-T. Yuan, A-C. Sun, J-H. Hsu, C.S. Tan, P.C. Kuo, W.M. Liao, H.Y. Lee J. Appl. Phys. 109 (2011) 07B714. [5] Fu-Te Yuan, L. J. Li,
Jen-Hwa Hsu, S. N. Hsiao, H. Y. Lee, Hsi-Chuan Lu, Sea-Fue Wang, C. Y. Shen, and An-Cheng Sun, J. Appl. Phys. (accepted)

Hiroaki Ono and Hiroyuki Awano
Toyota Technological Institute Information Storage Material Lab., JapanFor next-generation HDD, the planer patterned media which need neither pattern
etching nor smoothing processing is attractive.1),2) As a proposal of the new media,
ferro-magnetized patterned area in the flat anti-ferro-magnetized layer has been
prepared by using near field laser irradiation or masked ion implantation. On the ferromagnetized area, required data can be recorded. We prepared several kinds of TbFeCo/
Rh/TbFeCo tri-layers. When the Rh thickness is some period, strong anti-ferromagnetic coupling (AFC) is realized. In the combination, Rh thickness of the 1st peakof the anti-ferro-coupling was 0.45nm. Since the thickness of the TbFeCo was thickand Rh thickness was very thin, the transformation from AFC to FC can be control
easily. The coercive force was 1.5kOe. Also the Hc can be designed by controlling Tb
concentration. For example, in this case, the transformation temperature was 100 °C.It
is also easy to control by changing TbFeCo thickness. Moreover, the patterned media
can be applied as a write once HDD, since it is impossible to change recorded area for
the ferro-magnetized area.
1) I. Nakatani,T. Takahashi,M. Hijikata, T. kobayashi, K. Ozawa, and H. Hanaoka: Japanese Patent
No.888363, filed in June 1989. 2) T.Kato et al., J. Appl. Phys., 105, 07C117 (2009)

A. Khajehnezhad1, S. A. Sebt1, R. S. Dariani2 and M. Akhavan3*
1
Physics Research Center, Science and Research Branch, Islamic Azad University,
Tehran, Iran, Iran2
Physics, Alzahra University, Tehran, Iran3
Physics, Sharif University of Technology, Iran
FePt, L10 nanocrystals are expected as one of promising candidates for the magnetic recording media withultrahigh densities. The 3nm FePt NPs have been synthesized by the polyol method and analysed by TEM
analysis. The composition of the films was estimated to be approximately Fe62.40Pt37.60 by EDXS. Surface ofSi and SiO2 wafers have been covered by FePt nanoparticles and heated in 600°C for 1h to form L10 phase
nanoparticles [1]. FE-SEM and XRD analyses show uniform surface distributions of FePt, L10 nanoparticles.
The SiO2 [2] substrate prevents nanoparticles from coalescence during annealing and prevents them fromgrowth [3], hence, causing their size not to become more than 40nm. SiO2 wafer is more suitable than Si wafer
in separating the nanoparticles, which may be due to oxygen of surface bonding with nanoparticles. Presenceof 30mT magnetic field controls the size of nanoparticles around 25nm, which can be related to the reductionof random mobility in magnetic field and causes the nanoparticles to self-organize directionally. The larger
I(001)/I(111) for perpendicular magnetic field indicates that the easy axis of nanoparticles is aligned in thisdirection [4]. The magnetic field also controls the surface distribution during heating process.
1. S. Sun, Adv Matter 18, 393-403 (2006). 2. T. Ichitsubo, S. Tojo, T. Uchihara and E. Matsubara, Phys.
Rev. B 77, 094114 (2008). 3. Y. C. Wu, L. W. Wang, and C. H. Lai, Appl. Phys. Lett. 93, 242501 (2008). 4. M.
I. J. Beale, N. G. Chew, M. J. Uren, A.G. Cullis, and J.D. Benjamin, Appl. Phys. Lett. 46, 86(1985).

Kai Feng1, Jun Lu2* and Yicheng Wu1
1
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing
100190, China
2State Key Laboratory of Magnetism, Technical Institute of Physics and Chemistry,
Chinese Academy of Sciences, Beijing 100190, China
BiFeO3(BFO) is a heavily beaten compound in recent publications. BFO exhibits
simultaneous polar and magnetic order at room temperature, promising important
applications, but growth of pure BFO single crystals is really a great challenge. To
grow extremely pure BFO single crystals, we have systematically investigated Bi2O3Fe2O3 pseudo-binary system from the long-term crystal growth experiments, highperformance powder X-ray diffraction analysis and high temperature differential
thermal analysis instrument. The peritectic transition temperature of BFO wasdetermined to be 852±5˚C and Other typical characteristic temperatures in Bi2O3-Fe2O3
pseudo-binary phase diagram were reevaluated. It has been found that purity of grown
BFO single crystals depends greatly on crucible materials. When suitable kind of
crucibles were used, extremely high pure BFO single crystals could be easily obtainedwith maximum size above one centimeter.
[1] J. Lu et al., Eur. Phys. J. B, 75(4), 451-60(2010) (as cover story) [2] J. Lu et al., J. Cryst.
Growth,318, 936-41(2011) [3] J. Lu et al., A method of growing centimeter pure BiFeO3 single
crystals, Chinese Patent, 201110252660.5

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Magnetic anisotropy and chemical ordering in Fe-Pt films prepared by
low-temperature growth technique

Topology optimization of perpendicular magnetic recording headconsidering magnetic saturation effectNovel soft lithography technique for fabrication of Ni nanodots for use
as bit patterned media

Structural, electrical and magnetic properties of La-doped BiFeO3
ceramics.

The topology optimization method is an attractive scheme for magnetic device design
because an initial conceptual design can be obtained without any prototype model. However,studies concerning the three-dimensional magnetic device design by topology optimization
are rare. Even more, topology optimization of magnetic systems has been generallyaccomplished by using the two-dimensional finite element method while the nonlinear
saturation effect of the material property between magnetic field strength and magnetic flux
density has not been fully considered. This study proposes a topology optimization techniqueof the three-dimensional design as well as the two-dimensional design based on the density
method considering the nonlinear saturation effects. The proposed method makes it possible
to provide useful and practical process for magnetic system design and may lead to improved
design with light system weight. The proposed method is applied to the optimization
problem of a magnetic recording system. During the design process, the reluctivity ofmagnetic material is changed according to the nonlinear B-H relationship during magneto
static analysis. The sensitivity analysis and the update of design variables are accomplishedby the adjoint variable method and the sequential linear programming, respectively.

Magnetic disk drive technology has successfully reduced the size of multi-grain bits
to ~30 nm, and there are intensive industrial efforts to shrink the bit size further. This
work reports the development of a cheap, scalable polymer template lithography
technique of fabricating large arrays of magnetic nanostructures towards use as bit
patterned media, one of the prominent next generation data storage technologies.
The technique has been standardized and physical properties such as bit sizes, pitch
sizes and the storage densities have been calculated. Critical magnetic properties
such as magnetization reversal have also been studied and discussed to ascertain theplausibility of its use in futuristic high density magnetic data storage devices

Polycrystalline ceramic samples of Bi1-xLaxFeO3 (x=0.0, 0.1 and 0.2) have been
prepared by standard solid state reaction method using high purity oxides andcarbonates. The structure and formation of the compounds have been checked by X-ray
diffraction followed by energy dispersive X-ray microanalysis (EDAX) techniques.
There is a good agreement between observed and calculated X-ray diffraction patterns
obtained by performing the Rietveld refinement with a structural model using the noncentrosymmetric space group R3c. The lattice parameters have been refined but theover all structure remained the same. The microstructural studies have been carriedout using scanning electron microscopy. The dc conductivity of all the samples has
been measured and their activation energies were calculated from logσ vs 103/T
curves. Vibrating sample magnetometer (VSM) has been used to study the magnetic
behaviour of the compounds. It has been observed that with the increase of substitution
concentration of La, the insulating behaviour of the materials have been improved
and showing the antiferromagnetic to weak ferromagnetic behaviour. The results are
discussed in detail.

Nyun Jong Lee1, Jae Young Ahn1, Yu Jeong Bae1, Dominique Eyidi2*, Anny Michel2*
and Tae Hee Kim1*
1
Department of Physics, Ewha Womans University, Korea
2
Departement de Physique et Mecanique des Materiaux, Institut Pprime, UPR 3346,
CNRS-Universite de Poitiers-ENSMA, F86962 Futuroscope-Chasseneuil cedex,
FranceWe investigated the chemical ordering and perpendicular magnetic anisotropy (PMA)in L10 FePt and L12 FePt3 films. FePt films with different thickness of 35 and 70 A weregrown, at the substrate temperature Ts = 300 °C by MBE co-evaporation and layer-by-layer
growth, onto a MgO layer deposited on Si wafer. In order to optimize the growth of highlyordered FePt(001) films in conditions of low-temperature fabrication, the influence of athin (001)-oriented fcc Pt buffer layer on the c-axis oriented texture was explored by highresolution TEM and X-ray diffraction (XRD). Our results showed a strong enhancementof PMA without high-temperature annealing, for 35 A thick FePt films, while a decrease in
PMA was observed for L12 FePt3. By introducing a small percentage of Boron into the L12ordered FePt3, enhanced structural ordering was seen in XRD. However, no significant
change of magnetic properties was observed, in contradiction with the expectation to
induce PMA by altering the chemical ordering in FePt3 L12 phase. In this work, we discuss
the origin of spin reorientation transition phenomena related to our results. *corresponding
authors : taehee@ewha,ac,kr; Anny.S.Michel@univ-poitiers.fr

The 19th International Conference on Magnetism

Park Soon Ok*
Yonsei University Graduate school, Korea

Shivaraman Ramaswamy
Nanotechnology Research Center, SRM University, India[1] Park. S, Lee. D.H, Xu. J, Kim. B, Hong. S. W, Jeong. U, Xu. T, and Russell. T.P, 2009,“Macroscopic 10-Terabit-per-Square-Inch Arrays from Block Copolymers with Lateral Order,”Science, vol. 323, pp. 1030-1033. [2] Kikitsu. A, Kamata. Y, Sakurai. M and Naito. K, 2007,“Recent progress of patterned media,” IEEE Transactions on Magnetics, vol. 43,pp. 3685-3688. [3]Speliotis. D, 1984,'Media for high density magnetic recording', IEEE Transactions on Magnetics,
20, 5, 669 - 674.

July 12 (Thu)

Seungmin Baek, Hiroyuki Sakurai, Naoto Sagara, Pang Boey Lim and Mitsuteru
Inoue
Toyohashi University of Technology, Japan

248

poster Presentation

M. Roy, S. Jangid, S. K. Barbar and Indu Bala Thakur
Department of Physics, M. L. Sukhadia University, Udaipur, India

Topology optimization; finite element analysis; magnetic saturation effect; three dimensional
design; density method; adjoint variable method.

July 8-13, 2012 Busan, Korea

249

poster Presentation
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In situ X-ray absorption spectroscopy study on BaTiO3

Enhanced magnetic properties of Ni-doped BiFeO3 compounds

TC Evolution of Bulk and Optical Spectra of Nanocolloidal Fe-doped
Manganate CaMn1-xFexO3 (x = 0, 0.01, 0.03, 0.05)

July 12 (Thu)

Ferroelectric systems are under intensive study for both the point of view offundamental materials physics and the potential applications such as memories, sensors,
and transducers. The Ti4+ (d0-ness) systems which are the generally well known
ferroelectric as form ATiO3 structure (A=Ba and Pb), inter alia, have been extensively
investigated. To understand this system, both of structural and electronic investigations
must be completed together. Structurally, Ti ions in the TiO6 octahedra are moved
along the applied electric (E)-field, resulting in a symmetry lowing. However, we still
do not understand much about a change in the electronic structure between Ti 3d andO 2p states. Although the soft x-ray spectroscopy study at the oxygen absorption edgethat is regarded as a good approach for exploring the electronic structure, such study
accompanies an experimental difficulty; electron motion distortion under in situ E-field
condition. In this work, we introduce an approach for overcoming such difficulty inconventional x-ray absorption spectroscopy (XAS) measurement. By looking at the O
K-edge XAS of BaTiO3 via a fluorescence yield, we studied electronic structure andreveal that the observed spectra features are related with the structural changes under
the applied E-field.

Y. J. Yoo1, J. S. Park1, J. H. Kang2, J. Kim3, B. W. Lee3, M. S. Seo4 and Y. P. Lee1*
1
Physics, Hanyang University, Korea
2
Nano & Electronic Physics, Kookmin University, Korea
3
Physics, Hankuk University of Foreign Studies, Korea
4
Division of Materials Science, Korea Basic Science Institute, Korea
The structure and the magnetic properties of polycrystalline BiFeO3 and BiFe0.95Ni0.05O3
bulk ceramic compounds, which were prepared by solid-state reaction and rapid sintering,were investigated. High-purity Bi2O3, Fe3O4 and NiO powders were mixed with thestoichiometric proportions, and calcined at 450°C for 24 h to produce BiFe1-xNixO3. The
crystalline structure of samples was investigated at room temperature by using a Rigaku
Miniflex powder diffractometer. The field-dependent and the temperature-dependent
at high temperatures magnetization measurements were performed with a vibratingsample magnetometer. The temperature-dependent magnetization at low temperatures
was analyzed with Quantum Design superconducting quantum-interference-device(SQUID) magnetometer. The x-ray diffraction study demonstrates the compressive stressdue to the Ni substitution at the Fe site. The lattice constant of BiFe0.95Ni0.05O3 is smaller
than of BiFeO3 because of the smaller ionic radius of Ni3+ than that of Fe3+. The fielddependent magnetization of BiFe0.95Ni0.05O3 exhibits a clear hysteresis loop at 300 K. The
magnetic properties of BiFe0.95Ni0.05O3 were improved at room temperature because of theexistence of structurally compressive stress. The zero-field-cooled temperature-dependent
magnetization reveals that the magnetic transition temperature and the magnetic momentof BiFe0.95Ni0.05O3 are higher than those of BiFeO3.

Huyen-yen Duc Pham, Duc-thang Pham, Nam-nhat Hoang* and Duc-tho Nguyen
Faculty of Technical Physics and Nanotechnology, Vietnam National University,
University of Engineering and Technology, Viet Nam

Recently, the effect of magnetic reversal at low magnetic field was observed with themultiferroic Fe-doped CaMnO3 [Sol. Stat. Commun. 142 (2007) 525]. We report here theoptical behaviors of this class of compounds (CaMn1-xFexO3, x = 0, 0.01, 0.03, 0.05) whichwere prepared by using traditional ceramic method with parent oxides as precursors. The
analysis of structure showed the predominant orthorhombic phase with slight increased
cell constants according to doping content (from 3.743 to 3.746 Å). The investigation of
the Raman spectra also agreed with the increased Mn-O bond length according to doping,
therefore suggested the weakening of ferromagnetic exchange between Mn3+ and Mn4+
cations (exactly, from 0.61 to 0.52 eV). This weakening also developed together withthe reduction of Curie temperature (TC) (from 155 to 135 K), the shifts of infra-red (IR)absorption maxima towards the longer wavelengths and the narrowing of band-gaps (from0.45 to 0.14 eV). The absorption spectra also showed a clear absorption line near 1.2 eV
which is characteristic for Fe, and is composed mainly from 3d electron transition with achange in spin.

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Enhancement of magnetization in sulfur doped BiFeO3

Chunlong Shi, Jun Du and Xiaoshan Wu*
Physics, Nanjing University, China

Sulfur doped BiFeO3-xSx are synthesized by high pressure solid state reaction methodwith the high purity original materials of Fe2O3, Bi2O3, Bi2S3, S, and FeS. The pressure
remains 5 GPa during the sample preparations. We have compared the effects oforiginal materials on the final products, and got the optimum products with Fe2O3,
Bi2O3, and FeS as the original materials. Slight impurity of Bi2Fe4O9 is detected in the
products. A magnetization enhancement is confirmed to roughly more than 2 orders
with the above materials reaction. The saturation magnetization more than 0.75 emu/g at 1.5 Tesla, and the Hc is roughly 50 Oe. The good ferroelectric property is also
predicted. We argue that the enhancement of magnetization may due to the variation of
the chemical valence of iron.

PACS number: 75.47.Lx; 75.50.Ee; 74.25.Fy; 75.30.Kz
Keywords: perovskite, manganate, structure, optical

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Chiral skyrmions and magnetic bubbles in multiferroic materials

Magnetic modulation of electrical impedance in Bi-doped
La0.7Sr0.3MnO3Evidence of magnetic phase separation in LuFe2O4

Effects of chlorine and fluorine on the structure and magnetism in
BiFeO3

Xiuzhen Yu1*, Y. Tokunaga1, S. Seki2, Y. Kaneko3, S. Ishiwata2, M. Mostovoy4, N.
Nagaosa5 and Y. Tokura6
1
The Institute of Physical and Chemical Research, Japan
2
University of Tokyo, Japan
3
Japan Science and Technology Agency, Japan
4
University of Groningen, Netherlands
5
University of Tokyo, The Institute of Physical and Chemical Research, Japan
6
University of Tokyo, The Institute of Physical and Chemical Research, JST, Japan
Nanometric chiral skyrmions and magnetic bubbles have been successfully realized in multiferroic
materials Cu2OSeO3 and Sc-doped barium ferrite by means of Lorentz transmission electron microscopy.
Under the normal magnetic fields, chiral skyrmions with a topological number of -1 and a unique chirality, 50
nm in diameter, emerge in a non-centrosyemmetric helimagnet Cu2OSeO3. In analogy with the transition
from a helical spin structure to chiral skyrmions, a normal magnetic field turns the magnetic stripes into
a bubble lattice with a positional order and random chiralities in a hexaferrite BaFe0.79Sc0.16Mg0.05O19
with uniaxial anisotropy. By systematically investigating the dependences of magnetic configurations onmagnetic field, temperature and sample thickness, we reveal the differences between the spin textures ofchiral skyrmions and magnetic bubbles. First, the magnetic bubbles determined by the ratio of dipolar andexchange interactions show strong size dependence on magnetic field and sample thickness. The chiralskyrmions induced by Dzyaloshinskii-Moriya interaction, however, show less size dependence on theexternal factors. Second is a difference in chirality. The chiral skyrmions have a unique chirality determinedby the crystal chirality, while magnetic bubbles have two opposite chiralities, resulting in a variety ofzoological magnetic structure with varying external magnetic field.

Sujit Kumar Barik, M Aparnadevi and Ramanathan Mahendiran*
Physics, National University of Singapore, Singapore

In recent years, magnetic control of dielectric polarization in multiferroics andmagnetoelectrica has become a topic of considerble interest. Dielectric studies in thesematerials are often done using an impedance analyzer in the frequency range f = 10
to 10 kHz. As the frequency increase, dieletric permitivity decreses. Here, we showthat an interesting phenomenon occurs in MHz range in Bi doped La0.7Sr0.3MnO3.
With increasing freqeuncy of the ac current or ac voltage, both in- and out-of phasecompnents of electrical impedance show an abrupt increase that is accompanied by apeak around the Curie temperature. The peak decreases in magnitude and is suppressedin a field of 1 kOe. This results in a huge ac magnetoresistance (30-35 % for H = 1
kOe) and magnetoreactance (= 30-40 %). The origin of the magnetoreactance is notnecessarity due to change in capacitance but but it is suggested to magnetoindutanceeffect, which has not been seriously considered so far. The combination of huge ac
magneoresistance and magnetonductance in a single material provides multifunctional
capabilities. Results from our studies are compared to magnetocapacitance behavior
found in BiMnO3[1][1] T. Kimura, S. Kawamoto,I. Yamada, M. Azuma, M.Takano, Y. Tokura, Phys. Rev. B 2003, 67,
R180401 2003

Julie Bourgeois1, Gilles Andre2, Sylvain Petit2, Julien Robert2, Maria Poienar3, Jerome
Rouquette3, Erik Elkaim4, Maryvonne Hervieu1, Christine Martin1, Antoine Maignan1
and Francoise Damay2
1
Laboratoire CRISMAT, CNRS UMR 6508, 6 bvd Marechal Juin, 14050 CAEN CEDEX, France
2
Laboratoire Leon Brillouin, CEA-CNRS UMR 12, 91191 GIF-SUR-YVETTE CEDEX, France
3
Institut Charles Gerhardt, UMR CNRS 5253, Place Eugene Bataillon, cc1503, 34095 MONTPELLIER
CEDEX 5, France
4
Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin BP 48, 91192 GIF-SUR-YVETTE CEDEX, France
The magnetic properties of a polycrystalline sample of multiferroic LuFe2O4 [1] have been investigatedby means of magnetization measurements combined with neutron scattering, between 1.5 and 300K
[2]. Magnetic Bragg peaks appear below TN = 240K, and can be indexed using two propagation vectors,
corresponding to either a ferromagnetic or an antiferromagnetic stacking of the iron bilayers. The magnetic
arrangement in the ab plane follows a 1:2 pattern, which obeys the charge ordering one observed intransmission electron microscopy [3]. Neutron inelastic scattering data confirm the strong easy-axis
single-ion anisotropy of the iron spin in its trigonal environment, of about 8 meV at 5 K. Modeling of thediffraction data, based on a CO-type modulation of the spin ordering, shows coexisting magnetic phaseswith opposite signs of the intra-bilayer interaction, corresponding to two distinct magnetic transition
temperatures. Coexisting antiferromagnetic and ferrimagnetic phases, along with the enlarged axial
magnetic anisotropy, are necessary to describe the macroscopic magnetic properties of this compound.

Kaige Gao, Chunlong Shi and Xiaoshan Wu*
Physics, Nanjing University, China

Clorine and fluorine doped BiFeO3-xMx are synthesized by solid state reaction method
under high pressure and high temperature with the high purity original materials of
Fe2O3, Bi2O3, and FeCl2, or FeF2. The pressure remains 6 GPa and the temperature is
set to be 750 oC during the sample preparations. They are almost the single phase. We
have compared the chlorine and fluorine effects on the structure and magnetizationon the final products. Both doping samples show the weak magnetism at room
temperature, much larger than the pure BiFeO3, although the paramagnetic backgroundis strong. Chlorine doping show much larger magnetization than that of fluorine. We
argue that the magnetization results from the variation of the chemical valence of iron
ion and the distortion of FeO6 due to the element of oxygen replaced by fluorine orchlorine. The dielectric properties show us the small leakage may indicate the increaseof carriers. We expect a good dielectric properties may obtained by adjust the dopantsin BiFeO3.

[1] N. Ikeda et al., Nature (London) 436, 1136 (2005) [2] J. Bourgeois et al., submitted to Phys. Rev.
B (2012) [3] J. Bourgeois et al., to appear in Phys. Rev. B (2012)

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Studies on Bi1-xLaxFeO3 crystals in pulsed high magnetic fields

Theoretical study of PCAR measurement with d-wave
superconductors.

Magnetoelectric effect in mechanically mediated structure of TbFe2,
Pb(Zr,Ti)O3, and nonmagnetic flakes

Investigation of electricity coercive behavior of LSFMTO system using
ultrasonic mixing method

Masashi Tokunaga1, Mitsuru Akaki2, Hideki Kuwahara2, Kengo Oka1 and Takumi
Kihara1
1
The Institute for Solid State Physics, The University of Tokyo, Japan2
Department of Physics, Sophia University, Japan
BiFeO3 is known as the unique material that shows multiferroic nature at room temperature [1,2].
Application of high magnetic fields to this material induces a magnetic transition accompanied by asignificant change in the electric polarization [3-5]. Although the occurrence of this transition is explainedin the framework of the Ginzburg-Landau theory, in detail study is highly desirable to understand themicroscopic origin of the magnetoelectric effects in this material. In this work, we synthesized crystalsof Bi1-xLaxFeO3 with using the flux method, and studied their magnetic and dielectric properties inpulsed magnetic fields up to 55 T. Early experiments on the polycrystalline samples showed that partial
substitution of La for Bi reduces the magnetic field needed to cause the magnetic transition [6]. Our
isothermal magnetization measurements showed that the transition field at 4.2 K changes from 18 T to 15
T by La substitution. Our dielectric study revealed that the electric polarization shows significant change
accompanied with this magnetic transition. Therefore, the phenomena observed in BiFeO3 are reproducedin the reduced field scale in the La substituted system, which enables us more systematic studies to clarify
the microscopic origin of the magnetoelectric effects associated with the magnetic transition.
[1] J. Wang et al., Science 299, 1719 (2003). [2] G. Catalan and J. F. Scott, Adv. Mater. 21, 2463
(2009). [3] Yu. F. Popov et al., JETP Lett. 57, 69 (1993). [4] A. M. Kadomtseva, et al., JETP Lett.
79, 571 (2004). [5] M. Tokunaga et al., J. Phys. Soc. Jpn. 79, 064713 (2010). [6] G. Le Bras et al.,Phys. Rev. B 80, 134417 (2009).

The 19th International Conference on Magnetism

Hiroyuki Ohtori1 and Hiroshi Imamura2*
1
Univ. of Tsukuba, NRI-AIST, Japan
2
NRI-AIST, Japan

High spin polarization ferromagnetic metals are essential for creating highperformance spintronics devices, therefore it is important to estimate the value ofspin polarization quickly and efficiently. Point contact Andreev reflection (PCAR)
spectroscopy is a powerful method for measuring spin polarization of ferromagnetic
metals. However, most PCAR measurement were performed at very low temperatures,around 1.5 K, since the conventional s-type superconductor is used. If we use highTc superconductors, PCAR measurement can be performed at higher temperature. In
this study, we theoretically analyze the Andreev reflection in the ferromagnetic metal(FM) / insulator (I) / d-wave superconductor (dS) junctions. The superconducting
gap in momentum space is not uniform in the d-wave superconductor, therefore
the conductance suppression due to the insulator is affected by the difference of the
Fermi wave number between the ferromagnetic metal and superconductor. Especially,in the case of dx2-y2 model, we found that the bias voltage at which the normalized
conductance of the FM/I/dS junction drops is expressed as a function of the exchange
field of the ferromagnetic metal.

July 12 (Thu)J. S. Lee* and C. C. Kao
SSRL, SLAC National Accelerator Laboratory, USA

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poster Presentation

Yin-gang Wang* and Ke Bi
Nanjing University of Aeronautics and Astronautics, China

For most investigations on layered ME composites with excellent ME effect comparedto single phase materials and multiphase bulk composites, the classical structure isconstructed layer by layer through interface bonding. In this work, the proposed ME
structure is made up of two magnetostrictive TbFe2 alloys, one piezoelectric PZT
ceramic and two nonmagnetic glass flakes. When an external ac magnetic field Hac isapplied along the length direction of magnetostrictive TbFe2 flakes, the TbFe2 flakes
will produce an extensional strain. The strain then transfer to the PZT flake becauseof the end parts of PZT and TbFe2 flakes bonded with glass slides in a vertical plane.
Due to the piezoelectric effect, the PZT flake will induce a charge output. The interface
between magnetostrictive and piezoelectric phases is not required to achieve ME
coupling. Increasing Hdc from zero, αE,31 increases linearly until a maximum value isreached at 350 Oe, and then decreases subsequently. With further increase in Hdc,
αE,31 reaches a maximum value, and then decreases subsequently. There are several
resonance peaks at 200 Oe and 1<f<150 kHz and a giant ME voltage coefficient ashigh as 2.7 Vcm-1 Oe-1 can be obtained at the resonance frequency of 44.5 kHz.
1. C. Israel, N. D. Mathur, and J. F. Scott, Nature Mater. 7, 93 (2008). 2. C. W. Nan, M. I. Bichurin,
S. X. Dong, D. Viehland, and G. Srinivasan, J. Appl. Phys. 103, 031101 (2008). 3. M. Zeng, S. W. Or,
and H. L. W. Chan, Appl. Phys. Lett. 96, 203502 (2010).

Erfan Handoko1*, Azwar Manaf2 and Dede Djuhana2
1
Physics, Department of Physics, State University of Jakarta, Indonesia
2
Physics, Department of Physics, University of Indonesia, Indonesia

We have investigated electricity coercive behavior of La0.5Sr0.5Fe0.9Mn0.05Ti0.05O3(LSFMTO) system using ultrasonic mixing method. LSFMTO system is driven by
40 kHz frequency and calcinate process up to 750oC for 30 minutes. Then sintering
process also carried out by systematic various of temperature 900 oC, 1000 oC, and1100 oC respectively, with time preparation is same previously. Very interestingly,
the LSFMTO system exhibits ferroelectric (La,Sr)(Fe,Mn,Ti)O3 and ferromagnetic
SrFe12019 properties and minor phase La2O3 by XRD analyzation. We have also carriedout measurement of LSFMTO system using a systematic applied the external magnetic
field and electric polarization. The hysteresis curve of LSFMTO system shows theelectricty coercive (Ec) increases while saturation polarization (Pc) and remanentpolarization are tendency constant at the magnetic strength of 0.12 T. I believed that
our finding of LSFMTO system is potensial to multiferroic material.
1. Jifan Hu, et al, Materials Science and Engineering B 90, p.146-148 (2002). 2. O. Chmaissem etal, Physical Review B 74, 144415 (2006) 3. Y. L. Cheng, et al, Journal Magnetism and Magnetic
Material, 322, p 97-101 (2010)

July 8-13, 2012 Busan, Korea

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poster Presentation

poster Presentation

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Enhancement of multiferroic properties of solid state prepared La
doped BiFeO3

Pressure studies of LaAgSb2 utilizing new integrated pressure cell

Spin dynamics of multiferroic BiFeO3 single crystal

Electric polarization, toroidal moments, spin chirality, spin canting at
avoided level crossing induced by Dzyaloshinsky-Moriya interaction inV3 nanomultiferroics in transverse magnetic field

BiFeO3 (BFO) has generated widespread interest since it is a room-temperature
multiferroic. LaxBi1-xFeO3 (x= 0.05-0.4) are prepared through solid state reaction
method. X-ray diffraction for x ≤ 0.15 shows R3c and for x> 0.15 the structurechanges to Pbnm. The percentage of these phases present is estimated through Rietveld
analysis. Raman spectra for x ≤ 0.15 exhibit 8 peaks (4A+4E modes). There is no
shift in Raman modes indicating that La substitutes Bi in BFO. The dielectric constantincreases and leakage current decreases with x. The enhanced polarization may be dueto the distortion of the crystal lattice with La doping. With increase in La doping the
TN decreases. The magnetization (M) decreases up to 250 K and increases on further
cooling indicating the spin reorientation. A cusp in M-T is observed close to 50 K
indicating the spin glass behavior. M-H loops do not saturate even for field up to 6 T.
With La doping, HC and the magnetization increases dramatically in comparison to
x=0. Both Hc (~ 1.6 T) and Mr (0.27 emu/g) have maximum values for x =0.2 at 5 K.
The increase in the magnetic parameters is attributed to the break in the spin cycloid
structure.

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July 12 (Thu)(1) H. Fukamura et.al. J. Magn.Magn. Mater. 310, e367 (2007) (2) Manoj K. Singh et.al. Phys. Rev.
B. 77, 144403 (2008)

Jaehong Jeong1, E. A. Goremychkin2, T. Guidi2, K. Nakajima3, Gun Sang Jeon4, Shin-ae Kim5, S.
Furukawa6, Yong Baek Kim6, Seongsu Lee5, V. Kiryukhin7, S-w. Cheong7 and Je-geun Park1*
1
FPRD Department of Physics & Astronomy, Center for Strongly Correlated Materials
Research, Seoul National University, Seoul 151-747, Korea
2
ISIS Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX, United Kingdom
3
Neutron Science Section, MLF Division, J-PARC Center, Tokai, Ibaraki 319-1106, Japan
4
Department of Physics, Ewha Womans University, Seoul 120-750, Korea
5
Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353, Korea
6
Department of Physics, University of Toronto, Toronto M5S 1A7, Canada
7
Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers
University, Piscataway NJ 08854, USA
Multiferroic compounds are one of most challenging topics in the condensed matter physics [1] not only for
its fundamental importance but also for huge future applications. Although several systems are known to havemultiferroic behavior, there are few multiferroic materials that have both magnetic and ferroelectric transition
temperatures above room temperature. BiFeO3 is probably the only exception with Neel temperature at TN=650
K and Curie temperature at TC=1100 K [2]. In order to understand the spin dynamics of BiFeO3, we have carriedout inelastic neutron scattering experiments on ten co-aligned single crystals of BiFeO3 using AMATERAS
beamline at J-PARC and MERLIN beamline at ISIS. In particular, we used a so-called sample rotation method on
MERLIN to map out the full three-dimensional spin wave [3]. We have also calculated the spin wave dispersion
using Heisenberg Hamiltonian with two exchange parameters between the nearest and next nearest neighbors.
A Dzyaloshinskii-Moriya term that arises from the spiral magnetic structure of BiFeO3 was also examined. By
carefully examining the AMATERAS and MERLIN data, we could find, for the first time, the full spin wave
dispersion of BiFeO3 and determine the exchange parameters that are consistent with the experimental results.

Moisey Belinsky
School of Chemistry, Tel-Aviv University, Tel Aviv, Israel

The spin-frustrated V3 and Cu3 nanomagnets with the Dzialoshinsky-Moriya (DM) interaction havereceived great attention for potential application in quantum computation [1-8]. V3 with the out-of-plane
Dz and in-plane Dn DM interactions demonstrates the multiferroic behavior in longitudinal magnetic field
Bz||Z: field-induced polarization Pz(Bz) and toroidal moments Tz(Bz), which depend on the vector Κz(Bz)[scalar χ(Bz)] chirality, and complicated individual spin dynamics at avoided level crossing (ALC) [7].
In order to investigate the multiferroic behavior in transverse field Bx┴Z and B-reversal/rotation effects,
P(Bx), Tn(Bx), M(Bx)magnetization, Κz(Bx), χ(Bx) and spin canting were calculated for B┴Z. The spincurrent P~Is mechanism [9] is the driving force of Pz(Bx) with a maximum at ALC that corresponds toIs(max). The in-plane DM leads to the in-plane Tn(Bx) which exhibits T-flop under B-rotation/reversal.
Tn(B), χ(B), orbital moment M'(B), circular orbital current Io~χ [Pz(B), Κz(B), Is] show the switch on/off[reduction] under B-rotation within vertical XZ plane. Field behavior Pz(Bx), Tn(Bx) , M(Bx), Κz(Bx),Is, Io, and individual spin dynamics for Bx┴Z strongly differ from that for Bz||Z. V3 exhibits non-linear
reduction of Κz(Bx)vector chirality, χ(Bx)=0, and the entanglement effect. The V3 nanomultiferroics
demonstrate magnetically controlled anisotropic Pz(B), Tn(B), M(B), Κz(B), χ(B), M', Is, Io characteristics.

1) S-W. Cheong and M. Mostovoy, Nature Materials 6,13 (2007) 2) I. Sosnowska et al., J. Phys. C: Solid
State Phys. 15, 4835 (1982) 3) Jaehong Jeong et al., Phys. Rev. Lett. 108, 077202 (2012)

1. T. Yamase et al., Inorg. Chem. 43, 8150 (2004). 2. Y. Kohama et al., J. Solid. State. Chem. 182, 1468 (2009). 3. K.-Y. Choi etal., Phys.Rev.Lett. 96, 107202 (2006); Phys. Rev. B 77, 024406 (2008). 4. M. Trif et al., Phys.Rev Lett. 101, 217201 (2008). 5. M.
Trif et al., Phys.Rev. B 82, 045429 (2010). 6. M. F. Islam et al., Phys. Rev. B 82, 155446 (2010). 7. M.I. Belinsky, Phys. Rev. B
84, 064425 (2011). 8. M.I. Belinsky, Chem. Phys. 361, 137, 152 (2009). 9. H. Katsura et al ., Phys. Rev. Lett. 95, 057205 (2005).

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Magnetostructural coupling at the metal-insulator transition in
YBaCo2O5.5 as seen by synchrotron x-ray diffraction and absorption

Crystal & Magnetic structure studies of doped BiFeO3 multiferroic
compoundMagnetic and dielectric properties of the single crystals Sm 1xHoxFe3(BO3)4 and Sm1-xLaxFe3(BO3)4

Mössbauer studies of bismuth ferrite

In LnBaCo2O5.5 (Ln: lanthanide) cobaltites Ln and Ba cations order in alternating planes along thec-axis yielding an ordered arrangement of CoO5 pyramids and CoO6 octahedra. The presence of two
local environments for Co may be at the origin of proposed Co spin-state changes whose interplay
with the structural and electronic changes at metal-insulator transitions (MIT) are currently attracting
much attention [1-5]. We present a study of the magnetic, structural and thermoelectric properties of
YBaCo2O5.5 as a function of temperature. Our results evidence the presence of three magnetic transitions
with a strong magnetostructural coupling. We have used synchrotron x-ray powder diffraction to showthat the Pmmm orthorhombic structure transforms (on cooling) into a monoclinic (P112/a) phase
below TMI ~ 295 K by doubling the a-axis [6]. Concomitantly a ferromagnetic moment appears andthe Seebeck coefficient is enhanced. A further cooling leads to the successive appearance of Co AFM
structures (TN1 ~ 267 K, TN2 ~ 231 K), the crystal structure becoming again orthorhombic. Finally, we
present temperature dependent soft x-ray absorption data at the Co L3 edge. They discard the possibilityof a high to low spin state change in Co ions at octahedral sites across the MIT [7].

Multiferroics, materials combining multiple order parameters, offer an exciting way of coupling
phenomena such as electronic and magnetic order. The coexistence of different order parameter
permits potential applications in information storage, spintronics, and magnetic or electric fieldsensors. The perovskite BiFeO3(BFO) is known to be antiferromagnetic below the Neel temperatureof 640 K and ferroelectric with a high Curie temperature of 1100 K. According to the previous
doping studies of BFO, it is likely that non-stoichiometry and second-phase formation are the factors
responsible for leakage current in BFO. It has been suggested that oxygen nonstoichiometry leads
to valence fluctuations of Fe ions in BFO, resulting in high conductivity. To reduce the large leakage
current of BFO, one attempt is to make donor-doped BFO compounds. In this study, we have tried togenerate the new multiferroric material functioning on at room temperature. The candidate systems
are BiFeO3+BaMnO3 and BiFeO3+BaTiO3. These system have been fabricated by a solid-state
reaction method and flux method, respectively. The crystal and magnetic structure of these systems
are studied using XRD and neutron powder diffraction as functions of temperature. We will discuss
the magnetic and electric property of new multiferroic system working on at room temperature.

The trigonal rare-earth ferroborates with hantit ctructures is interested due to verystrong of the electric polarization induced by magnetic field. The research of single
crystals with double rare-earth subsystems such as Sm1-xRxFe3(BO3)4 (R = Ho, La) is
important for analysis microscopic mechanism of magnetoelectric interaction. The
single crystals of Sm1-xHoxFe3(BO3)4 with x = 0; 0.3; 0.5 and Sm1-xLaxFe3(BO3)4. with
х = 0.25; 0.5 were grown by a flux method. The magnetic and magnetodielectric
properties have been investigated. It has been revealed what magnetic behaviour andmagnetodielectric effect essential depended on x. The magnetic field influence on thechange in degree of dielectric penetrability is decreased with increasing x for bothunder study families. The decreasing of magnetodielectric effect is probably relatedwith influence of the racemic twinning.

[1] A. Maignan et al., J. Solid State Chem. 142, 247 (1999). [2] E. Suard et al., Phys. Rev. B 61, R11871(2000). [3] C. Frontera et al., Phys. Rev B 74, 054406 (2006). [4] V.P. Plakhty et al., Phys. Rev. B 71,
214407 (2005). [5] M. Soda et al., J. Phys. Soc. Jpn. 72, 1729 (2003). [6] J. Padilla-Pantoja et al., Phys.
Rev. B 81, 132405 (2010). [7] J. Padilla-Pantoja et al., J. Appl. Phys. 111, 234291 (2012) (In press).

1. T. Choi, S. Lee, Y. J. Choi, V. Kiryukhin, and S-W. Cheong Science 324, 63 (2009) 2. Junghwan
PARK, Sang-Hyun LEE, Seongsu LEE, Fabia GOZZO,Hiroyuki KIMURA, Yukio NODA, Young Jai
CHOI, Valery KIRYUKHIN, Sang-Wook CHEONG, Younjung JO, Eun Sang CHOI, Luis BALICAS,

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Magnetic field dependence of dielectric properties in LuFe2O4

The analysis of structure, magnetic and ferroelectric properties of Ba1xBixTi0.95Fe0.05O3

Far infrared spectroscopy of EuFe3(BO3)4

Jessica Padilla-pantoja, Javier Herrero-martin, Carlos Frontera and Jose Luis Garciamunoz
Institut de Ciencia de Materials de Barcelona, ICMAB-CSIC, Spain

Takashi Kambe*, Yukimasa Fukada, Tomoko Nagata and Naoshi Ikeda
Physics, Okayama university, JapanThe multiferroic properties in LuFe2O4 are of interest, in which contains equal amountof Fe2+ and Fe3+ in triangular lattice. This material shows a ferri-magnetic transition at
240K and three-dimensional charge ordering at around 320K. The dielectric propertyof this material is suggested with a valence fluctuation process of iron ions in the polarcharge ordered domain. Here we report a magnetic field variation of the dielectric
constant of single crystal LuFe2O4, and discuss with the valence fluctuation process ofiron charges in the magnetic domain wall.

Seongsu Lee
Neutron Science Division, KAERI, Korea

Evgeniy Eremin*, Irina Gudim, Vladislav Temerov and Alexander Eremin
Kirensky Institute of Physics SB RAS, Russia

The multiferroic material is a material which shows more than one primary ferroic order parameter
simultaneously and can be made by introducing the magnetic impurities into ferroelectric material[1]. BaTiO3 is known as a classical ferroelectric material, whereas the Fe-doped BaTiO3 is reported
to have a magnetic ordering. Although the Fe doping can induce the ferromagnetism in BaTiO3,
the ferroelectricity of this material is suppressed. In this report, we analyze the structure, magnetic
and ferroelectric properties of Ba1-xBixTi0.95Fe0.05O3 (0 ≤ x ≤ 0.05). XRD results indicate that the
tetragonal phase is merged with the hexagonal phase for x < 0.05. At x = 0.05, the pure tetragonalphase is observed. The magnetic field dependence of magnetization at room temperature for x= 0 shows a kind of antiferromagnetism. Introducing 2 % Bi doping, it shows the ferrimagnetic
properties. However, with the 5 % doping of Bi, the ferrimagnetic loop is disappeared andbecomes paramagnetic. It suggests that the superexchange between Fe3+ ions in octahedral
and pentrahedral sites associated with oxygen vacancy produces the ferromagnetism [2]. The
ferroelectric hysteresis loop with low leakage current is only observed for x = 0.02. These results
indicate that the multiferroic properties are observed in Ba0.98Bi0.02Ti0.95Fe0.05O3 sample.

Seungkyu Han, Yong Hui Li, Minseon Kim, Sam Jin Kim and Chul Sung Kim*
Physics, Kookmin University, Korea
Perovskite bismuth ferrite (BiFeO3) is a multiferroic material, having ferroelectric order(TC = 1,103 K) and antiferromagnetic order (TN = 643 K) [1]. It is a possible candidate for
information storage, spintronics, and sensors applications [2]. Here, we have measured themagnetic properties of BiFeO3 using x-ray diffractometer, field emission scanning electron
microscope (FE-SEM), vibrating sample magnetometer, and Mössbauer spectroscopy.
Single phased BiFeO3 was synthesized by a low-temperature hydrothermal method. FESEM results showed that the grain sizes of microsphere and microcube were about 80 μm
and 50 μm, respectively. BiFeO3 powder showed weak-ferromagnetic behavior with a small
magnetization value (Ms ~ 100 memu/g) at 295K. Rietveld refinement analysis showed thatFe-site and O-site splits into two pairs, respectively. The Mossbauer spectra of BiFeO3 wereanalyzed with 2-set sextet. Isomer shift (δ) values showed that Fe3+ ions existed in octahedral
site. Electric quadrupole shift (EQ) values suggested different lattice distribution at octahedral
site. Based on EQ values (0.02 ~ 0.1 mm/s), splitting into two partially occupied sites results
in a distorted FeO6 octahedral. The weak ferromagnetism observed in the hydrothermallyprepared BiFeO3 particles comes from distorted FeO6 octahedral, leading to incomplete
counterbalance between the antiferromagnetic sublattices of the Fe ions.
[1] G. A. Smolenskii and I. chupis, Sov. Phys. Usp. 25, 475 (1982). [2] J. Wang, J. B. Neaton,
H. Zheng, V. Nagarajan, S. B. Ogale, B. Liu, D. Viehland, V. Vaithyanathan, D. G. Schlom, U. V.
Waghmare, N. A. Spaldin, K. M. Rabe, M. Wuttig, and R. Ramesh, Science 299, 1719 (2003).

Gun Sang JEON, and Je-Geun PARK Journal of the Physical Society of Japan 80, 114714(2011)

Widi Yansen1, Kadek Juliana Parwanta1, Jaeyeong Kim1, Min Gyu Kang2, Chong YunKang2 and Bo Wha Lee1*
1
Physics, Hankuk University of Foreign Studies, Korea
2
Physics, Korea Institute of Science and Technology, Korea

July 12 (Thu)Suresh P and Srinath S*
School of Physics, University of Hyderabad, India

Sven Friedemann1*, Zhou Feng1, Takao Ebihara2, Christophe Thessieu3 and F Malte
Grosche1
1
Cavendish Laboratory, University of Cambridge, United Kingdom
2
Department of Physics, Shizuoka University, Shizuoka 422-8529, Japan3
easyLab Technologies Ltd., Earley Gate, Whiteknights Road, Reading, RG6 6BZ,
United Kingdom

Kirill N. Boldyrev1*, Taras N. Stanislavchuk2, Marina N. Popova1 and Sergey A.
Klimin1
1
Solid State Spectroscopy, Institute of spectroscopy RAS, Russia
2
Physics, New Jersey Institute of Technology, USA

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Synthesis and electrical characterization of Bi1-xYxFeO3 ceramics

Vikash Singh*, Manoj Kumar and R. K. Dwivedi
Physics & materials science & engg., Jaypee institute of information technology,
India

We present the results on the polarized far infrared absorption spectra of EuFe3(BO3)4
crystal in a wide range of temperature (3.5 - 300K). Rare-earth iron borates RFe3(BO3)4undergo the antiferromagnetic phase transition at temperatures below 40 K, and someof them exhibit a significant magnetoelectric and magnetoelastic effect. EuFe3(BO3)4
is known to exhibit two phase transitions, the structural one at TC = 58 K [1], and theantiferromagnetic ordering at TN = 34 K [2]. The phonon frequencies demonstratepronounced changes at TC, consistent with the observed peculiarities in the dielectric
constant and thermal expansion [3]. Smaller but clearly visible phonon shift wereregistered below TN, thus evidencing the spin-lattice interaction in the title compound.

Compositions within range 0.05 ≤ x ≤ 0.20 in the system Bi1-xYxFeO3 (BYFO) havebeen synthesized by solid state reaction method. Structural and electrical properties ofyttrium doped bismuth ferrite ceramics have been investigated. Single-phase formation
has been confirmed by x-ray diffraction, which has shown rhombohedral symmetry
with R3c space group at room temperature. Temperature dependent dielectric behavior
of BYFO ceramics with in composition range 0.05 ≤ x ≤ 0.20 at few frequencies
have shown an anomaly near the temperature which corresponds to magnetic phasetransition ‘TN’ for pure BiFeO3 material (i.e.370oC). Substitution of yttrium in BFO has
shown a shift in TN. The temperature dependence of ac conductivity indicates that the
conduction process may be influence by defects which occurs due to oxygen vacancies.

[1] M.N. Popova, Journal of Rare Earths, 27, 607 (2009). [2] M.N. Popova, Journal of Magnetismand Magnetic Materials, 321, 716 (2009). [3] A.M. Kadomtseva, Yu.F. Popov, G.P. Vorob’ev, A.P.
Pyatakov, S.S. Krotov, K.I. Kamilov, J. Low Temp. Phys., 36(6), 640 (2010).

1. N. A. Hill, Why are there so few magnetic ferroelectrics, J. Phys. Chem. B 104, 669 (2000). 2.
H. Singh, K.L. Yadav, Dielectric, magnetic and magnetoelectric properties of La and Nb codoped
bismuth ferrite, J. Phys.: Condens. Matter 23, 385901 (2011).

[1] Y. Shuai, S. Zhou, D. Burger, H. Reuther, and I. Skorupa, J. Appl. Phys. 109, 084105 (2011). [2] F.
Lin, D. Jiang, X. Ma, and W. Shi, J. Magn. Magn. Mater. 320, 691-694 (2008).

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The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

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poster Presentation
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Lattice engineering on transition metal oxide thin film
Chang Uk Jung*

Superconductivity of EuFe2As2 under high pressure

Concentration dependence of magnetic and transport characteristics
in EuFe2As2-xPx single crystals

Kinetic energy density of cooper pairs in Sr doped YBa2Cu3O7-δ single
crystals

Transition metal oxide having a perovskite structure showed a large spectrum ofphysical properties. YBa2Cu3O7 showed high temperature superconductivity,(La,Ca,Sr)MnO3 showed ferromagnetism with half metallicity, Pb(Zr,Ti)O3 showed
Ferroelectricity, and BiFeO3 showed coexistence of antiferromagnetism andferroelectricity. Recent advance in interface control revealed a 2d electron gas, interface
superconductivity, interface magnetism, oribital reordering, interface thermoelectriceffect at the interface of transition metal oxide. The effect of lattice distortion has beenstudied for a long time and recently showed that lattice distortion during thin film
growth can create new ground state. Especially ATiO3, (A=Sr, Y, Eu) was interesting. [Inbulk state, YTiO3 and EuTiO3 are magnetic insulator, and SrTiO3 is not ferroelectric.]
I will introduce the some current research on the progress on these materials In thiscase, only lattice mismatch between substrate and film was used. On the contrary
the available substrate is rather narrow. I will also introduce efforts to overcome thisproblem.

EuFe2As2 with the tetragonal ThCr2Si2-type structure exhibits a spin density wave(SDW) transition at 190 K, with a simultaneous structural change [1]. The SDWtransition is suppressed by applied pressure and bulk superconductivity appears around
2.5 GPa [1-3]. Furthermore, magnetic moments of Eu sublattice order magneticallyat To = 19 K. The value of To reveals no changes at pressures of up to 3 GPa [1-3].
We have studied the superconductivity and the magnetism of EuFe2As2 by measuring
dc magnetization and 57Fe nuclear forward scattering (NFS) under high pressure.
Magnetization at 2.6 GPa rapidly increases below 24 K and then gradually decreases
by the appearance of superconductivity. The size of the drop at low temperatures is
consistent with nearly 100 % shielding. Namely, bulk superconductivity appears underthe magnetic ordered state of Eu sublattice. The pressure dependence of 57Fe NFS
spectra shows the decrease of the hyperfine field Bhf of Fe sublattice with increasingpressure. Furthermore, it is found that the direction of Bhf varies around 2.6 GPa,
implying the changes of magnetic structure. In this presentation, we will discuss therelation between the superconductivity and the magnetism of EuFe2As2, considering
these results.

July 12 (Thu)[1] A. Ohtomo & H. Y. Hwang, Nature 427, 423 (2004), [2] N. Reyren et al., Science 317, 1196
(2007). [3] J. Chakhalian et al., Science 318, 1115 (2007). [4] S. C. Chae,et al., Appl. Phys. Lett. 89,
182512 (2006). [5] J. H. Haeni et al., om, Nature 430, 758 (2004). [6] June Hyuk Lee et al., Nature
466, 954 (2010). [7] C. U. Jung et al.,, Appl. Phys. Lett., 84, 2590 (2004). [8] B. W. Lee et al., J. ofAppl. Phys., 104, 103909 (2008). [9] B. W. Lee et al.,, APL 96, 102507 (2010).

Shugo Ikeda and Hisao Kobayashi
Graduate School of Material Science, University of Hyogo, Japan

Takanari Kashiwagi*, Takuya Ishikawa, Tomoki Goya, Youhei Jono, Akihiko
Nozawa, Kasumi Tashima and Kazuo Kadowaki
Univ. of Tsukuba, WPI-MANA, JST-CREST, Japan
EuFe 2As 2 exhibits the spin-density wave of Fe spins at TSDW=190 K andsubsequently magnetic order of Eu2+ moment at TN=19 K. It is also known that thiscompound shows the superconductivity by isovalent substitution of As to P and theTc value increases up to 28 K. We have studied magnetic and transport properties insingle crystal of the EuFe2As2-xPx system grown by the self-flux method. From themagnetization measurements at 5 K, we observed a saturation of magnetization of Eu2+
at HM ~ 1 T and a spin-flop like behavior at Hsf ~ 0.6 T for H||ab-plane. These fields
seem to decrease as x is increased, indicating reduction of the exchange interaction andthe uniaxial anisotropy. We also performed electron spin resonance measurements at
X-band on single crystals of EuFe2As2-xPx. The result shows that the resonance field
increases with decreasing temperature toward to TN=19 K below which a new line wasobserved. We will discuss these results including electron spin resonance experimentswith emphasis on the phase diagram of magnetism and superconductivity in EuFe2As2xPx.

[1] K. Matsubayashi et. al : Phys. Rev. B 84 (2011) 024502. [2] N. Kurita et. al : arXiv:
1103.4209v1. [3] T. Terashima et. al : J. Phys. Soc. Jpn. 78 (2009) 083701.

Ana Paula Aguiar De Mendonca1*, Rovan Fernandes Lopes1, Valdemar Das Neves
Vieira1, Fabio Teixeira Dias1, Douglas Langie Da Silva1, Paulo Pureur2, Jacob Schaf3,
Mauro Melchiades Doria4 and Frederik Wolff-fabris5
1
Universidade Federal de Pelotas, Brazil
2
Universidade Federal do Rio Grande do Sul, Brazil
3
Universidade Federal do Rio Grande so Sul, Brazil
4
Universidade Federal do Rio de Janeiro, Brazil
5
HZ Dresden-Rossendorf, Germany

The kinetic energy, K(T) is a relevant tool to sort the distinct proposal for the normal state and theirconsequent paring mechanisms in HTSC.[1,2] Motivated by this potential we report on reversible DC
magnetizations as a function of temperature of a series of YBa2-xSrxCu3O7-δ (x = 0, 0.02, 0.10, 0.25, 0.37
and 0.50) single crystals with the purpose to study the role of ion size chemical introduced disorder on the
average kinetic energy density (AKED) of Cooper pairs in the YBa2Cu3O7-δ superconducting state.[3] The
Sr ion size chemical disorder is introduced in YBa2Cu3O7-? structure by lattice distortion. The valuationof the AKED from reversible dc magnetization data is supported by viral theorem of superconductivity.
[1,2,4] The AKED preliminary results of the YBa1.9Sr0.1Cu3O7-δ single crystal show that the series of theisofield K(T) curves, obtained to the H = 10 kOe, scales in a common behavior that smoothly develops as
the temperature is increasing toward to the Tc, disappearing inside a common background for T > Tc. This
interested AKED behavior strongly suggests an existence of a unique superconducting condensate state. At
this time the dc magnetization measurements in additional samples are in progress.
1. S. Salem-Sugui, Jr., M. M. Doria, A. D. Alvaraga, V. N. Vieira, P. F. Farinas and J. P. Sinnecker, Phys. Rev. B 76, 132502(2007). 2. M. M. Doria, S. Salem-Sugui, I. G. de Oliveira, L. Ghivelder and E. H. Brandt, Phys. Rev. B 65, 144509 (2002). 3. V. N.
Vieira and J. Schaf , Phys. Rev. B 65, 144531 (2002). 4. M. M. Doria, J. E. Gubernatis and D. Rainer Phys. Rev. B 39, 9573 (1989).

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Structural and magnetic properties of doped iron oxo-selenides

Superconductivity in 4d, 5d pnictides

Resonance-like response in antiferromagnetically ordered
Fe1.02Te0.95Se0.05, studied by polarized inelastic neutron scatteringx

Sven Landsgesell1, Karel Prokes1 and Dimitri Argyriou2
1
M-I1, Helmholtz-Zentrum Berlin, Germany
2
European Spallation Source, Sweden

In the Cu oxide superconductors the Cu resides in a square planar geometry[1], while in the
Fe pnictide superconductors the Fe ion resides in a tetrahedrally coordinated position[2].
Both compounds may show a separating LaO layer between the superconducting sheets.
La2O3Fe2Se2 shows square planar Fe O sheets and offers a direct super exchange pathway
to the next nearest Fe neighbour via the Se, comparable to the iron arsenides[3]. These superexchange pathways are similar to the superconductors despite the difference and provide
a similar local environment for the Fe as is known for the Fe-superconductors[4]. We
investigated the changes in the physical properties in the iron oxo-selenides by varying theelectron density and structural components. We doped the parent compound with F, Cd andrare earths with smaller radii (La2O3-xFxFe2Se2, and La2-x(Cd/RE)xO3Fe2Se2, respectively).
Temperature dependent neutron diffraction of the samples mostly show an antiferromagnetic
order along the a-direction with a propagation of (0.5 0 0.5). We find indications for an
evolving transition in the physical properties, as decreasing TN for fluorine and rare earth
samples. This is comparable to the known doped iron superconductors and in contrast to theelectron deficient Cd doped samples that show an in creasing TN.
1 D. Vaknin et al., Phys. Rev. Lett. 58, 2802 (1987) 2 Y. Kamihara et al., J. Am. Chem. Soc. 130,3296 (2008) 3 E. Manousakis et al., Solid State Comm. 150, 62 (2010) 4 D.G. Free and J.S.O.
Evans, Phys. Rev. B 81, 214433 (2010)

Tomohiro Takayama1*, Daigorou Hirai1, Keisuke Kuwano1 and Hidenori Takagi2
1
Department of Advanced Materials, University of Tokyo, Japan2
Department of Physics, University of Tokyo, Japan
After the discovery of the iron arsenide superconductors, a tremendous effort hasgone into the search for new high-Tc superconductors. We explored 4d, 5d pnictides,
hoping to find superconductors which share important characteristics with Febased superconductors. We report two new superconducting systems with suchcharacteristics, but sufficiently different from Fe pnictides. (i) APt3P (A = Ca, Sr andLa) The new compounds APt3P crystallize in an antiperovskite structure with distorted
PPt6 octahedra. All of them display superconductivity below 6.6, 8.4 and 1.5 K for
Ca-, Sr- and LaPt3P, respectively. The highest-Tc compound SrPt3P exhibits strongcoupling s-wave superconductivity. The presence of multiple pocket Fermi surface
was inferred in SrPt3P, which might enhance the coupling with low-energy phonons.
(ii) RuPn (Pn = P, As) Binary RuPn crystallize in an orthorhombic MnP-type structure.
RuP and RuAs were found to show a metal to non-magnetic insulator transition at 270
and 200 K, respectively. The structural analysis evidenced another phase transition at
higher temperatures, indicative of pseudogap formation. The two transitions can besuppressed by Rh-doping. We discovered superconductivity with a maximum Tc = 3.7
K and 1.8 K at the critical doping level for suppressing the pseudogap-phase in Ru1xRhxP and Ru1-xRhxAs, respectively.

Karel Prokes1*, Arno Hiess2, Wei Bao3, Sven Landsgesell1, Elisa Wheeler4 and Dimitri Argyriou2
1
M-I1, Helmholtz Zentrum Berlin, Germany
2
European Spallation Source ESS AB, 22100 Lund, Sweden
3
Renmin University of China, 100872 Beijing, China
4
M-I1, Institut Laue-Langevin, 38042 Grenoble Cedex, France

Unconventional superconductivity in iron pnictides and chalcogenides [1] shows intriguing similarities withboth copper-oxide- and rare-earth-based superconductors. Common is a proximity to a magnetic order and an
existence of magnetic fluctuations [2]. Magnetic fluctuations change below the superconducting transition andare readily detectable by neutron inelastic scattering. The character of these has been shown to be related to thepairing mechanism and gap symmetry [3]. In all superconducting pnictides and chalcogenides one finds welldefined magnetic excitations centered close to the Q = (0.5, 0.5, 0) reciprocal position that strongly dispersewith increasing energy and peaking in the 6.5-9.8 meV range [2]. Polarization neutron experiment allows for adetermination of the in-plane and out-of-plane inelastic responses that are proportional to the relevant imaginaryparts of the dynamical susceptibility. While the fluctuations in FeTe1-xSex, x = 0.40 are nearly isotropic with aslightly enhanced component along the c axis [4,5], in BaFe1.9Ni0.1As2 they are have an in-plane 2D character[6]. In this contribution we report on a polarized neutron study showing that similar fluctuations also exist also in
antiferromagnetically ordered Fe1.02Te0.95Se0.05 above the magnetic phase transition.

Interplay between superconductivity and antiferromagnetism in BaFe2NixAs2 single crystals studied by 57Fe Mossbauer spectroscopy

Julian Andres Munevar Cagigas1, Hans Micklitz2, Chenglin Zhang3, Hui Quian Luo4,
Pengcheng Dai5 and Elisa Baggio-saitovitch1*
1
Brazilian Center for Research in Physics, Brazil
2
Centro Brasileiro de Pesquisas Fisicas, Brazil
3
Department of Physics, University of Tennessee, USA
4
Beijing National Laboratory for Condensed Matter Physics, China
5
Department of Physics and Astronomy, University of Tennessee, USA
We have performed magnetic susceptibility and 57Fe Mossbauer spectroscopy measurements on single
crystal mosaics of BaFe2-xNixAs2 (x=0.065, 0.075, 0.085). Our findings show antiferromagnetic order below
TN obtained from magnetic hyperfine field phase diagram, with superconductivity below TC obtained bysusceptibility measurements. Careful analysis of our Mossbauer data show that a decrease in the magnetic
hyperfine field is observed below TC and the effect is proportional to the difference between TN and TC, being
the largest when both temperatures become close. We argue this is caused by coexistence of superconductivity
and magnetism, since both phenomena come from the same Fe 3d electrons, and two possible scenarios arepresented. Magnetic volume fraction does not show any variation at or below TC, but a strong dependencewith doping level, most likely due to short range magnetic order that cannot be sensed by our 57Fe local probe,
probably caused by local inhomogeneities. A phase diagram is shown to illustrate how the variation of themagnetic volume fraction and the crossover between magnetism and superconductivity are related.

D. Hirai et al., arXiv:1112.0604[1] F.-C. Hsu, et al., Proc. Nat Acad. Sci. USA 105, 14262 (2008). [2] D. C. Johnston, Advances in Physics 59, 803(2010). [3] M. M. Korshunov and I. Eremin, Phys. Rev. B 78, 140509 (R) (2008). [4] P. Babkevich, et al., Phys. Rev. B
83, 180506 (R) (2011). [5] K. Prokes et al., to be published [6] O. J. Lipscombe, et al., Phys. Rev. B 82, 064515(2010).

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Phase separation of antiferromagnetism and superconductivity in
RbxFe2-ySe2 observed by Rb NMR

Elastic softening and electric quadrupole in iron pnictide
superconductor Ba(Fe1-xCox)2As2

Influence of filament diameter on superconducting properties of MgB2
multi-core wires

Magnetism in superconducting Ba0.78K.22Fe2As2 and EuFe2As1.4P0.6
single crystals studied by Mossbauer spectroscopy

Yoshiaki Kobayashi1*, Shunsuke Saiki1, Shouhei Kototani1, Masayuki Itoh1 andMasatoshi Sato2
1
Department of Physics, Graduate School of Science, Nagoya University, Japan
2
Research Center For Neutron Science And Technology, CROSS, JapanThe observation of the superconducting (SC) transition in AxFe2-ySe2 (A: alkali metalelements; Tc of ~30K) has been one of surprising things, because the transition was
found in the antiferromagnetic (AF) system with a large AF moment of ~3.3 μB/
Fe. Moreover, their electrical resistivity just above Tc is too large to conceive theoccurrence of the superconductivity. Here, to clarify whether the AF and SC states
are microscopically coexistent or just phase-separated, we have carried out NMR
measurements on both crystals with and without SC transition. The Rb-NMR spectra
below 300 K observed for these crystals are clearly separable into two parts withdifferent widths. The broader spectrum can be explained by the presence of theregion with the “blocked” antiferromagnetic spins proposed by the neutron magnetic
scattering studies [1]. The narrower spectrum for the crystal with SC transition canbe understood from its temperature dependence and spectral shape to stem fromthe superconducting region without Fe-vacancy ordering [1]. Thus, we can clearlyconclude that the superconductivity and the antiferromagnetism in the present system
are phase-separated.
[1] W. Bao, et al., Chin. Phys. Lett. 28, No. 8 (2011) 086104.

The 19th International Conference on Magnetism

Ryosuke Kurihara1, Koji Araki1, Keisuke Mitsumoto1, Mitsuhiro Akatsu1, Yuichi
Nemoto2, Terutaka Goto2, Yoshiaki Kobayashi3 and Masatoshi Sato4
1
Graduate School of Science and Technology, Niigata University, Japan
2
Graduate School of Science and Technology, Niigata University, JST-TRIP, Japan3
Department of Physics, Nagoya University, JST-TRIP, Japan
4
Department of Physics, Nagoya University, CROSS, JST-TRIP, Japan
We have performed ultrasonic measurements on iron based superconductor Ba(Fe1-xCox)2As2 in order
to investigate the mechanism of the superconductivity. The end-material BaFe2As2 shows structural andantiferromagnetic simultaneous transitions at~140K. With increasing Co concentration x, the temperatures ofthese transition are lowered and separated from each other. The superconductivity appears at x>0.03. In ourrecent work [1], the softening of the elastic constant C66 as large as 21% was observed for optimized samples
Ba(Fe0.9Co0.1)2As2 with decreasing temperature from 300K down to superconducting transition temperatureof TSC=23 K, while other elastic constants do not show softening. Here, we have measured elastic constantsof Ba(Fe1-xCox)2As2 samples with x=0,0.03 and 0.07, where only the C66 shows huge softening larger than
70% with decreasing temperature down to the structural transition temperature. The large softening of C66
in Ba(Fe1-xCox)2As2 with several Co concentration x≤0.10 has been reported by other groups [2,3]. This hugeelastic softening of C66 is caused by the quadrupole fluctuation associated with the degenerate dy’z and dzx’band aslant Γ and X points of the Brillouin zone. Quadrupole effects on the superconductivity in the present
system are discussed in relation to the s++ type symmetry of the superconductivity [4,5,6].
[1] T. Goto, et al., JPSJ 80 (2011) 073702. [2] R. M. Fernandes et al., PRL 105 (2010) 157003. [3]
M. Yoshizawa et al., JPSJ 81 (2012) 024604. [4] Y. Yanagi et al., JPSJ 79 (2010) 123707. [5] H.
Kontani et al., PRB 84 (2011) 024528. [6] T. Kawamata et al JPSJ 80 (2011) 084720.

Michael Reissner1*, Lukas Bulla1, I Husek2, T Melisek2 and P Kovac2
1
Institute of Solid State Physics, Vienna Universtity of Technology, Austria
2Institute of Electrical Engineering, Slovakia Academy of Sciences, Slovakia

Multi-core MgB2 wires with 19 filaments of different diameter were produced [1]. The
filaments are covered by a Ti shell and embedded in a Cu matrix. From outside thewires are stabilized by stainless steel tubes. Critical current densities were determinedfrom hysteresis loops using Bean's model [2]. Magnetic relxation measurements were
performed at 1, 3, and 5 T both in increasing and decreasing field for up to 30 min.
From these measurements mean effective activation energies were determined within
the flux creep theory of Anderson [3]. All samples were prepared in identical way. They
only differ in diameter of the filaments, which ranges between 30 and 15 μm. Influenceof the filament diameter on the superconducting properties, like critical current density,
irreversibility line and activation energies are discussed.
[1] P Kovac, I Husek, T Melisek, L Kopera, M Reissner Supercond. Sci. Technol 23 (2010) 065010 [2]C P Bean Phys. Rev. Lett. 9 (1962) 250 [3] P W Anderson Phys. Rev. Lett. 9 (1962) 309

July 12 (Thu)

Department of Physics, Hankuk University of Foreign Studies, Korea

254

poster Presentation

M. Wang, H. Luo, J. Zhao, C. Zhang, M. Wang, K. Marty, S. Chi, J. W. Lynn, A. Schneidewind, S. Li and P. Dai,
Physical Review B 81, (2010) 174524. M. Alzamora, J. Munevar, E. Baggio-Saitovitch, S. L. Bud'ko, Ni Ni, P. C.
Canfield and D. R. Sanchez, Journal of Physics: Condensed Matter 23, (2011) 145701. arXiv:1111.5853

Elisa Baggio-saitovitch1, Julian Munevar1, Hans Micklitz1, Genfu Chen2, Chenglin
Zhang3, Huiqian Luo4 and Pengcheng Dai5
1
Brazilian Center for Research in Physics, Brazil
2
Renmin University of China, China
3
Department of Physics and Astronomy, University of Tennessee, USA
4
Beijing National Laboratory for Condensed Matter Physics,, China
5
Department of Physics and Astronomy, University of Tennessee Neutron Scattering Division, ORNL, USA

We studied magnetism in superconducting Fe-pnictide single crystals using 151Eu and 57Fe Mossbauer
Spectroscopy. Neutron studies on Ba1-xKxFe2As2 single crystals revealed a decrease in Bragg peak intensity due
to iron moment or magnetic volume fraction reduction. 57Fe Mossbauer measurements on Ba0.78K0.22Fe2As2
single crystal mosaics were performed down to 1.5 K, revealing a decrease in the magnetic hyperfine field
below Tc, without change in magnetic volume fraction. Our data confirm a reduction of Fe magnetic moment
below Tc explaining also the neutron results. Such a decrease is caused by a spectral weight transfer whenentering the superconducting state. For EuFe2As1.4P0.6 compound, magnetism originates from Eu2+ moments.
Mossbauer spectra reveal magnetic hyperfine fields below TM = 18 K of Eu2+ moments. Data analysis
shows coexistence of ferromagnetism, from Eu2+ moments ordered along crystallographic c-axis, andsuperconductivity below TSC ~ 15 K. We find indications for a change of small Fe magnetic moment dynamics(~ 0.07 μB) at superconductivity onset: below TSC the Fe magnetic moments seem to be “frozen” within thea,b-plane. In both compounds we show a change in the Fe magnetic moment state when entering the SC state,
and discussion about coexistence of magnetism and superconductivity will be provided.
[1] Z. Ren et al., Chin. Phys. Lett. 25, 2215 (2008) [2] M. Lumsden et al., J. Phys: Cond. Mat. 22(2010) 203203. [3] H.H. Luetkens et al., Nat. Mater. 8 (2009) 305.

July 8-13, 2012 Busan, Korea

255

poster Presentation

poster Presentation

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Doping evolution of the in-plane London penetration depth in
Fe1+y(Te1-xSex) single-crystals

Static and dynamic properties of nearly optimaly doped
superconductor SmFeAsO0.86F0.14

Monte Carlo study of the magneto-elastic effects in Fe pnictides

Mass renormalization in isostructural Ru- and Fe-pnictides

2

2

2

2

1

Andrei Diaconu , Jin Hu , Tijiang Liu , Bin Qian , Zhiqiang Mao and Leonard Spinu
1
Advanced Materials Research Institute and Physics Department, University of New
Orleans, USA
2
Department of Physics, Tulane University, USA

July 12 (Thu)

Our work focuses on the doping evolution of the superconducting properties as derived
from penetration depth measurements as a function of temperature in single crystalsof Fe1+y(Te1-xSex) with y<0.02 and Se concentration spanning from 25% to 45%. The
London penetration depth is one of the most important characteristic parameter intype II superconductors, as it can give information about the pairing mechanism, with
its zero temperature value being directly related to the density of superconductive
electrons in the material. Precise measurements of the in-plane penetration depth λab asa function of temperature using a tunnel diode oscillator technique were performed ina dilution refrigerator down to a temperature of 30mK. By using a set of two mutuallycoupled planar inductors the probing ac field is uniform across the sample along thec axis with the variation in susceptibility solely due to supercurrents flowing in theab crystallographic plane. A complete study of the temperature and Se concentration
dependence of the physical properties derived from these measurements is presented.

1

1

1

1

Amitabha Ghoshray *, Mayukh Majumder , Kajal Ghoshray , Asok Poddar , Chandan
Mazumdar1 and David Berardan2
1
ECMP Division, Saha Institute of Nuclear Physics, Kolkata, India
2
Institut de Chimie Moleculaire et des Materiaux d’Orsay, Institut de Chimie
Moleculaire et des Materiaux d’Orsay, Univ. Paris-Sud 11, 91405 Orsay, France
We have reported resistivity, heat capacity, magnetization and 19F and 75As NMR
in polycrystalline sample of nearly optimaly doped superconductor SmFeAsO1-xFx(x = 14%). The resistivity shows linear dependence above 200 K and 50 - 160 K.
The linear dependence reveals non Fermi liquid behavior. The heat capacity data for
SmFeAsO0.86F0.14 exhibits a small jump at T_C~48K, indicating the bulk nature ofsuperconductivity. The field cooled magnetisation data deviates from Curie Weiss law
below 160 K. A small peak around 163 K was observed in 19F spin-spin and spinlattice relaxation rate showing evidence of structural phase transition driven by antiferromagnetic spin fluctuation. 75As NMR signal is detectable only above 180 K All
measurements point towards a possible existence of nematic ordering where structuralphase transition have been driven by anti-ferromagnetic spin-fluctuations at 163 K.
Their is a considerable FeAs and SmO layer interaction present in the system. The
results also revealed the coexistence of local and itinerant electronic states below 90 K
where two fluid model of heavy fermion holds. Coexistence of static anti-ferromagnetic
ordering due to Sm 4f electrons and superconductivity has also been observed.

A (J1, J2) model of the infinite square lattice of classical spins coupled by Heisenberg
exchange interactions that includes a spin-lattice interaction of the form A (Exx - Eyy)
(Sx2- Sy2) is used in Monte-Carlo simulations to determine a phase diagram in the
J1, J2, and A parameter-space. To facilitate phase transitions in the 2D system, we
also include a weak out-of-plane coupling to spins in adjacent planes (Jz). This phase
diagram is relevant to the parent materials of the newly discovered iron-pnictides
superconductors. Using first principles band calculations, both for the low and hightemperatures, we obtain realistic parameters to the model that allow the prediction ofpressure induced magnetic transitions.

Philip J.w. Moll1*, Jakob Kanter1, Ross Mc.donald2, Fedor Balakirev2, Peter Blaha3,
Karlheinz Schwarz3, Zbigniew Bukowski1, Nikolai D. Zhigadlo1, Sergiy Katrych1,
Kurt Mattenberger1, Janusz Karpinski1 and Bertram Batlogg1
1
Solid State Physics Laboratory, ETH Zurich, Switzerland
2
National High Magnetic Field Laboratory, Los Alamos National Laboratory, USA
3
Institute of Materials Chemistry, Vienna University of Technology, Austria
We have studied the angular-dependent de Haas-van Alphen oscillations of LaRu2P2 using
magnetic torque in pulsed magnetic fields up to 60 T. The observed oscillation frequencies are
in excellent agreement with the geometry of the calculated Fermi surface. The temperaturedependence of the oscillation amplitudes reveals effective masses m*(α) = 0.71 and m*(β) =0.99 me, which are enhanced over the calculated band mass by λcyc of 0.8. We find a similar
enhancement of λγ ~ 1 in comparing the measured electronic specific heat (γ =11.5mJ/mol
K2) with the total density of states from band-structure calculations. Remarkably, very similar
mass enhancements have been reported in other pnictides, LaFe2P2, LaFePO (Tc ~ 4 K), and
LaRuPO, independent of whether they are superconducting or not. This is contrary to thecommon perceptions that the normal-state quasiparticle renormalizations reflect the strengthof the superconducting pairing mechanism. To separate mass enhancement due to electron
correlations from e.g. electron-phonon interactions, high energy bandwidth measurements suchas ARPES would be highly desirable, thus leading to new questions about competing pairing inisostructural and isoelectronic Ru- and Fe-pnictide superconductors.
PHYSICAL REVIEW B 84, 224507 (2011)

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Potassium doping effect in double-chain BaFe2Se3

Effect of d-orbital characters of the Fe magnetic moment on theelectronic and magnetic properties of BaFe2As2

Geometrical Vortex Transition in the iron pnictide SmFeAs(O,F)

The role of spin fluctuation for the high Tc superconductivity in
LiFeAs, LiFeP, NaFeAs

Jinke Bao, Yunlei Sun, Wenhe Jiao, Yongkang Luo, Zhu'an Xu and Guanghan Cao*
Department of Physics, Zhejiang University, China
Compared to iron-based superconductors with two-dimensional FeAs(Se) layers,
BaFe2Se3 is a one-dimensional material consisting of Fe2Se3 double chains with Ba2+
cations intercalated. It exhibits antiferromagnetic order with ferromagnetic Fe4 blockof 2.8μB / Fe2+ below 255 K.[1][2][3] Considering the close relationship between
antiferromagneitsm and superconductivity, we performed a chemical doping withpotassium in this compound. Ba1-xKxFe2Se3 single crystals with different K content
were successfully grown. Resistivity measurements showed that all the crystals were
semiconducting with no superconducting transition above 3K. The magnetization of
Ba1-xKxFe2Se3 is anisotropic, and the sample of x=0.4 exhibits spin glass behavior.
*ghcao@zju.edu.cn[1] A. Krzton-Maziopa, E. Pomjakushina, V. Pomjakushin, D. Sheptyakov, D. Chernyshov, V. Svitlyk,
and K. Conder, J. Phys. Condens Matter 23, 402201 (2011). [2] J. M. Caron, J. R. Neilson, D. C.
Miller, A. Llobet, and T. M. McQueen, Phys. Rev. B 84, 180409(R) (2011). [3] Hechang Lei, Hyejin
Ryu, Anatoly I. Frenkel, and C. Petrovic, Phys. Rev. B 84, 214511 (2011).

Hyungju Oh and Hyoung Joon Choi*
Department of Physics and IPAP, Yonsei University, Korea

There have been many studies detailing the orbital character of band structures in
the iron-based superconductors. However, the orbital characters of the Fe magnetic
moment still remain unrevealed up to now. By performing first-principles calculationsof the electronic and magnetic properties with constraint on the real space shape of
Fe magnetic moments, we study the d-orbital characters of the Fe magnetic momentin BaFe2As2. We find that, depending on the d-orbital characters of the Fe magnetic
moment, the electronic properties of BaFe2As2 such as band gap, band dispersion, anddzx/dyz occupation change distinctively. Furthermore, we compare obtained band
structures with published angle-resolved photoemission spectroscopy (ARPES) result,and propose that the Fe magnetic moment in BaFe2As2 has in-plane dxy character. This
work was supported by the NRF of Korea (Grant Nos. 2011-0018306). Computational
resources have been provided by KISTI Supercomputing Center (Project No. KSC2011-C3-05).

Philip J.w. Moll1*, Luis Balicas2, Janusz Karpinski3, Nikolai Zhigadlo4 and Batlogg
Bertram5
1
Solid State Physics Laboratory, ETH Zurich, Switzerland
2
National High Magnetic Field Laboratory, Florida State University, USA
3
Solid State Physics, ETH Zurich, Switzerland
4
Solid State Laboratory, ETH Zurich, Switzerland
5
Solid State Theory, ETH Zurich, Switzerland
We have observed a distinct vortex matter transition in SmFeAs(O,F) (Tc~50K) uponcooling below T*~41K(=0.81Tc) into a highly mobile state for fields well aligned with the
FeAs layers. Below T*, the vortex core is confined between two adjacent FeAs planes by
periodic modulations of the superconducting order parameter within the unit cell. Vortex
motion parallel to the planes is even more pronounced at lowest temperatures, well below
Tc and Hc2, as the vortex cores avoid the highly effective pinning sites located in the FeAs
layers. For fields slightly out-of-plane (<0.3°) the vortices are again completely immobile
as they cross the planes and are hence strongly pinned by defects within the FeAs layers
resulting in large critical current densities at high fields and low temperatures (>106 A/cm2@5K, 14T[1]). These results indicate strong pinning localized in the FeAs layer to be thedominant factor for the highly effective pinning and thus show the pathway to improve thetechnological prospect of the pnictides.

July 12 (Thu)1

Cesar Jose Calderon Filho1*, Alex Antonelli1, David Vaknin2 and Gaston Eduardo
Barberis1
1
IFGW, State University of Campinas - UNICAMP, Brazil
2
Ames National Laboratory and Department of Physics, Iowa State University, USA

Geunsik Lee, Hyo Seok Ji and Ji Hoon Shim*
Chemistry, POSTECH, Korea

Based on fully self-consistent density functional theory and dynamical mean field
theory (DMFT) methods, we have studied the electronic spectrum of three isovalent
111 compounds, LiFeAs, LiFeP, NaFeAs. It has been known that while both LiFeAs
and LiFeP are intrinsic superconductors with the nodeless and nodal gap symmetries
respectively, NaFeAs exhibits spin density wave phase where superconducting
transition occurs with chemical doping. With our simulated electronic spectrums, we
examine the spin fluctuation mechanism for the high Tc superconductivity.

[1] P.J.W. Moll et al., 'High magnetic field scales and critical currents in SmFeAs(O,F) crystals.
Nature Materials 9, 628 (2010)

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Sr2VO3FeAs: Hybrid of a magnetic SrVO3 and a FeAs superconducting
layersCa(Fe1-xCox)2As2 under pressure: studies using single crystal neutron
diffraction

SmFeAsO1-xFx: Raman scattering and x-ray diffraction study under
low temperature and high pressure conditions

DFT+DMFT study on the electronic structure and anisotropy of
Sr2VO3FeAs superconductor.

Man Jin Eom1, Jae - Hyun Park1, Sewoong Na1, Younjung Jo2, Hu - Jong Lee1 and Jun
Sung Kim1*
1
Department of Physics, POSTECH, Korea
2
School of Physics and Energy Sciences, KNU, Korea

We investigate the upper critical fields up to 14T of Sr2VO3FeAs single crystals. For
Sr2VO3FeAs, where the perovskite SrVO3 layers are inserted between SrFe2As2 layers,
we observed a strong anisotropy of the upper critical field, compared with Hc2(T)of other pnictides. Strong anisotropy in Hc2 of Sr2VO2FeAs suggests that SrVO3
layer is insulating. Furthermore, we found the anomalous magnetoresistance in thenormal states up to T~150K indicating possible magnetic ordering in the SrVO3 layer.
Sr2VO3FeAs have a structural peculiarity that means each magnetic ordered layers
and charge reservoir layers. Thus, unlikely usual layered pnictide compounds, thiscompound provides the magnetic interaction.

Karel Prokes1, B. Ouladdiaf2, L. Harnagea3, S. Wurmehl3, B. Buechner3 and D. Argyriou4
1
M-I1, Helmholtz Zentrum Berlin, Germany
2
Institut Laue-Langevin, 38042 Grenoble Cedex, France
3
Leibniz-Institute for Solid State and Materials Research, (IFW)-Dresden, D-01171
Dresden, Germany
4
European Spallation Source ESS AB - Box 176, 22100 Lund, Sweden

Sofia Michaela Souliou1*, Mathieu Le Tacon1, Andrew C. Walters1, Chengtian Lin1,
Karl Syassen1, Bernhard Keimer1, Gaston Garbarino2, Michael Hanfland2, Wilson
Crichton2, Janusz Karpinski3 and Nicolai Zhigaldo3
1
Max-Planck-Institut fur Festkorperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany, Germany
2
European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France, France
3
Laboratory for Solid State Physics, ETH Zurich, CH-8093 Zurich, Switzerland, Switzerland

CaFe2As2 and related compounds exhibit extremely strong coupling of the magnetic and structural phasetransitions and sensitivity to an applied pressure. Undoped system undergoes a structural transformationfrom a high temperature tetragonal (T) phase to a structure with orthorhombic (O) symmetry that is
associated with the appearance of an antiferromagnetic order [1]. Upon application of a rather modest
pressure, both transitions are suppressed and superconductivity appears below 12 K [2]. For pressureslarger than 0.3 GPa another, so-called collapsed tetragonal (cT) phase with greatly reduced c parameter
appears [3]. Three different Ca(Fe1-xCox)2As2 single crystals with concentration x = 0.032, 0.051 and
0.063 were investigated by means of neutron diffraction under uniaxial and hydrostatic pressure. Regionof existence of the high-temperature tetragonal, low-temperature orthorhombic and pressure-induced
collapsed tetragonal phases have been determined. Structural details of the tetragonal phases at various
conditions have been determined and the corresponding p-T phase diagrams have been constructed. The
critical pressure of the T (or O) to cT transition decreases with increasing Co doping level. The behavior ishighly hysteretic and structural studies show no variation of the As positional parameter with pressure.

We present a comparative low-temperature Raman study on single crystals of the parent non-superconducting
SmFeAsO and the fluorine-doped superconducting SmFeAsO0.6F0.35 [1]. As in the compounds from the 122
family [2], clear renormalization of the c-axis polarized A1g(Sm) and the B1g(Fe) Raman-active modes
are observed through the magneto-structural transition in the parent compound. Splitting of the in-plane
Eg modes is also observed (like the reported in [3,4]). In the fluorine-doped compound, x-ray diffraction
measurements reveal the retention of the structural transition (similar to the one reported in [5]). Despite theabsence of a coupled magnetic transition, a renormalization of the c-axis polarized modes similar to the one
seen in the parent compound is observed, followed at lower temperature by an anomalous increase of thelinewidth of these phonons below the superconducting transition temperature. The effects of the structuraltransition on the phonon modes are further investigating by applying high pressure on the parent compound,allowing a direct comparison of the effect of pressure and doping on the lattice dynamics of the system.

[1] D. C. Johnston, Advances in Physics 59, 803 (2010). [2] M. S. Torikachvili, et al., Phys. Rev.
Lett. 101, 057006 (2008). [3] A. Kreyssig, et al., Phys. Rev. B 78, 184517 (2008).

256

The 19th International Conference on Magnetism[1] Z.-A. Ren et al., Chinese Physics Letters 25 (6), 2215 (2008) [2] M. Rahlenbeck et al., Phys.
Rev. B 80, 064509 (2009) [3] T. Yildirim, Phys. Rev. Let. 101, 057010 (2008) [4] L. Chauviere et al.,Phys. Rev. B 80, 094504 (2009) [5] A. Martinelli et al., Phys. Rev. Let. 106, 277001 (2011)

Hyo Seok Ji and Ji Hoon Shim*
Chemistry, POSTECH, Korea

Electron correlation effect on Fe 3d orbital has very important role in describing
electronic structure and anisotropy of iron-based superconductors.[1] By using
combination of the density functional theory (DFT) and dynamical mean field theory(DMFT), the electron correlation effect can be described well. In this study, we haveinvestigated the electronic structure and anisotropy of Sr2VO3FeAs superconductor.
Simple DFT result shows mixed band structures of Fe 3d and V 3d orbital, but theexperimental result shows only Fe 3d band near the Fermi level.[2] The DFT+U
method explains insulating V layer structure correctly[2, 3] but it cannot describe
whole electronic structure such as renormalized Fe 3d bands. So we apply the electron
correlation effect on the V 3d orbital as well as the Fe 3d orbital using DFT+DMFT.
With antiferromagnetic(AFM) ordering, V 3d bands split into -1 eV and 1 eV region,
which is consistent with experimental ARPES result.[2] Also we calculate electricalanisotropy γ=σ_xx/σ_zz which is important for determining dimensionality effect iniron-based superconductors. Calculated anisotropy value is much smaller than simple
DFT result and the result is well consistent with recent experimental result. This trend
is also consistent with the trend of previous work[1].
[1] H. S. Ji, G. Lee, and J. H. Shim, Phys. Rev. B 84, 054542 (2011). [2] T. Qian et al., Phys. Rev. B
83, 140513(R) (2011). [3] H. Nakamura and M. Machida, Phys. Rev. B 82, 094503 (2010).

July 8-13, 2012 Busan, Korea

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Behaviour of Magnetic and structural transitions upon Sr doping in
CaFe2As2 and EuFe2As2

Josephson effect in BaKFeAs inter-grain boundary junctions

DMFT study of the correlation effects on a topological insulator

Ground-state properties of a two-dimensional correlated topologicalinsulator

Neeraj Kumar*, Ruta Kulkarni, Sudesh Kumar Dhar and Arumugam Thamizhavel
Condensed Matter Physics and Materials Science, Tata Institute of Fundamental
Research, Mumbai, India

We have grown single crystals of Ca1-xSrxFe2As2 and Eu1-xSrxFe2As2. Our aim was tostudy the progression of SDW transition and the effect of dilution on Eu magnetismin EuFe2As1-xSrxFe2As2. CaFe2As2 and SrFe2As2 undergo magneto-structural transition
at 170 K and 205 K respectively[1,2]. With introduction of Sr in the CaFe2As2,
magneto-structural transition temperature increases, and it reaches 200 K in nominal
Sr0.5Ca0.5Fe2As2 indicating that Sr dominates Ca in determining the SDW and structuraltransition. Doping Fe with Co induces superconductivity in Ca0.5Sr0.5Fe2As2 below 12 K,
which surprisingly shows a signature of SDW transition at a high temperature of 170
K. In Eu1-xSrxFe2As2 series the AFM ordering temperature of Eu sublattice decreases
with increasing x while the structural/SDW transition temperature gradually varies
from 190 K to 200 K. Field induced ferromagnetic behaviour of the parent EuFe2As2
is also observed in the Sr doped compounds, the magnetic field needed to induce
ferromagnetism decreases with increasing Sr.

Sung-hak Hong1, Sung Hoon Lee1, Soon-gul Lee1*, Soon-gil Jung2, Nam Hoon Lee2and Won Nam Kang2
1
Department of Display and Semiconductor Physics, Korea University, Korea
2
BK21 Physics Division and Department of Physics, Sungkyunkwan University,
Korea
We have studied superconducting transition properties of Ba0.6K0.4Fe2As2 intergrainjunctions. The junctions were fabricated by focused ion beam (FIB). Prior to FIB
patterning, films were prepatterned into microbridges by a standard photolithography
and argon ion milling technique. The lowest-possible beam current of 1.5 pA wasused for the FIB pattern to minimize the etching damage to the bridge. The nominal
dimensions were 200 nm in width and 100 nm in length. Resistive transition, currentvoltage (I-V) characteristics, the temperature-dependent critical current (Ic), and thenormal state resistance (Rn) were measured. Measured transition properties indicatedthat the junctions were dominated mainly by Josephson coupling, showing resistivelyshunted-junction (RSJ) behaviors. At higher currents, multiple transitions wereobserved, which might be due to dynamics of Josephson vortices driven by transport
currents. Details of the measurement results will be discussed.

Tsuneya Yoshida*, Satoshi Fujimoto and Norio Kawakami
Department of Physics, Kyoto University, Japan

Recently, topological insulators are theoretically proposed in correlated electron
systems (e.g. Iridium oxides, Heusler compounds, and filled skutterudites)[1]. The
correlation effects on the topological insulators are expected to produce exotic states [2]and are extensively studied. The strong Coulomb interaction could drive the non-trivial
band insulator into a Mott insulator. In this paper, we study an extended BernevigHughes-Zhang model[3] including the on-site Coulomb interaction with DMFT.
We calculate the double occupancy at each orbital and the spin-Hall conductivity
which clearly distinguishes the trivial and non-trivial phases in our model. From theanalysis of these quantities, it is concluded that the topological insulator changes into
a trivial nonmagnetic Mott insulator via a first-order transition [4]. Therefore, thegap closing does not occur at the transition. In the presentation, we also address theantiferromagnetic instability.
[1] A. Shitade et al., Phys. Rev. Lett. 102, 256403 (2009), S. Chadov et al., Nature Materials 9 541545 (2010), B. Yan et al., arXiv 1104.0641. [2] D. A. Pesin et al., Nature Physics 6, 376 - 381 (2010). [3] B. A. Bernevig et al., Science 314 1757 (2006). [4] T. Yoshida et al., arXiv 1111.6250.

Yuto Takenaka* and Norio Kawakami
Department of Physics, Kyoto University, Japan

Recently, the topological band insulator (TBI) has attracted much interest in condensed
matter physics. The TBI is characterized by a nontrivial band structure, which has afull insulating gap in the bulk and gapless edge states on the boundaries. While theessential features of the TBI can be described as a one-body problem, there is muchinterest in the correlation effects on the TBI. In this study, we investigate a generalized
Bernevig-Hughes-Zhang model having electron correlations with the variational
Monte Carlo (VMC) method. In order to study how interactions affect the edge states
and bulk states, it is important to consider inhomogeneous nature due to the lack oftranslational symmetry perpendicular to the boundaries. For this purpose, we introduce
spatially-dependent variational parameters. We calculate the ground-state energy andthe momentum distribution to discuss how the correlation effects affect electronic
properties in the TBI.
[1] B. A. Bernevig, T. L. Hughes and S. C. Zhang, Science 314, 1757 (2006).

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Specific heat of the vortex lattice in iron-pnictide superconductors

Coexistence of different electronic phases in the K 0.8 Fe 1.6 Se 2
superconductor: a bulk-sensitive hard x-rays spectroscopy study

Self-consistent treatment of fully relativistic effect in the small bismuth
clusters Bin (2≤ n ≤ 7)

Magnetic impurity doping effect on bulk Rashiba spin splitting system
BiTeI

Miguel Araujo1 and Pedro Sacramento2
1
CFIF, Instituto Superior Tecnico, TU Lisbon and Department of Physics, Universitiyof Evora, Portugal
2
CFIF, Instituto Superior Tecnico, TU Lisbon, Portugal
We study a vortex lattice in a three-orbital model for iron-pnictide superconductors. A
gauge transformation, first introduced by Vafek-Tesanovic [1], is employed in orderto obtain an effective spatially periodic Hamiltonian that produces a spectrum ofBloch states and automatically includes quantum effects, such as the Berry phase andDoppler shift of quasi-particles, without resorting to semi-classical approximations. We
calculate the energy spectrum and specific heat as function of applied magnetic field.
The effect of disorder due to impurities and positional disorder of the vortices is also
addressed.
[1] O. Vafek, A. Melikyan, M. Franz and Z. Tesanovic, Physical Review B 63, 134509 (2001)

In AxFe2-ySe2 (11)-type chalcogenides superconductivity appears to occur only in Fe-deficient samples,
where the alkali metals are intercalated between the FeSe layers [1-3]. It has been demonstrated how
the ordering of the Fe vacancies can be correlated to superconductivity and how it can be controlled
by temperature treatments [2-6]. In particular the superconductivity can be tuned on a single sample
from an insulating state by post-annealing and fast quenching, and it is tempting to conclude that thesuperconductivity is achieved when the Fe-vacancies are in a disordered state [6]. Here we report on theelectronic and magnetic structure of K0.8Fe1.6Se2 superconductor by x-ray emission and high resolution
absorption spectroscopy. We report a study where the electronic and magnetic properties are investigatedat the same time as a function of temperature in several consistent thermal cycles. We discuss theeffects of ordered and disordered Fe vacancies on the electronic and magnetic structure, the existenceof memory effects on thermal cycles, and the relation between electronic and magnetic properties andsuperconductivity. The results obtained are finally compared with the electronic and magnetic properties of(11)-type chalcogenides [7].

Ely Aprilia1*, Haruki Katou2, Junpei Gotou2, Shinya Haraguchi2, Suprijadi Haryono3
and Tatsuki Oda4
1
Double Degree Program of Kanazawa university-Bandung Institute of Technology,
Indonesia
2
Graduate School of Natural Sciences and Technology, Kanazawa University, Japan
3
Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Indonesia
4
Institute of Science and Engineering, Kanazawa University, Japan

Jeongdae Seo and Jong- Soo Rhyee*
Applied Physics, Kyung Hee Universty, Korea

The energy scale of spin-orbit (SO) interaction reaches to the order of 0.1-1eV at the elements in the fifth lowof periodic table. Such interaction could cause effects on structural properties as well as on electronic ones.
Bismuth has been investigated by many researchers due to its largeness of SO coupling. Rashba effect, whichappears as the spin state splitting of surface bands, has been discussed intensively in the system which consists ofbismuth [1]. The phenomena which are related with new physics of topological insulator have been investigatedin a lot of bismuth systems [2]. In this context, bismuth clusters are interesting to investigate including relativistic
effects. In this work, we have studied structural and electronic properties in small bismuth clusters; Bi_n (2 ≤ n≤7). The Car-Parrinello molecular dynamics [3] and self-consistent fully relativistic calculations [4,5] have been
employed to investigate effects of SO coupling effects. It has been found that the clusters of odd number atoms
were found to carry magnetic moment with non-collinear magnetic configuration.

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[1] Jing Guo, et al, arXiv: 1101.0092; Y. Kawasaki, et al, arXiv: 1101.0896; J J Ying et al., New J. Phys. 13, 033008 (2011). [2] D.
M.Wang, et al, arXiv: 1101.0789 . [3] A. M. Zhang, et al, arXiv: 1101.2168v1. [4] Ricci et al. Supercond. Sci. Technol. 24, 082002 (2011).
[5] Bao Wei et al., Chin. Phys. Lett. 28, 086104 (2011) . [6] F. Han et al., arXiv :11031347. [7] L.Simonelli et al., submitted to PRB.

[1] Yu. M. Koroteev et al., Phys. Rev. Lett. 93, 046403 (2004). [2] Hsieh et al., Nature 452, 970 (2008).
[3] R. Car and M. Parrinello, Phys. Rev. Lett. 55, 2471 (1985). [4] T. Oda, A. Pasquarello, and R.
Car, Phys. Rev. Lett. 80, 3622 (1998). [5] T. Oda and A. Hosokawa, Phys. Rev. B 72, 224428 (2005).

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Hexagonal superconducting pnictide SrPtAs: an ab initio study

Step towards a ferromagnetic Josephson junction in YBCO/LCMO
heterostructures

Hidden topological order in URu2Si2

Topological charge pumping effect by the magnetization dynamics on
the Surface of 3D Topological Insulators

Sonny S. H. Rhim1, S. J. Youn2, Daniel Agterberg3, Michael Weinert3 and Arthur J
Freeman1
1
Physics and Astronomy, Northwestern University, USA
2
Physics Education and Research Institute of Natural Science, Gyeong Sang National
University, Korea
3
Physics, U. Wisconsin-Milwaukee, USA
We present an ab initio study on SrPtAs, a recently discovered hexagonal pnictide
superconductor. SrPtAs is distinct from other pnictides: (i) it has a hexagonal structureand (ii) a large spin-orbit interaction, whose consequence is not trivial. Based onelectronic structure calculations, a tight-binding Hamiltionian is constructed to analyze
the character of the spin-orbit interaction associated with the crystal structure. Further,
the pairing mechanism by phonon and spin fluctuation are analyzed from phonon
dispersion and susceptiblity with matrix element fully taken into account. Finally,
based on the band structure, we propose that electron doping could increase TC.

258

Laura Simonelli1*, Naurang L. Saini2, Marco Moretti Sala1, Y. Mizuguchi3, Y.
Takano3, H. Takeya3, T. Mizokawa4 and Giulio Monaco1
1
ESRF, France
2
Dipartimento di Fisica, Universit´a di Roma “La Sapienza” - P. le Aldo Moro 2, 00185 Roma, Italy
3
National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan and JST-TRIP, 1-2-1, Japan
4
Department of Physics, and Department of Complexity Science and Engineering, University of Tokyo, JapanThe 19th International Conference on Magnetism

Soltan Soltan1*, Magdy El-hagary2, Hanns-ulrich Habermeier3 and Nasser Alzayed4
1
Physics Department, Faculty of Science, Helwan University, 11792 Helwan, Cairo,
Egypt
2
Physics Department, College of Science,Qassim University, P.O. Box 6644 Buraidah
51452, Saudi Arabia
3
Max-Planck-Institute FKF, Heisenbergstrasse 1, 70569-Stuttgart, Germany
4
Physics Department, King Saud University, Saudi Arabia
High quality high-Tc superconductor/half metal ferromagnet/high-Tc superconductor
YBCO/LCMO/YBCO trilayers (SFS) with different orientation of CuO2 planes insuperconducting electrodes and different thicknesses of LCMO layers have beensuccessfully fabricated by employing pulsed laser deposition techniques. It has beenfound that a LCMO barrier with thickness of 2-3 unit cells is ferromagnetic with aCurie temperature close to the bulk value. The strong difference in magnetization loops
for different SFS-structures measured at T = 5K and the magnetic field parallel to theF-layers is caused by the presence of a superconducting current across the ferromagnet
in the (110) oriented SFS-structure with a thickness of the ferromagnetic layer =1nm.
This has been confirmed by measuring current-voltage characteristics in patterned
structures. This sample structure fulfils all prerequisites for the realization of high-Tc
SFS-Josephson junctions.

Tanmoy Das
Theoretical Division, Los Alamos National Laboratory, USA

July 12 (Thu)

July 12 (Thu)[1] Neeraj et. al. Phys. Rev. B, 79, 012504 (2009). [2] Krellner et al, Phys. Rev. B, 78, 100504(R)(2008)

Hiroaki T Ueda1*, Akihito Takeuchi1, Gen Tatara1 and Takehito Yokoyama2
Department of Physics, Tokyo Metropolitan University, Japan2
Department of Physics, Tokyo Institute of Technology, Japan
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We discuss a current dynamics on the surface of a 3-dimensional topological insulator
induced by magnetization precession of a ferromagnet attached. It is found that themagnetization dynamics generates a direct charge current when the precession axis iswithin the surface plane. This rectification effect is due to a quantum anomaly and is
topologically protected. The rectified current is useful in the sense that a direct current
is easy to detect experimentally. To see the effect of the fast-varying exchange field, westudy the current dynamics by the topological field theory. We adopt the dimensional
regularization to regularize the ultraviolet divergence, which is inevitable to study anelectromagnetic response of a topological insulator. As a result, the robustness of therectification to the fast-varying exchange field is confirmed.

July 8-13, 2012 Busan, Korea

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Tuning of carrier type in Mn-doped Bi2Se3

A recipe for new Topological Insulators based on bonds, bands,
symmetry and heavy atoms

Quantum phase transition from normal to topological insulator phasein Na2IrO3Topological insulating phase in cubic system: tight-binding approach

Young Ha Choi1, Nahyun Jo1, Kyujoon Lee1, Jumpei Kajino2, Toshiro Takabatake2
and Myung- Hwa Jung1*
1
Department of Physics, Sogang University, Korea
2
ADSM, Hiroshima University, Japan
Bi2Se3 is a good candidate for studying thermoelectric material as well as topological insulator.
[1] In order to promote the thermoelectric performance, it is good to connect two materials inseries with different charge carrier type. In Bi2Se3, the Se vacancies are dominant, which leads
to n-type charge carriers.[2] In order to tune the carrier type and carrier density, we have doped
Mn into Bi2Se3 and have studied their physical properties, mainly focusing on the thermoelectric
properties. The single crystals of MnxBi2-xSe3 (x=0.03, 0.05, 0.09 and 0.15) were grown bymelting the stoichiometric elements in an evacuated quartz ampoule. The Hall and thermoelectricmeasurements illustrate the change of carrier type from n to p type between x=0.03 and 0.05. The
transport measurements have shown the metallic behavior for x≤0.03 and nonmetallic behavior forx≥0.05 at low temperatures. This supports that the Fermi level of p-type samples lies in the surface
state between the bulk valence band maximum and the bulk conduction band minimum.[3] The
Seebeck coefficient increases linearly up to ~100μV/K at room temperature both n- and p-typesamples. This implies that Mn-doped Bi2Se3 is possible materials for thermoelectric application.

Lukas Muechler1, Binghai Yan2, Stanislav Chadov3, Haijun Zhang4, Frederick Casper1,
Shoucheng Zhang4 and Claudia Felser3*
1
Inst. fuer Anorg. Chemie, Johannes Gutenberg - Universitaet Mainz, Germany
2
Bremen Center for Computational Materials Science, Germany
3
Max-Planck-Institut fur Chemische Physik fester Stoffe, Germany
4
Department of Physics, Stanford University, USA
In this work we will present a recipe to find new Topological Insulators (TIs) basedon bonds, bands, symmetry and heavy atoms. A big issue concerning the compounds
known up to now is the control of the bulk carrier density to produce truly insulating
samples in the bulk. Using concepts from chemistry and supported by densityfunctional calcu- lations, we want to motivate an extended search for new compoundswith tunable bulk properties.

Choong H. Kim1, Heung Sik Kim1, Hogyun Jeong2, Hosub Jin3 and Jaejun Yu1*
1
Department of Physics and Astronomy, Seoul National University, Korea
2
Korea Institute of Science and Technology Information, Korea
3
Department of Physics and Astronomy, Northwestern University, USA

Na2IrO3 has been suggested to have a possible quantum spin Hall effect based on
the novel jeff=1/2 state arising from the 5d Ir states. From the electronic structure
calculation analysis of the band topology of Na2IrO3, however, it turns out that Na2IrO3
as it is should be a trivial insulator. We investigated the electronic structure of by
employing a tight-binding model for the layered iridium oxides with honeycomb
lattice. Our analysis for the layered iridates reveals that the topological nature of thespin-orbit coupled ground state depends on the trigonal crystal field and long-range
hoppings. From the first-principles-derived tight-binding Hamiltonian we determine
the phase boundary through the parity analysis and predict a quantum phase transition
from normal to topological insulator. It is suggested that Na2IrO3 can be a candidate
material which can have both non-trivial topology of bands and strong electron
correlations.

Hosub Jin, Jino Im and Arthur J. Freeman
Department of Physics and Astronomy, Northwestern University, USA

Recently, much attention has focused on three-dimensional strong topologicalinsulators as a new quantum state of matter, such as Bi2Se3 and Bi2Te3. Here we suggest
topologically non-trivial electronic structures in cubic systems based on the tightbinding analysis. Assuming the well separated s and p states and hopping parameters,
we can set up an 8x8 tight-binding Hamiltonian, and the trivial to non-trivial
topological phase transition occurs by tuning the hopping parameters or spin-orbit
coupling strength. Our tight-binding Hamiltonian is reduced to a 4x4 continuum model
which is the minimal model to describe the topological phase transition. Topologicallyprotected surface states in the slab geometry are also shown within our model.
Supported by the U.S. D.O.E.

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Magnetic edge profile in the Kane-Mele-Hubbard model

Optimizing the Bi2-xSbxTe3-ySey solid solutions to approach the intrinsic
topological insulator regime

Self-assembled nanowire with giant Rashba spin splitting

Topological insulator phase and Kitaev-like anisotropic exchangeinteractions in Li2IrO3Three dimensional (3D) topological insulators represent a new quantum state of materrealized in band insulators, which are predicted to present novel surface transport phenomena.
In reality, while a number of materials have been identified to be 3D TIs, most of them arepoor insulators in the bulk. Given this situation, search for new TI materials better suited forachieving the bulk insulating state is of obvious importance. In this presentation, we showthat there exist a series of “intrinsic” compositions for Bi2-xSbxTe3-ySey solid solutions where
the acceptors and donors compensate each other and present a maximally bulk-insulating
behavior. At such compositions, the resistivity can become as large as several Ωcm at low
temperature, and one can infer th role of the surface-transport channel in the nonlinear
Hall effect[1]. In particular, in the composition of Bi1.5Sb0.5Te1.7Se1.3, one can achieve a
surface-dominated transport where the surface channel contributes up to 70% of the total
conductance[2]. In addition, angle-resolved photoemission spectroscopy reveal that the Diraccone dispersion changes systematically so that the Dirac point moves up in energy withincreasing x, leading to a sign change of the Dirac carriers at x~0.9[3].

We found gaint Rashba-type split bands for Pt-induced nanowires on the Si(110)
surface by angle resolved photoemission spectroscopy (APRES) measurements. The
observed Rashba parameter is about 2.1eVA, which is among the largest ever reported
for Rashba systems and is unique in one-dimensional systems. Pt-induced nanowires
were also investigated by scanning tunneling microscopy (STM) and scanningtunneling spectroscopy (STS) at low temperature (78K). High resolution STM
topography images show that the wire has a width of 1.6nm and a X3 superstructure
along the wire. On the other hands, the STS measurements reveal well resolved local
density of states (LDOS) with a peak at -200meV and a characteristic dip at -300meVon the nanowire. These peak and dip energies corresponds well to the ARPES data; thetop edge and the Dirac-like crossing point energy of the Rashba-type spin split bands,
respectively. Furthermore, based on the dI/dV spectroscopic mapping, we confirmed
noticeable one-dimensional electron channels along the nanowire edges, which are
related to the gaint Rashba band. This implies a future application of the Pt-induced
nanowire structure in silicon-based spintronics devices.

From first-principles electronic structure calculations results, we set up an effective
tight-binding Hamiltonian for Li2IrO3 by constructing Wannier orbitals of lowenergy states near the Fermi level. The Wannier orbitals are found to be quite close
to the $j_{eff}=1/2$ state, which are recently suggested to exist in many other iridate
compounds. The model Hamiltonian is characterized bythe nontrivial second and third
nearest neighbor hopping inside Ir honeycomb lattice as well as relatively small but
significant inter-layer hopping terms. It is shown that the ratio between the nearest andthird nearest neighbor hopping determines the $Z_2$-invariant of this material, andthat it can be controlled by the lattice strain in our first-principles calculations. We alsosuggest realistic exchange interactions from effective Hamiltonian, which has various
nontrivial terms including the most strong Kitaev-type anisotropic exchange terms
within the same sublattice, rather small but significant Dzyaloshinskii-Moriya terms,and Heisenberg exchange interactions.

Hyeong Jun Lee1, Moo Young Choi1 and Gun Sang Jeon2*
1
Department of Physics and Astronomy and Center for Theoretical Physics, Seoul
National University, Korea
2
Department of Physics, Ewha Womans University, Korea
We investigate the magnetic state on the edge of the Kane-Mele-Hubbard model. The
ferromagnetic edge states are induced in a graphene nanoribbon by electron-electroninteractions while certain spin-orbit interactions are known to give rise to a gaplesscurrent-flowing state on the edge without electron-electron interactions. We use theHartree-Fock approximation to examine the nature of edge states in the presence ofthe Hubbard interaction in the Kane-Mele model. Computing the local magnetizationof a nanoribbon with various widths, we obtain the edge phase diagram with four
different phases for the ribbons of finite width and study how the magnetic properties
are affected by electron-electron interactions. In particular, we show that the edge
magnetic order survives for weak spin-orbit interactions in the thermodynamic limit.
The edge magnetic order penetrates towards the ribbon center. The resulting magnetic
profile gives its characteristic length which is found to be strongly affected by bothelectron-electron and spin-orbit interactions. Variations of its characteristic length turnout to be closely related to the phase transition between the topological insulator andthe antiferromagnetic insulator. Electron dispersions are also discussed.

Zhi Ren*, Alexey Taskin, Satoshi Sasaki, Kouji Segawa and Yoichi Ando
ISIR, Osaka University, Japan

Jewook Park, Min-cherl Jung, Sung Won Jung and Han Woong Yeom*
Department of physics, POSTECH, Center for atomic wires and layers(CAWL),
Korea[1] Z Ren, A.A. Taskin, S. Sasaki, K. Segawa, and Y. Ando, Phys. Rev. B 84, 165311 (2011). (Editors’
Suggestion) [2] A.A. Taskin, Z. Ren, S. Sasaki, K. Segawa, and Y. Ando, Phys. Rev. Lett. 107, 016801(2011). [3] T. Arakane, T. Sato, S. Souma, K. Kosaka, K. Nakayama, M. Komatsu, T. Takahashi, Z.
Ren, K. Segawa, and Y. Ando, Nat. Commun., in press.

Heung-sik Kim1, Choong H. Kim1, Hogyun Jeong2, Hosub Jin3 and Jaejun Yu1*
1
Department of Physics and Astronomy, Seoul National University, Korea
2
Korea Institute of Science and Technology Information, Korea
3
Department of Physics and Astronomy, Northwestern University, USA

RC09

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RC18

Theoretical study of spin texture in the Bi thin film

Exploration of Three-dimensional Rashba Materials

Ab initio study of topological surface state on Sb (111) surface withiron impurities

Structural and electrical properties of (111) oriented half-Heusler LaPt-Bi thin films

Hiroki Kotaka1*, Fumiyuki Ishii2 and Mineo Saito2
1
Graduate School of Natural Science and Technology, Kanazawa University, Japan
2
Faculty of Mathematics and Physics, Kanazawa University, JapanThe Spin-Orbit interaction (SOI) is very important effect for heavy atom like Bismuth.
Recently, first-principles study revealed that significant SOI effects on the electronic
structure and lattice bistability of Bi nanofilms.[1] In this study, we perform firstprinciples electronic structure calculations under the electric field for Bismuth thin film
and Bi (001) multi-layer surface. We revealed that the SOI combined with electric field(so called Rashba effect) is very important in Bi surface state and Bi edge state.[2] We
calculate spin polarization and spin direction for each band and k-points. Recently,
giant out-of-plane spin component on Bi (001) surface is discovered SR-ARPES
experiment.[3] We also calculate the spin structure of multi-layer Bi (001) surface, andour calculated result shows the detail of spin features at each k-point.
[1] H. Kotaka et al., e-JSSNT, Vol.7, pp.13-16, (2009). [2] H. Kotaka, F. Ishii, M. Saito, T. Nagao,
and S. Yaginuma, JJAP (2012). [3] A. Takayama et al., Phys. Rev. Lett. 106, 166401 (2011).

Manabu Kanou* and Sasagawa Takao
Materials and Structures Laboratory, Tokyo Institute of Technology, Japan
Strong spin-orbit interactions under the broken space inversion symmetry can induce
spontaneous spin polarization without external magnetic fields, which is known as
the (surface/interface) Rashba effect. On the other hand, due to the lack of a modelcompound, the Rashba effect in three-dimensions (bulk) has been poorly explored.
In this study, it is demonstrated that ternary compounds of bismuth tellurohalides,
BiTeX (X = Cl, Br, and I), are promising candidate compounds as ideal threedimensional Rashba materials. As the essential backbone for both fundamental andapplied research, this study established the growth of their sizable single crystals (>1 × 1 × 0.2 mm3). Furthermore, it was found that, for BiTeI, that electronic state (thecarrier concentration) can be adjusted from metallic to insulating ones by the choiceof the growth techniques. Realization of the 3D Rashba states, including the Fermi
surface topology for the corresponding carrier concentrations of the obtained crystals,
was confirmed by relativistic first-principles calculations. We will discuss that our
3D Rashba materials can be a leading player in spin-involved novel phenomena,
ranging from the metallic extreme (unconventional superconductivity) to the transportintermediate (spin Hall effects) to the novel insulating variant (3D topologicalinsulating states).

Jinhee Han, Hyungjun Lee and Hyoung Joon Choi*
Department of Physics and IPAP, Yonsei University, Korea

We study iron impurities on Sb (111) surface and their effects on topological surface
state by using an ab-initio pseudopotential density-functional method. We implemented
the spin-orbit interaction into the SIESTA in a form of additional fully non-local
projectors. To calculate electronic structure of topological surface states, we considera slab of Sb using a supercell containing 20 atomic layers with experimental bulk Sblattice parameters. We determine atomic positions of Fe impurities on Sb (111) surface
by minimizing the total energy, and calculate surface band structures near the Fermi
level. To find the impurity effects on the electronic structure of the surface states, we
simulate ARPES spectra as a function of impurity density on the surface and calculate
local density of states (LDOS) near the Fermi level. From the results, we find that Fe
impurity states are present near Fermi level and they strongly interact with the surface
states and produce a characteristic feature in LDOS on the top surface Sb layer. This
work was supported by the NRF of Korea (Grant No. 2011-0018306) and KISTISupercomputing Center (Project No. KSC-2011-C3-06).

July 12 (Thu)

July 12 (Thu)[1] D.M. Rowe, in : D.M. Rowe (Ed.), CRC Handbook of Thermoelectrics, CRC Press, Boca Raton, FL, 1995, p 90. [2] N.
P. Butch, K. Kirshenbaum, P. Syers, A. B. Sushkov, G. S. Jenkins, H. D. Drew, and J. Paglione, Phys. Rev. B. 81, 241301(R)(2010). [3] Y. L. Chen, J.-H. Chu, J. G. Analytis, Z. K. Liu, K. Lgarashi, H.-H. Kuo, X. L. Qi, S. K. Mo, R. G. Moore, D. H.
Lu, M. Hashimoto, T. Sasagawa, S. C. Zhang, I. R. Fisher, Z. Hussain, and Z. X. Shen, Science 329, 659 (2010).

Nozomi Sugimoto1*, Yohei Niimi1, Tetsuya Miyawaki1, Tatsuhiko Yoshihara1, Naoto
Fukatani1, Kenji Ueda1, Nobuo Tanaka2 and Hidefumi Asano1
1
Department of Crystalline Materials Science, Nagoya University, Japan
2
EcoTopia Institute, Nagoya University, Japan
Topological insulators are candidate materials for low-power and high-speed spintronics
devices, due to the dissipation less and spin-polarized electrons on the surface state.
Recently, we have reported structural properties of LaPtBi(001) thin films, one ofcandidate materials of half-Heusler topological insulator[1-2], grown by three-target
co-sputtering[3]. In this paper, we report preparation and properties of LaPtBi withdifferent crystalline orientation.By optimizing deposition rate for each element, (111)oriented LaPtBi thin films were obtained below 500°C on Sapphire-C substrates. On
the other hand, for films on YAlO3 substrates, both (001) and (111) orientations wereobserved below 500°C. X-ray photoelectron spectroscopy study is revealed that (111)oriented films exhibited chemical shifts and appearance of satellite peaks of La 3d,
which are attributed to charge transfer from Bi p and Pt d states to La d and f states dueto the mixture of these states in the valence band. Investigation and comparison of the
behaviors of LaPtBi thin films with different orientations will enable us to uncover theelectron and spin transport properties in the surface state due to the topological nature.
[1] S. Chadov et al., Nat. Mater. 9, 541 (2010). [2] H. Lin et al., Nat. Mater. 9, 546 (2010). [3] T.
Miyawaki et al., J. Appl. Phys., accepted.

260

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

261

poster Presentation

poster Presentation

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First-principles study of spin texture in the multilayer graphene onNi(111)

Shubnikov-de Haas oscillation in PuIn3

Competitive magnetic properties between the different anisotropic
SDW phases in heavy-fermion system Ce0.87La0.13(Ru1-xRhx)2Si2

Hybridization gap and the hidden order in the heavy fermion Kondo
lattice URu2Si2

Graphene, a two-dimensional honeycomb lattice consisting of C atoms, shows usefulproperties for spintronics applications. Recently, spin-split electronic states in thegraphene on Ni(111) is discussed extensively [1-3]. By using noncollinear spindensity functional theory implemented in openmx code[4], we predict spin-polarized
electronic states of the graphene on Ni(111) in real- and momentum-space. The Diraccone shaped band structure was broken by strong hybridization between monolayer
graphene and substrate Ni(111). On the other hand in the bilayer graphene on Ni(111),
the Dirac-cone shaped band recover only in minority spin. The relativistic spin-orbit
effect make non-collinear spin vortex (Rashba Effect) in the momentum space. This
spin noncollinearity in momentum space may make significant effects on the electricaltransport properties of the graphene/Ni(111).

R

G
UP

D

E
AD

[1] Yu. S. Dedkov, M. Fonin, U. Rudiger, and C. Laubschat, Phys. Rev. Lett. 100, 107602 (2008). [2]O. Rader, A. Varykhalov, and J. Sanchez-Barriga, D. Marchenko, A. Rybkin, and A. M. Shikin, Phys.
Rev. Lett. 102, 057602 (2009). [3] K. Sawada, F. Ishii, M. Saito, Phys. Rev. B 82, 245426 (2010). [4] T.
Ozaki, H. Kino, J. Yu, M. J. Han, N. Kobayashi, M. Ohfuti, F. Ishii, T. Ohwaki, H. Weng, M. Toyoda,

July 12 (Thu)and K. Terakura, http:// www.openmx-square.org/

Wan Kyu Park1*, Paul H. Tobash2, Filip Ronning2, Eric D. Bauer2, John L. Sarrao2,
Joe D. Thompson2 and Laura H. Greene1
1
University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
2
Los Alamos National Laboratory, Los Alamos, NM 87545, USA

Typical heavy-fermion compound CeRu 2Si 2 shows an SDW transition by thesubstitution of La at the Ce site with the gap perpendicular to the c-axis and the moment
along the c-axis(1). It shows another SDW transition with the gap and moment bothparallel to the c-axis by the substitution of Rh at the Ru site(2). In order to investigate
the two different SDW phases, we have measured the susceptibility χ and resistivity ρon single-crystalline Ce0.87La0.13(Ru1-xRhx)2Si2 for 0 ≤ x ≤ 0.4 in directions perpendicular(∠) and parallel (//) to the c-axis(3). The ρ∠ for 0 ≤ x < 0.05 shows a gap-type anomaly
at TN, whereas the ρ// for 0 ≤ x < 0.05 indicates a downward inflection or a shoulder
at around TN, suggesting the transverse SDW transition. For 0.05 ≤ x ≤ 0.075 theseanomalies become very small and a hysteresis is further seen between temperature
decreasing and increaseing process below TN. For 0.075 < x ≤ 0.3 the gap-type anomalyin ρ∠ disappears and a clear gap-type jump has been detected in ρ// at TN, suggesting
the longitudinal SDW transition. These behaviors would suggest that a competitive
magnetic phase occurs between the two anisotropic SDW phases.

What drives the second order phase transition that occurs at 17.5 K in the Kondo lattice
heavy fermion URu2Si2 remains unknown after two and half decades of research despiteubiquitous observation of gap-like behaviors. Determining the nature of the extracted
gaps, whether they are the order parameter or not, is a crucial task to resolving this hidden
order enigma. Quasiparticle scattering spectroscopy (QPS), better known as pointcontact spectroscopy, is a powerful technique to probe the bulk electronic properties by
exploiting a ballistic junction between two electrodes. Employing QPS, we have carriedout conductance measurements on URu2Si2 [1]. The differential conductance data exhibit
a distinct double-peak structure with pronounced asymmetry, a signature for a Fano
resonance in a Kondo lattice [2]. The extracted gap, a hybridization gap between therenormalized bands, opens well above the hidden order transition temperature, indicating
this hybridization gap is not the hidden order parameter. Our results place severe
constraints on the origin of the hidden order transition in URu2Si2. The work at UIUC is
supported by the U.S. DOE under Award No. DE-FG02-07ER46453. The work at LANL
is carried out under the auspices of the U.S. DOE, Office of Science.

(1) S. Quezel et. al., J. Magn. & Magn. Mater., 76 & 77, 403 (1988). (2) S. Murayama et. al., Phys.
Rev. B 56, 11092 (1997). (3) Y. Amakai et. al., J. Phys. Soc. Jpn. 80, SA062 (2011).

[1] W. K. Park et al., PRL 108, 246403 (2012) [2] M. Maltseva, M. Dzero, P. Coleman, PRL 103, 206402 (2009).

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Single Crystal Growth, Electrical and Magnetic Properties in ROs2Al10(R=rare earth)

Quadrupolar ordering in a caged compound PrOs2Zn20

Elastic constant of SmOs4Sb12 under high magnetic field

Resonant Raman effect on LaRu2Al10 and CeRu2Al10

Masahito Sakoda 1*, Kazuhiro Kubota 1, Eiichi Matsuoka 1, Hitoshi Sugawara 1,
Takahiro Sakurai2, Hitoshi Ohta3, Tatsuma D. Matsuda4 and Yoshinori Haga4
1
Department of Physics, Kobe University, Kobe 657-8501, Japan
2
Center for Supports to Research and Education Activities, Kobe University, Kobe 657-8501, Japan3
Molecular Photosciece Research Center, Kobe University, Kobe 657-8501, Japan
4
Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, JapanThe ternary rare-earth compounds ROs2Al10 (R = rare earth) crystallize with orthorhombic structure[1]. Among them, CeOs2Al10 have attracted much attention because of the heavy-fermion behavior
accompanied by a novel long-range order (LRO) at 28.7 K [2]. In order to understand the mechanismsof LRO, the information of physical properties of the reference compounds LaOs2Al10 and PrOs2Al10
is required. In this work, we have succeeded in growing single crystals of LaOs2Al10 and PrOs2Al10
by Al self-flux method, and investigated the physical properties by the X-ray diffraction, electricalresistivity, Hall effect and magnetic susceptibility. Both of LaOs2Al10 and PrOs2Al10 show the typicalmetallic temperature dependence of electrical resistivity without any indication of phase transitions.
LaOs2Al10 exhibits the Pauli paramagnetism with small temperature dependence, while PrOs2Al10
exhibits the Van Vleck paramagnetism with the Curie-Wiess behavior at high temperature with a large
magnetic anisotropy, which is most probably due to the crystalline electric field effect. All of theseresults indicate that the electronic structure of CeOs2Al10 is different from those of LaOs2Al10 andPrOs2Al10, and suggest that the 4f-electrons in CeOs2Al10 are related to the unusual ordering.

Kazuhei Wakiya1, Naohiro Nagasawa1, Keisuke T Matsumoto1, Takahiro Onimaru1,
Kazunori Umeo2 and Toshiro Takabatake1
1
AdSM, Hiroshima University, Higashi-Hiroshima, Japan
2
N-BARD, Hiroshima University, Higashi-Hiroshima, JapanPr-based intermetallic compounds with cubic crystal structures are expected toshow various phenomena arising from quadrupolar degrees of freedom, when the
crystal electric field (CEF) ground state of Pr3+ ion is the nonmagnetic Γ3 doublet.
Recently, it has been found that a caged compound PrIr2Zn20 with the Γ3 doublet
ground state undergoes a superconducting transition at Tc=0.05 K in the presence of
antiferroquadrupolar order below TQ=0.11 K [1, 2]. We have studied the isostructuralcompound PrOs2Zn20, with 5d electron one less than in PrIr2Zn20, by the measurementof the electrical resistivity ρ, magnetic susceptibility χ, and specific heat C in thetemperature range from 0.4 K to 300 K. On cooling below 5 K, χ(T ) approaches aconstant value, indicating a nonmagnetic CEF ground state. C(T ) shows a peak at
To=0.6 K, where no anomaly appears in the χ(T ). These findings strongly suggest anonmagnetic phase transition at To arising from the quadrupolar degrees of freedom.
Furthermore, the To is five times higher than TQ in PrIr2Zn20, which is possibly
attributed to enhancement of quadrupolar exchange interaction.
[1] T. Onimaru et al., J. Phys. Soc. Jpn. 79 033704 (2010). [2] T. Onimaru et al., Phys. Rev. Lett.
106 177001 (2011).

[1] V. M. T. Thieder et al., J. Mater. Chem. 8 (1998) 125. [2] T. Nishioka et al., J. Phys. Soc. Jpn. 78 (2009) 123705.

Tatsuya Yanagisawa1*, Shota Mombetsu1, Mitsuhiro Akatsu2, Yuichi Nemoto2, Shadi
Yashin3, Sergei Zherlitsyn3 and Joachim Wosnitza3
1
Department of Physics, Hokkaido University, Japan
2
Graduate School of Science and Technology, Niigata University, Japan
3
Dresden High Magnetic Field Laboratory, Forschungszentrum Dresden-Rossendorf,
Germany

Katsuaki Nagano1, Takumi Hasegawa1, Norio Ogita1, Masayuki Udagawa1, Hiroshi
Tanida2, Daiki Tanaka2, Masafumi Sera2, Takashi Nishioka3 and Masahiro Matsumura3
1
Graduate School of Integrated Arts and Sciences, Hiroshima University, HigashiHiroshima 739-8521, Japan
2
Institute for Advanced Material Research, Hiroshima University, Higashi-Hiroshima
739-8530, Japan
3
Graduate School of Advanced Sciences of Matter, Kouchi University, Kochi 7808520, JapanThe filled skutterudite compound SmOs4Sb12 exhibits a large electronic specific heat coefficient Υ~ 820 mJ K-2 mol-1, which is insensitive to an applied magnetic field H || <001>, and also shows aphase transition at 2.5 K with tiny ferromagnetic moment. The origin of the magnetically robust
heavy fermion state and an exotic phase transition are unsolved issues. The crystalline electric field(CEF) ground state of this compound has also not been settled, thus far. Owing to clarified whether
the CEF ground state is the Γ_8 quartet or Γ_7 doublet for Sm3+ ionic configurations, we havemeasured the elastic constant C_11 on single crystalline SmOs4Sb12 by using pulsed magnetic
fields up to 62 T. As a result, C_11 shows a minimum at around 10 T and gradually increase withincreasing magnetic field at 4.2 K. In the cubic symmetry, C_11 can be described as the sum of
the bulk modulus C_B and the Γ_3-type quadrupole susceptibility. Assuming that C_B is only
dominated by magneto-elastic effects of the weak ferromagnetic moment in the low magnetic
field region, the increasing tendency of C_11 at high magnetic field region could be explained by aquadrupole susceptibility with Γ_8 quartet CEF ground state.

LaRu2Al10 and CeRu2Al10 with space group Cmcm have the orthorhombic YbFe2Al10 type structure [1], where
the number of Raman active phonons is estimated as 10Ag + 9B1g + 6B2g + 8B3g by group theory. CeRu2Al10
shows the transition at T0 = 27 K [2, 3, 4], while LaRu2Al10 shows no anomaly. We reported the temperaturedependence of the phonon Raman spectra at the SCES 2011, where we could not observe all phonon modes by
only 514.5 nm excitation and no anomaly at T0 in CeRu2Al10. We concluded that the transition at T0 does notaccompany with the structural change. Recently we have employed several excitations light at 488.0 nm, 514.5
nm, 568.2 nm, and 647.1nm. We have observed the B1g mode missed by only 514.5 nm, that is, we observe allphonon modes by changing the excitation energy. In the guest atoms modes, the vibration along b axis shows
the intensity enhancement at 647.1 nm, but that along a or c axis does not show the case. Remarkable difference
between LaRu2Al10 and CeRu2Al10 is observed for the phonons at around 100 cm-1 in (y, z) polarization. These
differences are originated by the difference of the electronic states between them.

[1] S. Sanada et al., J. Phys. Soc. Jpn. 74 (2005) 246, [2] W. M. Yuhasz et al., Phys. Rev. B 71 (2005) 104402, [3]Y. Aoki et al., Physica B 378-380 (2006) 54, [4] T. Yanagisawa et al., J. Phys. Soc. Jpn. 80 (2011) 043601.

[1] Thieda V M T, et al, 1998 J. Mater. Chem. 8 125. [2] Strydom A M 2009 Physica B 404 2981 [3]Nishioka T, et al 2009 J. Phys. Soc. Jpn. 78 123705 [4] Muro Y, et al 2010 J. Phys.: Conf. Series 200 012136

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RD11

Anisotropic transport and magnetic properties of CeZn 11 single
crystals1

Spin-triplet superconductivity induced by ferromagnetic fluctuationsin UCoGe

27Al-NMR study for critical phenomena of metamagnetic transition in
UCoAl

Magnetic properties of β-US2 single crystals

After the discovery of superconductivity in the ferromagnetic (FM) UGe2 under pressure, FM
superconductors have attracted much interest, since in an itinerant FM superconductor with the presenceof a large energy splitting between the majority and minority spin Fermi surfaces, exotic spin-triplet
superconductivity has been anticipated. Among such FM superconductors, UCoGe [1] is one of the most
readily explored experimentally, because of its high superconducting transition temperature ~ 0.7 K and low
Curie temperature ~ 2.5 K at ambient pressure. Large anisotropic behaviors of superconductivity [2, 3] andlongitudinal FM fluctuations along the c axis (direction of the ordered moment) [4] are thought to link withthe mechanism of the superconductivity. From precise angle-resolved NMR and Meissner measurements
we found that the magnetic field along the c axis strongly suppresses the FM fluctuations and that thesuperconductivity is observed in the limited magnetic field region where the FM spin fluctuations are active.
These results combined with model calculations strongly suggest that the longitudinal FM spin fluctuations
tuned by H || c induce the unique spin-triplet superconductivity in UCoGe. As far as we know, this is the firstclear experimental example that FM fluctuations are intimately related with superconductivity.

UCoAl shows a first-order paramagnetism (PM)-ferromagnetism (FM) transition (metamagnetictransition) in small external magnetic field about 0.6 T applied only along its easy magnetization
axis, c-axis [1]. This first order transition line terminates at a “critical-end-point” at Tcr ~ 13 K.
Above Tcr the first order transition from PM to FM changes to crossover. This feature is apparently
similar to gas-liquid transition, where the order parameter and the tuning parameter are density ofmolecules and pressure, respectively. In fact, a gas-liquid transition is regarded to be mathematicallyequivalent to 3D-Ising FM transition [2], therefore we expect the metamagnetic transition in
UCoAl has the same physical framework as a gas-liquid transition. In order to investigate static anddynamic properties in the critical phenomena on UCoAl, we performed 27Al-NMR measurement
for a single-crystal UCoAl and measured Knight-shift K and nuclear spin-lattice relaxation rate 1/
T1 by varying temperature T and c-axis magnetic field Hc. In the poster presentation, I will show
the result of c-axis magnetization Mc (order parameter) and c-axis dynamical susceptibility Sc(fluctuations of order parameter) calculated from K and 1/T1T, as a function of (T, Hc) and discuss
similarities and differences from comparison with gas-liquid transition.

Uranium chalcogenides compounds UXS (X:S, Se and Te) have the same orthorhombic(Pnma) structure and those electronic state can easily be modified by changing theconstituting elements. UTeS is an Ising-type ferromagnet with a Curie temperature 87
K and shows metallic conductivity at all temperatures. USeS shows a semimetallic
resistivity. Electrical resistivity of USeS decreases with decreasing temperature
but increases steeply below 50 K, with an anomaly at the ferromagnetic ordering
temperature 24 K.US2 is similar to USeS at high temperature and the electricalresistivity of US2 decreases with decreasing temperature and increases steeply below
about 80 K, but US2 does not order magnetically. The electrical resistivity of US2 at
low temperature suppresses under a high pressure or a high magnetic field [1]. We
study the magnetic properties of US2 in detail by measuring magnetic susceptibility
and electric resistivity under a magnetic field.

[1] N. T. Huy et al., Phys. Rev. Lett. 99 (2007) 067006. [2] N. T. Huy et al., Phys. Rev. Lett. 100 (2008) 077002. [3]
D. Aoki et al., J. Phys. Soc. Jpn. 78 (2009) 113709. [4] Y. Ihara et al., Phys. Rev. Lett. 105 (2010) 206403.

[1] N. V. Mushinikov et al., Phys. Rev. B 59, 6877 (1999). [2] T. D. Lee et al., Phys. Rev. 87, 410 (1952).

H. Hodovanets, S. L. Bud'ko and P. C. Canfield*
Department of Physics and Astronomy, Ames Laboratory/Iowa State University, Ames
IA, USA
Anisotropic measurements of the magnetic and transport properties have been
performed on single crystals of CeZn11 in three different crystallographic directions.
M(H) for H$\perp c$ shows a broad metamagnetic transition at about 1.9 T with
Ms~ 1.6 $\mu_B$ per Ce. Analysis of the temperature dependence of M/H indicatesstrong magnetic anisotropy. Zero-field resistivity of CeZn11 shows a broad maximum,
characteristic of that of Kondo compounds, at around 10 K followed by a sharpchange of the slope and a kink corresponding to antiferromagnetic (AF) transition
at 2.0 K. Anisotropic temperature and field dependent magnetoresistance and H-Tphase diagrams will be discussed. $^1$ Work at the Ames Laboratory was supportedby the Department of Energy, Basic Energy Sciences under Contract No. DE-AC0207CH11358.

262

Hiroaki Okamoto1, Eiichiro Harada1, Yusuke Amakai1, Shigeyuki Murayama1*,
Hideaki Takano1, Naoki Momono1, Kazuyuki Matsubayashi2 and Yoshiya Uwatoko2
1
Graduate School of Engineering, Muroran Institute of Technology, Japan
2
Institute for Solid State Physics, University of Tokyo, JapanThe 19th International Conference on Magnetism

Taisuke Hattori1*, Yoshihiko Ihara1, Kosuke Karube1, Yusuke Nakai2, Kenji Ishida2, Yasuhiro Tada1,
Satoshi Fujimoto1, Norio Kawakami1, Kazuhiko Deguchi3, Noriaki K Sato3 and Isamu Satoh4
1Department of Physics, Graduate School of Science, Kyoto University, Japan2
Department of Physics, Graduate School of Science, Kyoto University. TRIP, JST, Japan3
Department of Physics, Graduate School of Science, Nagoya University, Japan
4
Institute for Materials Research, Tohoku University, Japan

Kosuke Karube 1 *, Taisuke Hattori 1 , Kenji Ishida 1 , Takuya Asai 2 , Takemi
Komatsubara3 and Noriaki Kimura2
1
Department of Physics, Graduate School of Science, Kyoto University, Japan2
Department of Physics, Graduate School of Science, Tohoku University, Japan
3
Center for Low Temperature Science, Tohoku University, Japan

July 12 (Thu)Fumiyuki Ishii1*, Hiroki Kotaka2, Keisuke Sawada2 and Mineo Saito1
1
Faculty of Mathematics and Physics, Kanazawa University, Japan
2
Graduate School of Natural Science and Technology, Kanazawa University, Japan

Yoshinori Haga1, Oscar Ayala-valenzuela2, Ross Mcdonald2, Chuck Mielke2, Eric D.
Bauer2, J N Mitchell2, P. H. Tobash2, Joe D. Thompson2 and Zachary Fisk1
1
Advanced Science Research Center, Japan Atomic Energy Agency, Japan2
Los Alamos National Laboratory, USA

Etsuji Yamamoto1*, Shugo Ikeda2, Hironori Sakai1, Tatsuma D. Matsuda1, Naoyuki
Tateiwa1, Yoshinori Haga1, Yoshichika Onuki3 and Zachary Fisk4
1
ASRC, Japan Atomic Energy Agency, Japan
2
Graduate School of Material Science, University of Hyogo, Japan
3
Graduate School of Science, Osaka University, Japan
4
University of California, USA[1] S. Ikeda et al., J. Phys. Soc. Jpn.76 (2009) 114704.

July 8-13, 2012 Busan, Korea

263

poster Presentation

poster Presentation

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RD21

Evidence of nodal gap structure in the skutteride superconductor
PrPt4Ge12

Effect of pressure on the YbNi3Ga9 single crystal

Tuning of the heavy-fermion ground state in YbNi3X9 (X=Al, Ga) by
substitution

Heavy-fermion properties of YbCu5-xAux (x = 0.5, 0.6, 0.7)

1

2

2

1

Jing Lei Zhang , Lin Jiao , Michael Nicklas , Roman Gumeniuk , Ye Chen , Lu Kai
Guo1, Li Na Wang1, Bin Hao Fu1, Walter Schnelle2, Helge Rosner2, Andreas Leithejasper2, Yuri Grin2, Frank Steglich2 and Hui Qiu Yuan1*
1
Department of Physics, Zhejiang University, China
2
Max Planck Institute for Chemical Physics of Solid, Germany

July 12 (Thu)In order to study the gap function of the newly discovered skutterudite superconductor
PrPt4Ge12 (T_{c}=7.9K), we have measured the London penetration depth Δλ(T) of thesingle crystalline PrPt4Ge12 down to 0.05Tc by using a tunnel diode oscillation (TDO)
based technique. Observation of a quadratic temperature dependence of Δλ below
0.3Tc indicates the existence of point nodes in the superconducting gap. The derived
superfluid density ρ_{s}(T) can be nicely fitted by the A-phase gap function of 3He(Δ(θ,φ)=Δ_{0} |K_{x}+iK_{y}|) with a fitting parameter of Δ_{0}=2.2k_{B}T_{c},providing new evidence for a possible p-wave superconductivity in PrPt4Ge12.

We have investigated the effect of pressure on the physical properties of singlecrystalline YbNi3Ga9. This compounds crystallize in a trigonal ErNi3Al9-type structure(space group R32). From the thermal, magnetic and transport study, YbNi3Al9 turns
out to be an intermediate valence compound with r = 30 mJ/molK [1]. The electricalresistivity and ac susceptibility of nonmagnetic heavy fermion compound YbNi3Al9
have been measured under hydrostatic pressure up to 11 GPa. With increasing pressure,the ferromagnetic ordering state was appeared over 9 GPa. These results suggested
that nonmagnetic Yb state change to the localized magnetic state, via quantum criticalpoint, by tuning the pressure. In this paper, we will discuss the electrical state of
YbNi3Al9 under pressure.
[1]T. Yamashita and S. Ohara; submitted to J. Phys. Soc. Jpn.

We have succeeded in synthesizing new Yb-based Kondo lattice systems YbNi3X9 (X =Al, Ga)
which crystallizes in the trigonal ErNi3Al9-type structure [1]. YbNi3Al9 shows typical featuresof a heavy-fermion antiferromagnet with Neel temperature of TN=3.4K and Sommerfeld
coefficient γ~100mJ/(molK2). In contrast, YbNi3Ga9 is an intermediate valence compound with
γ=30mJ/(molK2) and a high characteristic temperature of TK~600K. YbNi3X9 (X =Al, Ga)
is a great opportunity to investigate the tunability of heavy-fermion ground states in Yb-based
compound for using external control parameters such as pressure or doping. In this regard, weare investigating physical properties of mixed crystals of YbNi3Al9-YbNi3Ga9, doping system ofYb(Ni1-xMx)3X9 (M=3d transition-metal) and dilute system of (Yb1-xLux)Ni3X9. Here we report
Ni-site substitution effects on the antiferromagnetism of YbNi3Al9. For YbNi3Al9, the resistivity
shows a -logT dependence below 100K and a broad peak at about 40 K arising due to the Kondo
effect combined with the CEF excited state. In the lower-temperature region, a strong reductionin the extent of magnetic scattering associated with the antiferromagnetic ordering was observed
below TN=3.4 K. By Fe-substitution TN is decreased, while is increased by Cu-substitution. The
tunability of TN in Yb(Ni1-xMx)3X9 will be discussed.

[1] K. Yoshimura et al., J. Alloys Comp 262-263 (1997) 118 [2] M. Galli, E.Bauer, St. Berger, Ch.
Dusek et al. Physica B 312-313 (2002) 489 [3] J. He, N. Tsujii et al., J. Phys. Soc. Jpn 66 (1997)
2481

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Mossbauer spectroscopy of Fe doping valence fluctuating α-YbAlB4

Fermi surfaces in the mixed valent Yb system

Pressure effect studies in Ce 2T 3Ge 5 (T=Rh, Pd, Ir) by electricalresistivity

Valence fluctuating YbAlB4 compounds have two different crystal structures; α-YbAlB4andβ-YbAlB4 [1].β-YbAlB4 is the first compound which shows a Yb-based heavy fermion
superconductor with Tc = 80mK [2] and exhibits a pronounced non-Fermi-liquid behavior
above Tc. Meanwhile, α-YbAlB4 shows normal metallic behaviorsat low temperature.
Recently, the small substitution of Al by Fe in α-YbAlB4 revealed a breakdown of
the Fermi-liquid behavior with an antiferromagnetic order. We have studied magnetic
properties of α-Yb(Al0.75Fe0.25)B4 at low temperatures using 57Fe Mossbauer spectroscopy.
The observed Mossbauer spectrum at room temperature using single crystalline samples
is typical for a paramagnetic state. We analyzed the spectrum using a doublet. Fromthe intensity ration of the doublet, the principle z-axis of the diagonalized electric-field
gradient tensor is perpendicular to the c-axis. We observed a small magnetic hyperfine
field at 4.5K whitch comes from the antiferromagnetic ordering of Yb magnetic moments.
This small magnetic hyperfine field disappears around TN (~ 9K). These results indicatethat the magnetic structure is not simple in α-Yb(Al0.75Fe0.25)B4. Above TN, the observed
spectra change drastically with increasing temperature. Some of changes in the spectra
were related to anomalies in the temperature dependence of magnetization.

Hisatomo Harima*
Department of Physics, Kobe University, Japan

Many Yb-compounds have been crystalized recently in good quality, so that the deHaas-van Alphen effect is detected in those including the Yb-based heavy fermion
compounds, i.e., YbCu2Si2, YbAlB4. Non-magnetic Yb compounds are regarded
mostly as divalent Yb system, in which Fermi surfaces are well reproduced by using
conventional band structure calculations. In some of non-magnetic Yb compounds,
such as YbAl3, the valence of Yb-ion is diverted from Yb2+. Actually, the Fermi
surfaces of YbAl3 are very different in topology from those of divalent YbIn3. This is
the clear evidence of the 4f electrons really affect the formation of the Fermi surfaces
in YbAl3[1]. In Yb compounds, the dispersion of the 4f bands are very flat, then the
Fermi surfaces are very sensitive to the role of the 4f electrons. Recently the LDA+U
approach has shown that only the doublet ground states participate the Fermi surfaces
in YbCu2Si2[2]. The role of 4f electrons in mixed valent Yb system is discussed, for
YbAlB4 , YbCoGa5 and the related compounds.
[1] T. Ebihara, et.. al., J. Phys. Soc. Jpn. 69 (2000) 895. [2] Nguyen Duc Dung, et. al., J. Phys. Soc.
Jpn. 78 (2009) 084711.

Miho Nakashima1, Toshiyuki Uchiyama1, Toru Kawata1, Yasushi Amako1, Yusuke
Hirose2, Honda Fuminori2, Rikio Settai2 and Onuki Yoshichika2
1
Department of Physics, Faculty of Science, Shinshu University, Japan
2
Graduate School of Science, Osaka University, Japan

In the Ce2T3Ge5 system (T: transition metal) with the orthorhombic crystal structure, Ce2Ni3Ge5
is an antiferromagnet with a Neel temperature TN = 5.2 K. TN decreases with increasing pressure
and becomes zero at a critical pressure Pc = 3.9 GPa. The A and ρ0 values in the Fermi liquid
relation (the low-temprature electrical resistivity ρ = ρ0 + AT2) increase steeply above 3 GPa.
It seems to be the heavy fermion state around Pc, in which pressure region superconductivity
was found below 0.26 GPa [1]. We measured temperature dependence of electrical resistivityof Ce2Rh3Ge5, Ce2Ir3Ge5 and Ce2Pd3Ge5 under pressure in this study. These theree compounds
are all antiferromagnets at ambient pressure, showing kinks of resistivity at TN (=4.7, 9.5 and
3.8 K respectively)[2, 3, 4]. In Ce2Rh3Ge5 and Ce2Ir3Ge5 TN decreases with increasing pressure
and seems to be zero at a critical pressure Pc=0.4 and 2.0 GPa, while TN increases in Ce2Pd3Ge5
by pressure. We also found another anomaly at lower temperature, indicating TN splits into
two ordering TN1 and TN2 under pressure more than 0.2 GPa. TN 1 and TN 2 are both increasing
monotonously with increasing pressure up to 2.3 GPa.
[1] M. Nakashima, et al., J. Phys.: Condens. Matter 17 (2005) 4539. [2] C. Godart, et al., Solid
State Commun. 67 (1988) 677. [3] B. Becker, et al., Phys. B 230-232 (1997) 253. [4] Z. Hossain, etal., Phys. Rev. B 60 (1999) 10383.

[1] R. T. Macaluso et al., Chem. Mater. 19. 1918 (2007) [2] S. Nakatsuji et al., Nature Phys. 4, 603 (2008)

Yb compounds are very attractive for research because of their low temperature
anomalous behaviour. Recently, emphasis was given to the investigation of the solid
solution YbCu5-xMx (M = Ag, Au, In) crystallizing in the cubic AuBe5-type structure.
The substitution of Cu by M offers the possibility of studying the different evolutionsof the ground state depending on the M element (e.g. a valence transition in M = In,
Kondo-lattice behavior in M = Ag, magnetic ordering in M = Au) [1,2,3]. Here we
present the measurements of heat capacity and resistivity in the temperature scale 0.4-300 K for different applied magnetic fields 0 - 9 T of the YbCu5-xAux (x = 0.5, 0.6, 0.7)
system. The polycrystalline samples were prepared by induction-melting method, heattreated and then quenched in cold water. Phase purity was checked by electron probe
microanalysis (EPMA) and X-ray diffraction (XRD)[1] S. Ohara et al., J. Phys.: Conf. Series 273, 012048 (2011); T. Yamashita et al., to be published in
J. Phys. Soc. Jpn.

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Yui Sakaguchi1*, Shugo Ikeda1, Kentaro Kuga2, Keita Sone2, Satoru Nakatsuji2 andHisao Kobayashi1
1 Graduate School of Material Science, University of Hyogo, Japan
2 Institute for Solid State Physics, University of Tokyo, Japan

Magetic properties of heavy-fermion compounds Ce1-xLuxRu2Si2

Toru Sekiguchi1, Yusuke Amakai1, Shigeyuki Murayama1*, Hideaki Takano1, Naoki
Momono1, Kazuyuki Matsubayashi2 and Yoshiya Uwatoko2
1
Graduate School of Engineering, Muroran Institute of Technology, Japan
2
Institute for Solid State Physics, University of Tokyo, Japan
Typical heavy-fermion compound CeRu2Si2 with a tetragonal structure shows anantiferromagnetic transition by the substitution of La at the Ce site due to the negative
chemical pressure by the larger La ion(1). The substitution of Y introduces a decreaseof the specific heat coefficient γ and an increase of the Kondo temperature TK due tothe positive chemical pressure by the smaller Y ion(2). In order to study substitution
effect of Lu with the closed f-electron shell and the ion smaller than Y, we havemeasured the susceptibility χ and resistivity ρ on single-crystalline Ce1-xLuxRu2Si2 for0≤x≤0.2 perpendicular (∠) and parallel (//) to the c-axis.The χ// shows a maximum
and the Tmax increases with x. Since the Tmax is supposed to be the heavy-fermion
formation temperature proportional to 1/γ, the effective mass meff is considered
to increase with x. The resistivity ρ shows a shoulder by the Kondo effect and the
Tshoulder increases with x. This indicates an increase of TK due to the positive
chemical pressure by Lu. The low temperature resistivity follows the T2 law and thecoefficient A decreases with x. Since A is proportional to γ2, meff is again considered toincrease with x.
(1) S. Quezel et. al., J. Magn. & Magn. Mater., 76 & 77, 403 (1988). (2) M.J. Besnus et. al., J. Magn.
& Magn. Mater., 63 & 64, 323 (1987).

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Neutron scattering study on f-electron states of PrCu4Au

Unusual heavy fermion behavior in PrTr2Al20 (T = Nb, Ta) associatedwith Γ_3 quadrupolar degrees of freedom

Photoemission study on new Kondo lattice compounds YbNi3(Ga1-xAlx)9

Moment-bearing Tb substitution in CePt2Si2

Hiroki Kobayashi1, Kazuaki Iwasa1*, Kotaro Saito1, Keisuke Tomiyasu1, Daichi
Kawana2, Shuai Zhang3, Yosikazu Isikawa4, Jean - Michel Mignot5, Gilles Andre5,
Alexander I. Kolesnikov6, Andrei T. Savici6 and Garrett E. Granroth6
1
Department of Physics, Tohoku University, Sendai 980-8578, Japan
2
Condensed Matter Research Center and Photon Factory, Institute of Materials Structure
Science, KEK, Tsukuba 305-0801, Japan3
Department of Applied Chemistry, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
4
Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan
5
Laboratoire Leon Brillouin, CEA-CNRS, CEA/Saclay, 91191 Gif sur Yvette, France
6
Neutron Sciences D., Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
Pr-based compounds have recently been studied for heavy electron properties originating from 4f2
electron configuration, as in PrFe4P12 [1]. We extracted a large electronic-specific-heat-coefficient of
0.77 J/mol K2 from specific heat measurements on PrCu4Au [2]. This material is expected to undergo
an antiferromagnetic transition below 2.4 K. We investigate the role that f-electron states play in theseproperties using neutron scattering techniques. We used the spectrometers SEQUOIA at ORNL, 4F1 at
LLB, and TOPAN at JAEA to measure the temperature dependence, between 1.6 K and 100 K, of themagnetic excitations in PrCu4Au. The spectra are composed of several inelastic peaks. The crystal-fieldsplitting scheme with the triplet ground state, as suggested from the magnetization result [2], is a fair match
to the observed spectra. A quasielastic component was also detected. The temperature dependences of thespectral intensity and width are similar to those in other heavy electron systems. Diffraction experiments
for the powdered sample on the diffractometer G4-1 at LLB reveal antiferromagnetic peaks characterized
by the wave vector (1/2, 1/2, 1/2). This result can be interpreted as the type-II magnetic ordering on the fcc
sub-lattice of Pr ions. To summarize, PrCu4Au exhibits localized and strongly-hybridized f-electron states.
[1] H. Sugawara et al.: Phys. Rev. B 66 (2002) 134411. [2] S. Zhang et al.: J. Phys.: Condens. Matter 21 (2009) 205601.

264

Shigeo Ohara*, Hiroshi Kono and Tetsuro Yamashita
Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555,
Japan

Ivan Curlik1*, Mauro Giovannini2, Mariana Zapotokova3 and Marian Reiffers1
1
Institute of Experimental Physics, Slovakia Academy of Science, Watsonova 47, 040
01, Kosice, Slovakia
2
CNR-SPIN and Department of Chemistry, University of Genoa, Via Dodecaneso 31,
16 146, Genoa, Italy
3
Institute of Experimental Physics, Slovakia Academy of Science, Watsonova 47, 040
01, Kosice, Slovakia

The 19th International Conference on Magnetism

Ryuji Higashinaka, Akihiro Nakama, Ryoichi Miyazaki, Yuji Aoki and Hideyuki Sato
Department of Physics, Tokyo Metropolitan University, Japan

Recently, PrTr2X20 (Tr = transition metal, X = Zn, Al) compounds have attracted
much attention as a new candidate for investigating the quadrupolar Kondo effectbecause PrTr2Al20 (Tr = Ti, V) show non Fermi liquid behaviors and multipolarorderings attributed to nonmagnetic Γ_3 doublet ground state[1]. Recently, we foundthat PrNb2Al20 also has a nonmagnetic Γ_3 doublet ground state and does not show
any phase transitions down to 0.15 K[2]. In addition, this compound has a large
Sommerfeld coefficient γ(~ 1.2 J/molK2). This result suggests a possibility of theformation of unusual heavy fermion state attributed to the quadrupole moments ofΓ_3 state. In order to investigate the quadrupole-induced strongly correlated electronic
properties in PrTr2Al20 systematically we have grown single crystals of other Pr based
compound, PrTa2Al20, and performed specific heat, magnetization and electronictransport measurements. In C/T, PrTa2Al20 shows a peak around 0.6 K attributed tothe ordring of quadrupole moment and has a large gamma value of 1.6 J/molK2 at low
temperatures with little field dependence. In this presentation, we show recent resultsfor PrT2Al20 (T = Nb, Ta) and discuss the possibility of the formation of heavy fermion
formation induced by quadrupolar degrees of freedom.
[1] A. Sakai and S. Nakatsuji: J. Phys. Soc. Jpn. 71 063701 (2011). [2] R. Higashinaka et al.: JPS
Autumn meeting 23pPSA-37 (2010), JPS Spring meeting 28aEC-11 (2011).

Yuki Utsumi1, Hitoshi Sato2, Shigeo Ohara3, Tetsuro Yamashita3, Kojiro Mimura4,
Satoru Motonami4, Masashi Arita2, Shigenori Ueda5, Keisuke Kobayashi5, Kenya
Shimada2, Hirofumi Namatame2 and Masaki Taniguchi2
1
Graduate School of Science, Hiroshima University, Japan
2
Hiroshima Synchrotron Radiation Center, Hiroshima University, Japan
3
Graduate School of Engineering, Nagoya Institute of Technology, Japan
4
Graduate School of Engineering, Osaka Prefecture University, Japan
5
NIMS Beamline Station at SPring-8, National Institute for Materials Science, Japan
Recently, new Kondo lattice compounds YbNi3X9 (X=Al, Ga) were discovered [1]. YbNi3Al9 is a heavyfermion antiferromagnetic compound (TN=3.4 K), while YbNi3Ga9 is a valence fluctuating compound fromthe magnetic susceptibility measurements. These compounds are considered to be very suitable for researchof Yb-based Kondo lattice systems because they both possess the ErNi3Al9-type crystal structure, and the Al
and Ga ions are isovalent. In this study, we have carried out hard x-ray (hν~6 keV) and low energy (hν~7 eV)
excited photoemission spectroscopy (HAXPES and LEPES) on YbNi3X9 and mixed crystals YbNi3(Ga1-xAlx)9
to investigate the Yb valence and the Kondo resonance behavior. The Yb 3d HAXPES experiments revealed
that the Yb ion in YbNi3Al9 exists with almost trivalent state while that in YbNi3Ga9 strongly fluctuates withthe averaged Yb valence of ~2.5. The Al substitution for YbNi3Ga9 (x~0.1) changes the Yb ion toward trivalentstate. The LEPES spectra of YbNi3Ga9 clearly exhibit the Kondo resonance peak near the Fermi level (EF),and the peak is shifted toward EF and the intensity increases with lowering temperature. The extrapolated peakenergy at zero temperature provides TK~600 K for YbNi3Ga9 and the Al substitution lowers TK.

July 12 (Thu)1

T. Hirayama1, K. Matsubayashi1, T. Yamashita2, S. Ohara2 and Y. Uwatoko1*
1
University of Tokyo, Japan
2
Nagoya Institute of Technology, Japan

Moise Bertin Tchoula Tchokonte1*, Zwelithini Melford Mahlubi1, Paul De Villiers Du
Plessis2, Andre Michael Strydom2 and Dariuzs Kaczorowski3
1
Physics, University of the Western Cape, South Africa
2Physics, University of Johannesburg, South Africa
3Physics, Institute of Low Temperature and Structure Research, Polish Academy of
Sciences., Poland
The effects of substituting moment-bearing Tb in CePt2Si2 are reported through X-ray
diffraction (XRD), electrical resistivity (ρ(T)), magnetic susceptibility (χ(T)) andmagnetization (σ(μ0H)) measurements. XRD results for all compositions of the (Ce1xTbx)Pt2Si2 system indicate a tetragonal CaBe2Ge2-type structure with space group P4/
nmm. ρ(T) results indicate the evolution from a coherent Kondo lattice to incoherent
single-ion Kondo behavior up to 90% Ce substitution. χ(T) data at higher temperatures
follow the Curie-Weiss relation for all alloy compositions and given effective moment
values μeff which increase gradually from the expected value of 2.54 μB for the Ce3+
-ion to the expected value of 9.72 μB for the Tb3+-ion. At low temperature χ(T) data
exhibit antiferromagnetism in the concentration range 0.7≤ x ≤ 1. No evidence ofmetamagnetic behavior was observed from σ(μ0H) data for all compositions.

[1] S. Ohara et al., J. Phys.: Conf. Series 273, 012048 (2011); T. Yamashita et al., to be published in J. Phys. Soc. Jpn.

July 8-13, 2012 Busan, Korea

265

poster Presentation

poster Presentation

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Heavy Fermion Behavior of Yb2Ni12P7 Studied by 31P NMR

Engineered p-d exchange interaction of coupled double diluted
magnetic quantum dots

Pressure and magnetic-field induced non-Fermi-liquid behavior in
YbCo2Zn20

Nature of insulator-metal-insulator transitions in the ionic Hubbard
model

Takehide Koyama1, Kyohei Sugiura1, Koichi Ueda1, Takeshi Mito1, Takao Kohara1,
Tomohito Nakano2, Ryohei Satoh3, Katsuhiko Tsuchiya3 and Naoya Takeda2
1
Graduate School of Material Science, University of Hyogo, Japan
2
Faculty of Engineering, Niigata University, Japan
3
Graduate School of Science and Technology, Niigata University, Japan
We present results of the nuclear magnetic resonance measurement (NMR) of Ybbased intermetallic compound Yb2Ni12P7, which crystallizes in the hexagonal Zr2Fe12P7type structure [1]. Yb2Ni12P7 does not order magnetically down to 50 mK and forms theheavy fermion state. The electronic specific heat of Yb2Ni12P7 is markedly enhanced at
low temperatures (200 mJ/K2 mol-Yb). The magnetic susceptibility shows the CurieWeiss like behavior at high temperatures and has a noticeable hump at around 50 K.
We have performed NMR measurement to investigate the electronic properties ofYb2Ni12P7. The observed NMR line shows a complicated shape, reflecting the presenceof three non-equivalent P sites and local symmetries around them. The nuclear-spinlattice relaxation rate (1/T1) shows nearly T1T=const. behavior, which is consistent
with the delocalization of the 4f electrons.

Eun-young Kim
Seoul National University, Korea

This paper presents the effects of inserting a thick InGaN layer which was grown
between n-GaN and active layer by MOCVD. By adding the thick InGaN layer, we
expected the compensation of lattice mismatch between n-GaN and active layer. From
AFM results, QDs (Quantum Dots) were formed at around 200 A InGaN thickness
by TD (Threading Dislocation) termination effect. According to the result of TD
termination, the electrical and optical properties were improved due to the decreaseof non-radiative recombination area in active layer. The result of PL data shows PL
intensity increased by inserting the thick InGaN layer.

K. Zeppenfeld and W. Jeitschko, J. Phys. Chem. Solids, 54 (1993) 1527.

Kazuyuki Matsubayashi1*, Rina Yamanaka1, Yuta Saiga2, Tatsuya Kawae3 andYoshiya Uwatoko1
1
Institute for Solid State Physics, The University of Tokyo, Japan
2
Institute for Advanced Materials Research, Hiroshima University, Japan3
Department of Applied Quantum Physics, Faculty of Engineering, Kyushu
University, Japan

In heavy fermion systems, applying pressure and magnetic field controls the electronic
configuration, and thus anomalous behaviors appear at around magnetic quantum critical point(QCP), such as an unconventional superconductivity and Non-Fermi-liquid behavior. Recently,
YbCo2Zn20 have attracted much attention because of their heavy fermion state and proximity tothe pressure-induced QCP [1]. It is worth noting that the critical pressure of YbCo2Zn20 is lower
than that of other Yb based compounds. Therefore YbCo2Zn20 has an advantage of investigating
the behavior of Yb- based compounds near QCP. More interestingly, it is reported that ametamagnetic crossover appears at H ~ 0.6 T [2], however, the origin of this metamagnetic
behavior remains unclear. In order to shed light on the nature of the pressure- and field-induced
quantum critical behavior, we have measured the specific heat of YbCo2Zn20 under pressure
and magnetic field. We found that the low temperature specific heat in the vicinity of the criticalregion exhibits the power-law divergence. The temperature-pressure-magnetic field phase
diagram will be presented to sum up the physical properties.

Aaram Joo Kim1, Moo Young Choi1 and Gun Sang Jeon2*
1
Department of Physics and Astronomy, Center for Theoretical Physics, Seoul
National University, Korea
2
Department of Physics, Ewha Womans University, Korea
It is known that the ionic Hubbard model possesses a metallic phase between band andMott insulators in high dimensions. We study the phase diagram in the Bethe latticefor various strengths of the staggered lattice potential within the dynamical mean-field
theory (DMFT) combined with the continuous-time quantum Monte Carlo method.
We also investigate its zero-temperature limit by means of exact diagonalization as a
DMFT solver. Observed at finite temperatures are the crossover between the metallic
and band insulating phases and the first-order transition between the metallic and Mott
insulating phases, ending up with the critical point. It is discussed how such transition
behaviors evolve as the lattice potential is increased at low temperatures and whether
the finite- and zero-temperature results are consistent with each other.

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Electronic structure of RCu2Si2 (R=Yb, Y) studied by soft x-ray angleresolved photoemission spectroscopy

Quasi-particle localization by disorder in an incompressible fractional
quantum Hall state

Relationship between single-particle excitation and spin excitation at
the Mott transition

Variational cluster approach to the Hubbard model on the honeycomb
latticeAkira Yasui1, Shin-ichi Fujimori 1, Ikuto Kawasaki 2, Tetsuo Okane 1, Yukiharu
Takeda1, Yuji Saitoh1, Hiroshi Yamagami3, Akira Sekiyama4, Rikio Settai5, Tatsuma D
Matsuda6, Yoshinori Haga6 and Yoshichika Onuki5
1
Condensed Matter Science Division, Japan Atomic Energy Agency, Japan
2
Advanced Meson Science Laboratory, RIKEN Nishina Center for Accelerator-Based Science, Japan3
Department of Physics, Kyoto Sangyo University, Japan
4
Division of Materials Physics, Osaka University, Japan
5
Department of Physics, Osaka University, Japan
6
Advanced Science Research Center, Japan Atomic Energy Agency, Japan

In recent years, electronic structure of YbCu2Si2, which is a classical example of Yb-based valence fluctuation
compounds, has been studied by various experimental methods such as a quantum oscillation measurement[1] and an angle-integrated photoemission spectroscopy (AIPES) [2]. However, these results are inconsistenteach other. In fact, the band structure calculation which well describes the results of the quantum oscillation
measurement [1] cannot explain the AIPES spectrum. In the present study, we have performed the soft x-ray
angle-resolved photoemission spectroscopy (SX-ARPES) for YbCu2Si2 to understand the valence band
structure and the Fermi surface (FS) in a unified way. The SX-ARPES measurements were recorded in
BL23SU of SPring-8. We have observed that hybridized bands of Yb 4f electrons and conduction states crossthe Fermi level at 20 K, which is well below the Kondo temperature of TK = 50 K, in line with the valencefluctuating state of YbCu2Si2. We will discuss effects of Yb 4f electrons on its band structure by comparing
the ARPES spectra with those of a non-4f reference compound YCu2Si2.

Partha Goswami*
Physics department, D.B.College(University of Delhi),New Delhi, India

The strongly correlated electrons, together with disorder, organize themselves in a nontrivial way to form incompressible collective states for the filling fraction ν = 5/2 ina dirty bi-layer semi-conductor quantum well system. The theoretical analysis of thequantum phase transition(QPT) exhibited by this system has been carried out including
the single-particle quantum lifetime sensitive to the long range scattering and the usual
zero field short-range Drude scattering (transport lifetime). Since the tunneling terms
can be controlled by changing gate voltages, we find that, in principle, a completely
reversible sequence of events, viz. a crossover from the bi-layer fractional quantum
Hall state to the single-layer one followed by an entry to quantum critical state (andthe QPT to the bi-layer state beyond) and eventually a crossover to the single-layer
state, could be realized with the increase in inter-layer tunneling. The sequence, which
is manifestation of quasi-particle localization by disorder, could prove to be useful inperforming memory function and gating operation.

Masanori Kohno*
WPI Center for Materials Nanoarchitectonics, National Institute for Materials
Science, JapanThe Mott transition in the one- and two-dimensional Hubbard models is investigatedusing the Bethe ansatz, dynamical density-matrix renormalization group method,cluster perturbation theory, and random-phase approximation. I will show that thedispersion relation of single-particle excitation in a metallic phase leads continuously
to that of spin excitation of the Mott insulator.

July 12 (Thu)

July 12 (Thu)[1] Y. Saiga et al., J. Phys. Soc. Jpn 77 (2008) 053710 [2] M. Ohya et al., J. Phys. Soc. Jpn 79 (2010) 083601

Kazuhiro Seki* and Yukinori Ohta
Department of Physics, Chiba University, Japan

Physics of electrons on the honeycomb lattice, or graphene, is one of the topical issues
in condensed matter physics. Especially, the influence of electron correlations on
the magnetism and electronic states at the Fermi level, which is characterized by thelinear dispersion relation and vanishing density of states in the non-interacting case,is of particular interest. In this study, we apply the variational cluster approach to thehalf-filled Hubbard model on the honeycomb lattice. In order to study the semimetalinsulator transition and paramagnetic-antiferromagnetic insulator transition, we
introduce the bath hybridization strength and staggered magnetic field as variationalparameters. We calculate the single-particle spectra and magnetic order parameter as afunction of Coulomb interaction U, and discuss the implications of the results.

[1] N. D. Dung et al., J. Phys. Soc. Jpn. 78, 084711 (2009). [2] M. Matsunami et al., Phys. Rev. B 78, 195118 (2008).

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Anomalous increase of TC in UGa2 under pressure

NpCoGe, near quantum criticality?

Quantum criticality in Kondo quantum dot coupled to 2D topologicalinsulator

Onset of magnetic order in U2(Ni1-xFex)2Sn

Ladislav Havela1, A. Kolomiets2, J. Prchal1 and A. V. Andreev3
1
Department of Condensed Matter Physics, Charles University, Czech Republic2
Department of Physics, Lviv Polytechnic National University, Ukraine
3
Institute of Physics, Academy of Sciences of the Czech Pepublic, Czech Republic
UGa2 belongs to compounds quite thoroughly studied, although there is still noconsensus about the character of the 5f states. In particular, 5f2 or 5f3 localized andband-like 5f states were considered, none of those being able to explain all its features[1]. Response of magnetic properties to external pressure is an important indicator of
the situation of the 5f states. While band systems tend to a suppression of magnetic
moments and their ordering, magnetism based on localized states has insensitive sizeof moments and their ordering temperatures can weakly increase. Previous experiments[2] indicated a quite rapid increase (approx. 3 K/GPa) of the Curie temperature fromTC = 126 K up to p = 0.8 GPa. New resistivity experiments on UGa2 single crystal,
extending the pressure range up to 8 GPa, reveal a continuous linear increase, reaching
160 K without any sign of saturation. Such anomalously large increase can be only
understood in the framework of a two-band model, in which the compression leads to astronger hybridization of the 5f and other conduction-electron states.
[1] T. Honma et al., J. Phys. Soc. Japan 69 (2000) 2647. [2] A.V. Kolomiets et al., Physica B 259261 (1999) 238.

Eric Colineau*, Rachel Eloirdi, Jean-christophe Griveau, Piotr Gaczynski andAlexander ShickEuropean Commission, Joint Research Centre, Institute for Transuranium Elements,
Germany
The orthorhombic isostructural series AnTGe (An = actinide ; T = transition metal)
offers a unique opportunity to study the properties and trends of a system where
ferromagnetism and superconductivity coexist at ambient pressure in URhGe (TC =9.5K, TSC = 0.26K) [1] and UCoGe (TC = 3K, TSC = 0.7K) [2]. However, due tothe difficulty to handle them, transuranium systems are much less documented. In aneffort to bridge this gap, we have undertaken the study of the neptunium analogues
and have previously reported that NpRhGe exhibits an antiferromagnetic groundstate (TN = 21K, μNp = 1.14μB) [3]. In the present work, we have investigated
NpCoGe by dc magnetization, ac susceptibility, specific heat, electrical resistivity,
237Np Mossbauer spectroscopy and LSDA calculations. We find that NpCoGe orders
antiferromagnetically at TN=13K with an average ordered moment <mNp> = 0.8 μB.
The weak antiferromagnetic interactions (θp = -5.5K) are overcome by the applicationof a moderate magnetic field (B ~ 3T) that induces a metamagnetic phase. NpCoGe
appears as a more delocalized antiferromagnet than NpRhGe, which is consistent
with the trend observed in UTGe analogues. The proximity of NpCoGe to a quantum
critical point and its implications will be discussed.

Chung-hou Chung* and Salman Silotri
Electrophysics Dept., National Chiao-Tung University, HsinChu, Taiwan, R.O.C.,
TaiwanWe investigate theoretically the quantum phase transition between the one-channel
Kondo (1CK) and two-channel Kondo (2CK) fixed points in a quantum dot coupledto edge states of interacting 2D topological insulators (2DTI) with Luttinger parameter0<K<1. For K<1, the strong coupling 2CK fixed point was argued to be stable forinfinitesimally weak tunnelings between dot and the 2DTI based on the simple
scaling dimensional analysis. We re-examine the model beyond the scaling dimension
analysis via a controlled 1-loop renormalization group (RG) approach on the effective
Kondo model via bosonization and re-fermionization near the 2CK fixed point. We
find for K<1 the 2CK fixed point can be unstable towards the 1CK fixed point andthe system may undergo a quantum phase transition (QPT) between 1CK and 2CK
fixed points. The QPT in our model comes as a result of the combined Kondo and thehelical Luttinger physics in 2DTI, and it serves as the first example of the 1CK-2CKQPT accessible by a controlled theoretical approach. We extract quantum critical andcrossover behaviors from various thermodynamical quantities near the quantum criticalpoint.

Silvie Maskova1*, Ladislav Havela1, Aleksandre Kolomiets2, Alexander Andreev3,
Heinz Nakotte4, Joe Peterson4, Yurii Skourski5, Shadi Yasin5, Sergei Zherlitsyn5,
Joachim Wosnitza5 and Khrystyna Miliyanchuk6
1
Department of Condensed Matter Physics, Charles University in Prague, Czech Republic2
Department of Physics, Lviv Polytechnic National University, Ukraine
3
Institute of Physics, ASCR, Czech Republic
4
Department of Physics, New Mexico State University, USA
5
Dresden High Magnetic Field Laboratory, Helmholtz-Zentrum Dresden-Rossendorf, Germany
6
Faculty of Chemistry, Ivan Franko National University, Lviv, Ukraine
Single crystal of U2Ni2Sn and polycrystals U2(Ni1-xFex)2Sn and their hydrides were prepared so as to investigate
the character and stability of magnetism in U2Ni2Sn (antiferromagnet with TN = 26 K). We show that its
magnetism is uniaxial, with 3 metamagnetic transitions detected in magnetic fields up to 60 T along the tetragonal
c-axis. Such anisotropy manifests also in the paramagnetic state. Estimated difference of paramagnetic Curie
temperatures, 175 K, quantifies the anisotropy. The AF order disappears rapidly with the Fe substitution.
Magnetic susceptibility and specific heat of the sample with 20 % Fe reveals a great similarity to previously
studied NFL heavy-fermion U2Co2Sn [1]. The C/T upturn at low temperatures, very resistant to magnetic fields,
is suppressed with further increase of Fe concentration. Exposure to 100 bar H2 leads to the H-absorption forming
U2(Ni,Fe)2SnH2-x. U2Ni2SnH1.8 is AF (TN = 87 K), which is at least partly due to the lattice expansion (ΔV =7-10%). In the middle of the Fe concentration range, hydrogenation induces a ferromagnetic order. A detailed
study of the Fe-poor end, for which the approach to the NFL behaviour can be followed, is under way.
[1] J.S. Kim et al., Phys. Rev. B 62 (2000) 6986.

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The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

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poster Presentation

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Magnetic phase diagram of UCoAl

Transport properties of Ho1-XLuXB12 solid solutions

Magnetic orderings at the interface between Mott insulator and band
insulator

Phonon Induced Thermodynamic Properties of La1-xCaxCoO3

Tatsuma D. Matsuda1, Dai Aoki2, Naoyuki Tateiwa1, Etsuji Yamamoto1, Yoshinori
Haga1, Yoshichika Onuki3, Jacques Flouquet2 and Zachary Fisk4
1
ASRC, JAEA, Japan2
INAC/SPSMS, CEA-Grenoble, France
3
Graduate School of Science, Osaka University, Japan
4
University of California, USA

Slavomir Gabani1*, Ivan Batko1, Marianna Batkova1, Karol Flachbart1, Emil Gazo1,
Gabriel Pristas1, Iveta Takacova1, Alexey Bogach2, Nickolay Sluchanko2 and Natalya
Shitsevalova3
1
Centre of Low Temperature Physics, Institute of Experimental Physics SAS, Slovakia
2
General Physics Institute RAS, Russia
3
Institute for Problems of Materials Science NASU, Ukraine

Heavy fermion UCoAl is known to be a unique system with metamagnetic transition
from paramagnetic to ferromagnetic ground states in uranium-based compounds. Thiskind of metamagnetism and quantum criticality in strongly correlated electron systems
have attracted much attention because of expectation of new quantum phases. Recently,
we succeeded to grow a high quality single crystal of UCoAl by the Czochralski
pulling method and performed the magnetic measurements. In this presentation, we
will show the magnetic phase diagram of UCoAl in detail.

Recent studies of Ho1-xLuxB12 solid solutions have shown [1] that the antiferromagnetic(AF) order in geometrically frustrated system of HoB12 (x = 0, TN = 7.4 K) is linearlysuppressed to zero temperature, i.e. TN → 0, as lutetium concentration increases tox → xC 0.9. In this contribution, we present original results of electrical resistivity
measurements on Ho1-xLuxB12 single crystalline samples with x = 0, 0.2, 0.5, 0.7, 0.9, 1
in the temperature range 0.05 - 300 K and in magnetic fields (B) up to 8 T. Complex B
vs TN phase diagrams were received from precise temperature and field dependencesof resistivity with more AF phases for x ≥ 0.5 pointing to a possible quantum criticalpoint at xC 0.9. The scattering of conduction electrons in the AF phase and in theparamagnetic phase as well as Hall effect results are analyzed and discussed for various
concentrations x, when magnetic dilution increases with the increasing content of
nonmagnetic Lu ions in the Ho1-xLuxB12 system.

Recent experimental progress in crystal growth techniques enables us to investigate the complex oxide
hetrostructures as a new frontier for studies of strongly correlated electron systems. In such systems,
the main interest is put toward the metallic state around the interface, which is realized between
two different insulating compounds, such as SrTiO3/LaTiO3 and SrTiO3/LaAlO3 [1]. Intriguingly,
magnetism and superconductivity are also reported in such metallic interfaces [2]. Stimulated by thesefindings, we theoretically study the magnetic properties of the strongly correlated heterostructurecomposed a Mott insulator and band insulators. For this purpose, the single-band Hubbard modelwith long-range Coulomb interaction is investigated using the Hartree-Fock approximation [3]. We
find the electronic and magnetic phases specific to the interface, including a canted anttiferromagnetic
state and a charge-ordered state with checkerboard charge distribution. We elucidate the origin of
these phases is closely related to the spatial inhomogeneity which induces unconventional couplings
between spin and charge degrees of freedom. Additionally, the applied magnetic fields also reveal
other aspects of correlated heterostructures; a first order metamagnetic transition and field-induced
checkerboard charge-ordered state, which are also driven by the non-uniform charge distribution.

[1] S. Gabani, I. Batko, M. Batkova, K. Flachbart, E. Gazo, M. Reiffers, N. Shitsevalova, K.
Siemensmeyer and N. Sluchanko, 17th International symposium on boron, borides and relatedmaterials, Sept 11-17, 2011, Istanbul, Turkey.

[1] A. Ohtomo, et al., Nature 419, 378 (2002), A. Ohtomo, and H. Y. Hwang, Nature 427, 423 (2004).
[2] A. Brinkman, et al., Nat. Mater. 6, 493 (2006), J. Biscaras, et al., Nat. Commun. 1, 89 (2010). [3]Okamoto, and Millis, Phys. Rev. B 70, 075101 (2004).

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Renormalization-group exponents for competitions between interelectronic and phonon-mediated interactions in ladder systems

Low temperature thermal and electrical transport properties of ZrZn2
in high magnetic field

Strong Electron Correlation in Cu-doped CaO Nanocolloid

Dynamical antiferromagnetic phase transition after the quantum
quench in the fermionic Hubbard model

Wen-min Huang1*, Yiwei Cai2 and Hsiu-hau Lin2
1
Physics Division, National Center for Theoretical Sciences, Taiwan
2
Department of Physics, National Tsing Hua University, Taiwan

Yang Zou1*, Michael Sutherland1, Stephen Hayden2 and F. Malte Grosche1
1
Department of Physics, University of Cambridge, United Kingdom
2
Department of Physics, University of Bristol, United Kingdom

After developing a scaling ansatz for electron-electron interactions underrenormalization group transformation[1], we show that, with the inclusion of phononmediated interactions the ansatz, characterized by the divergent logarithmic length anda set of renormalization-group exponents, also works rather well. The superconducting
phases in a doped two-leg ladder are studied and classified by these renormalizationgroup exponents as demonstration. Finally, nontrivial constraints among the exponents
are derived and explained.

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[1] H.-Y. Shih, W.-M. Huang, S.-B. Hsu and H.-H. Lin, Phys. Rev. B 81, 121107(R) (2010).

Suguru Ueda1*, Norio Kawakami1 and Manfred Sigrist2
1
Department of Physics, Kyoto University, Japan
2
Theoretische Physik, ETH Zurich, Switzerland

Nguyen Thuy Trang1, Pham Thanh Cong2, Hoang Nam Nhat3*
1
Faculty of Physics, Vietnam National University, University of Natural Sciences, VietNam
2
Physikalisches Institut, Goethe-Universitat Frankfurt, Germany
3
Faculty of Technical Physics and Nanotechnology, Vietnam National University,
University of Engineering and Technology, Viet Nam
Theoretical prediction of magnetism induced by defects or doping in non-metallic
colloids has gained a renewed interests recently. In this work, we investigated thepossible appearance of magnetism in Cu doped CaO nanocolloids activated by
SPAN-80 in the framework of density functional theory (DFT). Despite of strong
antiferromagnetic super-exchange interaction between Cu2+ ions, the local magnetic
moment of Cu may appear due to colloidal agent attachment onto the surface of CaO
nanocluster (surface modification). The ferromagnetism attributes to the degenerationof Cu 3d orbitals in CaO crystal fields, the aspects of electron correlation and quantum
spin fluctuation.
PACS number: 42.30.R, 42.40.Ht, 42.30.Kq
Keywords: DFT, band-gap, CaO, calcium-oxide, mBJ, PBE, functional

Rasna Thakur*, Rajesh K. Thakur and N.k. Gaur
Department of Physics, Barkatullah University, Bhopal, India

Perovskite type cobaltate, La1-xCaxCoO3 (0 ≤ x ≤ 0.3) have been studied intensively
because of their wide range of unique physical properties. The fact that rare-earth
perovskite-type cobaltate are most suitable as a cathode material in solid oxide fuelcells (SOFC), makes the thermal behavior of these compounds highly important. As
these compounds are predominantly ionic in nature hence the lattice contributions tothe specific heat at constant volume (Cv(lattice)) of pure and Ca doped LaCoO3 has beenstudied and thereby thermal expansion is computed as function of temperature bymeans of Rigid Ion Model (RIM). We have systematically investigated the effect ofphonons on thermal properties, Debye temperature (θD), molecular force constant (f),Reststrahlen frequency (υ), cohesive energy (φ), and gruneisen parameter (γ) for La1xCaxCoO3 (0 ≤ x ≤ 0.3). Also the effect of phonons on the bulk modulus is studied
using the atoms in molecules (AIM) theory for pure and ca doped LaCoO3. We havefound that the computed properties reproduce well with the available experimental
data, implying that RIM represents properly the perovskite cobaltate La1-xCaxCoO3 (0≤ x ≤ 0.3). To our knowledge some of the properties for these complicated compounds
are reported for the first time.

July 12 (Thu)

July 12 (Thu)poster Presentation

Naoto Tsuji* and Philipp WernerInstitute for Theoretical Physics, ETH Zurich, Switzerland

Spontaneous symmetry breaking is a universal concept in physics that stretches widelyfrom condensed matter to cosmology. Recently it is getting feasible to study in detail
how symmetry is dynamically broken in correlated electron systems using an ultrafast
optical spectroscopy technique [1], which works as a key probe for electron correlationand fluctuations. Theoretically the phenomenon has been discussed with the GinzburgLandau (GL) theory, a macroscopic phenomenology. To capture the evolution of
the electronic structure, however, one needs a microscopic description, which is notwell understood. Here we take the fermionic Hubbard model, a typical microscopic
model for correlated electrons, and study how the antiferromagnetic order develops
from a paramagnetic initial state after the quantum quench using the nonequilibrium
dynamical mean-field theory. The system shows a multistep time evolution: (i) a fast
thermalization within the paramagnetic phase, (ii) an exponential growth of the orderparameter, and (iii) decay of collective excitations. We show how these features arereflected in the single-particle and optical-conductivity spectrum, and discuss thenature of antiferromagnetic fluctuations.
[1] R. Yusupov et al., Nat. Phys. 6, 681 (2010).

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Crystal Growth and Magnetic Order of Ni-doped CePdAl

Non fermi liquid behaviour in YFe2Ge2

The book-keeping fermion analysis of the double exchange model with
antiferromagnetic background

Itinerant magnetism in the hubbard model within the dynamicalcluster approximation

Veronika Fritsch1*, Sarah Woitschach2, Oliver Stockert2, Michael M. Koza3, Silvia
Capelli3 and Hilbert V. Loehneysen4
1Physikalisches Institut, Karlsruher Institut fuer Technologie, 76131 Karlsruhe,
Germany
2
Max-Planck-Institut fuer Chemische Physik fester Stoffe, 01187 Dresden, Germany
3Institut Laue-Langevin, 38042 Grenoble, France
4
Physikalisches Institut and Institut fuer Festkoerperphysik, Karlsruher Institut fuer
Technologie, 76131 Karlsruhe, Germany
CePdAl is a stoichiometric, antiferromagnetic compound (Neel temperature = 2.7 K) which
can be tuned to a quantum critical point (QCP) by hydrostatic [T. Goto et al., J. Phys. Chem. of
Solids 63, 1159 (2002)] or chemical pressure [Y. Isikawa et al., J. Phys. Soc. Jpn. 65, 117 (1996)].
The latter can be achieved by substituting Ni for Pd. Neutron-scattering experiments [A. Doenni
et al., J. Phys.: Condens. Matter 8, 11213 (1996)] pointed towards a partial frustration of the Ce
moments in CePdAl, making this system a promising candidate for investigating the influenceof frustration on quantum criticality. We have grown large single crystals of Ni-doped CePdAlby the Czochralski method. The samples were characterized by x-ray powder diffraction, atomic
absorption spectroscopy and x-ray Laue diffraction. Specific heat and inelastic neutron scattering
data of CePdAl yield a Kondo temperature of approximately 5 K. Magnetization measurements
display a strong magnetic anisotropy which is preserved in the Ni-doped compounds, where
the magnetic order is suppressed. Neutron-diffraction experiments indicate that short-range
correlations are present well above the Neel temperature. Below the Neel temperature, one thirdof the Ce moments display short-range order only, confirming the frustration in this system.

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The 19th International Conference on Magnetism

Yang Zou*, Zhuo Feng, Sven Friedemann and F. Malte Grosche
Department of Physics, University of Cambridge, United Kingdom

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Kyohei Nakano1*, Robert Eder2, Yukinori Ohta1 and Piotr Wrobel3
1
Department of Physics, Chiba university, Japan
2
Institute for Solid State Physics, Karlsruhe Institute of Technology, Germany
3Institute for Low Temperature and Structure Research, Poland

We analyse the double exchange model with antiferromagnetic background by the
book-keeping fermion method. First, we consider the motion of a single conduction
electron. We assume that the localized spins form the Neel state and the added
conduction electron forms only three types of states under the strong Hund-couplingassumption and we regard these states as the book-keeping fermion. Under theseassumptions, we calculate the spectral functions which show good agreement with theresults given by the exact diagonalizations for finite size clusters. We also study the
relation between the strength of the Hund coupling and the bandwidth in the lowerenergy region. The results show that the bandwidth approaches a finite value as theHund-coupling constant becomes close to infinity. The bandwidth even increases withincreasing the Hund coupling, which is in strong contrast to the expectation from thesemi-classical theory. Next, we consider the situation where there are finite numbers of
spin flips occurring in the down-spin sublattice in the Neel ordered state. Considering
the effects of the spin defects, we add a new book-keeping fermion and estimate theenergy of the spin defects by a perturbation theory. This theory gives the phase diagramcomparable with the numerical results.

Unjong Yu*
GIST college, Gwangju Institute of Science and Technology, Korea

There have been a lot of efforts to understand the itinerant magnetism because
ferromagnetism in many metallic magnets like iron, cobalt, and nickel is due to theitinerant magnetism. However, the mechanism and the stability of the itinerant magnetism
are not clear yet because the strong quantum mechanical correlation in time and space is
crucial in the itinerant magnetism. The Stoner model, which is the most popular model forthe itinerant magnetism, ignores those correlation effects and so is inadequate [1]. In thispaper, we studied the itinerant magnetism within the dynamical mean-field theory (DMFT)
and its cluster extension, dynamical cluster approximation (DCA). These two methods
are non-perturbative and fully include strong correlation effects [2]. Particularly, the DCA
incorporates spatial correlation (nonlocal effects) systematically and gives numericallyexact solution for the many-body problem [3]. We applied these two methods to study theferromagnetic and antiferromagnetic instability of the Hubbard model in the 2-dimensionalsquare lattice, the 3-dimensional cubic lattice, and the face-centered-cubic (fcc) lattice. We
show that the correlation in time and space reduces the critical temperature remarkably
and is essential to understand the itinerant magnetism.
[1] N. Majlis, The Quantum Theory of Magnetism, 2nd ed. (World Scientific Publishing, Singapore,2007), pp. 195-237. [2] D. Vollhardt et al., in Band-Ferromagnetism, edited by K. Baberschke et al.
(Springer-Verlag, Berlin, 2001), p. 191. [3] U. Yu et al., Phys. Rev. Lett. 104, 037201 (2010).

July 8-13, 2012 Busan, Korea

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poster Presentation
RF07

RF10

RF13

RF16

First Principles DFT+U Method for Strongly Correlating Electronic
Structure Systems

Spin-nematic and -singlet states in the Mott insulator phase of the S=1
two-dimensional Bose-Hubbard model

Spin-spectral-weight distribution and energy range of the parent
compound La2CuO4Magnetic properties of GdFe11Ti via first principal calculations.

First principles density functional+U pseudopotential (DFT+U PP) method freefrom any empirical parameters has been developed and applied to the electronic
structure calculations of strongly correlating electronic structure systems such as
FeO and LaVO3. The method can calculate the electronic structure of the systems
from first principles, being contrary to the conventional DFT+U PP method, whichuses empirical Ueff paramaters. The method primary calculates the Hubbard on-site
interaction parameter Ueff for localized electrons, using an approximate constrained
DFT technique, and then uses the calculated parameter in the DFT+U PP electronic
structure calculation. Examples of calculations resulted in Ueff of Fe 3d electrons ofanti-ferromagnetic FeO to be 5.11 eV (the empirical value is 5eV) and Ueffs of La
4f and V 3d electrons of paramagnetic LaVO3 to be 15.6 and 0.47 eV, respectively(the empirical values are 20.0 and 0 eV, respectively). The band gap structure ofthese materials was correctly described. Our method seems to be a promising toolfor investigating strongly correlating electronic structure systems for spintronics
applications, correctly describing the localized and itinerant nature of electrons of thesystems from first principles.

Because of the recent development in experimental cold-atom physics, a quantum gas microscope technique
has opened the door for detecting and manipulating single bosonic atoms at single site level in an opticallattice, just like scanning tunneling microscopy in solid-state physics. Quite recently, Endres et al [1]. used thistechnique to track the superfluid-Mott insulator (SF-MI) transition of spinless bosonic-atoms on an opticallattice in more detail, and found that correlated pairs of a doubly populated site and an unpopulated site which
representing the excitations in the MI, fundamentally determine the properties of the SF-MI transition, whichis consistent with recent numerical studies [2,3]. Theoretically, spin-1 bosonic atoms on a two-dimensionallattice is also of prime importance because it is a bosonic analogue of the two-dimensional fermionic (S=1/2)
Hubbard model, which has been exhaustively studied in the context of magnetism and high-temperature
superconductivity. Thus in this work, we study the ground state properties and quantum phase transitions of
S=1 two-dimensional Bose-Hubbard model, focusing on correlated pairs excitations based on a variational
Monte Carlo approach. We discuss the spin-structures in the MI, and present a consistent description of thetransition from the spin-nematic state to the spin-singlet state beyond mean-field theory.

The spectral-weight distribution in recent neutron scattering experiments on the parent
compound La2CuO4 (LCO) [1], which are limited in energy range to about 450 meV,is studied in the framework of the Hubbard model on the square lattice [2]. We findthat the higher-energy weight extends to about 566 meV and is located at and near
the momentum [pi,pi]. Our results confirm that the U/t value suitable to LCO is in therange between U/t=6 and U/t=8. The continuum weight energy-integrated intensity
vanishes or is extremely small at momentum [pi,0]. This behavior of the intensity is
consistent with that of spin waves, which are damped at [pi,0]. Our study combines
a number of theoretical and numerical approaches, including, in addition to standard
treatments [3], a new spinon approach for the spin excitations [4,5] and density matrix
renormalization group (DMRG) calculations for Hubbard cylinders [6].

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Correlation effect in ferromagnetic 3d transition metals

Dynamical instability in two-component bosonic systems in an opticallattice

J1J2 anti-ferromagnetic heisenberg model on bilayer honeycomb lattice

Muneyuki Nishishita1, Sudhakar Pandey2 and Dai Hirashima1*
1
Nagoya University, Japan
2
APTPC, Korea

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Yuta Toga1, Hiroki Tsuchiura1, Makoto Yamashita2 and Hisatoshi Yokoyama3
1
Department of Applied Physics, Tohoku University, Japan
2
NTT Basic Research Laboratories, NTT Corporation, Japan3
Department of Physics, Tohoku University, Japan[1]M. Endres, M. Cheneau, T. Fukuhara, C. Weitenberg, P. Schauß, C. Gross, L. Mazza, M. C. Banuls, L. Pollet, I.
Bloch, and S. Kuhr, Science 334 (2011) 200. [2] M. Capello, F. Becca, M. Fabrizio, and S. Sorella, Phys. Rev.
Lett. 99 (2007) 056402; Phys. Rev. B 77 (2008) 144517. [3] H. Yokoyama and M. Ogata, J. Phys. Chem. Solids
69 (2008) 3356; H. Yokoyama, T. Miyagawa, and M. Ogata, J. Phys. Soc. Jpn 80 (2011) 084607.

Rui Asaoka1, Yuta Toga1, Hiroaki Tsuchiura1 and Makoto Yamashita21Depertment of Applied Physics, Tohoku University, Japan
2
NTT Basic Research Laboratories, NTT Corporation, Japan

Because of the recent development in experimental technique, there has been an emerging
interest in dynamical properties of Bose-Einstein condensates (BEC) on an optical lattice.
In particular, quantum gas microscope technique has opened the door for real-timeobservation of single bosonic atoms at single site level in an optical lattice, which can act
as scanning tunneling microscopy in solid state physics. Quite recently, Greiner and his
co-workers used this technique to track the superfluid-Mott insulator (SF-MI) transitionof bosonic-atoms in real-space and time [1,2]. Further studies for dynamical propertiesof BEC may be only a matter in time. Dynamical analysis of BEC in strongly correlatedbosonic systems is also of interest in theoretical point of view. In particular, the dynamical
instability of SF in multi-component bosonic systems is of prime importance because
there would be entangled interplay among superfluidity, Mott physics, and possibly also
Anderson localization. Thus, in this work, we study the dynamical instability of the SF
phase of the two-component Bose-Hubbard model based on the dynamical Gutzwiller
approximation. We mainly focus on the effects of the dispersive current of one-component
on the stability of SF current of another component.

Jose Carmelo1, Miguel Araujo2, Steven White3 and Maria Sampaio1
1
Departament of Physics, University of Minho, Portugal
2
Departament of Physics, University of Evora, Portugal
3
Departament of Physics, University of California, USA

E. E. Kokorina*, M. V. Medvedev and I. A. Nekrasov
Laboratory of Theoretical Physics, Institute of Electrophysics, Russia

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[1] - N. S. Headings, S. M. Hayden, R. Coldea, and T. G. Perring, Phys. Rev. Lett. 105, 247001 (2010).
[2] - M. A. N. Araujo, J. M. P. Carmelo, M. J. Sampaio, and S. R. White, cond-mat.str-el.1201.5940.
[3] - N. M . Peres and M. A. N. Araujo, Phys. Rev. B 65, 132404 (2002). [4] - J. M. P. Carmelo,
Nucl. Phys. B 824, 452 (2010); Nucl. Phys. B 840, 553 (2010), Erratum. [5] - J. M. P. Carmelo,Ann. Phys. 327, 553 (2012). [6] - S. Yan, D. A. Huse, and S. R. White, Science 332, 1173 (2011).

Mojtaba Shoja Shabankah and Farhad Shahbazi
Physics, Isfahan University Of Technology, Iran

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July 12 (Thu)Tomoyuki Hamada1, Takahisa Ohno2 and Sadamichi Maekawa3
1
Central Research Laboratory, Hitachi Ltd., JST-CREST, Japan
2
National Institute of Materials Research, Japan
3
ASRC, JAEA, JST-CREST, Japan

July 12 (Thu)poster Presentation

Mott transition of ultracold Fermi-Fermi mixtures in optical lattices

Takahiro Ooi* and Seiichiro Suga
University of Hyogo, Japan

Recent experiment on spin-3/2 bilayer honeycomb lattice antiferromagnet Bi3 Mn4O12 (NO3) shows a spin liquid behavior down to very low temperatures. This behavior
can be ascribed to the frustration effect due to competitions between first and second
nearest neighbor antiferromagnet interaction. Motivated by the experiment, we study
J1J2Antiferromagnet Heisenberg model, using Mean field theory and Monte Carlosimulation. This calculation shows highly degenerate ground state. We also calculate
the effect of second nearest neighbor through z direction and show these neighbors
also increase frustration in these systems. In addition calculation of the effect of third
nearest neighbor shows that this interaction can lift the degenerate ground state to four
discrete states. The next step of these calculations is to consider quantum effect of theseinteractions by Word line quantum Monte Carlo method.

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[1] S. Okumura, H. Kawamura, T. Okubo, Y. Motome J. Phys. Soc. Jpn. 79, 114705 (2010) [2] J.
N. Reimers, A. J. Berlinsky, and A.-C. Shi , Phys. Rev. B 43, 865-878 (1991) [3] Hem C. Kandpal
and Jeroen van den Brink, PHYSICAL REVIEW B 83, 140412(R) (2011) [4] M Azuma, M Matsuda,
N Onishi, S Olga, Y Kusano, M Tokunaga, Y Shimakawa and N Kumada, Journal of Physics:
Conference Series 320 (2011) 012005. [5] L. Balents, Nature (London) 464, 199 (2010).

[1] W. S. Bakr et al., Science 329, 547 (2010). [2] M. Endres et al., Science 334, 200 (2011).

RF09

RF12

RF15

RG01

Mott transition in frustrated Hubbard model with spatial anisotropy:
Cellular dynamical mean field study

Mechanism for the high Neel temperature in SrTcO3

A hybrid exchange density functional study of La1-xCaxMnO3

Anisotropy in a high Landau level due to effective electron-electroninteractions

Tomoko Kita1*, Yuta Furukawa1, Takuma Ohashi2 and Norio Kawakami1
1
Department of Physics, Kyoto University, Japan2
Department of Physics, Osaka University, Japan

Geometrical frustration has attracted much interest in the field of strongly correlated
electron systems. In the frustrated systems, a lot of intriguing phenomena such as
the heavy fermion behavior in LiV2O4, spin liquid ground state in organic materials,
etc. have been observed and they have stimulated theoretical investigations offrustrated electron systems. In particular, the reentrant behavior in the Mott transitionin moderately frustrated systems, the heavy Fermi-liquid behavior around the Mott
transition, etc. are new aspects of the Mott transition and very interesting. In our recent
study on the kagome lattice system with spatial anisotropy [1] and also Ref. [2], it has
been found that the anisotropy is strongly enhanced around the Mott transition, which
stabilizes antiferromagnetic spin configurations. In this study, we apply the cellular
dynamical mean field theory combined with a continuous-time quantum Monte Carlosolver [3] to the Hubbard model on the anisotropic kagome and triangular lattices.
We systematically investigate the effects of the enhanced anisotropy around the Mott
transition on the quasiparticle spectra and spin correlation functions.
[1] Y. Furukawa et al.: Phys. Rev. B 82 (2010) 161101. [2] A. Yamada et al.: Phys. Rev. B 83 (2011)
195127. [3] G. Kotliar et al.: Phys. Rev. Lett. 87 (2001) 186401; P. Werner et al.: Phys. Rev. Lett. 97(2006) 076405.

270

The 19th International Conference on Magnetism

Ashis Kumar Nandy1, S. Middey1, Priya Mahadevan2* and D. D. Sarma3
1
Centre for Advanced Materials, Indian Association for the Cultivation of Science,
India
2
S.N. Bose National Centre for Basic Sciences, India
3
Solid State and Structural Chemistry Unit, Indian Institute of Science, India
The microscopic origin [1] of the high Neel temperature observed experimentallyin SrTcO3 [2] and CaTcO3 [3] has been examined using a combination of ab-initio
electronic structure calculations and mean-field solutions of a multi-band Hubbard
model. The G-type anti-ferromagnetic state is found to be robust for a large regionof parameter space, with large stabilization energies found, surprisingly, for smallvalues of intra-atomic exchange interaction strength as well as large bandwidths.
The microscopic origin of this is traced to specific aspects associated with the d3
configuration at the transition-metal site. Considering values of interaction strengths
appropriate for SrTcO3 and the corresponding 3d oxide SrMnO3, we find a ratio of 4:1
for the Neel temperatures as well as magnitudes consistent with experiment.
1. S. Middey, Ashis Kumar Nandy, Priya Mahadevan, D.D. Sarma, arXiv:1112.5587 2. E. E.
Rodriguez et. al., Phys. Rev. Lett. 106, 067201 (2011). 3. M. Avdeev et. al., J. Am. Chem. Soc. 133,
1654 (2011).

Romi Kaur Korotana1, Leandro Liborio1, Giuseppe Mallia1, Zsolt Gercsi2 andNicholas Harrison1
1
Chemistry, Imperial College London, United Kingdom
2
Physics, Imperial College London, United Kingdom
Manganites exhibit a rich variety of crytallographic, electronic and magnetic properties[1] manifested in ferromagnetic-, antiferromagnetic (collinear and canted)-, metallic-,
insulating-,charge- and orbital-ordered states. An insight into the competition and coupling
between various degrees of freedom in doped manganites is of interest for the optimisationof the magnetocaloric effect [2, 3] in such materials. In this work, hybrid-exchange density
functional theory (DFT) calculations have been carried out to determine the effects of A-site
doping on the structural, electronic and magnetic properties of perovskite-type manganites
La1-x Ax MnO3 , where A=Ca and x=0, 0.25, 0.50, 0.75 and 1. A magnetic stability plot forLa1-x Cax MnO3 is complied, in which the ferromagnetic (F), antiferromagnetic A-type (A-AF),G-type (G-AF) and C-type (C-AF) configurations are considered. At this level of theory, thestructural, magnetic ground states and electronic states at each of the compositions studied
are compared to available experimental data. This provides a basis for a first principles
description of the magnetocaloric effect in La1-x Cax MnO3 systems.
[1] J. B. Goodenough, in Handbook on the Physics and Chemistry of Rare Earths, vol 33, edited by K. A.
Gschneidner, Jr. et al. (Elsevier 2003), p. 249. Elsevier, Amsterdam (2003). [2] V. K. Pecharsky and K. A.
Gschneidner, Jr., J. Magn. Magn. Mater., 200, 44 (2002). [3] A. M. Tishin, in Handbook of Magnetic
Materials, edited by K. H. J. Buschow (North Holland, Amsterdam, 1999), Vol. 12, pp. 395-524.

Orion Ciftja
Prairie View A&M University, USA

Quantization of Hall resistivity in strongly correlated two-dimensional electronicsystems at high magnetic fields generally indicates the stabilization of novel electronic
quantum liquid phases of matter. This is the nature of the integer and fractional
quantum Hall states that stabilize at integer and fractional odd-denominator (notalways, though) filling factors of the Landau level. Away from certain filling factorsthat represent quantum Hall liquid states, different phases, some of them withunusually high magneto-transport anisotropy have been known to stabilize specially inhigh Landau levels. In this work, we try to understand the anisotropy of such quantum
phases in terms of effective electron-electron interaction potentials. To this effect, we
implement a full projection of the original Coulomb interaction potential in the suitable
Landau level. We find out that, in high Landau levels, thus for relatively weak magnetic
fields, a semi-classical description of the interaction potential between electrons appear
to be an adequate choice. The features of this semi-classical interaction potential inthis limit suggest ways how the energetic balance between density waves and/or liquid
crystalline phases might be sensitively affected.
[1] R. B. Laughlin, Phys. Rev. Lett. 50, 1395 (1983). [2] P. K. Lam and S. M. Girvin, Phys. Rev. B.
30, R473 (1984). [3] O. Ciftja and C. Wexler, Phys. Rev. B 67, 075304 (2003).

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poster Presentation
RG02

RG05

RG08

RG11

Bipolaron-Bipolaron interaction in many electron Holstein-Hubbard
modelElectronic Structure of ternary stannides RRu4Sn6 (R=Y, La, Pr, Ce,and Gd) compounds

Nonequilibrium states and I-V characteristics in one-dimensional bandand Mott insulators attached to electrodes

Multipole moments at Pr-site and electric field gradients at Sb-site in
PrOs4Sb12

Nonequilibrium states induced by an applied bias voltage (V) and the corresponding
current-voltage characteristics of one-dimensional models describing band and Mott
insulators are investigated theoretically by using nonequilibrium Green's functions[1].
We attach the models to metallic electrodes whose effects are incorporated into theself-energy. Modulation of the electron density and the scalar potential coming fromthe additional long-range interaction are calculated self-consistently within the Hartree
approximation. For both models of band and Mott insulators with length L_C, the bias
voltage induces a breakdown of the insulating state, whose threshold shows a crossover
depending on L_C[2]. It is determined basically by the bias V_{th}~Δ for L_C smaller
than the correlation length ξ=W/Δ where W denotes the bandwidth and Δ the energy
gap. For systems with L_C≫ξ, the threshold is governed by the electric field, V_{th}/L_C, which is consistent with a Landau-Zener-type breakdown, V_{th}/L_C∝Δ^2/
W. We demonstrate that the spatial dependence of the scalar potential is crucially
important for this crossover by showing the case without the scalar potential, where thebreakdown occurs at V_{th}∼Δ regardless of the length L_C.

PrOs4Sb12 is well known as an unusual superconductor with Tc = 1.85 K [1]. The
superconductivity might be related with the multipole moments of 4f2 electrons of Pr,
because the antiferro-quadrupole ordering is realized under applied magnetic fields[2]. So, it is important to study a role of the multipole moments of Pr to make clear thesystem of unusual superconductor PrOs4Sb12. The NQR frequency at Sb site shows
temperature dependence corresponding to the crystalline electric field splitting below
10 K, associated with the Pr3+^(4f2)-derived ground state [3]. This experimental result
suggests that the change of multipole components affect the electronic field gradients(EFG) at Sb-site. The LDA + U calculations have described the Fermi surfaces of
PrOs4Sb12 well [4]. It has been shown that EFG at Sb-site can be calculated by using
an FLAPW method and the calculated EFG reproduce well the experimental NQR
frequency [5]. Moreover, the multipole moments of Pr can be classified from thedensity matrix, which is used in the LDA + U method. we have analyzed how each
multipole component affects the EFG at Sb-site. Then we discuss the relationshipbetween multipole moments at Pr-site and EFG at Sb-site.

[1] K. Yonemitsu, J. Phys. Soc. Jpn. 78 (2009) 054705. [2] Y. Tanaka and K. Yonemitsu, Phys. Rev.
B 83 (2011) 085113.

[1] E. D. Bauer et al., Phys. Rev. B 65 (2002) 100506. [2] M. Kohgi et al., J. Phys. Soc. Jpn. 72 (2003)
1002. [3] M. Yogi et al., Phys. Rev. B 67 (2003) 180501(R). [4] H. Sugawara et al., Phys. Rev. B 66
(2002) 220504(R). [5] H. Harima, Physica B 378-380 (2006) 246.

Polarons and bipolarons have been long-term subjects of interest in many areasof condensed matter. The Holstein model describing the strong electron-phonon
interaction and the Hubbard model describing the strong electron-electron interaction
have played pivotal roles in various important physical systems, such as high Tc
superconductors and the CMR manganites. In real systems, the polaron-polaron andpolaron-bipolaron interactions might be of crucial importance. In order to investigate
the physics of polaron and bipolaron systematically, we have studied the combined
Holstein-Hubbard model treating both the electron-phonon and the electron-electroninteraction on an equal footing. We present our study on polaron-bipolaron andbipolaron-bipolaron interactions as a function of the electron-phonon coupling strengthand the electron-electron interaction U . We have calculated the ground state energy
and wave functions of the system by applying the conjugate-gradient technique ona variationally constructed basis. The obtained correlation functions, the bipolaronbinding energy, and the effective mass enables us to capture the intricate mechanisms
at play and their consequences.

Saad Elgazar1, A. M. Strydom1 and P. M. Oppeneer2
1
Physics, Johannesburg University, South Africa
2Physics, Uppsala University, Sweden

We report density functional calculations of the band structure and density of statesof the RRu4Sn6 (M=Y, La, Ce, and Gd) compounds. Our investigation is carriedout within the framework of the local density approximation, using a relativistic,
full-potential band-structure method. For the Ce-146 compound we find that LSDA
calculations predict a semiconducting ordered ground state whereas the othercompounds ordered in metallic states, in accordance with available experimental
measurements .

Takeshi Goho* and Hisatomo Harima
Department of Physics, Kobe University , Nada , Kobe 657-8501, Japan

RG03

RG06

RG09

RG12

Partial disorder in an Ising-spin Kondo lattice model on a triangularlattice

Local correlation effects in Mn doped GaAs

Enhancement of charge ordering by Zeeman effect in one-dimensional
molecular conductors

The effect of pairing fluctuations and disorder on the BCS-BEC
crossoverHiroaki Ishizuka* and Yukitoshi Motome
Department of Applied Physics, University of Tokyo, Japan

Igor Di Marco*, Olle Eriksson and Patrik Thunstrom
Physics and Astronomy - Materials Theory, Uppsala University, Sweden

Partial disorder, that is coexistence of paramagnetic and magnetically ordered sites,
is an intriguing example of exotic orders induced by geometrical frustration [1].
Experimentally, several metallic magnets with a triangular lattice structure, such as
UNi4B and Ag2CrO2, were reported to present such unique order. On the other hand,theoretical attempts to explore the partial disorder in two-dimensional localized spin
systems turned out to be unsuccessful so far; it is fragile against thermal fluctuations[2] and only exists as a quasi-long-range order at most [3]. To explore the possible
realization of the true long-range partially disordered phase in two dimensions, here
we theoretically investigate the effect of the coupling of localized moments to itinerant
electrons in an Ising-spin Kondo lattice model on a triangular lattice. We study the
low-temperature magnetic phases by a real-space Monte Carlo technique. As a result,
we obtained a long-range order of the partially disordered state at finite temperaturesin the vicinity of electron density n=1/3, where a two-sublattice stripe-type order andthree-sublattice ferrimagnetic order compete with each other and an electronic phaseseparation takes place at a lower temperature. Further details on the phase diagram andthe partially disordered phase will be given in the presentation.

WN
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I
W

[1] M. Mekata, J. Phys. Soc. Jpn. 42, 76 (1977). [2] S. Fujiki et al., J. Phys. Soc. Jpn. 53, 1371 (1984).
[3] T. Takagi and M. Mekata, J. Phys. Soc. Jpn. 64, 4609 (1995).

Hideo Yoshioka1, Hitoshi Seo2 and Yuichi Otsuka3
1
Department of Physics, Nara Women's University, Japan
2
Condensed Matter Theory Laboratory, RIKEN, Japan
3
Advanced Institute for Computational Science, RIKEN, Japan

A recent experiment observes increase of resistance with increasing the external
magnetic field in one-dimensional molecular conductor TPP[Co(Pc)(CN)_2]_2 [1]. The
positive magnetoresistance is independent of the direction of the magnetic field, andthen the origin of it is considered to be the Zeeman effect. Therefore, the experimentindicates that charge ordering (CO) is enhanced by the Zeeman effect. Stimulated by
the experiment, we theoretically investigate effect of uniform magnetic field on CO
in one-dimensional extended Hubbard model. In a previous study, the ground statewith coexistence of CO and 2k_F-SDW was investigated, but the amplitude of CO
does not show noticeable enhancement under the uniform magnetic field [2]. In thepresent study, the parameter region where only CO appears is studied. We find thefollowing results; (1) The amplitude of CO shows continuous enhancement under theexternal magnetic field. (2) Enhancement of CO is accompanied by both uniform andstaggered (4 k_F) component of magnetic moment. Our conclusion is consistent withexperimental finding in TPP[Co(Pc)(CN)_2]_2.

Pinaki Majumdar
Harish-Chandra Research Institute, India

A fermi liquid with weak attractive interaction undergoes a BCS transition to asuperconductor with reducing temperature. With increasing interaction strength thetransition temperature displays non-monotonic behaviour as the system heads towards
Bose condensation of preformed pairs. We use a new Monte Carlo tool, incorporating
amplitude and phase fluctuations of the pairing field, to map out this BCS-BEC
crossover in the attractive Hubbard model on large (40 X 40) two dimensional lattices.
Havingestablished this benchmark we discuss the role of disorder in this system. This
includes (i) the role of non-magnetic impurities where we track the superconductor
to insulator transition with increasing disorder, and (ii) the emergence of `gapless'superconductivity, the suppression of T_c, and the induced correlation between
scatterers themselves, in the case of magnetic impurities. Our method reproduces thestandard results in all these cases but allows unprecedented spatial resolution, andaccess to the dynamical response. We compare the results to imaging experiments on
disordered films.

[1] N. Hanasaki et al., J. Phys. Soc. Jpn. 75 (2006) 104743. [2] K. Kishigi and Y. Hasegawa, J.
Phys. Soc. Jpn. 69 (2000) 2145.

RG04

RG07

RG10

RG13

Basis reduction in the exact diagonalization method for the dynamical
mean-field theory

First-principles study on noncollinear magnetism and effects of spinorbit coupling in 5d pyrochlore oxide Cd2Os2O7

Contribution of electron-lattice and spin-orbit coupling to theinsulator-metal transition in VO2 and Sr2IrO4Transport properties of ferromagnetic material with AndersonHubbard centers

The exact diagonalization (ED) method for the dynamical mean-field theory is nearly
the only method to calculate electron spectra involving core levels, such as core-level
photoemission spectra, x-ray absorption/emission spectra, resonant inelastic x-ray
scattering, etc., in a strongly correlated electron systems. In order to overcome theproblem of the exponentially increasing Hilbert-space dimension by the number ofsites, the number of configurational bases for the ED method for the single-impurity
Anderson model is systematically reduced by their perturbative expansion startingfrom the lowest-energy configuration and consecutively allowing the hopping between
an impurity level and a conduction band. Comparison of resulting Green's functions
with exact ones in an imaginary frequency axis shows that bases up to the fourthorder is enough to render reliable results. Since the reduced Hilbert-space dimension
increases according to the power law, the available size of involved sites could begreatly enhanced to simulate core-level-related spectra with a large spin-orbital degreeof freedom.

Recently, increasing attention has been focused on 5d pyrochlore oxides A2B2O7 (B=Ir, Os, etc.) in searchfor unconventional phenomena induced by strong spin-orbit coupling. Cd2Os2O7 is a typical member ofthese compounds. Experimentally, it exhibits a metal-insulator transition at 227 K, below which a Neel orderappears [1]. Despite many experimental attempts, the nature of the low-temperature phase remains to beclarified; e.g., the magnetic structure is unknown. Furthermore, several peculiar properties have been reported
experimentally: (1) The transition temperature is the highest among pyrochlore oxides. (2) No clear charge
gap is seen in the temperature dependence of the resistivity despite the high transition temperature. Motivatedby these experiments, we investigate electronic structure of Cd2Os2O7 [2] using the local spin density
approximation + U method. We use a fully relativistic two-component first-principles computational code
[3] based on the projector augmented-wave method. We show that the so-called all-in/all-out magnetic orderis the most stable in a wide range of U. By analyzing an effective spin model, we show that the local <111>easy-axis anisotropy removes geometrical frustration to stabilize this non-collinear magnetic order. We also
compute the density of states and the electronic band structure and compare the results with experiments.

Mott insulating state in the strongly correlated electron system is often realized incompetition and/or cooperation with interactions other than the on-site Coulomb
repulsion energy, such as the electron-lattice coupling and the spin-orbit coupling．
One of representative examples is VO2 where the electron correlation and the Peierls
instability have been debated as a driving force to realize its metal-insulator transition
near room temperature. Another example is Sr2IrO4 which is now believed to have aspin-orbit-induced Mott insulator ground state. In this presentation, we discuss basedon optical spectroscopy of thin films how the insulating ground states of each systemevolve into the metallic states with a decrease of Peierls instability and the spin-orbit
coupling strength which together can give an insight in to the complex phases instrongly correlated electron system [1,2].

A competition between itinerant behavior and localization effects in strongly
correlated electron system of periodically spaced Anderson-Hubbard centersintroduced into narrow-band metal is studied. The configurational representation for
localized subsystem is used and the effective Hamiltonian is obtained by canonicaltransformation. Besides the spin-spin interactions and strong on-site Coulombinteraction, the model takes into account the hybridization with conduction band which
results in the indirect hopping and indirect exchange interactions. Lattice deformation
under the external pressure is taken into account and equilibrium value of latticestrain is found, having effect on both electrical and magnetic properties of the system.
Green functions for band and localized electrons are calculated. On this base, theenergy spectrum and magnetization are investigated as function of model parameters,
temperature and external pressure. For temperatures close to Curie temperature andpartial filling of conduction band the peculiarities of electronic conductivity are studied.
Concentration dependence of static conductivity exhibits different transport regimes.
Our results show that in the considered model the effects of localization are enhanced
even if external pressure promotes electrical conductivity.

Hyeong-do Kim*
Beamline Division, Pohang Accelerator Laboratory, Korea

Hiroshi Shinaoka, Takashi Miyake and Shoji Ishibashi
Nanosystem Research Institute, National Institute of Advanced Industrial Science andTechnology, Japan[1] A. Sleight et al., Solid State Comm. 14, 357 (1974); D. Mandrus et al., Phys. Rev. B 63, 195104(2001); A. Koda et al., J. Phys. Soc. Jpn. 76, 063703 (2007); Y. H. Matsuda et al., Phys. Rev. B 84,
174431 (2011). [2] H. Shinaoka, T. Miyake, and S. Ishibashi, arXiv:1111.6347. [3] QMAS (Quantum
MAterials Simulator) [http://qmas.jp/].

272

Yasuhiro Tanaka* and Kenji Yonemitsu
Institute for Molecular Science, JapanThe 19th International Conference on Magnetism

July 12 (Thu)Monodeep Chakraborty and B. I. Min
Department of Physics, Pohang University of Science and Technology, Korea

July 12 (Thu)poster Presentation

Jongseok Lee1, K. Shibuya2, Y. Krockenberger2, K. S. Takahashi2, M. Kawasaki3 and Y.
Tokura3
1
Department of Photonic and Applied Physics, Gwangju Institute of Science andTechnology, Korea
2
Cross-Correlated Materials Research Group (CMRG) and Correlated Electron
Research Group (CERG), RIKEN, Japan3
Department of Applied Physics, University of Tokyo, Japan

Yuriy Skorenkyy*, Oleksandr Kramar and Leonid Didukh
Physics Department, Ternopil National Technical University, Ukraine[1] J. S. Lee, Y. Krockenberg, K. Takahashi, M. Kawasaki, and Y. Tokura, Phys. Rev. B 85, 035101(2012). [2] J. S. Lee, K. Shibuya, M. Kawasaki, and Y. Tokura, submitted.

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273

poster Presentation

poster Presentation

RG14

RG17

RH02

RH05

First principles studies of organic charge transfer salts

Magneto-polaronic effects in molecular transistors as the consequenceof quantum uncertainty of the displacement of vibrating quantum dot.

Atomic scale disorder driven bicritical region in Sm0.5(Ca1-xSrx)0.5MnO3

Lifshitz transition with interactions in high magnetic fields: application
to CeIn3

Harald O. Jeschke, Anthony Jacko and Roser Valenti
Institut fur Theoretische Physik, Universitat Frankfurt, Germany

We study a number of BEDT-TTF based charge transfer salts in the framework of abinitio density functional theory and determine the parameters of the effective Hubbard
Hamiltonian describing the low energy excitations[1]. For the spin liquid candidate
kappa-(BEDT-TTF)2Cu2(CN)3, we investigate the question if the structures determinedat various temperatures lead to different effective Hamiltonian representations[2]. For
the Fabre salts (TMTTF)2X, we compare the properties of the underlying Hamiltonian
for a series of different anions X.
[1] H.C. Kandpal, I. Opahle, Y.-Z. Zhang, H. O. Jeschke, R. Valenti, Phys. Rev. Lett. 103, 067007(2009). [2] H. O. Jeschke, M. de Souza, R. Valenti, R. S. Manna, M. Lang, J. A. Schlueter, Phys. Rev.
B 85, 035125 (2012)

Glib A(alexandrovich) Skorobagatko1*, Sergey I. Kulinich2, Ilya V. Krive3 and Robert
I. Shekhter4
1
Department of Theoretical Physics, B.Verkin ILTPE of NAS of Ukraine, Kharkov,
Ukraine2
Department of Theoretical Physics, B.Verkin ILTPE of NAS of Ukraine, Kharkov,
Ukraine3
Department of Theoretical Physics, B.Verkin ILTPE of NAS of Ukraine
4
Department of Physics,, University of Gothenburg, SE-41296, Gothenburg, Sweden
The influence of magneto-polaronic effects induced by the quantum uncertainty ofthe displacement of quantum dot on electron transport through a single-level vibrating
quantum dot subjected to a transverse (to the current flow) magnetic field is considered. It is shown that the effects are most pronounced in the regime of sequential electron
tunneling, where a polaronic blockade of the current at low temperatures and ananomalous temperature dependence of the magnetoconductance are predicted.
1. G. A. Skorobagatko, S. I. Kulinich, I. V. Krive, R. I. Shekhter, and M. Jonson, Low Temp. Phys. 37,
1032 (2011).

Saurav Giri1*, Sk. Sabyasachi1, S. Majumdar1, S. Das2 and V. S. Amaral3
1
Solid State Physics, Indian Association for the Cultivation of Science, India
2
Department of Physics and CICECO, University of Aveiro, Portugal
3
Department of Physics and CICECO, University of Aveiro, India

Pedro Schlottmann*
Department of Physics, Florida State University, USA

On the verge of collapse of charge and orbital ordering a bicritical region occurs in hole doped
manganites which displays rich electronic phase diagrams in R0.5(Ca,Sr)0.5MnO3 [1]. Here,
we demonstrate a fascinating consequence of A-site disorder in intermediate members of a
new series Sm0.5(Ca1-xSrx)0.5MnO3. The Rietveld refinement of X-ray diffraction studies
reveal maximum structural distortions at x = ½. This is indicated by the highest value of ε [=√2b/(a+c), a, b, c being lattice constants] and most deviation of Mn-O-Mn bond-angle from180° compared to end compounds. An unusual behaviour in magnetic field-induced ultrasharp transition to ferromagnetic metallic (FMM) state and collapse of charge ordering isobserved both in magnetization and magnetoresistance curves for intermediate compositions
at much lower field compared to end compounds. When magnetic field is applied above
a critical field, FMM state appears and it retains high-field state, although magnetic field
decreased to zero. With decreasing field sweep rate, the transition shifts to higher fieldindicating a meta-magnetic transition. The atomic-scale local inhomogeneity/distortion arisingfrom the difference in ionic radii and/or the random Coulomb potential from ion mixture is
supposed to be critical behind such striking phenomena.

D

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OV

M

RG15

RG18

RH03

Dynamics of strongly correlated Fermi systems: The efffects of pairexcitations and exchange

Defect states and electron correlations in multi-orbital Mott insulators

11B-NMR study on Shastry Sutherland system TbB4

Martin Panholzer1*, Eckhard Krotscheck2, Helga M Boehm2, Robert Holler2 andThomas Lichtenegger2
1
Johannes Kepler University Linz, Austria
2Institut for Theoretical Physics, Johannes Kepler University Linz, Austria
Understanding the emergent properties of many body systems from the underlying microscopic
interactions is the major goal of condensed matter physics. Recent progress, in the understandingof the dynamics of strongly correlated systems, has been made by approximating the excitedwave function by a superposition of correlated particle-hole and 2-particle-2-hole excitations.
The amplitudes, describing these excitations, are obtained by minimizing the action integral. A
surprising result of this approach is the confirmation/prediction of the reemergence of collectivemode below the PHB in two dimensional 3He for density fluctuations. By including exchange theagreement of the calculated spectrum with the experiment was further improved for 3He. The next
step is to apply this tool to spin-density fluctuations, which are of inherent exchange character. Dueto the proximity of the ferromagnetic phase transition the fluctuations are at very low energies forlong wavelenth. This experimental finding is also present in a first implementation of our theory.
The presented approach is also applicable to other correltated fermi systems e.g. electrons anddipols in two dimensions. We predict this transition of the collective mode seen in 3He also for two
dimensional electrons. The capability in describing these systems is investigated.

Adolfo Avella1*, Peter Horsch2 and Andrzej Oles3
1
Dipartimento di Fisica 'E.R. Caianiello', Universita degli Studi di Salerno, Italy
2
Max Planck Institute for Solid State Research, Stuttgart, Germany
3
Jagellonian University, Krakow, Poland

We address the role played by defects in doped Mott insulators with active orbital
degrees of freedom. We observe that defects are characterized by rather complex
and rich physics which is well captured by a degenerate Hubbard model extended byseveral terms that describe crystal-field splittings, the orbital-lattice coupling, as well
as local terms generated by defects such as the Coulomb potential terms that act bothon a doped hole and orbitals of undoped sites (orbital polarization). We show thatthe multiplet structure of excited states generated in such systems by strong electroninteractions is well described in an optimized unrestricted Hartree-Fock approximation,
taking into account the usual symmetry breaking by the onset of magnetic and orbital
order. More importantly, we show that defect states are responsible for new featuresthat arise within the Mott-Hubbard gap and in the multiplet spectrum at high energy.
These states involve active orbital flavors at atoms b eing nearest neighbors of thedefect state, which are modified by the local defect-orbital Coulomb interactions.
The present study suggests a new mechanism for the Coulomb gap realized in thepresence of defect states and investigates the dependence of the orbitals on the orbital
polarization.

Bohm, H. M., Holler, R., Krotscheck, E. & Panholzer, M. Dynamic many-body theory: Dynamics ofStrongly Correlated Fermi Fluids. Phys. Rev. B 22, 224505 (2010).

In TbB4, the arrangement of Tb ions within the c-plane is topologically equivalent to the
Shastry Sutherland (S-S) lattice with geometrical frustration [1]. A well-known exampleof S-S lattice is SrCu2(BO3)2 which shows the characteristic magnetization plateaus
caused by the frustration. However, in TbB4, due to the quadrupole interaction and
RKKY interaction between classical spins, the appearance of the novel magnetism quite
different from SrCu2(BO3)2 is expected. The magnetization of TbB4 for H // c-axis shows
field-induced multi-step jump while the magnetization in the c-plane on which we focus
attention shows only one large jump at Hc = 15.9 and 12 T for H//[100] and H//[110]respectively [2]. In order to investigate the magnetic structure in high magnetic fields for
H//[100], we performed 11B-NMR experiments up to 17.5T for the single crystalline
TbB4. 11B-NMR spectra observed at low magnetic field changes drastically at Hc = 15.9
T, where the magnetization jump occurs. This result indicates the change of the magnetic
structure at the field-induced magnetic phase transition. In order to determine themagnetic structure, we have compared the observed NMR spectra with the calculation
based on the classical dipole-dipole interaction.

RH01

RH04

The induced effects of the Dzyaloshinskii-Moriya interaction on thethermal entanglement

Magnetism of the noncentrosymmetric compound CeNiC2-pressure
effects

Magnetotransport Property of the Hole-doped Delafossite
CuCr 0.97Mg 0.03O 2 with a Spin-3/2 Antiferromagnetic Triangular
Sublattice

The pairwise thermal entanglement in one-dimensional (1D) spin-1/2 XX model withadded Dzyaloshinskii-Moriya interaction and transverse magnetic field is studied
through fermionization technique. We have showed that, for fields less than quantum
critical point, the thermal entanglement decreases by increasing the temperature andvanishes at a field-independent critical temperature. On the other hand for fields
more than quantum critical value of the magnetic field (Fig. (1)(b)), NN spins are
not entangled at $T=0$. By increasing the temperature from zero, NN spins remainunentangled up to the first critical temperature $T_{c_{1}}(h)$. As soon as thetemperature increases from $T_{c_{1}}$, the thermal entanglement regain andtakes a maximum value and then decrease and reaches to zero at the second criticaltemperature $T_{c_{2}}(h)$.

Susumu Katano*, Toshiaki Kobayashi and Tohru Yoshida
Graduate School of Science and Engneering, Saitama University, JapanThe system RNiC2 (R=Rare-earth element) has a simple but a characteristicalnoncentrosymmetric crystal structure, and shows various novel physical properties suchas charge density waves (CDW) and complex magnetic structures. In the system thecompound of R=La shows unconventional superconductivity, and has been intensively
studied very recently. For CeNiC2 a few reports indicated that the incommensurate
antiferromagnetic state (ICAF) appears at around 20 K and this changes to thecommensurate antiferromagnetic structure (CAF) at about 10 K, then a ferromagnetic
state (F) takes place at around 2 K [1, 2]. However, since there are some clear
discrepancies in these studies the magnetism of this compound has been reinvestigatedin detail using a carefully prepared polycrystalline sample. It is found that there aredefinite magnetic moments in the paramagnetic state. With these moments the complex
antiferromagnetic states undergo, which replaces to a ferromagnetic state at low
temperatures. To investigate these magnetic states further, their pressure effects havebeen studied up to 2.5 GPa. The results show that the IC and CAF states at the higher
temperatures is fairly stable, whose transition temperatures increase at a rate of about 2
K/GPa. On the other hand the F state is changed little.
[1] K. Motoya, et al. J. Phys.Soc. Jpn. 66 (1997) 1124. [2] V.K. Pecharsky, et al. Phys. Rev. B 58
(1998) 497.

The 19th International Conference on Magnetism

Novel colossal magnetoresistance in NaCr2O4

Hiroya Sakurai 1*, Taras Kolodiazhnyi1, Yuichi Michiue 2 and Eiji Takayamamuromachi2
1Superconducting Properties Unit, National Institute for Materials Science, Japan
2
National Institute for Materials Science, Japan
We recently discovered new chromium oxide, NaCr2O4, to have calcium ferrite
type structure, in which spin frustration is expected. The compound shows cantedantiferromagentic transition at TN = 125 K and Arrhenius-type temperature dependenceof electrical resistivity. The resistivity below TN is greatly suppressed by magnetic field
and it remains to be a finite value at 0 K under H = 9 T. Thus, the magnetoresistanceratio, {rho(H)-rho(0)}/rho(0), becomes closer to -100% at low temperatures. The
similar behavior has been observed in some manganites, such as Pr0.7Ca0.3MnO3 andNd0.5Sr0.5MnO3, for which the competition between charge-ordered insulating phaseand ferromagnetic metallic phase causes colossal magnetoresistance (CMR) throughthe first-order transition. Unlike them, however, NaCr2O4 shows no thermal or field
hysteresis in its physical properties, and there is no ferromagnetic metallic phasecompositionally close to NaCr2O4. Therefore, CMR of the compound is considered tobe caused by a new mechanism. The magnetism of Ca1-xNaxCr2O4 strongly suggests
unusual electronic state of Cr4+ ions. We will present a possible mechanism of CMR in
NaCr2O4, in which spin frustration and the electronic state of Cr4+ ions play a key role.

[1] B.S.Shastry et al., Physica B 208 (1981) 1069. [2] S.Yoshii et al., Phys. Rev. Lett. 101 (2008) 087202.

RG16
Saeed Mahdavifar*
Department of Physics, University of Guilan, Iran

274

Tomoki Muto1, Takayuki Goto1, Akira Oosawa1, Shunsuke Yoshii2, Takahiko Sasaki3, Shinji
Michimura4, Fumitoshi Iga4 and Toshiro Takabatake4
1
Department of Physics, Sophia University, Japan
2
CINTS Tohoku University, Japan
3
Institute for Materials Research, Tohoku University, Japan
4
ADSM, Hiroshima University, Japan

RH06

July 12 (Thu)

July 12 (Thu)[1] Y. Takura, Rep. Prog. Phys. 69, 797 (2006).

Tetsuji Okuda1*, Satoshi Oozono1, Takumi Kihara2 and Masashi Tokunaga2
1
Kagoshima University, Japan
2
The University of Tokyo, ISSP, Japan

RH07
Low field study of Hall effect in GdB6

M. A. Anisimov1*, A. V. Bogach1, V. V. Glushkov1, S. V. Demishev1, N. A. Samarin1, N.
Yu. Shitsevalova2, A. V. Levchenko2, V. B. Filipov2 and N. E. Sluchanko1
1
Low Temperatures and Cryogenic Engineering Dept., A.M.Prokhorov General
Physics Institute of RAS, Russia
2
Institute for Problems of Materials Science NAS, Ukraine

Magnetotransport property of a hole-doped delafossite CuCr0.97Mg0.03O2 with a spin3/2 antiferromagnetic (AF) triangular sublattice was investigated by a pulsed highmagnetic field up to about 56 Tesla. [1] A dramatic change of magnetoresistance (MR)was observed with a variation of temperature (T), which is due to a development of
an AF correlation with a decrease in T. A negative MR is observed and the ratio iswell proportional to a square of magnetization above a Curie-Weiss temperature (θ),
which seems to suggest that the magnetic state above θ is well explained by a Kondolattice model [2] with a weak ferromagnetic Hund’s coupling between itinerant holes
and localized spins. However, below θ, the negative MR gradually deviates from thescaling relation with a decrease in T and is much enhanced around an AF transition
temperature (TN). Furthermore, a component of positive MR appears around TN. Sucha MR behavior is due to a critical enhancement of spin fluctuation around TN, which
may cause a nontrivial promotion of a 120° AF state by the Mg substitution [3,4].

GdB6 plays the important role for understanding of the mechanisms responsible for the
antiferromagnetic (AF) state formation in the rare earth hexaborides. However the magnetic
structure of GdB6 which is characterized by two successive AF transitions (AF(I) ordering
below T_N~15.5K, and AF(II) phase at T^*~4.7K) is still the subject of discussion [1]. In
current work we present the comprehensive study of Hall effect on the high quality single
crystals of GdB6 in the wide temperature interval (2-120K) at low magnetic fields (H≤1T). In
paramagnetic state Hall coefficient R_H is practically temperature independent and value of
R_H~-4•10^{-4}cm^3/C detected with the high accuracy is in accord with the results of lighthexaborides RB6 (R-La, Ce, Pr, Nd) published previously [2],[3]. The temperature decrease
below T_N induces the drastic enhancement of negative Hall coefficient (ΔR_H/R_H~ 64%).
The magnetic ordering at T^* (AF(I)-AF(II) transition) is accompanied by the appearance of
anomalous Hall effect which is detected in GdB6 for the first time. The complex analysis ofcharge transport parameters suggests the possible effect of 5d-states spin density polarizationin AF and PM states of GdB6.

[1] T. Okuda, S. Oozono, T. Kihara, and M. Tokunaga, in preparation. [2] N. Furukawa, J. Phys. Soc.
Jpn. 63, 3214 (1994). [3] T. Okuda, N. Jufuku, S. Hidaka, and N. Terada, Phys. Rev. B 72, 144403 (2005).
[4] T. Okuda, Y. Beppu, Y. Fujii, T. Onoe, N. Terada, S. Miyasaka, Phys. Rev. B 77, 134423 (2008).

[1] M.Amara, S.E.Luca et al., Phys. Rev. B v. 72, p. 064447 (2005). [2] Y. Onuki, A.Umezawa et al., Phys. Rev. B v.
40, p. 11195 (1989). [3] M.A.Anisimov, A.V.Bogach, V.V.Glushkov et al., arxiv cond-mat:1006.0124v1

July 8-13, 2012 Busan, Korea

275

poster Presentation
RH08

RH11

RH14

RH17

Theoretical study of structures and mechanical properties of M-type
hexagonal ferrites BaFe12O19

High-field NMR study on the charge in stability in quantum spin
system Cu3Mo2O9

Physical properties of the novel triangular-lattice silver oxides Ag2MO2(M = Co, Ga, Rh)

Kitaev-Heisenberg magnetism in honeycomb iridates A2IrO3(A=Li,Na)

Triangular antiferromagnets have been extensively studied by many scientists in termsof geometrical frustration. According to current theories, triangular antiferromagnets
show various exotic magnetic properties, e.g. chirality order, Kosterlitz-Thoulesstransition, a partially disordered state, etc. A series of layered Ag2MO2 compounds,
where M is a transition metal, are possible model compounds of triangularantiferromagnets. The crystal structure of Ag2MO2 consists of alternate stacks of an
M3+O2 layer and a (Ag2)+ layer. The former includes a triangular lattice of the M3+ ions,while the latter provides itinerant electrons from the quarter-filled Ag 5s band. The
triangular lattices are well separated from each other by the non-magnetic double Aglayer. A path does not exist for superexchange interaction between the M3+ spins on theadjacent triangular lattices. In addition, no cation disorder is expected between the M
and Ag ions. Ag2MO2 is, therefore, considered a suitable system to study the magnetic
properties of triangular antiferromagnets. We recently succeeded in synthesizing
Ag2MO2, M = Co, Ga, Rh, for the first time using a high-pressure technique. The
details of physical properties of Ag2MO2 will be reported.

5d transition-metal oxides can have unique properties because of the strong spin-orbit coupling andrelatively weak electron correlations. Layered perovskite iridate Sr2IrO4, for example, was revealed
to be Jeff=1/2 Mott-insulator where spin and orbital degrees of freedom are entangled with including
complex phase i[1]. The magnetism of such Jeff=1/2 Mott-insulator might be different from 3dtransition-metal Mott-insulator.Indeed in iridates, the superexchange coupling between Ir-O-Ir was
proposed to be anisotropic ferromagnetic when IrO6 octahedra form edge-sharing network, due
to the complex phase[2]. As a consequence, the spin-liquid state based on the Kitaev-model wastheoretically predicted when such edge-shared IrO6 octahedra compose a honeycom network. Suchunique lattice topology can be found in layered iridatesA2IrO3(A=Li,Na). Na2IrO3 is a frustrated
antiferromagnet with Tn=17K, and the θw=-125K. The strong antiferromagnetic interaction is
likely due to direct interaction between Ir 5d electrons. Meanwhile, Li2IrO3 exhibited less frustrated
magnetism with Tn=12K and θw=-12K, even with the similar structure. We argue that this seemingly
non-frustrated magnetism of Li2IrO3 likely originates from a coexistence of direct antiferromagnetic
and ferromagnetic superexchange interaction, exemplifying the Kitaev-Heisenberg model[3]. The
difference might come from the local structure, the honeycomb of Na2IrO3 is distorted but that of
Li2IrO3 is closer to ideal honeycomb.

July 12 (Thu)M-type hexagonal ferrite, BaFe12O19, has extensively studied in a wide range ofapplications such as microwave devices and permanent magnets due to high Curie
temperature, large saturation magnetization and good chemical stability. In this paper,
we have investigated the structure and elastic modulus of BaFe12O19 using atomistic
simulations. An interatomic potential based on the shell model is used for the structure
and properties of BaFe12O19. The shell model has been extensively used to a wide rangeof oxide materials since it is a simple and useful potential with the Coulomb interaction
incorporated with the short-ranged term for ionic characteristics, though it is incapableof describing the elemental components. The calculated results are in agreementwith experiments and previous theoretical studies. To our knowledge, although many
theoretical investigations have so far played an important role in understanding theproperties of magnetic materials, there have been few theoretical studies using theinteratomic potential for the structure and properties of BaFe12O19. The interatomic
potential employed has been shown to be capable of describing the Ba-based hexagonal
ferrites.

1

1

1

1

2

Keita Misoka , Takayuki Goto *, Haruhiko Kuroe , Tomoyuki Sekine , Takahiko Sasaki , Masashi
Hase3, Kunihiko Oka4, Toshimitsu Ito4 and Hiroshi Eisaki4
1
Department of Phisics, Sophia University, Japan
2
Institute for Materials Research, Tohoku University, Japan3
Department of Phisics, National Institute for Materials Science, Japan
4
National Institute of Advanced Industrial Science and Technology, JapanThe quasi-one-dimensional quantum spin system Cu3Mo2O9 with the two spin-degrees of
freedom, antiferromagnetic chain and dimer-like sites clinging around the chain undergoes
the long-range antiferromagnetic order at 7.9 K, associated with a weak ferromagnetic
moment. The system shows a small magnetization jump of 0.0033 μB at H* = 8.2 T, where
the anomalous charge instability appears [1], suggesting an existence of tight coupling
between spin and charge. In order to inverstigate the microscopic spin and charge states in
the high magnetic field, we have utilized Cu-NMR technique, which separately probes thespin and charge in the chain site Cu1, the dimer like sites Cu2 and Cu3 through hyperfine
coupling and electric quadruple interaction respectively. In this presentation, we show bydetailed analyses of spectra taken under a wide range of filed up to 17.5 T that the ordered
antiferromagnetic moment is dominated by Cu1, while the dimer-like sites only feel a
uniform hyperfine field but staggered one, and that the change inhomogenization takes
place in Cu2 and Cu3 in the vicinity of the field of magnetization jump H*.

Hiroyuki Yoshida and Masaaki Isobe
National Institute for Materials Science, Japan

Akihiko Kato1, Tomohiro Takayama2* and Hidenori Takagi3
1
Department of Applied Chemistry, University of Tokyo, Japan2
Department of Advanced Materials Science, University of Tokyo, Japan3
Department of Physics, University of Tokyo, Japan[1] B.J.Kim et al., Science 323,1329(2009) [2]G.Jackeli and G.Khaliullin, Phys.Rev.Lett. 102,017205(2009) [3]
J.Chaloupka et al., Phys.Rev.Lettt. 105,027204 (2010)

1. P. Shepherd, K. K. Mallick and R. J. Green, J. Magn. Magn. Mater. 311 (2007) 683. 2. G. V. Lewis and C. R. A.
Catlaw, J. Phys. C: Solid State Phys. 18 (1985) 1149. 3. P. Novak and J. Rusz, Phys. Rev. B 71 (2005) 184433.

1 T. Hamasaki et al., Phys. Rev. B77 134419 (2007).

RH09

RH12

RH15

RH18

Nonlinear susceptibility of gadolinium near curie temperature

Anisotropic spin excitations in spin-Peierls CuGeO3

Electrical and thermal transport properties of the polycrystalline(Cr86Ru14)1-xVx alloy system

Effects of the annealing conditions on the magneto-transport
properties of La0.7Sr0.3Mn1+dO3-manganese oxide composites

Takashi Shirane* and Shohei Sakurai
Sendai National College of Technology, JapanThe ac linear and nonlinear susceptibilities of an elemental ferromagnetic gadolinium
have been studied near the Curie temperature, to clarify the feature of the magnetic
phase transition with special emphasis on the behavior below the Curie temperature.
The temperature dependence of linear susceptibility is in good agreement with that ofan experimental result reported in ref. [1]. The first observation for the critical behaviorof the nonlinear susceptibility in gadolinium has been made at various field amplitudes.
The behavior of the nonlinear susceptibility is very sensitive to the field amplitude. The
field dependence of the susceptibilities are explained on the basis of a mean field theory
taken into account the domain structure[2]. The detailed discussion will be shown thefull paper in comparison with magnetization curves at various temperature below theCurie temperature.
[1] J. M. D. Coey, K. Gallangher, and V. Skumryev, J. Appl. Phys. 87 (2000) 7028. [2] T. Shirane,
Statistical and Condensed Matter Physics: Over the Horizon, ed. S. Fujita, T. Obata, and A. Suzuki(New York: Nova Science), p. 189-197, (2007).

Kazuhiko Ikeuchi1, Fumio Mizuno2, Ryoichi Kajimoto1, Yasuhiro Inamura3, Mitsutaka Nakamura3,
Kenji Nakajima3, Masaki Fujita4, Kazuya Aizawa3 and Masatoshi Arai3
1
Research Center for Neutron Science and Technology, Comprehensive Research Organization for
Science and Society, Japan2
Department of Physics, Tohoku University, Japan3
Neutron Science Section, J-PARC Center, Japan
4
Institute for Material Research, Tohoku University, Japan

Even though CuGeO3 is a well-known 1-dimensional quantum spin system that shows magnetictransition into a dimerized state with a spontaneous lattice distortion, it is not clear whether it isan archetypal material of a spin-Peierls system. In fact, neutron scattering experiment has still not
succeeded in assignment of the soft phonon mode accompanying the magnetic transition. Actually,
due to an antiferromagnetic coupling between the neighboring spin chains, the dimerization in thespin chain is close to the critical state [1][2][3], and it should not have a strong effect on a phonon. In
this time, we performed inelastic neutron scattering experiment on CuGeO3 with the Fermi chopper
spectrometer 4SEASONS at MLF/J-PARC in Japan. In order to further understand the inter-chain
coupling, we measured intensity-maps in a 4-dimensional (q,ω) space including the inter-chain
direction due to rotation of the aligned 17.2 g CuGeO3 single crystals in horizontal plane. In thisexperiment, we have clarified an anisotropy of the magnetic excitations below the spin-Peierls
transition temperature. This result suggests the inter-chain coupling correlates with the dimerizationin the spin-Peierls state on CuGeO3. We will present the detail of the magnetic excitations together
with new other features recently discussed in several theoretical models.

Leelakrishna Reddy, Aletta Roletta Prinsloo, Charles Johannes Sheppard and Andre
Micheal Strydom
Physics, University of Johannesburg, South Africa

Thermopower (S) and electrical resistivity (ρ) measurements on the (Cr86Ru14)1xVx alloy system with 0≤x≤0.144 reveal unique behaviour[1,2,3]. The onset of acommensurate (C) itinerant-electron antiferromagnetic spin-density-wave (SDW)
structure is marked by anomalies in ρ(T) and S(T), associated with the Neel temperature.
Focus is on the thermopower as it is more sensitive to the changes in the electronic
structure and scattering mechanisms that are of importance at the SDW transition[2].
For this series S(T) shows a broad valley for x≤0.032. The valley gradually becomes
more shallow with increasing x and is eventually replaced by a surplus of positive
thermopower for x=0.074, for which parallelism is seen between ρ(T) and S(T) as
in the case of Cr-V[2]. The size of the magnetic contributions to S and ρ strongly
correlates and decreases with increasing x; attributed to the addition of V to the systemthat destabilizes the CSDW structure. The effect of the addition of V will be explainedin terms of a model that relates the behaviour of S(T) to the energy dependence of thedecrease in the scattering rate of electrons by phonons and an increase in the resistivity
on decreasing temperature due to a decrease in the Fermi surface area[3].

Sang-im Yoo* and Hyo-jin Kim
Department of Materials Science and Engineering, Seoul National University, Korea

The effects of the annealing conditions on the magneto-transport properties ofthe pure La0.7Sr0.3MnO3(LSMO) and LSMO-manganese oxide composites were
carefully investigated in this study. While the ferromagnetic-paramagnetic transition
temperatures of all polycrystalline samples were insignificantly varied in the rangeof 359~368 K, low field magnetoresistance (LFMR) properties and dMR/dH values
were remarkably improved for the composite samples annealed at relatively hightemperature. For instance, with increasing the annealing temperature from 1300 to
1450°C, the LFMR ratios of 95 mol% LSMO - 5 mol% Mn2O3 composite sample
were increased from 0.8 % to 1.1 % at 300 K in 0.5 kOe, suggesting that a magnetic
disorder at the LSMO grain boundary, known as a key factor suppressing effective
spin-dependent scattering, could be greatly improved by high temperature annealing
process. Detailed annealing effects on the magneto-transport properties of samples
will be presented for a discussion. This work was supported by the Korea Research
Foundation Grant funded by the Korean Government (MOEHRD, Basic Research
Promotion Fund) (KRF-0417-20100021)[1] M. Nishi et al., PRB, 50,6508 (1994). [2] J. Riera et al., PRB, 51,16098 (1995). [3] M. C. Martin et al., PRB, 56, 3173 (1997).

[1] L. Reddy et al., J. Appl. Phys. 103 (2008) 07C903-1. [2] E. Fawcett et al., Rev. Mod. Phys. 66(1994) 25. [3] A. L. Trego et al., Phys. Rev. 166 (1968) 495.

RH10

RH13

RH16

RH19

Electron correlation and dynamical Jahn-Teller effect in orbitally
degenerate system

Neutron inelastic scattering on spin-peierls system TiOBr

Magnetic properties of the layered triangular-lattice antiferromagnets
CsM(MoO4)2 (M=V, Fe)

Temperature dependence of spin lattice relaxation time of proton
NMR in mixed antiferromagnets A1-xBxCl2-2H2OJoji Nasu and Sumio Ishihara*
Department of Physics, Tohoku University, Japan

Tetsuya Yokoo1, Shinichi Itoh1, Daichi Kawana1 and Jun Akimitsu2
1
High Energy Accelerator Research Organization, Japan
2
Aoyama Gakuin University, Japan

Quantum spin liquid state is one of the attractive subjects in correlated electron
systems. Recently, a possibility of the quantum spin liquid state is experimentally
reported in a layered copper oxide Ba3CuSb2O9 where the orbital degree of freedom
in a Cu ion and the dynamical Jahn-Teller effect (DJTE) are suggested to play someroles on an origin of the spin liquid state. Motivated from these recent experimental
results, we study the DJTE in a spin-orbital coupled system. In particular, we focus
on competitive or cooperative phenomena between the superexchange interaction andthe DJTE. A superexchange interaction part is derived from the d-p model and the
DJTE part for the low lying vibronic states is described by the orbital pseudo-spin andthe lattice vibration. We analyze the model which combines the two interactions on
a honeycomb lattice by using the Bethe approximation and the exact diagonalization
method. We find that the magnetic order is unstable in a wide parameter region and aspin-singlet dimer state associated with an orbital order is realized. With increasing the
DJTE, furthermore, the orbital order is strongly suppressed and a resonance state of thespin-orbital dimers appears.

Newly proposed spin-Peierls system TiOX (X: Cl, Br) has been revealed showing
exotic structural and magnetic properties such as a successive phase transition, onedimensional (1D) nature associated with orbital ordering of Ti ions and super-lattice
structure being related to the Peierls instability. It is pointed out that resulting only froman arrangement of Ti dxy orbital, the formation of 1D spin chains and the spin-Peierls
transition will be realized. Recently, it has been demonstrated that TiOBr also exhibits
two successive phase transitions similar to TiOCl at Tc1=27K and Tc2=47K. Here we
carried out inelastic neutron experiments in order to see the evidence of spin-Peierls
transition. The inelastic spectrum with a large amount of poly crystalline sample of
TiOBr shows the localized signal in the vicinity of the magnetic zone center Q=0.9A-1.
Observed spin gap like signal lies at energy of ΔE=10meV. The gap energy in TiOBr is
expected much higher from measured thermodynamic properties and by analogy with
TiOCl. Constant Q cuts of the observed S(Q,E) map show some Q-dependent structure
in its intensity indicating the signal is sample oriented. The Q structure quite reveals
the intensity is well explained by the powder averaged dynamical structure.

H. D. Zhou, et.al., Phys. Rev. Lett., 106 (2011) 147204.

The 19th International Conference on Magnetism

Masahiko Isobe and Yutaka Ueda
ISSP, Univ. of Tokyo, Japan

Two-dimensional triangular lattice antiferromagnets are of great interest concerning
the ordering in frustrated spin system. We have prepared powder samples of thelayered triangular-lattice antiferromagnets CsFe(MoO4)2 and CsV(MoO4)2 and haveinvestigated the magnetic properties. In CsFe(MoO4)2, a structural phase transition ataround 365K from P3m1 to P3 was detected. Also we observed the magnetic transition
at 4.4 K for CsFe(MoO4)2 and 26 K for CsV(MoO4)2. The magnetic properties of
CsFe(MoO4)2 are similar to that of the multiferroic RbFe(MoO4)2.

July 12 (Thu)

Wonha Moon*, Soyeon Kim, Heejung Lee, Jaehoon Yeom, Sangwon Lee and Seok
Bae
LG innotek, Korea

276

poster Presentation

Tatsuichi Hamasaki1, Kazuko Zenmyo2 and Hidenori Kubo2
Physics Department, Kyushu Sangyo University, Japan
2
Fukuoka Institute of Technology, Japan1

In the mixed antiferromagnet systems Ni1-xCoxCl2_2H2O and Ni1-xMnxCl2_2H2O, theCo substitution increases a little the transition temperature and the Mn substitution
decreases the transition temperature rapidly. In Ni-Co system, the concentration
dependence of the phase transition temperature is well explained by simple molecularfield theory. But, in Ni-Mn system, molecular field theory cannot explain it sufficiently.
Thus Mn spins in NiCl2_2H2O crystal show the peculiar behavior. Then, we havemeasured the temperature dependence of the spin-lattice relaxation time of proton
NMR, in order to understand the specificity of the Mn spins. We have prepared
the mixed antiferromagnets A1-xBxCl2-2H2O (A, B=Co, Mn, Ni). In Co-M (M=Ni,
Mn) system, in comparison with the Ni substitution, the Mn substitution induces asignificant impact on the relaxation time. In Mn-M (M=Ni, Co) system, the relaxation
time is affected by a small amount of substitution. In Mn-Co system, the reentrant
spin-glass phase appears at low temperature. The strange behavior of the relaxation
time at low temperature is believed to reflect that. A similar trend is seen at the lowtemperatures in the case of Ni substitution, too. We suppose that this may be attributed
to a kind of the instability of Mn spins.

July 8-13, 2012 Busan, Korea

277

poster Presentation
RH20

RH23

RI01

RI04

Electronic Structure and magneto-optical properties of Co2MnX alloys
where X = Ge, Sn and Pb: a first-principles investigation in LDA+U
approachHigh field element selective magnetometry in erbium iron garnet

Distribution of magnetization in the random ising models.

Nontrivial ferrimagnetism of the heisenberg model on the union jackstrip lattice

We report our ab initio calculational results on the electronic structures and magnetooptical (MO) properties of the ferromagnetic Co2MnX alloys where X= Ge, Sn and
Pb. Employing the +U corrections for the 3d valence bands of transition metal atoms
in addition to the conventional local density approximation (LDA), we investigate thecorrelation effect on the MO spectra in polar geometry as well as the detailed electronic
structures using the all-electron FLAPW [1] method. Results show that the correlation
effect results in a blue-shift of the peak positions and the large enhancement of the MO
spectra compared to the LDA results. We find that our results can be attributed to theincreased t2g-eg splitting of spin minority d-bands of both Co and Mn atoms, whichindicates the suppression of diagonal elements of optical conductivity at energy regionof 1~2 eV where the interband transitions are forbidden.[2][1] E. Wimmer, K. Krakauer, M. Weinert, and A. J. Freeman, Phys. Rev. B 24, 864 (1981). [2]Support by Basic Science Research Program (NRF-2010-0005387) and Priority Research Centers(2010-0029617) through the National Research Foundation of Korea.

Cornelius Strohm*, Thomas Roth, Peter J. E. M. Van Der Linden, Olivier Mathon and
Sakura Pascarelli
European Synchrotron Radiation Facility, 6 rue Jules Horowitz 38000 Grenoble,
FranceKazuyuki Matsumoto1, Tatsuya Yoshimoto1, Hiroki Mizuno1, Takuya Okada1, Yosuke
Ishikawa1 and Yasuhiro Akutsu2
1
Department of Applied Sciences, Muroran Institute of Technology, Japan2
Department of Physics, Graduate School of Sciences, Osaka University, Japan

Ferrimagnets play an important role for applications as well as from a fundamental pointof view. The rare earth iron garnets for example were at the heart of the demonstrationof the local molecular field theory [1] and later used for bubble memories, microwave
devices and optival isolators. The ferrimagnetic superexchange between the rare earth
and iron cations being mainly determined by bond angles and distances in the oxygen
polyhedra, results in molecular fields of the order of tens of Tesla [2, 3]. We have perfomed
element selective magnetometry on samples of Erbium Iron Garnet, using energy
dispersive x-ray magnetic circular dichroism at the Fe K-edge and the Erbium L-edges.
Pulsed fields of 30 T were generated by a high duty cycle miniature coil [4] and the signal
was acquired using a multiframe detection scheme exploiting the entire pulse duration of
1 ms [5]. Here we discuss mainly the results obtained at the Fe K-edge. At 65 K, below
the compensation point, two successive field induced phase transitions and the reversal of
the net magnetization of the Fe sublattices in the intermediate canted phase were observed,
while the Fe signal remains unchanged at 100 K, above the compensation point.

We investigate the two- and three-dimensional random Ising models by the Monte
Carlo method. The integrated distribution functions of site-magnetization are calculated
above and below the lower Griffith temperature. It is found that these functions havedistinct character above or below this temperature for the two-dimensinal random Isingmodel. However, for the three-dimensional random Ising model, this distinction cannot
be observed on contrast to the two-dimensional random Ising model. This behavior
may be explained by the percolation theory.

[1] L. Neel Science 174, 985 (1971). [2] A. E. Clark and E. Callen J. Appl. Phys. 39, 5972, (1968). [3] K.
Nakao, T. Goto and N. Miura J. of Magn. Magn. Mat. 54, 1363, (1986). [4] P. J. E. M. van der Linden
et al. Rev. Sci. Instrum. 79, 075104, (2008). [5] C. Strohm et al. J. of Synchrotron Rad. 18, 224, (2011).

In low-dimensional quantum spin systems with frustration, nontrivial magnetic
phenomena occur due to strong quantum fluctuation. One of the phenomena is a nonLieb-Mattis (NLM) ferrimagnetism[1][2], which is different from the well-known
Lieb-Mattis (LM) ferrimagnetism[3][4]. In contrast to the LM ferrimagnetism,
the spontaneous magnetization of the NLM ferrimagnetism changes graduallywith respect to the strength of frustration. Incommensurate modulation with longdistance periodicity in local magnetizations is also a characteristic behavior of the
NLM ferrimagnetism. However, there are only a few cases revealing the NLM
ferrimagnetism, which prevents us with understanding the mechanism of theoccurrence of the NLM ferrimagnetism. In this study, we examine the ground-state
properties of the S=1/2 Heisenberg model on the Union Jack strip lattice. We find theexistence of the NLM ferromagnetism by the numerical diagonalization and density
matrix renormalization group methods. We also discuss the relationship between the
NLM ferromagnetic state of this strip lattice and the intermediate canted state of the
S=1/2 Heisenberg model on the two-dimensional Union Jack lattice[5].
[1] S. Yoshikawa and S. Miyashita: J. Phys. Soc. Jpn. 74 (2005) Suppl. 71. [2] K. Hida: J. Phys.: Condens. Matter
19 (2007) 145225. [3] W. Marshall: Proc. Roy. Soc. A 232 (1955) 48. [4] E. Lieb and D. Mattis: J. Math. Phys. 3(1962) 749. [5] R. F. Bishop, P. H. Y. Li, D. J. J. Farnell, and C. E. Campbell: Phys. Rev. B 82 (2010) 024416.

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2D Heisenberg antiferromagnetism in spin-orbit Mott insulator Sr2IrO4

THz and infrared excitation spectrum below the Jahn-Teller transitionin Sr3Cr2O8

Berezinskii-Kosterlitz-Thouless trasition in two-dimensional p-state
clock model

Control of quantum critical points in bond disordered spin laddermaterials

We report on optical excitations observed recently in Sr3Cr2O8 by THz and infrared
spectroscopy. Low-energy excitations below 3 THz are detected by THz time domain
spectroscopy including the spin singlet to triplet excitations.[1] These excitations
can be divided into two different classes according to the temperaturedependent
properties. One is emergent right below the Jahn-Teller transition temperature, which
is determined by specific heat measurement to occur at 285 K. [1,2] The other appears
only below 100 K, where the fluctuations are sufficiently suppressed, consistent withthe temperature dependence of low-energy Raman modes. [3] Infrared transmission
measurements reveal a broad crystal-field excitation, which can be associated with anelectronic transition from E to T2 orbital states.

In two dimensions, the Berezinskii-Kosterlitz-Thouless (BKT) transition occurs inmodels with the U(1) symmetry. The helicity modulus, which measures the rigidity
against a global twist across the system, is useful for a detection of the transition
because of its distinctive feature, the universal jump at the transition point. Meanwhile,in the p-state clock model which has the Z_p symmetry, it is believed that the BKTtransition occurs when p is greater than 4 since the study by Jose et al. in 1977[1].
However, a recent numerical study by Baek et al. in 2010[2] detects an absence of theuniversal jump in the helicity modulus for p=5. This contradicts the Jose’s result. In thisstudy, we show that the helicity modulus as defined by Baek (HMB) remains finite forany p with the high-temperature expansion. Therefore, the universal jump in the HMB
cannot be observed whether the transition is the BKT or not. This casts a question on
the physical meaning of the HMB. We will present a systematic study of the helicity
modulus to clarify the universality class of the transition for p=5.

[1] Zhe Wang et al., Phys. Rev. B 83, 201102 (2011) [2] D. L. Quintero-Castro et al., Phys. Rev. B
81, 014415 (2010) [3] D. Wulferding et al., Phys. Rev. B 84, 064419 (2011)[1] J. V. Jose, L. P. Kadanoff, S. Kirkpatrick and D. R. Nelson, Phys. Rev. B 16, 1217 (1977) [2] S. K.
Baek and P. Minnhagen, Phys. Rev. E 82, 031102 (2010)

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Magnetoresistance and magnetic properties of oxygen deficient (Sr,Y)(Fe,Co)O3 perovskites

H i g h - f i e l d m u l t i - f re q u e n c y E S R i n t h e S = 2 H e i s e n b e r g
antiferromagnetic chain compound MnCl3(bpy)

Influence of interplanar coupling on the entropy and specific heat of
the bilayer ferromagnet

Triangular spin tubes with bond randomness

Karol Szalowski and Tadeusz Balcerzak*
Department of Solid State Physics, University of Lodz, Poland

Yoko Miura1* and Hirotaka Manaka2
1
Suzuka National College of Technology, Japan2
Department Graduate School of Science and Engineering, Kagoshima University,Japan

We report the results of high-field multi-frequency ESR experiments at 1.3 K on a
powder sample of MnCl3 (bpy) (bpy=2, 2'-bipyridine). This compound is one of therare examples of the spin 2 quasi-one-dimensional Heisenberg antiferromagnets, andthe magnetic properties on tiny single crystal samples were reported previously [1].
In our previous paper on this compound [2], we attained good agreement between
experiment and calculation on the temperature dependence of magnetic susceptibility
and the high-field magnetization process at 1.3 K. In this work, we have observedsome high-frequency resonance modes with a zero-field gap of about 800 GHz that
may correspond to the excitation modes at q=0 in the energy dispersion higher than the
triplet excitation mode of about 50 GHz at q=pi expected from the evaluated exchange
constant and the g-value.

The Ising-Ising and Ising-Heisenberg bilayer with a simple quadratic lattice ineach plane is studied using the pair approximation (PA) method. The foundationof formalism used has been developed in [1], where the phase diagrams for the
anisotropic bi- and multilayer system have been obtained. In this paper the method(leading to a complete self-consistent thermodynamics) is adopted for the entropy
and magnetic specific heat calculations. An interesting case is demonstrated when theexchange integrals in both planes are of unequal strength, and the interplanar coupling(Ising or Heisenberg) is relatively weak. In such a case, two peaks in the temperaturedependence of the specific heat can be observed. The isothermal change of the entropy
caused by application of the external magnetic field has been additionally calculated
for a wide temperature range. The entropy change in the field also shows a double
peak structure, similarly to the specific heat. Such a phenomenon may be of potential
interest for investigations of the magnetocaloric effect. The results of the PA method
have been compared with those obtained for two Ising-type planes by means of exact
diagonalization for finite clusters.

We studied X-ray diffraction and magnetic susceptibility experiments on nonequilateral triangular spin tubes composed of α-KCr1-xFexF4 (x=0-0.13), which
consists of one-dimensional Heisenberg antiferromagnets coexisting with geometricallyfrustrated spin systems with bond randomness. For x=0, an antiferromagnetic longrange order occurred at TN1 = 2.5(1) K and another phase transition occurred at TN2= 4.0(1) K, because superexchange interactions through the three Cr-F-Cr paths ineach non-equilateral triangle lost their equilibrium at low temperatures [1]. As a result,the values of spin-flop transition field drastically decreases with increasing x. This isprobably due to the close correlation between the spin structure in the antiferromagnetic
ordered state and the crystal structure as theoretically predicted by Nenert and Palstra,i.e., a magnetoelectric linear effect in which a magnetic field in an antiferromagnetic
ordered state induces electrical polarization. Thus we carefully verified the crystal
structure for x = 0-0.13.

Akiyo Matsumoto1, Tomohiro Takayama1 and Hide Takagi2*
1
Department of Advanced Materials, The University of Tokyo, Japan2
Department of Physics, The University of Tokyo, Japan

In 5d iridates, the interplay between spin-orbit coupling and modest electron correlation
produces novel electronic phases. Sr2IrO4 was recently found to be a Jeff =1/2 Mott
insulator where spin and orbital degrees of freedom are entangled[1]. The magnetic
coupling between such Jeff = 1/2 state, which could be critically different from that in
3d-based Mott insulators, is of particular interest. For example, the magnetic coupling
between Ir was theoretically proposed to be isotropic Heisenberg-type when IrO6 octahedra
form corner-sharing network[2]. We focused on Sr2IrO4 to reveal the magnetism of suchspin-orbit Mott insulator. Sr2IrO4 crystallizes in a K2NiF4-type perovskite structure, andmagnetically orders at 240K. We investigated the detailed magnetic susceptibilities on
the single crystals. The ground state was found to be antiferromagnetism, and the inplane susceptibility steeply increases just above the transition temperature likely due to
Dzialloshinski-Moriya interaction. Meanwhile, at higher temperatures, the in- and out-ofplane susceptibilities were almost isotropic. By analyzing the susceptibilities, we found thatthey can be well described by the 2D Heisenberg antiferromagnetism. This indicates thateven in the limit of strong spin-orbit coupling, Sr2IrO4 displays the isotropic Heisenberg
magnetism. This situation contrast with the 3d oxides, where spin-orbit coupling is
responsible for magnetic anisotropy.

Zhe Wang1*, Michael Schmidt1, Franz Mayr1, Diana Quintero-castro2, A. T. M.
Nazmul Islam2, Bella Lake2, Hans-albrecht Krug Von Nidda1, Alois Loidl1 andJoachim Deisenhofer1
1
Experimental Physics 5, Intitute for Physics, Augsburg University, Germany
2
Helmholtz-Zentrum Berlin fur Materialien und Energie, Germany

Yuta Kumano*, Yusuke Tomita and Masaki Oshikawa
ISSP, Japan[1] B. J. Kim et al., Science 323,1329 (2009) [2] G.Jackeli and G. Khaliullin, Phys. Rev. Lett. 102, 017205 (2009)

Jean-marie Le Breton1*, Youssef Rizki1, Yohann Breard2, Luc Lechevallier1 andAntoine Maignan2
1
Groupe de Physique des Materiaux - UMR 6634, CNRS - Universite de Rouen,
France2
CRISMAT, UMR 6508 CNRS, ENSICAEN - Universite de Caen, France
The magnetic and magnetoresistive properties of oxygen deficient (Sr,Y)(Co,Fe)O3 perovskites have been investigated in relation with the composition. The valence
state of Fe has been probed by 57Fe Mossbauer spectrometry. Sr1-xYxFe0.8Co0.2O3-d
and Sr0.8Y0.2Co1-xFexO3-d series were more particularly investigated. It appears that the
progressive replacement of Sr2+ by Y3+ and the Co/Fe substitution lead to a changeof the valence state of Fe and to a drastic change of the magnetic and magnetoresistive
properties, in relation with the variation of the Fe4+/Fe3+ ratio and the change inthe oxygen content. It is shown that the Sr0.8Y0.2Co0.5Fe0.5O3-d reveals the highest
magnetoresistance effect, in relation with the fact that the magnetic field induced
ferromagnetic alignement of the Fe/Co magnetic moments allows more metallic
pathaways to be created. This work was supported by the French Agence Nationale dela Recherche (project ANR-08-BLAN-0005-01).

Masayuki Hagiwara1*, Shojiro Kimura2, Yuichi Idutsu1 and Zentaro Honda3
1
KYOKUGEN, Osaka University, Japan
2
IMR, Tohoku University, Japan
3
Graduate School of Science and Engineering, Saitama University, Japan[1] G.E. Granroth et al., Phys. Rev. Lett. Vol. 77 (1996) 1616. [2] M. Hagiwara et al., to be
published in J. Phys.: Conf. Ser.

[1] K. Szalowski, T. Balcerzak, Physica A 391 (2012) 2197-2208.

278

Tokuro Shimokawa* and Hiroki Nakano
University of Hyogo, JapanThe 19th International Conference on Magnetism

July 12 (Thu)Tran Van Quang1, Jae Il Lee2 and Miyoung Kim3
1
Dept. of Physics, Ajou University, Suwon 443-749, Korea
2
Dept of Physics, Inha University, Incheon 402-751, Korea
3
Division of Energy System Research, Ajou University, Suwon 443-749, Korea

July 12 (Thu)poster Presentation

S Ward1*, H Ryll2, D Biner3, K W Kramer3, K Kiefer2, D F Mcmorrow1 and Ch Ruegg4
1
London Centre for Nanotechnology, University College London, United Kingdom
2Helmholtz Zentrum Berlin, Germany
3
Chemistry and Biochemistry, University of Bern, Switzerland
4
Laboratory for Neutron Scatering, Paul Scherrer Institut, Switzerland

Spin ladders are model systems of low dimensional quantum spins. There is now
considerable interest in materials which realise these ideal systems with solvable
Hamiltonians and rich phase diagrams. An archetypal spin ladder material in the lowenergy regime is (C5H12N)2CuBr4 whose phase diagram is completely accessible inlaboratory magnetic fields. The rung (Jr) and leg (Jl) exchange are 12.8 K and 3.4
K, respectively, and two field-controlled quantum critical points (QCPs) exist at 6.9
T and 14.5 T. (C5H12N)2CuCl4 is a related spin ladder material. The superexchange
between quantum Cu2+ spins is controlled by the halide atoms and is lowered to
Jr=3.4 K and Jl=1.3 K. The QCPs appear at the lower fields of 1.7 T and 4.3 T. A
common structure and rich chemical flexibility in the superexchange pathways allows
for partial halide substitution to create the bond disordered spin ladder materials(C5H12N)2CuBr4(1-x)Cl4x, while retaining ideal spin ladder geometry. We present
recent neutron scattering work and measurements of the magnetic and thermodynamic
properties on the substitution series, and demonstrate explicitly substitution-controlled
modification of exchange interactions as well as the effects of bond disorder on thespin ladder physics and QCPs.

[1] H. Manaka et al., J. Phys. Soc. Jpn. 80, 084714 (2011). [2] G. Nenert and T. T. M. Palstra, J.
Phys.: Condens. Matter 19, 406213 (2007).

July 8-13, 2012 Busan, Korea

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poster Presentation

poster Presentation

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A new approach to the characterization of aging, rejuvenation, andmemory effects in magnetic systems

Anomalous spin diffusion on the two-dimensional percolating network
in Rb2Mn0.6Mg0.4F4

Critical phenomena at the antiferromagnetic phase transition of
Azurite Cu3(CO3)2(OH)2

Novel Field-Induced Quantum Phase Transition of the KagomeLattice Antiferromagnet

We introduce a new approach to study non-equilibrium dynamics in magnetic systems. We
found that simple ferromagnets such as pure terbium and nickel aluminide foils actuallyresembles typical spin glasses such as Cu97Mn3 and Cd55Mn45Te, in behavior of out-of-phasecomponent of ac susceptibility and magnetic viscosity, when they are thermally perturbed
after isothermal aging. Briefly, it is not enough to conventionally measure such dissipative
properties for characterizing the non-equilibrium dynamics of these systems. In contrast,in the spin glasses, the relaxations of the uniform magnetization were accelerated at aconstant magnetic field, when the spin glasses were cooled/heated after the isothermal aging.
Surprisingly, such relaxations were reversed when they were subsequently reheated/recooled
to the original temperature, despite the persistence of the magnetic field. Because the uniform
magnetization mirrors the global evolution of the spin configuration, these reversions
indicate that the spin configurations are spontaneously restored to the original [1,2]. On theother hand, such reversions were never observed in the ferromagnets. This fact indicates thatferromagnetic correlations are unaffected by the thermal perturbations, unlike rejuvenation in
spin glasses. Thus, the observations of the uniform magnetization would be an additional key
to clarifying the features of non-equilibrium dynamics in magnetic systems.

Shinichi Itoh*
Institute of Materials Structure Science, High Energy Accelerator Research
Organization, Japan
Inelastic neutron scattering experiments were performed on a two-dimensional dilute
antiferromagnet, Rb2Mn0.6Mg0.4F4, with the magnetic concentration being close to thepercolation concentration, c_p = 0.593, well above the Neel temperature, and witha high energy-resolution of ΔE = 17.5 μeV. The energy spectrum obtained from theobserved dynamical structure factor S(q,E) integrated over wave number, q, throughout
almost the entire Brillouin zone, showed a power law dependence, S(E) ~ E^{-x}.
The diffusion on a percolating network is anomalous and it has been predicted that themean square displacement of a random walker is described by <R^2(t)> ~ t^{2/(2+θ)}with an exponent, θ, as a function of the time, t. The exponent in S(E) is described as
x = 1 - Df/(2+θ) with Df being the fractal dimension of the medium. The observed
exponent, x, was in good agreement with a theoretical value.

July 12 (Thu)[1] H. Mamiya and S. Nimori, New J. Phys. 12 (2010) 083007. [2] H. Mamiya and S. Nimori, J.
Appl. Phys, in press.

Pham Thanh Cong, Bernd Wolf*, Rudra Sekhar Manna, Andreas Bruhl, Sebastian
Kohler and Michael Lang
Physics Institute, Goethe-University Frankfurt (M), SFB/TR 49, D-60438 Frankfurt(M), Germany

The natural mineral Azurite, Cu3(CO3)2(OH)2, has been considered as a model substancefor the 1D distorted diamond chain, where unconventional magnetic properties result
from the interplay of strong quantum fluctuations, low dimensionality and frustratinginteractions. The system exhibits 3D long-range antiferromagnetic order at TN = 1.88 K.
Our measurements of the sound velocity, ultrasonic attenuation and thermal expansion showpronounced signatures at TN indicating a strong coupling to the lattice degrees of freedom.
We present a detailed investigation of the critical behavior of the sound velocity v22 andultrasonic attenuation α in the vicinity of TN. Our analyses reveal a power-law behaviorof the critical contributions v22cr ~ t-ζ and αcr ~ t-η over a decade of reduced temperaturet = (T - TN)/TN both above and below TN. While the value of η = 1.21, obtained above
TN, is close to the theoretical prediction for an anisotropy 3D Heisenberg antiferromagnet,
the critical exponent derived from the sound velocity of ζ = 0.056, being identical for
temperatures above and below TN, is at odds with this universality class. However, this value
is consistent with the critical exponent observed in recent neutron scattering measurements [1].

Toru Sakai1* and Hiroki Nakano2
SPring-8, Japan Atomic Energy Agency, Japan
2
Graduate School of Material Science, University of Hyogo, Japan1

The kagome-lattice antiferromagnet is investigated using the numerical exact diagonalization
up to 42-spin clusters. From our investigation of the magnetization process, we found anovel field-induced quantum phase transition, called the ``magnetization ramp'', at 1/3 ofthe saturation magnetization [1]. The finite-size scaling analysis of the critical exponents[2]indicated a significant difference of the magnetization ramp from the magnetization plateau
observed in the triangular-lattice antiferromagnet. The critical magnetization behavior atlower-field side of the magnetization ramp is same as that of the one-dimensional spin liquid.
In order to clarify a difference between the magnetization ramp and plateau, we study ageneralized anisotropic triangular-lattice model including the regular-triangular- and the
kagome-lattice antiferromagnets in the parameter space. It revealed a quantum phase transition
between the triangular- and kagome-lattices at 1/3 of the saturation magnetization. It meansthat the magnetization ramp of the kagome-lattice antiferromagnet is an essentially different
phenomenon from the magnetization plateau of the triangular-lattice one. The relation to therecent magnetization measurements on the volborthite and vesignieite[3] is also considered. In
addition we discuss about the spin gap issue of the kagome-lattice antiferromagnet [4].

[1] M. C. R. Gibbs et al., PRB 81, 140406(R), 2010

[1]H. Nakano and T. Sakai: J. Phys. Soc. Jpn. 79 (2010) 053707. [2]T. Sakai and H. Nakano: Phys. Rev. B 83 (2011)
100405(R). [3]Y. Okamoto, M. Tokunaga, H. Yoshida, A. Matsuo, K. Kindo and Z. Hiroi: Phys. Rev. B 83 (2011)
180407(R). [4]H. Nakano and T. Sakai: J. Phys. Soc. Jpn. 80 (2011) 053704.

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The linear soliton generated by Z2 vortex in quantum antiferromagnet

Quantum phase transitions in 1/3 plateau of the quantum spin tube

Dynamical properties of supersolid states in spin systems

Antiferromagnetic phase transition of K-Rb alloy nanoclusters
incorporated in sodalite

Pawel Rusek
Institute of Physics, Wroclaw University of Technology, PL, Poland

The order parameter of noncollinear Heisenberg antiferromagnet is a triad oforthonormal vectors,i.e. the space of available states is isomorphic to SO3 group. The
topology of SO3 manifold allows the existence Z2 vortices in a system. We show thatthe anisotropy essentially changes the structure of Z2 vortex in 2D spin system. On
the scale larger than the scale la defined by weak anisotropy energy the Z2 vortex is atermination of a linear soliton with the topological charge π1 (R) = Z2 . In the soft coreof this soliton the rotation angle of triad θ rapidly changes from the anisotropy locked
value θa to θ = π, jumps on the line to θ = -π, and then decreases to the value θa on thela distance from the line. The linear soliton can terminate on the other Z2 vortex or it
should go out to surface sample. The rapid change of θ in the soft core of linear soliton
causes the change of plaquette chirality there- the chirality change the sign on the line
initiating the creation of the chirality domain.

Kouichi Okunishi1*, Masahiro Sato2, Toru Sakai3, Kiyomi Okamoto4 and Chigaku
Itoi51
Department of Physics, Niigata University, Japan2
Department of Physics and Mathematics, Aoyama Gakuin University, Japan
3
Japan Atomic Energy Agency, SPring-8 and University of Hyogo, Japan
4
Department of Physics, Tokyo Institute of Technology, Japan
5
Department of Physics, Nihon University, Japan
We study quantum phase transitions in the 1/3 plateau state of the three-leg spin-1/2
tube, where the low-energy effective chirality degree of freedom plays an essentialrole. Using density matrix renormalization group and the effective chirality model,
we find that the chirality liquid, a novel spin imbalance phase and the vector-spinchirality ordered phase emerge without closing the plateau spin gap, as the leg couplingincreases. We also report the role of S_3-symmetry of the spin tube behind thesequantum phase transitions in detail.
K. Okunishi, M. Sato, T. Sakai, K. Okamoto and C. Itoi, arXiv:1109.0063

Yuta Murakami*, Takahi Oka and Hideo Aoki
Physics, University of Tokyo, Japan

It has been recognized that spin systems can be effectively thought of as boson models
as in magnon BEC[1]. Specifically, a possibility to realize supersolid(SS) states (inthe boson language) in spin systems is attracting recent attention, where a candidate isa frustrated spin-1/2 dimer model[2]. Here we study how the SS state accommodates
collective excitations with the spin-wave theory. [3] We find that the excitation
spectrum changes discontinuously as we go from a superfluid phase to an SS phase (thataccompanies an SDW; CDW in boson language). Quantitatively, an analytic relation
between the velocity of the Goldstone mode and the superfluid density is given. We
also calculate the spin-spin correlation function, Szz(q, ω), which translates to the
dynamical structure factor in cold-atom systems. We find the intensity of the mode as
estimated from the peaks in Szz(q, ω) sharply blows up toward the boundary of SS,
which is accompanied by a drastic change in the character of the roton mode. We alsomention the possibility to enlarge the SS phase region. These results obtained in theeffective boson model should also be directly applicable to cold bosonic atoms.
[1] T. Giamarchi, C. Ru egg, and O. Tchernyshyov, Nat. Phys. 4, 198 (2008). [2] P. Chen, C. -Y. Lai,
and M.-F. Yang, Phys. Rev. B(R) 81, 020409 (2010). [3]T. Sommer, M. Vojta, and K.W. Becker Eur.
Phys. J. B 23, 329-339 (2001).

July 12 (Thu)

Hiroaki Mamiya* and Shigeki Nimori
National Institute for Materials Science, Japan

Takehito Nakano*, Yuko Ishida, Atsufumi Hanazawa and Yasuo Nozue
Department of Physics, Graduate School of Science, Osaka University, Japan

Aluminosilicate sodalite possesses a bcc arrangement of nanospaces (beta-cages).
Alkali-metal nanocluster (A4)3+ can be formed in each beta-cage, where an s-electron
is shared by four alkali cations. (Na4)3+ clusters in sodalite are known to show
antiferromagnetism below the Neel temperature of 48 K [1]. By substituting heavier
alkali atoms for Na ones, the Neel temperature systematically increases, namely, 72 K
in (K4)3+ and 80 K in (K3Rb)3+ clusters [2]. In the present work, we have succeededin preparing K-Rb alloy clusters with a higher Rb concentration, (K1.5Rb2.5)3+.
Magnetic susceptibility obeys Curie-Weiss law and shows a peak at ~ 100 K. ESR
spectrum is suddenly broaden below ~ 90 K to be an asymmetric shape which canbe explained by powder pattern of antiferromagnetic resonance. These results clearly
indicate that the present sample exhibits an antiferromagnetic phase transition at
approximately 90 K which is higher than that in (K3Rb)3+. Substituting Rb for K
makes the size of s-electron wave function of the cluster larger because of the larger ion
size and the lower ionization energy of Rb. This reduces the U/t in the Mott-Hubbard
insulating state resulting in an increase in the kinetic exchange coupling between theadjacent clusters.
[1] V.I. Srdanov et al., Phys. Rev. Lett. 80, 2449 (1998). [2] T. Nakano et al., J. Phys. Soc. Jpn. 79,
073707 (2010).

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Exact results of a mixed spin-1/2 and spin-1 Ising model with bilinear
and three-site four-spin interactions on decorated planar lattices

Cs2CoCl4 - an effective XY-spin-½ compound in transverse magnetic
fieldsMagnetic phase transition of antiferromagnetic Cs3V2Cl9

A novel scaling method for critical phenomena studies: finite size
effects

Michal Jascur1*, Viliam Stubna1, Karol Szalowski2 and Tadeusz Balcerzak2
1
Institute of Physics, P.J. Safarik University in Kosice, Park Angelinum 9, 040 13 Kosice, Slovakia
2
Department of Solid State Physics, University of Lodz, ul. Pomorska 149/153, 90-236 Lodz, Poland

A mixed spin-1/2 and spin-1 Ising model on decorated planar lattices is investigatedusing a generalized decoration-iteration transformation technique [1]. In addition to thestandard bilinear nearest-neighbor interactions, we also consider three-site four-spin
interactions and the crystal field effects. In this contribution, exact expressions for thepartition function, critical temperatures and other thermodynamic quantities are obtained
and analyzed. Performing numerical calculations, we have found that in addition to thestandard ferromagnetic and paramagnetic phases there exists in the system also a peculiar
partly ordered phase, which possesses non-zero entropy at T = 0 and appears only for zerobilinear exchange interaction. In this phase, the decorating atoms occupy spin states ±1 and
0 with equal probability at all temperatures, while the nodal spins-1/2 are perfectly aligned
along easy axis and generate non-zero magnetization. Our calculations primarily clarify
the influence of many-body interactions in localized spin systems, which is apparently very
different from the standard pair interactions due to the different symmetries of relevantterms in Hamiltonian. However, the presented results may be of wider interest since theorigin of the three-site four-spin interaction is related to the magnetoelastic effect [2].
This work has been supported under grant VEGA No. 1/0234/12. [1] M. Jascur, Physica A 252 (1998)
217. [2] T. Iwashita, N. Uryu, J. Phys. C: Solid State Phys. 17 (1984) 855.

280

The 19th International Conference on Magnetism

Oliver Breunig1*, Eran Sela2, Benjamin Buldmann2, Markus Garst2, Petra Becker3,
Ladislav Bohaty3, Ralf Muller1 and Thomas Lorenz1
1
II. Physikalisches Institut, University of Cologne, Germany
2
Institut fur Theoretische Physik, University of Cologne, Germany
3Institut fur Kristallographie, University of Cologne, Germany

Cs2CoCl4 is a model system for studying the magnetism of one-dimensional spin
chains with XY anisotropy. It contains CoCl4 tetrahedra, which form one-dimensional
chains along the crystallographic b-axis. The orbital groundstate of Co2+ is split by
the crystal field into doublets and an easy-plane anisotropy of the magnetization isestablished. The ground-state doublet is separated from the first excited doublet state
by approximately 15 K, such that at temperatures between 0.3 and 4 K the compoundis well described by the one-dimensional XXZ model. We compare experimental dataof specific heat and thermal expansion to numerical calculations of the XXZ modelfor transverse magnetic fields; i.e., fields applied within the XY planes. Decreasing
temperature below 0.3 K, magnetic order arises at field-dependent temperatures
TC(H). Measuring thermodynamic properties with a magnetic field applied along the
crystallographic b-axis, we observe a series of magnetic transitions within the orderedstate. This work was supported by the DFG through SFB 608.

Hikomisu Kikuchi1, Takashi Tanaka1, Yutaka Fujii2, Akira Matsuo3 and Koichi Kindo3
1
Department of Applied Physics, University of Fukui, Japan
2
Research Center for Development of Far-Infrared Region, University of Fukui,Japan
3
ISSP, The University of Tokyo, Japan
Cs3V2Cl9 belongs to the family of hexagonal compounds A 3M2X9 (A=Cs, Rb,
M=transition metal ions, X=Cl, Br) in which M2X93- dimers are oriented along
crystallographic c-axis. Former work1) on polycrystalline sample of Cs3V2Cl9 reported
that intradimer interaction is ferromagnetic although ground state is nonmagnetic
because of relatively large zero-field-splitting. Dimers of Cs3V2Cl9 form triangularlattice in their c-plane so that the geometrical spin frustration effect is expected to occur
if interdimer interactions are antiferromagnetic. We measured magnetic susceptibility,
specific heat, high field magnetization and 133Cs-NMR using single crystal to study
magnetic properties of Cs3V2Cl9. The specific heat shows two anomalies at around 15
and 4 K suggesting successive phase transitions. Results will be discussed in terms of
the spin frustration.
1) B. Leuenberger et al. Inorg. Chem. 25, (1986) 2930.

Joao S Amaral1*, Jouke R Heringa2, Ekkes Bruck2 and Vitor S Amaral1
CICECO and Dept. of Physics, Universidade de Aveiro, Portugal
2
Delft University of Technology, Faculty of Applied Sciences, 2626 Delft, Netherlands

1

We present a novel approach for critical phenomena studies. By quantifying scaling plot
data overlap, we introduce a ‘goodness of scaling’ parameter, allowing an iterative search forthe ‘best’ critical exponent values for a given set of magnetization data. The main advantageof this method is going beyond the usual power-law fits of the critical isotherm or low fieldsusceptibility curve, by considering the complete equation of state and all data within the criticalregion. We consider Monte-Carlo simulated data of the 3D Ising model, and evaluate finitesize effects using our scaling method. Our results are in good agreement with the bibliography,
including the dependence of pseudo-critical exponents on system size [1]. Interestingly, we
have found that even with a strong dependence of these pseudo-critical exponents on systemsize, the equation of state is not affected by finite-size effects. The resulting scaling function isin good agreement with recent theoretical predictions for both exponent values and equationof state [2,3]. Our results suggest that while some effects may change the values of observed
critical exponents of a given magnetic system, the state equation may retain its identity. In asense, the state equation can be more universal than exponent values.
[1] Haggkvist R., Rosengren A., Lundow P. H., Markstrom K., Andren D., Kundrotas P., Adv. Phys.
56, 653-755 (2007). [2] Campostrini M., Pelissetto A., Rossi P., E. Vicari, Phys. Rev. E 65, 066127(2002). [3] D. O'Connor, J. A. Santiago, and C. R. Stephens, J. Phys. A 42, 045003 (2009).

July 8-13, 2012 Busan, Korea

281

poster Presentation
RI19

RI22

RJ03

RJ06

The transverse-field quantum Ising model on infinite-dimensional
structures using quantum Monte Carlo method and finite-size scaling

Stochastic treatment of magnetic moment relaxation in spin echomodelsMutual spin-transfer torque in vortex nano-oscillators

Theoretical study on frequency of vortex-antivortex pairs rotation in amagnetic thin-film with multi-contacts

The method of nuclear spin-echo amplitude calculation based on the density matrix technique isimproved. Spin echo model [1] was supplemented with stochastic consideration of the magnetic
moment relaxation provided by the interaction nuclear spin with fluctuating magnetic field. The
theory of reducible systems [2] was applied for solving stochastic differential equations. This
mathematical approach was adapted to find the solution of the Schrodinger equation for the timeevolution operator which describes behavior of a nuclear spin in the presence of a radiofrequency
pulsed magnetic field and fluctuating magnetic field. NMR spin echo for I = 1/2 is considered as
the simplest illustration of the method. Unlike classical approaches [3,4], It allows to calculate
spin-echo amplitude correctly over whole period of relaxation without any estimates. The
possibility of application of well-known Ito calculus [5] is also discussed. It was obtained moreaccurate formulae for spin-lattice relaxation time T1 and spin-spin relaxation time T2 .

We studied the emission response of spin transfer vortex oscillators with dynamic
polarizer. In these systems, mutual spin transfer torque between the two ferromagnetic
layers is at the origin of a very rich dynamics. By changing the injected current, we
could gain access to up to three dynamic modes. At high currents, mutual spin transfer
torque is at play and high-frequency dynamics is simultaneously excited in both layers.
The detected mode corresponds to a Slonckzewski’s windmill-like mode, which isstable in a large range of experimental conditions. The mode observed at low currents
corresponds to the commonly observed dynamics in nano-contact vortex oscillators, inwhich the vortex core is far away from the contact and current-in-plane spin-transfer
torque is at play. Surprisingly, we could gain access to a third mode at intermediate
currents, which we ascribe to the precession of a vortex in the thin ferromagnetic layer
under the contact area. This mode is of particular scientific interest because it allows
one to experimentally study the vortex dynamics in the small amplitude limit.

In a number of classical statistical-physical models, there exists a characteristic
dimensionality called the upper critical dimension above which one observes the meanfield critical behavior. Instead of constructing high-dimensional lattices, however,
one can also consider infinite-dimensional structures, and the question is whether
this mean-field character extends to quantum-mechanical cases as well. We therefore
investigate the transverse-field quantum Ising model on the globally coupled networkand on the Watts-Strogatz small-world network by means of quantum Monte Carlosimulations and the finite-size scaling analysis. We confirm that both of the structures
exhibit critical behavior consistent with the mean-field description. In particular,
we show that the existing cumulant method has difficulty in estimating the correct
dynamic critical exponent and suggest that an order parameter based on the quantummechanical expectation value can be a practically useful numerical observable todetermine critical behavior when there is no well-defined dimensionality.

Maxim Pavlovich Shlykov
National Research Centre 'Kurchatov Institute', Russia[1] Kravchenko E. A., Orlov V. G., Shlykov M. P., Magnetic properties of bismuth(III) oxy
compounds, Russian Chemical Reviews, 2006, 75 (1), 77-93 [2] Erougin N., Reducible systems,
Travaux Inst. Math. Stekloff, 1946, 13, 3-96 [3] Redfield A.G., On The Theory of Relaxation
Processes, IBM Journ. Res. Develop., 1957, 1, 19-31 [4] Bloembergen N., Purcell E. M., Pound R.V.,
Relaxation Effects in Nuclear Magnetic Resonance Absorption, Phys. Rev., 1948, 73, 679-712 [5]Gardiner, C. W., Handbook of stochastic methods for physics, chemistry and the natural sciences,
Springer, 1994, 13, 442

Xiaolei Wang, Ning Wang and Antonio RuotoloDepartment of Physics and Materials Science, City University of Hong Kong, Hong
Kong

Spin transfer torque (SST) induced magnetization dynamics is one of the key concepts
in spintronics and intensive studies have been conducted in the last two decades torealize STT based memories (Spin-RAM) and microwave oscillators. Finocchio etal. studied the STT induced magnetization dynamics in magnetic thin-film nanopillar
which has one aperture and found that the rotational dynamics of a vortex-antivortex(VA) pair produces the resistance oscillation [1]. Therefore, it is interesting to study
how the VA-pair dynamics in a multi-contacts system is influenced by the distance
between contacts. We performed micromagnetic simulations of a magnetic thin-film
where the spatially localized spin-polarized current was injected through two nanocontacts and found the rotation of VA pairs. If the distance between two contacts is
so large that the VA pair cannot interfere with each other, they independently rotate
around each contact. In contrast, when the distance becomes small, the single VA pairrotates around a large area in which the two contacts are included and the rotation
frequency drops down to about 60% of that of a single contact. Our results show that
we can control the frequency of the VA pair rotation by changing the distance between
the contacts.
[1] G. Finocchio, O. Ozatay, L. Torres, R. A. Buhrman, D. C. Ralph and B. Azzerboni, Phys. Rev. B
78 174408 (2008)

RI20

RJ01

RJ04

RJ07

Study of cluster heterogeneity scaling in the two-dimentional Ising
model

Vortex core switching on notched circular disks

Key role of temperature in ferromagnetic bloch point simulations

Parametric excitation and subcritical phase-locking in spin-transfer
vortex oscillators

Woo Seong Jo1, Su Do Yi1, Seung Ki Baek2 and Beom Jun Kim1*
1
Department of Physics and BK21 Physics Research Division, Sungkyunkwan
University, Suwon 440-746, Korea
2
School of Physics, Korea Institute of Advanced Study, Seoul 130-722, Korea
The cluster heterogeneity, defined as the number of distinct cluster sizes, was suggested
in [1] as an indicator of the phase transition in the percolation model. Noh et al. [2]found that the conventional finite-size scaling(FSS) form using the correlation-length
exponent ν does not describe the scaling of the cluster heterogeneity in the percolation
model and that the other exponent ν_H should be used instead. We apply the FSS formsuggested in [2] for cluster heterogeneity in the Ising model. Since there are two typesof clusters, (+) and (-) spin clusters, we calculate the heterogeneity of each type (H+and H-, respectively), and carry out FSS near critical temperature. We find that total
heterogeneity (H ≡ H+ + H-) scales with the exponent ν_H, as expected from [2] forthe percolation model.
[1] H.K. Lee, B.J. Kim, and H. Park, Phys. Rev. E 84, 020101(R) (2011). [2] J.D. Noh, H.K. Lee,and H. Park, Phys. Rev. E 84, 010101(R) (2011).

Tomonori Sato* and Yoshinobu Nakatani
University of Electro-Communications, JapanThe vortex core manipulation by field has been frequently reported. However, theminimization of switching field is still being debated. In general, the vortex coreswitching is performed by annihilation of vortex and anti-vortex, however the
nucleation of the pair requires large magnetic field. In this report, we proposed the
new switching mechanism to decrease switching field by using circular disks with
V-shaped notch. When the in-plane pulse field is applied, the vortex core moves to thenotch and annihilates automatically. After the field is switched off, the vortex core getsback by demagnetizing field. The vortex core polarity is controlled by the external field
perpendicular to the disk. In this switching mechanism, the vortex core switching is
performed by only the annihilation and nucleation of the vortex, therefore the switching
field is decreased compared with the circular disks without notch. We investigated thevortex core switching by micromagnetic simulation. A Permalloy disk with 200nm
diameter and 40nm thickness is used in the simulation. The field perpendicular to thedisk was fixed at 50 Oe. The result reveals that the minimum switching field decreases
60% compared with the case using the circular disk without notch.

Kristof M. Lebecki1*, Denise Hinzke1, Oksana Chubykalo-fesenko2 and Ulrich
Nowak1
1
Department of Physics, University of Konstanz, Germany
2
Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid,Spain
A Bloch point (BP) is known to play a crucial role during vortex core switching process [1].
Vortices themselves attract recently much attention since it was suggested to use them as amagnetic storage medium. For such an application BP-related vortex core properties like theswitching speed or stability of the final state are essential. This makes the BP an important
object of study. We present here results of numerical simulations, where the BP at elevatedtemperature is investigated. Our approach makes it possible to model its behavior without
problems related to its singular character [1,2] - as opposed to all BP simulations presented
in the literature so far. We have included temperature effects via Landau-Lifshitz-Blochequation [3]. Our implementation, basing on the OOMMF code, allow us to compare resultsof analytical theories with modern numerical approach. We focus our attention on permalloy
and conduct studies in the full temperature range. Firstly, we will present results of modelingan artificially pinned BP. This reveals details of its geometry, including its temperaturedependent radius. Secondly, we will present results of dynamical studies, where the vortex
core switches via nucleation, propagation and annihilation of a BP.

Paolo Bortolotti1*, C. Serpico2, E. Grimaldi1, J. Grollier1, V. Cros1, A. Fukushima3, H.
Kubota3, K. Yakushiji3, S. Yuasa3, K. Ando3 and A. Fert1
1
Unite Mixte de Physique CNRS/Thales, France
2
Dipartimento di Ingegneria Elettrica,Universita di Napoli 'Federico II', Italy
3
National Institute of Advanced Industrial Science and Technology (AIST), Japan

In the last decade several systems have been proposed to design low power consuming nano-oscillators.
One promising example is a MgO tunnel junction with a vortex free layer[1,2] (STVO). Classically,
oscillations at its natural frequency f_0 are obtained for currents larger than a critical value Ic. However, byapplying a rf-excitation current at 2f_0, i.e., parametric excitation[3,4], it is possible to force the system into
oscillation even in the subcritical current regime (I<Ic). The characteristics of such oscillation (emitted power
and linewidth) are not comparable to the ones obtained in the super-critical regime. Here we present thesynchronization of a parametric excitation to its own source in the subcritical regime. If I<Ic, no oscillation
is observed. If we inject a rf-current (-25 dBm) at 2f_0, a small signal (parametric excitation) appears. Whenthe rf-power is further increased (up to -15 dBm), the parametric signal gets synchronized. The resulting
oscillation has the characteristic of the synchronized signal even though is obtained at sub-critical currents.
Both mechanisms can be explained in the frame of non-linear vortex dynamics. Comparisons between theanalytical approach and experimental results are presented. Support from ANR VOICE PNANO-09_P23136, EU MASTER NMP-FP7-212257 and CANON-ANELVA for MTJ film are acknowledged.

1. S. Gliga, Y. Liu, and R. Hertel, J. Phys.: Conf. Ser., 303, 012005 (2011). 2. A. Thiaville, J. M. Garcia, R.
Dittrich, J. Miltat, and T. Schrefl, Phys. Rev. B 67, 094410 (2003). 3. D. A. Garanin, Phys. Rev. B 55, 3050 (1997).

[1] A. Dussaux et al., Nat. Comm. 1 1 (2010) [2] A.V. Khvalkovskiy et al, Phys. Rev. B 80 140401(R) (2009)[3] S. Urazhdin et al., Phys. Rev. Lett. 105, 237204 (2010) [4] S.Y. Martin Phys. Rev. B 84, 144434 (2011)

RI21

RJ02

RJ05

RJ08

Zero-temperature phase transition in a one-dimensional Ising
ferromagnet using Glauber dynamics with a synchronous update

Effect of oersted field on magnetic vortex core gyration

Polarization-selective signal propagation in a chain of vortices

Micromagnetic simulation for controlling the magnetic vortex chirality
by current-induced Oersted field

Il Gu Yi and Beom Jun Kim*
Physics, Sungkyunkwan University, Korea

Resently Glauber dynmaics for the one-dimensional Ising spin system at lowtemperature is studied variously not only experimentlly but also theoritically in thenano molecular system. Sznajd-Weron [Phys. Rev. E 82, 031120 (2010)] study theferro anti-ferro phase transition of the density of active bonds, and the behaviorof the relaxtion time which means the time needed to reach to steady state in thegeneralized zero temperature Glauber dynamcis. They suggested in that paper that the
one-dimensional Ising model subject to the zero-temperature synchronous Glauber
dynamics exhibits a discontinuous phase transition. We show here that the phasetransition instead of a continuous nature, and we identify critical exponents, \beta\approx 0, \nu \approx 1, and z \approx 2 via a systematic finite-size scaling analysis.
1. K. Sznajd-Weron, Phys. Rev. E 82, 031120 (2010). 2. N. Goldenfeld, Lectures on Phase
Transitions and the Renormalization Group (Addison-Wesley, Boston, 1992).

Tomonori Sato1*, Yoshinobu Nakatani1 and Teruo Ono2
1
University of Electro-Communications, Japan
2
Kyoto University, Japan

Recently, the vortex core manipulations by spin current are studied intensively.
Because spin current creates the Oersted field, there are some reports, which study
the effect of the field on the vortex core motion. When the vortex core is manipulatedby the current, the electrodes are usually attached on top of the disk. Therefore, thecurrent goes in and out from the top surface of the disk mainly. It makes the current
non-uniform, and it makes the Oersted field complex. In this work, we report the effectof the Oersted field and the current distribution on the vortex core gyration by ACcurrent by micromagnetic simulation. A Permalloy circular disk with 1.5μm diameterand 40nm thickness is used in the simulation. The AC current density is 2.66x1011A/
m2 mainly. The current frequency is varied around the resonant frequency of the
disk. The result reveals that the effect of the Oerstead field changes by the current
density, however the percentage of the effect of the Oersted field on the driving force
is 8% in maximum. Furthermore, the vortex core is affected by not only the in-planecomponents but also the out-of-plane component.

Andreas Vogel1*, Michael Martens1, Markus Weigand2 and Guido Meier1
1Institut fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung,
Universitaet Hamburg, Germany
2
Max-Planck-Institut fuer Intelligente Systeme, Germany
Dynamics on the subnanosecond time scale and potential technological applications give rise toa broad scientific interest in the dynamic properties of ferromagnetic microstructures with vortex
magnetization configuration. An excitation of the low frequency mode of gyration can be transferred
via dipolar interaction between neighboring ferromagnetic elements with the transfer efficiency
strongly depending on their separation and the relative configuration of the vortex-core polarizations [1].
The dependence on the core polarizations can be understood considering the time-dependent shapeof the external stay field. We employ time-resolved scanning transmission x-ray microscopy to study
the vortex-core dynamics in a chain of three stray-field coupled permalloy squares. After exciting thefirst element via a short in-plane magnetic field pulse, the excitation can be transferred through thechain. No response is observed in the third square for equal core polarizations of all elements but theexcitation can be transferred through the chain just by changing the polarization in the central element.
For alternating polarizations, a transfer efficiency of about 56% to the third square is achieved. The
chain can be switched back and forth between the transmitting and a locking state [2].
[1] A. Vogel, T. Kamionka, M. Martens, A. Drews, K. W. Chou, T. Tyliszczak, H. Stoll, B. Van
Waeyenberge, and G. Meier, Phys. Rev. Lett. 106, 137201 (2011); H. Jung, K.-S. Lee, D.-E. Jeong, Y.-S.
Choi, Y.-S. Yu, D.-S. Han, A. Vogel, L. Bocklage, G. Meier, M.-Y. Im, P. Fischer, and S.-K. Kim, Sci. Rep. 1,
59 (2011). [2] A. Vogel, M. Martens, M. Weigand, and G. Meier, Appl. Phys. Lett. 99, 042506 (2011).

282

Hiroshi Tsukahara, Hiroko Arai and Hiorshi Imamura*
AIST, JapanThe 19th International Conference on Magnetism

July 12 (Thu)

Su Do Yi1, Seung Ki Baek2, Jaegon Um2 and Beom Jun Kim1*
1
Department of Physics and BK21 Physics Research Division, Sungkyunkwan
University, Suwon 440-746, Korea
2
School of Physics, Korea Institute of Advanced Study, Seoul 130-722, Korea

July 12 (Thu)poster Presentation

Syuta Honda1*, Hiroyoshi Itoh2, Satoshi Yakata3 and Takashi Kimura3
Faculty of Pure and Applied Sciences, University of Tsukuba, Japan2
Department of Pure and Applied Physics, Kansai University, Japan
3
Advanced Electronics Research Division, INAMORI Frontier Research Center,
Kyushu University, Japan1

The polarity and the chirality are the magnetization direction and the magnetization curling of themagnetic vortex core, respectively. It is an important issue for developments of spintronics to control
these quantities. The magnetic polarity is easily controlled by an external magnetic field. However,
the magnetic chirality (MC) is not easily controlled. Recently, the MC in permalloy disks has been
controlled by the shape of the disk [1] and a current-induced Oersted field[2]. We study magnetization
dynamics for magnetization switching under the current-induced Oersted field at the permalloy thinfilm. By performing micromagnetic simulations based on the Landau-Lifshitz-Gilbert equation, weinvestigate an optimum condition for controlling the MC. We have calculated the magnetization
reversal process in the permalloy thin film under an external uniform magnetic field. Three types ofmagnetization structure have been observed during the magnetization switching without an electricalcurrent: a clockwise structure, a counterclockwise structure, and non-vortex core. Using the Oersted field
induced by an electrical current perpendicular to the thin film, we have successfully obtained the only
clockwise structure (or counterclockwise structure). Details of the results and analysis will be reported.
[1] S. Yakata, M. Miyata, S. Nonoguchi, H. Wada and T. Kimura, Appl. Phys. Lett., 97, 222503 (2010) [2]
S. Yakata, M. Miyata, S. Honda, H. Itoh, H. Wada, and T. Kimura, Appl. Phys. Lett., 99, 242507 (2011)

July 8-13, 2012 Busan, Korea

283

poster Presentation
RJ09

RJ12

RJ15

RJ18

Stability of the vortex structure on the core switching by AC current

Magnetic vortex dynamics in exchange-biased micron-sized structures

Switching dynamics of vortex cores in nanodots by azimuthal-spinwave-mode excitation

Vortex-gyration transfer rate and energy attenuation in coupled
nanodisks

July 12 (Thu)

Recently, magnetic disks with a vortex core have been considered as one of thecandidates for the storage devices, and many reports relating to the core switching by
spin current have been reported. Because the storage capacity depends on the magnetic
disk size, it is important to investigate the stability of the vortex structure on its size.
Until now, the disk size that the core can switch stable has not been reported. In thiswork, we investigate the stability on the core switching by micromagnetic simulation.
In the simulation, two methods are used, the method by the core switching simulation
by AC spin current and the method by the evaluation of the magnetic energy. The
switching simulation reveals that the core does not switch around the transition
dimension of magnetic disks between single-domain structure and the vortex structure
on a remanent state, and the disk diameter needs to be increased about 20 to 80 nm
for the stable core switching compared with the stability limit on the remanent state.
Furthermore, the result of the energy evaluation agreed with the result obtained by theswitching simulation. Therefore, the stability on the core switching can be estimated by
the magnetic energy.

Sofia De Oliveira Parreiras1*, Flavio Garcia2 and Maximiliano Delany Martins1
1
Applied Physics Laboratory, CDTN/CNEN, Brazil
2
Laboratorio Nacional de Luz Sincrotron, Brazil

The study of magnetic dots with magnetic vortex spin configuration has recently
attracted great scientific interest [1]. The great potential of applications of magnetic
vortices (as for example magnetic memories and nanoparticles for cancer treatment)draws attention for the investigation of vortex proprieties. In this work, we studied the
dynamics proprieties of exchange-biased vortex using the code OOMMF (NIST) [2]that applies the Landau-Lifshitz-Gilbert equation to simulate the spin configuration andcompute the energy and magnetization of microstructures. A series of micromagnetic
simulations for Permalloy/Fe50Mn50 disks with 0.5 ?m of diameter was done varying
the magnetic coupling constant between the layers. We had observed that the vortex
gyrotropic movement has a variable frequency that increases with the time, which is
not observed when exchange bias is absent. Under a rotating magnetic field acting in
the disks, the critical velocity for vortex polarity reversion increases with the coupling
constant and frequency. Our results show that the critical velocity can be adjusted in awide range by selecting the magnetic coupling constant and the oscillating frequency,
i.e., it is possible to control the critical velocity for vortex polarity inversion throughthe exchange bias coupling.

Myoung-woo Yoo, Jehyun Lee and Sang-koog Kim*
National Creative Research Initiative Center for Spin Dynamics & Spin-Wave Devices & Nanospinics
Lab, Research Institute of Adv. Materials, Dep. of Materials Sci. & Eng., Seoul Nat'l Univ., Seoul, Korea
Owing to a possibility of implementations of magnetic vortices in future information-storage devices,
vortex-core reversals have attracted much attention [1]. Very recently, ultrafast, low-power-driven coreswitching by azimuthal spin-wave mode was experimentally demonstrated [2]. Since their quantitativeinterpretation and deeper understanding remain elusive, we start to elucidate the underlying physics of theswitching dynamics. In this study, we performed micromagnetic simulations on a Permalloy disk of 302
nm diameter and 50 nm thickness. We correlate the critical velocities (vc) and gyrofields (hz,cri) to the coreswitching driven resonantly by azimuthal mode excitations. For given disk’s dimensions and geometry
used here, the vc increases to ~400 and ~700 m/s for m = -1 (clockwise) and +1 (counter-clockwise)modes, respectively, although vc is known to be ~330 m/s for the gyration-mode-assisted-core-switchingmechanism [3]. This difference originates from the difference of hz,cri between the gyration mode andazimuthal mode driven core switching mechanisms because the magnetization dip of mz = -1 is necessary
for the switching. From our calculations, hz,cri are estimated to be ~7 kOe and ~11 kOe for CW and CCW
azimuthal mode excitations, compared to the value of hz,cri = 3.3 kOe for the gyration mode excitation [4].

Ji-hye Kim, Ki-suk Lee, Hyunsung Jung, Dong-soo Han and Sang-koog Kim*
National Creative Research Initiative Center for Spin Dynamics & Spin-Wave Devices& Nanospinics Lab, Research Institute of Adv. Materials, Dep. of Materials Sci. &Eng., Seoul Nat'l Univ., Seoul, Korea
One of the most important research goals in current information-signal processing technologies is to enhancesignal-processing speed and to reduce energy loss[1]. In recent electronic devices, information-signal transports
are based on the motion of electron charges. Interestingly, coupled vortex oscillations in nanodots can be used
as an alternative mechanism of information-signal processing[2-4]. Here, we report a study of, by analyticaland micromagnetic numerical calculations, information-signal transfer in vortex-state nanodisks that isavailable with assistance of vortex-gyration transfer through the dynamic dipolar interaction. We analyticallyderived the vortex-gyration transfer rate and energy attenuation that are both technologically essential
parameters for controlling signal processing speed and energy loss in signal processing devices. It is found thatthe transfer rate can be controlled by the relative polarization configuration p1p2, the saturation magnetization
Ms, and the radius (R)-to-thickness (L) ratio R/L of given magnetic disks as well as interdistance. The energy
attenuation is governed by not only the intrinsic damping constant of a given material, but also the values of
Ms, L, and R. The analytical results are in reasonable agreements with micromagnetic simulation results. This
work provides a foundation of manipulating information-signal processing between vortex-state networks.

[1] C. L. Chien, F. Q. Zhu, and J.-G. Zhu, Physics Today 60, 40 (June, 2007) [2] M. J. Donahue andD. G. Porter, http://math.nist.gov/oommf/*Corresponding author: sangkoog@snu.ac.kr [1] B. Van Waeyenberge et al., Nature (London) 444, 461 (2006);
S. -K. Kim et al., Appl. Phys. Lett. 92, 022509 (2008). [2] M. Kammerer et al., Nat. Commn. 2:279 doi: 10.1038/
ncomms1277 (2011). [3] K.-S. Lee et al., Phys. Rev. Lett., 101, 267206 (2008). [4] M.-W. Yoo et al., Phys. Rev. B, 82,
174437 (2010). [5] This work was supported by the Basic Science Research Program through the National Research
Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology (No. 20110000441).

* Corresponding author : sangkoog@snu.ac.kr. [1] K. Bernstein et al., Proc. IEEE 98, 2169 (2010). [2] H. Jung et al., Appl. Phys.
Lett. 97, 222502 (2010). [3] H. Jung et al., Sci. Rep. 1, 59; DOI:10.1038/srep00059 (2011). [4] S. Barman et al., IEEE Trans. Magn.
46, 1342 (2010). [5] A. Vogel et al., Phys. Rev. Lett. 106, 137201 (2011). [6] This work was supported by the Basic Science Research
Program through the NRF of Korea funded by the Ministry of Education, Science and Technology (Grant No. 20110000441).

RJ10

RJ13

RJ16

RJ19

Time-averaged observation of magnetic vortex resonated in squareshaped NiFe films

Magnetic Vortex Echo

Logic operations based on magnetic-vortex-state networks

Effect of spin-motive force and spin-diffusion on a vortex dynamics

Motoi Kodama1, Koji Sekiguchi2 and Yukio Nozaki3*
1
Department of Physics, Keio University, Japan2
Department of Physics, Keio University, JST PRESTO, Japan3
Department of Physics, Keio University, JST CREST, Japan

A dynamics of magnetic vortex confined in a patterned ferromagnetic thin film attracts
much attention for both the fundamental and the technological points of view. The
observation of the trajectory of magnetic vortex core excited with an application ofac magnetic field or ac current is significant for the quantitative understanding of spin
dynamics. In this study, a time-averaged observation of magnetic vortex resonatedin square-shaped NiFe thin film was demonstrated by means of magnetic force
microscopy (MFM) to obtain the trajectory. A 30 nm-thick NiFe film with the lateralsize of 1x1um2 was fabricated on a coplanar waveguide that generates an ac magnetic
field of 1mT in amplitude. The resonant frequency of the magnetic vortex formed in the
NiFe film was calculated to 260 MHz that is much higher than the sampling frequencyof MFM. When the ac magnetic field with a frequency of 260 MHz was applied, acircular pattern with a uniform magnetic contrast appeared in the vicinity of center of
the NiFe film. The diameter of the circle is comparable with that of the trajectory ofmagnetic vortex core calculated with micromagnetic simulation.

Flavio Garcia1*, Joao Paulo Sinnecker2, Erico Novais2 and Alberto Passos Guimaraes2
1
Brazilian Sinchrotron Light Laboratory, Brazil
2
Centro Brasileiro de Pesquisas Fisicas, Brazil
The interest of magnetic vortices has greatly grown in the last years since these systems
present a myriad of promising applications, which are mainly related on their dynamics
aspects. When the vortex core is excited from its equilibrium position, it relaxes ina spiral motion, with a very well defined frequency, which is inversely proportional
to the disk aspect ratio. The sense of the gyrotropic motion is determined by the corepolarity. So, controlling the polarity, it is easy to control the sense of gyrotropic motion.
In this work, we analytically shown that, properly manipulating the dynamic propertiesof the vortex, namely its polarity, in an analogous way as it is done in Nuclear
Magnetic Resonance, it is possible to generate a magnetic vortex echo (MVE). Thisecho is similar to the spin echo, and it may provide fundamental information about the
dynamic properties of real arrays of vortices, e.g., magnetic coupling, inhomogeneities,
magnetic stability etc. To illustrate the MVE, we performed micromagnetic simulationof arrays of nanodisks, where it has been varying their most significant parameters toprove that the MVE can give significant information about the dynamic properties of
the real array of disks.

Hyunsung Jung1, Youn-seok Choi1, Dong-soo Han1, Young-sang Yu1, Ki-suk Lee1,
Mi-young Im2, Peter Fischer2 and Sang-koog Kim1*
1
National Creative Research Initiative Center for Spin Dynamics & Spin-Wave
Devices & Nanospinics Lab, Research Institute of Adv. Materials, Dep. of Materials
Sci. & Eng., Seoul Nat'l Univ., Seoul, Korea
2Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA
94720, USA
Logic operations based on coupled magnetic vortices were experimentally demonstrated. We utilized asimple chain structure consisting of three physically separated but dipolar-coupled vortex-state Permalloydisks as well as two electrodes for application of the logical inputs. We directly monitored the vortex
gyrations in the middle disk, as the logical output, by time-resolved full-field soft X-ray microscopy
measurements. By manipulating the relative polarization configurations of both end disks, two different
logic operations are programmable: the XOR operation for the parallel polarization, and the OR operation
for the antiparallel polarization. This work paves the way for new-type programmable logic gates basedon the coupled vortex-gyration dynamics achievable in vortex-state networks. The advantages are as
follows: a low-power input signal by means of resonant vortex excitation, low-energy dissipation during
signal transportation by selection of low-damping materials, and a simple patterned-array structure.

Jung-hwan Moon1, Aurelien Manchon2 and Kyung-jin Lee1*
1
Department of Materials Science and Engineering, Korea University, Seoul 136713, Korea
2
Materials Science and Engineering, Division of Physical Science and Engineering,
KAUST, Thuwal 23955, Saudi Arabia
Theoretically, it is known that the dynamics of magnetic texture highly depends on
damping (α) and non-adiabatic parameter (β). However, the value of β is controversial
both theoretically and experimentally. Moreover, it was recently reported that α and β are
also affected by the spin configuration. The former comes from spin-motive force(SMF)[1, 2] and the latter comes from torque which is exerted from spin-diffusion [3]. In orderto understand the spin dynamics under complex spin texture, it is needed to study theeffect of SMF and spin-diffusion on α and β. In this work, we performed micromagnetic
simulation using LLG equation with spin torque term, SMF, and spin-diffusion. The currentinduced dynamics of a vortex core is micromagnetically modeled using a computationalframework based on the fourth-order Runge-Kutta method. The model system is a circular
Permalloy disk with the thickness of 20 nm and the diameter of 270 nm which is vortex
favored dimension. Initial trajectory with spin-diffusion was shifted along y-axis direction
compared to that without spin-diffusion. It is because that the initial motion of a core motion
is governed by non-adiabaticity [4]. The further studies will be discussed in detail.

ArXiv:1201.3553*Corresponding author: sangkoog@snu.ac.kr This research was supported by the Basic Science Research Program throughthe National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science, and Technology (grantno. 20110000441). The operation of the microscope was supported by the Director, Office of Science, Office of Basic Energy
Sciences, Materials Sciences and Engineering Division, U.S. Department of Energy, under contract no. DE-AC02-05-CH11231.

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Diverging-converging spin vortex pairs in biquadratically interlayer
exchange coupled elements

Origin of the dipolar coupling between vortex-state disks

Vortex-gyration-mediated magnonic crystals

Soft X-ray microscopy of non-linear magnetic vortex core motion

Sebastian Wintz1*, Christopher Bunce1, Anja Banholzer1, Michael Koerner1, Sibylle
Gemming1, Artur Erbe1, Joerg Raabe2, Christoph Quitmann2 and Juergen Fassbender1
1Helmholtz-Zentrum Dresden-Rossendorf, Germany
2
SLS, Paul Scherrer Institut, Switzerland

Spin structures have been an interesting topic of magnetism research for many years.
Within this field, magnetic vortices have attracted much attention, due to their nontrivial topology and the various dynamic modes they exhibit [1]. A magnetic vortex
consists of a planar, flux-closing magnetization curl that turns out of the plane in thecentral nanoscopic core region. In a single layer structure, the curl’s radial components
typically cancel each other out. Recent investigations show that this also holds true
for multilayer vortex systems with bilinear interlayer exchange coupling [2]. Here
we report on pairs of diverging-converging spin vortices occurring in biquadraticallycoupled systems. Using magnetic scanning transmission x-ray microscopy (STXM)
we directly observe that the individual vortices of such pairs possess a residual radial
magnetization component, i.e. ∇Mxy≠0. This implies an additional perpendicularmagnetization divergence ∇Mz, for which we compare a continuous model withdiscrete micromagnetic simulations.
[1] S.-B. Choe et al., Science 304, 420 (2004). [2] S. Wintz et al., Appl. Phys. Lett. 98, 232511 (2011).

The 19th International Conference on Magnetism

Ki-suk Lee and Sang-koog Kim*
Seoul National University, Korea

Coupled vortex gyrations in spatially separated nanodisks have been studied theoretically[1,2],
experimentally[3-8], and numerically[9] owing to their possible applications as an alternative to current
signal processing devices with the advantage of negligible energy loss[7]. Fundamental phenomena
such as eigenfrequency splitting and its dependence on dot-to-dot interdistance[3,4,7] have been verified
experimentally and explained well by the normal mode representation[7,9]. In this work, we studied dynamic
dipole interaction of coupled vortex gyrations observed in two disks by micromagnetic simulation andanalytical approaches. Shibata et al.[1] reported that, based on rigid vortex model [10], the dynamic dipolarinteraction of the coupled vortex gyrations originates from the magnetostatic interaction that is induced by theside surface charges of each disk during the gyrations [1,2]. We extracted the interaction energies of the twodipolar-coupled disks and compared those that are obtained directly from the micromagnetic simulations andobtained from spin configurations based on two different side-charge-free[10] and rigid-vortex models. The
simulation result is in better agreement with the side-charge-free-model-based spin configurations than therigid-vortex-model one. These results imply that the dipolar energy of the coupled gyrations of neighboring
vortex-state disks originates dominantly from not the side surface charges of each disk, but the volume charges.
This work was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) fundedby the Ministry of Education, Science and Technology(No. 20110000441). [1] J. Shibata et al.,Phys. Rev.B 67,224404(2003).
[2] O.V. Sukhostavets, et al.,Appl. Phys. Express 4,065003(2011). [3] A. Vogel et al.,Phys. Rev. Lett.105,037201(2010). [4] S.
Sugimoto et al.,Phys. Rev. Lett.106,197203(2011). [5] A. Barman et al.,J. Phys. D.43,422001(2010). [6] H. Jung et al.,Appl.
Phys. Lett.97,222502(2010). [7] H. Jung et al.,Sci. Rep. 1,59;DOI:10.1038/srep00059(2011). [8] A. Vogel et al.,Phys. Rev.
Lett.106,137201(2011). [9] K.-S. Lee et al.,J. Appl. Phys.110,113903(2011). [10] K. Y. Guslienko et al.,J. Appl. Phys.91,8037(2002).

Dong-soo Han and Sang-koog Kim*
National Creative Research Initiative Center for Spin Dynamics & Spin-Wave Devices& Nanospinics Lab, Research Institute of Adv. Materials, Dep. of Materials Sci. &Eng., Seoul Nat'l Univ., Seoul, Korea
Recently, mutual energy transfer between spatially separated magnetic disks has been studied and interpreted
based on a coupled-vortex-oscillator model [1-5]. This novel energy-transfer mechanism provides theadvantages of tunable energy transfer rate, low-power input signal, and extremely low energy dissipation
for the case of using negligible damping materials. Here, we extended this study into magnonic crystals of
one-dimensional (1D) and 2D arrays of dipolar-coupled magnetic disks. We analytically and numerically
explored the fundamental modes of collective vortex-gyration excitations in such 1D and 2D disk-arraymagnonic crystals of four different ordering of vortex polarization (p) and chirality (C) states. Both theanalytical and numerical calculations show excellent quantitative agreement on contrasting dispersion
branches for different orderings of p and C states. Such collective vortex-gyration modes can be understoodin terms of the energy variation of dynamic dipolar interaction between the neighboring vortex-state disks.
These results provide for the possibility of vortex-gyration-mediated magnonic crystals as applications for
future signal processing devices, offering the advantages of low energy dissipation and low power input.
This work was supported by Basic Science Research Program through the National Research Foundation of
Korea (NRF) funded by the Ministry of Education, Science and Technology (No. 20110000441).
*Corresponding author: sangkoog@snu.ac.kr [1] J. Shibata et al., Phys. Rev. B 67, 224404 (2003). [2] J.
Shibata et al., Phys. Rev. B 70, 012404 (2004) [3] S. Barman et al., IEEE Trans. Mag. 46, 1342 (2010) [4] H.
Jung et al., Appl. Phys. Lett. 97, 222502 (2010); H. Jung et al., Sci. Rep. 1, 59 ; DOI:10.1038/srep00059 (2011);
A. Vogel et al. Phys. Rev. Lett. 106, 137201 (2011); S. Sugimoto et al. Phys. Rev. Lett. 106, 197203 (2011). [5]K.-S. Lee et al., J. Appl. Phys. 110, 113903 (2011); O.V. Sukhostavets, Appl. Phys. Express 4, 065003 (2011).

July 12 (Thu)Tomonori Sato* and Yoshinobu Nakatani
University of Electro-Communications, Japan284

poster Presentation[1] S. Zhang and S.-L. Zhang, Phys. Rev. Lett. 102, 086601 (2009). [2] J.-H. Moon, S,-M. Seo, and K.-J. Lee, IEEE Trans. Magn.,
vol. 46, p.2167 (2010) [3] A. Manchon, W.-S. Kim, and K.-J. Lee, unpublished. [4] J.-H. Moon et al., Phys. Rev. B 79, 134410 (2009).

Peter Fischer1, Brooke Mesler1, Mi-young Im1 and Kristen Buchanan2
CXRO, LBNL, USA
2
Colorado State U, USA
1

Magnetism on the nanometer length scale and its fast spin dynamics is a scientficallyhighly attractive and technologically relevant topic. It addresses fundamental magnetic
length scales e.g. magnetic exchange lengths in the sub-10nm range and fast timescales in the sub-ns regime where precessional and relaxation phenomena, domain
wall motion and vortex dynamics occur [1,2]. New technological concepts such as
spintronics require precise control the electron spin on a nanoscale with psec timing.
We use time magnetic soft X-ray microscopy providing a spatial resolution down
to 10nm and a temporal resolution below 100ps [3]. As one example, we reportexperimental results showing non-linear behavior in the resonant excitation ofmagnetic vortex cores with increasing amplitude of the exciting magnetic AC fields[4]. Supported by the Director, Office of Science, Office of Basic Energy Sciences,
Materials Sciences and Engineering Division, of the U.S. Department of Energy.
[1] L. Bocklage, et al. Phys Rev B 81, 054404 (2010) [2] S. Kasai, et al Phys Rev Lett 101, 237203(2008) [3] P. Fischer, Materials Today 13(9) 14 (2010) [4] B. Mesler et al J.Appl. Phys. (2012) inprint

July 8-13, 2012 Busan, Korea

285

poster Presentation
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Dynamics of successive minor hysteresis loops

On the relation between the magnetoelastic effect and the damping
constants of (Ni-Fe)1-xMx (M = Ag, Cr, Ga, Au, Pd, and Pt) films

Observation of non-kittel ferromagnetic resonance in Co/Cu
multilayer system

Composition dependence of the gilbert damping constant for co-basedheusler alloy

July 12 (Thu)

Cumulative growth of successive minor hysteresis loops in Co/Pd multilayers withperpendicular anisotropy was studied in the context of time dependent magnetization
reversal dynamics. We show that in disordered ferromagnets, where magnetization
reversal involves nucleation, domains’ expansion and annihilation, differences between
the time dependencies of these processes are responsible for accumulation of nuclei for
rapid domain expansion, for the asymmetry of forward and backward magnetization
reversals and for the respective cumulative growth of hysteresis loops. Loops stopchanging and become macroscopically reproducible when populations of upwardand downward nucleation domains balance each other and the respective upward anddownward reversal times stabilize.

Yasushi Endo*, Yoshio Mitsuzuka, Yutaka Shimada and Masahiro Yamaguchi
ECEI, Graduate School of Engineering, Tohoku University, JapanThe dynamics of magnetic thin films have received attention in magnetic device
applications such as recording heads, media, and MRAM. Although the dynamics
significantly depend on the damping constant α, which determines the strength of
damping torque in magnetic thin films, details about their damping mechanism,
especially the magnetoelastic effect on damping remain unclear. Herein to clarify theeffect of λs on α in (Ni-Fe)1-xMx films in detail, we evaluated α and λs in these films.
For M= Au, Pd, and Pt, α increases linearly and negative λs increases as x increases. In
contrasts, α and positive λs tend to increase almost linearly with x when M=Ag, Cr, and
Ga. These results provide clear evidence that α is correlated with λs in (Ni-Fe)-M films.
Furthermore, increments of α and the absolute value of λs to x are markedly enhancedin the order of M = Pt, Au, Pd, Cr, Ag, and Ga, suggesting that 5d transition metal
dopants are more influential on both α and λs than 3d and 4d transition metal dopants
due to the strong spin-orbit interaction of 5d dopants. Consequently, these results
demonstrate that a change in magnetostriction energy via transition metal dopants caneffectively control α.

Faris B. Abdul Ahad1, Yu-che Chiu1, Shang-fan Lee2* and Dung S Hung3
1
Institute of Physics, Academia Sinica, Taiwan
2
Institute of Physics, Academia Sinica, Taiwan
3
Information and Telecommunications Engineering, Ming Chuan University, Taiwan

In this research, we study the ferromagnetic resonance behavior (FMR) of Co/Cu multilayer system.
The samples stacking Ta (5nm) / [Co (4nm) / Cu (t)]*10 / Ta (5nm) with t = 0.5 ? 6 nm were preparedby dc magnetron sputtering in a multitarget sputtering chamber at room temperature and 1 mTorr of pureAr-pressure. The magnetoresistance (MR) was measured by the standard four point measurement withcurrent in plane (CIP) configuration using Quantum Design Physical Properties Measurement System(PPMS). The magnetic hysteresis loops were recorded using a Vibrating Sample Magnetometer (VSM).
FMR responses were measured at microwave frequencies by means of a Vector Network Analyzer (VNA)
equipped with a low pass filter circuit. Clear FMR responses were recorded for all samples, however,the noise increased for samples with thicker spacer. Then resonance frequencies (fr) acquired from FMR
responses. Theoretically, this FMR should follow Kittel frequency given by: fr=(γ/2π)√H(H+4πM).
However, our results shows that the resonace linewidth and the deviation of resonance frequency fromkittel behavior will increases as the spacer thickness increased. This behavior is the result of RKKY
interaction evident by the increased GMR and will be dicussed within the manuscript.

Yuichi Kasatani1, Shinya Yamada2, Masanobu Miyao3, Kohei Hamaya4, Hiroyoshi Ito5 and Yukio Nozaki6*
Department of Physics, Keio University, Japan2
Department of Electronics, Kyushu University, Japan3
Department of Electronics, Kyushu University / CREST, JST, Japan
4
Department of Electronics, Kyushu University / PREST, JST, Japan
5 Department of Pure and Applied Physics, Kansai University / CREST, JST, Japan
6 Department of Physics, Keio University / CREST JST, Japan
1

Spin polarized current attracts much attention to operate the magnetic memory devices. To reduce thespin current density, the materials with small Gilbert damping are needed. Recently, it is reported that the
Gilbert damping constant of Co-based Heusler alloy known as half-metallic ferromagnet is less than 0.01[1],although the Gilbert damping factor of Co-based Heusler alloy are closely related to crystalline structure
and concentration ratio. In this study, to understand the damping mechanism in high-quality L21-type Cobased Heusler alloy we measured ferromagnetic resonance (FMR) and estimated the Gilbert damping
factor. 25 nm thick L21-type Co2-xFexSi (x=0, 1, 1.5) films for which degree of crystalline order were foundto be about 70%[2] were grown on Si(111) substrates. The saturation magnetization of Co2-xFexSi with
x=0, 1, 1.5 are 1106, 1023 and 980 emu/cm3, respectively. SiO2 insulating layer and coplanar waveguides(CPW) which consists of Ti (5 nm)/Au (60 nm) were prepared. Following that, FMR was measured
using a vector network analyzer. The results show the Gilbert damping constant inversely proportional
to saturation magnetization. Considering the electron density of state from the ab initio calculation, thebroadening of FMR spectra is considered to be related to the electron density of state.

This work is partly supported by KAKENHI (No. 23686047) from MEXT, Japan, A-STEP from JST,Japan, and SRC.

1. N. Smith and P. Arnett, Appl. Phys. Lett. 78, 1448 (2001). 2. N. Smith, J. Appl. Phys. 90, 5768 (2001). 3. J. C. Jury, et.al,IEEE Trans. Magn. 38, 3545 (2002). 4. Z. Jin and H. N. Bertram, IEEE Trans. Magn. 38, 2265 (2003). 5. Abdul Ahad F.
B., Hung D. S., Chiu C. Y. and Lee S. F., IEEE Trans. Mag. 47, 4227 (2011). 6. Hung, D. S.; Fu, Y. P.; Lee, S. F.; Yao, Y. D.;
Abdul Ahad, Faris B, J. Appl. Phy. 107, 09A503 (2010). 7. B. Heinrich and J.F. Cohran, Adv. Phys. 42, 523 (1993).

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Gilbert damping constants of exchange biased NiFe/FeMn bilayers

Ultrafast magnetization dynamics of ferromagnetic systems inducedby mid infrared laser pulses

Neighboring layer dependence of ultrafast thermo-magnetic property
in GdFeCo films

Detection of picosecond magnetization dynamics of 50 nm magnetic
dots down to the single nanodot regime

The aim of the present study is to show how the ultrafast demagnetization and thesubsequent rapid re-magnetization occur when exciting a ferromagnetic material withlow energy infrared pulses. We have used mid-infrared femtosecond laser pulses (λ=[3-10 μm]) to excite CoPt3, Ni and Co ferromagnetic thin films. The magneto-opticalresponse is then probed in the visible (λ = 798nm). Our results show that even though
only intraband transitions occur, the demagnetization process and its subsequentrelaxation to the lattice and to the environment are still the dominant processes
involved in the magnetization dynamics. We also show that the material band structure
is important to interpret the thermalization dynamics of the spins that occur before
the heating of the lattice. For specific experimental configurations, we show that it ispossible to induce a motion of precession of the magnetization around the effective
magnetic field and observe it while it is damped. The magnetization dynamics induced
at 6.5 μm in nickel shows an oscillatory behaviour with a period of 2 ps. We attribute
this result to the excitation of a two-magnons mode on the NiO by an acoustic mode
generated in nickel.

Femtosecond pulsed laser light allow excitation of magnetic systems much shorter than the time scale ofthermal diffusion represented by conventional Fourier's law. In this time scale, heating and demagnetization
phenomena arise via strongly non-equilibrium non-adiabatic way, and cannot be explained by conventional
equilibrium thermo dynamics description[1]. In this study, we investigated the neighboring layer dependenceof ultrashort laser-induced thermal/magnetic response in layered GdFeCo films by all-optical pumpprobe method. Simultaneously, change of normalized reflectivity was measured for monitoring the time
evolution of electron temperature Te. We designed layered structures as same 20 nm thick GdFeCo withdifferent neighboring layers (conductive AlTi and insulating SiN). We found two characteristic time region
from magnetic behavior: (A) rapid step-like demagnetization and (B) following recovering process withprecessional motion. The time scale of (A) is conformed as within picoseconds range (time constant ~100fs) independently with film structure, which is much shorter than ferromagnetic resonance (period ~0.1 ns at
10 GHz ) and hundreds fs delayed with respect to the increase of Te. Following regime (B), film structuraldependency of precessional magnetic motion was appeared. The difference of precession frequency anddamping properties indicate the different time evolution of lattice temperature in magnetic layer.

We present the detection of the picosecond dynamics in arrays of 50 nm permalloy dots
down to the single nanodot regime by an all-optical time-resolved magneto-optical Kerr
effect microscope. The inter-dot separation (S) varies from 200 to 50 nm and simulated
magnetostatic fields shows a transition from magetostatically isolated to strongly coupled
regime as S decreases. Consequently, we observe a single precessional mode for S down to
75 nm, whose frequency increases with the decrease in S. At the smallest separation S = 50
nm, we observe a mode splitting. The simulated mode profile reveals that the dynamics ofa single 50 nm dot is dominated by the edge mode. In sparsely packed arrays we primarily
observe the isolated dynamics of the constituent dots in phase. For S = 50 nm, we observe anadditional backward volume magnetostatic mode of the array. The damping is minimum for
S = 200 nm but increases linearly with the decrease in S as a result of the dynamic dephasingof the precession of the weakly interacting dots. At S = 50 nm, the dephasing due to thesuperposition of two resonant modes results in a sudden increase in the apparent damping.

Jungbum Yoon, Hyeok-cheol Choi and Chun-yeol You*
Department of Physics, Inha Universirty, Korea

The physics of exchange bias effect has been studied intensively for the past decades,
however, a few experiments have been reported about the spin dynamics and damping
mechanism for the exchange biased systems. Recently, the vector network analyzer
ferromagnetic resonance (VNA-FMR) is employed to research the spin dynamics offerromagnetic thin films with wide range microwave frequencies. In this study, thedynamics magnetic properties of the NiFe/FeMn bilayers is investigated by VNA-FMR
with various external static field. The exchange bias is verified by vibrating sample
magnetometer and VNA-FMR with varying the thickness of FeMn. Spin dynamics andthe Gilbert damping constants of exchange biased NiFe/FeMn bilayers are investigatedby the analysis of FMR spectra. The exchange bias field induced asymmetry in themagnetization hysteresis loops. It implies the spin dynamics must be asymmetry
for positive and negative field region. We perform VNA-FMR measurement for
positive and negative fields. In results, we find that the apparent damping parameters
are different in the both field directions in the exchange biased NiFe/FeMn bilayers.
Therefore, we conjecture that the exchange bias layer acts differently, depends on therelative direction of the ferromagnetic layer magnetization to the exchange bias field.

Amani Zagdoud, Mircea Vomir, Michele Albrecht and Jean-yves Bigot
IPCMS, France

Arata Tsukamoto*, Tetsuya Sato, Shingo Toriumi, Ryutarou Shimizu and Akiyoshi Itoh
Electronics & Computer Science, College of Science and Technology Nihon
University, Japan[1] T. Kubota, S. Tsunegi, M. Oogane, S. Mizukami, T. Miyazaki, H. Naganuma and Y. Ando, Appl. Phys. Lett., 94 122504(2009). [2] S. Yamada, K. Hamaya, K. Yamamoto, T. Murakami, K. Mibu and M. Miyao, Appl. Phys. Lett., 96, 082511 (2010).

Bivas Rana, Dheeraj Kumar, Saswati Barman, Semanti Pal, Yasuhiro Fukuma,
Yoshichika Otani and Anjan Barman*
Condensed Matter Physics and Material Sciences, S. N. Bose National Centre For
Basic Sciences, India[1] I. Radu, K. Vahaplar, C. Stamm, T. Kachel, N. Pontius, H. A. Durr, T. A. Ostler, J. Barker, R. F. L. Evans,
R. W. Chantrell, A. Tsukamoto, A. Itoh, A. Kirilyuk, Th. Rasing and A. V. Kimel, Transient ferromagnetic-likestate mediating ultrafast reversal of antiferromagnetically coupled spins, Nature, 472 (2011) 205.

1. B. Rana, S. Pal, S. Barman, Y. Fukuma, Y. Otani, and A. Barman, Appl. Phys. Express 4, 113003 (2011). 2. A.
Barman, S. Wang, J. D. Maas, A. R. Hawkins, S. Kwon, A. Liddle, J. Bokor, H. Schmidt, Nano Lett. 6, 2939 (2006).
3. B. Rana, D. Kumar, S. Barman, S. Pal, Y. Fukuma, Y. Otani, and A. Barman, ACS Nano 5, 9559 (2011).

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Non-linear susceptibility and influence of the applied magnetic field on
ZFC/FC curves

Ferromagnetic resonance of bilayer CoFeB/NiFeSiB thin film

Magnetization dynamics in perpendicular magnetic anisotropy CoFeB/
MgO system

Femtosecond demagnetization in Ni: Electron-phonon spin flip
scattering from first principles

Florent Tournus*, Arnaud Hillion, Alexandre Tamion and Veronique Dupuis
LPMCN, CNRS & Univ. Lyon 1, France

ZFC/FC curves are widely used to characterize assemblies of magnetic nanoparticles.
They reflect the crossover between the blocked and superparamagnetic (SP) regime
with increasing temperature. With a low applied field a linear response can be assumed,
the shape of the curves is then independent of the applied field H, and a simple
theoretical modeling is possible: this allows efficient theoretical fits of experimental
curves. We have studied the influence of the applied field magnitude on the ZFC/
FC curves shape, both theoretically and experimentally. While the effect of H on theenergy barriers has already been discussed, its effect on the response of SP particles
has not been considered. However, this non-linearity manifests itself much before
the modification of the switching energy distribution. In addition to experimental
measurements on a diluted Co nanoparticle assembly, we have simulated ZFC/FC
curves for different applied fields, including the third-order susceptibility in the SP
response. The later depends on the anisotropy and does not at all correspond to aLangevin function around the blocking temperature. We find that the curves can besignificantly affected (in particular the low temperature limit of the FC) for quite low
applied fields, which are usually used in experiments.

The 19th International Conference on Magnetism

Sanghoon Jung1, Chang Ho Choi1, Jungbum Yoon2, Chun-yeol You2, Seung Hyun
Kim3, Young Keun Kim3 and Myung-hwa Jung1
1
Sogang University, Korea
2
Inha University, Korea
3
Korea University, Korea
Spin transfer torque magnetic random access memory (STT-MRAM) is one of thecandidates for next generation random access memory. For practical application, thedevice should have high thermal stability and low critical current density. They havestrong correlation with saturation magnetization (Ms) and damping constant (α) so that
we need to determine Ms and α. To study the damping mechanism of the thin films, wehave performed ferromagnetic resonance (FMR) experiments through vector network
analyzer with bilayer thin films of CoFeB(10-x nm)/NiFeSiB(x nm) (x=0,1,2,….,10).
We have fitted the FMR data with Lorentz function to get the information of resonancefrequency and line width. From these two fitting parameters, we could get Ms and α byKittel formula and Full Width at Half Maximum. As increasing x values, the Ms tends
to increase, whereas the α suddenly decrease and then saturate. This implies that theadded NiFeSiB layer in CoFeB plays a role to prevent the spins align along the field
direction.

Jeong Woo Sohn1, Ji-wan Kim1, Kyeong-dong Lee1, Hyon-seok Song1, Il-jae Shin2,
Byoung-chul Min2, Chun-yeol You3 and Sung-chul Shin4*
1
Department of Physics, Center for Nanospinics of Spintronic Materials, KAIST,
Korea
2
Center for Spintronics Research, KIST, Korea
3
Department of Physics, Inha University, Korea
4
Center for Nanospinics of Spintronic Materials, KAIST, Department of Emerging
Materials Science, DGIST, Korea
We study the ultrafast magnetization dynamics of perpendicularly magnetized MgO/CoFeB/Ta
and Ta/CoFeB/MgO stack structures which gains wide attention from a viewpoint of perpendicularmagnetic tunnel junctions. An all-optical time-resolved magneto-optical Kerr effect measurement
reveals that effective Gilbert damping α stays unchanged at ~0.02 in high external field regardlessof pump fluence, but it declines drastically with the increase of pump fluence in weak external field.
This can be explained by the enlarged apparent relaxation time due to slow remagnetization. Genuine
damping tends to attract the precessing magnetization vector towards the effective equilibrium axis,
while the tip of the reduced magnetization vector after pump pulse heating recovers growing awayfrom the effective axis. These two competing contributions determine the apparent relaxation time.
In a weak field regime, slow recovery of the magnetization vector results in the increased relaxation
time and low effective Gilbert damping. We believe that low Gilbert damping found in CoFeB/MgO
structure will be expected to reduce the critical current for current-induced magnetization switching.

July 12 (Thu)Alexander Gerber and Yoav W Windsor
School of Physics and Astronomy, Tel Aviv University, Israel

286

poster Presentation

Karel Carva1, Marco Battiato2 and Peter M Oppeneer2
1
DCMP, Charles University in Prague, Czech Republic
2
Uppsala University, Sweden

The femtosecond demagnetization discovered in 1996 [1] represents a critical test of magnetization
dynamics theories and may lead to many interesting applications. It is still far from being understoodon a microscopic level. Electron-phonon spin-flip scattering in Ni was suggested to be the microscopic
explanation of its femtosecond laser-induced demagnetization [2]. We have calculated the spin-flip
Eliashberg function [3] based on ab initio electron-phonon coupling matrix elements, which allows us
to obtain the spin-flip probability with much higher accuracy. We extend this method also to the regimeof non-equilibrated electron distributions relevant for ultrafast processes. We have found that the spinflip probability depends strongly on electron energy. We consider two cases for system excited by a laser:
thermalized very hot electron distributions, as well as highly non-equilibrium electron distributions that are
expected to be present immediately after the fs laser excitation. Employing this approach we compute theelectron-phonon SF rates. We find that the demagnetization rate is very low for any thermalized electron
distribution as compared to non-equilibrium distributions present within first femtoseconds following thepump laser [3]. This is due to the density of states and the specific energy-dependence of SF probability.
[1] E. Beaurepaire, J.-C. Merle, A. Daunois J.-Y. Bigot, Phys. Rev. Lett. 76, 4250 (1996). [2] B. Koopmans,
G. Malinowski, F. Dalla Longa, D. Steiauf, M. Fahnle, T. Roth, M. Cinchetti, M. Aeschlimann, Nature
Mater. 9, 259 (2010). [3] K. Carva, M. Battiato, P. M. Oppeneer, Phys. Rev. Lett., 107, 207201 (2011)

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poster Presentation
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Ultrafast magneto-acoustic pulses in a nickel film

The effect of surface anisotropy on the switching of a particle magnetic
momentUltrafast dynamics of ferromagnetic copd thin film by various
polarized probe beam

Relation between gilbert damping constants and perpendicularmagnetic anisotropy in Ti buffered Co/Ni multilayers

July 12 (Thu)We report about the ultrafast magnetization dynamics induced by magneto-acoustic
pulses in a 200-nm-thick Ni film generated with femtosecond laser pulses. The
magneto-acoustic pulses result from the coupling between the magnetization andthe acoustic waves generated by the laser pulses. In order to distinguish between
dynamical magnetic effects induced either by the thermal excitation or by the magnetoacoustic pulse, the spin dynamics is measured from both the front and rear sides of thefilm via the magneto-optical Kerr technique. It is found that the acoustic pulses excite
the magnetization on both sides of the film and the perturbation of the magnetizationis very efficient at the rear side (10% of the static one). Using a detailed modelingof magneto-acoustic pulses combining the concepts of acoustic pulse propagation
and ultrafast magnetization dynamics, we reproduce the magnetization dynamics on
both sides of the film. In addition, our results imply that the magnitude of magnetoacoustic pulses can be controlled and maximized by selecting proper substrates withsame ferromagnetic materials. We forecast that our results will have a strong impact
for making ultrafast magneto-acoustic devices, with the capability of sensing themagnetization at relatively long distances from acoustic pulses generated by the laser
pulses.

Shuang Guo and An Du*
Physical department, Northeastern University, China

The effect of surface anisotropy on the switching of a particle magnetic moment
Shuang Guo, An Du* College of Sciences, Northeastern University, Shenyang 110004,
China * Corresponding author(du_an_neu@126.com) The dynamic precessionof the moment for a spherical particle in a microwave field was studied by using
Landau-Lifshitz-Gilbert (LLG) equation. The spins inside the particle have singleion anisotropy and the ones on the surface of the particle have the surface anisotropy
normal to the surface. The switching field threshold was calculated for different surface
anisotropy with definite microwave frequency. It is found that the surface anisotropy
influences the switching field threshold, with the increase of the surface anisotropy, thethreshold increases, the switching speed of the magnetic moment increases obviously.
1. K. Rivkin, and J. B. Ketters, Appl. Phys. Lett. 89, 252507(2006). 2. J.G. Zhu, X. Zhu, and Y.
Tang, IEEE Trans. Magn. 44, 125(2008). 3. S. Okamoto, N. Kikuchi et al, Appl. Phys. Lett. 93,102506(2008). 4. S. Okamoto, N. Kikuchi, and O. Kitakami, Appl. Phys. Lett. 93, 142501(2008). 5. M.
Lgarashi, Y. Suzuki et al, J. Appl. Phys. 105, 07B907(2009).

S. H. Jung1, M. H. Jung1, Jin Pyo Hong2, Won Dong Kim3, Chanyong Hwang3* andJoo In Lee3
1
Department of Physics, Sogang University, Korea
2
Department of Pysics, Hanyang University, Korea
3
Center for Nano-imasing Technology, Korea Research Institute of Standards andScience, Korea

We study ultrafast dynamics of the ferromagnetic CoPd thin film by using timeresolved magneto-optical Kerr effect. In the case of using linearly polarized probe
beam, the spin precession is observed in the frequency of about 14 GHz in the rangeof large time scale. On the other hand, when the probe beam changes to circularpolarization, the large time scale precession disappears, and ultrafast precession(~100GHz) is observed in short time scale. We suppose that these result from themomentum change of probe beam from 0 to 1, and the ultrafast precession is related tointeraction between spin and circularly polarized photon.
1. J.-Y. Bigot, Physics 5, 11 (2012) 2. J.-Y. Bigot, M. Vomir, E. Beaurepaire, Nature Physics 5, 515(2009)

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RK20

Minimal precessional and switching currents for relaxing-precessional
magnetization reversal within a spin valve

Magnetization dynamics of GdFeCo nanostructures revealed withPEEM

Low temperature time domain THz spectroscopy of terbium gallium
garnet crystals

Jui-hang Chang*, Hao-hsuan Chen and Ching-ray Chang
Physics, National Taiwan University, Taiwan

The relaxing-precessional magnetization reversal [1] is studied from the point of viewof nonlinear dynamics. The solution of the Landau-Lifshitz-Gilbert equation with
spin-transfer toque [2] shows that there are two critical values, α_cs and α_cp, for thedamping constant, and α_cs < α_cp. Above α_cs the minimal switching current a_s is the same as the modified Stoner-Wolfarth (SW) limit [3] a_cs for the switching,
and above α_cp the minimal precessional current a_p is the same as the modified SW
limit a_cp for the onset of precession. For a given magnetic anisotropy and an arbitrary
in-plane bias field, condition a_s < a_cs < a_p < a_cp always happen, where a_s, a_p are functions of α_s, α_p, respectively. These investigations will be of importancefor the design of spin-torque-transfer magnetic random access memories [4] and nanooscillators [5].
[1] H. Morise and S. Nakamura, J. Magn. Magn. Mater. 306, 260 (2006). [2] J. C. Slonczewski,
J. Magn. Magn. Mater. 159, L1 (1996). [3] J. H. Chang, H. H. Chen, and C. R. Chang, Phys. Rev.
B 83, 054425 (2011). [4] U. Ebels, D. Houssameddine, I. Firastrau, D. Gusakova, C.Thirion, B.
Dieny, and L. D. Buda- Prejbeanu, Phy. Rev. B 78, 024436 (2008). [5] D. Houssameddine, U.
Ebels, B. Dela¨et, B. Rodmacq, I. Firastrau, F. Ponthenier, M. Brunet, C. Thirion, J. -P. Michel, L.
Prejbeanu-Buda, M. -C. Cyrille, O. Redon, and B. Diney, Nature Mater. 6, 447 (2007).

Souliman El Moussaoui1*, Loic Le Guyader1, Michele Buzzi1, Elena Mengotti1,
Laura J. Heyderman1, Frithjof Nolting1, Thomas A. Ostler2, Joe Barker2, Richard F.
L. Evans2, Roy Chantrell2, Arata Tsukamoto3, Akiyoshi Itoh3, Andrei Kirilyuk4, Theo
Rasing4 and Alexey V. Kimel4
1
Paul Scherrer Institut, Switzerland
2
Department of Physics, University of York, United Kingdom
3
Nihon University, Japan
4
Radboud University Nijmegen, Institute for Molecules and Materials, Netherlands
The manipulation of spins is a very exciting topic from fundamental point of view as well as for practicalapplications. Combining experiments and simulation, we have been able to demonstrate that a fs-opticalexcitation is sufficient to trigger magnetization reversal in GdFeCo nanostructures on very short timescales.
Employing a photoemission electron microscope (PEEM) at the SIM beamline, we have proved that we canmanipulate the magnetization of nanostructures by using a heat pulse only. Performing time resolved X-ray
magnetic circular dichroism (TR-XMCD) measurement we have observed that the magnetization reversal
within the structures occurs on a timescale faster than 100 ps and evidenced that the reversal occurs against
an external applied magnetic field. In our experiment the reversal happens only by heating the system on thetime scale of the exchange interaction of the two sublattices and does not require any other external stimulus.
'Ultrafast heating as a sufficient stimulus for magnetization reversal' T. A. Ostler, J. Barker, R. F. L. Evans, R. Chantrell, U. Atxitia, O.
Chubykalo-Fesenko, S. El Moussaoui, L. Le Guyader, E. Mengotti, L. J. Heyderman, F. Nolting, A. Tsukamoto, A. Itoh, D. Afanasiev,
B. A. Ivanov, A. M. Kalashnikova, K. Vahaplar, J. Mentink, A. Kirilyuk,Th. Rasing and A. V. Kimel, Nature Comm. 3, 666 (2012).

Rostislav V. Mikhaylovskiy*, Euan Hendry, Feodor Y. Ogrin and Volodymyr V.
KruglyakSchool of Physics, University of Exeter, United Kingdom

We have used the terahertz (THz) time domain spectroscopy to study high frequency
magnetic excitations in terbium gallium garnet (TGG) crystals cut along <111>
and <001> crystallographic planes. We demonstrate that a THz bandwidth transient
electromagnetic pulse can efficiently couple to magnetic moments in TGG. By
comparing the spectrum of the pulse before and after transmission through the crystal,
we are able to isolate the absorption corresponding to magnetic resonance modesof TGG. We measure and discuss the dependence of the observed modes upon thetemperature and the strength and orientation of the bias magnetic field with respect
to the crystallographic axes of the crystals. The magnetic modes are present at
temperatures above the Neel point, which is interpreted in terms of the field-induced
magnetic ordering. The illumination of the crystal with intense optical pulses withwavelength close to the TGG absorption band destroys the magnetic ordering. Thus,
the light induced demagnetization of TGG is observed. Our findings demonstrate thatthe time domain THz spectroscopy can be a powerful tool by which to study highfrequency properties of dielectric magnetic materials.

Hyonseok Song1, Kyeong-dong Lee1, Jeong-woo Sohn1, See-hun Yang2, Stuart S.p.
Parkin2, Chun-yeol You3 and Sung-chul Shin4*
1
Department of Physics and Center for Nanospinics of Spintronic Materials, KAIST, Daejeon 305-701, Korea
2
IBM Research Division, Almaden Research Center, San Jose, California 95120, USA
3
Department of Physics, Inha University, Incheon 402-751, Korea
4
Department of Physics and Center for Nanospinics of Spintronic Materials, KAIST, Daejeon 305-701,
Department of Emerging Materials Science, DGIST, Daegu 711-873, Korea

Recently, there has been a growing interest in spin-transfer-torque magnetic random access memory utilizing
perpendicularly magnetic anisotropy (PMA) materials in order to overcome thermal stability problems.
Since the critical current density depends on the Gilbert damping parameter, it has been an important
issue to understand and manipulate the Gilbert damping parameter in the PMA materials. In this work,
we have investigated PMA [Co/Ni] multilayers with Ti buffer layers by an all-optical pump-probe time
resolved magnetic optical Kerr effect (TR-MOKE). In particular, we have studied the variation of Gilbert
damping constant (α) and PMA as a function of the thickness of Ti buffer layer thickness (t). Since the PMA
and damping constant are strongly related with the spin-orbit coupling, both physical quantities must be
correlated. Clear damped oscillations of the magnetization are observed in TR-MOKE measurements. Afterbackground subtraction, the signal is fitted with a damped harmonic function, from which the precession
frequency (f) and the decay time (τ) are deduced. We obtained f and τ by fitting with Landau-LifshitzGilbert equation, and we could be estimated α. We find that The α and PMA values increased monotonicallywith increasing of t. This result clearly shows close relationship between PMA and α.

RK23
Chaotic motion of magnetic domain structure under alternate field

Michinobu Mino* and Yousuke Yamamoto
Department of Physics, Okayama University, Japan

Magnetic domain motion in a garnet thin film under alternate magnetic fields up to
5000 Hz has been investigated at room temperature. Domain structures and motions areobserved by using a high-speed video camera with the help of magneto-optical Faraday
effect. When a field frequency is low, the magnetization changes periodically and adomain pattern has a labyrinth structure. By increasing the field amplitude and driving
frequency, irregular oscillations of a magnetization appear. Under a rapidly oscillating
field, chaotic motions of domain are observed. In this region, domain structures havea disk-like shape. These disks grow from some crystal defects. And a growing pointshows a branch-like form.

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Time dependent dichroism induced near the surface plasmon of Au
nanoparticles

A study of magnetic domain and magnetization reversal in L-shaped
Py

Ferromagnetic resonance of a single micron dot using vector network
analyzer

Demagnetization dynamics observed by spin-resolved ultrafast x-ray
photoemission

Jean-Yves Bigot1* and Minji Gwon2
1
Institute de Physique et Chimie des Materiaux de Strasbourg, CNRS, Universite deStrasbourg, Korea
2
Ewha Womans University, Korea
We have studied the Surface Plasmon (SP) dynamics of Au Nanoparticles, with adiameter of 50 nm, excited by circularly polarized femtosecond laser pulses. We reportabout a new effect observed in a time resolved pump-probe experiment, analyzing
the polarization state of the probe pulses. It manifests as a circular dichroism and an
optical rotation induced in the vicinity of the SP when pumping with left (σ+) or right(σ-) circularly polarized pulses. We attribute this effect to a time dependent change ofthe orbital momentum of conduction electrons as the effect is more pronounced when
the nanoparticles are excited with a pump wavelength -pump = 800 nm as compared to
400 nm. Indeed, in that case the interband transitions from the d-band to the conduction
band are minimized with respect to the Drude electrons. The induced dichroism isresonant on the SP (560 nm). Its lifetime is comparable to the energy relaxation timeof the quasiparticles to the lattice. It suggests that the electron-phonon interactionis the main mechanism for the dissipation of this pump induced orbital momentum.
The detailed behavior of the SP dynamics as a function of probe wavelength, pumppolarization and pump-probe delay will be discussed.

The 19th International Conference on Magnetism

S.s. Lee, Wondong Kim, Byong Sun Chun and Chanyong Hwang*
Korea Research Institute of Standards and Science, Korea

The evaluation of characteristic of nanometer-sized magnetic domain is one of themost important issues in the fields of spintronics. We made the Py stripe with andwithout the L-shaped edge structure. First, magnetic domain and its reversal reversal
behavior were simulated with the use of OOMMF program. Depending on the
thickness, width of this L-shaped structure, magnetic domain and its reversal behavior
could be classified in several groups. We also used scanning electron microscope withpolarization analysis(SEMPA, or spin-SEM) to probe the magnetic domain pattern
predicted in the simulation.

Kazuto Yamanoi1, Satoshi Yakata2, Takashi Kimura2 and Takashi Manago1*
1
Department of Applied Physics, Fukuoka University, Japan
2
Inamori Frontier Research Center, Kyusyu University, Japan

Magnetization dynamics of small ferro-magnets in the gigahertz region have been
investigated intensively for the applications in microwave devices. It is based on theprecessional motion of magnetization and it is necessary to control one of each small
magnets in devices. In this paper, we investigated ferromagnetic resonance (FMR) ofa single miconscale dot of permalloy (Py) using a vector network analyzer (VNA). A
micron-scale Py dot and a coplanar wave guide were fabricated using electron beamlithography, electron beam evaporation and lift off technique. The thickness of the Py
dots was 30 nm, and the shapes were square and rectangle with a width and length of
1~10 um and 1~40 um, respectively. The FMR measurement was performed using
the VNA and probe station. In the square shape dot of 10 um, the resonant frequency
depends on magnetic fields, which was good agreement with the Kittel’s equationof a thin film. In the rectangle shape dots, the resonant frequency shifted to higher
frequency with increasing length. This tendency was remarkable for 1 um-width dots.
It means that demagnetization effect becomes large when the width is less than 1 um
for a thin film.

July 12 (Thu)

Jiwan Kim, Mircea Vomir and Jean-yves Bigot*
Physics, IPCMS, CNRS, France

288

poster Presentation

Thomas Michlmayr
Physics, ETH Zurich, Switzerland

We report on the experiment and the results of time- and spin-resolved photoemission.
Ultrafast demagnetization was first observed by Beaurepaire et al. in 1996 and many
approaches where done to support these findings. Our method allows for measuring
the whole valence band mediated by the cascade electrons emerging from thesample and therefore gives a direct measure of the sample's magnetization. Ultrafast
demagnetization is observed on thin films of Fe on W(110) by optical pumping at 800
nm and x-ray probing at 7 nm. The measured demagnetization time of 450 fs is limitedby the experiment. Although space charge effects limits the photoelectron gain themeasured spin asymmetry stays almost constant with increasing x-ray flux and only
drops at very high x-ray fluxes (> 4 nJ/pulse). We also show the feasibility of single
shot magnetic measurement. The experimental setup consists of a completely mobile
two chambers ultra-high vacuum system (preparation and measurement chamber) with
Mott-polarimeter which can be brought to the free electron laser FLASH, Hamburg.

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poster Presentation

poster Presentation

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Synchronized modes of in-plane/out-of-plane spin-torque oscillators in
MTJ with synthetic ferrimagnetic free layer

Spin-pumping and revelation of inverse spin-Hall effect in n-type Si atroom temperature

Domain wall pinning by stray field from NiFe on Co/Ni nano-wireElectric-field control of magnetic properties in cobalt by means of electric double layer

1

2

3

Masahiko Ichimura *, Ryoko Sugano , Saburo Takahashi and Sadamichi Maekawa
1
Central Research Lab., Hitachi, Ltd. and JST-CREST, Japan
2
IMR, Tohoku University and JST-CREST, Japan
3
Advanced Science Research Center, Japan Atomic Energy Agency and JST-CREST,Japan

July 12 (Thu)

There has been considerable interest in the phenomena of spin-torque oscillators (STO) inmagnetic tunnel junctions (MTJs) for device applications, as well as the current induced
magnetization switching (CIMS) resulting from the spin transfer torque (STT). In particular,
the MTJs with synthetic ferrimagnetic (SyF) free layer is important since we can expect
the cooperation and/or competition of the magnetization dynamics due to the interlayer
coupling between magnetizations in the ferromagnetic bilayer. We analyze the magnetization
dynamics self-consistently in the MTJs with SyF layer by iterative calculation following
two steps. The STT in the ballistic regime is estimated, and the magnetization reversal issimulated by the LLG method at the finite temperature. We discuss the effect of the interlayer
coupling on the STO. As the interlayer coupling increases, the change of the STO mode isobserved, where the STO mode moved from the out-of-plane precession (OPP) to in-planeprecession (IPP). From the mapping of the STO behavior on the plane with applied current
and interlayer coupling, synchronized mode of STO appears in the region where the effective
filed corresponding to the interlayer coupling is larger than the anisotropy field. These results
suggest that the STO appears even without external magnetic field.

Mariko Koike*, Eiji Shikoh, Teruya Shinjo and Masashi Shiraishi
Osaka University, Japan

Since spin-orbit interaction in n-type Si is very week due to its band structure andlattice inversion symmetry, observation of the spin-Hall effect in n-type Si has been
believed to be difficult. Here, we report successful observation of the inverse spin-Hall
effect (ISHE) in n-type Si at room temperature. The sample composes of a Ni80Fe20/
n-type Si film with a doping concentration of 1.0×1019 1/cm3. The n-type Si surface
was etched by hydrofluoric acid to remove the naturally-oxidized Si. A ferromagnetic
Ni80Fe20 was formed by using electron beam lithography and deposition methods on
the n-type Si. Two electrode-pads were attached to the n-type Si layer to detect theelectromotive force in the Si. In a ferromagnetic resonance condition of the Ni80Fe20,
a pure spin current was injected into the n-type Si layer by the spin pumping. If ISHE
is induced in the n-type Si, the spin current is converted to a charge current. Here, theISHE in the n-Si was observed. The output voltage due to the ISHE was estimated tobe 0.4μV. The voltage sign was inverted by the magnetization reversal of the Ni80Fe20.
In this presentation, we discuss details of the inverse spin-Hall effect in the n-type Si.

[1] S. S. P. Parkin, et al., Science 320, 190 (2008).

Electric-field effect on magnetism using a capacitance structure (gate electrode/insulator/ferromagnetic)
has actively investigated to open up a new technology for an electrically manipulation of magnetization [110]. Here, we show electric field control of magnetic properties in Co using an electrical double layer (EDL)
formed at the interface between the Co layer and a polymer film containing an ionic liquid. The polymer
film containing the ionic liquid was put on a 0.4-nm-thin-Co-film and Pt-thin-film was placed on the topof the polymer film as a gate electrode. For the direct detection of the magnetization under the gate-voltage(Vg), superconducting quantum interference device [6] was used. Magnetization curves were measured
at 300 K under the application of Vg from -2.0 V to +2.0 V. Dramatic change of coercivity was observed
depending on Vg. To investigate the mechanism of this, we measured temperature dependences of theremanent magnetization under the different Vg. The significant increase of Curie temperature from ~320 K
at Vg = 0 V to ~370 K at 2.0 V was observed. Thus, the dramatic change in corecivity at 300 K presented
here is attributed to this large modulation of Curie temperature [10].
[1] H. Ohno et al., Nature 408, 944, (2000). [2] D. Chiba, M. Yamanouchi, F. Matsukura and H. Ohno, Science 301, 943 (2003). [3] M.
Weisheit et al., Science 315, 349 (2007). [4] D. Chiba et al., Nature 455, 515 (2008). [5] T. Maruyama et al., Nature Nanotechnol.
4, 158 (2009). [6] M. Sawicki et al., Nature Phys. 6, 22 (2009). [7] M. Endo et al., Appl. Phys. Lett. 96, 22515 (2010). [8] H. Ohno,
Nature Mater. 9, 952 (2010). [9] Y. Yamada et al., Science 332, 1065 (2011). [10] D. Chiba et al., Nature Mater. 10, 853 (2011).

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Interface material effects on magnetic anisotropy and its electric field
induced variation in thin films

Critical current density and domain wall mobility in nanowires withexchange coupled hard-soft magnetic layers

Compositional dependence of critical current density for spin transfer
torque switching of amorphous GdFeCo for thermally assisted MRAM

Spin-torque magnetic resonance of superparamagnetic Fe nanoparticles in Fe/MgO/Fe magnetic tunnel junctions

The spintronics has grown up intensively to realistic applications in the technology of magnetic random accessmemory (MRAM) development. Such development has been remarkable in memory density, reading-writing
speed, and non-volatile property in cooperation with the technologies of spin-injection and physics of spintransfer torque. The basic physics about magnetism has been developing in the response to electric field (EF).
This has emerged as the connection with low power consumption device and small energy scale of magnetoelectric effects. For the thin films [1,2] as a memory, sensitivity and large response may be required in device
applications. Due to the limitation of EF penetration into the thin film, interface with a few metallic layers is
critical to determine the response to the EF. We have investigated MgO/Fe/M(001) (M = Au, Pt) [3,4] with using
the density functional calculation, in which the substrate of Pt was found to enhance the EF effect on magnetic
anisotropy. In this work, in order to investigate influences of stacking structure for the interface, we investigate
MgO/Fe/Pt/Au(001) and MgO/Fe/Pd/Au(001). In addition, results in MgO/Au/Fe/Au(001) are also discussed
in the connection with segregation effects of film preparation, which may be expected in experiments.

In this study, critical current density and domain wall mobility of current driven
domain wall motion in nanowires composed of TbFeCo and NiFe layers have beenstudied. TbFeCo layer has perpendicular magnetic anisotropy. Wires and electrode arefabricated by photolithographic method. Current pulses with width less than 100 ns
are applied to drive the domain wall in the wires. The domain structure is observed bya high resolution Kerr microscope. We found critical current density decreases in thesoft-hard bi-layered structure compared to a single TbFeCo layer. Nanowires of single
TbFeCo layer have critical current density of 5×106 A/cm2; however, the critical current
density in bi-layered structure has critical current density as small as 2 ×106 A/cm2. The
domain wall mobility is deduced from the dependence of domain wall velocity on theapplied current density. We found that the domain wall mobility improved by almost
two times with the introducing of the NiFe layer. Of particular interesting is that,micromagnetic simulations show that the Bloch walls in perpendicular TbFeCo wires
change to Neel walls with the introducing of NiFe layer. Our experimental results
suggest nano-wires composing of soft-hard layers suitable for race track memory.

Yuusaku Taguchi 1*, Haruki Kato 1, Shinya Haraguchi 1, Masahito Tsujikawa 2,
Masafumi Shirai3 and Tatsuki Oda4
1
Graduate School of Natural Sciences and Technology, Kanazawa University, Japan
2
CSIS, Tohoku University, Japan
3
CSIS, Tohoku University & RIEC, Tohoku University, Japan
4
Institute of Science and Engineering, Kanazawa University, Japan

Xiaoxi Liu1*, Liangqiu Gao2 and Akimitsu Morisako2
1
Department of Information Engineering, Shinshu University, Japan
2
Shinshu University, Japan[1] Y. Shiota et al., Appl. Phys. Express 2, 063001 (2009). [2] T. Nozaki et al., Appl. Phys. Lett. 96, 022506 (2010).
[3] M. Tsujikawa et al., J. Appl. Phys., 109, 07C107 (2011). [4] M. Tsujikawa et al., submitted for publication.

Bing Dai1*, Takeshi Kato1, Satoshi Iwata1 and Shigeru Tsunashima2
1
Department of Quantum Engineering, Nagoya University, Nagoya 464-8603, Japan2
Department of Research, NISRI, Yotsuya-dori 1-13, Chikusa-ku, Nagoya, 464-0819,
Japan

Spin transfer torque (STT) switching has been demonstrated in magnetic tunneling junctions(MTJ) with perpendicular magnetic anisotropy (PMA), which exhibits a low critical current
density compared to their in-plane counterparts [1]. In this paper, we fabricated giant magnetoresistance (GMR) devices consisting of bottom electrode/ [Pd (1.6)/Co (0.4)]6/Co40Fe40B20(0.5)/Cu (3)/ Gdx(Fe90Co10)100-x (10)/Cu (5)/top electrode (thickness in nanometer). The R-I
loops were measured for 120×180 nm2 cell with Gdx(Fe90Co10)100-x memory layers, and the
STT switching property of these devices was estimated from the resistance measurement after
applying current pulses with a duration of 100 ms. In TM-rich compositions, the average valueof the critical current density Jc increased from 2.0×107 A/cm2 for x = 22.3 at.% to 4.5×107 A/
cm2 for x = 24.0 at.% with increasing x, while the Jc reduced to 1.4×107 A/cm2 for RE-rich
Gd28.9(Fe90Co10)71.1. It is noted that the values of Jc are comparable to the results in conventional
MTJs[2]. The difference of Jc values may be due to the difference of the effective perpendicularanisotropy and/or the Curie temperature of the GdFeCo layer. The dependence of Jc on thecurrent pulse width and temperature will be discussed in the presentation.

Shinji Miwa, Norikazu Mizuochi, Teruya Shinjo and Yoshishige Suzuki
Graduate School of Engineering Science, Osaka University, Japan

During the past decade, electric detection and manipulation of submicron-scale
magnet have been conducted by using magnetoresistance (MR) effect and spin-torque.
Now, a great deal of interests in manipulating nano-scale magnets (or single-spin)
and physics of spin-torque in such a small system are taken. In this study, we employ
superparamagnetic Fe nano-particles and the single-crystal MgO based magnetic tunnel
junctions (MTJs) [1]. The magnetic resonance of super-paramagnetic Fe nano-particles
is electrically excited by spin-torque and detected by the spin-torque diode effect [2,3].
The structure of the MTJs is as follows: MgO(100) substrate/Fe film (50 nm)/MgO(1.35 nm)/Fe nano-particles (2.1 nm)/capping layer. All of the layers were grown by
molecular beam epitaxy. The RF detection mechanism is explained as the homodyne
detection of the applied RF current because of the oscillation of resistance at the same
frequency. In the measurements, the resonant peak was observed around 5 GHz undera magnetic field of 5 kOe at room temperature, for example. This represents that themagnetic resonance of superparamagnetic Fe nano-particles was electrically excited anddetected. We thank Y. Shiota, H. Tomita, G. Shiomi for valuable discussions. This work
is supported by Grant-in-Aid for Scientific Research (S), MEXT, Japan. (No. 23226001)[1]S. Ikeda, et al. Nature Materials 9, 721-724 (2010). [2]Y. Huai, et al. Appl.Phys.Lett. 82, 222510 (2005).

[1] S. Yuasa et al., Nature Mater. 3, 868 (2004). [2] A. A. Tulapurkar et al., Nature 438, 339 (2005).
[3] S. Ishibashi, S. Miwa et al., submitted.

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Effect of spin relaxation rate on the interfacial spin depolarization in
ferromagnet/oxide/semiconductor contacts

Spin Seebeck Effect in SiO2/Py structures

Microscopic theory of magnon-drag thermodynamic transport inferromagnetic metals

Spin Coulomb drag and optical excitations in low dimensional systems

Daisuke Miura* and Akimasa Sakuma
Department of Applied Physics, Tohoku University, Japan

Irene D'amico1 and Carsten A. Ullrich2
1
Physics, University of York, United Kingdom
2
Physics, University of Missouri-Columbia, USA

We study the thermodynamic transport carried by magnons in ferromagnetic metals.
In this study, the Peltier effect caused by a magnon heat current (magnon-drag Peltier
effect) is described in a microscopic model. Magnons can indirectly interact withelectric fields via electron-magnon interaction; we evaluate the magnon heat current
perturbatively with respect to the electron-magnon interaction in the 2nd order. As aconsequence, we found out that the magnon heat current is proportional to the spincurrent carried by the spin polarized electric current drifted by the electric filed, that is,
the magnon-drag Peltier coefficient is governed by the spin polarization of the electric
current. This is in contrast to the phenomenological result derived by Grannemann andBerger [1] in which the coefficient is proportional to the electric current directly. In
addition, we show the temperature dependence of the Peltier coefficient is T5/2 in low
temperature. These results indicate that, in the inverse effect (Seebeck effect) of thePeltier effect, the magnon heat current caused by a temperature difference induces thespin current, and the temperature dependence of the Seebeck coefficient is T3/2.

Within the remit of new quantum technologies, an intense effort is devoted to
improving our understanding of spin dynamics, with the aim of building novel
spintronics devices. In this context the theory of spin Coulomb drag (SCD) was
recently developed. It shows that Coulomb interactions are an intrinsic decay
mechanism for spin currents. As confirmed by experiments, SCD can be substantial
in semiconductors, and it is bound to become one of the most serious issues in spinpolarized transport, since, due to its intrinsic nature, it cannot be avoided even in thepurest material. More recently the influence of SCD on optical spin-injection and spinresolved optical experiments has been considered. Here we report on SCD effects
on intersubband optical spin excitations in III-V quantum wells, where SCD may
contribute substantially to the linewidth of spin plasmons. By going beyond the usual
local density functional approximation and properly including the effects due to theinhomogeneity of the system in the growth direction, we show that the quantization ofstates in the growth direction may strongly reduce the intrinsic plasmon linewidth.

Kun-rok Jeon1, Byoung-chul Min2, Youn-ho Park2, Young-hun Jo3, Hun-sung Lee1,
Chang-yup Park1 and Sung-chul Shin1*
1
Korea Advanced Institute of Science and Technology (KAIST), Korea
2
Korea Institute of Science and Technology (KIST), Korea
3
Korea Basic Science Institute (KBSI), Korea
The electrical injection and detection of spin-polarized carriers in semiconductors (SCs) has beensuccessfully achieved by employing spin tunnel contacts and the Hanle effects. However, many aspectsof the spin phenomena in these systems, e.g., (i) the location, magnitude, and sign of the induced
spin accumulation, (ii) the unusual bias and temperature-dependence of the spin signal, and (iii) the
unexpected short spin lifetime and its weak variation with temperature, require additional investigation.
Here, we report the effect of spin relaxation rate on the interfacial spin depolarization (ISD) fromthe local fields in ferromagnet (FM)/oxide/SC contacts [1]. The combined measurements of normal
and inverted Hanle effects reveal the effect of spin relaxation rate on the ISD [2] in CoFe/MgO/
Si and CoFe/MgO/Ge contacts. We have observed, despite the similar amplitudes of the interfacialroughness and local magnetic fields, significant differences of the ISD [2] depending on the host SC;
the spin accumulation exposed to similar local fields in different SCs give rise to a clearly different
ratio of the inverted Hanle signal to the normal one. This can be understood in terms of two competingmechanisms in the host SCs, namely the spin relaxation and spin precession due to the local fields.
[1] K. R. Jeon et al., arXiv:1110.5978v1. [2] S. P. Dash et al., Phys. Rev. B 84, 054410 (2011).

290

Control of a magnetic domain wall (DW) displacement in a ferromagnetic nano-wireis essential in its potential application for nonvolatile magnetic memories. Parkin etal. demonstrated a race track memory device by controlling DW displacement in a
NiFe nano-wire with notch structure [1]. However, the structure with notch has two
problems such as i) transformation of DW structure and ii) increase of current density
due to the change of the wire width between notch and wire part. Here, to make new
DW pinning method without the change of wire width, we focus on the DW pinningin Co/Ni nano-wire by the stray field from ferromagnetic stack.We prepared two typesof devices; one was a simple wire of Ta/Pt/[Co(0.2 nm)/Ni(0.6 nm)]4/Co(0.2 nm)/Pt/
Ta, and the other was a wire of Ta/Pt/[Co(0.2 nm)/Ni(0.6 nm)]4/Co(0.2 nm)/Pt/Ta on
which NiFe/SiO2 was stacked partly. To investigate an influence of the stray field fromthe NiFe stack, DW depinning field (Hdep) was measured for both types of wires. Hdepof the wire without the NiFe stack was 200 Oe, while the wire with that had larger Hdepof 700 Oe, indicating the effectiveness of the use of the stray field to control the DW
position.

Kazutoshi Shimamura1, Daichi Chiba2, Masashi Kawaguchi1, Shimpei Ono4, Shunsuke Fukami5,
Nobuyuki Ishiwata5, Kensuke Kobayashi3 and Teruo1*
1
Institute for Chemical Research, Kyoto University, Japan
2
Institute for Chemical Research, Kyoto University and PRESTO JST, Japan
3
Institute for Chemical Research, Kyoto University and Osaka University, Japan
4
Central Research Institute of Electric Power Industry, Japan
5
NEC Corporation, JapanThe 19th International Conference on Magnetism

Sang-il Kim1, Seung-young Park2, Byoung-chul Min3, Younghun Jo2, Kyung-jin Lee1*
and Kyung-ho Shin3
1
Department of Materials Science and Engineering, Korea University, Seoul 136713, Korea
2
Nano Material Research Team, Korea Basic Science Institute, Daejeon 305-333,
Korea
3
Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
Recently, spin version of Seebeck effect, the spin-Seebeck effects (SSE) was observed
experimentally at room temperature[1]. For the SSE, it is expected that the voltage sign at the
hot end is opposite to that at the cold end and the absolute magnitudes of the voltages at the
hot and cold ends are the same. However, it is often observed that an asymmetric magnitudeof the voltage at the hot and cold ends [2]. The origin of this asymmetric behavior is
attributed to an additional temperature gradient along the thickness direction, which generates
an additional voltage signal due to the anomalous Nernst-Ettingshausen effect(ANE) [2]. In
this study, we investigated the dependence of the SSE and the ANE on the thickness of theferromagnetic layer in SiO2/Py samples. In our results, the sign change in the voltage signal
between the hot and cold ends was not observed. Instead, we obtained an offset voltage
due to the mixture of SSE and ANE signals. We attribute this offset to the longitudinal SSE
caused by an additional temperature gradient along the thickness direction of Py layer. A
possible origin of the dependence of offset voltage on Py thickness will be discussed in detail.

July 12 (Thu)1

Ryo Hiramatsu1, T. Koyama1, D. Chiba1, S. Fukami2, N. Ishiwata2, Y. Nakatani3 and T.
Ono1*
1
Institute for Chemical Research, Kyoto University, Japan
2
Green Innovation Research Laboratories, NEC Corporation, Japan
3
University of Electro-communications, Japan[1] G. N. Grannemann and L. Berger, Phys. Rev. B 13, 2072 (1976).

[1] K. Uchida et al., Nature, 455, 778-781 (2008). [2] S. Bosu et al., Phy. Rev. B 83, 224401 (2011).

July 8-13, 2012 Busan, Korea

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poster Presentation

poster Presentation

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RL22

Perpendicular magnetic property and magnetic damping of very thin
CoFeB films

Spin-torque efficiency and magnetization reversal in three-dimensional
Rashba materials

Current induced transverse field versus Joule heating in Co/Pd
nanowires

Negative electron-beam resist hard mask ion beam etching process forthe fabrication of nanoscale spin transfer torque magnetic random
access memory device

A very thin CoFeB film with a perpendicular magnetic anisotropy is a promising material
for applications of spintronics devices, such as Spin-RAM and spin-logic circuit [1].
Development of materials with high magnetic anisotropy and low magnetic damping
is an important issue to achieve high thermal stability and low power consumption
in the spintronics devices. However, the relationship between magnetic damping andperpendicular anisotropy has not been systematically investigated. In this work, we haveinvestigated capping layer dependence of perpendicular magnetic property and magnetic
damping in very thin CoFeB films. The films were prepared by sputtering system. The
structure of the films were SiO2-sub./Ta(5)/MgO(0.9)/CoFeB(d)/X(5 nm), (X = Ta, Pd,
Cu, Ru, V, MgO). After the deposition of the films, annealing process was carried out at
250 - 350oC. Magnetic property and magnetic damping were respectively characterized by
SQUID and FMR [2]. Perpendicular magnetic anisotropy and damping strongly depends
on the capping layer material. For the Ta capping layer, CoFeB film below 1.4 nm showeda perpendicular anisotropy. However, magnetic damping was drastically enhanced forthe films with perpendicular anisotropy. Similar behavior was observed in the films withcapping layers of Pd and Ru. This work was supported by the FIRST program.

Kazuhiro Tsutsui and Shuichi Murakami*
Dept. of Physics, School of Science, Tokyo Institute of Technology, Japan

July 12 (Thu)

Hyungyu Lee1, Daehong Kim1, Bongho Kim1, Sungwoo Chun1, Seonjun Choi1 andSeung-beck Lee2*
1
Department of Electronic Engineering, Hanyang University, Korea
2
Institute of Nano Science and Technology, Hanyang University, Korea

In addition to the magnetization reversal by the spin-transfer torque, the magnetization
reversal driven by a strong spin-orbit coupling has been intensely investigatedexperimentally and theoretically [1,2]. In this presentation, we focus on 3D Rashba
models coupled with localized spins, and study the spin torque theoretically. This is
motivated by the recent discovery of BiTeI as 3D Rashba systems [3]. As a result,
we find that the spin torque in 3D Rashba models is largely enhanced in the highcarrier-density regime compared with 2D Rashba models. We also find that the spintorque efficiency defined as the ratio between the spin torque and the electric current isenhanced when the Fermi energy lies on only lower band, both in 3D and 2D. As wechange the Rashba spin-orbit coupling, the spin-torque efficiency becomes maximum
when the Rashba spin-orbit coupling is comparable to the exchange coupling to the
localized spins. The optimum spin-torque efficiency becomes large when the Rashba
spin-orbit coupling is large, and it is preferable for the magnetization reversal withsmaller amount of current injection.

There has been a tremendous effort in understanding of the electric current effect in
the ultra thin film of ferromagnetic materials[1, 2]. We have recently found that in the
nanowire made of a multilayer structure of Co/Pd, there is a current induced transverse
magnetic field[3]. Electric current could also cause Joule heating especially in the highcurrent densities. The Hall resistance has been measured at different current densities
for the magnetic fields in the easy axis direction. By increasing the current density,
there is a reduction in the switching field of the nanowire. We further performed themeasurement at different angles of the magnetic field with respect to the easy axisof the sample. From the asymmetry of the switching fields, one can approximate thecurrent induced transverse field. Furthermore, by using four-probe measurements, thenanowire resistance has been measured at different temperatures and the temperature
coefficient of the Co/Pd nanowire has been extracted. By measuring the resistanceof the nanowire at different current densities, we can approximate the nanowire
temperature during the measurement and its effect on the switching dynamics.

[1] A. Manchon and S. Zhang, Phys. Rev. B 78, 212405 (2008). [2] I. M. Miron et al., Nature Mater.
9, 230 (2010). [3] K. Ishizaka et al., Nature Mater. 10, 521 (2011).

[1] I. M. Miron, G. Gaudin, S. Auffret, B. Rodmacq, A. Schuhl, S. Pizzini, J. Vogel, and P.
Gambardella, Nat. Mater. 9, 230 (2010). [2] T. Suzuki, S. Fukami, N. Ishiwata, M. Yamanouchi,
S. Ikeda, N. Kasai, and H. Ohno, Appl. Phys. Lett. 98, 142505 (2011). [3] K. Narayanapillai, M.
Jamali, and H. Yang, MMM conference, Arizona (2011).

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Perpendicular magnetic tunnel junctions with TbFeCo-based pinned
layer and CoFeB-MgO free layer

A new circuit model for spin-torque oscillator including theperpendicular torque of magnetic tunnel junction

Improvement of generation efficiency of pure spin current using multiterminal spin injection

Magnetization reversal process of a Py nanodot under pure spincurrent injection

Spin-torque oscillator (STO) is a promising new technology for the future RF oscillator, which isbased on the spin transfer torque (STT) effect in magnetic multilayered nanostructure. It is expected
to overcome the limitations of the semiconductor-based device technology. In our previous work,
we have proposed a circuit-level model of the Giant Magneto-Resistance (GMR) STO. In this paper,
we present a physics-based circuit-level model of the Magnetic Tunnel Junction (MTJ)-based STO.
The new model includes the effect of perpendicular torque that has been ignored in the GMR STO
model. The variations of three major characteristics, generation frequency, mean oscillation power,
and generation linewidth of an MTJ STO are investigated by changing the amount of perpendicular
torque. The model is fully compatible with circuit-level simulators such as SPICE. The accuracy of
new model was verified by HSPICE simulation. The simulation results show an excellent agreementwith the experimental data. With our circuit model, we could compose a current mirror circuit that
contains an STO element and a multi-stage amplifier for signal amplification, such that a full circuitlevel simulation of MJT STO was accomplished for the first time.

Lateral spin valve structures have several advantages for the generation, manipulationand injection of the spin current because of their flexible probe configurations.
Particularly, nonlocal spin injection techniques enable us to create a pure spin current
which carries the spin information with extremely low propagation loss. However, ingeneral, the generation efficiency of the pure spin current is quite low. To solve thisserious obstacle, we propose a nonlocal spin injection with multi spin injectors. In
the present study, we fabricated the lateral valve structure consisting of a quadruple
Permalloy spin injectors and nonmagnetic Cu strip and show that the developed device
has two advantages. One is that the maximum generated spin current is strongly
enhanced. The other one is that the efficiency for generating a certain quantity of thespin current is significantly improved. We also show that the optimization of the device
dimension yields the further enhancement of the maximum generating spin current.

[1] S. Ikeda et al., Nature Material 9, 721 (2010). [2] S. Mizukami et al., Jpn. J. Appl. Phys. 40, 580 (2001).

Jungmin Han1*, Byoung-chul Min1, Kyung-jin Lee2 and Kyung-ho Shin1
1
Spin Device Research Center, Korea Institute of Science and Technology, Seoul 136791, Korea
2
Department of Materials Science, Korea University, Seoul 136-701, Korea
We have fabricated perpendicular magnetic tunnel junctions (pMTJs) with a CoFeB/
TbFeCo pinned layer and Ta/ CoFeB/ MgO free layer using in-situ annealing
process. The TbFeCo-based hybrid pinned layer is a useful approach to obtain a highperpendicular magnetic anisotropy (PMA). However, a high temperature annealing,
often required for MgO-based MTJs to obtain a high tunneling magnetoresistance(TMR), may deteriorate the PMA of TbFeCo films. Our experimental results show apossibility to obtain a reasonable TMR and high PMA simultaneously by conducting
an annealing process to achieve a grain-to-grain epitaxy in CoFeB/MgO/CoFeB layers
before depositing the TbFeCo layer. The pMTJs prepared by this process show atunneling magnetoresistance (TMR) ratio of 15% to 19 % at room temperature.
[1] S. Ikeda, K. Miura, H. Yamamoto, K. Mizunuma, H. D. Gan, M. Endo, S. Kanai, J. Hayakawa, F.
Matsukura & H. Ohno, Nature Materials 9, 721-724 (2010). [2] N. Nishimura,T. Hirai, A. Koganei,
T. Ikeda, K. Okano, Y. Sekiguchi, and Y. Osada J. Appl. Phys. 91, 5246 (2002). [3] Il-Jae Shin,
Byoung-Chul Min, Jin Pyo Hong, and Kyung-Ho Shin, Appl. Phys. Lett. 95, 222501 (2009).

Hyein Lim, Sora Ahn, Miryeon Kim, Jihye Shin, Jinju Lee, Seungjun Lee andHyungsoon Shin*Electronic Engineering, Ewha Womans University, Korea

1. HyeIn Lim, Sora Ahn, Seungjun Lee, and Hyungsoon Shin: SSDM (2011) p. 1466. 2. A. Slavin, and V. Tiberkevich: IEEE
Trans. Magn. 45 (2009) 1875. 3. P. Villard, U. Ebels, D. Houssameddine J. Katine, D. Mauri, B. Delaet, P. Vincent, M.-C. Cyrille, B.
Viala, J.-P. Michel, J. Prouvee, and F. Badets: IEEE J. Solid-State Circuits 45 (2010) 214. 4. Z. M. Zeng, P. Upadhyaya, P. Khalili
Amiri, K. H. Cheung, J. A. Katine, J. Langer, K. L. Wang, and H. W. Jiang: Appl. Phys. Lett. 99 (2011) 032503.

Shaojie Hu, Tatsuya Nomura, Seiji Nonoguchi and Takashi Kimura*
Advanced Electronics Research Division, INAMORI Frontier Research Center,
Kyushu University., Japan

M. Johnson and R. H. Silsbee, Phys. Rev. Lett. 55, 1790 (1985). T. Kimura, T. Sato, and Y. Otani,
Phys. Rev. Lett. 100, 066602 (2008). T. Kimura et al., Appl. Phys. Lett. 85, 3501 (2004).

To conduct MTJs etching process, Ta[1] hard masks are generally used for reactive
ion etching and ion beam etching (IBE) process due to relatively good selectivity overmagnetic metals. However, tapering of the Ta mask is unavoidable which results in theunderlying MTJ to become trapezoidal. Here we utilized negative electron-beam resist(NER) hard mask process to overcome the hard mask induced nano-patterning difficulties.
Arrays of 30 nm dot patterns 200 nm apart were defined by electron beam lithography
with a NER thickness of 90 nm. The IBE was performed using the NER as the hard mask
layer. During the IBE process, The IBE etch rate of the NER was 3 nm/min and since thetotal MTJ etching thickness was 36 nm with 2.1 nm/min etch rate, a 30 nm diameter NER
pillar with 90 nm thickness was enough to produce the 30 nm diameter MTJ nanopillars.
And redeposition of the etched material on side walls of the NER protects the resist fromtapering, resulting in vertical side profiles in the etched MTJs.
[1] X. Peng, S. Wakeham, A. Morrone, S. Axdal, M. Feldbaum, J. Hwu, T. Boonstra, Y. Chen, J.
Ding, Vacuum. 83. 1007 (2009)

Tatsuya Nomura, Seiji Nonoguchi and Takashi Kimura*
Kyushu University, JapanA new type lateral spin valve structure based on a pair of closely located Permalloy
nanopillars has been developed. This structure enables us to flow a large amount of
current, resulting in the injection of a large pure spin current into a ferromagentic
nanodot entirely. We investigated the magnetization reversal process of the Permalloy
nanodot under dc pure spin current injection from the field dependence of the nonlocal
spin valve signal. The dc pure spin current was generated by flowing the dc current
with an ac excitation current in the nonlocal current terminal. The nonlocal spin valve
signal without the dc current exhibits a clear bipolar signal typically observed in theconventional lateral spin valve.[1,2] The nonlocal signal curve shows the systematicchanges with increasing the dc pure spin current and its variation strongly depends onthe current intensity and polarity. This means that the reversal process of the Py dot isstrongly modified by the pure spin current injection.
[1] F.J.Jedema,A.T.Filip,B.J.vanWees,Nature410(2001)345. [2] T. Kimura et al. Appl. Phys. Lett.
85, 3501~3503 (2004)

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RL24

Thickness and magnetic anisotropy dependence of anomalous Nernst
effect in L10-FePt films

Current induced localized domain wall oscillators in NiFe /Cu /NiFenano-stripe

Electrical transport properties of Co2MnSi Schottky diodeSpin transfer effect in FePt nanowires: controlling the stochasticity of
domain wall depinning using constrictions

Kota Hasegawa, Masaki Mizuguchi*, Ken-ichi Uchida, Eiji Saitoh and Koki
Takanashi
Institute for Materials Research (IMR), Tohoku University, JapanThe anomalous Nernst effect (ANE) is a thermomagnetic effect which gives rise to anelectric field perpendicular to both temperature gradient and saturation magnetization.
Although ANE has been known phenomenologically for a long time, only a few
studies have been reported, and the mechanism has not fully been understood. L10FePt with high magnetic anisotropy (Ku) attracted much attention for recent years as apromising material for “spin caloritronics” [1]. In this paper, we have made systematicinvestigation on the thickness and Ku dependence of ANE in perpendicularly
magnetized FePt(001) films. FePt(001) films were deposited on MgO(001) single
crystal substrates at 500°C. The thickness was varied in the range from 7 to 40 nm.
Ku was changed in the range from 3.0×106 to 2.7×107 erg/cc, depending on the degreeof L10 order which was controlled by the deposition temperature from 300 to 500°C.
It is found that the anomalous Nernst coefficient (Qs) does not depend on the film
thickness. On the other hand, Qs increases with decreasing Ku. These results suggest acontribution of spin wave in ANE.
[1] T. Seki et al., Solid State Comm., Vol. 50, 496 (2010).

Liang-juan Chang1, Pang Lin2 and Shang-fan Lee1*
1
Institute of Physics, Academia Sinica, Taiwan
2
Department of Materials Science & Engineering, National Chiao Tung University,
TaiwanWe study domain wall (DW) oscillations induced by the injection of a dc current througha nanowires containing artificial symmetric protrusions with Permalloy based pseudo
spin valve (NiFe 12 nm/Cu 8 nm/NiFe 24 nm). An experimental analysis was carried out
to describe the variation of differential resistance dV/dI by applying in-plane dc current
with pinned DWs. When the DWs are pinned at the traps, we have observed a reversible
motion of the DWs by changing the applied in-plane dc current. The peak in dV/dI
associated with the reversible change of magnetoresistance has been taken as evidence of
current induced coherent DW oscillation between the pinned regimes which gives rise to
the peak. The excited critical current shifts symmetrically with respect to H. It is expectedfrom the DW trap with symmetrical potential landscape. The dynamics of localized DW
oscillations under application of dc current was examined by micromagnetic simulations(OOMMF). The frequency f of DW oscillation decreases from 1.5 GHz to 0.95 GHz as H
increasing. This simple concept of DW based oscillators could be used as radio frequency
assisted writing in magnetic recording technology.
* Corresponding author e-mail: leesf@phys.sinica.edu.tw

292

Mahdi Jamali, Xuepeng Qiu, Kulothungasagaran Narayanapillai and Hyunsoo Yang*
Electrical and Computer Engineering, National University of Singapore, Singapore

The 19th International Conference on Magnetism

In-bok Baek1, Xianhong Li1, Seongjae Lee1*, Chil Seong Ah2, Jong-heon Yang2, Chan
Woo Park2, Han Young Yu2, Moongyu Jang2 and Gun Yong Sung2
1
Department of Physics, Research Institute for Natural Sciences, Hanyang University, Seoul,
133-791, Korea
2
Electronics and Telecommunications Research Institute (ETRI), Daejon, 305-700, Korea
Recently, the spintronic device has attracted considerable attentions due to its possibility to lead a newgeneration of electronic devices by utilizing spin degree-of-freedom. Especially, silicon is a very attractive
material for the spin channel of spintronic devices due to a weak spin-orbit coupling [1] and a long spin
lifetime of ~ 10 ns [2, 3], while Co2MnSi being a half-metallic Heusler compound is regarded as a promising
candidate for the spin injection/detection electrodes due to a possible complete spin polarization. [4, 5] In thiswork, the electonic transport chracteristics of Co2MnSi/Si Schottky diodes are studied for the investigation ofspin electrode/channel interface quality, in which Co2MnSi was prepared under various process conditions.
We found that the Schottky barrier height of Co2MnSi decreased from 0.56 to 0.52 eV and 0.44 to 0.36 eV
for electron and hole, respectively, with increasing RTA temperature from 450 to 550°C. Also, the ideality
factor close to unity for RTA temperature of 450°C significantly degraded as it changed to 550°C, indicating
the increase of interface trap density. Deduced from our electrical results, the manufactured Co2MnSi is
expected as a promising ferromagnetic material for the applications in silicon spintronic devices.
[1] I. Zutic, J. Fabian, and S. C. Erwin, Phys. Rev. Lett. 97, 026602 (2006). [2] G. Lancaster, J. A. V. Wyk and E. E.
Schneider, Proc. Phys. Soc. London 84, 19 (1964). [3] J. Fabian, A. Mathos-Abiague, C. Ertler, P. Stano, and I. Zutic,
Acta Phys. Slov. 57, 565 (2007). [4] Y.ohdaira, M. Oogane, H. Naganuma, and Y. Ando Appl. Phys. Lett. 99, 132513(2011). [5] P. J. Brown, K. U. Neumann, P. J. Webster and K. R. A. Ziebeck, J. Phys.: Condens. Matter 12, 1827 (2000).

July 12 (Thu)

Mikihiko Oogane*, Miho Kubota, Kei Sato, Hiroshi Naganuma and Yasuo Ando
Applied Physics, Tohoku University, Japan

Jean-philippe Attane1, Van Dai Nguyen1, Alain Marty1, Lucien Notin1, Cyrille Beigne1,
Juan Carlos Rojas-sanchez1, Stefania Pizzini2 and Laurent Vila1
1
Universite Joseph Fourier, BP 53, 38041, Grenoble and INAC/ CEA Grenoble, 17
avenue des Martyrs, France
2
Institut Neel, CNRS, 25 avenue des Martyrs, 38042 Grenoble, France
In this contribution, we present dynamic measurements of domain wall (DW) depinning from structuraldefects, in nanowires processed from single FePt layers and FePt/Pd(Pt)/FePt spin-valves. Statisticalanalysis reveals that in such systems, the DW depinning is stochastic, and that this stochasticity has two
origins. The first one is thermal activation, which helps the wall to cross the energy barrier associatedto the defect. The second one originates from the ability of the DW to get pinned randomly along
different micromagnetic configurations, each one corresponding to a given depinning fields. We study
the influence of different constriction types on the dynamic of DW depinning, using spin-valve-based
nanowires. The depinning probability function is found to exhibit very different behaviors, which dependon the types of constriction: it is partially possible to control the stochastic behavior of DW depinning bytuning the shape of constrictions. Additionally, we showed that the probability function of DW depinningcan be varied by applying a DC current, the effect of the spin torque on thermal and configurational
stochasticities being similar to those of a field. The measured spin transfer torque efficiency is very high(~10-13T.m2A-1), and is similar for single FePt layers and FePt-based spin-valves.
C. Burrowes et al., Nat. Phys. 6, 17 (2010) A. Mihai et al., Phys. Rev. B 84, 014411 (2011)

July 8-13, 2012 Busan, Korea

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poster Presentation
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RM02

Electric field effect on magnetic coercivity of Fe 3 O 4 /BaTiO 3heterostructures

Electrical detection of the spin Hall effects in the InAs quantum wellstructure

Electrical spin injection and detection in GaAs with ferromagnetic
metal/MgO junctions

Magnetism and Electronic Structures of SiC nanoribbons: Role ofdefects

Tae Young Lee, Joonyeon Chang*, Hyun Cheol Koo, Hyung-jun Kim and Suk Hee
Han
Korea Institute of Science and technology, Korea

Gul Rahman1* and J. M. Morbec2
Department of Physics, Quaid-i-Azam University,Islamabad, Pakistan
2
Instituto de Ciencias Exatas, Universidade Federal de Alfenas, 37130-000, Alfenas,
MG, Brazil

1

Electric field control of the magnetic coercivity of half metallic Fe3O4 epitaxial thin films
on BaTiO3(001) is demonstrated at room temperature, with a view to developing a new
type of highly spin polarized electron source, where the magnetization orientation of thespin source can be controlled by electric field. Fe3O4 films were grown on BaTiO3(001)substrates by reactive molecular beam epitaxy in an oxygen atmosphere at a pressure of
1×10-6 Torr. The Fe3O4 films show a clear Verwey transition at ~120 K, ensuing the highquality of the films grown. The electric field variation of the in-plane magnetic coercivityof Fe3O4 films was measured using Kerr effect, exhibiting a hysteretic behavior, where themagnetic coercivities for positive and negative electric fields at ±10 kV/cm show distinct
values. Since a possible strain effect due to ferroelectric domain switching of BaTiO3
should be equivalent for both electric field polarities over the switching field, anotherpossible mechanism such as polarization charge accumulation at the interface likely has
its origin in the electric field effect, associated with carrier induced modulation of theelectronic states of Fe3O4. Work supported in part by Industrial Technology Research
Grant Program in 2009 from NEDO, Japan.

Spin Hall effect (SHE) becomes intriguing because it generates and manipulates carrier
spins in non-magnets without external magnetic field. Use of perpendicularly polarized
spin currents for spin field effect transistor is a quite promising because precession of
perpendicularly polarized spins can be manipulated by Rashba spin orbit coupling in theabsence of the applied field along momentum direction [1]. The SHEs are electricallymeasured for an InAs quantum well (QW) structure where Rashba field of 8.5 Tesla
is induced. The device is composed of an InAs channel and Pd/CoFe multilayers withperpendicular magnetization, which allows to detection of spin Hall voltages. The spinpolarized electrons with perpendicular orientation cause a charge accumulation at theedge of the InAs channel probed by spin Hall voltage. This charge accumulation induces atransverse voltage. We observe large spin Hall resistance up to 9.3 mΩ and spin Hall angle
is found to be about 0.01. According to the theoretical reports [2, 3], one of its origins is
spin-orbit scattering of conduction electrons through side-jump or skew scattering. The
SHEs are emerging from the side-jump scattering of flowing spins in the InAs QW and thescattering direction is determined by spin orientation with spontaneous magnetization.

[1] G. Venkataiah, Y. Shirahata, M. Itoh, and T. Taniyama, Appl. Phys. Lett. 99, 102506 (2011).

REFERENCES [1] Koo et al., Science. 325, 1515 (2009). [2] J. E Hirsch, Phys. Rev. Lett. 83, 1834
(1999). [3] J. Zhang, Phys. Rev. Lett. 85, 393 (2000).

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RM03

Dependence of current-induced effective rashba field andperpendicular magnetic anisotropy on annealing temperature

Bias-voltage controlled tunneling resistance in a ferromagnet-metalinsulator-ferromagnet tunneling junction

Transistorless 3D STT-MRAM Architecture

Bulk and surface half-metallic ferromagnetism in transition-metal
chalcogenides with rocksalt phase from first-principles calculations

Ki-seung Lee1, Byung Chul Min1, Kyung Jin Lee2* and Kyung-ho Shin1
1
Spin Convergence Research Center, Korea Institute of Science and Technology,
Korea
2
Departments of Materials Science and Engineering, Korea University, Korea

Manipulation of local magnetization using electrical current has attracted considerable interest
due to its rich physics and potential applications for a new class of spintronic devices. It wastheoretically proposed that Rashba-type spin-orbit coupling (SOC) caused by inversion symmetry
breaking yields a new type of current-induced effective magnetic field [1], i.e. Rashba field of
which direction is perpendicular to both the direction of current-flow and that of the inversion
symmetry breaking. The existence of this Rashba field in the structure consisting of non-magnetic
metal | ferromagnetic metal | oxide was recently confirmed experimentally [2]. We previously
investigated the effect of the ferromagnetic film thickness on the Rashba spin transfer torque(STT), as well as its effect on the perpendicular magnetic anisotropy. The magnetic anisotropy
clearly showed surface properties, while the surface nature of the Rashba field remained elusive.
In this work, we further investigate the dependence of current-induced effective Rashba field andperpendicular magnetic anisotropy on annealing temperature. Experiments were carried out on
Pt(3nm)|Co(0.6nm)|MgO(2nm) samples with the annealing temperature from 300OC up to 450
O
C. In this presentation, the effect of annealing treatment will be discussed.

Sui-pin Chen*
Department of Electrophysics, National Chiayi University, Taiwan

We adopt the spin-polarized free-electron model [1-3] and extend our previous work [4]to study the tunneling resistance change in a ferromagnet/metal/insulator/ferromagnet
magnetic tunneling junction [5], and find a method for changing the tunneling
resistance. Unlike the traditional method of varying the magnetizations configuration
between the two ferromagnetic layers, the proposed method uses the polarity of abias voltage with a small strength to change the tunneling resistance. Under suitableconditions, we show that both tunneling resistance changes resulting from the polarityof the bias voltage and from the magnetizations configuration are equal in magnitude,
and are larger than that in a conventional ferromagnet/insulator/ferromagnet magnetic
tunneling junction.
[1] S. Zhang and P. M. Levy, Phys. Rev. Lett. 81, 5660 (1998). [2]J. Yang, J. Wang, Z. M. Zheng, D.
Y. Xing and C. R. Chang, Phys. Rev. B 71, 214434 (2005). [3] S.-P. Chen and C.-R. Chang, IEEE
Trans. Magn. 45, 2410 (2009). [4] S.-P. Chen, J. Appl. Phys. 107, 09C716 (2010). [5] S. Yuasa, T.
Nagahama and Y. Suzuki, Science 297, 234 (2002).

[1] A. Manchon and S. Zhang, Phy. Rev. B 78, 212405 (2008) ; Phys. Rev. B 79, 094422 (2009). [2] I.
M. Miron et al., Nature Mater. 9, 230 (2010).

The intrinsic conductance mismatch between ferromagnetic metals (FM) andsemiconductors is a critical obstacle in spin injection, and inserting a thin tunnel
barrier, especially MgO, is expected to hurdle this problem. [1] In this study, we reportelectrical measurements of spin polarization in GaAs coming from efficient spin
injection through MgO tunneling barrier. The whole epitaxial layers of FM/MgO/GaAs
structures were prepared in-situ process using cluster MBE. To reduce the depletion
layer of Schottky barrier, doping modulated GaAs layer has been inserted in thevicinity of the interface between GaAs and MgO layers. Large voltage drop (ΔV = 6.3
mV at 10 K when I = -0.9 mA in Fe/MgO/GaAs structure) between the baseline andthe dip of Hanle curve is observed at various temperatures up to 400 K in a 3-terminal
Hanle measurement geometry. The Lorentzian fitting of the Hanle curve gives 234 ps
spin lifetime of n-doped GaAs and 952 nm spin diffusion length at 300 K.
[1] G. Schmidt, D. Ferrand, L.W. Molenkamp, A.T. Filip and B.J. van WeesPhys. Rev. B 62, R4790(2000).

Weizhong Wang*
University of Wisconsin - Milwaukee, USA

The MTJ based devices are fabricated through thin film deposition and patterningwhich are intrinsically capable for 3D vertical multiple layers integration. However,current MRAM architecture requires at least one isolation transistor in each MRAM
cell(1). Since there is no mature 3D CMOS technology available, isolation transistor
prevent the progress on developing 3D MRAM. Therefore the races on MRAM area
density improvements are all based on aggressive horizontal cell size scaling. This
paper introduces a new transistor-less MRAM architecture to enable vertical 3-D
integration. Since the MTJ devices are essentially two terminal resistors, an arrayof MTJ devices form a connected resistor network. We introduce a 3D architecturewith new read/write operation to address individual MTJ cells. Comparing withconventional STT-MTJs, our preliminary simulation results show (1) little penalties onboth speed and power consumption during read operation;(2) little penalty on writing
speed; and (3) 2x to 3x penalty on writing power consumption depending on TMR ratio
of MTJs. The proposed STT-MRAM architecture can greatly enhance the area densityof STT-MRAM and beat CMOS or any single layer based memory technologies.

Magnetism in diamagnetic materials such as defective SnO2, ZnO, or SiC got
particular attention to probe and understand the source and nature of magnetism inthese materials. Particularly, the role of intrinsic defects, e.g. a vacancy which is themain source of magnetism, motivated many scientists around the world. The defectformation energies of vacancies in these diamagnetic materials are very large which
limit its experimental synthesis. Here, we focused on SiC nanoribbons (NRs) to probe
the native defects and their interacations with the alien light element impurities, e.g.,
B, N, in terms of magnetism. Using ab-initio calculations based on density-functional
theory (DFT), our extensive results indicate that silicon or carbon vacancy per cell
induces magnetic moment in SiCNRs, whereas SiCNR with Si+Si divacancy has
almost zero magnetic moment. The half-metallic behavior, which is very important for
spintronics devices, of SiC NRs is maintained in the presence of one C or Si vacancy
per cell. The Si or C vacancies have high defect formation energies, howevere, we
found that foreing impurities B or N significantly reduced the defect formation energyof vacancies in SiCNRs.

Guoying Gao* and Kailun Yao
School of Physics, Huazhong University of Science and Technology, China

In the past decade, most of transition-metal pnictides and chalcogenides with metastable zincblende structure were predicted to be half-metallic ferromagnets. So far, however, only four ofthem, zinc-blende CrAs, MnAs, CrSb, and CrTe, have been realized experimentally in the formof thin films or multilayers because of the instability of the zinc-blende phase. Here we predict
with first-principles calculations that all three rocksalt CrTe, VPo, and CrPo are half-metallic
ferromagnets with the half-metallic gaps of 0.03, 0.18, and 0.31 eV, respectively. Importantly,
the rocksalt phases are approximately 0.19-0.33 eV per formula unit lower in energy than thecorresponding zinc-blende phases for these three half-metallic compounds, which indicate it ismore possible to fabricate these binary compounds with rocksalt phase than the zinc-blende phasein the form of thin films or multilayers. We also study the (111) surface properties of rocksalt CrTeand CrPo, and find the Te- (Po-)terminated (111) surface is more stable than the Cr-terminated (111)
surface, and both Cr- and Te- (Po-)terminated (111) surfaces preserve the bulk half-metallicity.
The present work will not only add to the understanding of these binary half-metals, but will also
stimulate experimental efforts toward fabrication and utilization of these systems in spintronics.

(1) Tehrani, S.; Slaughter, J.M.; Deherrera, M.; Engel, B.N.; Rizzo, N.D.; Salter, J.; Durlam, M.;
Dave, R.W.; Janesky, J.; Butcher, B.; Smith, K.; Grynkewich, G.; 'Magnetoresistive random accessmemory using magnetic tunnel junctions', Proceedings of the IEEE, Volume: 91 , Issue: 5, 2003 ,pp.703 - 714[1] T. Graf, C. Felsler, and S. P. P. Parkin, Prog. Solid State Chem. 39, 1 (2011). [2] C. Felser, G. H. Fecher, and B. Balke,
Angew. Chem. Int. Edn 46, 668 (2007). [3] M. I. Katsnelson, et al., Rev. Mod. Phys. 80, 315 (2008). [4] S. K. Bose and J.
J. Kudrnovsky, Phys. Rev. B 81, 054446 (2010). [5] G. Y. Gao and K. L. Yao, Appl. Phys. Lett. 91, 082512 (2007). [6] J. J.
Deng, et al., J. Appl. Phys. 99, 093902 (2006). [7] G.Y. Gao, K.L. Yao, N. Li, J. Phys.:Condens. Matter 23, 075501 (2011).

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Spin motive force driven by magnetization dynamics

A highly (001) textured Ge/MgO/bcc-ferromagnet system prepared byultra-high vacuum sputtering

Collision of cobalt atom with Alq3 molecule thin film: a molecule
dynamics study

Magneto-transport properties of Fe thin films in an external electric
field

Junichiro Ohe
Toho University, JapanThe current-induced magnetization dynamics realized in spintronics devices involve
both of charge and spin degrees of freedom. Recently, it has been pointed out that themagnetization dynamics induces an effective electric field acting on the conduction
electrons through the spin Berry phase. The effective electric field, or a 'spin motive
electric field', was investigated for a simple one-dimensional domain wall. It isdifficult to estimate analytically this effective electric field in actual systems, because
the magnetization dynamics obeys the non-linear Landau-Lifshitz equation. In thisreport, we investigate the the spin motive force and the measurable voltage by solving
Landau-Lifshitz-Gilbert equation numerically. We propose several structures thatshow measurable spin motive force. We also compare the our numerical results andexperimental results.
J. Ohe and S. Maekawa, J. Appl. Phys. 105, 07C706 (2008) J. Ohe et al., Appl. Phys. Lett., 95,
123110 (2009) Y. Yamane et al, Phys. Rev. Lett. 107, 236602 (2011) M. Hayashi et al, Phys. Rev.
Lett. (2012) in press

Soogil Lee1, Sanghoon Kim1, Jungho Ko1, Sangho Lee1, Jangyup Son1, Seung-heon
Chris Baek2, Seok-hee Lee2 and Jongill Hong1*
1
Materials Science and Engineering, Yonsei University, Seoul 120-749, Korea
2
Dept. of Electrical Engineering, Korea Advanced Institute of Science and Technology(KAIST), Daejeon, 305-701, Korea

Observation of spin accumulation in semiconductor is very fascinating for fundamental physics and applications
as well. Many important progresses have recently been made in this field. For example, the insertion of a tunnel
barrier at the interface between ferromagnet (FM) and semiconductor has increased the chemical potential
difference at the interface [1]. Ge/MgO/bcc-FM has been intensively studied because of an epitaxial growth of
MgO on a Ge substrate due to small lattice mismatch (~4%) between Ge(001)[100] and MgO(001)[110]. As
a result, the symmetry-related spin-dependent tunneling is expected to occur at the Ge/MgO/bcc-FM junction.
The successful growth of the single-crystal Ge(001)/MgO(001)/bcc-FM(001) stack has been reported [2,3].
However, these results have been obtained using a molecular beam epitaxy technique which may not besuitable for applications in the industry. Here, we show that a highly (001) textured Ge/MgO/CoFeB junction
can be achieved by an ultra-high vacuum sputtering technique. We will discuss the effect of various deposition
conditions on the (001) texture of MgO/CoFeB deposited on (001) Ge. The quantitative and qualitative analysesof the structures of MgO/CoFeB layers will be presented based on the results of x-ray diffractometry andtransmission electron microscopy. Finally, we will examine the tunneling characteristics of the junction.
[1] Abert Fert and Henry Jaffres, Physical Review B 64, 184420 (2001) [2] Wei Han, et al., Journal of
Crystal Growth 312, 44 (2009) [3] Kun-Rok Jeon, et al., Crystal Growth and Design 10, 1346 (2010)

294

Seong Hoon Shim1, Kyung-ho Kim1, Hyung-jun Kim1, Yun-hi Lee2 and Joonyeon
Chang1*
1Spin Convergence Research Center, Korea Institute of Science and Technology,
Korea
2
Department of Physics, Korea University, Korea

The 19th International Conference on Magnetism

Yun-peng Wang, Ling-ling Tao and Xiu-feng Han*
Institute of Physics, Chinese Academy of Sciences, China

Yun-Peng Wang, Xiu-Feng Han and Ling-Ling Tao Beijing National Laboratoryof Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences,
Beijing 100190, China Hai-Ping Cheng Department of Physics and Quantum Theory
Project, University of Florida, Gainesville, Florida 32611, USA Molecular dynamics
simulations on deposition of cobalt atom onto tris(8-hydroxyquinoline) aluminum(Alq3) molecule thin film are presented. A Lennard-Jones potential calibrated by firstprinciple calculations was used to describe Alq3-Co interactions. Microscopic collision
process was analyzed by looking into one trajectory. Statistics of final positions andpenetration depths of cobalt atoms show that cobalt atoms with low initial energy
penetrate little into Alq3 thin film and stay near the surface of Alq3 thin film while
cobalt atom with high initial energy penetrates significantly into Alq3 thin film.
Consequently, thickness of Alq3/cobalt interface is equal to roughness of Alq3 surface
if initial energies of cobalt atoms are small, but 1 nanometer larger than roughness of
Alq3 thin film if initial energies of cobalt atoms are large. Injected cobalt atoms lose
their kinetic energies via collision with 8-hydroxyquinoline ligands of Alq3 molecules.
DFT calculations show hybridization of carbon and oxygen due to cobalt and sizable
charge transferred from cobalt to nearest Alq3 molecule.

July 12 (Thu)Tomoyasu Taniyama*, Taiichiro Nozaki, Yasuhiro Shirahata, Gorige Venkataiah and
Mitsuru Itoh
Materials and Structures Laboratory, Tokyo Institute of Technology, Japan

July 12 (Thu)poster Presentation

Kohji Nakamura1*, T. Akiyama1, T. Ito1, M. Weinert2 and A. J. Freemnan3
1
Physics Engineering, Mie University, Japan2
Physics, University of Wisconsin-Milwaukee, USA
3
Physics and Astronomy, Northwestern University, USA

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poster Presentation

poster Presentation

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Role of interfacial B impurity in magnetocrystalline anisotropy at
MgO/Fe interface

A model of chain of ellipsoid-rings for magnetic nanotubes

Magnetic properties of Fe-doped NiO nanoparticles

Covalent immobilization of biotin on superparamagnetic nanoparticles

An interface induced-perpendicular magnetocrystalline anisotropy (MA), as observedin the MgO/CoFeB,[1] has attracted much attention in magnetic application. From
first-principles, previously, we demonstrated a perpendicular MA at the MgO/Feinterface due to a weak Fe d_z-O p_z hybridization[2], but it still need to discuss arole of interfacial B impurity. Here, we extend investigation to include the interfacial B
impurity. Calculations were carried out by using FLAPW method[2]. First, the phasestability at the MgO/Fe interface was determined based on calculated total energy witha model of an MgO monolayer on a five-layer Fe, where the B were incorporated ininterstitial positions at top, second, and third Fe-interface-layers. Results indicate thatthe B favors to segregate to the interface so as to form an MgO/FeB/Fe interface. Then,the MA energy (E_(MA)) was calculated by using the second variation SOC method
and the force theorem. The calculated E_(MA) has a large positive value of 0.69 eV for
the ideal MgO/Fe, indicating a perpendicular MA. For the MgO/FeB/Fe, the E_(MA)turns out to be almost zero (-0.02 eV), which indicates no interface MA, due to an
enlargement of the Fe-MgO interlayer distance by the interfacial B atoms.

Numerical calculation of magnetic properties is a very effective way to understand thewhole magnetic behavior of nanotubes. Currently, the most studies of calculation ofmagnetic properties of nanotubes are mainly grounded on the Stoner-Wohlfarth (S-W)
model, starting from an elongated prolate ellipsoid with single-domain. But, it is hard
to imagine how such an ellipsoid is arranged in the hollow tubular structure and hence
the realization of predicted magnetic properties has been hindered by the experimental
difficulties. In the present article, an alternative model of chain of ellipsoid-rings is
proposed to calculate the magnetic properties of nanotubes, where the chain of rings
with ellipsoid particles is assumed to compose nanotube. Based on this new model,
we calculate the magnetic properties of nanotube and further discuss the influenceof tubular geometric parameters on the magnetic properties. All the results are wellconsistent with the experimental data of Ni nanotube and moreover are available for
the Ni nanowire. Consequently, our model provides an easy and general approach toboth magnetic nanotubes and magnetic nanowires.

Akinobu Kurokawa*, Takuya Yanoh, Shinya Yano, Hiromasa Takeuchi, Kazuki
Onuma, Takaya Kondo, Kazunari Miike, Toshiki Miyasaka and Yuko Ichiyanagi
Physics, Yokohama National University, JapanNiO is known as a P-type semiconductor with wide band gap between 3.2 eV and
3.5 eV, and expected as a new material of diluted magnetic semiconductor. Magnetic
properties of NiO nanoparticles with several nanometers were observed and blocking
temperature(TB) was determined to be 17 K, while Neel temperature of NiO bulk
crystal exhibits TN=523 K. In this study, Fe ions were doped into NiO nanoparticles inorder to obtain higher blocking temperature. Ni1-xFexO (x=0, 0.05, 0.1) nanoparticles
with several nanometers encapsulated with amorphous SiO2 were prepared by ournovel preparation method. NiO single phase structure was confirmed from the x-ray
diffraction measurements. It is considered that Ni ions are replaced to Fe ions exactly.
This fact was also supported by X-ray absorption fine structure measurements.
Magnetization measurements were performed by SQUID magnetometer for obtained
samples. Temperature dependence of magnetization showed that TB shifted from 17
K to 57 K as the amount of Fe ions increased, and below TB, ferromagnetic behaviors
were observed. Coercive force (HC) increased from 0.8 kOe to 1.5 kOe as theamount of Fe ions increased. This phenomenon can be explained by characteristics of
extremely small particles in this system.

July 12 (Thu)[1] S. Ikeda, et.al. , Nature Mater. 9, 721 (2010) . [2] K. Nakamura, et.al. , Phys. Rev. B81, 220409(2010) .

Among the magnetic materials, the nano-scale structured magnetite, Fe3O4 is
widely applicable magnetic nanparticles (MNPs). MNPs offer attractive possibilities
in biomedicine, biosensor, and separation processes because of their uniqueproperties of superparamagnetism, biocompatibility and low toxicity. The ease ofsynthesis and subsequent surface functionalization of MNPs with a desired material
improve biocompatibility which creates an avenue of delivering multimodal andmultifunctional MNPs. In this study, a simple protocol of covalent immobilizationof biotin on the surface of MNPs for improving biocompatibility and cell viability ofthe original MNPs has been demonstrated. MNPs were prepared using a solution offerrous and ferric ions. The anchoring of 3-aminopropyltrimethoxysilane with MNPs
resulted due to the formation of Fe-O-Si covalent linkage which is quite strong andhaving free amino group. The hydroxyl groups of the biotin were activated by N,N'disuccinimidyl carbonate followed by conjugation with MNPs-NH2 to afford BiotinMNPs. The conjugation of biotin to MNPs was confirmed by FT-IR, XPS and EDX.
The Biotin-MNPs showed superparamagnetic character as investigated by SQUID.

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First-principles study on magnetic anisotropy of Co/Pt(111) film inelectric field

First-principles GGA+U calulations of half-metallicity in wurtzite
NiO/ZnO(0001) superlattices

Uniaxial strain effects on spinel ferrite nanoparticles containing Nd
and B elements

Fabrication of (Mn-Al)/Pd or Ni with Core-Satellite Structured
Magnetic Particles

Electric field (EF) control of magnetism is attractive for spintronics devices. In
recent research, it has been shown that EF affects not only magnetic moment but also
spin conduction and magnetic anisotropy[1-4]. In particular, it has been found thatcombination of the 3d and 5d metals in EF causes large effects on magnetic anisotropy.
In this study, we investigate the dependence of the magnetic anisotropy energy (MAE)
and the magnetic moment of Co/Pt(111) on EF by first-principles calculations. We
employ the fully relativistic full-potential linear-combination-of-atomic-orbitals method
based on the density-functional theory within the local-spin-density approximation.
The exchange-correlation energy functional is the Perdew-Wang parameterization of
the Ceperley-Alder results. We have found that the magnetic moment of the Co atom
is in proportion to EF. The results of the calculations of the MAE and the other details
will be shown at the conference.

Wurtzite NiO has been predicted to display half-metallicity and have only smalllattice mismatch with wutzite ZnO [1]. It is interested to explore the possibillity ofthe so-called all oxides spintronics obtained by the hybrid structrues consisted of thewurtize NiO and ZnO [2]. In this contribution, the structural, electronic, and magnetic
properties of wurtzite NiO/ZnO(0001) superlattice were investigated by means ofdensity functional calculations using spin-polarized generalized gradient approximation
GGA and GGA+U schemes. We demonstrate that these superlattices retain their halfmetallic behavior leading to a complete, i.e., 100%, spin polarization of the conduction
electrons.This property makes the wurtzite NiO/ZnO(0001) heterostructures to be
excellent candidates for high-efficiency magnetoelectronic devices.

Sho Yasuda* and Shugo Suzuki
Division of Materials Science, Faculty of Pure and Applied Sciences, University ofTsukuba, JapanX. H. Zhou
National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics,
Chinese Academy of Sciences, China[1] R. Q. Wu, G. W. Peng, L. Liu, and Y. P. Feng, Appl. Phys. Lett. 89, 082504 (2006) [2] Z. Chen, L.
Miao, and X. Miao, AIP ADVANCES 1,022124 (2011)[1]T. Maruyama, Y, Shiota, T. Nozaki, K. Ohta, N. Toda, M. Mizuguchi, A. Tulapurkar, T. Shinjo, M.
Shiraishi, S. Mizukami, Y. Ando and Y. Suzuki: Nature. Vol.4 (2008) 158 [2]D. Chiba, S. Fukami,
K. Shimamura, N. Ishiwata, K. Kobayashi, and T. Ono: Nature Mater. Vol.10 (2011) 853. [3]M.
Tsujikawa and T. Oda: Phys. Rev. Lett. Vol.102 (2009) 247203. [4]K. Nakamura, T. Akiyama, and T.
Ito: Phys. Rev. B Vol.81 (2010) 220409.

Masaki Mito1, Seiya Saisho2, Hiroyuki Deguchi1, Takashi Iwamoto3 and Atsushi
Takahara4
1
Department of Basic Science, Kyushu Institute of Technology, Japan2
Department of Applied Science for Integrated System Engineering, Kyushu Instituteof Technology, Japan
3
Institute for Sustainability Research and Education, Hosei University, Japan
4
Institute for Materials Chemistry and Engineering, Kyushu University, Japan

Youn-kyoung Baek*, Jung-goo Lee and Chul-jin Choi
Powder & Ceramic Division, Korea Institute of Materials Science, Korea

We studied the uniaxial strain effects on spinel ferrite nanoparticles that containined Ndand B elements (Nd : Fe : B = 10.4 : 83.5 : 6.1) and had the particle size of 5.1 nm. In
diffused magnetic nanoparticles, the magnetic easy-axis is distributed randomly, and it
is impossible to add the strain along a specific structural axis of each particle. However,in order to control the magnetic property of the magnetic nanoparticles, the applicationof the uniaxial strain for the particles with the uniform easy-axis vector is preferable
to that of hydrostatic pressure for randaomly diffused particles. In this study, magnetic
easy-axis of each particle was arranged by solidifying an epoxy resin containing theparticle at the dc magnetic field of 1 T, resulting in creating an assembly of uniformly
oriented nanoparticles. Afterward, the strain was applied along both the magnetic
easy-axis and hard-axis. In both situations, the magnetic blocking temperature had
the maxmimum at the strain of about 3-5 kbar. The difference between two strainexpeirments appeared at pressure of above 10 kbar.

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Magnetic ground state of TM/Graphene/TM films

Magnetic properties of La doped nanocrystalline Z-type ferrite
nanopowders synthesized via co-precipitation method

The magnetic proximity effect in Fe 3 O 4 core/γ-Mn 2 O 3 shell
nanoparticles

The effect of hydrostatic pressure on the Morin transition in hematite
nanoparticles

Dongyoo Kim, Arqum Hashmi and Jisang Hong*
Department of Physics, Pukyong National University, Korea

Using the full potential linearized augmented plane wave (FLAPW) method, we haveinvestigated the magnetic properties of transition metal (TM)/Graphene/transition
metal (TM) structure. We have explored magnetic properties of metal/grapheme/
metla systems, which is Co(1 ML)/Graphene/Ni(1 ML). Co(1ML)/Graphen/Ni(1ML)
film have the AFM ground state. The calculated magnetic moment of Ni is -0.22 μB,
while the Co layer has 1.50 μB. In calculation of optimized structure, we have thatthe distance between carbon and Co is 2.07 A and it is 2.04 A for carbon and Ni. The
relative height difference between two carbon atoms in grapheme layer is 0.29 A.
To understand the effect of buckling geometry of graphene, we have performed thecalculation whithout any buckling factor of graphene layer. The magnetic ground state
is not changed, and calculated magnetic moment of Ni and Co are -0.60 and 1.70,
respectively. This implies that the AFM coupling is an intrinsic property of Co(1ML)/
Gr/Ni(1ML) system. Also, we will present the magnetic properties of Co(2ML)/Gr/
Ni(1ML) and Co(1ML)/Gr/Ni(2ML) systems. This work was supported by KCAP
located in Sogang University funded by the Ministry of Education, Science, andTechnology (MEST) through the National Research Foundation of Korea (NRF-2011C1AAA001-2011-0030278) and by KOSEF (No. R01-2008-000-20014-0).

Mohamed M. Rashad1*, M. Rasly1, H. M. Elsayed2, A. A. Satter2 and I. A. Ibrahim1
1Advanced Materials Department, Central Metallurgical Research and Development
Institute, Egypt
2
Physics Department, Ain Shams University, Egypt
Co2Z type hexagonal ferrites powders doped with La3+ ions (Ba3-XLaXCo2Fe24O41
where X=0.0, 0.05, 0.10 and 0.15) were prepared using co-precipitation method. The
results revealed that single phase CO2Z type ferrite was formed from the precipitatedprecursor in presence of SDS as anionic surfactant and then preheated at 600oC
for 4h and then post annealed at 1300oC for 6h. Moreover, the crystallite size andthe porosity,% of the formed powders were increased whereas the unit cell volume
were decreased by increasing the La3+ substitution. The microstructure of the formed
powders appeared as hexagonal platelet like structure. The DC resistivity of theobtained CO2Z was decreased as La3+ content increased. The saturation magnetization(Ms= 53.7-55.5 emu/g) was slightly increased with substitution of La3+. Moreover,
two resonance frequencies peaks are observed through the imaginary part of complex
permeability meanwhile a decrease in the real part of magnetic permeability throughX-band frequencies. The reasons are discussed using electromagnetic theory.
1- G. Shihai, Z. Yanghuan, F. Zekun, W. Xinlin, H. Huahui, J. Rare Earths 25(2007)220-225 2-X.Wang, L. Li, S. Su, Z.
Gui, Z. Yue, J. Zhou, J. Eur. Ceram. Soc. 23(2003)715-720. 3- J. J. Xu, C. M. Yang, H. F. Zou, Y. H. Song, G. M. Gao, B.C.
An, S. C. Gan, J. Magn. Magn. Mater. 321(2009)3231-3235. 4-L. Qin, H. Verweij, Mater. Lett. 68(2012)143-145.

296

Long Giang Bach1, Md. Rafiqul Islam2 and Kwon Taek Lim2*
Department of Imaging System Engineering, Pukyong National University, 608-737,
Busan, Korea
2
Department of Imaging System Engineering, Pukyong National University, Busan,
Korea
1

The 19th International Conference on Magnetism

S. M. Yusuf* and P. K. Manna
SOLID STATE PHYSICS DIVISION, BHABHA ATOMIC RESEARCH CENTRE,
MUMBAI 400085, India

The phenomenon of ‘proximity effect’ is very popular in the context of superconductor/
non-superconductor heterostructures. In the present study, we report the magnetic
proximity effect in a core-shell nanoparticle system by employing dc magnetizationand neutron diffraction techniques. In a heterostructure, the substrate, used for its
deposition, often modifies the magnetic properties of the deposited layers. However, a
core-shell nanoparticle system, being substrate-free, rules out any such possibility. We
have observed magnetic proximity effect in a Fe3O4 core/γ-Mn2O3 shell nanoparticle
system, in terms of an enhancement of the Curie temperature (Tc) of the γ-Mn2O3 shell(~66K) compared to its bulk value (~40K), and the presence of magnetic ordering in
its so-called paramagnetic region (i.e. above 66K). The origin of these two features has
been ascribed to the proximity of the γ-Mn2O3 shell with a high-Tc Fe3O4 core (~858K
in bulk form) and an interface exchange coupling between core and shell. Interestingly,
no exchange bias effect is found due to a weak interface exchange coupling between
core and shell. The present study brings out the importance of the relative strength ofinterface coupling in governing the simultaneous occurrence of the magnetic proximity
effect and the exchange bias phenomenon in a single system.

July 12 (Thu)Koji Hotta*, Kohji Nakamura, Toru Akiyama and Tomonori Ito
Mie University, JapanSen Yang*, Junfeng Gong and Xiaoping SongDepartment of Materials Physics, Xi'an Jiaotong University, China

Luana Caron1*, Davide Peddis2, Lorenza Suber3, Dino Fiorani3 and Per Nordblad4
1 Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, TU Delft Mekelweg
15, 2629JB Delft, Netherlands
2 Dipartimento di Scienze Chimiche, Universita degli Studi di Cagliari,, Cittadella Universitaria diMonserrato 09042 Cagliari, Italy
3 Istituto di Struttura della Materia, Area della Ricerca di Roma, CNR Via Salaria km 29500, CP
10-00016 Monterotondo Stazione, Rome, Italy
4 Department of Engineering Sciences, Uppsala University Box 534, 751 21 Uppsala, Sweden

Recently, hematite particles have been the subject of intensive studies in areas as diverse as magnetic storage
media, photo electrodes and catalysis[1,2]. Hematite is an antiferromagnetic system that displays a spin
reorientation from uniaxial to canted antiferromagnetism at the Morin temperature[3]. Particle shape, size andmicrostructural defects have strong influence on the Morin temperature and thus can be used to tune the system’smagnetic response. It is known that the Morin transition temperature decreases along with particle size as a resultof the increasing lattice spacing[4], whereas an increase of the Morin temperature under hydrostatic pressure isobserved in the bulk material[5]. In a novel approach, we report on the effect of hydrostatic pressures on hematite
rhombohedral nanoparticles of narrow size distribution<DTEM> = 93 ± 2 nm[6]. Pressure was found to increase
the Morin temperature at a rate of ~ 5 K/kbar and considerably decrease thermal hysteresis. These results strongly
contrast with the effects of pressure on the bulk material where a milder influence of pressure on both the Morintemperature and thermal hysteresis is observed.
[1] Zhihong Jing, Shihua Wu, Mater. Lett. 58, 3637 (2004) [2] K. Sivula, F. Le Formal and M. Gratzel, ChemSusChem 4, 417 (2011) [3] F. J. Morin, Phys. Rev. 78, 819 (1950) [4] D.
Schroeer and R. C. Nininger, Phys. Rev. Lett. 19, 632 (1967) [5] T. G. Worlton and D. L. Decker, Phys. Rev. 171, 596 (1968) [6] L. Suber et al., Phys. Chem. Chem. Phys. 12, 6984 (2010)

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Ultra-thin MgO coating of superparamagnetic magnetite nanoparticles
by combined co-precipitation and sol-gel synthesis

Structural and magnetic anomalies in CoAl2O4 nanocrystals

Structure effects on the magnetic behavior in Fe oxide based
nanoparticles

Magnetodielectric effect of Fe2O3 nanoparticles embedded in SiO2
glass matrix

July 12 (Thu)Superparamagnetic magnetite nanoparticles coated with an ultra-thin (~1 nm) magnesium oxide (MgO)
layer have been synthesized by combining co-precipitation and sol-gel methods. A thorough chemical andstructural characterization has been carried out by means of HRTEM, XRD, EDS, DLS and TGA. Aberration
corrected HRTEM experiments with sub-angstrom spatial resolution have allowed us to distinguish the ultrathin MgO shell that grows epitaxially on the magnetic cores. The capability of the MgO shell to protect themagnetic nuclei from oxidation up to 600ºC has been demonstrated. The magnetic properties of the material
have been studied before and after the coating procedure. The superparamagnetism of the magnetite nuclei
at room temperature is preserved even after calcination. The possibility of obtaining particles of controlled
size coated with an isolating layer of nanometric thickness and high thermal stability makes the combinationof the two synthesis methods used in this work a starting procedure to obtain nanometric powders suitable
for technological applications, such as high-frequency electronics. These particles, after the appropriatedfunctionalization, are also potential candidates to be used in biomedical applications

Koichi Sato1, Takashi Naka1, Takayuki Nakane1, Minori Taguchi1, Dinesh Rangappa2,
Satoshi Ohara3 and Tadafumi Adschiri41National Institute for Materials Science, Japan
2
International Advanced Research Centre for Powder Metallurgy & New Materials, India
3
Joining and Welding Research Institute, Osaka University, Japan
4
WPI, Advanced Institute for Materials Research, Tohoku University, Japan
In this study, we investigated magnetic properties of spinel CoAl2O4 nanocrystals (NCs) synthesized by asupercritical hydrothermal synthesis. We confirmed that all the samples are composed of the single phase
CoAl2O4 by the X-ray diffraction measurements. Crystalline sizes are controlled to be 4 ? 8 nm. We also
found that the inversion parameters of the samples, describing the cation distribution are more than 0.3 [1,2],
being much higher than bulk specimens previously reported. We conducted magnetization and, dc- and acsusceptibility measurements. All the samples show paramagnetic behavior above 70 K. The effective Bohrmagnetons and the Weiss temperatures are 2.6 - 2.8 μB and -40 - -50 K. The effective Bohr magnetons are
smaller than 4.4 - 4.6 μB reported on specimens with the low inversion parameters [3,4]. The susceptibilities
deviate from Curie-Weiss law below 40 - 50 K. From the results of the magnetization measurements, it was
found that spontaneous magnetization, 0.1 μB/Co, emerges below 40 K in the samples with the size of 4
nm. The reduced Bohr magnetons and the emergence of the spontaneous magnetization indicate that in our
NC samples, a certain magnetic phase, being different from those of bulk specimens, appears below 40 K.

Amilcar Labarta*, Carlos Moya, Nicolas Perez, Arantxa Fraile, Oscar Iglesias andXavier Batlle
Fundamental Physics, University of Barcelona, Spain

A key question in magnetic nanoparticles (NP) is how the nanostructure modifies their magnetic and electronic
properties. As the particle size is reduced, deviations from bulk behaviour have been widely reported andattributed to both the appearance of a magnetically disordered surface layer and finite-size effects, thus giving
rise to a decrease in the particle magnetization, an exchange field acting on the core and an increase in theanisotropy. In order to elucidate those phenomena we have carried out STEM, XAS, XMCD and magnetization
measurements in Fe oxide based NP models, aiming at the real-space characterization at the sub-nanometerscale of a single NP to characterize the particle structure, surface magnetization, and the dependence of thelatter on the strength of the surface bond to a bio-molecule coating. We also aim at the quantification of theorbital and spin contributions to the NP magnetic moment. The key role of the crystal quality is thus suggested,because particlelike behaviour above about 5 nm in size is observed only when NP are structurally defective.
These conclusions are supported by Monte Carlo simulations. It is also shown that thermal decomposition is achemical route capable of producing high-crystal quality NP with bulklike properties.

Hung-cheng Wu, Sudip Mukherjee and Hung-duen Yang*
Department of Physics, National Sun Yat-sen University, Taiwan

Magnetic iron-oxide (doping 0.5 mole %) nanoparticles (NPs) have been synthesizedin silica glass matrix, prepared by the sol-gel method with different annealing
temperatures. XRD, TEM and XANES show the presence of NPs of Fe2O3 and Fe3O4
crystalline phase (< 5 nm). An interesting colossal enhancement of dielectric constantwith diffuse phase transition is observed around room temperature due to the thermally
activated oxygen vacancies. The magnetodielectric effect observed in the glass
composites is considered to be associated with magnetoresistance changes, depending
on NPs size.

[1] N. Tristan, J. Hemberger, A. Krimmel, H-A. Krug von Nidda, V. Tsurkan, and A. Loid, Phys. Rev. B 72, 174404 (2005) [2] T.
Suzuki, H. Nagai, M. Nohara, and H. Takagi, J. Phys. Condensed matter 19, 145265 (2007). [3] H. St. C. O'neill, Eur. J. Mineral. 6,603 (1994). [4] A. Nakatsuka, Y. Ikeda, Y. Yamasaki, N. Nakayama, and T. Mizota, Solid State Commun. 128, 85 (2003).

1. N. Perez, F. Bartolome, L.M. Garcia, J. Bartolome, M.P. Morales, C.J. Serna, A. Labarta and X. Batlle, Applied Physiscs Letters
94, 093108 (2009). 2. P. Guardia, N. Perez, A. Labarta and X. Batlle, Langmuir , 26, 5843-5847 (2010). 3. X. Batlle, N. Perez,
O. Iglesias, A. Labarta, F. Bartolome, L.M. Garcia, J. Bartolome, A.G. Roca, M.P. Morales, and C.J. Serna, Journal of Applied
Physics 109, 07B524 (2011). 4. Work in collaboration with: F. Bartolome, L.M. Garcia, J. Bartolome (ICMA-CSIC, Spain); M.P.
Morales and C.J. Serna (ICMM-CSIC, Spain); M. Varela, J. Salafranca and J. Gazquez (OAK-Ridge National Laboratory, USA).

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Synthesis and characterization of ultra-small magnetic FeNi/G and
NiCo/G nanoparticles

Preparation of chains of single-domain Ni nanoparticles with collinear
direction of magnetization

Magnetic properties of surface-functionalized nano-particles

Tuning the concentration of magnetic Co nanoparticles in In2O3 withoxygen pressure and concentration of tin

Mariana Castrillon1, Alvaro Mayoral 2, Cesar Magen3, Johan G. Meier1, Clara
Marquina4*, Silvia Irusta5 and Jesus Santamaria5
1
Technological Institute of Aragon (ITA), Zaragoza, Spain
2
Instituto de Nanociencia de Aragon (INA)- Laboratorio de Microscopias Avanzadas (LMA),
Universidad de Zaragoza, Spain
3
Instituto de Nanociencia de Aragon (INA)- Laboratorio de Microscopias Avanzadas (LMA),
Departamento de Fisica de la Materia Condensada Universidad de Zaragoza, Spain
4
Instituto de Ciencia de Materiales de Aragon-ICMA, CSIC-U. Zaragoza, Spain
5
Instituto de Nanociencia de Aragon- INA, Networking Research Center on Bioengineering,
Biomaterials and Nanomedicine, CIBER-BBN U. Zaragoza, Spain
Ultra-small magnetic nanoparticles consisting of NiCo and FeNi alloys coated by graphitic shells (NiCo/G
and FeNi/G) have been synthesized by a procedure similar to that described by Seo et al. [1]. The cores, which
retained the face-centered cubic (fcc) symmetry of the original bulk metals, together with the graphitic coating
have been characterized by means of aberration corrected scanning transmission electron microscopy (STEM).
The particles have mean sizes of 2.6 nm and 6.2 nm for NiCo/G and FeNi/G, respectively. The samples containa large fraction of superparamagnetic nanoparticles at room temperature. The thermal stability of the particles
is enhanced by the graphite shell, and the graphite coated FeNi and NiCo are stable under oxygen atmosphereup to 170 C. Non-coated bimetallic FeNi and NiCo have also been prepared. Their chemical characterization
revealed the massive oxidation of the bimetallic nanoparticles in absence of the graphite coating (oxygen content
higher that 60 at. %). This fact confirms the effectiveness of the graphite shell in preventing the magnetic coresfrom oxidation and therefore preserving their magnetic properties even at high temepratures.
1.- Seo W. S. et al., Nature Mater. 5 (2006) 971-6

S A Nepijko1*, D Kutnyakhov1, I E Protsenko2, H J Elmers1, R Wiesendanger3 and G
Schoenhense1
1
Institute of Physics, University of Mainz, Germany
2
Department of Applied Physics, Sumy State University, Ukraine
3
Institute of Applied Physics, University of Hamburg, Germany

Ann Kathrin Michel1, Mathias Kraken1, Jochen Litterst1*, Yannick Guari2, Joulia
Larionova2, Lenaic Lartigue2, Jerome Long2 and Alessandro Lascialfari3
1
IPKM, TU Braunschweig, Germany
2
Institut Charles Gerhardt, Universite Montpellier II, France
3
CNRNANO, Univ. Milano, Italy

Networks of ferromagnetic nanoparticles have been proposed to form quantum cellular automata [1]. We
present a fabrication method based on self-organized growth on stepped surfaces for fairly regular nanoparticles
arranged in a one-dimensional chain, that are suitable for this application. We studied Ni nanoparticles withsizes in the range 80-130 nm on a highly-ordered pyrolytic graphite (HOPG) substrate and succeeded toprepare one-dimensional chains of these single-domain particles characterized by the same direction of theirmagnetization. The nanoparticles were found to decorate atomic cleavage steps on the basal surface and theirdistances are small enough to give rise to strong dipolar coupling. The necessary and sufficient conditions are:(i) 3D growth mechanism along with non-wetting behaviour, (ii) the dielectric substrate has atomic cleavage
steps, (iii) the size of the ferromagnetic particles is smaller than the characteristic domain size but still above
the transition into the superparamagnetic state and, finally, (iv) the distances between the particles are smallenough for dipolar coupling. The study was carried out using atomic-force (AFM) and magnetic-force (MFM)
microscopy. The approach of ordering ferromagnetic nanoparticles into one-dimensional chains is of particularinterest because chains are a basic block for storage and transport of information.

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[1] R.P. Cowburn, M.E. Welland, Science 287 (2000) 1466

Marzook S. Alshammari1*, Mohammed S. Alqahtani1, Qi Feng1, S. Alfahad2, M. Alotibi2, A.
Alyamani2, A. M. H. R. Hakimi3, S. M. Heald4, H. J. Blythe1, A. M. Fox1 and G. A. Gehring1
1
Department of physics and astronomy, University of Sheffield, United Kingdom
2
Nanotechnology center, King Abdulaziz City for Science and Technology, Saudi Arabia
3
Department of Materials Science and Metallurgy, University of Cambridge, United Kingdom
4
Advanced Photon Source, Argonne National Laboratory, USA
This study shows the power of combining magnetic measurements with magnetic circular dichroism (MCD)to detect the contribution to the magnetism from metallic Co nanoparticles, and the result that the formationof nanoparticles is suppressed by the inclusion of tin. Thin films of (In1-0.95Co0.05)2O3 were deposited using
pulsed laser deposition (PLD) on sapphire substrates. The magnetism and the amount of cobalt in nanoparticles
increased with the oxygen deficiency in the PLD chamber and also after annealing in vacuum as expected andas confirmed using Extended X-ray Absorption Fine Structure. The MCD spectra show two features that are
well fitted by a combination of the spectrum from the nanoparticles in the In2O3 matrix, as calculated using
Maxwell-Garnett theory, and a contribution from polarized carriers [1]. The changes in the magnetization and
the MCD are used to get a quantitative estimate of the contribution of the nanoparticles magnetization to thetotal magnetization in each sample. Adding 5% of Sn made little difference to the saturation magnetization
but the signal due to Co nanoparticles was completely suppressed and that from polarized carriers enhanced
strongly. This indicates that, the magnetization of the carriers in Sn and Co co doped In2O3 is particularly high.
Hakimi, et al, Physical Review B 84, 085201 (2011).

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Magnetization measurements and blocking temperature distribution
in magnetic nanoparticle systems

Influence of the morphology on the magnetic properties ofdodecanethiol-capped Au anoparticles

Study of aqueous dispersions of magnetic nanoparticles by magnetic
and rheological measurements

Synthesis, structural, and magnetic properties of strontrium
hexaferrite nanoparticles with La, Sm doping and core/shell structureby the sol-gel hydrothermal process

Taehoon Lee1, Seunghyun Kim1, Sungwon Yoon2, Byoung Jin Suh2*, Zeehoon Jang1
and Kyunghyun Kim3
1
Department of Physics, Kookmin University, Korea
2
Department of Physics, The Catholic University of Korea, Korea
3
Biotechnology & Bioinformatics, Korea University, Korea
We present magnetization measurements on a variety of magnetic nanoparticle
ensembles. The samples are; (1) Artificailly synthesized Helicobacter Pylori ferritinreconstituted with three different Fe ions/ferritin ratio, 160, 2000, and 4000. (2)Commercial horse spleen ferritin (3) CoPt nanoparticles with average particle size of
2 nm. Temperature dependence of magnetization has been measured using a SQUID
magnetometer. Measurement sequence has been modified from a typical field-coolsequence and the measurements have been performed with field “stop-resume” steps
at the regular temperature interval. Using a phenomenological model, we could extract
the moment weighted blocking temperature distributions in the samples from theexperimental data. The model is based on the assumptions that; 1) the particles in theensembles can be uniquely categorized in terms of the blocking temperature. 2) the
particles with the same blocking temperature will have the same field and temperaturedependence of the magnetization. 3) the particles are non-interacting with each other.
With the obtained distributions, the numerical simulations are performed to reproduce
the field-cool magnetization data and zero-field-cool magnetization data.

The 19th International Conference on Magnetism

Daniel Ortega1, Eider Goikolea2, Jose Javier Garitaonandia2, Maite Insausti2, Hyodo
Zhang3, Kiyonori Suzuki3 and Fernando Plazaola2
1
Department od Physics and Astronomy, University College London Gower Street
WCIE 6BT London, United Kingdom
2
Zientzia eta Teknologia Fakultatea Euskal Herriko Unibertsitatea, Spain
3
Department of Materials Engineering, Monash University, Australia
It has been proved that Au nanoparticles (NP) coated with certain molecules can present different magnetic
characters, ranging from superparamagnetism to permanent magnetism at room temperature (RT) [1-3]. We have
prepared ferromagnetic dodecanethiol-capped Au NPs with a high magnetic signal of 1.7 emu/gr and coercive
field of 85 Oe at RT. An analysis by high resolution electron microscopy reveals that the NPs are composed by ~200 atoms forming multi-twinned structured nanocrystals of ~ 2 nm with icosahedral or decahedral morphologies
where well ordered fcc twinned entities are joined forming an only nanocrystal with a spatial 5-fold symmetry.
The external morphology is conditioned by the final stabilization of the NP and, with a surface to bulk atoms ratio
up to ~ 75% and a magnetism located exclusively in the surface atoms, the morphology plays a crucial role in thedefinition of the magnetic character of the NP. In a comparative view with the multidomain structures presented
in bulk materials, we argue that borders among the twinned nanosized entities would act as pinning centers,
hindering the alignment of the magnetic moments between entities and promoting the coercive field.
[1] Y. Yamamoto, T. Miura, M. Suzuki, N. Kawamura, H. Miyagawa, T. Nakamura, K. Kobayashi, T. Teranishi,
and H. Hori, Phys. Rev. Lett. 93 116801 (2004). [2] P. Crespo, R. Litran, T. C. Rojas, M. Multigner, J. M. de laFuente, J. C. Sanchez-Lopez, M. A. Garcia, A. Hernando, S. Penedes, and A. Fernandez, Phys. Rev. Lett. 93
087204 (2004). [3] J. S. Garitaonandia, M. Insausti, E. Goikolea, M. Suzuki, J. D. Cashion, N. Kawamura, H.
Ohsawa, I. Gil de Muro, K. Suzuki, F. Plazaola, and T. Rojo, Nanoletters 8 661 (2008).

July 12 (Thu)

Laura De Matteis1, Laura Custardoy1, Rodrigo Fernandez-pacheco2, Cesar Magen3,
Jesus M De La Fuente4, M R Ibarra5 and Clara Marquina6*
1
Instituto de Nanociencia de Aragon- INA, Universidad de Zaragoza, Spain
2
Laboratorio de Microscopias Avanzadas (LMA) - Instituto de Nanociencia de Aragon (INA,
Universidad de Zaragoza, Spain
3
Laboratorio de Microscopias Avanzadas (LMA) - Instituto de Nanociencia de Aragon (INA,
Departamento de Fisica de la Materia Condensada Universidad de Zaragoza Fundacion ARAID, Spain
4
Instituto de Nanociencia de Aragon- INA, Universidad de Zaragoza Fundacion ARAID, Spain
5
Instituto de Nanociencia de Aragon (INA)- Laboratorio de Microscopias Avanzadas (LMA),
Departamento de Fisica de la Materia Condensada Universidad de Zaragoza, Spain
6
Instituto de Ciencia de Materiales de Aragon-ICMA, Departamento de Fisica de la Materia
Condensada CSIC-Universidad de Zaragoza, Spain

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poster Presentation

Shalini M1, Mahesh Samant2, Radha S3* and D. C. Kothari3
1
Department of Physics and UM-DAE CBS, University of Mumbai, India
2
National Center for Nanosciences and Nanotechnology, University of Mumbai, India
3
Department of Physics, University of Mumbai, India
The observed magnetic tunability of light transmission through a ferrofluid [1] can be effectively understoodin terms of the inter-particle interaction that can be estimated from the magnetic and rheological properties ofthese fluids. The present study reports complementary magnetic and rheological measurements of synthesizedaqueous dispersions of ferrite nanoparticles, using a commercial ferrofluid as a standard. The aqueous
dispersions of the ferrite nanoparticles were synthesized by co-precipitation using suitable precursors andsurfactants. The dispersions were stable for reasonably long durations and the particle size was estimatedto be 10-28 nm from XRD measurements. The room temperature magnetization measured in a SQUID
magnetometer up to fields of 1 Tesla showed superparamagnetic behaviour of the powder and the dispersion
with the background signal of the liquid varying from a diamagnetic to a paramagnetic behaviour. The room
temperature rheological behaviour in zero magnetic field of both the standard and synthesized dispersion
was investigated by measuring the viscosity as a function of shear rate from 1-1000s-1. The viscosity ofthe dispersion increased with increasing shear rate reaching a constant value at higher shear rates; while thestandard sample showed almost no change in viscosity with shear rate conforming to a Newtonian behaviour.
[1] M. Shalini, D. Sharma, A. A. Deshpande, D. Mathur, Hema Ramachandran and N. Kumar, Eur. Phys. Jour. D 66 (2012) 30.

Hue Thi Minh Dang1, Dien Xuan Luong1, Hoang Duc Tran1, Huong Manh Phan2 and Chinh Dang Huynh1*
1Department of Inorganic Chemistry, Hanoi University of Science and Technology, Viet Nam
2
Department of Physics, University of South Florida, USA

SrFe12O19 nanoparticles have been prepared by the sol-gel hydrothermal method.
These SrFe12O19 nanoparticles have been doped with La, Sm and coated with NiFe2O4,
CoFe2O4 nanoparticles by the sol-gel and the self-assembly method, respectively.
Properties of the nanoparticle samples were charaterized by powder X-ray diffraction
with the Rietveld refinement, transmission electron microscope, scanning electron
microscopy with energy dispersive spectrometer, and vibrating sample magnetometry.
SEM micrograhs of the samples showed the spherical shape of NiFe2O4, CoFe2O4
nanoparticles located above on the surface of SrFe12O19 hexagonal platelet shape.
TEM micrographs showed the particle size of core and shell. With the core/shell
nanoparticles, the saturation magnetization was decreased but coercivity was increased
with SrFe12O19/CoFe2O4 sample.
[1.] Alex Goldman, Modern Ferrite Technology, Springer; 2nd edition (2005). [2.] Smit J., Wijn H.P.J, Ferrits-Physicalproperties of ferritmagnetic oxides in relation to their technical application, Philip Technical Library, Eindhoven, (1959). [3.] L.A.
Garcia-Cerda, O.S. Rodriguez-Fernandez, P.J. Resendiz-Hernandez, Journal of Alloys and Compounds 369 (2004) 182-184. [4.]Malick Jean, Virginie Nachbaur, Julien Bran, Jean-Marie Le Breton, Journal of Alloys and Compounds 496 (2010) 306-312.
[5.] Xiaofeng Yang, Qiaoling Li, Jingxian Zhao, Baodong Li, Yongfei Wang, Journal of Alloys and Compounds 475 (2009) 312315. [6.] T. T.V. Nga , N.P. Duong, T.D. Hien, Journal of Alloys and Compounds 475 (2009) 55-59.

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poster Presentation

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A facial fabrication of the superparamagnetic Fe 3 O 4 @ TiO 2
microspheres and its photocatalytic application

Light induced ferromagnetism of nanocrystalline CuCr2Se4 particles

Effects of the DyH3 and Dy2O3 powder addition on the magnetic andmicrostructural properties of Nd-Fe-B sintered magnet

Effects of grain size and interface state on the coercivity in Nd-Fe-B/
Nd thin films

Effective way for enhancing the magnetic properties as well as saving the Dy content in the Nd-Fe-B basedmagnet is to develop the core-shell microstructure using the Dy2O3, DyF3 or DyH3 powder doping [1, 2]. The
DyH3-doped magnet shows the most improved results [2]. However, the role of DyH3 powder has not been
identified yet. In this study, we investigated the magnetic and microstructural changes of the DyH3-doped(2.4 wt.%) Nd27.68Dy4.89Febal.B1.0M2.4 (wt.%) sintered magnet comparing with those of the Dy2O3-doped (2.0
wt.%) magnet. The coercivity of Dy2O3-doped magnet slightly increased (30.13→30.71 kOe) with a little
remanence reduction (11.59→11.56 kG) comparing with the undoped magnet. However, the coercivity of the
DyH3-doped magnet increased (30.13→31.9 kOe) without sacrificing remanence (11.59→11.6 kG). Coreshell microstructure was well developed when the DyH3 powders were added comparing with the Dy2O3doped magnet. The hydride powder doping enhanced the diffusion of Dy because the dissolution of thehydrogen in the Nd2Fe14B increased the lattice parameter and the point defects. The hydride was also known asa solid lubricant role at the grain boundaries [3]. As a result, the core-shell microstructure and the (00L) grainalignment of the DyH3-doped magnet was more developed than those of Dy2O3-doped magnet.

High coercivity in sintered Nd-Fe-B magnets is the crucial subject, especially in view of ahigh demand for developing Dy-saving magnets [1]. In order to approach this matter, thegrain refinement and the interfacial microstructure control are known long to be the promising
methods [2, 3]. In this work, the effect of Nd coating on the coercivity has been investigatedin the Nd2Fe14B thin films with different grain sizes. As the Nd2Fe14B layer thickness tNFB
was decreased from 70 nm to 5 nm, the coercivity exhibited a gradual increase behavior from
6.5 kOe to 16 kOe, and from 17.5 kOe to 26.2 kOe for the Nd-Fe-B and Nd-Fe-B/Nd films,
respectively. It should be noted that the amount of Hc increase by the Nd coating was about 10
kOe irrespective of Nd-Fe-B layer thickness tNFB. AFM observations showed that the average
Nd2Fe14B particle size of the tNFB = 5 nm film is about 60 nm, which is much smaller thanthe critical size for the single domain in the Nd2Fe14B phase. These results therefore suggestthat a proper interface state is extremely important to achieve high coercivity not only in larger
grain system but also in smaller particle one.

[1] S. E. Park, T. H. Kim, S. R. Lee, D. H. Kim, S. Namkung, and T. S. Jang, IEEE. Tran. Magn. 47, 10(2011). [2] G. Yan, P. J. McGuiness, J. P. G. Farr, and I. R. Harris, J. Alloys Compd. 491, L20 (2010). [3]S. Guo, R. J. Chen, Y. Ding, G. H. Yan, D. Lee, and A. R. Yan, J. Phys.: Conf. Ser. 266, 012030 (2011).

[1] S. Sugimoto, Proc. on the 21th Int. Workshop on Rare-earth Permanent Magnet and their
Applications, Bled, Slovenia (2010) 103. [2] K. H. Muller, D. Eckert, A. Handstein, P. Nothnagel, and J.
Schneider, J. Magn. Magn. Mater., 83, (1991) 195. [3] J. D. Livingston, J. Appl. Phys., 57, (1985) 4137.

1Over the past few decades, semiconductor photocatalysts have attracted much attention because of theirapplications in new energy fields where they represent a promising strategy for splitting water to provide
clean hydrogen energy, and their use in the photocatalytic degradation of polluted atmosphere and wastewaterin environmental remediation[1,2]. Among the reported photocatalysts, titanium dioxide (TiO2) is one of
the most studied semiconductors for photocatalytic reactions because of its high activity, chemical stability,
robustness against photocorrosion, low toxicity and availability at low cost, especially for the detoxification ofwater and air [3,4]. In this study, we have successfully synthesized of multifunctional core/shell (Fe3O4/TiO2)
submicron particles with controlled shell thickness. In the first step, superparamagnetic Fe3O4 submicronparticles were fabricated by one-step hydrothermal method. In the second step, the surface of Fe3O4 submicronparticles was coated with TiO2 by atomic layer deposition (ALD) method. Through this method, the thicknessof shell was accurately tunable. The recyclable Fe3O4@TiO2 particles exhibit excellent catalytic properties forthe oxidation reaction of 2,4,6-trichlorophenol (2,4,6-TCP) in aqueous solution.

July 12 (Thu)[1]. A. Fujishima, K. Honda, Nature, 238, 37 (1972) [2]. X. C. Wang, K. Maeda, A. Thomas, K. Takanabe, G. Xin, G. M.
Garlsson, K. Domen, M. Antonietti, Nat. Mater., 8, 76 (2009) [3]. T. L. Thompson, J. T. Yates Jr., Chem. Rev. 106, 4428 (2006)[4].A. C. Rodrigues, M. Boroski, N. S. Shimada, J. C. Garcia, J. Nozaki, N. Hioka, J. Photochem. Photobiol. A 194, 1 (2008)

A novel method to synthesize ternary chalcogenide nanoparticles was developed withmicrowave-assisted polyol reaction in this study. Copper chloride, chromium acetate andmetallic selenium were used as precursors with stoichiometric ratios in poly ethylene glycol. The
system was purged with argon and then the mixed reactants were irradiated for 60 minutes with
60% of the instrument power. Products were collected, centrifuged, washed with ethyl alcoholin order to remove poly ethylene glycol and dried overnight under inert atmosphere. Magnetic
moment of CuCr2Se4 nanoparticles was measured from 300 K to 750 K with external magnetic
field of 500 Oe in argon atmosphere and Curie temperature was calculated as 445 K. Fromthe hysteresis loop, magnetic property was ferromagnetic and its saturation magnetization andcoercive force were measured to 15 emu/g and 80 Gauss respectively. Nanocrystalline CuCr2Se4
particles were dispersed in the matrix of light transparent resin so as to investigate light induced
effect on the magnetic properties. Er-laser with the wavelength of 1.5 µm was employed as lightsource. Light illumination in an external magnetic field increased the magnetization and thisincrement of magnetization (δJ) to initial magnetization (J) showed a maximum.
1. Mingos D.M.P. The application of microwaves in chemistry // Res. Chem. Intermed., 1994, V. 20, P. 85-91. 2.
Baran M., Szymczak R., Szymczak H., Tsurkan V. Spin glass like behavior of magnetization in anion substituted
CuCr2Se4 magnetic semiconductor // J. Magn. Magn. Mater., 1995, V. 140-144, P. 2043-2047. 3. Boukari H.,
Kossacki P., Bertolini M., Ferrand D., Cibert J., Tatarenko S., Wasiela A., Gaj J.A., Dietl T. Light and electricfield control of ferromagnetism in magnetic quantum structures // Phys. Rev. Lett., 2002, V. 88, N. 20, P. 204-207.

Kunihiro Koike1*, Takanao Kusano1, Daisuke Ogawa1, Mizuno Yoshiyuki1, Miyazaki
Takamichi2, Yasuo Ando2 and Hiroaki Kato1
1
Graduate School of Science and Engineering, Yamagta University, Japan
2
Graduate School of Engineering, Tohoku University, Japan

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RO06

Synthesis of high moment magnetite (Fe3O4) nanoparticles by simple
modified polyol method

Magnetite nanoparticles in hybrid aerogel and PEG encapsulated ofmagnetite nanoparticles for the hyperthermia application

Magnetic properties of nano-composite Nd-Fe-B thick-film magnets
prepared by vacuum arc deposition

Interface state and coercivity in Nd-Fe-B/Dy films(Synthesis of high moment magnetite (Fe3O4) nanoparticles by simple modified
polyol method) Mohamed Abbas and CheolGi Kim Center for NanoBioEngineeringand Spintronics, Department of Materials Science and Engineering, Chungnam
National University, Daejeon 305-764, Korea Abstract Single phase magnetite withhigh saturation magnetization and 50 nm as a medium range particles size has beensynthesized by in expensive and surfactant-free simple modified polyol method using
FeCl2.4H2O as a precursor of iron and Poly Ethylene Glycol (PEG) as a solvent andreducing agent simultaneously. X-ray diffraction (XRD) and EDS analysis indicatedthat, formation of purely magnetite (Fe3O4) without presence of any other phase.
Transmission electron microscopy (TEM) also show that the synthesized nanoparticles
are almost sphere in shape. The magnetic properties of the synthesized magnetite
nanoparticles were measured by means Physical Property Measurement System(PPMS-VSM) at different temperature and shows that the as-synthesized NPs wereferromagnetic with high moment 91.7 emu/g at 5 K. Corresponding author. Tel:+82428216236 E-mail address: cgkim@cnu.ac.kr (Prof/ CheolGi Kim)

Magnetite nanoparticles have received intensive attractions because of theirapplications as magnetic carriers in drug targeting and hyperthermia in tumor
treatment. However, magnetite nanoparticles with 10 nm in diameter easily aggregate
themselves to form large secondary particles. To disperse magnetite nanoparticles,
this research paper suggests the infiltration of magnetite nanoparticles into hybrid
silica aerogels. The PEG encapsulate of magnetite is to disperse magnetite up in PBS
solution. The well-dispersion of magnetite is necessary for target the tumor cells
and hyperthermia treatment. Methyltriethoxysilicate (MTEOS) based hybrid silica
aerogels were synthesized by a supercritical drying method. To incorporate magnetite
nanoparticles into the hybrid silica aerogels, we immersed it into magnetite precursor
solution. The surfaces of magnetite nanoparticles were modified by PEG(polyethylene
glycol). The infiltration and PEG coating of magnetite nanoparticles were identified
by XRD, FT-IR and TEM. Vibrating Sample Magnetometer analysis showed thatthe composite of the magnetite and hybrid silica aerogel is superparamagnetic. The
temperature behaviors of the magnetite composite and the surface coated magnetite
nanoparticles were discussed in the context of the change of magnetite particles with
PBS for Hyperthermia application.

Mohamed Abbas Ali Ahmed and Cheolgi Kim*
Material Science and Engineering, Chungnam National University, Korea

Eunhee Lee and Chang-yeoul Kim
KICET, Korea

Tomoaki Tsutsumi1, Masaki Nakano1*, Takeshi Yanai1, Fumitoshi Yamashita2 andHirotoshi Fukunaga1
1
Nagasaki University, Japan
2
MInebea Co. Ltd., Japan

In order to upgrade the torque of the small motor comprising a multi-polarly magnetizedrotor with isotropic thick-film magnets [1], enhancement in remanence of the isotropic thickfilm is indispensable. We, therefore, prepared nano-composite Nd-Fe-B/Alpha-Fe isotropic
thick-films by using a vacuum arc deposition method [2]. This contribution reports the effectof the composition and the power of arc deposition on the magnetic properties. Samples
were prepared by using several targets with the compositions of NdXFe14B + Nb0.5 at.% (X=1.4~2.0). The voltage and capacitance varied in order to control the power range between
11 and 44 J. As the power was fixed at 44 J, use of a Nd1.6Fe14B + Nb0.5 at. % target enabled
us to obtain the highest (BH)max value. Although the deposition rate decreased fromapproximately 20 to 5 microns per hour due to the power reduction from 44 to 11 J, the valueof (BH)max could be improved by approximately 15 kJ/m3 at the target composition of
Nd1.6Fe14B + Nb0.5 at. %. Resultantly, we succeeded in obtaining a 29 micron-thick Nd-Fe-B
thick-films with the remanence, coercivity and (BH)max values of 0.92 T, 390 kA/m and 79
kJ/m3, respectively.

Jin Umezawa1, Yoshiki Sakai1, Kunihiro Koike1*, Daisuke Ogawa1, Yoshiyuki
Mizuno1, Takamichi Miyazaki2, Yasuo Ando2 and Hiroaki Kato1
1
Graduate School of Science and Engineering, Yamagta University, Japan
2
Graduate School of Engineering, Tohoku University, Japan
It is believed that the Nd-rich phase plays an important role for the coercivity emhancementin the Nd-Fe-B magnets [1-2]. In the case of Dy-diffusion-processed Nd-Fe-B magnets [3],however, it is still not clear whether only the Dy-rich shell or both Dy-shell and the Nd-richphase is indispensible for the high coercivity. Therefore, we fabricated a model interface
system, which consists of the Nd2Fe14B layer with the Dy and Nd overlayers in order to study
the relationship between microstructure near the interface and the coercivity. Nd2Fe14B particles
with the c-axis normal to the film plane were constructed by using HV or UHV sputteringsystems. We introduced high-melting-point bcc metals, Ta or Mo, as an underlayer on theheat-resistant glass or sapphire c-plane single-crystal substrates. When the temperature of thesubstrate during a deposition of the 1 μm thick Nd-Fe-B layer was 620°C, the demagnetization
curve of this film without rare-earth overlayers exhibited a nice squareness with coercivity Hc =3.3 kOe. On the other hand, preliminary experiments on the post-annealed Nd-Fe-B films with
the Dy overlayer showed a significant increase in Hc of up to above 15 kOe.

[1] F. Yamashita et al., IEEE Trans. Magn. 46, 2012 (2010). [2] M. Nakano et al., J. Appl. Phys. 109, No.7, 07A755-1 (2011).

[1] K. H. Muller, D. Eckert, A. Handstein, P. Nothnagel, and J. Schneider, J. Magn. Magn. Mater.,83, (1991) 195. [2] F. Vial, F. Joly, E. Nevalainen, M. Sagawa, K. Hiraga, and K.T. Park, J. Magn.
Magn. Mater., 242-245, (2002) 1329. [3] H. Nakamura, K. Hirota, M. Shimao, T. Minowa, and M.
Honshima, IEEE Trans. Magn., 41 (2005) 3844.

RN22

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RO07

Study of Structural, morphological and optical properties of SrFe12-x
Cox O19 (x= 0, 0.1, 0.2) hexaferrite nanoparticles

Effect of the Cu content on the microstructural and magnetic
properties of Nd-Fe-B sintered magnets

Corrosion resistance and corrosion behaviors of sintered rare-earthmagnets in different corrosive environments

Investigation on the magnetic and crystalline structures of die-upset
Nd-Fe-B magnets

Morteza Zargar Shoushtari*, Ebrahim Mousavi Ghahfarokhi and Fereshte Ranjbar
Physics, Shahid Chamran University of Ahvaz, IranA series of M-type strontium hexaferrite samples having nominal composition SrFe12-x
Cox O19 (x = 0.0, 0.1 and 0.2) with different morphologies have been synthesized via
sol gel method. For synthesis of samples, first a precursor gel was prepared using thesol-gel method. The mixture of KCl and dry-gel was calcined at 1000 ˚C for 2 h toobtain the needle-like nano- SrFe12-x Cox O19. The rod-like and bubble nano- SrFe12-x
Cox O19 was prepared by calcining the mixture of KBr and dry-gel or KI and dry-gel,respectively, and spherical nano- SrFe12-x Cox O19 was prepared only by calcined drygel. The structure and morphology of samples were systematically characterized by Xray diffraction (XRD), scanning electron microscopy (SEM). The optical propertiesof samples were investigated by UV-Vis. The result of XRD of samples showed that
the M-type hexagonal structure can be maintained for all the samples without the
segregation of secondary phases. The FT- IR frequency bands in the range 560 - 580
cm-1 and 430 - 470 cm-1 in the all of samples corresponds to the formation of tetrahedral
and octahedral clusters of metal oxides in ferrites, respectively.

Tae-hoon Kim1, Seong-rae Lee1*, Seok Namkung2 and Tae-suk Jang2
1
Korea University, Korea
2
Sunmoon University, Korea

The Cu addition in the Nd-Fe-B sintered magnet improves the coercivity after the post-sintering
annealing (PSA) because the continuous Nd-rich grain boundary phase (GBP) and the metastable
C-Nd2O3 phase were formed [1-3]. However, the magnetic properties of the commercial magnet
were deteriorated when the Cu content of the magnet is higher than 0.15 at.% (optimized Cu
content). In this study, we investigated the Cu content effects on the microstructural and magnetic
properties of sintered 12Nd-2.7Dy-(76.45-x)Fe-xCu-6B-2.65M (at.%, x=0.2, 0.3, 0.4, 0.5) magnets.
The coercivity was decreased (28.7→26.1 kOe) with increasing the Cu content, but the remanence
was unchanged. Two kinds of Cu enriched Nd-rich triple junction phases (Cu-rich TJP), such as
5~10 at.% Cu containing Nd-rich TJP (Culow-rich) and 35~45 at.% Cu containing Nd-rich TJP(Cuhigh-rich), were observed. The Culow-rich TJP was the stable h-Nd2O3, but the Cuhigh-rich TJP
was the metastable C-Nd2O3 phase. The thickness and Fe content of Nd-rich GBP was increased
with increasing Cu content because the oversaturated Cu atoms in the GBP substitutes with the Featoms near the GBP//Nd2Fe14B interfaces. As a result, the magnetic decoupling through the Nd-rich
GBP was deteriorated and the coercivity was decreased when the Cu content of the magnet is high.
[1] F. Vial, F. Joly, E. Nevalainen, M. Sagawa, K. Hiraga, and K. T. Park,.J. Magn. Magn. Maters. 242-245,
1329 (2002). [2] W. F. Li, T. Ohkubo, T. Akiya, H. Kato, K. Hono, J. Mater. Res. 24, 413 (2009). [3] M. Matsuura, S.
Sugimoto, T. Fukada, R. Goto, N. Tezuka, Journal of Physics: Conference Series. 200, 082019 (2010).

300

Kyoung-hoon Bae1, Tae-hoon Kim1, Seong-rae Lee1*, Seok Namkung2 and Tae-suk
Jang2
1
Korea University, Korea
2
Sunmoon University, Korea

The 19th International Conference on Magnetism

Anhua Li*, Wei Li, Jiajie Li, Haibo Feng, Zhaohui Guo and Minggang Zhu
Division of Functional Materials, Central Iron & Steel Research Institute, China

Sintered rare-earth magnets possessing outstanding magnetic properties are widely appliedin many fields. However, corrosion resistance has been a problem with the magnets owing
to the high chemical activity of the phases rich in rare earth elements [1]. The Nd-richphases of the Nd-Fe-B magnets can react with water vapor and oxygen in a damp andhumid atmosphere. The electro-chemical corrosion occurs for Nd-Fe-B magnets in a highhumidity atmosphere because of the difference of corrosion potential between the matrix
Nd2Fe14B phase and the boundary Nd-rich phase [2]. In this article, Corrosion resistanceof sintered Nd-Fe-B and Sm-Co magnets was investigated in steady-state damp heat
(HH), neutral salt spray (NSS) and pressure cooker (PCT) climates. The effects of alloy
composition and different corrosive environments on magnetic flux loss were discussed.
It shows that the corrosion rates of sintered Nd-Fe-B magnets in HH and NSS climates
exhibit a obvious parabolic trend, flux loss in the above three kinds of climates have aapproximate linear trend. The corrosion resistance of sintered Nd-Fe-B magnets can be
improved by Dy partially substitution for Nd and minor Co addition. The sintered Sm-Co
magnets show very good corrosion resistance in the above three kinds of climates.
Sintered rare-earth magnets; corrosion resistance; corrosion behavior; different corrosive
environments

July 12 (Thu)

Kyong-hoon Choi1, Eun-mee Kim2, Seung-lim Oh3, Do-yeon Kim4 and Jin-seung Jung4*
Material R&D Division, H & Global Co. Ltd., Korea
2
Gangneung Center, korea Basic Science Institute, Korea
3­Material R&D Division, H & Global Co. Ltd., Korea
4
Department of Chemistry, Gangneung-Wonju National University, Korea

Dongsoo Kim*, Kookchae Chung and Choljin Choi
Korea Institute of Materials Science, Korea

Yikun Fang1*, Wei Li1, Xiaolu Yin2, Zhaohui Guo1, Minggang Zhu1 and Sy-hwang Liou2
Division of Functional Materials Research, Central Iron and Steel ResearchInstitute,Beijing 100081, China
2
Department of Physics and Astronomy and Nebraska Center for Materials andNanoscience, University of Nebraska- Lincoln, Lincoln, NE 68588, USA1

Die-upsetting is used to prepare anisotropic Nd-Fe-B magnets due to high magnetic texture in which thec-axis of Nd2Fe14B grains is parallel to the loading direction. [1] Though many papers have reported on the
structures of high-textured Nd-Fe-B magnets [2-5], there are still some issues needed to be clarified, such as
how about the uniformity of the magnetic structures and how to improve the uniformity. In this paper, x-ray
diffraction (XRD) and magnetic force microscopy (MFM) are used to reveal the crystalline and magnetic
structures of die-upset Nd13.62Fe75.70Co4.45B5.76Ga0.47 magnets. It is found that the ratio of the XRD peak intensity
I(006)/ I(105) from center to edge of the sample decreases from 1.86 to 1.35. The magnetic configurations of
the central of the sample are typical interaction domains. The interaction domains are formed due to the strong
inter-granular exchange interaction and magnetostatic interaction between grains. However, on the edge ofthe sample the non-interaction domains present. The XRD and MFM results may relate to the non-uniformityof the effective strain that generated during the die-upsetting process. This indicates we need to improve theuniformity of the strain distribution for the development of high-performance magnets.
[1] R. W. Lee, Appl. Phys. Lett. 46, 790 (1985). [2] K. Khlopkov, O. Gutfleisch, D. Hinz, K.-H. Muller, and L.
Schultz, J. Appl. Phys. 102, 023912 (2007). [3] Y. G. Liu, L. Xu, Q.F. Wang, W. Li, and X. Y. Zhang, Appl. Phys.
Lett. 94, 172502 (2009). [4]R. Zhao, W. C. Zhang, J. J. Li, H. J. Wang, M. G. Zhu, and W. Li, J. Magn.16, 294 (2011).
[5] Y. K. Fang, X. L. Yin, R. Zhao, S. Valloppilly, W. Li, M. G. Zhu, S. H. Liou, J. Appl. Phys.(2012) in press.

July 8-13, 2012 Busan, Korea

301

poster Presentation

poster Presentation

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RO14

RP02

A novel approach -microwave assisted sintering - for preparation ofhigh performance permanent magnets

Effect of small Dy-alloy powder additions on the coercivity of NdFeB
sintered magnets

Effect of magnetic heat-treatment on magnetic properties andcorrosion behavior of Nd6Fe72-xCoxB22(x=10, 20, 30) nanocomposite
ribbons

Chin Shan Lue, H. F. Liu and C. N. Kuo
Physics, National Cheng Kung University, Taiwan

A large portion of the cost for the fabrication of permanent magnets is due to the energy needed forsintering. Any improvement for the sintering process with respect to time and energy will reduce the cost
and will increase the market of permanent magnets considerably. Based on the most recent development inmicrowave applications reported by R. Roy (1) , where it was demonstrated that sintering of metal powdersa surprising application- is possible with microwaves (in view of the known fact that bulk metals reflectmicrowaves), we have employed microwaves to sinter Nd-Fe-B at a fraction of time and energy, comparedto the conventional resistive/radiant heating in excess of 1000 0C for many hours, and in many cases
homogenizing also at high temperatures. Microwave heating is a volumetric heating involving conversionof electromagnetic energy into thermal energy, which is instantaneous, rapid and highly efficient. In thiswork, we will present the emerging possibilities for sintering Nd-Fe-B and Sm-Co permanent magnets aswell as the opening of new possibilities for metal bonded magnets by employing microwave radiation, thatis already used for ferrites by various groups. Supported by the project NANOPERMAG of the EUMINWOO LEE
Sunmoon University, Korea

Recently, demand of high performance NdFeB sintered magnets is rapidly increasing
mostly due to expansion of wind generators and hybrid electric vehicles. For traction
motors of hybrid electric vehicles, the coercivity of NdFeB sintered magnet isrequired to exceed 25 kOe. For such high coercivity, partial substitution of Dy for Nd
in Nd2Fe14B of NdFeB sintered magnet is practically inevitable, with the sacrifice ofmagnetization value and the increase of material cost. Because the price of Dy is very
high and keeps increasing due to its scarcity, it is important to reduce the amount of Dy
in NdFeB magnets as much as possible without losing coercivity. Recent researches on
NdFeB magnets, therefore, are mainly focused on Dy-saving methods. In this study, as
an effort to develop a Dy-saving method, small Dy-TM alloy powder was mixed with
NdFeB magnet powder and then a sintered magnet was fabricated by a conventional
process. When 1.9 wt% of DyCo powder was mixed, the coercivity of the sinteredmagnet increased about 4 kOe, indicating 20% of Dy saving effect. More experimental
results will be discussed in this presentation.

July 12 (Thu)

Nanocomposite rare-earth magnets consisting of a hard and a soft magnetic phase haveattracted considerable attention because the remanence enhancement in exchange couplednanocomposite alloys has potential importance as a way to achieve high values of the
maximum energy product (BH)max. It is well established that the magnetic properties ofnanocrystalline two-phase magnets are strongly dependent on its microstructure. A uniform
microstructure and a well-coupled grain interface should be two essential conditions
for a well-performing nanocomposite. Magnetic annealing has been tried to perfect the
microstructure and enhance the magnetic properties. In this paper, Nd6Fe72-xB22(x=10,20,30)
ribbons were heat-treated with or without an external magnetic field of 3 kOe in argon
atmosphere in the temperature range of 600-750°C for 10 min. It is found that magnetic heattreatment enhances both coercivity and remanence ratio of the Nd6Fe72-xCoxB22(x=10,20,30)
ribbon, and decrease the annealed temperature obtained the optimum magnetic properties
due to the uniform distribution and preferential orientation of α-Fe and Nd2Fe14B grains. The
corrosion behavior of Nd6Fe72-xCoxB22(x=10, 20, 30)nanocomposite ribbons with or without
an external magnetic field is discussed in detail.

We present a study of the phase transition behavior in Ce3Co4Sn13 using 59Co nuclear
magnetic resonance (NMR) spectroscopy. The quadrupole splitting, Knight shift, andspin-lattice relaxation rate (1/T1) below and above the phase transition temperature
To have been identified. All measured NMR quantities exhibit pronounced features ataround To=155 K except for the Knight shift. It thus excludes the magnetic origin forthe observed transition. In addition, the x-ray diffraction results below and above To
confirm the absence of a crystal structural change, suggesting that the peculiar phasetransition is possibly driven by the charge-density-wave (CDW) formation. As a matterof fact, the double-peak feature in the 59Co NMR central line smears out below To
which can be associated with the spatial modulation of the electric field gradient (EFG)
due to incommensurate CDW superlattices. Furthermore, a distinct peak found in the
spin-lattice relaxation rate near To can be accounted for by the thermally-driven normal
modes of the CDW.

Q.G. Ji, B.X. Gu, S.L. Tang et al. J.Magn.Magn.Mater. 257 (2003) 146.

RERERENCES 1. R. Roy, D. Agrawal, J. Cheng and S. Gedevanishvili, Nature, 399, pp.668-670, 1999

RO09

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RP03

Preparation of Nd-Fe-B thin films with columnar structure and theirstructure and magnetic properties

Coercivity of near single domain size Nd-Fe-B-type alloy particles

Study on magnetization reversal behavior for the annealed Nd2Fe14B/
α-Fe nancomposite alloys

Analysis of 1/f noise characteristics of magneto-optical Kerr effectmeasured from Co/Pt and NiFe/Pt multilayers thin film

The addition of heavy rare earth elements is essential for Nd-Fe-B sintered magnet
to obtain high-performance characteristic at high temperature. However, a reductionof these additive elements is strongly required since the price of these elements has
increased in recent years. It was reported that the additive elements such as Cu andGa were diffused and concentrated into the grain boundary phase (GBP) [1, 2], andthe magnetic coupling between the main phases is thought to reduce by the GBP.
In order to improve the hard magnetic properties, therefore, the control of the GBP
is indispensable. In this study, the Nd-Fe-B thin films with well-defined columnar
structure have been prepared and structure and magnetic properties have been also
investigated. The samples were prepared by using an ultra-high vacuum sputteringsystem. The thickness of the Nd-Fe-B layer was varied in the range of 50 ~ 300 nm.
From the X-ray diffraction patterns, the peaks from Nd2Fe14B (004), (006), and (008)were observed for all the samples. This indicates that the films grew with a strong (001)texture. A good magnetic squareness and relatively high coercivity of 8.3 kOe wereobtained for the Nd-Fe-B films with t = 100 and 200 nm.

Fine particles of Nd-Fe-B alloy in near single domain size have increasingly found new
applications for high performance micro-magnet. However, because of high oxygenaffinity and high specific surface area, the ultra-fine Nd-Fe-B-type particles are readilyoxidized in air, hence causing a radical coercivity loss. In the present study, an ultrafine Nd-Fe-B-type particles in near single domain size was prepared by ball milling of
HDDR-treated Nd12.5Fe80.6B6.4Ga0.3Nb0.2 alloy. The prepared near single domain
size Nd-Fe-B-type powder (≒ 0.3 um) had high coercivity over 9 kOe. However, thecoercivity was radically reduced as the temperature increased in air (< 2 kOe at 200°C). Room temperature long-term stability of coercivity of the fine powder in air wasinvestigated for 1 month, and the coercivity was decreased by rate of 0.5 kOe/week.
Feasibilty of surface nitrogenation of the fine powder for improving the long-term
stability of coercivity was studied. Long-term stability of coercivity of the nitrogenatedfine powder was improved markedly. The nitrogenated powder showed no coercvity
reduction even after 1 month in air at room temperature. In this article, the surface
passivation of near single domain size Nd-Fe-B-type particles by nitrogenation forimproving long-term stability of coercivity is to be discussed.

Shota Suzuki, Yuki Hatayama and Toshiyuki Shima
Tohoku Gakuin University, Japan

Hae-woong Kwon1 and J H Yu2
1
Pukyong National University, Korea
2
KIMS, Korea[1] C. Y. You, Y. K. Takahashi, K. Hono, J. Appl. Phys., 108, (2010) 043901. [2] T. Sato, H. Kato, T.
Shima, Y. K. Takahashi, K. Hono, J. Magn. Magn. Mater., 323 (2011) 163-166.

Pengyue Zhang1, Minxiang Pan1, Hongliang Ge1, Luke Yang1, Ming Yue2 andWeiqiang Liu2
1
College of Materials Science & Engineering, China Jiliang University, Hangzhou
310018, China
2
College of Materials Science & Engineering, Beijing University of Technology,
Beijing 100124, Chin

Effect of thermal annealing on the magnetization reversal behavior of α-Fe/Nd2Fe14B
alloys has been investigated. A drastic increase of the remanence Mr from 0.67T up
to 0.87T and remanence ratio Mr/Ms from 0.66 up to 0.76, respectively, is observedin the α-Fe/Nd2Fe14B alloys annealed at 610 oC as compared with the as-quenchedsample. Whereas the further annealing at 680 oC results in a strongly increase of thecorecivity Hc as high as 491 kA/m but a slight decrease in Mr. The analysis result of
the magnetization reversal behavior shows that the maximum value of the integrated
recoil loop area about 1.58 kJ/m3 is obtained in the α-Fe/Nd2Fe14B alloys at theannealing temperature of 610 oC, significantly lower than other annealed samples.
This indicates a significant advantage for the application of this material as permanent
magnets in electrical machines and generators due to a low energy loss. Keywords:
Nanocomposite; Magnetization reversal behavior; Recoil loop
*E-mail: Zhang_Pengyue@cjlu.edu.cn.

Djati Handoko, Sang-hyuk Lee and Dong-hyun Kim*
Physics Department, Chungbuk National University, Korea

We have investigated 1/f noise characteristic of the polar and longitudinal magnetooptical Kerr effect (MOKE). The hand-made MOKE measurement system was set
using diode laser as a light source. Si photodetector was used as a detector where thebias has been systematically controlled. To increase a signal-to-noise ratio, the laser
light was modulated with the lock-in amplification frequency referenced from themechanical chopper in the frequency ranges up to 4 kHz. Noise characteristics of the
optical/electrical/mechanical error were systematically examined. To separate the noise
contribution from the ferromagnetic layer and from the intrinsic measurement error,
various configurational changes were made for the lock-in frequency as well as the bias
voltage of the Si photodetector. Magnetic noise properties under a different magnetic
field were systematically investigated as well. For a perpendicular anisotropy sample,
Co/Pt multilayer film was investigated while for an in-plane anisotropy sample, NiFe/
Pt bilayer film was investigated. The noise characteristics with respect to the multilayer
thickness variations were examined as well. The 1/f noise characteristics observed fora wide range regardless of the lock-in frequency change or the film thickness change
implies that there might be a universal characteristics in the MOKE signal noise,
arising from the sample itself.

RO10

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RP01

RP04

Microstructure of (Nd,Dy)-Fe-B permanent magnet by spark plasma
sintering

Effect of annealing temperature on microstructure, magnetic
properties and corrosion resistance of NdFeB/α-Fe nanocomposite
magnets

Construction of a versatile neutron-scattering spectrometer
HERMES-E using renovated Ge monochromator crystals

Photoemission electron microscopy of three-dimensional magnetization
configurations in core-shell nanostructures

Sun Yong Song, Jin Woo Kim and Young Do Kim*
Division of Materials Science and Engineering, Hanyang University, Korea

Sintered (Nd,Dy)-Fe-B magnets are widely used in various parts such as motor, generators,
actuators, and so on because of their outstanding magnetic properties. (Nd,Dy)-Fe-B sinteredmagnets are generally composed of the Nd2Fe14B hard magnet phase as a matrix and a Ndrich phase at the triple junction [1,2]. However, typical sintered (Nd,Dy)-Fe-B magnets arelimited in their applications due to low curie temperature[3]. Many researchers have shownthat the magnetic properties of (Nd,Dy)-Fe-B magnets are structure sensitive, and dependent
on the distribution of the rare-earth-rich phases, average grain size and size distribution.
Particularly the grain size of Nd2Fe14B was essentially important for high magnet properties.
In this study, we focused on controlling of the grain size to enhance magnetic properties
by the spark plasma sintering process. The starting powder with the composition of
Nd13Dy2Fe76.2TM2.8B6 was prepared by strip casting and jet milling process. The raw powder
was pre-sintered for preventing collapsibility of anisotropy. After the pre-sintering, (Nd,Dy)Fe-B magnet was fabricated by spark plasma sintering process under 30 MPa with various
temperatures. Consequently we had made the (Nd,Dy)-Fe-B sintered magnet with grain sizeof 5.9 μm. The grain size was effectively controlled by spark plasma sintering.
[1] M.Sagawa,S.Fujimura,N.Togawa,H.Yamamoto,Y.Matsuura,J.Appl.Phys.55 (1984)2083-2087.
[2] H.J.Wang,Z.H.Guo,A.H.Li,X.M.Li,W.Li,J.Magn.Magn.Mater.303(2006) e392-e395. [3] W.F.Li,T.
Ohkubo,K.Hono,M.Sagawa,J.Magn.Magn.Mater.321(2009) 1100-1105.

302

Qiong Wu, P.z. Zhang*, M.x. Pan, Z.s. Wang and H.l. Ge
China Jiliang University, China

The 19th International Conference on Magnetism

Minxiang Pan, Pengyue Zhang*, Hongliang Ge, Hangfu Yang and Qiong Wu
Magnetism key laboratory of Zhejiang Province, China Jiliang University, 310018
Hangzhou, China

REFeB based nanocomposite alloys have attracted much attention in both the scientificcommunity and bonded magnet industry. However, lower coercivity and poor corrosion
resistance limit their applications. Both the practical coercivity and corrosion resistanceare sensitive to the character of phase constitute in the microstructure. Sintered NdFeB
magnet is the poor corrosion resistance due to the presence of the highly corrosive Ndrich phase. As no Nd-rich phase is formed in the NdFeB/α-Fe nanocomposite magnets,
these alloys should be more corrosion resistant than the NdFeB sintered magnet. In thiswork, the effects of annealing temperature on the microstructure, magnetic properties
and corrosion resistance in NdFeB/α-Fe alloys were investigated. It is shown thatafter heat treatment, the alloys mainly consist of two phases: a hard magnetic phase of
Nd2Fe14B (space group P42/mnm) and a soft magnetic phase of α-Fe (Im3m), and thatno other phases are identified. Moreover, the optimum corrosion resistance of NdFeB/
α-Fe magnets was observed with the annealing temperature at 610°C. Keywords:
Nanocomposite, Magnetic property, corrosion resistance*E-mail: Zhang_Pengyue@cjlu.edu.cn.

Haruhiro Hiraka1*, Kenji Ohoyama1, Manabu Ohkawara1, Naoki Murakami1, Yasuo
Yamaguchi1, Kazuma Okubo2, Michiro Furusaka2, Yoshiaki Kiyanagi2, Shin Ae Kim3,
Chang Hee Lee3, Kohei Morishita4, Kazuo Nakajima4 and Kazuyoshi Yamada5
1
Institute for Materials Research, Tohoku University, Japan
2
Division of Quantum Science and Engineering, Graduate School of Engineering,
Hokkaido University, Japan
3
HANARO, Korea Atomic Energy Research Institute, Korea
4
Graduate School of Energy Science, Kyoto University, Japan
5
Advanced Institute for Materials Research, WPI, Tohoku University, Japan

We propose an efficient way, which increases a number of neutron spectrometers
in a research-reactor facility. The first key is to making use of a characteristic Gecrystal monochromator, which discretely emits Bragg reflections to different scattering
angles at the same time. The second is to save the instrumental space by using curved
and deformed Ge-wafer crystals as a monochromator or an analyzer. Indeed, we areplanning to double a neutron-powder diffractometer of Tohoku University (HERMES[1]) that is working at a research reactor JRR-3, Tokai, Japan; a versatile neutronscattering spectrometer HERMES-E is now under construction next to HERMES.
[1] K. Ohoyama et al., Jpn. J. Appl. Phys. vol. 37 (1998) 3319.

July 12 (Thu)

Dimitrios G Niarchos1*, Margarit Gjoka1, Eamon Devlin1, George Hadjipanayis2,
Amparo Borrell Tomas3, Maria Dolores Salvador Moya3 and Felipe L Penaranda-foix4
1
Institute of Materials Science, NCSR DEMOKRITOS, Greece2
Department of Physics and Astronomy, U of Delaware, Newark, DE, USA
3
Institute of Materials, Technology Polytechnic University of Valencia, Camino de Vera, s/n 46022, Spain
4
School of Communication, 4 School of Telecommunication, Polytechnic University of Valencia, Camino
de Vera, s/n 46022, Spain

NMR study of the phase transition behavior in Ce3Co4Sn13

Judith Kimling1, Florian Kronast2, Stephan Martens1, Tim Boehnert1, MichaelMartens1, Julia Herrero Albillos2, Logane Tati Bismaths2, Ulrich Merkt1, Kornelius
Nielsch1 and Guido Meier1*
1
University of Hamburg, Germany
2
Helmholtz-Zentrum Berlin fuer Materialien und Energie, Germany
We present a photoemission electron microscopy method that combines magnetic imaging of thesurface and of the inner magnetization in three-dimensional core-shell nanostructures [1]. The
structure investigated consists of a cylindrical nickel core that is completely surrounded by a shell ofiron oxide and silicon oxide layers. The method enables one to image the magnetization configurationof the nickel core even though the shell is thicker than the mean-free path of the photoelectrons.
Characteristic L3 and L2 edges can be observed not only in the yield of the photoelectrons emitted
from the surface of the nanostructure but also in its shadow. X-ray magnetic circular dichroism in
the electron yield of the x rays absorbed and transmitted by the multilayered nanowire allows for theindividual imaging of the magnetization configurations of the iron oxide tube and the nickel core. The
method suggests novel approaches for the characterization of the magnetic and material properties ofcomplex three-dimensional nanostructures. Financial support by the DAAD via the Project 50725506
and by DFG via the SFB 668 and the GrK 1286 as well as the Forschungs- und Wissenschaftsstiftung
Hamburg via the Exzellenzcluster “Nano-Spintronik” is gratefully acknowledged.
[1] J. Kimling, F. Kronast, S. Martens, T. Boehnert, M. Martens, J. Herrero-Albillos, L. TatiBismaths, U. Merkt, K. Nielsch, and G. Meier, Phys. Rev. B 84, 174406 (2011).

July 8-13, 2012 Busan, Korea

303

RP05

RP08

RP11

RP14

Development of high-field ESR system using SQUID magnetometerand its application to measurement under high pressure

Imaging magnetic responses of nanomagnets by X-ray PhotoEmission
Electron Microscopy

Asteroid curve of GMR films on the practical substrate under the
stressA new type of spin-polarized scanning tunneling microscopy forobserving an in-plane magnetization component with high resolution

Takahiro Sakurai1*, Kohdai Fujimoto2, Susumu Okubo3, Hitoshi Ohta3 and Yoshiya
Uwatoko4
1
Center for Supports to Research and Education Acti, Kobe University, Japan
2
Graduate School of Science, Kobe University, Japan3
Molecular Photoscience Research Center, Kobe University, Japan
4
Institute of Solid State Physics, University of Tokyo, Japan

Florian Kronast1*, Julia Herrero-albillos2, Oliver Sandig1, Julia Kurde1, T Noll1,
Florian Roemer3, Nina Friedenberger3 and M Farle3
1
Helmholtz Zentrum Berlin fur Materialien und Energie, Albert-Einstein-Str. 15,
12489 Berlin, Germany
2
Centro Universitario de la Defensa, Carretera Huesca s/n, Zaragoza, Spain
3
Universitat Duisburg-Essen, Lotharstr.1, 47048 Duisburg, Germany

We have developed high-field ESR system using commercial SQUID magnetometer, inwhich ESR is observed as a change of magnetization. [J. Phys.: Conf. Ser. 334 (2011)
012058.] The advantage of this method as compared with conventional high-field ESR isthat the measurement can be done very easily. Moreover, the macroscopic magnetization
measurement can be made simultaneously. Although the sensitivity of this system islower than that of ESR system using cavity, it is comparable with that of transmission
type ESR system. Recently, we have succeeded in performing ESR measurement underhigh pressure by this ESR system. The pressure is generated by a widely used clamped
type piston-cylinder pressure cell whose cylinder is made of non-magnetic CuBe alloy.
Since all inner parts are made of zirconium oxide, the electromagnetic wave can be
introduced into the sample space. Therefore, we can measure the magnetic moment ofsample and obtain ESR signal under pressure. The pressure is available up to 1.5 GPa.
This is the easiest ESR system which gives us pressure dependence ESR spectra as far
as we know. The setup of this system and several results will be shown in detail.

The Spin-resolved PhotoEmission Electron Microscope (SPEEM) is a permanently installed setup at
the X-ray synchrotron radiation source BESSY, Helmholtz-Zentrum Berlin. The capabilities of excellent
spatial resolution and an energy- and polarization-tunable light source make this end-station ideal formagnetic imaging and micro-spectroscopy with quantitative analysis. The application of magnetic fields
while measuring significantly expands the technique of magnetic imaging. A dedicated magnetic sample
holder incorporating both DC and AC magnetic field with additional temperature control has recently
been developed. The SPEEM end-station, in combination with this novel sample holder enables the insitu control of the magnetic state and direct observation of the corresponding magnetic response. Two
selected examples demonstrate these capabilities: magnetization curves of individual Fe nanocubes,
and the local magnetic ac susceptibility in and microstructures as a function of temperature. In the latterexample, a surprising onset of finite size effects at the micro-scale has been observed, with a significant
reduction of the ordering temperature in microstructures compared to the extended film. These results wereobserved specifically as a result of these improvements in the PEEM technique. In combination with otherpossibilities, such as depth resolved imaging, new insights to magnetic nanostructures can be realized.

RP06

Kazuhiko Okita1, Kazushi Ishiyama2 and Hideo Miura3
1
Industrial Instrumentation Division, Tohoku Steel Co., L7td., Japan
2
Research Institute of Electrical Communication, Tohoku University, Japan3
Department of Nanomechanics, Graduate School of Engineering, Tohoku University,
Japan

Magnetic thin films usually have some of magnetostriction effect. After forming electric devices,
this effect sometimes deteriorates the sensitivity of sensors such as read heads of hard disk drives,
HDD, or the bit stability of memories such as magnetic random access memories, MRAM,
through the inverse magnetostriction phenomenon. We need, therefore, to understand themagnetostriction effect on a film deposited on an actual wafer and the influence from the stressto it. In the previous paper, we showed the novel method of measuring the magnetostriction
constant on the practical substrate [1]. In this paper, by using this method we measured theasteroid curves of the magnetic thin film of the giant magnetoresistance, GMR, on the practicalwafer with varying applied stress on it. This result showed that the coercive force parallel to theeasy axis, Hc, of a magnetic thin film with a negative sign of magnetostriction constant was
decreasing with increasing tensile stress and the coercive force parallel to the hard axis, Ha,
was also decreasing. For the film with the positive sign one, Hc and Ha were increasing withincreasing tensile stress. And we showed the Hc was roughly proportional to the applied stress.

Daichi Nara1, Takuya Nakamura1, Atsuhiko Nakamoto1, Ryu Kageyama1, Elaiyaraju
Srinivasan2, Kazuyuki Koike1 and Hideo Matsuyama1*
1Department of Physics, Faculty of Science, Hokkaido University, Japan
2
Creative Research Institution (CRIS), Hokkaido University, Japan

To obtain a high resolution image routinely even from the rough surface of a ferromagnetic
sample with a spin-polarized scanning tunneling microscope (SP-STM) operating inmodulating tip magnetization mode [1], we have developed an SP-STM using a micrometersized magnetic tip integrated onto the magnetic recording head of a hard disk drive. The tip
apex was formed into a round shape with a diameter of less than one micrometer by using a
focused ion beam instrument. Driving the recording head with a signal generator to switch
the magnetization of the tip apex periodically generates an unnecessary artificial current flow
into a current-to-voltage (IV) converter through stray capacitance, which prevents detectionof the spin-polarized tunneling current precisely. To reduce the artificial current, we added ahomemade circuit that generates a countercurrent against the artificial current into the inputof the IV converter. We tried to image both the topography and the spin polarization of aniron thin film deposited on a magnetic recording medium whose local roughness was on
the order of several nanometers due to the crystal grains of the medium. This is the first spin
image of a magnetic thin film having such a rough surface obtained with an SP-STM.

[1] K. Okita, K. Ishiyama and H. Miura, 'Magnetostriction Measurement of GMR Films on thepractical substrate', Journal of Physics, Conference Series 200 (2010) 112008[1] U. Schlickum, W. Wulfhekel, and J. Kirschner, Appl. Phys. Lett. 83, 2016 (2003).

RP09

RP12

RP15

Alternating magnetic force microscopy: direction detectable imaging
of static and alternating magnetic field with high spatial resolution

Development of high-sensitivity cantilever-detected ESR measurement
using a fiber-optic interferometer.

Micromagnetic study on the perturbative effect of magnetic force
microscopy probes on 90° asymmetric Neel walls in a soft magnetic material

Violation of Hund's third rule in structurally disordered ferromagnets

We have developed a new functional MFM named as “Alternating Magnetic Force Microscopy(A-MFM)” which enables us to measure static and alternating magnetic fields with the polarity offield direction [1-5]. A-MFM utilized the frequency modulation of a cantilever oscillation generated
by an off-resonance alternating magnetic force between a magnetic sample and a magnetic tip. The
alternating magnetic force was extracted by a lock-in amplifier for the frequency demodulated signalof the cantilever oscillation. For the static magnetic field from a sample, a soft magnetic tip which ware
driven by an AC magnetic field was used to detect the static magnetic field with high sensitivity. On theother hand, for the alternating magnetic field from a sample, such as a magnetic writing head, a hardmagnetic tip was used. A-MFM can measure a magnetic force without surface short-range forces anddirectly detect the direction of perpendicular magnetic fields. When the tip-sample distance became
short, spatial resolution was improved. In the conference, we will demonstrate high performance of
A-MFM and show high-resolution magnetic field images with a resolution of less than 10 nm for highdensity recording media and magnetic writing heads. This study was supported by SENTAN, JST.

Cantilever-detected high-frequency electron spin resonance (ESR) is a powerful method
for terahertz ESR spectroscopy of a tiny magnetic sample at low temperature [1,2]. In thistechnique, a small magnetization change associated with ESR transition is detected as deflectionof a sample-mounted cantilever. So far, we have succeeded in ESR detection at 370 GHz using
a commercial piezoresistive microcantilever. The spin sensitivity was estimated to ~1012 spins/
gauss. In order to further increase the sensitivity, we adopt a fiber-optic-based detection systemusing a Fabry-Perot interferometer in place of piezoresistive system. Fabry-Perot cavity isformed between an optical-fiber end and microcantilever surface, and a change in interference
signal, corresponding to the cantilever deflection, is sensitivity detected. This system is suitable
for low-temperature and high-magnetic field experiments because of its compact setup and lessheat dissipation. We will combine our fiber-optic detection system with a 15 T superconducting
magnet and BWO light sources covering a wide frequency range 200-1200 GHz. Test
measurement with Co Tutton salt is now in process to estimate the system performance. In thepresentation, details of our experimental setup and test results will be presented.

It is important to clarify the dependence of perturbative effect of MFM probes upon probe parameters andexperimental conditions[1]. In this study, 3D micromagnetic simulation has been performed to evaluate
the perturbative effects on magnetization states and force gradient signals of 90° asymmetric Neel walls
in a 100nm-thick patterned permalloy film. The signals are computed by varying the position of the probe
assuming the stripe shape. The different signal distortions are observed depending upon the combinationof the out-of-plane component of the magnetization direction of wall and the magnetization direction of
the probe. In the parallel case, signal asymmetry originated from the asymmetric wall structure is enhanced
and the normalized contrast defined as the difference of the maximum and minimum values of the signal
divided by probe saturation magnetization(Ms) is increased. In the antiparallel case, signal asymmetryis suppressed and the normalized contrast is decreased. When probe Ms is increased further (antiparallelcase), the out-of-plane component direction of wall is reversed being accompanied by the jump of the
Neel cap positions. The probe Ms dependences of signal distortions such as contrast variation and distancechange between the signal peaks which correspond to the measured wall width are also presented.

Hitoshi Saito1, Ito Ryoichi1, Kodai Hatakeyama1, Zhenghua Li2, Genta Egawa1 andSatoru Yoshimura1
1
Graduate School of Engineering and Resource Science, Akita University, Japan
2
Venture Business Laboratory, Akita University, Japan[1] H. Saito et al. J. Appl. Phys. 105 (2009) 07D524, [2] H. Saito et al. J. Appl. Phys. 107 (2010)09D309, [3] W. Lu et al. Appl. Phys. Lett. 96 (2010) 143104, [4] W. Lu et al. IEEE Trans. Magn. 46(2010) 1479, [5] H. Saito et al. J. Appl. Phys. 109 (2011) 07E330

Yuki Tokuda1, Eiji Ohmichi2* and Hitoshi Ohta3
1
Graduate School of Science, Kobe University, Japan
2
Graduate School of Science, Kobe University, Japan3
Molecular Photoscienece Research Center, Kobe University, Japan

Hironori Asada1*, Hidenori Kubo1, Hazrina Abu Seman1, Takashi Manago2 andHiromi Kuramochi3
1
Yamaguchi University, Japan
2
Fukuoka University, Japan
3
National Institute for Materials Science, Japan

Vassilios Kapaklis1*, Panagiotis Korelis1, Bjorgvin Hjorvarsson1, Athanasios Vlachos2,
Iossif Galanakis3, Panagiotis Poulopoulos3, K. Ozdogan4, Makis Angelakeris5, Fabrice
Wilhelm6 and Andrei Rogalev6
1
Department of Physics and Astronomy, Uppsala University, Sweden
2
Department Materials Science, University of Patars, Greece
3
Department Materials Science, University of Patras, Greece
4
Department of Physics, Yildiz Technical University, Turkey
5
Department of Physics, Aristotle University of Thessaloniki, Greece
6
European Synchrotron Radiation Facility, France
Violation of Hund's third rule caused by structural disorder is observed for the induced
magnetic moment of Zr, using x-ray magnetic circular dichroism. The induced spinand orbital magnetic moments are antiparallel in the crystalline state, but parallel inan amorphous state of the investigated Co- and Fe-based materials. First-principles
calculations are used to provide physical insight into the dependency of the spin-orbit
coupling on the interatomic distance and coordination number.
V. Kapaklis, P. T. Korelis, B. Hjorvarsson, A. Vlachos, I. Galanakis, P. Poulopoulos, K. Ozdogan,
M. Angelakeris, F. Wilhelm, and A. Rogalev, Violation of Hund's third rule in structurally disorderedferromagnets, Phys. Rev. B 84, 024411 (2011).

[1] E.Ohmichi, N. Mizuno, M. Kimata, and H.Ohta, Rev. Sci. Instrum. 79, 103903 (2008) [2]
E.Ohmichi, and T.Osada, Rev. Sci. Instrum 73, 3022 (2002)[1] J. M. Garcia, et al., Appl. Phys. Lett. 79, 656 (2001).

RP07

RP10

RP13

RP16

30 T pulsed-high-magnetic-field and element-selective magnetization
studies using soft x-ray magnetic circular dichroism

Study of the epitaxial growth and perpendicular magnetic domain
structure of ordered FePt thin film on MgO substrate using HRTEM
and electron holography

Development of a non-conventional ESR spectrometer with acomposite antenna system and an electronically controlled tuning andmatching circuit

Bulk Cr tips with full spatial magnetic sensitivity for spin-polarizedscanning tunneling microscopy

Yasuo Narumi1*, Tetsuya Nakamura2, Misaki Hayashi1, Hiroyuki Nojiri1, Kenji Kodama3, Toko
Hirono2, Wataru Ito4, Rie Umetsu1, Ryosuke Kainuma5, Koichi Kindo6 and Toyohiko Kinoshita2
1
Institute for Materials Research, Tohoku University, Japan
2
Japan Synchrotron Radiation Research Institute/SPring-8, Japan3
Department of Mechanical Engineering, Nara National College of Technology, Japan
4
Department of Materials and Environmental Engineering, Sendai National College of Technology, Japan
5
Graduate School of Engineering, Tohoku University, Japan
6
Institute for Solid State Physics, The University of Tokyo, JapanWe demonstrate the applicability of 30 T pulsed-high-magnetic-field to observe magnetic circular dichroism(MCD) of antiferromagnetic compounds in soft x-ray energy regions, in which there are magnetically importanttransition energies, L-edge of 3d transition metal and M-edge of 4f rare earth elements. We have developed a
specially designed pulse magnet equipped with an ultra-high-vacuum environment and a portable capacitor
bank for synchrotron soft x-ray experiments [1]. A time-resolved total electron yield method is used to record
x-ray absorptions in synchronization with pulsed-high-magnetic-fields and periodic switching of circularly
polarized soft x-rays. We have measured elements-selective magnetizations of Ni, Co and Mn in the NiCoMnIn
alloy which shows a large field-induced strain accompanied by a drastic change of the magnetization [2]. All 3dtransition metal elements show steep non-linear increases of the MCD intensities around 15 T corresponding to
the metamagnetic transition. This high-magnetic-field soft x-ray MCD result directly evidences that all magnetic
elements contribute to the field-induced shape memory effect in the NiCoMnIn alloy.
[1] T. Nakamura et al., Appl. Phys. Express 4, 066602 (2011). [2] R. Kainuma et al., Nature 439, 957 (2006).

304

poster Presentation

The 19th International Conference on Magnetism

W. H. Lee1, J. H. Yoo2, J. M. Yang2 and J. K. Park1*
1
Department of Materials Science and Engineering, Korea Advanced Institute of
Science and Technology, Korea
2
Measurement and Analysis Team, National Nanofab Center, Korea

The epitaxial film of ordered FePt, showing the c-axis normal to the film plane, wassuccessfully grown on top of MgO substrate using DC-magnetron co-sputtering technique.
The electron holography study showed that a columnar epitaxial film displayed only a weakstray-field signal due to the presence of columnar boundaries. The growth of a continuous(full) epitaxial film however revealed characteristic Lorentz TEM images for the perpendicularmagnetic domains. The electron hologram indicated the presence of the stray-fields of induction
originating from the perpendicular magnetizations. It was shown that the sense of stray fields
and thus the sense of perpendicular magnetizations could be determined by analyzing thecontraction and expansion behavior of hologram fringes which were parallel to the reference
fringes. Furthermore, direct hologram information was detected in a thicker epitaxial film byapplying high resolution electron holography. Perpendicular magnetic domain structure was
directly revealed in the unwrapped phase image and was confirmed by the measurement of theline profile of phase-shift. The estimation of the local strength indicated that the perpendicularinduction strength was varying from about 0.33T to about 0.61T depending on the domain size.
The variation of induction strength was due to a weak ordering of the film.

Alexey Ponomaryov1, Kwang Yong Choi2, Byoungjin Suh3 and Zeehoon Jang4*
1
Physics, Chungang University, Korea
2
Physics, Chungang, Korea
3
Physics, The Catholic University of Korea, Korea
4
Physics, Kookmin University, Korea

We present a new development of non-conventional Electron Spin Resonance (ESR) spectrometer, in which thesweeping frequency is available in the wide range of frequency. This is a modification of the previous system
without using a cavity and with two antennas one for the microwave transmission and the other for the ESR
signal detection.[1] In contrast to previous work[1], utilization of microstrip antenna as a transmitter provided
us the capability of wide-frequency operation between 0.8 and 10 GHz. On the other hand, the use of loop
antenna as a detector with tuning and matching circuit enhanced ESR signal. In order to simplify tuning andmatching circuit and make resonance condition easily reproducible, conventional capacitors were replaced withvaractor diodes. This allowed us to avoid any mechanical action during tuning and matching procedure, since thecapacitance of the diodes was changed by applying different DC voltages. Compared to Ref.[1], such a scheme
increased S/N ratio several times in a wide frequency range. For testing the developed system, a homemade
magnet with water-cooling system was used. The efficiency of the ESR spectrometer was checked by measuring
a signal of 1,1-diphenil-2-picrylhydrazyl (DPPH) sample at different frequencies at room temperature.
[1] Z. H. Jang, B. J. Suh, M. Corti, L. Cattaneo, D. Hajny, F. Borsa, and M. Luban, Rev. Sci. Instrum. 79, 46101 (2008).

July 12 (Thu)

July 12 (Thu)poster Presentation

Anika Schlenhoff, Andreas Sonntag*, Stefan Krause, Gabriela Herzog and Roland
Wiesendanger
University of Hamburg, Germany

Spin-polarized scanning tunneling microscopy (SP-STM) is a powerful techniqueto access the magnetic properties of a surface on the atomic scale. Here, magnetic
tips are usually prepared by extensive in-situ metal evaporation, demanding for a tip
exchange mechanism inside the microscope. Using magnetic bulk tips is an elegant
way to circumvent these efforts. For example, bulk chromium tips are reported to besuitable for SP-STM, exhibiting an in-plane magnetic sensitivity [1]. Since they are
antiferromagnetic, their influence on the sample magnetization in terms of stray fieldinteraction is negligible. We perform SP-STM experiments on the sample system
of 1.8 atomic layers Fe/W(110) with the magnetization lying in the plane on themonolayer and pointing perpendicular to the plane on the double layer [2]. Our study
demonstrates that Cr bulk tips can be used to image the complete magnetic structureand hence are sensitive to both the in-plane as well as the out-of-plane-component ofsample magnetization [3]. Analyzing magnetic SP-STM maps enables the full spatial
characterization of the tip.
[1] A. L. Bassi et al., Appl. Phys. Lett. 91, 173120 (2007). [2] M. Pratzer et al., Phys. Rev. Lett. 87,
127201 (2001). [3] A. Schlenhoff et al., Appl. Phys. Lett. 97, 083104 (2010).

July 8-13, 2012 Busan, Korea

305

RP17

RP20

RP23

RQ03

Polarization state of scattered light in apertureless reflection-mode
magneto-optical scanning near-field optical microscopy

2D reflection-type electron spin filter increasing the detection efficiency
in spinresolved spectroscopy by 4 orders of magnitude

Observation of the magnetic domain using scanning electron
microscopy with polarization analysis

Magnetization of single ferromagnetic-grain obtained fromobservation of field-induced-translation in a chamber-type μg system.

Yongfu Cai1, Mitsuharu Aoyagi1, Sanyalak Niratisairak1, Akira Emoto2, Tatsutoshi
Shioda3 and Takayuki Ishibashi1*
1
Department of materials science and technology, Nagaoka University of Technology,Japan
2National institute of advanced industrial science and technology (AIST), Japan3
Department of Electrical Engineering, Nagaoka University of Technology, JapanD Kutnyakhov1, M Kolbe1, P Lushchyk1, M Jourdan1, K Medjanik1, S A Nepijko1,
H J Elmers1, C Tusche2, J Kirschner2, F Giebels3, H Gollisch3, R Feder3 and G
Schoenhense1*
1
Institute of Physics, University of Mainz, Germany
2
Max Planck Institute of Microstructure Physics, Germany
3
Theoretische Festkoerperphysik, Universitaet Duisburg-Essen, Germany

Magneto-optical scanning near-field optical microscopy (MO-SNOM) has attracted attention because of its
high spatial resolution in magnetic imaging. We are developing a reflection-mode apertureless scanning nearfield optical microscopy (a-SNOM). The sample is a patterned Chromium film with a thickness of 20nm
deposited on a glass substrate. The a-SNOM images are measured with Si tip that has an extremity’s radiusof 7nm, and with an illumination of 408 nm with an incident angle of 45 degree. Scattered light caused by aninteraction between the near-field wave and the sample was measured as a signal for a-SNOM image. Finitedifference time-domain (FDTD) method was used to calculate the polarization state of the scattered light. The
a-SNOM images of Cr patterns were successfully obtained with a spatial resolution of 30-40nm. In addition,
we found that the extinction ration of the scattered light back to the same direction with the incidence wasbetter than 100, which is an enough polarization property for obtaining MO images. FDTD simulation
reproduced that the scattered light preserved its polarization state. These results showed that the a-SNOM is apromising technique to obtain high-resolution magnetic images with a resolution of several tens nm.

Spin-resolved electron spectroscopy is characterized by a low figure of merit FoM= S²I/Io typically 10-4; S
spin sensitivity, I/Io reflectivity. Electron diffraction from W(001) in the (00) LEED spot facilitates parallel
detection of 3800 data points in our imaging spin filter behind a PEEM [1], and 960 behind a hemisphericalenergy analyzer [2]. We achieved a “2D FoM” of 1.7 being four orders of magnitude higher than the previous
value. We further studied the dependence of the spin sensitivity and reflectivity as a function of scattering
energy and angle of incidence. The experimental setup includes a spin-polarized GaAs electron source,
hemispherical analyzer and a Delaylinedetector. Intensities, spin-orbit-coupling induced asymmetries and FoM
were calculated via a relativistic layer KKR SPLEED code [3]. The superior performance of multichannel spin
detection facilitates experiments on highly reactive surfaces like in-situ prepared Heusler films [4] or radiationsensitive organic layers [5] and paves the way to single-shot experiments at ultra bright fs-sources like FELs.
Funded by DFG (Scho341/9), Stiftung Innovation (project 886) and centre of complex materials COMATT.

Sang Sun Lee, Moon Seob Bae, Wondong Kim and Chanyong Hwang*
Korea Research Institute of Standards and Science, Korea

We have developed a scanning electron microscope with polarization analysis(SEMPAor spin-SEM) for the nano-scale observation of magnetic domain structure. A typicalmicro Mott type spin detector with 25 kV operating voltage, shows the effective
Sherman function in the range between -0.3~-0.35, which is relatively low valued. Inorder to get higher Sherman function, we optimized all geometrical factors and theaccelerating voltage. First, we tried Monte Carlo simulation by increasing operating
voltage from 25 kV to 50 kV. At 40 kV of acceleration voltage with optimized 120
degrees of scattering angle, a better effective Sherman function was obtained comparedwith the value operated at 25 kV(-0.5 : -0.3). Base on this simulation, we havedeveloped the high-efficiency Mott spin detector with 40 kV operating voltage. Alsoa secondary electron deflector, and transfer lens system has been optimized. In orderto test performance of the new spin detector, the thick Fe film sample was prepared on
Si substrate using an evaporation method. We will show several different images of Fe
films depending on the oxidation condition.

Chiaki Uyeda1, Kenta Kuwada2 and Keiji Hisayoshi2
1Graduate School of Science, Osaka university, Japan
2
Graduate school of Science, Osaka university, JapanA new principle to measure saturated magnetization Ms of a single ferromagnetic-grain
is proposed, which is based on free translation of the grain caused by field-gradient force.
The motions were observed in a diffused (~10Pa) μG condition (0.01G). It is confirmed
for the first time that a classical conservation rule between field-induced potential andkinetic energy is conserved for a translating magnetic-grain. Accordingly, Ms is obtained
from the relationship between sample velocity and field intensity observed at different
sample positions. The Ms value is obtained even for a nano-sized sample, provided thattranslation is observed by an ultra-violet fluorescence microscope [1]. This is because themethod does not require mass measurement; it is also free of the interfering signal emitted
from a sample holder [1]. The above two factors has been the major problem in detecting
magnetization of single grain in conventional methods. A chamber-type drop shaft toproduce μG, which can be introduced in an ordinary laboratory, was newly developed
to realize routine Ms measurement. Here, size of drop capsule was reduced to 30cm indiameter by introducing a magnetic circuit composed of an NdFeB permanent magnet.

[1] E. Betzig, et. al., Appl. Phys. Lett. 61,142(1992). [2] Y. Mitsuoka, et. al., J. Appl. Phys. 83,3998(1998). [3] T. Yoshida, et. al., J. Magn. Soc. Jpn. 23,1960(1999).

[1] C. Tusche et al., APL 99 (2011) 032505; [2] M. Kolbe et al., PRL 107 (2011) 207601; [3] R.
Feder, Polarized Electrons in Surface Physics (World Scientific, Singapore, 1985); [4] M. Hahn etal., APL 98 (2011) 232503; [5] K. Medjanik et al., JACS 134 (2012) 4694

RP18

RP21

RQ01

RQ04

Application of image processing to determine size distribution ofmagnetic nanoparticles

Element selective magnetization measurements under high magnetic
fieldPrecision broadband ac measurement system for magnetotransport,
magnetopolarization and magnetoelectric properties

application of magnetoimpedance effect for protein biomarker
detection

X-ray Magnetic Circular Dichroism (XMCD) spectroscopy is a well-establishedexperimental tool to study the microscopic origin of magnetism allowing one to determine
separately spin and orbital magnetic moments of each element in both amplitude anddirection. So far, XMCD has been extensively used to investigate mainly ferro- or
ferrimagnetic materials, and only very few studies have been performed on paramagnetic
compounds. In this presentation we describe first a new experimental set-up dedicated tohigh field XMCD measurements that has been recently installed at the ESRF beamline
ID12. Static magnetic field of up to 17 Tesla is generated by a superconducting solenoid.
The sample is mounted on a cold finger of a He continuous flow cryostat allowing to
set the temperature in the range from 2.2 K to 300 K with a stability of about 100 mK.
Performances of this set-up are illustrated with results of element selective magnetization
measurements in various systems: (i) Intrinsic magnetic moment in gold nanoparticles
grown onto naturally thiol-containing proteinatious archaeal surface layer has been
evidenced by field dependent XMCD at the Au L2,3-edges[1]; (ii) Extrinsic origin ofroom temperature ferromagnetism in diluted magnetic semiconductors has been provenwith field and temperature dependent XMCD measurements[2].

For complex or strongly correlated magnetic materials, broadband ac measurements
provide much richer dynamic information than static or quasistatic measurements,
which would help one to understand more clearly how magnetic materials of interest
respond to various external excitations. After many-year researches, we have developed
a suite of precision broadband ac magnetic measurement system based on novel
broadband digital lock-in amplifier techniques, which can work from sub 1 Hz to above
1 GHz. In addition to multi-channel lock-in amplifier techniques, to realize broadband
ac transporting and polarizability measurement from sub 1 Hz to above 100 MHz,transmission-line bridge compensation techniques have been used so as to measurecomplex ac magnetoresistance and Hall coefficient simultaneously in a precision way.
Broadband ac magnetoelectric measurement system has also been set up for evaluatingcomplex magnetoelectric coupling coefficient, which including not only magnitude but
also phase lag. For various magnetotransport and magnetoelectric measurements, wehave developed measuring software which supports fully automatic tests.

Ultra-low concentration detecting of biomolecules, has gain increasing interest sincevarious protein biomarkers for cancer or chronic diseases are present at very low levels
at the early stages of the disease development [1].In this work, we present the results ofthe development of a sensor prototype working in a principle of label free for monitoring
the effects on the immobilization of the biomolecular using giant magnetoimpedance.
Amorphous ribbons were tested in different biomoleculars. The MI response of thesensive elements made from ribbons was measured with a various biomolecular inorder to demonstrate the capacity of monitoring the immobilization of biomolecule. To
demonstrate the sensitivity and specificity of this GMI sensor platform for biomolecule
detection and quantification, we have used this platform to successfully detect andquantify the biomolecules. To apply to the real biomarker and verify the sensitivity of
GMI-based magnetic sensor, we used the biomarker scheme using the applied the real
protein on the magnetic sensor surface. The capture antibodies (P21 mono antibody)are first immobilized on the positive magnetic sensor surfaces. The advantage of thisapproach consists in the possibility to design a biosensor with enhanced sensitivity andthe application for detection of small amounts of biomolecules.

Udomchok Phromsuwan1*, Yaowarat Sirisathitkul2, Chitnarong Sirisathitkul1 andBunyarit Uyyanonvara3
1
School of Science, Walailak University, Thailand
2
School of Informatics, Walailak University, Thailand
3
School of Information, Computer and Communication Technology (ICT), Sirindhorn
International Institute of Technology (SIIT), Thammasat University, Thailand
Digital image processing has increasingly been implemented in analyzing micro- andnanostructured materials and would be an ideal tool to characterize the morphology andposition of self-assembled magnetic nanoparticles for high density recording. In thiswork, magnetic nanoparticles were synthesized by the modified polyol process using
Fe(acac)3 and Pt(acac)2 as starting materials. Transmission electron microscopy (TEM)
images of an as-synthesized product were taken with a resolution of 800 x 800 pixels,
72 dot per inch and then inspected using image processing algorithms on MatLab.
The grayscale image was converted to a binary image by using Otsu’s thresholding.
An individual particle was then detected by using the closing algorithm with disk
structuring elements and the canny edge detection. The areas of detected particles werefilled and small objects were removed. A centroid, diameter and area of each particle
were finally evaluated. The average diameter is 4.62 nm with a standard deviation of
0.52 nm. The degree of polydispersity of magnetic nanoparticles can then be comparedusing size distribution from the image processing.

Andrei Rogalev* and Fabrice Wilhelm
European Synchrotron Radiation Facility, France[1] C.Uyeda et al: Jpn. Phys. Soc. Jpn. 79, 064709 (2010).

Jun Lu*, Baogen Shen and Xiaoping Shao
State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of
Sciences, China

D.g. Park and Hoon Song
korea atomic energy research institute, Korea[1] S. Selenska-Pobell et al., Nanomater. nanotechnol., 1 (2011), 8 [2] A. Ney et al., New J. Phys., 13 (2011) 103001[1] J. Lu et al., Meas. Sci. Technol., 19, 045702-6(2008) [2] J. Lu et al., IEEE Trans. Magn., 44(9),2127-9(2008) [3] J. Lu et al., A kind of precision broadband anti-noise lock-in frequencymeter,
Chinese Patent, 201110380805.X

RP19

RP22

RQ02

RQ05

Microfabrication of a MEMS cantilever for mechanically detected
high-frequency ESR measurement

POLI: The new single crystal polarized neutron diffractometer forinvestigation complex magnetic structures at FRM-II

Detection of magnetic beads using an extraordinary magnetoresistancesensor fabricated with unpatterned semiconductor substrate

Ac Calorimetry under Pulsed High Magnetic Field

Jian Sun* and Jurgen Kosel
King Abdullah University of Science and Technology, Saudi Arabia

1

POLI is a new single crystal polarized neutron diffractometer [1] at the hot sourceof the 'Forschungsneutronenquelle Heinz Maier-Leibnitz' (FRM-II) in Garching,
Germany. It is designed to perform spherical neutron polarimetry (SNP) in zero field
as well as classical polarized neutron diffraction (PND) measurements (flipping ratio)
under applied magnetic fields. Among the intended applications of this instrument are:complex magnetic structures and magneto-electric coupling in multiferroics, magnetic
structure and spatially resolved spin densities in molecular magnets, magneticallyordered superconductors, strongly correlated transition metal oxides and spin
chain compounds. The instrument is unique in the sense that it combines a variablewavelength focussing monochromator with the use of 3He spin-filter cells (SFC) tocreate polarized, short wavelength neutrons. A new zero-field polarimeter Cryopad [2,3] has been built in cooperation between RWTH and ILL. On the detector side, thepolarisation-analysis and detection unit DECPOL (again with 3He-spin filter cells) isused. This setup called 'POLI-HEIDI' is operational and open for users at FRM-II over
JCNS proposal system. Its properties will be demonstrated in this talk.

A strong geometry dependent magnetoresistance effect, the so-called extraordinary
magnetoresistance (EMR), has been observed in semiconductor/metal hybrid
structures. It is based on the redistribution of the current from the metal shunt into
the semiconductor causes by the Lorentz force. A typical EMR device consists of apatterned semiconductor mesa and metal shunt. When the dimensions of the device
are reduced, for example, to increase the sensitivity, the alignment of the metal contact
with the semiconductor bar becomes more difficult. Furthermore, the patterning
process inescapably causes some damage to the semiconductor thereby reducing theperformance. In this work, we report a new EMR device fabrication process, which
does not require patterning of the semiconductor substrate reducing the complexity of
the fabrication and omitting any kind of damage of the semiconductor. The sensitivityof this device is 0.58 μT/√Hz, which is twice as high as the one of the patterned sensor.
The device is employed to detect superparamagnetic beads of 2.8 μm in diameter,
which is the first time this is demonstrated with an EMR sensor. Applying the beads tothe sensor surface results in a voltage signal of 100 μV.

Ac calorimetry measurement adapted for use of the pulsed high magnetic field will bepresented. This technique is quite useful to investigate the thermal properties underhigh magnetic field beyond the steady magnetic field range. In addition, it is also
possible to capture a transient phenomena under fast sweep magnetic field. Resultant
examples will be presented in detail.

Eiji Ohmichi1*, Yoshimasa Yasufuku2 and Hitoshi Ohta3
1
Graduate School of Science, Kobe University, Japan
2
Graduate School of Science, Kobe University, Japan3
Molecular Photoscience Research Center, Kobe University, Japan

Mechanically detected high-frequency electron spin resonance (ESR) is a promising
tool for high-resolution terahertz (THz) ESR spectroscopy of tiny magnetic samples.
So far we succeeded in multi-frequency ESR detection for 80-370 GHz and achieveda spin sensitivity on the order of 109 spins/Gauss[1,2]. In this study, a prototype
microcantilever is fabricated in order to further improve the sensitivity and flexibilityof our ESR measurement system. Microcantilevers are fabricated from silicon-oninsulator (SOI) wafers using standard MEMS techniques such as lithography, wet
etching, and RIE. By using commercial SOI wafers, fabrication cost and the numberof process can be substantially reduced. Two types of cantilevers for capacitive
and optical detection are fabricated in this study. The former has lateral dimensionsof 4 mm x 8 mm, and is anodically bonded to a glass substrate to form capacitiveelectrodes. The latter has dimensions of 50 μm x 200 μm, and is equipped with a gold
mirror for Fabry-Perot detection. Application to high-frequency ESR measurement is
now in progress and details will be reported in the presentation.
[1]E. Ohmichi, N. Mizuno, M. Kimata, and H. Ohta, Rev. Sci. Instrum. 79 (2008) 103903. [2]E.
Ohmichi, N. Mizuno, S. Hirano, and H. Ohta, J. Low Temp. Phys. 159 (2010) 276.

306

poster Presentation

The 19th International Conference on Magnetism

Vladimir Hutanu*, Martin Meven, Gernot Heger and Georg RothInstitut fur Krystallographie, RWTH Aachen University, Germany

July 12 (Thu)

July 12 (Thu)poster Presentation[1] M. Gomez and G. Silvestri, “Lung cancer screening,” Am. J. Med. Sci., vol. 335, pp. 46-50,
2008

Yuji Inagaki1, Tatsuya Kawar1, Akira Matsuo2 and Koichi Kindo2
applied quantum physics, kyushu university, Japan2
institute for solid state physics, the university of tokyo, Japan[1] V. Hutanu, M. Meven, E. Lelievre-Berna, G. Heger, Physica B 404, 2633 (2009). [2] F. Tasset,
Physica B 156-157, 627 (1989). [3] E. Lelievre-Berna, “Novel polarized neutron tools”, I. Anderson& B. Guerard, Editors, Proceedings of SPIE 4785, 112-125 (2002).

July 8-13, 2012 Busan, Korea

307

poster Presentation

poster Presentation

RQ06

RQ09

RQ12

RQ15

Specific heat and thermal expansion of Sr1-xCaxRuO3High pressure inductive measurements using microcoils in anvil cells

Homemade microcalorimetry equipment, with magnetic fields up to 9
Teslas, for magnetocaloric measurements

Highly sensitive cantilever magnetometryin static and dynamic modes
for micro-scale samples

Rasna Thakur1*, Archana Srivastava2, Rajesh K. Thakur1 and N.k. Gaur1
1
Department of Physics, Barkatullah University, Bhopal, India
2
Department of Physics, Sri Satya Sai College for Women, Bhopal, India
We have investigated the thermodynamic properties of perovskite ruthnate Sr1CaxRuO3 (0≤ x ≤1) probably for the first time by means of Rigid Ion Model (RIM).
The lattice contributions to the specific heat and thermal expansion of pure and Ca
doped SrRuO3 as a function of temperature (0 K≤ T ≤ 1000 K) are reported. The
systematic trend of variation of specific heat and the closer agreement with theexperimental data reveal the suitability and appropriateness of RIM, for Sr1-xCaxRuO3(0≤ x ≤1) perovskite ruthnates. The calculated lattice specific heat gives Debye
temperature (478.4 K) which is consistent with experimental value (480 K). Our
calculated value of 494.4 K for CaRuO3 is in very good agreement with the reported
value of 495 K. The Atoms in Molecules (AIM) theory is used to determine the bulk
modulus of these compounds. Further, the value of Gruneisen parameter is calculated
which is within the range 2-3 as reported earlier for perovskite family. In addition, theresults on cohesive energy (φ), molecular force constant (f), restsrahlen frequency (υ),
Debye temperature(θD) and gruneisen parameter (γ) are also presented. Our resultson cohesive and thermal properties revealed by using RIM reproduces well with theavailable experimental data.
x

Swee K. Goh1*, Thomas Meissner2, Patricia Alireza1 and Juergen Haase2
1
University of Cambridge, United Kingdom
2
University of Leipzig, Germany

Diamond or Moissanite anvil cells are routinely employed to reach pressures higher
than 35 kbar. However, due to the presence of the gasket and the limited sample space,inductive type measurements have been challenging. To overcome these challenges,
we place a microcoil inside the gasket hole of the anvil cell. With an increase in thefilling factor and the close proximity between the sample and the coil, this arrangement
has so far enabled us to perform AC susceptibility [1], the de Haas-van Alphen effect[2], tunnel-diode oscillator [3] and Nuclear Magnetic Resonance [4,5] experiments.
Technical aspects associated with the preparation of these pressure cells will bepresented, with particular emphasis placed on recent NMR experiments performed
using this technique.
[1] P. L. Alireza et al., Rev. Sci. Instrum. 74, 4728 (2003) [2] S. K. Goh et al., Curr. Appl. Phys. 8,304 (2008) [3] S. K. Goh et al., arXiv:1107.0689 (2011) [4] J. Haase, S. K. Goh et al., Rev. Sci.
Instrum. 80, 073905 (2009) [5] T. Meissner, S. K. Goh et al., Phys. Rev. B 83, 220517(R) (2011)

J. V. Leitao*, P. Van Dommelen, F. Naastepad and E. Bruck
Delft University of Technology, Netherlands

The magnetocaloric effect (MCE) has gains relevance as a cheap and environmentallyfriendly alternative to the current household vapor cycle refrigerators. The mostcommon method for calculating the MCE of a material, due to its technical andmathematical practicality, is the application of Maxwell’s thermodynamic equation
to a set of magnetic isotherms so as to calculate the magnetic entropy change [1].
The other current alternative for this calculation is through the adiabatic temperaturechange. Unfortunately, even though a working magnetocaloric refrigerator should rely
much more on an adiabatic (Brayton) cycle [2], such calculation is usually hinderedby the lack of a proper measurement system that would allow for reliable specific heatmeasurements with an applied magnetic field. Our group has recently constructed
such a device, using a 9 Tesla cryostat, allowing for liquid helium temperatures, andmicrocalorimetry chips from the company Xensor Integration. This equipment, besides
the usefulness in magnetocalorics research, is an invaluable tool in the study andinvestigation of any form of phase transitions where the application of a magnetic field
may play a significant role. We now report the overall characteristics of this equipment
and further illustrate it with a few early measurements performed on it.

Heonhwa Choi1, Yun Won Kim2 and Jae-hyuk Choi1*
Nano Science, University of Science and Technology ; Divison of Physical metrology,
KRISS, Deajeon 305-340, Korea
2
Display and Semiconductor Physics, Korea University, Chungnam 339-800 ;Divison of Physical metrology, KRISS, Deajeon 305-340, Korea
1

Recently, dynamic modecantilever magnetometriesusing an ultra-soft cantilever with
attonewton dynamic force sensitivity arebecoming a very powerfultool for measuring
the magnetic properties of micrometer-sized samples. In spite of its high sensitivity, thedynamic mode measuring a cantilever’s resonance frequency shifthas a limitation thatit requires anisotropic magnetic samples,andhigh or moderate external magnetic fields.
Therefore, we suggest a new type of a cantilever magnetometry with no limitation onmagnetic anisotropy and external magnetic field, a cantilever forcemagnetometrywhichmeasuresastatic displacement of a cantilever in a well-defined magnetic field gradient.
Its principle and experimental details including the magnetometry’sstructure arepresented, which are accompanied by the results of measurement at T = 3.5 K on asmall magnetic moment of 1.84 x 10-14 A m2 using both static and dynamic modes
revealing the high sensitivity of the static mode.

RQ07

RQ10

RQ13

RQ16

Voltage-current characteristics of superconductor-normal metal
contact junctions measured by a picovoltmeter

Microwave synthesis and characterization of the series of co4-xfexsb12
high temperature thermoelectric materials

Nucleation and development of clustered state in hole doped
manganites and cobaltites

Pulsed high magnetic fields for synchrotron and neutron applications

Wan-seop Kim*, Mun-seog Kim, Po Gyu Park, Kyu-tae Kim and Danbee Kim
KRISS, Korea

A picovoltmeter based on a DC SQUID has been developed for improvement ofJosephson voltage measurement uncertainty to better than ΔV/V = 50 x 10-12. An
output to input ratio of 108 is achieved using a proper current feed-back system.
The performance of the picovoltmeter demonstrated by the Voltage(V)-Current(I)measurements on a Cu-wire with a diameter of 0.25 mm and a length of 10 mm showsthat a voltage resolution is of about 10-12 V (pV) and a corresponding resistanceresolution is order of 10 μΩ. In addition, the current sensitivity of the picovoltmeter
was found to be 2x10-7 A/Φ0, where Φ0 is the magnetic flux quantum. Here we
present voltage steps induced by magnetic flux trap in the V-I curve measurements
for a bulk cylinder-type Pb wire with a diameter of 0.25 mm. The step height wasobserved to change abruptly in an irregular manner, but in multiple of 6 pV. Moreover,dissipation behavior of the remnant voltage observed in the V-I curves for thick filmsof superconductor/normal metal/superconductor contact junctions will be discussed.

An alternative route has been followed for a rapid synthesis of skutterudites as it was suggested by Biswas etal. (1) using microwave assisted synthesis. Microwave heating and sintering (involve microwaves only at 2.45
GHz and 915 MHz frequencies) is fundamentally different from the conventional sintering, which involves
radiant/resistance heating followed by transfer of thermal energy via conduction to the inside of the body being
processed. Microwave heating is a volumetric heating involving conversion of electromagnetic energy into
thermal energy, which is instantaneous, rapid and highly efficient. The use of microwave energy for materials
processing has major potential and real advantages over conventional heating. These include: - Time andenergy savings. - Rapid heating rates (volumetric heating vs. conduction). - Considerably reduced processing
time and temperature. - Fine microstructures - Lower environmental impact. Using the microwave-assisted
synthesis, here we report our effort to synthesize the series of Co4-xFexSb12 using this novel approach,which gave high quality materials with little or no impurity in a fraction of time compared to the conventional
synthesis. We will present data for structural, microstructural and thermoelectric properties and compare withmaterials synthesized with conventional approach. Supported by the project NEXTEC of the EU

A. V. Lazuta 1, V. A. Ryzhov 1, V. P. Khavronin 1, P. L. Molkanov 1 and Ya. M.
Mukovskii2
1
Petersburg Nuclear Physics Institute, Gatchina, St.Petersburg 188300, Russia
2
Moscow Steel and Alloys Institute, Leninskii prosp. 4, Moscow 117936, Russia
The origination of the ferromagnetic (F) metallic (M) clusters in a paramagnetic (P) state of the hole
doped manganites was well established [1-3]. Study of this state in the hole doped cobaltites is the
topic of the current research activity [4,5]. It is found by measurements of the nonlinear magnetic
responses (the second and third orders) that an universality exists in the nucleation and development of
the clustered states (CS) in these systems which proceed into three stages. On cooling, during the firststage, the F clusters nucleate at the preferential sites that are likely produced by variation in oxygen anddoping stoichiometry. Second stage is characterized by a sharp increasing concentration of the isolated
F clusters. A coalescence of the clusters into large-scale complexes containing some amount of the Fdomains is associated with the third stage that can end with formation of a percolative FM network.
This scenario is demonstrated by using the data obtained on the single-crystalline manganites Pr1-x
CaxMnO3 (x = 0.2, 0.25; the F insulators) and single-crystalline cobaltite La0.7Sr0.3CoO3 (a F metal). A
new effect is found in the latter, in which the CS in the P metallic regime is observed for the first time.

Fabienne Duc*, Xavier Fabreges, Paul Frings, Marc Nardone, Julien Billette, Jerome
Beard, Abdelaziz Zitouni and Geert Rikken
Laboratoire National des Champs Magnetiques Intenses - CNRS Grenoble-Toulouse,
FranceAs is well known, a magnetic field, together with temperature and pressure, is a very
important and efficient thermodynamic parameter for the investigation of condensed
matter. It can be used as an external variable to tune the ground and excited states
properties of a given magnetic system. The last ten years have seen a growing interestfor the combined use of pulsed high magnetic fields (up to 40 T) at synchrotron andneutron sources. Because of the larger flux of synchrotron x-ray sources comparedto neutron facilities, the development efforts have been first focused on synchrotron
methods. Neutron diffraction has complementary features to x-ray diffraction, andunique capabilities for studying microscopically the magnetic properties of materials.
Here, we will present the various devices developed by the LNCMI, Toulouse tocombine pulsed high magnetic fields with synchrotron and neutron techniques. Thesedevelopments are performed in close collaboration with the ESRF, Grenoble forsynchrotron applications and with the ILL and CEA, Grenoble for neutron diffraction.
We will discuss the main limitations for the use of pulsed magnetic fields related totheir low duty cycle. Those instrumental developments will be illustrated by somerecent results.

1. K. Biswas, et al. MRS Bulletin 46, pp. 2288-2290 (2011). 2288-229 2. R. Roy, et al. Nature 399, pp. 668-670 (1999).

[1] M. B. Salamon, M. Jaime, Rev. Mod. Phys.73 (2001) 583. [2] V.A. Ryzhov, A.V. Lazuta, I.D. Luzyanin
et al., Zh. Eksp. Teor. Fiz. 121 (2002) 678. [3] A.V. Lazuta, V.A. Ryzhov, V. P. Khavronin et al., Funct.
Mater. 17 (2010) 11 and Ref. therein. [4] C. He, S. El-Khatib, S. Eisenberg et. al., Appl. Phys. Lett. 95 (2009)
222511. [5] A. V. Lazuta, V.A. Ryzhov, A. I. Kurbakov et al., Solid State Phenom. 168-169 (2011) 457.

RQ08

RQ11

RQ14

RQ17

Development of high resolution cryogenic particle detectors using amagnetic calorimeter

Development of SI-STM optimized for 3D(x,T,B) phase-diagram-wide
FTSTS mapping on high Tc superconductors

Measurements and analysis of core loss including higher harmonic
induction waveforms using superposition principle and steinmetz’s law

Characteristics of an SQUID system with a superconductive shield forbiomagnetic measurements

We are constructing an SI-STM optimized for 3D(x,T,B) phase-diagram-wide QPImapping on high Tc superconductors, Kondo systems and SCESs. It is based on Panstyle STM design for high magnetic field compatibility and yet has enough symmetry
required for covering a wide temperature range with minimal drift. Also it has multiple
sample storage at 4K for unlimited reuse of samples with various dopings. Its primary
goal is to extend the SI-STM measurement coverage over the most significant regimeof the 3D phase diagram for unique determination of the mechanisms of high Tc
superconductivity using the fully-phased Green-function-based cross-sectional FTSTS
analysis method.

Non-oriented electrical steels have been used in rotating electric machines. Magnetic
induction waveforms of stator cores of induction motors have ac major hysteresis
loop of driving frequency and ac minor loops due to the slip. Prediction of core loss
including higher harmonic is one of important task for high efficiency induction
motor design[1]. In this work, we have constructed core loss measuring system which
could control waveform of magnetic induction the same as generated from waveform
synthesizer using analog negative feed-back system and test specimen was used air
flux compensated ring core. Using the developed measuring system, we can measured
core losses of ac minor loops which depend on the peak amplitude and positionin major hysteresis loop and theses core losses obeyed Steinmetz’s law. Core loss
including minor loops could be calculated superposition principle of the core loss frommajor hysteresis loop and the core losses from minor loops which come from higher
harmonic induction.

We have fabricated a magnetoencephalography (MEG) system having a
superconductive shield helmet. By using the perfect diamagnetic effect of thesuperconductor (Pb), superconducting quantum interference device (SQUID)
magnetometers inside the Pb enclosure can be shielded from external magnetic
disturbances, and this effect can be used to enhance the signal quality of biomagnetic
signals. Along the surface of the helmet, the shielding factor (SF) was from 28 to 57
dB, depending on the position of the SQUID from the edge. SF reduced rapidly as
the distance from Pb surface increased. The shielded helmet-shape MEG system hasa noise level of about 7 fT/Hz1/2 at 1 Hz, and 3 fT/Hz1/2 at 100 Hz. Auditory evokedbrain signals were measured and were compared in the case of superconductive shield
and without shield, and confirmed big improvement of the signal quality by using
superconductive shield.

W.S. Yoon1,2, Y.S. Jang1, S.J. Lee1, G.B. Kim1, H.J. Lee1,2, K.B. Lee1, M.K. Lee1, Y.N.
Yuryev1, Y.H. Kim1,2
1
Korea Research Institute of Standards and Science
2
University of Science and Technology
Micro-calorimeters operating at low temperatures have become important tools inmany aspects of science because of their high energy resolution much beyond the limitof semiconductor based detectors. These sensitive detectors measure the temperaturedependent properties of sensor materials such as their resistance or magnetization.
In metallic magnetic calorimeters, a small concentration of erbium doped in gold
host provides a paramagnetic system, in which the magnetization is inversely
proportional to the temperature. A metallic film of the sensor material is fabricated ona superconducting meander-type pickup coil connected to an input coil of a SQUID
current sensor. An absorber, another gold foil, is employed to detect incident alphaparticles. The gold foil absorber and the magnetic temperature sensor are thermallyconnected by gold bonding wires. The kinetic energy of each particle is converted intoa temperature increase of the absorber/sensor assembly. In the present report, the recent
progress on high resolution alpha spectrometers using these detectors is discussed
together with an application to radionuclide analysis.

308

Alexandra Ioannidou1*, Margarit Gjoka2, Dimitris G Niarchos2, A Borrell3, M D
Salvador4 and F L Penaranda-foix5
1
Institute of Materials Science, NCSR Demokritos, Athens, Greece
2
Institute of Materials Science, NCSR DEMOKRITOS, Greece
3
Instituto de Tecnologia de Materiales (ITM), Universidad Politecnica de Valencia, Camino de Vera,, Spain
4
Instituto de Tecnologia de Materiales (ITM), Universidad Politecnica de Valencia, Camino de Vera, s/n,
46022 Valencia, Spain
5
Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas,
Universidad Politecnica de Valencia, Camino de Vera, s/n, 46022 Valencia, Spain

The 19th International Conference on Magnetism

Seokhwan Choi1, Jimin Kim1, Chanhee Kim1, Jaewook Kim1, Hwansoo Suh2 andJhinhwan Lee1*
1
Physics, KAIST, Korea
2
FRL, SAIT, Korea

Duhyung Yeon and Derac Son*
Physics, Hannam university, Korea[1] D. Son “AC hysteresis loop measurement of stator-tooth in induction motor”, IEEE Trans. on
Magn., Vol.35, No.5, p.3931~3933(1999)

July 12 (Thu)

July 12 (Thu)[1]Debye P, 1926, Some observations on magnetisation at a low temperature, Ann. Phys. 81: 1154-1160; [2]Tishin A.M, Spichkin Y.I, 2003, The Magnetocaloric Effect and its Applications, MPG Books Ltd., Bodmin, 2003;

Kwon Kyu Yu, Kiwoong Kim, Hyuckchan Kwon, Jin Mok Kim and Yong Ho Lee
Brain and Cognition Measurement Lab, KRISS(Korea Research Institute of Standards
and Science), Korea[1] Y. H. Lee, “A low noise multichannel magnetocardiogram system for the diagnosis of heart electric activity”, Korean society of
medical and biological Eng., Vol. 27, pp. 154-163, 2006. [2] R. H. Kraus, “ First Results for a Superconducting Imaging-Surface
Sensor Array for Magnetocardiography”, Recent Advances in Biomagentism Proceeding, pp. 43-46, 1999. [3] D. B. Hulsteyn, “Superconducting Imaging Surface Magnetometery”, Rev. Sci. Instrum., Vol. 66, pp. 3777-3784. [4] H. Ohta,“A 64-channel wholehead SQUID system in a superconducting magnetic shield”, Supercon. Sci. Technol., Vol.12, pp. 762-765, 1999.

July 8-13, 2012 Busan, Korea

309

poster Presentation

poster Presentation

RQ18

RQ21

RR01

RR04

Radio-frequency atomic magnetometer for sensitive susceptibility
detection

26 T+ steady magnetic field for neutron science at HZB Berlin

Preparation of γ-Fe4N and ε-Fe3N particles with high magnetizationfor electromagnetic wave absorption applications

Magneto-motive force and torque analysis of squirrel cage induction
motor with rotor or stator faults

Alkali-metal magnetometers use the coherence precession of polarized atomic spins to detect andmeasure magnetic fields. Previously, the interaction between light and atoms allows magnetometers
to detect and measure magnetic fields, with sensitivity of 10 fT/√Hz [1]. Atomic magnetometerssuch as spin-exchange relaxation free (SERF) regime magnetometer and coherence population
trapping (CPT) magnetometer have been designed to detect of varying magnetic fields mainly at low
frequency. Therefore, detection of weak fields at high frequencies up to several megahertz requires analternative detection method. To observe the Nuclear magnetic resonance (NMR) signals at several
tens of kilohertz, RF (Radio-Frequency) atomic magnetometer can be used. RF magnetometer has afundamental sensitivity limit on the order of 0.01 fT/√Hz [2, 3]. In RF magnetometer, the oscillating
magnetic field causes the polarization of each spin to rotate along the pumping axis, with the transverse
spin component increasing until the polarization is perpendicular to the pump axis. The resonant RF field
eventually makes all of the processing spins coherent. In this study, the measured SNR corresponded toa sensitivity of 50 fT/√Hz at 25 kHz and such results will be useful to atomic NMR detector.

The Helmholtz Zentrum Berlin is building in collaboration with the National High
Magnetic Field Laboratory, Tallahassee, FL, USA a new series-connected hybrid
magnet system for neutron scattering experiments [1]. Two conical endings of 30°
opening angle enable neutrons to hit the sample and to be detected either in the forward
or backward direction. To achieve a maximum field with the present technology, a
13 T superconducting Nb3Sn cable-in-conduit coil is combined with resistive insert
coils of 13 T to 19 T, depending on electric power, to give a maximum of 26 to 32
T. The magnet that provides a 50 mm diameter room temperature bore in horizontal
orientation will be permanently mounted at the dedicated time-of-flight instrument
ExED 76 m away from the neutron source. The contribution describes the mostimportant design features of the system (the 20 kA, 8 MW power supply, the helium
refrigerator system for cooling of the superconducting coil and the 4-8 MW watercooling system for cooling of the resistive coil), the status of the fabrication of thecomponents, the outline of the building for the technical infrastructure and the status of
the installation of the most important components.
[1] P. Smeibidl et al., J. Low Temp. Phys. 159, 402 (2010).

High-Ms ferromagnetic iron nitrides have vast applications on microwave absorbing
and magnetic recording. In this study, we successfully used a simple nitrogen
treatment to prepare cubic γ-Fe4N and hexagonal ε-Fe3N powder. Both kinds ofpowders are synthesized by the nitriding process of the commercial micro-scale Fe
and Fe2O3 powders, at 550°C for 5 hours during a flowing mixture of NH3 and H2
gas. Our pure γ-Fe4N powder exhibits a high saturation magnetization of 15.03 kG atroom temperature, which is slightly lower than that of bulk Fe (22.0 kG @ 4 K) but isconsiderably higher than that of γ-Fe2O3 (4.0 kG @ 4 K). The ε-Fe3N powder including
a slight amount of γ-Fe4N was also synthesized by heating the commercial Fe2O3
powder with the same procedure. The chemical stabilities of both γ-Fe4N and ε-Fe3N
powder are superior to that of the pure Fe and have high level of mechanical hardness.
The mircostructures and electron spin resonances of our iron nitrides were also studied.

Cheol Soo Goo1, Seok-myeong Jang2 and Yu Seop Park2
1
Insturmentation and Control Assessment Department, Korea Institute of Nuclear
Safety, Korea
2
Electrical Engineering, Chungnam National University, Korea
Torque characteristics of high voltage induction motor are simulated under thecondition of under voltage and broken rotor bars. The motor is high voltage squirrel
cage induction type for driving force of pumps and valves in nuclear power plant. In
the simulation, a rotor with health and broken bars, stator winding deterioration andvoltage drop 25% alone and combination with bar faults were used. Then the results
were analyzed. The effects of rotor faults on the torque-speed curve were comparedaccording to the number of the rotor faults. The results revealed that voltage drop andthe number of the rotor fault at high speed span is directly proportional to its effect on
the curve, but the curve indicated the opposite at the low speed span due to the rotor
impedance increase. In stator, winding faults made a distortion of the phase magnetomotive force and reduction of co-energy at the gap which cause vibration, harmonics
and total power decrease.

This work was supported by the National Science Council, Taiwan under the NSC 98-2112-M-007016-MY3 project.

[1] J. C. Allred, R.N. Lyman, T.W. Kornack and M.V. Romalis, Phys. Rev. Lett. 89, 130801 (2002) [2]
S.-K. Lee, K. L. Sauer, S. J. Seltzer, O. Alem, and M. V. Romalis, Appl. Phys. Lett. 89, 214106 (2006) [3]
I.M. Savukov, S.J. Seltzer and M.V. Romalis, Journal of Magnetic Resonance 185 (2007) 214-220

July 12 (Thu)

Ming-fong Tai1*, Hsin-tzu Liu2, C. M. Lin3 and Huan-chiu Ku1
Department of Physics, National Tsing Hua University, Taiwan
2
Department of Chemical Engineer, National Tsing Hua University, Taiwan
3
Department of Applied Science, National Hsingchu University of Education, Taiwan

1

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Cancellation coil allows precision magnetic measurements with strong
magnetization field inside a shielded enviroment

A simple method for measuring blocking temperatures

Methods for determining the quality of magnetic fluids

Evaluation of materials degradation of ferromagnetic steels for various
magnetized states using a hysteresis scaling law

Seong-min Hwang, Kiwoong Kim*, Chan Seok Kang, Seong-joo Lee and Yong-ho Lee
Brain and Cognition Measurement Lab., Korea Research Institute of Standards andScience, Korea

A great number of precision magnetic measurements can benefit significantly from, or in somecases, even require strong prepolarization fields (Bp) and magnetically shielded environments.
We devised a cancellation coil (CC) to neutralize the Bp on electrically conductive shield wallsthat may otherwise induce currents on the walls to produce a lingering transient residual field (Btr)
inside the shielded environment and disrupt the measurement operations. The CC was designed
using the inverse problem method to effectively neutralize magnetic fields generated on theshield walls by the Bp coil. The implemented CC was evaluated by measuring the resulting Btr
after strong pulsed Bp using a fluxgate magnetometer at different magnetometer positions andcancellation coil currents (ICC). We have conducted multi-mode component analysis on the
Btr measurements to reveal two dominant components, where the component with shorter time
constant comes from the current induced around the shield side walls and the other with longer
time constant from the current induced on the ceiling and floor of the MSR. The analysis also
allows optimization of ICC for each of the top, side, and bottom sections of the CC to enablesignificantly easier fine-tuning of individual sections of the CC to enhance CC performance.

Mansor Hashim1, Ghazaleh Bahmanrokh2 and Ismayadi Ismail1
1Institute of Advanced Technology, Universiti Putra Malaysia, Malaysia
2
Physics Department, Faculty of Science, Universiti Putra Malaysia, Malaysia
We describe a new method for measuring a blocking temperature, much simpler thanthat involving a SQUID. Nanoparticles of Co, Co coated with Au,Co-Pt and Co-Pt
coated with Au were prepared by the reverse micelle microemulsion method. The
four magnetic powder specimens were each pressed to yield a disc. A Hall-effectprobe blade surface was stuck intimately against one flat surface of the disc. Properly
analysed, this arrangement allows the probe to detect the normal component, BN,projecting from the disc since, at the interface, BN (air) = BN (disc). Use of thisrelation led to the determination of a magnetic moment near the disc surface. By
simply cooling this arrangement of disc + probe in a probe station to 15K, a graph ofthe magnetic moment was clearly peaked at a temperature which, unmistakably, wasthe blocking temperature, TB. For the four different samples TB lies between 40K and
45K.

Viorica Chioran
University Babes-Bolyai - Cluj Napoca / Romania, Romania

The conversion parameter of the magnetic properties of magnetic fluids is a physicalquantity describing the quality of those fluids from a technological point of view.
This study determines the value of this parameter for three samples of magnetic
fluid. Many technical applications require magnetic fluids with specific magnetic
properties such as very high magnetization at saturation point or rheological properties
involving high fluidity (very low viscosity). The sample with bigger density (1070 kg/m3) also has a larger solid volume fraction (0, 059). Increasing the solid part/ fluid
volume increases the density and viscosity of that fluid. A magnetic fluid with a larger
magnetic part/ volume (0,031) has a higher magnetization at saturation point (0,0138
A/m). The parameter always has sub-unitary values because inside the volume of themagnetic fluid, the percentage of the solid part is larger then that of the magnetic part.
Responsible for this is the nonmagnetic layer at the surface of the particles. For the
fluid samples studied, regardless of the magnetic and physic diameter, the nonmagnetic
layer of particles has the same value: a = 0,83 nm. Good quality of a magnetic fluid isindicated by a high value of the conversion parameter.

July 12 (Thu)Hyun Joon Lee1, Han Seb Moon1, Yong-ho Lee2, Seong-joo Lee2, Kwon-kyo Yu2 andKiwoong Kim2*
1
Pusan National University, Korea
2
Korea Research Institute of Standards and Science (KRISS), Korea

P. Smeibidl, Karel Prokes*, H. Ehmler, O. Prokhnenko and A. Tennant
M-I1, Helmholtz Zentrum Berlin, Germany

Satoru Kobayashi*, Yusuke Ishibashi and Ryo Baba
Department of Materials Science and Engineering, Iwate University, Japan

We have examined a hysteresis scaling behavior of magnetic minor hysteresis loops
for ferromagnetic low carbon steels under DC-biased magnetic field and/or remanent
magnetization state. For all minor loops with dominant contribution of irreversible
Bloch wall motion, a scaling relation between the hysteresis loss and maximum
magnetization shows the same curve from very low to high magnetization regime,
suggesting the invariant pinning mechanism for the irreversible wall motion. In theintermediate magnetization regime, the relation follows the usual Steinmetz law witha power-law exponent of about 1.5, whose coefficient increases with defect density.
The method using a hysteresis scaling can be a useful technique of evaluating materials
degradation of ferromagnetic steels in an unknown magnetic state, which is commonly
encountered on on-site measurements.

Seong-min Hwang, Kiwoong Kim, Chan Seok Kang, Seong-Joo Lee, and Yong-Ho Lee, Appl. Phys. Lett. 99, 132506 (2011)
Seong-min Hwang, Kiwoong Kim, Chan Seok Kang, Seong-Joo Lee, and Yong-Ho Lee, submitted to J. Appl. Phys. 111,
083916 (2012)

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Development of a SQUID based ultra-low-field MRI system

Optimization of operation condition of orthogonal fluxgate sensor
fabricated with Co based amorphous wire

A study on magnetic fluid viscosity

Seong-joo Lee, Kiwoong Kim*, Chan Seok Kang, Seong-min Hwang and Yong-ho
Lee
Brain and Cognition Measurement Lab., Korea Research Institute of Standards andScience, Korea
We obtained 2-dimensional Magnetic Resonance Imaging (MRI) image of a phantom
in fields of a few microtesla by using a dc Superconducting QUantum Interference
Device (SQUID) based MRI system. Microtesla MRI technique is a challenging
application based on SQUID technology. The high sensitivity of the SQUID
magnetometer enables measurement of very weak magnetic resonance signals evenfor the low Larmor frequency in microtesla fields. Measuring the nuclear magnetic
resonance (NMR) signals at such a low field gives many benefits like development ofan open-type low-cost surgery-monitoring MRI system, high-contrast cancer detector,
etc. In this presentation, we introduce experimental details for ultra-low-field (ULF)
MRI.

Yongmin Kim1, Young-hak Kim2, Sang-ho Lim3, Cang-seob Yang4 and Kwang-ho
Shin1*
1
Dept. of Information and Communication Engineering, Kyungsung University,
Korea
2
Pukyong National University, Korea
3
Korea University, Korea
4
Agency forDefense Development, Korea

Orthogonal fluxgate (OFG) sensors have an additional advantage comparing with conventional fluxgate sensors
in their simple structure [1-2]. Because the sensitivity of an OFG is typically proportional to its winding number N,
cross section area of its magnetic core A, and operation frequency f, the f should be as high as possible to prevent
reduction of the sensitivity in the case of small-sized OFG sensors in which the N and A are restricted. The f islimited due to the LC resonance occurred by inductance and stray-field capacitance of the pickup coil around themagnetic core and transmission line, coaxial line in this study, as well as performance of the signal conditioning
circuit in common. And the sensitivity could be also reduced according to increase of operation frequency due
to the skin effect if the sensor is operated in the frequency range of near MHz. We present how to optimize
the operation condition including frequency of the OFG fabricated with a CoFeSiB amorphous wire with thediameter of 100 μm in this paper. The LC resonance frequency according to external capacitances was calculatedwith an equivalent circuit and FEM analysis to calculate the magnetization distribution in a high frequency.

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Theoretical design of magnetic energy harvesting module

Viorica Chioran
University Babes-Bolyai - Cluj Napoca / Romania, Romania

Kunihisa Tashiro*, Hiroyuki Wakiwaka and Yu Uchiyama
Shinshu University, Japan

This paper shows the results of a study of the parameters that the viscosity of magnetic
fluids depends on, in the absence of magnetic fields. Viscosity’s and shearing tension’s
dependence on the rheologic component and shearing speed was verified for several
samples of kerosene based magnetic fluid with the same dimensional distribution
but various concentrations, at different temperatures. Experimental results show one
situation where the sample P1 has a non-Newtonian character over a small interval of
shearing speeds. An increase in fluid viscosity indicates that bonds between particles
are formed inside the fluid. As shearing speeds increase these bonds disappear.
Samples P and P2 show Newtonian character over the shearing speed interval where
viscosity remains constant. By comparing viscosity values of samples at different
temperatures and shearing speeds, decreasing viscosity while increasing temperature
is observed due to the activation energy of viscous flow. A linear increase of shearing
tension with the increase of shearing speed was observed for the studied samples atdifferent temperatures. The slope of this line can be used to determine the dynamic
viscosity’s value. For the considered samples, viscosity strongly depends on several
factors: density, concentration, temperature (by Arrhenius’s Law) and shearing speed (byNewton’s equation).

Energy harvesting is a key technology to build a sustainable society. In previous
paper, we focused on a magnetic power-line noise as a reusable energy. In this paper,
we present a theoretical design method of magnetic energy harvesting module. This
module consists of an air-core coil and resonant capacitor. With a simple RLC circuit
model, we derive a equation of the harvesting energy as a function of coil size. In
order to demonstrate the magnetic field, a uniform magnetic field is generated by ourdeveloped coil system. From the experimeted results, we successfully demonstrated theenergy harvesting of 100 mW from a magnetic field of 0.09 mT at 60 Hz. This value
is good in agreement with the estimated results. The harvested energy is proportional
to the square of the magnetic flux density. However, ICNIRP2010 provide a guideline for human helth that an acceptable level in a public space is 0.2 mT at power-line
frequency. We also reveal the required coil size to harvest a demanded energy.

[1] E. Paperno, E. Weiss and A. Plotkin, IEEE Trans. Magn., 44, 4018 (2008). [2] I. Sasada, J. Appl. Phys., 91, 7789 (2002).

310

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

311

poster Presentation
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A study on detecting and determining the shape of small axial cracks
by using magnetic flux leakage in ndt system of pipe

Torque characteristics of interior permanent magnet synchronous
motor for electrical hydraulic power steering system

Magnetic NDE for sensitization of Inconel 600 alloy

A study on new permanent magnet configuration for high thrust
density in permanent magnet synchronous linear motor

July 12 (Thu)

There is the source of energy that is used widely all over the world, which is oil andnatural gas. Oil and gas is supplied for industries or home consumers through pipelines.
Most pipelines are laid to underground and exposed the external environment. By
these conditions pipelines have some bad effects like the metal loss, corrosions andany other damages. For preventing accidents, these defects have to be detected by theNon-destructive testing(NDT). The magnetic flux leakage(MFL) method among the
NDT methods is suitable for testing pipelines which the magnetic characteristic ofhas high magnetic permeability. The system that MFL method applies to is called thepipeline inspection gauge, MFL PIG. The previous MFL PIG has high performancefor detecting the metal loss and corrosions. But MFL PIG cannot detect the cracks
which occurred by the difference of pressure between the inside and outside ofpipelines and the shape of is long and very narrow. Cracks occures frequently in thepipelines and the risk of the accident from the cracks is higher than that from the metal
loss and corrosions. The circumferential MFL(CMFL) PIG performs magnetic field
circumferentially and can maximize the magnetic flux leakage at the cracks.

Su-jin Hwang1 and Ki-chan Kim2*
1
Daedong movel company, Korea
2
Hanbat national university, Korea

In the paper, a 12 V-DC interior permanent magnet synchronous motor for electric
hydraulic power steering (EHPS) was designed for the purpose of improving its torqueperformance. The EHPS is a steering system that uses the battery power of the vehicle,
which is weaker than the power of the hydraulic power steering system. Because of
the spatial limitation, the IPMSM, which has high-power characteristic and excellent
performance within the field weakening area at a high rotating speed, is advantageous.
To improve the torque performance, the average torque was increased by increasing
the rotor size. In addition, because the torque ripple is detected as vibration when
the steering wheel is operated, the shape of the barrier was modified to change theinductance element of the axis and reduce the torque ripple. The optimally designed
model characteristics were analyzed using the finite element method to comparatively
analyze the parameters. It is expected that this study will be important reference data tounderstand the characteristics of the IPMSM as well as of the EHPS.

Hiroaki Kikuchi, Takaki Sumimoto, Yasuhiro Kamada and Satoru Kobayashi
Faculty of Engineering, Iwate University, Japan
Inconel 600 alloy, Ni base alloy, is used as steam generators in nuclear power plants,
and sensitization occurs along grain boundary with heat treatment on this material. The
sensitization causes a degradation of corrosion resistance and generates stress corrosion
crack [1], [2]. Therefore nondestructive evaluation (NDE) technique for sensitizationof Inconel alloy is quite important so as to keep the integrity of plants. Inconel 600
alloy has usually paramagnetic property, however, it shows ferromagnetic properties
along grain boundary when sensitization occurs: this means NDE using magnetism
is possible. Thus, in this study, Inconel 600 alloys were heat treated at 873 K from 0
to 400 hours and their magnetic properties were investigated in detail. Magnetization
increases with increasing time of heat treatment and takes a maximum. On theother hand, coercivity decreases with the increase in time. We confirmed that only
characteristics at the grain boundaries changes ferromagnetic by MFM observation. As
trial for industrial application, heat treated Inconel 600 alloy has scanned by magnetic
field sensor, and the changes of magnetization nondestructively were successfully
obtained. The result indicates the feasibility of magnetic NDE for sensitization ofInconel 600 alloy.

Taewoo Kim and Junghwan Chang*Electrical Engineering, Dong-A University, Busan, 604-714, Korea

WN
A
R

D

TH
I
W

[1] Tomy Sebastian, Vineeta Gangla, 'Analysis of Induced EMF Waveforms and Torque Ripple in a
Brushless Permanent Magnet Machine,' IEEE Trans. on Industrial Applications, Vol. 32, No. 1, 1996. [2]A. M. Elrefais, T. M. Jahns and D. W. Novotny, 'Analysis of Surface Permanent Magnet Machines with
Fractional Slot Concentrated Windings', IEEE Trans on Energy Conversion, vol. 21, no. 1, pp. 34-43, 2006

[1] M. Kowaka, H. Nagano, T. Kubo, Y. Okada, M. Yagi, O. Takaba, T. Yonezawa and K. Arioka,
Nuclear Technologies, Vol. 55, pp. 394-404 (1981). [2] J. D. Wang, D. Gan, Materials Chemistry
and Physics, Vol. 70, pp. 124-128 (2001).

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Control of working temperature of isothermal magnetic entropychange by hydrogen absorption into La0.8Nd0.2(Fe0.88Si0.12)13 for magnetic
refrigerant

Edge auxiliary teeth design of stationary discontinuous armature PMLSM with concentrated winding

Comparison of characteristics between the PM synchronous motor
and the induction motor for electric vehicle

Design of stationary pole pieces in a coaxial magnetic gear

S Fujieda1*, A Fujita2, K Fukamichi1 and S Suzuki1
1Institute of Multidisciplinary Research for Advanced Materials, Tohoku Univ., Japan
2
Dept. of Materials Science, Graduate School of Engineering, Tohoku Univ., Japan

Hydrogen absorption into La0.8Nd0.2(Fe0.88Si0.12)13 has been investigated to obtain large
magnetocaloric effects (MCEs) near room temperature for applications to magnetic
refrigeration. La(Fe0.88Si0.12)13 exhibits large MCEs just above the Curie temperature
TC = 195 K because of the itinerant-electron metamagnetic (IEM) transition [1]. The
MCEs due to the IEM transition are enhanced by the partial substitution of Nd for La[2]. It was confirmed that TC of La0.8Nd0.2(Fe0.88Si0.12)13 is increased from 193 K to 318
K by hydrogen absorption with keeping the IEM transition because the unit cell volume
is expanded. Note that the isothermal magnetic entropy change ΔSm due to the IEM
transition in a magnetic field change of 2 T for La0.8Nd0.2(Fe0.88Si0.12)13H1.1 was evaluatedto be about -23 J/kg K at TC = 288 K, which is larger than ΔSm = -19 J/kg K at TC = 276
K for La(Fe0.88Si0.12)13H1.0. The relative cooling power RCP = 179 J/kg of the former
also is larger than 160 J/kg of the latter. Accordingly, it is concluded that the partial
substitution of Nd improves the MCEs near room temperature.
[1] A. Fujita et al., Phys. Rev. B 67 (2003) 104416. [2] S. Fujieda et al., Mater. Sci. Forum 561-565 (2007) 1093.

Yong-jae Kim1, Sung-jin Kim1* and Sang-yong Jung2
1
Department of Electrical Engineering, Chosun University, Korea
2
School of Information and Communication Engineering, Sungkyunkwan University, Korea

Recently, in order to resolve the problem of high cost, we have proposed the stationary discontinuous armature
PM-LSM in which the armature is engaged only when accelerated and decelerated operations are necessary,
when PM-LSM is used with long-distance transportation systems in factories [1]. As the armatures arearranged discontinuously in the PM-LSM, the number required is dramatically decreased. In this case, several
stator blocks can be arranged at certain intervals within the overall running route. The space between theblocks without the stator is called the free-running section, and the mover in this section drives under its own
inertia. However, the stationary discontinuous armature PM-LSM contains the edges which always exist as aresult of the discontinuous arrangement of the armature [2]. For this reason, cogging force generated between
the “entrance end” and the “exit end” has become a problem. Therefore, we have examined the edge cogging
force by installing the auxiliary teeth at the armature’s edge in order to minimize the cogging force generated
when the armature is arranged discontinuously. We obtain the edge cogging force by using 2-D numericalanalysis with a FEM and also by adjusting the width, height and the length of pitch of auxiliary teeth.
[1] Yong-Jae Kim, Masaya Watada, Susumu Torii and Daiki Ebihara, “Constant Load Angle Control of the DiscontinuousPrimary Linear Synchronous Motor without Position Feedback”, The Fourth International Symposium on LINEAR
DRIVES FOR INDUSTRY APPLICATIONS, pp.113-116, 2003. [2]Yong-Jae Kim, Masaya Watada, Susumu Torii, Hideo
Dohmeki and Daiki Ebihara, “The Influence which Outlet edge of the Discontinuous Primary Linear Synchronous Motor
Exerts on the Drive of Secondary Mover”, The 5th International Power Electronics Conference, pp.859-864, 2005.

Mi-jung Kim, Ik-sang Jang, Ki-doek Lee, Jae-jun Lee, Jeong-ho Han, Tae-chul Jeongand Ju Lee*
Hanyang University, Korea

This paper presents the characteristics over a wide speed range of the interior permanent magnet
synchronous motor(IPMSM) and the induction motor(IM) for an application of electric vehicle
drive. In generally, IPMSM have higher performance than IM. The performance: torque,efficiency, power factor etc. are compared at rated speed of 2,843rpm and maximum speed of
10,000rpm. The induction motor operating constant speed is not need to consider the control
property; however, the adjustable speed drive applications such as traction motor are should
be deliberated for control. In this paper, the characteristics of IPMSM and IM controlled by
space vector PWM are illustrated and verified by experiment. In case of IPMSM, the efficiency
map was made up through driving simulation considering the actual control. It was carried out
MTPA control until constant torque operating region and applied the field weakening control
under constant power region. In case of induction motor, V/f control maintained a constant ratioof voltage versus current was carried out until constant torque operating region and applied
the constant voltage variable frequency control under constant power region. As illustrated in
Figure 1, overall efficiency of IPMSM has high level than IM about 5%.

Daekyu Jang and Junghwan Chang*Electrical Engineering, Dona-A University, Saha-gu, Busan, 604-714, Korea
Magnetic gears have been proposed by unique advantage compared with mechanicalgears, such as contactless power transmission. In addition, they can limit a torqueunder overloaded condition and have excellent performances on noise, vibration andreliability [1]. However, their use in industries has been very limited due to poor torquedensity, low transmission ratio and transmitted toque performances. Of magnetic gears,
a coaxial magnetic gear is a common configuration and extensively studied for its
relative high performances [2]. It is consist of inner rotor, outer rotor and stationarypole pieces in between the rotors. The stationary pole pieces have an important role intorque transmission by modulating the air gap flux density distribution adjacent to innerand outer rotor. However, they also generate unwanted harmonics resulting in torqueripples and vibration. This paper proposes variants of stationary pole pieces to gainhigh performances in torque transmission. It also has mechanical and manufacturing
advantages in transmitting torque by a structure combining each pole pieces. The finite
element analysis shows the produced torque has reduced harmonic components in bothsides of rotors.

[1] Z. Q. Zhu and David Howe, 'Electrical Machines and Drives for Electric, Hybrid, and Fuel cell Vehicles', Proceedings of theIEEE, Vol. 95, No. 4, pp 746-765, April 2007. [2] J. Herbst, J. Hahne, H. Jordan, H. Liu, A.Gattozzi and Ben Wu, 'Challenges inthe Design of a 100 kW Induction Motor for a PHEV Application', Vehicle Power and Propulsion Conference, pp 408-413, 2009.

[1] K.Atallah, S.D. Calverley and D. Howe, “Design, analysis and realization of a high performancemagnetic gear”, IEEE proc.-Electr. Power Appl, vol. 151, No. 2, pp.135-143, March. 2004. [2]Noboru Niguchi, Katsuhiro Hirata, Masari Muramatsu and Yuichi Hayakawa, “Transmission
Torque Characteristics in a Magnetic Gear,” ICEM conf, pp 1-6, sept. 2010.

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Characteristic analysis of induction motor for electric vehicleaccording to electric loading and magnetic loading

Inductively coupled LC resonators as displacement sensor

Comparison of simultaneously measured pulse waveforms from both
hands using permanent magnet-hall pulsimeter sensors

Design techniques for reducing torque ripple in permanent magnet
flux switching motor

Ki Young Sung1 and Ki-chan Kim2*
1
SPG Co,. Ltd., Korea
2
Hanbat national university, Korea

In the paper, an inductive motor for electric vehicle that was designed for compact
car modification was selected as the basic model, and its performance change was
examined according to the change in the electric and magnetic loading related to therotor slot. The characteristic changes according to the change in the loading wereanalyzed for two speed ranges: the low speed (near the base speed) and the high speed(maximum speed with field weakening control). To provide the characteristic analysis
conditions according to the change in the slot shape of the reference model, the rotor
bar depth was changed with the rotor teeth width fixed to vary the electric loading, andthe rotor teeth width was changed with the rotor bar area fixed to vary the magnetic
loading. The characteristics of the inductive motor were analyzed via the analysisof the characteristics according to the parameters of the equivalent circuit based on
the magnetic circuit method and via the electromagnetic analysis based on the finite
element method to consider the nonlinear characteristic of the motor parameters.
[1] Z.Zhang, F.profmo, a. tenconi, 'Improved design for elelctric vehicle induction motors using an optimisation procedure'.
Electric Power Applications, IEE Proceedings, vol, 143, pp.410-416, 1996 [2] T. Wang, P. Zheng, Q. Zhang, and S. Cheng,'Design Characteristics of the induction motor used for hybrid electric vehicle'. IEEE Tracnsaction on Magnetics, vol. 41,
pp. 505-508, 2005 [3] I. Boldea and S. A. Nasar, 'The induction machine handbook'. Boca Raton, CRC Press, 2002

The 19th International Conference on Magnetism

Yongmin Kim and Kwang-ho Shin*
Dept. of Information and Communication Engineering, Kyungsung University, Korea
In this paper, we present novel displacement sensor composed of a pair of LC
resonators. The LC resonator was formed by serial connection of 300-turn Cu wire
wound on a rectangular NiZn ferrite (20 × 3 × 4 mm) core and SMD capacitor (3.2 ×
1.6 mm). The resonance frequencies of two resonators are adjusted to be identical witheach other. By this, we could obtain the sensor output linearly dependent of distance
between two LC resonators, because the mutual inductance is proportional to distance
between two resonators in a few centimeters. The sensor was designed by a sequenceof magnetic field simulation with a FEM tool (COMSOL) and circuit calculation witha SPICE. The sensitivity estimated by S = fr/D was about 480 kHz/m, where, fr andD are resonance frequency and distance between two resonators, respectively. The
proposed sensor would be a promising displacement sensor when it takes an active partin an environment surrounded by serious electrical/magnetic noise, since it could be
operated in extremely narrow frequency range.

Sang-suk Lee1, Jong-gu Choi2, Il-ho Son1, Keun-ho Kim1, Nam-kyu Lee1 and Hyunsung Cho11
Oriental Biomedical Engineering, Sangji University, Korea
2
Eastern-Western Biomedical Engineering, Sangji University, Korea
Two radially arterial pulses of dual hands using the prototype of a clamping clip
pulsimeter equipped with permanent magnet and Hall device are compared andanalyzed. The phase difference of two pulse wave signals is dominantly presented
from the simultaneous measuring clinical pulse wave signals for twenty two maleparticipants at their 20’s. It is possible to analyze that the fast and slow pulse wave forright hand and left hand depend on the muscle property of arms rather than the total
length of blood vessel due to cardiovascular circulatory system.
[1] S. S. Lee, M. C. Ahn, and S. H. Ahn, J. Magnetics. 14, 132 (2009). [2] M. F. P. O’Rourke, R. P.
Kelly, A. P. Avolio, 'The Arterial Pulse', 1st Ed.; Lea & Febiger: Philadelphia, PA, USA, 1992 [3] S. W.
Kim, Y, G, Choi, H. S. Lee, D. H. Park, D. G. Hwang, S. S. Lee, G. W. Kim, S. G. Lee, and S. J. Lee, J.
Appl. Phys. 99, R908 (2006).

July 12 (Thu)

Hui Min Kim and Gwan Soo Park*
School of Electronic and Electrical Engineering, Pusan National University, Korea

312

poster Presentation

Daohan Wang1, Xiuhe Wang2 and Sang-yong Jung1*
Sungkyunkwan University, Korea
2
Shandong University, China
1Permanent magnet flux switching motor (PMFSM) is a novel double salient machine
which employ the PM instead of the field winding for excitation and contains only one setof armature winding so has the advantage of low cost power converter and extreme highefficiency. It has a potential for taking place of BLDC in some applications, such as fans
and air ventilation machines. Due to the different structure and operation principle fromtraditional permanent magnet machine, the generated torque ripple in PMFSM is very
critical and rather unique compared to the common PM machines. In this paper, the design
techniques of reducing the torque ripple in PMFSM has been presented. Different kindsof design approaches have been presented to reduce the torque ripple with comparing themean output torque. Analytical method is first presented to investigate the influence anddetermine the design parameters thus reduce the computational effort. Then FEA simulation
is employed to validate the analysis above. Finally, time stepped FEA simulation is being
employed to investigate the performance with different approaches adopted.
[1] Z. Q. Zhu, A. S. Thomas, J. T. Chen, and G. W. Jewell, “Cogging Torque in Flux-Switching Permanent
Magnet Machines,” IEEE Trans. Magn., vol. 45, no. 10, pp. 4708-4711, Oct. 2009. [2] Z. Q. Zhu, J. T. Chen,
D. Howe, S. Iwasaki, and R. Deodhar, “Design of multi-tooth flux-switching permanent magnet brushless ac
machines for low speed direct drives,” IEEE Trans. Magn., vol. 44, no. 11, pp. 4313-4316, 2008.

July 8-13, 2012 Busan, Korea

313

poster Presentation

poster Presentation

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The analysis of line-start permanent magnet machine with saliency
ratio

Numerical analysis on iron loss and pm loss of permanent magnet
synchronous motor considering the carrier harmonics

A study on Voltage-PWM control of switched reluctance generator at
low speed

Electromagnetic separation of the brown coal ash of thermal power
stations

In this paper, decisive influences of the inverter harmonic on iron loss characteristic for PMSM (Permanent
Magnet Synchronous Motor) are numerically investigated with the FEM (Finite Element Method).
Particularly, analysis is carried out based on a multi-layer buried PMSM, which is newly designed for EV
drive system and its rotor contains ferrite magnets. First of all, not only the design criteria and the specificationof the designed PMSM but also the features of the motor like torque ripple, Back-EMF are represented. In
addition, the remarkable iron loss analysis result, that is obtained using 3-D FEM considering skewed stator
structure, is covered in priority. Then its each harmonic component is identified using the FFT (Fourier Fast
Transform) and that is compared with iron loss characteristic in case of sinusoidal input current which is
not include harmonic component. Finally, the efficiency at each operating point is calculated considering
loss analysis results. Meanwhile, entire analysis is performed through various operating conditions using
intrinsically real input current values implemented by testing performance of the manufactured model.

This paper is a study on switched reluctance generator’s control method---VoltagePWM. It can be used to regulate the current to a desired value by varying the averageapplied voltage in the switched reluctance generator . The advantages of VoltagePWM control at low speed are more than high speed which may make the applicationof PWM difficult. The switched reluctance machine can operate as a generator as well
as a motor by simply changing the firing angles. Some main control methods we often
used are Chopped Current Control (CCC), Angular Position Control (APC) and PWM
Control . The controller could regulate control variables, such as current level, turn-on
and turn-off angles, supply voltage and so on. Different control methods will be carriedout by regulating some variables in different conditions. For example, at low speed, thed.c link voltage is controlled by varying the set-point current or the duty-cycle and athigh speed by varying the control angles. Because of excitation current is closely linear
relation to duty cycle, so many applications determine this control method.

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Yun-ho Jeong1, Kyung-won Jeon1, Yong-jae Kim2 and Sang-yong Jung1*
1
School of Electronic and Electrical Engineering, Sungkyunkwan Univ, Korea
2
Dept. of Electrical Engineering, Chosun University, Korea

July 12 (Thu)[1] Z.Q.Zhu, Y.S.Chen, D.Howe, 'Iron Loss in Permanent-Magnet Brushless AC Machines Under Maximum Torque
Per Ampere and Flux Weakening Control', IEEE Trans. on Magnetics, vol. 38, No. 5,pp. 3285-3287, Set. 2002. [2]Katsumi Yamazaki, Shinjiro Watarim 'Loss Analysis of Permanent-Magnet Motor Considering Carrier Harmonics
of PWM Inverter Using Combination of 2-D and 3-D Finite-Element Method', IEEE Trans. on Magnetics, vol. 41,
No. 5,pp. 3285-3287, May. 2005. [3] G. Ombach, J. Junak, 'Torque ripple optimization of skewed IPM motor forfield weakening operation', Electrical Machines and Systems (ICEMS) 2011, pp. 1-7, Aug. 2011.

Sun Ning1, Dawoon Choi2, Jian Li1 and Yunhyun Cho2*
1
DongA-university, China
2
DongA-university, Korea[1]Miller, T.J.E. Electronic Control of Switched Reluctance Machines. MPG Books Ltd, Bodmin,
Cornwall. 2001. [2]K.Kannan , Dr.S.Sutha. The 4th International Power Engineering and Optimization
Conference (PEOCO2010), ShahAlam, Selangor, Malaysia.23-24 June 2010. [3] Jianzhong Sun,
Fengxian Bai, Special type electroc machine and control China waterpub press, 2005.137-143.

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Analysis of non-linear characteristics of linear compressor

Defect depth estimation based on the analysis of interference defects
on the underground gas pipelines

The measurement procedure of the equivalent core loss in a PM motor

Park Daegeun and Cho Yunhyun*
Dong-A University, Korea

Min-Ho Kim1, Bok-Jin Oh1, and Doo-Hyun Choi2*
1
Graduate School of Electrical Engineering and Computer Science, Kyungpook
National Univ., Korea
2
School of Electronics Engineering, Kyungpook National Univ., Korea

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Underground gas pipelines have corrosions and deformations due to both the naturalcauses such as moisture and ground pressure and the artificial causes such as faulty
construction, etc. So, periodic pipeline inspection is essential. In NACE (national
association of corrosion engineers) standard, it is advised to replace the pipeline whena defect’s depth is over 50% of the pipeline’s thickness. Therefore, the study to analyze
the defect’s depth and its progress is meaningful. Especially when defects more than
two are closely located, the interaction among these defects accelerates the progress ofdefection. In this paper, the interference defects on underground pipelines are analyzed
and their depths are estimated effectively. Experimental results show that the proposed
method can effectively estimate the depth of the interference defects.

Guo Jhih Yan1*, Ming-hung Jian1 and Chia-sheng Huang2
1
Micro/Meso Mechanical Manufacturing R&D Section, Metal Industries Research &Development Centre, Taiwan
2
Codent Tech Co. Ltd, Taiwan
For the development of high efficiency motor, the core loss decrease is one of the most important tasks.
However, the calculated core loss in the design stage is not so accurate because the specification provided
by material manufacturer usually obtained by ideal test condition in simple geometry, i.e. single sheet tester
and toroidal tester. Therefore, a method that can measure the core loss with the practical shape of motor
stator/rotor core includes every aspect of the manufacturing effects is required. This paper proposed arefined procedure based on torque metric method. Among several proven measuring methods, it is a directly
measuring method that can be applied to the actual motor. Typical torque method uses a motor driving a
specimen at a specific speed and then measures the drag torque. However, it is time consuming and requires
higher precision torque meter. Instead, the proposed method measures the speed-power characteristic curveof the driving motor with/without the test motor. From the difference of the speed-power characteristic,
the core loss at various speeds can be obtained. Several conventional PM motors are taking as examples todemonstrate this procedure and to investigate the core loss influenced by manufacturing.

Shavkat Malikov1, Valeriy Pikul1, Nuranya Mukhamedshina1, Vladimir Sandalov2 andElvira Ibragimova2*
1
Institute of Nuclear Physics, Uzbekistan
2
Radiation physics of solids and material science, Institute of Nuclear Physics,
Uzbekistan

Tens millions of brown coal ash have accumulated near thermal power stations (TPS) in
Uzbekistan, so their utilization has become quite actual. So far the ash is used for cement.
However the ash is well known to contain a large amount of valuable elements, including~3.13%Fe2O3 in Russian coal. Element analyses of the brown coal ash from Angren TPS
were done with the neutron activation techniques and 3.6%Fe, 0.084%Mn, 0.063%Zr andalso 0.023% of rare earth elements have been determined. The ash samples were undergone
to electromagnetic separation, and the magnetic fraction was 3.7%, where the content of
Fe increased to 58%. Then the magnetic fraction was separated with the standard screen
grader into 7 classes from 0.4 to 0.05mm. Two times increase of the contents of Fe and rareearth elements have been found in the fine fractions of 0.1-0.05mm. Optical absorption
spectroscopy of water solutions of the magnetic fractions has revealed the presence of Fe2+
and Fe3+ ions. Microscopic analysis of the fine fractions has shown that there are black ironmicrospheres of 0.02-0.05mm sizes, which can be used for cleaning of technological liquid
waste by means of the high gradient magnetic field, and powder metallurgy.

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July 12 (Thu)

Kwang Hee Kim, Jian Li and Yun Hyun Cho*
Dong-A University, Korea

Studies on viscidity in ferrofluids of Fe3O4

Han Gu1, Zhaozhen Jiang2, Aimei Zhang3 and Xiaoshan Wu2
1
Advance Functional Materials Lab and Department of Physics, Changshu Instituteof Technology, Changs, China
2
Lab of Solid State Microstructures, Dept Physics, Nanjing University, China
3
College of Science, Hohai University, China
Fe3O4 nanoparticles with superparamagnetic properties are synthesized by sol-gel
approach. Fe3O4 nanoparticles are coated using the amorphous silica. The viscidityof the coated Fe3O4 nanoparticles increases as the particles is incorporated in theimpregnant, which may due to the magnetic interactions. At room temperature, theferrofluid viscidity increases momotonically with increasing the concentration of
Fe3O4 nanoparticles, the ratio of surface activity. With rising the temperature, theferrofluid viscidity becomes larger. The applied magnetic field has also effects on the
ferrofluid viscidity. The switching process of the applied magnetic field may increase
the ferrofluid viscidity, although the ferrofluid viscidity increases with increasing theapplied magnetic field. Dynamic properties of the magnetic particles in the impregnant
are also discussed in the present.

[1]N. Stranges, and R. D. Findlay, “Measurement of Rotational Iron Losses in Electrical Sheet,” IEEE
TRANSACTIONS ON MAGNETICS, Vol. 36, No. 5, Sep, 2000, pp. 3457-3459. [2]W. Arshad, etc, “Incorporating
lamination processing and component manufacturing in electrical machine design tools,” in Industry
Applications Conference, 2007. 42nd IAS Annual Meeting. Conference Records, 2007, pp. 94-102. [3]YouguangGuo, etc, “Measurement and Modeling of Rotational Core Losses of Soft Magnetic Materials Used in Electrical
Machines: A Review,” IEEE TRANSACTIONS ON MAGNETICS, Vol. 44, No. 2,Feb, 2008, pp. 279-291.

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Torque harmonics and reduction design characteristics of induction
motor for electric vehicle propulsion

Comparison on electromagnetic losses of super high speed PM motor/
generator with slot and slotless stators

MFL signal enhancement based on exponential smoothing

Non-contact magnetic evaluation of ferromagnetic plate and its
compensation of unknown air gap

Kyung-won Jeon1, Seungho Lee1, Yong-jae Kim2 and Sang-yong Jung1*
1
School of Electronic and Electrical Engineering, Sungkyunkwan Univ., Korea
2
Dept. of Electrical Engineering, Chosun University, Korea

This paper deals with torque harmonic characteristics of induction motor for electric vehicle (EV).
For calculate phase stator harmonic leakage flux of a three phase induction motor, an analysis method
is determine relationships with stator teeth design. In particular, torque harmonics including EMF
harmonics at whole speed ranges are analyzed by the finite element method (FEM). Torque harmoniccomponents are identified with Fourier fast transform (FFT). Torque harmonics are generated dueto the different phase windings interaction and they can be reduced by applying a stator teeth design.
The electromagnetic field and corresponding harmonics of an electrical machine are calculated using
the FEM, the harmonic winding factors show how the torque harmonics can be reduced significantly
by good stator teeth design. The novel design methods to compensate the specified torque harmonics
are proposed. Then, its effectiveness is clarified according to the representative control strategies for
induction motor such as maximum torque per ampere (MTPA) and flux-weakening control.
[1] Lee S., Kim Y.-J., Jung S.-Y., “Numerical Investigation on Torque Harmonics Reduction of Interior PM Synchronous
Motor With Concentrated Winding”, IEEE Trans on. Magnetics, vol.48, no.2, pp.927-930, Feb. 2012. [2] Yamazaki K.,
Suzuki A., Ohto M., Takakura T., Nakagawa S., “Equivalent Circuit Modeling of Induction Motors Considering Stray
Load Loss and Harmonic Torques Using Finite Element Method”, IEEE Trans on. Magnetics, vol.47, no.5, pp.986-989,
May. 2011. [3] Bianchi N., Alberti L., “MMF Harmonics Effect on the Embedded FE Analytical Computation of PM
Motors”, IEEE Trans on. Industry Applications, vol.46, no.2, pp.812-820, Mar-Apr. 2010.

314

The 19th International Conference on Magnetism

Jin Hak Jang1, Jian Li2 and Yun Hyun Cho1*
1
Dong-A University, Korea
2
Dong-A University, China

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Su-yeon Jeong1, Jong-hwa Kim2 and Doo-hyun Choi2*
1
Graduate School of Electrical Engineering and Computer Science, Kyungpook
National Univ., Korea
2
School of Electronics Engineering, Kyungpook National Univ., Korea
Nowadays, as industrialization is in progress worldwide and economy grows rapidly,
demand for the energy supply of oil and gas has also increased. Currently, over millionsof kilometers of underground gas pipeline has been established worldwide. The
maintenance of pipeline is needed for the efficient supply of energy, but in reality, it is
impossible for human experts to investigate all the underground pipelines in order toconfirm whether a pipe has deterioration or damage because of the pipe’s geographicalposition. So, automatic nondestructive testing methods by using MFL (magnetic
flux leakage) signal are currently studied actively to detect and extract defects on thepipeline. The raw signals acquired from MFL sensors contain the signals of defects, aswell as noise and distortion caused by various underground environments. In this paper,
MFL signal is enhanced by using several smoothing techniques. Through experiments,
it is confirmed that the distortion of raw signal by noise canceling can be reduced.

Young-hak Kim1 and Kwang-ho Shin2*
1
Pukyong National University, Korea
2
Dept. of Information and Communication Engineering, Kyungsung University,
Korea

This paper represents a magnetic hysteresis model-assisted measurement method
for non-contact evaluation of ferromagnetic plates in the case of the air gap between
the test sample and the sensor probe is unknown. Our method involves measuring
hysteresis loops from a test sample using a sensor probe in close proximity to thesample and measuring inductance spectra according to the various air gap. The sensor
outputs were simulated based on a magnetic hysteresis model (Jiles-Atherton model)
to describe the magnetic property of the sample. In this study, the measurement wasapplied to characterize a series of Fe-C samples. However, it is hard to confirm thepermeability of a sample when the air gap is unknown, since the magnetic resistanceof magnetic circuit composed of the sample and the sensor probe is affected by air
gap size. The main idea of our study is that the frequency spectrum of inductance ofthe magnetic circuit is unaffected when the air gap is adequately small, even if theamplitude of inductance is directly dependent on air gap. The magnetic hysteresis
measured with unknown air gap was compensated by measured inductance spectra,
and was found to agree with nonlinear FEM analysis.

July 8-13, 2012 Busan, Korea

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poster Presentation

poster Presentation

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The several analysis techniques of high speed induction motor forcopper die casting

Magnetoelectric CoFe2O4-PZT thin film composites grown by pulsed
laser deposition

M doping element localization by the molecular field theory in the
GaxFe2-xO3:M thin films

Optical properties of (SrMnO 3) n/(LaMnO 3) 2n superlattices: An
insulator-to-metal transition observed in the absence of disorder

Ioanna Giouroudi1*, Mohammed Alnassar2, Roland Groessinger3 and Juergen Kosel2
1
Institute of Sensor and Actuator Systems, Vienna University of Technology, Austria
2
Division of Physical Sciences and Engineering, King Abdullah University of Scienceand Technology, Saudi Arabia
3
Institute of Solid State Physics, Vienna University of Technology, Austria

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Magnetoelectric materials open the way towards new applications through controllingmagnetic or electric polarization with electric or magnetic field, respectively.
Ga0.6Fe1.4O3 is predicted magnetoelectric with non zero magnetization at room
temperature. High quality GFO thin films having similar magnetic properties tothose of the bulk materials have been produced only recently. However their electric
properties failed to be properly characterized until now because of important leakage
currents originating from a hopping mechanism between Fe2+ and Fe3+ within the
structure. Recently, we succeeded to strongly lower the leakage currents of these films
by chemical doping. The determination of the cationic distribution within the structure
is a key point for the knowledge of these phases, because it is at the origin of theevidenced magnetic and electrical properties of these materials. We present here an
original approach to determine the localization of the M doping element based on themolecular field theory. Different modeling associated with the different substitution
possibilities have been performed within the frame of this theory and are comparedwith the experimental values.

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Effect of magnetic reynolds number variation on MHD convection
inside an enclosure

Synthesis and magnetic property of multiferroic DyMnO 3nanoparticles in mesoporous silica

Interplay between magnetization and polarization in epitaxial(Ga,Fe)2O3 thin films with additional ion-substitutions into Fe sites

Mohsen Pirmohammadi*
MAPNA Group, Iran

Numerically investigation is carried out for magnetohydrodynamics natural convection
in an enclosure. The vertical walls are maintained isothermal at different temperatures
and the other walls are adiabatic. The magnetic field is applied horizontally. The nonlinear governing equations for the fluid flow and heat transfer are solved for threemagnetic Reynolds numbers (10-5, 10-3 and 0.1). The Rayleigh number, the Hartmann
number and the Prandtl number are considered 105, 80 and 0.01, respectively. A
finite volume code based on Patankar's SIMPLER method is utilized. It is found thatwhen the magnetic Reynolds number (Rem) is very low (10-5 and 10-3) the magnetic
field distribution in the cavity is not affected by flow field and as Rem increases themagnetic field in x and y direction is not constant. Also it is observed that as Rem
increases the rate of heat transfer changes.

Takayuki Tajiri1*, Kenta Hamamoto2, Yuhki Ando2, Hiroyuki Deguchi2, Masaki Mito2
and Atsushi Kohno1
1Faculty of Science, Fukuoka University, Japan
2
Faculty of Engineering, Kyushu Institute of Technology, JapanR. H. Shin1, J. H. Lee1, S. H. Oh2, W. Jo2*, C. Lefevre3, F. Roulland3, A. Thomasson3, C.
Meny3 and N. Viart3
1
Department of Physics and CNRS-EWHA International Research Center, Ewha
Womans University, Korea
2
Department of Physics, Ewha Womans University, Korea
3
Institute of Physics and Chemistry of Materials of Strasbourg, France

Andrea Perucchi1, Leonetta Baldassarre1, Alessandro Nucara2, Paolo Calvani2,
Carolina Adamo3, Darrell G Schlom3, Pasquale Orgiani4, Luigi Maritato4 and Stefano
Lupi5
1
Sincrotrone Trieste, Italy
2
CNR-SPIN and University of Rome 'Sapienza', Italy
3
Cornell University, USA
4
CNR-SPIN and University of Salerno, Italy
5
CNR-IOM and University of Rome 'Sapienza', Italy
We measure the optical conductivity, σ1(ω), of (SrMnO3)n/(LaMnO3)2n superlattices (SL)for n=1, 3, 5, and 8 and 10 < T < 400 K. Data show a T-dependent insulator to metaltransition (IMT) for n=3, driven by the softening of a polaronic mid-infrared band. At
n=5 that softening is incomplete, while at the largest-period n=8 compound the MIR
band is independent of T and the SL remains insulating. One can thus first observe the
IMT in a Manganite system in the absence of the disorder due to chemical doping.
Unsuccessful reconstruction of the SL optical properties from those of the original bulk
materials suggests that (SrMnO3)n/ (LaMnO3)2n heterostructures give rise to a novel
electronic state.
A. Perucchi et al., Nano Letters 10 (12), 4819-4823 (2010)

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Preperation of hexagonal YFeO3 powder and thin film

Hanju Lee, Kyoungchul Kim, Sujin Lee, Sul A Choi and Kiejin Lee*physics, Department of physics, Sogang university, Korea
In the past few years, multiferroic materials, characterized by coexistence of two or
more ferroicity, have attracted much attention due to their interesting properties. Amongthe magnetic ferroelectric materials, there is an important class, hexagonal manganeseoxides (RMnO3, R: rare-earth element), which have been extensively studied becauseof its unusual property. However, hexagonal iron oxides (RFeO3), which have a similar
structure to RMnO3, have been rarely reported due to a preferred formation to theorthombic or garnet phase. Here, we report that the hexagonal phase can be easily
prepared as a powder and thin film from chemical solution deposition method (CSD).
The crystallization temperature, crystal structure, magnetic and electric properties of
the thin film and powder were investigated. The hexagonal phase was observed at
750-800, and at higher temperature (>850) orthombic phase appeared. The observed
structure belonged to the paraelectric P63/mmc phase, rather than ferroelectric phase.
Samples showed paramagnetic property at room temperature caused by geometricallyfluctuated magnetism in tri-angular spin lattice.

Multiferroic compound DyMnO3 shows antiferromagnetic ordering with TN ~ 40 K and
Dy spin ordering below about 6 K. The ferroelectricity is attributed to lattice modulationaccompanied by the antiferromagnetic order. We are interested in the size effect on
DyMnO3 nanoparticles with particle size of a few nano-meters. We synthesized DyMnO3nanoparticles and investigated their magnetic property. The DyMnO3 nanoparticles weresynthesized in the pores of a mesoporous silica SBA-15 with pore diameter of about 8
nm. SBA-15 was used as a template to equalize the particle size in the fabrication of the
DyMnO3 nanoparticles. The X-ray diffraction pattern for DyMnO3 nanoparticles showssome broad Bragg peaks corresponding to crystal structure of DyMnO3 bulk crystals. The
size of nanoparticles was estimated to be about 10 nm based on the Bragg peaks and using
Scherrer’s equation. The temperature dependence of DC magnetic susceptibilities for thenanoparticles exhibited a magnetic irreversibility between field-cooled susceptibility andzero-field-cooled one below about 40 K and an increase in susceptibilities due to magnetic
ordering among the Dy spins below about 5 K. The magnetization curves exhibited
hysteresis loop below blocking temperature. DyMnO3 nanoparticles were successfully
synthesized with size of about 10 nm and showed superparamagnetic behaviors.

(Ga,Fe)2O3 (GFO) is a promising material for room-temperature multiferroic because of highmagnetic TC as 370 K when Ga = 0.6 and Fe = 1.4. However, multiferroic properties of GFO
in thin film type is controversial because most of polarization-electric field hysteresis curves
in GFO showed leaky behaviors due to large leakage current. In this research, we focused on
the improved magnetic and electric properties of GFO thin films as multiferroic by decreasing
their leakage current. The main origin probably lies on electron hopping between Fe3+ and Fe2+
octahedron sites which can co-exist due to charge neutrality by oxygen vacancy. Therefore, we
tried to decrease leakage current by substituting Fe2+ site with divalent cation. The ion-substituted
GFO thin films were epitaxially deposited along the b-axis by pulsed laser deposition at 750°C
for 15 min in oxygen partial pressure of 200 mTorr on SrRuO3/SrTiO3 (111) substrates. The
films showed the strongly reduced leakage current up to 5~6 order of magnitude. Magnetic
properties of the doped GFO thin films were investigated by SQUID measurement. Ferroelectric
polarization as a function of external field was measured in macroscopic and microscopic
schemes. Magnetoelectric interactions of the epitaxial thin-films will be addressed in this talk.

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Magnetic annealing effects on properties of the multilayer BaTiO3 /CoFe2O4 thin films

Magnetic properties of Co1-xMnxFe2O4 (x=0-0.5) - PZT thin films
fabricated by sol-gel spin coating method

Fabrication and characterization of heusler-alloy/perovskite
heterostructures
Kohei Kobayashi, Keita Sakuma*, Naoto Fukatani, Tetsuya Miyawaki, Kenji Ueda
and Hidefumi Asano
Nagoya University, Japan

Veerendra Kumar Guduru1, Alix Mccollam1, Sander Wenderich2, Michelle Kruize2,
Uli Zeitler 1*, Alexander Brinkman 2, Jan Kees Maan 1, Mark Huijben 2, Hans
Hilgenkamp2, Gertjan Koster2, Guus Rijnders2 and Dave Blank2
1
HFML/IMM,Radboud University Nijmegen, Netherlands
2
MESA+ Institute for Nanotechnology, University of Twente, NetherlandsCo(1-x)MnxFe2O4 (x=0-0.5) thin films were fabricated on PZT layer by sol-gel spin
coating method in order to investigation of influence of Mn-substitution in CoFe2O4
on the magnetic properties. The films were fabricated on the PZT layer which waspreviously fabricated on Pt(111)/Ti/SiO2/Si substrate using the same method. The phase
identification of the samples was studied by X-ray diffractometry analysis. Magnetic
properties of the samples were also measured using a vibrating sample magnetometer.

Multiferroic heterostructures composed of ferromagnetic half-metal and ferroelectric materials haveattracted significant interest due to the potential applications for nanoscale devices. Heusler-alloy /perovskite heterostructures are expected to emerge the interface magnetoelectric1) and tunnel electroresistance effect. In this study, to explore the potential of Heusler-alloy / perovskite heterostructures, wehave investigated multiferroic and transport properties of heterostructures composed of half-metallic
Heusler-alloy Fe2CrSi (FCS) and ferroelectric perovskite Ba0.7Sr0.3TiO3 (BSTO). BSTO was firstly
deposited on MgO and LaAlO3 substrates by magnetron sputtering, followed by the deposition of
FCS at 550-750°C. Structural characterization revealed that FCS grew epitaxially on BSTO with therelationship of BSTO(001)[100]||FCS(001)[110]. From M-H curve of the BSTO (100 nm) / FCS(150 nm) bilayer, saturated magnetization of 417 emu/cc was obtained. The ferroelectric propertiesof La0.7Sr0.3MnO3 (LSMO) / BSTO (100 nm) / FCS (50 nm) were measured, and the maximum
remaneant polarization was 73 μC/cm2. From these results, ferromagnetic and ferroelectric properties
were preserved in BSTO/FCS heterostructures. From the analysis of I-V characteristics, Schottkyemission was found to be a dominant leakage mechanism in LSMO / BSTO / FCS. The BSTO / FCS
heterostructure is a promising candidate for fabricating multiferroic devices.

A two-dimensional electron system (2DES) with remarkable electronic properties can berealized at the interface between two band insulators LaAlO3 and SrTiO3 (1). Dependingon growth conditions, this 2DES has been found to show a superconducting ground state(2), magnetic ordering (3) and even co-existence of these two properties (4-5). The originof the magnetic behaviour at the interface is still unclear, and to try to understand it wehave performed magneto-transport studies on LaAlO3/SrTiO3 heterostructures in highmagnetic fields up to 33 T, and low temperatures down to 0.3 K. We observed negative
magnetoresistance (nMR) which is nearly identical for all field orientations in the temperature
range from 4 K to 350 mK. This nMR could be related to reduced spin scattering due to thealignment of spins at the interface (3). At low magnetic fields, the nMR is very sensitive totemperature and at temperatures below 1 K an unusual time dependent magnetic hysteresis
appears for field below 3 T. We propose a magnetocaloric effect model to explain thehysteretic behaviour, and propose that the possible underlying origin of the hysteresis is theco-existence of ferro- and antiferromagnetic phases in the spin system.

1) K. Yamauchi et al., Appl. Phys. Lett. 91, 062506 (2007)

1) A. Ohtomo and H.Y. Hwang, Nature 427, 423, 2004. 2) N. Reyren et al., Science 317, 1196, 2007. 3) A. Brinkman et al.,Nature Materials 6, 493, 2007. 4) L. Li et al., Nat Phys 7 (10), 762-766, 2011. 5) J.A.Bert et al., Nat Phys 7 (10), 767-771, 2011.

Yuqiang Dai1, Jianming Dai1*, Xianwu Tang1 and Qiangchun Liu2
1
Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese
Academy of Sciences, China
2
School of Physics and Electronic Information, Huaibei Normal University, China
Multilayer BaTiO3/CoFe2O4 thin films are prepared via chemical solution deposition
method with and without magnetic field annealing process, respectively. The
microstructural, magnetic, dielectric and the ferroelectric properties of the films areinvestigated. It is observed that the dielectric constant, polarizations and magnetizationsof the multilayer thin films are improved with magnetic field annealing process.
Moreover, for the magnetic field annealing films, the saturation magnetization withmeasuring magnetic field vertical to the film surface is much higher than that parallelto the film surface.

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Christophe Lefevre1*, Ran Hee Shin 2, Ji Hye Lee 2, Seol Hee Oh 2, Alexandre
Thomasson1, Francois Roulland3, Christian Meny1, William Jo2 and Nathalie Viart3
1
CNRS, France
2
Department of Physics, Ewha Womans University, Korea
3
Universite de Strasbourg, France

The 19th International Conference on Magnetism

M. Khodaei, S. A. Seyyed Ebrahimi* and R. Vaghar
Center of Excellence for Magnetic Materials, School of Metallurgy and Materials,,
University of Tehran, IranJuly 13 (Fri)Do-kwan Hong1*, Jae-hak Choi1, Byung-chul Woo1, Dae-hyun Koo1 and Chan-woo
Ahn2
1
Korea Electrotechnology Research Institute, Korea
2
Dong-A University, The department of mechanical engineering, Korea

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Magnetic hysteretic effects in LaAlO3 /SrTiO3 Heterostructures

July 8-13, 2012 Busan, Korea

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poster Presentation
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Synthesis and magnetoelectric properties of multiferroic composites on
the cobalt ferrite - pzt system

Magnetisation in different multiferroic YMO (Yttrium Manganese
Oxide) thin films

Preparation and properties of inverse perovskite Mn3GaN thin films

Ferroelectric-domain-switching controlled magnetism in CoFeB/PMNPT multiferroic heterostructure

Recently Yttrium manganese oxides (YMO): hexagonal YMnO3 and orthorhombic
YMn2O5 have attracted considerable attention as both of these compounds exhibit
multiferrocity but the microscopic origins are different. Here we stabilize thin films ofdifferent phases of YMO by pulsed laser deposition from a single h-YMnO3 target andcharacterize them with various techniques and perform magnetization measurements.
It is observed that the phase stability and crystallinity of YMO thin films depend on
the substrate used and oxygen partial pressure (OPP). Oriented and polycrystalline
growth of h-YMnO3 and O-YMn2O5 phase film are observed on different substrates.
ZFC,FC (Magnetisation verses Temperature ) and MH magnetization measurementsof these multiferroic films were performed. All the multiferroic thin films show
the antiferromagnetic transition in ZFC measurements which is forbidden in FC
measurements. MH behavior at both sides of magnetic transitition is in good agreementin these multiferroic thin films.

There has been considerable interest in antiperovskite Mn3GaN because of its intriguing
physical properties such as negative thermal expansion, magneto-volume effect andpiezomagnetic effect(1). Mn3GaN is expected to be advantageous to fabricate thin-film
hybrid devices with various perovskite oxides, since it has a cubic antiperovskite structure
virtually identical with the perovskite oxides. However, there is no report on growthof Mn3GaN thin films and heterostructures. In this paper, we report on the preparationand properties of Mn3GaN thin films as well as ferroelectric Ba0.7Sr0.3TiO3/Mn3GaN
heterostructutes. Mn3GaN films were deposited on (001) SrTiO3 and LaAlO3 substrates at
450~650°C by ion beam sputtering of a sintered stoichiometric target. Ba0.7Sr0.3TiO3films
were prepared at 650~750°C by magnetron sputtering. In-plane and out-of-plane
X-ray diffraction analysis revealed that on SrTiO3 substrate Mn3GaN films were growncoherently with the in-plane lattice parameter aMGN of 0.3903 nm. On LaAlO3 substrate
a Ba0.7Sr0.3TiO3 layer and subsequently a Mn3GaN layer were grown epitaxially with therelationship of LaAlO3(001)[100]//Ba0.7Sr0.3TiO3(001)[100]//Mn3GaN (001)[100]. These
Mn3GaN thin films showed a metallic temperature dependence of resistivity with 0.8-0.9mΩcm at room temperature. It was found that the Ba0.7Sr0.3TiO3/Mn3GaN heterostructutes
exhibited a colossal magnetocapacitance effect.

In the present study we prepared and investigated the properties of bulk particulatecomposites made from cobalt ferrite (COF) and a soft piezoelectric material (PZT).
We chose COF and soft PZT due to their high magnetic and piezoelectric parametersrespectively. Composite samples, according to the formula xCOF(1-x)PZT with 0 ≤ x ≤1 were prepared by mixing the COF and PZT powders, pressing them as discs and thensintered at 1200 C for 3 hours. Structural, magnetic, piezoelectric and magnetoelectriccharacteristics of the sintered composites were then determined as a function of theweight fraction of COF into PZT and magnetic fields. The ME coefficient shows amaximum value about 70 mV/cmOe for composites containing 40 % COF and 60%
PZT, in a DC magnetic field of 3 kOe at a frequency of 1KHz of the ac magnetic field.
Some of the dielectric and piezoelectric properties of the composite samples, as afunction of the weight fraction x, were also determined. The results were discussed interms of the recent theoretical cube model of different connectivities of particles of one
phase embedded into the matrix of the second phase.

1. Bas B. Van Aken, Thomas T. M. Palstra, Alessio Filippetti and Nicola A. Spaldin,Nature
Materials,Vol 3, 2004, pp.164-170 2 L. C. Chapon, P. G. Radaelli, G. R. Blake, S. Park and S.W.
Cheong, Phys.Rev.Letter 96, 097601 (2006) 3. W. Prellier, M P Singh and P Murugavel, J. Phys.:
Condens. Matter 17 (2005) R803-R832 4. A Munoz et al 2002 J. Phys.: Condens. Matter 14 3285

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Detailed structural study of BiFeO3/SrRuO3 heteroestructures grown
on SrTiO3 (001) substrates

Dependence of magnetoelectric response on magnetostrictive content
in composite multiferroics

Ferroelectric and magnetic properties of BiMnO3 thin films

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Magnetoelectric multiferroics exhibit a strong coupling between ferromagnetic and ferroelectricordering. The coupling between these two types of orderings may occur naturally or be mediated via
mechanically. This coupling is very weak in single phase multiferroics. The design and investigationof composites of magnetostrictive and piezoelectric phases have shown magnetoelectric couplingorders of magnitude higher than that of single phase multiferroics. The mechanical deformationin magnetostrictive and piezoelectric phases results in the coupling between the two constituents.
The multiferroic CoFe2O4-BaTiO3 (CFO-BTO) composites with nanoscale mixture of the twoconstituents were prepared by solgel process. Four different compositions, with varying percentage
of constituents, were investigated. X-ray diffraction revealed the coexistence of the two phases.
Magnetic properties of the CFO-BTO nanocomposites were examined which were consistent withthe composition. The magnetoelectric coupling between CFO and BTO was demonstrated by an
external magnetic field induced change in capacitance. The magnetoelectric coupling was found to
be not only dependent on the applied magnetic field but also on the composition of the composites.
It has a nonlinear dependence on magnetostrictive content.

Multiferroic materials have attracted much attention due to their interesting new physics and potential
applications in new multifunctional devices. In multiferroic materials, the magnetization can be tuned byelectric fields, which open a new way to reach high integration density and low power consumption in
information storage. In the shorter term, niche applications are more likely to emerge in the two-phasesystems [1], so there have been lots of work on the electric-field control of magnetism via the piezostrain in ferromagnet-ferroelectric heterostructures[2, 3]. However, the reports related to magnetoelectric(ME) effect via ferroelectric domain switching are still limited. Thus, we have studied the electric-field
control of magnetism in Co20Fe40B20/Pb(Mg1/3Nb2/3)0.7Ti0.3O3(PMN-PT)(001) two-phase-system. Nonvolatile and volatile changes of magnetization related to different types of ferroelectric domain switchingwere found and the ratio between them changes with temperature. The angular-dependence of electricfield control of magnetism indicates that some magnetic domains rotate 90°, which is consistent with
our in situ electric-field-dependent magnetic force microscopy data. The results were explained byconsidering the ferroelectric domain switching induced magnetic anisotropy. This work is helpful forunderstanding the coupling between magnetism and ferroelectric domain switching.
[1] W. Eerenstein et al., Nature 442, 759 (2006). [2] C. Thiele et al., Phys. Rev. B 75, 054408 (2007).
[3] J. J. Yang et al., Appl. Phys. Lett. 94, 212504 (2009).

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Mohsin Rafique1*, Syed Qamar Ul Hassan1, Muhammad Saifullah Awan2 and Sadia
Manzoor1
1
Physics, COMSATS Institute of Information Technology, Islamabad, Pakistan
2
Center for Nano and Micro Devices (CNMD), COMSATS Institute of Information
Technology, Islamabad, Pakistan

Peisen Li1, Yonggang Zhao1*, Sen Zhang1, Lifeng Yang1, Syed Rizwan2, Qianping
Chen1, Jiawei Wang1 and Xiufeng Han2
1
Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics,
Tsinghua University, China
2
Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, China(4) P. Lukashev, et al., Phys. Rev. B 78 184414 (2008)

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Claribel Dominguez1, John Edward Ordonez1, Maria Elena Gomez1, Wilson Lopera1 and Pedro Prieto2
1
Thin Film Group, Department of Physics, Universidad del Valle, A.A. 25360, Cali, Colombia
2
Center of Excellence for Novel Material CENM, Calle 13 # 100-00 320-1026, Cali, Colombia

July 13 (Fri)Manish Kumar*, R.j. Choudhary and D.m Phase
UGC-DAE CSR, UGC-DAE CSR Indore,Madhya Pradesh, India

Hiroki Tashiro, Ryosuke Suzuki*, Tetsuya Miyawaki, Kenji Ueda and Hidefumi
Asano
Department of engineering, Nagoya University, Japan

Min-hwa Jung and Yoon-hee Jeong*
Department of Physics, Pohang University of Science and Technology, Korea
BiMnO3 is heralded widely as a rare case of multiferroicity with simultaneous
existence of both ferroelectricity and ferromagnetism. Ferroelectricity in BiMnO3,
however, still remains controversial as various results do not converge on a definite
conclusion [1-3]. In order to shed light on this issue, we have synthesized BiMnO3
thin films on Nb:SrTiO3 substrates by PLD method. Measurements of various physicalproperties such as dielectric properties, PE hysteresis loop, and piezoelectric d33 do
not show any significant evidence of ferroelectricity for all films. Thus, we are led toconclude that BiMnO3 is not ferroelectric in accordance with a theoretical calculation[4-5]. Also of interest is the ferromagnetism of BiMnO3 and, in particular, its magnetic
easy direction. We also investigate the magnetic properties of the films with in and outof the plane orientations. From these measurements, the magnetic easy direction isinferred for the monoclinic phase BiMnO3. In conclusion, the present study offers a fullcharacterization of the ferroelectric and magnetic properties of multiferroic BiMnO3.
[1] T. Kimura, S. Kawamoto, I. Yamada, M. Azuma, M. Takano, and Y. Tokura, Phys. Rev. B 67,
180401 (2003) [2] M. Grizalez, E. Martinez, J. Caicedo, et al.,, Microelectronics Journal 39, 1308
(2008) [3] A. A. Belik, S. likubo, T. Yokosawa, et al., J. Am. Chem. Soc. 129.971 (2007) [4] A.J. Hattand N.A. Spaldin, Eur. Phys. J. B 71,435 (2009) [5] Shichidou T, Oguchi T (2006) Multiferroicity of
BiMnO3 reexamined from first principles. Presented at APS meeting March Meeting, Baltimore, MD.

Multiferroic properties of BaTiO3 - Zn1-xCoxO multilayer thin films

Anuraj S1, Shivaraman Ramaswamy1*, Helen Annal Therese1, C Gopalakrishnan1 and
A Karthigeyan2
1Nanotechnology Research Center, SRM University, India
2
Department of Physics and Nanotechnology, SRM University, India
Near room temperature ferroelectric and ferromagnetic hysteresis is observedin horizontal superlattice system of BaTiO3 - Zn1-xCoxO (x > 0.2) [BTO - ZCO]
multilayered thin films. The multilayered thin films were prepared on Si substrateby alternate deposition of BTO and ZCO layers to a thickness of 350 nm using
pulsed laser deposition technique. Analysis of the prepared thin film by x-ray powder
diffraction and electron microscopic techniques confirm the polycrystalline natureof the multilayered film. Dielectric and the magnetic properties studied on themultilayered thin film at different temperatures exemplified the coupling between theirdual order parameters and it is mediated through an electric field effect at the interface.
1. Multiferroic properties of Bi0.8La0.2FeO3/CoFe2O4 multilayer thin films. Shan-Tao Zhang, Yi
Zhang, Zhen-Lin Luo, Ming-Hui Lu, Zheng-Bin Gu, Yan-Feng Chen., Applied Surface Science 255(2009) 5092-5095. 2. Multiferroic BaTiO3-CoFe2O4 Nanostructures., H. Zheng, J. Wang, S. E.
Lofland, Z. Ma, L. Mohaddes-Ardabili, T. Zhao, L. Salamanca-Riba, S. R. Shinde, S. B. Ogale, F.
Bai, D. Viehland, Y. Jia, D. G. Schlom, M. Wuttig, A. Roytburd, R. Ramesh. Science 303, (2004) 661.

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Lattice engineering on transition metal oxide thin film
Chang Uk Jung*

Raman analyses of oxygen defects in hexagonal HoMnO3 thin films

Ferroelectric polarization induced magnetic anisotropy in Co40Fe40B20/
YMnO3 multiferroic heterostructure

Study of structural phase transition and multiferroic properties ofSamarium substituted BiFeO3 thin films

Department of Physics, Hankuk University of Foreign Studies, Korea

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The 19th International Conference on Magnetism

Xiang-bai Chen1, Nguyen Thi Minh Hien2, D. Lee3, T. W. Noh3 and In-sang Yang2
1
Konkuk University, Korea
2
Ewha Womans University, Korea
3
Seoul National University, Korea
Oxygen defects are usually unavoidable in synthesizing oxide thin films. In this study,
we investigated the origins of the oxygen defects in hexagonal manganites HoMnO3
epitaxial thin films through Raman spectroscopy. We found that the oxygen defects inhexagonal HoMnO3 thin films have different effects on different phonon modes andon magnon scattering. Our analyses indicated that the oxygen defects in hexagonal
HoMnO3 thin films would be mainly correlated with the basal O3 and/or O4 oxygenions. Furthermore, our analyses of oxygen defects predicted that the Mn 3d orbitals
would be more strongly hybridized with the apical O1 and/or O2 2p orbitals than thebasal O3 and/or O4 2p orbitals. This prediction is consistent with our resonant Raman
scattering study and earlier first-principle calculations of electronic structures ofhexagonal manganites.

Jiawei Wang1, Yanggang Zhao1*, Peisen Li1, Sen Zhang1, Syed Rizwan2, Xiufeng
Han2, Xuefeng Sun3, Yuanjun Yang4, Qianping Chen1 and Xin Zhang1
1
Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua
University, China
2
Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, China
3
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science andTechnology of China, China
4
National Synchrotron Radiation Laboratory, University of Science and Technology of China, China

Multiferroic (MF) materials have attracted much attention due to their interesting new physics and potential
for exploring novel multifunctional devices. The research of magnetic anisotropy in MF heterostucture is an
important aspect. One of the key issues in the MF heterostructures is the effect of ferroelectric (FE) polarization onmagnetic anisotropy. So far, however, a lot of work has been carried out on MF heterostructures with crystalline
ferromagnetic films. Actually, MF heterostructures involving amorphous ferromagnetic materials are also very
interesting due to the absence of magnetocrystalline anisotropy and low coercive force Hc. We have studied thecoupling between amorphous magnetic Co40Fe40B20 (CFB) and YMnO3 (YMO) in the heterostructure with CFB
film grown on YMO (110) substrates. A large uniaxial magnetic anisotropy (UMA) was observed from room
temperature to 10 K with magnetic easy axis (MEA) along the polarization direction of YMO. More interestingly,
the angular dependence of coercive force Hc shows a non-monotonous behavior. The results were discussed
by considering the coupling between the FE domain in YMO and magnetism in CFB. This work is helpful forunderstanding the effect of FE polarization on magnetic anisotropy in MF heterostuctures.

July 13 (Fri)C. Miclea1*, L. Amarande1, L. Trupina1, M. Cioangher1, C. T. Miclea2 and C. F.
Miclea1
1
National Institute for Materials Physics, Bucharest, Romania
2
Hyperion University, Bucharest, Romania

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poster Presentation

Mahdiyar Bagheri, Shivaraman Ramaswamy*, Helen Annal Therese and C
Gopalakrishnan
Nanotechnology Research Center, SRM University, India
In this study we report the effect of samarium substitution on the structure andmultiferroic properties of BiFeO3 thin films. The Bi1-xSmxFeO3 thin films of various
thicknesses were sputter deposited on to Si substrates. Magnetic and electric propertiesof the thin films were studied by vibrating sample magnetometer, impedance analyzer
and I-V characterizer. Samarium substitution-driven structural phase transition wasstudied by x-ray diffraction at room temperature. Samarium doping was found to
modify structural properties of Bi1-xSmxFeO3 thin film. The phase transition was foundto destruct cycloid spin structure of BiFeO3 that resulted in amplified magnetoelectricinteractions. The substitution of Sm was found to be a promising way to control the
conductivity and leakage current of film by suppressing the formation of oxygen
vacancies.
1. Hiroshi Uchida, Risako Ueno, Hiroshi Funakubo, and Seiichiro Koda, J. Appl. Phys.100, 014106(2006) 2. E. Ohshima, Y. Saya, M. Nantoh and M. Kawai Solid State Commun. 116 (2000), p.73.

July 8-13, 2012 Busan, Korea

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poster Presentation

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Study of ferroelectricity in Eu substituted BiMnO3 films

Charge disproportion, spin and orbital states in the tri-layered
nickelate La4Ni3O8 from first principles

Fermi surface study on the rattling-induced superconductor KOs2O6

Shivaraman Ramaswamy*, Helen Annal Therese and C Gopalakrishnan
Nanotechnology Research Center, SRM University, India
In this paper, we report evidence of ferroelectricity in europium substituted manganite(Bi1-xEuxMnO3) thin films synthesized via sol gel synthesis and dip coating method
on a single-crystal (1 0 0) substrates. The films were post treated by annealing at
500°C. X-ray diffraction measurements were used to analyze the crystal structure
and phase purity of the thin films. AFM measurements were performed to investigate
surface morphology; quantitative values of roughness and grain size which are in therange between 30 and 150 nm. Ferroelectric characterization was conducted at low
temperatures and at 300 K. Hysteresis loops (polarization vs. voltage) were obtained,showing enhanced ferroelectricity at room temperature in the 10% Eu substituted
BiMnO3 film. Resistance vs. temperature measurements were performed, whichindicated this to be very robust insulating material. Moreover, all films show small
dielectric dispersion and dielectric loss.

Hua Wu*Department of Physics, Fudan University, Shanghai, China

Several mixed-valent layered nickelates were synthesized very recently [1,2], inthe effort to search an analog to the hole doped cuprates. Here we have studied
the electronic structure and the magnetism of the tri-layered La4Ni3O8, using theconfiguration-state constrained LDA+U calculations. Our results show that La4Ni3O8
would be a charge homogeneous low-spin half metal in the ferromagnetic state. In
contrast, the C-type antiferromagnetic state is insulating and has a charge disproportionof the formal 2Ni+/Ni2+ type, thus accounting for several experimental observations.
The high-spin (S=1) Ni2+ state and its orbital configuration are found to be against
the crystal-field level picture. We note that it would be interesting to explore, fornovel magnetism and superconductivity, the Ni2+ low-spin S=0 state and the partiallyoccupied x2-y2 band structure of the Ni+/Ni2+ mixed-valent nickelate.

SB08

Taichi Terashima1*, Nobuyuki Kurita1, Andhika Kiswandhi2, Eun-sang Choi2, James S.
Brooks2, Kota Sato3, Jun-ichi Yamaura3, Zenji Hiroi3, Hisatomo Harima4 and Shinya
Uji1
1
National Institute for Materials Science, Japan
2
National High Magnetic Field Laboratory, USA
3
ISSP, Univ. of Tokyo, Japan
4
Graduate School of Scienece, Kobe Univ., Japan

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[1] V. V. Poltavets et al., Phys. Rev. Lett. 104, 206403 (2010). [2] V. V. Poltavets, M. Greenblatt, G. H.
Fecher, and C. Felser, Phys. Rev. Lett. 102, 046405 (2009).

Magnetic properties and structure evolution along R2RhIn8 series

Petr Cermak1*, Marie Kratochvilova1, Jan Prokleska1, Marie-helene Lemee-cailleau2,
Bachir Ouladdiaf2 and Pavel Javorsky1
1
Department of Condensed Matter Physics, Charles University in Prague, Czech
Republic
2
Institut Laue-Langevin, France
Intermetallic compounds R2RhIn8 (R = rare earth) are structurally related to a class of Ce-based
heavy-fermion superconductors. Study of their magnetic structure and behavior is important forunderstanding mechanism of the unconventional heavy-fermion superconductivity. We havesuccessfully grown single crystals of these compounds with R = Nd, Tb, Dy, Ho, Er and Tmfrom the melt in the In flux. We report the evolution of the magnetic properties of this series. All
studied compounds exhibit antiferromagnetic behavior with the Neel temperatures up to 43 K
for Tb compound. Magnetization and specific heat measurements have revealed metamagnetictransitions to another antiferromagnetic phase for Tb, Dy and Ho compounds. We show detailed
magnetic phase diagrams for all these compounds and compare with results reported for
Nd2RhIn8 [1]. Low temperature magnetic structures were studied by neutron diffraction at theInstitute Laue-Langevin on VIVALDI Laue diffractometer and four-circle D10 diffractometer.
From these experiments, propagation vector k = (1/2, 1/2, 1/2) and magnetic structure of studiedcompounds were determined. We present comparison of our results with the magnetic structureof Ce2RhIn8 and other isostructural compounds from RRhIn5 [2] and R2CoGa8 [3] series.
[1] J. G. S. Duquea, et al., J. Magn. Magn. Mater. 323 (2011) 954-956 [2] N. V. Hieu, et al., J. Phys.
Soc. Japan 75 (2006) 074708 [3] D. A. Joshi Phys. Rev. B 77 (2008) 174420

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Experimental evidence for Exchange bias in polycristalline BiFeO3 /Ni81Fe19

Carrier doping to the novel layered nickelate

Transient analysis of the current density and temperature distributionof the MgB2 superconductor in the He atmosphere

Second magnetization peak and magnetic field distribution insuperconductor

Multiferroic (MF) materials have been the subject of extensive studies in the past decade since itallows a coupling of ferroelectric and magnetic orders in a single phase. Among all the multiferroic
materials studied so far, BiFeO3 (BFO) exhibits the coexistence of ferroelectric and antiferromagnetic
orders at room temperature. Magnetic heterostructures with a ferromagnetic thin film exchange
biased to an antiferromagnetic-BFO film may allow an electric field influence on the magnetic
hysteresis properties of the bilayer. The exchange coupling and exchange bias involving MF/
F systems has previously been obtained with either epitaxial BFO [1] or BFO bulk materials [2].
However, the exchange coupling between a ferromagnetic film and a polycrystalline multiferroic was
not studied. Furthermore, previous studies have shown that polycrystalline BFO exhibits multiferroic
properties. We report experimental evidence for exchange bias in polycrystalline BiFeO3/Ni81Fe19
bilayers, grown by RF sputtering [3]. Our measured 17 Oe shift corresponds to exchange energy perunit area of interface coupling the two films of 11×10-3 erg/cm2 comparable with similar epitaxial
grown systems. The azimuthal behavior of longitudinal and transverse components of magnetization
reveals the presence of induced unidirectional and biquadratic anisotropies.

Recently a series of new layered nickelate (Lnn+1NinO2n+2) (Ln=La, Nd) has beensynthesized with using CaH2 as a reducing agent or hydrogen gas. The crystal structureis the analogue of so-called Ruddlesden-Popper phase, and basically the same crystal
structure with high-Tc superconducting cuprate, consisting of insulating block layer
and two-dimensional NiO2 layer. Interestingly Ni ions in these materials can have thesame electronic configuration with Cu2+ 3d9 in high-Tc cuprate, suggesting that this is apromising candidate for another high-Tc material. Therefore, we have tried to carrierdope to Ln and Ni sites of (Lnn+1NinO2n+2) (Ln=La, Nd) with n=2, 3, and ∞ using
Ca, Cu, Co ions in order to tune the electronic state of Ni. If the Ni electronic stateis adjusted to 3d9.15 or 3d8.85 which are the same cases with those of optimum doping
level for the emergence of high-Tc in cuprate. We will present the detailed result in theconference.

[1] H. Bea et al., Phys. Rev. Lett. 100, 017204 (2008) [2] J. Dho et al., J. Appl. Phys. 106, 073914(2009) [3] T. Hauguel et al., J. Appl. Phys. 110, 073906 (2011).

In this paper, the transient analysis is carried out for the type II superconductor material
MgB2 in liquid Helium atmosphere. The strong nonlinearity of the E-J relationshipnear critical current poses a challenge in such calculations for getting practical values
in other models employed for Ohmic materials. For this reason, the curl-curl equationand the variable magnetic field quantity are employed as the unknown in solving thePDE by the finite element method. The temperature distribution by the generated heatin the superconductor is calculated by the coupled conduction and convection module.
Using the nominal experimental values for the exponential current fundamental
characteristics like the magnetic flux, current distribution density and temperature
profile in the superconductor are calculated for 2D axis symmetric cylindrical cases.
The study gives the limiting current values to avoid heat generation and shows thedevelopment of the mixed state and finally the normal state with the time. Effect ofchanging the magnitude of current and time constant is also studied. Ripple effect at thesurface is observed due to difference in the inner and outer magnetic flux distribution.

Denis Gokhfeld
L.V. Kirensky Institute of Physics, Russia

The peak effect on M-H loop of superconductors is analyzed within the frameworkof the extended critical state model (ECSM) [D. M. Gokhfeld, D. A. Balaev, S. I.
Popkov, K. A. Shaykhutdinov, M. I. Petrov, Physica C 434, 135 (2006)]. The second
magnetization peak is referred to the vortex lattice transition or the normal phase riseoccurred at a certain magnetic field value. According to ECSM, these processes extend
from the surface of a sample (or a granule) to inside due to the magnetic field gradient.
Any experimental M-H loops are fitted by assigning the appropriate distributionof the magnetic field in the sample and the field dependence of the critical current
density. ECSM predicts that the asymmetry of M-H loop produces the mismatch of thepeak positions in the field increasing and decreasing branches. The peak in the field
increasing cycle is situated at lower H value than one in the field decreasing cycle.

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Parit variation in the rectangular array of periodic holes onsuperconducting thin film

Occurrence of superconductivity and structural variations in the Sr1-xT22xGe2 layer system (T = Ni, Pd, and Pt; x ≥ 0)

Meissner-like effect on normal- superfluid interface of imbalanced
Fermi gas

Superconductivity in LuGe2 single crystals

Kamran Muhammad1* and Qiu Xiang Gang2
1
Physics, COMSATS Institute of IT, Islamabad, Pakistan
2
Institute of Physics, Chinese Academy of Sciences, Beijing, China

Superconductivity has been full of surprises and wonder. One of the most elegant
properties of superconductors is the quantization of magnetic flux in units of φ0=h/2e,where h is the Planck constant of quantum mechanics, and 2e the electron-pair charge
serving the fundamental building block of the superconducting condensate. Here we
report our discovery of a new twist of this phenomenon in a film geometry perforated
with a periodic lattice of sub-micron holes, a variation of the flux quantization based on
the parity of the number of the flux quanta. Measured in terms of magneto-resistanceat temperatures just below the transition temperature of the bulk superconductor, wefind that superconductivity is most enhanced at odd multiples of the flux quantum.
We explain the phenomenon by noting that thermal quasi-particles, which see thesuperconducting flux quantum only as half, are in fact suppressed at these flux values.
In fields larger than the thermodynamic critical field, where quasi-particles dominate,magneto-resistance minima only occur at such odd values.

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H. M. Iftekhar Jaim1 and Klaus Barner2
1
Department of Mechanical, Material and Aerospace Engineering, University ofCentral Florida, USA
2
Department of Physics (4 Physik),, University of Gottingen, F. Hund Platz 1, 37077
Gottingen, Germany

The 19th International Conference on Magnetism

H. C. Ku1, I. A. Chen1, C. H. Hung1, C. Y. Lin1, S. J. Wang1, Y. B. You1, M. F. Tai1 andY. Y. Hsu2
1
Department of Physics, National Tsing Hua University, Taiwan
2
Department of Physics, National Taiwan Normal University, Taiwan

Superconducting transition temperature Tc of the body-centered-tetragonal (bct)122 Sr(Ni1-yPdy)2Ge2 (0 ≤ y ≤ 1) layer system (space group I4/mmm) increases
monotonically from 0.87 K for 3d-Ni SrNi2Ge2 to 3.12 K for 4d-Pd SrPd2Ge2.
However, due to larger atomic radius of 5d-Pt, the bct stoichiometric Sr(Pd1-yPty)2Ge2
phase (I4/mmm) is unstable and a structural transformation to a vacancy stabilized
superstructure Sr1-x(Pd1-yPty)2-2xGe2 with orthorhombic space group Pmna may beformed. Trace of superconductivity with Tc ranging from 5-10 K in the Sr1-xPt2-2xGe2
system was observed but very difficult to be stablized. This structural transformationis very similar to the high temperature superconducting system K1-xFe2-2xSe2 with I4/
mmm and two superstructure space groups Pmna and I4/m, where superconductivity
Tc up to 32 K was reported only in the bct I4/m system. This work was supported by
Grant No. NSC98-2112-M-007-013-MY3 of National Science Council of Republic ofChina.

Neda Ebrahimian* and Mohammad Mehrafarin
Physics Department, Amirkabir University of Technology,Tehran 15914, Iran

The observation of phase separation between the superfluid (SF) core and a normal (N) shell aroundthe core in ultra-cold Fermi gases has been reported by the new experiments of MIT and Ricegroups[1-2]. Much researches have been done about the N-SF interface[3-5]. In this article, we
examine the N-SF interface of a imbalanced Fermi gas with two spin species, in the presence of a
weak magnetic field. In our analysis, we consider a constant magnetic field in the N side and anticipate
the possibility of the Meissner-like effect in the SF side. We take into account the various scattering
regions of the BCS regime and analytically obtain the transmission coefficients by using the perturbed
Bogoliubov equations. It suffices to remark that the leading order term in transmission coefficients are
independent of the energy of incident quasiparticles. Then, we calculate the heat conductivity acrossthe interface at sufficiently low temperatures. We describe how the heat conductivity is affected by the
Meissner effect and the species imbalance. Also the relation between the additional heat conductivity
and penetration depth is obtained. The corresponding graphs is also plotted and discussed.
Furthermore, we show the dependence of the heat conductivity on average chemical potential.
References: [1] G. B. Partridge, W. Li, R. I. Kamar, Y. A. Liao, and R. G. Hulet, Science 311, 503 (2006). [2] M.
W. Zwerlein, A. Schirotzek, C. H. Schunck, and W. Ketterle, Science 311, 492 (2006). [3] B. Van Schaeybroeck
and A. Lazarides, Phys. Rev. Lett. 98, 170402 (2007). [4] N. Ebrahimian, M. Mehrafarin, and R. Afzali,
Physica B 407, 140 (2012). [5] N. Ebrahimian, M. Mehrafarin, and R. Afzali, To be published Physica C:
Superconductivity (2012).

July 13 (Fri)July 13 (Fri)Tony Hauguel, Souren P Pogossian, David Toyo Dekadjevi*, Jean-philippe Jay,
Mikhail Indenbom, David Spenato and Jamal Ben Youssef
Laboratoire de Magnetisme de Bretagne, CNRS-Universite Europeene de Bretagne,
FranceYoshiki Sakurai, Yoshihide Kimishima and Masatomo Uehara*
Yokohama national university, JapanN. H. Sung1, A. I. Coldea2, S. K. Choi2, H. Kim3,4, R. Prozorov3,4, and B. K. Cho1,5*
1School of Materials Science and Engineering, Gwangju Institute of Science andTechnology (GIST), Gwangju 500-712, Korea
2
Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1
3PU, United Kingdom
3
The Ames Laboratory, Ames, Iowa 50011, USA
4
Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011,
USA
5
Department of Photonics and Applied Physics, Gwangju Institute of Science andTechnology (GIST), Gwangju 500-712, Korea
Superconducting binary germanide LuGe2 single crystals were synthesized using ahigh-temperature metal flux method. Several shiny plate-like single crystals wereobtained and the compound has the orthorhombic ZrSi2-type structure (a = 3.9817 Å, b
= 15.5573 Å, c = 3.8477 Å). Superconducting phase transition temperature at Tc = 2.35
K was confirmed by temperature- and magnetic-field-dependent magnetization, andelectrical resistivity measurement. In addition, we observed anomalous phase transitionat around T = 4 K, and confirmed the conventional superconductivity by heat capacity
measurement. Including these results, we will discuss the nature of LuGe2 single
crystals in detail.

July 8-13, 2012 Busan, Korea

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Mutual interplay of magnon BEC and superconductivity
Zygmunt Bak*

Superconductivity and structural transition of RPt2Si2 ( R = Y, La, Lu )Magnetic field-induced odd-frequency superconductivity in s-wave
superconductors

Superconducting fluctuations near the Mott critical point

We present a theoretical study of the mutual interplay of magnon Bose-Einsteincondensate and superconductivity /SC/, provided that they are simultaneously present.
As a rule these phenomena are treated separately but it is evident that , at least in thecase of triplet SC, there arises coherence in the electron as well as in the magnetic
system. Therefore it is reasonable to assess whether magnon BEC can facilitatetransition to the superconducting state. Such situation should arise when the electron
pairing arises due to the magnetic interactions . In this case electron pair is accompanied
by a cloud of magnons and below critical temperature there arises composed electronmagnon condensate. We point out that there are experimental evidences that magnetic
coherence reduces or even switches off the destructive effect of magnetic excitations
on SC. We prove that in the case of triplet superconductivity there should appear thequadrupolar coherence and what’s more quadrupolar interactions contribute to theelectron pairing. We give arguments that Josephson tunneling and “second sound”
experiments in magnon and electron condenstes with various junction and setups canserve as a cross-tests verifying/falsifying hypothesis that in some systems SC is basedon magnetic interactions.

The RPt2Si2 compounds, where R stands for a rare-earth element, have a tetragonal
CaBe2Ge2-type structure. LaPt2Si2 and YPt2Si2 are superconductors with Tc~2
K[1]. On the other hand, the compounds with R = La and Pr show anomalies in thetemperature dependence of electrical resistivity[2,3]. These compounds are metallic
but the resistivity shows a step at T* ~ 110 K, which is attributable to a charge density
wave (CDW) transition. In order to detect a periodic lattice distortion due to CDW,
we performed selected area electron diffraction (SAED) and X-ray diffraction (XRD)
measurements at low temperatures. It was found that (2 2 0) reflection peak was split
into two sub-peaks with equal intensity below T* in XRD measurements. This factindicates that LaPt2Si2 has an orthorhombic symmetry at low temperatures. The SAED
patterns show (n/3 0 0) superlattice reflections with n = 1 and 2 below T*. These results
strongly support the formation of CDW in LaPt2Si2. In contrast, we did not observe
any anomalies in the temperature dependence of resistivity except the superconducting
transition for YPt2Si2 and LuPt2Si2. These results are suggestive of no significant
relation between CDW and superconductivity in the RPt2Si2 compounds.
[1] R.N. Shelton et al, Solid State Commun. 52 (1984) 797. [2] F C Ragel, et al , J. Phys. Condens.
Matter 20 (2008) 055218. [3] M. Kumar et al. Phys. Rev. B 81 (2010) 125107.

July 13 (Fri)2

3

Masashige Matsumoto *, Mikito Koga and Hiroaki Kusunose
1
Department of Physics, Fuclty of Science, Shizuoka University, Japan2
Department of Physics, Fuculty of Education, Shizuoka University, Japan3
Department of Physics, Ehime University, JapanThe wavefunction of the Cooper pair of the conventional BCS state is characterized
by the even parity (s-wave) and spin singlet state. It is well known that an external
magnetic field modifies the wavefunction of the Cooper pair and breaks theconventional BCS superconducting state. We find that the wavefunction of themodified Cooper pair contains a spin triplet component with the s-wave orbital
symmetry. While the spin triplet s-wave Cooper pair is forbidden owing to the fermion
property, it is permitted in the generalized theoretical framework containing the oddfrequency dependence of the order parameter. We investigate this point on the basis of
the self-consistent calculation in the Eliashberg theory and find that the odd-frequency
order parameter coexists with the even-frequency one [1]. We also report how physicalproperties are affected by the induced odd-frequency superconducting order parameter[2].
[1] M. Matsumoto, M. Koga, and H. Kusunose, J. Phys. Soc. Jpn. Vol. 81, 033702 (2012).
[2] H. Kusunose, M. Matsumoto, and M. Koga, Phys. Rev. B Vol. 85, 174528 (2012).

Moon-sun Nam1, Cecile Meziere2, Patrick Batail2 and Arzhang Ardavan1
1
The Clarendon Laboratory, Department of Physics, University of Oxford, United
Kingdom
2
Laboratoire MOLTECH-Anjou, UMR 6200 CNRS-Universite d'Angers, 2 Boulevard
Lavoisier, F-49045 Angers, France
The Nernst effect, the voltage that occurs transverse to crossed temperature gradient andmagnetic field applied to a conductor, is a sensitive probe of superconducting fluctuations inunconventional superconductors such as the high-Tc cuprates [1] and organic superconductors[2]. The isostructural kappa-phase organic compounds (BEDT-TTF)2X offer a series ofmaterials ranging from weakly correlated superconductors (X = Cu(NCS)2) through strongly
correlated superconductors (X = Cu[(N(CN)2]Br) to Mott insulators (X = Cu[(N(CN)2]
Cl) as the bandwidth decreases and the importance of correlations increases. We previously
showed that while there are no fluctuations significantly above Tc in the weakly correlated
superconductor, there are strong superconducting fluctuations at temperatures up to 50% above
Tc in the strongly correlated superconductor [2], suggesting that the proximity of the Mott statedrives the fluctuating state. Here, by alloying the strongly correlated and the Mott insulating
materials, we tune the system towards the Mott critical point. Superconductors in the vicinityof the critical point exhibit a large and magnetic-field-dependent Nernst effect, characteristic ofsuperconducting fluctuations, at even higher temperatures. The effect is apparent over the wholetemperature range for which the conductivity is metallic, up to 50K, about six times Tc.
[1] Y. Wang, et al., Phys. Rev. B 73, 024510 (2006) [2] M.-S. Nam et al., Nature 449, 584 (2007)

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Studies of the absolute value of lambda in unconventional
superconductors

Magnetic property in ferromagnetic superconductor UGe 2 above
ferromagnetic critical pressure

Enhanced pinning properties and the zero-resistance state in melttextured high-Tc superconductors probed by pulsed magnetic fields

Anomalous hall effect in superconductors with spin-orbit interaction

Jeehoon Kim*, Filip Ronning, N. Haberkorn, L. Civale, J. D. Thompson and Roman
Movshovich
Los Alamos National Laboratory, USA

The superconducting coherence length ($\xi$), magnetic penetration depth ($\lambda$), andtheir anisotropy are fundamental parameters that characterize superconducting materials. The
value of $\xi$ can be estimated from the superconducting upper critical field ($H_{c2}$)
using the Ginzburg-Landau theory. In contrast to $\xi$, precise determination of the absolute$\lambda$ value is notoriously difficult. In this talk we present a simple, robust, and modelindependent technique to measure $\lambda$ using magnetic force microscopy (MFM),
and discuss our recent results of the measurements of the absolute value of $lambda$ in avariety of unconventional superconductors, such as MgB2, borocarbides, and pnictides. In
MgB2 we will discuss the influence of the intra-band contributions on the superconducting
properties and scattering effect between the two bands. In a recently discovered Ca10(Pt3As8)[(Fe1-xPtx)2As2]5 (x=0.097) single crystal, we observed large $\lambda$. Large $\lambda$ andhigh anisotropy in this system enhance thermal fluctuation, which leads to a liquid vortex
phase in this low-temperature (T$_c$= 11 K) superconductor. Also, we will discuss the effectof irradiation on the value of $\lambda$ in Ca0.5Na0.5Fe2As2. Finally, we will present our
results on the anisotropy of $\lambda$ in a pnictide Ba-122 system, which shows a different
temperature dependence from that of H$_{c2}$.

Naoyuki Tateiwa1*, Yoshinori Haga1, Tatsuma D Matsuda1, Eetsuji Yamamoto1,
Yoshichika Onuki2 and Zachary Fisk3
1
Advanced Science Research Center,, Japan Atomic Energy Agency, Japan
2
Graduate School of Science, Osaka University, Japan
3
University of California, USA
UGe_2 is a ferromagnet with the Curie temperature of 54 K at ambient pressure.
The ferromagnetic transition temperature decreases with increasing pressure. The
superconductivity appears in the pressure region of 1.0-1.6 GPa where UGe_2 is in
the ferromagnetic state. Ferromagnetic state disappears above P_c =1.6 GPa. Previous
studies up to 2 GPa showed that the broad maximum appears in the temperaturedependence of the ac magnetic susceptibility and that the ferromagnetic state is
induced at metamagnetic field H_m above P_c. These phenomena are resemblance to
weak ferromagnetic compound in the 3d electron system such as ZrZn_2. In this study,
we have measured the dc-magnetization up to 4.1 GPa using the ceramic anvil highpressure cell. We confirmed the maximum at T_max in the temperature dependence ofthe dc magnetic susceptibility. With increasing pressure, T_max is increased from 24 K
at 1.9 GPa to 32 K at 2.6 GPa. The peak structure around T_max becomes broader withincreasing pressure and disappears above 4 GPa. The metamagnetic transition field H_
m increases rapidly with increasing pressure. We discuss the experimental results withthe phenomenological spin-fluctuation theory.

Fabio Teixeira Dias1*, Valdemar Das Neves Vieira1, Douglas Langie Da Silva1, Sabrina Esperanca
Nunes1, Frederik Wolff-Fabris2, Erik Kampert2, Jacob Schaf3 and Joan Josep Roa Rovira4
1
Department of Physics, Universidade Federal de Pelotas, 96010-900, Pelotas, Brazil
2
Dresden High Magnetic Field Laboratory, HZ Dresden-Rossendorf, 01314, Dresden, Germany
3
Universidade Federal do Rio Grande do Sul, 91501-970, Porto Alegre, Brazil
4
Universite de Poitiers, 86962, Poitiers, France

Pedro D Sacramento1, M. A. N. Araujo2, V R Vieira1, V K Dugaev3 and J Barnas4
Departamento de Fisica and CFIF, Instituto Superior Tecnico, TULisbon, Portugal
2
Departamento de Fisica and CFIF, Universidade de Evora, Portugal
3
Department of Physics, Rzeszow University of Technology, Poland
4
Department of Physics, Adam Mickiewicz University, Poland
1

Among several techniques to grow high-temperature superconductors, melt-textured techniques have emerged as analternative way to produce materials with physical properties needed for some technological applications. In this work
we have studied the correlation between the magnetic irreversibility line and the zero-resistance state in melt-textured
YBaCuO samples (Y123) with inclusions of Y211 phase particles by performing magnetization and magnetotransportmeasurements in DC and pulsed magnetic fields up to 60 T and temperatures down to 1.5 K [1]. Our results show for inplane magnetic fields an irreversibility field higher than 40 T at 77 K which evidences a strong pinning effect due to theinterface of the Y211 particles embedded in the Y123 phase. We have observed effects of the intrinsic pinning due to theanisotropic superconductivity of the Y123 phase. Access to pulsed high magnetic fields reveals a suppression of the lowtemperature magnetic irreversibility field relative to BC2. These results show experimental evidences for field-induced
microscopic quantum fluctuations as observed in different high-Tc superconductors. Our findings in melt-textured
YBCO samples exclude the possibility that the zero-resistance state and the magnetic irreversibility merge in this field
range [2,3,4], showing evidences of weak granularity and providing a good candidate for technological applications.

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[1] J. Schaf, P. Pureur, F. Dias, V. Vieira, P. Rodrigues Jr., and X. Obradors, Phys. Rev. B 77, 134503 (2008). [2] C. Ebnerand D. Stroud, Phys. Rev. B 31, 165 (1985). [3] P. Pureur, R. Costa, J. Roa-Rojas, and P. Prieto, Phys. Rev. B 61, 12457 (2000).
[4] J. Rosenblatt, P. Peyral, A. Raboutou, and C. Lebeau, Physica B 152, 95 (1988).

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Self-consistent calculations of the effects of disorder in d- and s-wave
superconductors

Electron and hole transmission through superconductor - normal
metal interfaces

Phenomena of vortex pinning by composite pinning array on Nb films

Kurt Gloos* and Elina Tuuli
Department of Physics and Astronomy, University of Turku, Finland

Sheng Hao Wang1*, Lance Horng1, T. C. Wu2, Chien-miao Chen1, R Cao1 and J. C.
Wu1
1
Dept. of Physics, National ChangHua University of Education, Taiwan
2
Dept. of Electronic Engineering, National Formosa University, Taiwan

Analysis of the local current density in HTS coated conductors using
low-temperature scanning laser and hall probe microscopy

The kernel polynomial method (KPM) [1], as an approach for deriving highly accurate
spectral properties of large sparse matrices, is very suitable for the numerical study
on the Anderson localization problem. We investigate the effects of disorder in thetwo-dimensional inhomogeneous superconductors within the KPM by solving selfconsistently the Bogoliubov-de Gennes equations [2, 3]. Comparing the behaviors
of optical conductivity and the time evolutions of single particle Green’s function insuperconducting phases with different pairing symmetries, we find that the delocalized
screening effect on the localized quasiparticle states is sufficiently larger in the d-wave
superconductor than that in the s-wave superconductor. Within a considerable large
range of disorder strength, the disorder-induced pseudogap state is derived close to thes-wave superconductor-insulator transition.

We have investigated the transmission of electrons and holes through interfaces
between superconducting aluminum (T_c = 1.2 K) and various normal metals (copper,
gold, palladium, platinum, silver) using Andreev-reflection spectroscopy at T = 0.1 K.
Most of the contacts had the typical Andreev reflection spectra and could be analyzed
with the modified BTK theory. We included Dynes' lifetime as a fitting parameterΓ in addition to superconducting energy gap 2Δ and normal reflection describedby Z. For contact areas from 1 nm2 to 10 000 nm2 the BTK Z parameter was 0.5,
corresponding to transmission coefficients of about 80%. This is considerably larger
than estimated based on reports of other experimental methods (proximity effectand CPP resistance of multilayers) or expected theoretically. The small variation of
Z indicates that the interfaces have a negligible dielectric tunneling barrier and thatFermi surface mismatch does not depend on the normal metal. Our results contradict
standard expectations and call for a revision of the interpretation of the BTK theory
and normal reflection. This is an especially important topic for applying Andreevreflection spectroscopy to unconventional superconductors or for measuring the local
spin polarization of ferromagnets.

In type II superconductor, magnetic fields can penetrate into the superconductor
inhomogeneously as an array of vortices. The interaction of these vortices and vortexpin interactions in the superconductor give rise to a rich variety of static and dynamicalphases. In our study, smaller pinning sites at the center of every hexagonal cell wereadded when fabricating film with honeycomb array to obtain films with composite
pinning array. It has been prepared on Si3N4-coated Si wafers using electron-beamlithography in conjunction with reactive ion etching. Then a dc sputtering completed
the four-terminal geometry niobium films over the composite array. MR measurements
were carried out by a four-probe technique. Special matching peaks of critical currents
are exhibited at different temperatures in the measurements. The positions and structuresof the matching peaks seem irregular and are very different from the structures of thematching peaks for previously explored films, such as films with triangular, square, or
honeycomb pinning arrays. Considering the multiple-vortex filling of different pinningsites, we can give a reasonable explanation to this interesting phenomenon.

Long He and Yun Song*Department of Physics, Beijing Normal University, China[1] A. Weisse, G. Wellein, A. Alvermann, and H. Fehske, Rev. Mod. Phys. 78, 275 (2006). [2] L.
Covaci, F. M. Peeters, and M. Berciu, Phys. Rev. Lett. 105, 167006 (2010). [3] Y. Nagai, Y. Ota, and
M. Machida, J. Phys. Soc. Jpn. 81, 024710 (2012).

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The 19th International Conference on Magnetism

July 13 (Fri)Institute of Physics, Institute of Physics, Jan Dlugosz University, Czestochowa,
Poland, Poland

Yutaro Nagano1*, Nobutaka Araoka1, Akihiro Mitsuda1, Hirofumi Wada1, Masaki
Ichihara2, Masahiko Isobe2 and Yutaka Ueda2
1
Department of Physics, Kyushu University, Japan
2
Institute for Solid State Physics, University of Tokyo, Japan

Sang Kook Park, Bo Ram Cho, Hee Yeon Park and Hyeong-cheol Ri*
Department of Physics, Kyungpook National University, Korea

Local current density in HTS coated conductors was investigated using Lowtemperature Scanning Laser and Hall Probe Microscopy (LTSLHPM). We prepared
GdBCO and YBCO coated conductors to study the spatial distribution of the current
density in a single bridge. Inhomogeneity of the local critical temperature in thebridge was analyzed from experimental results of scanning laser microscopy near thesuperconducting transition. The local transport and screening current in the bridge werealso investigated using scanning Hall probe microscopy. From experimental resultsof scanning laser and Hall probe microscopy, we have observed the redistribution ofcurrent density and the critical temperature caused by defects of the HTS layer.

T. C. Wu, R. Cao, T. J. Yang, L. Horng, J. C. Wu, Jan Kolacek, Solid State Commun. 143, 171 (2010) ,R Cao, Lance Horng, T. J. Yang, T. C. Wu, J. C. Wang, and J. C. Wu, J. Appl. Phys. 107, 09E129 (2010),T. C. Wu, J. C. Wang, Lance Horng, J. C. Wu, and T. J. Yang1, J. Appl. Phys. 97, 10B102 (2005)

July 8-13, 2012 Busan, Korea

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poster Presentation

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Cooper pairing between conduction and localized electrons in heavyfermion systems

Evidence for multiband order parameters in the stong-coupling
LaRu4As12 Skutterudite Superconductor

Low temperature properties of the weakly-coupled noncentrosymmetric superconductor LaNiC2

The momentum and frequency dependences of the self-energy inducedby the spin fluctuations for the cuprate superconductors

Keisuke Masuda1* and Daisuke Yamamoto2
1
Department of Physics, Waseda University, Japan
2
Condensed Matter Theory Laboratory, RIKEN, Japan

We study the Cooper pairing between a conduction electron (c electron) and a localized
f electron, referred to as the c-f paring, as a mechanism of s-wave superconductivity
in heavy-fermion systems. To describe the physics of heavy-fermion systems, we startfrom the periodic Anderson model. We apply the Schrieffer-Wolff transformation to thismodel considering the situation where the f level is sufficiently deep and the Coulomb
repulsion is finite but large. The resulting effective Hamiltonian includes direct andspin-exchange interactions between c and f electrons, which can be the driving force
for the formation of the Cooper pairs. Within the mean-field approximation, we showthat the c-f pairing state with anisotropic s-wave symmetry appears in a large region of
the phase diagram. Such a pairing state can be realized when the quasiparticle band of
the f electrons, which is formed by the strong Coulomb repulsion, is located near theenergy level of the conduction band. We also discuss the relationship between the c-f
pairing proposed here and the s-wave superconductivity found in the experiments on
CeRu2 and CeCo2.

Tomasz Cichorek1, Lukasz Bochenek1, Ryszard Wawryk1, Roman Puzniak2 andZygmunt Henkie1
1 Institute of Low Temperature and Structure Research, Polish Academy of Sciences,
Wroclaw, Poland
2 Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
Superconducting properties of high-purity LaRu4As12 single crystals with the highest
critical temperature Tc = 10.45 K among the fully filled-skutterudite superconductors
were investigated by dc magnetization, electrical resistivity, torque, and specific heatmeasurements both as a function of temperature and magnetic field. At B = 0 and
below about Tc/2, the electronic specific heat exhibits two-band features, as concluded
from an α-model analysis. Multi-band effects are further inferred from a nonlinear
magnetic-field dependence of the electronic specific heat coefficient in the zerotemperature limit as well as from a positive curvature of the upper critical field in thevicinity of Tc. Our findings, combined with results of previous de Haas-van Alphen
experiments, suggest that enhanced superconductivity in LaRu4As12appears along witha spherical Fermi-surface sheet enclosing a small volume in the center of the Brillouinzone.

Jian Chen1, Jing Lei Zhang1, Lin Jiao1, Lin Yang1, Tian Shang1, Michael Nicklas2,Frank Steglich2 and Hui Qiu Yuan1*
1
Physical Department, Zhejiang University, China
2
Max Planck Institute for the Chemical Physics of Solids, Dresden, Germany
In a non-centrosymmetric (NCS) superconductor, an asymmetric potential gradientyields an antisymmetric spin-orbit coupling (ASOC), which splits the degeneracy of
conduction electron, and allows the admixture of spin-singlet and spin-triplet pairing
states, leading to accidental nodes in the energy gap [1,2]. It was shown that the timereversal symmetry is broken in the weakly correlated intermetallic compound LaNiC2[3] but its pairing symmetry is still under debate. Here we present the low temperature
specific heat C(T) and the magnetic penetration depth λ(T) for LaNiC2. It is foundthat both λ(T) and Ce(T)/T can be well described by a phenomenological two-gap
model. The Sommerfeld parameter, γ(H), increases steeply at low fields and eventually
get saturated with increasing magnetic field, being also consistent with the behaviorof two-gap superconductivity. We argue that the ASOC is weak in LaNiC2 and thespin-singlet state dominates in the pairing states, giving rise to two-gap-like BCS
superconductivity.

Seung Hwan Hong and Han-yong Choi*
Department of Physics, SungKyunKwan University, Korea

We solve the momentum resolved d-wave Eliashberg equation to investigate theconsistency of the spin fluctuation induced superconductivity theory for the cuprates.
The effective interaction between electrons (Eliashberg function) is modeled in termsof the magnetic excitation spectrum measured by the inelastic neutron scattering on the
LSCO superconductors reported by Vignolle et al[1]. The magnetic excitation spectrum
consists of three parts: the resonance mode near 40-70 meV and the incommensurateparts above and below the resonance mode. The resonance mode has a peak at (π,π).
The low energy incommensurate part makes a nonmonotonic momentum dependenceof the diagonal and off-diagonal self-energies. On the other hand, the resonance mode
makes a monotonic momentum dependence of the self-energy. The angle dependenceof the superconducting gap is influenced by the effects of these two energy scales.
These results are compared with the ARPES experiments.
[1] B. Vignolle et al., Natrue Physics 3, 163 (2007)[1] P. A. Frigeri, D. F. Agterberg, A. Koga, and M. Sigrist, Phys. Rev. Lett. 92, 097001 (2004). [2] H. Q.
Yuan, D. F. Agterberg, N. Hayashi, P. Badica, D. Vandervelde, K. Togano, M. Sigrist, M. B. Salamon, Phys.
Rev. Lett. 97, 017006 (2006). [3] A. D. Hillier, J. Quintanilla, R Cywinski, Phys. Rev. Lett. 102, 117007 (2009).

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SC01

Low-temperature thermoelectric properties of the electron-doped
Perovskites Sr1-xCaxTi1-yNbyO3

NMR Study of magnetic order and the FFLO state in CeCoIn5

Magnetic penetration depth and $H$-$T$ phase diagram in SrPd2Ge2

Novel non-centrosymmetric superconductors in 113 and 111 crystal structures

Electron-doped perovskite SrTiO3 is known to be one of candidates for an n-type
thermoelectric (TE) oxide. [1] In this study, we tried to improve a TE property of alightly-electron-doped SrTiO3 single crystal below room temperature by substitutionsof Ca and Nb for Sr and Ti. We found that SrTi0.99Nb0.01O3 shows a large power factor
of about 90 μW/K2 cm at 50 K and the largest dimensionless TE figure-of-merit (ZT ~0.07) below 40 K among the ever-reported materials. The good n-type TE response isdue to a distinct electron-phonon interaction which could relate to the superconducting
state [2], which enlarges a Seebeck coefficient not through an enhancement of effective
mass, but through a change of relaxation time. On the other hand, a Ca2+ substitution
for Sr2+ increases the ZT at 300 K for Sr1-xCaxTi0.97Nb0.03O3 from 0.08 to 0.105. The
enhancement of ZT originates not only in a large reduction of a thermal conductivity
due to an introduced randomness into the crystal structure, but also in an unexpectedenhancement of Seebeck coefficient by the Ca substitution.

A strongly-correlated superconductor, CeCoIn5 is believed to host a Fulde-FerrellLarkin-Ovchinnkov (FFLO) state in a restricted region of high field and very low
temperature. In addition to the field evolution of NMR results for H//a-axis [1], we
will report recent results of the angle,θ, dependence of external fields with respect tothe ab planes down to ~50mK. Detail phase diagram for θ-, B-, and T-parameters is
obtained. The NMR spectra change dramatically upon entering the novel SC phase.
A well-separated peak structure at the In(2b) site suggests the occurrence of themagnetic order which is emerging only in the newly-discovered SC state. The structureof the spin density wave (SDW) is modified with angle and field. The Knight shiftof CeCoIn5 provides a direct evidence for the emergence of the spatially-distributed
normal quasiparticle region. The quantitative analysis for the field evolution of theparamagnetic magnetization and low-lying energy quasiparticle density of state isconsistent with the nodal plane formation, which is characterized by an order parameterin the FFLO state.
[1] K. Kumagai et al., Phys. Rev. Lett. 106, 137004 (2011).

[1] T. Okuda, K. Nakanishi, S. Miyasaka, and Y. Tokura, Phys. Rev. B 63, 113104 (2001). [2] H. Suzuki, H.
Bando, Y. Ootuka, I.H. Inoue, T. Yamamoto, K. Takahashi, and Y. Nishihara, J. Phys. Soc. Jpn. 65, 1529
(1996). [3] J. Fukuyado, K. Narikiyo, M. Akaki, H. Kuwahara, and T. Okuda, Phys. Rev. B, to be published.

1

In-plane magnetic penetration depth, $\lambda(T)$, was measured in single crystals of
SrPd2Ge2 superconductor down to 50 mK and in magnetic fields up to $H_{dc} = 1$ T byusing a self - oscillating tunnel diode resonator operating at 16 MHz with amplitude of $H_{ac}≈ 20$ mOe. In the pure Meissner state, at $H_{dc}=0$, $ \lambda(T)$ saturates exponentiallyapproaching $T\rightarrow 0$ indicating fully gapped superconductivity in SrPd$_2$Ge$_2$.
In a magnetic field, the measured penetration depth is given by $\lambda^2 = \lambda^2_L +\lambda^2_C$, where $\lambda^2_C ~ B/j^2_c$ is the Campbell penetration depth and $j_c$
is the critical current density. For $H < 0.4$ T, the shortest $\lambda_C$ (strongest pinning) isachieved not at the lowest, but at some intermediated temperature. Additionally, $Δ \lambda(T)$shows hysteresis between zero field cooling and field cooling measurements, which is anindication of non - parabolic pinning potential. Another interesting feature is a pronounced
finite diamagnetic response above bulk superconducting transition, which could be related tosuperconducting fluctuations. Combining all measurements, the entire $H-T$ phase diagramof SrPd2Ge2 has been constructed. Possible pairing mechanism and the superconducting gap
structure, unusual vortex response and field - and temperature dependent critical current density
will be discussed.

Superconductivity (SC) in materials that don’t possess a center of inversion due to their crystal structure has
been recently found in materials like CePt_3Si[1]. The lack of inversion-symmetry gives rise to an electricalfield and therefore leads to an antisymmetric spin-orbit coupling (ASOC) of the Rashba-type[2]. This causes
a splitting of the Fermi surface, thereby leading to a superposition of spin-singlet and spin-triplet Cooper pairs
in the SC condensate. Intriguing features like nodes in the superconducting gap, as well as H_c2 exceeding
the Pauli-Clogston limit, may occur. However, besides Li_2Pt_3B[3], spin-triplet pairing seems only to be
dominant in heavy fermion systems. In order to study these features in further detail, new ternary compounds
like BaPtSi_3[4], SrPdSi_3, SrPdGe_3[5], SrPtSi_3 and SrPtGe_3 of BaNiSn_3 type (space group I/4mm)
as well as promising 111-types like LaPtSi[6,7] and LaIrSi[8] have been investigated, since there is a tuning
possibility regarding the quadratic atomic number dependency (Z²) of the spin-orbit coupling. Measurementsof the electrical resistivity and the specific heat have been conducted to analyze the superconducting groundstate. Additionally, μSR measurements have been performed to proof the microscopic pairing mechanism of
the Cooper pairs. The results obtained so far indicate s-wave fully gapped BCS SC.

SB25

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SB31

Evolution of pairing potential in ladder materials underrenormalization group transformations

MgB2 coated conductors grown at various temperatures by hybrid
physical-chemical vapor deposition

Eliashberg function of the overdoped Bi2212 superconductors deduced
from the high resolution laser ARPES intensity

Yen-chen Lee1*, Wen-min Huang2 and Hsiu-hau Lin1
1
Department of Physics, National Tsing Hua University, Taiwan
2
Physics Division, National Center for Theoretical Sciences, Taiwan

It is generally believed that electron-electron interactions are responsible for pairformation in unconventional superconductors. However, how electrons can form
pairs in the presence of repulsive interactions remains counterintuitive and puzzling.
Many studies suggest that spin fluctuations provides the “pairing glues” to account for
the unconventional pairing. Here we take a different route: finding effective pairing
potential at different length scales by renormalization group approach. We focus on
the unconventional superconductivity in ladder materials and show how the profile
of electron-electron interactions evolves under renormalization group transformation.
Starting with repulsive short-ranged interaction, compelling evidence for spatiallystructured attractive interactions emerges in long-wavelength limit and explains theunconventional pairing symmetry naturally. Comparisons with other theoretical
approaches and potential generalization to two dimensions are discussed at the end.

324

H. Kim1, N. H. Sung2, M. A. Tanatar1, B. K. Cho2 and R. Prozorov1*
1
The Ames Laboratory, USA
2
School of Materials Science and Engineering, Gwangju Institute of Science andTechnology, Korea

The 19th International Conference on Magnetism

Mahipal Ranot1, K. H. Cho1, Soon-gil Jung1, Won Nam Kang1*, S. Oh2 and K. C.
Chung3
1
Physics, Sungkyunkwan University, Suwon, Korea
2
National Fusion Research Institute, Korea
3
Korea Institute of Machinery and Materials, Korea

For practical applications, MgB2 superconductor (Tc~39 K) in the form of wires andtapes are required to be produced in long lengths to replace the conventional metallic
superconductors, such as Nb-Ti and Nb3Sn. In this work, we have grown MgB2 coatedconductors by depositing MgB2 films directly on the flexible Hastelloy tapes at various
temperatures ranging from 520 to 600 °C by using HPCVD. The MgB2 coated conductors
exhibit critical temperatures ranging from 37.5 to 38.5 K with superconducting transition
width (Tc) of about 0.3?0.8 K. X-ray diffraction analysis revealed that the MgB2 coatedconductors are polycrystalline in nature. It was found that the MgB2 coated conductorgrown at 520 °C had dense microstructure with good grain connectivity. However, uponincreasing the growth temperature from 520 to 600 °C deterioration of grain connectivity
takes place and void formations were observed. The critical current density (Jc) of theorder of Jc(5 K, 0 T) ~107 and Jc(5 K, 3 T) ~105 A/cm2 was obtained for the MgB2 coatedconductor fabricated at 520 °C. The fabrication process, crystallographic orientations,surface morphologies and superconducting properties [Tc, Jc (H)] of MgB2 coatedconductors grown at various temperatures will be discussed in detail.

Jin Mo Bok1*, Han-yong Choi1, Junfeng He2, X. J. Zhou3 and C. M. Varma4
1
Department of Physics, SungKyunKwan University, Suwon 440-746, Korea
2
Institute of Physics, Chinese Academy of Sciences, Beijing 100190., China
3
Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
4
Department of Physics and Astronomy, University of California, Riverside, CA
92521, USA
We report the diagonal and off-diagonal Eliashberg functions a2F(+) and a2F(-) ofoverdoped Bi2212 supercondcutors deduced from the high resolution laser APRES
experiments. By fitting the momentum distribution curves of the ARPES intensity
employing the superconducting Green's function, the diagonal and off-diagonal selfenergies along several cuts in the Brillouin zone are extracted. Then, the diagonal andoff-diagonal Eliashberg functions are deduced by inverting the d-wave Eliashberg
equation using, respectively, the conrresponding self-energies. We will present the
momentum and frequency dependences of the Eliashberg function a2F(+) and a2F(-).
We then compare these results with other experiment and calculation results.

Friedrich Kneidinger1*, Ernst Bauer1, Herwig Michor1, Gerfried Hilscher1, Isolde Zeiringer2,
Peter Rogl2, Nataliya Melnychenko3, Leonid Salamakha4 and Adrian Hillier5
Institute of solid state physics, Vienna University of Technology, Austria
2Institute of physical chemistry, University of Vienna, Austria
3
Inorganic Chemistry Department, Ivan Franko National University of Lviv, Ukraine
4
Ivan Franko Lviv National University, Ukraine
5
ISIS facility, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation
Campus, United Kingdom

July 13 (Fri)July 13 (Fri)Tetsuji Okuda1*, Junichi Fukuyado1, Kurahito Narikiyo1, Mitsuru Akaki2 and Hideki
Kuwahara2
1
Kagoshima University, Japan
2
Sophia University, Japan

Ken-ichi Kumagai1*, Hiroyuki Shishido2, Takasada Shibauchi2 and Yuji Matsuda2
1
Department of Physics, Hokkaido University, Sapporo, 060-0810, Japan2
Department of Physics, Kyoto University, Kyoto 606-8502, Japan[1] E. Bauer et al., Phys. Rev. Lett. 92, 027003 (2004) [2] Y.A. Bychkov and E. I. Rashba, JETP Lett 39, 78 (1984)[3] M. Nishiyama et al., Phys. Rev. Lett. 98, 047002 (2007) [4] E. Bauer et al., Phys. Rev. B 80, 064504 (2009)[5] K. Miliyanchuk et al., Journal of Physics: Conference Series 273, 012078 (2011) [6] K. Klepp & E.Parthe,
Acta Crystallogr. B38, 1105 (1982) [7] J. Evers, G. Oehlinger and A. Weiss, Solid State Communications, Vol.
50, No. 1, pp. 61-62, (1984) [8] K. Klepp & E.Parthe, Acta Crystallogr. B38, 1541 (1982)

SC02
Non-fermi liquid behavior of d-wave superconductor

Pankaj Singh*, Ajay Pratap Singh Gahlot, Manju Rani and Partho Goswami
Physics Department, Deshbandhu College, University Of Delhi, India
The d+id-density wave (Chiral DDW) order, at the anti-ferromagnetic wave vector
Q = (π,π), is assumed to represent the pseudo-gap (PG) state of a hole-doped cuprate
superconductor. The d-wave superconductivity (DSC), driven by an assumed attractive
interaction, is discussed within the BCS framework together with the d+id ordering.
The single-particle excitation spectrum in the CDDW + DSC state is characterized by
the Bogoluibov quasi-particle bands-a characteristic feature of SC state. The coupled
gap equations are solved self-consistently together with the equation to determine
the chemical potential (μ). With the pinning of the van Hove-singularities close to μ,
one is able to calculate the thermodynamic properties of the under-doped cuprates
in a consistent manner. Apart from the known facts that PG and DSC represent
two competing orders as the former brings about a depletion of the spectral weightavailable for pairing in the anti-nodal region of momentum space and the depletionof the spectral weight below Tc at energies larger than the gap amplitude, we finda conspicuous feature that the electronic specific heat displays non-Fermi liquidbehavior( anomalous temperature dependence) in the CDDW + DSC state.

July 8-13, 2012 Busan, Korea

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poster Presentation
SC03

SC06

SC09

SC12

Low temperature enhancement of the critical current in CeCoIn5.
Possible signature of magnetic orderElectronic structure of a superconducting boride, ZrB12

Phase transition of a heavy fermion superconductor in a high magnetic
field : entanglement analysis

Spin-orbit coupling and the superconductivity in simple-cubicpolonium

We report on vortex dynamics, dc magnetization and RF penetration depth measurements in
the heavy fermion compound CeCoIn5 down to low temperatures, T=50 mK. No strong pining
is observed as expected for a clean limit superconductor which does not break spontaneously
any additional symmetries besides the U(1)-gauge. CeCoIn5 display clear logarithmic relaxation
curves as expected from Kim-Anderson theory. The temperature dependence of the relaxation
rate, S, with a small but finite residual value indicate that quantum tunneling plays a significant
role in the vortex creep only at very low temperatures. Remarkably, a new phase transition
marked by a strong increase in the remnant magnetization, Mrem is observed around T = 0.3 K
in low magnetic fields just high enough to put the sample in the Bean critical state. Moreover,this anomaly is corroborated by the DC magnetization and RF measurements at very low fields.
We extended the vortex dynamics investigation to Pb irradiated CeCoIn5. While the defects
created by irradiation have a clear effect on the relaxation rates the enhancement of Mrem
still takes place at the same temperature. Our findings are consistent with the existence of amagnetically ordered phase, deep inside the superconducting state.

Sangeeta Thakur1, Deep Narayan Biswas Biswas2, Nishaina Sahadev3, Geetha
Balakrishnan4 and Kalobaran Maiti5*1
Department of Condensed Matter Physics and Materials' Science, Tata Institute ofFundamental Research Colaba, Mumbai - 400 005, India
2
Tata Institute of Fundamental Research Colaba, Mumbai - 400 005, India
3
Tata Institute of Fundamental Research, Colaba, Mumbai - 400 005, India
4
Department of Physics, University of Warwick, Coventry, CV4 7AL, UK, United
Kingdom5
Tata Institute of Fundamental Research Colaba Mumbai 400005, India
Borides have attracted a great deal of attention followed by the finding of varied interesting
properties. ZrB12 is one such compound exhibiting highest superconducting criticaltemperature (Tc = 6 K) in MB12 family. In order to probe the electronic states responsible
for superconductivity in this compound, we studied the electronic structure of single
crystalline ZrB12 using high resolution photoemission spectroscopy and ab initio band
structure calculations. Zr 3d core level spectra exhibit signature of satellite features indicating
finite correlation among the conduction electrons. The B 1s spectra appears to be sharp withunusual asymmetry, presumably due to surface contributions as found in hexaborides. In
the valence band spectra, the spectral density of states reveal a dip at the Fermi level, which
gradually increases with the decrease in temperature down to 10 K. The band structure results
indicate dominant contribution from the B 2p electronic states in the valence band. However,the photon energy dependence in the experimental spectra indicate large contribution fromthe Zr 4d states near Fermi level suggesting their important role in the superconductivity.

Reza Afzali1* and Neda Ebrahimian2
1
Physics Department, K. N. Toosi University of Technology, Tehran 15418, Iran2
Physics Department, Amirkabir University of Technology, Tehran 15914, Iran

When the magnetic field is acting on the spin of electrons only, a transition from a normal to amodulated superconducting state or FFLO superconductor state may occur at low temperatures[1-3].
A FFLO superconducting state, accompany with an order parameter that oscillates spatially, may bestabilized by a high applied magnetic field or a molecular field. CeCoIn5 is a sample of heavy-fermion
superconductor[4]. Initially experiments on CeCoIn5 indicate that in this substance a FFLO state in a
exchange field is realized. Quantum multipartite entanglement is a new procedure for investigating
quantum phase transition[5-6], which is one of the interesting topics in condensed matter. In thisarticle, we deal with to the phase transition of FFLO state of CeCoIn5 to the normal state by obtaining
quantum multipartite entanglement of the system. For this purpose, using normal and anomalous Greenfunctions and density matrix, concurrence, as a measure of bipartite entanglement, is obtained. Then,order parameter and magnetic field dependence of multipartite entanglement in momentum space iscalculated. The phase transition is determined and the behavior of the system based on order parameteris discussed. Furthermore, the phase transitions of both BCS and FFLO states to the normal state arecompared.

Chang-jong Kang, Kyoo Kim and B. I. Min*
Physics, POSTECH, Korea

Polonium is the only element which has the simple-cubic (SC) structure in the
periodic table. We have studied its structural stability based on the phonon dispersion
calculations using the first-principles all-electron full-potential band method. We havedemonstrated that the strong spin-orbit coupling (SOC) in SC-Po suppresses the Peierls
instability and makes the SC structure stable. Further, we have investigated the possiblesuperconductivity in SC-Po, and predicted that it becomes a superconductor with Tc~ 4 K at ambient pressure. The transverse soft phonon mode at q ~ 2/3 R, which isgreatly affected by the SOC, plays an important role both in the structural stability andthe superconductivity in SC-Po. We have explored effects of the SOC and the volume
variation on the phonon dispersions and superconducting properties of SC-Po.

References: [1]Fulde P and Ferrell R A 1964 Phys. Rev. A 135 550 [2]Larkin A I and Ovchinnikov Y N 1965
Sov. Phys. JETP 20 762 [3]Takada S and Izuyama T 1969 Prog. Theor. Phys. 41 635 [4]Radovan H A, Fortune
N A, Murphy T P, Hannahs S T, Palm E C, Tozer S W and Hall D 2003 Nature 425 51 [5] Amico L, Fazio R,
Osterloh A and Vedral V 2008 Rev. Mod. Phys. 80 517 [6] Brandao F G S L 2005 New J. Phys. 7 254

SC04

SC07

SC10

SC13

Superconducting phase diagram in fcc phase of Cs3C60; A pressure
dependence of resistivity

On the nature of an energy barrier between (π,0) and (0,π) magnetic
orders in Fe pnictides

Spin and charge excitations in antiferromagnetic metallic phase inmulti-orbital systems: A case study of chromium

Stability of FFLO states in optical lattices with layered structure

Takashi Kambe*, Yuta Suzuki, Seizi Shibasaki, Keitaro Tomita and Yoshihiro
KubozonoPhysics, Okayama university, Japan

Cs3C60 crystallizes three polymorphic phases; A15, fcc and bco. Two polymorphs, A15
and fcc phases, show pressure induced superconducting transitions around 38 K and
35 K, respectively. Here we report a resistivity for fcc phase of Cs3C60 as a function ofpressure and present a dome-shaped superconducting phase diagram.

Alexander Yaresko1*, Lilia Boeri2, Vladimir Antropov3 and Ole Krogh Andersen2
1
Andersen, Max Planck Institute for Solid State Research, Germany
2
Max Planck Institute for Solid State Research, Germany
3
Ames Laboratory, Ames, Iowa, USA

Koudai Sugimoto1, Eiji Kaneshita2, Kenji Tsutsui3 and Takami Tohyama1*
1
Yukawa Institute for Theoretical Physics, Kyoto University, Japan
2
Sendai National College of Technology, Japan
3
Condensed Matter Science Division, JAEA, Japan

Akihisa Koga* and Yasuharu Okawauchi
Department of Physics, Tokyo Institute of Technology, Japan

Recently, ultracold fermions with spin-imbalanced populations have attracted muchinterest. One of the interesting questions is how the Fulde-Ferrell-Larkin-Ovchinnikov(FFLO) phase, where Cooper pairs are formed with a finite total momentum, is realized
in the system. In the two dimensional optical lattice with a confining potential, it has
been pointed out that two kinds of FFLO states are realized[1,2]. On the other hand,such FFLO states with a three-dimensional structure have not been studied so wellalthough the interlayer coupling should be important for realistic optical lattice systems.
Motivated by this, we investigate the stability of the superfluid state in a layered
fermionic optical lattice system with a confining potential, using the Bogoliubov deGennes equations. It is clarified that in the imbalanced case, the introduction of theinterlayer hopping stabilizes the radial FFLO state, while makes the angular FFLO
state unstable. We also discuss the system size dependence of the superfluid groundstate. It is clarified that in a certain ring region the A-FFLO state is indeed realized in alarge system.

As temperature is lowered most of undoped Fe arsenides, parent compounds forrecently discovered Fe based superconductors, undergo a transition into a collinear
state with stripe-like magnetic order in which anti-ferromagnetic (AFM) Fe chainsare ferromagnetically ordered along the direction perpendicular to the chains. Twosuch collinear magnetic structures, characterized by ordering vectors (π,0) or (0,π),
are connected by infinite number of non-collinear states with two AFM sublatticesof second Fe neighbors rotated by an arbitrary angle with respect to each other. In aclassical Heisenberg model all these states are degenerate. Band structure calculation
show, however, that the degeneracy is lifted already at the mean field LSDA level andthat in Fe arsenides (π,0) and (0,π) magnetic orders are separated by an energy barriercomparable to the energy difference between Neel and stripe AFM orders. We discussa microscopic origin of the energy barrier and demonstrate that it is caused by closely
related to underlying band structure. The results for Fe arsenides are compared to
BaMn2As2 and hypothetical KFe2Se2 for which we found that a non-collinear 90-degreespin arrangement is more favorable than collinear ones. A doping dependence of thebarrier is also discussed.

Since the discovery of Fe-based superconductors, it has been recognized that theinterplay of spin, charge, and orbital degrees of freedom is the key to understanding
the physics of multiband itinerant systems. Antiferromagnetic (AF) phase seen in
the parent compounds of Fe-based superconductors is a good example to study themulti-orbital physics in the metallic phase. The AF metallic phase similar to theparent compounds is realized in a simple chromium metal with AF order. To makea unified view in the AF metallic phase of multi-orbital systems, we study spin andcharge excitations in AF Cr. We calculate the optical conductivity, neutron scattering
spectra, and Cr L-edge resonant X-ray scattering (RIXS) spectra based on the meanfield theory for the multi-band Hubbard model and the random-phase approximation.
The calculated results of the optical conductivity and neutron scattering spectra arecompared with corresponding experimental data. The d etailed polarization andmomentum dependence in RIXS is also discussed with predictions for the experiments.

SC05

SC08

SC11

SC14

The superconducting phases of URu 2 Si 2 from sound velocity
measurements

Electronic structures and magnetic properties of LnFeAsO

The dirty crossover - signature of a robust superfluid in the unitary
regime.

Flux quantization and its magnetic relaxation in a micrometer-sized
superconducting ring of niobium

B S Shivaram1, V W Ulrich1 and D G Hinks2
1
Physics, University of Virginia, USA
2
Materials Science Division, Argonne National Labs, USA

High resolution measurements of the changes in the longitudinal sound velocity ina magnetic field have been performed in the zero temperature limit in high quality
single crystals of URu2Si2. These measurements reveal two distinct signatures
attributable to multiple superconducting phases. A step change in the sound velocity,
for propagation in the basal plane, is observed at the critical field, Bc2. This step
broadens considerably as T tends to Tc with a concomitant decrease in magnitude. A
second step is observed at a field ~0.5 Bc2 and it's magnitude remains constant at all
temperatures. Inductive measurements of the transitions in a magnetic field, however,reveal only a single signature which coincides with the lower step change in the soundvelocity. Measurements performed with B oriented at various angles between the a andc-axes reveal a weaker angular dependence of the lower step and confirm the rapid fall
off of Bc2 close to B||c-axis. A multiple superconducting phase diagram for URu2Si2 is
proposed.

Chang Hyun Yi, Ju Young Kim, Jae Kyung Chang, and Joo Yull Rhee
Department of Physics, Sungkyunkwan University, Suwon 440-746, Korea
Recently, high transition-temperature superconductivity was discovered in theironpnictide RFeAsO (R=rare-earths) family of materials. Among them, LaFeAsO
undergoes a tetragonal-to-orthorhombic phase transition at ~160 K followed by an
antiferromagnetic ordering at ~145 K. This material has also been reported to undergoa spin-density wave transition near 150 K. Through first-principles calculations we
tried to understand the electronic structures and magnetic properties of LaFeAsO. We
used full-potential linearized-augmented-planewave method in the antiferromagnetic
ground state with orthorhombic phase. The physical origin of the SDW formation will
be discussed.

IIT Guwahati
IIT Guwahati, India

We perform a systematic study of the BCS-BEC crossover in an ultracold fermionic
gas in presence of a weak white noise-like random disorder which is incorporated
in our mean-field treatment via Gaussian fluctuations. A careful investigation ofdifferent mean field quantities as a function of the interparticle interaction reveals anonmonotonic behavior in the the condensate fraction data as disorder is included
in our calculations. The inflexion point is seen to occur in the unitary regime, andafterwards there is a gradual depletion of the condensate density in the BEC side,
thereby corroborating a robust paradigm of superfluidity in the unitary regime.
Motivated by this result, we study the spectral gap and the density of states in the
crossover region and their responses to the disorder. We further include a comparative
discussion on the role of the pair and phase coherence lengths in this region in presenceof disorder to assess how these results can be relevant to the ongoing discussion. Dueto tremendous progress taking place in the experimental front in manipulating atoms
on an optical lattice in presence of (speckle) disorder, a stable superfluid scenario in theunitary limit, as proposed here, may soon be realizable.

July 13 (Fri)C. F. Miclea1*, M. Nicklas2, A. C. Mota3, M. M. Altarawneh4, C. Miclea1, N.
Harrison4, J. Thompson4, F. Steglich2 and R. Movshovich4
1
National Institute for Materials Physics, 077125 Bucharest-Magurele, Romania
2
Max-Planck-Institute for Chemical Physics of Solids, 01187 Dresden, Germany
3
Solid State Laboratory, ETH Zurich, Switzerland
4
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

July 13 (Fri)poster Presentation[1] Y. Chen, Z. D. Wang, F. C. Zhang, and C. S. Ting, Phys. Rev. B 79, 054512 (2009) [2] Y. Yanase,Phys. Rev. B 80, 220510 (2009)

Jae-hyuk Choi1*, Heon-hwa Choi1, Yun-won Kim2, Soon-gul Lee2 and Mahn-soo
Choi3
1
Division of Physical Metrology, Korea Reserach Institute of Standards and Science,
Korea
2
Dep. of Display and Semiconductor Physics, Korea University, Korea
3
Dep. of Physics, Korea University, Korea
We developed a high-sensitivity cantilever force magnetometry, which is capableof direct measurement of the magnetic moment of micron-scale samples at low
magnetic fields and low temperatures, and studied magnetic properties of a 100 nmthick Nb superconducting ring with 4 micrometer radius and 2 micrometer width. At atemperature of 3.5 K, we observed flux quantization of h/2e period using ac torque anddc force magnetometries with attonewton and sub-piconewton sensitivity, respectively,
determining the magnetic moment of each flux quantum. First demonstration ofmagnetic relaxation at single flux quantum level is also presented, which provides
information about the dynamics of thermally-activated single flux quantums dependingon their number.

Prof. S.S. Mandal, Indian Association for Cultivation of Science, Kolkata, India Prof. Y. Yanase,Niigata University, Japan

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The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

327

poster Presentation

poster Presentation

SC15

SC18

SC21

Measurement of rat biomagnetic signals by using a HTS-SQUID
systemDesign, fabrication, and testing of a cooling system using solid nitrogenfor a 3 T/60-mm RT bore superconducting HGMS

Removal of silica and copper ions from CMP wastewater via magnetic
seeding aggregation using superconducting HGMS

In-seon Kim* and San Ahn
Division of Convergence Technology, Korea Research Institute of Standards andScience, Korea

Jung-bin Song, Kwang Lok Kim, Dong Gyu Yang, Yoon Hyuck Choi, Jongseok Lee
and Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea

We have measured biomagnetic signals in rats by using a high-TC SQUID
magnetometer system employing a small magnetically shielded box. For the rat cardiac
magnetic field measurements, healthy Wistar Kyoto rat and spontaneously hypertensive
rat were anesthetized and fixed on a plastic xyz-stage in supine position inside themagnetically shielded box. Well defined P- , QRS- and T-waves were observed on
the rat cardiac magnetic field measurements. We investigated circular measurements
based on the hexaxial reference system, i.e., 12 measurement points were determinedalongside the circumference of a circle centered at the heart position. These results
were quite promising for use in biomedical applications of heart disease rat model
study by using the high-TC SQUID magnetometer system.

SC24

Jongseok Lee, Jung-bin Song, Dong Gyu Yang, Yeonjoo Park and Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea

D

D

E
OV

E
OV

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M

Evidence of two-band gap superconductivity in LaRu2P2

Tetsuya Fujiwara1*, Harunobu Sagawa1, Kazuyuki Matsubayashi2, Yoshiya Uwatoko2
and Toru Shigeoka1
1Graduate School of Science and Engineering, Yamaguchi University, Japan
2
Institute for Solid State Physics, University of Tokyo, Japan
We investigate the electronic transport properties and the superconducting gap characteristics
of LaRu2P2. Superconducting transition was recognized at Tc = 4.4 K in LaRu2P2 single
crystal as reported in ref [1]. Values of upper critical field Hc2 estimated from the electricalresistivity under magnetic field are isotropic in this system. These are good accordance withthe results by Ying et al.[2]. However, they, although, claimed that LaRu2P2 is a conventional
superconductor, so called BCS type, it was revealed that LaRu2P2 single crystal obtained inthis work shows a remarkably larger Hc2 than that expected from GL theory at considerably
low temperature. In addition, we observed two clear discontinuities of specific heat at Tc1= 4.4 K and Tc2 = 4.0 K, respectively, in specific heat as a function of temperature. Eachtransition temperature vary obeying Hc2(t)=Hc2(0)(1-t2)/(1+t2), here, t = T/Tc, indicatingthat both discontinuities at Tc1 and Tc2 are attributed to superconducting transitions. So, we
tried to analyze thermodynamic properties of LaRu2P2 by a two-band gap model [3]. In
consequence, the numerically calculated C(T) curve was well reproduced experimentallymeasured specific heat as a function of temperature when Δ1/kTc1 and Δ2/kTc2 wereassumed to be 1.5 and 3.0, respectively.
[1] T. Fujiwara et al., J. Phys.: Conf. Ser. 273, 012112 (2011). [2] J. Ying et al., Supercond. Sci.
Technol. 23, 115009 (2010). [3] H. Padamsee et al., J. Low. Temp. Phys. 12, 387 (1973).

SC16

SC19

SC22

SC25

Evolution of the effective mass approaching the quantum critical pointin the heavy fermion superconductor CePt2In7

Purification of chemical mechanical polishing wastewater using a 2G
HTS high gradient magnetic separation system

Removal of silica and copper ions from CMP wastewater via magnetic
seeding aggregation using superconducting HGMS

Proximity effect for asymmetrical three layered F/S structures inexternal magnetic fieldDong Gyu Yang, Jung-bin Song, Young-gyun Kim, Jongseok Lee, Yeonjoo Park and
Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea

Jongseok Lee, Jung-bin Song, Dong Gyu Yang, Yeonjoo Park and Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea

D

We report Shubnikov-de Haas measurements on micro-structured CePt2In7 single
crystals under high pressures. CePt2In7 belongs to the CemMnIn3m+2n heavy fermion
family and orders antiferromagnetically below 5.5 K. Applying pressure induces asuperconducting phase and suppresses the AFM order with the Neel temperature
extrapolating to a quantum critical point. The magnetic fluctuations associated with
the QCP are thought to stabilize the unconventional superconducting phase. The
evolution of the effective electronic masses approaching the quantum critical point isessential to the understanding of the electronic correlation leading to unconventional
superconductivity. To this end we have developed a method to contact micro-structured
samples inside a diamond anvil cell allowing for complex sample shapes and several
electric contacts.

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Maxim V. Avdeev, Sergey L. Tsarevskii and Yurii N. Proshin*
Theoretical Physics Department, Kazan Federal University, Russia

We study the critical temperature Tc of the three-layered ferromagnet/superconductor(F/S) structures at the external magnetic field H parallel to the film. For the F1/S/F2
and F1/F2/S asymmetrical trilayers the triplet superconducting component is generated
at noncollinear magnetizations of the F layers. Assuming that all S and F layers are
dirty we solve boundary problem for the Usadel function. The results of numericalcalculations for Tc as function thicknesses both F1 and F2 layers at various parameters
F/S structure are resented. The application to the spin-switch problem is discussed. We
found that asymmetry can essentially change the spin-switch observation condition.

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Thermal stability of an epoxy-impregnated HTS racetrack coil without
turn-to-turn insulation for rotating machines

Effect of liquid cryogen on a 2G HTS magnet using a mixed cryogen
cooling system

Powder neutron diffraction study of HoCoGa5

Influence of proximity effect with Umklapp processes on the Josephsoncurrent in the SFS nanostructure

Oh Jun Kwon, Kwang Lok Kim, Yoon Hyuck Choi, Hyun-jin Shin and Haigun Lee*
Department of Materials Science and Engineering, Korea University, Korea

Kwang Lok Kim, Jung-bin Song, Yoon Hyuck Choi, Dong Gyu Yang and Haigun
Lee*
Department of Materials Science and Engineering, Korea University, Korea

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Riki Kobayashi1*, Koji Kaneko1, Shuichi Wakimoto1, Naoyuki Sanada2, Ryuta
Watanuki2, Kazuya Suzuki2 and Songxue Chi3
1
Quantum beam science directolate, Japan atomic energy agency, Japan2
Department of Advanced Materials Chemistry, Yokohama National University,
Japan
3
Quantum beam science directolate, Oak Ridge National Laboratory, USA
Ternary compound ACoGa5(A=rare earth or actinide) attracts a much attention due to hightemperature superconductivity in PuCoGa5 and related compounds. In addition, recent
study on TbCoGa5 reveals another interesting aspects of this system ; successive transitions
in TbCoGa5 could be “components-separated orders” which may arise from a novel typeof frustration between multipole. HoCoGa5 also exhibits successive transitions at TN1 = 9.6
K and TN2 = 7.5 K. In order to investigate nature of these transitions in HoCoGa5, neutron
powder diffraction experiment were carried out. Appearance of superlattice refractions
was clearly observed below TN1. In addition, we observed that both peak position andintensity of superlattice peaks abruptly change at TN2 on cooling. The observed peak in
the phase I(T < TN2) and II(TN2 < T < TN1) can be described with q1=(1/2 0 1/2) and
q2=(1/2 0 τ) with τ=0.35, respectively. The determined propagation vector of the phase
I is the same as that of TbCoGa5, whereas that of phase II is altered. Detailed magnetic
structure analysis for both phases are in progress.

July 13 (Fri)July 13 (Fri)Jakob Kanter1*, Philip J. W. Moll1, Filip Ronning2, Sven Friedemann3, Patricia L
Alireza3, Michael Sutherland3, P. Tobash2, J. Thompson2, Eric D. Bauer2 and Bertram
Batlogg1
1
Laboratory for Solid State Physics, ETH Zurich, Switzerland
2
Los Alamos National Laboratory, Los Alamos, New Mexico, USA
3
Cavendish Laboratory, University of Cambridge, United Kingdom

Vadim Tumanov and Yurii N. Proshin*
Theoretical Physics Department, Kazan Federal University, Russia

We consider the Josephson effect in symmetric superconductor-ferromagneticsuperconductor (SFS) system. The Josephson current is calculated as a function of theferromagnetic layer thickness d. The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) pairs
in the F layer have a nonzero wave vector, and the transformation the BCS pairs to the
FFLO pairs (and vice versa) at passing through SF (FS) borders may be proceeded
through the Umklapp processes [1]. To estimate the influence of proximity effectwe use the expansion of superconductor energy in the powers of an order parameter(near the critical temperature Tc). We take into account the dependence of the criticaltemperature Tc from the phase difference φ between the order parameter in the left andright S side of the SFS contact. Our results are compared with known data for the Nb/
CuNi/Nb nanostructures [2] where the critical Josephson current oscillations due totransitions between 0 and π phase state were observed. A good agreement is obtainedby taking into account the Umklapp processes.
1. Yu. A. Izyumov, Yu. N. Proshin, and M. G. Khusainov, Physics/Uspekhi 45, 109 (2002) 2. V.V.
Ryazanov et al., Rev. Low Temp. Phys. 136, 385 (2004)[1] J. L. Sarrao et al., Nature 420, 297 (2002). [2] F. Honda et al., Physica B 359, 1147 (2005). [3] N.
Sanada et al., J. Phys. Soc. Jpn. 78, 073709 (2009).

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Superconducting characters under pressure in heavy fermion
compounds CeIr(In1-xCdx)5 studied by In-NQR

Angle dependence of the Landau level spectrum in twisted bilayer
graphene

Influence of geometry on the edge states of Bi Nanoribbons

Mitsuharu Yashima
Engineering Science, Osaka University, Japan

Min-young Choi, Young-hwan Hyun and Yoonbai Kim*
Department of Physics, Sungkyunkwan University, Korea

A full quantum study on gapless modes and Axion electrodynamics in
topological insulator heterostructure systems

The heavy fermion compounds CeMIn5 (M = Co, Rh, Ir) have provided to study the
relationship between antiferromagnetism and superconductivity. CeCoIn5 becomessuperconducting with $T_c$ = 2.3 K at ambient pressure1. This value is the highest
record in the Ce-based heavy fermion superconductors. Since the existence of
antiferromagnetic spin fluctuations is confirmed, it is expected that superconductivity
is induced by antiferromagnetic spin fluctuations in CeCoIn 5. CeRhIn 5 is an
antiferromagnet with $T_N$ = 3.8 K at ambient pressure. Taking into account thelattice parameters of CeIrIn5, it is speculated that an antiferromagnetic order is realized
at ambient pressure, but it actually shows superconductivity with $T_c$ = 0.4 K.
The value of $T_c$ is very low, as compared with the other CeMIn5 compounds.
$T_c$ increases with increasing pressure and reaches about 1 K around 3 GPa, but
antiferromagnetic spin fluctuations are greatly suppressed with the application ofpressure. These results suggest that the superconducting mechanism of CeIrIn5 may bequite different from that of the other CeMIn5 compounds. In order to investigate theunconventional superconducting characteristics in CeIrIn5, the nuclear-quadrupoleresonance (NQR) measurements were performed under pressure in pure and Cd-doped
CeIrIn5.

In the context of the low-energy effective theory, the exact Landau level spectrumof quasiparticles in twisted bilayer graphene with small twist angle is analyticallyobtained by spheroidal eigenvalues. We analyze the dependence of the Landau levels
on the twist angle to find the points where the twofold degeneracy for twist angles
is lifted in the nonzero modes and below (above) which massive (massless) fermion
pictures become valid. In the perpendicular magnetic field of 10 tesla, the degeneracy
is removed at approximately 3 degrees for a few low levels, specifically approximately
2.56 degrees for the first pair of nonzero levels and approximately 3.50 degrees forthe next pair. Massive quasiparticle appears at the angle less than 1.17 degrees in 10
tesla, which matches perfectly with the recent experimental results. Since our analysis
is applicable to the cases of arbitrary constant magnetic fields, we make predictions
for the same experiment performed in arbitrary constant magnetic fields. For example,
for 40 tesla we get the critical angle of 2.34 degrees and the sequence of angles
5.11,7.01,8.42,... for the pairs of nonzero energy levels. The symmetry restoration
mechanism behind the massive (massless) transition is conjectured to be a tunneling(instanton) in momentum space.

Two-dimensional (2D) topological insulators or 2D quantum spin Hall (QSH) systems
provide an intriguing physical phenomena in condensed matter physics. The 2D QSHphase is a band insulator but has gapless edge states. The salient feature of these edge
states is that they are topologically protected. Here, using first-principles densityfunctional calculations, we investigate the effect of geometry on the edge states in zigzag
Bi nanoribbon (ZBNR) reported as a 2D QSH system.[1] We consider various edge
geometries involving the ideal termination, relaxation, and rebonded reconstruction. We
find that the rebonded reconstruction geometry is thermodynamically more stable thanother geometries. Since the transition from the reconstruction to the relaxation geometry
is kinetically feasible, the edge structure of ZBNR is expected to exhibit the orderdisorder transition as a function of temperature. We also find that the metallic featureof edge states is preserved with respect to the shear distortion and bond alternation,
but it is dramatically altered to produce a band-gap opening through the rebonded
reconstruction. We discuss such an influence of geometry on the edge states of ZBNR interms of the penetration depth of the edge states.

Xiao-Liang Qi, Taylor L. Hughes, and Shou-Cheng Zhang, Phys. Rev. B 78, 195424 (2008). Jeffrey C.
Y. Teo and C. L. Kane, Phys. Rev. B 82, 115120 (2010).

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Giant and twofold oscillations of magnetoresistance in topologicalinsulators Sb2Te3 and Bi2Te3 single crystals

Surface band structure study of Bismuth-based ternary topologicalinsulators

Magnetotransport measurements in pulsed magnetic fields: a case for
Fermiology studies in superconductors and topological insulators

Topological insulators are quantum materials with an insulating bulk state and a topologically protected
two dimensional metallic surface states.1,2 Unique electronic properties, such as the quantum spin Hall
effect, magnetoelectric effects, magnetic monopoles, and elusive Majorana states, are expected fromtopological insulators.3,4 Topological insulators have great potential applications in spintronics and quantum
information processing, as well as magnetoelectric devices with higher energy efficiency.5,6 To understandthe macroscopic properties of the topological surface states and to investigate the possibility of their device
applications, transport and magnetic measurements of high-quality single crystals are indispensable.
Anisotropic magneto-transport properties were studied in p-type Sb2Te3 and n-type Bi2Te3 topologicalinsulators through angular dependent magnetoresistance (MR) measurements. Giant MR of up to 230% was
observed, which exhibits linear at high fields without any trend towards saturation. The giant MR displays
a strong anisotropy, up to 210%, and twofold symmetry at different temperatures and fields. The giant MR
might be due to intravalley and intervalley scattering, and the strong anisotropy might result from anisotropiesof Fermi surface. The observed giant anisotropic MR of the Sb2Te3 and Bi2Te3 topological insulators could
find applications in magneto-electronic devices based on topological insulators, such as magnetic sensors.
1. M. Z. Hasan and C. L. Kane, Rev. Mod. Phys. 82, 4 (2010). 2. X. L. Qi and S. C. Zhang, Rev. Mod.
Phys. 83, 1057 (2011). 3. B. A. Bernevig, T. L. Hughes, and S. C. Zhang, Science 314, 1757 (2006). 4. D.
Hsieh, D. Qian, L. Wray, Y. Xia, Y. S. Hor, R. J. Cava, and M. Z. Hasan, Nature 452, 970 (2008). 5. J. E.
Moore, Nature 464, 194 (2010) 6. X. L. Wang, S. X. Dou, and C. Zhang, NPG Asia Mater. 2, 31 (2010).

Utilization of topological surface states is expected to lead to new vistas in electronics
and fundamental physics. However, most of the known topological insulators either do
not feature necessary band structure conditions (location of Dirac point with respect tothe bulk band) or lack topological invariants essential for certain class of applications.
Using angle-resolved photoemission spectroscopy (ARPES), we reveal the electronic
band structure topology of a family of ternary spin-orbit insulators some of whichfeature functional electronic structure with in-gap Dirac point while others featurenovel topological invariants (weak Z2 invariants) in crystalline form. These Bi-based
ternary topological insulators provide a natural access to lattice matched magneticallyordered states to be utilized in future devices.

Frederik Wolff-fabris1*, Jun Sung Kim2, Erik Kampert1, Joonbum Park2, Man Jim
Eom2, Sergei Zherlitsyn1, Thomas Herrmannsdoerfer1 and Jochen Wosnitza1
1
Dresden High Magnetic Field Laboratory (HLD), HZDR, Germany
2
Department of Physic, Pohang University of Science and Technology, Korea

Superconductors and Dirac materials, such as graphene and topological insulators, are intensively
studied in high magnetic fields. In this work, we present the current status of magnetotransportmeasurements at the Dresden High Magnetic Field Laboratory (HLD) and discuss examples ofphase-diagram and fermiology investigations in different compounds [1,2], as well as the new
Dirac material [3] SrMnBi2. Typical experiments in magnetic fields up to 85 T with 25 to 150 ms
pulse duration in samples spaces up to 16 mm are performed by discharging a 50 MJ capacitor
bank. We use standard four-probe-technique measurements with AC currents up to 200 kHz andthe longitudinal and transverse (Hall effect) voltages signals from the samples are digitized with afast recording system. We observed quantum oscillations in magnetotransport measurements up
to 63 T on crystals of SrMnBi2 and, together with other techniques, this demonstrates that there
is a Dirac dispersion in the electronic structure of the double-sized Bi square net. However, incontrast to graphene, the Dirac cone in SrMnBi2 is highly anisotropic which suggests that the Bi
square net can provide a new platform for highly anisotropic Dirac fermions. Aknowledgements
Work at the HLD was supported by EuroMagNET II (No. 228043).

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Engineering and manipulating topological qubits in 1D quantum wires

Topological aspects and transport properties of edge states in themulti-band superconductor Sr2RuO4First-principles study of spin texture in the multilayer graphene onNi(111)

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The 19th International Conference on Magnetism

Yoshiki Imai1*, Katsunori Wakabayashi2 and Manfred Sigrist3
1
Department of Physics, Saitama University, Japan
2
International Center for Materials Nanoarchitectonics, National Institute forMaterials Science, Japan
3
Theoretische Physik, Eidgenossische Technische Hochschule Zurich, Switzerland

Motivated by the spin-triplet chiral p-wave superconductor Sr2RuO4, we investigate
the edge state of multi-band superconductor by means of the three band tight-binding
model including inter-orbital hybridization and spin-orbit coupling effects. These bands
correspond to the alpha, beta and gamma bands of Sr2RuO4 where alpha and beta bands
have hole- and electron-like characters, respectively. In particular we focus on the
topological aspects and transport properties in the chiral spin-triplet phase. Althougha full quasiparticle excitation gap in the bulk system, gapless edge states appear andaffect both spontaneous spin and charge currents which give rise to anomalous andspin Hall effect. In this context, we study the interplay between electron- and hole-likeparticles and the effect of the genuinely two-dimensional gamma band in the formationof these edge states and edge currents. The topological aspects and correlation effects
on this system are also discussed.

Magnetic properties of rare earth doped Bi2Te3

Nahyun Jo, Youngha Choi, Kyujoon Lee and Myung-hwa Jung*
Physics, Sogang University, Korea
Bi2Te3 is one of 3-dimensional topological insulators together with Bi2Se3 and Bi2Sb3.
[1] Recently, Binghai Yan et. al have theoretically reported that LaBiTe3 is a strong
topological insulator. [2] We could conjecture that rare-earth materials have fascinating
magnetic properties, since it has filled outer shell ( 5s25p6 ) and simulataneously
unfiled inner shell (4f n). [3] Therefore, we made both LaxBi2-XTe3 and CexBi2-XTe3,
and measured transport and magnetic properties. LaxBi2-XTe3 is diamagnetic, while
CexBi2-XTe3 is paramagnetic at low temperature. From the modified curie-wiess fit,
we could obtain the effective magnetic moment of 2.56μB. This value demonstrates
that the Ce ion is in trivalent state. However, the carrier density of CexBi2-XTe3 isobserved to be on order smaller than that of Bi2Te3, giving rise to a strong increaseof carrier mobility. These results support a scenario of strong topological insulator.
Furthermore, a magnetoresistance ratio of CexBi2-XTe3 is 1600% at 70kOe, eventhough ferromagnetic FexBi2-XTe3 have 600% magnetoresistance ratio at 70kOe.
[1] Y.L. Chen et. al., SCIENCE, 325, 178 (2005) . [2] Binghai et. al. PRB, 82, 161108(R) (2010). [3]Charles Kittel, Introduction to Solid State Physic (John Wiley & Sons, Inc, New Jersey, 2005 ) .

[1] V. A. Gaparov, F. Wolff-Fabris, D. L. Sun et al. JETP 93, v.1, p. 29 (2010); [2] M. V. Kartsovnik, T. Helm, K. Putzke et al.
New Journal of Physics 13, 015001 (2011); [3] J. Park, G. Lee, F. Wolff-Fabris et al. Physical Review Letters 107, 126402 (2011).

SD02
Panagiotis Kotetes1, Alexander Shnirman2 and Gerd Schon1
1
Institut fur Theoretische Festkorperphysik, Karlsruhe Institute of Technology,
Germany2
Institut fur Theorie der Kondensierten Materie, Karlsruhe Institute of Technology,
Germany

Three dimensional topological insulator heterostructure systems show the various novel phenomena
such as gapless modes localized at defects or the Axion response in three dimensional topologicalinsulator-magnetic insulator heterostructures. The origin of these phenomena is the nontrivial
topology in both momentum and real spaces. Dealing with the spatial coordinates as the adiabatic
parameter in the heterostructure systems, one can introduce the semiclassical Hamiltonian, which
describes topological properties of the heterostructure system. On the other hand, in some cases,
it also happens that semiclassical approaches fail to describe correctly topological features. In thisstudy, we present full quantum treatment for three dimensional topological insulator heterostructure
systems without the semiclassical approximation. We, first, prove the index theorem for gaplessmodes in line defects of the topological insulator-magnetic insulator heterostructure systems.
Secondly, we demonstrate a full quantum calculation for the surface quantum anomalous Hall
effect at the interface of the topological insulator-magnetic insulator heterostructure without using
the Axion effective action. We also show that gapless modes in line defects and the Axion response
may be governed not only by helical Dirac fermions on the surfaces, but also by gapped boundstates at the interface, the contribution of which was missed in previous studies.

[1] M. Wada, S. Murakami, F. Freimuth, and G. Bihlmayer, Phys. Rev. B 83, 121310(R) (2011).

SD04
Madhab Neupane1, S.-y. Xu1, C. Liu1, L. A. Wray2, N. Alidoust1, A. Fedorov3, Y. S.
Hor4, T.-r Chang5, H.-t. Jeng6, H. Lin7, B. Bansil7, R. J. Cava4 and M. Z. Hasan1
1
Physics, Princeton University, USA
2
Physics, Princeton University & ALS, Berkeley, USA
3
Physics, ALS, Berkeley, USA
4
Chemistry, Princeton University, USA
5
Physics, National Tsing Hua University,, China
6
Physics, National Tsing Hua University & Institute of Physics, Academia Sinica,,
China
7
Physics, Northeastern University, USA

Ken Shiozaki1*, Takahiro Fukui2 and Satoshi Fujimoto1
1
Depertment of Physics, Kyoto University, Japan
2
Depertment of Physics, Ibaraki University, Japan

July 13 (Fri)July 13 (Fri)Hyun-jung Kim1, Gustav Bihlmayer2, Stefan Bluegel2 and Jun-hyung Cho1*
1
Department of Physics and Research Institute for Natural Sciences, Hanyang
University, Korea
2Peter Gruenberg Institut and Institute for Advanced Simulation, Forschungszentrum
Juelich and JARA, Germany

SD01
Zengji Yue, Xiaolin Wang* and Shixue Dou
Spintronic and Electronic Materials Group, Institute for Superconducting &Electronic Materials, University of Wollongong NSW 2522,, Australia

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Fumiyuki Ishii1*, Hiroki Kotaka2, Keisuke Sawada3 and Mineo Saito1
1
Faculty of Mathematics and Physics, Kanazawa University, Japan
2
Graduate School of Natural Science and Technology, Kanazawa University, Japan
3
Graduate School of Natural Science and Technology,, Kanazawa University, Japan

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Iron doping effect in topological insulator: Bi2Te3

Nahyun Jo1, Youngha Choi1, Kyujoon Lee1, Jungwon Jang2, Jinhee Kim2, Akio
Kimura3 and Myung-hwa Jung1*
1
Physics, Sogang University, Korea
2
Korea Research of Standards and Science, Korea
3
Physics, Hiroshima University, Japan
Bi2Te3 is well-known topological insulator with anti-site defects which complicatesthe manipulation of the Fermi level. It has also been reported that surface band of
topological insulators is open when magnetic ions are doped, because magnetic ionsare able to break the time reversal symmetry. In this report, we doped magnetic ionsof Fe into Bi2Te3 and studied the properties and the corresponding electronic structure.
We found that a small amount of Fe ions less than 0.4% do not open the surface gap,
but reduce the anti-site defects. Thus, Fe-doped Bi2Te3 has linear magnetoresistancewith high mobility (15,074cm2v-1s-1) which is three times higher than Bi2Te3 while
Bi2Te3 has a deviation from the linear dependence of magnetoresistance. The reductionof anti-site defects enhances the sample quality, so that we could observe quantum
oscillations such as Shubnikov de Haas and de Haas van Alphen effect. In addition,
the spin-dependent ARPES data also demonstrate both clear surface state without gap
opening and canted spin components in the c axis.

July 8-13, 2012 Busan, Korea

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poster Presentation
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Magneto transport properties of topological insulator nanoribbons of
Bi2Te3

Electronic structure and transport properties of pt based heusler
compounds with C1b structure for topological quantum phenomena

Topological phase in a one-dimensional interacting fermion system

Hong-seok Kim1, Hosun Shin2, Eun-kyoung Jeon3, Kung-won Rhie1, Ju-jin Kim4,
Jeong-o Lee3, Jaeyong Song2 and Yong-joo Doh1*
1
Dept. of Display and Semiconductor Physics, Korea University Sejong Campus,
Korea
2
Korea Research Institute of Standards and Science, Korea
3
Korea Research Institute of Chemical Technology, Korea
4
Dept. of Physics, Chonbuk National University, Korea

Siham Ouardi1, Gerhard H. Fecher1, Shekhar Chandra2, Gloskovskii Andrei3 andFelser Claudia1
1
Johannes Gutenberg University and Max Planck Institute for Chemical Physics ofSolids, Dresden, Germany
2
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
3Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg - University,
Mainz, Germany

We report on the magneto transport properties of topological insulator nanoribbonsof Bi2Te3. The Bi2Te3 nanoribbons were grown using the electrodeposition processes
and contacted with 100-nm-thick cobalt electrodes. At low temperature below T =10 K, the magnetoreistance increases with a magnetic field, B, which is attributed
to a weak antilocalization effect. When the magnetic field (B) is applied parallelto the ferromagnetic electrodes on top of the nanoribbon, a switching behavior of
the magnetoresistance is observed near B = 400 Oe. Temperature and gate voltage
dependences of the spin valve effect is discussed as well.

Many of the Heusler compounds based on heavy elements with 1:1:1 composition and C1b structure are zeroband gap insulators and exhibit partially an inverted band structure [1]. Based on a topologically protected
electronic surface states, this class of materials is supposed to open up innovative directions for futuretechnological applications in spintronics, quantum computing and thermoelectrics. The density of states of Pt
based Heusler compounds PtMZ (M = Y, Gd, Lu and Z= Sb, Bi) were investigated by bulk sensitive hard X-ray
photoelectron spectroscopy. The measured valence band spectra are clearly resolved and in well agreement withthe first-principles calculations of the electronic structure of the compounds. Close to the Fermi energy, the linear
behavior of the measured spectra at high excitation energy where influences of the surface can be neglected
improve bulk origin of the Dirac-cone type density [2]. Furthermore, the temperature dependence of electricalconductivity, Hall mobility, Seebeck coefficient and thermal conductivity were investigated. The promisingproperties of those compounds open a high potential for new technological applications.

SE02

Huaiming Guo
Department of physics, Beihang University, China

We study a one-dimensional (1D) interacting topological model by means of theexact diagonalization method. The topological properties are first examined with theexistence of the edge states at half-filling. We find that the topological phases are not
only robust to small repulsive interactions, but also are stabilized by small attractive
interactions, and also finite repulsive interaction can drive a topological nontrivial
phase into a trivial one while the attractive interaction can drive a trivial phase into a
nontrivial one. Next we calculate the Berry phase and parity of the bulk system andfind that they are equivalent in characterizing the topological phases. With them weobtain the critical interaction strengths and construct part of the phase diagram in theparameters’ space. Finally we discuss the effective Hamiltonian at the large-U limit andprovide an additional understanding of the numerical results. These results could be
realized experimentally using cold atoms trapped in the 1D optical lattice.
1: Xiao-Liang Qi and Shou-Cheng Zhang, Rev. Mod. Phys. 83, 1057 (2011). 2: J. E.
Moore, Nature (London) 464, 194 (2010). 3: M. Z. Hasan and C. L. Kane, Rev. Mod.
Phys. 82, 304 (2011). 4: Huaiming Guo and Shun-Qing Shen, Phys. Rev.B 84, 195107(2011).

[1] S. Chadov, X. Qi, J. Kubler, G. H. Fecher, C. Felser, and S. Zhang, Nat Mater 9, 541 (2010). [2] S. Ouardi, C. Shekhar, G.
H. Fecher, X. Kozina, G. Stryganyuk, C. Felser, S. Ueda, and K. Kobayashi, Appl. Phys. Lett. 98, 211901 (2011).

We performed soft point contact spectroscopy on the Ce-based heavy fermion systems(CeIn3, CeCoIn5, CeRhIn5, CeIrIn5, and Ce2RhIn8) with silver epoxy replacing a
conventional tip. Unlike CeIn3 where the conductance dI/dV is enhanced below TN(=10K), the conductance of CeRhIn5 at zero bias voltage is rapidly enhanced below
8K, which is higher than TN of CeRhIn5 (=3.8K). Heavy fermion compounds witha magnetic order often show intermediate states that are characterized by a broadenhancement of conductance at temperatures higher than TN, while heavy fermion
compounds without magnetic ordering reveal asymmetric conductance line-shape
below characteristic temperature T*. The antiferromagnet Ce2RhIn8 is unique in thatthe intermediate state shows a V-shaped dip around zero biased voltage and is enhancedwith decreasing temperature below 25K, which is much higher than T*=5K. Below
TN=2.8K, a symmetric peak at zero bias voltage in the conductance spectra is enhanced
within the V-shaped dip with decreasing temperature. We interpret the symmetric peak
and V-shaped dip around zero bias as manifestation of the antiferromagnetic (AFM)
order and Kondo dip in the Kondo lattice system, respectively, indicating that Ce2RhIn8
is at a boundary between AFM and Kondo states.

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Structural investigations of the topological insulators Bi2Se3-xTex

Gapless interface states in topological insulator/semiconductor
heterostructures

Robustness of 1D topological superconductors with Majorana edge
states against lattice modulation

Evidence of a spin gap above the magnetic ordering temperature andcrystal field excitations in CeOs2Al10

Geetha Balakrishnan1*, Ravi Singh1, Devashibhai Adroja2, Kevin Knight2 andMatthias Gutmann2
1
Department of Physics, University of Warwick, United Kingdom
2
ISIS Facility, Rutherford Appleton Laboratory, United Kingdom

July 13 (Fri)Soft point contact spectroscopy in the antiferromagnet Ce2RhIn8

Eunsung Park1, Xin Lu2, Chung Jae Won3, Nam Jung Hur3, Eric D. Bauer2, Joe D.
Thompson2 and Tuson Park1*
1
Department of Physics, Sungkyunkwan University, Korea
2
Condensed Matter & Magnet Science Group, Los Alamos National Laboratory, USA
3
Department of Physics, Inha University, Korea

The binary phases Bi2Se3 and Bi2Te3 have been discovered to exhibit three dimensional
topological insulating behaviour. However, these compounds are not insulators wheninvestigated in the bulk. Bi2Se3 is generally known to exhibit n-type conductivity
and Bi2Te3 exhibits n or p-type conductivity depending on the synthesis conditions.
The bulk conductivity exhibited by these materials are seen as being detrimental
to the investigation of their surface conducting properties. We have examined theintermediate compositions Bi2Se3-xTex in order to study the role played by vacancies
and anti-site defects in determining the bulk conduction mechanisms. We reportdetailed structural refinements obtained by neutron diffraction experiments on severalof the intermediary phases and draw correlations between the defect structures andtheir conducting / semiconducting / insulating behaviour.

Hugo Aramberri and Carmen Munoz*
ICMM- Consejo Superior de Investigaciones Cientificas, Spain

Based on first principles calculations we investigate the existence of topologicallynontrivial states at the interface between a topological insulator (TI) and asemiconductor (S) in TI/S heterostructures. We find that the emergence of gapless states
depends on the symmetry of the junction, being protected by mirror symmetry. We
discuss their characteristic dispersion and spatial distribution and analyze the quantum
interference between helical states and its influence on the spin texture of the quasi
two-dimensional states as a function of the semiconductor thicknesses. From the firstprinciples calculations, we derive an effective Hamiltonian, which captures the salient
topological features. The effective model combined with a Green function matching
method [1] allow us to investigate the evolution of the interaction between interface
helical Dirac fermions from finite heterostructures to actual seminfinite interfaces andtherefore to analyze the novel behavior of the spin-charge coupling in two-dimensional
layered systems with strong spin-orbit coupling.

Masaki Tezuka* and Norio Kawakami
Department of Physics, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502,
Japan

PG

U

ED

D
RA

[1] M. C. Munoz, V. R. Velasco and F. Garcia-Moliner, Phys. Rev. B. 39 (1989) 1786; M. C. Munoz
and M. P. Lopez Sancho, Phys. Rev. B. 41 (1990) 8412.

D T Adroja1*, P P Deen2, A D Hillier1, Y Muro3, J Kajino4, T Takabatake4, A M
Strydom5, P Peratheepan5, F Demmel1, J R Stewart1 and J Taylor1
1
ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX, United Kingdom
2
European Spallation Source, St Algatan 4, Box 176 Lund 221 00, Sweden
3
Liberal Arts and Sciences, Toyama Prefectural University, Kurokawa 5180, Imizu 939-0398, Japan
4
Department of Quantum matter, ADSM, and IAMR, Hiroshima University, Higashi-Hiroshima, 739-8530,
Japan
5
Physics Department, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa
Recently, the opening of a spin gap has been reported in the intermetallic compounds CeT2Al10 (T = Ru
and Os) below TN = 27-29K through heat capacity and magnetic susceptibility measurements. Various
theoretical models have been proposed to explain the spin gap formation, for example a spin-Peierls and
RVB models of Hanzawa for CeRu2Al10. To understand the nature of the spin gap formation in CeOs2Al10,
we have carried out low and high energies inelastic neutron scattering (INS) measurements between 4.5 and
65K. Our INS studies reveal a clear sign of a spin gap of 11meV at 4.5K and of 4meV at 35K, while above
45K the observed response transformed into a quasielastic line with linewdith of ~ 8 meV. The observationof a spin gap above TN suggests that its origin is not only due to the gapped spin wave, but also related tothe hybridization between 4f- and conduction electrons. Moreover the high energy INS study reveals two
crystal field (CEF) excitations at 37 and 57meV. We have carried out an analysis of the INS data along withthe single crystal susceptibility based on the CEF model, which gives good fit to both data sets.

SD14

SD17

SE01

SE04

Josephson effects in Bi2Se3 topological insulator nanoribbons

Thermoelectric transport in topological insulators

Temperature-pressure phase diagram of quadrupolar order in
PrTr2Al20 (Tr=Ti,V)

Role of quantum fluctuations in forming heavy-fermions for Ca2xSrxRuO4

Hyunho Noh1, Lee-seul Park2, Eun-kyoung Jeon3, Hong-seok Kim4, Jeong-o Lee3, Jin
Seok Lee2, Jinhee Kim1 and Yong-joo Doh4*
1
Korea Research Institute of Standards and Science, Korea
2
Dept. of Chemistry, Sookmyung Women’s University, Korea
3
Korea Research Institute of Chemical Technology, Korea
4
Dept. of Display and Semiconductor Physics, Korea University Sejong Campus,
Korea
Topological insulators are exotic materials with bulk band gap and metallic edge
states which are protected on their own boundary topologically. Here, we report on
the fabrication and measurement results of the superconducting proximity junctionsof topological insulator nanoribbons of Bi2Se3. Single-crystalline Bi2Se3 nanoribbons
are synthesized using the vapor-liquid-solid method, while the superconducting Al
electrodes are formed on top of the nanowire. When a magnetic field (H) is appliedalong the axial direction, the magneto-resistance data exhibit quasi-periodic oscillations
with an average periodicity of H* ~ 0.4 T, which is consistent with the AharonovBohm oscillations. In the superconducting state, the supercurrent branch with a criticalcurrent of Ic ~ 90 nA is clearly observed in the current-voltage curve as a result of thesuperconducting proximity effect in Bi2Se3 nanoribbon. Quantized voltage steps of the
Bi2Se3 nanoribbon Josephson junction under the microwave irradiation satisfy the ac
Josephson relation.

Oleg Tretiakov*
Physics and Astronomy, Texas A&M University, USA

We study the thermoelectric properties of three-dimensional topological insulatorswith many holes (or pores) in the bulk. We show that at high density of these holes
the thermoelectric figure of merit, ZT, can be large due to the contribution of the
conducting surfaces and the suppressed phonon thermal conductivity. The maximum
efficiency can be tuned by an induced gap in the surface states dispersion throughtunneling, magnetic impurities, or external magnetic fields. The large values of ZT,
much higher than unity for reasonable parameters, make this system a strong candidate
for applications in heat management of nanodevices, especially at low temperatures.
O. A. Tretiakov, Ar. Abanov, and Jairo Sinova, Applied Physics Letters, 99, 113110 (2011).

Toshiki Tanaka1, Kazuyuki Matsubayashi2*, Akihiko Hisada2, Akito Sakai2, Satoru
Nakatsuji2, Yoshiya Uwatoko2 and Yasunori Kubo3
1
Graduate School,Nihon Univ, Japan
2
Institute for Solid State Physics, The University of Tokyo, Japan
3
College of Humanities and Sciences,Nihon Univ, Japan
PrTr2Al20 (Tr=Ti,V) crystallizes in a cubic CeCr2Al20 type structure with the space group Fd3?m. According to neutron experiment, crystal electric field (CEF) ground state of Pr ion is thenon-Kramers Γ3 doublet [1]. Reflecting the non-magnetic ground state, PrTi2Al20 and PrV2Al20
exhibit quadrupolar ordering at TQ ~ 2.0 K and 0.6 K, respectively. It is notable that the lowtemperature electrical resistivity of PrV2Al20 shows √T dependence, suggesting the quadrupolar
Kondo effect[2]. In the present study, we have measured electrical resistivity under highpressure on PrTr2Al20 (Tr=Ti,V) single crystals in order to clarity the pressure dependence of TQ
and Kondo effect. Electrical resistivity of PrTi2Al20 shows the broad maximum centered at ~50
K due to incoherent Kondo-scattering processes on the ground state and the excited CEF level.
With increasing pressure, the magnitude of this anomaly increases while the peak position isunchanged. At lower temperatures, it is found that a clear resistive drop at TQ ~ 2 K at ambientpressure. TQ first increases and shows the maximum under pressure. We will present the phase
diagram of PrTi2Al20 together with that of PrV2Al20.

July 13 (Fri)SD12

Naoya Arakawa and Masao Ogata
Department of Physics, The University of Tokyo, Japan

In order to understand a role of quantum fluctuations in forming heavy-fermionsfor Ca2-xSrxRuO4, we investigated the effect of quantum fluctuations on the massenhancement on the basis of the three-orbital Hubbard model for the Ru-t2g-orbitals.
In this presentation, I show the momentum-dependence of both the spin and charge
susceptibilities for the tight-binding models at x = 2.0 and 0.5 within the random
phase approximation (RPA). I also present the variation of γe, obtained by using theHellmann-Feynman theorem and the RPA, between x=2.0 and 0.5 and address a role ofboth the spin and orbital fluctuations in enhancing γe for Ca2-xSrxRuO4.

[1]:T. J. Sato, S. Ibuka, A. Sakai and S. Nakatsuji: Meeting Abst. Phys. Soc. Jpn,Vol.65, Issue 2, Pt. 3,(2010) p. 584 [2]:A.Sakai, S.Nakatsuji : J. Phys. Soc Jpn. 80 (2011) 063701

332

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

333

poster Presentation
SE05

SE08

SE11

SE14

Study of long range magnetic ordering and spin gap formationin Ce(Ru1-xFex)2Al10 through muSR and neutron scattering
measurements
1
1
2
3
3
4

Spin-density wave order in the 2D heavy fermion system CePt2In7

Electrical resistivity measurement under pressure in the heavy fermion
antiferromagnetic compound Ce2PtGa12

Universal behavior in the nonlinear magnetic response of strongly
correlated metals

1

ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX, United Kingdom
Liberal Arts and Sciences, Toyama Prefectural University, Kurokawa 5180, Imizu 939-0398, Japan
Department of Quantum matter, ADSM, and IAMR, Hiroshima University, Higashi-Hiroshima,739-8530, Japan4
Physics Department, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa
5European Spallation Source, St Algatan 4, Box 176 Lund 221 00, Sweden
2
3

Martin Mansson1*, Jun Sugiyama2, Yasmine Sassa1, Bastian M. Wojek3, Thomasz
Durakiewicz4, Krunoslav Prsa1, Olof Gotberg3, Calin Rusu5, Daniel Andreica5,
Stephane Pons6, Marco Grioni6, Oscar Tjernberg3 and Eric D. Bauer4
1
Lab. for Solid State Physics, ETH Zurich, Switzerland
2
Toyota Central Research and Development Labs. Inc., Japan
3
Materials Physics, Royal Institute of Technology, KTH Stockholm, Sweden
4
Los Alamos National Laboratory, USA
5
Faculty of Physics, Babes-Bolyai University, Romania
6
Institute of Condensed Matter Physics, EPF Lausanne, Switzerland

Ryo Sasaki1, Kazuyuki Matsubayashi1, Takuya Shiraishi2, Tetsuro Yamashita2, Shigeo
Ohara2 and Yoshiya Uwatoko1
1
Institute for Solid State Physics, the University of Tokyo, Kashiwa, Chiba 277-8581,
Japan
2
Department of Engineering Physics, Electronics and Mechanics, Graduate School ofEngineering, Nagoya Institute of Technology, Nagoya 466-8555, JapanCe-based heavy-fermion ternary compounds have been of interest because of
their exotic physical properties under pressure, such as magnetic ordering andsuperconductivity.[1] In these systems, there is a competition between magnetic orderof f-electrons (RKKY effect) and the screening of magnetic moments (Kondo effect)
producing large effective electron masses. Ce2PtGa12 orders antiferromagnetically at 7
K, and specific heat measurements suggest that it is a moderate heavy-fermion systemwith γ ≒ 191 mJ/mol K2. For understand of competition between RKKY and Kondo
effect, We have measured the electrical resistivity under pressure on Ce2PtGa12 single
crystal. In this paper, we will report the suppression of the antiferromagnetic orderunder higher pressure and discuss the electronic state in the vicinity of the criticalpressure.

B S Shivaram1, D G Hinks2, B Nartowt3 and Pradeep Kumar3
Department of Physics, University of Virginia, USA
2
Materials Science Division, Argonne National Labs, USA
3
Department of Physics, University of Florida, USA1

A diverse class of strongly correlated electronic materials irrespective of whether
they order magnetically or not, often exhibit a peak in the temperature dependenceof the linear magnetic susceptibility, χ1. In non-linear susceptibility measurements on
a number of heavy electron materials including in single crystals of the prototypicalstrongly correlated metal, UPt3, we find that there exists a peak in the third ordersusceptibility, χ3 as well. This peak in χ3 occurs at a temperature T3, which is roughly
half the temperature T1, at which the peak in χ1 appears. This proportionality between
T3 and T1 also reported previously in other heavy fermion systems implies a universal
behavior in the nonlinear magnetic response of correlated metals. The observed
proportionality between T3 and T1 can is explained by a model which assumes a singlet
ground state for the spins present in a crystalline electric field with a concomitant
doublet excited state, separated from the ground state by an energy Δ. This model also
yields metamagnetic behavior at a magnetic field corresponding to Δ.

We have carried out muon spin relaxation (muSR) and inelastic neutron scattering (INS)investigations on Ce(Ru1-xFex)2Al10 (x=0, 0.3, 0.5, 0.8 and 1) compounds to investigate theorigin of the spin gap formation. Our muSR study confirms the long-range magnetic ordering
below 26K in x=0, 0.3 and 0.5, while x=0.8 and 1.0 remains paramagnetic down to 1.2K.
Furthermore, INS measurements of x=0 clearly reveal the presence of a spin gap of 8meV at 5K.
Interestingly at 5K the spin gap excitation broadens in x=0.3 and exhibits two clear INS peaks at
7.6(0.3) and 11.1(2.0)meV in x=0.5. Moreover the x=0.8 sample, which remains paramagnetic
down to 1.2K, reveals a clear sign of a spin gap of 10-12 meV, with strong Q-dependent intensitythat follows a spin-dimer structure factor. The observation of a spin gap in the paramagnetic
sample (x=0.8) opens a question, what is the origin of the spin gap in CeT2Al10 (T=Ru andOs) compounds? Possibilities include gapped spin wave, hybridization gap, spin-dimer or a gap
opening on a small part of the Fermi surface. Our analysis of the Q-dependent intensity reveals
that the mechanism of the spin gap in the x=0.8 sample is possibly due to spin-dimer formation.

The title compound is a recently discovered heavy fermion material where the spacing between Ce-In
planes is drastically increased. Consequently, CePt2In7 inherit a truly 2D electronic structure. It was recently
discovered that CePt2In7 is not only AF (TN=5.3 K) at ambient pressure but also becomes SC underpressure with a maximum transition temperature Tc=2.1 K at P=3.12 GPa. At lower pressures an intriguing
coexistence of the AF order and SC phase is found, and that with increasing pressure Tc is increasing while
TN decreases. The growth of the SC on the expense of the AF order suggests a crossover behavior of the Ce4f electrons from localized to itinerant, similar to what is considered for the well-known CeRhIn5 compound.
In the presented work the low-temperature microscopic magnetic properties of the quasi-2D heavy fermion
compound, CePt2In7 are investigated by using μSR. Clear evidence for the formation of a SDW order ispresented. The magnetic order parameter fit well to a modified BSC gap-energy function in a strong-coupling
scenario, possibly predicting the evolution of unconventional pairing in the pressure induced superconducting
phase of this compound. Finally, we also present recent pressure dependent μSR data.

SE06

SE09

SE12

SE15

Specific heat of structure-disordered heavy-fermion CexY80-xMn20
alloys

Metal-nonmetal transition in Cr partial substituted Ni0.96S

Anisotropy of URhGe

X-ray absorption studies of the Ce2Rh1-xIrxIn8 intermetallic compounds

Yusuke Amakai1*, Shinya Tanaka1, Yasuhiro Shiojiri1, Naoki Momono1, Hideaki
Takano1, Shigeyuki Murayama1, Yoshihisa Obi2 and Koki Takanashi2
1
Graduate School of Engineering, Muroran Institute of Technology, Japan
2
Institute for Material Research, Tohoku University, Japan

Recently, we have reported physical properties of structure-disordered (a-)CexY80xMn20 alloys which show a heavy fermion state in the non-Bloch system withouttranslation symmetry[1]. The specific heat Cp for present alloys follows γT + βT3
down to about 10 K. The T-linear coefficient γ shows a large value (~200 mJ/CemolK2) and almost independent of the Ce-concentration. However, the Cp/T vs. T2
plot of T < 10 K deviates from the T-linear relation with decreasing temperature. In
this work, in order to clarify the factor of the deviation of Cp/T for a-CexY80-xMn20
alloys, we have measured the low-temperature specific heat. We have estimated thetemperature TA of the deviation from the Cp/T vs. T2 plot for present alloys. The TA isabout 10 K, and almost independent of the Ce-concentration. Therefore, the deviationfrom the Cp/T for the present alloys would be considered the crystalline-electric-field
splitting of the six-fold degenerate level of the Ce3+ ion. Detailed discussions will bepresented at the conference.
[1] Y. Amakai, et. al., Phys. Rev. B, 79(2009)245126.

[1] R. T. Macaluso et al., J. Solid State Chem. 178 (2005) 3547.

Funding Source: Swiss National Science Foundation (Project 6, NCCR MaNEP), U.S. DOE Oce of
Sciences, VR Sweden and Toyota CRDL.

Masanori Matoba*, Yoichi Kamihara and Shuichiro Anzai
Center for Applied Physics and Physico-Informatics, Keio University, Japan
Hexagonal NiAs-type NiS exhibits a first-order metal-nonmetal transition (MNT) at Tt=263K,
resulting from the opening of narrow charge-transfer (CT) gap between the S 3p band and theupper Hubbard band [1,2]. The low temperature phase is the nonmetallic antiferromagnetic
state, while the high temperature phase shows metallic and Pauli-paramagnetic behavior[3,4]. The substitution of vacancies for Ni atoms in NiS lowers Tt to be suppressed to be
zero at d=0.035 in Ni1-dS, so that metallic Ni0.96S do not exhibit the MNT [5,6]. In this study,
we synthesized Cr-partial substituted Ni0.96S or (Ni1-xCrx)0.96S by a solid state reaction in an
evacuated silica tube to reveal the Cr-partial substitution effect on the physical propertiesof metallic Ni0.96S by the measurements of X-ray diffraction, electrical resistivity, magnetic
susceptibility, and thermopower. Surprisingly, (Ni1-xCrx)0.96S clearly exhibits the MNT, while
metallic Ni0.96S do not exhibit the MNT. The Tt increases with x sharply from x=0.025 (Tt=50
K) to x=0.09 (Tt=260 K) by Cr-partial substitution for Ni in Ni_{0.96}S. At the conference,electronic nature of Cr-partial substituted Ni0.96S or (Ni1-xCrx)0.96S with ability for the opening ofCT-gap will be discussed from the viewpoint of the strongly correlated electron systems.
[1] A. Fujimori, H. Namatame, M. Matoba and S. Anzai, Phys. Rev. B 42, 620 (1990). [2] M. Imada, A. Fujimori, and Y.
Tokura, Rev. Mod. Phys. 70, 1039 (1998). [3] J. T. Sparks and T. Komoto, Phys. Lett. A 25, 398 (1967). [4] S. Anzai
and K. Ozawa, J. Phys. Soc. Jpn. 24, 271 (1968). [5] R. Brusetti, J. M. D. Coey, G. Czjzek, J. Fink, F. Gompf and H.
Schmidt, J. Phys. F 10, 33 (1980). [6] M. Matoba and S. Anzai and A. Fujimori, J. Phys. Soc. Jpn. 60, 4230 (1991).

Jack M Barraclough1*, Edward A Yelland1 and Andrew D Huxley2
1
School of Physics and Astronomy, University of St Andrews and Scottish Universities
Physics Alliance (SUPA), United Kingdom
2
School of Physics, University of Edinburgh and SUPA, United Kingdom
The heavy fermion material URhGe has garnered interest in recent years as an
unconventional superconductor. It shows coexistence of ferromagnetism and p-wave
superconductivity[1], and superconductivity which is re-entrant in magnetic field[2].
We now believe the latter effect to be the result of proximity to a topological change
in the Fermi-surface[3]. In this poster I report recent resistivity measurements on
samples of URhGe with well-defined current direction. Most previous works do notconsider this when reporting resistivity, however we find that some features can varysignificantly as a function of current direction. We discuss how these findings constrain
the anisotropy of the Fermi surface, and the possibility of a field dependent and/or
anisotropic scattering rate. I also present data taken on high quality samples close to thequantum critical point. Interestingly, there is no enhancement of the superconducting
Tc near the QCP compared to that observed with the field applied entirely along the
crystalline b-axis, where a low temperature tricritical point is present.
[1] F Hardy and A D Huxley, PRL 94 247006 (2005) [2] F Levy et al, Science 308 1343 (2005) [3]
E A Yelland et al, Nature Physics 7, 890-894 (2011)

Cris Adriano1, Nilmar Silva Camilo2, Leandro F Bufaical3, Leticie Medonca Ferreira4,
Eduardo N Hering5, Pascoal G. Pagliuso1 and Raimundo Lora-serrano2*
1
Instituto de Fisica 'Gleb Wataghin' UNICAMP, CP 6165, 13083-970 Campinas, SP, Brazil
2
Instituto de Fisica, Universidade Federal de Uberlandia, 38400-902 Uberlandia-MG, Brazil
3
Instituto de Fisica, Universidade federal de Goias, Goiania-GO, 74001-970, Brazil
4
Instituto de Fisica e Matematica, Universidade Federal de Pelotas (UFPel), CP 354, 96010900 Pelotas, Brazil
5
Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio deJaneiro, RJ, Brazil

July 13 (Fri)D T Adroja *, A D Hillier , Y Muro , J Kajino , T Takabatake , P Peratheepan , A M
Strydom4, P P Deen5, J R Stewart1, J Taylor1, F Demmel1 and M Adams1

July 13 (Fri)poster Presentation

Within the series of heavy fermions Ce2Rh1-xIrxIn8 compounds it has been recently observed the occurrenceof two low-temperature superconducting (SC) phases as a function of temperature both at ambient pressure
and under applied pressure for intermediate Ir-content (x~0.25-0.7) with remarkable different behavior ofboth states as a function of pressure and x [1]. The details of the observed results seem to be reminiscentof the two SC phases found in the CeRh1-xIrxIn5 system, thus related to the higher dimensionality andstructural disorder for the Ce2-1-8 systems. Here, we report the results of extended x-ray absorption finestructure measurements performed on Ce2Rh1-xIrxIn8 (x = 0.0, 0.25, 0.75 and 1.0) at T = 10, 150 and 300
K at the Rh K-edge and at the Ce and Ir-L3 absorption edges in order to check the extent of the structural
disorder at the Rh-Ir atomic sites and their relevance for the SC phases observed in the resistivity andspecific heat measurements in these compounds. Our results point to the trivalent state of the Ce ions, andthat there is no evidence of phase separation in the lowest measured temperature.
[1] E. N. Hering, H. A. Borges et al. Phys. Rev. B 82 184517 (2010)

SE07

SE10

SE13

SE16

Synchrotron X-ray diffraction study on crystal structure of URu2Si2

A study of ni-substitution and pressure effects on the heavy-fermion
Superconductor CeCu2Si2

Study of spin wave and spin gap in single crystals of CeRu2Al10 using
inelastic neutron scattering measurements

Polarized neutron diffraction study on the magnetic ordering in
UMn2Al20

Chihiro Tabata1*, Reiji Kumai2, Kensuke Kobayashi2, Hironori Nakao2, Yoichi
Murakami2, Makoto Yokoyama3, Hiroyuki Hidaka1, Tatsuya Yanagisawa1 and Hiroshi
Amitsuka1
1
Graduate School of Science, Hokkaido University, Japan
2
CMRC and PF, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Japan
3
Faculty of Science, Ibaraki University, Japan
URu2Si2 (the tetragonal ThCr2Si2 type crystal structure; space group I4/mmm) has
attracted much interest because of its peculiar phase transition at 17.5 K (≡To) [13]. Despite more than 25 years of intense research trying to identify the orderparameter, the intrinsic nature of the phase transition has not been elucidated [4]. The
ThCr2Si2 structure includes a free position parameter, z, of the Si 4(e) site. Since the
Si ions are located at the second nearest-neighbor position of the U ions, the precise
determination of the z parameter might provide useful information for evaluation of
hybridization effects of 5f orbits with Si s, p states, calculations of a band structure,
analyses for 29Si-NMR spectra, and so on. These pieces of knowledge might offer aclue to solving the issue of hidden order in URu2Si2. We will report our latest studyof structural analyses of a single crystal of this material based on the X-ray diffraction
measurements performed at BL-8A and B in the Photon Factory KEK.
[1] T.T.M. Palstra et al., Phys. Rev. Lett. 55, 2727 (1985). [2] M.B. Maple et al., Phys. Rev. Lett. 56, 185 (1986).
[3] W. Schlabitz et al., Z. Phys. B 62, 171 (1986). [4] J.A. Mydosh and P.M. Oppeneer, arXiv:1107.0258v1 (2011).

334

The 19th International Conference on Magnetism

Yoichi Ikeda*, Yuzo Ito, Shingo Araki and Tatsuo C Kobayashi
Graduate School of Natural Science and Technology, Okayama University, JapanThe heavy-fermion superconductor CeCu2Si2 shows an attractive enhancement of T_caround a critical pressure (~ 4.5 GPa), at which the T-linear variation of resistivity, theenhancement of the residual resistivity, the rapid decrease of T2-coefficient and a sign ofa valence crossover have been observed [1-3]. These characteristics have been believed
to be signatures of the critical valence fluctuations associated with a valence transition
around its critical-end point [4, 5], while we have been requiring more signatures forclarification of the fascinating phenomena. Effects of the Ni substitution on CeCu2Si2
are investigated by means of specific heat and electrical resistivity measurements. A
characteristic T-linear dependence of the resistivity is observed around x ~ 0.1 with afractional resistivity drop due to filamentary superconductivity. In addition, a variationof the power index n of a fit to ρ-ρ_0 = aT^n at low temperatures against T_1^max
at which the resistivity shows a maximum is almost fully identical to the result of thehigh pressure experiment [1]. We would like to discuss for the similarities between Ni
doping and pressure and the origin of the anomalous Fermi liquid state.
[1] A. Holmes et al., PRB 69 (2004) 024508. [2] K. Fujiwara et al., submitted to J. Phys.: Conf. Ser.
(SCES2011) Cambridge. [3] J. -P. Rueff et al., PRL 106 (2011) 186405. [4] K. Miyake, J. Phys.:
Condens. Matter 19 (2007) 125201. [5] G. Seyfarth et al., arXiv:1111.4873v1.

D T Adroja1*, E A Goremychkin1, A D Hillier1, Y Muro2, J Kajino3 and T Takabatake3
ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX, United Kingdom
2
Liberal Arts and Sciences, Toyama Prefectural University, Kurokawa 5180, Imizu
939-0398, Japan3
Department of Quantum matter, ADSM, and IAMR, Hiroshima University, HigashiHiroshima, 739-8530, Japan1

We have carried out inelastic neutron scattering (INS) investigations on single crystalsof CeRu2Al10 using the high neutron flux spectrometer MERLIN at ISIS facility. The
crystals (total mass of 2.4g) were mounted in the b-c scattering plane. We carried out
measurements using neutron incident energy Ei=20 meV at 4.5 K for b // ki and c //ki. We have seen a clear dispersive spin wave type excitations coming out from the[1 0 0] and [0 2 0] antiferromagnetic zone centres with a single ion anisotropic gap of~4.5 meV. On the other hand along [0 0 L] direction the spin excitations exhibit weak
dispersion with almost Q-independent gap of 8 meV. The intensity of the peak along[0 0 L] is maximum at L = 0 and decreases with increasing L value, like Ce3+ magnetic
form factor. These results may suggest that excitations in the ab-plane can be explainedby the gaped spin wave, but along [0 0 L] is dominated by the hybridization effect. We
will present a detail analysis of the observed excitations.

Przemyslaw Swatek1*, Piotr Wisniewski1, Arsen Gukasov2 and Dariusz Kaczorowski1
Institute for Low Temperatures and Structure Research, Polish Academy of Sciences,
Wroclaw, Poland
2
Laboratoire Leon Brillouin, CEA-CNRS, CE-Saclay, 91191 Gif sur Yvette, France
1

The ternary intermetallic compounds UX2Al20 (X = Ti, V, Nb, Ta, and Cr), crystallizing with the cubic
CeCr2Al20-type crystal structure, were characterized in the literature as weak Pauli paramagnets [1-3].
In striking contrast, the isostructural phase UMn2Al20 was reported to order ferromagnetically due to thepresence of magnetic moments on the uranium atom sites [4]. In this contribution, we present the resultsof our polarized neutron diffraction study on a high-quality single crystal of UMn2Al20, which was also
carefully characterized by means of X-ray diffraction, microprobe, magnetic, electrical transport andheat capacity measurements. The bulk properties were found very similar to those published in Ref. 4.
In particular, the ferromagnetic transition at TC = 17 K was clearly revealed from the magnetic data,
while the temperature-dependent specific heat and electrical resistivity were found nearly featureless. The
magnetization density maps derived from the neutron diffraction data, showed that the ferromagnetismin UMn2Al20 arises due to the magnetic moments carried on the manganese atoms, while the uranium
sublattice remains nonmagnetic. This result appears perfectly consistent with the behavior of the UX2Al20 (X= Ti, V, Nb, Ta, and Cr) compounds, in which the U atoms do not exhibit any magnetic moments.
[1] S. Niemann and W. Jeitschko, J. Solid State Chem., 114, 337 (1995). [2] K. Okuda et al. J. Phys. Soc. Jpn. 58, 4296 (1989).
[3] P. Swatek and D. Kaczorowski, J. Solid State Chem., submitted. [4] C. H. Wang et al., Phys. Rev. B 82, 094406 (2010).

July 8-13, 2012 Busan, Korea

335

poster Presentation
SE20

SE23

Antiferromagnetic ordering in single-crystalline Ce2IrSi3

Study of vibron quasibound state in CeAg1-xCuxAl3, 0<x<1

Electronic structure studies of UPt3 using soft x-ray angle-resolved
photoemission spectroscopy and band calculation

The novel cerium-based ternary silicide Ce2IrSi3, crystallizing with fully orderedderivative of the hexagonal AlB2-type unit cell, has recently been characterized as a
Kondo lattice that orders antiferromagnetically at TN = 1.3 K [1]. An antiferromagnetic
character of the ordering was inferred merely from the specific heat and electricalresistivity data, collected in applied magnetic fields. With the aim at verification of thepresumed nature of the ground state, we have performed magnetic studies down to
0.46 K and in external magnetic fields up to 7 T using a SQUID magnetometer. The
results unambiguously corroborated the antiferromagnetic phase transition at 1.3 K,
and additionally revealed pronounced magnetic anisotropy in the ordered state. The
magnetization component measured within the hexagonal ab plane was found muchlarger than that taken along the c axis. This finding indicates that the magnetic moments
in Ce2IrSi3 are confined to the basal plane. In a magnetic field of 0.5 T applied within
the easy plane, the compound undergoes a metamagnetic-like phase transition. In turn,upon applying magnetic field along the hexagonal c axis some complex, yet more
subtle changes in the magnetic structure seem to occur.
[1] M. Szlawska and D. Kaczorowski, Phys. Rev. B 84 (2011) 094430

Cesar De La Fuente1*, Agustin Del Moral1, Devashibhai T. Adroja2 and Jon Taylor2
1
Fisica de la Materia Condensada, University of Zaragoza & ICMA(CISC), 50071,
Zaragoza, Spain
2
ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX.,
United Kingdom
The Ce-systems have attracted considerable interest due to the duality between
the itinerant and the localized nature of 4f-electrons and the presence of strong
electron-electron correlations. On the other hand, it is well known that the electronphonon interaction drives the BCS-superconductivity. The nature of electron-phonon
interaction in Ce-based compounds has its origin in an effective strong magnetoelastic
coupling between some phonon modes and the Ce-localized states arising from crystalfield influence at some reciprocal space regions with high DOS, as in CeAl2 [1], andrecently CeCuAl3 [2]. We have studied of crystal-field electron-phonon excitations
along the series CeAgxCu1-xAl3 (0<x<1), where the magnetoelastic coupling changes
and disappears at critical concentration ? 0.65 under the hybridization of Cu and Ag
d-bands with 4f-electrons. A screening model of dielectric permitivity was developed
to expling this behaviour from a 3D-antiferromagnet in CeCuAl3 to a in-basal-plane
2D-weakly ferromagnet for CeAgAl3 [3]; both with a Kondo temperature inferior to 10
K.
[1] P.Thalmeier and P.Fulde, Phys.Rev.Lett 49 (1982) 1588 [2] D.T. Adroja, A. Del Moral, et al., submitted for publication to PRL(2011). RB720579 [3] T. Muranaka and J. Akimitsua, Physica C: Superconductivity, Vols. 460-462, Part 1, Pages 688-690 (2007).

SF03

Hiroshi Yamagami1, Ikuto Kawasaki2, Shin-ichi Fujimori2, Akira Yasui2, Tetsuo
Okane2, Yukiharu Takeda2, Yuji Saitoh2, Yoshinori Haga3, Etsuji Yamamoto3 andYoshichika Onuki4
1
Department of Physics, Kyoto Sangyo University, Japan
2
Condensed Matter Science Division, Japan Atomic Energy Agency, Japan
3
Advanced Science Research Center, Japan Atomic Energy Agency, Japan
4
Graduate School of Science, Osaka University, Japan
Electronic structure and Fermi surface of heavy fermion superconductor UPt3 havebeen studied by de Haas-van Alphen experiments and various theories [1], and it issuggested that U5f itinerant band model is more comparable with the experiments. In
order to observe the valence band structure of UPt3 directly, angle-angle photoemission
spectroscopy had been done using a discharge lamp [2]. However a 3-dimensionalband structure of UPt3 has been not understood well. We have carried out soft x-ray
angle-resolved photoemission spectroscopy experiment with the twin-helical undulator
beamline BL23SU of SPring-8, and as a result the U5f itinerant bands of UPt3 can bedetected together with the Pt 5d bands. In the paper we will discuss the band structureof UPt3 with a LDA band calculation.
[1] G. J. McMullan et al., New J. Phys. 10, 053029 (2008). [2] T. Ito et al., Phys. Rev. B 59, 8923
(1999).

Quantum critical end point (QCEP) emerges in a pressure - temperature - magnetic field phase diagram in
ferromagnetic (FM) materials with tricriticality.[1-3] In UGe2,[1,2] a first-order metamagnetic transition,
which appears above a critical pressure of ~1.5 GPa, possesses a critical end point (CEP) at a finite T_
CEP, above which the transition changes to crossover. The T_CEP decreases under pressure, and reaches
0 K at the QCEP (P_QCEP ~ 3.6 GPa and H_QCEP ~ 18 T). In case of UCoAl, the QCEP is located at
P_QCEP ~ 1.5 GPa and H_QCEP ~ 7 T.[3] Both systems exhibit the similar wing structures of the firstorder plane, but they are quantitatively different. It is an interesting issue what induces such difference
and what kinds of quantum criticality is involved in the vicinity of QCEP with both instabilities of themagnetism and the Fermi surface. In this presentation, we focus on 59Co-NMR measurements for
UCoAl at ambient pressure [4] and under pressure. A contrasting behavior between the nuclear spin
relaxation rates 1/T1 and 1/T2 demonstrate that strong Ising-type magnetic fluctuation develops at around
CEP. The drastic pressure evolution of the fluctuations toward the QCEP is also reported.
[1] V. Taufour et al., Phys. Rev. Lett. 105, 217201 (2010). [2] H. Kotegawa et al., J. Phys. Soc. Jpn. 80, 083703 (2011).
[3] D. Aoki et al., J. Phys. Soc. Jpn. 80, 094711 (2011). [4] H. Nohara et al., J. Phys. Soc. Jpn. 80, 093707 (2011).

SE18

SE21

SF01

SF04

Berezinskii-kosterlitz-thouless transition in heavy fermion superlattices

Magnetic properties of cubic GdTi2Al20 single crystal

Field-dependent instability of the candidate quantum spin liquid in
EtMe3Sb[Pd(dmit)2]2 as revealed by NMR.

The metal-insulator transition in ferromagnetic chromium hollandite

Jian-huang She* and Alexander V Balatsky
T-4, Los Alamos National Lab, USA

Recently unconventional superconductivity has been observed in epitaxially grown
heavy fermion superlattices, where Cooper pairs are confined within two-dimensional
Kondo lattices (Nature Physics 7, 849(2011)). Here we propose to understand theseexperiments within the framework of Berezinskii-Kosterlitz-Thouless Transition.
The observed behavior of the superconducting transition temperature can beunderstood in terms of phase fluctuations controlled by vortex-antivortex (un)binding.
Reasonable agreement is found with the experiments. Furthermore, we predict alarge renormalization of the penetration depth, which can be measured by future
experiments. Evolution of the gap is explained by invoking effects of the interface.

Ramesh Kumar K, Ruta N Kulkarni, Sudesh Kumar Dhar and Thamizhavel A*
Department of Condensed Matter Physics and Materials Science, Tata Institute ofFundamental Research, Mumbai 400005, India
The compounds crystallizing the RCr2Al20-type cubic crystal structure having 184
atoms in the unit cell with 8 formula units per unit cell, have attracted a great dealof interest as they exhibit a variety of interesting magnetic properties. For example,
PrTi2Al20 is the first example of a non-magnetic doublet ground state system, which
exhibits a ln T behaviour in the electrical resistivity, indicating the Kondo effect[1]. Similarly, SmTi2Al20 also exhibits Kondo effect [2]. Here we report on the
single crystal growth and the transport and magnetic properties of an iso-structuralcompound: GdTi2Al20. Single crystals of GdTi2Al20 were grown by high temperature
solution growth using molten aluminum as flux. Large size single crystals with welldefined triangular shaped facets corresponding to (111) plane were obtained. The
stoichiometry and the phase purity of the single crystal were confirmed by means ofenergy dispersive analysis by x-ray diffraction analysis. The estimated lattice constantfrom the x-ray diffraction was 14.682 A. It was found that GdTi2Al20 undergoes anantiferromagnetic ordering at TN = 2.6 K. We will present our results on the magnetic
and transport properties of GdTi2Al20.

Georgios Koutroulakis1*, Tong Zhou2, Stuart E. Brown2, Joe D. Thompson1 and Reizo
Kato3
1
Los Alamos National Laboratory, USA
2
UCLA, USA
3
RIKEN, Japan

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[1] A. Sakai and S. Nakatsuji, J. Phys. Soc. Jpn. 80 (2011) 063701. [2] R. Higashinaka et al, J.
Phys. Soc. Jpn. 80 (2011) 093703.

Yutaka Ueda1*, Masahiko Isobe1, Tooru Yamauchi1, Akiko Nakao2, Hironori Nakao2,
Yukinori Ohta3 and Takehisa Konishi3
1
Institute for Solid State Physics, University of Tokyo, Japan
2
Condensed Matter Research Center and Photon Factory, IMSS, KEK, Japan
3
Chiba University, Japan
We discovered a metal to insulator transition (MIT), retaining ferromagnetic in the insulator phase, in
ferromagnetic K2Cr8O16 [1]. The MIT is accompanied by a structural change from a tetragonal to a
monoclinic structures [2,3]. In the low temperature monoclinic insulator phase, there is no evidenceof charge separation/order. Instead, the characteristic displacements of the Cr and O sites, resulting in
Cr-O bond alternations, are observed in the rectangular columns formed by the four chains (the fourchain columns). This indicates a lattice-dimerization with the formation of Cr-tetramer in the four-chain
columns. The observed structural characteristics and electronic structure calcualtions lead us a modelof MIT caused by the Peierls instability in the quasi-one-dimensional four-chain column [2], namely
the MIT is a “pure” Peierls transition of spinless fermions (fully spin polarized electrons). On the other
hand, isostructural RbxCr8O16 shows a ferromagnetic transition at Tc= 270 K but does not show any
distinct MIT. Rb-deficiency could be a reason for the absence of MIT. In a solid solution system, K2yRbyCr8O16, the lattice parameters increase with increase of y. Tc also increases as Rb concentration
increases. This is consistent with the decrease of Tc with increasing hydrostatic pressure in K2Cr8O16.
[1] K. Hasegawa et al., Phys. Rev. Lett. 103 (2009) 146403. [2] T. Toriyama et al., Phys. Rev. Lett.
107 (2011) 266402 [3] A. Nakao et al., J. Phys. Soc. Jpn. to be published.

SE19

SE22

SF02

SF05

Basic properties of the intermetallics APd5Al2 (An=Ce, Th, U, Np, Pu,
Am)

Investigation of the heavy fermion Ce3Ir4Sn13 by electrical resistivity
under pressure

Magnetic states in quasi-2-D iridium oxides with large spin-orbit
coupling

Composition and transverse field-tuned quantum criticality in NbFe2

Jean-christophe Griveau*, Krzysztof Gofryk, Eric Colineau, Thomasz Klimczuk andJean Rebizant
ITU-JRC-EC, Germany

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Jackeline Collave Garcia1, Scheilla Maria Ramos2*, Eduardo Bittar3, Pascoal Pagliuso3,
Eduardo Hering2, Magda Fontes2, Hortencio Alves Borges1 and Elisa Baggio-saitovitch2
1
Pontificia Universidade Catolica do Rio de Janeiro - PUC-Rio, Brazil
2
Centro Brasileiro de Pesquisas Fisicas, Brazil
3
Universidade Estadual de Campinas, Brazil
The Ce3Ir4Sn13 is a heavy fermion compound with an electronic specific heat γ = 670mJ/mol-CeK2 [1,2] forwhich two anomalies, at 0.6K and 2.1K, can be found on specific heat. Magnetic susceptibility data indicate thatthe anomaly at 0.6K is due to an antiferromagnetic ordering, while the transition at 2K is non-magnetic. The
later one could be related to a change of the band structure accompanied by a lattice expansion[3] as was verified
by XRD. This compound crystallizes in a cubic Yb3Rh4Sn13 perovskite-like arrangement, with 40 atoms per unit
cell [4]. In this work, we are studying the electrical resistivity (100mK< T < 300K and P<25kbar) performed on
single crystals of Ce3Ir4Sn13, grown using a Sn self-flux technique. Our main motivation is to clarify the originof the phase transition that occurs at 2K and to investigate the possibility of a vanishing of the Neel temperature
over a quantum crititcal point. Our results show a Kondo-like increase of the resistivity at higher temperatures
and a very sharp peak at 2K that moves to lower temperatures with applied pressure. Magnetic susceptibility
measurements will be performed to investigate the behavior of the Neel temperatura under pressure.
[1]. H.Sato, T. Fukuhara, S.Iwakawa, Y.Aoki, I. Sakamoto, S. Takayanagi and N. Wada, Physica B 186-188(1993) 630. [2]. S. Takayanagi, H.Sato, T.Fukuhara, N. Wada, Physica B 199-200 (1994) 49. [3]. C. Nagoshi,
H.Sugawara, Y. Aoki, S. Sakai, M. Kohgi, H. Sato, T. Onimaru, T. Sakakibara, Physica B 359-361 (2005) 248250 [4]. L. Mendoca Ferreira*, E,M. Bittara, M.A. Pires, R. R. Urbano, O. Aguero, I. Torriani, C. Rettori, P.G.
Pagliuso, A. Malachias, E. Granado, A. Caytuero, E. Baggio-Saitovich, Physica B 384 (2006) 332-335.

336

Quantum critical end point in ucoal proved by NMR measurements

Hisashi Kotegawa1, Hiroki Nohara1, Hideki Tou1, Tatsuma D. Matsuda2, Etsuji
Yamamoto2, Yoshinori Haga2, Zachary Fisk3, Yoshichika Onuki4, Valentin Taufour5,
Dai Aoki5, Georg Knebel5 and Jacques Flouquet5
1
Kobe University, Japan
2
JAEA, Japan
3
University of California, USA
4
Osaka University, Japan
5
CEA-Grenoble, France

The 19th International Conference on Magnetism

July 13 (Fri)SE17
Maria Szlawska* and Dariusz Kaczorowski
Institute of Low Temperature and Structure Research, Polish Academy of Sciences,
Wrocław, Poland

July 13 (Fri)poster Presentation

Masaaki Isobe1*, Hirotaka Okabe1 and Jun Akimitsu2
1Strongly Correlated Materials Group, National Institute for Materials Science(NIMS), Japan2
Department of Physics and Mathematics, Aoyama Gakuin University, JapanThe discovery of the novel Mott insulating state in Sr2IrO4 has developed a new research field
on solid-state physics [1]. The strong spin-orbit coupling with the moderate on-site Coulombinteraction in the 5d electron system yields the unconventional Jeff = 1/2 Mott groundstate. The 'spin-orbit Mott state' is similar to conventional Mott states in 3d or 4d electron
systems. However, the Jeff = 1/2 state is a considerably complex state hybridizing spin andorbital degrees of freedom. Therefore, investigation of this state may give a new insight
into d-electron physics, and it may lead to possible unusual cooperative phenomena such as
anisotropic superconductivity. In this presentation, we review electronic and magnetic statesin the novel K2NiF4-type iridate Ba2IrO4 [2]. We found that Ba2IrO4 is a quasi-2-D (squarelattice) Heisenberg antiferromagnet (TN ~ 240 K) in which the magnetic moment (~0.34
mB/Ir-atom) is significantly reduced by the low-dimensional quantum spin fluctuation witha large magnetic correlation |J|. Its electronic state undergoes an M-I transition from the Mott
insulating state to a non-Fermi-liquid state under high pressure (PC ~ 13.8 GPa) [3]. Thesebehaviors are very similar to those in low-dimensional cuprates.
[1] B.J. Kim et al., Phys. Rev. Lett. 101, 076402 (2008); Science 323, 1329 (2009). [2] H. Okabe etal., Phys. Rev. B 83, 155118 (2011). [3] H. Okabe et al., Phys. Rev. B 84, 115127 (2011).

Sven Friedemann1, Max Hirschberger1, Yang Zou1, William J Duncan2, Andreas Neubauer3,
Thomas Bauer4, Louis Pedrero5, Manuel Brando5, Christian Pfleiderer3 and F Malte Grosche1
1Cavendish Laboratory, University of Cambridge, United Kingdom
2
Department of Physics, Royal Holloway, University of London, United Kingdom
3
Physik Department E21, TU Munchen, Germany
4
Max Planck Insitute for Chemical Physics, Dresden, Germany
5
Max Planck Institute for Chemical Physics of Solids, Germany
The low-temperature band magnet NbFe2 can be tuned by varying composition, magnetic field or pressure,providing an attractive candidate system for investigating quantum criticality in a transition metal compound.
Near the composition-tuned quantum critical point, NbFe2 displays signatures of a logarithmic Fermi liquid
breakdown: The electronic specific heat diverges logarithmically ΔC~T lnT and the resistivity exhibits
non-Fermi-liquid forms Δρ~T3/2 at low temperature T [1]. This quantum critical behavior is linked tothe suppression of an antiferromagnetic phase in slightly Nb-rich samples which is stabilized towards Ferich samples. In addition, NbFe2 with slight Fe excess features a ferromagnetic ground state underlying
the antiferromagnetic phase. We find the ordered moment to point along the crystalline c-direction in
the ferromagnetic state. Importantly, the transition temperature of this ferromagnetic ground state can besuppressed in a magnetic field perpendicular to the direction of the ordered moments, promoting NbFe2 as aninteresting candidate to study transverse field tuning in an Ising-like metallic system. We report the significant
suppression of Fermi liquid behavior close to the transverse-field induced quantum phase transition.
Moreover, we utilize susceptibility measurements to study the nature of this quantum phase transition.
[1] M. Brando, W. J. Duncan, D. Moroni-Klementowicz, C. Albrecht, D. Gruener, R. Ballou, and F. M. Grosche, Phys. Rev. Lett. 101, 026401 (2008).

July 8-13, 2012 Busan, Korea

337

poster Presentation
SF06

SF09

SF12

SF15

Tuning ferromagnetism in Ce1-xLaxAuGe: A specific heat and magnetic
susceptibility study

Vibron quasi-bound state in the non-centrosymmetric tetragonal
heavy-fermion compound CeCuAl3

Unusual normal-state magnetotransport in the heavy-fermion
superconductor Ce2PdIn8

Renormalized parameters and convergence of energy scales on theapproach to local quantum critical points

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We have investigated the non-centrosymmetric tetragonal heavy-fermion
antiferromagnetic compound CeCuAl3 (TN=2.5 K) using inelastic neutron scattering(INS). Our INS results unequivocally reveal the presence of three magnetic excitations
centred at 1.3, 9.8, and 20.5 meV. These spectral features cannot be explained within
the framework of crystal-electric-field (CEF) models and recourse to Kramers’
theorem for a 4f1 Ce3+ ion. To overcome these interpretational difficulties, we haveextended the vibron model for cubic CeAl2 of Thalmeier and Fulde to tetragonal pointgroup symmetry. This extension provides a satisfactory explanation for the position
and intensity of the three observed magnetic excitations in CeCuAl3, as well as theirdependence on momentum transfer and temperature. On the basis of our analysis, we
attribute the observed series of magnetic excitations to the existence of a vibron quasibound state.

Daniel Gnida*, Marcin Matusiak and Dariusz Kaczorowski
Institute of Low Temperature and Structure Research, Polish Academy of Sciences,
PolandThe normal-state behavior in the heavy-fermion superconductor Ce2PdIn8 [1,2] hasbeen probed by means of Hall coefficient (RH) and transverse magnetoresistivity (MR)measurements. Anomalous non-Fermi-liquid-like features, observed below 8 K in
both RH(T) and MR(T), are related to underlying quantum critical point, previously
evidenced in the specific heat and the electrical resistivity data [1-5]. Intriguing
magnetotransport properties observed in this compound exhibit close similarity to thosereported before for CeCoIn5 and can be explained in terms of the recently developed
theory in which anisotropy of the Fermi surface and strong backflow scattering of
charge carriers on critical AF spin fluctuations are taken into account. What’s more,
the magnetotransport in Ce2PdIn8 is shown to exhibit novel types of scaling that may
appear universal for similar systems being at the verge of magnetic instability.
[1] D.Kaczorowski, A.Pikul, D.Gnida, and V.H.Tran, Phys. Rev. Lett. 103 (2009) 027003; ibid
104 (2010) 059702. [2] D.Kaczorowski, D.Gnida, A.Pikul, and V.H.Tran, Solid State Commun.
150 (2010) 411. [3] J.K.Dong, H.Zhang, X.Qiu, B.Y.Pan, Y.F.Dai, T.Y.Guan, S.Y.Zhou, D.Gnida,
D.Kaczorowski, and S.Y.Li, Phys. Rev. X 1 (2011) 011010. [4] Y.Tokiwa, P.Gegenwart, D.Gnida, andD.Kaczorowski, Phys. Rev. B 84 (2011) 140507(R). [5] V.H.Tran, D.Kaczorowski, R.T.Khan, andE.Bauer, Phys. Rev. B 83 (2011) 064504.

D. J. G. Crow1*, Yunori Nishikawa2 and Alex Hewson1
Department of Mathematics, Imperial College London, United Kingdom
2Graduate School of Science, Osaka City University, Japan1

We consider a two impurity/dot Anderson model, where the impurities, hybridized
with separate conduction baths, are coupled by antiferromagnetic exchange interaction
J and a direct interaction U12. The model has two types of quantum critical points
associated, respectively, with a transition between Kondo singlet to a local state, anda transition to a local charge ordered state. Using exact expressions for the spin andcharge susceptibilities in terms of renormalized parameters we predict the values of
the renormalized parameters on the approach to both types of critical point in termsof a single energy scale T*, such that at the critical point T*--> 0. From numerical
renormalization group calculations we give complete phase diagram, and from ananalysis of the low energy fixed point deduce the renormalized parameters. The results
confirm the predictions of the renormalized perturbation theory and determine thevalue of T*. The emergence of a single energy scale which goes to zero at a quantum
critical point may be a general feature which would lead to a natural explanation of E/Tscaling which has been observed at the quantum critical points of some heavy fermion
compounds.

SF07

SF10

SF13

SG01

Anomalous hybridization effects in the cubic quadrupole systems
PrTr2Al20 (Tr= Ti, V)

Pressure-induced quantum criticality in the heavy-fermion compound
CeCoGe2.2Si0.8

Specific heat and thermal conductivity studies of UCu4+xAl8-x compounds

NMR study of magnetic properties of Eu1-xSrxMnO3

Akito Sakai*, Eoin O’farrell and Satoru Nakatsuji
ISSP, University of Tokyo, Japan

July 13 (Fri)D T Adroja1*, A Del Moral2, C De La Fuente2, A Fraile1, E A Goremyhkin1, J Taylor1,
A Hillier1 and F Fernandez-alonso1
1
ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX, United Kingdom
2
Laboratorio de Magnetismo, Depto Fisica Materia Condensada, Universidad deZaragoza & ICMA, Spain

The Kondo effect, the screening process of magnetic dipole moments by conduction(c) electrons,
is a well-known many-body phenomenon and recognized as a key mechanism which induces a
lot of interesting phenomena. Interestingly, nonmagnetic version of the Kondo effect, so-called
quadrupolar Kondo effect, is theoretically predicted for the f2 Γ3 crystalline electric field grounddoublet[1]. In this theory, the ground state is no longer Fermi liquid due to the overscreening of
the quadrupole moment by c-electrons. However, it is still uncertain what will happen in a realsystem with lattice periodicity. We have revealed that Kondo effect is observed in cubic PrTr2Al20
for the first time in materials which have nonmagnetic Γ3 ground doublet. Quadrupolar ordering isobserved at TQ = 2.0 K (Ti) and 0.6 K (V) respectively, and in particular ferroquadrupolar orderingin PrTi2Al20[2, 3, 5, 6]. Interestingly, anomalous metallic behaviors were observed in PrV2Al20
above TQ, most likely attributed to the quadrupolar Kondo effect. In this presentation, we willreport the results of low temperature thermal and transport measurements of PrTr2Al20 and discuss
the possibility of the quadrupolar Kondo effect and quantum critical effect of quadrupolar ordering.
[1] D. L. Cox, Phys. Rev. Lett. 59 (1987) 1240. [2] Akito Sakai and Satoru Nakatsuji, J. Phys. Soc. Jpn. 80(2011) 063701. [3] T. J. Sato, S. Ibuka, Y. Nambu, T. Yamazaki, A. Sakai and S. Nakatsuji, arXiv0301828.
[4] M. Matsunami, M. Taguchi, A. Chainani, R. Eguchi, M.Oura, A. Sakai, S. Nakatsuji and S. Shin, Phys.
Rev. B 84 (2011) 193101. [5] T U. Ito, W. Higemoto, K. Ninomiya, H. Luetkens, C.Baines, A. Sakai and S.
Nakatsuji, J. Phys. Soc Jpn. 80 (2011) 113703. [6] M. Koseki et al., J. Phys. Soc. Jpn. 80 (2011) SA049.

J. Larrea J.1*, K.-A. Lorenzer2, M. Muller1, S. Paschen1, J. Teysser3 and H. Ronnow4
1
Institute of Solid State Physics, Vienna University of Technology, Wiedner Haupst. 8 - 10, 1040 Vien, Austria
2Institute of Solid State Physics, Vienna University of Technology, Austria
3
De Physique de la Matiere Condensee, Universite de Geneve, Quai Ernest-Ansermet 24, 1211 Geneve,
Switzerland
4
Laboratory for Quantum Magnetism, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne, Switzerland

The pressure-tuned quantum critical point (QCP) of the antiferromagnetic heavy-fermion compound
CeCoGe2.1Si0.9 was claimed to be dominated by different effects on both sides of the QCP: on the magnetic
side spin fluctuations govern the criticality, while on the non-magnetic side the criticality is dominated bydisorder that quenches the spin fluctuations [1]. Here we study high-quality CeCoGe2.2Si0.8 samples [2], withresidual resistance ratios four times larger than those of the previously investigated CeCoGe2.1Si0.9 samples.
Interestingly, while DC magnetic susceptibility measurements show that the Neel temperature of TN = 4K
at zero pressure is only slightly reduced by pressure up to 3.0 kbar, a much stronger decrease is observed forthe specific heat anomaly. We will present electrical resistivity and specific heat measurements up to 15 kbar
and down to 0.05 K, and establish the pressure - temperature phase diagram for CeCoGe2.2Si0.8. The criticalbehavior shall be compared to the one observed for both CeCoGe2.1Si0.9 and the pure reference compound
CeCoGe3 [3]. We hope that this investigation will elucidate the role of disorder. Acknowledgement: 'Financial
support by the European Research Council (ERC Advanced Grant No 227378) is acknowledged.'[1] Alzamora M., Fontes M. B., Larrea J., Borges H. A., Baggio-Saitovitch E. M., Medeiros S. N. Phys. Rev. B 76 125106(2007). [2] J. Larrea J, J. Teyssier, H. Ronnow, M. Muller, S. Paschen. Submitted to J. Phys: Conf. Ser. [3] G. Knebel, D.
Aoki, G. Lapertot, B. Salce, J. Flouquet, T. Kawai, H. Murunaka, R. Settai, Y. Onuki . J. Phys. Soc. Jpn. 78, 074714 (2009).

Farzana Nasreen1, Milton Torikachvili2, Karunakar Kothapalli3, Yoshimitsu Kohama4,
Vivien Zapf5 and Heinrich Nakotte6*
1
Department of Physics & Astronomy, University of Nevada, Las Vegas, NV 89154, USA
2
Department of Physics, San Diego State University, San Diego CA 92182, USA
3
Department of Material Science and Engineering, University of Maryland, College Park, MD, 20744, USA
4
The Institute for Solid State Physics, The University of Tokyo, Japan
5
MPA-National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, New
Mexico 87545, USA
6
Department of Physics, New Mexico State University, Las Cruces, NM 88003, USA
We report the thermal-conductivity and specific-heat measurements for eight UCu4+xAl8-x compounds (0 ≤ x≤ 2.0) as a function of temperature and magnetic field. Previous studies provided evidence of a transition frommagnetic to a non-magnetic heavy fermion state at xcr = 1.15. Here we present complementary thermal-property
studies as a function of temperature (55 mK - 300 K) and applied magnetic field (0 - 15 T). Specific heat dataof non-magnetic compound at xcr = 1.15 shows logarithmic divergence of low-temperature C/T and this nonFermi liquid (NFL) behavior can be attributed to the proximity of a quantum critical point. Non-magnetic
compounds with higher Cu content (x > xcr) exhibit unusual temperature scaling in the specific heat possibly due
to an increase in disorder between Cu and Al. The complete study of magnetic field effect on NFL behavior washampered by high contribution from nuclear Schottky anomaly at low temperatures. The thermal conductivity
data show stark contrast between the magnetic (x = 0.5) and non-magnetic compound (x = 1.75) - as evidenced
in Lorentz numbers for example. Our results confirm that a simple free-electron picture is inadequate for thedescription of the low-temperature thermal conductivity properties in non-magnetic UCu4+xAl8-x compounds.

Kenji Shimizu1, Masanori Yamaguchi1, Shujuan Yuan2 and Shixun Cao2
1
Physics, Faculty of Science, University of Toyama, Japan2
Physics, Shanghai University, China
Perovskite-type manganite EuMnO3 is known to be a compound with narrow eg-band
width due to small Eu3+ ionic radius compared to La3+. The Eu1-xSrxMnO3 shows complex
magnetic properties, depending on Sr concentration x [1,2]. We have carried out 55Mn
spin-echo NMR measurements on polycrystalline Eu1-xSrxMnO3 (0≤x≤0.5) samples
at 4.2 or 1.4K, in order to clarify the microscopic local magnetic state of Mn ions andthe inhomogeneity in the compounds. Typical NMR spectra have been observed in thefrequency range from 250MHz to 400MHz. For the A-type antiferromagnetic EuMnO3,
the resonance frequency is about 260MHz, which is much lower than that observed for
Mn3+ in La1-xSrxMnO3. For 0.1 ≤ x ≤ 0.4, the resonance lines, corresponding to Mn4+ and
Mn3+, have been observed around 310MHz and 390MHz, respectively. Furthermore,
the spectra originated from Mn2+ have been observed around 590MHz for 0.1≤x≤0.4.
For Eu0.5Sr0.5MnO3, the NMR spectrum spreads widely with several distinct peaks in thefrequency range from 250MHz to 410MHz. In Eu1-xSrxMnO3, the spin-glass like behavior
has been observed around x = 0.5[1,3]. The present NMR spectrum for Eu0.5Sr0.5MnO3shows that the compound is in the inhomogeneous state due to competition between theantiferromagnetic and the ferromagnetic interactions.
[1] Y. Tomioka et al., Phys. Rev. B 80 (2009) 174414. [2] Y. Tadokoro et al., Solid State Ionics 108(1998) 261. [3] A. Sundaresan et al., Phys. Rev. B 55 (1997) 5596.

SF08

SF11

SF14

SG02

Non-fermi-liquid properties of the non-centrosymmetric heavyfermion compound CePtSi: a magnetic field study.

Anomalous thermoelectric effects in the heavy fermion superconductor
Ce2PdIn8

Dynamical cluster approximation results of the two-orbital Hubbard
model

NMR study of successive magnetic transitions in A-site orderedperovskite LaMn3Cr4O12

Andre Strydom
Physics, University of Johannesburg, South Africa

The ternary intermetallic compound CePtSi and its nonmagnetic equivalent LaPtSi
form in the non-centrosymmetric tetragonal space group I41/md [1]. The structure isan ordered variant of the ThSi2 type which provides dedicated atomic sites for each of
the rare-earth atom, Pt, and Si. CePtSi is a heavy-fermion compound with a very large
electronic specific heat coefficient [2] and apparently with no spontaneous magnetic
ordering. Non-Fermi-liquid (nFL) behaviour found at low temperatures in a Pt-Si
variational study of CePtSi has been reported [3], as well as aspects of nFL signaturesat the verge of magnetic ordering in CePtSi doped with Ge [4]. In this work we focus
on the low-temperature behaviour of magnetic susceptibility, electrical resistivity, andspecific heat of CePtSi together with comparative properties in LaPtSi. The focus is on
the influence of applied magnetic fields and the stability of nFL scaling in CePtSi as afunction of field.
1. K. Klepp, and E. Parthe, Acta Cryst. B38 (1982) 1105. 2. W. H. Lee, and N. R. Shelton, Phys. Rev.
B 35 (1987) 5369. 3. T. Goetzfried et al, J. Low Temp. Phys. 127 (2002) 51. 4. F. Steglich et al, J.
Low Temp. Phys. 95 (1994) 3.

The 19th International Conference on Magnetism

Marcin Matusiak, Daniel Gnida and Dariusz Kaczorowski*
Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Poland

G

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Hunpyo Lee1, Yu-zhong Zhang2, Harald Jeschke1 and Roser Valenti1*
1
Institute for Theoretical Physics, University of Frankfurt, Germany
2
Physics, Tongji University, China

The orbital-selective phase transition (OSPT), which is induced by the interplayof a narrow band of localized electrons and a wide band of itinerant electrons, hasbeen intensively explored in the multi-orbital systems. Using a dynamical cluster
approximation including the short-range correlation as well as quantum fluctuations,
we would like to analyze the behaviors of both degenerate two-orbital Hubbard
model, where both orbitals have equal bandwidths and one orbital is constrained to beparamagnetic, while the second one is allowed to have an antiferromagnetic solution
and two-orbital Hubbard model with different bandwidth at half-filling. The OSPT,
Fermi-liquid (FL), non-FL, and insulator behaviors are observed in the both cases.
Finally, we would discuss the implications of the results in the context of the Fe-based
superconductors.
Phys. Rev. B 84, 020401(R) (2011). Ann. Phys. 523, No. 8-9, 689 (2011). Phys. Rev. Lett. 104,026402 (2010).

July 13 (Fri)

Buyisiwe M. Sondezi-mhlungu and Andre M. Strydom
Physics, University of Johannesburg, South Africa

338

poster Presentation

Y. Kawasaki 1, S. Takase 1, Y. Kishimoto 1, T. Ohno 1, I. Yamada 2, K Shiro 2, R.
Takahashi2, K. Ohgushi3, N. Nishiyama4, T. Inoue4 and T. Irifune4
1
Institute of Technology and Science, The University of Tokushima, Japan
2
Graduate School of Science and Engineering, Ehime University, Japan
3
Institute for Solid State Physics, University of Tokyo, Japan
4
Geodynamics Research Center, Ehime University, Japan

In a simple ABO3 perovskite, when 75% of the A-site cations are substituted by anotherelement, an A-site-ordered perovskite with a chemical formula of A'A3B4O12 can be formed.
These materials have attracted much attention, because they show a rich variety of physicalphenomena, such as heavy-fermion behavior in CaCu3Ru4O12 and giant magnetoresistancein CaCu3Mn4O12. These features may be related to the A-A and A-B exchange interactions inaddition to the usual B-B exchange interaction seen in simple perovskite materials. Recently,
new A-site ordered perovskite, LaMn3Cr4O12, was prepared by using high pressure synthesis.
The measurements of magnetic susceptibility and specific heat suggest two antiferromagnetictransitions at 150 K and 50 K in LaMn3Cr4O12. In this conference, we report microscopic
investigation on the magnetic properties of this material probed by La NMR. The resonanceline moderately broadens below 150 K and disappears below 50 K. These results are
consistent with the two antiferromagnetic transitions. The temperature dependence of Knight
shift indicates that the transition at 150 K is associated with the B-site Cr spin ordering andthe other at 50 K is due to the A-site Mn spin ordering.

July 8-13, 2012 Busan, Korea

339

poster Presentation

poster Presentation

SG03

SG06

SG09

SG12

Magnetic properties of single crystalline U2Fe3Ge

Anomalous increase of TC in UGa2 under pressure

Magnetic susceptibility measurements at high pressures down to T=0.5
K with SQUID magnetometer

Evidence of rattling transition in caged compounds LaRu2Zn20 and
LaIr2Zn20: La-NMR studies

We develop a 3He-insert attached to MPMS SQUID magnetometer and a pressure
cell in order to measure magnetic susceptibility and magnetization precisely at highpressures down to T=0.5 K[1]. The 3He insert is made by stainless steel pipe with theinner diameter of 6.2mm and outer diameter of 6.5 mm. The liquid 3He is condensed
in the stainless pipe. The vacuum jacket made of a copper pipe with the outer diameterof 8.6 mm is soldered to the stainless pipe, which is also used for the heat exchange
between 3He gas and 4He bath at T=1.7K. The temperature was measured by RuO2
thermometer mounted on the 3He container. A main body of piston-cylinder pressure
cell is made from Be-Cu. The outer diameter of the cell is 6 mm, while the innerdiameter is 1.8mm which corresponds to the size of the teflon cell.

Recently, RT2Zn20 (R = Pr, La; T = Ir, Ru) has attracted much attention because of the coexistence ofsuperconductivity and a quadrupole ordered state observed in PrIr2Zn20[1,2] Superconductivity is also observedin LaRu2Zn20 (Tc=0.2 K) and LaIr2Zn20 (Tc=0.6 K), but not in PrRu2Zn20[1]. PrRu2Zn20 and LaRu2Zn20
undergo first-order structural phase transition at Ts=138 and 150 K, respectively, whereas LaIr2Zn20 undergoes
second-order structural phase transition at Ts=200 K. To investigate the structural phase transition in RT2Zn20,
139La(I=7/2) nuclear magnetic resonance (NMR) measurements have been carried out for LaRu2Zn20 and
LaIr2Zn20. For both compounds, quite narrow La-NMR line-widths less than 5 kHz without nuclear quadrupole
splittings above Ts changes their spectral shape with broad tails distributed over the frequency range of 0.8 MHz,evidencing the lowering of the symmetry at La site[3]. Around Ts, the nuclear spin-lattice relaxation rate (1/T1)
show an unusual enhancement associated with the slowing down of the EFG fluctuations[3].To gain further
insights, we have measured the nuclear spin-spin relaxation rate (1/T2) for both compounds. We have found thatthe temperature dependence of 1/T2 has maximum around Ts associated with the structural phase transition. We
will discuss low-energy spin dynamics in RT2Zn20 from microscopic points of view.

Ladislav Havela1, A. Kolomiets2, J. Prchal1 and A. V. Andreev3
1
Department of Condensed Matter Physics, Charles University, Czech Republic2
Department of Physics, Lviv Polytechnic National University, Ukraine
3
Institute of Physics, Academy of Sciences of the Czech Pepublic, Czech Republic

A number of Laves phases exist in intermetallic compounds based on uranium andtransition metals. The compact structure of such phases, which leads to small U-U
spacing and high U coordination numbers, gives rise to the 5f band and strong
hybridization with the non-f states. U2Fe3Ge is a new ternary Laves phase [1],crystallizing in the Mg2Cu3Si-type structure, an ordered variant of the hexagonal
MgZn2-type (C14, P63/mmc). It exhibits very short U-U distances (below the Hill limit)
along the c-axis (3.2 Å), still reaching a ferromagnetic order ( TC = 55 K). Surprisingly
the Fe sub-lattice does not carry any significant ordered moment. A single crystal of
U2Fe3Ge was prepared by the Czochralski method (a = 5.182(2) Å and c = 7.850(1) Å).
Magnetization isotherms measured along the principal axes indicate that the magnetic
moments lie in the basal plane of the hexagonal lattice, with the spontaneous magnetic
moment of 1 μB/f.u. and no anisotropy within the basal plane. Magnetic moments
are therefore perpendicular to the nearest U-U link, but the anisotropy values areanomalously low comparing e.g. to isostructural UNi2.

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Yoshiaki Sato1*, Shun Makiyama1, Yasutaka Sakamoto1, Tadahiko Hasuo1, Yuji
Inagaki1, Tetsuya Fujiwara2 and Tatsuya Kawae1
1
Department of Applied Quantum Physics, Kyushu University, Japan
2
Graduate School of Science and Engineering, Yamaguchi University, Japan[1] Y. Sato, Y. Nakamura, H. Morodomi, T. Hasuo, Y.Inagaki, T. Kawae, H. S. Suzuki and T. Kitai:
To be appeared in Journal of Physics: Conference Series.

[1] T. Onimaru, K. T. Matsumoto, Y. F. Inoue, K. Umeo, Y. Saiga, Y. Matsushita, R. Tamura, K. Nishimoto, I.
Ishii, T. Suzuki, and T. Takabatake: J. Phys. Soc. Jpn. 79 (2010) 033704. [2] T. Onimaru, K. T. Matsumoto,Y. F. Inoue, K. Umeo, T. Sakakibara, Y. Karaki, M. Kubota, and T. Takabatake: Phys. Rev. Lett. 106 (2011)
177001. [3] K. Asaki, H. Kotegawa, H. Tou, T. Onimaru, K. T. Matsumoto, Y. F. Inoue, T. Takabatake[1] M.S. Henriques et al., Solid State Commun. 148 (2008) 159.

SG04

SG07

SG10

SG13

Magnetic properties of a 5d transition metal oxide AOsO4 (A = K, Rb,
Cs)

Phase transition between paramagnetic and spin polarized states in
MnSi

Extinction of photo-luminescence of Mn-doped ZnS nanocolloids inweak magnetic field

Unconventional magnetic ordering in spin-orbit mott insulator withhoneycomb lattice

The extinction of light passing through a nanocolloidal medium containing ferromagnetic oxide(such as Fe3O4) putting inside a cavity of weak magnetic field has been observed [1-3]. Here forthe first time we report the extinction of photo-luminescence of Mn-doped ZnS nanocolloid under
the applied field of 270 Gauss. The Mn-doped ZnS nanopowders have been synthesized by using
the hydrothermal method from zinc acetate and natri thiosulfat as the precursors (with SPAN-80
as the surfactant). The particle size was determined to be within 10-20 nm; the lattice constant a= 5.41(2) A. The exitation wavelength was 623.8 nm from a He-Ne laser. We have observed asystematic reduction of photo-luminescence of a given liquid nanocolloid with time at applied fieldof 270 Gauss, despite of the field direction and field development (upwards or downwards). The
50% extinction was achieved after 30 min and the saturation extinction after 1 hour. The memory
effect was shown to preserve for more than 2 hours. We have measured the temperature of thesample during the experiment which was kept constant at 70 oC. We believe the PL extinction was
associated with the magnetic ordering but the ordering inside a liquid medium is a surprise.

Iridates have recently attracted much attention due to a novel $S_{\rm eff}=1/2$ Mott insulating state,driven by the interplay of moderate electronic correlations with strong spin-orbit coupling. We havesynthesized A2IrO3 (A=Na,Li) which is a layered system with Ir moments sitting on a Honeycomb lattice.
Theoretically, this system has been proposed as solid-state realization of the Heisenberg-Kitaev(HK)model, treating the superposition of isotropic antiferromagnetic exchange and highly anisotropic Kitaev
type ferromagnetic nearest neighbor exchange. HK model predicts gapless spin-liquid ground state withMajorana fermionic excitations in Kitaev Limit[1]. Na2IrO3 shows a Mott insulating state of $S_{\rmeff}=1/2$ moments with predominant antiferromagnetic coupling, indicated by a Weiss temperature of$\Theta_W=-116$ K[2]. A bulk antiferromagnetic transition occurs at a much reduced temperature of$T_N = 15$ K, indicates substantial frustration. Resonant X-ray magnetic scattering for the Na system
indicates an unconventional most-likely zig-zag magnetic structure[3]. For Mott insulating Li2IrO3 weobserve a similar ordering temperature of 15 K, while the $\Theta_W$ is drastically reduced to $-33K$.
These observations are compatible with an enhancement of the Kitaev contribution compared to the
Na-system, suggesting that Li2IrO3 is located closer to the Kitaev limit[4]. Work supported by Erasmus
Mundus EURINDIA project and the AvH foundation.

1. S.V.Demishev et al., Phys. Rev.B 85, 045131 (2012)

1. John Philip, J. M. Laskar and Baldev Raj. Appl. Phys. Lett. 92, 221911 (2008). 2. Rajesh Patel. Pure Appl. Opt. 11 (2009)
125004 (5pp). 3. R.V. Mehta, Rajesh Patel, Rucha Desai, R.V. Upadhyay and Kinnari Parekh. Phys. Rev. Lett. 96,127402 (2006).

[1] J. Chaloupka et al., Phys. Rev. Lett. 105, 027204 (2010). [2] Y. Singh and P. Gegenwart, Phys. Rev. B 82, 064412 (2010). [3] X.
Liu et al., Y.Singh et al., Phys. Rev. B {\bf 83}, 220403(R) (2011). [4] Y. Singh, S. Manni, P. Gegenwart, arXiv:1106.0429

SG05

SG08

SG11

SG14

Enhancement of curie temperature due to the coupling between fe
itinerant electrons and Dy localized electrons in DyFe2Zn20

ESR in mnsi: Heisenberg localized magnetic moments and spinpolarons

Electronic structure of A-site ordered perovskite CaCu3Ti4O12 studied
by angle-resolved photoemission spectroscopy

YCr6Ge6: A kagome metal?

The cubic RX2Zn20 has been recently insensitively examined, where R is rareearth atom and X is Fe, Co, Ru, etc. The exchange interaction between R-R is weakbecause R atoms are diluted in this compound. In fact, for X = Co and Ru, Tc is lessthan 10 K for any R. In the case of Fe, however, Tc is significantly enhanced, andthe origin of this high Tc is suspected to be involved the magnetism of Fe atoms. But
the origin is not clear at present. We examined the magnetic properties and specificheat of DyFe2Zn20, and revealed experimentally unusual magnetic anisotropies, i.e.,large magneto-crystalline anisotropy at 2 K, which nature, however, disappears in thetemperatures above 30 K below Tc. We analyzed these anomalous properties based on
the three assumptions: (1) crystalline electric field and exchange interaction between
R and R, (2) simplified Moriya theory for Fe, and (3) exchange interaction between
R and Fe. As a result, the enhancement of Tc, the strong magnetic anisotropy at low
temperatures, the disappearance of the magnetic anisotropy below Tc down to 30 K,
and no anomaly of magnetic specific heat at Tc, etc. were well reproduced by thiscalculation.

High frequency (60 GHz) electron spin resonance (ESR) has been studied inmanganese monosilicide, MnSi, single crystals [1]. The measurements performed
within the 4.2-300 K temperatures range at the applied magnetic field up to 70
kOe have demonstrated that the magnetic resonance in MnSi is due to localized
magnetic moments of the Heisenberg type with the g factor depending only slightly
on temperature, g ~ 1.9-2. At the same time, it has been found that the ESR linewidthis determined by spin fluctuations and can be quantitatively described in the wide
temperature range (4.2 K < T < 60 K) in the framework of the Moriya theory using
the SL(T) function. The revealed deviations from the model of weak itinerant electron
magnetism commonly used for the description of the magnetic properties of MnSi
indicate a possible spin-polaron nature of the unusual magnetic properties of thisstrongly correlated metal.

July 13 (Fri)

Junichi Yamaura, Kenya Ohgushi and Zenji Hiroi
Institute for Solid State Physics, University of Tokyo, Japan

We investigate the magnetic properties of AOsO4 (A = K, Rb, Cs) which takes a 5d1
electron configuration and would provide us with an interesting playground for spinorbit physics. The compound crystallizes in the scheelite structure comprising a
distorted diamond network of Os atoms. Magnetic susceptibility at high temperatures
shows Curie-Weiss behavior with Weiss temperatures of -94, -29 and 12 K for the K,
Rb and Cs compounds, respectively. For the K and Rb compounds, broad humps areobserved at 55 and 35 K upon cooling and followed by antiferromagnetic transitionsat 38 and 22 K, respectively. For the Cs compound, in contrast, no antiferromagnetictransition is observed down to 2 K, but an anomaly appears at 151 K, below which
the Weiss temperature is reduced to 3 K. Markedly, the magnetic effective moments
estimated from the Curie constants are 0.85, 0.84, and 0.86 Bohr magneton for the K,
Rb, and Cs compounds, which are much smaller than the spin-only value of 1.73 Bohrmagneton for S = 1/2. Probably a large spin-orbit coupling must be taken into account.

Yosikazu Isikawa1, Toshio Mizushima1, Souta Miyamoto1, Keigou Kumagai1, Mako
Nakahara1, Hiroaki Okuyama1, Takashi Tayama1, Tomohiko Kuwai1 and Pascal Lejay2
1
Graduate School of Science and Engineering, University of Toyama, Japan
2
Institute Neel, MCMF, CNRS, France

340

Hideki Tou1*, Kenji Asaki1, Hisahi Kotegawa1, Takahiro Onimaru2, Keisuke T.
Matsumoto2, Yukihiro F Inoue2 and Toshiro Takabatake2
1
Department of Physics, Graduate School of Science, Kobe University, Japan
2
ADSM, Hiroshima University, JapanThe 19th International Conference on Magnetism

Sergey Demishev*, Vladimir Glushkov, Inna Lobanova, Vsevolod Ivanov, Nickolay
Sluchanko and Alexey Semeno
Low Temperatures and Cryogenic Engineering, General Physics Institute of RAS,
RussiaThe of high-field region of the magnetic phase diagram of MnSi is probed by magnetization,
resistivity and magnetoresistance measurements carried out in the temperature range 1.8-300 K
for magnetic fields up to 8 T [1]. It is shown that the phase boundary between paramagnetic (PM)phase and spin-polarized (SP) phase is well-defined, has no positive slope as it was suggested
previously, and appears to be practically vertical corresponding to transition temperature Tc~30 K.
We argue that broad maxima of the resistivity and magnetization derivatives, which develops inthe diapason T >Tc, are not associated with a “diffuse” SP-PM transition and are a consequenceof the specific form of functional dependences of these quantities in the paramagnetic phase. It
is found that in the paramagnetic phase of MnSi a universal relation between magnetoresistanceand magnetization, Δρ/ρ= a0M2, holds in a wide range where magnetoresistance vary bymore than two orders of magnitude. The analysis of the transport and magnetic resonance data
favors the explanation of magnetic properties of MnSi by Heisenberg-type localized magnetic
moments rather than by itinerant magnetism approach. A low temperature anomaly at T~15K
corresponding to magnetoresistance and g factor changes is reported.

Sergey Demishev*, Alexey Semeno, Vladimir Glushkov, Nickolay Sluchanko andNickolay Samarin
Low Temperatures and Cryogenic Engineering, General Physics Institute of RAS,
RussiaHong-van Bui1, Van-ben Pham1, Nam-nhat Hoang2* and Van-chau Dinh2
1
Faculty of Physics, Vietnam National University, University of Natural Sciences, Viet
Nam
2
Faculty of Technical Physics and Nanotechnology, Vietnam National University,
University of Engineering and Technology, Viet Nam

H. J. Im1*, M. Tsunekawa2, T. Sakurada1, K. Kawata1, T. Watanabe1, K. Takegahara1,
H. Miyazaki3 and S. Kimura4
1
Department of Advanced Physics, Hirosaki University, Japan
2
Faculty of Education, Shiga University, Japan3
Department of Environmental and Materials Engineering, Nagoya Institute ofTechnology, Japan
4
UVSOR Facility, Institute for Molecular Science, Japan
We present angle-resolved photoemission spectroscopy (ARPES) results of A-siteordered perovskite CaCu3Ti4O12 (CCTO), which shows extremely high-dielectric
constant over a wide range of temperature from 100 to 600 K and has an insulator
phase in contrast to a metal phase from the result of LDA band calculation. We haveobserved the clear band dispersions, located in the higher binding energy than that
expected in the LDA calculation, and the negligible spectral weight at the Fermi levelin agreement with the results of electrical resistivity measurements. From the ARPES
results, we suggest that CCTO is Mott-insulator caused by the strong correlation effectsof the electrons in Cu 3d - O 2p hybridization bands.

Soham Manni1*, Yogesh Singh2 and Phlipp Gegenwart1
1
I. Physikalisches Institut, Georg-August-Universitaet Goettingen, Germany
2
IISER Mohali, India

July 13 (Fri)Margarida Henriques1*, Denis Gorbunov2, Ladislav Havela3, Alexander Andreev2 andAntonio Goncalves1
1
UCQR, Technological and Nuclear Institute, Portugal
2
Institute of Physics, Academy of Sciences of the Czech Republic, Czech Republic
3
Department of Condensed Matter Physics, Faculty of Mathematics and Physics,
Charles University, Czech Republic

Yui Ishii1*, Yoshihiko Okamoto1, Junichi Yamaura1, Hisatomo Harima2 and Zenji
Hiroi11
ISSP, Univ. Tokyo, Japan
2
Dept. of Physics, Kobe Univ., Japan
Itinerant electrons on a kagome lattice are known to generate a flat band without
dispersion. It is expected that the flat band causes exotic phenomena induced by the
kagome geometry such as a flat-band ferromagnetism. However, this has not been
experimentally observed in real compounds, possibly because the flat band tends tobe located far from the Fermi level. We have been looking for a candidate compoundto realize “kagome metal” and recently focused on YCr6Ge6. It crystallizes in the
HfFe6Ge6-type structure (space group P6/mmm) where Cr atoms form a kagome lattice.
Band-structure calculations show that a flat band really exists slightly below EF
near the Γ point toward the Κ and Μ points. This suggests that hole doping, such as
the chemical substitution of Ga for Ge, would make the flat band emerge at EF. We
successfully synthesized single crystals of YCr6Ge6 and YCr6Ge6-xGax by the flux
method. A Curie-Weiss like behavior is observed in magnetic susceptibility for bothcompounds. We will show the magnetic and transport properties and try to reveal thecharacteristics of the kagome metal.

1. S.V.Demishev et al., JETP Letters, 93, 213 (2011)

July 8-13, 2012 Busan, Korea

341

poster Presentation

Raman scattering spectra of PrRu2Zn20

Norio Ogita1*, Takumi Hasegawa1, Masayuki Udagawa1, Keisuke Matsumoto2,
Takahiro Onimaru2 and Toshiro Takabatake2
1
Graduate School of Arts and Sciences, Hiroshima Univ., Japan
2
Graduate School of Advanced Sciences of Matter, Hiroshima Univ., Japan

SG21

SH02

Metal-insulator and spin-state transition in polycrystalline (Pr1-yREy)1CaxCoO3 (RE=rare earth elements) in magnetic fields

Optimal design of IPMSM having double barrier for minimizing
cogging torque and torque ripple

Unidirectional thermal effects in current-induced domain wall motion

x

1

1

1

1

1

2

1

Jacob Torrejon1, Gregory Malinowski1, Javier Curiale1, Andre Thiaville1*, Daniel
Lacour2, Francois Montaigne2 and Michel Hehn2
1
Laboratoire de Physique des Solides, Universite Paris-Sud, CNRS , 91405 Orsay,
France2
Institut Jean Lamour, Universite Nancy I, 54506 Vandoeuvre-les-Nancy, France

PrRu2Zn20 has the cubic structure with Fd-3m, where Pr-ion is encapsulated in
the Frank-Kasper cage by 16 Zn atoms. In analogy of the filled skutterudites, thiscompound is expected to be observed an anharmonic Pr vibration and exotic physicalproperties due to orbital degrees of freedom of the local f electrons. shows structuraltransition at Ts=138K and remains a normal state in electronic conductivity down
to 0.04K. On the other hand, isostructural PrIr2Zn20 shows an antiferro-quadrupolarordering(Tq=0.11K) and a superconductivity(Tc=0.05K), without structural change
above Tq. The difference of the low temperature properties between PrRu2Zn20 and
PrIr2Zn20 might be originated from the structural transition, however, the origin of thestructural transition and also the crystallographic structure below Ts are not clarified.
Therefore, we have measured Raman scattering spectra of PrRu2Zn20. Among theRaman active phonons; 3Ag+4Eg+9T2g, 2Ag+4Eg+6T2g peaks are observed at room
temperature. With decreasing temperature, 4 peaks are newly observed below Ts in
T2g spectra. This suggests the structural change around Ts. In comparison with Eg
spectra, the observation of the similar energy peaks in both spectra suggests the crystal
structure below Ts seems to be lower than cubic structure.

Hyoung Uk Nam , Hyun Rok Cha , Kwang Heon Kim , Dae Young Lym and Tae
Won Jeong11
Automotive R&D, Korea Institute of Industrial Technology, Korea
2
Department of Electrical Engineering, University of the Chonnam, Korea

We have measured the temperature dependences of the resistivity and themagnetic susceptibility in various magnetic fields up to 17 T and 5 T, respectively,
for polycrystalline (Pr 1-y REy) 1-x CaxCoO 3 (RE=rare earth elements). For(Pr0.8Sm0.2)0.7Ca0.3CoO3 sample, a metal-insulator transition (MIT) and spin-statetransition (SST) between the intermediate (IS) and the low spin (LS) states almost
simultaneously took place around 40 K at 0 T. The MI-SST temperature decreased
with increasing magnetic field, and the MI-SST was suddenly suppressed above 10 T.
The MI-SST temperatures were about 38 K at 5 T and 29 K at 9 T. In the samples withhigher y, in which the MI-SST temperature at 0 T was higher, the reduction of the MISST temperature became small and the MI-SST survived up to the highest magnetic
field in this study. The similar behavior was observed in other RE substituted samples.
The obtained results suggest that the magnetic field stabilizes the IS state, which
contrasts with the fact that the application of the external pressure induces the LS state.
We discuss the origin of the magnetic field effect on the MI-SST.

In this paper, a design method for shape optimization of stator and rotor of a double barrier inthe form of IPMSM for NEV(Neighborhood Electric Vehicle) is proposed. IPMSM has two big
problems which are high cogging torque and high torque ripple that causes performance degradationof the motor and noise, and vibration during the motor rotation. To solve the problem, ways of
reducing the cogging torque and torque ripple as a method for forming the shape of the motor statorand rotor factors were searched. Especially, the factors which greatly affected cogging torque andtorque ripple were studied and verified their mutual connection. Moreover it was found that themost influential factors was the slot open and the slot teeth angle. The results of the experiment
which reduced cogging torque and torque ripple verified, while the optimization proceeded on thebasis of the factors that were searched. So the prototype of the optimized IPMSM was designed, its
performance was evaluated. The optimization was verified by the performance evaluation.

SG16

SG19

SG22

SH03

Superconducting state in KSn2 with a MgZn2-type (C14) Laves phasestructure

Magnetic field-induced lattice effects in a quasi-2D organic conductor
close to the Mott metal-insulator transition

Implementation of first-principle calculation in combination with adynamical cluster approximation

Effect of the oersted field on current-induced domain wall motion anddomain wall chirality in multilayer nanostripes

Organic charge-transfer salts of the κ-phase (BEDT-TTF)$_2$X family have been recognized as prototypes forstudying electronic correlation phenomena [1]. Their ground states can be tuned either by varying the counter
anion X or by applying external pressure. For the X = Cu[N(CN)2]Cl salt, for example, the ground state is an
antiferromagnetic-Mott insulator, whereas for X = Cu[N(CN)2]Br, it is a superconductor. Fully deuterated single
crystals of the latter substance are located on the verge of the Mott metal-insulator (MI) transition and, for thisreason, constitute a material of particular interest for exploring the critical behavior of the π-electron system
around the Mott transition [2,3]. Here we present ultra-high-resolution dilatometry studies at varying magnetic
fields on a fully deuterated X = Cu[N(CN)2]Br salt. Our thermal expansion data reveal two remarkable features:(i) the Mott MI transition temperature T$_{MI}$ = (13.6 ± 0.6)K is insensitive to fields up to 10 T, (ii) for
fields along the interlayer b-axis, a B-induced first-order transition at T$_{SF}$ = (9.5 ± 0.5)K is observed.
This transition manifests itself in a sharp negative spike in the expansivity, whose position is found to be field
insensitive. Possible scenarios to describe this field-induced phase transition will be discussed.

While the combination of the local density approximation (LDA) with dynamicalmean field theory (DMFT) opened the door to a realistic description of correlated
compounds, the improvement of the method is ongoing. In this work, we present a
combination of LDA with the dynamical cluster approximation (LDA+DCA) in theframework of the full-potential linear augmented plane-wave method, and compare ourresults to LDA+DMFT calculations as well as experimental observations on SrVO3.
We find a qualitative agreement of the momentum resolved spectral function with
angle-resolved photoemission spectra (ARPES) and former LDA+DMFT results. Asa correction to LDA+DMFT, we observe more pronounced coherent peaks below theFermi level, as indicated by ARPES experiments. In addition, we resolve the spectral
functions in the ${\bf K}_{0}=(0,0,0)$ and ${\bf K}_{1}=(\pi,\pi,\pi)$ sectors of
DCA, where band insulating and metallic phases coexist. Our approach can be applied
to correlated compounds where not only local quantum fluctuations but also spatial
fluctuations are important.

We have been searching for a new superconductor including alkali metal elements
using high pressure / high temperture technique. High-pressure synthesis technique has
been successfully employed in the search for new materials and new superconductors.
To use a closed system for high pressure synthesis is effective not only to stabilize acomposition but also to expand a solid-solution range. We successfully synthesized
the polycrystalline sample of KSn2 as a main phase and discovered that KSn2 was asuperconductor with Tc = 3.2 K. KSn2 has a hexagonal MgZn2-type (C14) structure(space group P63/mmc, No.194) called Laves phase. The magnetization versus
magnetic field curve shows a typical type-ll superconducting behavior. We determined
the lower critical field and penetration depth, to be about Hc1(0) = 150 Oe and λGL(0) =210 nm, respectively, using the Ginzburg-Landau equations. From the density of statecalculations, we found that Sn p-orbital mainly contributes near the N(EF) level andplays an important role for the superconducting state in KSn2.

Mariano De Souza1*, Andreas Bruel2, Christian Strack2, Dieter Schweitzer3 andMichael Lang2
1
Physics, Universidade Estadual Paulista - Unesp (Sao Paulo State University), Brazil
2
Physics, Goethe-Universitat Frankfurt, Germany
3
Physics, Stuttgart Universitat, Germany[1] N. Toyota, M. Lang, J. Muller, Low-Dimensional Molecular Metals 2007, Springer, Germany[2] M. de Souza, A. Bruehl, Ch. Strack, B. Wolf, D. Schweitzer, M. Lang, Phys. Rev. Lett. 99, 037003(2007) [3] L. Bartosch, M. de Souza, M. Lang, Phys. Rev. Lett. 104, 245701 (2010)[1] Y.D. Yao, D.R. Huang, J.C. Wang, S.H. Liou, S.J. Wang, 1997, IEEE Tran. Magn. 33 1997: 4095. [2] N. Bianchi, S.
Bolognani, 2008, IEEE Trans. Ind. Appl. 38 (5) 2002 : 1259. [3] T. Ishikawa, M. Matsuda, M. Matsunami, 1998, IEEE Trans.
Magn. 34 (5) 1998 : 3503. [4] Z.Q. Zhu, D. Howe, E. Bolte, B. Ackermann, 1993, IEEE Trans. Magn. 29 1993:124. [5] Hong
E, Ben-Ahmed AH, Lucidame J. 1997, Switching flux permanent magnet polyphased synchronous machine. In: Proceedingsof the 7th European conference on power electronics and applications, Trondheim, Norwegen, 1997: p. 903-908.

Hunpyo Lee1, Kateryna Foyevtsova1, Johannes Ferber1, Markus Aichhorn2, Harald
Jeschke1 and Roser Valenti1*
1
Institute for Theoretical Physics, University of Frankfurt, Germany
2
Institute for Theoretical and computational Physics, TU Graz, Austria

We show unidirectional motion of a domain wall (DW) due to thermal effects inpermalloy nanostrips using magnetic force microscopy on a RF-contacted sample. A
deterministic thermal driven motion has been found for current excitation in the rangeof few nanoseconds. The cooperation between thermal effect and spin transfer torqueinduces larger and more effective displacements towards the center of nanostrip, thehotter part. The thermal effects are generated by Joule heating, and amplified by poor
heat diffusion through thick SiO2 (100 nm). An important issue in thermal transport
is the temperature gradient related to the positions of sinks (thick Au electrodes),responsible (partly at least) for the unidirectional DW motion towards hotter part. Suchbehaviour has been recently predicted by magnons spin transfer [1]. On the other hand,the propagation of DW could be affected by other thermoelectric effects. However, we
anticipate the spin currents created by Spin Seebeck effect [2] or anomalous Nernst
effect [3] to be small compared to the critical current density for DW motion.
[1] D. Hinzke et al; PRL 107, 027205 (2011). [2] K. Uchida et al; Nature 455, 778 (2008). [3] S. Y.
Huang et al ; PRL 107, 216604 (2011).

Stefania Pizzini1*, Zahid Ishaque1, Jan Vogel1, Vojtech Uhlir1, Nicolas Rougemaille1,
Olivier Fruchart1, Jean-christophe Toussaint1, Julio Camarero2, Julio C. Cezar3 andFausto Sirotti4
1
Institut Neel, Centre National de la Recherche Scientifique, Grenoble, France
2
Universidad Autonoma de Madrid, Spain
3
European Synchrotron Radiation Facility (ESRF), Grenoble, France
4
Synchrotron SOLEIL, Gif sur Yvette, France

arXiv:1111.0890

Current-induced domain wall motion is more efficient in Permalloy(Py)/Cu/Co trilayer nanostripes thanin single Py nanostripes. We used time-resolved photoemission electron microscopy combined with x-ray
magnetic circular dichroism (XMCD-PEEM) to image the magnetic configuration in the Py layer ofthese nanostripes, during the current pulses, with 50ps time resolution. During the current pulses the Py
magnetization tilts towards the transverse direction. The large tilt angles (up to 70°) can be reproduced by
micromagnetic simulations only when both the Oersted field and the magnetostatic interactions between Py
and Co are taken into account. Magnetic Force Microscopy (MFM) measurements were performed on Py/
Metal bilayer nanostripes, with different metal thicknesses, varying the transverse field for a given current
density. We show that the Oersted field stabilizes transverse domain walls with a transverse component parallelto the Oersted field, even for widths and thicknesses of the Py layer for which vortex walls are more stable.
Once the chirality of the wall is compatible with the Oersted field, the domain wall moves with current pulses
without changing configuration, indicating that the Walker breakdown is suppressed. This phenomenon could
therefore explain the large domain wall velocities that we have observed in Py/Cu/Co nanostripes.

SG17

SG20

SH01

SH04

Layered nanosized structures on basis of diluted magnetic
semiconductors and heusler alloys

Metallic transition of the colossal magnetoresistance material FexMn1xS (x=0.18) under high pressure

Oscillatory transformative domain wall inner structure of depinningdomain wall around notched ferromagnetic wire

Domain-wall motion in permalloy nanowires with magnetic soft spots

Evgeny Sergeevich Demidov*, Ekaterina Pavlova, Aleksandr Bobrov, Vitaliy
Podolskii, Valeriy Lesnikov, Sergey Gusev and Anton Tronov
Solid State Electronics Chair, Nizhny Novgorod State University, Russia

342

1

Tomoyuki Naito *, Hiroko Sasaki , Motoharu Kato , Satoru Ogawa , Hiroyuki
Fujishiro1, Terukazu Nishizaki2 and Norio Kobayashi2
1
Iwate University, Japan
2
Institute for Materials Research, Tohoku University, Japan

Shota Miyazaki, Kenji Kawashima, Tsukasa Ipponjima, Michinori Fukuma and Jun
Akimitsu
Physics and Mathematics, Aoyama Gakuin University, Japan

July 13 (Fri)

SG18

Yoshimi Mita1*, Tomoko Kagayama2, G. M. Abramova3, G. A. Petrakovskii3 and V. V.
Sokolov4
1
Materials Physics, Engineering Science, Osaka University, Japan
2
Center of Quantum Science and Technology under Extreme Conditions, Osaka
University, Japan
3
L.V.Kirensky Institute of Physics, Russia
4
A.V.Nikolaev Institute of Inorganic Chemistry, Russia

The laser and RF magnetron synthesis of nanosized layers of the diluted magnetic semiconductors(DMS) on the basis of compounds III-V and elementary semiconductors Ge or Si with Mn or
Fe impurities and Co2MnSi Heusler alloys (HA) on single crystal substrates GaAs, Si or Al2O3
with ferromagnetism till 500K was earlier demonstrated [1-3]. In this report our new researchesof properties of DMS Si:Mn and magnetic tunnel junctions (MTJ) with ferromagnetic HA
plates and dielectric interlayer are presented. The features of FMR of MTJ with ferromagnetic
exchange interaction, anisotropic negative magnetoresistance, I-V nonlinearity and hysteresis
of MTJ and single DMS and HA layers at small current density were observed at 77-300К.
The high-resolution transmission electron microscopy (HRTEM) and selected area electron
diffraction (SAED), made on JEM-2100F of JEOL, show that the laser synthesis of epitaxial
layers of DMS Si:15%Mn/GaAs with Curie point 500K, perfect diamond like crystal structureand self-organized superlattice is possible. Supported by RFBR (08-02-01222-a, 11-02-00855a), the Ministry of Education of Russian Federation (projects 2.1.1/2833 and 2.1.1/12029) andthe State contract № 02.740.11.0672 of the Federal purpose program <<Scientific and scientificpedagogical cadre of innovative Russia>>2009-2013 is acknowledged.

The discovery of the colossal magnetoresistance in FexMn1-xS solid solutions [1] aroused
many researcher’s interests in studying the physical properties of this system. We studied
the pressure induced phase transition of FexMn1-xS (x=0.18) by infrared (IR) reflection and
X-ray analysis up to 40 GPa at room temperature. It is shown by X-ray analysis that thestructure of this sample is NaCl type at ambient pressure and a structural change starts around17 GPa and the mixed phase between the NaCl type low pressure phase and the structure
unknown high pressure phase continues up to around 25 GPa. On the other hand, the IRreflectivity increases from 15 GPa and becomes highly remarkable around 20 GPa. The
spectra do not show any changes from 30 GPa. These results suggest that the phase transitionof FexMn1-xS (x=0.18) at room temperature starts around 15 GPa and completes around 30
GPa and the high pressure phase is not a band overlapping semimetal but a true metallic.

[1] E.S. Demidov, V.V. Podolskii, V.P. Lesnikov et al, JETP, 106, 110 (2008). [2] E.S. Demidov, B.A. Aronzon, S.N. Gusev etal, JMMM, 321 (2009) 690. [3] E.S. Demidov, b, V.V. Podolskii, B.A. Aronzon et al, Bull. RAS: Physics, 74 (2010) 1389.

G.A. Petrakovskii, L.I. Ryabinkina, N.I. Kiselev, D.A. Velikanov, A.F. Bovina, G.M. Abramova, JETP
Lett. 69 (1999) 949.

The 19th International Conference on Magnetism

Dede Djuhana1*, Bambang Soegijono1, Hong-guang Piao2, Suhk Kun Oh3, Seong-cho
Yu3 and Dong-hyun Kim3
1
Physics, Department of Physics, University of Indonesia, Indonesia
2
Materials Science and Engineering, Department of Materials Science andEngineering, Tsinghua University, Beijing, China
3
Physics, Chungbuk National University, Cheongju 361-763, Korea

We have investigated domain wall (DW) depinning behavior around a geometric notch in ferromagnetic
nanowires by means of micromagnetic simulation [1]. Nanowires with different notch geometries bychanging a depth (d) and a half-width of the notch (s) have been considered. A domain wall with a transverse
wall structure is initially prepared to be positioned at the notch. Depinning field pulse of 1 ns duration isapplied to trigger DW depinning behavior with a systematic variation of depinning field strengths. With
increase of s, the domain wall depinning field tends to decrease. Change of an aspect ratio is also considered,
where a relatively insensitive variation of depinning field is observed with respect to the aspect ratio d/s greater than 2. With variation of depinning field strength, we have found that DW internal structurechanges during the depinning process. At lower depinning field (< 4 mT), DW keeps the initial tranverse
wall structure during the depinning process, whereas higher depinning field (> 4 mT), DW is depinned
with a transformation of the inner structure with antivortex soon after DW has escaped from the notch. The
transformation of the DW inner structure is obviously related to the Walker breakdown phenomenon.
[1] M. J. Donahue and D. G. Porter, OOMMF User’s Guide, http://math.nist.gov/oommf (2002).

July 13 (Fri)

SG15

poster Presentation

Andreas Vogel1*, Sebastian Wintz2, Theo Gerhardt1, Lars Bocklage1, Thomas Strache2,
Mi-young Im3, Peter Fischer3, Juergen Fassbender2, Jeffrey Mccord4 and Guido Meier1
1Institut fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung, Universitaet Hamburg, Germany
2
Institut fuer Ionenstrahlphysik und Materialforschung, Helmholtz-Zentrum Dresden-Rossendorf, Germany
3
Center for X-ray Optics, Lawrence Berkeley National Laboratory, USA
4
Institut fuer Materialwissenschaften, Christian-Albrechts-Universitaet zu Kiel, Germany
Recent concepts of nonvolatile data-storage devices involve the controlled motion of magnetic domain walls(DWs) in nanowires [1]. To realize such a device, a manageable fabrication process of reproducible and reliable
pinning sites for individual DWs is required. We use irradiation with chromium ions to create local confining
potentials via an effective reduction of the saturation magnetization in lithographically predefined regions. Fielddriven pinning and depinning at the so-called magnetic soft spots is directly observed using x-ray microscopy[2]. The shape of the potential is characterized via micromagnetic simulations and electrical measurements of
the anisotropic magnetoresistance. Moreover, we demonstrate reliable DW depinning by single current pulses
in a permalloy nanowire containing a square-shaped magnetic soft spot [3]. A DW can be moved back and forth
between different soft spots along a wire. Lower requirements on the resolution of the lithography equipment
in comparison to geometric constrictions on the nanoscale, a small distribution of properties due to parallel
processing of many pinning sites during implantation, and fine tunability of the strength of the pinning potential
via the chromium ion fluence make the magnetic soft spots a promising candidate for applications.
[1] D. A. Allwood, Gang Xiong, M. D. Cooke, C. C. Faulkner, D. Atkinson, N. Vernier, R. P. Cowburn, Science 296, 2003 (2002);
S. S. P. Parkin, U. S. Patent No. US 683 400 5 (2004). [2] A. Vogel, S. Wintz, J. Kimling, M. Bolte, T. Strache, M. Fritzsche,
M.-Y. Im, P. Fischer, G. Meier, and J. Fassbender, IEEE Trans. Magn. 46, 1708 (2010). [3] A. Vogel, S. Wintz, T. Gerhardt, L.
Bocklage, T. Strache, M.-Y. Im, P. Fischer, J. Fassbender, J. McCord, and G. Meier, Appl. Phys. Lett. 98, 202501 (2011).

July 8-13, 2012 Busan, Korea

343

poster Presentation
SH05

SH08

SH11

SH14

Direct observation of nearly mass-less domain walls in nanostripes
with perpendicular magnetic anisotropy

Simulations of field driven domain wall motion in permalloy nanowires
with difference dimension

Domain wall motion by thermal gradients in Fe/W(110)Dynamics of domain-wall oscillations in magnetic nanorings driven by
circularly rotating fields

Important inertial effects have been recently shown for domain walls in permalloy nanostripes. Thesetransient effects, giving rise to an effective domain wall (DW) mass, are caused by deformations of
the DW internal structure when a current pulse is applied. We have used time-resolved photoemission
electron microscopy combined with x-ray magnetic circular dichroism to study current-induced DW
motion in Pt/Co/AlOx nanostripes with perpendicular anisotropy and Rashba spin-orbit coupling. We
show that in these nanostripes the DWs move at constant speed during the current pulse and inertial
effects are much smaller than in permalloy nanostripes, i.e. the delay of the linear motion with respect
to the pulse is less than 1 ns and the transient motion is smaller than 30 nm. The transient displacement
δq depends of the change of generalized DW angle φ : δq = -Δ/α δφ where Δ the domain wall width atrest and α the damping parameter. The negligible inertia in our system is accounted for by the narrow
DW width and the small DW angle due to the presence of a transverse magnetic field of Rashba origin.
Such small inertial effects could be efficiently exploited in devices based on manipulation of DWs.

Chia-chi Chang1, Chao-hsien Huang2, Tian-chiuan Wu3, Jong-ching Wu2 and Lance
Horng2
1
Department of Physics, National Changhua University of Education, Taiwan
2
Department of Physics, Taiwan SPIN Research Center, National Changhua
University of Education, Taiwan
3
Department of Electronic Engineering, National Formosa University, Taiwan

In recent years, the domain wall motion in permalloy nanowire has been intensively
investigated because it could give promise of a new type memory with many
advantages. In our researches, the domain wall motion in permalloy nanowires driven
by external magnetic field have been simulated by a commercial software LLG
simulation. The simulated results presented that the velocity of DW motion increases
below a critical field value which is called Walker breakdown field; above that field thevelocity of domain wall obviously decrease. The velocity of the domain wall and thecritical field is dependent on the dimension of the nanowire. The domain wall velocity
increases as the wire width increases, and the critical field decreases as wire width
increases with non-linear relation.

The Spin Seebeck effect recently observed [1] has opened new areas of research in magnetic materials.
One consequence of the Spin Seebeck effect is the movement of domain walls in magnetic materials [2].
In our current research we have studied the behavior of a domain wall in the presence of a thermal gradientin a 2D system by using the atomistic spin dynamics approach present in the UppASD code [3, 5]. This isbased in the Landau-Lifshitz-Gilbert equation, where the atomistic spins are described using a Heisenberg
Hamiltonian constructed from parameters obtained from first principles calculations. Temperature effects
are taken into account by Langevin dynamics [3-4]. The system chosen is a monolayer of Fe on W (110)which exhibits a large anisotropy while having a soft exchange [5], resulting in domain wall thickness ofthe order of~ 1 - 2 nanometers. By subjecting this material to a thermal gradient we are able to observea temperature dependent movement of the domain wall as well as changes of the spatial magnetization
profile of the system. We compare this temperature gradient driven motion with the spin transfer torquedriven domain wall motion observed for the system when subjected to a current.

Youn-seok Choi, Young-sang Yu, Dong-soo Han, Hyunsung Jung, Ki-suk Lee andSang-koog Kim*
National Creative Research Initiative Center for Spin Dynamics & Spin-Wave Devices& Nanospinics Lab, Research Institute of Adv. Materials, Dep. of Materials Sci. &Eng., Seoul Nat'l Univ., Seoul, Korea

The manipulation of magnetic domain walls in geometrical confinements such as nanostrips and nanorings
has become essential in information device technologies [1]. In particular, ring structures have attracted muchattention because domain walls can be easily positioned and manipulated by the application of magnetic fields
or currents [2-4]. In the present work, we studied possible transverse domain-wall (TW) oscillations with certain
frequency ranges in magnetic nanorings driven by circularly rotating fields on the nanoring plane. We useda permalloy nanoring with an onion state that has a tail-to-tail and a head-to-head transverse wall. From themicromagnetic simulations, it was found that the frequency of the TW oscillations varies with the frequency andamplitude of the applied rotating field. Moreover, the frequency range of the persistent TW oscillations become
wider for a stronger field amplitude, as far as the frequency range is below a certain critical frequency value. We
also found a phase diagram of the characteristic TW oscillation dynamics on the plane of the field strength andfrequency. We will present our interpretations of those simulation results based on analytical calculations.

1. GEOFFREY S. D. BEACH*, CORNELIU NISTOR, CARL KNUTSON, MAXIM TSOI ANDJAMES L. ERSKINE, nature materials VOL 4 OCTOBER 2005 2. Andrew Kunz, IEEE Trans.
Mag. VOL. 42, NO. 10, OCTOBER 2006 3. Stuart S. P. Parkin,* Masamitsu Hayashi, Luc Thomas,
Science 320, 190 2008

[1] K. Uchida, et al. Observation of the spin Seebeck effect. Nature, 455:778, 2008. [2] D. Hinzke, and U. Nowak. Domain Wall
Motion by the Magnonic Spin Seebeck Effect. Phys. Rev. Letters, 107:027205, 2011. [3] B. Skubic et al.. A method for atomistic
spin dynamics simulations: implementations and examples. J. Phys.: Condens. Matter, 20:315203, 2008. [4] V. P. Antropov etal. Spin dynamics in magnets: Equation of motion and finite temperature effects. Phys. Rev. B, 54:1019, 1996. [5] A. Bergman,
et al. Magnon softening in a ferromagnetic monolayer: A first-principles spin dynamics study. Phys. Rev. B, 81:144416, 2010.

SH06

SH09

SH12

SH15

Modified phase diagram of domain walls in FeNi/Cu/Co nanostripes

Voltage control of magnetisation and magnetic domain configurations
in magnetostrictive epitaxial Fe1-xGax thin films

Transverse domain wall motion in notched ferromagnetic nanowire byspin transfer torque

Modeling field-induced transformations of domain walls in magnetic
stripesNicolas Rougemaille1*, Vojtech Uhlir1, Olivier Fruchart1, Zahid Ishaque1, Jan Vogel1,
Stefania Pizzini1, Zoukaa Kassir-bodon1, Aurelien Massboeuf2, Andrea Locatelli3,
Onur Mentes3, Michal Urbanek4 and Jean-christophe Toussaint1
1
Institut Neel, Centre National de la Recherche Scientifique, Grenoble, France
2
Laboratoire d'Etude des Materiaux par Microscopie Avancee, INAC/CEA, Grenoble,
France3
Sincrotrone ELETTRA, Trieste, Italy
4
Institute of Physical Engineering, Brno University of Technology, Brno, Czech
Republic
Magnetic domain walls (DWs) confined in nanostructured magnetic materials display a wealth of specificstatic and dynamic physical properties. For magnetic nanostripes with sub-micron widths and in-planemagnetization, head-to-head DWs are either of transverse (TW) or vortex (VW) type and are characterized
by a chirality, asymmetry and/or polarity. Due to their small size and fast dynamics, magnetic domain walls
are promising candidates in the area of information processing and storage. The dynamic properties ofthese DW under application of current pulses through the spin transfer torque (STT) is one of the exciting
subjects of spintronics. We used numerical simulations and analytical modelling to predict the phase
diagram of transverse versus vortex walls in Py/Cu/Co trilayer nanostripes, in which high current-induced
DW velocities have been observed. The DW is located in the Py layer while the Co layer is initialized as
single domain. We have found that due to magnetostatic interactions between Py and Co magnetizations,
the TWs are energetically significantly more favourable in the Py layer of the trilayer nanostripes than insingle Py nanostripes. We have experimentally verified part of this modified phase diagram with different
microscopy techniques, including Magnetic Force Microscopy and Photoelectron Emission Microscopy.

Duncan E Parkes1, Stuart A Cavill2, Aidan T Hindmarch3, Peter Wadley1, Fintan Mcgee1,
Kevin W Edmonds1, Richard P Campion1, Andrew W Rushforth1* and Bryan L Gallagher1
1School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
2
Beamline I06, Diamond Light Source Chilton, Didcot, Oxfordshire OX11 0DE, United Kingdom
3
Centre for Materials Physics, Durham University, South Road, Durham, DH1 3LE, United Kingdom

The control of ferromagnetic domains and domain walls by electrical means is a desirable objective forapplications in many existing and proposed information storage[1,2] and logical processing[3] devices. One
route to achieve this goal is via hybrid ferromagnet/piezoelectric transducer devices [4-6] in which a voltage
applied to the transducer induces mechanical strain in the ferromagnet affecting the magnetic anisotropy throughthe inverse magnetostriction effect. We have implemented epitaxially grown thin films of Fe81Ga19 in such a
device. Through a combination of magnetotransport measurements, magneto-optical Kerr effect (MOKE) andhigh resolution photoemission electron microscopy (PEEM) we demonstrate that our epitaxial films possess an
exceptionally large magnetostriction (enhanced over that previously observed in bulk samples[7]) and a strong
cubic magnetocrystalline anisotropy. We exploit these properties to achieve voltage control of the magnetisationand magnetic domain walls, including the reconfiguration of ordered domain patterns in structured geometries,
and non-volatile switching of the magnetisation in the absence of external magnetic fields. Such functionalities
will be directly applicable to information storage and processing technologies.

Arnab Ganguly, Anjan Barman and Saswati Barman*
Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for
Basic Sciences, Saltlake, Kolkata, India, India*Corresponding author: sangkoog@snu.ac.kr [1] S. S. P. Parkin et al., Science 320, 190 (2008). [2] J. Rothman et al.,Phys. Rev. Lett. 86, 1098-1101 (2001). [3] M. Klaui et al., Phys. Rev. B 68, 134426 (2003). [4] Y. Hou et al., Appl. Phys. Lett
98, 042510 (2011). [5] This work was supported by the Basic Science Research Program through the National Research
Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (Grant No. 20110000441).

Andrzej Janutka
Institute of Physics, Wroclaw University of Technology, Poland

We have investigated domain wall motion in notched permalloy nanowires driven by
spin polarized current. We solve modified Landau-Lifshitz Gilbert equation including
the effect of spin-transfer torque by micromagnetic simulation. The ferromagnetic
ground states for the studied geometries show transverse domain walls located at
different regions depending upon the position, shape, dimension and symmetry of thenotch in the nanowire. We have studied the effect of the spin torque on domain-walldisplacement and domain-wall velocity. We find that the domain wall velocity is higher
for single notched nanowire as compared to multiple notches. For rectangular notchesof dimension 10 nm x 5 nm, transverse domain wall is pinned at one edge of the notch
but it gets depinned for current density ~ 108 A/m2. We observe the current induced
domain wall oscillation followed by a damped periodic translational motion of thetransverse wall along with a switching of transverse domain wall from ‘?’ to ‘V’ likeconfiguration and vice versa via head to head or tail to tail domain wall formation.

WN
A
R

D

TH
I
W

[1] W.J. Gallagher and S.S.P. Parkin, IBM J. Res. & Dev. 1, 5 (2006). [2] S.S.P. Parkin, M. Hayashi, and
L. Thomas, Science 320, 190 (2008). [3] D.A. Allwood, et al. Science 309, 1688 (2005). [4] Sang-Koog
Kim et al., J. Mag. Mat. Res. 267, 127 (2003), [5] J-W Lee et al., Appl. Phys. Lett. 82, 2458 (2003). [6] A.W.
Rushforth et al., Phys. Rev. B. 78, 085314 (2008). [7] A.E. Clark, et al. J. Appl. Phys. 93, 8621 (2003).

1. Z. Li and S. Zhang, Phys.Rev. B, 70, 024417 (2004) . 2. A. Thiaville, Y. Nakatani, J. Miltat, and N.
Vernier, J. Appl. Phys. 95, 7049 (2004) . 3. M. Hayashi, L. Thomas, C. Rettner, R. Moriya, X. Jiang,
and S. S. P. Parkin, Phys. Rev. Lett. 97, 207205, (2006). 4. P. Chureemart, R. F. L. Evans and R. W.
Chantrell, , Phys.Rev. B 83, 184416 (2011).

SH07

SH10

SH13

SH16

Effect of current on a threshold width for a dimensional transition of
domain wall dynamics in Co/Ni

Restricted oscillation period effect in the domain wall propagation
after walker breakdown

Domain wall configuration and magneto-transport properties in dual
spin-valve with

Interaction between propagating spin-waves and domain walls on a
ferromagnetic nanowire

Kab-jin Kim1*, D. Chiba1, K. Kobayashi1, S. Fukami2, M. Yamanouchi2, H. Ohno2
and T. Ono1
1
Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan
2
Center for Spintronics Integrated Systems, Tohoku University, 2-1-1 Katahira, Aobaku, Sendai 980-8577, Japan

Xiao-ping Ma1, Zhe Fan1, Je-ho Shim2, Sang-hyuk Lee2, Djati Handoko2, Hong-guang
Piao3* and Dong-hyun Kim2
1
Science of College, Huaihai Institute of Technology, China
2
Department of Physics, Chungbuk National University, Korea
3
Materials Science and Engineering, Tsinghua University, China

The effect of current on the dimensional transition of domain wall (DW) motion isinvestigated in Co/Ni nanowires by accompanying magnetoresistance measurement. As
reducing the nanowire width, we found that the domain wall (DW) motion is changed
from stripe pattern expansion to purely wall motion, implying that the dimensionaltransition from 2D to 1D. The threshold width for this transition is found to strongly
depend on the relative direction of magnetic field and current on DW: parallel(antiparallel) direction has much smaller (larger) transition width, which is mainly
because of different forces mechanism by magnetic field and current. The present work
provides the upper boundary for domain-wall-motion based devices applications.

Understanding and control of dynamic behaviors for magnetic domain wall (DW) in
ferromagnetic nanowire has become one of important issues in realization of potential
spintronic applications such as DW logic and memory devices. In this work, we haveintensively explored antivortex DW dynamic behaviors in ferromagnetic nanowires after
Walker breakdown by means of the mircomagnetic simulation [1]. The nanowire has 2000nm length. The wire width w varied from 25 to 100 nm, and the wire thickness t varied
from 0.5 to 12 nm. In all simulation, the material parameter of Permalloy is used. The unit
cell dimension is 2.5×2.5×t nm3 and the Gilbert damping constant α = 0.01.We have foundthat the DW dynamic behavior in the ferromagnetic nanowire significantly depend on thewire thickness and width. Interestingly, the oscillation period of the DW propagation is not
significantly change with variation of the wire thickness is only dependent the wire width. By
detailed analysis, we propose that there could be a new mechanism to restrict the oscillation
period of the DW propagation in the ferromagnetic nanowire after the Walker breakdown.

(Acknowledgement) This work was partly supported by a Grant-in-Aid for Scientific Research and
FIRST Program from JSPS.

[1] M. J. Donahue and D. G. Porter, OOMMF User's Guide, from http://math.nist.gov/oommf (2002).

344

Jonathan Philippe Chico Carpio1*, Anders Bergman1, Lars Bergqvist2 and Olle
Eriksson1
1
Physics and Astronomy (Materials Theory Division), Uppsala University, Sweden
2
Dept. of Materials Science and Engineering, Royal Institute of Techonolgy (KTH), Sweden

The 19th International Conference on Magnetism

July 13 (Fri)Stefania Pizzini1*, Jan Vogel1, Marlio Bonfim2, Olivier Boulle3, Emilie Jue3, Nicolas
Rougemaille1, Mihai Miron3, Ales Hrabec1, Gilles Gaudin3, Julio C. Cezar4 and Fausto
Sirotti51
Institut Neel, Centre National de la Recherche Scientifique, Grenoble, France
2
Departamento de Engenharia Eletrica, Universidade do Parana, Curitiba, Brazil
3
Spintec, CEA/CNRS/UJF/GINP, INAC, Grenoble, France
4
European Synchrotron Radiation Facility (ESRF), Grenoble, France
5
Synchrotron SOLEIL, Gif-sur-Yvette, France

July 13 (Fri)poster Presentation

Byong Sun Chun1*, Chanyong Hwang1, Han-chun Wu2, Mohamed Abid3, Su Jung
Noh4 and Young Keun Kim4
1
Korea Research Institute of Standards and Science, Korea
2
CRANN, School of Physics, Trinity College Dublin, Ireland
3
Ecole Polytechnique Federale de Lausanne, Switzerland
4
Department of Materials Science and Engineering, Korea University, Korea

June Seo Kim1, Martin Staerk2, Jungbum Yoon3, Chun Yeol You3, Luis Lopez-diaz4,
Eduardo Martinez4 and Mathias Klaeui1*1Institut fuer Physik, Johanes Gutenberg-Universitaet Mainz, Germany
2
Fachbereich Physik, Universitaet Konstanz, Germany
3
Department of Physics, Inha University, Korea
4
Department of Physics, Universidad de Salamanca, Spain

The effect of the direction of the applied magnetic field on the magneto-transport properties
including domain wall (DW) configuration and magnetization reversal process has beenstudied with a synthetic antiferromagnet-based dual spin-valve (SAF-DSV) structure (i.e.
the SV structure is doubled symmetrically with respect to the FM). We can tune the DW
configuration and its reversal process from a vortex to a transverse type by changing thedirection of applied magnetic field respect to the nano-scale constricted SAF-DSV. Whenthe field is applied along the perpendicular direction to the nano-scale constricted SAF-DSV,
the perpendicular magnetic moments are developed due to the transverse magnetization
reversal process. This multi step switching process reflects the pinning and depinning of a
DW at the nano-scale constriction. Our results also show an asymmetric depinning field.
We demonstrate, if nano-scale constriction is asymmetric along its length, i.e. expansions
from both sides of the neck into the two nanowires are not identical, and then an asymmetricenergy barrier to domain wall propagation is formed. This is due to the difference in DW
width, which leads to an asymmetry in the domain wall depinning forces.

The recent discovery that propagating spin waves (SWs) move a domain wall has
created a new possibility to manipulate magnetization [Dong-Soo, Han et al., Appl.
Phys. Lett. 94, (2009) 112502]. Here, we numerically investigate the interaction
between propagating spin waves and a transverse domain wall in a nanowire byusing micromagnetic simulations. In order to understand the mechanisms that lead todomain wall motions, we calculate to domain wall velocity and the depinning fields
for a pinned domain wall that is depinned in and against the direction of the spin wave
propagation. We find that the physical origin of the spin wave induced domain wallmotion strongly depends on the propagating spin wave frequency. At certain spin wave
frequencies, transverse domain wall oscillations lead to transverse wall displacementby the spin waves, while at other frequencies, large reflection and effective momentum
transfer are the main drivers of the spin wave induced domain wall motion.

July 8-13, 2012 Busan, Korea

345

poster Presentation
SI01

SI04

SI07

SI10

Spin oscillations in a free molecular magnet

Clocking schemes for soliton propagation in a ferromagneticallycoupled quantum-dot chain

Ultrafast transfer of spin in a non-collinearly magnetized multilayer

Magnon excitation studies in strongly correlated electron systems

Applying an external acoustic wave, we study spin oscillations in a magnetic
nanoparticle that is free to rotate about its anisotropy axis. Using Hamiltonian of arotated two-state spin system, we have shown that superposition of spin and rotational
states makes a crucial effect on spin oscillations which exhibit quantum beats of themagnetization. In order to study such a beat structure, we compute dynamics of themagnetization by employing a perturbative approach, and discuss conditions underwhich this novel quantum effect can be generated. The results are expected to be tested
in existing experimental techniques.

1

1

2

3

Kyeong-dong Lee *, Hyon-seok Song , Chun-yeol You and Sung-chul Shin1
Department of Physics and Center for Nanospinics of Spintronic Materials, KAIST,
Korea
2
Department of Physics, Inha University, Korea
3
Department of Physics and Center for Nanospinics of Spintronic Materials, KAIST,
and Department of Emerging Materials Science, DGIST, Korea

Transmission of magnetic signals along the ferromagnetically-coupled quantum-dot
chain is an essential property to realize the magnetic quantum cellular automata. In
the dot chain, a magnetic signal is represented by a topological soliton with a head-tohead or tail-to-tail state. The soliton is exceptionally stable coming from the topologyof the system potential-energy surface, and could be driven by an external magnetic
field. In addition to the external field, a global clocking field is used to further control
propagation speed. We investigate the effect of the clocking field along the hard axis tovary the propagation speed, together with the local trigger field along the easy axis toinitialize the soliton propagation by utilizing micromagnetic simulation. Interestingly,
it is found that the required static field to initiate the soliton motion is a little larger
than the minimum field to maintain the soliton motion, and only local trigger fieldis required to initiate the soliton propagation. Furthermore, we reveal the role of the
global clocking field in the propagation speed, unexpectedly, the clocking field impedes
the soliton motion.

Koen Kuiper*, Sjors Schellekens and Bert Koopmans
Eindhoven University of Technology, Netherlands

Femtosecond laser pulses can trigger intriguing dynamic phenomena in magnetic
systems such as quenching of magnetization within 100 fs. An effect hardly exploredis that due to the laser heating high densities of hot electrons are generated, which
can lead to transfer of spin angular momentum across different nano-layers at a
femtosecond timescale. By controlling these spin currents, we effectively combine
the field of spin-caloritronics with ultrafast magnetization dynamics, providing
access to spin-caloritronics at ultimate timescales and a unique opportunity for thedevelopment of new spintronic devices. Malinowski et al. [1] showed in a timeresolved MO-Kerr effect experiment that spin-dependent transfer of hot electrons
can speed up the demagnetization process. Here, in order to maximize the torqueapplied by these electrons, we explore laser induced dynamics in a SiOx/Pt/Co/Al(~1nm)/Co/Al sample with a non-collinear orientation of the magnetization, i.e. an inplane magnetized top Co- and an out-of-plane bottom Co-layer. We provide a proofof-principle demonstration of laser-induced spin transfer across the Al spacer layer.
The absorbed spin transfer and torque on the magnetization of the receiving layer
cause an ultrafast canting of its magnetization, which is experimentally observed as a
successively induced GHz-precession of the in-plane magnetized Co layer.

WN
A
R

D

TH
I
W

[1] G. Malinowski, F. Dalla Longa, J.H.H. Rietjens, P.V. Paluskar, R. Huijink, H.J.M. Swagten, and B.
Koopmans, Nature Phys. 4, 855-858 (2008).

SI02

SI05

SI08

SI11

Effects of nonlinear spin dynamics on spin pumping

Spin wave propagation in single crystal Au(001)/Fe(001)/MgO(001)waveguides

Investigation of spin wave interference circuit with metallic thin film
Nana Sato1, Koji Sekiguchi2* and Yukio Nozaki3
1
Department of Physics, Keio University, Japan2
Department of Physics, Keio University, PRESTO, JST, Japan3
Department of Physics, Keio University, CRESTO, JST, Japan

Magnetoplasmonic hybrid nanoparticles

Francesco Pineider1*, Giulio Campo2, Cesar De Julian Fernandez1 and Claudio
Sangregorio1
1
Department of Chemistry, University of Florence, CNR-ISTM, Italy2
Department of Chemistry, University of Florence, Italy

The needs for the development of future computing and information storage devices have
led the emerging field of spintronics. Since spin waves can propagate macroscopic distancein ferromagnetic material, they can be used as information carrier. Typically spin wave
propagations were investigated using garnet films or permalloy films, both of which have small
crystallographic anisotropy. Here we investigated spin wave propagations using spin wave
spectroscopy technique [1] in single crystal Fe waveguides with cubic and uniaxial surface
anisotropies. The sample, Au(001)-50nm/ Fe(001) / MgO(001)-10nm, were fabricated on
MgO(001) substrate using MBE system. We varied thickness of Fe (0.5-20 nm), waveguide
width (1-100 µm), and distance of two antennae (0-40 µm). The static in-plane magnetic
field was applied perpendicular to waveguide. In this way, magneto-static surface waves
were propagated along the ferromagnetic waveguides. The group velocity of spin wave wasestimated from the oscillation period in transmission spectra. It was about 8.5 µm/ns in 20
nm thick waveguide under 500 Oe external magnetic field. We found that this value linearlydecreases as decreasing the thickness. The contribution of magnetic anisotropies as functions ofthickness and width of ferromagnetic layer to the spin waves was also investigated.

Spin waves are promising phenomenon for the future spintronic devices with low power
consumption. For the realization of the spin wave device, we focused on the interference
effect of spin waves[1]. Magnetostatic surface wave (MSSW) was excited in a NiFe thinfilm by applying a continuous RF field. In order to excite and detect MSSW, a pair ofasymmetric coplanar wave guides (ACPWs) was fabricated on the NiFe thin film. The
MSSW was excited by one ACPW, and its signal was detected by the other ACPW as an
induced voltage in a real-time oscilloscope. The advantage of continuous excitation liesin that the MSSW signal becomes stable in time and space, enabling us to sensitively
detect the spin wave interference. For the observation of spin wave interference, anotherstrip line was inserted in the middle position between the ACPWs. From ACPWs in bothsides of the inserted strip line two different MSSWs having opposite wave vectors were
excited. By changing the phase of RF fields, the phase difference between two MSSWs
was controlled. Induced voltage signal at the inserted strip line was changed according
to the phase difference, indicating that we can observe the interference of MSSWs.

Magnetoplasmonics is a very promising branch of active plasmonics that uses a magnetic field
to modulate plasmon resonance: [1] the field-mediated modulation of the plasmonic response of
nanoparticles is expected to have strong implications in light guiding applications on plasmon
resonance-based sensing. [2,3] In this paper we show how ordinary gold nanoparticles' opticalproperties are modified by the magnetic field and describe the origin of such magnetoplasmonic
behaviour. Then, using a combined approach with the aid of magneto-optics, magnetometry
and x-ray spectroscopy we investigate several routes to increase the response to the magnetic
field by adding a magnetic moiety to the gold nanoparticle. We found that when a transition
metal oxide is added to the gold core in core@shell and heterodimer geometries, the twomaterials (magnetic and plasmonic) behave independently, thus giving rise to bifunctional
magnetic-plasmonic nanoparticle hybrids. True magnetoplasmonic behaviour is insteadfound when a higher degree of hybridisation exists between the two moieties, as in the casewhen metallic magnetic metals are added to the gold moiety, thus achieving an enhancementof the magnetic response of the optical properties and giving rise to a synergic, non-additive
spectroscopic signature in the magneto-optical spectrum.

Sankha Subhra Mukherjee, Praveen Deorani, Siddharth Rao, Jae Hyun Kwon andHyunsoo Yang*
ECE, National University of Singapore, Singapore
Spin pumping has garnered significant interest in recent times. Most of the studies ofspin pumping have been on systems in which the magnetization dynamics was linear.
In nonlinear dynamics, however, large-angle, nonlinear, chaotic dynamics are regularly
produced. We explore the nature of spin pumping signals resulting from nonlinear
magnetization dynamical phenomenon. The device geometry comprises of a permalloy(Py) layer in contact with a nonmagnetic Pt layer. Magnetization dynamics is producedin the system by an rf signal applied to a coplanar waveguide patterned on top. Spininjected into the Pt is converted, due to the inverse spin Hall effect (ISHE), to a charge
current and has been measured across the Pt layer. We will show that the system understudy shown some high peaks at certain frequencies. The frequencies at which thepeaks occur have been shown to be non-stochastic, even though one would expect
them to be stochastic. Also, a frequency shift in the precessional resonant frequency has
been observed as a function of the applied power. A similar shift had been previously
observed in spin wave nonlinear dynamics in a different configuration. The origin of
the peaks and frequency shifts are discussed.

Yoichi Shiota, Shinji Miwa, Norikaze Mizuochi, Teruya Shinjo and Yoshishige
Suzuki*
Graduate School of Engineering Science, Osaka University, Japan[1] M. P. Kostylev et al., Appl. Phys. Lett. 87, 153501 (2005)[1] V. Vlaminck, et al., Science 322, 410 (2008)

1. V. Temnov et al., Nature Photon., 2010, 4, 107. 2. Anker, J. N. et al. Nature Mater.2008 7, 442. 3.
Mayer, K. M., Hafner, J. H. Chem. Rev. 2011, 111, 3828.

SI03

SI06

SI09

SI12

Sharp spectral linewidth in spin torque oscillator with perpendicularmagnetized Co/Pd free layer

Microscopic theory on the spin relaxation in an inhomogeneous spin
dynamics

Current-induced magnetization dynamics of synthetic antiferromagnetic free layers

Inhomogeneous standing spin wave excited by the patterned periodic
electrode

There has been some scientific and practical interest in spin torque oscillator (STO) using
perpendicular materials [1]. For application of STO to information-communication nano
RF devices, it is important to investigate linewidth properties, although comprehensive
understanding of linewidth properties in STO using perpendicular materials is still lacking.
In this study, we have measured spin torque oscillation in giant magnetoresistance devices
having a Co/Pd extended free layer and a NiFe/CoFe nanomagnet fixed bilayer. The total
thickness of Co/Pd is 2.4 nm, and it was confirmed that Co/Pd has perpendicular magnetic
anisotropy by vibrating sample magnetometer. Spin torque oscillation was measured
under the low in-plane magnetic field using spectral analyzer. Microwave signal inducedby spin transfer torque was clearly observed with oscillating frequency at 3.3 GHz. Thisfrequency increased with increasing applied current i.e. positive nonlinear frequency shift.
Obtained minimum spectral linewidth was 13 MHz, which is very small, compared withthat of previous work on perpendicular materials [2]. Our results suggest that applying thelow magnetic field to the Co/Pd film plane is efficient to obtain sharp spectral linewidth.
This work was partly supported by Strategic Japanese-German cooperative program(ASPIMATT) from JST and by Japan Society for Promotion of Science.

The mechanisms of Gilbert damping in materials with inhomogeneous spin dynamics
are more complicate than that with homogeneous spin dynamics (Kittel mode). It is
well known that the magnetic impurities contribute to Gilbert damping with Kittel
mode, on the other hand, the nonmagnetic impurities don’t affect that. Recently, it
has become clear that in the presence of spin waves (inhomogeneous dynamics), thenonmagnetic impurities contribute to Gilbert damping constant, α [1]. In this case, αis proportional to square of wave vector q in the limit q→0. The aim of our study is toclarify the q-dependence of α in the entire q range from microscopic theory. Our model
is described by s-d model which consists of localized spins, and conducting electrons.
In addition to this, we consider the nonmagnetic and magnetic impurities scattering.
We obtain the precise expression of α from the linear response theory. Consequently,
we find that α is proportional to 1/q in k↑-k↓<q<k↑+k↓ (k↑,↓ are Fermi vector eachspin) due to the Stoner excitation, and is continuously changed into the form of α0+Aq²
in 0<q<k↑-k↓. α0 originates from the magnetic impurities scattering while Aq² is
attributed to both the magnetic and nonmagnetic impurities scattering.

The spin polarized current-induced magnetization dynamics is studied theoretically in the frame of the driftdiffusion model [1-3] for two different spin-valve (SV) structures: (i) single free layer (SSV) Pol/Cu/FM and(ii) synthetic anti-ferromagnetic free layer (SyAF-SV) Pol/Cu/FM/Ru/FM. In a first step we have analyzed
the effect of the angular dependence of the spin transfer torque (STT) on the magnetization dynamics for
SSVs. For this four SSVs were considered: SSV1 (Co(3.5)/Cu(3)/Co(3)), SSV2 (Co(3.5)/Ru(3)/Co(3)),
SSV3 (Co(3.5)/Cu(3)/Py(3)), and SSV4 (Co(3.5)/Ru(3)/Py(3)). The polarizing layer, Co(3.5), is fixed. We
found that these four different structures have different magnitudes and angular dependences of STT leading
to different current - magnetic field phase diagrams with different critical values and ranges for dynamics.
In the case of SyAF-SVs the drift-diffusion model allows us to take account of not only STT at Cu/FM but
also STTs at FM/Ru and Ru/FM interfaces. The corresponding phase diagram is distinct from the one where
STT across Ru has not been considered. Hence, this reveals that the STT through Ru considerably affects
the dynamics of a synthetic free layer. We discuss the results as a function the strength of the RudermanKittel-Kasuya-Yosida (RKKY)-type exchange interactions through Ru.

Yuki Kawada*, Hiroshi Naganuma, Mikihiko Oogane and Yasuo Ando
Applied Physics, Tohoku university, Japan[1] S. M. Mohseni et al., Phys. Status Solidi RRL 5, 432 (2011). [2] C. H. Sim et al., J. Appl. Phys. 109, 07C905 (2011).

346

Cecilia I. Ventura1*, Marcello Acquarone2 and Ivon R. Buitrago3
1
Teoria de Solidos, Centro Atomico Bariloche, and Univ. Nac. Rio Negro,, Argentina
2
IMEM-CNR, Dip. di Fisica, Universita di Parma, Italy
3
Teoria de Solidos, Centro Atomico Bariloche, and Inst. Balseiro, Argentina

The 19th International Conference on Magnetism

Nobuyuki Umetsu, Daisuke Miura and Akimasa Sakuma
Tohoku University, Japan[1]Y. Tserkovnyak, E. M. Hankiewicz, and G. Vignale, Phys. Rev. B 79, 094415 (2009).

Seo-won Lee1, Daria Gusakova2, Liliana Buda-prejbeanu2, Ursula Ebels2, Bernard
Dieny2 and Kyung-jin Lee1*
1
Department of Material Science and Engineering, Korea University, Korea
2
SPINTEC, UMR CEA/CNRS/UJF & G-INP, INAC, France[1] A. Brataas, Y. V. Nazarov, and G. E. W. Bauer, Phys. Rev. Lett. 84, 2481 (2000); A. Brataas, Y. V. Nazarov,and G. E. W. Bauer, Eur. Phys. J. B 22, 99 (2001). [2] J. Barnas, A. Fert, M. Gmitra, I. Weymann, and V. K.
Dugaev, Phys. Rev. B 72, 024426 (2005). [3] S. W. Lee and K. J. Lee, J. Kor. Phys. Soc. 55, 1501 (2009).

July 13 (Fri)Gwang-hee Kim
Physics, Sejong University, Korea

July 13 (Fri)poster Presentation

Kohei Kiseki1, Satoshi Yakata1 and Takashi Kimura2*
1
Kyushu University, Japan
2
Kyushu Univsersity, Japan

There has been a great deal of attention in the spin waves excited in ferromagnetic films
because of their various potential applications such as spin-wave-based logic circuitand the interconnection device between the electric and spintronic devices. Efficient
excitation and manipulation of the spin wave are important issues for the realizationsof practical device applications. Spin wave interference in three dimensional spin
structures may enhance the amplitude of the spin oscillation. For this purpose, we here
systematically investigated the thickness dependence of resonant frequency of thestanding spin wave. We prepared Permalloy films with various thicknesses and excite
the standing spin wave by using a periodic nonmagnetic Cu electrode. The resonant
frequency of the spin wave was found to increase with the Permalloy thickness. Thiscan be understood by the increase of the non-excited layer around the bottom ofPermalloy layer, which induces the effective magnetic field to the excited layer via
the exchange interaction. We also perform similar studies of the standing spin wave
in the other ferromagnetic structures exchange biased and ferromagnetic/nonmagnetic
multi-layered film and present the optimized structure for increasing the output signal
induced by the spin wave excitation.

July 8-13, 2012 Busan, Korea

347

poster Presentation
SI13

SI16

SJ01

SJ04

Observation of spin-waves by time-resolved magneto-optic kerr effectmicroscopeSpin-transfer induced spin waves of a magnetic point contact with aconfined domain wall

Fast SpinRAM simulation by GPU

Atomistic modelling of magnetization dynamics with spin torqueSpin transfer torque driven magnetoresistive random access memory (SpinRAM) is
one of the candidates of the next generation non volatile memory, and it is studied
intensively. Micromagnetic simulation is one of the methods to study it. In the
SpinRAM simulation, because the size of the MTJ element is small, the numberof the calculation cells is small, and the calculation for one simulation takes only a
few minutes. However in the real analysis, more than millions of simulations arerepeated with different conditions, the total simulation time becomes huge. Speed upof the simulation is important. Recently, a Graphic Processing Unit (GPU) is used toaccelerate the micromagnetic simulation. The acceleration rate strongly depends on thenumber of the calculation cells, and a huge number of the calculation cells is required
to achieve high speed up ratio. Speed up can not be expected in SpinRAM simulation
by GPU. In this paper, we propose the simulation method to calculate a number ofthe MTJ elements in parallel by GPU, and achieve 75 times of the speed up ratio
in maximum. This study was supported by New Energy and Industrial Technology
Development organization (NEDO) partly.

The dynamics of the magnetization following the introduction of a spin current isstudied by using an atomistic model coupled with spin accumulation. The evolutionof the magnetization and spin accumulation in a trilayer system are calculated selfconsistently, the interaction between magnetisation and spin current provided by ans-d exchange term. A spin-polarised current is introduced into the system containing
a domain wall whose width is varied by changing the anisotropy constant. The
magnetisation is calculated using an atomistic model based on the Heisenberg
exchange energy and spin dynamics introduced via the Landau-Lifshitz-Gilbertequation. The net spin torque contributes two important components: the adiabatic(AST) and nonadiabatic torques (NAST). We show that both arise naturally whencalculated directly from the spin accumulation. The maximum value of the AST and
NAST are considered for each thickness of domain wall. Both torques decrease as thedomain wall thickness increases. The nonadiabaticity factor, defined as the ratio of the
NAST and AST is also shown. Increasing the domain wall thickness gives rise to asmall angle between magnetisation in domain wall. Interestingly the degree of NAST
tends to decay to zero as the thickness of DW increases relative to the spin diffusion
length.

Spin-wave is an ordering of the magnetization when the magnetization of aferromagnet is tilted away from its equilibrium state. The spin-waves in metallic thinfilms have been recently studied as an emerging field of magnetism for magnetic
recording and spintronics devices. The spin-waves can be detected by either electricalor optical method for either frequency or time domain, respectively. In the frequency
domain the ferromagnetic resonance has been commonly employed to detect the
spin-waves, whereas in the time domain, it is typical to detect damped oscillation ofmagnetization excited by a short magnetic pulse via an inductive or optical apparatus.
Here we report the experimental results on the spin-waves by use of all optical pumpprobe method. 20-nm-thick Co thin films are prepared on a GaAs substrate by dc
magnetron sputtering. The pump beam is focused onto a spot with a diameter 1 μm ofa sample under an applied magnetic field 2 kOe at normal direction of the film surface.
The spin-waves are then observed by controlling the tilt angle of the probe beam witha fixed pump beam. Using this method, a propagating spin-wave can be measured
directly and further analysis will be discussed.

Spin-transfer induced microwave oscillation will be a powerful candidate forapplications in future wireless telecommunication technologies. According to Ref.
[1], the oscillation of a domain wall between the Bloch- and Neel-type magnetic
configurations is induced by a direct current and the corresponding oscillation
frequency is proportional to the current density. It is also known that the current
injected through a point contact can excite a variety of spin wave modes [2-4]. It is
intriguing to ask if such spin wave modes can be excited in a thin magnetic layer
connected to a magnetic point contact containing a domain wall. From our calculation
we found that three different kinds of spin wave modes can be excited in the thinfilm depending on the bias current density. The low frequency mode just above thethreshold is the propagating spin wave mode. Then the oscillation frequency increases
drastically with increasing the current density and reaches more than 100 GHz. At highcurrent density the excited spin wave mode is a propagating mode with a large angle
precession. We also found that applied field independence of the frequency for thesecond mode. We shall discuss the physics behind the excitation of spin wave modes.

Phanwadee Chureemart, Richard F. L. Evans, Irene D'amico and Roy W. Chantrell
Physics, University of York, United Kingdom[1] M. Franchin, T. Fischbacher, G. Bordignon, P. de Groot, H. Fangohr, Phys. Rev. B 78, 054447 (2008).
[2] J. C. Slonczewski, J. Magn. Magn. Mater. 195, L261 (1999). [3] A. Slavin and V. Tiberkevich, Phys.
Rev. Lett. 95, 237201 (2005). [4] D. V. Berkov and N. L. Gorn, Phys. Rev. B. 80, 064409 (2005).

SI14

SI17

SJ02

SJ05

Nuclear magnetic resonance study of proton dynamics in ZnO

Spin-torque-nano-oscillator using the perpendicular magnetized
CoFeB/MgO/CoFeB magnetic tunnel junctions

Micromagnetic simulations for the spin dynamics and Gilbert damping
constants in nano-dot with perpendicular magnetic anisotropy

Highly parallelized micromagnetic simulator using fast multipole
methodSpin dynamics and the magnetic damping of a nano-dot ellipse with perpendicularmagnetic anisotropy (PMA) are presented by the micromagnetic simulations. While thein-plane static magnetic field is applied to the long axis of the ellipse, the small in-plane
RF magnetic field is applied to the short axis of the ellipse to mimic the ferromagnetic
resonance (FMR) technique. The susceptibility can be obtained by the power spectraof fast Fourier transform (FFT) from magnetizations dynamics. There are two regionsin the external static field dependence resonance frequencies for typical PMA system.
(I) With small external field, the magnetization is tilted to the static field direction
with the finite angle from the film normal. (II) If the static field is strong enough, themagnetization is aligned to the static field, where the Zeeman energy overcomes the
PMA energy. In this simulation, the extract Gilbert damping constants from the line
widths of the resonance peaks from two different regions. Surprisingly enough, theobtained values (α_I = 0.0165 and α_II = 0.0194) are different from the input value (α= 0.027). It implies that the experimentally obtained α can be different from the realvalues.

We have developed an alternative method for computing the magnetostatic field of arbitrary-shaped
ferromagnetic systems instead of fast Fourier transform (FFT). The method is based on the Taylor
expansion of the potential, as is required by the fast multipole method (FMM)[1][2], the most efficientmethod known for calculating mangnetostatic fields in very large systems. The FMM scales as O(N) inboth time and space complexity compared to the direct method with O(N2), or FFT with O(N logN)[3]and even easier to be parallelized, which is a more valuable solution for larger ferromagnetic systems.
Graphical processing units (GPU) are now increasingly viewed as data parallel compute coprocessors thatcan provide significant computational performance at low price[4]. We have developed a micromagnetic
simulator using the parallelized method with GPU and have tested in various configurations. In that casespeedups of over a factor 100X can easily be obtained compared to the CPU-based OOMMF[5] program
developed at NIST. The tests are carried out with μMag Standard Problem[6] #1,#2,#3,#4.

Jun Kue Park, Kyu Won Lee and Cheol Eui Lee*
Department of Physics, Department of Physics and Institute for Nano Science, Korea
University, Seoul 136-713, Korea

July 13 (Fri)

Hiroko Arai, Hiroshi Tsukahara and Hiroshi Imamura*
Advanced industrial science and technology (AIST), Japan

Kiyoaki Oomaru* and Yoshinobu Nakatani
The University of Electro-Communications, Japan

Hydrogen acting as a dopant is widely known in compound semiconductors including
many oxides. However, in order for such doping to be technologically relevant, thethermal stability of the H-donor must be enough to avoid degradation during device
operation at and above room temperature. Here, we have carried out 1H NMR
measurements in order to understand proton motions in the ZnO lattice at temperatures
between 200 K and 400 K. In our post-annealed ZnO, there are two proton species, oneof which can be assigned to protons at interstitial sites (Hi+) in ZnO. The other species
shows no appreciable motion in the temperature range. The distinct activation energies
obtained for the Hi+ motion, 0.27 eV and 0.42 eV, are associated with the reorientation
around the bonding oxygen atom and hopping between neighboring oxygen atoms,
respectively. These activation energies for diffusion, obtained from the spin-spin
relaxation measurements, are in close agreement with those obtained from ab initio
calculations.
[1] J. K. Park, K. W. Lee, W. Lee, C. E. Lee, D.-J. Kim, and W. Park, Solid State Commun. 152, 116(2012). [2] M. G. Wardle, J. P. Goss, and P. R. Briddon, Phys. Rev. Lett. 96, 205504 (2006). [3] L.
-Q. Wang, X. -D. Zhou, G. J. Exarhos, L. R. Pederson, C. Wang, C. F. Windisch, and C. Yao, Appl.
Phys. Lett. 91, 173107 (2007).

Hiroshi Naganuma1*, Nobuhito Inami1, Yuki Kawada1, Mikihiko Oogane1, Yasuo
Ando1, Kotaro Mizunuma2, Hideo Sato3, Michihiko Yamanouchi3, Shoji Ikeda4 andHideo Ohno4
1
Department of Applied Physics, Tohoku University, Japan
2
RIEC, Tohoku University, Japan
3
CSIS, Tohoku University, Japan
4
CSIS, RIEC, Tohoku University, Japan
Perpendicular magnetized free layer in the magnetic tunnel junctions (p-MTJs) has advantages for spintorque-nano-oscillator because coherent precession, high output power, and increasing precession frequency
due to high magnetocrystalline anisotropy, can be expected. In this study, the microwave transmission
properties were investigated for the p-MTJs using thin CoFeB. The multilayer was prepared by UHV
sputtering system and patterned it into 40-nm-sized junctions with coplanar waveguide electrode. The
microwave properties were measured under the in-plane magnetic field of 3 kOe to tilt the free layer. The
tunnel magnetoresistance ratio was 70% and 0.9% for the out-of-plane and in-plane direction, respectively.
Below -0.24 mA, the spin torque noise was observed with broad signal. The STO signal was clearly observed
above -0.30 mA at 6 GHz, and the second harmonic signal was not observed due to the single-precessionmode by small junction size. The linewidth and output power was 650 MHz and 1.1 nW, respectively. Power
has a potential to be more enhanced by stabilizing the pinned layer to increase the relative angle between
free and pinned layer. This study was partly supported by ASPIMATT (JST), by Grant-in-Aid for Young
Scientists A (No. 22686001), by FIRST program (JSPS), and by Maekawa-Houonkai foundation.

Jungbum Yoon1, Chun-yeol You1* and Myung-hwa Jung2
1
Department of Physics, Inha Universirty, Korea
2
Department of Physics, Sogang Universirty, Korea

Sung-hyun Lee1, Chun-yeol You+ and Sung-chul Shin3*
1
Department of Physics and Center for Nanospinics of Spintronic Materials, KAIST, Daejeon 305-701, Korea
2
Department of Physics, Inha University, Incheon 402-751, Korea
3
Department of Physics and Center for Nanospinics of Spintronic Materials, KAIST, Daejeon 305-701, Korea,
Department of Emerging Material Science, DGIST, Daegu 711-873, Korea[1] L. Greengard and V. Rokhlin, J. Comp. Phys. 73, 325-348 (1987). [2] P. B. Visscher and D. M. Apalkov, 'Simple
recursive Cartesian implementation of fast multipole algorithm', [3] R. Ferre, 'Large scale micromagnetic calculations forfinite and infinite 3D ferromagnetic systems using FFT', Comp. Phys. Commun., 105, 169-186 (1997). [4] CUDA, http://
www.nvidia.com [5] OOMMF, http://math.nist.gov/oommf [6] μMag, http://www.ctcms.nist.gov/~rdm/mumag.org.html

SI15

SI18

SJ03

SJ06

Micromagnetic study of magnonic band gaps in waveguides with aperiodic variation of the saturation magnetization

Planar approximation for spin-transfer devices with tilted polarizer

Micromagnetic study on micro-structured ferromagnetic thin film forhigh frequency device applications

Effect of calculation conditions on the numerical simulation ofmagnetic materials with random magnetic anisotropy

The ferromagnetic metallic thin films of Fe has been considered as promising materials
for on-chip microwave devices, owing to the much higher saturation magnetization Ms
compared with a conventional material of yttrium iron garnet (YIG). Understandingof demagnetizing effects, related to Ms, is important for the design of micro-structured
devices with the high Ms material[1]. In the present study, geometrical effects of microstructured magnetic thin films on high frequency magnetic properties are numericallyinvestigated with micromagnetic simulations. The standard material parameters of Fewith cubic anisotropy are assumed in the simulation. The values of μ’ (@ 1 GHz) andthe resonance frequency fFMR for various aspect ratios w/t are compared. The increaseof μ’ with the decrease of w/t is attributable to the size effect in fFMR, related to thedemagnetizing coefficient along the film normal direction. It should be noticed thatthe μ’ for the same w/t with different w and t is identical. The results suggest that thedemagnetizing effect on the high frequency magnetic properties becomes prominent
for the w/t smaller than 400 in the structured Fe thin film.

Numerical simulation was performed on magnetic materials with random anisotropy.
An assembly of magnetically interacting grains with randomly oriented uniaxial
anisotropy was provided and magnetization was calculated using the Landau-LifshitzGilbert equation. The magnetization in a particular grain is assumed to align in thesame direction (single spin model).[1] Calculations were carried out for N × N × N
three dimensional cells changing cell sizes from 5 to 40 nm. The interaction at theinterface between grains was taken into account by the interaction energy between theunit vectors representing grain magnetization directions. N was changed from 10 to 64.
In the case of N = 10, the relation between coercive forces and grain sizes was obtained
to be δ = 5.7 in Hc ~ D^δ, and fits to the primitive theory of random anisotropy model(RAM) δ = 6. As the N increased, the δ tends to decrease slightly from 5.7 to 4.2.
The grain sizes where the coercive force becomes less dependent on the grain size,
suggesting the natural exchange length, did not changed much.

Florin Ciubotaru*, Andrii V. Chumak, Bjoern Obry, Alexander A. Serga and Burkard
Hillebrands
Faculty of Physics, University of Technology, Kaiserslautern, Germany
Spin wave propagation in micro-sized magnonic crystals (MCs) is intensively studied
due to their potential technological application for signal processing in spintronic
devices. Here we report on micromagnetic simulations [1] of the spin wave propagation
in a MC realized as a permalloy (Ni80Fe20) waveguide with a periodical variation ofits saturation magnetization. In real structures the variation of magnetization can beachieved by using an ion implantation technique. The 2 μm-wide waveguide of 40 nm
thickness is magnetized transversal to its long axis. The MC lattice constant is equal
to 1 μm. The spin-wave transmission characteristics have been studied as a functionof the width of the implanted areas and of the level of the magnetization variation M/
M0. Frequency band gaps were clearly observed in the spin-wave transmission spectra.
The dependences of the depth, width and the position in frequency and space of therejection band gaps on the above parameters are referred in our studies. The role ofthe higher order spin-wave width modes on the MC properties is discussed as well.
Support from DFG (grant SE-1771/1-2) is gratefully acknowledged.
[1] OOMMF open code, M. J. Donahue, and D. G. Porter, Report NISTIR 6376, NIST,
Gaithersburg, MD (1999).

The 19th International Conference on Magnetism

Ya. B. Bazaliy*Department of Physics and Astronomy, University of South Carolina, Columbia SC,
USA and Institute of Magnetism of NASU, Ukraine
Planar spin-transfer devices with dominating easy-plane anisotropy can be describedby an effective one-dimensional equation for the in-plane azimuthal angle [1-3]. Sucha description maps the Landau-Lifshitz-Gilbert equation on the Newton equation forthe motion of classical particle in a one-dimensional potential and thus provides anintuitive understanding of the magnetic dynamics, allowing one to obtain qualitative
results without performing detailed calculations. We apply the effective planar equation
to describe magnetic switching and precession states in spin transfer devices with tilted
polarizer [4]. The approach allows one to list the possible dynamic regimes, including
the precession cycles, and sketch the switching diagram of the device.
[1] Ya. B. Bazaliy, Appl. Phys. Lett. 91, 262510 (2007). [2] Ya. B. Bazaliy, Phys. Rev. B 76,
140402(R) (2007). [3] Ya. B. Bazaliy and F. Arammash, Phys. Rev. B 84, 132404 (2011). [4] Ya. B.
Bazaliy, Phys. Rev. B 85, 014431 (2012).

Keigo Ito, Teppei Takashima, Terumitsu Tanaka* and Kimihide Matsuyama
ISEE, Kyushu University, Japan[1] N. Cramer et al., J. Appl. Phys., 87, 6911 (2000)

July 13 (Fri)Sang-jun Yun1, Jae-chul Lee2, Kyung-ho Shin2 and Sug-bong Choe1*1Department of Physics and Astronomy, Seoul National University, Korea
2
Spin Device Research Center, Korea Institute of Science and Technology, Korea

348

poster Presentation

S. J. Lee1, Suguru Sato1, Hideto Yanagihara1, Eiji Kita1* and Chiharu Mitsumata2
1
Institute of Applied Physics, University of Tsukuba, Japan
2
Graduate School of Engineering, Tohoku University, Japan[1] S.-J. Lee, S. Sato, H. Yanagihara, E. Kita, and C. Mitsumata, J. Magn. Magn. Mater. 323 (2011)28.

July 8-13, 2012 Busan, Korea

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poster Presentation

poster Presentation

SJ07

SK01

SK04

SK07

Vortex and antivortex formation in magnetic rolled-up nanotubes

Top composite free layer non-collinear spin valve for hysteresis-free
GMR sensors

Spin-polarized itinerant electrons in Co2MnAl and Co2MnSi studied
by magnetic Compton scattering

Variation of point-contact andreev reflection spectra offerromagnetically ordered metals

Magnetic nanotubes have attracted considerable attention owing to both fundamental and technologicalinterest1-2. Using a rolling-up fabrication technology3, patterned multilayer tubes can be prepared that exhibit
significant modifications of magnetic behaviors compared to those of thin-film structures4-5. In order to elucidate
the underlying physics, we conducted micromagnetic simulations of possible spin configurations in rolled-up
nanotubes. When a permalloy platelet of dimensions 400 x 400 x 5 nm3 is rolled up, various spin configurations
are found to be either C-state, vortex(V) state or anti-vortex(AV) state in the plane of thin films with more spins
being forced to be aligned along the tube axis. Therefore, the region whose spins are aligned transversely to thetube axis is compressed. The modified spin alignment is supposed to increase the anisotropy magnetoresistanceratio. Although the reorientation of local magnetizations in the rolled-up tubes results in increases of the exchange
energy, it reduces much more the magnetostatic energy, particularly for AV state. Consequently, the total energies
of various spin configurations are similar. The cores in the V and AV states of the rolled-up tubes show anotherinteresting feature: the stray fields inside the tubes are cancelled out at the positions.

Vladimir V. Ustinov*, Michael A. Milyaev, Larisa I. Naumova, Tatiana P. Krinitsina
and Vladimir V. Proglyado
Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, Russia
Top spin valves Ta/[FeNi/CoFe]/Cu/CoFe/FeMn/Ta based on FeMn antiferromagnet
with varying [Fe20Ni80/Co90Fe10] composite free layer parameters and Cu interlayer
thickness were prepared by DC magnetron sputtering. GMR characteristics of spin
valves (SV) were investigated under the conditions of non-collinear SV geometrywhen the applied magnetic field and pinning direction for bottom magnetic layer
are not collinear. It was shown that the value of low field hysteresis caused by freelayer magnetization reversal can be reduced down to 0.1 Oe keeping the GMR ratio
about 10 % by using both layers thicknesses and non-collinearity angle variation.
The magnetoresistive sensitivity of non-collinear is about 1 %/Oe. Low-hysteresis
free layer magnetization reversal is mainly due to coherent rotation of magnetization.
The dependences of low field hysteresis value and GMR ratio on the Cu spacer layer
thickness and the angle between applied magnetic field and pinning direction arepresented.

July 13 (Fri)This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) fundedby the Ministry of Education, Science and Technology (No. 20110000441). 1. S. Allende, J. Escrig, D. Altbir, E. Salcedo, M. Bahiana,
The Eur. Phy. J. B 66, 37 (2008). 2. E. J. Smith et al., Nano Letters 11, 4037 (2011/10/12, 2010). 3. O. G. Schmidt, K. Eberl, Nature
410, 168 (2001). 4. C. Muller et al., Appl Phys Lett 100, 022409 (2012). 5. C. Muller et al., Appl Phys Lett 94, 102510 (2009).

Investigating the spin-polarized itinerant electron states in the intermetallic alloys and compounds
is indispensable for the development of potential spintronic materials. In this work, we have studied
the relationship between the number of sp itinerant electrons and the spin moment in the compounds
Co2MnZ (Z=Al or Si), using synchrotron-based Magnetic Compton scattering (MCS)[1], which
provide the bulk spin-polarized electron momentum distributions, ie. magnetic Compton profiles(MCPs). The shape of MCPs depends on the number of spin-polarized electrons of occupied orbitals,
and the area of MCP corresponds to the spin moment. Co2MnZ (Z=Al or Si) is a good system toinvestigate the spin-polarized itinerant electron states since the number of sp itinerant electrons canbe changed without affecting the number of 3d electrons. The following results were obtained . 1. The
total spin moment increases by 1 μB/f.u. from Co2MnAl (4μB/f.u.) to Co2MnSi (5μB/f.u.), with one sp
electron difference. 2: The proportion of the partial spin moment carried by sp itinerant electrons issame for Co2MnAl and Co2MnSi. From these findings, additional sp electrons occupy the 3d electronstates and increases the localized spin moment. This enhances the spin polarization of itinerant
electrons through the indirect magnetic exchange interaction.

Elina Tuuli* and Kurt Gloos
Department of Physics and Astronomy, University of Turku, Finland

Point-contact Andreev reflection (AR) spectra of ferromagnets are usually fitted withmodified BTK models that take into account the spin polarization. On the other hand,
AR spectra of non-magnetic metals are often described by a BTK model that includes
Dynes' lifetime parameter. The two models yield rather similar spectra and can in fact
be used to fit the spectra of both magnets and non-magnets. The differences between
them are most pronounced at low temperatures but strongly suppressed by thermal
smearing. We have applied the two models to point contacts between the classicalband ferromagnets Co, Fe, and Ni and the conventional superconductors Nb, Ta, andAl as function of temperature. The spectra varied between an absent superconducting
signal and an occasional Josephson-like anomaly with a large resistance drop atzero bias, while many spectra had the typical Andreev reflection double-minimum
structure. However, we could reproduce the expected constant polarization of theferromagnet and a BCS-type dependence of the superconducting gap only in a few
cases. This unexpected variation could be related to the interplay of ferromagnetismand superconductivity at the interfaces.

[1] M. J. Cooper, P. E. Mijnarends, N. Shiotani, N. Sakai, and A. Bansil, in X-ray Compton scattering, Oxford
University Press, Oxford, 2004.

SJ08

SK02

SK05

SK08

Magneto resistance study using micro magnetic simulations inpermalloy nano ladder

Strong <111> texture and low hysteresis in MnIr-based top spin valve

Venkateswarlu Dasari*, Vineeth Mohanan Parakkat and Anil P. S. Kumar
Physics, Indian Institute of Science, India

Mikhail Milyaev, Larisa Naumova, Vyacheslav Proglyado, Tatiana Krinitsina,
Nataliya Bannikova and Vladimir Ustinov
Institute of Metal Physics UB RAS, Russia

Evidence of inelastic tunneling in magnetic tunnel junctions via
capacitance-voltage characteristics

Fabrication of Highly Sensitive Magnetic Tunnel Junctions for Biomagnetic Field Sensor Application

Micromagnetic simulation is one of the tools to investigate magnetization reversal mechanism
in nano-wires and nano structures. In the open source simulators like OOMMF[1], magneto
transport studies viz., Anisotropic Magnetoresistance (AMR) is not available and is nontrivial since it involves solving the generalized Laplacian equation for getting the spatial
distribution of current density[2]. In the case of nano wires, the current density is considered
to be uniform[3]; in this quasi uniform state one can apply phenomenological expression inderiving the AMR. We apply this condition in OOMMF-simulations and is compared withthe commercial software “LLG-simulator”[4]. For this purpose, we considered single wire oflength(L) 1000nm, width(W) 100nm and thickness(t) 5nm. Both the simulators agree witheach other within a maximum error of 5%. Further, we studied a ladder structure formedby joining these two wires, with interconnects of L=100nm, W=20nm and t=5nm. In thisladder structure, we varied number of steps by keeping the periodic separation as 50nm. It
was found that the coercivity falls non-linearly from 312 to 255G when the number of steps
increased from 1 to 13. The resistance measured at remanence states drops linearly, whichindicates the decrease in remanence due to the local nucleation centers.

“Spin valve” nanostructures with GMR and TMR are widely used in spintronics. In
some devices the hysteresis of magnetoresistance must be negligible. The hysteresis is
weak in the spin valves with <111> axial texture. In this work we study the dependenceof the free layer hysteresis loop width on the texture strength that is characterized by the
FWHM of rocking curve. The top spin valves [Ta, (Ni80Fe20)60Cr40)]/Ni80Fe20/Co90Fe10/
Cu/Co90Fe10/Mn75Ir25/Ta with various thickness of the magnetic and nonmagnetic layers
are investigated. On the base of magnetic, magnetoresistance and XRD data the nonlinear
dependence between FWHM of rocking curves measured at the integrated (111) Bragg
peak of Ni80Fe20, Co90Fe 10 and Cu layers and free layer coercivity is established. A
correlation between GMR ratio and FWHM is not revealed. It is shown that in the spin
valve Ta(50A)/NiFe(30A)/CoFe(20A)/Cu(22A)/CoFe(25A)/MnIr(50A)/Ta(20A) withsharp <111> texture, GMR ratio of 10.6 % and minimal coercivity of 8.7 Oe, the freelayer hysteresis can be effectively reduced down to few tenth of Oersted [1]. This study is
supported by RFBR, project No. 10-02-00590, by the Program of Presidium RAS, projectNo. 12-P-2-1051, and OFI-UB RAS, project No. 11-2-23-NPO.

1. M. J. Donahue and D.G. Porter, http://math.nist.gov/oommf 2. S. Manikonda, M. Berz and K. Makino,IEEE Trans. Comp., 4, 1604 (2005) 3. C. Hassel, F. M. Romer, R. Meckenstock, G. Dumpich, and J.
Lindner, Phys. Rev. B, 77, 224439 (2008) 4. M. R. Scheinfein, http://llgmicro.home.mindspring.com/[1] V.V. Ustinov et al. Phys. Met. Metallogr. in press.

[1] P. Padhan et al., Appl. Phys. Lett. 90, 142105 (2007).

[1] S. Yuasa et al, Nat. Mater., 3 (2004) 868. [2] S. S. P. Parkin et al, Nat. Mater., 3 (2004) 862 [3] D.
Mazumdar et al, J. Appl. Phys., 103 (2008) 113911. [4] J. M. Almeida et al, J. Appl. Phys., 105 (2009)
07E722. [5] K. Fujiwara et al, Jpn. J. Appl. Phys., 50 (2011) 013001

SJ09

SK03

SK06

SK09

Soft layer driven switching of microwave-assisted magnetic recording
on segmented perpendicular media

Low temperature crystallization process in Co2FeSi Heusler alloy thinfilms

Spin-polarization measurements for Co2MnSi using Co2MnSi/MgO/
NbN epitaxial tunnel junctions

Oscillatory exchange coupling and strong magnetoresistance effect in
Fe/AgX/Fe (001) heterostructures with X=Cl and Br

In this work, we use micromagnetic modeling to investigate microwave-assisted
magnetic recording on segmented perpendicular media. Two types of microwave
fields, sinusoidal and finite bandwidth square microwaves, have been chosen forour study. We show that microwave fields, when applied to the soft segment, canassist the magnetization reversal of the hard segment. The calculated assisted
frequencies are insensitive to the variation of inter-segment exchange coupling ofsegmented perpendicular media. Our results suggest that sinusoidal microwave fields
are practically more feasible than square microwave fields for the soft layer driven
switching mechanism of segmented perpendicular media.

One of the major challenges for Heusler alloys is to achieve a high L21 ordering at
low annealing temperatures in order to limit interdiffusion in multilayer devices.
We report a low temperature crystallization process of polycrystalline Co2FeSi films
using in-situ imaging techniques. 20nm thick Co2FeSi films were annealed in-situ up
to 600°C with both TEM and diffraction patterns recorded. We show that the grain
crystallization starts to occur at 230°C with no additional nucleation occurring after
30 minutes but further annealing does improve the grain ordering. By varying the
growth conditions it is possible to change the number of nucleation sites and also themedian grain size. Through varying the initial film morphology it is possible to change
the number of nucleation sites and also the median grain size from 20 to 250nm.
Magnetic measurements show that the magnetic moment is over 80% of the theoreticalvalue predicted [1]. This shows that a high degree of ordering can be created forpolycrystalline films after a low temperature anneal of less than 300°C.

Spin-polarization measurements were carried out for the Co-based Heusler alloy, Co2MnSi (CMS,
for short), using CMS/MgO/NbN epitaxial tunnel junctions. The layer structure was as follows:(from the substrate side) MgO buffer (10 nm) /NbN (10 nm)/MgO barrier (1.4-3.2 nm)/CMS (3nm)/Co50Fe50 (1nm)/IrMn (10nm)/Ru cap (5 nm). All the samples were successively depositedon MgO(001) single-crystal substrates in an ultrahigh vacuum chamber. Spin-polarization
measurements were carried out at 1.5 K using the conventional lock-in technique. The spinpolarizations (P) were evaluated for three different film compositions of CMS: Co2Mn0.72Si0.81,
Co2Mn1.00Si0.81, and Co2Mn1.40Si0.81. At H = 0 T, typical differential conductance curves were clearlyobserved, and were well-fitted by the modified-BTK theory [1]. The superconducting energy gap
extracted from the analysis was about 2.5 meV [2]. The P values evaluated at H = 8 T were 0.41,
0.50, and 0.54 for respective CMS films. Thus, the P increased with increasing Mn-composition in
CMS films. This result is consistent with the increase of the TMR ratios for CMS/MgO/CMS fullyepitaxial magnetic tunnel junctions, and can be qualitatively understood from the view point of the
suppression of minority-spin in-gap states that resulted from the reduction of CoMn anti-sites [3].

Jing Qiang Goh1*, Zhi-min Yuan2, Lei Shen2, Tiejun Zhou2 and Yuan Ping Feng1
1
Department of Physics, National University of Singapore, Singapore
2
Data Storage Institute, Agency for Science, Technology and Research, Singapore

1) C.-K. Goh, Z. min Yuan, T. Zhou, L. Wang, and B. Liu, J. Appl. Phys. 105, 07B908 (2009). 2) C.-K.
Goh, Z. min Yuan, and B. Liu, Appl. Phys. Lett. 94,152510 (2009). 3) J.-G. Zhu and Y. Wang, IEEE
Trans. Magn. 47, 4066 (2011).

Luke Fleet1, M. J. Walsh1, J. Sagar1, T. Nakayama2 and A. Hirohata1*
1
The University of York, United Kingdom
2
Nagaoka University of Technology, Japan[1] A. Hirohata, and Y. Otani, Epitaxial Ferromagnetic Films And Spintronic Applications(Transworld Research Network, 2009).

350

Soichiro Mizusaki1, Tomohiro Ohnish1, Masayoshi Itou2, Yoshiharu Sakurai2, Tadashi C Ozawa3, Hiroaki
Samata4, Yoshihiko Noro5 and Yujiro Nagata1
1
Aoyama Gakuin University, Japan
2
Japan Synchrotron Radiation Research institute (JASRI/SPring-8), Japan
3
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Japan
4
Kobe University, Japan
5
Kawazoe Frontier Technologies, Co. Ltd., JapanThe 19th International Conference on Magnetism

Ajeesh M Sahadevan1*, Gopinadhan Kalon2, Charanjit S Bhatia1 and Hyunsoo Yang2
1
Department of Electrical & Computer engineering, National University ofSingapore, Singapore
2
Department of Electrical & Computer engineering, NUSNNI-Nanocore, National
University of Singapore, Singapore
Magnetic tunnel junctions (MTJ) have played a key role in the development of HDDs as well as next
generation non-volatile memories. For high speed applications, capacitance and RC time constant analysis of
MTJs becomes very important. Also for metal-insulator-metal structures with extremely thin tunnel barriers as
in MTJs, the capacitance is mainly determined by the interface properties of the structure as the electric field
penetration becomes significant. Since in MTJs the interfaces are very critical in determining the tunnelingmagnetoresistance (TMR), study of capacitance becomes very relevant for better understanding of thesedevices. We report the temperature dependence of C-V characteristics in MTJs. All our MTJs show a negative
tunneling magnetocapacitance (TMC) with a magnitude lower than the TMR [1]. At temperatures lower than
100 K, a zero-bias anomaly appears in the C-V profile. The behavior is similar to inelastic tunneling or zerobias anomaly in MTJs. Zero-bias anomaly in the R-V characteristics of MTJs has been attributed to magnon
and phonon assisted tunneling or thorough impurities inside the barrier. But since the capacitance is mainly
contributed from the interfaces, the origin of these effects is from the interfaces rather than the bulk.

Ken-ichi Matsuda, Takaho Shinoki, Tomoyuki Taira, Tetsuya Uemura and Masafumi
Yamamoto
Div. of Electronics for Informatics, Hokkaido University, Japan[1] G. J. Strijkers, Y. Ji, F. Y. Yang, C. L. Chien, and J. M. Byers, Phys. Rev. B, 63 (2001) 104510. [2] H.
Yang, S.-H. Yang, C. Kaiser, and S. Parkin, Appl. Phys. Lett., 88 (2006) 182501. [3] M. Yamamoto, T.
Ishikawa, T. Taira, G.-f. Li, K.-i. Matsuda, and T. Uemura, J. Phys.: Cond. Matt., 22 (2010) 164212.

Kosuke Fujiwara1*, Mikihiko Oogane1, Takuo Nishikawa2, Saeko Yokota1, Hiroshi
Naganuma1 and Yasuo Ando1
1
Department of Applyed Physics, Tohoku University, Japan
2
LC Business Department, Konicaminolta Opto,Inc., Japan

July 13 (Fri)Jehyun Lee1, Denys Makarov2, Robert Streubel2, Carlos Cesar Bof Bufon2, Celine
Vervacke2, Dieter Suess3, Josef Fidler3, Oliver G Schmidt2 and Sang-koog Kim1*
1
National Creative Research Center for Spin Dynamics & Spin-Wave Devices and Nanospinics
Lab., Research Institute of Adv. Materials, Dep. of Materials Sci. & Eng., Seoul Nat'l Univ., Korea
2
Institute for Integrative Nanosciences, IFW Dresden, Germany
3Institute of Solid State Physics, Vienna University of Technology, Austria

The discovery of large tunnel magneto-resistance (TMR) effect of over 200% in MgO basedmagnetic tunnel junctions (MTJs)[1,2] enabled us to design highly sensitive magnetic fieldsensors[3,4], such as a bio-magnetic field sensor. For this purpose, we need MTJs with a highsensitivity and hysteresis-free responses. In this study, we fabricated MTJs with a NiFe70/
Ru0.9/ CoFeB3 (in nm) bottom synthetic ferri-coupled free layer and an MgO barrier layer.
This thick NiFe layer serves low magnetic anisotropy[5]. The MTJs were annealed at 325°C
by applying a magnetic field. After the first annealing, we rotated direction of the magnetic
field to 90 degree and annealed at 300°C. This second annealing redirects easy axis of pinned
layer. The TMR properties were measured using DC four probes with an applied magnetic
field along the hard axis of the free layer, and we have successfully observed the very highsensitivity of 25.3%/Oe and hysteresis free response. Developed MTJs are promising forbio-magnetic sensor application. This work was partly supported by S-Innovation program,
Japan Science and Technology Agency (JST).

Petru Vlaic1* and Emil Burzo2
1
Biophysics Department, University of Medicine and Pharmacy 'Iuliu Hatieganu'
400023 Cluj-Napoca, Romania
2
Faculty of Physics, Babes-Bolyai University RO-400084 Cluj-Napoca, Romania
AgCl and AgBr silver halides crystallize under ambient conditions in rock salt geometry having
lattice parameters epitaxially compatible with Fe structure. AgCl and AgBr compounds are widebang gap semiconductors with indirect band gaps of 3.2 eV and 2.69 eV, respectively. Thus
Fe/AgX/Fe (001) magnetic tunnel junctions (MTJs) with X=Cl and Br may represent feasible
heterostructures for comparative studies with sp based Fe/MgO/Fe and Fe/NaCl/Fe junctions
as well as for spintronic applications. In present contribution structural, electronic and magnetic
properties of Fe/AgX/Fe (001) MTJs are theoretically investigated by means of a self-consistentGreen’s function technique for surface and interfaces implemented within tight-binding linear
muffin-tin orbital (TB-LMTO) method. The spin-dependent transport properties are determinedby means of Kubo approach implemented within TB-LMTO formalism. Formation of sharp
Fe/AgCl(AgBr) interfaces and enhancement of interfacial Fe magnetic moments are predicted.
Metal induced gap states on both anion and cation sites are observed. Oscillatory exchange
couplings between ferro- and antiferromagnetic states with decreasing amplitude are evidenced.
Spin-dependent transport properties are determined by the complex band structures of AgCl and
AgBr barriers. Tunneling magnetoresistance ratios as high as 3500 % are predicted for Fe/AgCl/
Fe MTJs in asymptotic regime and even higher values for Fe/AgBr/Fe junctions.

July 8-13, 2012 Busan, Korea

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poster Presentation
SK10

SK13

SK16

SK19

Transport properties in double MgO barrier magnetic tunnel junctions
with Fe nano-particles

Local atomic structure analysis of ferromagnetic semiconductor
GeMnTe by atomic resolution holography

Tunneling magnetoresistance effect in magnetic tunneling junctions
with a high resistance ferromagnetic oxide Fe2.5M0.5O4(M = Mn, Zn)
electrodeHalf-metallic properties of (001) surfaces of the Cr substituted rocksalt GeTe-based compounds

Interplay between spin dependent electron tunneling and Coulomb blockade effect [1,2] is one of themost attractive subjects in spintronics field because it is expected to give rise to remarkable tunnel
magnetoresistance (TMR) effect as well as exhibit fascinating phenomena such as Kondo effect[3]. And
in order to realize this interplay, double barrier magnetic tunnel junctions (MTJs) with ferromagnetic
nano-paricles are good candidates. In this research, double barrier MTJs with structure of MgO(001)substrate/MgO/Cr/Fe/MgO/Fe particles(t = 0.12 - 1.37)/MgO/Fe/Au (unit in nanometer) are fabricated.
An average diameter of the Fe nano-particles estimated by Langevin function fitting reveals an almost
linear relation with t for t ≤ 1.02 nm. Coulomb blockade effect was observed for t ≤ 1.02 nm, and thet dependence of the Coulomb energy of the Fe nano-particles was explained consistently by a simple
capacitance model. Interestingly, electron tunneling spectra (dI/dV) and TMR show a dip around zero
bias at low temperatures. A suppression of the TMR around zero bias implies a phenomenon like Kondo
physics. The transport properties in the double barrier MTJs having Fe nano-particles were also comparedwith those in a double barrier MTJ with the continuous middle Fe layer and a single barrier MTJ.
Acknow ledgements: This work is supported by Grant-in-Aid for Scientific Research (S), MEXT,
Japan. (No. 23226001). [1]. S. Mitani et al. Phys. Rev. Lett. 81, 2799 (1998). [2]. H. Sukegawa etal. Phys. Rev. Lett 94, 068304 (2005). [3]. K. I. Lee et al., Phys. Rev. Lett. 98, 107202 (2007).

Naohisa Happo1*, Yuki Takehara1, Makoto Fujiwara1, Koichi Tanaka1, FumihikoMatsui2, Hiroshi Daimon2, Tomohiro Matsushita3, Kyoko Okada3, Shinya Senba4,
Shinya Hosokawa5, Kouichi Hayashi6 and Hironori Asada7
1
Graduate School of Information Sciences, Hiroshima City University, Japan
2
NAIST, Japan
3
SPring-8/JASRI, Japan4
Ube National College of Technology, Japan
5
Hiroshima Institute of Technology, Japan
6
IMR, Tohoku University, Japan
7
Yamaguchi University, JapanThe IV-VI diluted magnetic semiconductor GeMnTe is expected as a spintronics material, because it shows aferromagnetic order below 190 K at x = 0.08 [1]. It is believed that its ferromagnetism is a carrier induced type.
However, another possibility is a cluster formation of a ferromagnetic MnGe binary alloy. The solution can beobtained by an investigation of the crystal structure around the each element. Recently, we have investigated
the atomic arrangement around the Ge and Mn atoms in the GeMnTe by an X-ray fluorescence holography(XFH) [2, 3]. The obtained atomic images from the XFH suggest that the Mn atoms replace with the Geatoms in the host GeTe, the Mn position is stable in the exact positions of the anion fcc sub lattice [2], and the
Ge position is fluctuated [3]. We have also performed the Te 4d photoelectron holography (PEH) in order toinvestigate the local structure around the Te atoms in the GeMnTe thin film single crystal. The obtained atomic
image from the PEH suggests that the Te atoms are not located at the exact positions of the fcc anion sublattice.

Eiji Shikoh1*, Teruo Kanki2, Hidekazu Tanaka2, Teruya Shinjo1 and Masashi Shiraishi1
1Eng. & Sci., Osaka University, Japan
2
ISIR, Osaka University, Japan

Recently, molecular spintronics has attracted much attention. To improve the spin injection
efficiency from ferromagnetic electrodes into molecular materials, by avoiding an impedancemismatch problem, the use of high resistance ferromagnetic electrodes is more accessible than othermethods. In this study, a high resistance ferromagnetic oxide Fe2.5M0.5O4(FMO: M = Mn, Zn) was
focused and observation of a tunneling magnetoresistance (TMR) effect in magnetic tunneling
junctions (MTJs) with an FMO electrode was implemented. MTJs composed of MgO(100)-sub.
/ FMO(thickness, 25-30 nm) / Al-O(1.5-2) / Ni80Fe20(20) were fabricated by using pulsed laser
deposition, EB deposition, photolithography, Ar ion milling, and sputtering. Magnetic properties
were investigated with magnetic Kerr effect measurements. Magnetoresistance properties were
measured with a 4-terminal-method. A TMR effect reflecting the magnetization processes of the both
ferromagnetic electrodes in the MTJs with M = Mn was successfully observed, and the TMR ratio
was approximately 0.85% at room temperature (RT) [1]. The spin-polarization of FMO with M =Mn at RT was estimated to be at least 0.94%[1]. Higher spin-polarization is expected by improving
the interface and the barrier qualities between the ferromagnetic electrodes.

Kalpana Kamalkishor Landge, Beata Bialek and Jae Il Lee*
Physics, Inha university, Korea

Much effort has been devoted to the development of new magnetic materials for the
spintronic applications. Recently, new half-metallic ferromagnets based on the rock-salt
semiconductor GeTe were found [1]. In the bulk structure, GeTe becomes half-metalwhen some of Ge atoms are substituted by Cr or V. We report the properties of (001)surfaces of Cubic CrGe3Te4 and tetragonal CrGeTe2 with two different terminations,i.e. GeTe and CrTe terminations, as obtained by using the FLAPW [2] within GGA.
We found that both CrTe- and GeTe-terminated CrGe3Te4 and CrGeTe2 (001) surfaces
conserve the half-metallic properties of their bulk structures by analyzing the DOS andconfirmed from the integer value of total magnetic moment (MM) per unit cell. The
center layer energy gap is much larger as compared to its bulk. The energy gap and half
metallic gap became wider with the larger substitution of Ge atom by Cr atoms. In the
CrTe-terminated surface the MM of the Cr atom at the surface layer has been enhanced
as compared to the center layer Cr atoms by the surface effect. The calculated value of
MM on Cr at the top layer of the surfaces is 3.7 μB in the both system.
[1] Y. H. Zhao, W. H. Xie, L.F. Zhu, and B. G. Liu, J. Phys.: Condens. Matter 18, 10259 (2006). [2] E.
Wimmer, H. Krakauer, M. Weinert, and A. J. Freeman, Phys. Rev. B 24, 6864 (1981), and references
therein ; M. Weinert, E. Wimmer, and A. J. Freeman, Phys. Rev. B 26, 4571 (1982).

[1] Y. Fukuma, et al., Appl. Phys. Lett. 93 (2008) 252502. [2] N. Happo, et al., Jpn. J. Appl. Phys.
50 (2011) 05FC11. [3] N. Happo, et al., e-Journal of Surface and Nano Technology 9 (2011) 247.

[1] E. Shikoh, et al., Solid State Commun. 151, 1296 (2011).

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Characterisation of Epitaxial and Polycrystalline Co2FeSi thin films

Dependence of the tunneling magnetoresistance on the inserted
nonmagnetic layer

Monitoring of gamma radiation interaction in PHR sensor

Electronic structure and spin polarization of Co2-xFe1+xSi Heusler alloy

The Planar Hall Resistance (PHR) sensors have been found to be capable of magnetic
micro and nano bead detection as the signal to noise ratio in these PHR sensors
are higher by several orders compared to others magnetoresistive biosensors. In
addition, the spin valve multilayer are considered as novel structures for a highsensitivity and uniform magnetization rotation compared to exchange biased bilayer
structure for planar Hall resistance sensors.(1). In this work, we discussed a method
for immobilization of magnetic labels on the PHR sensor for sensitive detection ofmagnetic labels. We used photolithography to generate the functionalized sensor
surface to demonstrate the capacity of monitoring the immobilization of biomolecule.
The PHR sensor was irradiated by Co source up to 80 Gy and the sensor characteristic
was compared with non irradiated one. The field sensitivity obtained by the slope (ΔV/ΔH) of the field-voltage curve was not changed by high dose irradiation up to 80 Gy.
The sensitivity of the PHR sensor was identified detecting the different concentration ofmagnetic beads. We have successfully demonstrated the immobilization of streptavidin
coated magnetic bead to the single stranded oligonucleotide on the Au coated PHR
sensor surface for the detection of magnetic labels.

We study the electronic structure and spin polarization for Co-based Heusler alloys
of Co2-xFe1+xSi using the first principles calculations to discuss the spin injection
into semiconductors and paramagnetic metals. Half-metallic Heusler alloys suchas Co2MnSi, Co2FeSi, and Fe2MnSi are promising materials for spin generator,
injector, and detector. Recently, epitaxial films of Fe2MnSi [1] and Co2FeSi [2] havebeen successfully fabricated on Ge or Si substrates and the spin-dependent transport
properties have been measured. Obtained results seem sensitive to the degree ofdisorder and the composition of the alloy. In this contribution, we examine composition
dependence of the electronic structure for Co2-xFe1+xSi by performing band calculations
based on the density-functional theory (DFT) in the generalized gradient approximation(GGA) using the projector-augmented wave (PAW) method. It is shown that the spinpolarization defined by the total DOS decreases from +100% at x=0 and changes thesign with increasing Fe composition x because the half-metallicity is lost. However,the spin polarization defined by the s-component of DOS (partial DOS) keeps positive
although it decreases with increasing x from x=0 to x=2.

James Sagar1, Hiroaki Sukegawa2, Leonardo Lari3, Vlado K Lazarov3, Seiji Mitani4
and Atsufumi Hirohata5*
1
Department of Physics, University of York, United Kingdom
2Magnetic Materials Centre, National Institute for Materials Science (NIMS), 1-2-1
Sengen, Tsukuba 305-0047, Japan3
Department of Physics, University of York, York, YO10 5DD, United Kingdom
4Magnetic Materials Centre, National Institute for Materials Science (NIMS), 1-2-1
Sengen, Tsukuba, Japan
5
Department of Electronics, University of York, York, YO10 5DD, United Kingdom
We have grown and characterised both epitaxial and polycrystalline Co2FeSi thin films using
UHV magnetron and HiTUS sputtering. The structure of the films has been studied using XRD,
TEM and STEM. The combination of these techniques allows analysis of the structure and defects
within the films. Magnetic characterisation has been carried out using AGFM and VSM. UHV
magnetron sputtered films have been found to become increasingly L21 ordered after annealing
above 500°C. HiTUS deposited samples form a polycrystalline film from and amorphous Co, Fe
and Si matrix after annealing at 500°C for 3, 6 and 9 hours with large (50nm-250nm) L21 and B2ordered grains. This growth process results in films with large Hc (>500Oe) these values are twoorders of magnitude greater than those found for epitaxial films [1]. The magnetic response of thesepolycrystalline films has been found to improve with the use of a 6nm Cr or Ag buffer layer. This isshown by a decrease is Hc and an increase in Ms to greater than 85% of the theoretical value.

Changsik Choi and Byung Chan Lee*
Department of Phyics, Inha University, Korea

When a crystalline nonmagnetic (NM) layer was inserted between the tunnel barrier
and a magnetic layer in magnetic tunnel junctions (MTJs), it was observed that thetunneling magnetoresistance (TMR) decayed and oscillated as a function of the
thickness of the nonmagnetic layer. In this paper, the TMR dependence on the NM
layer is investigated theoretically. The conductance was calculated with the LandauerButtiker formalism, and the conductance difference between the parallel and antiparallel magnetizations was given in an analytical form with the spin-dependent
reflection amplitudes. In order to check the validity of our model, numericalcalculations were carried out. An effective mass theory was adopted for the electronic
structure of each material, and several cases were considered. It was shown that oursimple model agreed well with the results of the numerical calculations. Our model
can be applied also to more realistic cases with the full-band structures. The oscillation
period was determined from the extremal vectors of the Fermi surface of the NM
material, and the selection rules for the oscillation period were obtained. Comparisonswith the experimental data and the previous theoretical results will be presented.

D.g. Park and Hoon Song
korea atomic energy research institute, Korea

Hiroyoshi Itoh1* and Syuta Honda2
1
Department of Pure and Applied Physics, Kansai University, Japan
2
Faculty of Pure and Applied Science, University of Tsukuba, Japan[1] P. E. Sheehan and L. J. Whitman, Nano lett. 5, 803 (2005).

[1] K. Hamaya et al.: Phys. Rev. Lett. 102 (2009) 137204. [2] A. Yamada et al.: Appl. Phys. Lett. 96(2010) 082511.

July 13 (Fri)Pham Van Thach, Do Bang, Shinji Miwa, Takayuki Nozaki, Eiichi Tamura, Norikazu
Mizuochi, Teruya Shinjo and Yoshishige Suzuki*
Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 5608531, Japan

July 13 (Fri)poster Presentation[1] J.Sagar, et al, IEEE. Trans. Mag, 47, 2440 (2011)

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Inverse spin polarization at benzene/iron interface

The bulk Fe-Mo double perovskite analyzed from a small clusters
perspective

Reactively sputtered MgAl2O4 barrier layers for Heusler tunnel
junctions

Large enhancement of Kerr rotation of GMR periodic patterns using
Pt / Co free layer

Souraya Goumri-said*, Mohammed Benali Kanoun, Udo Schwingenschlogl andAurelien Manchon
Physical Sciences and Engineering Division, King Abdullah University of Science andTechnology (KAUST), Saudi Arabia
Organic spin-valves involving an organic spacer inserted between two magnetic electrodes havebeen successfully realized and led to sizable magnetoresistance ratios [1-3]. The accurate design ofthe interfacial electronic structure controlling the spin injection is critical to obtain high performancedevices. Intriguingly, recent reports claimed that interfacial spin polarization may be reversed in somecases [4, 5]. We address the nature of the spin polarization Benzene/ Fe (100) interface using ab-initio
approach. The surface is modeled by 6 layers of Fe (100) and the position of the Benzene molecule
on Fe (100) surface is determined by a combination of the chemisorption of the π-molecule on thereactive surface and the strong interaction of the d-metal orbital with π-molecule orbitals. We find thatthe presence of the Benzene molecule dramatically modifies the electronic structure of the interface andcan lead to drastic change in the interfacial spin polarization. While the Benzene molecule becomesslightly magnetic (0.032 μB by C atom), it is found that the polarization of the interfacial Fermi electrons
is reversed from 0.59 (pure Fe surface) to -0.70 (Fe/Benzene interface). This polarization reversal isanalyzed in terms of orbital overlaps between the Benzene p-orbitals and Fe-d orbitals .
[1] V. Dediu, M. Murgia, F. C. Matacotta, C. Taliani, and S. Barbanera, Solid State Commun. 122, 181 (2002).
[2] Z. H. Xiong, D. Wu, Z. Valy Vardeny, and J. Shi, Nature 427, 821 (2004); Yoo et al., Nature Materials
9, 638 (2010) [3] C. Barraud, et al. Nature Physics 6, 615 (2010) [4] Atodiresei et al, Phys. Rev. Lett. 105,
066601 (2010) [5] M. Saeys, M. Reyniers, and G. B. Marin, J. Phys. Chem. B 106, 7489 (2002).

352

The 19th International Conference on Magnetism

Eliel Carvajal Quiroz1*, Raul Oviedo Roa2, Miguel Cruz Irisson1 and Oracio Navarro3
1
Instituto Politecnico Nacional, ESIME-Culhuacan, Mexico
2
Programa de Investigacion en Ingenieria Molecular, Instituto Mexicano del Petroleo, Mexico
3
Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico,
MexicoBeing the Sr2FeMoO6 double perovskite among the promising materials for spintronic
applications, the bulk case was studied in this work; but attention was focused, also, on theoctahedral arrangements FeO6 and MoO6 as well as on FeO4 and FeMoO11 clusters. Calculations
were made using Density Functional Theory (DFT) and the Perdew-Burke-Ernzerhof (PBE)
functional within the Generalized Gradient Approximation (GGA) scheme. In order tounderstand the differences in the behavior among up- and down-spin electrons observed in thehalf-metallic Sr2FeMoO6 double perovskite, the orbitals and density of states were analyzed. Our
results reveal that the half-metallic character is present ever since the isolated (FeO6)4- cluster
and is a consequence of the non-zero spin at Fe atom coming from t2g orbitals. The (MoO6)6octahedra does not inhibit the perovskite half-metallic character because this Mo-containing
cluster has a zero total spin. In addition, Sr atoms were aggregated to the studied cluster, notjust because of the searched relation between the bulk material and the cluster units properties,
because they give the impression that play a relevant role to become stable the charge eventhough the energy deepest of the states contributed by them. Acknowledgments: Work supported
by Multidisciplinary Project SIP-IPN: 2012-1439, PAPIIT-IN108710 UNAM.

Keima Inagaki*, Naoto Fukatani, Kenichiro Mari, Hirohito Fujita, Tetsuya Miyawaki,
Kenji Ueda and Hidehumi Asano
Crystalline Materials Science, Nagoya University, Japan
Magnetic tunnel junctions (MTJs) using epitaxial MgO barriers have attracted great interest
because they exhibit large tunnel magnetoresistance (TMR) ratios. However, the large latticemismatch (about 4%) between MgO and half-metallic Heusler alloy induces misfit dislocations
and antisite disorder at the surface of ferromagnetic electrode[1]. Thus, coherent growth of MTJ is
important for further improvement of device performance. This study focuses on spinel MgAl2O4
as a tunnel barrier lattice-matched with half-metallic Heusler alloy. We fabricate a Fe2CrSi/
MgAl2O4 junction by reactive sputtering, which can control the crystallinity and degree ofoxidation of the films strictly, and investigate its crystal structure and electrical transport properties.
MgAl2O4 films were deposited from a MgAl2 target in Ar+O2 atmosphere. Epitaxial Fe2CrSi /MgAl2O4 junctions were obtained by inserting an ultrathin MgAl2 interlayer, which worked as aprotection layer for oxidization at the surface of Fe2CrSi. The rocking width of MgAl2O4 (004)
was around 1º, which is small value compared to that of the electron-beam evaporated MgO[2].
Current-voltage curve was fitted by Simmons’ tunneling theory, and we obtained barrier hight φ =0.86-0.95 eV for the Fe2CrSi/MgAl2O4/CoFe MTJ. Present epitaxial MgAl2O4 barrier depositedby reactive sputtering is expected to realize high performance spintronic devices.
[1]T. Miyajima, M. Oogane, Y. Kotaka, T. Yamazaki, M. Tsukada, Y. Kataoka, H. Naganuma, and Y. Ando: Appl. Phys. Express 2(2009) 093001. [2]G. X. Miao, Y. J. Park, and J. S. Moodera: Phys. Rev. Lett., 100 (2008) 246803.

Kakeru Wada1, Tsukasa Kobayashi1, Yuuki Oshino1, Hiroshi Ono2, Tatsutoshi Shioda2, Kenji
Machida3, Ken-ichi Aoshima3, Kiyoshi Kuga3, Hiroshi Kikuchi3, Naoki Shimidzu3, Akira
Emoto4 and Takayuki Ishibashi1*
1
Department of Materials Science Technology, Nagaoka University of Technology, Japan2
Department of Electrical Engineering, Nagaoka University of Technology, Japan
3
Science and Technical Research Laboratories, Japan Broadcasting Corp, Japan
4
National Institute of Advanced Industrial Science and Technology, Japan

Magneto-optical spatial light modulator (MO-SLM) driven by spin transfer switching is a promising device
for holographic 3D display. However, a small Kerr rotation angle is an issue to be solved to realize the MOSLM. In this paper, we report an enhancement of Diffraction Magneto-Optic Kerr Effect (DMOKE) obtainedfor periodic GMR patterns. A GMR structures with Pt/Co free layer were used in this experiment. The samples
were patterned into periodic structures with sizes of 5-50 μm and pitches of 10-100 μm. SiO2 was depositedon the etched area after the patterning to obtain flat surfaces. DMOKE of the GMR patterns were measured byusing a He-Ne laser with a wavelength of 632.8 nm and an incidence of 30°. DMOKE hysteresis loops wereclearly observed, corresponding to the magnetization reversal of the free layers, and Kerr rotation angles of (1,0)
and (1,1) diffraction spots were measured to be 0.5°, which is six times larger than a polar Kerr rotation angle
measured before the patterning. We consider that the large enhancement of DMOKE is due to an interference
effect occurred in the periodic GMR structures embedded in SiO2. This work was supported by the NICT.
K. Aoshima et al, Appl Phys Let, 44, 052507 (2007)

July 8-13, 2012 Busan, Korea

353

poster Presentation

poster Presentation

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Ab-initio and tight-binding calculations of magnetic anisotropy
phenomena in CoPt

Ab-initio calculation of the magnetic properties of bn nanoribbon

Half-metallicity in hydrogenated carbon nanotubes

Enhancement of spin signal in all-metallic lateral spin valves with halfmetallic heusler alloy

Ordered CoPt alloys hold potential for applications in high density magnetic recording due to the combination of
exchange and spin-orbit interactions giving rise to large magnetic anisotropies. Tunneling Magnetoresistance [1] andTunneling Anisotropic Magnetoresistance [2] have been demonstrated in tunneling devices with CoPt electrodes.
Controlling the spin-orbit coupling (SOC) phenomena is essential as the same anisotropy that ensures thermal
stability of a memory element makes the writing by external magnetic fields or electric currents challenging. An
alternative to the spin transfer torque (STT) effect in multi-domain systems is based on current induced polarizationof the conduction electron spins in structures possessing SOC and lacking inversion symmetry. Switching of aferromagnetic layer induced by in-plane current has been shown recently in a Co-Pt bilayer [3]. Another promising
way of controlling the magnetic anisotropy via SOC utilizes lattice strains induced by piezo stressors. We study
SOC effects in strained CoPt multilayer structures using a relativistic full-potential linearized augmented plane-wave
method. We compare the variations of anisotropies of magnetic total energies (MAE) and density of states (ADOS)
also to our tight-binding calculations using a realistic Slater-Koster parametrization which provide more practicalbasis for further research of magnetotransport anisotropies in CoPt based nanostructures.

The emerging field of spin electronics (spintronics) has been continuously attracting
researchers. Substantial theoretical and experimental efforts have been made in thequest to find the candidates for future spintronics devices. Recently, the search for
new spintronics materials has also included graphene-based materials due to thetheoretical prediction that this type of material may show the half-metallic property.
Here, we present the results of a density functional theory within a generalized gradientapproximation study of Boron Nitride (BN) nanoribbon. The objective of this study is
to determine whether this type of material will be ferromagnetic or antiferromagnetic
if the width is varied. Our results show that the narrow zigzag shaped BN nanoribbon
prefers ferromagnetic or antiferromagnetic state depending on the width. Thus, bycontrolling the width (and growth direction) it is possible to manipulate the magnetic
property of this material. These results are of the scientific interest in exploring themagnetic properties of BN-based nanoribbon for future spintronics.

Kyu Won Lee, Gi-wan Jeon and Cheol Eui Lee*
Physics, Korea University, Korea

Zigzag-edge graphene nanoribbons (ZGNRs) show half-metallicity arising from edgelocalized electron states under an electric field, enabling fully spin-polarized electricalcurrent and thus providing a basis for spintronics. While carbon nanotubes (CNTs),
obtained by rolling up the ZGNRs, have themselves no edges, edge states have been
identified in hydrogenated CNTs. Thus, whether or not the CNTs can be half-metallic
under an electric field becomes an issue of great interest. Here, our density functional
theory (DFT) calculations show that the edge states in the CNTs are unstable under anelectric field due to the spin-conserving electron transfer between the edges, but a large
enough transfer barrier between the edge states, obtained by controlling the adsorption
patterns, can render the CNTs half-metallic. Our results can be extended to most carbon
systems thus opening a new route to materials engineering and providing a deeper
understanding of the electronic properties of π-bond network edges.
1. Y-W. Son, M. L. Cohen, S. G. Louie, Nature 444, 347 (2006 ). 2. Z. Sljivancanin, Phys. Rev. B 84,
085421 (2011).

[1] Gukcheon Kim, Yuya Sakuraba, Mikihiko Oogane, Yasuo Ando, and Terunobu Miyazaki, Appl. Phys. Lett. 92, 172502 (2008). [2] B. G. Park, J. Wunderlich, D. A. Williams,
S. J. Joo, K.Y. Jung, K. H. Shin, K. Olejnik, A. B. Shick, and T. Jungwirth, PRL 100, 087204 (2008). [3] Ioan Mihai Miron, Kevin Garello, Gilles Gaudin, Pierre-Jean Zermatten,
Marius V. Costache, Stephane Auffret, Sebastien Bandiera, Bernard Rodmacq, Alain Schuhl, and Pietro Gambardella, Nature 476, 189-193 (2011).

July 13 (Fri)A lateral spin valve (LSV), consisting of two ferromagnetic wires connected with
one non-magnetic wire, is one of the promising devices to convert charge currents topure spin currents, and vice versa. The conversion ratio is, however, still too small,because of the large spin absorption in ferromagnetic wires. Recently, Fukuma et al.
have demonstrated that inserting the MgO barrier between ferromagnetic and nonmagnetic wires suppresses the spin absorption, resulting in the enhancement of thespin signal[1]. Here, we demonstrate another way, using the half-metallic Heusler
alloy as ferromagnetic electodes. The devices were fabricated from a film stack of
SiO2(2)/Cu(10)/Co2FeGa0.5Ge0.5(25)/Ag(10)/Cr(1) on MgO substrate (unit in nm).
The non-magnetic wire was made of 100 nm-thick Cu. The typical wire width was
150 nm, while the distance between two ferromagnetic wires was 350 nm. The nonlocal resistance observed is 12.8 mΩ at room temperature that increases up to 44.8mΩ below 10 K[2]. These values are much larger than those in typical LSVs made of
Permalloy and Cu in previous reports, indicating the advantage of the half-metallic
Heusler alloys as ferromagnetic electrodes in LSV.
[1]Y. Fukuma, L. Wang, H. Idzuchi, S. Takahashi, S. Maekawa, and Y. Otani, Nature Mater. 10, 527 (2011). [2]Y.
K. Takahashi, S. Kasai, S. Hirayama, S. Mitani, and K. Hono, Appl. Phys. Lett. 100, 052405 (2012).

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Spin polarization of half-metallic Heusler alloy Co2MnSi by Andreev
reflection measurements

Synthesis and functional properties of polycrystalline Fe3Si-basedmagnetic tunnel junctions

Enhanced perpendicular magnetic anisotropy in Fe/(MgAl 2)OX
bilayer structures with interface optimization processes

Effect of electron beam rapid thermal annealing on the TMR of
CoFeB/MgO/CoFeB magnetic tunnel junctions

Iduru Shigeta1*, Yuya Nishisako1, Kohei Harumori1, Akinari Okubo2, Rie Y. Umetsu3,
Masakazu Ito1, Keiichi Koyama1, Ryosuke Kainuma2 and Masahiko Hiroi1
1
Department of Physics and Astronomy, Kaghosima University, Japan2
Department of Materials Science, Tohoku University, Japan
3
Institute for Materials Research, Tohoku University, Japan

We report spin polarization measurements of half-metallic Heusler alloy Co2MnSi. Heusler
alloys are regarded as the most promising half-metallic materials for spintronics applications
because of their high Curie temperature and low coercivity. Recently, large tunnelingmagnetoresistance (TMR) value was experimentally reported from a Co2MnSi/Al-O/Co2MnSi
magnetic tunnel junction (MTJ), which was attributed to the half-metallicity of Co2MnSi.
Therefore, we have determined the spin polarization of Co2MnSi by the Andreev reflection
technique. Polycrystalline Co2MnSi samples were fabricated by using a high-frequency
induction furnace. We have made planar-type junctions by depositing Pb on the polishedsurface of the polycrystalline Co2MnSi samples. The differential conductance of Co2MnSi/Pb
planar-type junctions was measured between 1.5 K and 10K by the lock-in amplifier technique.
The obtained differential conductance was able to be fitted very well by the modified BlonderTinkham-Klapwijk (BTK) model. We have found the spin polarization of approximately 50%
from the analysis of Andreev reflection measurements of half-metallic Heusler alloy Co2MnSi.

Alexander Goikhman 1*, Galina Kupriyanova 1, Roberto Mantovan 2, Andrei
Zenkevich3 and Ksenia Maksimova1
1
REC 'Functional Nanomaterials', Imanuel Kant Baltic Federal University, Russia
2
Laboratorio MDM IMM-CNR, Italy
3
NRNU 'Moscow Engineering Physics Institute', Russia

Magnetic tunnel junctions (MTJs), consisting of two ferromagnetic (FM) layers separated by ultrathintunnel barrier are key elements in a wide range of spintronic devices, particularly, as bit elements in magnetic
memories and as reading heads in racetrack memory concept. The improvement of the MTJs tunnel
magnetoresistance (TMR) might be attained by the selection of the materials with high spin-polarizationand the appropriate combination of FM electrodes and tunnel barrier [1]. In this work, we discuss theapplicability of a half-metal Heusler alloy Fe3Si as an top and bottom electrodes in MTJ, the material which
has been poorly adopted so far [2,3]. MTJs based on polycrystalline Fe3Si ferromagnetic (FM) electrodes
and both SiO2 and MgO tunnel (~1~3 nm) insulators (TI) have been grown by the combination of pulsed
laser deposition (using two-laser co-deposition approach) and ion beam assisted deposition techniques. The
morphology, phase composition and structural properties of individual layers as well as the intermixing andchemical reactions at the FM/TI interface have been investigated. The magnetic properties of the trilayers
and preliminary TMR measurements on Fe3Si-based MTJs obtained at wide range of temperatures (2-400 K)
will be presented, aiming at the evaluation of potential of Fe3Si-based MTJs for spintronics.

J.w Koo1, S Mitani2, H Sukegawa2, Z.c Wen2, T Niizeki2, S Kasai2 and K Inomata2
1
University of Tsukuba, Tsukuba National Institute for Material Science, Japan
2
National Institute for Materials Science, Tsukuba, Japan

Ferromagnetic metals (FM) electrodes with large perpendicular magnetic anisotropy(PMA) are actively being investigated. Recently PMA arising at the interface between a
FM and an oxide layer such as CoFeB/MgO [1] and Co2FeAl/MgO [2] were reported.
The PMA at which between FMs and oxide barrier materials has attracted muchattention not only for the STT-MRAM applications but also for spintronic devices
with electric field control of magnetization. The detailed mechanism of the interface
PMA is still an open question since the experimental reports, in particular the materials
examined, are much limited. Here, we report the enhanced PMA in Fe/MgAl2OX
structures with the effective perpendicular magnetic anisotropy energy density (Keff)~ 3 erg/cm3. In the case of an Fe layer with a crystalline (MgAl2)OX layer, it exhibited
perpendicular magnetization characteristics, and the value of Keff was increased from~ 0 to ~3 erg/cm3 with increasing annealing temperature. Furthermore, even in the Felayer with amorphous (MgAl2)OX, a large interface magnetic anisotropy was obtained.
[1] S. Ikeda et al., Nature Mater. 9, 721 (2010) [2] Z. C. Wen et al., Appl. Phys. Lett. 98, 242507(2011).

1. S.D. Bader, S.S.P. Parkin, Annu. Rev. Condens. Matter Phys. 2010, 1:71-88 2. Y. Ando, K. Hamaya et al.,Appl. Phys. Lett. 2009, 94 182105 3. K. Harada, K.S. Makabe et al., J. of Phys.: Conf. Ser. 2011, 266 012088

Ganesh K Rajan 1, Shivaraman Ramaswamy 2*, C Gopalakrishnan 2 and John
Thiruvadigal3
1
Nanotechnology Research Center, SRM University, India
2
SRM University, India
3
Department of Physics and Nanotechnology, SRM University, India
In this paper, we present our studies on the effect of Electron Beam Rapid Thermal
Annealing (ERTA) on the structural evolution and related transport properties of
CoFeB/MgO/NiFe MTJ. The MgO based tunneling junctions were fabricated in a DCRF magnetron sputtering system with a base pressure 2 X 10-7 mBar. An e-beam gunwith a 3kV power supply was used to facilitate electron bombardment on the MTJ for
the purpose of rapid annealing .We observed the evolution of TMR in CoFeB/MgO/
NiFe MTJ when subjected to ERTA. The main factor that distinguishes this study fromother rapid annealing based studies is that the evolution of TMR happened within avery short annealing time (20 seconds). We observed an ultrafast crystallization of the
FM layers of the MTJ which resulted in the evolution of TMR.
1. S. Yuasa, T. Nagahama, A. Fukushima, Y. Suzuki and K. Ando, Nature Mater., vol. 3, pp. 868 - 871, Dec.
2004. 2. S. S. P. Parkin, C. Kaiser, A. Panchula, P. M. Rice, B. Hughes, M. Samant and S. H. Yang, Nature
Mater., vol. 3, pp. 862 - 867, Dec. 2004. 3. R. Cao, T. Moriyama, W. G. Wang, X. Fan, J. Kolodzey, S. H.
Chen, C. R. Chang, Y. Tserkovnyak, B. K. Nikolic and J. Q. Xiao, IEEE Trans. Mag., vol. 45, pp. 3434 3440, Oct. 2009.

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Electronic properties of Co2FexMn1-xSi Heusler alloys studied by hard
X-ray photoelectron spectroscopy

Half-metallic properties of the (001) surfaces of the half-heusler
compounds GeKCa and SnKCa

Graphene nano-ribbon and the ripple effectPreparation of Ti-N films for a capping layer of a CoFeB/MgOmagnetic tunnel junction

A. Gloskovskii1, S. Ouardi1, G. H. Fecher2, S. Thiess3, W. Drube3, B. Detlefs4, T. Kubota5, Y. Ando5
and C. Felser2
1
Johannes Gutenberg University, Mainz, Germany
2
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
3
Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
4
ESRF, Grenoble, France
5
Department of Applied Physics, Graduate School of Engineering, Tohoku University, Japan

One major research area where Co2 based Heusler compounds are investigated is on TMR junctions.
Fully epitaxial magnetic tunnel junctions (MTJs) with a Co2YZ thin film as a base electrode and a
MgO tunnel barrier exhibit high TMR ratios. Quaternary Co2FexMn1-xSi (CFMS) Heusler alloys areeven more promising because the substitution of Mn by Fe increases the number of valence electrons
and therefore leads to higher Curie temperatures above 1000 K. Kubota et al. found a maximum
TMR ratio for Co2FexMn1-xSi (x = 0…1)-CoFe MTJs [1] for Fe fractions of between x=0.4 and 0.6.
The halfmetallic character disappeared for samples with x≥0.8. The reason of this behaviour is still
unknown. A B2 and L21 site ordered stack of MgO substrate/ Cr [40 nm] buffer layer/ Co2FexMn1-xSi[30 nm]/ MgO [2 nm]/ AlOx [1.3 nm] (x = 0, 0.2…1.0) films was studied at beamline P09 at PETRA
III and beamline ID32 at the ESRF. The hard X-Ray photoelectron spectroscopy studies were
performed with an excitation energy of 6 keV. It was found that the position of Co 2p core levels andthe density of states in the valence band region strongly depend on the Fe/Mn ratio.
[1] Takahide Kubota, Sumito Tsunegi, Mikihiko Oogane, Shigemi Mizukami, Terunobu Miyazaki, Hiroshi
Naganuma, and Yasuo Ando APL 94 (2009) 122504

354

Shinya Kasai, Yukiko Takahashi, Shigeyuki Hirayama, Seiji Mitani and Kazuhiro
Hono
National Institute for Materials Science, JapanThe 19th International Conference on Magnetism

Lee-hyun Cho1, Beata Bialek1, Jae Il Lee1* and Miyoung Kim2
1
Physics, Inha University, Korea
2
Division of Energy System Research, Ajou University, Korea

The sp or d0 half-metallic materials have been attracted more and more increasing
attention. A recent first-principles calculation found that the half-Heusler compounds,
GeKCa and SnKCa, are half-mtallic [1]. We investigated the magnetic and halfmetallic properties of the (001) surfaces of the GeKCa and the SnKCa by using the allelectron full-potential linearized augmented plane wave method [2] within generalized
gradient approximation. We considered two different terminations for each compound,i. e. Ge (or Sn) and KCa terminations. From the calculated density of states, wefound that the Ge or the Sn termination reserves the half-metallicity, while the KCa
termination for both compounds is not half-metallic. The magnetic moments for thesurface Ge and Sn atoms are much enhanced compared to the bulk values, but the KCa
surface for both compounds is almost magnetically dead.
[1] J. Chen, G. Y. Guo, K. L. Yao, and M. H. Song, J. Alloy. Compd. 509, 10172 (2011). [2] E.
Wimmer, H. Krakauer, M. Weinert, and A. J. Freeman, Phys. Rev. B 24, 864 (1981), and references
therein ; M. Weinert, E. Wimmer, and A. J. Freeman, Phys. Rev. B 26, 4571 (1982).

Hsin-han Lee, Kuo-chin Chen and Ching-ray Chang*Physics, National Taiwan University, Taiwan
Graphene is a possible nano-device in the future. There are several experiment andtheory exhibit that the graphene would generate the ripple in some conditions[1-3], andthere is a “geometrical effect” on the curved surface with Rashba spin-orbit effect[4].
We investigate the transport property and the spin density accumulation on thegraphene nano-ribbon with the ripple. This research used the non-equilibrium Greenfunction(NEGF) of the Landauer formula[5.6] to compute the numerical results for thesystem.
[1] C. H. Lui, Li Liu, K. F. Mak, George W. Flynn and Tony F. Heinz, Nature 462, 339-341 (2009)[2] Daniel Huertas-Hernando, F. Guinea, and Arne Brataas, Phys. Rev. B 74, 155426 (2006) [3]
Z. Wang and M. Devel, Phys. Rev. B 83, 125422 (2011) [4] T.-C. Cheng, J.-Y. Chen and C.-R.
Chang , Phys Rev B. 84. 214423 (2011) [5] S. Datta. .Electronic transport in mesoscopic systems'.
Cambridge University Press, Cambridge (1995) [6] S. Datta. .Quantum Transport: Atom toTransistor'. Cambridge University Press, Cambridge (2005).

July 13 (Fri)Jan Zemen1, Jan Masek2 and Tomas Jungwirth3
1
School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
2
Institute of Physics ASCR v.v.i., Na Slovance 2, 182 21 Praha 8, Czech Republic
3
Institute of Physics ASCR v.v.i., Czech Republic & University of Nottingham, United Kingdom

Jeffrey Rufinus
Science Division, Widener University, USA

Atsushi Sugihara*, Soichiro Osaki and Ryoichi Nakatani
Osaka University, Japan

CoFeB/MgO-MTJ is the most promising system for Spin-RAM because of its hightunnel magneto-resistance (TMR) [1]. Recently, perpendicular magnetic anisotropy(PMA) which was expected to reduce current density for magnetic switching by spintransfer torque (Jc0) down to applicable value (<10a A/cm2) was reported at reduced
CoFeB layer thicknesses (<1.5 nm) [2]. However, drastic increase of damping constant(α) was observed as the reduction of the CoFeB thickness, which consequently leadto high Jc0 (3.9 x 106 A/cm2). The possible cause of the increase of α is interdiffusion
between Ta capping layer and CoFeB layer[3], [4]. Therefore, a capping layer material
whose thermal stability is high than that of Ta is necessary. Our study is to observea better capping layer material for CoFeB/MgO-MTJ than Ta. We focused on Ti-Nand prepared CoFeB layers capped by Ta and Ti-N on MgO substrates and annealed
them at various temperatures (Tas) up to 800 ˚C. Clearly different behavior at over
Ta=600 ˚C in Ta dependence of saturation magnetization of CoFeB was indicated that
Ti-N possessed higher thermal stability than Ta. Our results suggested that Ti-N was apromising capping material for reduction of Jc0 in CoFeB/MgO-MTJ.
[1] S. Ikeda et al., Appl. Phys. Lett., 93, 082508 (2008). [2] S. Ikeda et al., Nature Mater. 9, 721(2011). [3] H. Meng et al., J. Appl. Phys. 110, 033904 (2011). [4] W. G. Wang et al., Appl. Phys.
Lett. 99, 102502 (2011).

July 8-13, 2012 Busan, Korea

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poster Presentation
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Half-Metallic Molecular Wire on Silicon Surface

Magnetic properties of mechanically alloyed Fe-Cu particles

Synthesis and magnetic properties of zinc ferrite nanocrystals andtheir applications

Diffracted magneto-optical Kerr effect of Co anti-dot structure indifferent arrangements

Based on DFT calculations including the molecular dynamic simulations, at first time,
we describe a feasible reaction path to make a robust half metallic Mo-borine sandwich
molecular wire on hydrogen-terminated Si(001) surface along [100] direction. The
wire is chemically bonded to the surface, therefore, it is solid enough against thermoperturbation, at least up to room temperature. Meanwhile, the electronic and magnetic
properties of this molecular wire are tunable via an external electric field (EEF), andthe wire exhibits multifunctional electronic and magnetic states, which allows it towork as a multistep molecular switch or/and multistep information storage component.
Fantastically, this surface wire seems independent from the underplayed silicon bulk
even under EEF situations since bulk properties have not been affected. This is because
the charge transfers are constrained within the wire and the upmost layer Si atoms only.
All of these features should be meaningful in the applications of molecular electronics
or spintronics in near future.

Osamu Kohmoto, Masakazu Uchida and Yasushi Matsushima
Okayama University, Japan

Mechanically alloyed powders have metastable structure. In the Fe-Cu phase
diagram, both the Fe and Cu are known to have quite small solubility in to Cu andFe, respectively, at room temperature. We have prepared x at% Cu-Fe particles bymechanical alloying. The starting materials were pure Fe and Cu powers. The crystallite
sizes of Fe with 700 A for bcc(110) and Cu with 45 nm for fcc(111) decreases below 20
nm at milling time of 500 h. The 500-h-milled alloys with x=0-30 % Cu show a single
bcc phase, and the alloys with x=35-100 % Cu show a single fcc phase. Co-existenceof fcc and bcc phases is not observed at x=30 and 35 %Cu. However, at x=30 at %,a slight increase in the mass density deduced by lattice parameter is observed and thedensity jumps by 0.85 g/cm3 at 35 at%. The magnetization at 16 kOe decreases from
200 emu/g with increasing Cu content, however, it has a sudden decrease at 35at% Cuof the phase boundary. The magnetization reaches zero at x=90 % Cu. Coercive force
increases initially with the Cu content, however, it has a sudden jump at the phaseboundary.

Yang Yang, Xiaoli Liu, Chin Shen Ong and Jun Ding*
Materials Science and Engineering, National University of Singapore, Singapore

We studied magnetic properties of zinc ferrite nanoparticles via thermal decomposition,
whereas zinc ions partially replace iron ions at A sites with a nominal composition of(Zn0.5Fe0.5)Fe2O4. Our first-principle calculation has shown that Zn ion has significantly
lower formation energy at A-site compared to the substitution of B-site and anenhancement of saturation magnetization of 10-20% is obtained due to the reductionof the total magnetic moment of A-site which is antiferromagnetically coupled with
B-site. The iron and zinc precursors [Fe(acac)3, Zn(acac)2.xH2O] were used in thesynthesis of zinc ferrite particles. We have found that a molar ratio of zinc precursor
to iron precursor of 1:2 is required for the end product of (Zn0.5Fe0.5)Fe2O4. It has beenfound that magnetization measured at room temperature is dependent sensitively
on particles. Room temperature magnetization reaches 100.9 emu/g for zinc ferrite
nanoparticles with an average particle size of 85 nm. The value is significantly larger
than that of bulk Fe3O4 (80-90 emu/g). The as-synthesized zinc ferrite particles withan average particle size of 26 nm were selected for magnetic fluid hyperthermia. AftermPEG surface coating, the particles could be well dispersed in water. A comparative
high SAR value of 630 W/g was obtained.

To fullfill the increasing requirement for the miniaturization of magnetic materials, theeffective extraction of information from the nano-scale structures becomes hot issue. Someof techniques, such as diffracted magneto-optical Kerr effect (DMOKE), magnetic-force
microscopy and Lorentz scanning transmission electron microscopy, have been utilized toread the magnetic information. As a derivative technique of MOKE, which can be applied in
describing the magnetic hysteresis loops, the DMOKE provides us more unique performance,since the diffracted light is more sensitive to the change of the magnetization distribution inmagnetic material. Micromagnetic simulation is also a useful method to study the process ofmagnetization reversal. In order to get the distribution of magnetization, the Object Oriented
Micromagnetic Framework (OOMMF) program with periodic boundary condition was
employed. By combining DMOKE and the micromagnetic simulation, we can theoreticallyand experimentally get more exact magnetic information. We investigated the transverse
DMOKE and the magnetization-reversal process in rhombic and square lattice arrangementsof Co anti-dot structures. The hysteresis loops of the diffracted beams are described by themagnetic form factor. The shape of hysteresis loops of the diffractions, especially, at the points
of inflection of the loop, is expected to indicate a special distribution of magnetization.

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SL10

Structural and magnetic studies of sol-gel prepared hexagonal
BaFe12O19

Temperature dependence of the coercive force of ferromagnetic TMAl-O (TM=Fe, Co) granular films

Nanocrystallite size-induced changes in the magnetic and transport
properties of La1-xCaxMnO3 (x = 1/8, 3/8, 5/8) manganite

Monodisperse magnetic nanoparticles: effects of surfactant
concentration on the reaction between Fe(acac)3 and Pt(acac)2

Barium hexaferrite particles prepared by sol-gel method was characterisedusing X-ray diffraction spectroscopy (XRD), Field emission scanning electron
microscopy (FeSEM), Superconducting Quantum Interference Device (SQUID) and
Thermogravimetric analysis (TGA). Nano-sized particles BaFe12O19 and Fe2O3 wereobtained after calcination at 8000C. The BaFe12O19 microstructure showed an averagegrain size of 200nm and recorded a saturation and remanent magnetisation of 60 and
35 emu/g, respectively. In addition, a commercially available BaFe12O19 was alsostudied. The feature observed was quite distinctive and was mostly in platelets form
and much larger in size. It has a saturation and remanent magnetisation of 70 and 5
emu/g, respectively. The poor remanent magnetism of this commercially available
BaFe12O19 was due to large particle size and accompanied by an increased in surface
area. TGA performed at 1000°C recorded about 1.8% wt loss in the sol-gel preparedbarium hexaferrite compared with 0.2% as observed in the commercial product.

Temperature development of the coercive force (Hc) of ferromagnetic TM-Al-O
granular films has been investigated in a temperature range from 290 K down to 5 K.
Each film is prepared using the magnetron sputtering method. During the depositing
process, a dc magnetic field was applied parallel to the film surface to induce in-plane
uniaxial anisotropy. An Fe-Al-O granular film shows no clear in-plane anisotropy
at 290 K. On the other hand, Co-Al-O films show clear in-plane anisotropy at 290
K. The Hc of the Fe-Al-O film is found to be almost independent of temperature.
In contrast that of Co-Al-O films strongly depends on temperature. The Hc of CoAl-O films along the easy axis increases rapidly with decreasing temperature. Thisbehavior in the Hc also depends on the Co-concentration. For films with lower Coconcentration and larger electrical resistivity, enhancement of the Hc becomes larger at
the lowest temperature. The Hc of Co-Al-O films shows characteristic behavior at low
temperatures. It increases with decreasing temperature, following a logarithmic law
below about 50 K.

Magnetization, magnetic hysteresis loops/isotherms, linear and non-linear ac
susceptibility, electrical resistivity and magnetoresistance measurements have been
performed on 40 nm nanocrystalline La1-xCaxMnO3 (x = 1/8, 3/8, 5/8). Compared to thebulk, reducing the crystallite size down to 40 nm results in the following changes. For x =1/8 [1], lowers paramagnetic insulating (PMI)- ferromagnetic insulating (FMI) transition
temperature T_(c) to 143 K, induces the metal-insulator (MI) transition at T_(MI) = 77
K and charge ordering (CO)/orbital ordering (OO) transition at T_(CO/OO) = 35 K but
leaves the insulating cluster spin glass transition temperature T_(g), the temperature T_(JT) below which short-range antiferromagnetic (AF) order coexists with OO and thespin-wave stiffness at 0 K, D(0) = 35(2) meVA2, essentially unaltered. For x = 3/8, lowers
T_(MI) to 234 K, a second-order (first-order) PMI-FMI phase transition occurs at T_(c) = 273.5 K when the applied magnetic field, H = 0 (H ≠ 0), D(0) retains its bulk value[2] 145(5) meVA2 and T_(CO) reduces to 30 K. For x = 5/8, FM and CO ordering in theinsulating state sets in at T_(c) = T_(CO) = 270 K and transition to the AF/OO phaseoccurs at T_(AF) = 50 K.

Yat Choy Wong1*, Geok Bee Teh2, Sun Yung Kim1 and James Wang1
1
Faculty of Engineering and Industrial Sciences, Swinburne University of Technology,
Australia
2
Division of Chemistry and Biology, School of Arts and Science, Tunku Abdul
Rahman College, Malaysia

Shintaro Nakamura1*, Akira Yoshihara2, Shigehiro Ohnuma3 and Tsutomu Nojima1
1
Institute for Materials Research, Tohoku University, Japan
2
Ishinomaki Senshu University, Japan
3
Research Institute for Electromagnetic Materials, Japan

Yugandhar Bitla and S. N. Kaul*
School of Physics, University of Hyderabad, Central University P.O., Hyderabad 500 046, India[1] Y. Bitla and S. N. Kaul, J. Appl. Phys. 111, xxxx (2012) at press. [2] J. J. Rhyne et al., J. Magn.
Magn. Mater. 226-230, 775 (2001).

Komkrich Chokprasombat1*, Phimphaka Harding1, Chitnarong Sirisathitkul1, Pongsakorn
Jantaratana2, Sujittra Chandarak3 and Rattikorn Yimnirun4
1
School of Science, Walailak University, Thailand
2
Department of Physics, Kasetsart University, Thailand
3
School of Ceramic Engineering, Institute of Engineering, Suranaree University of Technology,
Thailand4
School of Physics, Institute of Science, Suranaree University of Technology, Thailand

Magnetic properties of monodisperse nanoparticles for ultrahigh density recording and biomedical
applications are sensitive to their shape and size distributions. These attributes are, in turns, dictatedby several parameters during the synthesis and heat treatments. In this work, monodisperse
magnetic nanoparticles with size of around 4-5 nm were synthesized by the modified polyol
process with 1.0 mmol Fe(acac)3 and 0.5 mmol Pt(acac)2 as starting materials. The as-synthesized
nanoparticles were transformed from their superparamagnetic phase to the ferromagnetic state byannealing in argon atmosphere at 570 C for 1 hour. Without any reducing agents, concentrationof surfactants (oleic acid and oleylamine) of 1.5 - 4.5 mmol affected morphology and magnetic
properties of the nanoparticles. When 2.5 mmol of each surfactant was used, the as-synthesized
nanoparticles have the smallest variations in size and shape. However, the higher concentration ofoleic acid and oleylamine led to a higher coercivity in annealed nanoparticles which are related tothe size distribution. These results indicated that the appropriate amount of surfactants must be usedin order to optimize the size distribution and magnetic hysteresis of nanoparticles.

SL02

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SL11

Magnetization reversal process in antiferromagnetically coupled (Co/
Pd)/Ru/(Co/Pd) multilayer dot pattern

Microscopic dipole-exchange theory for magnonic crystal arrays ofinteracting ferromagnetic nanorings

Magnetic and magneto-optical properties of bilayered Co/Ni anti-dot
arraysHollow MnCO3 and MnSiO3 nanosphares

Shunji Ishio1*, Yuta Kobayashi1, Takashi Hasegawa1, Akira Arakawa1, Hiromi Sasaki1,
Zhongjie Yan2 and Xi Liu2
1
Department of Materials Science and Engineering, Akita University, Japan
2
Venture Business Laboratory, Akita University, Japan
Magnetization reversal process, exchange interaction Hex between layers andcoercivity in the antiferromagnetically coupled (Co/Pd)/Ru/(Co/Pd) dot patterns werestudied as a function of dot size. Pd10.5/[Pd0.7/Co0.4]4/Ru0.4/[Co0.4/Pd(1.5 nm)]6 weresputtered onto pre-patterned Si substrates. Dot shape was designed to be 100 - 3000
nm square. Magnetization measurements revealed that top and bottom layers havea perpendicular magnetic anisotropy and couple each other antiferromagnetically atremanent state. MFM measurement indicated that the magnetic state of each layer
becomes single domain below side length d=200 nm. Complicated magnetization
reversal process was observed. The magnetization reversal starts from a nucleationof reverse domain at dot edge in the reversal from the↑/↓ (↓/↑) state to the ↑/↑ (↓/↓)
state, while the coherent rotation type behaviour was found in the ↑/↑ (↓/↓) to ↑/↓(↓/↑) reversal. Hex was about 2.2 kOe in the film and decreases to less than 1 kOe at
d=100 nm. Coercivity is about 1 kOe for the film and is almost constant independently
on the dot size. The magnetization reversal process and the dependence of Hex andcoercivity on dot size are discussed in terms of the structural and magnetic property ofintermediate Ru layer in patterned dots.

356

H. Y. Zheng1, N. G. Deshpande1, X. R. Jin1, J. Y. Rhee2, K. W. Kim3 and Y. P. Lee1*
1
Physics, Hanyang University, Korea
2
Physics, Sungkyunkwan University, Korea
3
Information Display, Sun Moon University, Korea

The 19th International Conference on Magnetism

Jan Borchmann, Hoa Nguyen and Michael Cottam
Department of Physics and Astronomy, University of Western Ontario, Canada

A microscopic theory is employed to study magnonic crystals represented by onedimensional arrays of ferromagnetic nanorings. The Hamiltonian-based formalism
includes exchange and dipole-dipole coupling within each ring, the long-range dipolar
coupling between rings, and an external applied magnetic field. Depending on theapplied field, as well as the size of the rings and the inter-ring spacing, the arrayelements may be in a vortex, onion (bidomain), or other inhomogeneous magnetization
state. Numerical results are reported for the magnonic bands and gaps in Permalloy
nanorings with outer diameter typically 80 to 120 nm, thickness typically 15 to 30 nm,
and spacing varied between 10 and 100 nm. For low values of the field (e.g., 0.02 T)
along the length of the array, the vortex state is favored energetically and it is foundthat the magnonic bands are fairly broad and the gaps are relatively small, particularly
when the spacing is reduced. Conversely, at larger fields (e.g., 0.2 T) favoring theonion state, the magnonic bands are narrower and the gaps larger. Varying the innerdiameter of the rings, as well as the spacing, can control the transition fields between
the different states, which may be advantageous for device applications.

July 13 (Fri)Yunhao Lu1, Yuan Ping Feng2* and Shuo-wang Yang3
1
National University of Singapore, Zhejiang University of China, Singapore
2
National University of Singapore, Singapore
3
Institute of High Performance Computing, Singapore

July 13 (Fri)poster Presentation

N. G. Deshpande1, H. Y. Zheng1, J. S. Hwang1, S. J. Lee1, Y. P. Lee1*, J. Y. Rhee2 and K.
W. Kim3
1
Physics, Hanyang University, Korea
2
Physics, Sungkyunkwan University, Korea
3
Information Display, Sun Moon University, Korea

Zvonko Jaglicic1, Jin Bae Lee2, Hae Jin Kim2 and Janez Dolinsek3
1
Dept. of Physics, Institute of Mathematics, Physics and Mechanics & University of
Ljubljana, FGG, Slovenia
2
Division of Materials Science, Korea Basic Science Institute, Daejeon 305-333,
Korea
3
Condensed Matter Physics, J Stefan Institute, University of Ljubljana, Jamova 39,
SI-1000 Ljubljana, Slovenia

In this study, we have successfully fabricated bilayered Co/Ni anti-dot arrays using
photolithography and controlled wet-etching processes. Such a ferromagnetic structure wasmade by sequentially depositing Co (40 nm)/Ni (5 nm) bilayer on a Si substrate. The anti-dot
patterning with a hole diameter of 1 -m was done only on the upper Co layer, while the Ni
underlayer was kept uniform. The magnetic properties of anti-dot arrays were investigated byusing a superconducting-quantum-interference-device magnetometer and by magnetic-force
microscopy (MFM). The longitudinal Kerr rotation (LKR) of the zeroth- and the first-orderdiffracted beams were measured at an incidence angle of 30°. Significantly, it was observedthat the LKR of the first-order diffracted beam is nearly 4 times larger than that of the zerothorder beam. The simulated results for the hysteresis loops matched qualitatively well withthe experimentally obtained ones. The MFM images revealed well-defined periodic domain
structures which can be ascribed to the anisotropies such as magnetic uniaxial anisotropy,
configurational anisotropy, etc. We observed that the magnetization reversal of such a systemproceeds through the formation and the annihilation of domains. The observed changes in themagnetic properties are closely related to the patterning that hinders the domain-wall motion.

Magnetic nanoparticles can be used in many different applications ranging from medicine,electromagnetic wave detectors to digital information storage. Hollow nanosphares offers
additional functionality. For example they show improved electrochemical performancefor batteries or can be used for drug delivery. We synthesised MnCO3 and MnSiO3
hollow nanospheres with a diameter of few nanometers and thickness of only few atomic
layers. In the MnSiO3 hollow nanospheres a small concentration of Mn3O4 was detectedfrom magnetic measurements. Its strong ferrimagnetic signal at TN = 42 K suppressed
the signal of intrinsic magnetic properties of MnSiO3 nanospheres. On the other hand in
the MnCO3 nanospheres no Mn3O4 was detected which enable us to study their dc andac magnetic properties. The Neel temperature at around 33.5 K is between the reported
values for MnCO3 single crystal (34.3 K) and powder sample (31.0 K)[1]. A coercive
field and remanent magnetization of MnCO3 nanospheres measured at 5 K are decreased
in comparison to the bulk system.
[1] A. Kosterov, T. Frederichs, T. von Dobeneck, Physics of the Earth and Planetary Interiors 154 (2006) 234-242.

July 8-13, 2012 Busan, Korea

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poster Presentation
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SL21

Shape-controlled synthesis and magnetic properties of FePt nanocubes

Magnetization reversal in patterned arrays of (001)Fe particles

Influence of asymmetric permalloy ring on magnetization
configuration and switching behavior

Magnetic dot-antidot lattice for control of magnetic anisotropy

Maj Hanson1*, Rimantas Brucas2 and Erik Wahlstrom3
1
Department of Applied physics, Chalmers university of technology, Sweden
2
Department of Engineering Science, Solid State Physics,, Uppsala University,
Sweden3Institutt for fysikk, NTNU, Norway

In this article, synthesis of monodisperse iron-platinum (FePt) nanoparticles byreduction of platinum acetylacetonate followed by thermal decomposition of ironpentacarbonyl in the presence of oleic acid and oleylamine stabilizers is reported,
Particle shape is controlled by the addition of Mo(CO)6, our synthesis yields particles
with shapes that are close to cubic and their size can be controlled from 7 to 10 nm, In
order to form FePt film, Then the self-assembly FePt nanocubes were annealed at 700°C for an hour did the FePt nanoparticle transform to the fct phase.The phase analysis,
structure, and magnetic properties were determined by X-ray diffraction (XRD), High
resolution transmission electron microscope (HRTEM), Scanning electron microscopeand vibrating sample magnetometer (VSM) techniques.

Arrays of elliptical Fe particles prepared by patterning [1] of epitaxial (001)Fe films
may serve as model systems for studies of the processes of magnetization reversal in
sub-micron size particles. In this work we studied such systems with film thicknesses
in the range between 10 nm and 50 nm. Ellipses with aspect ratio 1:3 were preparedwith their short axes being 50, 100 and 150 nm and varying inter-particle distances.
The magnetic domain state and the magnetization reversal of individual particles were
investigated by magnetic force microscopy (MFM) and micromagnetic calculations.
Magnetization curves of the arrays, comprising about 106 particles, were measured
with an alternating gradient force magnetometer (AGM). Within the range of actual
sizes we find that the largest particles may be left in a multi- or bidomain (MD) state
after demagnetization whereas the smallest show single-domain (SD) properties. In
particular we analyze the influence of interactions and the transition from MD to SD
behaviour as displayed in the shape of the hysteresis curves and in the MFM images
taken after remanent demagnetization. The single particle properties are compared withresults from micromagnetic calculations.

By introducing an inner circle shifted along the diameter of outer circle, an asymmetric ring and theasymmetric ratio (R) are defined to control over the vortex state (flux-closure state) nucleation andannihilation field in asymmetric Permalloy (Py) rings. Series of asymmetric Permalloy rings withdifferent diameter and asymmetric ratio were prepared to observe the magnetic switching behavior
and the magnetization configuration. The asymmetry of Py rings with thickness of 20 nm, outer
diameter (Do) of 300, 500, 800 nm, inner diameter (d) of 100, 150, 200, 250, 300 nm, and shift
length (S) of 30, 50, 70, 100, 120, 150 nm. Numerical micromagnetic simulations are carried out
using the object-oriented micromagnetic framework (OOMMF) software. With applied field fromthe positive to negative magnetic field, the magnetic field at which the vortex nucleate in the Py ringis defined as the nucleation field (Hn). The annihilation field (Han) is the magnetic field where thevortex annihilate. Linear relations of vortex state nucleation and annihilation fields to asymmetricratio were found, and are useful mainly for controlling the nucleation and annihilation fields.

Sadashivaiah Sakshath*, Kalappattil Vijaysankar, Karki S Bhagyashree, Subray V
Bhat and P. S. Anil Kumar
Department of Physics, Indian Institute of Science, Bangalore, India
The magnetic anisotropy of epitaxial Fe/GaAs(100) films varies with thickness ofthe film.[1, 2] We have prepared rectangular lattices of antidots using epitaxial 35monolayer (ML) Fe/GaAs(100) films deposited by Pulsed laser deposition in an
ultrahigh vacuum chamber whose base pressure was less than 2exp(-10) Torr. 10ML
MgO/35ML Fe/GaAs(100) film was controllably etched to reduce the thickness oflithographically defined regions of the Fe film to 19ML and capped with MgO before
liftoff. Thus square antidot regions of size 200nm containing Fe of thickness lower
than the surrounding matrix were created. Thus we have created a 2 dimensional
magnetic system having a uniform material composition but controlled lateral variationof local magnetic anisotropy. The spacing between the antidot regions is varied from~ 200nm to 400nm. Investigations of magnetic anisotropy on the dot-antidot bilayer
were performed using Magneto-Optical Kerr effect in longitudinal configuration andFerromagnetic Resonance. Anisotropy constants are evaluated and it shows that theratio of the magnitude of the uniaxial anisotropy to the magnitude of the four foldanisotropy is much higher (0.96) in the dot-antidot bilayer even with a square lattice.
This is discussed in terms of exchange coupling between the antidot region and thesurrounding matrix.

1. M. Hanson et al. JAP 85 (1999) 2793

1. P. Vavassori, R. Bovolenta, V. Metlushko and B. Ilic, J. Appl. Phys. 99, 053902 (2006) 2. E. Saitoh, M. Kawabata, K.
Harii, H. Miyajima and T. Yamaoka, J. Appl. Phys. 95, 1986 (2004) 3. X. H. Wang, W. K. Peng, and W. S. Lew, J. Appl.
Phys. 106, 043905 (2009) 4. A. Subramani, D. Geerpuram, V. Baskaran, J. Friedlund, and V. Metlushko, Physica C 437438, 293 (2006) 5. F. Giesen, J. Podbielski, B. Botters, and D. Grundler, Phys. Rev. B 75, 184428 (2007)

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SL22

Magnetic properties of NiO/Ni(OH)2 core-shell nanostructures

Controllable structure and magnetic properties of cobalt nanowires bytuning deposition voltage

Fabrication of high aspect ratio nanoscale magnetic tunnel junction
etch mask by oxygen plasma assisted resist trimming

Effect of diameter of the wires on magnetic properties ofelectrodeposited CoNiP hard magnetic nanowires

Antiferromagnetic materials show interesting and anomalous properties when their size
is reduced to nanodimensions. The magnetic susceptibility is increased with decreasing
particle size(1). Bulk NiO is antiferromagnetic and recent studies showed that NiOnanoparticles exhibit aging and memory effects similar to that of spin glasses(2). The
finite size and surface effects play major role in determining the magnetic behaviour ofthese nanoparticles(3). We have synthesized NiO nanoparticles by a simple chemicalroute followed by calcination. The freshly prepared sample was dispersed in water,then filtered and dried in air to get NiO/Ni(OH)2 core-shell type nanostructures.
These nanostructures were characterized by using different techniques and magnetic
properties using SQUID-VSM. Magnetic properties of nanoparticles of NiO, Ni(OH)2,and NiO/Ni(OH)2 have been compared to study the effect of Ni(OH)2 layer on NiO.
Low temperature M-H curves showed considerable difference in the coercivities
and saturation magnetization values of the core-shell structure. From ZFC and FC
measurements it is observed that magnetic behaviour of the NiO/Ni(OH)2 core-shell
nanoparticles differs substantially from that of bare NiO and Ni(OH)2 nanoparticles.
The observed changes are explained in terms of lower size of NiO core and the effectof different inter-particle interactions with and without the hydroxide layer.

Xiu Xiu Fan1, Hai Ning Hu2 and Zhong Shi3*
1
Surface Physics State Laboratory and Department of Physics, Fudan University,
China
2
School of Mathematics and Physics, Shanghai University of Electric Power, China
3
Department of Physics, Tongji University, China

Bongho Kim1, Daehong Kim1, Sungwoo Chun1, Hyungyu Lee1, Seonjun Choi1 andSeung-beck Lee2*
1
Department of Electronic Engineering, Hanyang University, Seoul, Korea
2
Department of Nanoscale Semiconductor Engineering, Hanyang University, Seoul,
Korea

Magnetic properties of Co nanowires have been shown to be controlled by various growth parameters. The
deposition voltage shows great convenience in controlling microstructure. Reported results were mostly
focused on low voltages[1-4]. In this work, Co nanowires were fabricated into ordered AAO templates by dc
electrodeposition in a wide range of deposition voltage at 20°C. With deposition voltages of 2.0 and 4.5 V, Co
nanowires are of hcp(100) and fcc(220) along the nanowire-axis, respectively. Two structures coexist for medium
voltages. For all samples, the easy axes of magnetocrystalline (Kmc) and shape (Ksh) anisotropy make angles toeach other. For low voltages, Kmc and Ksh are close to each other, resulting in small coercivity Hc(||) and Hc(┴)
for H parallel and perpendicular to nanowire-axis. Since Kmc is one order smaller than Ksh and thus the easyaxis lies along the nanowire-axis for high voltages, large Hc(||) is obtained at room temperature. For low and highvoltages, Hc(||) first decreases and then increases with a minimum at 200 K, and increases monotonically with T
increasing from 50 to 390 K[5], respectively. The angular dependence of Hc shows a combined magnetic reversal
process which can be described by curling and/or transverse domain wall modes[6].

The development of large-area, nanostructure patterning with high aspect ratios is a challenging
problem that must be addressed for potential applications in high performance nanoscale devices[1].
When negative resist pillar patterns are formed using electron beam lithography,the forward andbackward scattering of the electrons limit the resolution therefore, the resist layer should be thinner.
When the patterned resist pillars were used as dry etching masks, the resist polymer during theprocess requires the pillars to have high aspect ratio. Also,due to chemical processing, high aspectratio resist pillars have a high probability of falling over due to capillary forces on the pillars[2].
We report on a simple method to overcome the low aspect ratio and the collapse of resist by using
oxygen plasma assisted resist trimming.Firstly,We used 170 nm thick negative electron beam resist
and patterned 55 nm dot arrays using 80 kV electron-beam.Next, resist trimming process was doneusing oxygen plasma ashing at 50 W and 0.1 Torr for 70 seconds.This process resulted in 5 nm
trimming in all direction. Therefore the 70 s ashing resulted in a 30 nm diameter and 145 nm tall
resist pillar increasing the aspect ratio from 3 to 5, which is about 70 % increase.

1. J. T. Richardson and W. O. Milligan, Phys. Rev. 102, 1289 (1956). 2. S. D. Tiwari and K. P. Rajeev, Phys. Rev. B,
72, 104433 (2005). 3. R. H. Kodama, Salah A. Makhlouf and A. E. Berkowitz, Phys. Rev. Lett. 79, 1393 (1997).

1. H. Zeng, R. Skomski, and et al., Phys. Rev. B 65, 134426 (2002). 2. H. Zeng, M. Zheng, and et al., J. Appl. Phys. 87, 4718 (2000). 3. H. Pan, B. Liu,and et al., J. Phys. Chem. B 109, 3094 (2005). 4. X. H. Han, Q. F. Liu, and et al., J. Phys. D: Appl. Phys. 42, 095005 (2009). 5. J. Sanchez-Barriga, M.
Lucas, and et al., Phys. Rev. B 80, 184424 (2009). 6. M. Vazquez and L. G. Vivas, physica status solidi (b) 248, 2368 (2011).

SL14
Structual and magnetic properties of MFe2O4 (M=Ni, Mg) nano hollow
spheres
K. Konishi1*, T. Sakurai1, Y. Nagano2, N. Manabe2 and Y. Morimoto2
Department og Physics, Graduate School of Science and Engineering, Ehime
University, Japan2
Department og Physics, Faculty of Science, Ehime University, Japan

1

Hollow sphere structures have recently received considerable attention because of
their novel interior geometry and surface functionality. In this report, sub-micrometersized hollow spheres assembled from ferrite nanoparticles have been prepared by a wet
chemial process. Measurements of dc-susceptibility and magnetization were carriedout on samples of MFe2O4 (M= Ni, Mg) nanoparticles with average diameter 4-5
nm, and hollow spheres (500 nm in diameter) with about 12-17nm thickness shell. A
superparamagnetic-type blocking process is observed in the ZFC and FC magnetizationand magnentic susceptibility for all samples. Furthermore, a behavior due to surface
spin freezing of nanoparticles is found in Ni-ferrite. The surface spin freezing
temperatures Tf are quite lower than the blocking temperature, and the magnetic fielddependence is different between nanoparticle and hollow sphere. The spin-glass natureof Ni-ferrite nanoparticle is demonstrated by the magnetice field dependence of Tf
following the well known Almeida-Thouless line. In contrast, Tf (H) of Ni-ferrite
hollow sphere hints at failure of Gabay-Toulouse theory as well as the AT type.

The 19th International Conference on Magnetism[1] G. Wastlbauer and J. A. C. Bland, Adv. Phys. 54, 137 (2005) [2] S. Sakshath et al, J. Appl. Phys. 109, 07C114 (2011)

Tuan Tu Le1*, Pham Hong Quang1, Luu Van Thiem2, T.s. Ramulu3 and Cheolgi Kim3
1
Faculty of physics, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh
Xuan, Hanoi, Viet Nam
2
Faculty of Engineering Physics and Nanotechnology, College of Technology, Vietnam National
University,144 Xuan Thuy, Caugiay, Hanoi, Viet Nam
3
Deparment of Materials Science and Engineering, Chungnam National University, Daejeon 305764, Korea

The magnetic properties in CoNiP nanowires arrays with diameter of nanowires in range of 50-800nm
were investigated. All the samples were prepared by electrodeposition method with pH of 3.1 and room
temperature. The electrochemical potential of CoNiP were determined by cycle voltammetary. The crystalline
structure and morphology of the samples were characterized by X-ray diffraction (XRD) and ScanningElectron Miroscopy (SEM), respectively. The hysteresis loops were measured at room temperature using
vibrating sample magnetometry (VSM) and alternating gradient magnetometry (AGM) with magnetic field
applied perpendicular and parallel to the wire axis. The mixture of fcc and hcp polycrystalline phases of the
CoNiP based nanowires has been indicated by the XRD pattern. The obtained results show that with 800 nm
of diameter of the nanowires we can obtain maximum coercivity value (2070 Oe). The uniaxial anisotropy
values dependent on diameter of the wires are calculated. The anisotropy of the samples are quasi-onedimensional anisotropic is also found when diameter of the wires are less than 500 nm.

[1] Hwan-Jin Jeon, Kyoung Hwan Kim,. Nano Lett. 2010, 10, 3604-3610 [2] Toshihiko
TANAKA,Mitsuaki MORIGAMI,Nobufumi ATODA,. Jpn. J. Appl. Phys. Vol. 32 (1993) PP.6059-6064[1] A. Fert, L. Piraux, Journal of Magnetism and Magnetic Materials 200 (1999) 338 [2] Shan Guan and Bradley J. Nelson, Journal of The Electrochemical Society, 152 (4)(2005) C190 [3]R.N. Emerson, C. Joseph Kennady, S. Ganesan, Thin Solid Films 515 (2007) 3391 [4] P. Cojocaru, L. Magagnin, E. Gomez, E. Valles, Journal of Alloys andCompounds 503 (2010) 454 [5] Takanari Ouchi, Naofumi Shimano, Takayuki Homma, Electrochimica Acta 56 (2011) 9575

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SL23

Magnetotransmission effect in Nd0.5Sr0.5MnO3 nano-composites

Magnetic properties of iron(III) oxide nanostructures by hydrothermal
synthesis

Switching behavior of lithographically defined grid of permalloy
nanowires studied with magnetoresistance

Elena Mostovshchikova, Natalya Loshkareva, Andrey Telegin*, Nikolay Solin,
Sergey Naumov and Sergey TeleginInstitute of Metal Physics UD of RAS, Russia
Magnetic and optical properties of composites on the base of Nd0.5Sr0.5MnO3 powders diluted in dielectric
matrix have been studied. Nd0.5Sr0.5MnO3 manganite is interesting due to existence of two different typeof phase transitions: the first one is from paramagnetic semiconductor to the FM metallic state near TC250 K, the second one is from the FM metallic state to CE-type AFM insulating state with charge ordering
near TCO-160 K [1]. The giant negative magnetotransmission effect (relative change of natural lighttransmission under the magnetic field) up to 14% in the field H = 0.8 T was revealed for Nd0.5Sr0.5MnO3composites near TC in the infrared range. The charge ordering and AFM state may by destroyed bydecreasing of grains to nanoscale size [2] resulting in appearing of new effects. The remarkable featureof Nd0.5Sr0.5MnO3 nano-composite with average grain size about 100 nm is an existence of significant
magnetotransmission about 7% in the wide temperature range near and far below TC. It was explainedby the significant contribution of nano-particle shells with disordered spins to the magnetic properties ofnano-composite. Finally, such a composite material is a promising candidate for future magneto-opticalapplications [3].
[1] H. Kawano, R. Kajimoto, H. Yoshizawa, Y. Tomioka, H. Kuwahara, and Y. Tokura. Phys. Rev. Lett. 78, 4253 (1997)[2] R.H. Kodama. JMMM 200, 359 (1999); R.H. Kodama and A.E. Berkowitz. Phys. Rev. B 59, 6321 (1999) [3] A.B.
Granovskii, Yu.P. Sukhorukov, A.V. Telegin et al, J. of Experimental and Theoretical Physics, 112, No1, 77 (2011)
Supported by the program of DPS RAS “Physics of new materials and structures”, grant MK-1048.2012.2 and RFBR
grants No 10-02-00038, 11-02-00252, 12-02-00208

358

Chao-hsien Huang1*, Lance Horng1, Nian-jia Cheng2, Tian-chiuan Wu3 and Jong-ching Wu1
1
Department of Physics, National Changhua University of Education, Taiwan
2
Institute of photonics, National Changhua University of Education, Taiwan
3
Department of Electronic Engineering, National Formosa University, Taiwan

Raquel A Ribeiro*, Allan M Xavier and Flavio L Souza
Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC - UFABC,
BrazilThe hydrothermal synthesis of nanoparticles enables functional control on the
distribution of particle size, morphology and crystallinity by controlling the synthesis
parameters. The synthesis of nanoparticles of iron oxide by this method was performedby raising the temperature of a autoclavable bottle containing a solution of iron(III)chloride, sodium nitrate and hydrochloric acid in appropriate quantities. Iron oxide
powders synthesized under conditions previously published in the literature weretreated in a box furnace at temperatures of 390, 450, 550 and 800 °C. For these samples
we performed structural, morphological and magnetical characterization. The imagesof transmission electron microscopy provide evidence that the 1D nanostructuresof iron(III) oxide, are joined by surfaces with non-oriented crystallographic planes,suggesting that the growth of these particles occurs by oriented coalescence. After
heat treatment a phase transition occurs from akaganeite to hematite. Magnetization
measurements show that akaganeite presents weak magnetic behavior, whereas thehematite phase presents a larger remnant magnetization and coercive field. We thankthe support of Brazilian agencies FAPESP and CNPq.

July 13 (Fri)Mingge Zhou1*, Wei Li2, Minggang Zhu2, Dong Zhou2 and Yanglong Hou3
1
Division of Functional Materials, Central Iron and Steel Research Institute, China
2Central Iron and Steel Research Institute, China
3
Department of Advanced Materials and Nanotechnology, College of Engineering,
Peking University, China

Mangesh B. Mahajan and P. A. Joy*
Physical and Materials Chemistry, National Chemical Laboratory, Pune, India

July 13 (Fri)poster Presentation

Venkateswarlu Dasari, Vineeth Mohanan Parakkat and Anil P. S. Kumar
Physics, Indian Institute of Science, India

We report the switching behavior of a grid [1] of permalloy nanowires fabricated using
e-beam lithography and DC-magnetron sputtering followed by lift-off process. The
wires are of 20 nm thickness and about 120 nm wide. The periodicity between thewires is maintained at one micron throughout the grid. The grid is made as a Hall bar
geometry which consists of few hundreds of junction regions. The magnetoresistancestudy indicate that the node regions in the grid acts as defects in the horizontal wires
in longitudinal magnetic field, which in turn leads to the nucleation of domains. Thus,
the switching process in the horizontal wires is governed by these defect centers[2]. The switching field varies from 80 Oe to 140 Oe for transverse to longitudinalmagnetoresistance. The non zero coercivity (80 Oe ) in transverse magnetoresistance isdue to the presence of nodes. These nodes possess four-fold anisotropy with easy axes
along the diagonal directions. Further, the micro-magnetic simulations using Object
Oriented Micro Magnetic Framework (OOMMF) with the two dimensional periodic
boundary condition, gives the information about the domain configuration which
supports our experimental findings.
1. S. P. Li, A. Lebib, D. Peyrade, M. Natali, Y. CheN, W. S. Lew and J. A. C. Bland J. Appl. Phys. 90,
521 (2001) 2. A. O. Adeyeye and M. E. Welland, J. Appl. Phys. 92, 3896 (2002)

July 8-13, 2012 Busan, Korea

359

poster Presentation

poster Presentation

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SM01

SM04

Magnetization reversal modes in narrow FePt nanowires with highperpendicular anisotropy

Arrays of interacting ferromagnetic nanofilaments: small-angle
neutron diffraction study

Breakdown of barkhausen critical scaling behavior with increasing
domain wall pinning in fe thin films

Magnetic phase diagram for non-epitaxial Cr/Gd/Cr-multilayers

1

2

1

1

Van Dai Nguyen , Laurent Vila , Matthieu Tissier , Alain Marty , Murat Cubukcu , Piotr
Laczkowski1, Williams Savero-torres1, Juan-carlos Rojas Sanchez1 and Jean-philippe Attane1
1
Universite Joseph Fourier, BP 53, 38041, Grenoble and INAC/ CEA Grenoble, France
2
LPTMC, CNRS-UMR 7600, Universite Pierre et Marie Curie, boite 121, 4 Pl. Jussieu, 75252
Paris Cedex, France

In this contribution, we present the dependence of magnetization reversal modes in FePt nanowires withthe width ranging from 2000 nm to 30nm using magneto-transport and magnetic force microscopy (MFM)
measurements. Magneto-transport measurements showed an enhancement of magnetic coercivity whenreducing the width. Theoretical calculations suggest that this coercivity increase is not only due to the
suppression of available propagation paths but also to the contribution of the roughness. Further studyof the magnetization reversal process using MFM shows that three different reversal modes can appear.
Indeed, for widths above 500 nm, the structure of the reversed magnetic domains appears to be similar to
those of the continuous FePt film: the reversed magnetic domain grows and expands within a dendritic
structure. For widths below the characteristic dendrite width (~300 nm), the reversal takes place by
propagation of a single DW that reverse the whole wire. Finally, we show that another behavior appears
at very low widths: when reducing the widths below 50 nm, the propagation field becomes larger than
the nucleation field. Nucleation thus occurs randomly, the reversal consisting in a mix of nucleation andpropagation. Such behavior could prevent the use of ultra-narrow wires for DW-based spintronic devices.

July 13 (Fri)22

Natalia Grigoryeva *, Sergey Grigoriev , Arseniy Syromyatnikov , Andrey
Chumakov2, Helmut Eckerlebe3, Kirill Napolskiy4, Ilya Roslyakov4 and Andrey
Eliseev4
1
Faculty of Physics, Saint Petersburg State University, Russia
2
Konstantinov Petersburg Nuclear Physics Institute, Russia
3Helmholtz Zentrum Geesthacht, Germany
4
Moscow State University, Russia

1

2

3

1

2

Hun-sung Lee , Kwang-su Ryu , Chun-yeol You , Kun-rok Jeon , Stuart S. P. Parkin
and Sung-chul Shin1*
1
Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701,
Korea
2
IBM Research Division, Almaden Research Center, San Jose, CA 95120, USA
3
Department of Physics, Inha University, Incheon 402-751, Korea

We report a breakdown of Barkhausen critical scaling behavior in Fe films withincreasing domain wall pinning by means of a Kerr microscope, capable of direct
domain observation. From the the domain reversal patterns in the films, we find that the
Barkhausen jump size generally decreases with increasing Fe thickness, showing theincreased domain wall pinning density. Surprisingly, the power-law scaling behavior of
Barkhausen jump size distribution gradually disappears as pinning of domain walls in
the Fe layer increases. This is due to the fact that magnetization reversal mechanism ischanged from a random Barkhausen avalanche dominant mode to thermally activateddomain wall creep dominant mode.

Andres Rosales Rivera1*, Juan Fernando Jaramillo1, Nicolas Antonio Salazar1, Olatz
Idigoras2 and Andreas Berger2
1
Laboratorio de Magnetismo y Materiales Avanzados, Universidad Nacional de
Colombia, Sede Manizales, Colombia, Colombia
2
CIC nanoGUNE Consolider, Tolosa Hiribidea 76, E-20018 Donostia-San Sebastian,Spain
In this work, the low-temperature phase and critical behavior at high temperature of
inhomogeneous gadolinium-chromium samples were investigated using DC magnetization
measurements. The samples were prepared as Cr(50nm)/Gd(100nm)/Cr(50nm) multilayersgrown onto Si(110) single crystal substrates by means of sputter deposition. The samples’
inhomogeneity was controlled by annealing at different temperatures Tan = 200, 400, and
500°C during 10 minutes, and their magnetization was measured using zero field cooling (ZFC)
and field cooling (FC) procedures at several applied fields. In the vicinity of room temperature,
the magnetic behavior of the samples is compatible with a ferromagnetic ground state,
which undergoes a rounded ferromagnetic (F)-paramagnetic (P) phase transition at a criticaltemperature, Tc. At temperatures below Tc, however, differences between the magnetization
measured in the zero field cooling (Mzfc) and field cooling (Mfc) procedures are observed.
Mfc decreases with increasing temperature. Mzfc increases with increasing temperature and,in addition to the F-P phase transition at Tc, shows a peak at a certain temperature Tg < Tc. It
was also found that Mzfc is time dependent at low field and irreversible below an irreversible
temperature Ti(H). A (H,T) phase diagram that contains Tc, Ti(H) and Tg(H) is presented foreach of the samples.

J. P. Attane et al., Phys. Rev. B, 84, 144418 (2011) J. P. Attane et al., Phys. Rev. B, 82, 024408 (2010)

Magnetic properties of spatially ordered arrays of interacting nanofilaments have been studied
by means of small-angle diffraction of polarized neutrons. Several diffraction maxima or rings
that correspond to the scattering of the highly ordered structure of pores/filaments with hexagonal
packing have been observed in neutron scattering intensity maps. The interference (nuclear-magnetic)
and pure magnetic contributions to the scattering have been analyzed during the magnetic reversalof the nanofilament array in a field applied perpendicular to the nanofilament axis. The averagemagnetization and the interference contribution proportional to it increase with the field and aresaturated at H = Hs. The magnetic reversal process occurs almost without hysteresis. The intensityof the magnetic contribution has hysteresis behavior in the magnetic reversal process for both thepositive and negative fields that form the field dependence of the intensity in a butterfly shape. It has
been shown that this dependence is due to the magnetostatic interaction between the filaments inthe field range of H ≤ Hs. A theory for describing the magnetic properties of the arrays of interacting
ferromagnetic nanofilaments in the magnetic field has been proposed.

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SM02

SM05

Structural and magnetic behaviour of nanocrystalline CaFe2O4

Magnetic properties of nanometer scale FeCr antidot array system

Enhanced critical fields in MnSi thin films

Revealing the volume magnetic anisotropy of Fe films epitaxied on
GaAs(001) surface

S. N. Dolia*, Arvind Samariya, Arun S. Prasad, P. K. Sharma, M. S. Dhawan and S. P.
PareekDepartment of Physics, University of Rajasthan, Jaipur, India
Abstract. Study of the structural and magnetic properties of the nanoparticles of large
cation substituted ferrite, CaFe2O4 have been reported here. The cubic spinel phase of
CaFe2O4 could be synthesized effectively in nanocrystalline form of size 5.9 nm using
advanced sol-gel method. The sample was then heated at 1000 °C leading to bulk
size of orthorhombic structure. Very interestingly, the nanoparticles of CaFe2O4 get
transformed from cubic spinel structure to its characteristic orthorhombic structure on
annealing at 1000 0C. Rietveld profile refinement of the XRD patterns was performed
to study the nature of crystal structure. The SQUID magnetization measurements
divulged that the nanocrystalline sample is superparamagnetic above the blocking
temperature of 150 K whereas the bulk sample is ferromagnetic even at room
temperature. The reduction in saturation magnetization in the case of nanoparticles
as compared to its bulk counterpart has been explained on the basis that the magnetic
moments in the surface layers of a nanoparticle are in a state of frozen disorder. The
departure of the field cooled curve from the zero field cooled curves in the momentversus-temperature plot, further confirmed the room temperature superparamagnetic
behavior of the nanocrystalline CaFe2O4.

Shivaraman Ramaswamy and Geo George Philip
Nanotechnology Research Center, SRM University, India

In this work, we have fabricated periodic nanometer scale antidot array of FeCr. The deposition was
done using electron beam evaporation. The substrate was first coated with 100nm of a suitable resist(ZEP-520A) using spin coating. Then, the mask was patterned on the substrate using an electron
beam attached to field emission scanning electron microscope to generate the necessary pattern.
After the development, the FeCr (40nm) was coated onto the resist at 0.1A/s using electron beam
evaporation. The antidot pitch was maintained at 400nm and the antidot diameter was found to be
300nm. The magnetic nature of the sample was characterized using vibrating sample magnetometerand the in-plane magnetic anisotropy of the system was investigated using torque magnetometer.
Further, the magnetoresistance measurements were taken using an inline four point probe. The results
indicate that the antidot array system has a predominant ferromagnetic nature, has an n-fold rotational
symmetry with relation to the magnetic anisotropy. The easy axis, the hard axis of magnetization
along with the net anisotropic energy has also been determined. All data have been appropriate
discussed in the work. The use of antidot array systems for various applications is an intriguing newarea of research.
E.R. Spada, G.M.C. Pereira, E.F. Jasinski, A.S. da Rocha, O.F. Schilling, M.L. Sartorelli. Anisotropic magnetoresistancein electrodeposited cobalt antidot arrays. Journal of Magnetism and Magnetic Materials 320 (2008) 253-256. L.J.
Heyderman, S. Czekaj, F. Nolting, D.H. Kim, P. Fischer. Cobalt antidot arrays on membranes: Fabrication andinvestigation with transmission X-ray microscopy. Journal of Magnetism and Magnetic Materials 316 (2007) 99-102. M.
Tanaka, K. Itoha, H. Iwamotoa, A. Yamaguchia, H. Miyajimaa, T. Yamaokab Magnetic properties of nanometer-scale FeNi
antidot array system. (2006).

Dirk Menzel*, Josefin Engelke, Tommy Reimann and Stefan Suellow
Institute for Condensed Matter Physics, Technische Universitaet Braunschweig,
Germany
The magnetic properties of the cubic helimagnet MnSi are governed by the
Dzyaloshinskii- Moriya interaction which in the bulk stabilizes a helical ground state
below 29 K with a spin-helix wavelength of 18 nm and a propagation vector along
the [111] direction. Recently, MnSi has attracted a lot of attention after a skyrmion
lattice had been discovered in the so called A-phase. We have prepared thin MnSi
films on Si(111) substrate by alloying a single Mn layer into the substrate as well as bycodeposition of Mn and Si. RHEED analysis in combination with TEM investigation
reveals that codeposition leads to smooth films whereas the alloying process generates
rather three dimensional MnSi islands. In comparison to bulk material, the films show
an enhanced magnetic ordering temperature of 45 K, which has been determined using
SQUID magnetometry. Magnetization, resistivity, magnetoresistance, and Hall effectmeasurements have been performed on the films. They show that the critical fields
describing the transition from the helical to a conical spin phase and from the conicalphase to a parallel spin alignment are dependent on the film thickness and enhanced incomparison to single crystalline MnSi.

G. Chen1, J. Zhu1, J. Li2 and Yizheng Wu3
1physics department, Fudan university, China
2
Physics department, Fudan university, China
3phyiscs department, Fudan university, China

Fe film grown on GaAs(001) is a model system for studying the spin injection froma ferromagnetic layer into the semiconductor substrate. The Fe/GaAs(001) system
exhibits a remarkable in-plane uniaxial magnetic anisotropy (UMA) with an easy
axis (EA) parallel to the GaAs[110] direction, and such UMA is usually believedto originate entirely from the Fe/GaAs interface. In this contribution, we will show
our quantitative studies on the thickness dependent magnetic anisotropy in Au/Fe/
GaAs(001) system using the magneto-optic Kerr effect with a rotating magnetic field.
Through a clear 1/dFe relation of the UMA, we found a UMA component with the EA
parallel to the GaAs direction which originates from the volume contribution. Suchvolume UMA is sensitive to the growth temperature and also strongly correlate with
the interface anisotropy. We can conclude that both the volume anisotropy and theinterfacial anisotropy are related to the ordered atomic structure at Fe/GaAs interface.
Our results may introduce a new aspect for further understanding the origin of UMA in
Fe/GaAs(001) system.
1) G. Chen, J. Zhu, J. Li, F. Z. Liu, and Y. Z. Wu， Appl. Phys. Lett. 98, 132505(2011)

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Magnetoresistance of helimagnetic ordering in single crystal FeGe
nanowires

Fabrication of Al-Ni core-shell structured particles via electroless ni
plating

Magnetism and Cr2O3-Fe2O3 structure of CoFe/Cr-NOL surface

Structures and magnetic properties of ultrathin Ni/Cu(100) in
hydrochloric acidTae-eon Park1, Byoung-chul Min1, Dong-jea Seo2, Younho Park1, Heon-jin Choi2 andJoonyeon Chang1*
1Spin Device Research Center, KIST, Korea
2
Deparment of Materials Science and Engineering, Yonsei University, Korea
We report on the synthesis, structural characterization, and magneto-transport of single
crystalline FeGe NWs. Transition metal silicides and germanides have attracted a lot of
attention because of their chiral cubic helimagnetism as a consequence of the DzyaloshinskiiMoriya interaction. FeGe is known to have a high Neel temperature and helical spin orderwith a relatively long period. In addition, one dimensional-confinement of the spin structure
might enhance the helical magnetic ordering of FeGe NWs as the nano-confinement often
alter or improve the properties. We have synthesized single crystalline FeGe NWs by CVD
process without any catalyst. We have investigated the helimagnetic ordering in FeGe NWs byusing electrical and magneto-transport measurements. When the magnetic field was applied
longitudinal to the NW axis, the signature of the helimagnetism in the FeGe NWs was observed
up to near room temperature. The magneto-transport measurements reveal three magnetic statesof the FeGe NWs: the helimagnetic state, conical helimagnetic state, and ferromagnetic state.
The magnetic transitions from the conical helimagnetic state to ferromagnetic state in FeGe
NWs was clearly observed and occurred at much higher field those observed in the bulk FeGe.
The relationship between nano-sized confinement and the conical helimagnetic state will be
discussed in detail.

360

1

The 19th International Conference on Magnetism

Youn-kyoung Baek*, Jung-goo Lee, Sangsun Yang and Chul-jin Choi
Powder & Ceramic Research Division, Korea Institute of Materials Science, Korea

Al alloy powders have been of much interest in recent years due to their various
applications such as metallurgical, chemical, paint & pigment industries, aerospace
applications due to their lightness in weight and processability. Major research efforts
have been made for improving their functionalities by addition or deposition ofalloying elements such as Ni and by controlling the structure. However, it is difficult
to fabricate these alloy powders by traditional metallurgical process and it is necessary
to evolve new methods. Core-shell structured particles are attracting considerable
attention as a consequence of their potential application in different areas of scienceand technology. Functionalizing the Al core with suitable shell materials indeed opens
the door to specific physical, chemical and optical performances of Al. However, due
to the oxide layer present on Al surface, it is difficult to plate Al with any metal or
metallic base surface coating by post wet deposition techniques. Thus, we fabricated
Al-Ni core-shell structured powders using electroless Ni plating. The pre-treatment
was conducted for the formation of Ni shell as well as removal of the oxide layer.
The formation of Ni shell on Al core powder was confirmed by SEM, XRD and VSM
results.

July 13 (Fri)1

Naoki Shimomura1*, Kazuya Sawada2, Tomohiro Nozaki1, Masaaki Doi3 and Masashi
Sahashi11Department of Electronic Engineering, Graduate School of Engineering, Tohoku
University, Japan
2
Toshiba Corporation, Japan
3
Tohoku Gakuin University, Japan
Magnetoelectric (ME) effect has been investigated for realizing electric controlled spintronic
device, such as MERAM. Cr2O3 is the most promising material for the application due to highNeel temperature (TN : ~307K). Switching exchange bias field by applying electric field using
bulk Cr2O3 (0.6mm) has been reported [1]. Recently, we have observed high blocking temperature(TB : ~250K) of CoFe/Cr-NOL (Nano-Oxide-Layer) containing Cr2O3 and Fe2O3 (TN ~ 950K)
in its surface, in spite of the ultrathin thickness (less than 1nm). The NOL is prepared by Natural
Oxidation (N.O.) of CoFe and ultrathin (1ML) Cr layer [2]. To clarify the reason of high TBof the NOL is important for achieving thin Cr2O3 film that shows ME effect higher than room
temperature. In this study, we have investigated the structure and magnetic property of CoFe/CrNOL by varying constitution condition, such as deposition system and N.O. intensity. It was foundthat mixing of Cr into CoFe layer before N.O. and high N.O. intensity cause the formation of
Cr2O3-Fe2O3 solid solution in NOL surface, which lower the TB. It is indicated that the presence of
not Cr2O3-Fe2O3 solid solution but the existence of both Cr2O3 and Fe2O3 is needed for high TB.

Jyh-shen Tsay*, Chun-liang Lin, An-wei Wu, Ying-chieh Wang and Yu-chieh Tseng
National Taiwan Normal University, Taiwan

Microstructure and magnetic properties of ultrathin Ni/Cu(100) prepared by way ofelectrochemical approaches are investigated. In a pure supporting electrolyte, the STM
image of the chloride covered Cu(100) surfaces show the formation of 90-degree stepedges of the terraces as a result of the electrochemical annealing [1]. After adding
NiCl2, the hydrogen evolution reaction is advanced to a more positive potential. Nickel
atoms attach onto the steps and the surface shows single atomic steps corresponding toa layer-by-layer growth. As the coverage of Ni increases, large amount of clusters formon the surface. The adsorption of chloride anions occurs on the top of the films [2]. For
thin Ni layers, no magnetic hystsresis is observed due to the lowered Curie temperaturefor ultrathin overlayers. As the Ni coverage increases, hystsresis loop is observed with
in-plane anisotropy of the films. For thicker films spin reorientation transition occursthat may be due to the strain relaxation in the Ni overlayer. The high squareness of themagnetic hysteresis loops confirms the smooth interfaces of the Ni films.
[1] S.L. Tsay, et al, Phys. Chem. Chem. Phys. 12, 14950 (2010); [2] P.Y. Yen, et al, J. Phys. Chem. C
115 (2011) 23802.

[1] Xi He, Yi Wang, Ning Wu, Anthony N. Caruso, Elio Vescovo, Kirill D. Belashchenko Peter A. Dowben, and Christian Binek,
Nature Mater. 9, 579 (2010). [2] K. Sawada, N. Shimomura, M. Doi, and M. Sahashi, J. Appl. Phys 107, 09D713 (2010).

July 8-13, 2012 Busan, Korea

361

poster Presentation
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Improvement in structural and magnetic properties of laser ablated
Ni-Zn Ferrite thin films

Effects of dimensionality on magnetization of Ho and Sm-doped
BiFeO3 thin films

Growth temperature dependence of crystal orientation and magnetic
properties of CoMn2O4 thin films

Magnetic coupling in manganite-based thin film heterostructures
studied by Electron Holography

Zinc, as known as non-magnetic element, has been doped into Nickel-Ferrites underthin film form, with a hope to modify its structural and magnetic properties, in order tohave the appropriate requirements for high frequency applications. Laser ablated Ni1xZnxFe2O4 (0 ≤ x ≤1) thin films grown on R-cut Al2O3 (0001) substrates using pulsed
laser deposition (PLD) technique are single phase with (l l l) orientation, and they
are room temperature strongly ferromagnetic, while others’ similar works reported
ferromagnetism only at low temperatures. Additionally, the higher HC value in ourfilms compared to what others reported indicates that somehow we have found an
appropriate way to make Ni-Zn ferrites become potential candidates for modernminiaturization of electronic devices. The zero field cooled ? field cooled (ZFC-FC)
magnetization curves for all the films shows the blocking temperature (TB) suggestinga strong anisotropy. Research on Ni1-xZnxFe2O4 (0 ≤ x ≤1) thin films would be very
promising for device market.

Taeyoung Koo1, Jaeyoung Kim1, Sunhee Kang2, Illwon Kim2, Yoonhee Jeong3, Myunghwa
Jung4 and Jonghyun Song5*
1
Pohang Accelerator Laboratory, Korea
2
Physics, Ulsan University, Korea
3
Physics, Pohang University of Science and Technology, Korea
4
Physics, Sogang University, Korea
5
Physics, Chungnam National University, Korea

Luis Alfredo Rodriguez1, Lorena Marin2, Cesar Magen3*, Irene Lucas4, Pedro Antonio Algarabel4,
Luis Morellon2, Jose Maria De Teresa4 and Manuel Ricardo Ibarra1
LMA-INA, Universidad de Zaragoza, 50018, Zaragoza, Spain
2
INA, Universidad de Zaragoza, 50018, Zaragoza, Spain
3
LMA-INA and ARAID, Universidad de Zaragoza, 50018, Zaragoza, Spain
4
ICMA, Universidad de Zaragoza-CSIC, 50009, Zaragoza, Spain
1

Advances in nanofabrication of magnetic nanomaterials leads to search for new tools to measure physicalproperties at the nanoscale, such as magnetization. Accurate characterization of the magnetization states innanostructures is of the utmost importance in the development new devices such as magnetic tunnel junctions(MTJs) [1]. Transmission electron microscopy (TEM) techniques such as Electron Holography (EH) allows thequantitative imaging of the magnetization states of ferromagnetic materials with unprecedented spatial resolution
at the nanometer level [2]. Furthermore, EH can be combined with the in situ variation of external parameters suchas magnetic and electric fields, temperature, etc. In particular, we use a TEM cryo-holder to image magnetization
states of ferromagnets with low TC (down to 100 K) while varying in situ the magnetic field applied by theobjective lens of the TEM. In this work, we present the EH study of the magnetization switching of La-Sr and LaCa manganite thin films (TC = 180 and 300 K, respectively) and manganite-based MTJs [3]. The (de)coupling ofmagnetic electrodes in MTJs is analyzed by performing hysteresis loops at 100 K to determine the switching fields
from the direct observation of the magnetization orientation of the electrodes upon magnetic field [4].

BiFeO3 is promising multiferroic material due to high ferroelectric (1100 K) and antiferromagnetic (650K) ordering temperatures. Reports of other groups have suggested that by reducing the dimensionality, thespiral magnetic ordering could be suppressed [1]. Thus, multiferroics in thin films and nanocrystalline forms
could enhance the magnetic properties [2]. In BiFeO3, if Bi is substituted by a small amount of divalent or
trivalent metal ions, or Fe is substituted by transition metal ion, a significant enhancement in magnetization
can be achieved. We have prepared the nanocrystalline RE-BiFeO3 (RE = Sm and Ho) by using sol-gel
method to be target materials for thin films fabrication. RE-BiFeO3 films were grown on LaAlO3 substrates
using pulsed laser deposition technique. All the films show a single phase of rhombohedral structure withspace group R3c. Significant changes in the structural properties were observed as the thickness of the films
increases. The magnetization observed in the case of Ho is much higher than those reported in literature
and also Sm-doping shows better magnetization values. The magnetization increases as the film becomesthinner. This is a strong evidence for the origin of surface magnetism that exist in the films.

CoxMn3-xO4(0≤x≤3), which crystallize in the spinel structure, are strong candidates of multiferoics which can beused in various technical applications due to their thermal, electrical and magnetic properties. In the present work,
we report on the growth of epitaxial CoMn2O4 thin films on Nb-doped SrTiO3(001) substrate using Pulsed Laser
Deposition and their magnetic properties. With all other growth parameters fixed, the growth temperature (Tg) waschanged from 720oC to 920oC. The sample with Tg =720oC shows a strongly tensile strained epitaxial crystal
structure with the orientation of (400). The M-H loops shows a ferrimagnetic behavior with the coercive field of~1.7 T. However, with increasing Tg up to 870oC, the tensile strained crystal domain becomes weaker whereas
the domain of mixed orientations of relaxed (400) and (004) appear and has gained predominance. The M-H loops
shows a weakened ferrimagnetism compared to the sample with Tg =720oC. With further increasing Tg to 920oC,
interestingly, the crystal structure turns to be oriented (004) and the magnetic properties exhibit enhanced saturated
magnetization with negligible coercive field. These observations indicate that the growth temperature plays acrucial role in determining the crystal structure and magnetic properties of CoMn2O4 thin film.

[1] P. Thakuria and P. A. Joy, J. Appl. Phys. 97 (2010) 162504. [2] J. Wang, J. B. Neaton, H. Zheng, V. Nagarajan, S. B. Ogale, B. Liu, D. Viehland, V.
Vaithyanathan, D. G. Schlom, U. V. Waghmare, N. A. Splandin, K. M. Rabe, M. Mutting and R. Ramesh, Science, 299 (2003) 1717 .

[1]. V. Eladio, M. R. Rosa, L. M. V. Jose, and G. M. Oscar, Chem. Mater. 8, 1078 (1996). [2]. H. T. Zhang and X. H. Chen, Nanotechnology 17, 1384 (2006).

[1] S Yuasa et al., Nat. Mat. 3 (12): 868-871 (2004); S. S. P. Parkin et al. Nat. Mat. 3 (12): 862-867 (2004). [2] R. E. Dunin-Borkowski, M. R. McCartney, D. J. Smith, Electron
Holography of Nanostructured Materials. In Encyclopaedia of Nanoscience and Nanotechnology; Nalwa, H. S., Ed.; American Scientific Publishers: Stevenson Ranch,
California, 2004; Vol. 3, pp 41-100. [3] M. Bowen et al., Appl. Phys. Lett. 82, 233 (2003). [4] E. Javon, A. Masseboeuf, C. Gatel and E. Snoeck, J. Appl. Phys. 107, 09D310 (2010)

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A basic study of magnetic anisotropy strength control using FeSiB
magnetostrictive thin film

Substrate-dependent electronic anisotropy of epitaxial multiferroic
DyMnO3 and Dy0.8Ca0.2MnO3thin films

Structure and magnetic properties of Fe3O4 thin films on different
substrates by Pulsed Laser Deposition

Properties of hybrid superconductor/ferromagnet (SC/FM) multilayers

The Magneto-Impedance (MI) sensors are used for various applications [1, 2]. A magnetic anisotropy
controlling is important to improve sensitivity of MI sensor. Therefore, our research group proposed a newand simpler method to control magnetic anisotropy using inverse-magnetosriction and difference of thermal
expansion coefficient in bimetal thin film[3]. To exploit the proposed method, investigation of a fabrication ratio
between two layers (thickness and length) requires due to the sensitivity of proposed MI sensor is determined bychanges in fabrication ratio. In this paper, we introduce the changes of magnetic anisotropy field (Hk) strength
to develop high and adjustable sensitive MI sensor according to changes in geometrical properties of layers. The
thin films were deposited by RF magnetron sputter. Fe72Si14B14 and Molybdenum were used for the magnetic
and conductive layer, respectively. The fabricated thin films annealed to release the local stress. We carriedout magnetic domain observation by Kerr-microscope. Moreover, Hk value was obtained by VSM. Basedon the experiments, we could confirm that Hk value was controlled by the geometrical properties because thegeometrical properties can determine the generated stress in the magnetostrictive magnetic layer. This research
provides the fabrication range and expectation of the sensitivity of MI sensor.

We investigated the substrate-dependent electronic structure and anisotropic bondingof the Mn 3d states in DyMnO3 and Dy0.8Ca0.2MnO3 thin films on SrTiO3(001) and
LaAlO3(110) substrates using polarization-dependent x-ray absorption spectroscopy(XAS) at O K-, Mn L- and Mn K-edges for three polarizations, E || a, E || b andE || c. Polarization-dependent x-ray absorption spectra at O K-, Mn L23- and Mn
K-edges of orthorhombic DyMnO3/LaAlO3(110) thin films show a strong polarization
dependence, whereas orthorhombic DyMnO3 /SrTiO3(001) thin films show nearly
isotropic spectral structure. The main peak in polarized Mn L2,3-edge XAS spectraof DyMnO3/LaAlO3(110) thin films for the E || b polarization lies at a lower energy
than for polarizations E || a and E || c. This indicates a great anisotropy in Mn 3d-O
2p hybridization, reflecting an orbital ordering and a highly anisotropic coplanar
Mn-O bonding in DyMnO3/LaAlO3(110) thin films. Orbital ordering of eg-orbital
and the highly anisotropic in-plane Mn-O bonding is an indispensable factor to theformation of complicated incommensurate modulated magnetic structures observedin orthorhombic DyMnO3. The present results provide important implications for the
microscopic understanding of the multiferroic DyMnO3.

Magnetite is an attractive magnetic oxide to be used in magneto-transport applications.[1]Many
researchers have studied how to optimize the deposition condition for high quality magnetite thinfilms.[2]In this work,magnetite thin films were deposited on different substrates at temperatures
varying from 100°C to 450°C,and their structure,magnetic and magneto-transport properties havebeen studied. XPS and Raman spectra reveal single phase of Fe3O4 on all the substrates.When film
thickness is small and temperature is relatively high(>300°C),magnetite thin films on single crystal
SiO2,Si and amorphous glass exhibit strong (111) texture,no matter they have either a huge latticemismatch or none matching with Fe3O4.The (111)texture can be formed at lower temperature(100°C)
on (002)-ZnO due to the minimization of both surface and interfacial energy.The films on (0001)Al2O3 show (111)-epitaxial structure in a large temperature range(100-450°C). The saturated
magnetization for all the (111)oriented magnetite films are in the reported thin-film range.Magneto
resistance up to 4% has been obtained.The out-of-plane MR exhibit quadratic behavior up to 6000
Oe,whereas the in-plane MR is linear in this regime,which suggests the presence of anti-phaseboundaries.[3]Large substrate-induced strain was found in the films grown on Al2O3 due to the latticemismatch (8%),which significantly affected the magnetic anisotropy of the thin film.
[1] H. Liu, E.Y. Jiang, H.L. Bai, R.K. Zheng, H.L. Wei, X.X. Zhang, Appl. Phys. Lett. 83 (2003) 3531. [2] S. Kale, S.M. Bhagat, S.E. Lofland,
T. Scabarozi, S.B. Ogale, A. Orozco,S.R. Shinde, T. Venkatesan, B. Hannoyer, B. Mercey, W. Prellier, Phys.Rev. B 64 (2001) 205413. [3] W.
Eerenstein, T. T. M. Palstra, S. S. Saxena, and T. Hibma Phys. Rev. L 88 (2002) 247204.

[1] A. I. Buzdin. Rev. Mod. Phys., 77(3):935, 2005. [2] Y. T. Xing, H. Micklitz, T. G. Rappoport, M. V. Milo sevi c, I. G. Sol orzano-Naranjo, and E. BaggioSaitovitch. Phys. Rev. B, 78(22):224524, 2008. [3] Y. T. Xing, H. Micklitz, W. T. Herrera, T. G. Rappoport, and E. Baggio-Saitovitch. The European Physical Journal
B - Condensed Matter and Complex Systems, 76:353{357, 2010. [4] E. A. Demler, G. B. Arnold, and M. R. Beasley. Phys. Rev. B, 55(22):15174{15182, Jun 1997. [5]I. A. Garifullin. Journal of Magnetism and Magnetic Materials, 240(1-3):571 - 576, 2002. 4th International Symposium on Metallic Multilayers.

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Magnetic properties of co thin films on polyethylene naphthalateorganic substrates

Enhanced magnetization by substitution of Zn2+ in Fe3O4 films

Influence of crystallographic orientation on the magnetic properties of
NiFe, Ni, and Co epitaxial fcc films grown on single-crystal substrates

Effect of substrate on the anisotropic magnetotransport in
Sm0.45Nd0.10Sr0.45MnO3 thin films

Jaewon Shin*, Sung Hoon Kim, Genki Kitazawa, Shuichiro Hashi and Kazushi Ishiyama
Research Institute of Electrical Communication, Tohoku University, Japan

July 13 (Fri)Tae-young Kim1*, Anupati Telugu Raghavender2, Sugawara Takashi3, Makio Kurisu3 andNguyen Hoa Hong4
1
Physics, Seoul National University, Korea
2
Physics, Seoul National University, India
3
Physics, Ehime university, Japan4
Physics, Seoul National University, France[1]Y. Murayama, T. Ozawa, S. Yabukami, K. Ishiyama, and K.I. Arai, “High-Frequency Carrier-Type Magnetic Field Sensor with a Sub-pT
Resolution Using a Magnetic Film and a Transmission Line,” J. Magn. Soc. Jpn, 31, 17-22, 2007. [2]T. Morikawa, Y. Nishibe, H. Yamadera,
Y. Nonomura, M. Takeuchi, and Y. Taga, “Giant Magneto-Impedance Effect in Layered Thin Films,” IEEE Trans. Magn., 33, 4367-4372,
1997. [3] Jaewon Shin, Sung Hoon Kim, Yasuaki Suwa, Shuichiro Hashi, Kazushi Ishiyama, “Control of In-plane Uniaxal Anisotropy of
Fe72Si14B14 Magnetostrictive Thin Film Using a Thermal Expansion Coefficient,” J. Appl. Phys (will be published in April)

Hideo Kaiju*, Taro Abe, Kenji Kondo and Akira Ishibashi
Research Institute for Electronic Science, Hokkaido Univerisity, Japan

Recently we have proposed spin quantum cross (SQC) devices, in which molecules
are sandwiched between two edges of magnetic thin films deposited on organic
substrates with their edges crossed. According to our recent calculation, SQC devices
exhibit large magnetoresistance effect at room temperature. In this study, towards the
fabrication of SQC devices, we have investigated magnetic properties and surface
morphologies of Co thin films on polyethylene naphthalate (PEN) organic substrates.
Co thin films were thermally evaporated on PEN substrates under a magnetic field in ahigh vacuum chamber. The magnetization curves were measured by focused magnetooptic Kerr effect techniques at room temperature. The surface morphologies wereanalyzed by atomic force microscope. As a result, the surface roughness decreases
from 1.3 to 0.55 nm with increasing the Co thickness up to 55 nm, where a two-stepsmoothing phenomenon can be seen. As for magnetic properties, the coercive force
and the squareness of the hysteresis loop show the maximum values at a Co thicknessof 5.3 nm. This peak is due to the rotation of the uniaxial magnetic anisotropy formed
from both the induced magnetic anisotropy and the shape magnetic anisotropy affectedby the surface morphologies of Co/PEN and PEN substrates.

The 19th International Conference on Magnetism

Kueih-tzu Lu, S. C. Haw, T. L. Chou, J. M. Lee, S. A. Chen and J. M. Chen
National Synchrotron Radiation Research Center, Taiwan

Chang-yup Park1, Jong-hyun Song2, Chun-yeol You3 and Sung-chul Shin4*
1
Department of Physics and Center for Nanospinics of Spintronic Materials, Korea
Advanced Institute of Science and Technology, Daejeon 305-701, Korea
2
Department of Physics, Chungnam National University, Daejeon 305-764, Korea
3
Department of Physics, Inha University, Incheon 402-751, Korea
4
Department of Physics and Center for Nanospinics of Spintronic Materials, KAIST,
Daejeon, Department of Emerging Materials Science, DGIST, Daegu, Korea
Fe3O4 is one of the key materials as efficient spin injector for spintronic device. Thereby
considerable researches have been carried out to obtain high magneto resistance ratio(MR), however no report show enough MR because of interface concerned problems
and uncertainty of half metallic identity itself. Hence we choose Fe3O4 to investigate
its nature and enhancement of magnetic and electric properties by substitution of Zn2+
ion. Firstly we carried out magnetization hysteresis loop measurement by means ofalternating gradient magnetometer. To find out a role of Zn substitution, we fabricatedFe1.8Zn1.2O4 film and the saturation magnetization strikingly enhanced to 283 emu/cc
from 79 emu/cc of the epitaxial Fe3O4 film. We believe that the 3.6 times enhancement
is ascribed to the substitution of Zn2+ ion instead of Fe ion at tetrahedral A site whichspin is antiparallel to that of Fe ion at octahedral B site in inverse spinel structure of
Fe3O4.

Xuelian Huang, Yang Yang and Jun Ding*
Materials Science and Engineering, National University of Singapore, Singapore

Taiki Ohtani*, Tetsuroh Kawai, Mitsuru Ohtake and Masaaki Futamoto
Chuo Univercity, Japan

NiFe, Ni, and Co crystals with fcc structure are soft magnetic materials and have been used in magnetic
thin film devices like magnetic heads and sensors. Magnetic property varies depending on the film texture[1,2]. In the present study, Ni80Fe20 (at. %), Ni, and Co films with fcc (100) and (111) orientations wereprepared by hetero-epitaxial growth on single-crystal substrates of GaAs(100) and Al2O3(0001). The
magnetic anisotropy, the magnetization structure, and the magnetostriction were investigated by employing
RHEED, XRD, Bitter, and magnetostriction measurements. NiFe, Ni, and Co films of fcc(100) orientation
showed four-fold symmetries in-plane magnetic anisotropy. The easy magnetization axes were parallel to[011] and [01-1] directions. 90° magnetic domain walls were observed for the epitaxial films. The in-planemagnetization properties were reflecting the magnetocrystalline anisotropies of respective bulk fcc crystals.
On the contrary, the in-plane magnetization properties were isotropic for NiFe, Ni, and Co films withfcc(111) orientation. In magnetostriction measurement, the magnetostriction behavior of epitaxial magnetic
thin film depended delicately on the magnetic domain structure and the domain wall motion under an
influence of magnetic field. At the conference, the inter-relationships of magnetic anisotropy, magnetization
structure, and magnetostriction will be discussed for these epitaxial thin films.
[1] Y. Nukaga, M. Ohtake, M. Futamoto, F. Kirino, N. Fujita, N. Inaba.: IEEE Trans. Magn., vol. 45, pp.
2519-2522, 2009. [2] M. Ohtake, T. Tanaka, K. Matsubara, F. Kirino, M. Futamoto.: J. Phys.: Conf. Ser., vol.
303, pp. 012015_1-6, 2011.

U. D. Chacon Hernandez1, Y. T. Xing2, William E. Alayo1, Magda B. Fontes1, Jorge L. Gonzalez3, Liying
Liu4, G. Solorzano4 and E. Baggio-saitovitch1
1
Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil, Brazil
2
Universidade Federal Fluminense Niteroi, Brazil, Brazil
3
Universidade Federal do Espirito Santo, Vitoria, Brazil, Brazil
4
PUC-Rio de Janeiro, Brazil

July 13 (Fri)Raghavender A T1*, Nguyen Hoa Hong1, Ekaterina Chikoidze2, Yves Dumont2 andKurisu Makio3
1
Department of Physics and Astronomy, Seoul National University, Korea
2
Laboratoire GeMAC, Universite de Versailles, France
3
Department of Physics, Ehime University, Japan

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poster Presentation

Recent research on systems that contain two types of materials (hybrid systems) shows that new phenomena canbe observed. One of such hybrid systems is superconductor/ferromagnet (SC/FM) nanocomposites, which shows
coexistence of superconductivity and ferromagnetism with unusual properties. We use niobium (Nb) as thesuperconducting layers with fixed thickness (50 nm) and cobalt or permalloy (NiFe) as the ferromagnetic layerswith different thickness (5, 10 and 20 nm). The films prepared by magnetron sputtering deposition technique,have been characterized by x-rays diffraction and in some cases the cross section at interface were studied by
TEM. Characterization of SC and FM transitions was done by resistivity and magnetization measurements. The
properties of superconductor changed at the SC/metal interface because of the proximity effect, for example,
decrease of Tc. Moreover, the magnetic layers between superconducting layers will give have more influence on
the superconductivity due to its stray field. Our results show that when the external magnetic field is close to theupper critical field Hc2, the SC/FM multilayers can have a vortex solid to a liquid phase transition. We believethat the stray field of the magnetic layers contributes to the melting of the vortex solid state.

Pawan Kumar1, M. K. Srivastava1, G. D. Verma2, R. K. Dwivedi3 and H. K Singh1
Quantum Phenomena and Applications, National Physical Laboratory (CSIR), India
2
Department of Physics, IIT Roorkee, India
3
Department of Physics & Materials Science and Engineering, Jaypee Institute ofInformation Technology (Deemed University), India1

Sm0.45Nd0.10Sr0.45MnO3 thin films on single crystal LAO and STO substrates wereprepared by ultrasonic nebulized spray pyrolysis. The PM-FM transition was observed
at TC - 153 K and 150 K in film on LAO and STO, respectively. The magnetic moment
was found to be smaller in film on STO and it showed stronger bifurcation between the
ZFC-FC magnetization. The isothermal M-H loops measured with H applied paralleland normal to the film surface showed that the easy axis was in the film plane, while
the hard axis was along the normal. The dominance of the shape anisotropy explains
the in-plane magnetic easy axis. Large low field magnetoresistance (MR) is observed inboth films. The occurrence of significantly smaller peak anisotropic magnetoresistance(AMR) at a temperature lower than the TIM and the broadening of the AMR-T curve
suggest that films on STO have higher fraction of the AFM-COI phase. The differencein the magnetotransport anisotropy in the set of films has been explained in terms of
substrate induced strain, e.g., STO provides tensile strain, which is known to favor the
AFM-SE and CO-OO phases.

July 8-13, 2012 Busan, Korea

363

poster Presentation
SM19

SN02

SN05

SN08

Magnetism of multilayer (CoNiPsoft/CoPhard)n films

Rotor structure optimization of interior permanent magnet by using
response surface method

An effective skew method for torque ripple reduction in surfacemounted permanent magnet motor

Structural and magnetic properties of nanocrystalline BaFe 12O19
synthesized by microwave-hydrothermal method

Due to limited energy sources and environmental pollution issues recently, the needsof high efficiency electricity equipments are steadily increasing. Among them, an IPM
is being developed for the application of eco-friendly vehicle. An Interior Permanent
Magnet has a structure of inserted permanent magnet in the inner rotor. These motor
requires high torque and low torque ripple. It was designed with 8 pole 36 slot of
stator and rotor, alternating N pole and S pole of permanent magnet and triangle
type permanent magnet. In order to find the optimized condition, Central Composite
Designs method and Box-Behnken method of Response Surface Method were used forfinding design variable and minimizing variation of design variable. Comparing two
Surface Reaction Methods, electromagnetic finite element method analysis based on
inserting variation of design variables, torque, torque ripple, harmonics were obtained
and optimized final value was obtained by safety factor through mechanical stiffness
analysis.

This paper deals with an effective skew method for surface-mounted permanent
magnet motor (SPMSM). Skew is a common method to reduce cogging torque andtorque ripple as well, and it can be done by continuous way in small machines or multistepwise method in big machines [1-2]. Generally, these conventional ways assume thatthe magnetic flux density distributions are same in axial direction and the contributionof the rotor on the generated torque is also same in all axial direction. However, theair-gap flux density is not uniform in axial direction, and it is rapidly reduced at bothends of the motor. Especially, in the pancake type motor, the influence of end sides issignificant. Thus, for skew to be effective, non-uniform air gap flux density distribution
in axial direction should be considered. In this paper, one method for an effective skew
is suggested by considering flux density distribution in axial direction, and the results
will be confirmed by 3D finite element analysis.

The nanocrystalline BaFe12O19 powders were prepared by Microwave-Hydrothermal(M-H) method at 200°C/45 min. The as synthesized powders were characterized byusing X-ray diffraction (XRD). The present were densified at different temperatures i.e.,
750°C, 850°C, 900°C and 950°C for 1h using microwave sintering method. The phaseformation and morphology studies were carried out using XRD and field emission
scanning electron microscopy (FE-SEM). The average grain sizes of the sinteredsamples were found to be in the range of 185 to 490 nm. The magnetic properties suchas saturation magnetization and coercive field of sintered samples were calculated
based on magnetization curves. A possible relation between the magnetic hysteresis
curves and the microstructure of the sintered samples was investigated.

The (CoNiPsoft/CoPhard)n films were prepared by chemical deposition method.
The content of phosphorus was 8 % at. in each layer. In hard magnetic layer the CoP
was in hexagonal state and in soft magnetic layer the CoNiP was in amorphous state.
The thickness of each layer was t = 4 nm. Magnetic measurements were made withvibrating-coil magnetometer in temperature range T = 77 ÷ 400 K and in magnetic
fields H < 10 kOe. We investigated changes of magnetic parameters in dependence
on number of layers in multilayer structure. In our experiments number of layer pairs
was n ≤ 15. Earlier [1] it was established that the coercive force (HC) of CoP layers
depends on layer thickness and HC rises when layer thickness increases. In given caseat nitrogenous temperatures the coercive forces of soft magnetic and hard magnetic
layers were ~ 20 Oe and ~ 1000 Oe, respectively. The combination of these layers into
structure leads to substantial change of magnetic behavior of structure in whole [2]. It
attracts attention that the soft magnetic layer determines the behavior of magnetizationof film structure decreasing the coercive force of system.
[1] A.V. Chzhan, G.S. Patrin, et al., Phys. Met. Metalloved., 109 (2010) 1. [2] A.V. Chzhan, G.S.
Patrin, et al., Bull. Russ. Acad. Sci. Phys., 76, (2012) 180

Jung-ho Han, Ik-sang Jang, Mi-jung Kim, Ki-doek Lee and Ju Lee*
Electrical Engineering, Hanyang University, Korea[1] Ian P. Brown, Robert D. Lorenz, “Response Surface Methodlogies for the Design of Induction Machine Self-Sensing Rotor
Position Saliencies”, Proceeding of International Conference on Electrical Machines and Systems, p1354-1359, 2007 [2] I. P.
Brown and R. D. Lorenz, 'Response surface methodologies for the design of induction machine self-sensing rotor position saliencies,'
ICEMS, 2007. [3] K. Ide, I. Murokita, S. Mitsujiro, O. Motomichi, N. Yukio, J. I. Ha, and S. K. Sul, 'Finite element analysis ofsensorless induction machine by high frequency injection,' Proc. of the IPEC, Tokyo, Japan, 2000.

K Sadhana and K Praveena
Materials Research Centre, Indian Institute of Science, Banglore-560012, India, India[1] R. Islam, I. Husain, A. Fardoun, and K. McLaughlin, 'Permanent Magnet Synchronous Motor
Magnet Designs with Skewing for Torque Ripple and Cogging Torque Reduction,' IEEE Trans. Ind.
Appl., vol.45, no.1, pp.152-160, 2009. [2] Y. Donmezer, L.T. Ergene, 'Skewing effect on interior type
BLDC motors,' ICEM XIX International Conference, pp.1-5, 2010

SM20

SN03

SN06

SN09

Significant change in the antiferromagnetic-to-ferromagnetic phasetransition temperature of epitaxial FeRh thin films by Ga substitution

Magnetization reversal behavior of FePt/MgO/FePt thin film

Effect of carbon additive on the TbCu7-type melt spun Sm(Co, M)7(M=Ti, Zr, Hf, V, Nb and Ge) ribbons

Research magnetic properties of Fe-O alloys with different texture
degrees and ratios of phases using simulating

Ippei Suzuki1*, Mitsuru Itoh1, Tetsuya Sato2 and Tomoyasu Taniyama1
1
Materials and Structures Laboratory, Tokyo Institute of Technology, Japan2
Department of Applied Physics and Physico-Informatics, Keio University, Japan

B2 ordered FeRh alloys exhibit fascinating magnetic properties such as the firstorder magnetic phase transition from the antiferromagnetic (AF) to ferromagnetic(FM) states at around 400 K. For a step toward the incorporation of this material into
devices, the control of the transition temperature in a thin film form is one of the mostcritical issues. In this study, we find that Ga substitution in FeRh efficiently reduces
the transition temperature down to room temperature, making the use of this materiala reality. A 30-nm-thick FeRh thin film and a Ga-substituted FeRh(Ga-FeRh) were
epitaxially grown on MgO(001) substrates by molecular beam epitaxy. The temperaturedependent magnetization of the epitaxial films clearly demonstrates the reduction of
the transition temperature down to room temperature. The change in the transition
temperature can be understood in terms of a possible change in the electronic statesnear the Fermi level due to the lattice expansion, leading to a more stable FM state in
Ga-FeRh. In fact, the out-of-plane lattice parameters calculated from the XRD patterns
are found to expand from 2.990 to 3.003 Å by the Ga substitution. Work supported inpart by Industrial Technology Research Grant Program in 2009 from NEDO, Japan.

Hiroki Iwama, Shinji Matsumoto, Katsuya Sugawara, Kotaro Sato, Masaaki Doi and
Toshiyuki Shima
Tohoku Gakuin University, Japan
L10 ordered FePt alloy has attracted much attention, since they are believed to be goodcandidates for future magnetic devises. It is also thought to overcome the problemof thermal fluctuation in nano-meters scale. A lot of studies such as thin films andself-assembled nano particles have been investigated [1-3]. However, the magnetic
properties of the multilayered FePt alloy have not been completely clarified. In orderto understand the magnetization reversal, FePt/MgO/FePt trilayer films have been
fabricated and detailed magnetic domain observation have been investigated. FePt
bottom layer was co-deposited with Fe and Pt on Au buffer layer by using an UHVcompatible magnetron sputtering system. Then, the intermediate MgO layer and
FePt top layer were deposited. Finally, the samples were annealed at Ta of 600 ºC.
The magnetic domain structure was observed by magnetic force microscope (MFM)
in applied fields up to ±6 kOe. Remarkable steps of the magnetization in the second
quadrant were observed for all the samples. This is thought to arise from the differencein the chemical ordering of top and bottom FePt layers. Independent magnetization
reversal of the top and bottom FePt layers was clearly observed at the FePt/MgO/FePt
circular dots by the MFM measurements.
[1] T. Shima et al., Appl. Phys. Lett. 99. 033516 (2006). [2] T. Shima et al., Appl. Phys. Lett. 81.
1050 (2002). [3] S. Matsumoto et al., J. Phys.: Conf. Ser. 266. 012038 (2011).

C.c. Hsieh1, H.w. Chang2, C.w. Shih1, W.c. Chang1* and C.c. Shaw3
1
National Chung Cheng University, Taiwan
2Tunghai University, Taiwan
3Superrite Electronics Co. Ltd, Taiwan

Recently, Sm-Co compounds with TbCu7-type structure have received intensive
attention due to their excellent intrinsic magnetic properties, which have potential
to be used as the starting materials for making bonded magnets for above 150 oC
applications. Our previous studies indicated that pure TbCu7-type structure could
be obtained easily in melt spun Sm(Co,M)7 (M=Ti, Zr, Hf, V, Nb and Ge) ribbons.
Based on the purpose of developing Sm(Co,M)7 alloys with TbCu7-type structure
for practical usage, effect of carbon on the microstructure and magnetic propertiesof melt spun SmCo7-xMxC0.1 (M=Ti, Zr, Hf, V, Nb and Ge; x=0-0.3) ribbons werestudied. Based on the XRD and TEM analysis, a pure 1:7 phase could be kept for the
ribbons with M= Nb, and Ge, but carbide phases, eg. TiC for M=Ti, ZrC for M=Zr,
Sm2C3 for M=Hf, and SmCoC2 for M=V, respectively, were found for other ribbons.
Nevertheless, a slight C addition may effectively refine the microstructure and improve
both the intrinsic coercvity and the magnetic energy product in all the studied ribbons.
Among them, the SmCo6.9V0.1C0.1 ribbons with σr=58.7 emu/g, iHc=13.5 kOe and (BH)
max=9.3 MGOe, and SmCo6.9Hf0.1C0.1 ribbons with σr=61.6 emu/g, iHc=11.8 kOe and(BH)max=10.3 MGOe are suitable for the bonded magnet applications.

Alexey Lileev*, Ivan Pelevin and Anna Starikova
National University of Science and Technology 'MISIS', Russia

The present article is concerned with investigation of magnetic properties of Fe-O
alloys, simulating their magnetic behaviour and causation of the high-coercivity
state of these alloys. Initial materials were powder so-called “Blue dust” and mixtureof this powder with Fe powder with different rations of these phases. “Blue dust”
is a powder of Fe2O3, it’s a natural Indian raw. Reserves of this material sufficientlarge, so a production material with high magnetic properties from it is an urgent
problem. Initial samples were powdered in high-energy ball mill for different time
periods. This treatment leads to phase transformation. The phase compositions were
investigated by X-ray analysis. The impact of time of milling and initial composition
on magnetic properties was explored. Milled nanocrystalline powders were subjected
to a low-temperature crystallization annealing in magnetic field. It leaded to phasetransformation. Powder was pressed into cubic shape samples. The dependenceof magnetic properties on composition after annealing was also investigated. The
computer simulating was used to understand which phase is cause og forming the highcoercitive state of material. Initial parameters were set so that result corresponds toexperimental data. The parameter changing showed quite how each of them influenceon magnetic properties.

SN01

SN04

SN07

SN10

Structural and magnetic properties of Sm2Co17 nanoflakes prepared bysurfactant-assisted ball milling

Efficiency and torque density improvement of interor permanantmagnet synchronous motor

Study of designed induction motor on cryogenic LNG pump system

Study on FePt/Fe exchange coupling nanocomposite thin films

In this Paper, I designed LNGs main cargo pump's motor using LNGs ship. LNGs
ship has made a high value product and won steady demand order in every year.
However, in Korea, when we make a LNGs ship, we import the key products fromother countries(It's almost 60% of order price). So, we need to develop original skill
about key product. LNGs main cargo pump's motor is submerged, and induction
motor type. In this paper, first of all, design the induction motor using constants atroom temperature. And then, we re-design the motor considering an extremely low
temperature. This motor's working operation temperature is -163°C. Because of that, it
can make a special design. In other words, we don't need to think about heat loss as likeas room temperature. In this reason, we consider about losses by current density andflux density. First, coil loss is generated a heat. So, it can be cooling the coil heat loss
immediately. On the other hands, magnetic saturation has effect on characteristics ofmaterial (specially, B-H curve). So, we think about magnetic saturation, even it works
at low temperature.

Granular FePt films with island microstructures have been deposited by DC magnetron
sputtering. The FePt grain size and distance among FePt grains could be controlled bytuning sputtering condition. An iron layer was deposited on the controllable island FePt
film to produce FePt/Fe nanocomposite thin film. The composite films show a hard/soft
magnetic exchange coupling after annealing, because the FePt grains in the composite
film became L10 structure with good hard magnetic properties after annealing. The
exchange coupling could be modified by tuning granular FePt structure and thicknessof Fe layer, which means it’s promising to produce FePt/Fe nanocomposite magnet
with good magnetic properties by this method.

Ming Yue, Rui Pan, Xiaofei Yin, Dongtao Zhang, Weiqiang Liu and Jiuxing Zhang
College of Materials Science and Engineering, Beijing University of Technology,
China
Microstructure, crystal structure and magnetic properties were studied for Sm2Co17
nanoflakes prepared by surfactant-assisted high energy ball milling with heptane andoleic acid as the milling medium. Effect of ball milling time on the crystallographicalignment evolution and coercivity of the nanoflakes were systematically investigated.
Microstructure observation shows that the Sm2Co17 nanoflakes have an average
thickness of less than 100 nanometers with an aspect ratio as high as 100. For the 2hours ball milled nanoflakes, the intensity ratio between (004) and (302) reflection
peaks, which indicates the degree of c-axis crystal texture of the Sm2Co17 phase,reaches the maximum value among all the samples, revealing that the strongest c-axis
crystal texture was obtained in this nanoflakes. As the ball milling time increases, theintensity ratio drops gradually indicating that the long time milling process undermines
the c-axis crystallographic alignment of Sm2Co17 phase in the nanoflakes. On the other
hand, it is found that as the ball milling time increases from 2h to 10h, the coercivityof the nanoflakes firstly increases, peaks at 2.8kOe for 8h, and then decreases again.
Further investigation indicates that the microstructure evolution plays an important rolein the coercivity variance of the Sm2Co17 nanoflakes.

364

Taewoo Kim and Junghwan Chang*Electrical Engineering, Dong-A University, Busan, 604-714, Korea

The 19th International Conference on Magnetism

Mi Jung Kim, Ki Doek Lee, Jae-jun Lee, Jeong-ho Han, Tae-chul Jeong, Woong-chanChae and Ju Lee*
Hanyang University, Korea
The motor should be designed with a minimum of because motor weight has quite large
portion in totality mass; because there is no generator as electrical vehicle, the highefficiency is demanded in order to increase the 1 charging distance. In this paper, thetechnique is presented for progression of the torque density and the efficiency through therelative electric loading and the shape of rotor magnet. In case of the established model,
the required torque satisfied at the rated speed and maximum speed, however, the torquedensity is low. When the mass of occupied by the motor is going to be bulky, 1 charging
distance is decrease due to the increase in the driving load. The current density wasincreased to boost the torque density. The motor size could be decreased owing to change
the current density, but there is a weakness at efficiency. The copper loss is enlarging withthe current density. To increasing both of them efficiency and power density, the relative
magnetic loading also should increase according to increase the relative electric loading.
To increase the relative magnetic loading, redesign the PM shape of rotor.
[1] Yukio Honda, Tomokazu Nakamura, Toshiro Higaki, Yoji Takeda, 'Motor design consideratioin and test results of aninterior permanent magnet synchronous motor for electric vehicles', IEEE Industry Applications Society, Annual Meeting,pp. 75~82, 1997 [2] Sung-Il Kim,etc., “Optimization for reduction of torque ripple in interior permanent magnet motor byusing the taguchi method”, IEEE Trans. on magnetics, vol. 41, no.5, pp. 1796~1799, 2005

Jinsung Kim and Gwansoo Park*
Pusan National University, Korea

July 13 (Fri)Gennady Patrin 1, Marina Pal'chik 2, Dmitry Balaev 2, Semion Kiparisov 2 andKonstantin Patrin2
1
Siberian Federal University, Russia
2
Institute of Physics of Siberian Branch of Russian Academy of Sciences, Russia

July 13 (Fri)poster Presentation

Wenli Pei
ATM, Northeastern University, China

1. Kneller E F, Hawig R. The exchange-spring magnet: a new material principl for permanent
magnets. Magnetics [J], IEEE Transactions on Magnetics, 1991. 27(4): 3588- 3560. 2. Zhou J,
Skomski R, Li X, et al. Permanent-magnet properties of thermally processed FePt and FePt-Fe
multilayer films [J], IEEE Transactions on Magnetics, 2002, 38(5Part 1): 2802-2804.

L.Dlufiewicz, J. Kolowrotkierwicz, W. Szelag, M. Barancki, and R. Neumann, Electrical Motor
for Liquid Gas Pump, SPEEDAM, pp.311-316 (2006). Shiyley R, Miller H, Development of a
Submerged Winding Induction Generator for Cryogenic Application, Conf. of IEEE Symp. on
Electrical Insulation, pp.243-246 (2000). Rush, S, Submerged Motor LNG Pumps in Send-out
System Service, Pumps&System, pp.32-37, (2004). Stephen J. Chapman, Electric Machinery
Fundamentals, pp.380-425, (2003).

July 8-13, 2012 Busan, Korea

365

poster Presentation
SN11

SN14

SO02

SO05

Effects of Sm content on thermal stability of sintered Sm2Co17 magnets

A new mechanism of electromagnetic linear-actuator using a magnetic
silicone rubber

Magnetic and resonance properties of Bi24(CoBi)O40

Compensated magnetism in double perovskites A2CrFeO6 (A=La,Sr)

The cubic bismuth oxide is characterized by charge ordering of bismuth ions. A studyof magnetic moment of cobalt ions is used to establish the valence state of bismuthions. The aim of study is to establish the interrelation between spin and elastic
subsystems. Measurements of the magnetization was carried out over the temperature
range 4K-300 K in the field H=50 kOe and the magnetization curve M(H) was
determined at the temperatures T=5 K and T=300 K. The temperature dependenceof magnetic susceptibility is well fitted to the Curie-Weiss law with the Curie-Weisstemperature θ=- 12.3 К and the effective magnetic moment is μ=5.08μB . The bismuth
cobaltit is paramagnetic at T >4 K. The electron paramagnetic resonance (EPR)
spectra were recorded from 77 K to 300 K at 9.3 GHz. The g- factor increases versus
temperature that can be qualitatively explained by local deformation of structure atvariation of bismuth ion valence. As a result, the magnetic anisotropy field is enhanced
at the heating. EPR linewidth varies linearly with temperature that is explained by spinphonon interaction. Relaxation of magnetic moment is due to strong interaction withthe elastic lattice.

Precise compensation of magnetic moment in solid state compounds is very rare. An
example is the so-called half-metallic antiferromagnet (HMAFM), which has one
metallic spin channel and the other insulating spin channel with the zero net moment.
Double perovskite compounds of A2BB’O6 have been theoretically investigatedas the most promising candidates for the last 15 years. Very recently, nearly wellordered epitaxial La2CrFeO6 films, theoretically predicted to be a HMAFM, weresynthesized using pulsed laser deposition. This sample shows the saturated moment of~2 μB, implying the ferrimagnetically ordered S=3/2 Cr3+ and S=5/2 Fe3+. This results
are controversial to the previous experimental results on artificial LaCrO3/LaFeO3
superlattices, which proposed a ferromagnetic order, as well as the existing theoreticalpredictions. In this presentation, we will revisit this system with first principles
calculations using LDA+U, the modified Becker-Johnson functional, and fixed spin
moment. Our results are consistent with the recent experimental results, showing aferrimagnetic insulating La2CrFeO6. Furthermore, we have investigated the Sr-analog
Sr2CrFeO6, which is as yet unsynthesized. Contrary to La2CrFeO6, this system has thetetravalent Cr and Fe ions with antialigned S=1 moments, resulting in zero net moment.
Our findings suggest a precise HMAFM Sr2CrFeO6.

SO03

SO06

Field induced phase transitions and magnetocaloric properties in Er1LuxFe2O4 compound

Possible half-metal antiferromangetism in double perovskites
A2VMnO6 (A=La,Sr)

Investigations on environment stability of the Sm2Co17 type magnets have been oneof hot pots on applications of Sm-Co based magnets. Effects of heavy rare-earth
elements substitute Sm on temperature coefficient of remanence (?) of the magnets
have been investigated systematically [1]. Sm2Co17 magnet with high coercivity has
the best thermal stability among all permanent magnets [2]. The reversible temperature
coefficient ? was zero in the (Sm1-xGdx)(CoFeCuZr)z magnet when x=0.55[3]. In thispaper, the dependence of Sm content on temperature coefficient of 2:17 type Sm-Co
magnets at different temperature were investigated. As shown in Fig.1, the temperature
coefficient increased with temperature when z value of the magnets is the same. While,the temperature coefficients of remanence firstly decreased and then increased withz value at the same temperature. When z=7.87, magnet with the best temperaturestability, the highest coercivity and the lowest temperature coefficient of remanence
were obtained.
[1]Chen Christina, Gong Wei, Michael Walmer H. Journal Applied Physics, 2002, 91(10): 8483.
[2]Li D, Misdrum H F, and Strnat K J. Journal Applied Physics, 1988, 63(8): 3984. [3]Liu Jinfang,
Payal Vora and Michael Walmer. Journal of Iron Steel Research International, 2006, 13: 319.

Takanori Fukushi, Sung Hoon Kim*, Shuichiro Hashi and Kazushi Ishiyama
Research Institute of Electrical Communication, Tohoku University, Japan

We propose a new mechanism of electromagnetic linear-actuator for biomedical applications suchas an artificial muscle and medical micro-robots [1-3]. The proposed mechanism requires twoarmatures and magnetic rubber in the DC-solenoid. The proposed structure is series connection:
armature_1, magnetic rubber, and armarture_2. Therefore, D.C magnetic field produces attractive
force between the two armatures. At that time, the magnetic rubber causes increase of attractive
force because the magnetic rubber was fabricated by iron powders with silicone elastormer (36 : 64
wt %), as a cylindrical shape (diameter:12 mm and height: up to 8.9 mm). Its magnetic properties
were measured by VSM; magnetization and coercive force are 50 emu/g and 40 Oe, respectively.
We compared magnetic force between the two armatures with the magnetic rubber and with a nonmagnetic rubber in magnetic field of 600 Oe. We found the magnetic rubber made the attractive force
1.7 times larger. This also means the use of magnetic rubber makes the low power consumption. The
largest advantages of this magnetic rubber are the increase of attractive force, generation of reaction
force, and the flexibility as soft elastmer, so it can be used for various biomedical applications. The
details will be introduced in the conference.
[1] B.Kim, M.G.Lee, Y.P.Lee, Y.Kim, and G.Lee, “An earthworm-like micro robot using shape memory alloy actuator,” Sens. Actuators A.,
125, 429-437, 2006. [2] H.Lu, J.Zhu, Z.Lin, and Y.Guo, “An inchworm mobile robot using electromagnetic linear actuator,” Mechatronics,
1-10, 2009. [3] T.Niino, S.Egawa, H.Kimura, and T.Higuchi, “Electrostatic Artificial Muscle: Compact, High-Power Linear Actuators with
Multiple-Layer Structures,” Proc. IEEE Micro Electro Mechanical Systems Workshop, 94, 130-135, 1994

SN12

SN15

Simulation of die-upsetting process of hot-deformed magnets

Novel microcrystalline Co-Zr-B RE-free hard magnetic alloys

Bin Lai*, Huijie Wang, Minggang Zhu and Wei Li
Division of Functional Materials, Central Iron & Steel Research Institute, China
A plastic deformation simulation was performed by using a three dimensional finite element
method based deformation modeling software in order to clearly understand the die-upsetting
process in detail. It was found by the plastic deformation simulation that the effective strains of
Nd-Fe-B die-upset magnets reduced from the middle to the ends of magnetic specimens along
the c-axis, or the press direction, so the crystallographic orientation deteriorated for the grains
approached to both ends of die-upset magnets. The magnetic properties were improved withincrease of effective strains of die-upset magnets.The remanence Br and maximum energy
product (BH) m were high for the specimens, machined from the central region of magnets,
because the microstructure of die-upset magnets was homogeneous and grains were aligned
well in the central region of deformed magnets according to the simulation. Experimentally,
the magnetic properties, X-ray diffraction patterns and microstructure of hot-deformed NdFe-B magnets were studied. The magnetic properties were improved with decreased height ofmagnet specimens which were obtained by symmetrically removing both ends of die-upset
magnets. The grain misalignment was as enhanced from the middle to both ends of die-upset
magnets along c-axis.The microstructural characterization was verified by experiment.

Sofoklis Makridis and Evagelos Gkanas
Department of Mechanical Engineering, University of Western Macedonia, Greece
The investigation of rapidly solidified alloys is important both for the basic information
it gives about the structural and compositional limits of magnetism and for thetechnical potential of new alloys. Co-based amorphous alloys have the advantage ofrelatively high saturation flux density and low magnetostriction. The glass formability
and technical magnetic properties of rapidly solidified Co(rich)-Zr-B alloys were
investigated in the composition range Co82ZrxB20-x. in order to determine the glass
forming range and explore the magnetic characteristics as a function of compositionand quenching rate. The alloys were found to be completely glassy for low x whereas
all the other compositions studied were completely or partially crystalline. The typicalglassy alloys showed good soft magnetic properties. The crystalline alloys with Zr
content higher than 80 % in Boron were characterized by a coercive force in excess of
4 kOe. Slow-cooled samples of the same composition showed coercivity in the orderof 120 Oe.

[1] Yutaka, Matsuura, J. Magn. Magn. Mater. 303 (2006) 344 [2] N. Yoshikawa, T. Iriyama, and H. Yamada. IEEE Trans. Magn., 35 (1999)
3268 [3] T. Harada, M. Fujita, T. Kuji, Journal of Alloys and Compounds, 243 (1996) 139 [4] T. Saito, M. Fujita, T.kuji, et al., J. Appl. Phys.,
83 (1998) 6390 [5] Y. Yoshida, Y. Kasai, T. Watanabe, et al., J. Appl. Phys. 69 (1991) 5841 [6] D. N. Brown, B. Smith, B.M.Ma, et al., IEEE
Trans. Magn., 40 (2004) 2895 [7] M. Leonowicz, D. Derewnicka, M. Wozniak, et al., 153/154 (2004) 860

x

Peng Zhang1, Ying-de Zhang1, Young-yeal Song1, Jae-yeong Kim2, Bo-wha Lee2 andSeong-cho Yu1*
1
Physics, Chungbuk National University, Korea
2
Physics, Hankuk University of Foreign Studies, Korea

Rare earth (RE)-ferrites have attracted attention in recent years due to their various
phase transitions (PTs) near room temperature. Their magnetic phase is determined bycompetition between antiferromagnetic and ferrimagnetic coupling of the localized
Fe ions. Magnetocaloric effect (MCE) reaches the maximum near the magnetic PT
temperature. Despite of many works of the PT, however, there are very limited works
on MCE in the RE-ferrites with two RE elements. In this work one has investigatedfield induced magnetic PT properties and MCE in the vicinity of the PT point.
Stoichiometric polycrystalline samples of Er1-xLuxFe2O4 (0.1 ≤ x ≤ 0.8) were preparedby solid-state reaction method. Magnetic measurements were performed using a
SQUID magnetometer. Fig.1 gives isothermal M-H curves of Er0.9Lu0.1Fe2O4, fromwhich the field induced PT can be seen clearly from the magnetization curves in therange of 208 K-240 K indicating a first order structural type PT[1]. Fig. 2 showsmagnetic entropy change (ΔSM) curves. With a maximum field of 1 T and 3 T, themaximum value of ΔSM are 0.49 J•kg-1K-1and 1.04 J•kg-1K-1 at 249 K, respectively.
The maximum ΔSM were appeared near the transition temperature and their MCE will
be explained in terms of PTs.

Kyo-hoon Ahn1 and Kwan-woo Lee2*
1
Department of Applied Physics, Graduate School, Korea University, Sejong, Korea
2
Department of Display and Semiconductor Physics, Korea University, Sejong, Korea

Myung-chul Jung1, Young-joon Song1 and Kwan-woo Lee2*
1
Department of Applied Physics, Graduate School, Korea University, Sejong, Korea
2
Department of Display and Semiconductor Physics, Korea University, Sejong, Korea

A half-metallic antiferromagnet (HMAFM) is half-metallic without macroscopic
magnetic moment. HMAFM has been considered a promising candidate of a spin
injector in spintronics, though no true HMAFM has been established yet. Very recently,
A well-ordered double perovskite La2VMnO6, which was theoretically predicted to
be HMAFM 15 years ago, has been synthesized by pulsed-laser deposition. Contrary
to the theoretical predictions, the saturated magnetic moment of 2 μB/f.u. implies
an ferrimagnetically ordered S=1 V3+ and S=2 Mn3+ ionic state, below TN=20 K.
Besides, the synchrotron radiation photoemission measurement indicates an insulating
La2VMnO6 with a gap of 0.9 eV, instead of being half-metallic. In this presentation,
we will revisit this system using various first principles calculations to unravel these
discrepancies between the previous theoretical suggestions and the experimental
results. Furthermore, our calculations suggest that the Sr-analog Sr2VMnO6 is aferrimagnetic half-metal, contrary to the ferrimagnetic insulator La2VMnO6.

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SO04

SO07

Synthesis of high magnetic moment nanowires for encoding anddecoding of barcode segments for multiplexing bio- applicationsFirst-principles study on the half-metallicity of full-Heusler alloy
Co2VGa (111) surface

Magnetic properties of heusler-type Ni-Mn-Ga glass-coated microwires

Focused magneto-optic kerr effect spectroscopy in Ni75Fe25 and Fe
ferromagnetic thin films on organic substrates

Torati Sri Ramulu1, Reddy Venu1, Brajalal Sinha1, Xinghao Hu1, Sook Soo Yoon2 andCheol Gi Kim1*
1
Material science and engineering, Chungnam national university, Korea
2
Material science and engineering, Andong national university, Korea
Abstract: Sequential template electrochemical synthesis of multisegment nanowires withmagnetic and non-magnetic segments have been extremely significant for barcoding,multiplexing and biosensing applications [1,2]. Especially, Hard magnetic segment with highsaturation magnetization and remenance materials are more convenient for multiplexing
biological applications. In the present article we have synthesized three different types ofmagnetic nanowires ( CoNiP, CoPtP and CoFeP) for a magnetic segment of barcode nanowires
by electrochemical deposition technique using a polycarbonate membrane with a diameter of
50 nm. The length of the nanowires was found to be around 6 μm. We compared the magnetic
properties of all the synthesized materials and found to be the CoPtP magnetic nanowires havehigher saturation and remenence. In order to demonstrate the decoding of barcode nanowires
using the magnetoresistance sensor in flow cytometry, we calculated the spatial distribution of
the stray magnetic field produced by the barcode nanowire by means of finite element method(FEM) using the commercial Maxwell software. The CoPtP shows most higher spatial variationcompared to the CoFeP and CoNiP, which means CoPrP is most advantageous composition forthe hard magnetic segment.
[1] K. B. Lee, S. Park, and C. A. Mirkin, 2004, Angew. Chem. Int. Ed., 43, 3048 [2] A. K. Salem, P. C. Searson And K. W. Leong, Nat.Mat., 2003, 2, 668.

366

Sergey Stepanovich Aplesnin1, Maksim Nicolaevich Sitnikov1, Lubov Victorovna
Udod2 and Dmitrii Anotol'evich Velicanov2
1
M.F. Reshetnev Siberian State Aerospace University, Russia
2
L.V. Kirensky Institute of Physics, Russia

The 19th International Conference on Magnetism

Hongpei Hong, Kailun Yao* and Guoying Gao
physics, Huazhong university of science and technology, China

A recent experimental study indicates that full-Heusler alloy Co2VGa exhibits halfmetallic ferromagnetism and the magnetic moment measured at 5 K is independentof high pressure up to 12.1 kbar (T. Kanomata et al Phys. Rev. B 82, 144415 (2010)).
Using the full potential linearized augmented plane-wave method, we here further
investigate the structural, electronic and magnetic properties of all possible (111)
surfaces of Co2VGa. Both structural relaxation and calculated surface energy revealthat Ga-terminated surface is more stable than other terminations. From the analysis of
the spin-polarized density of states, we find that the half-metallicity confirmed in bulk
Co2VGa is lost at Co-terminated surfaces but still maintained at V-terminated and Gaterminated surfaces. Moreover, the obtained magnetic moments show that the atomic
magnetic moments of the (111) surfaces are greatly different from the bulk values.

Valeria Rodionova1, Maxim Ilyn2, Valentina Zhukova2*, Alexander Granovsky3, Alexander
Aronin4, Galina Abrosimova4 and Arcady Zhukov5
1
Dpto. de Fisica de Materiales and Faculty of Physics, UPV/EHU San Sebastian, Lomonosov
Moscow State University and Immanuel Kant Baltic Federal University, Russia
2
Dpto. de Fisica de Materiales, UPV/EHU, Spain
3
Dpto. de Fisica de Materiales and Faculty of Physics, UPV/EHU, San Sebastian, Spain andLomonosov Moscow State University, Moscow, Russia
4
Insitute of solid State Physics, RAS, Chernogolovka, 142432, Moscow Region, Russia
5
Dpto. de Fis. Mater., UPV/EHU San Sebastian and IKERBASQUE, Basque Foundation for
Science, Bilbao, Spain

Studies of magnetic shape-memory alloys (MSMAs) attracted growing attention within last few years owing
to significant magnetic-field-induced strain (MFIS) useful for applications in actuators, sensors and for energy
harvesting. From point of view of applications, miniaturizing of MSMA-based devices based on small-size MSMA
materials is quite important. Main advantage of Ni-Mn-Ga Heusler-type microwires is related with composite
character, allowing production of long microwire from brittle Ni-Mn-Ga alloy. Consequently the aim of this paper
is to present results on Heusler-type Ni49.5Mn25.4Ga25.1 glass-coated microwires. We fabricated few metres long
microwire and measured magnetization, M, versus magnetic field, H, curves in as-prepared and annealed up to 790
K microwires. After annealing M(H) curves drastically changed: in as-prepared microwires magnetic transformation
appears around 175 K. The sample seems contain the second magnetic phase which orders at low temperature
giving rise to fast increase of the magnetization below 30 K. Meanwhile common ferromagnetic behaviour wasobserved at around 325 K for the annealed sample without any evidence of existence of second magnetic phase.
X-ray diffraction allows to detect significant structural changes after annealing. Obtained results are discussed taking
into account strong internal stresses induced by fabrication of composite microwires and high quenching rate.

July 13 (Fri)Minggang Zhu, Haibo Feng, Wei Li, Yikun Fang, Wenchen Zhang and Wei Pan
China Iron & Steel Research Institute Group, China

July 13 (Fri)poster Presentation

Kenji Kondo*, Hideo Kaiju and Akira Ishibashi
Laboratory of Quantum Electronics, Research Institute for Electronic Science, Japan

We have developed the theory of focused magneto-optic Kerr effect (MOKE) for
multilayer thin films and applied it to the surface magnetic properties, which have been
observed by focused MOKE, for Ni75Fe25 and Fe thin films evaporated on polyethylene
naphthalate (PEN) organic substrates. We have experimentally obtained the Ni75Fe25
thickness dependence of Kerr rotations for as-deposited thin films and exposed thinfilms at an atmosphere for 1-year, respectively. The theoretical thickness dependencesof Kerr rotations have been calculated using magneto-optic constants Q’s of 0.01*exp(- i 48π/180) and 0.025*exp (- i 57π/180), respectively. The calculated results are ingood agreement with the experimental data. Also, the Ni75Fe25 thin films exposed for
1-year show larger magnetization than the as-deposited Ni75Fe25 thin films in the rangeof 1-20 nm. We consider that the reason is that the surface of Ni75Fe25 has transformed
to locally Fe-rich surface because of the segregation of Fe. We have also measured theKerr rotations of Fe deposited on PEN. The Q of Fe/PEN was 0.025*exp (- i 47π/180).
To our knowledge, the magneto-optic constants have been estimated for ferromagnetic
thin films on PEN for the first time.

July 8-13, 2012 Busan, Korea

367

poster Presentation
SO08

SO11

SO14

SO17

The structural and magnetic properties of the magneto-caloric
compounds Mn0.66Fe1.29P1-xSix (x = 0.34, 0.37 and 0.42)

Elastic anisotropy in ferromagnetic shape memory alloy of nonstoichiometric Ni2MnGa1-xInx

Magnetic properties of Cu70.9Al18.1Mn11 ferromagnetic shape memory
alloy

Magnetorefractive effect in manganites

The magneto-caloric effect (MCE) is the thermal response of a magnetic material to an applied magnetic
field, results in a change of temperature.[1,2] (Mn,Fe)2(P,Si) compounds are known for their potential forroom-temperature magnetic refrigeration, due to large MCE and tunable working temperatures, cheap
and abundant raw materials.[3] In this study, the single phase compounds Mn0.66Fe1.29P1-xSix (x = 0.34,
0.37 and 0.42) have been synthesized. The crystal and magnetic structure have been investigated bymeans of neutron and X-ray powder diffraction. The refinement shows the compounds crystallize in the
hexagonal Fe2P-type structure (P-62m). The 3f site is nearly completely occupied by Fe atoms, the 3g site
is occupied by Mn atoms and the excess Fe atoms, while the P and Si are randomly mixed. It is shownthat the average magnetic moment in the 3g site is larger than that in the 3f site, 2.64 versus 1.81 μB for
the compound with x = 0.34 at 10 K. The alignment of the magnetic moment has changed from almost
c-direction to a-b plane with increasing Si content from x = 0.34 to x = 0.42. The compounds show astrong magnetic field induced transition, small magnetic hysteresis and large magnetic entropy changes.

In magnetic shape memory (MSM) effect, the elastic and magnetocrystalline anisotropies
play an important role. Moreover, experiments reported an enhancement of the MSE
effect in a non-stoichiometric metallic compounds.[1] Here, in order to discuss a roleof the non-stoichiometry, we developed a method for determining elastic property of
non-stoichiometric compounds from first principles calculations and cluster expansion
method,[2] and applied to non-stoichiometric Ni2MnGa1-xInx. For calculations, first,
the formation energies of ordered structures as functions of volume V and c/a, ΔE_o(V,c/a), were calculated by using the FLAPW method.[3] Then, by using the cluster
expansion method, the formation energy of a disordered state with non-stoichiometriccompositions, ΔE_o(V,c/a), were obtained in terms of many-body correlation functions.
Elastic properties of the bulk modulus, B, and the elastic tetragonal anisotropy,
C’=(C_11-C_12)/2, were numerically obtained from the ΔE_d(V,c/a) of the disorderedstate. Results indicate that the B has an almost linear relation with respect to x. However,a deviation from stoichiometric composition is found to enhance the elastic tetragonal
anisotropy; e.g., for a non-stoichiometric composition of x=0.125, the C’ decreases by 0.4
GPa compared to that in x=0, and the C’ increases when the x increases over about 0.125.

[1] V.K. Pecharsky and K.A. Gschneidner, Phys. Rev. Lett. 78, 4494 (1997). [2] E. Bruck, J. Phys D: Appl. Phys. 38, p. R381-R391 (2005). [3] D. T.
Cam Thanh, E. Bruck, N. T. Trung, J. C. P. Klaasse, K. H. J. Buschow, Z.Q. Ou, O. Tegus and L. Caron, J. Appl. Phys. 103, 07B318 (2008)[1] R. Kainuma et al., Nature 439, 957 (2006). [2] J. W. D. Connolly and A. R. Williams, Phys. Rev.
B 59, R2486 (1998). [3] K. Nakamura, et al., Phys. Rev. B 67, 14405 (2003).

SO09

SO12

SO15

SO18

Faraday rotation characteristics in wide-gap magnetic semiconductor
ZnMnTe and ZnMnSe films

Structure and properties of double perovskite system La2Co1-xFexMnO6(x=0, 0.1, 0.2, 0.3)

Magnetic properties of dioxygen molecules confined in single-walledcarbon nanotubes

Electroresistance and joule heating effects in manganite thin films

Masaaki Imamura*
Electrical Engineering, Fukuoka Institute of Technology, Japan

II-VI based magnetic semiconductors with a wide optical band gap are expected toshow high potential for optical applications utilizing short wavelength laser diodes,
such as 532-nm green and 475-nm blue LDs [1]. ZnMnTe and ZnMnSe exhibit theirabsorption edges at 428-544 and 428-458 nm, respectively [2]. The edge is not so
influenced by the Mn concentration, as is typically observed in CdMnTe. We haveconfirmed that the Faraday rotation in the ZnMnTe films deposited on quartz glass
substrates is large near the absorption edge. Crystallinity was evaluated using an x-ray
diffractometer. The preferred (111) growth reported previously for CdMnTe films on
QG substrates was also observed in the ZnMnTe and ZnMnSe films with weaker peakintensities.This paper reports the Faraday rotation angle of those films synthesised on
QG substrates by using molecular beam epitaxy with a thickness of 2 μm. A Faradayeffect signal observed for the ZnMnTe film using a 532-nm green LD has shown that
ZnMnTe films are useful for green lights.We developed equipment for observing the
Faraday effect directly under ac magnetic fields generated by a ring magnet. The resultsof a direct Faraday rotation observation sucessfully made for the ZnMnTe films underac fields are shown.

Fumiya Kitanishi*, Kohji Nakamura, Toru Akiyama and Tomonori Ito
Mie University, Japan

The-tan Pham, Huyen-yen Pham and Nam-nhat Hoang*
Faculty of Technical Physics and Nanotechnology, Vietnam National University,
University of Engineering and Technology, Viet Nam

Insulating ferromagnets of type RE2AMnO6 where A is transition metal and RE rareearth have received a renewed interest. Although the bulk La2CoMnO6 has been
extensively studied, its Fe-doped possed several questions that should be addressed.
The substitution of Fe into the B site induced the increase in ferromagnetism at thecost of TC. It was also accompanied by a structure transition from orthorhombic tomonoclinic. The monoclinic crystal symmetry occurred in the space group P21/n,with cell parameters a = 5.532 A, b=5.492 A, c=7.784 A, beta = 89.92°. The magnetic
measurement showed that the magnetization reached maximum value of 4.7uB/ u.c.
This value agrees well with the theoretically expected value.

The ferromagnetic shape memory alloy (FSMA) of nominal composition
Cu70.9Mn11Al18.1 has been studied through electronic transport, dc magnetization andac susceptibility measurements. Unlike other Cu containing shape memory alloys,
Cu-Mn-Al systems of alloys show interesting magnetic behaviour. Ferromagnetismin Cu-Mn-Al alloys come from the Rudermann-Kittel-Kasuya-Yosida (RKKY) typeferromagnetic exchange interaction between Mn atoms. The studied alloy undergoes
ferromagnetic to glassy transition below martensitic transition (MT). Clear frequency
shift in ac susceptibility measurement is observed near the step like anomaly present in
the zero field cooled dc magnetization data, which actually indicates the onset of spinglass freezing in the sample. Isothermal magnetization (M) measurement as a functionof magnetic field (H) at 5K with field cooled condition (sample cooled in presence ofdifferent magnetic field) has been performed but no shift in M(H) loop is observed. It
indicates that no exchange pinning is originated in the sample due to field cooling.

Andrey Telegin*, Yurii Sukhorukov and Vladimir Bessonov
Institute of Metal Physics UD of RAS, Russia
We studied a magnetic-field-induced change in reflectivity (magnetoreflection) and transmission(magnetotransmission) of natural light in La1-xAxMnO3 (A=Ca,Sr,K,Ag) manganites possessed the colossal
magnetoresistance effect (CMR)[1-3]. It was showed the magnetoreflection and magnetotransmission
effects in manganites are an optical response to the CMR in the IR-region. Effects can reach tens ofpercents in the field of 0.3-1 T near the magnetic phase transition temperature. The observed phenomena
are connected with the change of ratio between the localized and delocalized charge carriers under themagnetic field applied [2]. At the same time, there is no strict correlation between these effects and CMR
in the visible range. The observed phenomena are connected with the alteration of the optical density
under the magnetic field in the range of interband transitions [3]. Magnitude of effects is one order as lessas that in the IR-region. The nature of observed effects in manganites can be satisfactory explained within
the framework of the theory of magnetorefractive effect [4]. The results of study of magnetoreflection andmagnetotransmission in manganites may be proposed for creation of different magnetic and electronic
sensors and light modulators.
[1] Yu.P. Sukhorukov, A.V. Telegin, A.B. Granovsky et al., J. of Experimental and Theoretical Physics, 138, No 3, 402 (2010). [2] A.B.
Granovskii, Yu.P. Sukhorukov, A.V. Telegin et al, J. of Experimental and Theoretical Physics, 112, No1, 77 (2011) [3] Yu.P. Sukhorukov, A.V.
Telegin, A.B. Granovsky et al, J. of Experimental and Theoretical Physics, 141, No1, 160 (2012) [4] Yurasov A.N., Bakhvalova T.N., Telegin A.V.
et al, Abstracts of the 20th International Conference on Soft magnetic materials SMM-2011, Greece, 18-22 September, p.244
Supported by the program of DPS RAS “Physics of new materials and structures”, grant MK-1048.2012.2 and RFBR grants No
10-02-00038, 11-02-00252, 12-02-00208

Yusuke Nakai 1*, Shin Tadera 1, Haruka Kyakuno 1, Keitaro Harada 1, Kazuyuki
Matsuda2, Kazuhiro Yanagi1 and Yutaka Maniwa1
1
Department of Physics, Graduate School of Science, Tokyo Metropolitan University,Japan
2
Faculty of Engineering, Kanagawa University, Japan
Materials confined in quasi-1D single-walled carbon nanotubes (SWCNTs) exhibits uniqueproperties that differ from the bulk counterparts [1]. Among many kinds of intercalates, a
dioxygen molecule (O2), which has a spin S = 1 in the ground state, confined in SWCNTs
may offer well-defined environment to investigate the physics of a quasi-1D spin-1 magnet.
We present magnetic susceptibility and x-ray diffraction measurements as well as theoreticalsimulations on the dioxygen molecules confined in SWCNTs. Our XRD measurements
confirmed that the O2 molecules are absorbed inside the SWCNTs at low temperatures. Our
magnetic susceptibility data shows the signature of the opening of a gap in spin excitations at
low temperatures, which differs from bulk O2 molecules. We interpret this result in terms of 1D
antiferromagnets with S = 1, which is supported by our first-principles calculation suggestingthat an isolated O2 molecule inside a SWCNT of over 0.8 nm in diameter possess a spin S = 1.
We will also discuss the condensed structure of O2 inside SWCNTs on the basis of our XRD
data and molecular dynamics simulations [2].

Luis Pena, Regina Galceran, Zorica Konstantinovic, Alberto Pomar, Bernat Bozzo,
Lluis Balcells, Felip Sandiumenge and Benjamin Martinez*
Magnetic Materials and Functional Oxides, ICMAB - CSIC, Spain
Electroresistance (ER), i.e. electric field- and/or current-induced resistance switching,has attracted much attention recently because of the possibility of using it for the
implementation of resistance random access memories (ReRAM). Although ER isa quite common phenomenon in transition metal oxides, that has been extensively
studied both theoretically and experimentally, the precise mechanism involved is notclear yet. In this work we report on the ER measurements in patterned La2/3Sr2/3MnO3(LSMO) thin films prepared by sputtering. In order to analyze Joule heating effects
we have evaporated a Pt layer on top of the LSMO path to have access to theactual temperature of the sample while measuring resistance of LSMO path or I(V)characteristic curves. I(V) curves have been measured at different temperatures and thecorresponding resistance values are compared with that of the R(T) curve taking into
account the actual temperature of the sample in order to clarify the role of Joule heatingin the observed change of the resistance.

[1] Y. Maniwa et al., Chem. Phys. Lett. 401 (2005) 534. [2] K. Hanami et al., J. Phys. Soc. Jpn. 79(2010) 023601.

[1] M. Imamura et al., IEEE Trans. Magn. 42, 3078 (2006). [2] M. Imamura et al., J.Appl.Phys. 99,
08M706 (2006).

SO10

SO13

SO16

SO19

Magnetism and multiplets in Fe-phthalocyanine molecules

Density-functional study on spin-crossover in several Fe-based
molecules

Magneto-elastic coupling and magnetocaloric effect in Fe2P-based MnFe-P-Si compounds

Magnetocaloric effect and other properties of cold rolled Gd ribbons

Spin crossover (SCO) complexes are now very potential candidates for applications
such as molecular switches, display and memory devices [1]. The SCO phenomenon
can be qualitatively explained by the ligand field model, however, designing transition
metal complexes with expected SCO behavior is still a big challenge in the field ofmaterials science. In this paper, in order to explore more about the way to control
SCO behavior of transition metal complexes, we present a density functional study
on the geometric structure, electronic structure and SCO of a series of eight Fe-based
molecules [2-7]. Our calculated results show that SCO in these Fe-based molecules
is accompanied with charge transfer between the Fe atom and ligands. This causeschange in the electrostatic energy (ΔU) as well as the total electronic energy of thesemolecules. Moreover, our calculated results demonstrate an important contribution of
the interionic interactions to ΔU, and there is the relation between ΔU and the thermal
hysteresis behavior of SCO in these molecules. These results should be helpful fordeveloping new SCO molecules.

Structural, magnetic and magnetocaloric properties of Fe2P-based Mn-Fe-P-Si
compounds were investigated. The study reveals a strong magneto-elastic coupling thatstarts to develop in the paramagnetic state and grows when the ferromagnetic transition
temperature is approached. This magneto-elastic coupling over a large temperature
range around the transition temperature results in a first-order phase transition withabrupt changes in lattice parameters. Moreover, a correlation is observed between thehysteresis and the discontinuous changes in lattice parameters at the transition. The
gradual development of the magneto-elastic coupling near the transition temperature,
which is attributed to competition between moment formation and bonding [1],contributes to a reduced hysteresis. We also show the thermal evolution of the magnetic
moments. Interestingly, the magnetic moments on the 3f site are formed and gradually
increase in the paramagnetic state, and suddenly jump to a larger value when magnetic
order is established.

Yukie Kitaoka1*, Kohji Nakamura1, Toru Akiyama1, Tomonori Ito1, Michael Weinert2
and Arthur J. Freeman3
1
Mie University, Japan
2
University of Wisconsin-Milwaukee, USA
3
Northwestern University, USA
A challenge to miniaturize devices for novel magnetic application now extends to treating theextreme limit of a single atom or molecule. Moreover, for molecules with transition-metals,
multiplets are essential aspects of their electronic structure. It is often difficult, however, toevaluate such multiplets within a given ligand (or crystal) symmetry. Here, we carry out firstprinciples calculations with the FLAPW method[1] for Fe-phthalocyanine (FePc), in which
the multiplets are treated by imposing a density matrix constraint on the d-orbital occupation
numbers. Results predict that there are three stationary multiplets - ³Eg (d²xy, d²z2, d³xz+yz),³B2g (dxy, dz2, d4xz+yz), and ³A2g (d²xy, d²z2, d²xz+yz) - in a single FePc molecule, and totalenergy calculations demonstrate that the ground state is the ³A2g. Furthermore, a columnar
stacking of the FePc molecules (as seen in α-FePc) changes the ground state to ³Eg due tohybridization between adjacent molecules. In qualitative agreement with recent XMCD
experiments[2], the magnetic anisotropy energy for the columnar stacking structure has a large
negative value of 0.6 meV/molecule, indicating that the magnetization favors pointing in theplanar direction, and a large orbital moment of 0.14 μB is induced.
[1] Wimmer, Krakauer, Weinert, Freeman, PRB 24, 864 (1981); Weinert, Wimmer, Freeman, PRB 26, 4571 (1982). [2]Bartolome, Garcia, Filoti, Gredig, Colesniuc, Schuller, Cezar, Phys. Rev. B 81, 195405 (2010).

368

S Chatterjee1, S Giri2 and S Majumdar2*
1
UGC-DAE Consortium for Scientific Research, Kolkata Centre, India
2
Department of Solid State Physics, Indian Association for the Cultivation of Science,
India

The 19th International Conference on Magnetism

July 13 (Fri)Zhiqiang Ou1*, L. Zhang1, N.h. Dung1, L. Van Eijck2, M. Avdeev3, A.m. Mulders4 and E. Bruck1
1
FAME Section, R3, Faculty of Applied Sciences, Delft University of Technology, Netherlands
2
NPM2 Section, R3, Faculty of Applied Sciences, Delft University of Technology, Netherlands
3
Australian Nuclear Science and Technology Organisation,Locked Bag 2001, Kirrawee DC NSW 2232,
Australia
4
School of Physical, Environmental and Mathematical Sciences, UNSW in Canberra, ACT 2610, Australia

July 13 (Fri)poster Presentation

Tuan Anh Nguyen* and Thanh Van Nguyen
Faculty of Physics, Hanoi University of Science, Viet Nam[1]. H. A. Goodwin, et.al., Top. Curr. Chem. 233, 1 (2004). [2]. Nicolas Moliner, et.al., Inorganica Chimica
Acta, 291, 279 (1999). [3]. B. Weber, W. Bauer, J. Obel, Angew. Chem. Int. Ed. 47, 10098 (2008). [4]. Gaelle
Dupouy, et.al., Inorg. Chem., 47, 8921 (2008). [5]. B. Weber, et.al., Inorg. Chem. 47, 487 (2008). [6]. B. Weber,et.al., Eur. J. Inorg. Chem. 4891 (2008). [7]. B. Weber, et.al., Eur. J. Inorg. Chem. 5527 (2009).

N. H. Dung1*, L. Zhang2, Z. Q. Ou1 and E. Bruck1
1
Delft University of Technology, Netherlands
2
BASF Netherlands B.V & Delft University of Technology, Netherlands[1] N. H. Dung, Z. Q. Ou, L. Caron, L. Zhang, D. T. Cam Thanh, G. A. de Wijs, R. A. de Groot, K. H.
J. Buschow, E. Bruck, Adv. Energy Mater. 1, 1215 (2011).

Sergey V. Taskaev1, Vasiliy D. Buchelnikov1, Igor V. Bychkov1, Anatoliy P. Pelennen2, Oliver Gutfleisch3,
Konstantin P. Skokov4, Vladimir V. Khovaylo5, Victor V. Koledov6 and Vladimir G. Shavrov6
1
Physics department, Chelyabinsk State University, Chelyabinsk, Russia
2South-Ural State University, Chelyabinsk, Russia
3
Technische Universitat Darmstadt, Darmstadt, Germany
4
IFW, Dresden, Germany
5
MISIS, Moscow, Russia
6
IRE RAS, Moscow, Russia

The number of papers devoted to magnetic refrigeration, magnetocaloric materials and high-field magnetic
systems has grown at an exponential rate in the past 10 years (K.A. Gschneidner et al., 2008) [1]. Since FirstInternational Conference on Magnetic Refrigeration at Room Temperature many researches in different countries
mobilize their efforts in the field of constructing commercial magnetic refrigerator. There are numerous different
magnetocaloric alloys such as La-Fe-Si, Gd-Si-Ge, Ni-Mn-X (X = Ga, In, Sn, Sb) [2-3]. Usually the magnetic
refrigerant materials are either packed in a magnetocaloric bed as small spheres attached around a disk as a ribbon
or separated in a pile of thin, equally spaced sheets. Thus one the ways of engineering MCE materials is tightly
connected with preparing very thin (a few microns) ribbons of high value MCE alloys with good mechanicalproperties. At present rapid solidification is the main technique for producing this kind of materials [4]. In ourwork we investigate magnetocaloric effect, magnetic and mechanical properties of Gd cold rolled samples ofdifferent thickness. Both theoretical and experimental aspects of the investigation are discussed.
1. Gschneidner K.A. Jr. et al. Thirty years of near room temperature magnetic cooling: Where we are today and future prospects, Int. J. Refrig, 31, 945 (2008).
2. A. Planes, L. Manosa, and M. Acet, J. Phys.: Condens. Matter 21, 233201 (2009). 3. X. Moya, L. Manosa, A. Planes, S. Aksoy, M. Acet, E. Wassermann, and
T. Krenke, Phys. Rev. B. 75, 184412 (2007). 4. P. M. Shan et al. Magnetic behavior of melt-spun gadolinium, Phys. Rev. B. 77, 184415 (2008).

July 8-13, 2012 Busan, Korea

369

poster Presentation
SO20

SO23

SO26

SO29

Fabrication and properties of double perovskite SrLaVRuO6

Magnetic properties and magnetocaloric effect in shape memory alloys
Ni-Mn-Ga

Balance between the growth rate of ferromagnetic phase anddemagnetizing fields in itinerant electron metamagnetic transition of
La(Fe0.88Si0.12)13

Electronic structure calculations and the magnetic properties of
Ru2FeZ (Z = Al and Ga)

Hitomi Yako* and Asaya Fujita
Tohoku university, Japan

Ramesh Kumar K and Thamizhavel A*
Department of Condensed Matter Physics and Materials Science, Tata Institute ofFundamental Research Mumbai 400005, India

Strong interplay between an itinerant electron metamagnetic (IEM) transition andmagnetocaloric effects in NaZn13-type La(FexSi1-x)13 has been investigated.[1-3] Recently,
we have demonstrated that progress of the IEM transition is influenced by the demagnetization
effect in La(Fe0.88Si0.12)13.[4] Especially, the progress is arrested in midstream even under themagnetic fields, μH larger than the critical value, μHc by setting longitudinal direction of thesample perpendicular to the field direction ( θ = 90 degrees ). In the present study, the angulardependence of the transition progress is examined and the influence of demagnetization effecton the IEM transition is discussed. The time-dependent magnetization measurements werecarried out at 200 K under the constant value of μH by changing θ from 0 to 90 degrees. The
transition starts to proceed under the magnetic field larger than μHs. However, the transitionis arrested in midstream, and the completion of transition emerges only after μHc exceeds thethreshold value, μHt. The values of μHs and μHt are evaluated to be 0.60 and 0.75 T for θ =30 degrees and 0.70 and 1.00 T for 90 degrees, respectively. The growth rate of ferromagnetic
phase is dominated by keeping the balance with demagnetizing fields.

After the discovery of half-metallic character in NiMnSb by de Groot et al. Heusler
alloys have drawn much attention due to the possible application in magneto-electronic
devices [1,2]. In the quest of finding half-metallic character in 4d transition element
based Heusler alloy we present the electronic structure and magnetic properties
of Ru2FeGa/Al. The band structure calculations were done using the state-of-theart density functional technique with the PWSCF code [3]. The equilibrium lattice
parameter was found by fitting energy vs volume data to the Murghnan equation ofstate. At the equilibrium lattice parameter the total energy difference between the nonmagnetic state and ferromagnetic state was observed to be of the order of 5 meV whichsuggest that these systems are having stable magnetic ground state. In ferromagnetic
ground state the lattice parameter was observed to be 5.988 A for Ru2FeGa and 5.982
A for Ru2FeAl. From the DOS Vs Energy diagram it is found that the systems are nothalf-metallic in nature. However, the calculation showed very high spin polarization at
the Fermi level. The spin polarization (P) value was found to be 83 % in both the cases.

Half-metallic antiferromagnets (HMAF) exhibiting both fully spin-polarized chargetransport and zero net magnetic moment are expected to provide not only a fertile
playground for fundamental research but also new spintronic devices. Although thetheoretical calculations predicted candidates for HMAFs, experimental searches for
HMAFs have so far been unsuccessful. This paper reports on the fabrication andproperties of SrLaVRuO6 polycrystalline bulks and epitaxial films. SrLaVRuO6 bulks
were synthesized by a solid-state reaction at 1100~1350 °C in Ar + (0~3) % H2 gas.
Structural characterization revealed that the main phase of the bulk samples was ofa double perovskite crystal structure with lattice parameters of 0.7888~0.7905 nm.
However, all the bulks contained the impurity phase (Sr3V2O8), which is a nonmagnetic
semiconductor. The bulks exhibited magnetization values of 10-3 μB per formula unit
at 77 K, negative paramagnetic Curie temperature values and metallic temperaturedependence of the resistivity. These properties are assumed to be intrinsic to double
perovskite SrLaVRuO6 by considering the nonmagnetic semiconducting nature ofSr3V2O8. Moreover, SrLaVRuO6 thin films were prepared on LaAlO3, SrTiO3 (001)substrates by magnetron sputtering. Structural characterization revealed that these thinfilms were grown epitaxially on these substrates, and phase pure double perovskite.

Rafael Fayzullin, Vasiliy Buchelnikov, Sergey Taskaev and Mikhail Drobosyuk
Chelyabinsk State University, Russia

The magnetocaloric effect (MCE) is the ability of magnetic materials to heat up or
cool down when placed in or removed from an external magnetic field. The magnetic
materials with large values of MCE can be applied in the magnetic refrigeration
technique [1]. Recent experimental studies have shown that Ni-Mn-Ga Heusler alloys arealso attractive for the application in magnetic refrigeration [2]. In this work the magnetic
and magnetocaloric properties of the ferromagnetic shape memory alloys Ni2+xMn1xGa (x=0.07; 0.08; 0.09) were experimentally studied. The MCE measurements were
performed by the setup produced by AMT&C [3]. In this setup, the adiabatic temperaturechange ΔTad was measured by a direct method with help of a thermocouple. Magnetic
field up to 2 T was created by Halbach permanent magnet. The magnetic field strength
was measured by Hall probe. Signals from the thermocouple and Hall probe wererecorded simultaneously what allowed us to measure ΔTad as a function of magnetic field
H. All alloys exhibit the positive MCE typical near the second-order phase. Our MCE
measurements of Ni2+xMn1-xGa have shown that the maximal MCE is observed near theCurie point. The maximal values of MCE are 1.2 - 1.6 K near the room temperature.

J. H. Park, S. K. Kwon, and B. I. Min, Phys. Rev. B 65 (2002) 174401.

[1] K. Gschneidner, Jr. and V.K. Pecharsky, Int. J. Refrig., 31 (2008) 945. [2] A. Planes, L. Manosa,
and M. Acet, J. Phys.: Condens. Matter. 21 (2009) 233201. [3] Y.I. Spichkin, et al, Proc. 3rd IIF-IIR
Intern. Conf. Magnetic Refrigeration at Room Temperature, IIF/IIR (2009) 173.

[1] A. Fujita et al., J. Appl. Phys., 85, 4756-4758, ( 1999 ). [2] F. X. Hu et al., Appl. Phys. Lett., 78, 3675-3677, ( 2001 ). [3] O.
Gutfleisch et al., J. Appl. Phys., 97, 10M305:1-10M305:3, ( 2005 ). [4] H. Yako et al., IEEE Trans, Mag., 47, 2482-2485, ( 2011 ).

1. R. A. de Groot, F. M. Mueller, P. G. van Engen and K.H. J. Buschow , Phys. Rev. Lett. 50 2024
(1983). 2. C. Felser, G. H. Fecher, and B. Balke Angew. Chem. Int. Ed., 46 688 (2007). 3. S. Baroni
et al http://www.pwscf.org/

SO21

SO24

SO27

SO30

Giant magnetoresistive effect in non-magnetic silicon

Magnetic susceptibility avalanches in thermally-induced first-orderphase transition of La(Fe0.88Si0.12)13 magnetocaloric compound

Temperature dependent structural and magnetic properties of Ni-MnIn Heusler alloy glass-coated microwires

Disorder effects in giant magnetocaloric materials

Tae Ho Lee1, Hong-seok Kim1, Woo Lee2 and Yong-joo Doh1*
1
Dept. of Display and Semiconductor Physics, Korea University Sejong Campus,
Korea
2
Korea Research Institute of Standards and Science, Korea
Recently magnetoresistive effects in non-magnetic semiconductors, particularly
silicon, have gained considerable attention owing to the large magnitude of the effect,
which is comparable, or even larger than, that of the performance of commercial
giant-magnetoresistance devices. The underlying mechanism responsible for the giant
magnetoresistance in silicon, however, has not yet been fully explored. Here we reportthat a simple device, based on a lightly doped silicon substrate contacted with two
indium contacts, shows a positive magnetoresistance over 10,000 per cent for magnetic
fields between 0 and 1 T at low temperature of 3 K. Current-voltage characteristics
exhibit a nonlinear behavior, which is highly sensitive to temperature and magnetic
field. We have extensively studied magnetoresistive effect in silicon with varying bias
voltage, temperature, electrode spacing, and the relative angle between the substrate
and the applied magnetic field. Since our device is based on a conventional silicon
platform and is highly sensitive to low magnetic field, it could be used to develop new
devices of silicon-based magnetoelectronics.

Asaya Fujita* and Hitomi Yako
Department of Materials Science, Tohoku University, Japan

Magnetic materials with large magnetocaloric effects due to the first-order phase transition
attract attention as candidates for room temperature magnetic refrigerants. NaZn13type La(FexSi1-x)13 compounds exhibit thermally-induced first-order ferromagnetic (F) paramagnetic (P) transition at the Curie temperature Tc and the itinerant-electron metamagnetictransition takes place above Tc [1]. Evolution of the transition determines the operating speedof magnetic refrigeration, therefore, a detailed observation is necessary. In the present study,
appearance of the avalanche behavior [2] in the progress of thermally-induced transition has
been examined by measuring the magnetic susceptibility χ. The value of χ upon cooling at
0.4 K / min. exhibits a smooth variation across the transition and its first derivative, dχ/dT,shows no jerky change. Meanwhile, the avalanche-like behavior is observed in dχ/dT aroundTc upon heating. Furthermore, the number and height of avalanches are dramatically changed
by external magnetic fields. Generally, the avalanche behavior is induced by the quencheddisorders, however, such a mechanism can not explain the influence of magnetic field.
Considering the fact that the kinetics of the transition is influenced by the demagnetization
effect [3], these results indicate that the nucleation- growth behavior is affected by the magnetic
dipole interaction.
[1] A. Fujita, S. Fujieda, Y. Hasegawa, K. Fukamichi: Phys. Rev. B 67 (2003), 104416. [2] E. Vives, J. Ortin, L. Manosa, I. Rafols, R. Perez-Magrane, A.
Planes: Phys. Rev. Lett. 72 (1994), 1694. [3] H. Yako, S. Fujieda, A. Fujita, K. Fukamichi: IEEE Trans. Magn. 47 (2011), 2482.

Magnetic shape-memory alloys (MSMAs) attracted growing attention owing to shape memory effect, originated from thecoupling between magnetic and structural ordering. From point of view of technological applications, miniaturizing of MSMAbased devices using MSMA particles, wires, ribbons, films, bi- and multilayers, pillars is quite important. Here we report on
studies of magnetic properties of non-stoichiometric Heusler-type Ni50Mn34.5In15.5, Ni48Co2Mn35In15 and Ni49.5Mn25.4Ga25.1 glasscoated microwires prepared using Taylor-Ulitovsky technique. The principle interest in glass-coated microwires is relatedwith their composite character allowing to control the strength of internal stresses. We measured magnetization curves atdifferent temperatures. As-prepared microwires did not show ferromagnetic ordering at room temperature. From temperaturedependence of magnetization we found that annealed microwires showed Curie temperature about 270 K (Ni50Mn34.5In15.5
microwires), between 225K and 240 K (Ni48Co2Mn35In15 microwires with different metallic nucleus diameters) and 315 K for
Ni49.5Mn25.4Ga25.1. Microwires Ni50Mn34.5In15.5, Ni48Co2Mn35In15 and Ni49.5Mn25.4Ga25.1 exhibited phase transition at 240 K, 115
K and 300 K respectively. From point of view of applications the most promising properties exhibit thinnest Ni49.5Mn25.4Ga25.1
microwire (with metallic nucleus diameter 10,4 mkm and total diameter of 16 mkm) showing the phase transition near Curie
temperature.

Joao S Amaral*, Soma Das and Vitor S Amaral
CICECO and Dept. of Physics, Universidade de Aveiro, Portugal
In striving for mass production of magnetocaloric materials for refrigeration applications, one
has to face the fact that these will not be laboratory-grade materials, and will necessarily present
composition gradients due to lower quality reagents. Some consequences are expected: themaximum value of magnetic entropy change (ΔSM) should decrease compared to a “pure”
material, and broadening of the ΔSM(T) curves, as observed in elementary ferromagnets [1].
Some theoretical work has focused on this topic, for second-order phase transition systems [25]. Still, these theoretical considerations do not directly apply to giant magnetocaloric materials.
We present a study on the effect of disorder on the magnetic and magnetocaloric propertiesof first-order phase transition systems, via the use of the Bean-Rodbell [6] model. Disorder isshown to “smooth” the discontinuities on magnetization and ΔSM, and also affect magnetic
hysteresis. For sufficiently large disorder, the ΔSM(T) curves resemble the distribution function.
We discuss how the magnetic field dependence of ΔSM is affected by disorder, in light of a“second-order like” dependence of ΔSM on applied magnetic field, for disordered LaFeSi
samples [5]. Aging effects on hydrogenated LaFeSi samples, that degrade even in storage [7],are discussed taking into account our theoretical simulations.
[1] Gschneidner Jr. K. A., Pecharsky V. K., Tsokol A. O., 2005, Rep. Prog. Phys. 58 1479. [2] Romanov A. Y., V. P.
Silin V. P., 1997, Phys. Met. Metallogr. 83, 111. [3] Amaral J. S. et al., 2008, J. Non-Cryst. Solids 354, 5301. [4]Bahl C. R. H., et al., 2011, J. Magn. Magn. Mat. 324 564. [5] Lyubina J. et al., 2011 Phys. Rev. B. 83 012403. [6]Bean C. P., Rodbell D. S., 1962, Phys. Rev. 126 104. [7] Barcza, A. et al., 2011, IEEE Trans. Magn. 47 3391.

SO22

SO25

SO28

SO31

Effect of Fe substitution on Ni-Mn-In shape memory alloys: Magnetic
and magneto-structural properties

Phase coexistence and magnetocaloric effect on martensitic transitionin Ni-Co-Mn-Sn metamagnetic shape memory alloy

Magnetooptical Kerr effect enhancement in Co/TiO2 layered films

On the Curie temperature dependency of the Magnetocaloric effectRadha S1, Ashwin Mohan2 and A. K. Nigam2*
1
Department of Physics, University of Mumbai, India
2
Department of Condensed Matter Physics and Materials Science, Tata Institute ofFundamental Research, India
The Ni-Mn based ferromagnetic shape memory alloys have been extensively investigated for theirmultifunctional properties emerging by suitable chemical substitutions. The off-stoichiometric Ni50Mn25+xIn25-x
exhibit martensitic transition for In concentration in the range 13-16 at%. In the Ni50Mn35In15 alloy, theferromagnetic transition occurs at Curie temperature TC = 305 K with a concommitant austenite to martensitic
transition. A large inverse magnetocaloric effect and anomalous magnetic behavior have earlier been reported
for this alloy [1]. The present work reports the effect of Fe-substitution (0.5 to 2 at%) on the magneto-structuraltransition and magnetic behavior of the Ni50Mn35In15 alloy. The martensitic transition goes down to 255 K for
1at% Fe alloy with strong hysteresis between zero field-cooled (ZFC) and field-cooled (FC) data while it nearly
disappears for the 2at% Fe alloy. The 0.5 at% Fe substituted alloy shows a temperature dependent field-induced
metamagnetic transition between 250-220K while this transition is not observed up to fields of 6T in 1at% Fe
substituted alloy. A thermal hysteresis in the temperature dependence of resistance is observed between heating
and cooling cycles due to austenitic-martensitic transitions up to 1 at% Fe substitution. The substitution of 2 at%
Fe suppresses the martensitic transition without affecting the ferromagnetic transition.
[1] P.A. Bhobe, K.R. Priolkar and A.K. Nigam, Appl. Phys. Lett. 91 (2007) 242503

370

Valeria Rodionova1*, Mikhail Ipatov2, Maxim Ilyn3, Valentina Zhukova4, Alexander Granovsky5 and Arcady Zhukov6
1
I. Kant Baltic Federal University, UPV/EHU, Lomonosov Moscow State University, Russia
2
UPV/EHU, Spain
3
Centro de Fisica de Materiales, CSIC/UPV, Spain
4
Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, Spain
5
Lomonosov Moscow State University, IKERBASQUE, Basque Foundation for Science, Russia
6
Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU,IKERBASQUE, Basque Foundation for Science, Spain

The 19th International Conference on Magnetism

Bo Gao1*, Wen Guan1, Yu Wang1, Sen Yang1, Xiaoping Song1, Fengxia Hu2, Jirong Sun2 andBaogen Shen2
1
MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an
Jiaotong University, China
2State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, China
Since the discovery of the metamagnetic shape memory effect in Ni45Co5Mn36.7In13.3 Heusler alloys [1], a memberof studies on magnetocaloric effect (MCE) have been made in metamagnetic shape memory alloys. It is foundthat metamagnetic shape memory alloys exhibit large MCE in the vicinity of martensitic transformation. But for
the first-order transition, whether and to what extent the Maxwell relation is applicable are problems requiring
further study [2]. In this paper, we will discuss the appropriate approach to evaluate the MCE in Ni-Co-MnSn alloys. The energy dispersive spectrometer shows that the sample composition is Ni43.2Co3.1Mn41.8Sn11.9. The
thermo-magnetic curves indicate the martensitic transformation can be driven by the magnetic field. It is observedthat metamagnetic transition takes place in a wide temperature range from the magnetization isotherms. The
entropy change calculated by Maxwell relation is up to 30J/kgK under a field change of 0-5T. Meanwhile, we
calculated the entropy change based on heat capacity measured under 0 and 5T, and an entropy change of ~3J/
kgK is obtained for a field change of 0-5T. According to the different results from magnetic and calorimetricmeasurements, we find that the Maxwell relation should be used with caution on martensitic transformation
including phase coexistence.
[1] R. Kainuma, Y. Imano, W. Ito, Y. Sutou, H. Morito, S. Okamoto, O. Kitakami, K. Oikawa, A. Fujita, T. Kanomata, and K. Ishida, Nature 439, 957 (2006)[2] G. J. Liu, J. R. Sun, J. Shen, B. Gao, H. W. Zhang, F. X. Hu, and B. G. Shen, Appl. Phys. Lett. 90, 032507 (2007)

July 13 (Fri)

Ryosuke Zenzai*, Tetsuya Miyawaki, Kenji Ueda and Hidefumi Asano
Crystalline Materials Science, Nagoya University, Japan

July 13 (Fri)poster Presentation

Victor Polyakov1, Konstantin Patrin1, Klaudia Polyakova1*, Vitaly Seredkin1 andGennady Patrin2
1
L.V. Kirensky Institute of Physics, SB RAS, Russia
2
Siberian Federal University, Russia

Joao H Belo1, Joao S Amaral2*, Andre M Pereira1, Soma Das2, Vitor S Amaral2 andJoao P Araujo1
1
IFIMUP and IN, Dept. de Fisica e Astronomia, FCUP, 4169-007 Porto, Portugal
2
CICECO and Dept. of Physics, Universidade de Aveiro, Portugal

As is known, the magneto-optical properties of the composite metal-dielectric systems
are determined by the volume of a magnetic phase and the properties of a dielectric
matrix or dielectric layers. Of special interest are the magneto-optical properties of thecomposite films containing TiO2 whose permittivity is higher as compared to SiO2 andAl2O3. Here, we report the results of the magneto-optical study of Co/TiO2 multilayers.
Particularly we studied spectral dependence of the polar Kerr effect of Co / TiO2
layered structure of with various number of layers. The composite Co/TiO2 periodic
structures consisting of 2--12 pairs of layers (n) were prepared by sequential depositionof Co and titanium oxide by ion-plasma sputtering and reactive ion-plasma sputtering,
respectively, onto glass substrates. The respective thicknesses of magnetic and titaniumoxide layers were 5 and 17 nm. Study of spectral dependence of polar Kerr effectshowed that the spectra of the Co/TiO2 layered structures are resonance, with the large
growth of the angle of rotation near the resonance. The maximum angle of rotation
nonmonotonically depends on the number of layers. The maximum Kerr rotation angle(2θk=7.3 deg) observed at a wavelength of 540 nm corresponds to n = 8.

A theoretical study of the magnetcaloric effect dependency on simple ferromagnetic
microscopic parameters is here presented. Considering the Bean-Rodbell model [1] ofmagnetovolume coupling within the Weiss mean field theory, the magnetic entropy changeof systems undergoing first and second order magnetic phase transition was numericallysimulated. Through these simulations, the magnetic entropy change behavior was studied asa function of: Tc , spin value, applied field changes and the nature of the transition considered.
The main result found for both first and second order magnetic transitions systems is the linear
dependency of the ΔSM(T) maximum value on Tc2/3 . By starting from the magnetization mean
field state equation an approximated expression for the magnetic entropy change as a functionof microscopic magnetic parameters was reached, confirming the Tc2/3 dependency. We havefound that many ferromagnetic systems, both undergoing second (GdTbCo [2], RR’Al [3] (R =rare earth), RCoMn [4]) and first-order (MnFePAs [5], GdSiGe [7], RCo [7]) phase transitions,obey this relation between the magnetocaloric effect and Tc.
[1] Bean C. P., Rodbell D. S., 1962, Phys. Rev. 126 104. [2] K. Zhou et al. Solid State Commun. 137,
275 (2006). [3] N. Duc, D. Anh, and P. Brommer, Physica B - Cond. Matter 319, 1 (2002). [4] A. K.
Pathak et al., J. Magn. Magn. Mater. 323, 2436 (2011). [5] O. Tegus et al., Physica B - Cond. Matter
319, 174 (2002). [6] K. A. Gschneidner, V. K. Pecharsky, and A. O. Tsokol, Rep. Prog. Phys. 68, 1479
(2005). [7] N. Duc, D. Anh, and P. Brommer, Physica B - Cond. Matter 319, 1 (2002).

July 8-13, 2012 Busan, Korea

371

Author Index

Author Index

Author IndexA

374

Akama, Takamitsu

PG07

143

Amaral, Vitor S.

KB06

108

Arai, Hiroko

RJ06, SI16

283, 348

Akatsu, Mitsuhiro

RB05, RD07

254, 263

SA11
IA02, PI06, QB22318
90, 151, 190

Arai, Masatoshi

DA01, RH12

56, 276

Arakawa, Akira

SL02

356

Abbamonte, P.

PH10

148

Akatsuka, Hiroyuki

PB34

125

Amarande, L.
Amato, Alex

Abbasian Arani, A. A.

PO30

182

Akbari, Alireza

PD06

132

Amemiya, Kenta

BH06

47

Arakawa, Naoya

SE04

333

Abbasian Arani, Ali Akbar

PO28

181

Akdogan, Ozan

CB05, KB04

49, 108

Amitsuka, Hiroshi

PD07, QC25, SE07

133, 196, 334

Araki, Koji

RB05

254

Abdel - Hafiez, M.

QF22

207

Akerman, Johan

CE01, CE02, PK13

51, 162

Amyan, Adham

QA11, QJ11

184, 222

Araki, Shingo

HC02, PE15, QC18, SE1084, 138, 195, 334

Abdul Ahad, Faris B.

RK07

287

Akerman, Johanna

KE01

110

Analytis, James

HA05

84

Araki, Yusuke

QJ12

222

Abdullah, Nor Hapishah

BJ06

48

Akhavan, M.

QP23

249

Anand, Vivek Kumar

QB14

189

Aramberri, Hugo

SD16

332

Abe, Kazutaka

IF02

94

Akimitsu, Jun

IE04

94

Arango, Y. C.

QF22

207

QA10, QA13, QA17

184, 175, 185

Andersen, Ole Krogh

SC07

326

Araoka, Nobutaka

SB14

322

Abe, Taro

SM09

362

60, 121, 130, 143,
211, 212, 276, 337,
342

Anane, AbdelmadjidAbe, Nobuyuki

DF03, PB06, PB07, PC21,
PG09, QG22, QG28,
RH13, SF02, SG16

Andersson, Gabriella

EI03

71

Araujo, Joao P

SO31

371

Abid, Mohamed

PJ14, SH13

157, 345

Akiyama, T.

RM04

295

Andersson, Yvonne

PM10

169

Araujo, M. A. N.

SB21

323

Abo, Gavin Sky

JH04

104

Akiyama, Toru

RM05, SO10, SO11

296, 368

Ando, K.

CE03, ID02, RJ07

51, 93, 283

Araujo, MiguelRB25, RF13258, 271

Abramova, G. M.

SG20

342

Akutsu, Yasuhiro

RI01

279

Ando, Kazuya

AI02

39

Arbelo Jorge, Elena

CH04

54

Abrosimova, Galina

SO04

367

Alameda, Jose Maria

GG03

80

Ando, Ken

KF01

110

Ardavan, Arzhang

SB20

323

Abrudan, Radu

EC04

66

Alaria, Jonathan

PI04

151

Ando, Koji

BI01

47

Arenholz, Elke

DH01

62

Acquarone, Marcello

SI10

347

Alayo, William E.

SM17

363

Ando, Y.

SK24

354

Arepalli, Sivaram

PJ32

160

Aczel, A. A.

GF01

79

Alayo, Willian

PL09, QM14

165, 233

Ando, Yasuo

GF01

79

FA03

72

Alba Venero, D.

QM06

232

54, 70, 71, 110, 292,
301, 346, 348, 351

Arguello, C.

Adachi, Hiroto

Argyriou, D.

RB17

256

Adachi, Nobuyasu

KC02

108

Albert, Barbara

PI05

151

CH02, EI02, EJ01, KD04,
RL13, RO05, RO06, SI03,
SI17, SK08

Argyriou, Dimitri

RB01, RB07

254, 255

Adachi, Yoshiya

PG04, QI05

143, 218

Albertini, Franca

AG02

37

Ando, Yoichi

HI01, RC1189, 260

Argyriou, Dimitri N.

PA10

117

Adam, Philip

CH01

54

Albrecht, Michele

RK05

286

Ando, Yuhki

SA03

316

Argyriou, Dimitrios

CI01

54

Adam, Sorin

PM06

168

Albrecht, Ole

FD02

74

Andrade, Bruna

QL01

228

Arhan, H. Z.

GA01

75

Adamo, Carolina

SA08

317

Aldus, Robert

PO12

179

Andre, Gilles

JB05, RA11, RD14

100, 251, 264

Arikan, Mustafa

GH03

81

Adams, M

SE05

334

Aleshkevych, Pavlo

QM17

234

Andreev, A. V.

QG07, QI03, QI09, RD26

209, 218, 219, 266

Arima, Takahisa

PG20, QD02, QO13

145, 196, 242

Adams, T.

PI09

152

Alfadhel, Ahmed

PM27

171

Andreev, A.v.

GJ03

82

Arima, Taka-hisa

Adams, Tim

DF02

60

Alfahad, S.

RN18

299

Andreev, Alexander

RE09, SG03

267, 340

IA04, PA12, PG14,
QA10, QA13, QA17

91, 117, 144, 184,
175, 185

Adenot Engelvin, Anne Lise

AJ01

39

Alff, Lambert

PI05

151

Andreev, Alexander V.

QI19

220

Arinicheva, Olga

QJ13

223

Adiga, Shilpa

QA23

186

Algarabel, P. A.

KC05, PJ23

109, 158

Andrei, Gloskovskii

SD15

332

Arita, Masashi

RD20

265

Adriano, Cris

SE15

335

Algarabel, Pedro Antonio

SM16

363

Andreica, Daniel

CD04, SE08

51, 334

Arita, Ryotaro

AE05, QC04

36, 192

Adroja, D T

KA02, SE03, SE05, SE13,SF09107, 333, 334, 335,
338

Ali, Md. Ehesan

BC02

42

Angelakeris, Makis

RP15

305

Arnold, Z.

PJ23

158

Ali, Naushad

CH01

54

Angst, Manuel

QA23

186

Arnold, Zdenek

PM11

169

Adroja, Devashibhai

PC12, SD13

128, 332

Aliakbari Miyan Mahaleh, M.

PO30

182

Anh Nguyen, T. N.

PK13

162

Aronin, Alexander

SO04

367

Adroja, Devashibhai T.

SE20

336

Alidoust, N.

SD04

330

Anh Tuan, Duong

PJ15

157

Arora, Sunil Kumar

PH16

149

Adschiri, Tadafumi

RN11

298

Aliouane, Nadir

PA10

117

Anh, D. T. K.

QG11

210

Arredondo, Yesenia

QG21

211

Aeppli, Gabriel

PJ17

157

Alireza, Patricia

PC02, RQ09

127, 308

Anil Kumar, P. S.

PH04

147

Arshi, Nishat

PN15

174

Afzali, Reza

SC09

327

Alireza, Patricia L

SC16

328

Anisimov, M. A.

QC22, RH07

195, 275

Artyukhin, Sergey

CI01

54

Agbelele, Arsene

QA27

187

Allred, Jared M

QB13

189

Annal Therese, Helen

QA25

186

Arvanitis, D.

DD02

58

Agrestini, Stefano

BF03

45

Al-mahdawi, Muftah

PJ11

156

Annett, James

JA05

99

Arzhnikov, Anatoly

BF04

45

Agterberg, Daniel

RB26

258

Alnassar, Mohammed

SA02

316

Antohe, Stefan

QK20

227

Asada, Hironori

143, 233, 305, 352

Agui, Akane

PM02

167

Alonso, J

QM06

232

Antonelli, Alex

RB18

257

PG06, QM10, RP12,
SK13

Ah, Chil Seong

RL21

293

Alotibi, M.

RN18

299

Antos, Roman

KD03

109

Asai, Shinichiro

PH12

148

Ahmad, Dawood

QB25

191

Alqahtani, Mohammed S.

RN18

299

Antropov, Vladimir

SC07

326

Asai, Takuya

RD08

263

Ahmad, Ehsan

EH04

70

Al-senany, Nourh A.

PG01

142

Anwar, M S

PN15

174

Asai, Yugo

PM18

170

Ahmed, Faheem

PM14, PN15

169, 174

Alshammari, Marzook S.

RN18

299

Anzai, Shuichiro

SE09

334

Asaka, Souta

BG04

46

Ahmed, Mohamed Abbas Ali RN21300

Altarawneh, M. M.

SC03

326

Aoki, Dai

SG12

341

RR31

316

Altarawneh, Moaz

BA01, EA03

40, 64

Asano, Hidefumi

Ahn, Cheol-woo

DJ02

63

Althoyaib, S

QL21

231

Aoki, Haruyoshi

30, 100, 134, 268,
337
193, 194

Asaki, Kenji

Ahn, Chan-woo

HP11, JC02, PD17, RE10,
SF03
QC10, QC11

PJ12, PL12, RC18, SA07,
SA17, SO20

156, 165, 261, 317,
319, 370

Ahn, Ho-seong

PM19, PM21170

Altshuler, Tatiana Semenovna PE09

137

Aoki, Hideo

EB02, RI14

65, 281

Asano, Hidehumi

PB34, SK18

125, 353

Ahn, Jae Young

QP18

248

Alvarez, Lorena

QO26

245

Aoki, Kento

QA05

183

Asano, Takayuki

PG17, QF11, QF14

145, 205, 206

Ahn, Kyo-hoon

SO05

367

Alvarez, Pablo

JJ04

106

Aoki, Yuji

RD17

264

Asaoka, Rui

RF11

270

Ahn, San

SC15

328

Alves, E.

QM13

233

Aoshima, Ken-ichi

SK21

353

Aschenbach, Konrad Hsu

EG01

69

Ahn, Sora

RL17

292

Alyamani, A.

RN18

299

Aoyagi, Mitsuharu

RP17

306

Ashida, Takuya

PB25, PL10124, 165

Aichhorn, Markus

SG22

343

Alzayed, Nasser

RB29

258

Aoyama, Satoshi

PH20

150

Aslibeiki, B.

PI23

154

Ain, Qurat-ul

PB13

122

Amakai, Yusuke

RA08

250

Aso, Naofumi

PD14, QC11134, 194

RH12

276

121, 185, 221, 263,
265, 334

Aparnadevi, M

Aizawa, Kazuya

PB08, QA19, QJ04,
RD06, RD22, SE06

Apinaniz, Estibaliz

QH16

215

Asokan, K

PG27

146

Akagi, Yutaka

PG23

146

Amako, Yasushi

QH04, RD19

213, 265

Aplesnin, Sergey

QG05

209

Asokan, K.

QO27

245

Akahoshi, Daisuke

QE20, QF21

202, 207

Amaral, Joao S

RI18, SO30, SO31

281, 371

Aplesnin, Sergey Stepanovich PF01, SO02

139, 367

Assmus, Wolf

QE14

201

Akaki, Mitsuru

PA06, PA19, QA05,
RA06, SB24

116, 119, 183, 250,
324

Amaral, V. S.

RH02

275

Aprilia, Ely

RC02

259

Asthana, Saket

PN18

175

Amaral, Vitor S

RI18, SO30, SO31

281, 371

Arac, Erhan

QO24

244

Atkinson, Del

QO24

244

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index375

AI04, GE01, QK15,
QK16, QK17, RL24, SL24

39, 78, 226, 293,
360

Bak, Zygmunt

SB11

322

Barnes, Crispin

BH01

46

Bending, Simon

QO24

244

Baker, Peter J

PN23

175

Barnes, Crispin H.w.

PN23

175

Bendix, Jesper

BC02

42

Atxitia, U.

GD03

78

Baker, Peter. J.

QG19

211

Baron-gonzalez, Aura Janeth

EC04

66

Bera, A. K.

DH05

62

Atxitia2, U

FC01

73

Bakr, Mohammed

CA03

49

Barraclough, J. M.

GC01

77

Beran, Premysl

BE05

44

Au, Yat-yin

EH04, HD03

70, 85

Balaev, Alexander

PI11

152

Barraclough, Jack M

SE12

335

Berardan, David

RB15

256

Augendre, Emmanuel

AI04

39

Balaev, Dmitry

SM19

364

Barrera, Gabriele

AG02

37

Berger, Andreas

SM04

361

Augstine, Saji

QO27

245

Balagurov, Leonid A

PN22

175

Barshilia, Harish C

PK16

163

Berger, Claire

PN16

174

Augustine, Tan Lee

QL02

228

Balakhonov, Sergey

ED06

67

Barski, Andre

AI04, DD01

39, 58Berger, H.

PI09

152

Augustine, Tan Tuck Lee

PN03

172

Balakirev, Fedor

RB21

257

Barthelemy, Agnes

AE03, HE04, QA27

36, 86, 187

Berger, Helmuth

QA20

185

Avanesyan, Grisha

ID03

93

Balakrishnan, G.

CC04, II02

50, 97Barthelemy, M.

PO23

181

Bergman, Anders

SH11

345

Avdeev, M.

SO08

368

Balakrishnan, Geetha

GF03, SC06, SD13

79, 326, 332

Barthelemy, Marie

FC02

73

Bergmann, Christoph

AB02

34

Avdeev, Maxim

IJ03

97

Balatsky, A. V.

QB08

188

Bartolome, Fernando

EF03, GG03, GG05, QI14

68, 80, 220

Bergqvist, Lars

SH11

345

Avdeev, Maxim V.

SC25

329

Balatsky, Alexander

KG01

111

Bartolome, Juan

EF03, GG03, GG05

68, 80

Berkowski, Marek

QB30

192

Avella, Adolfo

RG18

274

Balatsky, Alexander V

EB04, SE1865, 336

Basak, Susmita

BA04

41

Bernhard, Christian

HA02

83

Aviani, Ivica

IA02

90

Balbashov, A. M.

PA15

118

Bascones, Elena

QB18

190

Berntsen, Magnus

HA03

83

Avignon, Michel

QG21, QO26

211, 245

Balcells, Lluis

IH01, SO18

95, 369

Bascones, Elena .

QB19

190

Bersweiler, Mathias

KF02

110

Avila, M A

QJ05

221

Balcerzak, Tadeusz

RI03, RI09

279, 280

Basso, Vittorio

HH01

88

Bertacco, Riccardo

AI03, DE03

39, 59Avila, Marcos A.

QO03

241

Baldassarre, Leonetta

SA08

317

Batail, Patrick

SB20

323

Berthet, Patrick

GF05

79

Avramov, Pavel V

BH05, BH06

46, 47

Baldes Bango, Fernando

GG03

80

Bataille, Alexandre

DD05

59

Berthier, Claude

IC02

92

Awan, Muhammad Saifullah

SA15

318

Baldovi, J.

BC01

42

Batista, Cristian D

JD01

100

Bertram, Batlogg

RB19

257

Awana, V. P. S

QM24

235

Balents, Leon

JD03, PL08

101, 165

Batko, Ivan

RE13

268

Besnard, Celine

QC13

194

Awano, Hiroyuki

GE04, JE04, PJ09, QP20

78, 102, 156, 248

Balicas, Luis

CC02, EA03, JA02, RB19

50, 64, 98, 257

Batkova, Marianna

RE13

268

Bessais, Lotfi

PM06

168

Awschalom, David D.

AI01

39

Balke, Benjamin

QN19

239

Batlle, X.

BD01, ED03

43, 66

Bessonov, Vladimir

SO17

369

Ayala, Oscar

QB13

189

Ballou, Rafik

AC04

35

Batlle, Xavier

BD04, RN14

43, 299

Beyer, Markus

HA02

83

Ayala-valenzuela, Oscar

GC03

77

Baltz, Vincent

AI04, BD02, DD01

39, 43, 58

Batlogg, B.

PC29, PI15

131, 153

Bezmaternykh, Leonard N

CI04

55

Azarevich, Andrey

QC20

195

Bance, Simon

DE01

59

Batlogg, Bertram

RB21, SC16

257, 328

Bezmaternykh, Leonard N.

PA02

116

Azuma, Masaki

QE10

201

Bando, Hiroshi

PM13

169

Battiato, Marco

RK12

287

Bhagyashree, Karki S

SL21

359

Bandou, Hisamitu

PC05

127

Bauer, Andreas

DF02, QC17, QH24

60, 195, 216

Bharathi, A.

QA14

184

Banerjee, Animesh

CG05

53

Bauer, E D

EA03

64

Bhat, Shwetha G.

CG04

53

Attane, Jean-philippe

Author Index

Author Index

B

376

B., Parvatheeswara Rao

BJ05

48

Bang, DoJE04, SK10

102, 352

Bauer, E.

QB31, QD10

192, 198

Bhat, Subray V

SL21

359

Baba, Ryo

RR05

311

Bang, Dong H.

CJ03

55

Bauer, E. D.

FB01, QB1273, 189

Bhatia, Charanjit S

SK05

351

Babaei Brojeny, Aliakbar

PC16

129

Bang, Ngac An

AJ06

40

Bauer, E.d.

PC19

129

Bhatia, Charanjit Singh

PJ08

156

Babic, Michal

BH03

46

Banholzer, Anja

RJ11

284

Bauer, Eric D

FB03

73

Bhatia, Pushpinder Gupta

PN06

173

Bach, Long Giang

RN05

297

Bannikova, Nataliya

SK02

350

Bauer, Eric D.

PN17

174

80

Bansil, A.

HI02

89

77, 127, 263, 328,
333, 334

Bhatt, Pramod

Badini Confalonieri, Giovanni A. GG04

GC03, PC03, RD09,
SC16, SE02, SE08

Bhattacharya, Pallab

CG05

53

Bae, Dong Sik

PH21

150

Bansil, Arun

BA04

41

Bauer, Ernst

IA02, SC0190, 325

Bi, KeRA12

251

Bae, Joohyung

QK12

226

Bansil, B.

SD04

330

Bauer, Thomas

SF05

337

Bialek, Beata

SK19, SK27

353, 354

Bae, Jungchan

PM17

170

Bao, Guizhi

PC20, QJ07

130, 222

Bauer, Uwe

AD02, AE01

35

Bianchi, Andrea

JC01

100

Bae, Kyoung-hoon

RO02

301

Bao, Jinke

RB13

256

Baum, Max

AA05

33

Bianchi, Andrea D.

CD04, PD05

51, 132

Bae, Moon Seob

RP23

307

Bao, Nina

DD03

58

Baumbach, R.

QB31

192

Bianchi, M.

II02

97

Bae, Seok

RH08

276

Bao, Wei

RB07

255

Baumberger, Felix

II02

97

Bibes, ManuelAE03, HE04, QA27

36, 86, 187

Bae, Taejin

JI02

105

Bar-ad, S.

BD01

43

Baumgarten, Martin

HC04

85

Bickel, Jessica E.

IH03

96

Bae, Yu Jeong

CB01, PJ17, QP18

49, 157, 248

Baranov, Denis G.

HD05

86

Bayle-guillemaud, Pascale

AI04, DD01

39, 58

Bigot, J.-y.

PO23

181

Baek, In-bok

RL21

293

Baranov, Nikolai V.

QN10

238

Bazaliy, Ya. B.

SI18

348

Bigot, Jean-yves

FC02, RK05, RK13, RK1573, 286, 288

Baek, Seung Ki

RI19, RI20

282

Baranov, Nikolay

QG04

208

Beach, Geoffrey

AE01

35

Bihlmayer, Gustav

SD06

331

Baek, Seung-heon Chris

RL30

294

Baranov, Nikolay V.

QI08

219

Beard, Jerome

RQ16

309

Billette, Julien

RQ16

309

Baek, Seungmin

QP15, QP16

247, 248

Barbar, S. K.

RA03

249

Beatrice, Cinzia

HH01

88

Biner, D

RI05

279

Baek, Younkyoung

PM24

171

Barberis, Gaston Eduardo

RB18

257

Beaurepaire, Eric

GI03

82

Biondo, Armando

QM15

234

Baek, Youn-kyoung

RN06, SL29

297, 360

Barbiellini, Bernardo

BA04

41

Beck, Adli

QH22

216

Biswas, Abhijit

PN28

176

Baggio-saitovitch, E.

SM17

363

Barco, Reginaldo

PG03

142

Becker, Petra

AA05, QA22, RI12

33, 186, 280

Biswas, Deep Narayan Biswas SC06

326

Baggio-saitovitch, Elisa

PL09, QM14, QM15,
RB10, RB11, SE22165, 233, 234, 255,
336

Barcones, Beatriz

JE01

101

Behnia, Kamran

KJ04

114

Biswas, S.

PL07

165

Barik, Sujit Kumar

PI01, RA08

150, 250

Beigne, Cyrille58, 71, 78, 226, 293

Bitla, Yugandhar

SL07

357

Bagheri, Mahdiyar

QA25, SA22

186, 319

Barisic, Neven

CA03

49

DD01, EI04, GE01,
QK15, QK16, RL24

Bittar, Eduardo

SE22

336

Bahmanrokh, Ghazaleh

RQ22

310

Barker, J

FC01

73

Bekyarova, Elena

PN16

174

Bjorck, Matts

EI03

71

Bahramy, M.s.

II02

97

Barker, Joe

RK17

288

Belinsky, Moisey

RA25

253

Blackburn, S.

PD05

132

Bahramy, Mohammad Saeed

AE05

36

Barman, Anjan

HD04, RK11, SH1285, 287, 345

Bellaiche, Laurent

QA27

187

Blaha, Peter

RB21

257

Bai, X. J.

PL20

167

Barman, Saswati

HD04, RK11, SH1285, 287, 345

Belo, Joao H

SO31

371

Blanco, J. A.

GH05

81

Bai, Zhaoqiang

QP06

246

Barnas, J

SB21

323

Ben Youssef, Jamal

SA24

320

Blanco, Jesus A.

JJ04

106

Baik, Seung-kyu

QM22

235

Barnas, Jozef

DB03

57

Benatmane, N.

PK13

162

Blanco, Juan Maria

AJ02

40

Baines, Christopher

AB02, CD04

34, 51

Barner, Klaus

SB06

321

Bencok, Peter

PA15

118

Blanco-canosa, Santiago

BA03

41

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

377

378

Author Index

Blank, DaveDH02, SA10

62, 317

Bourdarot, Frederic

JC02

100

Bunce, Christopher

RJ11

284

Carva, Karel

RK12

287

Blasco, Javier

EC04

66

Bourgeois, Julie

RA11

251

Bunkov, Yury

IC04

92

Carvajal Quiroz, Eliel

SK15

352

Blavette, Didier

BD02

43

Bourges, Philippe

DA01

56

Burdin, Sebastien

PD04

132

Casa, Diego

DC03

58

Blinova, Julia

PB22

123

Bouzehouane, Karim

AE03

36

Burkov, Alexander T

QI12, QI13

219

Casanova, Felix

HE02

86

Bluegel, Stefan

SD06

331

Boyn, Soeren

HF01

87

Burzo, Emil

SK09

351

Casanove, Marie-jose

IH01

95

Blugel, Stefan

IH03

96

Bozzo, Bernat

SO18

369

Bussetti, Gianlorenzo

PL21

167

Casola, Francesco

IC02

92

Blum, Christian

QH24

216

Braden, Markus

AA05

33

Bustamante, Rodney

KB06

108

Casoli, Francesca

AG02

37

Blundell, Stephen. J.

QG19

211

Braicovich, Lucio

BA03

41

Buzzi, Michele

RK17

288

Casper, Frederick

RC10

260

Blythe, H. J.

RN18

299

Brambilla, Alberto

PL21

167

Bychkov, Igor V.

SO19

369

Castan, Celia

EF03

68

Boarino, Luca

AG02

37

Bramwell, Steven

CC01

50

Bychkov, Igor Valer'evich

QH17

215

Castan-guerrero, Celia

GG03, GG05

80

Bobade, Santosh M

QO11

242

Bran, Christina

DG01

61

Byeon, Hyehyeon

PN08, PN09, QM04

173, 232

Castano, F.

ED03

66

Bobak, Andrej

QE01, QE02

199

Bran, Cristina

DG03, EI03

61, 71

Byzov, Ilya

QL07

229

Castellano-hernandez, E.

ED03

66

Bobrov, Aleksandr

SG17

342

Bran, Julien

DG02, PJ22

61, 158

RN09

298

Bochenek, Lukasz

SB26

324

Brandenburg, Jens

QA11

184

C

Castrillon, Mariana
Caux, Jean-sebastien

IC05

92

Bochenek, Łukasz

PE19

139

Brandl, G.

PI09

152

Cabra, Daniel C.

QE26

203

Cava, R. J.

SD04

330

Bocher, Laura

AE03

36

Brando, ManuelAB02, QH12, SF05

34, 214, 337

Cai, Jinzhu

PN05, QL04

172, 228

Cava, Robert J

QB13

189

Bocklage, Lars

SH04

343

Braun, Anke

PE07

137

Cai, Yiwei

RE11

268

Cavill, Stuart A

SH09

344

Bode, Matthias

AD03

35

Braun, H. B.

PJ26

159

Cai, Yong

QC09

193

Cazayous, Maximilien

PD17, QA27

134, 187

Bodensiek, Oliver

PE03

136

Braun, Hans - Benjamin

GF02

79

Cai, Yongfu

RP17

306

Celegato, Federica

AG02, DG04

37, 61

Boehm, Helga M

RG15

274

Breard, Yohann

BB03, RH22

41, 278

Cai, Yongqing

QP06

246

Cermak, Petr

SB08

321

Boehm, M.

QE19

202

Brede, Jens

GH02

81

Caizer, Costica

PO07

178

Cezar, Julio

PI08

152

Boehnert, Tim

RP04

303

Brenac, Ariel

EI04

71

Caldas, Heron

KG04

112

Cezar, Julio C.

SH03, SH05

343, 344

Boeni, Peter

DG01

61

Brenig, Wolfram

EC05

66

Calderon Filho, Cesar Jose

RB18

257

Cha, Hyun Rok

QO20, SG21

244, 343

Boeri, Lilia

SC07

326

Breunig, Oliver

RI12

280

Calderon, Maria Jose

QB18, QB19

190

Cha, Yun-yeop

PO06, PO10

178

Bof Bufon, Carlos Cesar

SJ07

350

Bridges, F.

CF01

52

Callaudin, Aurelie

KJ04

114

Chacon Hernandez, U. D.

SM17

363

Bogach, A. V.

QC22, RH07

195, 275

Bridoux, G.

DI01

62

Calloni, Alberto

PL21

167

Chacon, A.

PI09

152

Bogach, Alexey

QC20, RE13

195, 268

Brinkman, Alexander

DH02, SA10

62, 317

Calvani, Paolo

SA08

317

Chadov, Stanislav

CH04, II03, RC10

54, 97, 260

Bogach, Alexey V.

QC19

195

Broholm, C.

CF01

52

Calvo, Irene

EF03

68

Chadova, Kristina

II03

97

Bogdanov, Savva

QG02

208

Brookes, Nicholas

PI08

152

Camarero, Julio

SH03

343

Chae, Keun Hwa

PG27, QO27

146, 245

Bohaty, Ladislav

AA05, RI12

33, 280

Brooks, James S.

SB05

321

Camilo, Nilmar Silva

SE15

335

Chae, Woong-chan

SN04

364

Bok, Jin Mo

SB31

325

Brown, Stuart E.

GB03, SF01

76, 337

Campbell, Stewart

EF02

68

Chai, Yi Sheng

PA09

117

Boldt, Regine

PC27

131

Brucas, Rimantas

SL15

358

Campbell, Stewart J

QG26

212

Chai, Yisheng

JB02

99

Boldyrev, Kirill N.

PA20, RA24

119, 253

Bruck, E.

RQ12, SO08, SO16

309, 368, 369

Campbell, Stewart James

QG09

209

Chakraborty, Monodeep

RG02

272

Bombardi, Alessandro

BF03

45

Bruck, Ekkes

PM10, RI18

169, 281

Campion, Richard

IE03

93

Chaloupka, Jiri

BA03

41

Bonanni, Alberta

BE03

44

Brueckl, Hubert

AH01

38

Campion, Richard P

SH09

344

Chan, Ho Bun

BC05

42

Bonell, Frederic

PK20

163

Bruel, Andreas

SG19

342

Campo, Giulio

CB04, SI1149, 347

Chan, Mun K.

CA03

49

Bonfim, Marlio

SH05

344

Bruhl, Andreas

RI13

281

Campo, Javier

79, 108, 146, 243

Chan, Wen-yuan

PK02

160

Boni, Peter

DF02

60

Brune, Harald

BC02

42

GF04, KB06, PG22,
QO16

Chandarak, Sujittra

SL10

357

Bonilla, Marcela

EF03

68

Buchanan, Kristen

RJ20

285

Canfield, P. C.

GA01, IA05, RD0275, 91, 262

Chandra, Shekhar

SD15

332

Bonn, Doug

BA01

40

Buchelnikov, Vacily

PI20

154

Cantoni, Matteo

AI03

39

Chandra, Sumal

PB24, QG03

124, 208

Booth, John Graham

QG01

208

Buchelnikov, VasiliyPM22, QH05, SO23

171, 213, 370

Cao, C. D.

PL20

167

Chandrasekaran, Gopalakrishnan

PO21, QA25, QN26

180, 186, 240

Boothroyd, A. T.

PC22, PI03, QN01

130, 151, 236

Buchelnikov, Vasiliy D.

QO12, SO19

242, 369

Cao, Guanghan

AB04, IJ04, RB13

34, 98, 256

Chang, Bin

HJ05

90

Boothroyd, Andrew

AF01, DH03

36, 62

Buchelnikov, Vasily Dmitrievich QH17

215

Cao, Helin

HI02

89

Chang, Cheng-hsun

PK02

160

Boothroyd, Andrew T

HA04

83

Buchner, B.

QF18

206

Cao, R

SB19

323

Chang, Chia-chi

SH08

344

Borchers, Julie

KD02

109

Buckow, Alexander

PI05

151

Cao, Rong

PC30

131

Chang, Ching Hao

KI04

113

Borchmann, Jan

SL05

356

Buda-prejbeanu, Liliana

SI09

347

Cao, Shixun

SG01

339

Chang, Ching-ray

QK22, RK14, SK30

227, 288, 355

Borges, Hortencio Alves

SE22

336

Bud'ko, S. L.

GA01, IA05, RD0275, 91, 262

Cao, W.n.

PL02

164

Chang, H.w.

SN06

365

Borges, R. P.

QM13

233

Budnick, Joseph I.

HA03

83

Capelli, Silvia

RE12

268

Chang, Hun

CI03, PA01, PA03

55, 116

Boris, A. V.

GA03

75

Budrikis, Zoe

KE01

110

Capik, Marek

IB01

91

Chang, J.

PC01, PI15

126, 153

Borovsky, Michal

QE02

199

Buechner, B.

QE23, QF22, RB17

203, 207, 256

Caprile, Ambra

HH01

88

Chang, Jae Kyung

QH29, SC08

217, 326

Borozdina, Yulia

HC04

85

Buechner, Bernd

QH24

216

Cardona, S.

BC01

42

Chang, Johan

HA03

83

Borrell, A

RQ10

308

Bufaical, Leandro F

SE15

335

Carlos, Luis D.

KB06

108

Chang, Joonyeon

Borrmann, Horst

QD07

197

Buhot, Jonathan

PD17

134

Carlotti, Giovanni

GG02

80

109, 159, 166, 225,
226, 294, 295, 360

Bortolotti, P.

ID02

93

Bui, Hong-van

SG10

341

Carman, Gregory P.

QA15

185

KC04, PJ30, PL16, QK10,
QK11, QK12, QK13,
RL28, RL31, SL26

Bortolotti, Paolo

CE03, ID03, RJ07

51, 93, 283

Buitrago, Ivon R.

SI10

347

Carmelo, Jose

RF13

271

Chang, Jui-hang

RK14

288

Bosak, Alexei

PA08

117

Bukowski, Z

QB06

188

Caron, Luana

PM10, RN07

169, 297

Chang, Junghwan

RR16, RR17, SN05

313, 365

Boseggia, S.

QN01

236

Bukowski, Z.

PC01

126

Carpenter, Michael A

EF03

68

Chang, Liang-juan

RL18

292

Bouchenoire, L.

QN01

236

Bukowski, Zbigniew

RB21

257

Carretero, Cecile

QA27

187

Chang, P. C.

PE02

136

Bouillot, Pierre

CC03

50

Buldmann, Benjamin

RI12

280

Carta, Daniela

CB04

49

Chang, P. H.

PC13

128

Boulle, Olivier

SH05

344

Bulla, Lukas

RB08

255

Carter, Matthew

GH03

81

Chang, Sung

QA20

185

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

379

380

Author Index

Chang, T.-r

SD04

330

Cheng, Chih-wei

PK11, PK15, PK19

162, 163

Choi, Dong Hoon

EH02

70

Chung, Chung-hou

DB04, RE06

57, 267

Chang, W.c.

SN06

365

Cheng, Hong-wen

QM09

233

Choi, Doo-hyun

RR23, RR27

314, 315

Chung, D. Y.

GA01

75

Chanthbouala, Andre

IE04

94

Cheng, Nian-jia

SL18

359

Choi, Eun Sang

GJ02, PA2182, 119

Chung, J.- H.

PH03

147

Chantrell, Roy

RK17

288

Cheng, Po-wen

BJ01

47

Choi, Eun-sang

SB05

321

Chung, Jaeho

PA01

116

Chantrell, Roy W

FC01

73

Cheng, Tsung-i

PK19

163

Choi, Han-yong

SB31, SB32

325

Chung, Jae-ho

CI03, JB02, PA03, PA04

55, 99, 116

Chantrell, Roy W.

QK09, SJ04

225, 349

Cheon, Jinwoo

CB01, PO15, PO1649, 179

Choi, Heonhwa

RQ15

309

Chung, K. C.

SB28

324

Chantrell, Rw

FC01

73

Cheong, S. W.

AA04

33

Choi, Heon-hwa

SC14

327

Chung, Kookchae

RN23

300

Chao, C. H.

PK01

160

Cheong, S.w.

PH10

148

Choi, Heon-jin

QK11, SL26

225, 360

Chung, Kook-chae

QM22

235

Chao, Wu

QO15

243

Cheong, S.-w.

QA04

183

Choi, Hong Chul

PE17

138

Chung, Sunjae

PK13

162

Chapon, Laurent C

BF03, CI02

45, 55Cheong, Sang-wook

PP06, QF20

28, 207

Choi, Hyeok Cheol

QM18, QM20

234

Chung, Sunjea

CE02

51

Chapon, Laurent C.

GF03

79

Cheong, S-w.

RA22

253

Choi, Hyeok-cheol

RK02

286

Churagulov, Bulat

ED06

67

Charnukha, Aliaksei

GA03

75

Cheptiakov, Denis

PI21

154

Choi, Hyoung Jin

QN03, QN09

236, 237

Chureemart, Phanwadee

SJ04

349

Chatterjee, S

SO14

369

Chern, G.

PK11, PK15, PK19

162, 163

Choi, Hyoung Joon

QK21, RB16, RC15

227, 256, 261

Cibert, Joel

DD01

58

Chattopadhyay, S

QL14

230

Chern, Gung

QM11, QM25

233, 235

Choi, Jae-hak

RR31

316

Ciccacci, Franco

PL21

167

Chaturvedi, Anurag

DJ01

63

Chernets, Ivan A.

QO12

242

Choi, Jae-hyuk

PB21, RQ15, SC14

123, 309, 327

Cichorek, Tomasz

PE19, SB26

139, 324

Chaudhary, S.

PG27

146

Chernobrovkin, Alexey

ED06, KI05

67, 113Choi, Jong-gu

BH02, PL11, RR15

46, 165, 313

Cieslak, Jakub

QH18

215

Che, Sun Chang

QG18

211

Chernyshov, Dmitry

PA14

118

Choi, Jong-jin

DJ02

63

Ciftja, Orion

RG01

271

Chebotkevich, Ludmila

AG05, QM05

38, 232

Chi, Songxue

SC23

329

Choi, Joon-hwan

DJ02

63

Cinal, Marek

AD02

35

Cheikhrouhou, Abdelwaheb

DJ05

64

Chiba, D.

BE02, RL07, SH07

44, 291, 344

Choi, Jun Woo

KC04

109

Cioangher, M.

SA11

318

Cheikhrouhou-koubaa, Wissem DJ05

64

Chiba, Daichi

RL10

291

Choi, K. Y.

QF13

206

Cisarova, Ivana

BB04, PD1942, 135

Chen, Bin

PC02, PC09

127, 128

Chicinas, Ionel

EJ03

72

Choi, Ki-young

JA03

98

Ciubotaru, Florin

SI15

348

Chen, C. - T.

QB28

191

Chico Carpio, Jonathan Philippe SH11345

Choi, Kwang Yong

RP13

305

Ciuta, G.

JH02

104

Chen, Chien-miao

SB19

323

Chien, Chia-ling

FA04

72

Choi, Kyong-hoon

RN20

300

Civale, L.

QB31, SB12

192, 322

Chen, Chih_yung

PK09

161

Chikako, Moriyoshi

QD14

198

Choi, Mahn-soo

SC14

327

Cizmar, E.

QF02, QF03

204

Chen, Chih-wen

QN08

237

Chikoidze, Ekaterina

SM07

362

Choi, Min-young

SD03

330

Cizmas, Corneliu Bazil

PM06

168

Chen, Chih-yung

QM01

231

Chin, Yi-ying

PI08

152

Choi, Moo Young

RC08, RE07

260, 267

Clarke, Simon J.

HA04

83

Chen, G F

QB11

188

Chioran, Viorica

RR02, RR03

311

Choi, Seokhwan

RQ11

308

Clarke, Simon. J.

QG19

211

Chen, G.

SM05

361

Chiu, Yu-che

RK07

287

Choi, Seonghoon

QL08

229

Claudia, Felser

SD15

332

Chen, Genfu

RB11

255

Chizhik, Alexander

CJ04

56

Choi, Seongil

PG24

146

Claydon, J S

QO24

244

Chen, H.m.

PK11, PK15

162

Chizhik, Alexandr

AJ02

40

Choi, Seonjun

QP19, RL22, SL19

248, 293, 359

Clemente-juan, J. M.

BC01

42

Chen, Hao-hsuan

RK14

288

Cho, B. K.

SA09

317

Coey, Michael

PO32

182

QM27

236

161, 220, 224, 321,
325

Choi, Sul A

Chen, Hsin-hsien

PK04, QI15, QK03, SB10,
SB30

Choi, Sungil

PI10

152

Coisson, Marco

AG02, DG04

37, 61

Chen, I. A.

SB04

320

Cho, Bo Ram

SB22

323

Choi, Won Young

QK13

226

Colak, Levent

KB04

108

Chen, J.

QB12

189

Cho, Chae Ryong

PN21, QL18

175, 231

Choi, Y.j.

PH10

148

Coleman, Piers

HP22

30

Chen, J. M.

SM11

362

Cho, Daeheum

QG17

211

Choi, Yong Nam

PN20, QL18

175, 231

Colineau, Eric

RE03, SE19

266, 336

Chen, Jian

SB29

325

Cho, Deo-kyong

PG24

146

Choi, Yoon Hyuck

122, 123, 125, 126

Colis, Silviu

PI04

151

Chen, Jin-ming

QB21

190

Cho, Hyun Jin

PG25

146

PB16, PB18, PB35, PB36,
PB38

Collin, Sophie

HE04

86

Chen, K.l.

QM27

236

Cho, Hyunduck

PJ17

157

Choi, Young Ha

RC07

260

Collins, S. P.

QN01

236

Chen, Kuo-chin

QK22, SK30

227, 355

Cho, Hyun-sung

RR15

313

Choi, Youngha

SD10, SD11

331

Collins, Steve

DH03

62

Chen, L. M.

IC03

92

Cho, Jun-hyung

SD06

331

Choi, Youn-seok

DE05, RJ16, SH1460, 285, 345

Conder, Kazimierz

PI21, PO17, QF23

154, 180, 207

Chen, Lin

QK23

227

Cho, K.

QC23

196

Chokprasombat, Komkrich

SL10

357

Cong, Pham Thanh

HC04, QE14, RI13

85, 201, 281

Chen, M.j.

QM27

236

Cho, K. H.

SB28

324

Choo, Seongmin

PN19

175

Cong, Rihong

PH02

147

Chen, P.

AA04

33

Cho, Kwang Lae

PI13

152

Choo, Seong-min

QO10, QO11

242

Continentino, Mucio A.

KG04

112

Chen, Qianping

SA19, SA20

319

Cho, Lee-hyun

SK27

354

Chou, Chih-chieh

QA20

185

Continenza, Alessandra

QG25

212

Chen, S. A.

QB21, SM11

190, 362

Cho, Myeong Woo

QN09

237

Chou, T. L.

SM11

362

Coqblin, B.

QD10

198

Chen, S. C.

PH01

147

Cho, Sang-uk

PH22

150

Choudhary, R.j.

SA14

318

Coqblin, Bernard

PE01

136

Chen, Shih-jia

QM09

233

Cho, Sunglae

70, 176, 177, 244

Chowdhury, Prasanta

PK16

163

Cordoba, Rosa

DG05

61

Chen, Sui-pin

RL29

294

EH05, PN29, PN30,
QO22, QO23

Chu, Ching-wu

JA02

98

Cornell, N.

QB12

189

Chen, Szu-wei

AD01

35

Cho, Suyeon

GF05

79

Chu, Yu-hsun

AD01

35

Coronado, Eugenio

BC01

42

Chen, Wei-hsiang

IH06, PL03, PL13

96, 164, 166

Cho, Yong Chan

PN20, PN21

175

Chuan'an, Cui

QO21

244

Corrias, Anna

CB04

49

Chen, Wen-chen

PL18

166

Cho, Yong-chan

PH22, QL18

150, 231

Chubykalo-fesenko, O

FC01

73

Cossu, Fabrizio

QP01

245

Chen, Xiang-bai

SA16

318

Cho, Yun Hyun

RR19, RR24

314

Chubykalo-fesenko, O.

GD03

78

Costache, M. V.

DI01

62

Chen, Xing-yuan

QA03

183

Cho, Yunhyun

RR25

315

Chubykalo-fesenko, Oksana

RJ04

283

Cote, Michel

PD05

132

Chen, Xumin

AD03

35

Choe, Sug-bong

KE03, SI13

110, 348

Chudo, Hiroyuki

PC03

127

Cottam, Michael

QG12, SL05

210, 356

Chen, Y.

QB12

189

Choi, Chang Ho

RK06

286

Chumak, Andrii V.

SI15

348

Cowburn, Russell

KE02

110

Chen, Yao-jung

PL03

164

Choi, Changsik

SK14

352

Chumakov, Andrey

SL27

360

Cowlam, Neil

PG01

142

Chen, Ye

RD12

264

Choi, Choljin

RN23

300

Chun, Byong Sun

IH04, PJ14, RK18, SH1396, 157, 288, 345

Crassous, Arnaud

AE03

36

Chen, Yen-cheng

PC18

129

Choi, Chuljin

PM24

171

Chun, Sae Hwan

JB02, PA09

99, 117

Crichton, Wilson

RB20

257

Chen, Yong P.

HI02

89

Choi, Chul-jin

JH04, KH04, RN06, SL29

104, 112, 297, 360

Chun, Sae-hwan

PA04

116

Cristiani, G.

ED05

67

Chen, Zhe

AJ03, JI06

40, 105

Choi, Dawoon

RR25

315

Chun, Sungwoo

QP19, RL22, SL19

248, 293, 359

Crooker, Scott A

JD01

100

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

381

Author Index

Cros, V.

CE03, CE06, ID02, RJ07

51, 52, 93, 283

De La Fuente, Jesus M

RN08

298

Didukh, Leonid

RG13

274

Dufour, Catherine

DD05, KD02, KF02

59, 109, 110

Cros, Vincent

HF01, ID03, IE04

87, 93, 94

De La Torre, A

II02

97

Dieny, Bernard

BD02, SI09

43, 347

Dugaev, V K

SB21

323

Crow, D. J. G.

SF15

339

De Leo, Natascia

AG02

37

Dietl, T.

BE02

44

Dukhnenko, A.

JC04

100

Crowell, Paul A

CG01

53

De Loubens, Gregoire

ID03

93

Dietl, Tomasz

BE03, DD02

44, 58Dukhnenko, A. V.

PE12

138

Cruz Irisson, Miguel

SK15

352

De Matteis, Laura

RN08

298

Dilley, N.

IA05

91

Dumas, R. K.

CE02, PK13

51, 162

Cubukcu, Murat

AI04, GE01, QK15,
QK16, QK17, SL24

39, 78, 226, 360

De Pedro, I.

GH05

81

Dilullo, Andrew

GH02

81

Dumas-bouchiat, F.

JH02

104

De Pedro, Imanol

JJ04

106

Ding, Jun

58, 249, 357, 363

Dumesnil, Karine

DD05, KD02, KF02

59, 109, 110

Cuello, Gabriel

JJ04

106

De Ranieri, Elisa

IE03

93

DD03, QP22, SL06,
SM14

Dumont, Matthieu F.

KB03

107

Curiale, Javier

SH02

343

De Souza, Mariano

QJ11, SG19

222, 342

Dinh, Van-chau

SG10

341

Dumont, Yves

SM07

362

Curlik, Ivan

QD08, RD21

197, 265

De Teresa, J. M.

KC05

109

Dinia, Aziz

PI04

151

Duncan, William J

QH12, SF05

214, 337

Custardoy, Laura

RN08

298

De Teresa, Jose Maria

DG05, SM16

61, 363

Dirks, Andreas

FE03

75

Dung, Dang Duc

176, 177, 244

Custers, J.

CD01

50

Decker, Regis

GH02

81

Divis, Martin

HJ04, QC21, QJ02

90, 195, 221

PN29, PN30, QO22,
QO23

Custers, Jeroen

BB04, PD18, PD1942, 134, 135

Decourt, Rodolphe

EH03

70

Djuhana, Dede

RA15, SH01

251, 343

Dung, N. H.

SO16

369

Cywinski, Robert

JA05

99

Deen, P P

SE03, SE05

333, 334

Dkhil, Brahim

QA27

187

Dung, N.h.

SO08

368

Deguchi, Hiroyuki

PB25, PG09, PG10,
QG19, RN03, SA03

124, 143, 144, 211,
297, 316

Dluzewski, Piotr

DD02, QB30

58, 192

Dunn, J.

HA05

84

Do, Anh Thi Kim

CJ05

56

Dunne, Peter

PO32

182

Author Index

D

382

Da Silva, Douglas

PB33

125

Deguchi, Kazuhiko

PD14, PD20, RD05

134, 135, 262

Do, Bang

PJ09

156

Dunsiger, Sarah Ruth

GF01

79

Da Silva, Douglas Langie

PB09, PB11, RB09, SB18

121, 255, 323

Deheer, Walt A.

PN16

174

Do, Thang Viet

CJ05

56

Duo', Lamberto

PL21

167

Da Silva, Mathieu

KF02

110

Deisenhofer, Joachim

PA23, RH24

119, 278

Dobkowska, Sylwia

BE03

44

Duong, Thiet Van

EH05

70

Da Silva, R. C.

QM13

233

Dejneka, Alexandr

AH02, BH03

38, 46

Dobrynin, Alexey

PA15

118

Duong, Tuan Anh

EH05

70

Daadmehr, Vahid

PB23

123

Dekadjevi, David Toyo

SA24

320

Doenni, Andreas

JJ05, PH02

106, 147

Dupuis, Veronique

KB05, QN06, RK03

108, 237, 286

Dabkowska, H.

GF01

79

Del Moral, A

SF09

338

Doerr, Mathias

PH04

147

Duque, Jose G. S.

PI19

153

Dabkowska, Hanna A

JD01

100

Del Moral, Agustin

SE20

336

Dogan, Fatih

CG05, IE01

53, 93

Durakiewicz, Thomasz

SE08

334

Dabkowski, A.

GF01

79

Del Real, Rafael Perez

DG03

61

Doh, Jaewon

PO14

179

Durr, Hermann Andreas

GD02

77

Dabrowski, Maciej

AD02, EI01

35, 70Del Val, Juanjo

PJ25

158

Doh, Yong-joo

SD12, SD14, SO21

332, 370

Dussaux, A.

CE03, CE06, ID02

51, 52, 93

Dadras, Sedigheh

PB23

123

Delfanazari, Kaveh

KJ01

113

Doi, Masaaki

SM03, SN03

361, 364

Dvornik, Mykola

EH04, JG01

70, 103

Daegeun, Park

RR20

314

Delley, B.

PC01

126

Doi, Naohiro

QE13

201

Dwevedi, Sandhya

PG19

145

Dai, Bing

RL08

291

Delmas, Claude

EH03

70

Dolgov, O. V.

GA03

75

Dwivedi, R. K.

RA27, SM18

253, 363

Dai, Jia

QB07

188

Delmo, Michael P.

PN12

174

Dolia, S. N.

SL25

360

Dyadkin, Vadim A.

DF04

60

Dai, Jianhui

AB04, IJ04

34, 98Delval, Juanjose

DJ03

63

Dolinsek, Janez

SL11

357

Dyadkina, Ekaterina

QM08

232

Dai, Jianming

SA01

316

Demidenko, Olga

QG05

209

Dominguez, Claribel

SA12

318

Dyakina, Veronika

PC07

127

Dai, Pengcheng

GA02, RB10, RB1175, 255

Demidov, Evgeny Sergeevich

SG17

342

Doria, Mauro Melchiades

RB09

255

Dai, Yuqiang

SA01

316

Demishev, S. V.

PE12, QC22, RH07

138, 195, 275

Dos Santos, Maria Elenice

QA06

183

E

Daimon, Hiroshi

SK13

352

Demishev, Sergey

Dou, Shixue

EF02, QG09, SD01

68, 209, 330

Ebels, Ursula

SI09

347

JB05, RA11

100, 251

ED06, KI05, QC20,
SG07, SG08

67, 113, 195, 340

Damay, Francoise

Drechsler, S.-l.

QF18, QF22

206, 207

Ebert, Hubert

II03

97

D'amico, Irene

QK09, RL12, SJ04

225, 291, 349

Demishev, Sergey V.

QC19

195

Dreiser, Jan Gui-hyon

BC02

42

Ebihara, Takao

RA19

252

Dan, Nguyen Huy

AJ06

40

Demmel, F

SE03, SE05

333, 334

Drews, Andre

FD02

74

Ebisu, Shuji

QH14, QO07

215, 241

Dang, Dung Duc

EH05

70

Dempsey, Nora

JH02

104

Driver, Sarah L

EF03

68

Ebrahimian, Neda

SB07, SC09

321, 327

Dang, Hue Thi Minh

RN19

299

Demsar, Jure

HA02

83

Drobosyuk, Mikhail

PM22, SO23

171, 370

Echevarria-bonet, C.

QD10

198

Dang, N. V.

RA01

249

Deng, Guochu

PI21, PO25

154, 181

Drube, W.

SK24

354

Eckerlebe, Helmut

SL27

360

Danis, Stanislav

QI01

217

Denisovsky, Andrey N.

QO12

242

Drymiotis, Fivos R

QO09

242

Eckert, James C

PK09, QM01

161, 231

Danzenbacher, Steffen

CD03, PD1251, 133

Deorani, Praveen

EG03, PJ08, SI02

69, 156, 346

Du Plessis, Paul De Villiers

RD23

265

Eckold, Gotz

AA05

33

Daou, Ramzi

JD01

100

Deranlot, Cyril

HE04

86

Du, AnRK16

288

Eckstein, Martin

EB02

65

Dariani, R. S.

QP23

249

Deranlot, Cyrile

CG03

53

Du, JunPL01, RA13

164, 251

Eddrief, Mahmoud

QL06

229

Das, A.

PI12

152

Derlet, Peter

QF20

207

Du, M-h

GF01

79

Eder, Robert

PF14, RF03

141, 269

Das, Kaustuv

HD04

85

Deshpande, N. G.

SL08, SL09357

Dua, P.

QH26

217

Edmonds, Kevin W

SH09

344

Das, Pintu

QA11, QJ11

184, 222

Desilets-benoit, Alexandre

CD04

51

Duan, Truong Cong

HC02

84

Egashira, Yusaku

PE10

137

Das, Pranab Kumar

QJ17

223

Detlefs, B.

SK24

354

Duanmu, Qingyong

PK03

160

Egawa, Genta

RP06

304

Das, S.

PL07, RH02

165, 275

Devereaux, T.

EB01

64

Dubenko, Igor

CH01

54

Egetenmeyer, Nikola

CD04

51

Das, S. D.

GA01

75

Devillers, Thibaut

BE03, DD01

44, 58Dubey, Sheshmani K.

PN01

172

Eggert, Sebastian

HC04

85

Das, Soma

SO30, SO31

371

Devlin, Eamon

BJ02, RO08

47, 302Dubi, Yoni

KG01

111

Eguchi, Gaku

PC20

130

Das, Tanmoy

HI03, QB08

89, 188

Dewhurst, Charles

DF04

60

Dubiel, Stanislaw M

PG03, QH18

142, 215

Eguchi, Ryo

JE04

102

Dasari, Venkateswarlu

SJ08, SL23

350, 359

Dey, G K

PM01

167

Dubowik, J.

QG27

212

Ehlers, Georg

CC03

50

Davesne, Vincent

GI03

82

Dhar, Sudesh Kumar

QJ17, RB24, SE21223, 258, 336

Duc Dung, Dang

PJ15

157

Ehmler, H.

RQ21

310

Davis, J. C. Seamus

CA02

48

Dhawan, M. S.

SL25

360

Duc, Fabienne

RQ16

309

Einaga, Yasuaki

QC07

193

Davison, Toby

EH04

70

Dho, Joonghoe

PL15, QM21

166, 235

Duc, Nguyen Huu

AJ06

40

Eisaki, H.

QB28

191

De Bergevin, Francois

AF01

36

Di Marco, Igor

RG06

272

Ducruet, Clarisse

AI04

39

Eisaki, Hiroshi

De Brion, Sophie

KB06

108

Diaconu, Andrei

RB12

256

Dudzik, Esther

EC04

66

48, 56, 183, 184,
187, 189, 191, 276

De Julian Fernandez, Cesar

CB04, SI1149, 347

Dias, Fabio

PB10, PB33

121, 125

Duerr, George

GG02

80

CA02, DA04, QA05,
QA07, QA09, QB02,
QB15, QB29, RH11

De La Fuente, Cesar

SE20

336

Dias, Fabio Teixeira

PB09, PB11, RB09, SB18

121, 255, 323

Duff, Gerard

GF02

79

El Hafid, Hassan

EH03

70

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index383

Author Index

El Jazouli, Abdelaziz

EH03

70

Falvello, Larry

QO16

243

Filippov, Vladimir Borisovich

PE09

137

Fujibayashi, David E.

PC26

131

El Moussaoui, Souliman

RK17

288

Fan, C.

IC03

92

Finazzi, Marco

PL21

167

Fujieda, S

RR08

312

Elgazar, Saad

RG05

272

Fan, Raymond

PA15

118

Finger, Thomas

AA05

33

Fujii, Yutaka

QE16, QE21, QF09,

202, 205, 206, 281

El-hagary, M A

QL21

231

Fan, Xiu Xiu

SL16

358

Fink- Finowicki, Jan

JJ03

106

El-hagary, Magdy

RB29

258

Fan, Zhe

SH10

344

Fiorani, Dino

RN07

297

Fujimori, Atsushi

DA02

56

Eliseev, Andrey

SL27

360

Fang, Dong

IE03

93

Fiorillo, Fausto

HH01

88

Fujimori, Hiroaki

ID04

93

Elizabeth, Suja

PH04

147

Fang, Yikun

RO07, SN11

301, 366

Fischbacher, Johann

DE01

59

Fujimori, Shin-ichi

RD25, SE23

266, 337

Elkaim, Erik

RA11

251

Fantechi, Elvira

CB04

49

Fischer, Gerda

QL05

228

Fujimoto, Kohdai

RP05

304

Ellis, Tim

JE01

101

Farhan, M. Arshad

QH27

217

Fischer, Peter60, 88, 92, 285, 343

Fujimoto, Satoshi

RC01, RD05, SD09

259, 262, 331

Elmers, H J

QM12, RN12, RP20

233, 298, 306

Farle, M

RP08

304

DE05, HG02, ID01, RJ16,
RJ20, SH04

Fujisawa, M.

KI05

113

Elmers, Hans-joachim

AG04, CH04

38, 54

Fassbender, Juergen

RJ11, SH04

284, 343

Fisher, B. -

PD03

132

Fujisawa, Masashi

QE10, QE16

201, 202

Eloi, Jean-charles

KB01

107

Faulhaber, Enrico

QC24

196

Fisher, Ian

HA05

84

Fujishiro, Hiroyuki

SG18

342

Eloirdi, Rachel

RE03

266

Fauque, Benoit

KJ04

114

Fisk, Zachary

RR08

312

RN01

296

Fayzullin, Rafael

PM22, SO23

171, 370

Fujita, Asaya

SO24, SO26

370, 371

Elwindari, Nastiti

BJ03

48

Fdez-gubieda, M. L.

QM06

232

77, 100, 135, 28,
184, 222, 263, 268,
322, 337

Fujita, A

Elsayed, H. M.

GC03, JC01, PD23,
PP03, QA11, QJ11,
RD11, RE10, SB15, SF03

Fujita, Hirohito

PL12, SK18

165, 353

Emam-ismail, M

QL21

231

Fear, Natalia

PK09, QM01

161, 231

Fitzsimmons, M.

BD01

43

Fujita, Kazuhiro

CA02

48

Emmel, Mirko

CH03

54

Fecher, G. H.

QG24, SK24

212, 354

Fitzsimmons, M. R.

QM18

234

Fujita, Masaki

41, 124, 125, 276

Emoto, Akira

RP17, SK21

306, 353

Fecher, Gerhard H.

CH03, QN19, SD15

54, 239, 332

Fitzsimmons, Mike

KD02

109

BA04, PB29, PB30, PB32,
RH12Emoto, Shun

PK12

162

Feder, R

RP20

306

Flachbart, K.

QC22

195

Fujita, Takahito

QH02

213

Enders, Axel

AD03

35

Fedorov, A.

SD04

330

Flachbart, Karol

QC20, QI02, RE13

195, 218, 268

Fujiwara, Kosuke

SK08

351

Endo, Keita

PG04

143

Fedorov, Dmitry

EE01

67

Fleck, Catherine L

BF03

45

Fujiwara, Makoto

SK13

352

Endo, Yasushi

QM07, RK04

232, 286

Feiguin, Adrian

JD01

100

Fleet, Luke

CG02, PJ17, SK03

53, 157, 350

Fujiwara, N.

QB23

190

QB16

189

Endoh, Tetsuo

BI02

47

Felser, C.

QG24, SK24

212, 354

Fleury, Eric

AJ05

40

Fujiwara, Naoki

Engelke, Josefin

SM02

361

Felser, Claudia

54, 32, 97, 239, 260

Flouquet, Jacques

JC02, PC17, RE10, SF03

100, 129, 268, 337

Fujiwara, Tetsuya

QI18, SC24, SG09

220, 329, 341

Enoki, Kentaro

PD13

134

CH03, CH04, HP72, II03,
QN19, RC10

Folcke, Emeric

BB03, KB02

41, 107

Fukada, Yukimasa

RA18

252

Enoki, Masanori

PB29, PB30, PB32, QH10

124, 125, 214

Feng, Chunmu

AB04

34

Follath, Rolf

CD03

51

Fukami, S.

RL07, SH07

291, 344

Entani, Shiro

BH05, BH06, QL15

46, 47, 230

Feng, Haibo

RO04, SN11

301, 366

Fontes, Magda

SE22

336

Fukami, Shunsuke

RL10

291

Entel, Peter

QH05

213

Feng, Kai

RA02

249

Fontes, Magda B.

SM17

363

Fukamichi, K

RR08

312

Fukatani, Naoto

PJ12, PL12, RC18, SA07,
SK18

156, 165, 261, 317,
353

Eom, Jonghwa

PJ30, QK06

159, 225

Feng, Qi

RN18

299

Forcen-vazquez, Elena

QO16

243

Eom, Man Jim

SD07

331

Feng, Shiping

PB28

124

Forostiak, Serhiy

BH03

46

Eom, Man Jin

RB14

256

Feng, Wuwei

QO22

244

Fox, A. M.

RN18

299

Fukazawa, H.

QB28

191

Epicier, Thierry

KB05

108

Feng, Xinliang

QK14

226

Foyevtsova, Kateryna

SG22

343

Fukazawa, Hideto

187, 189, 198, 201

Erbe, Artur

RJ11

284

Feng, Yuan Ping

SJ09, SK34

350, 356

Fraga, G L F

PG03

142

QB02, QB15, QD12,QE12Erekhinsky, M.

BD01, BD04

43

Feng, Yuanping

GI04, QP06

82, 246

Fraile, A

SF09

338

Fukui, Takahiro

SD09

331

Eremin, A. V.

QK07

225

Feng, Zhou

RA19

252

Fraile, Arantxa

RN14

299

Fukuma, Michinori

PB06, SG16

121, 342

Eremin, Alexander

RA23

253

Feng, Zhuo

RE15

268

Franco, N.

QM13

233

Fukuma, Yasuhiro

85, 86, 233, 287

Eremin, E. V.

QK07

225

Fenske, Jochen

QM02

231

Francoual, Sonia

CI04, QA01

55, 182

HD04, HE05, QM10,
RK11

Eremin, Evgeniy

RA23

253

Ferber, Johannes

SG22

343

Franken, Jeroen

CH05, EI06, GE02, JE01

54, 71, 78, 101

Fukunaga, Hirotoshi

CC04

50

Fernandez Baldis, Federico

QL06

229

Franken, Jeroen H.

IE02

93

JH01, PM08, PM09,
RO03

104, 168, 301

Erfanifam, S.
Eriksson, Olle

RG06, SH11272, 345

Fernandez Barquin, L.

QD10, QM06

198, 232

Franz, Christian

QC17

195

Fukushi, Syousuke

JI01

105

SN14

366

Ernst, Stefan

JC01

100

Fernandez-alonso, F

SF09

338

Fratesi, Guido

PL21

167

Fukushi, Takanori

Eshraghi, M.

PI24

154

Fernandez-pacheco, Rodrigo

RN08

298

Freeman, Arthur

EC02

65

Fukushima, A.

CE03, CE06, ID02, RJ07

51, 52, 93, 283

Espinosa, Francisco

QO26

245

Ferrari, Alberto

PL21

167

Freeman, Arthur J

RB26

258

Fukushima, Akio

47, 87, 94, 110, 163

Estrada, Francisco

QO26

245

Ferraz, Alvaro

PD04

132

Freeman, Arthur J.

RC16, SO10

261, 368

BI01, HF01, IE04, KF01,
PK20

Etgens, Victor

QL06

229

Ferreira, P.

QM13

233

Freeman, Paul G

PI03

151

Fukushima, Tetsuya

KF04

111

130

Fukuta, R.

CF04

53

PH07, PI07

148, 151

Evans, Rfl

FC01

73

Ferriani, Paolo

IH02

96

Freeman, Paul G.

PC22

Evans, Richard F. L.

RK17, SJ04

288, 349

Fert, A.

CE03, CE06, ID02, RJ07

51, 52, 93, 283

Freemnan, A. J.

RM04

295

Fukuta, RyuichiroEverschor, Karin

DF02

60

Fert, Albert

ID03, IE04, PP01

93, 94, 28

Friedemann, Sven

SB24

324

PJ26

159

Fetisov, Leonid Yu

PN22

175

73, 128, 214, 252,
268, 328, 337

Fukuyado, Junichi

Eves, John

FB04, PC09, QH12,
RA19, RE15, SC16, SF05

Fullerton, Eric E

PK09, QM01

161, 231

Ewings, Russell A.

HA04

83

Feyerherm, Ralf

EC04

66

Friedenberger, Nina

RP08

304

Fuminori, Honda

RD19

265

Exl, Lukas

DE01

59

Fidler, Josef

SJ07

350

Friemel, Gerd

JC04

100

Funaki, Nakaba

PN24

176

Eyidi, Dominique

QP18

248

Fidrysiak, Maciej

QE24

203

Frings, Paul

RQ16

309

Furdyna, J. K.

173, 229, 232

Figueroa, Adriana I

EF03

68

Fritsch, Veronika

RE12

268

PN08, PN09, QL08,
QM04

F

384

QF17, RI15

Fijalkowski, Marcin

PD21

135

Frontera, Carlos

EC04, RA1766, 252

Furomoto, Yoshitoki

QP09, QP10, QP11

246, 247

Fabreges, Xavier

AA03, RQ16

33, 309

Fikacek, Jan

BB04

42

Frost, Christopher D

IC05

92

Furukawa, Kohsuke

KC06

109

Fabris, Frederik

PB10, PB33

121, 125

Filipek, Stanislaw M.

QI06

218

Fruchart, Olivier

SH03, SH06

343, 344

Furukawa, Nobuo

GB01, PA07

76, 117Fabrizi, Federica

AF01

36

Filipov, V. B.

JC04, PE12, QC22, RH07

100, 138, 195, 275

Fu, Bin Hao

RD12

264

Furukawa, S.

RA22

253

Faina, Bogdan

BE03

44

Filipov, Vladimir

QC20

195

Fu, Hua-hua

QK18

227

Furukawa, Satoshi

DA04

56

Faini, Giancarlo

FD03

74

Filipov, Vladimir B.

QC19

195

Fu, Tsu-yi

IH06

96

Furukawa, Yuji

QB15, QE12

189, 201

Falck, Augusto

PB33

125

Filippetti, Alessio

PF03

139

Fuente, C De La

SF09

338

Furukawa, Yuta

RF09

270

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

385

Author Index

Furusaka, Michiro

RP01

303

Gavrilkin, Sergey Yu.

QC19

195

Gradhand, Martin

EE01

67

Fuse, Takahiro

PF11

141

Gawryluk, Dariusz J.

QB30

192

Glushkov, Vladimir V.

QC19

195

Graf, Matthias

KG01

111

Fuseya, Yuki

KJ04

114

Gazo, Emil

QI02, RE13

218, 268

Gnezdilov, Vladimir

QE27

203

Grams, Christoph

QA22

186

Fusil, Stephane

AE03

36

Ge, H.l.

RO14

303

Gnida, DanielAB03, SF1234, 339

Granado, Eduardo

PI19

153

Futamoto, Masaaki

ED01, PM18, SM15

66, 170, 363

Ge, Hongliang

RO13, RO15

302, 303

Go, Naoto

PK12

162

Granovsky, Alexander

CH01, SO04, SO27

54, 367, 371

Geerts, Y. H.

EH02

70

Godinho, M.

QM13

233

Granroth, Garrett E

PI07

151

Gegenwart, P

DC03

58

Godlewski, Marek

DD02

58

Granroth, Garrett E.

RD14

264

Author IndexG

386

SG07, SG08

Gabani, S.

QC22

195

Gegenwart, Philipp

FB03

73

Goetzke Macedo, Daniela

PB10

121

Grbic, Michael

IC02

92

Gabani, Slavomir

QC20, QD12, QI02, RE13

195, 198, 218, 268

Gegenwart, Phlipp

SG13

341

Goff, Jon

DH03

62

Greene, L. H.

GA01

75

Gaczynski, Piotr

RE03

266

Gehring, G. A.

RN18

299

Gofryk, K.

FB01

73

Greene, Laura H.

RD09

263

Gahlot, Ajay Pratap Singh

SC02

325

Geibel, C.

QB14

189

Gofryk, Krzysztof

SE19

336

Gretarsson, Hlynur

DC03

58

Gaita-arino, A.

BC01

42

Geibel, Christoph

DC03

58

Greven, Martin

CA03

49

RP15

305

34, 51, 73, 100, 107,
133, 193, 195, 197

Gog, Thomas

Galanakis, Iossif

Goh, Jing Qiang

SJ09

350

Grigera, Santiago

EA04

64

Galceran, Regina

IH01, SO18

95, 369

AB02, CD03, FB04, JC01,
KA03, PD12, QC09,
QC18, QD07

Goh, Swee K

FB04

73

Grigoriev, Sergei

QM08

232

Gallagher, Andrew

KB04

108

Geim, Andre

PP07

29

Goh, Swee K.

PC09, RQ09

128, 308

Grigoriev, Sergey

DF04, SL2760, 360

Gallagher, Bryan L

SH09

344

Gemming, Sibylle

RJ11

284

Goh, Swee Kuan

PC02

127

Grigorieva, Anastasiya

ED06, KI05

67, 113

Gallais, Yann

PD17

134

Geng, Y. X.

PM03

167

Goho, Takeshi

RG11

273

Grigoryeva, Natalia

SL27

360

Galyas, Anatoly

QG05

209

Genossar, J. -

PD03

132

Goikhman, Alexander

DD04, SK26

59, 354

Grigoryeva, Natalya

QM08

232

Gambarelli, Serge

AI04

39

George, Jean - Marie

HE04

86

Goikolea, Eider

RN13

298

Grimaldi, E.

CE06, ID02, RJ07

52, 93, 283

Gandhi, Ashish Chhaganlal

QP07

246

George, Jean-marie

AI04, CG03

39, 53

Gokhfeld, Denis

SB09

321

Grin, Yuri

RD12

264

Gang, Qiu Xiang

SB01

320

Georges, Antoine

AB04

34

Goko, T.

GF01

79

Grioni, Marco

SE08

334

Ganguly, Arnab

SH12

345

Georgii, Robert

DF02

60

Gollisch, H

RP20

306

Grisewood, N.

PJ26

159

Gan'shina, Elena A

PN22

175

Gerasimov, Evgeny G.

QI08

219

Goltz, Till

AB02

34

Grishin, Alexander

CJ01

55

Ganz, Philipp R.

QL05

228

Gerber, Alexander

DE02, RK01

59, 286

Golubov, A. A.

GA03

75

Griveau, Jean-christophe

RE03, SE19

266, 336

Gao, Bo

SO25

370

Gerber, Simon

CD04

51

Gomes, Angelo M

QO09

242

Groessinger, Roland

SA02

316

Gao, Guoying

PN10, RM03, SO01

173, 295, 366

Gercsi, Zsolt

RF15

271

Gomez Sal, J. C.

GH05, QD10

81, 198

Grois, Andreas

BE03

44

Gao, Kaige

RA14

251

Gerhardt, Theo

SH04

343

Gomez, Maria Elena

SA12

318

Grollier, J.

CE03, CE06, ID02, RJ07

51, 52, 93, 283

Gao, Liangqiu

RL05

290

Geurts, Christian

JE01

101

Goncalves, Antonio

SG03

340

Grollier, Julie

HF01, ID03, IE04

87, 93, 94

Gao, Lu

AH04

38

Ghaffari, Muhammad

PN03

172

Gong, Junfeng

RM08

296

Grosche, F Malte

FB04, QH12, RA19, SF05

73, 214, 252, 337

Gao, Tie Ren

BD05

43

Ghiringhelli, Giacomo

BA03

41

Gonzalez, Jorge L.

SM17

363

Grosche, F. Malte

RE14, RE15

268

Garbarino, Gaston

JJ04, RB20

106, 257

Ghoshal, Sayak

PJ28

159

Gonzalez, Julian

CH01, CJ04

54, 56

Grosche, Malte

PC02, PC09

127, 128

Garcia - Garcia, A.

KC05, PJ23

109, 158

Ghoshray, A

QM24

235

Gonzalez, Julianmaria

DJ03

63

Gruber, Manuel

GI03

82

Garcia - Munoz, Jose Luis

PA13

118

Ghoshray, Amitabha

RB15

256

Gonzalez, Lorena

DJ03

63

Grundler, Dirk

GG02

80

Garcia, Carlos

PJ25

158

Ghoshray, K

QM24

235

Goo, Cheol Soo

RR04

311

Grunin, Alexey

DD04

59

Garcia, Fernando A.

PI19

153

Ghoshray, Kajal

RB15

256

Goodilin, Evgenii

ED06, KI05

67, 113

Grytsyuk, Sergiy

QP01, QP02

245

Garcia, Flavio

RJ12, RJ13

284

Giamarchi, Thierry

CC03

50

Gopalakrishnan, C

181, 319, 320, 355

Gschneidner, Jr., Karl

JJ01

106

Garcia, Jackeline Collave

SE22

336

Giannopoulos, George

DD06, QP12, QP13

59, 247

PO24, SA21, SA22,
SA23, SK32

Gu, BoJF03

102

Garcia, Javier

DG03

61

Giblin, S. R.

PI03

151

Goraus, Jerzy

PD21

135

Gu, G.

GA01

75

Garcia, Luis

EF03

68

Giebels, F

RP20

306

Gorbunov, D. I.

QI03, QI09

218, 219

Gu, Genda

HA03

83

Garcia, Luis Miguel

GG03, GG05, QI14

80, 220

Gillett, J.

GA01

75

Gorbunov, Denis

SG03

340

Gu, Han

RR29

315

Garcia, Noel A.

QB18

190

Gillon, Beatrice

GF04

79

Goremychkin, E A

SE13

335

Guan, Wen

SO25

370

Garcia, Vincent

AE03

36

Gingras, M. J. P.

GF01

79

Goremychkin, E. A.

RA22

253

Guari, Yannick

RN15

299

Garcia-flores, Ali F.

PI19

153

Ginting, Dianta

RA01

249

Goremyhkin, E A

SF09

338

Gubbiotti, Gianluca

GG02

80

Garcia-garcia, Javier

PI18

153

Giouroudi, Ioanna

SA02

316

Gorria, Pedro

JJ04

106

Gubkin, Andrey

QG04

208

Garcia-munoz, Jose Luis

EC04, RA1766, 252

Giovannini, Loris

GG02

80

Goryunov, Yuriy Vladimirovich IG02, PE09, QG23

95, 137, 212

Gubkin, Andrey F.

QN10

238

Garcia-saiz, A.

GH05

81

Giovannini, Mauro

IA02, QD08, RD21

90, 197, 265

Goswami, Partha

PB01, RE02

120, 266

Gudim, I

QJ16

223

Garitaonandia, Jose Javier

QH16, RN13

215, 298

Giri, S

QL14, SO14230, 369

Goswami, Partho

SC02

325

Gudim, Irina

IJ01, RA23

97, 253

Garnweitner, Georg

JG06

104

Giri, S.

PL07

165

Gotberg, Olof

HA03, SE08

83, 334

Gudim, Irina A

CI04

55

Garst, Markus

DF02, RI12

60, 280

Giri, Saurav

RH02

275

Goto, Junpei

PL06

164

Gudim, Irina A.

PA02

116

Gasche, T. P.

QM13

233

Givord, D.

JH02

104

Goto, Takayuki

RH03, RH11

275, 276

Guduru, Veerendra

DH02

62

Gastelois, Pedro

EI01

70

Givord, Dominique

EJ03

72

Goto, Terutaka

RB05

254

Guduru, Veerendra Kumar

SA10

317

Gataullin, Eduard

PE08

137

Gjoka, Margarit

BJ02, RO08, RQ10

47, 302, 308

Gotou, Junpei

RC02

259

Guenther, Marco

PI05

151

Gaudin, Gilles

SH05

344

Gkanas, Evagelos

SN15

366

Gottlieb-schoenmeyer, Saskia QH24

216

Guerrero, Sebastian

QF20

207

Gaulin, Bruce D

JD01

100

Gladczuk, Leszek

QM17

234

Gotze, Kathrin

QD07

197

Guetari, Rim

PM06

168

Gaur, N.k.

QA14, RF04, RQ06

184, 269, 308

Glavatskyy, I.n.

QG27

212

Gouchi, Jun

QC03

192

Guidi, T.

RA22

253

Gautam, Sanjeev

PG27, QO27

146, 245

Gloos, Kurt

SB16, SK07

322, 351

Goumri-said, Souraya

QL17, SK12230, 352

Guillot, Maurice

QJ15

223

Gavilano, Jorge

PO17, QF20

180, 207

Gloskovskii, A.

SK24

354

Gouvea, Cristol De Paiva

PB11

121

Guimaraes, Alberto Passos

RJ13

284

Gavilano, Jorge L.

CD04

51

Gloter, Alexandre

AE03

36

Goya, Tomoki

RB06

255

Guimaraes, Marcos H. D.

GI05

82

Gavrichkov, Vladimir

PD01

132

Glushkov, V. V.

PE12, QC22, RH07

138, 195, 275

Goyal, Neeraj

QJ17

223

Gukasov, Arsen

SE16

335

Gavrilkin, S.

QC22

195

Glushkov, Vladimir

ED06, KI05, QC20

67, 113, 195, 340

Grabs, Ilka Marina

JG06

104

Guleria, Anupam

QB14

189

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

387

Author Index

Gumeniuk, Roman

RD12

264

Ham, Chan

PO13

179

Harumori, Kohei

SK23

354

Henriques, Margarida

SG03

340

Gunduz Akdogan, Nilay

EJ04

72

Hamada, Rika

QH28

217

Haruna, Daiki

QG10

209

Her, Eun Ju

CB01

49

Guo, Guan Yu

JI05

105

Hamada, Tomoyuki

RF07

270

Haryono, Suprijadi

RC02

259

Hering, Eduardo

SE22

336

Guo, Hong

QK02

224

Hamamoto, Kenta

SA03

316

Hasan, M. Z.

SD04

330

Hering, Eduardo N

SE15

335

Guo, Huaiming

SD18

333

Hamano, Suguru

IG05

95

Hasan, M. Zahid

HI02

89

Heringa, Jouke R

RI18

281

Guo, Lu Kai

RD12

264

Hamasaki, Tatsuichi

RH19

277

Hase, Masashi

147, 183, 184, 276

Hernandez, Yenny

QK14

226

Guo, Shuang

RK16

288

Hamaya, Kohei

HE01, RK1086, 287

PH02, QA05, QA07,
QA09, RH11

Hernandez-velasco, Jorge

PI18

153

Guo, Zhaohui

PK18, RO04, RO07

163, 301

Hamrle, Jaroslav

CH03, QH19

54, 216

Hasegawa, Kota

RL15

292

Hernando, Blanca

DJ03

63

Gurevich, Alexander

JA02

98

Han, Dong-soo

60, 285, 345

Hasegawa, Takahiro

QI17

220

Herng, Tun Seng

DD03

58

Guritanu, Violeta

QD07

197

DE05, RJ16, RJ17, RJ18,
SH14

Hasegawa, Takashi

SL02

356

Herrero Albillos, Julia

GG03, RP04

80, 303

Guryeva, Tatyana

QM19

234

Han, Guchang

QP06

246

Hasegawa, Takumi

127, 145, 263, 342

Herrero-albillos, Julia

EF03, GG05, QI14, RP08

68, 80, 220, 304

Gusakova, Daria

SI09

347

Han, Jeong-ho

RR14, SN04

313, 364

PC05, PG16, RD10,
SG15

Herrero-martin, Javier

EC04, PA15, RA1766, 118, 252

Gusev, Sergey

SG17

342

Han, Jinhee

RC15

261

Hasegawa, Takuya

QA05, QA07, QA09

183, 184

Herringer, S N

BC05

42

Gusin, Pawel

PG26

146

Han, Jung Hoon

DF01

60

Hashemi, S. E.

PO29

182

Herrmannsdoerfer, Thomas

PC27, SD07

131, 331

Gutersloh, Daniel

PE07

137

Han, Jung-ho

SN02

364

Hashemi, Sayed Ebrahim

PO27

181

Herschbach, Christian

EE01

67

Gutfleisch, Oliver

DJ04, KH01, SO19

63, 112, 369

Han, Jungmin

RL14

292

Hashi, Shuichiro

PO20, SM08, SN14

180, 362, 366

Hervieu, Maryvonne

RA11

251

Guth, Konrad

KH01

112

Han, S. W.

PG11

144

Hashim, Mansor

BJ06, RQ22

48, 310Herynek, Vit

BH03

46

Gutmann, Matthias

SD13

332

Han, Sang Wook

PB12

122

Hashimoto, Susumu

CE05

52

Herzer, Giselher

PM04

168

Gutowska, M. U.

PH06, PM05

147, 168

Han, Seungkyu

RA26

253

Hashimoto, Takuya

BG04

46

Herzog, Gabriela

HF03, RP16

87, 305

Guziewicz, Ela

DD02

58

Han, Suk Hee

225, 226, 294

Hashmi, Arqum

RM07

296

Hewson, Alex

SF15

339

Gvasaliya, SeverianCC03, IJ06

50, 98

QK11, QK12, QK13,
RL28

Hassinger, Elena

JC02

100

Heyderman, Laura

HP62

31

Gwon, M. J.

PO23

181

Han, Sukhee

QK10

225

Hasuo, Tadahiko

SG09

341

Heyderman, Laura J.

RK17

288

Gwon, Minji

RK15

288

Han, Suk-hee

PJ30

159

Hatakeyama, Kenichi

QN02

236

Hicks, Trevor

IJ03

97

Gwon, Yoonjung

PN08, PN09, QM04

173, 232

Han, Tianheng

QE27

203

Hatakeyama, Kodai

RP06

304

Hidaka, Hiroyuki

QC25, SE07

196, 334

Gyawali, Parshu R.

PJ01

154

Han, Xiufeng

QK02, SA19, SA20

224, 319

Hatayama, Nobukuni

PF08

140

Hien, Nguyen Thi Minh

SA16

318

Han, Xiu-feng

RM01

295

Hatayama, Yuki

RO09

302

Hierro Rodriguez, Aurelio

GG03

80

Han, Yibo

QF06

204

Hatch, R.

II02

97

Hiess, Arno

AA05, RB07

33, 255

Author Index

H

388

Haam, So Young

JB02

99

Han, Young Ho

BJ04, QN13

48, 238

Hattori, Taisuke

RD05, RD08

262, 263

Higasginaka, Ryuji

QE13

201

Haase, Juergen

RQ09

308

Hanazawa, Atsufumi

RI17

281

Hauguel, Tony

SA24

320

Higashinaka, Ryuji

RD17

264

Haazen, Pascal P.

IE02

93

Handayani, Ismudiati Puri

PH17

149

Havela, Ladislav

QI19, RD26, RE09, SG03

220, 266, 267, 340

Hikihara, Toshiya

JD04

101

Haberkorn, N.

QB31, SB12

192, 322

Handayani, Puri I.

PA24

119

Haverkort, Maurits Wim

QC09

193

Hild, K

QM12233

Habermeier, H. -u.

ED05

67

Handoko, Djati

RP03, SH10

303, 344

Haw, S. C.

QB21, SM11

190, 362

Hilgenkamp, Hans

DH02, SA10

62, 317

Habermeier, Hanns-ulrich

RB29

258

Handoko, Erfan

RA15

251

Hayakawa, J.

IF01

94

Hill, John

DC03

58

Hachiuma, Suguru

QA05

183

Haney, Paul M.

EE02

67

Hayashi, Hisashi

QD17

199

Hill, R. W.

HA05

84

Hackl, Rudi

CA03

49

Hanfland, Michael

RB20

257

Hayashi, Junichi

PD10

133

Hillebrands, Burkard

HD01, SI1585, 348

Haddon, Robert C.

PN16

174

Hanh, Duong Thi

HC02, PE15

84, 138

Hayashi, Kouichi

SK13

352

Hiller, Adrian

PC12

128

Hadiyawarman, H

QL09

229

Hanson, Maj

SL15

358

Hayashi, Masamitsu

IF05

94

Hillier, A

SF09

338

Hadjipanayis, George

BJ02, CB05, DD06, EJ04,
KB04, RO08

47, 49, 59, 72, 108,302

Hanyu, Takahiro

BI02

47

Hayashi, Misaki

RP07

304

Hillier, A D

SE03, SE05, SE13333, 334, 335

Hao, Lin

PK03

160

Hayashida, Minami

QC18

195

Hillier, A. D.

KA02

107

Hadjipanayis, George C.

GJ01

82

Happo, Naohisa

SK13

352

Hayato, Miyagawa

PN24

176

Hillier, Adrian

JA05, SC01

99, 325

Haenni, Nora

QG14

210

Hara, Masahiro

KC06

109

Hayden, Stephen

RE14

268

Hillion, Arnaud

QN06, RK03

237, 286

Haga, Yoshinori

GC03, HP11, IG04,
PC28, PD09, PD13,
PD23, QC03, RD01,
RD11, RD25, RE10,
SB15, SE23, SF03

77, 30, 95, 131, 133,
134, 135, 192, 262,
263, 266, 268, 322,
337

Hara, Shigeo

QE17, QF09

202, 205

Hayn, Roland

CD03

51

Hilscher, Gerfried

SC01

325

Harada, Eiichiro

RD06

263

He, Chenchong

AJ03, JI06

40, 105

Hindmarch, Aidan T

SH09

344

Harada, Kazunori

KF05

111

He, Chunyong

DH01

62

Hinks, D G

SC05, SE14326, 335

Harada, Keitaro

SO515

369

He, Junfeng

SB31

325

Hinzke, Denise

FA02, FC03, RJ04

72, 74, 283

Harada, Ken

AF03, PG15

37, 144

He, Long

SB13

322

Hirai, Daigorou

RB04

254

Hagemann, Hans

QC13

194

Harada, Masashi

PO17

180

He, Pan

JI05

105

Hirai, Daishi

QD06

197

Hagihala, Masato

QE18

202

Haraguchi, Shinya

AE02, PL06, RC02, RL02

36, 164, 259, 290

He, Zhangzhen

PA18, QF24

118, 207

Hiraka, Haruhiro

QG18, RP01

211, 303

Hagiwara, M.

CF01

52

Haraldsen, Jason

KG01

111

Heald, S. M.

RN18

299

Hirakawa, Sentaro

QI13

219

Hagiwara, Makoto

PB25

124

Haraldsen, Jason T

EB04

65

Hedo, Masato

PD14, QC11, QI12, QI13

134, 194, 219

Hiramatsu, Ryo

RL07

291

Hagiwara, Masayuki

PD13, PI06, QB09, QB24,
QF06, QH02, RH25

134, 151, 188, 191,
204, 213, 278

Harding, Phimphaka

SL10

357

Heger, Gernot

RP22

306

Hirano, Masahiro

QC08

193

Hardy, Vincent

JB05

100

Hehn, Michel

KF02, SH02

110, 343

Hirano, Masanori

QB15

189

Hagymasi, Imre

PD15

134

Hardy, Walter

BA01

40

Heiliger, Christian

DI03

63

Hiraoka, N.

QB21

190

Hahn, Byung-dong

DJ02

63

Hari, Murali Krishnan

QO24

244

Heinze, Stefan

AF02, IH02, IH03, PG1236, 96, 144

Hiraoka, Nozomu

QC09

193

Hajiri, Tetsuya

AD04, QD18

35, 199

Harima, Hisatomo

IE03

93

Hirashima, Dai

PF19

142

RN18

299

30, 264, 273, 321,
341

Heiss, Dominik

Hakimi, A. M. H. R.

HP11, RD16, RG11,
SB05, SG14

Hemberger, Joachim

QA22

186

Hirata, Wataru

QB24

191

Halbedel, Bernd

QO02

241

Harnagea, L.

RB17

256

Hemmi, K.

CF04

53

Hirata, Yasuyuki

QO13

242

Hall, Anders

QH11

214

Harrison, N.

SC03

326

Hemmi, Kazuhiro

PH07

148

Hiratsuka, Yusuke

DE04

60

Hall, Michael

HH02, KH03

88, 112Harrison, Neil

BA01, EA03, PB02, QB1340, 64, 120, 189

Hendry, Euan

GD04, RK2078, 289

Hirayama, Shigeyuki

SK31

355

Halue, K.

PE17

138

Harrison, Nicholas

RF15

271

Henkie, Zygmunt

PE19, SB26

139, 324

Hirayama, T.

RD15

264

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index389

Hirohata, A.

SK03

350

Hor, Y. S.

SD04

330

Huijben, Mark

DH02, SA10

62, 317

Iida, Hiroki

QC10, QC11

193, 194

Hirohata, Atsufumi

PJ17, SK11

157, 352

Hord, Roland

PI05

151

Hung, C. H.

SB04

320

Iikubo, Satoshi

PB32, QH09, QH10

125, 214

Hiroi, Masahiko

QG13, QG15, QH08,
QN20, SK23

210, 214, 239, 354

Hori, Akihiro

HC03, QF25

85, 208

Hung, Dung S

RK07

287

Iimura, S.

QB23

190

Hori, Shiori

QM16

234

Hunt, C. R.

GA01

75

Iizuka, T

QJ05

221

JA04, PC17, PG16,
QE03, QE05, QE08,
QE13, QG16, SB05,
SG04, SG1499, 129, 145, 199,
200, 201, 210, 321,
340, 341

Hori, Yusuke

PD10

133

Hur, Nam Jung

SE02

333

Iizuka, Takuya

QD07

197

Horigane, K.

QE15

201

Hur, Namjung

PI10, QA24, QM23

152, 186, 235

Ikeda, Hiroaki

QC04, QC08

192, 193

Horihata, A.

CG02

53

Husek, I

RB08

255

Ikeda, Masami

QB24, QF06

191, 204

Horng, Herng-er

AH03, GH01, QM27

38, 80, 236

Hutanu, Vladimir

PA14, RP22

118, 306

Ikeda, Naoshi

RA18

252

Hirono, Toko

RP07

304

Horng, Lance

PC30, SB19, SH08, SL18

131, 323, 344, 359

Huxley, A. D.

GC01

77

Ikeda, Shoji

QP14, SI17

247, 348

Hirose, Yusuke

PB27, PD08, PD13, RD19

124, 133, 134, 265

Horsch, Peter

RG18

274

Huxley, Andrew

GC04

77

Ikeda, Shugo

IG04, RB03, RD11, RD13

95, 254, 263, 264

Hirsch, Konstantin

KD01

109

Horvatic, Mladen

IC02

92

Huxley, Andrew D

SE12

335

Ikeda, Yoichi

QC18, SE10

195, 334

Hirschberger, Max

SF05

337

Hosaka, Tomohiro

QA05, QA07, QA09

183, 184

Huynh, Chinh Dang

RN19

299

Ikedo, Yutaka

PO17

180

Hirtenlechner, Eva

QG14

210

Hosokawa, Shinya

SK13

352

Hwang, Chan Yong

PJ14

157

Ikehara, Yuki

GJ02

82

Hisada, Akihiko

SE01

333

Hosono, H.

QB23

190

Hwang, Chanyong

CF04

53

QG13

210

Hosono, Hideo

PC23, QB16, QC08

130, 189, 193

43, 96, 235, 288,
289, 307, 345

Ikeuchi, K.

Hisamatsu, Toru

BD03, IH04, IH05,
QM26, RK18, RK19,

Ikeuchi, Kazuhiko

DA01, PI07, RH12

56, 151, 276

Hisayoshi, Keiji

PN11, RQ03

173, 307

Hosono, Kazuhiro

PJ18

157

RP23, SH13

Ikeura, Tohru

PD16

134

Hjorvarsson, Bjorgvin

AF05, RP1537, 305

Hossain, Z.

QB14

189

Hwang, Do Guwn

PO09, PO10

178

Ikuo, Nakai

QC01

192

Hjorvarsson Bjorgvin

QH11

214

Hossinzadeh, Nahid

PB15

122

Hwang, Do Gwen

PO06

178

Ilyn, Maxim

SO04, SO27

367, 371

Ho, Huei-ying

PL03, PL13, QM09

164, 166, 233

Hotta, Chisa

BC05

42

41

Im, Dae Yeong

QO20

244

Hoa Hong, Nguyen

SM07, SM10

362

Hotta, Koji

RM05

296

357

Im, H. J.

SG11

341

Hoang, Nam-nhat

RA10, RF02, SG10, SO12251, 269, 341, 368

Hotta, Takashi

PF11

141

122, 144, 149, 183

RC16

261

Hodgson, Matthew

QK09

225

Hou, Yanglong

SL12

358

PB12, PG11, PH14,
QA04

Im, Jino
Im, Mi-young

60, 88, 285, 343

Hodovanets, H.

RD02

262

Howard, A.

QB12

189

Hoeijmakers, Mark

GE02, JE01

78, 101

Hrabec, Ales

SH05

344

Hwang, Jungmin

PA21

119

DE05, HG02, RJ16, RJ20,
SH04

Hradil, K.

PI03

151

310

74, 188

81

RQ19, RQ20

FE01, QB10

GH02

Hwang, Seong-min

Imada, Masatoshi

Hoffmann, Germar

68, 212

Hsiang, Hsing-i

BJ01, QN24, QN25

47, 240

312

111

EF02, QG26

RR10

KF05

Hofmann, Michael

Hwang, Su-jin

Imai, Yoji

97

Hsiao, S. N.

PK06, QP17

161, 248

217

142, 330

II02

QH25

PF17, SD05

Hofmann, PhilipHyun, Seung Ill

Imai, Yoshiki

169

Hsieh, C.c.

SN06

365

119

135

PM10

PA22

PD20

Hoglin, Viktor

Hyun, Sung Wook

Imai, Yuya

33

Hsu, Chuang-han

AD01

35

330

143

AA05

SD03

PG09

Holbein, Simon

Hyun, Young-hwan

Imakyurei, Takumi
Imamura, Hiorshi

RJ06

283

Holder, Matthias

CD03

51

Hsu, Jen-hwa

PK06, QP17

161, 248

Imamura, Hiroshi

HF02, JG03, RA09, SI16

87, 103, 250, 348

Holler, Robert

RG15

274

Hsu, Pin-jui

AD01

35

Imamura, Masaaki

PN26, SO09

176, 368

Hollmann, Nils

PI08, PI17

152, 153

Hsu, Wei-hung

QN25

240

Imanaga, Yukihiro

DE04

60

Holmes, Stuart N

PN23

175

Hsu, Y. Y.

SB04

320

Imperia, Paolo

PO12

179

Honda, Fuminori

HP11, PB27, PD08,
PD13, PD1630, 124, 133, 134

Hsueh, Wang-jung

AD01

35

Imura, Keiichiro

QD18

199

Hu, Chong Der

QF26

208

Inaba, Kensuke

PF02

139

Honda, Hiroyuki

PG22

146

Hu, Fengxia

SO25

370

Inada, Yoshihiko

PC20, QJ07

130, 222

Honda, S.

CG02

53

Hu, Guanghui

QJ06

221

Inagaki, Keima

SK18

353

Honda, Syuta

RJ08, SK20

283, 353

Hu, Hai Ning

SL16

358

Inagaki, T.

QH09

214

Honda, Zentaro

QF06, RH25

204, 278

Hu, Jin

RB12

256

Inagaki, Yuji

Hong, Cheng Hai

QN03

236

Hu, R.

QC23

196

202, 206, 229, 230,
307, 341

Hong, Do-kwan

PM25, RR31

171, 316

Hu, Shaojie

RL20

293

QE18, QF14, QL11,
QL12, QL13, RQ05,
SG09

Hong, Hongpei

SO01

366

Hu, Xinghao

PO19, SN13

180, 366

Hong, Jeongmin

PN16

174

Hu, Zhiwei

PI08, PI17

152, 153

Hong, Jin Pyo

RK19

289

Huang, Chao-hsien

SH08, SL18

344, 359

Hong, Jinki

PJ31, PK21, QK10

159, 163, 225

Huang, Chia-sheng

RR26

315

Hong, Jisang

JH03, RM07

104, 296

Huang, Chiuan-fa

PK06, QP17

161, 248

Hong, Jongill

JI02, RL30

105, 294

Huang, Chonghui

PG21

145

Hong, K.- P.

PH03

147

Huang, J. H.

PM03

167

Hong, Kwang Pyo

QN09

237

Huang, Jin-hua

PC14

129

Hong, S. C.

PG11

144

Huang, K.w.

AH03

38

Hong, Seung Hwan

SB32

325

Huang, Ssu-yen

PC14

129

Hong, Soon Cheol

KI01, PB12

112, 122

Huang, Wen-min

RE11, SB25

268, 324

Hong, Sung-hak

PB21, RB27

123, 258

Huang, Xiao-lan

IH06

96

Hong, Tae Min

QN22

240

Huang, Xuelian

SM14

363

Hong, Tao

BC05

42

Huber, Rupert

HA02

83

Hong, Yang-ki

JH04, KH04

104, 112

Hudl, Matthias

EI03

71

Honma, Yuki

PH05

147

Hueso, Luis E.

HE02

86

Hono, K

BG01

45

Hugli, Remo Viktor

GF02

79

Hono, Kazuhiro

IF03, SK31

94, 355

Huh, Mooyoung

PM23

171

Honolka, Jan

AD03

35

Huhtinen, Hannu

PB20

123

Author Index

Hiroi, Zenji

390

Author Index

The 19th International Conference on Magnetism

Hwang, Harold
Hwang, J. S.
Hwang, Jihoon

BA02
SL08

I
Ibarra, M R

RN08

298

Ibarra, M. R.

KC05, PJ23

109, 158

Ibarra, Manuel Ricardo

DG05, PG08, SM16

61, 143, 363

Ibragimova, Elvira

RR28

315

Ibrahim, I. A.

RN01

296

Ichihara, Masaki

SB14

322

Ichikawa, Akihiro

QB26

191

Ichimura, Masahiko

PJ07, RL01

155, 290

Ichiyanagi, Yuko

PO02, QL03, RN02

177, 228, 297

Ide, Tetsuto

PH15

149

Ideta, Yukiichi

QF24

207

Idigoras, Olatz

SM04

361

Inami, Nobuhito

EI02, SI1770, 348

Ido, Masayuki

PB08

121

Inami, Toshiya

IG03, QI10

95, 219

278

Inamura, Yasuhiro

RH12

276

243

Indenbom, Mikhail

SA24

320

QA27

187

Idutsu, Yuichi
Idzikowski, Bogdan

RH25
QO17

Idzuchi, Hiroshi

HE05

86

Infante, Ingrid

Ieda, Jun'ichi

JE02, JF02, KF03

102, 111

Ingvarsson, Snorri

GH03

81

Ienaga, Koichiro

QL11, QL12, QL13

229, 230

Innocenti, Claudia

CB04

49

Iga, Fumitoshi

PC05, PE10, RH03

127, 137, 275

Ino, Hiromitsu

PG05

143

196

Inomata, K

SK29

355

206

Inomata, Koichiro

EH01, IF03, IF05

69, 94

JC04

100

Igarashi, Hideki
Igarashi, Kazuhiro

QC25
QF15

Igarashi, Suguru

PB06

121

Inosov, Dmytro

Igawa, Naoki

JJ05

106

Inoue, J.

CG02

53

Iglesias, Oscar

KB06, RN14

108, 299

Inoue, Katsuya

143, 144, 146, 211

Iglesias-silva, E.

CB02

49

PG09, PG10, PG22,
QG22

Ignatchik, Oleg

QD07

197

Inoue, Mitsuteru

QP15, QP16

247, 248

Iguchi, Daisuke

PC17

129

Inoue, T.

SG02

339

Iguchi, Satoshi

GB04

76

Inoue, Y. F.

EF01

68

Ihara, Yoshihiko

PC15, RD05

129, 262

Inoue, Yukihiro F

SG12

341

Insausti, Maite

RN13

298

July 8-13, 2012 Busan, Korea

Author Index

Author Index

391

392

Author Index

Inui, Ken

PN07

173

Isomura, Shinsaku

PK07, QP08

161, 246

Jaim, H. M. Iftekhar

SB06

321

Jeong, Yeon-ho

PM25

171

Inumaru, Kei

PE10

137

Isono, Takayuki

PC17

129

Jaime, Marcelo

JD01

100

Jeong, Yoon Hee

PA11, PN28, QA16

117, 176, 185

Ioannidou, Alexandra

RQ10

308

Isozaki, Toshiyuki

QK19

227

Jain, Abhinav

AI04, CG03

39, 53Jeong, Yoonhee

SM13

363

Ion, Lucian

QK20

227

Itai, Kazumasa

PD15

134

Jakiela, Rafal

DD02

58

Jeong, Yoon-hee

SA18

319

Ionescu, Adrian

PN23

175

Itkis, Mikhail E.

PN16

174

Jakob, Gerhard

CH03

54

Jeong, Yun-ho

RR22

314

Ipatov, Mihail

AJ02, CJ02, PJ25

40, 55, 158

Ito, Eisuke

CB01

49

Jal, Emmanuelle

AD02

35

Jesche, Anton

CD03

51

Ipatov, Mikhail

SO27

371

Ito, Hiroyoshi

RK10

287

Jalli, Jeevan

JH04

104

Jeschke, Harald

SF14, SG22

339, 343

Ipponjima, Tsukasa

SG16

342

Ito, Keigo

SJ03

349

Jamali, Mahdi

EG03, GE03, PJ20, RL19

69, 78, 158, 293

Jeschke, Harald O.

RG14

274

Iqbal, Muhammad Waqas

QK06

225

Ito, Keita

KF05

111

Jamet, Matthieu

PL03

164

QK06

225

Ito, Masakazu

210, 239, 354

Ji, Gaofeng

QB07

188

Irie, Ryotaro

PH15

149

QG13, QG15, QN20,
SK2339, 53, 58, 71, 78,
226

Jhang, Hau-chun

Iqbal, Muhammad Zahir

AI04, CG03, DD01, EI04,
GE01, QK16
RR17

313

Ji, Hyo Seok

RB22, RB23

257

Irifune, T.

SG02

339

CA03

49

Irifune, Tetsuo

PE10

137

Ito, Takahiro

Iritani, Kensuke

QC08

193

Ito, Tomonori

Irusta, Silvia

RN09

298

Ito, Toshimitsu

Irvine, Andrew C.

IE03

93

Isasa, Miren

HE02

86

Isayama, Akira

QO18

Ishaque, Zahid

Jang, Daekyu
295Jang, H.

PH10

148

Ji, Lina

AD04, QD18

35, 199

Jang, Hyuk-jae

AE04

36

Ji, Qing

PJ05

155

RM05, SO10, SO11

296, 368

Jang, Ik-sang

RR14, SN02

313, 364

Ji, Sungdae

QE15

201

QA05, QA07, QA09,
RH11183, 184, 276

Jang, Jin Hak

RR24

314

Jia, Q.

QB31

192

Jang, Jung-tak

CB01, PO15, PO1649, 179

Jia, Quanxi

EB04

65

Ito, Wataru

PB06, QG08, RP07

121, 209, 304

Jang, Jungwon

QO10, SD11

242, 331

Jian, Ming-hung

RR26

315

243

Ito, Yuichiro

PH15

149

Jang, Moongyu

RL21

293

Jiang, Zhaozhen

RR29

315

SH03, SH06

343, 344

Ito, Yuzo

SE10

334

Jang, Pyungwoo

PM20

170

Jiao, L.

QB12

189

Ishibashi, Akira

SM09, SO07

362, 367

Itoh, Akiyoshi

BG03, RK08, RK1745, 287, 288

Jang, Seok-myeong

RR04

311

Jiao, Lin

RD12, SB29

264, 325

Ishibashi, Hiroki

PI02

151

Itoh, Atsushi

PC28

131

Jang, Tae-suk

RO01, RO02

300, 301

Jiao, Wenhe

RB13

256

Ishibashi, Shoji

GB03, RG07

76, 272

Itoh, Hiroyoshi

RJ08, SK20

283, 353

Jang, Y. S.

RQ08

308

Jin, Hosub

RC13, RC16, RC17

261

Ishibashi, Shota

KF01

110

Itoh, Masayuki

PK21

163

Jin, Jung-il

EH02

70

KD03, RP17, SK21

109, 306, 353

56, 150, 187, 191,
206, 254

Jang, Youngjae

Ishibashi, Takayuki

Jang, Z. H.

QF13

206

Jin, X. R.

SL09

357

Ishibashi, Yusuke

RR05

311

DA01, PH19, PH20,
PH23, QB04, QB26,
QF15, RB02

Jang, Zeehoon

RN10, RP13

298, 305

Jin, Xiaofeng

JF01, JF05

102, 103

Ishida, K.

KJ01

113

207, 227, 294, 364

Jangid, S.

RA03

249

Jingwei, Cui

QJ01

221

Ishida, Kenji

QC08, QH13, RD05,
RD08

193, 215, 262, 263

QF24, QK19, RL25,
SM20

Janjan, S. M.

QM05

232

Jo, Euna

BF05, JG05, PA09, PH1845, 104, 117, 149

Itoh, Ryusuke

QA05, QA07, QA09

183, 184

Jansen, Ron

AI05, DI02

39, 63

Jo, Jeong Hong

PL16

166

Ishida, Yuko

RI17

281

Itoh, Shinichi

PI07, RH13, RI10

151, 276, 280

Janson, O.

QF22

207

Jo, Nahyun

RC07, SD10, SD11

260, 331

Ishihara, Sumio

GB02, PI07, RH10

76, 151, 276

Itoi, Chigaku

RI11

280

Jantaratana, Pongsakorn

SL10

357

Jo, W.

SA06

317

Ishii, Akira

PN13

174

Itou, Masayoshi

SH15

345

Jo, William

SA05

317

RC09, RC19

260, 262

41, 143, 144, 162,
351

Janutka, Andrzej

Ishii, Fumiyuki

BA04, PG05, PG13,
PK12, SK04

Jaramillo, Juan Fernando

SM04

361

Jo, Woo Seong

RI20

282

Ishii, H.

QB21

190

Itou, Tetsuaki

BC04, QE22

42, 203

Jardim, Daniela Regina

PO08

178

Jo, Younghun

HF05, RL06

87, 290Ishii, Rikako

QF21

207

Ivanov, Alexandre

JC04

100

Jascur, Michal

RI09

280

Jo, Young-hun

CE04, RL03

52, 290Ishii, Yasuyuki

QB02

187

Ivanov, Vsevolod

SG07

340

Jastrabik, Lubomir

AH02

38

Jo, Younjung

RB14

256

Ishii, Yui

SG14

341

Ivanov, Vsevolod Yu.

QC19

195

Javanparast, B.

GF01

79

Johansson, Borje

EC01

65

Ishijima, Hiroyuki

PN07

173

Ivanshin, Vladimir

PE08

137

Javorsky, Pavel

QI01, SB08

217, 321

Johnston, David C

QE12

201

Ishikawa, Hajime

QE05, QE08

200

Iversen, B.

II02

97

Jay, Jean-philippe

SA24

320

Johrendt, Dirk

QB22

190

Ishikawa, Jun J

PG14

144

Iwakawa, Ken

PD13, QH03

134, 213

Jean, Malick

DG02, PJ22

61, 158

Jomura, Mitsuhiro

QM10

233

Ishikawa, Takuya

RB06

255

Iwama, Hiroki

SN03

364

Jendelova, Pavla

BH03

46

Jonietz, Florian

DF02

60

Ishikawa, Yosuke

RI01

279

Iwamoto, Takashi

RN03

297

Jeng, H.-t.

SD04

330

Jono, Youhei

RB06

255

Ishikawa, Yusuke

PD14

134

Iwasa, A.

QI03

218

Jeon, Byeong Jo

JB02

99

Jonsson, Petra

QH11

214

Ishikawa, Yuya

QF09, QF17

205, 206

Iwasa, K.

CF04, PL14

53, 166

Jeon, Byung-gu

JB02

99

Joo, Dae-suk

PM25

171

Ishimatsu, Naoki

PN20

175

Iwasa, Kazuaki

PI07, RD14

151, 264

Jeon, Eun-kyoung

SD12, SD14

332

Joo, Sungjung

PJ31, PK21, QK10

159, 163, 225

Ishio, Shunji

SL02

356

Iwasa, Yoshihiro

AE05

36

Jeon, Gi-wan

PN25, SK28

176, 355

Joo, Younghoon

PO13

179

Ishiwata, N.

RL07

291

Iwasaki, Hitoshi

CE05

52

Jeon, Gun Sang

RA22, RC08, RE07

253, 260, 267

Joseyphus, Raphael Justin

AJ04

40

Ishiwata, Nobuyuki

RL10

291

Iwasawa, Kotaro

PE11

137

Jeon, Kun-rok

RL03, SM01

290, 361

Jourdan, M

RP20

306

Ishiwata, S.

RA05

250

Iwase, Hiroaki

PD20

135

Jeon, Kyung-won

RR21, RR22

314

Jourdan, Martin

CH04

54

Ishiwata, Shintaro

PA12

117

Iwata, Satoshi

RL08

291

Jeon, Seungmok

EH05

70

Joy, P A

QN12

238

Ishiyama, Kazushi

PO20, RP11, SM08,
SN14

180, 305, 362, 366

Iyama, Ayato

QA12

184

Jeon, Sung Jae

PM28

172

Joy, P. A.

SL13

358

Iyo, A.

QB28

191

Jeong, Hogyun

RC13, RC17

261

Ju, Hye Sun

QN05

237

Ishizuka, Hiroaki

RG03

272

Iyo, Akira

PO19

180

Ju, Sol

PC19

129

RD14, SG05

264, 340

56, 120, 124, 187,
189, 191

Jeong, Ilgyo

Isikawa, Yosikazu

DA04, PB05, PB26,
QB02, QB15, QB29

Jeong, In-bum

IB03

91

Jue, Emilie

SH05

344

Islam, A. T. M. Nazmul

PA23, RH24

119, 278

PC17, PC28, PD16

129, 131, 134

Jeong, Jaehong

RA22

253

Julian, Stephen

EA04

64

Ismail, Ismayadi

BJ06, RQ22

48, 310

HJ05

90Jun, Akedo

PN14

174

Isnard, O.

QG07, QI03

209, 218

J

Jeong, Jinwon
Jeong, Se-young

PH22, PN20, PN21, QL18

150, 175, 231

Jung, Chang Uk

RA28

254

Isnard, Olivier

EJ03

72

Jablonski, A.

DD02

58

Jeong, Su-yeon

RR27

315

Jung, Dahee

HJ05

90

Isobe, Masaaki

PC21, RH14, SF02

130, 277, 337

Jacko, Anthony

RG14

274

Jeong, Tae Won

QO20, SG21

244, 343

Jung, Heejong

HB02, PM16

84, 170

Isobe, Masahiko

QD03, RH16, SB14, SF04

196, 277, 322, 337

Jaffres, Henri

AI04, CG03, HE04

39, 53, 86

Jeong, Tae-chul

RR14, SN04

313, 364

Jung, Hyunsung

DE05, RJ16, RJ18, SH1460, 285, 345

Isoda, Makoto

QE11

201

Jaglicic, Zvonko

SL11

357

Jeong, Y. H.

PM26

171

Jung, Jin-seung

RN20

300

The 19th International Conference on Magnetism

Ito, T.

Itoh, Mitsuru

Izawa, Koichi

RM04

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index393

Author Index

Jung, Jonghoon

PL19

167

Kamarad, Jiri

PM11

169

Kanter, J.

PI15

153

Kawana, D.

CF04

53

Jung, Jong-suck

QA12

184

Kamazawa, Kazuya

PO17

180

Kanter, Jakob

RB21, SC16

257, 328

Kawana, Daichi

PI07, RD14, RH13

151, 264, 276

Jung, K.y.

PJ31

159

Kambale, Rahul Chandrakant QM23

235

Kao, C.-c.

PH10, RA04

148, 249

Kawanaka, Hirofumi

PM13

169

Jung, Kuyeol

PK21

163

Kambe, Shinsaku

PD09

133

Kao, Chih-kuei

IH06

96

Kawanishi, Yohei

HE03

86

Jung, M. H.

RK19

289

Kambe, Takashi

RA18, SC04

252, 326

Kapaklis, Vassilios

AF05, EI03, RP1537, 71, 305

Kawar, Tatsuya

RQ05

307

Jung, Min Hwa

PN28

176

Kameli, P.

PI24

154

Karaki, Y.

EF01

68

Kawasaki, Ikuto

RD25, SE23

266, 337

Jung, Min-cherl

RC14

261

Kameli, Parviz

PI23

154

Karaki, Yoshitomo

CC05

50

Kawasaki, M.

RG10

273

Jung, Min-hwa

SA18

319

Kamenev, K. V.

GC01

77

Karamat, Shumaila

PN03, QL02

172, 228

Kawasaki, S

QB11

188

Jung, Mung-hwa

PJ31

159

Kami, Daisuke

PO03

177

Karipoth, Prakash

AJ04

40

Kawasaki, Y.

SG02

339

Jung, Myung- Hwa

RC07

260

Kamihara, Yoichi

QB16, QC07, SE09

189, 193, 334

Karla, J. Merazzo

GG05

80

Kawasaki, Yu

QF24

207

Jung, Myung-chul

SO06

367

Kamihara, Youichi

QC08

193

Karpinski, J.

PC01

126

Kawashima, Kenji

PB06, PB07, SG16

121, 342

Jung, Myung-haw

QO11

242

Kamimori, Tastuo

PG05

143

Karpinski, Janusz

RB19, RB20, RB21

257

Kawashima, Naoki

DC04

58

Jung, Myunghwa

SM13

363

Kamimori, Tatsuo

QG10

209

Karthigeyan, A

SA21

319

Kawata, K.

SG11

341

Jung, Myung-hwa

PC12, PK17, PN19,
QH07, QO10, RK06

128, 163, 175, 214,
242, 286, 331, 349

Kamionka, Thomas

FD02

74

Karthik, T

PN18

175

Kawata, Tomokazu

PD22

135

Kampert, Erik

KB06, PB11, SB18, SD07

108, 121, 323, 331

Karube, Kosuke

RD05, RD08

262, 263

Kawata, Toru

RD19

265

Kanai, Noriko

QD17

199

Kasagi, Teruhiro

QN02

236

Kazakov, Alexander

CH01

54

SD10, SD11, SJ02
Jung, S. H.

RK19

289

Kanai, Yasushi

BG04

46

Kasai, S

SK29

355

Kazuhei, Wakiya

QC16

194

Jung, Sanghoon

RK06

286

Kanatzidis, M. G.

GA01

75

Kasai, Shinya

HG02, ID04, IF05, SK31

88, 93, 94, 355

Kazunori, Umeo

QC16

194

312, 313, 314

Kanazawa, Ikuzo

PB31

125

Kasatani, Yuichi

RK10

287

Kazuo, Watanabe

QJ01

221

169

Kane, Shashank N.

AJ05

40

Kashiwagi, T.

KJ01

113

Kazuyuki, Matsubayashi

QI17, QJ01

220, 221

GE04, JE04

78, 102

Kashiwagi, Takanari

RB06

255

Ke, W. P. Ke

IC03

92

Jung, Sang-yong

Author Index

Jung, Sol

RR11, RR18, RR21, RR22
PM15

Jung, Soon-gil

GA04, RB27, SB28

76, 258, 324

Kanehira, Toma

Jung, Sung Won

RC14

261

Kaneko, Chikafumi

PH05

147

Kassir-bodon, Zoukaa

SH06

344

Keiderling, Uwe

DF02

60

Jungwirth, T.

IF01

94

Kaneko, Koji

JJ05, QJ09, SC23

106, 222, 329

Kastil, Jiri

PM11

169

Keimer, B.

GA03

75

Jungwirth, Tomas

BE05, BI03, IE03, SK22

44, 47, 93, 354

Kaneko, Masaki

QD18

199

Kataev, V.

QE23, QF22

203, 207

Keimer, Bernhard

41, 49, 97, 100, 257

QI05

218

Katano, Susumu

RH01

274

BA03, CA03, IJ02, JC04,
RB20

Juranyi, Fanni

PO17

180

Kaneko, Takejiro

Juraszek, Jean

QA27

187

Kaneko, Tatsuya

PF09, PF10

140

Katayama-yoshida, Hiroshi

KF04

111

Keisuke, Matsumoto T

QC16

194

36

Kaneko, Ulisses F

PI19

153

Kato, Akihiko

RH17

277

Kelekci, Ozgur

PJ24

158

Kaneko, Y.

CG02, RA05

53, 250

Kato, Harukazu

QD06

197

Keller, Lukas

PH02, PI05

147, 151

Kaneko, Yoshio

PH08

148

Kato, Haruki

PL06, RL02

164, 290

Keller, Thomas

GC04

77

336, 371

Kaneshita, Eiji

CA01, SC10

48, 327

Kato, Hiroaki

EJ01, RO05, RO06

71, 301

Kennedy, Shane J

QG09

209

199

Kanetsuki, Hiroaki

PG05

143

Kato, Kenichi

QF25

208

Kennedy, Shane Joseph

EF02

68

48

Kang, Boyoun

QI15

220

Kato, Masaru

PC26

131

Kenzelmann, M.

QE19

202

BF05, JG05, PA09, PH1845, 104, 117, 149

Kato, Motoharu

SG18

342

Kenzelmann, Michel

CD04, QF20

51, 207

Jurchescu, Oana D.

AE04

KK, Ramesh Kumar
K. Sato, Noriaki
K., Samatha

QD18
BJ05

Kabiraj, D.

PG27

146

Kang, Byeongki

Kachi-terajima, Chihiro

QF21

207

Kang, Byeongwon

PB03

120

Kato, Reizo

BC04, SF0142, 337

Kepa, M.

GC01

77

Kaczorowski, Dariusz

AB03, QD05, SE16,
SE17, SF1234, 197, 335, 336,
339

Kang, Byung-sub

PN31

177

Kato, Takashi

PO18

180

Kezsmarki, Istvan

PA14

118

Kang, Chan Seok

RQ19, RQ20

310

Kato, Takeshi

RL08

291

Khademi, F.

PI24

154

Kang, Chang-jong

SC12

327

Kato, Tomoki

PC23

130

Khajehnezhad, A.

QP23

249

Kang, Chong Yun

RA21

252

Katoh, Hisashi

PN07

173

Khalil, H. M. Waseem

PJ24

158

Kang, Han Sam

QN15

238

Katoh, Kenichi

QD09

197

Khaliullin, Giniyat

BA03

41

Kang, Hanhim

QH26

217

Katori, Hiroko Aruga

QD13

198

Khalyavin, D. D.

KA02

107

Kang, J. H.

RA07

250

Katou, Haruki

RC02

259

Khan, Mohammed N. Islam

EI02

70

Kang, J.k.

QO27

245

Katrych, Sergiy

RB21

257

Khan, Nawazish Ali

PB13

122

Kang, J.-s.

BB02, PG11, PH14,
QA04

41, 144, 149, 183

Katsufuji, T.

PA04

116

Khan, Tahir Rao

IA02

90

Kaul, S. N.

QD10, QM06, SL07

198, 232, 357

Khan, Yasmin

QO25

244

Kang, Jeong Soo

PB12

122

Kawada, Yuki

SI03, SI17

346, 348

Kharchenko, M. F.

PH06

147

QL15

230

Kawae, Tatsuya

QE18, QF14, QL11,
QL12, QL13, RE04, SG09

202, 206, 229, 230,
267, 341

Kharchenko, Yu.

PH06

147

Khasanov, Rustem

CD04, IA02, QB22

51, 90, 190

Kaczorowski, Dariuzs

RD23

265

Kadowaki, Hiroaki

QE13

201

Kadowaki, K.

KJ01

113

Kadowaki, Kazuo

RB06

255

Kagayama, Tomoko

PB05, PB27, PC23, SG20

120, 124, 130, 342

Kageyama, Ryu

RP14

305

Kaiju, Hideo

SM09, SO07

362, 367

Kainuma, Ryosuke

PG04, PG07, QG08,
RP07, SK23

143, 209, 304, 354

Kajimoto, Ryoichi

DA01, RH12

56, 276

Kang, Jun-goo

Kajino, J

SE03, SE05, SE13333, 334, 335

Kang, Min Gyu

RA21

252

Kajino, J.

KA02

107

Kang, Sun Hee

PA11, QA16

117, 185

Kawagoe, T.

PL04

164

Khavronin, V. P.

RQ13

309

135, 260

Kang, Sung

QG16, QH15

210, 215

Kawaguchi, Masashi

RL10

291

Khim, Seunghyun

JA03

98

214

Kang, Sunhee

SM13

363

Kawaguchi, Shogo

PI02

151

Khizroev, Sakhrat

PN16

174

109

Kang, W. N.

GA04, PB03

76, 120

Kawahara, Shin-ichi

EI05

71

Khmelevskyi, Sergii

EF05

68

RB27, SB28

258, 324

Kawai, Tetsuroh

PM18, SM15

170, 363

Khodaei, M.

QM28, SA04

236, 316

Kawakami, Norio

DB05, HI04, PF16, RC01,
RC04, RD05, RF01, RF09

57, 89, 141, 259,
262, 269, 270

Khokhlov, Alexey R

QO14

243

Khomskii, Daniel

PA17

118

DA01, QF07, QF08,
QF1056, 205

Khovaylo, Vladimir

DJ04

63

Khovaylo, Vladimir V.

SO19

369

Kajino, Jumpei
Kajino, Junpei
Kakazei, G. N.

PD24, RC07
QH07
KC05

Kakehashi, Yoshiro

EF04, PB24, PF05, QG03

68, 124, 140, 208

Kang, Won Nam

Kalon, Gopinadhan

SK05

351

Kang, Woun

KJ04

114

Kaloni, Thaneshwor Prashad

PN02

172

Kanjilal, D.

PG27

146

313

Kanke, Yasushi

PI16

153

120

Kanki, Teruo

SK16

353

238

Kanoda, Kazushi

BC03

42

Kawamoto, Atsushi

PC15

129

Khusainov, Mansur G.

QA26

186

PG04, PG07, QH21

143, 216

Kawamura, Naomi

IG03, QD17

95, 199

Khusainov, Marat M.

QA26

186

Kamada, Yasuhiro
Kamada, Yukihiro
Kamal, Khaja Mohaideen

394

SE21, SO29

RR13
PB05
QN12

Kawamata, Takayuki

Kamal, Mydeen

IA02

90

Kanomata, Takeshi

Kamarad, J.

PJ23

158

Kanou, Manabu

RC12

260

Kawamura, Yukihiko

JJ05

106

Khvalkovskiy, A.v.

ID02

93

Kanoun, Mohammed Benali

QL17, SK12230, 352

Kawamura, Yukihiro

PD10, PD22, QD06

133, 135, 197

Khvalkovskiy, Alexey

ID03, IE04

93, 94

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

395

Khym, S.

QL08

229

Kim, Gwang-hee

SI01

346

Kim, Ju-jin

SD12

332

Kim, Suhyun

QO11

242

Ki, Sanghoon

PL15, QM21

166, 235

Kim, Gyutae

PJ30

159

Kim, Jun Sung

RB14, SD07

256, 331

Kim, Sumin

PM15

169

Kida, Takanori

QB09, QF06

188, 204

Kim, H.

IA05, QC23, SB30

91, 196, 325

Kim, June Seo

FD03, QK14, SH1674, 226, 345

Kim, Sun Yung

SL01

356

Kiefer, K

RI05

279

Kim, Hae Jin

SL11

357

Kim, Jung Dong

PM28

172

Kim, Sung Baek

PI13

152

Kihara, Takumi

PA06, QA09, QG08,
RA06, RH04

116, 184, 209, 250,
275

Kim, Hanbit

JB02

99

Kim, Jungeun

HC03

85

Kim, Sung Hoon

PO20, SM08, SN14

180, 362, 366

Kim, Hee Seung

PI14

153

Kim, Jungho

DC03

58

Kim, Sung Wng

PC23

130

RC13

261

Kim, Junghwa

IJ02

97

Kim, Sung Yong

PK10

162

Kihou, K.

QB28

191

Kim, Heung Sik

Kihou, Kunihiro

QB02, QB15

187, 189

Kim, Heungsik

DC03

58

Kim, Jun-young

PN23

175

Kim, Sung-beak

PA04

116

Kijima, Hanae

JI01

105

Kim, Heung-sik

RC17

261

Kim, Juyoung

QI15

220

Kim, Sungho

KH04

112

Kikkawa, Akiko

QJ09

222

Kim, Hojung

PH21

150

Kim, K. W.

SL08, SL09357

Kim, Sunghyun

PO06

178

Kikoin, Konstantin

FE04

75

Kim, Hong-seok

SD12, SD14, SO21

332, 370

Kim, Kab-jin

KE03, SH07

110, 344

Kim, Sung-jin

RR11

312

206

Kim, Ho-sup

QM22

235

Kim, Kee Hoon

PJ16

157

312

55, 98, 99, 116, 117,
123

Kim, Sungyong

RR07

CI03, JA03, JB02, PA04,
PA09, PB23

Kim, Tae Hee

CB01, PJ17, QP18

49, 157, 248

Author Index

Kikuchi, Hikomistu

396

Author Index

QF17

Kikuchi, Hikomisu

RI15

281

Kim, Hui Min

Kikuchi, Hikomitsu

QE16, QE21, QF04, QF09

202, 204, 205

Kim, Hwijun

PM17, PM23, PM24

170, 171

Kim, Keun-ho

RR15

313

Kim, Tae Wan

PJ24

158

Kikuchi, Hiroaki

RR13

313

Kim, Hwiseok

PO14

179

Kim, Ki Yeon

QM18, QM20

234

Kim, Tae-hoon

RO01, RO02

300, 301

Kikuchi, Hiroshi

SK21

353

Kim, Hyeong-do

RG04

272

Kim, Ki-chan

RR09, RR10

312

Kim, Tae-suk

PJ31

159

Kikuchi, Yoshihiro

PF17

142

Kim, Hyo-jin

PJ19, QO28, RH18

157, 245, 277

Kim, Kiwoong

179, 309, 310

Kim, Taewan

PJ16, PK10, PK17

157, 162, 163

Kikuchi, Yuhei

QB27

191

Kim, Hyung Joon

JB02

99

PO11, RQ17, RQ18,
RQ19, RQ20

Kim, Taewoo

RR16, SN05

313, 365

PK10

162

Kim, Kwang Hee

RR19

314

Kim, Tae-young

SM10

362

Kim Anh, Do Thi

AJ06

40

Kim, Hyung Jun

Kim, Aaram Joo

RE07

267

Kim, Hyungjun

PJ16

157

Kim, Kwang Heon

QO20, SG21

244, 343

Kim, Taeyueb

QK10

225

Kim, Ahri

PM15

169

Kim, Hyung-jun

Kim, Wan-seop

RQ07

308

282

PB16, PB18, PB35, PB36,
PB38122, 123, 125, 126

RI19, RI20, RI21

109, 166, 225, 226,
294, 295

Kim, Kwang Lok

Kim, Beom Jun

KC04, PL16, QK11,
QK12, QK13, RL28, RL31

Kim, Won Dong

RK19

289

Kim, Bongho

QP19, RL22, SL19

248, 293, 359

Kim, Hyungsuk K. D.

QA15

185

Kim, Kwang S

QH26

217

Kim, Wondong

Kim, Bongjae

PG11

144

Kim, Hyungyu

QP19

248

Kim, Kyeong-sup

PN31

177

BD03, IH04, QM26,
RK18, RP23

43, 96, 235, 288,
307

Kim, Bum-su

QL18

231

Kim, Hyun-jung

SD06

331

Kim, Kyoo

SC12

327

Kim, Won-kyung

PH22, PN20, PN21

150, 175

Kim, Bun-su

PN20

175

Kim, Ill Won

PA11, QA16

117, 185

Kim, Kyoungchul

SA09

317

Kim, Y C

QB25

191

Kim, Byeong-geon

PL15, QM21

166, 235

Kim, Illwon

SM13

363

Kim, Kyoung-whan

EE05, HP21

68, 30Kim, Y. H.

RQ08

308

Kim, Changsoo

BF05, JG05, PA09, PH1845, 104, 117, 149

Kim, In Gee

QG20

211

Kim, Kyung Ho

KC04

109

Kim, Y.i.

PB19

123

Kim, Chang-yeoul

RN24

300

Kim, Ingyu

JB02

99

Kim, Kyung-ho

PL16, QK12, RL31

166, 226, 295

Kim, Yong Baek

RA22

253

Kim, Chanhee

RQ11

308

Kim, In-seon

SC15

328

Kim, Kyunghyun

RN10

298

Kim, Yong-jae

RR11, RR21, RR22

312, 314

Kim, Chelgi

QO19

243

Kim, J.

RA07

250

Kim, Kyungwan

HA02

83

Kim, Yongjin

PO06

178

Kim, Cheol Gi

SN13

366

Kim, J.-y.

BD03, PG11, QA04

43, 144, 183

Kim, Kyung-whan

PJ33

160

Kim, Yongmin

Kim, Cheolgi

PO19, QN22, RN21, SL22

180, 240, 300, 359

Kim, Jae Nyeong

QJ19

224

Kim, Kyu-tae

RQ07

308

PO14, PO26, QO08,
RQ23, RR12

179, 181, 242, 310,
312

Kim, Chin Mo

PA22

119

Kim, Jae Young

PA11

117

Kim, Mi Jung

SN04

364

Kim, Yoonbai

SD03

330

Kim, Choong H.

RC13, RC17

261

Kim, Jaehyun

PO06

178

Kim, Mi-jung

RR14, SN02

313, 364

Kim, Young Do

RO10

302

Kim, Chul Sung

PA22, PI13, PI14, RA26

119, 152, 153, 253

Kim, Jae-sung

AD03

35

Kim, Min-ho

RR23

314

Kim, Young Keun

KC04, PJ14, RK06, SH13

109, 157, 286, 345

Kim, Chung Koo

CA02

48

Kim, Jaewook

RQ11

308

Kim, Minseon

RA26

253

Kim, Young Kwang

PK10

162

Kim, Chung Man

QH07

214

Kim, Jaeyeong

RA21

252

Kim, Miryeon

RL17

292

Kim, Young-gyun

PB17, PB37, PB40

122, 126

Kim, Chungman

QO11

242

Kim, Jae-yeong

SO03

367

Kim, Miyoung

RH20, SK27

278, 354

Kim, Young-hak

179, 181, 310, 315

Kim, D. H.

PG11

144

Kim, Jaeyoung

SM13

363

Kim, Mun-seog

RQ07

308

PO14, PO26, RQ23,
RR30

Kim, D. -w.

PO23

181

Kim, Jae-young

AF04

37

Kim, N.

QF13

206

Kim, Young-june

DC03

58

Kim, D.h.

PH14, QA04

149, 183

Kim, Jeehoon

QB31, SB12

192, 322

Kim, Ran-hyang

BH02

46

Kim, Youngkwang

PJ16

157

Kim, D.y.

EC01

65

Kim, Ji Wan

QM20

234

Kim, Rokyeon

GF05

79

Kim, Yun Won

RQ15

309

Kim, Daehong

QP19, RL22, SL19

248, 293, 359

Kim, Ji-hye

RJ18

285

Kim, S. B.

PG11

144

Kim, Yun-won

SC14

327

Kim, Daehyun

PB12

122

Kim, Jimin

RQ11

308

Kim, S.b.

PH10

148

Kimel, Alexey V.

RK17

288

Kim, Danbee

RQ07

308

Kim, Jin Mok

RQ17

309

Kim, Sam Jin

RA26

253

Kimishima, Yoshihide

SB03

320

Kim, Dohyang

PM17

170

Kim, Jin Woo

RO10

302

Kim, Sang-beom

PM16, PM19, PM21

170

Kimling, Judith

RP04

303

Kim, Dong H.

QL16

230

Kim, Jinhee

QO10, SD11, SD14

242, 331, 332

Kim, Sanghoon

RL30

294

Kimura, Akio

KF05, SD11

111, 331

Kim, Dong Young

PM28

172

Kim, Jin-hee

CF03

52

Kim, Sang-il

RL06

290

Kimura, Kenta

CC05

50

Kim, Dong-hyun

RP03, SH01, SH10

303, 343, 344

Kim, Jinsung

SN07

365

Kim, Sang-koog

EF04

68

PK21

163

Kim, Jiwan

RK13

288

60, 284, 285, 345,
350

Kimura, Nobuyuki

Kim, Dongseok

DE05, RJ14, RJ15, RJ16,
RJ17, RJ18, SH14, SJ07

Kimura, Noriaki

Kim, Dongsoo

RN23

300

Kim, Ji-wan

FC02, RK09

73, 287

Kim, Seong-gon

KH04

112

PC28, QC03, QC10,
QC11, RD08

131, 192, 193, 194,
263

Kim, Dongyoo

JH03, RM07

104, 296

Kim, Jiyeon

PI10

152

Kim, Seung Hyun

RK06

286

Kimura, S.

KA02, SG11

107, 341

Kim, Do-yeon

RN20

300

Kim, Jong Hee

QN22

240

Kim, Seunghyun

RN10

298

Kimura, Shin-ichi

AD04, QD07, QD18

35, 197, 199

Kim, Eun-mee

RN20

300

Kim, Jong-hwa

RR27

315

Kim, Shin Ae

RP01

303

Kimura, Shoji

QI18

220

Kim, Eunseong

PC25

130

Kim, Jongryoul

HB02, PM16

84, 170

Kim, Shin-ae

PI10, RA22

152, 253

Kimura, Shojiro

PI06, QG15, RH25

151, 210, 278

Kim, Eun-young

RE01

266

Kim, Jong-woo

DJ02

63

Kim, Soo Hyun

QH07

214

Kimura, Takashi

Kim, G C

QB25

191

Kim, Joon-il

QK23

227

Kim, Soohyun

PC12

128

Kim, G. B.

RQ08

308

Kim, Ju Young

QH29

217

Kim, Soo-whan

PC12

128

AG03, HE01, KC06,
QK24, QL11, RJ08,
RK21, RL20, RL23, SI1237, 86, 109, 228,
229, 283, 289, 293,
347

Kim, G. W.

PM14

169

Kim, Ju_young

SC08

326

Kim, Soyeon

RH08

276

Kimura, Tsuyoshi

JB01, QA12

99, 184

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

397

398

Author Index

Kindo, K.

GJ03, QI03

82, 218

Knight, Kevin

SD13

332

Koike, Mariko

RL04

290

Kotegawa, Hisashi

PD25, SF03

136, 337

Kindo, Koichi

HC03, PA18, PD13,
PE10, PG17, QE16,
QF11, QF14, QF17, RI15,
RP07, RQ05

85, 118, 134, 137,
145, 202, 205, 206,
281, 304, 307

Knowles, Elisabeth S.

KB03

107

Koike, Yoji

QF07, QF08, QF10

205

Kotetes, Panagiotis

II04

97

Ko, Jungho

JI02, RL30

105, 294

Koinuma, Hideomi

PH22, PN21, QL18

150, 175, 231

Kothapalli, Karunakar

SF13

339

Ko, K.-t.

PH10

148

Kokorina, E. E.

RF16

271

Kothari, D. C.

RN16

299

Ko, Kowan-young

QG01

208

Kokubu, Mitutane

QD12

198

Kotliar, G.

PE17

138

King, Phil

II02

97

Ko, Kyoung Chul

QG17

211

Kolano - Burian, A.

PM05

168

Kotnala, R.

PG27

146

Kino, Ryo

QA09

184

Ko, Rock Kil

QB25

191

Kolbe, M

RP20

306

Kototani, Shouhei

QB04, RB02

187, 254

Kinoshita, Toyohiko

RP07

304

Ko, Seung Hyo

CB01

49

Kolbe, Michaela

CH04

54

Koubaa, Mohamed

DJ05

64

Kinouchi, Hiroaki

QB29

191

Ko, Sung-won

QG01

208

Koledov, Victor V.

SO19

369

Kouh, Taejoon

PA22

119

Kiparisov, Semion

SM19

364

Ko, Wonsuk

PO13

179

Kolesnikov, Alexander I.

RD14

264

Kousaka, Yusuke

60, 143, 211, 212

Kirchner, Stefan

JC01

100

Kobayashi, H.

CG02

53

Kollath, Corinna

CC03

50

DF03, PG09, QG22,
QG28

Kirillov, Oleg A.

AE04

36

Kobayashi, Hiroki

RD14

264

Kolodiazhnyi, Taras

RH06

275

Koutroulakis, Georgios

PC03, SF01

127, 337

Kirilyuk, Andrei

RK17

288

Kobayashi, Hisao

QD11, RB03, RD13

198, 254, 264

Kolomiets, A.

RD26

266

Kovac, Jozef

IB01, QO17

91, 243

Kirschner, J

RP20

306

Kobayashi, K.

SH07

344

Kolomiets, Aleksandre

RE09

267

Kovac, P

RB08

255

Kirschner, Jurgen

AD02, AE01, EI01

35, 70

Kobayashi, Keisuke

RD20

265

Kolomiets, Olexander

QI19

220

Kovylina, M.

BD01

43

Kiryukhin, V.

RA22

253

Kobayashi, Kensuke

RL10, SE07

291, 334

Komaki, Yasuhiro

QD12, QE12

198, 201

Kovylina, Miroslavna

BD04

43

Kiseki, Kohei

AG03, SI1237, 347

Kobayashi, Kohei

SA07

317

Komarek, Alexander

PI17

153

Kowalczyk, M.

PH06, PM05

147, 168

Kishimoto, Kengo

QM10

233

Kobayashi, M.

PC01, PC29, PI15

126, 131, 153

Komatsubara, Takemi

RD08

263

Kowalik, Iwona

DD02

58

Kishimoto, Y.

SG02

339

Kobayashi, Masaki

HA03

83

Komorida, Yuki

KB06

108

Koyama, Keiichi

Kishimoto, Yutaka

QF24

207

Kobayashi, Nobukiyo

JI01

105

Kondo, A.

QI03

218

GJ02, QG15, QH08,
QI05, QN20, SK23

82, 210, 214, 218,
239, 354

Kishine, Jun-ichiro

DF03, PG09, PG10,
QG22, QG28

60, 143, 144, 211,
212

Kobayashi, Norio

QF10, SG18

205, 342

Kondo, Akinori

PE10

137

Koyama, Kuniyuki

PB25, QC05

124, 193

Kobayashi, Riki

SC23

329

Kondo, Kenji

QK05, SM09, SO07

224, 362, 367

Koyama, T.

RL07

291

Kobayashi, Satoru

PH05, PI22, RR05, RR13

147, 154, 311, 313

Kondo, Takaya

QL03, RN02

228, 297

Koyama, Takehide

QD15, RD24

198, 266

Koyama, Tsukasa

AF03, PG15, QG22,QG2837, 144, 211, 212

Kisielewski, Marek

AD05

Kiss, T.

QB28

191

Kobayashi, Tatsuo C

QF25, SE10208, 334

Konishi, K.

SL14

358

Kiswandhi, Andhika

SB05

321

Kobayashi, Tatsuo C.

HC03, QC18

85, 195

Konishi, Takehisa

KG03, PF10, PF15, SF04

111, 140, 141, 337

Kita, Eiji

PG05, PI16, QI04, QM16,
SJ06

143, 153, 218, 234,
349

Kobayashi, Tatsuya

QB24

191

Konno, Rikio

PF08

140

Koyanagi, Tsuyoshi

QM10

233

Kobayashi, Toshiaki

RH01

274

Konno, Toyohiko J.

KB05

108

Koyota, Yuya

PD11

133

Kita, Tomoko

RF09

270

Kobayashi, Tsukasa

SK21

353

Kono, Hiroshi

RD18

265

Koza, Michael M.

RE12

268

Kitagawa, Jun

EG05

69

Kobayashi, Yoshiaki

56, 187, 191, 254

Konstantinovic, Zorica

IH01, SO18

95, 369

Kozono, Yuuki

CE05

52

Kitagawa, Shunsaku

QC08

193

DA01, QB04, QB26,
RB02, RB05

Koo, Bon Heun

PM14, PN15

169, 174

Kraemer, Karl

QG14

210

Kitagawa, Susumu

HC03, QF25

85, 208

Kobayashi, Yuta

SL02

356

Koo, Dae-hyun

PM25, RR31

171, 316

Kraken, Mathias

JG06, RN15

104, 299

Kitagawa, Yutaro

QA10

184

Kobiyama, Takuya

QD13

198

Koo, Hyun Cheol

159, 225, 226, 294

Kramar, Oleksandr

RG13

274

Kitai, Tetsuo

QI05

218

Kodama, Kenji

RP07

304

PJ30, QK11, QK12,
QK13, RL28

Kramarenko, Elena Yu

QO14

243

Kitamura, T.

KJ01

113

Kodama, Motoi

RJ10

284

Koo, Hyuncheol

QK10

225

Kramer, K W

RI05

279

Kitanishi, Fumiya

SO11

368

Kodama, Yuta

QE20, QF21

202, 207

Koo, Hyun-joo

PH11

148

Kramer, Steffen

IC02

92

Kitaoka, Yoshio

DA04, PB26, QB29

56, 124, 191

Kodderitzsch, Diemo

II03

97

Koo, J.w

SK29

355

Kratochvilova, Marie

Kitaoka, Yukie

SO10

368

Kodera, Mitsuru

EC03

65

Koo, Tae Yeong

PA11, QA16

117, 185

PC10, PD18, PD19,
QJ14, SB08

128, 134, 135, 223,
321

Kitazawa, Genki

SM08

362

Koehler, Daniel

PC27

131

Koo, Taeyoung

SM13

363

Krause, Stefan

HF03, HF04, RP16

87, 305

Kitazawa, Hideaki

JJ05, PH02, PH09, QA09,
QJ02106, 147, 148, 184,
221

Koehler, Juergen

QJ18

223

Koopmans, Bert

DD02

58

BE05

44

54, 71, 78, 93, 101,
347

Krawczyk, M.

Koenraad, Paul

CH05, EI06, GE02, IE02,
JE01, SI07

Krawczyk, Maciej

QO05

241

Kito, Hijiri

QB02

187

Koerner, Michael

RJ11

284

Kopeliovich, Alexander I

PJ02

155

Krellner, Cornelius

34, 51, 73, 100, 133

Kittaka, S.

EF01

68

Koga, Akihisa

SC13

327

Korbecka, A.

BE02

44

AB02, CD03, FB04,
JC01, PD12

Kittaka, Shunichiro

QJ08

222

Koga, Mikito

SB17

323

Korekawa, Tomoya

PN07

173

Kremer, Reinhard

JB04

99

Kiyanagi, Yoshiaki

RP01

303

Koh, Eui-kwan

EH02

70

Korelis, Panagiotis

RP15

305

Kremer, Reinhard K

PH11

148

Kiyokawa, Takayasu

QA02

182

Kohama, Yoshimitsu

SF13

339

Korolev, Alexey

PB14

122

Kreuzpaintner, Wolfgang

DG01

61

Klaeui, Mathias

FD03, QK14, SH1674, 226, 345

Kohara, Takao

QD12, QD15, RD24

198, 266

Korolyov, Alexandre

QL07

229

Krinitsina, Tatiana

PB22, SK02

123, 350

Klaui, Mathias

CH04, JE03

54, 102

Kohda, Makoto

KC03

108

Korotana, Romi Kaur

RF15

271

Krinitsina, Tatiana P.

SK01

350

Klauss, Hans-henning

AB02, PI05, QB22, QJ03

34, 151, 190, 221

Kohlbrecher, Joachim

QF20

207

Kosaka, Masashi

QD13, QI16

198, 220

Krishnakumar, Varadharajan

QC13

194

Klein, Olivier

ID03

93

Kohler, Sebastian

RI13

281

Koseki, Gen

PD11

133

Krishnan, Murali

PK16

163

Klemm, R. A.

KJ01

113

Kohlhepp, Juergen

JE01

101

Koseki, Minoru

PD11

133

Krive, Ilya V.

RG17

274

Klicpera, Milan

QI01

217

Kohmoto, Osamu

SL03

356

Kosel, Juergen

SA02

316

Krockenberger, Y.

RG10

273

Klimczuk, Thomasz

SE19

336

Kohn, Kay

PI16

153

Kosel, Jurgen

PJ06, PM27, RQ02

155, 171, 307

Kroha, Johann

PF07

140

Klimin, Sergey A.

RA24

253

Kohno, Atsushi

SA03

316

Koshiba, Shyun

PN24

176

Krompiewski, Stefan

QK04

224

Klingeler, R.

QE23, QF18, QF22

203, 206, 207

Kohno, Masanori

RE05

267

Kossick, Martin

KD01

109

Kronast, FlorianFD03, GG05, RP04, RP08

74, 80, 303, 304

Klintberg, Lina

FB04, PC0973, 128

Kohori, Y

QB28

191

Koster, Gertjan

DH02, SA10

62, 317

Krotscheck, Eckhard

RG15

274

Klintberg, Lina Esther

PC02

127

Kohori, Yoh

187, 189, 198, 201

Kota, Yohei

PJ10, PL17156, 166

Krueger, Benjamin

FD02

74

Kloc, Christian

AE05

36

QB02, QB15, QD12,QE12Kotaka, Hiroki

RC09, RC19

260, 262

Krug V Nidda, Hans-albrecht

RH24

278

Klyatskaya, Svetlana

GH02

81

Koichi, Takase

QD14

198

Kotani, Y.

QB28

191

Kruger, Natalia

QE14

201

Knebel, Georg

JC02, SF03

100, 337

Koike, Kazuyuki

HG01, RP1487, 305

Koteawa, Hisashi

QB17

189

Kruglyak, Volodymyr

EH04, HD03, JG01

70, 85, 103

Kneidinger, Friedrich

SC01

325

Koike, Kunihiro

EJ01, RO05, RO06

71, 301

Kotegawa, Hisahi

SG12

341

Kruglyak, Volodymyr V.

GD04, QO05, RK2078, 241, 289

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

399

400

Author Index

Kruize, Michelle

DH02, SA10

62, 317

Kumar, Pradeep

SE14

335

Lake, Bella

IC05, PA23, RH24

92, 119, 278

Lee, Donghae

QH15

215

Krychowski, Damian

PE06

137

Kumar, Rajesh

PH16

149

Lam, Duong Duc

PK20

163

Lee, Dong-hae

QG16

210

Krycka, Kathryn

KD02

109

Kumar, Ravi

PH16

149

Lam, V. D.

RA01

249

Lee, Dong-il

PM19, PM21

170

Krzysteczko, Patryk

IF04

94

Kumar, Shalendra

PM14, PN15

169, 174

Landa-canovas, Angel

PI18

153

Lee, Eunhee

RN24

300

Ku, H. C.

SB04

320

Kumar, Vinod

PH16

149

Landee, C P

BC05

42

Lee, Eunsook

PG11, PH14, QA04

144, 149, 183

Ku, Huan-chiu

RR01

311

Kumari, Poonam

PI12

152

Landee, C. P.

QF02

204

Lee, Geunsik

QH26, QH27, RB22

217, 257

Ku, Jang Hae

PJ30

159

Kummer, Kurt

PD12

133

Landge, Kalpana Kamalkishor SK19

353

Lee, H. J.

RQ08

308

Kuang, Lulin

PB28

124

Kuo, C. N.

PH01, RP02

147, 303

Landsgesell, Sven

RB01, RB07

254, 255

Lee, H. Y.

PK06, QP17

161, 248

Kubetzka, Andre

IH02, IH03

96

Kuo, K. M.

QM25

235

Lang, Michael

PB19

123

BH03

46

Kuo, Nan-hong

QF26

208

85, 201, 222, 281,
342

Lee, H.k.

Kubinova, Sarka

HC04, QE14, QJ11, RI13,
SG19

Lee, Ha Na

PJ24

158

Kubo, Hidenori

RH19, RP12

277, 305

Kuo, Yung-kang

PE02

136

Langbehn, Bruno

KD01

109

Lee, Haigun

122, 123, 125, 126

Kubo, Katsutaka

PG17, QF11

145, 205

Kupriyanova, Galina

SK26

354

Langenberg, Andreas

KD01

109

Kubo, Kazuki

AI02

39

Kuramochi, Hiromi

PG06, RP12143, 305

Langie, Douglas

PB10

121

PB16, PB17, PB18, PB35,
PB36, PB37, PB38, PB39,
PB40

Kubo, Kazuya

BC04

42

Kurde, Julia

RP08

304

Langridge, Sean

KE01, PN23

110, 175

Lee, Hak Bong

PA01

116

Kubo, Yasunori

SE01

333

Kurihara, Ryosuke

RB05

254

Larbalestier, David

JA02

98

Lee, Hak-bong

CI03, PA03

55, 116

Kubota, H.

CE03, CE06, ID02, RJ07

51, 52, 93, 283

Kurisu, Makio

PN07, QG11, SM10173, 210, 362

Larde, Rodrigue

43, 61, 72, 107, 158

Lee, Hakjoon

PN09

173

Kubota, Hitoshi

BI01, HF01, IE04, KF01,
PK20

47, 87, 94, 110, 163

Kurita, Kohei

PD11

133

BD02, DG02, EJ03,
KB02, PJ22

Lee, Hana

PJ16, PK10

157, 162

Kurita, Nobuyuki

SB05

321

Lari, Leonardo

SK11

352

Lee, Hanju

SA09

317

Kubota, Kazuhiro

RD01

262

Kuroda, Keisuke

PD25

136

Larionova, Joulia

RN15

299

Lee, Han-oh

FB01

73

Kubota, M.

EF01

68

Kuroe, Haruhiko

119, 183, 184, 276

Larrea J., J.

CD01, SF1050, 338

Lee, Hee-ju

QL18

231

Kubota, Miho

RL13

292

PA19, QA05, QA07,
QA09, RH11

Lartigue, Lenaic

RN15

299

Lee, Heejung

RH08

276

Kubota, T.

SK24

354

Kurokawa, Akinobu

PO02, QL03, RN02

177, 228, 297

Lascialfari, Alessandro

RN15

299

Lee, Hsin-han

QK22, SK30

227, 355

Kubota, Takahide

CH02

54

Kurosawa, Tohru

PB08

121

Lau, Tobias

KD01

109

Lee, Hu - Jong

RB14

256

Kubota, Tatsuro

BC04

42

Kusano, Takanao

RO05

301

Laubschat, Clemens

CD03, PD1251, 133

Lee, Hunju

PM23

171

Kubota, Yoshiki

HC03, PI02, QF25

85, 151, 208

Kusunose, Hiroaki

SB17

323

Lausberg, Stefan

AB02

34

Lee, Hunpyo

SF14, SG22

339, 343

Kubozono, Yoshihiro

SC04

326

Kutnyakhov, D

RN12, RP20

298, 306

Laver, Mark

KD02, QF20

109, 207

Lee, Hun-sung

RL03, SM01

290, 361

Kucherenko, Yuri

PD12

133

Kuwada, Kenta

RQ03

307

Lawicki, Arkadiusz

KD01

109

Lee, Hyeong Jun

RC08

260

Kuchko, Andriy

JG01

103

Kuwahara, Hideki

SK11

352

Lee, Hyun Joon

RQ18

310

AB02

34

116, 119, 183, 250,
324

Lazarov, Vlado K

Kuchler, Robert

PA06, PA19, QA05,
RA06, SB24

Lazo, Cesar

AF02, PG1236, 144

Lee, Hyun Jung

JC03

100

Kudo, Kazutaka

QF10

205

Kuwai, Tomohiko

SG05

340

Lazuta, A. V.

RQ13

309

Lee, Hyun Sook

PO06, PO09, PO10

178

Kudrevatykh, N. V.

QI03

218

Kuwana, Kanako

QF25

208

Le Breton, Jean-christophe

AI04

39

Lee, Hyungjun

QK21, RC15

227, 261

Kudrevatykh, N.v.

GJ03

82

Kuwano, Keisuke

RB04

254

Le Breton, Jean-marie

RL22, SL19

293, 359

QG27

212

Kuzian, R. O.

QF18

206

41, 43, 61, 72, 107,
158, 278

Lee, Hyungyu

Kudryavtsev, Y. V.

BB03, BD02, DG02,
EJ03, KB02, PJ22, RH22

Lee, Hyun-woo

67, 68, 30, 110, 160

Kuepferling, Michaela

HH01

88

Kuzmin, D. Aleksandrovich

QH17

215

Le Guyader, Loic

RK17

288

EE02, EE05, HP21, KE03,
PJ33

Kuga, Kentaro

CD02, IG03, QD01,
RD13

51, 95, 196, 264

Kuz'min, M. D.

GJ03, QI03, QI09

82, 218, 219

Le Tacon, Mathieu

CA03, RB20

49, 257

Lee, In Kyu

PI14

153

Kuznetsov, Alexey V.

QC19

195

Le Tacon, Matthieu

BA03

41

Lee, J H

QB25

191

Kuga, Kiyoshi

SK21

353

Kuznetsova, Elena

PB22

123

Le, Cuong V.

QL16

230

Lee, J.

QB31

192

Kuhns, Phil

JA02

98

Kwilu, Augustin Lutondo

KD04

110

Le, Tuan Tu

SL22

359

Lee, J. H.

SA06

317

Kuiper, Koen

SI07

347

Kwon, Hae-woong

RO12

302

Lebecki, Kristof M.

RJ04

283

Lee, J. M.

QB21, SM11

190, 362

Kulemanov, Ivan V

PN22

175

Kwon, Hyuckchan

RQ17

309

Lebreton, Jean-christophe

CG03

53

Lee, J. Y.

PB03

120

Kulinich, Sergey I.

RG17

274

Kwon, Jae Hyun

EG03, HD02, PJ08, SI02

69, 85, 156, 346

Lechevallier, Luc

BD02, RH22

43, 278

Lee, J.-s.

PH10, RA04

148, 249

Kulka, A.

PH06

147

Kwon, Joonhyun

PK04, QK03

161, 224

Ledue, Denis

EJ03

72

Lee, Jae Il

RH20, SK19, SK27

278, 353, 354

Kulkarni, Prabhanjan Dilip

PK16

163

Kwon, O. Y.

PM26

171

Lee, B. W.

RA07

250

Lee, Jae-chul

KE03, SI13

110, 348

Kulkarni, Ruta

QJ17, RB24

223, 258

Kwon, Oh Jun

PB16, PB18, PB35

122, 123, 125

Lee, B.c.

PJ31

159

Lee, Jae-hyun

PO15, PO16

179

Kulkarni, Ruta N

SE21

336

Kwon, Oryong

KI01

112

Lee, Bo Wha

RA21

252

Lee, Jaejin

JH04, KH04

104, 112

Kumada, Nobuhiro

QE10

201

Kwon, Sangil

BF05, JG05, PA09, PH1845, 104, 117, 149

Lee, Bowha

QL09

229

Lee, Jae-jun

RR14, SN04

313, 364

Kumagai, Keigou

SG05

340

Kwon, Seung Hyuk

QN09

237

Lee, Bo-wha

SO03

367

Lee, Jee Yong

QG20

211

Kumagai, Ken-ichi

SB27

324

Kwon, Woo Jun

PI14

153

Lee, Bumsung

JA03, PA04

98, 116

Lee, Jehyun

RJ15, SJ07

285, 350

Kumai, R.

CF04

53

Kwon, Yong Seung

CF03

52

Lee, Byung Chan

SK14

352

Lee, Jeong Soo

QM18, QM20

234

Kumai, Reiji

PH07, SE07

148, 334

Kwon, Young-wan

EH02

70

Lee, Byungchan

PK21

163

Lee, Jeonghyeon

QK03

224

Kumano, Yuta

RI02

279

Kyakuno, Haruka

SO515

369

Lee, C. H.

QB28

191

Lee, Jeong-o

SD12, SD14

332

Kumar, Anil P. S

QM03

232

Kyomi, Takuya

PO18

180

Lee, Chang Hee

RP01

303

Lee, Jhinhwan

CA02, RQ11

48, 308

Kumar, Anil P. S.

CG04, SJ08, SL2353, 350, 359

Lee, Chang Hoon

EH02

70

Lee, Ji Hye

SA05

317

Kumar, Dheeraj

HD04, RK1185, 287

Lee, Changhee

PJ17

157

Lee, Jin Bae

SL11

357

Kumar, G. Ravi

PI12

152

Labarta, A.

BD01

43

Lee, Changhoon

QJ18

223

Lee, Jin Seok

SD14

332

Kumar, Manish

SA14

318

Labarta, Amilcar

BD04, KB06, RN14

43, 108, 299

Lee, Cheol Eui

PG25, PN25, SI14, SK28

146, 176, 348, 355

Lee, Jin Yong

QG17

211

Kumar, Manoj

RA27

253

Lacour, Daniel

KF02, SH02

110, 343

Lee, Chi-hung

PC18

129

Lee, Jinho

CA02

48

Kumar, Neeraj

RB24

258

Laczkowski, Piotr

78, 226, 360

Lee, Chul-ho

QB02, QB15, QB29

187, 189, 191

Lee, Jinju

RL17

292

Kumar, P. S. Anil

PJ28, SL21

159, 359

GE01, QK15, QK16,
QK17, SL24

Lee, D.

SA16

318

Lee, Jinyong

PO09

178

Kumar, Pawan

QL10, SM18

229, 363

SN12

366

Lee, Der-sheng

QM11, QM25

233, 235

Lee, Jinyoung

PO10

178

The 19th International Conference on Magnetism

L

Lai, Bin

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

401

Author Index

Lee, Jongseok

Lee, Seungho

RR21

314

Li, Bodong

PM27

171

Lin, C. Y.

SB04

320

Lee, Seunghun

PH22, PN20, PN21, QL18

150, 175, 231

Li, Carissa H.

KB03

107

Lin, Chengtian

IJ02, RB20

97, 257

289

Lee, Seung-hun

AC02

34

Li, D. X.

QJ10

222

Lin, Chun-liang

SM06

361

RR14, SN02, SN04

313, 364

Lee, Seungjun

RL17

292

Li, Fashen

QN21, QN23

239, 240

Lin, H.

SD04

330

PM17

170

Lee, Seungkyo

PK04, QK03

161, 224

Li, Feng

QK01

224

Lin, Hsin

HI02

89

PC14, RK07, RL18

129, 287, 292

Li, Gang

JA02

98

Lin, Hsiu-hau

RE11, SB25

268, 324

PB17, PB36, PB37, PB39,
RG10122, 126, 273

Lee, Joo In

RK19Lee, Ju
Lee, Juho
Lee, Jung Won

QN09

237

Lee, Shang-fan

Lee, Junggoo

JH04, PM24

104, 171

Lee, Soogil

RL30

294

Li, Hang

IE01

93Lin, Jianhua

PH02

147

Lee, Jung-goo

KH04, RN06, SL29

112, 297, 360

Lee, Soonchil

BF05, JG05, PA09, PH1845, 104, 117, 149

Li, J.

PL02, SM05

164, 361

Lin, Ko-wei

PL18

166

Lee, Junghyon

PK04

161

Lee, Soon-gul

PB21, RB27, SC14

123, 258, 327

Li, Jiajie

RO04

301

Lin, Kurt

PO13

179

Lee, Junhyun

IA03

91

Lee, Sujin

SA09

317

Li, Jian

RR19, RR24, RR25

314, 315

Lin, Lu-kuei

PC14

129

Lee, K. B.

RQ08

308

Lee, Suk Ho

JB02

99

Li, Jichao C

KI02

113

Lin, Minn-tsong

AD01

35

PB21, RB27

123, 258

Li, Li

PN05, QL04

172, 228

Lin, Pang

RL18

292

Lee, Ki Doek

SN04

364

Lee, Sung Hoon

Lee, Ki-doek

RR14, SN02

313, 364

Lee, Sungbin

JD03, PL08

101, 165

Li, Liang

PL06

164

Lin, Ruei-lin

QN24

240

Lee, Kiejin

SA09

317

Lee, Sung-hyun

SJ05

349

Li, Lingwei

QJ06

221

Lin, T.

GF01

79

Lee, Ki-seung

RL26

294

Lee, Sungsu

QI15

220

Li, Long-jie

QP17

248

Lin, Wei-yan

QM09

233

Lee, Ki-suk

DE05, RJ14, RJ16, RJ18,SH1460, 284, 285, 345

Lee, Tae Ho

SO21

370

Li, Peisen

SA19, SA20

319

Lin, Z. W.

GA01

75

Lee, Tae Young

RL28

294

Li, Q.

GA01

75

Ling, D. C.

PC13

128

Lee, Kiyoung

PN23

175

Lee, Taehoon

RN10

298

Li, Qing

PO01

177

Liou, Sy-hwang

RO07

301

Lee, Kwan-woo

PF06, SO05, SO06

140, 367

Lee, W. H.

RP10

304

Li, TianBE03

44

Liou, Yung

QM09

233

Lee, Kyeong-dong

RK09, RK22, SI04

287, 289, 346

Lee, Wei-cheng

GA01

75

Li, Tong

DD03

58

Lipinski, Stanislaw

PE06

137

Lee, Kyu Won

PG25, PN25, SI14, SK28

146, 176, 348, 355

Lee, Woncheol

JH04

104

Li, W F

DD06

59

Lisboa-filho, Paulo Noronha

QA06

183

Lee, Kyujoon

PC12, PK17, PN19,
QO10, RC07, SD10,
SD11

128, 163, 175, 242,
260, 331

Lee, Woo

SO21

370

Li, Wanfeng

CB05, EJ04

49, 72

Lisenkov, Sergey

QA27

187

Lee, Y. P.

QG27, RA07, SL08, SL09

212, 250, 357

Li, Wei

DD02

58

SB25

324

163, 239, 301, 358,
366

Lisowski, W.

Lee, Yen-chen

PK18, QN21, RO04,
RO07, SL12, SN11, SN12

Lisyansky, Alexander A.

HD05

86

PL03

164

JG06, RN15

104, 299

Lee, Kyung Jin

RL26

294

Lee, Ying-chen

Li, Weimin

QP22

249

Litterst, Jochen

Lee, Kyungdong

QM23

235

Lee, Yong Ho

RQ17

309

Li, Wen-hsien

PC18, PO25, QA20

129, 181, 185

Litvinova, Tatyana

PE08

137

Lee, Kyung-jin

CE04, EE02, EE05, HF05,
HP21, PJ33, RJ19, RL06,
RL14, SI09

52, 67, 68, 87, 30,
160, 285, 290, 292,
347

Lee, Yong Woo

PN28

176

Li, Xianhong

RL21

293

Liu, C.

SD04

330

Lee, Yong-ho

RQ18, RQ19, RQ20

310

Li, Yanfeng

QN21

239

Liu, C. Y.

PC13

128

Lee, Young S.

QE27

203

Li, Yingjie

PN07, QC01

173, 192

Liu, Chang

HI02

89

RQ08

308

Lee, Yun-hi

RL31

295

Li, Yong Hui

RA26

253

Liu, Chieh-wen

QM27

236

BF03

45

PL18

166

Lee, M. K.

402

Author Index

Lee, N.

AA04

33

Lees, Martin R

Li, YuanCA03, JC04

49, 100

Liu, Chi-hsin

Lee, N. H.

PB03

120

Lefevbre, Williams

KB02

107

Li, Yufan

JF05

103

Liu, Chunli

QL09

229

Lee, Nam Hoon

GA04, RB27

76, 258

Lefevre, C.

SA06

317

Li, Yuke

AB04, IJ04

34, 98

Liu, Dongping

QK02

224

Lee, Nam-kyu

RR15

313

Lefevre, Christophe

SA05

317

Li, Z

QB11

188

Liu, H. F.

RP02

303

Lee, Nyun Jong

PJ17, QP18

157, 248

Legarra, Estibaliz

QH16

215

Li, Zhenghua

RP06

304

Liu, H. L.

PC13

128

Lee, Paul

PN03, QL02

172, 228

Legut, Dominik

CH03, QH19

54, 216

Liang, Ruixing

BA01

40

Liu, Hsin-tzu

RR01

311

AA05

33

EJ02

71

Lee, S.- H.

PH03

147

Leist, Jeannis

Liang, Shiheng

QK02

224

Liu, J. Ping

Lee, S. J.

RQ08, SJ06, SL08308, 349, 357

Leitenstorfer, Alfred

HA02

83

Liao, Shu-hsien

QM27

236

Liu, Jun-ming

PA05

116

Lee, S.s.

RK18

288

Leithe-jasper, Andreas

RD12

264

Liao, Yen Fa

QC12

194

Liu, Liying

SM17

363

Lee, Sang Sun

RP23

307

Lejay, Pascal

SG05

340

Liao, Yen-fa

QC09

193

Liu, Mei

QB01

187

Lee, Sangho

RL30

294

Lemaitre, Aristide

CG03

53

Liborio, Leandro

RF15

271

Liu, Qiang

PI17

153

Lee, Sanghoon

BE01, PN08, PN09,
QL08, QM04

43, 173, 229, 232

Lemee-cailleau, Marie-helene SB08

321

Lichtenegger, Thomas

RG15

274

Liu, Qiangchun

SA01

316

Lemmens, P.

PI09

152

Lichtenwalner, Daniel J.

AH04

38

Liu, Tao

PK18

163

Lee, Sang-hyuk

RP03, SH10

303, 344

Lemmens, Peter

QE27

203

Lileev, Alexey

QJ13, SN09

223, 365

Liu, Tijiang

RB12

256

Lee, Sanghyun

PG24, PI10

146, 152

Lemus, Jose

QO26

245

Lim, Byunghwa

PO19

180

Liu, Wei

PN04

172

Lee, Sangji-suk

PL11

165

Lenertz, Marc

PI04

151

Lim, Hyein

RL17

292

Liu, Weiqiang

RO15, SN01

303, 364

Lee, Sang-suk

BH02, RR15

46, 313

Lengyel, Edith

AB02

34

Lim, Jaein

QO19

243

Liu, X.

173, 229, 232

Lee, Sang-wha

PO04

177

Leon, Gladys

QB18, QB19

190

Lim, Jung Tae

PA22, PI13

119, 152

PN08, PN09, QL08,
QM04

Lee, Sangwon

RH08

276

Leon, L. M.

CB02

49

Lim, Kwon Taek

RN05

297

Liu, Xi

SL02

356

Lee, Sangyeop

QM04

232

Leonyuk, Nicolay I.

PA20

119

Lim, Pang Boey

QP15, QP16

247, 248

Liu, Xiaoli

SL06

357

Lee, Sang-yun

PM16, PM19, PM21170

Lepadatu, Serban

QO24

244

Lim, Sang Ho

PL16, QK12

166, 226

Liu, Xiaoxi

PK07, QP08, RL05

161, 246, 290

Lee, Seok-hee

RL30

294

Lesne, Edouard

HE04

86

Lim, Sang-ho

RQ23

310

Liu, Xuerong

DC03

58

Lee, Seongjae

RL21

293

Lesnikov, Valeriy

SG17

342

Lim, Sanghyun

PO11

179

Liu, Yi

JB03

99

Lee, Seong-joo

RQ18, RQ19, RQ20

310

Letellier, Florent

BD02

43

Lim, Seon-ho

PO14

179

Liu, Ying Dan

QN03

236

Lee, Seong-rae

RO01, RO02

300, 301

Leung, Chi Wah

DH04

62

Lim, Yong-sik

PN31

177

Liu, Zuli

PO01

177

Lee, Seongsu

HJ05, PI10, QA24, RA20,
RA2290, 152, 186, 252,
253

Levchenko, A. V.

QC22, RH07

195, 275

Lim, Yun-seog

PM19, PM21

170

Liu, Zu-li

QK18

227

Levchenko, Anna Vasilievna

PE09

137

Lima Sharma, Ana

QO09

242

Liuqiang, Wen

QO15

243

Lee, Seo-won

SI09

347

Lewinska, S.

PH06, PM05

147, 168

Lin, C T

QB20

190

Lobanova, Inna

SG07

340

Lee, Seung Goo

QN22

240

Li, Anhua

RO04

301

Lin, C. M.

RR01

311

Locatelli, Andrea

SH06

344

Lee, Seung-beck

QP19, RL22, SL19

248, 293, 359

Li, Bin

QB01

187

Lin, C. T.

GA03

75

Locatelli, Nicolas

ID03

93

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

403

404

Author Index

Lockwood, David

QG12

210

Lym, Dae Young

SG21

343

Makiyama, Shun

SG09

341

Martin-rodriguez, Damian

QH16

215

Lodya, Lonzeche J. Augustin

QH22

216

Lynn, Jeffrey W.

QA20

185

Makridis, Sofoklis

SN15

366

Martins, Maximiliano Delany

RJ12

284

Loew, U.

QE23

203

SK26

354

Marty, Alain

Loewenhaupt, Michael

PH04, QC24

147, 196

M

Maksimova, Ksenia
Maleyev, Sergey V.

DF04

60

EI04, GE01, QK15,
QK16, QK17, RL24, SL24

71, 78, 226, 293,
360

Logg, Peter

PC02

127

M, Aparnadevi

PI01

150

Malikov, Shavkat

RR28

315

Masek, Jan

BE05, SK2244, 354

Lohneysen, Hilbert V.

EA01, EG0264, 69M, Manivelraja

QD04

197

Malinowski, Gregory

SH02

343

Maskova, Silvie

QI19, RE09

220, 267

Loidl, Alois

PA23, RH24

119, 278

M, Shalini

RN16

299

Maljuk, Andrey

IJ02

97

Masoudpanah, S. M.

QM28

236

Lombardo, Pierre

CD03

51

M. Tachiki, M.

KJ01

113

Mallia, Giuseppe

RF15

271

Massboeuf, Aurelien

SH06

344

Long, Jerome

RN15

299

M., Ramesh

BJ05

48

Malone, Liam

JC02

100

Masthoff, Ingke Christine

JG06

104

Long, Phan The

AJ06

40

Ma, Li

JI05

105

Mal'tsev, Viktor V.

PA20

119

Masti, S A

QN14

238

Lonzarich, Gil

BA01

40

Ma, Long

QB07

188

Malyuk, Andrey

PA10

117

Masuda, Keisuke

SB23

324

Lopera, Wilson

SA12

318

Ma, Qinli

CH02

54

Mamiya, Hiroaki

JJ05, RI07

106, 280

Masuda, Ryo

QM16

234

Lopes, Rovan Fernandes

PB09, RB09

121, 255

Ma, Xiao-ping

SH10

344

Manabe, N.

SL14

358

Masuda, Takatsugu

QA02

182

Lopez-diaz, Luis

SH16

345

Maan, Jan Kees

DH02, SA10

62, 317

Manaf, Azwar

BJ03, QN16, RA15

48, 239, 251

Masui, T.

HA01

83

Lopez-quintela, M. A.

CB02

49

Maca, Frantisek

BE05

44

Manago, Takashi

PG06, RK21, RP12143, 289, 305

Masumoto, Hiroshi

JI01

105

Lora-serrano, Raimundo

PI19, SE15

153, 335

Macedo, Claudio Andrade

PF13

141

Manaka, Hirotaka

QE09, QH02, RI06

200, 213, 279

Mathai, Cijy

CG04

53

Lord, James S.

PO17

180

Macedo, Marcelo

QL01

228

Manami, Onizawa

QD14

198

Mathon, Olivier

HG04, RH23

88, 278

Lorenz, Thomas

RI12

280

Machida, Kenji

SK21

353

Manchon, Aurelien

AE03

36

QF18

206

Machida, Yo

PC17, PC28, PD16

129, 131, 134

Matiks, Y.

GA03

75

Lorenzer, K. - A.

CD01, SF1050 , 338

Mackenzie, Andrew

EA04

64

53, 67, 93, 155, 156,
159, 160, 230, 285,
352

Mathur, Neil D

Lorenz, W. E. A.

CG05, EE03, IE01, PJ06,
PJ13, PJ29, PJ34, QL17,
RJ19, SK12

Matoba, Masanori

QC07, QC08, SE09

193, 334

Lortz, Rolf

DH04

62

Maclaughlin, Douglas E.

CD04

51

Mandal, Ruma

HD04

85

Matsubara, Takeshi

PC17

129

Loshkareva, Natalya

SL17

358

Madami, Marco

GG02

80

Manivannan, Nallayian

PB23

123

Matsubayashi, K.

QH09, RD15

214, 264

Lott, Dieter

DG01, QM02, QM08

61, 231, 232

Maeda, Youichi

QD02

196

Maniwa, Yutaka

SO515

369

Matsubayashi, Kazuyuki

Louahadj, Lamis

AI04

39

Maegawa, Satoru

BC04, QE22

42, 203

Mankey, Gary J.

QM02

231

Louca, Despina

BF02

44

Maehira, Takahiro

QC14, QC15

194

Manna, P K

QP05

246

PD14, QD17, QI18,
QN20, RD06, RD22,
RE04, SC24, SE01, SE11134, 199, 220, 239,
263, 265, 267, 329,
333, 335

Lowe, Konrad

KH01

112

Maekawa, Sadamichi

RN04

297

Matsuda, Kazuyuki

SO515

369

PC13

128

72, 102, 111, 155,
160, 28, 270, 290

Manna, P. K.

Lu, C. R.

Manna, Rudra Sekhar

QJ11, RI13

222, 281

Matsuda, Ken-ichi

SK06

351

Lu, Chun-i

AD01

35

FA03, JE02, JF02, JF03,
KF03, PJ07, PJ34, PP02,
RF07, RL01

Manni, Soham

SG13

341

Matsuda, M.

PH03

147

Lu, Hantao

EB03

65

Maeno, Yoshiteru

PC20

130

Manske, Dirk

CA03, KJ03

49, 114

Matsuda, Masaaki

HJ03

90

Lu, JunPA21, QK23, RA02,
RQ01

119, 227, 249, 307

Maeta, Takashi

PB27

124

Mansson, M.

PC29, PI15

131, 153

Matsuda, Ryotaro

HC03, QF25

85, 208

Maeter, Hemke

PI05, QJ03

151, 221

Mansson, Martin

QJ08

222

QB21

190

Magalhaes, S. G.

QD10

198

83, 151, 180, 207,
334

Matsuda, Saori

Lu, K. T.

HA03, PI06, PO17, QF20,
SE08

Matsuda, Tatsuma

JC02

100

Lu, Kueih-tzu

SM11

362

Magalhaes, Sergio

PE01

136

Mantovan, Roberto

SK26

354

Matsuda, Tatsuma D

Lu, Wei

AJ03, JI06

40, 105

Magen, Cesar

61, 80, 298, 363

Manzoor, Sadia

SA15

318

95, 133, 135, 266,
322

Lu, Xin

FB01, SE02

73, 333

DG05, GG05, RN08,
RN09, SM16

IG04, PD09, PD23, RD25,
SB15

Mao, Zhiqiang

RB12

256

Matsuda, Tatsuma D.

RD01, RD11, RE10, SF03

262, 263, 268, 337

Lu, Yunhao

SK34

356

Magishi, Ko-ichi

QC05

193

Maple, M. Brian

BB01

41

Matsuda, Tatsuma Daruma

HP11

30

Lubhelwane, Siyanda

QH22

216

Magnavita, E. Thizay

QO03

241

Marcatoma, Justiniano

PL09

165

Matsuda, Yasuhiro H.

IG03

95

Lucas, Irene

SM16

363

Magni, Alessandro

HH01

88

Marchetti, Gionni

QK09

225

Matsuda, Yuji

IA01, QC04, SB27

90, 192, 324

Ludwig, Frank

AH01

38

Mahadevan, Priya

HC01, RF1284, 270

Marcin, Jozef

IB01, QO17

91, 243

Matsudaira, Ken-ichiro

PH23

150

Lue, C. S.

PE02, PH01

136, 147

Mahajan, Mangesh B.

SL13

358

Margaris, George

CB03

49

Matsueda, Hiroaki

EB03

65

Lue, Chin Shan

RP02

303

Mahdavifar, Saeed

RG16

274

Mari, Kenichiro

SK18

353

Matsuhira, Kazuyuki

CC05, QE13

50, 201

Luetkens, Hubertus

AB02, PI05, PI17, QB22,
QJ03

34, 151, 153, 190,
221

Mahendiran, Ramanathan

PI01, QL10, RA08

150, 229, 250

Marin, Lorena

SM16

363

Matsui, Fumihiko

SK13

352

Mahlubi, Zwelithini Melford

RD23

265

Maritato, Luigi

SA08

317

Matsui, Kazuki

PD10

133

Luis, F.

BC01

42

Mahmoodi, M.

PO27, PO29, PO31

181, 182

Markiewicz, R. S.

HI02

89

Matsuishi, S.

QB23

190

Lukasiewicz, Malgorzata I

DD02

58

Mahmoodi, Mostafa

PO28

181

Markiewicz, Robert S.

BA04

41

Matsuishi, Satoru

PC23, QB16

130, 189

Luke, G. M.

GF01

79

Maignan, Antoine

BB03, JB05, RA11, RH22

41, 100, 251, 278

Marques-ferreira, Pablo

PI19

153

Matsukawa, Michiaki

PI22

154

Lummen, Tom T. A.

HG04, PA24

88, 119

Maikov, Vladislav

QL07

229

Marquina, Clara

RN08, RN09

298

Matsukura, F.

BE02

44

Lumpkin, Greg

PO12

179

Maisuradze, Alexander

CD04

51

Marrows, Chris

QO24

244

Matsukura, Fumihiro

QP14

247

Lunov, Oleg

AH02

38

Maiti, Kalobaran

PE14, SC06

138, 326

Marrows, Christopher

KE01

110

Matsumoto, Akiyo

RH21

278

Luo, Hui Quian

RB10

255

Maitre, Adeline

EJ03

72

Marsilius, Mie

PM04

168

Matsumoto, K. T.

EF01

68

Luo, Huiqian

RB11

255

Majetich, Sara

GG01

80

Martens, Michael

FD02, RJ05, RP04

74, 283, 303

Matsumoto, Kazuyuki

RI01

279

Luo, Yongkang

AB04, IJ04, RB13

34, 98, 256

Majewski, J. A.

BE02

44

Martens, Stephan

RP04

303

Matsumoto, Keisuke

SG15

342

Luong, Dien Xuan

RN19

299

Maji, Bibekananda

QO04

241

Marti, X.

IF01

94

Matsumoto, Keisuke T

RD04

262

Lupi, Stefano

SA08

317

Majumdar, Pinaki

RG12

273

Marti, Xavier

BE05

44

Matsumoto, Keisuke T.

SG12

341

Luque, F.j.

DD02

58

Majumdar, S

QL14, SO14, PL07, RH02

165, 230, 275, 369

Martin, Christine

JB05, RA11

100, 251

Matsumoto, Masashige

SB17

323

Lushchyk, P

RP20

306

Majumder, M

QM24

235

Martin, I.

FB01

73

Matsumoto, Naoki

QM10

233

Lutsev, Leonid

QM08

232

Majumder, Mayukh

RB15

256

Martin, Jose Ignacio

GG03

80

Matsumoto, Rie

HF01, IE04

87, 94

Luzon, Javier

GF04

79

Makarov, Denys

SJ07

350

Martinez, Benjamin

IH01, SO18

95, 369

Matsumoto, Sayaka

PM02

167

Lv, Bin

JA02, PN05, QL04

98, 172, 228

Maki, Makoto

PB04

120

Martinez, Eduardo

SH16

345

Matsumoto, Shinji

SN03

364

Lv, Chen

IJ04

98

Makio, Kurisu

SM07

362

Martinez-perez, M. J.

BC01

42

Matsumoto, Shoutaro

PN24

176

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

405

406

Author Index

Matsumoto, Tatsuya

QM29

236

Medvedev, M. V.

RF16

271

Milyaev, Michael A.

SK01

350

Miyamachi, Toshio

GI03

82

Matsumoto, Yoshihiro

BH05, BH06

46, 47

Mehrafarin, Mohammad

SB07

321

Milyaev, Mikhail

SK02

350

Miyamoto, Koji

KF05

111

Matsumoto, Yosuke

CD02, QD01

51, 196

Mei, Li-then

QN25

240

Mimura, Kojiro

RD20

265

Miyamoto, Souta

SG05

340

Matsumoto, Yuji

PD09, PD23

133, 135

Meier, Guido

PE17, PG11, RG02, SC12

138, 144, 272, 327

Miyao, Masanobu

HE01, RK1086, 287

QD06, RD10

197, 263

74, 88, 283, 303,
343

Min, B. I.

Matsumura, Masahiro

FD02, HG02, RJ05, RP04,
SH04

Min, Byoung Chul

QM18

234

Miyasaka, Hitoshi

QF21

207

Matsumura, Takeshi

QI10

219

Meier, Johan G.

RN09

298

Min, Byoung-chul

CF04, HA01

53, 83

KC06

109

Meindl, Manfred

AH01

38

52, 287, 290, 292,
360

Miyasaka, S.

Matsunaga, Takahiro

CE04, RK09, RL03, RL06,
RL14, SL26

Miyasaka, Shigeki

PH07, PI07, QB24

148, 151, 191

Matsunami, Masaharu

AD04, QD18

35, 199

Meisel, Mark W.

KB03

107

Min, Byung Chul

RL26

294

Miyasaka, Toshiki

QL03, RN02

228, 297

Matsuo, A.

QI03

218

Meissner, Thomas

RQ09

308

Min, C

BG01

45

Miyata, Atsuhiko

AC03

34

Matsuo, Akira

HC03, PG17, QE16,
QF11, QF14, QF17, RI15,
RQ05

85, 145, 202, 205,
206, 281, 307

Melander, Emil

AF05

37

Min, Gyeong Im

CF03

52

Miyata, Masahiko

AG03

37

Melisek, T

RB08

255

Min, Jin Hong

QN15

238

Miyawaki, Tetsuya

Melkov, Gennady

JG02

103

Min, K. J.

PJ24

158

PJ12, PL12, RC18, SA07,
SA17, SK18, SO20

156, 165, 261, 317,
319, 353, 370

Matsuo, Mamoru

KF03

111

Melnychenko, Nataliya

SC01

325

Minh, Nguyen Van

PH14

149

Miyazaki, H.

SG11

341

Matsuoka, Eiichi

PE11, PE13, QF04, QI10,
QI16, RD01

137, 138, 204, 219,
220, 262

Meloche, Eric

QG12

210

Minnullin, Arthur

QA26

186

Miyazaki, Hidetoshi

AD04, QH28

35, 217

Mena, Mattia

QG14

210

Mino, Michinobu

RK23

289

Miyazaki, Ryoichi

RD17

264

Matsuoka, Yuki

QH20

216

Mendonca, Ana P. Aguiar De

PB09, RB09

121, 255

Minola, Matteo

BA03

41

Miyazaki, Shota

SG16

342

Matsushima, Yasushi

SL03

356

Meng, Kangkang

QK23

227

Miotkowski, Ireneusz

HI02

89

Miyazaki, Takamichi

EJ01, RO06

71, 301

Matsushita, Takuya

QI07

218

Mengotti, Elena

RK17

288

Mirebeau, Isabelle

AA03

33

Miyazaki, Terunobu

CH02

54

Matsushita, Tomohiro

SK13

352

Mentes, Onur

SH06

344

Miron, Mihai

SH05

344

Mizokawa, T.

RB28

258

Matsuura, Keisuke

PG17, QF14

145, 206

Meny, C.

SA06

317

Misawa, Takahiro

PE18, QB10

139, 188

Mizuguchi, Masaki

JI04, QL15, RL15

105, 230, 292

Matsuura, Masato

PB30, PB32

125

Meny, Christian

AJ05, SA05

40, 317

Misek, Martin

BB04, QJ14

42, 223

Mizuguchi, Y.

RB28

258

Matsuyama, Hideo

RP14

305

Menzel, Dirk

QM08, SM02

232, 361

Misiorny, Maciej

DB03

57

Mizuguchi, Yoshikazu

QB09, QB17

188, 189

Matsuyama, Kimihide

QM29, QP09, QP10,
QP11, SJ03

236, 246, 247, 349

Menzel, Matthias

IH03

96

Misoka, Keita

RH11

276

Mizukami, Shigemi

CH02, EJ01

54, 71

Merazzo, Karla J.

GG04

80

Misu, Tekeshi

KC02

108

Mizumaki, Masaichiro

IG03, QD17

95, 199

Matsuzaka, S.

CG02

53

Merchant, P.

QE19

202

Misuraca, Jennifer

QK23

227

Mizuno, Fumio

RH12

276

Mattauch, Stefan

DG01

61

Merkt, Ulrich

RP04

303

Mita, Yoshimi

SG20

342

Mizuno, Hiroki

RI01

279

Mattenberger, K.

PI15

153

Mertig, Ingrid

EE01

67

Mitani, S

SK29

355

Mizuno, Yoshiyuki

RO06

301

Mattenberger, Kurt

RB21

257

Meshcheriakova, Olga

QN19

239

Mitani, Seiji

69, 94, 352, 355

Mizunuma, Kotaro

SI17

348

Matusiak, Marcin

AB03, SF1234, 339

Mesler, Brooke

RJ20

285

EH01, IF03, IF05, SK11,
SK31

Mizuochi, Norikaze

SI05

346

Matuura, Masato

PB29

124

Mesot, J.

PC01

126

Mitchell, J N

GC03

77

Mizuochi, Norikazu

RL11, SK10

291, 352

Mayoral, Alvaro

RN09

298

Mesot, Joel

IC02, QF20

92, 207

Mito, Masaki

PG13, SK04

144, 351

QO16

243

Metaxas, Peter

IE04

94

108, 124, 143, 144,
211, 297, 316

Mizusaki, Soichiro

Mayoral, Isabel

Mizushima, Toshio

SG05

340

Mayr, Franz

PA23, RH24

119, 278

Methfessel, Torsten

AG04

38

KB06, PB25, PG09,
PG10, QG19, RN03,
SA03

Moeller, A.

QE23

203

Maziarz, W.

PM05

168

Metoki, Naoto

IG04, JJ05, PH09, QJ09

95, 106, 148, 222

Mito, Takeshi

QD12, QD15, RD24

198, 266

Moeller, Thomas

KD01

109

Mazidian, Bayan

JA05

99

Mettus, Denis

CH01

54

Mitrelias, Thanos

BH01

46

Moessner, R.

CC04

50

Maziewski, Andrzej

AD05

Meven, Martin

PA14, RP22

118, 306

Mitsen, Kirill V.

QC19

195

Mohammad Shafique, Anwar PM14

169

Mazrouei Sebdani, S.

PO27, PO29, PO30,
PO31

181, 182

Meziere, Cecile

SB20

323

Mitsuda, Akihiro

IG05, QD03, QD15, SB1495, 196, 198, 322

Mohan, Ashwin

SO22

370

Mi, J.l.

II02

97

Mitsuda, Setsuo

PH05

147

Mohn, Peter

EF05

68

Mazrouei Sebdani, Saeed

PO28

181

Mibu, Ko

QM16

234

Mitsui, Takaya

QM16

234

Mohseni, S. M.

CE02, PK13

51, 162

Mazumdar, Chandan

RB15

256

Michel, Ann Kathrin

RN15

299

Mitsui, Yoshifuru

GJ02, QH08

82, 214

Mokrousov, Yuriy

IH03

96

Mazzoli, Claudio

BF03, PA1545, 118

Michel, Anny

QP18

248

Mitsumata, Chiharu

KH02, SJ06

112, 349

Molavi, Mostafa

PC16

129

Mc Gill, S.

AA04

33

Michihiro, Yoshitaka

QF24

207

Mitsumoto, Keisuke

RB05

254

Mole, R. A.

PI03

151

Mc.donald, Ross

RB21

257

Michimura, Shinji

IG03, RH03

95, 275

Mitsunaga, Daisuke

QH08, QN20

214, 239

Mole, Richard A

QG26

212

QI10

219

Mitsuzuka, Yoshio

RK04

286

Molegraaf, Hajo

DH02

62

Mccollam, Alix

DH02, SA10

62, 317

Michimura, Sinji

Mccord, Jeffrey

SH04

343

Michiue, Yuichi

RH06

275

Miura, Daisuke

RL09, SI06

291, 346

Molenda, J.

PH06

147

Mcdonald, Ross

GC03

77

Michlmayr, Thomas

RK24

289

Miura, Hideo

RP11

305

Molenkamp, Laurens Wigbolt AC01

34

Mcdonald, Ross D

QB13

189

Michor, Herwig

IA02, SC0190, 325

Miura, Katsuya

QP14

247

Molkanov, P. L.

RQ13

309

Mcgee, Fintan

SH09

344

Micklitz, Hans

RB10, RB11

255

Miura, Tomohiro

PB29

124

Moll, Philip J. W.

SC16

328

Mcintyre, Garry

IJ03, PO25

97, 181Miclea, C.

SA11, SC03

318, 326

Miura, Tomoya

PG04

143

Moll, Philip J.w.

RB19, RB21

257

SA11, SC03

318, 326

Miura, Yasunao

PD13

134

Molodtsov, Serguei L.

CD03, PD1251, 133

Mcmichael, Robert D

EG01

69

Miclea, C. F.

Mcmorrow, D F

RI05

279

Miclea, C. T.

SA11

318

Miura, Yoko

QE09, RI06

200, 279

Molokeev, Maxim

PI11

152

Mcmorrow, D. F.

QN01

236

Middey, S.

RF12

270

Miura, Yoshio

IF02

94

Mombetsu, Shota

RD07

263

Mcmorrow, Des

QG14

210

Mielke, Chuck

BA01, GC03

40, 77

Miwa, Shinji

JD04

101

AF01

36

Mignot, Jean - Michel

RD14

264

110, 163, 291, 346,
352

Momoi, Tsutomu

Mcmorrow, Desmond

KF01, PK20, RL11, SI05,
SK10

Momono, Naoki

Md Nor, Anis Faridah

QM29

236

Mihashenok, Natalia

PI11

152

Miyagawa, Kazuya

BC03

42

PB08, QA19, QJ04,
RD06, RD22, SE06

121, 185, 221, 263,
265, 334

Measson, Marie-aude

PD17

134

Miike, Kazunari

QL03, RN02

228, 297

Miyahara, Shin

GB01, PA07

76, 117

Monaco, Giulio

RB28

258

Medarde, Marisa

PO17

180

Mijnarends, Peter E.

BA04

41

Miyake, Atsushi

PB27, PC21, PC23

124, 130

Mondragon, Reginaldo

QO26

245

Medicherla, V R R

PE14

138

Mikhaylovskiy, Rostislav V.

GD04, QO05, RK2078, 241, 289

Miyake, Kazumasa

IG01

95

Montaigne, Francois

KF02, SH02

110, 343

Medjanik, K

RP20

306

Miki, Hiroyuki

DJ04, QG18

63, 211

Miyake, Kohsaku

CE05

52

Montbrun, Richard

EG02

69

Medonca Ferreira, Leticie

SE15

335

Millan, Angel

KB06

108

Miyake, Takashi

RG07

272

Monteiro, Pedro M.d.s.

PN23

175

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

407

408

Author Index

Monteiro, Rodrigo S.

QO03

241

Mueller, Jens

QA11, QJ11

184, 222

Nagai, Kousuke

PG09

143

Nakao, H.

CF04, PL14

53, 166

Montoncello, Federico

GG02

80

Mueller, M.

CD01

50

Nagalakshmi, Ramamoorthi

QC13

194

Nakao, Hironori

148, 151, 334, 337

Moon, Eun-gook

JD05

101

Mueller, Marc

EG02

69

Nagano, Katsuaki

RD10

263

PH07, PH08, PI07, SE07,
SF04

Moon, Han Seb

RQ18

310

Mufti, Nadang

AB02

34

Nagano, Takuma

PG10

144

Nakao, Yuya

PG09

143

Moon, Jung-hwan

CE04, EE05, HP21, RJ19

52, 68, 30, 285

Mufti, Nandang

PH17

149

Nagano, Y.

SL14

358

Nakashima, Miho

QH04, RD19

213, 265

Moon, Kyoung-woong

KE03

110

Muhammad, Kamran

SB01

320

Nagano, Yutaro

SB14

322

Nakashima, Naoya

QL12, QL13

230

Moon, Seung Ho

CB01, PO15, PO1649, 179

Muhlbauer, SebastianCC03, DF02

50, 60Naganuma, Hiroshi

QE21

202

RH08

276

Muir, Jack

PO12

179

54, 70, 110, 292,
346, 348, 351

Nakata, Hayato

Moon, Wonha

CH02, EI02, KD04, RL13,
SI03, SI17, SK08

Nakatani, Ryoichi

DE04, EI05, PK08, SK33

60, 71, 161, 355

Morais, Paulo Cesar

PO08

178

Mukadam, M. D.

PN17

174

Nagaosa, N.

RA05

250

Nakatani, Y.

RL07

291

Morales, R.

BD01, ED03

43, 66

Mukai, Kazuhiko

PO17

180

Nagaosa, Naoto

AE05, DF01

36, 60Nakatani, Yoshinobu

Morales, Rafael

BD04

43

Mukhamedshina, Nuranya

RR28

315

Nagasawa, N

PC04

127

HG02, QP03, RJ01, RJ02,
RJ09, SJ01

88, 245, 282, 284,
349

Morales, Ricardo

QO26

245

Mukherjee, Sankha Subhra

EG03, HD02, PJ08, SI02

69, 85, 156, 346

Nagasawa, N.

EF01

68

Nakatsuji, S.

CF01

52

Morbec, J. M.

RM02

295

Mukherjee, Sudip

RN17

299

Nagasawa, Naohiro

RD04

262

Nakatsuji, Satoru

Morellon, Luis

SM16

363

Mukhin, A. A.

PA15

118

Nagashima, Ryo

QB15

189

50, 51, 95, 144, 196,
264, 333, 338

Morenzoni, Elvezio

PB20, QL19

123, 231

Mukhin, Alexander

PA13

118

Nagata, Shoichi

QH14

215

CC05, CD02, IG03,
PG14, QD01, RD13,
SE01, SF07

Moretti Sala, Marco

BA03, RB28

41, 258

Mukhopadhyay, Sutirtha

IC02

92

Nagata, Tomoko

RA18

252

Nakayama, T.

SK03

350

Morgan, Jason

KE01

110

Mukovskii, Ya. M.

RQ13

309

Nagata, Yujiro

PG13, SK04

144, 351

Nakayama, Takayoshi

PF15

141

Mori, Shigeo

AF03, PG15, QG22,QG2837, 144, 211, 212

Mukuda, Hidekazu

DA04, PB26, QB29

56, 124, 191

Naghavi, S. S.

QG24

212

Nakmura, Tetsuro

QC07

193

Mulders, A.m.

SO08

368

Nair, K. G. M.

PN01

172

Nakotte, Heinrich

SF13

339

Moriki, Takahiro

QH15

215

Muller, M.

SF10

338

Naito, Makoto

PG13

144

Nakotte, Heinz

RE09

267

Morimoto, Kazuhiro

AE05

36

Muller, Ralf

RI12

280

Naito, Tomoyuki

SG18

342

Naletov, Vladimir V.

ID03

93

Morimoto, Y.

SL14

358

Mun, E. D.

IA05

91

Naka, Makoto

GB02

76

Nallamuthu, Sengodan

QC13

194

Morinaga, Rei

QE13

201

Mun, Eundeok

QB13

189

Naka, Takashi

RN11

298

Nam, Chunghee

KC01

108

Morioka, T.

PG24

146

Munchenberger, Jana

IF04

94

Nakada, Kengo

PN13

174

Nam, Hyoung Uk

QO20, SG21

244, 343

Morisako, Akimitsu

PK07, QP08, RL05

161, 246, 290

M. Cagigas, Julian Andres

RB10

255

Nakagawa, Shigeki

HB03

84

Nam, Moon-sun

SB20

323

Morishita, Kohei

RP01

303

Munevar, Julian

RB11

255

Nakagawa, T

QM12

233

Nam, Nguyen Hoang

HC02, PE15

84, 138

Morita, Kyohei

PD25

136

Munoz, Carmen

KI02, SD16

113, 332

Nakagawa, Takeshi

AG04, EI01

38, 70Nam, Yoon Jae

PL16

166

Moriyama, Takumi

KD03

109

Munzenberg, Markus

DI03

63

Nakahara, Mako

SG05

340

Namatame, Hirofumi

RD20

265

Moro, Maria

PG08

143

Murakami, Naoki

RP01

303

Nakai, Ikuo

PN07

173

Namkung, Seok

RO01, RO02

300, 301

Morodomi, Hiroki

QE18, QF14

202, 206

Murakami, Shuichi

RL16

292

Nakai, Yusuke

QC08, RD05, SO515

193, 262, 369

Nandy, Ashis Kumar

RF12

270

Morosov, Alexander I

PL05

164

Murakami, Y.

CF04, PL14

53, 166

Nakajima, K.

RA22

253

Nanto, Dwi

QH01

213

Mosendz, O.

BG02

45

Murakami, Yoichi

SE07

334

Nakajima, Kazuo

RP01

303

Naohiro, Nagasawa

QC16

194

Moshchalkov, Victor

QC19, QC20

195

Murakami, Youichi

PH07, PH08, PI07

148, 151

Nakajima, Kenji

RH12

276

Napolskiy, Kirill

SL27

360

Moskvin, Alexander

PB14

122

Murakami, Yuta

RI14

281

Nakajima, Taro

PH05

147

Nara, Daichi

RP14

305

Moskvin, Evgeny V.

DF04

60

Murakawa, H.

PA14

118

Nakama, Akihiro

RD17

264

Nara, So

QG18

211

Mostovoy, M.

RA05

250

Muramoto, Shingo

IF02

94

Nakama, Takao

PD14, QC11, QI12, QI13

134, 194, 219

Naramoto, Hiroshi

BH05, BH06

46, 47

Mostovoy, Maxim

CI01, DF01

54, 60Murasawa, Y.

PL04

164

Nakamoto, Atsuhiko

RP14

305

Narayanapillai, K.

GE03, PJ20, PJ21, RL19

78, 158, 293

Mostovshchikova, Elena

SL17

358

Murata, Atsushi

QM16

234

Nakamoto, Go

QG11

210

Nardone, Marc

RQ16

309

Mota, A. C.

SC03

326

Murayama, Shigeyuki

QI12, QI13

219

Narikiyo, Kurahito

SB24

324

JD02, PE18, PG23, RG03

101, 139, 146, 272

185, 192, 221, 263,
265, 334

Nakamura, Ai

Motome, Yukitoshi

QA19, QC01, QJ04,
RD06, RD22, SE06

Nakamura, Hiroyuki

HJ02, QA12, QH13

90, 184, 215

Nartowt, B

SE14

335

Motonami, Satoru

RD20

265

Murayama, Sigeyuki

PB08

121

Nakamura, Kazuma

QB10

188

Narumi, Y.

GJ03

82

Motoya, Kiyoichiro

HJ03, PH15, QE13

90, 149, 201

Mure, Elena

IE02, JE01

93, 101

Nakamura, Kohji

65, 295, 296, 368

Narumi, Yasuo

PG17, QF09, RP07

145, 205, 304

Motoyama, Gaku

QC03

192

Muro, Y

SE03, SE05, SE13333, 334, 335

EC02, RM04, RM05,
SO10, SO11

Naruse, Koki

QF10

205

M. Ghahfarokhi, Ebrahim

RN22

300

Muro, Y.

KA02, QC12107, 194

Nakamura, Mitsutaka

RH12

276

Nascimento, Valberto Pedruzi QM15

234

Movshovich, R.

QB31, SC03

192, 326

Muro, Yuji

PD24, QE13

135, 201

Nakamura, Mitsuteru

PD11

133

Nasirpouri, Farzad

QM05

232

Movshovich, Roman

SB12

322

Muromachi, Eiji

PC21

130

Nakamura, Saori

QH14

215

Nasreen, Farzana

SF13

339

Moya, Carlos

RN14

299

Murphy, J.

QC23

196

Nakamura, Shintaro

SL04

356

Nasu, Joji

RH10

276

Moya, Maria Dolores Salvador RO08

302

Murphy, T.

IA05

91

Nakamura, Takuya

RP14

305

IG02, QG23

95, 212

Moya, Xavier

AE03

36

M. Ghahfarokhi, S Ebrahim

PB15

122

Nakamura, Tetsuya

RP07

304

Nateprov, Alexandr
Nikolaevich

Moyoshi, Taketo

HJ03, PH1590, 149

Musfeldt, J. L.

AA04

33

Nakamura, Toshiyuki

IG03

95

Nath, Ramesh

QE12

201

Mruczkiewicz, Michal

QO05

241

Mutka, Hannu

BC02

42

Nakane, Takayuki

RN11

298

Naumov, Sergey

SL17

358

Mryasov, Oleg

JI03

105

Muto, Tomoki

RH03

275

Nakanishi, Yoshiki

PD11

133

Naumova, Larisa

SK02

350

Mryasov, Oleg N

KH04

112

Myakon'kikh, Veronika

PC07

127

Nakano, Hiroki

QE07, QE11, RI04, RI16

200, 201, 279, 281

Naumova, Larisa I.

SK01

350

Mryasov, Oleg N.

JF04

103

Mysik, Alexey

QL07

229

Nakano, Kyohei

PF12, RF03

141, 269

Navarro, Oracio

QG21, QO26, SK15

211, 245, 352

Msomi, Justice

QL20

231

Navarro-quezada, Andrea

BE03

44

QF20

207

JH01, PM08, PM09,
RO03

104, 168, 301

Mudry, Christopher

N

Nakano, Masaki

Navas, D.

ED03

66

Mudryk, Yaroslav

JJ01

106

Na, Sewoong

RB14

256

Nakano, Takehito

HC02, PE15, RI17

84, 138, 281

Nazmunnahar, Mst.

DJ03

63

Muechler, Lukas

RC10

260

Naaman, Ron

GI02

81

Nakano, Tomohito

RD24

266

Nedelko, N.

PH06, PM05

147, 168

Muehlbauer, S. Clemens

IJ06

98

Naastepad, F.

RQ12

309

Nakao, A.

CF04

53

Nekrasov, I. A.

RF16

271

Muellen, Klaus

QK14

226

Nafradi, Balint

PA14

118

Nakao, Akiko

PH07, SF04

148, 337

Nelson- Cheeseman, Brittany

DH01

62

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

409

410

Author Index

Nelson, C.s.

PH10

148

Ninios, Kostas

BC05

42

Novitskiy, Nicolay

QM08

232

Ohashi, Masashi

QJ12

222

Nelson, Christie S.

PA02

116

Ninomiya, Keisuke

PN26

176

Nowak, Uli

FC03

74

Ohashi, Takuma

RF09

270

Nemnes, George Alexandru

QK20

227

Niratisairak, Sanyalak

RP17

306

Nowak, Ulrich

FA02, RJ04

72, 283

Ohashi, Tatsuro

KC03

108

Nemoto, Yuichi

RB05, RD07

254, 263

Nishi, Yusuke

QD18

199

Nozaki, Hiroshi

PI06, PO17

151, 180

Ohdaira, Yusuke

EI02

70

Nenert, G.

QF22

207

Nishihara, Sadafumi

QG22

211

Nozaki, Taiichiro

RL25

294

Ohe, Junichiro

RL27

294

Nenert, Gwilherm

PI17, QJ02

153, 221

Nishihara, Yoshikazu

PM13

169

Nozaki, Takayuki

BI01, KF01, PK20, SK10

47, 110, 163, 352

Ohe, Jun-ichiro

FA03, FD04

72, 74

Nepijko, S A

QM12, RN12, RP20

233, 298, 306

Nishikawa, Takuo

SK08

351

Nozaki, Tomohiro

PL10, SM03

165, 361

Ohgushi, K.

SG02

339

Neu, Volker

DG01

61

Nishikawa, Yunori

SF15

339

Nozaki, Yukio

IA04, QO13, SG04

91, 242, 340

DF02, QH12, SF05

60, 214, 337

Nishimoto, Satoshi

PF09, PF12140, 141

103, 246, 284, 287,
347

Ohgushi, Kenya

Neubauer, Andreas

JG03, QP09, RJ10, RK10,
SI08

Ohishi, Kazuki

QB02, QB04

187

Neumann, I.

DI01

62

Nishimura, Katsuhiko

QI04, QJ06

218, 221

Nozawa, Akihiko

RB06

255

Ohkawara, Manabu

RP01

303

Neupane, Madhab

HI02, SD04

89, 330

Nishimura, Naoto

PD13

134

Nozue, Yasuo

HC02, PE15, RI17

84, 138, 281

Ohkubo, Tadakatsu

IF03

94

Neusser, Sebastian

GG02

80

Nishimura, Taizo

PG17

145

317

Ohmichi, Eiji

RP09, RP19

304, 306

Ng, Dickon H.l.

BE04

44

Nishino, Yoichi

QH28

217

Nugroho, Agung

CC05, PH1750, 149

Ohnish, Tomohiro

SK04

351

Ngubane, Jeanette

QH22

216

Nishioka, Takashi

PD10, QD06, RD10

133, 197, 263

Nunes, Sabrina Esperanca

SB18

323

Ohnishi, Nozomi

QE10

201

Nguyen, Anh T. N

CE02

51

Nishisako, Yuya

SK23

354

PG13

144

Nguyen, Anh Tuan

QF16

206

Nishishita, Muneyuki

PF19

142

O

Ohnishi, Tomohiro
Ohno, H.

BE02, CG02, SH07

44, 53, 344

Nguyen, Duc-tho

RA10

251

Nishitani, Koji

QD15

198

O' Farrell, Eoin

HA05

84

Ohno, Hideo

BI02, HP52, QP14, SI1747, 31, 247, 348

Nguyen, Hoa

SL05

356

Nishitani, Y.

BE02

44

O' Farrell, Eoin T. C.

CD02

51

Ohno, Masumi

QF10

205

Nguyen, Hong T. M.

QL16

230

Nishiumi, Naoto

QC18

195

O’farrell, Eoin

SF07

338

Ohno, T.

SG02

339

Nguyen, Khanh Duy

QA10, QA17

184, 185

Nishiyama, Kouhei

QD12

198

Obi, Yoshihisa

SE06

334

Ohno, Takahisa

RF07

270

Nguyen, Sinh Huy

CJ05

56

Nishiyama, Masahide

BC04, QE22

42, 203

Obry, Bjoern

SI15

348

Ohno, Takashi

QF24

207

Nguyen, Thanh Van

SO13

368

Nishiyama, N.

SG02

339

Obry, Bjorn

HD01

85

Ohno, Y.

CG02

53

Nguyen, Thuy-trang

RF02

269

Nishiyama, Norimasa

PE10

137

Ochai, Akira

QD11

198

Ohnuma, Shigehiro

JI01, SL04

105, 356

Nguyen, Tiep H.

QL16

230

Nishizaki, Terukazu

SG18

342

Ochiai, Akira

QJ08

222

Ohoyama, Kenji

QG18, RP01

211, 303

Nguyen, Tuan Anh

SO13

368

Nitta, Junsaku

KC03

108

Ochoa, Martha Teresita

QO26

245

Ohsawa, Takashi

BI02

47

Nguyen, Van Dai

GE01, QK15, QK16,
QK17, RL24, SL2478, 226, 293, 360

Niyogi, Sandip

PN16

174

Oda, Migaku

PB08

121

Ohsuka, T

PC04

127

Nizhankovskii, Victor

JJ03

106

Oda, Tatsuki

AE02, PL06, RC02, RL02

36, 164, 259, 290

Ohsumi, Hiroyuki

IA04, QO13

91, 242Nguyen, Van Thanh

QF16

206

Nizzoli, Fabrizio

GG02

80

Odkhuu, Doji

QO23

244

Ohta, Hitoshi

Nhlapo, Ta

QL20

231

No, Young-il

BH02

46

Odkhuu, Dorj

KI01

112

113, 137, 199, 201,
204, 262, 304, 306

Ni, NiQB13

189

Noad, H. M. L.

GF01

79

Oezelt, Harald

DE01

59

KI05, PE11, QE03, QE10,
QF04, RD01, RP05, RP09,
RP19

Niarchos, Dimitrios

EJ04

72

Noda, Kazuto

PF16

141

O'farrell, Eoin Conor

QD01

196

Ohta, Tsuyoshi

QI04

218

Niarchos, Dimitrios G

RO08

302

Nogami, A.

PA04

116

Ogata, Masao

SE04

333

Ohta, Yukinori

Niarchos, Dimitris G

BJ02, DD06, QP12,
QP13, RQ10

47, 59, 247, 308

Noguchi, Tomoaki

PE10

137

Ogawa, Daisuke

EJ01, RO05, RO06

71, 301

111, 140, 141, 267,
269, 337

Noh, Han-jin

HJ05, PB12

90, 122

Ogawa, Satoru

SG18

342

KG03, PF09, PF10, PF12,
PF14, PF15, RE08, RF03,
SF04

Nicklas, M.

SC03

326

Noh, Hwayong

PJ16, PJ24

157, 158

Ogita, Norio

127, 145, 263, 342

Ohtake, Mitsuru

ED01, PM18, SM15

66, 170, 363

Nicklas, Michael

AB02, IA02, RD12, SB29

34, 90, 264, 325

Noh, Hyunho

SD14

332

PC05, PG16, RD10,
SG15

Ohtani, H.

QH09

214

Nie, Wenxing

PF18

142

Noh, Seung-hyun

PO15, PO16

179

Ognev, Alexey

AG05, QM05

38, 232

Ohtani, Hiroshi

QH10

214

Nie, Yuefeng

HA03

83

Noh, Su Jung

PJ14, SH13

157, 345

Ogrin, Feodor Y.

RK20

289

Ohtani, Taiki

SM15

363

Niedermayer, Ch.

QE19

202

Noh, T. W.

HP12, SA1630, 318

Oguchi, Tamio

EC03

65

Ohtomo, Manabu

BH05, BH06

46, 47

Niedermayer, Christof

HA03

83

Nohara, Hiroki

SF03

337

Oguri, Akira

PE16

138

Ohtori, Hiroyuki

RA09

250

Nielsch, Kornelius

RP04

303

Noji, Takashi

QF07

205

Ogusu, Hiroki

PC17

129

Ohuchi, Syuya

PI22

154

Niemeyer, Markus

KD01

109

Nojima, Tsutomu

SL04

356

Oh, Hangdeok

PO04

177

Ohya, Masahiro

PD08

133

Niermann, Daniel

QA22

186

Nojiri, H.

PG24

146

Oh, Hyungju

RB16

256

Ohzuku, Tsutomu

PO17

180

Nigam, A K

QO04

241

Nojiri, Hiroyuki

QF09, RP07

205, 304

Oh, Ok Kyun

QN17

239

Oikawa, Hiroto

EI05

71

Nigam, A. K.

QH06, SO22

213, 370

Nolas, George S.

DJ01

63

Oh, S.

SB28

324

Oka, Kengo

RA06

250

Nigam, A.k

PG19

145

Noll, T

RP08

304

Oh, S. H.

SA06

317

Oka, Kunihiko

183, 184, 276

Nii, Yoichi

QA10, QA13

184, 175

Nolting, Frithjof

BC02, RK1742, 288

Oh, Sang-soo

QM22

235

QA05, QA07, QA09,
RH11

Niimi, Yasuhiro

HE03, ID04

86, 93

Nomura, Hikaru

DE04

60

Oh, Se-jung

GF05

79

Oka, Takahi

RI14

281

Niimi, Yohei

RC18

261

Nomura, Kentaro

AE05

36

Oh, Seol Hee

SA05

317

Oka, Takashi

EB02, HI05

65, 89Niizeki, T

SK29

355

Nomura, Ryuya

QL11

229

Oh, Seung-lim

RN20

300

Oka, Toshihide

QB11

188

Niizeki, Tomohiko

IF03

94

Nomura, Tatsuya

KC06, QK24, RL20, RL23

109, 228, 293

Oh, Suhk Kun

SH01

343

Okabe, Hirotaka

PC21, SF02

130, 337

Niki, Haruo

QH14

215

Nonoguchi, Seiji

109, 228, 229, 293

Oh, Suhk-kun

QH01

213

Okada, Hironari

PG07, QH21

143, 216

Nikolaev, Pavel

PJ32

160

KC06, QK24, QL11,
RL20, RL23

Oh, Sunjong

QO19

243

Okada, Kyoko

SK13

352

Nikolenko, Victor V.

QO12

242

Nordblad, Per

PM10, QH11, RN07

169, 214, 297

Oh, Yoon Seok

JB02

99

Okada, Takuya

RI01

279

Nikseresht, Neda

QF23

207

Noro, Yoshihiko

PG13, SK04

144, 351

Oh, Young Kun

PB40

126

Okamoto, Hiroaki

RD06

263

Nilsen, Gøran J.

QE05, QE08

200

Notin, Lucien

71, 78, 226, 293

Ohara, Jun

IJ05

98

Okamoto, J.

PL14

166

Nimori, S.

QJ10

222

EI04, GE01, QK15,
QK17, RL24

Ohara, S.

RD15

264

Okamoto, Kazuaki

KF05

111

Nimori, Shigeki

PI22, RI07

154, 280

Novais, Erico

RJ13

284

Ohara, Satoshi

RN11

298

Okamoto, Kiyomi

RI11

280

Ning, F. L.

GF01

79

Novak, Vit

BE05

44

Ohara, Shigeo

199, 265, 335

Okamoto, YoshihikoNing, Sun

RR25

315

Noverola, Humberto

QO26

245

QD17, RD18, RD20,
SE11

JA04, QE03, QE05,
QE08, QE27, SG1499, 199, 200, 203,
341

The 19th International Conference on Magnetism

Nucara, Alessandro

SA08

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

411

412

Author Index

Okane, Tetsuo

RD25, SE23

266, 337

Orihashi, Hiroki

QH08, QN20

214, 239

Pandey, Sudhakar

PF19

142

Park, Sungyu

PC25

130

Okawauchi, Yasuharu

SC13

327

Orii, Daisuke

PC21

130

Pandiyan, Manoj

DH03

62

Park, Tae-eon

SL26

360

Okazaki, K.

QB28

191

Orlov, Andrey F

PN22

175

Panholzer, Martin

RG15

274

Park, Tuson

FB01, PC19, SE02

73, 129, 333

Okazaki, Ryuji

PH12, QC06

148, 193

Ortega, Daniel

RN13

298

Panigrahi, B. K.

PN01

172

Park, W. K.

GA01

75

Oki, Soichiro

HE01

86

Ortiz, Christian

PJ29

159

Pankrats, A

QJ16

223

Park, Wan Kyu

RD09

263

Okita, Kazuhiko

RP11

305

Osakabe, Toyotaka

QI16

220

Pankrats, Anatolii

IJ01

97

Park, Wongoo

GF05

79

Okubo, Akinari

SK23

354

Osaki, Soichiro

SK33

355

Paolasini, Luigi

AF01

36

Park, Yeonjoo

PB18, PB37, PB39, PB40

123, 126

Okubo, Kazuma

RP01

303

Oshikawa, Masaki

PF18, QF11, RI02

142, 205, 279

Papaioannou, Evangelos

AF05

37

Park, Youn Ho

QK11

225

Okubo, S.

KI05

113

Oshino, Yuuki

SK21

353

Parakkat, Vineeth Mohanan

QM03, SJ08, SL23

232, 350, 359

Park, Young Woo

QN15, QN17

238, 239

Okubo, Susumu

QE03, QE10, QF04, RP05

199, 201, 204, 304

Oshiro, Morihito

QH14

215

Pardo, J. A.

KC05, PJ23

109, 158

Park, Young-woo

QN07

237

Okuda, Mitsuhiro

KB01

107

Ostler, Thomas A.

RK17

288

Pareek, S. P.

SL25

360

Park, Younho

SL26

360

Okuda, Taichi

KF05

111

Ota, Satoshi

PO03

177

Park, B.-g.

PG11, QA04

144, 183

Park, Youn-ho

RL03

290

Okuda, Tetsuji

RH04, SB24

275, 324

Ota, Y.

QB28

191

Park, Byong-guk

IF01

94

Park, Yu Seop

RR04

311

Okunishi, Kouichi

RI11

280

Otani, Yoshichika

85, 86, 93, 287

Park, Chan Woo

RL21

293

Parker, Dinah. R.

QG19

211

Okutomi, Yoshihito

CE05

52

HD04, HE03, HE05,
ID04, RK11

Park, Chang-yup

RL03, SM12290, 362

Parker, G.

BG02

45

Okuyama, Daisuke

PA12

117

Otsubo, Toru

QI10

219

Park, D.g

HH03

88

Parkes, Duncan E

SH09

344

Okuyama, Hiroaki

SG05

340

Otsuka, Hiromi

JD06

101

Park, D.g.

168, 178, 307, 353

Parkin, Stuart

HP41

31

Oles, Andrzej

RG18

274

Otsuka, Shintaro

PO18

180

PM07, PO05, RQ04,
SK17

Parkin, Stuart S. P.

SM01

361

Olivetti, Elena Sonia

DG04

61

Otsuka, Yuichi

RG09

273

Park, Dong-soo

DJ02

63

Parkin, Stuart S.p.

RK22

289

Omura, Kumiko

PI06

151

Otsuka, Yuto

QP09, QP10, QP11

246, 247

Park, Eunsung

SE02

333

Parreiras, Sofia De Oliveira

RJ12

284

Oner, Yildirhan

QG06, QJ15

209, 223

Ott, Hans Rudolf

IC02

92

Park, Gwan Soo

237, 246, 312

Parwanta, Kadek J.

QL09

229

Ong, Chin Shen

SL06

357

Ou, Z. Q.

SO16

369

QN04, QN05, QP04,
RR07

Parwanta, Kadek Juliana

RA21

252

Ong, N. P.

AB04

34

Ou, Zhiqiang

SO08

368

Park, Gwang-seo

QO10

242

Pascarelli, Sakura

RH23

278

Onimaru, T

PC04

127

Ouardi, S.

SK24

354

Park, Gwansoo

SN07

365

Paschen, S.

CD01, SF1050, 338

Onimaru, Takahiro

EF01, PD24, RD04,
SG12, SG15

68, 135, 262, 341,
342

Ouardi, Siham

CH03, SD15

54, 332

Park, H. L.

PM26

171

Pascua, Gwendolyne

PI05, PI17, QB22, QJ03

151, 153, 190, 221

Ouladdiaf, B.

RB17

256

Park, Hae Jung

QN07, QN17

237, 239

Pascual, Jose Ignacio

PG08

143

Ono, Akiko

PC20, QJ07

130, 222

Ouladdiaf, Bachir

SB08

321

Park, Hee Yeon

SB22

323

Pashkevich, Yurii G.

QJ03

221

Ono, Hiroaki

QP20

248

Ouyang, Yuyu

AH04

38

Park, Insuk

QB25

191

Pashkin, Alexej

HA02

83

Ono, Hiroshi

SK21

353

Ovchinnikov, Alexander

DF03

60

Park, Insung

PJ16, PK10, PK17

157, 162, 163

Pasquale, Massimo

DG04

61

Ono, Shimpei

RL10

291

Ovchinnikov, Alexander Sasha QG22

211

Park, J.- G.

PG24

146

Passamani, Edson Caetano

QM15

234

Ono, T.

RL07, SH07

291, 344

Ovchinnikov, S. G.

QK07

225

Park, J. H.

IA05

91

Paszkowicz, Wojciech

DD02

58

Ono, Teruo

GE05, HG02, RJ02, RL10

79, 88, 282, 291

Oviedo Roa, Raul

SK15

352

Park, J. K.

RP10

304

Patel, Sheena K. K.

PK09, QM01

161, 231

Ono, Toshio

QE22

203

Owaki, Yasuhiro

PE15

138

Park, J. M. S.

PH03

147

Pathak, Arjun Kumar

CH01

54

Onoda, Shigeki

JD03

101

Oyamada, Akira

BC04, QE22

42, 203

Park, J. S.

RA07

250

Patil, Sujata M.

QD16

199

Onodera, Hideya

QI10, QI16

219, 220

Ozawa, Kiyoshi

PH02

147

Park, J.-h.

PH10

148

Patil, Swapnil

PE14

138

Onosaka, Atsuhi

JA04

99

Ozawa, Tadashi C

SK04

351

Park, Jae - Hyun

RB14

256

Patlagan, L.

PD03

132

Onuki, Yoshichika

HP11, PB27, PC28,
PD08, PD13, PD16,
QC03, QH03, RD11,
RD25, RE10, SB15, SE23,SF0330, 124, 131, 133,
134, 192, 213, 263,
266, 268, 322, 337

Ozdogan, K.

RP15

305

Park, Jae Hyun

CE04

52

Patoary, M. Atiqur R.

PB24, PF05

124, 140

Ozerov, M.

QF02, QF03

204

Park, Jae Y.

CJ03

55

Patra, Ajit K

QK14

226

Park, Jae-hoon

AA01, AF04, JB02

33, 37, 99

Patrin, Gennady

PJ27, SM19, SO28

159, 364, 371

Park, Jae-hyuk

PN14

174

Patrin, Konstantin

PJ27, SM19, SO28

159, 364, 371

Onuma, Kazuki

QL03, RN02

Oogane, Mikihiko

P
P, D.

PC22

130

Park, Je Geun

HJ01

89

Patthey, L.

PC01

126

228, 297

P, Suresh

RA16

252

Park, Je-geun

GF05, PI10, RA22

79, 152, 253

Patthey, Luc

PD12

133

CH02, EI02, EJ01, RL13,
SI03, SI17, SK08

54, 70, 71, 292, 346,
348, 351

P. D., Babu

QD04

197

Park, Jewook

RC14

261

Paudyal, Durga

JJ01

106

P. Del Real, Rafael

GG04

80

Park, Ji Hun

PN20, PN21

175

Paulose, P. L.

PC11, QD16

128, 199

Oogane, Mikiko

KD04

110

Padilla, Jessica

EC04

66

Park, Jihoon

JH04, KH04

104, 112

Paulose, P.l.

QB14

189

Oogane, Yuta

QD06

197

Padilla-pantoja, Jessica

RA17

252

Park, Jin-hong

DF01

60

Pautrat, Alain

DG02, EH03

61, 70Ooi, Takahiro

RF17

271

Paglione, J.

QB07

188

Park, Jong C.

CJ03

55

Pavlova, Ekaterina

SG17

342

Oomaru, Kiyoaki

SJ01

349

Pagliuso, Pascoal

SE22

336

Park, Joonbum

SD07

331

Pavlukhina, Oksana

PI20

154

Oomi, Gendo

PJ03

155

Pagliuso, Pascoal G.

SE15

335

Park, Jun Kue

SI14

348

Pecharsky, Vitalij

JJ01

106

Oosawa, Akira

RH03

275

Pal, A

QM24

235

Park, Junghwan

PG24

146

Peddis, Davide

RN07

297

Oozono, Satoshi

RH04

275

Pal, Semanti

HD04, RK1185, 287

Park, Ju-young

JB02

99

Pedersen, Bjoern

QH24

216

Openeer, Peter

FC03

74

Palacio, Fernando

KB06, PG22, QO16

108, 146, 243

Park, Kwang-jun

PL11

165

Pedersen, Kasper Steen

BC02

42

Oppeneer, P M

QM12

233

Pal'chik, Marina

SM19

364

Park, Lee-seul

SD14

332

Pedrero, Louis

SF05

337

Oppeneer, P. M.

RG05

272

Palm, Eric

GJ02

82

Park, Po Gyu

RQ07

308

Pedrero, Luis

AB02

34

Oppeneer, Peter

BC02

42

Palstra, T.t.m

PH17

149

Park, San Youn

QA16

185

Peets, Darren

IJ02

97

Oppeneer, Peter M

RK12

287

Pan, M.x.

RO14

303

Park, Sang Kook

SB22

323

Pei, Wenli

SN10

365

Ordonez, John Edward

SA12

318

Pan, Minxiang

RO13, RO15

302, 303

Park, Seonghun

AF04

37

Peiro, Julian

AI04, CG03

39, 53

Orel, Valerii

BH01

46

Pan, Rui

SN01

364

Park, Seung-young

CE04, HF05, RL06

52, 87, 290

Pelegrini, Fernando

PL09, QM14, QM15

165, 233, 234

Orench, Ines Puente

QI01

217

Pan, Wei

ED02, SN1166, 366

Park, Sungkyun

QM18, QM20

234

Pelennen, Anatoliy P.

SO19

369

Orgiani, Pasquale

SA08

317

Pandey, Srikrishna

PJ32

160

Park, Sungmin

QO10

242

Pelevin, Ivan

SN09

365

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

413

Pena, Luis

IH01, SO18

95, 369

Pisana, S.

BG02

45

Proglyado, Vladimir V.

SK01

350

Ramakrishnan, S.

QB14

189

Pena, Octavio

QA06

183

Piskunova, Nataly Ivanovna

PF01

139

Proglyado, Vyacheslav

SK02

350

Ramanathan, Mahendiran

QA18

185

Penaranda-foix, F L

RQ10

308

Pistora, Jaromir

CH03, QH19

54, 216

Prokes, Karel

QL02

228

RO08

302

Pitcher, Michael. J.

QG19

211

212, 254, 255, 256,
310

Ramanujan, Raju V

Penaranda-foix, Felipe L

QG26, RB01, RB07,
RB17, RQ21

Ramasamy, Shivaraman

PO21

180

Pepe, Giulio

IJ03

97

Pizzini, Stefania

RL24, SH03, SH05, SH06

293, 343, 344

Prokhnenko, O.

RQ21

310

Ramaswamy, Shivaraman

Pepin, Catherine

PD04

132

Plazaola, Fernando

QH16, RN13

215, 298

Prokleska, Jan

KB03

107

Pleiderer, Christian

QC17

195

42, 90, 128, 195,
221, 321

181, 240, 249, 319,
320, 355, 360

Peprah, Marcus K.

BB04, HJ04, PC10,
QC21, QJ02, SB08

PO24, QN26, QP24,
SA21, SA22, SA23,
SK32, SL28

Peratheepan, P

SE03, SE05

333, 334

Plumb, N. C.

PC01

126

Prokofiev, A.

CD01

50

Ramesh, Palanisamy

PN16

174

Pereira, Andre M

SO31

371

Poddar, Asok

RB15

256

Prokscha, Thomas

PB20, PN23, QL19

123, 175, 231

Ramos, Scheilla Maria

SE22

336

Perez - Mato, Juan Manuel

PA13

118

Podgornykh, S. Mikhailovich

PC07

127

Proselkov, O.

BE02

44

Ramulu, T.s.

SL22

359

SG17

342

Proselkov, Oleg

DD02

58

Ran, S.

GA01

75

Perez, Nicolas

RN14

299

Podolskii, Vitaliy

Perez, Olivier

EH03

70

Pogorelov, Yu. G.

KC05

109

Proshin, Yurii N.

QA26, SC25, SC26

186, 329

Rana, Bivas

RK11

287

Perkert, Sandra

AG04

38

Pogossian, Souren P

SA24

320

Proshkin, Alexey

QG04

208

Rangappa, Dinesh

RN11

298

Perov, Nikolai

CH01, PN22, QO14

54, 175, 243

Poienar, Maria

JB05, RA11

100, 251

Proshkin, Alexey V.

QI08

219

Rani, Manju

SC02

325

Perring, Toby G.

HA04

83

Pokharel, Ramesh K.

PJ01

154

Proskurin, Igor

DF03

60

Ranjan, Vishal

GI05

82

Perry, Robin

EA04

64

Polak, Christian

PM04

168

Proskurina, Ekaterina

QG04

208

Ranjbar, Fereshte

RN22

300

RN12

298

Ranot, Mahipal

SB28

324

Persson, Jrg

QA23

186

Politi, Paolo

KE01

110

Protsenko, I E

Perucchi, Andrea

SA08

317

Polyakov, Andrey

PD05

132

Prozorov, R.

IA05, QC23, SB30

91, 196, 325

Ranzieri, P.

AG02

37

Peters, Robert

DB05

57

Polyakov, Victor

SO28

371

Prsa, Krunoslav

PI06, QF20, QF23, SE08

151, 207, 334

Rao, G.s.n.

BJ05

48

Peterson, Joe

RE09

267

Polyakova, Klaudia

SO28

371

Prudnikov, Valerii

CH01

54

Rao, Siddharth

PJ08, SI02

156, 346

Petit, S.

QF18

206

Pomar, Alberto

SO18

369

Pruschke, Thomas

FE03, PE03

75, 136

Rashad, Mohamed M.

RN01

296

Petit, Sylvain

AA03, DD05, JB05, RA11

33, 59, 100, 251

Pomjakushin, Vladimir

PI05, PO17

151, 180

Przybylski, Marek

AD02, AE01, EI01

35, 70Rasing, Theo

GD01, RK1777, 288

QM17

234

Rasly, M.

RN01

296

Petrakovskii, G. A.

SG20

342

Pomjakushin, Vladimir Yu.

PH02

147

Przysłupski, Piotr

Petrenko, O. A.

CC04

50

Pomjakushina, E.

QF23

207

Puente Orench, Ines

KB06

108

Rawat, Rajdeep Singh

PN03, QL02

172, 228

Petrenko, Oleg A

BF03

45

Pomjakushina, Ekaterina

IJ06, PI21, PO1798, 154, 180

Puente-orench, Ines

JJ04

106

Ray, R.

PL07

165

Petrenko, Oleg A.

GF03

79

Pong, W. F.

PB12

122

Pujari, P K

PM01

167

Raychaudhuri, Arup Kumar

HD04

85

Petrova, Elena A

PN22

175

Ponomaryov, A. N.

QF13

206

Pureur, Paulo

121, 125, 142, 255

Razzoli, E.

PC01

126

Petrovic, C.

QC23

196

Ponomaryov, Alexey

RP13

305

PB09, PB10, PB33, PG03,
RB09

Rebizant, Jean

SE19

336

RH15

277

Petti, Daniela

AI03

39

Pons, Stephane

SE08

334

Putri, Witha B. K.

PB03

120

Reddy, Leelakrishna

Petzold, Vivien

QD07

197

Pop, Viorel

EJ03

72

Puzniak, Roman

QB30, SB26

192, 324

Redinger, Josef

EF05

68

Pfleiderer, C.

PI09

152

Popkov, Sergei

PI11

152

Pyshkin, Pavel V

PJ02

155

Regnat, Alexander

QC17, QH24

195, 216

Pfleiderer, ChristianDF02, GC04, QH12,
QH24, SF05

60, 77, 214, 216,
337

Popova, Marina N.

PA20, RA24

119, 253

QE19

202

Porer, Michael

HA02

83

Q

Regnault, L. P.
Reichel, Franz

DE01

59

RA10

251

Portemont, Celine

AI04

39

Qamar Ul Hassan, Syed

318

Reichlova, Helena

BE05

44

Reiffers, Marian

QC13, QD08, QD12,
QI02, RD21

194, 197, 198, 218,
265

Pham, Duc-thang

414

Author Index

SA15

Pham, Huyen-yen

SO12

368

Porter, Daniel Graham

DH03

62

Qian, Bin

RB12

256

Pham, Huyen-yen Duc

RA10

251

Pospisil, Jiri

HJ04, PC10, QC21, QJ02

90, 128, 195, 221

Qiu, Xue Peng

BD05

43

Pham, Thang D.

QL16

230

Postava, Kamil

CH03

54

Qiu, Xuepeng

PJ20, PJ21, RL19

158, 293

Reimann, Tommy

SM02

361

Pham, The-tan

SO12

368

Potapova, Nadezhda M.

DF04

60

Qiu, Z. Q.

IH05

96

Reiner, J.

BG02

45

Pham, Van-ben

SG10

341

Potthoff, Michael

PE05, PE07

136, 137

Qiu, Z.-q.

BD03, QM26

43, 235

Reisner, G. M.

PD03

132

Phan, Huong Manh

RN19

299

Poudyal, Narayan

EJ02

71

Quan, Zhiyong

PN04

172

Reiss, Gunter

IF04

94

Phan, Manh-huong

DJ01

63

Pouget, Stephanie

EI04

71

Quang, Pham Hong

SL22

359

Reissner, Michael

QH18, RB08

215, 255

Phan, T. L.

RA01

249

Poulopoulos, Panagiotis

RP15

305

Quang, Tran Van

RH20

278

Ren, Chung-yuan

QE25

203

Phase, D.m

SA14

318

Pourovskii, Leonid

AB04

34

Quintanilla, Jorge

JA05

99

Ren, Wei

QA27

187

Philip, Geo George

SL28

360

Prabhakaran, D.

DH03, PI03, QN01

62, 151, 236

Quintero-castro, Diana

RH24

278

Ren, Xiaobing

JJ02, PG21

106, 145

Phillip, Geo George

QA25

186

Prabhakaran, Dharmalingam

AF01

36

Quitmann, Christoph

RJ11

284

Ren, Zhi

RC11

260

Phillips, P.

GA01

75

Pradhan, N. S.

PN01

172

Qureshi, Navid

PI08

152

Repaka, D V Maheswar

QA18

185

Phromsuwan, Udomchok

RP18

306

Pramuji, Hinu

BJ03

48

QN16

239

Piamonteze, Cinthia

BC02

42

Prasad, Arun S.

SL25

360

R

Repi, V. Vekky R.
Ressouche, Eric

IJ03, IJ06, PA13

97, 98, 118

Piantek, Marten

PG08

143

Praveena, K

GJ05, QN18, SN08

83, 239, 365

R, Ramasamy

PO21, QN26

180, 240

Reyes, Arneil P.

JA02

98

Piao, Hong-guang

SH01, SH10

343, 344

Prchal, J.

RD26

266

Raabe, Joerg

RJ11

284

Reyren, Nicolas

HE04

86

Picone, Andrea

PL21

167

Prchal, Jiri

BB04, PD18, PD19, QJ14

42, 134, 135, 223

Radaelli, Greta

DE03

59

Rezania, Hamed

QF12

205

Picozzi, Silvia

AA02, PA1233, 117Prestat, Eric

AI04

39

Radovic, M.

PC01

126

Rhee, Chan Hyuk

PI13

152

Pietosa, Jaroslaw

QB30

192

Prestigiacomo, Joseph

CH01

54

Radu, Florin

EC04

66

Rhee, J. Y.

SL08, SL09

357

Pikul, Adam

QD05

197

Prevost, B.

PD05

132

Rafique, Mohsin

SA15

318

Rhee, Jang-rho

PL11

165

Pikul, Valeriy

RR28

315

Prida, Victor

DG03

61

Rafiqul Islam, Md.

RN05

297

Rhee, Joo Yull

QH29, SC08

217, 326

Piligkos, Stergios

BC02

42

Prieto, Pedro

SA12

318

Raghavender, A T

SM07

362

Rhie, K.

PJ31

159

Pineider, Francesco

CB04, SI1149, 347

Primo, Fernando Lucas

PO08

178

Raghavender, Anupati Telugu SM10

362

Rhie, Kungwon

PK21, QK10

163, 225

Piquini, Lucas K.

QO03

241

Prinsloo, Aletta Roletta

RH15

277

Rahman, Gul

RM02

295

Rhie, Kung-won

SD12

332

Pirmohammadi, Mohsen

RR32

316

Pristas, Gabriel

QD12, QI02, RE13

198, 218, 268

Rajan, Ganesh K

SK32

355

Rhim, Sonny S. H.

RB26

258

Pirogov, Alexander

QG02

208

Profeta, Gianni

QG25

212

Raju, M

PG27

146

Rho, Min-suk

BH02

46

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

415

416

Author Index
Sakuma, Akimasa

CH02, KH02, PJ10, PL17,
RL09, SI06

54, 112, 156, 166,
291, 346

352

Sakuma, Keita

PB34, PJ12, SA07

125, 156, 317

248

Sakurada, T.

SG11

341

SC24

329

Sakurada, Takashi

JI04

105

Sagayama, Hajime

PG14, PG20, QA13

144, 145, 175

Sakurai, Hiroshi

PK12, PM02

162, 167

58

Saha, S. R.

QB07

188

Sakurai, Hiroya

PH19, RH06

150, 275

PH04

147

Saha, Susmita

HD04

85

Sakurai, Hiroyuki

QP15, QP16

247, 248

Rougemaille, Nicolas

SH03, SH05, SH06

343, 344

Sahadev, Nishaina

SC06

326

Sakurai, Shohei

RH09

276

309

Roulland, F.

SA06

317

Sahadevan, Ajeesh

GE03

78

Sakurai, T.

KI05, SL14

113, 358

AI03

39

Roulland, Francois

SA05

317

Sahadevan, Ajeesh M

SK05

351

Sakurai, Takahiro

Riseborough, Peter S

PD02, PE01

132, 136

Rouquette, Jerome

RA11

251

Sahashi, Masashi

CE05, PJ11, PL10, SM03

52, 156, 165, 361

PE11, QE03, QE10,
QF04, RD01, RP05

137, 199, 201, 204,
262, 304

Ritter, C

QJ16

223

Rovezzi, Mauro

BE03

44

Sahoo, Roshnee

QH06

213

Sakurai, Yoshiharu

Ritter, Clemens

IJ01

97

Rovira, Joan Josep Roa

PB11, SB18

121, 323

Sahu, Subrata Kumar

BH04

46

BA04, PG05, PG13,
PK12, SK04

41, 143, 144, 162,
351

Ritter, Franz

QE14

201

Rowley, Stephen

AB04

34

Saidaoui, H. B. Mohamed

PJ13

156

Sakurai, Yoshiki

SB03

320

Ritz, Robert

GC04

77

Roy, Beas

QE12

201

Saiga, Yuta

RE04

267

Salamakha, Leonid

SC01

325

Ritzmann, Ulrike

FA02

72

Roy, M.

PN01, RA03

172, 249

Saikai, Nobutaka

PB08

121

Salamati, H.

PI23, PI24

154

Riva, Michele

PL21

167

Roy, Pierre

IE03

93

Saiki, Shunsuke

QB04, RB02

187, 254

Salamom, M. B.

QB12

189

Rivas, J.

CB02

49

Rubacheva, Anastasia D

PN22

175

Saines, Paul

PC02

127

Salazar Mejia, Catalina

QO09

242

Riyadi, Syarif

PH17

149

Ruben, Mario

GH02

81

Saini, Naurang L.

RB28

258

Salazar, Nicolas Antonio

SM04

361

Rizal, Conrad

PJ01

154

Ruck, Michael

PC27

131

Saisho, Seiya

RN03

297

Salce, Bernard

PC17

129

Rizki, Youssef

BB03, RH22

41, 278

Rudajevova, Alexandra

PD18

134

Saito, Hidekazu

AI05

39

Salles, B.

CE06

52

Rizwan, Syed

SA19, SA20

319

Rueffer, Rudolf

HG04

88

Saito, Hitoshi

RP06

304

Salman, Zaher

BC02, PB20, PN23, QL19

42, 123, 175, 231

Robert, Julien

JB05, RA11

100, 251

Ruegg, Ch

RI05

279

Saito, Kesami

KC03

108

Salvador, M D

RQ10

308

Rodionov, Igor

CH01

54

Ruegg, Ch.

QE19

202

Saito, Kotaro

RD14

264

Samant, Mahesh

RN16

299

Rodionova, Valeria

AJ02, DD04, SO04, SO27

40, 59, 367, 371

Ruegg, ChristianIC02, QF23, QG14

92, 207, 210

Saito, Mineo

RC09, RC19

260, 262

Samanta, Tapas

CH01

54

Rodmacq, Bernard

BD02

43

Rufinus, Jeffrey

SK25

354

Saito, Mitsuru

QA17

185

Samardak, Alexander

AG05

38

Rodriguez Fernandez, J.

GH05

81

Rugi, Francesco

CB04

49

Saito, T.

QB28

191

Samardak, A. Sergeevich

QM05

232

Rodriguez Fernandez, Jesus

JJ04

106

Rui, Wenbing

PL01

164

Saito, Takahito

QC05

193

Samarin, N. A.

QC22, RH07

195, 275

Rodriguez, Luis Alfredo

DG05, GG05, SM16

61, 80, 363

Ruotolo, Antonio

DH04, RJ03

62, 283

Saito, Takashi

PE13, QC05

138, 193

Samarin, Nickolay

ED06, KI05, SG08

67, 113, 340

Rodriguez-blanco, Clara

GF04

79

Rusek, Pawel

RI08

280

Saito, Takeshi

PD11

133

Samariya, Arvind

SL25

360

R. velamazan, Jose Alberto

GF04, PG22

79, 146

Rusek, Paweł

QE24

203

Saito, Taku

QB02, QB15

187, 189

Samata, Hiroaki

SK04

351

Roehlsberger, Ralf

QM19

234

Rushforth, Andrew W

SH09

344

Saito, Toshiaki

QE20, QF21

202, 207

Sampaio, Joao

HF01, IE04

87, 94

Roemer, Florian

RP08

304

Rusponi, Stefano

BC02

42

Saitoh, Eiji

AI02, FA01, KF03, RL15

39, 72, 111, 292

Sampaio, Maria

RF13

271

Roessler, Sahana

PH04

147

Rusu, Calin

SE08

334

Saitoh, Yuji

RD25, SE23

266, 337

Sampathkumaran, E V

PE14

138

Rogalev, A.

QG07

209

Ruzicka, Jiri

BH03

46

Sakaguchi, Jyunya

PD13

134

Sampathkumaran, E. V.

QD16

199

Rogalev, Andrei

PA08, RP15, RP21

117, 305, 306

Ryabinkina, Ludmila

QG05

209

Sakaguchi, Yui

RD13

264

Sanada, Naoyuki

SC23

329

Rogalev, Andrey

PN22

175

Ryll, H

RI05

279

Sakai, Akito

CD02, SE01, SF07

51, 333, 338

Sanai, Tatsunori

KF05

111

Roger, Michel

DH03

62

Ryoichi, Ito

RP06

304

Sakai, Eijiro

QC14, QC15194Sanchez Llamazares, Jose Luis JJ04

106

Rogl, Peter

SC01

325

Ryu, Jisu

HP21, KE03, PJ33

30, 110, 160

Sakai, Hideaki

PA12

117

Sanchez Marcos, Jorge

JJ04

106

Rojas Sanchez, Juan-carlos

QK16, QK17, SL24

226, 360

Ryu, Jungho

DJ02

63

Sakai, Hironori

IG04, PD09, RD11

95, 133, 263

Sanchez-costa, Jose

GF04

79

Rojas, D. P.

QD10

198

Ryu, Kwang-su

SM01

361

Sakai, Junya

QL11

229

Sanda, Minoru

PG17, QF11, QF14

145, 205, 206

Rojas, Juan-carlos

AI04

39

Ryzhov, V. A.

RQ13

309

Sakai, Naoki

QL03

228

Sandalov, Vladimir

RR28

315

Rojas-sanchez, Juan Carlos

QK15, RL24

226, 293

PH02

147

Sandig, Oliver

RP08

304

Rokkaku, Tsugumi

QG13

210

S

Sakai, Osamu
Sakai, Seiji

BH05, BH06, QL15

46, 47, 230

Sandiumenge, Felip

IH01, SO18

95, 369

Romanov, A

BH01

46

S, Anuraj

SA21

319

Sakai, T^oru

QE11

201

Sando, Daniel

QA27

187

Romanova, Oksana

QG05

209

S, Radha

RN16, SO22

299, 370

Sakai, Toru

QE07, RI11, RI16

200, 280, 281

Sangregorio, Claudio

CB04, SI1149, 347

Ronning, F

EA03

64

S, Srinath

QD04, RA16

197, 252

Sakai, Yoshiki

RO06

301

Santamaria, Jesus

RN09

298

Ronning, F.

FB01, QB1273, 189

S. Suzuki, Hiroyuki

QD18

199

Sakaida, Masaru

PF16

141

Santava, Eva

QI01

217

Ronning, Filip

RD09, SB12, SC16

263, 322, 328

Saadaoui, Hassan

PB20, QL19

123, 231

Sakakibara, T.

CD01, EF01

50, 68

Santos, Tiffany

AD03, BG02

35, 45

Ronnow, H.

SF10

338

Sablina, Klara

PI11

152

Sakakibara, Toshiro

50, 201, 213, 222

Sarachik, Myriam P.

IC01

92

Ronnow, Henrik M

QF23

207

Sabyasachi, Sk.

RH02

275

CC05, QE13, QH03,
QJ08

Sarkar, Sujit

QF26

208

Ronnow, Henrik Moodysson

IC02

92

Sachdev, Subir

IA03

91

Sakamoto, Hirotoshi

HC03

85

Sarma, D. D.

RF12

270

Rosales Rivera, Andres

SM04

361

Sacramento, Pedro

RB25

258

Sakamoto, Naonori

KC02

108

Sarrao, John L.

RD09

263

Rosch, Achim

DF02

60

Sacramento, Pedro D

SB21

323

Sakamoto, Yasutaka

SG09

341

Saruya, Takeshi

KF01

110

Roshanmehr, M.

PI24

154

Sacuto, Alain

PD17

134

Sakano, Rui

PE16

138

Sasagawa, Takao

QO18

243

Roshchin, I. V.

BD01

43

Sadhana, K

GJ05, QN18, SN08

83, 239, 365

Sakata, Masafumi

PC21

130

Sasaki, Hiroko

SG18

342

Roslyakov, Ilya

SL27

360

Sadowski, J.

BE02

44

Sakata, T.

PL04

164

Sasaki, Hiromi

SL02

356

Rosner, H.

QF22

207

Saeed, Yasir

QO01

240

Sakoda, Masahito

PE13, RD01

138, 262

Sasaki, N.

CF04

53

Rosner, Helge

AB02, QD07, RD1234, 197, 264

Saenz De Pipaon, Cristina

PG22, QO16

146, 243

Sakshath, Sadashivaiah

SL21

359

Sasaki, Ryo

SE11

335

Rhyee, Jong- Soo

RC05

259

Ross, Caroline A

HP51

31

Safaeizadeh, Elham

PO27, PO29

181, 182

Rhyee, Jong-soo

CF03

52

Ross, Caroline A.

KC01

108

Sagar, J.

SK03

350

Ri, Hyeong-cheol

SB22

323

Roßner, Helge

FB04

73

Sagar, James

SK11

Ribeiro, Andre Neves

PF13

141

Roth, Georg

PA14, RP22

118, 306

Sagara, Naoto

QP16

Ribeiro, B.

QM13

233

Roth, Thomas

HG04, PA24, RH23

88, 119, 278

Sagawa, Harunobu

Ribeiro, Raquel A

SL20

359

Rother, Niklas

PE05

136

Ribeiro, Raquel A.

QO03

241

Rothman, Johan

DD01

Richter, Curt A.

AE04

36

Rotter, Martin

Rijnders, Guus

DH02, SA10

62, 317

Rikken, Geert

RQ16

Rinaldi, ChristianThe 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

417

418

Author Index

Sasaki, Satoru

GB04

76

Schafer, Hanjo

HA02

83

Seike, Masayoshi

KF04

111

Shaofeng, Lin

QO21

244

Sasaki, Satoshi

RC11

260

Schafers, Markus

IF04

94

Seiro, Silvia

QC09, QC18, QD07

193, 195, 197

Sharbaf Zadeh, Asghar

PC16

129

Sasaki, Takahiko

GB04, RH03, RH11

76, 275, 276

Schalenbach, Maximilian

QA22

186

Seki, Harumi

PC15

129

Sharma, A. K

QN14

238

Sasano, Masashi

PN07

173

Schau-magnussen, Magnus

BC02

42

Seki, Kazuhiro

PF09, PF14, RE08

140, 141, 267

Sharma, Bharat Kumar

KI01

112

Saso, Tetsuro

PF17

142

Schedler, Roland

QG02

208

Seki, S.

RA05

250

Sharma, Neetika

PI12

152

Sassa, Y.

PC29, PI15

131, 153

Scheffer, Jurg

PA04

116

Seki, Takeshi

JG03, KC03

103, 108

Sharma, P. K.

SL25

360

Sassa, Yasmine

HA03, SE08

83, 334

Schelhas, Laura

QA15

185

Sekiguchi, Koji

RJ10, SI08

284, 347

Sharma, Sandeep

AI05

39

Sasso, Carlo Paolo

DG04, HH01

61, 88Schellekens, Adrianus

EI06

71

Sekiguchi, Toru

RD22

265

Shavrov, Vladimir G.

SO19

369

Sato, Hideo

QP14, SI17

247, 348

Schellekens, Sjors

SI07

347

Sekimoto, S.

KJ01

113

Shavrov, Vladimir Grigor'evich QH17

215

Sato, Hideyuki

PE13, QC05, RD17

138, 193, 264

Schepotin, I

BH01

46

Sekine, Akihiko

GB02

76

Shaw, C.c.

SN06

365

Sato, Hirohiko

QE17, QF09

202, 205

Schierle, E.

PC22

130

Sekine, Chihiro

133, 135, 197

Shaykhutdinov, Kirill

QA08

183

Sato, Hitoshi

RD20

265

Schlage, Kai

QM19

234

PD10, PD11, PD22,
QD06

She, Jian-huang

SE18

336

Sato, Kazuhisa

KB05

108

Schlenhoff, Anika

HF03, HF04, RP16

87, 305

Sekine, Tomoyuki

119, 183, 184, 276

Sheikhzadeh, G. A.

KF04

111

Schlom, Darrell G

SA08

317

PO27, PO29, PO30,
PO31

181, 182

Sato, Kazunori

PA19, QA05, QA07,
QA09, RH11

Sato, Kei

RL13

292

Schlottmann, Pedro

KA04, PA21, PE04

107, 119, 136

Sekiyama, Akira

RD25

266

Sheikin, I.

GC01

77

Sato, Kentaro

PB29, PB30, PB32

124, 125

Schmalzl, Karin

AA05, QM02

33, 231

Sela, Eran

RI12

280

Sheikin, Ilya

HP11

30

Sato, Kiyoo

QI04

218

Schmidiger, David Jan

CC03

50

Selezneva, Nadezshda

QG04

208

Shekhter, Robert I.

RG17

274

Sato, Koichi

RN11

298

Schmidt, Burkhard

DB02, QE04

57, 200

Sellmyer, David

CB05

49

Shen, Baogen

RQ01, SO25

307, 370

Sato, Kota

SB05

321

Schmidt, Michael

PA23, RH24

119, 278

Seman, Hazrina Abu

RP12

305

Shen, Bao-gen

ED05

67

Sato, Kotaro

SN03

364

Schmidt, Oliver G

SJ07

350

Semeno, A. V.

PE12

138

Shen, Chenyi

IJ04

98

Sato, Masahiro

JD04, RI11

101, 280

Schmidt, Rene

AF02, HG03, PG1236, 88, 144

Semeno, Alexey

ED06, KI05, SG07, SG08

67, 113, 340

Shen, Jian

AG01

37

Sato, Masatoshi

DA01, QB04, QB26,
RB02, RB05

56, 187, 191, 254

Schmidt, Wolfgang

QM02

231

Semeno, Alexey V.

QC19

195

Shen, Lei

GI04, QP06, SJ09

82, 246, 350

Schmiedeshoff, G. M.

IA05

91

Semisalova, Anna

QO14

243

Sheppard, Charles Johannes

RH15

277

Sato, Mitsuhide

QF08, QF10

205

Schmitt, T.

PC01

126

Semisalova, Anna S

PN22

175

Shermadini, Zurab

QB22

190

Sato, Mototsugu

QJ04

221

Schmitt, Thorsten

BA03

41

Senba, Shinya

QM10, SK13233, 352

Sherokalova, Elizaveta

QG04

208

Sato, Nana

SI08

347

Schmitz, Defleft

IH01

95

Sendilkumar, A

QD04

197

Sherstobitova, Elena

QG02

208

Sato, Noriaki

PD20

135

Schneidewind, Astrid

QC24

196

Sengupta, Pinaki

DC04

58

Sherstobitova, Elena A.

QN10

238

Sato, Noriaki K

RD05

262

Schnelle, Frank

QJ11

222

Senna, Mamoru

QL07

229

Shevchenko, A

BH01

46

Sato, Noriaki K.

PD14

134

Schnelle, Walter

RD12

264

Seo, Ambrose

PA16

118

Shi, Chunlong

RA13, RA14

251

Sato, Suguru

SJ06

349

Schoenemann, Rico

PC27

131

Seo, Dong-jea

SL26

360

Shi, Jianzhong

QP22

249

Sato, Taku J

QE13

201

Schoenhense, G

QM12, RN12, RP20

233, 298, 306

Seo, Hitoshi

GB03, RG09

76, 273

Shi, M.

PC01

126

Sato, Tetsuya

RK08, SM20

287, 364

Schon, Gerd

II04

97

Seo, Jeongdae

RC05

259

Shi, Ming

PD12

133

Sato, Tomonori

HG02, RJ01, RJ02, RJ09

88, 282, 284

Schonhense, Gerd

CH04

54

Seo, Juyeon

PO06

178

Shi, Yi

PN27

176

Sato, Yoshiaki

SG09

341

Schotter, Joerg

AH01

38

Seo, M. S.

RA07

250

Shi, Z.

PL20

167

Sato, Yuji

PL10

165

Schrefl, Thomas

DE01

59

Seo, Soo-man

HF05, HP21, PJ33

87, 30, 160

Shi, Zhong

BD05, JI05, SL1643, 105, 358

Satoh, Isamu

RD05

262

Schreyer, Andreas

DG01, QM02

61, 231

Seo, Soonbeom

PC19

129

Shibasaki, Seizi

SC04

326

Satoh, Ryohei

RD24

266

Schrittwieser, Stefan

AH01

38

Seong, W. K.

PB03

120

Shibauchi, Takasada

FB02, QC04, SB27

73, 192, 324

Satter, A. A.

RN01

296

Schroeder, Henning

KD01

109

Sera, Masafumi

QI10, RD10219, 263

Shibuya, K.

RG10

273

Savero-torres, Williams

GE01, QK15, QK16,
QK17, SL2478, 226, 360

Schroeder, Silke

IH02

96

Seredkin, Vitaly

SO28

371

Shick, Alexander

RE03

266

Schuller, Ivan K

BD01

43

Serga, Aleksandr

HD01

85

Shield, Jeffrey E

KB02

107

Savici, Andrei T

PI07

151

Schuller, Ivan K.

BD04, ED03

43, 66

Serga, Alexander A.

SI15

348

Shigeoka, Toru

QI18, SC24

220, 329

Savici, Andrei T.

RD14

264

Schvets, I V

PH16

149

Sergey, Faleev

JF04

103

Shigeta, Iduru

QG13, QG15, SK23

210, 354

Sawa, A.

PL14

166

Schwabe, Andrej

PE05, PE07

136, 137

Serpico, C.

RJ07

283

Shih, C.w.

SN06

365

Sawa, H.

CF01

52

Schwarz, Alexander

AF02, HG03, PG1236, 88, 144

Serrano-ramon, Luis

DG05

61

Shih, Ying-ta

ED02

66

Sawada, Kazuya

SM03

361

Schwarz, Karlheinz

RB21

257

Serrate, David

IH02, PG08

96, 143

Shikama, T.

QJ10

222

Sawada, Keisuke

RC19

262

Schwarzacher, Walther

KB01

107

Sese, Javier

GG03, GG05

80

Shikoh, Eiji

Sawada, M.

PH14

149

Schweitzer, Dieter

SG19

342

Sessi, Violetta

AD03

35

AI02, ED04, PN12, RL04,
SK1639, 66, 174, 290,
353

Sawada, Masahiro

PN20

175

Schweitzer, Sebastian

QK14

226

Seto, Makoto

QM16

234

Shim, In-bo

PI14

153

Sawami, Kazuma

QJ12

222

Schwingenschlogl, U.

PN02

172

138

KJ01

113

Schwingenschlogl, Udo

230, 240, 245, 352

Shim, J.h.

QH25

217

Sawatzki, Simon

KH01

112

QL17, QO01, QP01,
QP02, SK1230, 124, 133, 134,
265, 266

PE17

Sawamura, M.

HP11, PB27, PD08, PD13,
PD16, RD19, RD25

Shim, J. H.

Seung Mok, Jeon

PJ15

157

Shim, Je-ho

SH10

344

Sawicki, M.

BE02

44

Schwobel, Jorg

GH02

81

Severing, A.

KA02

107

Shim, Jeong Hyun

BF05

45

Sawicki, Maciej

BE03, DD02

44, 58Sebastian, S. E.

GA01

75

Severing, Andrea

QC09, QC12193, 194

Shim, Ji Hoon

JA03, QH27, RB22, RB23

98, 217, 257

Sayanagi, Richard

PK09, QM01

161, 231

Sebastian, Suchitra

BA01

40

Seyfarth, G.

PD05

132

Shim, Ji-hoon

QH26, QJ18, QJ19

217, 223, 224

Sazonov, Andrew

PA14

118

Sebt, S. A.

QP23

249

51

Shim, Seong Hoon

RL31

295

Schaadt, Daniel M.

QL05

228

Sechovsky, Vladimir

Seyyed Ebrahimi, S. A.

QM28, SA04

236, 316

BH02

46

PM26

171

42, 90, 128, 134,
135, 195, 221, 223

Shim, Sung-ah

Schaefer, R.

BB04, HJ04, PC10, PD18,
PD19, QC21, QJ02, QJ14

Shamba, Precious

QG09

209

Shima, Toshiyuki

RO09, SN03

302, 364

Schaefer, Rudolf

HB01

84

Sedlak, Kamil

AB02

34

Shang, T.

QB12

189

Shimada, Daisuke

QN20

239

Schaf, Jacob

PB09, PB10, PB11, PB33,
RB09, SB18

121, 125, 255, 323

Segal, Amir

DE02

59

Shang, Tian

SB29

325

Shimada, Kenya

RD20

265

Segawa, Kouji

RC11

260

Shao, Xiaoping

RQ01

307

Shimada, Yutaka

QM07, RK04

232, 286

The 19th International Conference on Magnetism

Settai, Rikio

Seyfarth, Gabriel

CD04

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

419

420

Author Index

Shimakawa, Yuichi

QE10

201

Shiomi, Mitsuhiro

QP03

245

Singh, Ravi

SD13

332

Sondezi-mhlungu, B. M.

SF06

338

Shimamoto, Kohei

ED01

66

Shiota, Yoichi

PK20, SI05

163, 346

Singh, Surendra

QM18

234

Sone, Keita

QD01, RD13

196, 264

Shimamura, Kazutoshi

RL10

291

Shiozaki, Ken

SD09

331

Singh, Vikash

RA27

253

Song, Fengqi

PN27

176

Shimano, Ryo

PA12

117

Shipton, E

PK09, QM01

161, 231

Singh, Yogesh

DC03, SG1358, 341

Song, Hoon

168, 178, 307, 353

Shimba, Kazuaki

QN11

238

Shirage, Parasharam M

DA04

56

Sinha, Bhavesh Bharat

QM22

235

PM07, PO05, RQ04,
SK17

Shimidzu, Naoki

SK21

353

Shirage, Parasharam M.

QB29

191

Sinha, Brajalal

QO19, SN13

243, 366

Song, Hyonseok

RK22

289

Shimizu, Katsuya

PB05, PB27, PC21, PC23

120, 124, 130

Shirahata, Yasuhiro

QK19, RL25

227, 294

Sinha, S. K.

BD01

43

Song, Hyon-seok

RK09, SI04

287, 346

Shimizu, Kenji

SG01

339

Shirai, Masafumi

IF02, KI03, RL02

94, 113, 290

Sinnecker, Joao Paulo

RJ13

284

Song, Jaeyong

SD12

332

Shimizu, Ryutarou

RK08

287

Shiraishi, Masashi

PI16

153

Song, Ji Yeon

BJ04, QN13

48, 238

PB26

124

39, 66, 174, 290,
353

Siratori, Kiiti

Shimizu, Sunao

AI02, ED04, PN12, RL04,
SK16

Sirena, Martin

QL06

229

Song, Jin Dong

QK11

225

Shimizu, Tomohiro

PO18

180

Shiraishi, Takuya

SE11

335

Sirisathitkul, Chitnarong

RP18, SL10306, 357

Song, Jindong

QK10

225

Shimizu, Yasuhiro

PH19, PH20, PH23, QF15150, 206

Shirakashi, Jun-ichi

EG05

69

Sirisathitkul, Yaowarat

RP18

306

Song, Jong Han

QO27

245

Shimizu, Yusei

QC25

196

Shirakawa, Naoki

QD13

198

Sirotti, Fausto

SH03, SH05

343, 344

Song, Jong Hyun

PA11

117

Shimojima, T.

QB28

191

Shirakawa, Tomonori

PC08, PG18

128, 145

Sitnikov, Maksim Nicolaevich

SO02

367

Song, Jonghyun

SM13

363

Shimokawa, Takaya

PM08, PM09

168

Shirane, Takashi

RH09

276

Skashita, Naomi

QM07

232

Song, Jong-hyun

SM12

362

Shimokawa, Tokuro

RI04

279

Shiratsuchi, Yu

EI05, PK08

71, 161

Skaugen, Arvid

CI04, QA01

55, 182

Song, Jung-bin

122, 126

Shimomura, Koji

QI06, QI07, QI08

218, 219

Shiro, K

SG02

339

Skidanov, Vladimir

PG02

142

PB17, PB36, PB37, PB38,
PB39

Shimomura, Naoki

PL10, SM03

165, 361

Shiroka, Toni

IC02

92

Skokov, Konstantin

DJ04

63

Song, Kie-moon

PN31

177

Shimotani, Hidekazu

AE05

36

Shishido, Hiroyuki

SB27

324

Skokov, Konstantin P.

SO19

369

Song, Ki-myung

QA24

186

Shimura, Y.

CD01

50

Shitsevalova, N. Yu.

JC04, PE12, QC22, RH07

100, 138, 195, 275

Skorenkyy, Yuriy

RG13

274

Song, Sun Yong

RO10

302

Shimura, Yasuyuki

CC05, QH03, QJ08

50, 213, 222

Shitsevalova, Natalia

QC20, QD12

195, 198

Skorobagatko, Glib A

RG17

274

Song, Xiaoping

JJ02, PG21, RM08, SO25

106, 145, 296, 370

Shin, H. -y.

PO23

181

Shitsevalova, Natalja Yu.

QC19

195

Skorvanek, Ivan

IB01, QO17

91, 243

Song, Young Sang

PA01

116

Shin, Hosun

SD12

332

Shitsevalova, Natalya

RE13

268

Skourki, Y.

QF18

206

Song, Young-joon

PF06, SO06

140, 367

Shin, Hyungsoon

RL17

292

Shitsevalova, Natasha

QI02

218

Skourski, Y.

GJ03, QI03

82, 218

Song, Young-sang

CI03, PA03, PA04

55, 116

Shin, Hyun-jin

PB16, PB18, PB35, PB40

122, 123, 125, 126

Shiue, C.h.

PK11, PK15

162

Skourski, Yurii

PC27, RE09

131, 267

Song, Young-yeal

PM12, PN31, SO03

169, 177, 367

Shin, Il Jae

QM18

234

Shivaram, B S

SC05, SE14326, 335

Skrotzki, Richard

PC27

131

Song, Yun

SB13

322

Shin, Il-jae

RK09

287

Shlykov, Maxim Pavlovich

RI22

282

Skumryev, Vassil

PA13

118

Sonntag, Andreas

HF03, HF04, RP16

87, 305

Shin, Jaewon

PO20, SM08

180, 362

Shnirman, Alexander

II04

97

Slavin, Andrei

JG02

103

Soon Ok, Park

QP21

248

Shin, Jihye

RL17

292

Shoji, Kimura

QJ01

221

Slawska - Waniewska, A.

PH06, PM05

147, 168

Soriano, N.

ED03

66

Shin, Jinsik

QM04

232

Shoshi, Astrit

AH01

38

Slebarski, Andrzej

PD21

135

Sota, Shigetoshi

EB03

65

Shin, Jong Moon

PN21, QL18

175, 231

Shue, Jyh-ron

IH06

96

Sluchanko, N. E.

JC04, PE12, QC22, RH07

100, 138, 195, 275

Soulantika, Katerina

AH01

38

Shin, Jun-yeong

BH02

46

Shueh, Chin

PL18

166

Sluchanko, Nickolay

RB20

257

PJ31

159

Shukla, Dinesh K.

QA01

182

67, 113, 195, 218,
268, 340

Souliou, Sofia Michaela

Shin, K.h.

ED06, KI05, QC20, QI02,
RE13, SG07, SG08

Sousa, Marcos

PL09

165

Shin, Kwang-ho

PO14, PO26, QO08,
RQ23, RR12, RR30

179, 181, 242, 310,
312, 315

Shukla, Dinesh Kumar

CI04, PH16

55, 149

Sluchanko, Nickolay E.

QC19

195

Sousa, Marcos Antonio De

QM14

233

Shunichiro, Kittaka

QC16

194

Smadici, S.

PH10

148

Souza, Flavio L

SL20

359

Shin, Kyung Ho

QO11

242

Si, Q.

CD01

50

Smeibidl, P.

RQ21

310

Sparks, Patricia D

PK09, QM01

161, 231

Shin, Kyungho

QK10

225

Si, Qimiao

AB01

33

Smekhova, A.

QG07

209

Spehling, Johannes

AB02

34

Shin, Kyung-ho

CE04, KE03, RL06, RL14,
RL26, SI1352, 110, 290, 292,
294, 348

Siahatgar, Mohammad

DB02, QE04

57, 200

Smekhova, Alevtina G

PN22

175

Speliotis, Thanassis

DD06, QP12, QP13

59, 247

Sichelschmidt, Jorg

QD07

197

Sniadecki, Zbigniew

QO17

243

Spenato, David

SA24

320

Shin, R. H.

SA06

317

Sidorenko, A.

CD01

50

Snoeck, Etienne

DG05

61

Spiesser, Aurelie

AI05

39

Shin, Ran Hee

SA05

317

Sidorov, V. A.

FB01

73

So, Yoshitaka

PC28

131

Spinu, Leonard

RB12

256

Shin, S.

QB28

191

Siemensmeyer, Konrad

QI02

218

Sobczak, W.

DD02

58

Springell1, R.

QN01

236

Shin, Sang-hoon

QK11

225

Sigov, Alexander S

PL05

164

Soegijono, Bambang

SH01

343

Sri Ramulu, Torati

SN13

366

Shin, Sung Chul

QM20

234

Sigrist, Manfred

RF01, SD05

269, 330

Soh, Joon-young

PM16

170

Srikanth, Hariharan

DJ01

63

Shin, Sung-chul

RK09, RK22, RL03, SI04,
SJ05, SM01, SM12

287, 289, 290, 346,
349, 361, 362

Sikolenko, Vadim

QG02

208

Soh, Kwang-sup

BH02

46

Srinivasan, Elaiyaraju

RP14

305

Sikora, Marcin

HG04

88

Soh, Yeong-ah

PJ17

157

Srinivasan, Radha

PN06, QO25

173, 244

Shin, Yooleemi

EH05, PN29, PN30

70, 176, 177

Silotri, Salman

RE06

267

Sohn, Jeong Woo

RK09

287

Srivastava, Amit P

PM01

167

Shinaoka, Hiroshi

JD02, RG07

101, 272

Silva, Nuno

KB06

108

Sohn, Jeong-woo

RK22

289

Srivastava, Archana

RQ06

308

Shinde, Kiran

QM22

235

Silva, Petrucio

QL01

228

Sohrabi, Mahdi

PC16

129

Srivastava, D

PM01

167

Shingubara, Shoso

PO18

180

Simmet, Thomas

AH02

38

Sokolov, D.

GC01

77

Srivastava, M. K.

SM18

363

Shinjo, Teruya

AI02, ED04, PN12, RL04,
RL11, SI05, SK10, SK16

39, 66, 174, 290,
291, 346, 352, 353

Simonelli, Laura

RB28

258

Sokolov, Dmitry

GC04

77

Stadler, Shane

CH01

54

Simonet, Virginie

AC04, IJ03

35, 97

Sokolov, V. V.

SG20

342

Staerk, Martin

FD03, SH16

74, 345

Shinkevich, Sergey

QF19

207

Singh, Braj Bhusan

PG27

146

Sokolovskiy, Vladimir

PI20, QH05

154, 213

Stamps, Robert

KE01

110

Shinohara, Takafumi

QC18

195

Singh, D. J.

GF01

79

Solin, Nikolay

SL17

358

Stanislavchuk, Taras N.

RA24

253

Shinoki, Takaho

SK06

351

Singh, H. K

SM18

363

Solorzano, G.

SM17

363

Starikova, Anna

QJ13, SN09

223, 365

Shinozaki, Kazuo

KC02

108

Singh, J. P.

PK11, PK15

162

Soltan, Soltan

QL21, RB29

231, 258

Steadman, Paul

PA15

118

Shioda, Tatsutoshi

RP17, SK21

306, 353

Singh, Jitendra Pal

PG27

146

Solyom, Jeno

PD15

134

Stebliy, Maxim

AG05

38

Shiogai, Junichi

KC03

108

Singh, Nirpendra

QO01

240

Son, Derac

RQ14

309

Stefanoski, Stevce

DJ01

63

Shiojiri, Yasuhiro

SE06

334

Singh, Pankaj

SC02

325

Son, Il-ho

RR15

313

Stefanowicz, Wiktor

BE03, DD02

44, 58

Shiokawa, Yohei

EG04

69

Singh, R S

PE14

138

Son, Jangyup

RL30

294

Steffens, Paul

AA05

33

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

421

422

Author Index

Steglich, F.

SC03

326

Sugano, Y

PC04

127

Suzuki, Michi-to

QC04

192

Takaesu, Yoshinao

PD14, QC11, QI12, QI13

134, 194, 219

Steglich, Frank

AB02, FB04, JC01, KA03,
QC09, QC18, RD12,SB29

34, 73, 100, 107,
193, 195, 264, 325

Sugawara, Hitoshi

PD25, PE11, PE13, QC05,
QF04, RD01

136, 137, 138, 193,
204, 262

Suzuki, Ryosuke

SA17

319

Takagi, H.

QH09

214

Suzuki, S

RR08

312

Takagi, Hide

RH21

278

Sugawara, Katsuya

SN03

364

Suzuki, Shota

RO09

302

Takagi, Hidenori

IA04, RB04, RH17

91, 254, 277

Stein, Aaron

KE01

110

Sugawara, Tetsuya

QC10

193

Suzuki, Shugo

RM06

296

Takagi, Seishi

PB25, PG10

124, 144

Stein, Jonas

AA05

33

Sugihara, Atsushi

SK33

355

Suzuki, Takafumi

DC04

58

Takagi, Yasushi

EI01

70

Steinigeweg, Robin

EC05

66

Sugimoto, Koudai

SC10

327

Suzuki, Takao

JI03

105

Takahara, Atsushi

RN03

297

Steinke, Lucia

AB02

34

Sugimoto, Kunihisa

PA12, PG20

117, 145

Suzuki, Yoshishige

IF01

94

BE05

44

Sugimoto, Nozomi

RC18

261

110, 163, 291, 346,
352

Takahashi, H.

Stelmakhovych, Olya

KF01, PK20, RL11, SI05,
SK10

Takahashi, Hidefumi

QC06

193

Stepanov, Gennady V

QO14

243

Sugimoto, Satoshi

ID04, QN11

93, 238

Suzuki, Yuri

DH01

62

Takahashi, Hirokazu

PL17

166

Steppke, Alexander

AB02

34

Sugishima, Masaki

QD03, QD15

196, 198

Suzuki, Yuta

SC04

326

Takahashi, K. S.

RG10

273

Steren, Laura

QL06

229

Sugiura, Kyohei

RD24

266

Svec, Peter

IB01, QO17

91, 243

Takahashi, Ken-ichiro

PM08, PM09

168

Stewart, Greg

DA03

56

Sugiyama, Jun

PI06, PO17, SE08

151, 180, 334

Svoboda, Pavel

QI19

220

Takahashi, Kohki

QG08, QH08, QN20

209, 214, 239

Stewart, J R

SE03, SE05

333, 334

Sugiyama, Kiyohiro

HP11, PD13, QH03

30, 134, 213

Swagten, H.j.m.

PK17

163

Takahashi, Masahiro

QC05

193

Stiles, Mark D.

EE02

67

Sugiyama, Tomoyoshi

QJ08

222

Swagten, Henk

CH05, EI06, GE02, JE01

54, 71, 78, 101

Takahashi, R.

SG02

339

Stobiecki, Feliks

AD05

Suh, B. J.

QF13

206

Swagten, Henk J.

IE02

93

Takahashi, Rui

PH15

149

Stockert, Oliver

GC02, QC24, RE1277, 196, 268

Suh, Byoung Jin

RN10

298

Swatek, Przemyslaw

SE16

335

Takahashi, Saburo

FA03, PJ07, RL01

72, 155, 290

Stoeffler, Daniel

PI04

151

Suh, Byoungjin

RP13

305

Syassen, Karl

RB20

257

Takahashi, Shin

QO07

241

Stoermer, Michael

DG01

61

Suh, Hwansoo

RQ11

308

Sykova, Eva

BH03

46

Takahashi, Y K

BG01

45

Stognij, Alexandr

QM08

232

Sukegawa, H

SK29

355

Syljuasen, Olav F.

QF19

207

Takahashi, Yoshinori

PF08

140

Stoll, Hermann

FD01

74

Sukegawa, Hiroaki

EH01, IF03, IF05, SK11

69, 94, 352

Syoji, Daiki

PH15

149

Takahashi, Yoshiyuki

PO03

177

Stollenwerk, Tobias

PF07

140

Sukhorukov, Yurii

SO17

369

Syromyatnikov, Arseniy

SL27

360

Takahashi, Youtarou

PA12

117

Strache, Thomas

SH04

343

Sukovatitsina, Ekaterina

QM05

232

Syrovets, Tatiana

AH02

38

Takahashi, Yukiko

SK31

355

Strack, Christian

SG19

342

Sumimoto, Takaki

RR13

313

Syudou, Mitsuhiro

PB25

124

Takahiro, Onimaru

QC16

194

Strack, Philipp

IA03

91

Sumiyama, Akihiko

QC03

192

Szalowski, Karol

RI03, RI09

279, 280

Takamatsu, Shuhei

PC06

127

Strassel, Dominik

HC04

85

Sun, An-cheng

PK06, QP17

161, 248

Szewczyk, A.

PH06, PM05

147, 168

Takamichi, Miyazaki

RO05

301

Strecka, Jozef

QF06

204

Sun, D. L.

GA03

75

Szlawska, Maria

SE17

336

Takanashi, Koki

Streltsov, Sergey

PA17

118

Sun, Dan

EA04

64

Sztenkiel, Dariusz

DD02

58

JG03, JI04, KC03, QL15,
RL15, SE06

103, 105, 108, 230,
292, 334

Strempfer, Joerg

CI04, QA01

55, 182

Sun, H.d

QL02

228

Szymczak, Henryk

JJ03

106

Takano, Atsuki

QG16

210

Streubel, Robert

SJ07

350

Sun, Jian

RQ02

307

Szymczak, Ritta

JJ03

106

Takano, Hideaki

Strichovanec, P.

KC05

109

Sun, Jirong

SO25

370

121, 185, 221, 263,
265, 334

Strichovanec, Pavel

GG05

80

Sun, Ji-rong

ED05

67

T

PB08, QA19, QJ04,
RD06, RD22, SE06

Takano, Y.

RB28

258

Strigari, Fabio

QC09, QC12193, 194

Sun, Peijie

KA03

107

Tabata, Chihiro

QC25, SE07

196, 334

Takano, Yasu

BC05

42

Strocov, V.

PC29, PI15

131, 153

Sun, Wei

PK18, QN21

163, 239

Tabata, Yoshikazu

HJ02, QH13

90, 215

Takano, YoshihikoQB09, QB17

188, 189

Strocov, V. N.

PC01

126

Sun, X. F.

IC03

92

Tacchi, Silvia

GG02

80

Takao, Sasagawa

RC12

260

Strohm, Cornelius

HG04, PA24, RH23

88, 119, 278

Sun, Xuefeng

SA19

319

Tada, Yasuhiro

RD05

262

Takasaki, Aya

QH20

216

Strokov, Vladimir

HA03

83

Sun, Young

JB03

99

Tadataka, Watanabe

QD14

198

Takase, S.

SG02

339

Strydom, A M

SE03, SE05

333, 334

Sun, Yunlei

RB13

256

Tadera, Shin

SO515

369

Takashi, Sugawara

SM10

362

Strydom, A. M.

CD01, RG05

50, 272

Sundar, Anuraj

QA25

186

Tadokoro, Tomoya

PA06, PA19

116, 119

Takashima, Teppei

QM29, SJ03

236, 349

Strydom, Andre

SF08

338

Sung, Gun Yong

RL21

293

Taetz, T.

QE23

203

Takata, Emika

QF11

205

Strydom, Andre M.

SF06

338

Sung, Ki Young

RR09

312

Taga, Yuki

PD08

133

Takata, Masaki

HC03, PA12, QF25

85, 117, 208

Strydom, Andre Michael

RD23

265

Sung, Kil-dong

PL19

167

Taguchi, Katsuhisa

FD04

74

Takatsu, Hiroshi

QE13

201

Strydom, Andre Micheal

RH15

277

Sung, N. H.

SB30

325

Taguchi, Minori

RN11

298

Takayama- Muromachi, Eiji

PH19

150

Stubna, Viliam

RI09

280

Sung, Nakheon

SB10

321

Taguchi, Yasujiro

PA12

117

Takayama, Tomohiro

RB04, RH17, RH21

254, 277, 278

Stupakiewicz, Andrzej

AD05

Sunglae, Cho

PJ15

157

Taguchi, Yuusaku

AE02, RL02

36, 290

Takayama-muromachi, Eiji

RH06

275

Su, C.w.

PK11, PK15

162

Sunyol, Joanjosep

DJ03

63

Tahir, Mukarram A.

AH04

38

Takeda, Hikaru

PH19

150

Su, Chien-yu

ED02

66

Suresh, K G

PM01, QO04

167, 241

Tai, M. F.

SB04

320

Takeda, Hiroki

PB07

121

Su, Yixi

QA23

186

Suresh, K. G.

QH06

213

Tai, Ming-fong

RR01

311

Takeda, Keiki

PD10

133

Suard, Emmanuelle

IJ03

97

Suryanarayanan, Ramanathan PI22

154

Taira, Tomoyuki

SK06

351

Takeda, Mahoto

QG16, QH15

210, 215

Suarez, Jaime Raul

QO26

245

Suter, Andreas

PI05, PN23

151, 175

Tajima, S.

CF04

53

Takeda, Masataka

QI12, QI13

219

Suber, Lorenza

RN07

297

Sutherland, Michael

HA05, RE14, SC1684, 268, 328

Tajima, Setsuko

HA01, PH07, PI07, QB24

83, 148, 151, 191

Takeda, Naoya

RD24

266

Subias, Gloria

EC04

66

Suzuki, Hiroyuki S

JJ05

106

Tajiri, Takayuki

PG09, SA03

143, 316

Takeda, Shogo

PO03

177

Suda, Ryutaro

EG05

69

Suzuki, Hiroyuki S.

QJ09

222

Takabatake, T

RD25, SE23

266, 337

PB22

123

Suzuki, Hisao

KC02

108

127, 221, 333, 334,
335

Takeda, Yukiharu

Sudareva, Svetlana

PC04, QJ05, SE03, SE05,
SE13

Takegahara, K.

SG11

341

Suellow, Stefan

SM02

361

Suzuki, Ippei

QK19, SM20

227, 364

Takabatake, T.

EF01, KA02

68, 107

Takeguchi, Masaki

QG16

210

Suemasu, Takashi

KF05

111

Suzuki, Kazunori

DA01

56

Takabatake, Toshiro

QA09

184

EG02, QL05

69, 228

Suzuki, Kazuya

QM16, SC23

234, 329

Takehara, Yuki

SK13

352

Suess, Dieter

SJ07

350

Suzuki, Kiyonori

RN13

298

135, 137, 194, 197,
214, 260, 262, 275,
341, 342

Takehana, Kanji

Suergers, ChristophTakemura, Yasushi

PO03

177

Suga, Seiichiro

PF02, RF17139, 271

Suzuki, Kosuke

PK12

162

PD24, PE10, QC12,
QD09, QH07, RC07,
RD04, RH03, SG12,
SG15

Takenaka, K.

QH09

214

Sugano, Ryoko

PJ07, RL01

155, 290

Suzuki, Kousuke

PM02

167

QI02, RE13

218, 268

Takenaka, Yuto

RC04

259

The 19th International Conference on Magnetism

Takacova, Iveta

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

423

424

Author Index

Takeshita, Nao

QD12

198

Tashiro, Kunihisa

RR06

311

Thiaville, Andre

AJ01, SH0239, 343

Tomitaka, Asahi

PO03

177

Takeshita, Soshi

IA04, QO13

91, 242

Taskaev, Sergey

PM22, QH05, SO23

171, 213, 370

Thiem, Luu Van

SL22

359

Tomiyama, Yo

PE11

137

Takeuchi, Akihito

EE04, RC06

67, 259

Taskaev, Sergey V.

QO12, SO19

242, 369

Thiess, S.

SK24

354

Tomiyasu, Keisuke

RD14

264

Takeuchi, Hiromasa

PO02, QL03, RN02

177, 228, 297

Taskin, Alexey

RC11

260

Thiet, Duong Van

PN30, QO22

177, 244

Tompsett, David

PC02

127

Takeuchi, Tetsuya

HP11, PB27, PD08, PD1330, 124, 133, 134

Tatara, Gen

EE04, FD04, RC06

67, 74, 259

Thirumurugan, Arun

AJ04

40

Tompsett, David A.

PC09

128

Takeuchi, Tsunehiro

PO17

180

Tateiwa, Naoyuki

SK32

355

Tong, Peng

BF02

44

RB28

258

30, 135, 263, 268,
322

Thiruvadigal, John

Takeya, H.

HP11, PD23, RD11,
RE10, SB15

Thomas, Andy

DI03, IF04

63, 94

Tonnerre, Jean-marc

AD02

35

Takeya, Hiroyuki

QB17

189

Tatetsu, Yasutomi

QC14, QC15

194

Thomas, Christopher

PD04

132

Toperverg, Boris P.

DG01

61

Takeyama, Shojiro

AC03

34

Tati Bismaths, Logane

RP04

303

Thomasson, A.

SA06

317

Torikachvili, Milton

SF13

339

Takigawa, Masashi

QE08

200

Tatsuoka, Sho

PE13, QC05

138, 193

Thomasson, Alexandre

SA05

317

Toriumi, Shingo

RK08

287

Takimoto, Tetsuya

JC03, QC04

100, 192

Tauber, Katarina

EE01

67

Thompson, J D

EA03

64

Toriyama, Tatsuya

KG03, PF10, PF15

111, 140, 141

Takuya, Manabe

BC05

42

Taufour, Valentin

JC02, SF03

100, 337

Thompson, J.

SC03, SC16

326, 328

Torrejon, Jacob

AJ01, SH0239, 343

Talaat, Ahmed

AJ02, CJ02

40, 55

Tayama, Takashi

QE13, SG05

201, 340

Thompson, J. D.

FB01, QB12, QB31, SB1273, 189, 192, 322

Tortarolo, Marina

QL06

229

Talham, Daniel R.

KB03

107

Taylor, A. J.

QB31

192

Thompson, J.d.

PC19

129

Toru, Shigeoka

QI17, QJ01

220, 221

Tamaki, Yuki

PD14

134

Taylor, Alice Elizabeth

HA04

83

Thompson, Joe D

JC01

100

Toshiro, Sakakibara

QC16

194

Tamatsukuri, Hiromu

PH05

147

Taylor, J

SE03, SE05, SF09

333, 334, 338

Thompson, Joe D.

QC16

194

QN06, RK03

237, 286

Taylor, Jon

SE20

336

77, 127, 263, 333,
337

Toshiro, Takabatake

Tamion, Alexandre

GC03, PC03, RD09,
SE02, SF01

Toth, Sandor

PA23

119

Tamura, Dai

PD11

133

Tchoula Tchokonte, M. Bertin

RD23

265

Thongmee, Sirikanjana

GJ04

83

Tou, Hideki

PD25, QB17, SF03, SG12

136, 189, 337, 341

Tamura, Eiichi

KF01, SK10

110, 352

Tedesco, Antonio Claudio

PO08

178

Thuesen, Christian Aa.

BC02

42

Toulemonde, Olivier

PI17

153

Tamura, Eiiti

ED04

66

Tegus, O.

PM03

167

Thunstrom, Patrik

RG06

272

Tournus, Florent

KB05, QN06, RK03

108, 237, 286

Tanaka, Arata

PI08, QC12152, 194

Teh, Geok Bee

SL01

356

Tian, Jinzeng

PK03

160

Toussaint, Jean-christophe

SH03, SH06

343, 344

Tanaka, Daiki

RD10

263

Teichert, Anke

QM20

234

Tiberkevich, Vasil

JG02

103

Toyoda, Shingo

PG20

145

Tanaka, Hidekazu

QC11, QE22, SK16

194, 203, 353

Tekielak, Maria

AD05

Tiberto, Paola

AG02

37

Toyokawa, Shuhei

ED04

66

Tanaka, K.

HA01

83

Telegin, Andrey

SL17, SO17

358, 369

Timirgazin, Marat

BF04

45

Toyoki, Kentaro

PK08

161

Tanaka, Kenya

PE13, QC05

138, 193

Telegin, Sergey

SL17

358

Ting, Yi-wen

PL18

166

Tozawa, Katsunori

PJ12

156

Tanaka, Koichi

SK13

352

Temerov, V

QJ16

223

Tissier, Matthieu

SL24

360

Tozer, Stan

PC09

128

Tanaka, Masaaki

QM16

234

Temerov, Vladislav

RA23

253

Titvinidze, Irakli

PE05, PE07

136, 137

Tran, Duc H.

PB03

120

Tanaka, Nobuo

RC18

261

Temerov, Vladislav L

CI04

55

Tjeng, Liu Hao

PI08, PI17, QC09, QC12152, 153, 193, 194

Tran, Hoang Duc

RN19

299

Tanaka, Shigeki

PC23

130

Tennant, A.

RQ21

310

Tjernberg, O.

PC29

131

Tran, L M

QB06

188

Tanaka, Shinya

SE06

334

Tennant, D. Alan

IC05

92

Tjernberg, Oscar

HA03, SE08

83, 334

Tran, Vinh Hung

QB06

188

Tanaka, Takashi

RI15

281

Tenya, Kenichi

PD07

133

Tjia, May On

PH17

149

Tretiakov, Oleg

SD17

332

Tanaka, Terumitsu

QM29, QP09, QP10,
QP11, SJ03

236, 246, 247, 349

Terada, Noriki

JJ05, PH09, QJ09

106, 148, 222

Tkachenko, Vira

JG01

103

Trioni, Mario Italo

PL21

167

Terasaki, Akira

KD01

109

Tobash, P H

EA03

64

Trohidou, Kalliopi

CB03

49

Tanaka, Toshiki

SE01

333

Terasaki, Ichiro

PH12, QC06

148, 193

Tobash, P.

SC16

328

Tronov, Anton

SG17

342

Tanaka, Toshiyuki

QA19

185

Terashima, Taichi

SB05

321

Tobash, P. H.

GC03

77

Trupina, L.

SA11

318

Tanaka, Yasuhiro

RG08

273

Terazawa, Shinsuke

QH13

215

Tobash, Paul H.

RD09

263

Tsai, C.c.

PK11, PK15

162

QI08

219

Tobola, Janusz

QH18

215

Tsai, Du-cheng

PK02

160

Tanatar, M. A.

IA05, QC23, SB30

91, 196, 325

Terentev, Pavel B.

Tang, Shengjun

KD03

109

Terent'ev, Pavel E.

QN10

238

Toews, W. H.

HA05

84

Tsai, M.c.

PK11

162

Tang, Xianwu

SA01

316

Tereshina, E. A.

QG07

209

Toga, Yuta

RF10, RF11

270

Tsarevskii, Sergey L.

SC25

329

Tange, Hatsuo

PG05

143

Terrade, Damien

CA03

49

Togawa, Yoshihiko

QI10, RD10219, 263

Teruya, Atsushi

QI13

219

37, 60, 144, 211,
212

Tsay, Jyh-shen

Tanida, Hiroshi

AF03, DF03, PG15,
QG22, QG28

IH06, PK02, PL03, PL13,
SM06

96, 160, 164, 166,
361

Tanigaki, Katsumi

QI10

219

Tetsuya, Fujiwara

QI17, QJ01

220, 221

Tohyama, Takami

CA01, EB03, SC10

48, 65, 327

Tselepi, Marina

BH01

46

PC31

131

Tokiwa, Yoshi

FB03

73

Tseng, Yu-chieh

SM06

361

Taniguchi, Hiromi

GB04

76

Tewari, Bhagya Sindhu

Taniguchi, Kouji

QA13

175

Teysser, J.

SF10

338

Toko, Kaoru

KF05

111

Tsevelmaa, Tumurbaatar

KI01

112

Taniguchi, Masaki

RD20

265

Tezuka, Masaki

HI04

89

Tokuda, Yuki

RP09

304

Tsirlin, A.

QF22

207

Taniguchi, Tomohiro

HF02

87

Tezuka, Nobuki

QN11

238

Tokunaga, Masashi

RF11

270

QE21

202

Thabet Mliki, Najeh

PM06

168

116, 118, 184, 185,
209, 250, 275

Tsuchiura, Hiroaki

Taniguchi, Toshifumi

Tsuchiura, Hiroki

KH02, QB27, RF10112, 191, 270

Taniguchi, Yusuke

QH04

213

Thach, Pham Van

SK10

352

PA06, PA18, QA09,
QA17, QG08, RA06,
RH04

Tsuchiya, Katsuhiko

RD24

266

RA03

249

Tokunaga, Y.

RA05

250

Tsuchiya, Yoshinori

PH09

148

Taniyama, Tomoyasu

QK19, RL25, SM20

227, 294, 364

Thakur, Indu Bala

Tao, Lingling

QK02

224

Thakur, Rajesh K.

QA14, RF04, RQ06

184, 269, 308

Tokunaga, Yo

PD09

133

Tsuei, K. D.

QB21

190

Tao, Ling-ling

RM01

295

Thakur, Rasna

QA14, RF04, RQ06

184, 269, 308

Tokura, Y.

PA14, RA05, RG10

118, 250, 273

Tsuei, Ku Ding

QC12

194

Tao, Qian

IJ04

98

Thakur, Sangeeta

SC06

326

Tokura, Yoshinori

HP31, PA12, PH08, PI07

30, 117, 148, 151

Tsuei, Ku-ding

QC09

193

Tarafder, K

QM12

233

Thaler, A.

GA01

75

Tolbert, Sarah

QA15

185

Tsuji, Naoto

EB02, RF05

65, 269

Tarantini, C.

JA02

98

Thalmeier, Peter

DB02, PD06, QE04

57, 132, 200

Tomas, Amparo Borrell

RO08

302

Tsujii, Hiroyuki

QL11, QL12, QL13

229, 230

SE21, SO29

336, 371

Tomas, Milagros

QO16

243

Tsujikawa, Masahito

AE02, KI03, PL06, RL02

36, 113, 164, 290

Tarasov, A. S.

QK07

225

Thamizhavel, A

Tarigan, Kontan

PM12

169

Thamizhavel, Arumugam

QJ17, RB24

223, 258

Tomita, Hiroyuki

KF01

110

Tsujimoto, M.

KJ01

113

Tartakovskaya, Elena V.

QM02

231

Thanh, Pham Thi

AJ06

40

Tomita, Keitaro

SC04

326

Tsukahara, Hiroshi

RJ06, SI16

283, 348

Tashima, Kasumi

RB06

255

Thanh, Tran Dang

AJ06

40

Tomita, Norikazu

PF04

139

Tsukamoto, Arata

BG03, RK08, RK1745, 287, 288

Tashiro, Hiroki

SA17

319

Therese, Helen Annal

SA21, SA22, SA23

319, 320

Tomita, Yusuke

JD02, RI02

101, 279

Tsunashima, Shigeru

RL08

291

Tashiro, Hiroshi

QE22

203

Thessieu, Christophe

RA19

252

Tomita, Yuusuke

QB17

189

Tsunekawa, M.

SG11

341

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

425

Author Index

Author Index

Tsunoda, Masakiyo

PL17

166

Uhlirova, Klara

BE05, PD18, PD1944, 134, 135Vallejo, Emmanuel

QG21

211

Viraphong, Oudomsack

EH03

70

Tsunoda, Yorihiko

PI16

153

Uimin, Michael

QL07

229

Van Den Brink, Arno

EI06

71

Virgin, Lawrence. N.

AH04

38

Tsurkan, Vladimir

PA23

119

Uji, Shinya

SB05

321

Van Den Brink, Jeroen

DC02

58

Vlachos, Athanasios

RP15

305

Tsurunaga, Aiko

QN02

236

Ukleev, Victor

QM08

232

Van Der Heijden, E.h.m.

PK17

163

Vlaic, Petru

SK09

351

Tsuruta, Kousuke

QE20

202

Ullrich, Carsten A.

RL12

291

Van Der Heijden, Mark

JE01

101

Vogel, Andreas

HG02, RJ05, SH04

88, 283, 343

Tsutaoka, Takanori

QI06, QI07, QI08, QN02

218, 219, 236

Ulrich, V W

SC05

326

Van Der Linden, Peter J. E. M. HG04, PA24, RH23

88, 119, 278

Vogel, Jan

SH03, SH05, SH06

343, 344

Tsutsui, Kazuhiro

PJ18, RL16

157, 292

Ulysse, Christian

FD03

74

Van Dommelen, P.

RQ12

309

Vojta, Matthias

EA02

64

Tsutsui, Kenji

CA01, SC10

48, 327

Um, Jaegon

RI19

282

Van Eijck, L.

SO08

368

Volegov, Alexey

QG04

208

Tsutsumi, Kenji

PB29, PB30, PB32

124, 125

Um, Youngje

QB03

187

Van Lierop, Johan

PL18

166

Volkov, N. V.

QK07

225

Tsutsumi, S.

QB23

190

Umehara, Izuru

QJ06

221

Van Loosdrecht, P.h.m

PH17

149

Volkov, Nikita

PI11

152

Tsutsumi, Tomoaki

RO03

301

Umeo, K

PC04, QJ05

127, 221

Van Loosdrecht, Paul H. M.

HG04, PA24

88, 119

Volkova, O.

QF22

207

Tuan, Duong Anh

PN29, QO22

176, 244

Umeo, K.

EF01, KA02

68, 107

Van Wees, Bart J.

GI05

82

Volkova, Olga

QE27

203

Tugarinov, V

QJ16

223

Umeo, Kazunori

QD09, RD04

197, 262

Vanacken, Johan

QC19, QC20

195

Vomir, M.

PO23

181

Tumanov, Vadim

SC26

329

Umetsu, Hiroshi

QA13

175

Vanecek, Vaclav

BH03

46

Vomir, Mircea

FC02, RK05, RK1373, 286, 288

Tung, Min-jue

QN08

237

Umetsu, Nobuyuki

SI06

346

Varaprasad, B

BG01

45

Von Bergmann, Kirsten

IH02, IH03

96

Turnbull, M M

BC05

42

Umetsu, Rie

RP07

304

Varga, Marek

IB01

91

Von Issendorff, Bernd

KD01

109

Tusche, C

RP20

306

Umetsu, Rie Y

QG08

209

Varga, Rastislav

PJ25

158

Von Molnar, Stephan

QA11, QJ11, QK23

184, 222, 227

Tutsch, Ulrich

HC04

85

Umetsu, Rie Y.

SK23

354

Varma, C. M.

SB31

325

Vorderwisch, Peter

PO25

181

Tuuli, Elina

SB16, SK07

322, 351

Umezawa, Jin

RO06

301

Varnakov, S. N.

QK07

225

Vorobiev, Alexei

QM08

232

Uneda, Kentaro

BC03

42

Vasambekar, P. N.

QN14

238

Vorotynov, Alexander

IJ01

97

Unno, Tetsuya

PM02

167

Vasilakaki, Marianna

CB03

49

Vovk, A.

KC05

109

426

Ubana, Tatsuya

BG03

45

Upton, Mary

DC03

58

Vasiliev, A.

QF22

207

Vu, Khai Van

CJ05

56

Uchida, Atsuko

JD01

100

Urbanek, Michal

SH06

344

Vasyuchka, Vitaliy

HD01

85

Vundisa, Khuselwa

QH22

216

Uchida, Kaori

QG15

210

Urbano, Ricardo R.

JA02

98

Vavassori, Paolo

GG05

80

Vuong, Nguyen Van

EJ02

71

Uchida, Ken-ichi

RL15

292

Urcelay - Olabarria, Irene

PA13

118

Vavilova, E.

QE23, QF22

203, 207

Vyalikh, Denis V.

CD03, PD1251, 133

Uchida, Masakazu

SL03

356

Urtizberea, Ainhoa

KB06

108

Vazquez, Manuel39, 61, 80

Uchida, Shinichi

CA02

48

Useinov, Artur

PJ06

155

AJ01, DG03, GG04,
GG05

Uchida, Shin-ichi

PB05

120

Ushiki, Yuji

QO07

241

Veber, Philippe

EH03

70

Wachnicki, Lukasz

DD02

58

Uchida, Takashi

EF04

68

Ustinov, Vladimir

SK02

350

Vecchini, Carlo

DH03

62

Wada, Eiji

QK19

227

Uchima, Kiyoharu

PD14, QI12, QI13

134, 219

Ustinov, Vladimir V.

SK01

350

Vedmedenko, Elena

IH03

96

Wada, Hirofumi

Uchiyama, Toshiyuki

RD19

265

Uthayakumar, S.

DH03

62

Vehsthedt, Erin

IE03

93

AG03, IG05, QD03,
QD15, SB1437, 95, 196, 198,
322

Uchiyama, Yu

RR06

311

Uto, Haruka

PM09

168

Veis, Martin

KD03

109

Wada, Kakeru

SK21

353

Uda, Yuuki

PN24

176

Utsumi, Yuki

RD20

265

Velazquez, Matias

EH03

70

Wadley, Peter

BE05, SH09

44, 344

Udagawa, Masafumi

PG23

146

Utsumiya, Kazuhisa

JG03

103

Velicanov, Dmitrii Anotol'evich SO02

367

Wagh, Aditya A.

PH04

147

Udagawa, Masayuki

PC05, PG16, RD10,SG15127, 145, 263, 342

Uvarov, N.v.

QG27

212

Velikanov, D

QJ16

223

Wagner, M.

PI09

152

Uwatoko, Y.

QH09, RD15

214, 264

Velikanov, Dmitriy

PI11

152

Wahlstrom, Erik

SL15

358

Udod, Lubov Victorovna

SO02

367

Uwatoko, Yoshiya

RL25

294

Waintal, Xavier

PJ13

156

QH23

216

Ventura, Cecilia I.

SI10

347

Wakabayashi, E.

PL04

164

Uechi, Ayaka

QH14

215

134, 199, 219, 220,
239, 263, 265, 267,
304, 329, 333, 335

Venkataiah, Gorige

Uebayashi, KazuhikoVenu, Reddy

SN13

366

Wakabayashi, Katsunori

SD05

330

Ueda, H.

PH03

147

PD14, QD17, QI12, QI18,
QN20, RD06, RD22,
RE04, RP05, SC24, SE01,
SE11

Vera-marun, Ivan J.

GI05

82

Wakabayashi, Yusuke

QA12

184

Ueda, Hiroaki

AC03

34

Uyeda, Chiaki

PN11, RQ03

173, 307

Verba, Roman

JG02

103

Waki, Takeshi

HJ02, QH13

90, 215

Ueda, Hiroaki T

RC06

259

Uykur, E.

HA01

83

Vergnaud, Celine

AI04, CG03, EI04

39, 53, 71

Wakimoto, Shuichi

BA04, SC23

41, 329

Ueda, Kenji

PB34, PJ12, PL12, RC18,
SA07, SA17, SK18, SO20

125, 156, 165, 261,
317, 319, 353, 370

Uykur, Ece

PH07

148

Verma, G. D.

SM18

363

Wakiwaka, Hiroyuki

RR06

311

Uyyanonvara, Bunyarit

RP18

306

Veron, Emmanuel

EH03

70

Wakiya, Kazuhei

RD04

262

Ueda, Koichi

QD15, RD24

198, 266

SJ07

350

Wakiya, Naoki

KC02

108

Ueda, Shigenori

KF05, RD20

111, 265

V

Vervacke, Celine
Viart, N.

SA06

317

Waldmann, Oliver

BC02

42

Ueda, Suguru

RF01

269

V. Leitao, J.

RQ12

309

Viart, Nathalie

SA05

317

Walker, H. C.

QN01

236

Ueda, Takuya

EC03

65

V. Loehneysen, Hilbert

RE12

268

Vieira, V R

SB21

323

Walker, Helen

AF01

36

Ueda, Tomonari

QE10

201

V., R.reddy

QD04

197

Vieira, Valdemar

PB10, PB33

121, 125

Wallacher, Dirk

QG26

212

Ueda, Y.

PH03

147

Vaezi, H.

PI23

154

Vieira, Valdemar Das Neves

PB09, PB11, RB09, SB18

121, 255, 323

Walsh, M. J.

SK03

350

Ueda, Yutaka

IA04, PH20, PH23,
QD03, QF24, RH16,
SB14, SF04

91, 150, 196, 207,
277, 322, 337

Vaghar, R.

SA04

316

Vijaysankar, Kalappattil

SL21

359

Walters, Andrew C.

RB20

257

Vaknin, David

RB18

257

Vila, Laurent

QA20

185

AE03, EC04, IH01

36, 66, 95

39, 78, 226, 293,
360

Wang, Chih-jen

Valencia, Sergio

AI04, GE01, QK15,
QK16, QK17, RL24, SL24

Wang, Chin-wei

PC18, QA20

129, 185

Uehara, Masatomo

SB03

320

Valenta, Jaroslav

QJ14

223

Vilanova, Enrique

CH03

54

Wang, Daohan

RR18

313

Uematsu, Daisuke

PG14

144

Valenti, Roser

RG14, SF14, SG22

274, 339, 343

Vilas-vilela, J. M.

CB02

49

Wang, Fen

JB03

99

Uemura, Tetsuya

SK06

351

Valenzuela, Belen

QB18, QB19

190

Villamor, Estitxu

HE02

86

Wang, Hailong

DG06

61

Uemura, Y. J.

GF01

79

Valenzuela, S. O.

DI01

62

Villegas, J. E.

ED03

66

Wang, Huijie

SN12

366

Ueno, T.

PH14

149

Valiska, Michal

HJ04, QC21

90, 195

Villegas, Javier E.

BD04

43

Wang, James

SL01

356

Uesaka, Masanori

QF08

205

Val'kov, Valery V.

QC02

192

Vinai, Franco

AG02

37

Wang, Jianli

EF02, QG09, QG26

68, 209, 212

Uhlir, Vojtech

SH03, SH06

343, 344

Valldor, Martin

PI08

152

Vinogradov, Alexey P.

HD05

86

Wang, Jiawei

SA19, SA20

319

The 19th International Conference on Magnetism

W

July 8-13, 2012 Busan, Korea

Author Index

Author Index

U

427

428

Author Index

Wang, Jingdai

PK18

163

Weil, M.

QF22

207

Won, Jonghan

KD02

109

Xiong, Peng

QA11, QJ11, QK23

184, 222, 227

Wang, Junfeng

PA18, QF14

118, 206

Weinert, M.

RM04

295

Won, Mi Hee

PA22

119

Xu, Cenke

JD05

101

Wang, Ke

QO24

244

Weinert, Michael

RB26, SO10

258, 368

Wong, Franklin

DH01

62

Xu, Jianbin

PN27

176

Wang, L.m.

QM27

236

Weller, D.

BG02

45

Wong, Yat Choy

SL01

356

Xu, Jianli

JF05

103

Wang, Li Na

RD12

264

Wells, Barrett O.

HA03

83

Woo, Byung-chul

PM25, RR31

171, 316

Xu, Qingyu

PL01

164

Wang, N L

QB11

188

Wen, Hai-hu

JA01

98

Woo, J. H.

PO23

181

Xu, S.-y.

SD04

330

Wang, Ning

RJ03

283

Wen, J. S.

GA01

75

Woodcock, Tom G

KH01

112

Xu, Suyang

HI02

89

Wang, S.

QE19

202

Wen, Z.c

SK29

355

Wosnitza, J.

50, 82, 204, 218

Xu, Xiao

QG08

209

Wang, S. J.

SB04

320

Wen, Zhechao

EH01

69

CC04, GJ03, QF02,
QF03, QI03

Xu, Xiaohong

PN04

172

Wang, Shen

PN05, QL04

172, 228

Wen, Zhenchao

IF05

94

Wosnitza, Joachim

PC27, PD05, RD07, RE09

131, 132, 263, 267

Xu, Z. J.

GA01

75

Wang, Sheng Hao

SB19

323

Wenderich, Sander

DH02, SA10

62, 317

Wosnitza, Jochen

QD07, SD07

197, 331

Xu, Zhuan

AB04, IJ04

34, 98Wang, Shuang

IC02, QF23

92, 207

Wenderoth, Martin

KA01

106

330

Xu, Zhu'an

RB13

256

Wang, Tao

QN23

240

Wermeille, D.

QN01

236

Wray, L. Andrew

HI02

89

Xue, Qi-kun

II01

96

Wang, W.

GC01

77

Werner, Michael

QO02

241

Wrobel, Piotr

RF03

269

Xue, Xiaobo

PL01

164

Wang, Weizhong

RL32

295

Werner, Philipp

EB02, RF05

65, 269

Wu, An-wei

SM06

361

Xuliang, Lv

QO15, QO21

243, 244

Wang, X. M.

IC03

92

Weymann, Ireneusz

DB03

57

Wu, Chau-chung

AH03

38

Wang, Xiao Lei

DH04

62

Whangbo, Myung-hwan

PH11, QJ18

148, 223

Wu, Chun-ming

PO25

181

Y

Wang, Xiaolei

RJ03

283

Wheeler, Elisa

RB07

255

Wu, Guang Heng

QG09

209

Y, Nguyen Thi Tinh

QE16

202

Wang, Xiaolin

SD01

330

White, Rudelle

QH22

216

Wu, Han Chun

PJ14

157

Yadav, A. D.

PN01

172

Wang, Xiaoping

PK03

160

White, Steven

RF13

271

Wu, Han-chun

SH13

345

Yadav, C. S.

PC11

128

Wang, Xiuhe

RR18

313

Wieckowski, J.

PH06, PM05

147, 168

Wu, Hsian-yuan

PK06

161

Yadavalli, Tejabhiram

PO21, QN26

180, 240

Wang, Xuefeng

PN27

176

Wienholdt, Sonke

FC03

74

Wu, Hsing-hsuane

PL13

166

Yagasaki, Katsuma

QI12, QI13

219

Wang, Xuhui

EE03, PJ29, PJ34

67, 159, 160

Wierschem, Keola

DC04

58

Wu, Hua

PI08, SB02

152, 320

Yagi, Takehiko

PD11, PD22

133, 135

Wang, Yin-gang

RA12

251

Wiesendanger, R

RN12

298

Wu, Hung-cheng

RN17

299

Yakata, Satoshi

AG03, RJ08, RK21, SI1237, 283, 289, 347

Wang, Ying-chieh

SM06

361

Wiesendanger, Roland

370, 371

PG21, SO25

145, 370

36, 81, 87, 88, 96,
144, 28, 305

SO24, SO26

Wang, Yu
Wang, Yun-peng

RM01

295

AF02, GH02, HF03,
HF04, HG03, IH02, IH03,
PG12, PP05, RP16

Wang, Z.s.

RO14

303

Wiesenmayer, Erwin

QB22

Wang, Zhe

PA23, RH24

119, 278

Wieser, Robert

Wang, Zhi-hong

ED05

67

Wanikawa, Yasushi

QF25

Warczewski, Jerzy

PG26

Ward Jones, Sarah

Wray, L. A.

SD04

Wu, J. C.

SB19

323

Yako, Hitomi

Wu, J. W.

PO23

181

Yakovchuk, Viktor

PJ27

159

Wu, Jong-ching

PC30, SH08, SL18

131, 344, 359

Yakovleva, M.

QE23

203

190

Wu, Lin

JF05

103

Yakushiji, K.

CE03, CE06, ID02, RJ07

51, 52, 93, 283

IH03

96

Wu, QiongRO13, RO14

302, 303

Yakushiji, Kay

47, 87, 94, 110, 163

Wijnheijmer, Ineke

BE05

44

Wu, S.-c.

QG24

212

BI01, HF01, IE04, KF01,
PK20

208

Wildes, Andrew

IJ03

97

Wu, Sheng Yun

QP07

246

Yamada, H.

PL14

166

146

Wildes, Andrew R.

GF03, PG01

79, 142

Wu, T. C.

SB19

323

Yamada, I.

SG02

339

KB01

107

Wilhelm, Fabrice

PA08, RP15, RP21

117, 305, 306

Wu, Te-ho

PL18

166

Yamada, K.

QE15

201

Ward, S

RI05

279

Wille, Hans-christian

QM19

234

Wu, Tian-chiuan

PC30, SH08, SL18

131, 344, 359

Yamada, Kazuyoshi

Ward, Simon

QG14

210

Willers, Thomas

PI08, QC09, QC12152, 193, 194

Wu, Wenlong

EA04

64

BA04, PB29, PB30, PB32,
QG18, RP01

41, 124, 125, 211,
303

Warin, Patrick

EI04

71

Williams, T. J.

GF01

79

Wu, Xiaoshan

88

219

Windsor, Yoav W

RK01

286

155, 161, 172, 228,
251, 315

HG02

QI10

PJ05, PK05, PN05, QL04,
RA13, RA14, RR29

Yamada, Keisuke

Watahiki, Masanori

Yamada, Shigeki

QA02, QD02

182, 196

Watanabe, C.

KJ01

113

Winkler, H.

CD01

50

Wu, Yicheng

RA02

249

Yamada, Shinya

HE01, RK1086, 287

Watanabe, Eri

BC04

42

Winterlik, Jurgen

QN19

239

Wu, Yizheng

PL02, SM05

164, 361

Yamada, Tsutomu

PO03

177

Watanabe, Hiroshi

PC08, PG18

128, 145

Wintz, Sebastian

RJ11, SH04

284, 343

Wulferding, Dirk

QE27

203

Yamada, Yuji

QB15

189

Watanabe, Isao

PO17, QB02

180, 187

Wirth, Steffen

JC01, PH04

100, 147

Wulfhekel, Wulf

GI03

82

Yamagami, Hiroshi

HP11, RD25, SE2330, 266, 337

Watanabe, Kazuo

GJ02, QG15, QH08,
QI1882, 210, 214, 220

Wisniewski, Andrzej

QB30

192

Wunderlich, Joerg

IE03, IF01

93, 94

Yamaguchi, Akira

QC03

192

Wisniewski, Piotr

SE16

335

Wurmehl, S.

RB17

256

Yamaguchi, Masahiro

QM07, RK04

232, 286

Watanabe, Masatoshi

PO03

177

Witkowski, Bartlomiej S

DD02

58

Wurmehl, Sabine

QH24

216

Yamaguchi, Masahito

QK19

227

Watanabe, Masayuki

KG03

111

Wittlin, Aleksander

QB30

192

SG01

339

Watanabe, S.

QB28

191

Woelfle, Peter

EB04

65

X

Yamaguchi, Masanori
Yamaguchi, Nobuhiro

QG19

211

Watanabe, Shintaro

QI13

219

Woike, Theo

AB02

34

Xaba, Bongani

QH22

216

Yamaguchi, Shuhei

QG19

211

Watanabe, T.

SG11

341

Woitschach, Sarah

RE12

268

Xavier, Allan M

SL20

359

Yamaguchi, Yasuo

QG18, RP01

211, 303

Watanuki, Ryuta

SC23

329

Wojcieszyk, Daniel

PG26

146

Xia, Zhengcai

QI11

219

Yamaki, Yuki

PH08

148

Wattiaux, Alain

PI17

153

Wojek, B. M.

PC29, PI15

131, 153

Xiang, Tao

FE02

75

Yamamoto, Daisuke

SB23

324

Wawryk, Ryszard

SB26

324

Wojek, Bastian M.

HA03, SE08

83, 334

Xianmin, Zhang

CH02

54

Yamamoto, Eetsuji

SB15

322

Weber, Katharina

AB02

34

Wolf, Bernd

HC04, QE14, RI13

85, 201, 281

Xiao, F.

QF02

204

Yamamoto, Etsuji

Wechke, E.

PC22

130

Wolf, Thomas

HA02

83

Xiao, Gang

GH03

81

Wees, Bart J. Van

AI05

39

Wolff-fabris, Frederik

121, 255, 323, 331

Xiao, Jiang

PJ34

160

30, 95, 131, 134,
135, 192, 263, 268,
337

Wei, D. H.

PK01

160

PB09, PB11, RB09, SB18,
SD07

HP11, IG04, PC28, PD13,
PD23, QC03, RD11,
RE10, SE23, SF03

Xiao, Wen

DD03

58

Yamamoto, Keiichi

PD10

133

Wei, Dahai

HE03

86

Wolfle, Peter

KG01

111

Xiao, Yu

QK01

224

Yamamoto, Koji

PD20

135

Wei, Jianqiang

QN23

240

Won, Choongjae

PI10

152

Xiaodi, Wen

QO15

243

Yamamoto, Masafumi

SK06

351

Weickert, Franziska

JD01

100

Won, Chung Jae

SE02

333

Xiaopeng, Li

QO21

244

Yamamoto, Masaki

QH13

215

Weigand, Markus

RJ05

283

Won, Hyuk

QN04, QP04

237, 246

Xin, Yan

PA21

119

Yamamoto, Shoji

IJ05, JG04

98, 103

Weihe, Hoegni

BC02

42

Won, Jaehyuk

PN08, PN09, QM04

173, 232

Xing, Y. T.

SM17

363

Yamamoto, Takashi

QC07

193

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

429

430

Author Index
You, Chun-yeol

RK02, RK06, RK09,
RK22, SI04, SJ02, SJ05,
SM01, SM12

286, 287, 289, 346,
349, 361, 362

76

You, Y. B.

SB04

320

179

Youn, S. J.

RB26

258

RP10

304

Young, A. T.

QI14

220

Yoo, Kyung Jun

JA03

98

Young, Olga

GF03

79

203

Yoo, Myoung-woo

DE05, RJ1560, 285

Yu, Han Young

RL21

293

QG28

212

Yoo, Sang-im

PJ19, QO28, RH18

157, 245, 277

Yu, Ing-song

DD01

58

Yano, Shinya

PO02, QL03, RN02

177, 228, 297

Yoo, Taehee

PN08, QL08

173, 229

Yu, J H

RO12

302

104, 301

Yanoh, Takuya

PO02, QL03, RN02

177, 228, 297

Yoo, Woosuk

PK17

163

Yu, Jaejun

58, 79, 111, 261

RF10, RF11

270

Yansen, Widi

RA21

252

Yoo, Y. J.

QG27, RA07

212, 250

DC03, GF05, KG02,
RC13, RC17

Yamashita, T.

RD15

264

Yanushkevich, Kazimir

QG05

209

Yoo, Yeong-min

BH02

46

Yu, Jun Sang

PO09

178

Yamashita, Tetsuro

QD17, RD18, RD20,SE11199, 265, 335

Yao, Kailun

PN10, PO01, RM03,
SO01173, 177, 295, 366

Yooleemi, Shin

PJ15

157

Yu, Kwon Kyu

RQ17

309

Yoon, Dong Young

PA09

117

Yu, Kwon-kyo

RQ18

310

Yamauchi, Hiroki

QI16

220

Yao, Kai-lun

QK18

227

Yoon, Jungbum

74, 286, 345, 349

Yu, R.

CD01

50

Yamauchi, KunihikoAA02, EC03, PA1233, 65, 117

Yao, Y. D.

PK01

160

FD03, RK02, RK06,
SH16, SJ02

Yu, S. C.

RA01

249

Yamauchi, Tooru

SF04

337

Yao, Yeong-der

IH06

96

Yoon, Kwan-seob

PO14

179

Yu, Seong Cho

AJ06

40

Yamaura, Junich

QO13

242

Yaresko, Alexander

SC07

326

Yoon, S.

PO23, QF13

181, 206

Yu, Seong-cho

Yamaura, Junichi

JA04, QE05, SG04, SG1499, 200, 340, 341

Yarikov, Stanislav

PJ27

159

Yoon, Seok Soo

PM28

172

PM12, PN31, QH01,
SH01, SO03

169, 177, 213, 343,
367

Yamaura, Jun-ichi

IA04, PC17, PG16, SB05

91, 129, 145, 321

Yashima, Mitsuharu

DA04, QB29

56, 191

Yoon, Seungha

PK04, QK03

161, 224

Yu, Unjong

RF06

269

Yamazaki, Yohei

PG07, QH21

143, 216

Yashin, Shadi

RD07

263

Yoon, Sook Soo

SN13

366

Yu, Weiqiang

QB07

188

Yan, Biao

AJ03, JI06

40, 105

Yashina, Lada V

PN22

175

Yoon, Sung Wook

PI13

152

Yu, Xiuzhen

RA05

250

Yan, Binghai

RC10

260

Yasin, Shadi

RE09

267

Yoon, Sungwon

RN10

298

Yu, Xuezhe

DG06

61

Yan, Guo Jhih

RR26

315

Yasuda, Sho

RM06

296

Yoon, W. S.

RQ08

308

Yu, Young-sang

DE05, RJ16, SH1460, 285, 345

Yan, Li Qin

PA04

116

Yasuda, Takashi

QH21

216

Yoon, Woon-ha

DJ02

63

Yuan, Fu-te

PK06, QP17

161, 248

Yan, Li-qin

JB03

99

Yasufuku, Yoshimasa

RP19

306

Yoshichika, Onuki

RD19

265

Yuan, H. Q.

QB12

189

Yan, Zhongjie

SL02

356

Yasuhiro, Morosawa

QD14

198

Yoshida, Hajime

QI05

218

Yuan, Hongtao

AE05

36

Yanagi, Kazuhiro

SO515

369

Yasui, Akira

RD25, SE23

266, 337

Yoshida, Hiroyuki

199, 200, 203, 277

Yuan, Hui Qiu

RD12, SB29

264, 325

Yanagihara, Hideto

PI16, QM16, SJ06

153, 234, 349

Yasui, Yukio

DA01, PH12, QC06

56, 148, 193

QE03, QE05, QE08,
QE27, RH14

Yuan, Shujuan

SG01

339

Yanagisawa, Tatsuya

QC25, RD07, SE07

196, 263, 334

Yasuoka, Hiroshi

PC03

127

Yoshida, K.

CG02

53

Yuan, Xueyong

PL01

164

Yanai, Takeshi

JH01, PM08, PM09,
RO03

104, 168, 301

Yeche, Nicolas

AB02

34

Yoshida, Kazuetsu

BG04

46

Yuan, Zhi-min

SJ09

350

Yehia, M.

QE23

203

Yoshida, Makoto

QE08

200

Yuasa, S.

CE03, CE06, ID02, RJ07

51, 52, 93, 283

Yanase, Youichi

PC06

127

Yelland, Ed

GC01

77

Yoshida, Tohru

RH01

274

Yuasa, Shinji

Yang, Cang-seob

RQ23

310

Yelland, Edward A

SE12

335

Yoshida, Tomohiko

KD03

109

AI05, BI01, HF01, IE04,
KF01, PK20

39, 47, 87, 94, 110,
163

Yang, Chan-ho

GB05

76

Yellen, Benjamin B.

AH04

38

Yoshida, Tsuneya

RC01

259

Yue, Ming

RO15, SN01

303, 364

Yang, Charles Shieh-yueh

AH03

38

Yen, Nguyen Hai

AJ06

40

Yoshida, Yasuo

IH02

96

Yue, Zengji

SD01

330

Yang, Dong Gyu

PB17, PB36, PB37, PB38,
PB39122, 126

Yeom, Han Woong

RC14

261

Yoshida, Yusuke

PG10

144

Yufu, Shigeyuki

PB04

120

Yeom, Jaehoon

RH08

276

Yoshihara, Akira

SL04

356

Yukawa, Koichi

PC05

127

Yang, Dong-seok

QH01

213

Yeon, Duhyung

RQ14

309

Yoshihara, Tatsuhiko

RC18

261

Yuki, Shozo

QN11

238

Yang, Hangfu

RO13

302

Yermakov, Anatoly

QL07

229

Yoshihiro, Kuroiwa

QD14

198

Yukitake, Chikano

PB04

120

Yang, Hong-chang

AH03, QM27

38, 236

Yi, Chang Hyun

QH29, SC08

217, 326

Yoshii, Shunsuke

RH03

275

Yun, Sang-jun

KE03, SI13

110, 348

Yang, Hung-duen

QA20, RN17

185, 299

Yi, Hee-taek

QF20

207

Yoshikawa, Takuro

PI16

153

Yun, Won Seok

KI01, QG20

112, 211

Yang, Hyunsoo

EG03, GE03, HD02,
PJ08, PJ20, PJ21, RL19,
SI02, SK05

69, 78, 85, 156, 158,
293, 346, 351

Yi, Il Gu

RI21

282

Yoshiki, Takano

QD14

198

Yunhyun, Cho

RR20

314

Yi, Jiabao

QL19

231

Yoshimi, Kazuyoshi

GB03

76

Yunoki, Seiji

PC08, PG18

128, 145

Yi, Su Do

RI19, RI20

282

Yoshimoto, Tatsuya

RI01

279

Yuryev, Y. N.

RQ08

308

Yang, In-sang

PH14, SA16

149, 318

Yildiz, Fikret

EI01

70

Yoshimura, Kazuyoshi

PC02, PC09

127, 128

Yusa, Hitoshi

PE10

137

Yang, J. M.

RP10

304

Yim, H. I.

PM15

169

Yoshimura, Satoru

RP06

304

Yusuf, S M

QO06, QP05

241, 246

Yang, Jinhu

PC02, PC09

127, 128

Yimnirun, Rattikorn

SL10

357

Yoshio, Miura

KI03

113

Yusuf, S. M.

DH05, PN17, RN04

62, 174, 297

Yang, Jong-heon

RL21

293

Yin, Xiaofei

SN01

364

Yoshioka, Hideo

RG09

273

Yusuke, Amakai

QC01

192

Yang, L.

QB12

189

Yin, Xiaolu

RO07

301

Yoshitake, Junki

PE18

139

Yutani, K.

KA02, QC12107, 194

Yang, Lei

PK03

160

Yoda, Yoshitaka

QD11

198

Yoshiuchi, Shingo

PD08, PD13, PD16

133, 134

Yutani, Keisuke

PD24

135

Yang, Lifeng

SA20

319

Yogi, Mamoru

QH14

215

Yoshiya, Uwatoko

QI17, QJ01

220, 221Yuu, Okawara

QJ01

221

Yang, Lin

SB29

325

Yokoi, Atsushi

JI01

105

Yoshiyuki, Mizuno

RO05

301

Yang, Luke

RO15

303

Yokoo, Tetsuya

PI07, RH13

151, 276

Yoshizawa, Masahito

PD11

133

Z

Yang, S.y.

QM27

236

Yokota, Saeko

SK08

351

You, Biao

PL01

164

Zablotskii, Vitalii

AD05, AH02, BH03

38, 46

Yang, Sangsun

SL29

360

Yokoyama, Chiori

QF04

204

You, Chun Yeol74, 234, 345

Zagdoud, Amani

RK05

286

Yang, See-hun

RK22

289

Yokoyama, Hisatoshi

RF10

270

FD03, QM18, QM20,
SH16

Zagrebin, Mikhail

QH05

213

Yang, Sen

JJ02, RM08, SO25

106, 296, 370

Yokoyama, Makoto

PD07, SE07

133, 334

Zaharko, O.

QE19

202

Yang, Seolun

AD03

35

Yokoyama, T

QM12

233

Zaharko, Oksana

QF20

207

Yamamoto, Yousuke

RK23

289

Yang, Shuo-wang

SK34

356

Yokoyama, Takehito

PJ18, RC06

157, 259

Yamamura, T.

QJ10

222

Yang, Tao

PH02

147

Yokoyama, Toshihiko

AG04, EI01

38, 70

Yamanaka, Rina

RE04

267

Yang, Tim

KC03

108

Yonemitsu, Kenji

RG08

273

Yamanaka, Shoji

PE10

137

Yang, Yang

SL06, SM14

357, 363

Yoneyama, Naoki

GB04

Yamane, Yuta

JE02, JF02

102

Yang, Yuanjun

SA19

319

Yoo, Dongwon

PO16

Yamanoi, Kazuto

RK21

289

Yang, Zhaorong

QA21

186

Yoo, J. H.

Yamanouchi, M.

SH07

344

Yano, Kazuo

PG05, QI04

143, 218

Yamanouchi, Michihiko

QP14, SI17

247, 348

Yano, Midori

QE22

Yamasaki, Y.

CF04, PL14

53, 166

Yano, Shin-ichiro

Yamasaki, Yuichi

PH08

148

Yamashita, Fumitoshi

JH01, RO03

Yamashita, Makoto

The 19th International Conference on Magnetism

July 8-13, 2012 Busan, Korea

Author Index

Author Index

Author Index

431

432

Author Index

Zahradnik, Martin

KD03

109

Zhao, Yonggang

SA20

319

Zvyagin, A. A.

CC04, QF02

50, 204

Zakhidov, A.

QB12

189

Zhao, Yu-jun

QA03

183

Zvyagin, S.

QF03

204

Zaleski, A J

QB06

188

Zhao, Z. Y.

IC03

92

Zvyagin, S. A.

QF02

204

Zaleski, T A

QB06

188

Zhaoyang, Zeng

QO15

243

Zwicknagl, Gertrud

DB02, PC24

57, 130

Zamani, Atieh

QH11

214

Zheludev, Andrey

CC03, IJ06, PI06

50, 98, 151

Zamudio-bayer, Vicente

KD01

109

Zhen, X.g.

QE18

202

Zang, Jiadong

DF01

60

Zheng, G -q

QB11

188

Zanini, L. F.

JH02

104

Zheng, Guo-qing

PC20

130

Zapf, Vivien

SF13

339

Zheng, H. Y.

SL08, SL09

357

Zapf, Vivien S

QB13

189

Zherlitsyn, S.

CC04

50

Zapotokova, Mariana

QD08, RD21

197, 265

Zherlitsyn, Sergei

RD07, RE09, SD07

263, 267, 331

Zarefy, Amjaad

BD02

43

Zhigadlo, N. D.

PC29

131

Zargar Shoushtari, Morteza

PB15, RN22

122, 300

Zhigadlo, Nikolai

RB19

257

Zeiringer, Isolde

SC01

325

Zhigadlo, Nikolai D.

RB21

257

Zeitler, Uli

KB06, SA10

108, 317

Zhigaldo, Nicolai

RB20

257

Zeitler, Ulrich

DH02

62

Zhou, Dong

QN21, SL12

239, 358

Zemen, Jan

SK22

354

Zhou, Haidong

PA21

119

Zeng, Minggang

GI04

82

Zhou, Mingge

SL12

358

Zeng, Rong

QG09

209

Zhou, S. M.

PL20

167

Zenkevich, Andrei

SK26

354

Zhou, Shaoxiong

IB02

91

Zenmyo, Kazuko

RH19

277

Zhou, Shiming

BD05, JI05

43, 105

Zenzai, Ryosuke

SO20

370

Zhou, Tiejun

SJ09

350

Zhang, Aimei

PK05, RR29

161, 315

Zhou, Tong

SF01

337

Zhang, Caihong

BE04

44

Zhou, X. H.

RM09

296

Zhang, Chenglin

RB10, RB11

255

Zhou, X. J.

SB31

325

Zhang, Dongtao

SN01

364

Zhu, Hong

PK03

160

Zhang, Fapei

QK01

224

Zhu, J.

PL02, SM05

164, 361

Zhang, Fengming

PN05, QL04

172, 228

Zhu, Jian Xin

KG01

111

Zhang, Haijun

RC10

260

Zhu, Liming

QL03

228

Zhang, Hyodo

RN13

298

Zhu, Minggang

239, 301, 358, 366

Zhang, J. L.

QB12

189

QN21, RO04, RO07,
SL12, SN11, SN12

Zhang, Jing Lei

RD12, SB29

264, 325

Zhu, Tao

PK14

162

Zhang, Jiuxing

SN01

364

Zhu, Weihua

PK05

161

Zhang, L

BG01

45

Zhu, Yao-hui

QK08

225

Zhang, L.

SO08, SO16

368, 369

Zhu, Zengwei

KJ04

114

Zhang, P.z.

RO14

303

Zhu†, Meng

EG01

69

Zhang, Peng

SO03

367

Zhukov, Arcady

Zhang, Pengyue

RO13, RO15

302, 303

AJ02, CH01, CJ02, CJ04,
PJ25, SO04, SO27

40, 54, 55, 56, 158,
367, 371

Zhang, Rong

PN27

176

Zhukova, Valentina

Zhang, Sen

SA19, SA20

319

AJ02, CJ02, PJ25, SO04,
SO27

40, 55, 158, 367,
371

Zhang, Shoucheng

HP71, RC1032, 260

Zilch, Christian

AH01

38

Zhang, Shuai

RD14

264

Ziman, Timothy

JF03

102

Zhang, Weimin

QF04

204

Zimmermann, Martin Von

CI04

55

Zhang, Wei-min

QE03, QE10

199, 201

Zitko, Rok

PE03

136

Zhang, Wenchen

SN11

366

Zitouni, Abdelaziz

RQ16

309

Zhang, Xiaozhong

HP61

31

Zivieri, Roberto

GG02

80

Zhang, Xin

SA19

319

Zivkovic, Ivica

QF20

207

Zhang, Y.

JH02

104

Zlatic, Veljko

IA02

90

Zhang, Yi-jie

DB04

57

Zlotnikov, Anton O.

QC02

192

Zhang, Ying

EJ02

71

Zomer, Paul J.

GI05

82

Zhang, Ying-de

SO03

367

Zorko, Andrej

AC04

35

Zhang, Yiwen

JI01

105

Zou, Tao

JB03

99

Zhang, Yu-zhong

SF14

339

Zou, Wenqin

PN05, QL04

172, 228

Zhao, Huaisong

PB28

124

Zou, Yang

RE14, RE15, SF05

268, 337

Zhao, Jianhua

DG06, QK23

61, 227

Zuberek, Ryszard

JJ03

106

Zhao, Pei

PK18

163

Zukeran, Chojun

QI13

219

Zhao, X. R.

PL20

167

Zukovic, Milan

QE01, QE02

199

Zhao, Xudong

CA03

49

Zuo, Wenliang

QN23

240

Zhao, Yang

QA20

185

Zvezdin, K.a

ID02

93

Zhao, Yanggang

SA19

319

Zvezdin, Konstantin

ID03, IE04

93, 94

The 19th International Conference on Magnetism

Author Index

Author Index

Author Index

July 8-13, 2012 Busan, Korea

433

MEMO

434

The 19th International Conference on Magnetism

MEMO

July 8-13, 2012 Busan, Korea

435

MEMO

436

The 19th International Conference on Magnetism

MEMO

July 8-13, 2012 Busan, Korea

437

MEMO

438

The 19th International Conference on Magnetism

MEMO

July 8-13, 2012 Busan, Korea

439

MEMO

440

The 19th International Conference on Magnetism

Conference Secretariat
People-X, Inc., 1F Haeoreum Bldg, 748-5, Yeoksam-dong, Gangnam-gu, Seoul 135-080, Korea Tel: +82-2-557-8422 Fax: +82-2-566-6087 Email: icm@icm2012.org