KENSREPORT
XV

ISSN 1343– 1072

KENS REPORT XVHigh Energy Accelerator Research Organization

KENS REPORT-XV

2003–2006

2003 ⁄ 2006

KENS

High Energy Accelerator Research Organization
KENSKEK Progress Report 2006-4 M© High Energy Accelerator Research Organization (KEK), 2006
KEK Reports are available from:
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KENS REPORT-XV
2003-2006―a―RAT&CAT
T.KAMIYAMA(Hokkaido Univ.)

FOX
M.TAKAHASHI(Univ. of Tsukuba)

LAM-D
T.SATOH(NIMS)FOX
LAM-D

RAT CATINC
S.ITOH
(KEK)

HIT

INC
LAM-40
WINK

EXCED

HIT
K.ITOH(Kyoto Univ.)

ARISA

VEGA
PORE
Vega
K. MORI(Kyoto Univ.)

SWAN

PORE, ARISA
N.TORIKAI
(KEK)

LAM40
Y.KAWAKITA(Kyushu Univ.)

EXCED
T.YOKOO(KEK)

LAM-80ET
SIRIUS
SiriusT.KAMIYAMA(KEK)

Thermal neutron port
H2O moderator@ ambient temperature

Cold neutron port

http://neutron-www.kek.jp/

LAM-80ET
I.TSUKUSHI(Chiba Inst. of Tech.)

Solid CH4 moderator @20K
SWAN
T.OTOMO(KEK)PREFACE
KENS has pioneered research using pulsed neutrons as tools to investigate thestructure of matters and the dynamics of atoms for over a quarter century. It
first started its operation in 1980 with 500 MeV and 2 µA of proton beam, andachieved the scientific use of spallation neutron source in Japan. After leading
pulsed neutron society for 26 years, KENS was closed in March 2006. During its
operating history, several upgrades of installed spectrometers and beam lines were
performed to keep giving a better chance of succeeding with certain innovative
experiments. In 2000, the whole target moderator reﬂector assembly was renewed
to greatly increase its ﬂexibility of use.
The start of the construction of J-PARC initiated in 2001 was another main event,which is the joint project between KEK and JAEA. This next generation neutron
source would be operated with 1 MW and commissioned in May 2008. Much
effort is being paid for designing spectrometers and developing neutron devices.
It is our great pleasure to deliver the KENS Report XV, here, we review thescientiﬁc activities (B1 & B2 program report) and development of neutron devices(A1 & A2 program report) including other activities at KENS in the year of
2003-2006.
We are grateful C. Yoshioka, J. Takano and E. Watanabe for their help on theeditorial.

December 2006
Editor of KENS Report XV
Tetsuya YOKOO―c―KENS - staff
S.IkedaM.KawaiT.Kamiyama
H.Shimizu
S.NaitoS.ItohT.OtomoN.Torikai
T.Ino
T.YokooS.MutoEngineer
S.SatoH.Sagehashi
N.Kaneko
T.Tahara
Y.Kobayashi
M.Nagai―e―

CONTENTS

I. FACILTY REPORT
Overview of the Progress at KENS ……………………………………………………………………………………… 3
S. Ikeda
Beam-line Operation …………………………………………………………………………………………………… 14
S. Muto, H. Fujimori, N. Kaneko, T. Tahara and Y. Kobayashi
Scientiﬁc Review on KENS, KEK and P3IB, BATAN Research Collaboration ……………………………………… 15
E. Kartini and T. Kamiyama
Research and Development of New Solid Electrolyte for Rechargeable Battery Indonesian International
Joint Research Program (RUTI) …………………………………………………………………………………… 17
E. Kartini

II. SCIENTIFIC HIGHLIGHT
Spin-Lattice Coupling of Multiferroic (Lu,Y)MnO3 …………………………………………………………………… 29
S. Lee, M. Kang, F. Shikanai, T. Kamiyama and J.-G. Park
In Situ Neutron Diffractions for Austenite Transformation during Heating and Ferrite Transformation during Cooling … 31
P.G. Xu, Y. Tomota, M. Yonemura, T. Shinozaki and T. Kamiyama
Nanostructure of Ionic Amphiphilic Diblock Copolymer Monolayer on the Water Surface …………………………… 34
H. Matsuoka, E. Mouri, P. Kaewsaiha, Y. Furuya and Y. Suetomi
Low Energy Excitation of Polymer Thin Films ………………………………………………………………………… 37
R. Inoue, T. Kanaya, K. Nishida, I. Tsukushi and K. Shibata
Magnetic Excitations in CoO …………………………………………………………………………………………… 39
K. Tomiyasu and S. Itoh
Spin-dependent Quantum Renormalization Factor in One-dimensional Heisenberg Antiferromagnets ……………… 41
S. Itoh, Y. Endoh, K. Kakurai and H. Tanaka
Structure and Absorption Mechanism of Carbon Materials for High Capacity Secondary Battery …………………… 43
M. Nagao, C. Pitteloud, T. Kamiyama, T. Otomo, K. Itoh, T. Fukunaga, K. Tatsumi and R. Kanno
Local Structure of β-V2D : Pair Distribution Function Analysis and Reverse Monte Carlo Modeling ………………… 45
K. Itoh and T. Fukunaga
Pulsed-neutron Diffraction Investigations of Long-period Commensurate Modulation of TbRu2Ge2 in
an External Magnetic Field ………………………………………………………………………………………… 46
S. Kawano, K. Murogaki, M. Takahashi and T. Shigeoka―i―III. EXPERIMENTAL REPORT
Crystal Structures
Hydration Kinetics of Tricalcium Silicate ……………………………………………………………………………… 53
K. Mori, Y. Shiraishi, K. Iwase, M. Yonemura, F. Shikanai, T. Wuernisha, D. Sulistyanintyas, K. Itoh,
M. Sugiyama, T. Kamiyama, K. Oishi, M. Kawai and T. Fukunaga
TOF Neutron Powder Diffraction Study on the Time Dependence of Phase Transition at Room Temperature ofQuenched La1.5Pr0.5CuO4 …………………………………………………………………………………………… 54
T. Wuernisha, M. Yonemura, Y. Ikeda and M. Azuma
Crystal Structure of A-site Deﬁcient Superconductor Ca2-xCuO2Cl2 …………………………………………………… 57
I. Yamada, M. Azuma, A. A. Belik, S. Harjo, T. Kamiyama, Y. Shimakawa and M. Takano
High Temperature Phase of Fe-doped Lanthanum Gallate …………………………………………………………… 58
K. Mori, K. Shibata, T. Fukunaga, K. Itoh, M. Sugiyama, K. Iwase, S. Harjo, A. Hoshikawa, T. Ishigaki
and T. Kamiyama
Development of Rietveld-PDF Collaboration Analysis System on Vega ……………………………………………… 59
K. Mori, T. Fukunaga, K. Iwase, T. Wuernisha, M. Yonemura, D. Sulistyanintyas, F. Shikanai, K. Itoh,
M. Sugiyama, T. Ishigaki and T. Kamiyama
Ferroelectric Property and Crystal Structure of (Bi,La)4(Ti,Si)3O12 as a Bulk Ferroelectric Material ………………… 62
Y. Idemoto, T. Miyahara, N. Koura and T. Kamiyama
Impurity Induced Insulator-Metal Transition in Sr3(Ru1-xMnx)2O7…………………………………………………… 64

T. Arima, R. Mathieu, J. P. He, Y. Onose, Y. Kaneko and Y. Tokura
Structure Phase Transition in Fe-heavily-substituted Copper Oxide Superconductor FeSr2YCu2O6+δ ………………… 65
T. Mochiku, Y. Hata, K. Iwase, M. Yonemura, S. Harjo, A. Hoshikawa, K. Oikawa, T. Ishigaki, T. Kamiyama,
H. Fujii, F. Izumi, K. Kadowaki and K. Hirata
Neutron Powder Diffraction Study of Y2C3 Superconductor …………………………………………………………… 67
T. Mochiku, T. Nakane, H. Kito, H. Takeya, S. Harjo, T. Ishigaki, T. Kamiyama, T. Wada and K. Hirata
Crystal Structure Analysis of Hydrogen Absorbing Ti-Cr-Mo Alloys ………………………………………………… 68
K. Iwase, T. Kamiyama, Y. Nakamura, K. Mori, M. Yonemura, S. Harjo and E. Akiba
Microstructure Studies of Hydrated Ca3SiO5………………………………………………………………………… 70

K. Mori, S. Takata, I. Tsukushi, T. Otomo, K. Itoh, M. Sugiyama, K. Oishi, M. Kawai and T. Fukunaga
Study on Ferromagnetism and Oxygen Incorporation of Diluted Magnetic Semiconductor (Ga,Mn)N ……………… 71
T. Takeda, S. Ohtaki, S. Kikkawa and T. Ishigaki
Sr Substitution Effect on Pr(Ba,Sr)2Cu3Oy : Structural, Electrical and Magnetic Properties …………………………… 72
Y. Takahashi, T. Wuernisha, F. Sano, M. Yoneyama, S. Harjo, Y. Takano, T. Kamiyama and K. Sekizawa
Thermal Expansion Behavior of Cementite Polycrystals - Effect of Curie Point on Thermal Expansion - …………… 74
S. Harjo, T. Kamiyama, Y. Shiota, Y. Tomota, T. Suzuki and M. Umemoto
Structure and Mecanical Behavior of Heavily Drawn Pearlite and Martensite in a High Carbon Steel ……………… 77
Y. Shiota, Y. Tomota and T. Kamiyama
Effect of Lamellar Spacing on Deformation of a Pearlite Steel……………………………………………………… 80

T. Shinozaki, S. Morooka, T. Suzuki, M. Yonemura, Y. Tomota and T. Kamiyama
Tensile Behavior of a TRIP-DP Steel by In Situ Neutron Diffraction ………………………………………………… 83
A. Narui, S-C. Chen, S. Morooka, K. Ikeda, M. Yonemura, Y. Tomota and T. Kamiyama― ii ―

Tensile Behavior of an Austempered Ductile Cast Iron Studied by In Situ Neutron Diffraction ……………………… 85
H. Ogawa, S. Morooka, T. Shinozaki, M. Yonemura, Y. Tomota and T. Kamiyama
In Situ Neutron Diffraction with a Time of Flight Method during Tensile Deformation for a Heavily Drawn
Pearlite Steel ……………………………………………………………………………………………………… 88
Y. Shiota, Y. Tomota, S. Harjo and T. Kamiyama
Crystal Structure of Li(MnyFe1-y)PO4 and Its Delithiated Phases ……………………………………………………… 90
A. Yamada, Y. Takei and M. Yonemura
Room Temperature Miscibility Gap in LixFePO4 ……………………………………………………………………… 92
A. Yamada, H. Koizumi and S. Nishimura
Structure Reﬁnement of Barium Titanate BaTi2O5……………………………………………………………………… 94
M. Yashima, R. Tu, T. Kamiyama, K. Mori, T. Goto and H. Yamane
Evaluation of the Residual Strain for the Practical Composite Nb3Sn Wires with Pre-bending Treatment …………… 95
S. Awaji, H. Oguro, G. Nishijima, P. Badica, K. Watanabe, F. Shikanai, T. Kamiyama and S. Harjo
Variation of Hydrogen Occupation in LaNi4.78Sn0.22Dx Along the P-C Isotherms Studied by In Situ
Neutron Powder Diffraction ……………………………………………………………………………………… 97
Yumiko Nakamura, Robert C. Bowman, Jr. and Etsuo Akiba
Neutron Powder Diffraction Study of Protonic Conductor K3H(SeO4)2 ………………………………………………100
F. Shikanai, R. Kiyanagi, M. Yonemura, K, Iwase, D. Sulistyanintyas, T. Wurnisha, K. Mori, T. Ishigaki,
S. Ikeda and T. Kamiyama
Powder Neutron Diffraction Study of a α,β-Unsaturated Thioamide Derivative ………………………………………102
T. Ohhara, S. Ikeda, T. Hosoya, Y. Ohashi, K. Oikawa, A. Hoshikawa and T. Kamiyama
Solid Monolayers of n-Heptane Adsorbed on MgO (100) at Submonolayer and Multilayer Coverages ………………104
A. Inaba and N. Sakisato
Neutron Diffraction Measurement of a Layered Cobalt Oxide SrCo6O11 ………………………………………………106
T. Saito, T. Wuernisha, T. Kamiyama, S. Ishiwata, Y. Takeda, Y. Shimakawa and M. Takano

Liquid and Glasses
Local Structural Effect for Fe-doping in LaGa1-xFexO3-δ ………………………………………………………………109
K. Mori, K. Shibata, K. Itoh, M. Sugiyama and T. Fukunaga
The Local Structure around Lithium Atoms in Lithium Storage Compounds Studied by Neutron Diffraction ………110
H. Sakaguchi, Y. Nagao, K. Itoh, T. Fukunaga and T. Esaka
Structure of Supercooled Water Conﬁned in MCM-41 Porous Silica …………………………………………………112
T. Yamaguchi, M. Otsuji and K. Yoshida
Short-range Structure of Sodium Borate Glasses Containing Al2O3 ……………………………………………………114
N. Ohtori, M. Togashi, K. Takase, K. Handa, J. Ide, K. Itoh, T. Fukunaga and N. Umesaki
Short-range Structure of Borate Glasses Containing High-content Alkaline-earth Oxides ……………………………115
N. Ohtori, M. Togashi, K. Takase, K. Handa, J. Ide, K. Itoh, T. Fukunaga and N. Umesaki
Network Structure in Tl2O-TeO2 Glasses and Oxygen Coordination around Tellurium ………………………………116
Y. Iwadate, T. Hattori, M. Misawa, T. Fukunaga, K. Itoh, K. Fukushima S. Nishiyama, Y. Itoh and M. Suzuki
Analysis of Local Structure in Semiconductive B2O3-SnO Glasses ……………………………………………………119
Y. Iwadate, T. Hattori, M. Misawa, T. Fukunaga, K. Itoh, K. Fukushima, S. Nishiyama, K. Suzuki,
T. Michii and T. Murayoshi
Structure and Intercalation Mechanism of Electrolytic MnO2 …………………………………………………………121― iii ―

M. Nagao, C. Pitteloud, T. Kamiyama, T. Otomo, K. Itoh and R. Kanno
Structure and Intercalation Mechanism of Chemical Treated Electrolytic MnO2 ………………………………………123
C. Pitteloud, M. Nagao, K. Itoh and R. Kanno
Structure and Absorption Mechanism of Carbon Materials for High Capacity Secondary Battery ……………………124
M. Nagao, C. Pitteloud, T. Kamiyama, T. Otomo, K. Itoh, T. Fukunaga, K. Tatsumi and R. Kanno
Network Structure in the Ionic Conducting Chalcohalide Glasses ……………………………………………………126
T. Usuki, T. Furukawa, K. Nakajima and Y. Kameda
Network Structure and Conduction Pathways in AgBr-doped Chalcogenide Glasses …………………………………128
T. Usuki, Y. Onodera, T. Furukawa, Y. Murakami and Y. Kameda
Structure Determination of New Superionic Composite Glass (AgI)x(NaPO3)1-x ………………………………………130
E. Kartini, A. Purwanto and T. Kamiyama
Local Structural Analysis of LixMPO4 (M = Fe, Mn, x = 0, 1) …………………………………………………………132
A. Yamada, H. Koizumi and K. Ito
Structural and Hydration Properties of Amorphous Ca3SiO5…………………………………………………………134

K. Mori, Y. Shiraishi, K. Iwase, M. Yonemura, K. Itoh, M. Sugiyama, T. Ishigaki, T. Kamiyama, K. Oishi,
M. Kawai and T. Fukunaga
Structural Study on Amorphous Cu-Ta Alloys Prepared by Mechanical Alloying under Ar and D2 Atmospheres ……135
K. Itoh, K. Yoshimura, H. T. Takeshita, K. Mori, M. Sugiyama and T. Fukunaga
Structural Study on Nano-crystalline FeTiD0.97 : Local Environment around Deuterium in the Grain Boundary………138
K. Itoh, K. H. Sasaki, H. T. Takeshita, K. Mori, M. Sugiyama and T. Fukunaga
Structural Observation of Amorphous LaNi5D3.3 ………………………………………………………………………141
K. Itoh, T. Shoumura, K. Mori, M. Sugiyama and T. Fukunaga
Structural Observation of Li2S-GeS2 Glasses ……………………………………………………………………………142
K. Itoh, K. M. Sonobe, K. Mori, M. Sugiyama and T. Fukunaga
Atomic Conﬁguration of Metal Atoms in Amorphous (Ti0.676Zr0.324)D0.31 Studied by Reverse Monte Carlo Modeling…144
K. Itoh, K. Aoki and T. Fukunaga
Neutron Scattering Studies on Relaxation and Excitation Phenomena in Structurally Aperiodic System by LAM-40~ Study of low frequency protein dynamics on LAM-40 at KENS; hydration, boson peak and dynamical transition ~ ………146

H. Nakagawa, Y. Joti, A. Kitao, K. Shibata, N. Go and M. Kataoka
Neutron Scattering Study on Relaxation and Excitation Modes in Condensed Matters Using LAM-D
Vibrational Excitation of Liquid GeTe Mixture at the Eutectic Composition……………………………………149

Y. Kawakita, H. Shigeta, Y. Kato and S.Takeda
Neutron Scattering Studies on Relaxation and Excitation Phenomenain Structurally Aperiodic System by
LAM-40 — Dynamics of molten Cuprous halides — ……………………………………………………………151
Y. Kawakita, Y. Kato, H. Fujii, S. Takeda and K. Shibata
Possible Observation of Local Structure by Neutron Resonant Scattering in Single Crystal AgCl and AgBr …………154
M. Kofu, T. Yokoo and Y. Kawakita
QENS Study of Amorphous Poly(vinyl acetate) below Tg ………………………………………………………………156
I. Tsukushi and T. Kanaya
Low-Energy Dynamics in Typical and Untypical Network Silicate Glasses:Silica (SiO2) and Forsterite (Mg2SiO2) …157
K. Suzuya, S. Kohara and K. Shibata
Inﬂuence of Polytypic Structure on Low-Frequency Vibrational Mode of n-Alkanes …………………………………158
F. Kaneko and H. Kubota― iv ―

Effects of Structural Change at Eutectic Composition in Liquid Ge-Te Mixture on the Relaxation Process …………159
S. Takeda, Y. Kawakita and Y. Kato
Mixing State of DMF-FA Solutions Studied by Small-Angle Neutron Scattering Technique …………………………161
T. Takamuku, K. Fujii, Y. Umebayashi, S. Ishiguro and T. Otomo
Temperature Dependence of Microheterogeneity for Acetonitrile-Water Mixtures Investigated by Small-Angle
Neutron Scattering Technique……………………………………………………………………………………162

T. Takamuku, Y. Noguchi, H. Iwase and T. Otomo
Pressure-Induced Remixing of 1-propanol-water-KCL Mixture ………………………………………………………163
M. Misawa, A. Onozuka, S. Takata, T. Sato, M. Sugiyama and T. Otomo
Study of Dffusion Dynamics of Supercritical Aqueous Solution using Neutron Quasielastic Scattering……………165

M. Nakahara, N. Matubayasi, Y. Kameda, H. Iwase, T. Otomo and S. Ikeda
Structure of the Ionic Liquid 1-butyl-3-methylimidazolium Hexaﬂuorophosphate ……………………………………166
M. Kanakubo, Y. Hiejima, K. Minami, T. Aizawa, H. Nanjo, Y. Amo, T. Usuki and Y. Kameda
Coherent Quasielastic Neutron Scattering of Liquid Sn ………………………………………………………………169
T. Kamiyama, T. Masaki and T. Itami
Hydration Structure of Carbonate Ion Studied by Neutron Diffraction with 12C/13C Isotopic Substitution Method…171

Y. Kameda, M. Sasaki, S. Hino, Y. Amo and T. Usuki
Environmental Structure around the Amino Group of Glycine Molecule in Concentrated Aqueous Solutions
Absorbing CO2 ……………………………………………………………………………………………………173
Y. Kameda, Y. Inoue, M. Sakano, M. Sasaki, Y. Amo and T. Usuki
Stractual Study of Liquid GexSb4-xS6 Alloys ……………………………………………………………………………175
F. Kakinuma and T. Fukunaga
Structural Study of Liquid Sb-S Mixtures ………………………………………………………………………………176
F. Kakinuma and T. Fukunaga
Hydrogen-Bonded Structure of Concentrated Aqueous Solutions Involving DL- and L-Alanine Molecules …………178
Y. Kameda, M. Sasaki, M. Yaegashi, Y. Amo and T. Usuki
Low Energy Excitations for the Binary Glass of Water and Glycerol …………………………………………………180
A. Inaba and N. Sakisato
Formation of 2-D Ice at the Initial Stage of Crystallization in a Binary Solution of Water and Glycerol ………………181
A. Inaba and N. Sakisato
Small Angle Neutron Scattering of Two-dimensionally Ordered Ice Formed in a Binary Solution of
Water and Glycerol …………………………………………………………………………………………………183
A. Inaba and N. Sakisato
Local Structure and Dissolution Characteristics of CsCl-NaCl Melts …………………………………………………185
Y. Iwadate, N. Umesaki, M. Misawa, T. Fukunaga, N. Ohtori, K. Itoh, K. Fukushima, A. Kajinami,
H. Matsuura, M. Myochin, H. Kofuji, K. Suzuki, T. Michii and T. Murayoshi
Analysis of Dissolution Characteristics of Rare Earth Chlorides and Oxychlorides ……………………………………187
Y. Iwadate, N. Umesaki, M. Misawa, T. Fukunaga, N. Ohtori, K. Itoh, K. Fukushima, A. Kajinami,
H. Matsuura, M. Myochin, H. Kofuji, K. Suzuki, T. Michii and T. Murayoshi

Large Scale Structures
Basic Study on Estimation of Surface Roughness by Neutron Reﬂectometry …………………………………………191
T. Hirayama, K. Inoue, T. Ebisawa, S. Tasaki, M. Hino and N. Torikai―v―

Reﬂectometric Investigation of Hybrid Langmuir Films Consisting of a Perﬂuorinated Fatty Acid anda Block Copolymer with Hydrophobic and Perﬂuoroalkyl Side Chains ……………………………………………193
K. Mitamura, T. Imae, N. Torikai, E. Mouri and H. Matsuoka
Neutron Reﬂectometric Investigation of a Dendrimer/Nanoparticle Hybrid Film at Air/water Interface ………………194
K. Mitamura, M. Ujihara, N. Torikai and T. Imae
Structural Observation of Block Copolymer Thin Films with Transmission Electron Microtomography
and Neutron Reﬂectivity ……………………………………………………………………………………………195
K. Niihara, N. Torikai, U. Matsuwaki, Y. Nishikawa and H. Jinnai
Neutron Scattering Studies on Relaxation and Excitation Phenomenain Structurally Aperiodic System by
LAM-40 –Dynamics of Polymer Thin Films– ……………………………………………………………………198
R. Inoue, T. Kanaya, K. Nishida, I. Tsukushi and K. Shibata
Molecular Recognition of Human Killer Cell Immunoglobulin-like Receptor (KIR/CD158) Family …………………200
K. Maenaka, D. Kohda, T. Taida and I. Tsukushi
Small-angle Characterization of Multimetric Variants Related to Parkinson’s Disease of Ubiquitin
Carboxyl-terminal Hydrolase L1 in Water by Small-angle Neutron Scattering ……………………………………201
S. Naito, H. Mochizuki, T. Yasuda, Y. Mizuno, M. Furusaka, S. Ikeda, H. M. Shimizu, T. Adachi,
J. Suzuki, S. Fujiwara, S. Aoki and K.Wada
Surface Swollen Layer in Polymer Films Induced by Sorbed Gas Molecules …………………………………………202
Y. Fujii, K. Tanaka, T. Nagamura and N. Torikai
Structural Study on Concentrated Block-Copolymer Brushes in Dry State by Neutron Reﬂectometry ………………204
K. Okayasu, S. Yamamoto, Y. Tsujii, T. Fukuda, N. Torikai and M. Takeda
Structure of Lipid Nanotube by Small-angle Neutron Scattering ………………………………………………………206
K. Yoshida, T. Yamaguchi and S. Lee
In-Situ Neutron Reﬂectivity Studies of DNA Adsorption by Cationic Lipid Monolayer at Different
Calcium Ion Concentrations ………………………………………………………………………………………208
T-L. Lin, J-C. Wu, U-S. Jeng and N. Torikai
In-Situ Neutron Reﬂectivity Studies on the DNA Adsorption by the Lipid Monolayer at the Air-liquid Interface
at Different pH Values ………………………………………………………………………………………………212
T-L. Lin, J-C. Wu, U-S. Jeng and N. Torikai
Neutron Reﬂectivity Study on TAT Peptides and Proteins at the Charged Lipid Monolayers …………………………215
A. Farhan, C. Lee, G. Tae, K. Shin and N. Torikai
Neutron Reﬂectivity Measurement of the Gibbs Monolayer of Ionic Liquid [BMIM]BF4 Aqueous Solution …………217
T. Tohyama, K. Kanai, Y. Ouchi, K. Seki, D. Kim and N. Torikai
Analysis of Structure of Poly(2-Methacryloyloxyethyl Phosphorylcholine) Brush at the Aqueous Interface
by Neutron Reﬂectivity ……………………………………………………………………………………………218
M. Kobayashi, K. Miyamoto, N. Hosaka, K. Ishihara and A. Takahara
Neutron Reﬂectivity for the Structural Analyses of the Silsesquioxane-ﬁlled Polymer Thim Films …………………220
N. Hosaka, K. Miyamoto, N. Torikai and A. Takahara
Effects of NaI Salt on Structure of a Spin-Coated DMPC Lipid Film …………………………………………………222
N. L. Yamada and N. Torikai
Study on Surface Segregation in Miscible Polymer Mixture of Poly(4-Trimethylsilylstyrene) / Polyisoprene
Based on Neutron Reﬂectivity………………………………………………………………………………………224
D. KAwaguchi, M. Ohya, N. Torikai, A. Takano and Y. Matsushita― vi ―

Surface Segregation of Water-soluble Block in Fluctuating Block Copolymer Melts …………………………………225
H. Yokoyama, S. Han, T. Ishizone and N. Torikai
Temperature Dependence of Interfacial Structures of Microphase-Separated Block Copolymers ……………………227
N. Torikai, A. Noro, D. Kawaguchi, A. Takano and Y. Matsushita
Magnetic Structure of Exchange-biased Fe/Cr Thin Film ………………………………………………………………228
K-Y. Kim, Y-S. Hwang, J-G. Park, N. Torikai, M. Takeda, S-W. Han and S-C. Shin
Observation of Electrode Surface for Lithium Batteries ………………………………………………………………229
K. Sakamoto, W. Cho, M. Yoshioka, H. Konishi, N. Sonoyama, M. Yonemura, N. Torikai, A. Yamada and R. Kanno
Recent Research Activities on a Polarized Neutron Reﬂectometer (PORE) ……………………………………………230
N. Torika, M. Takeda, H. Asaoka, T. Hirano, H. Hayashida, M. Hino, M. Kitaguchi, M. Mizusawa, K. Sakurai,
R. Cubitt, K. Ikeda, K. Hirota, H. M. Shimizu, M. Yonemura, M. Yoshioka, K. Sakamoto and R. Kanno

Dynamics
Inelastic Neutron Scattering from Kondo Semiconductor CeOs4Sb12 …………………………………………………235
C.P. Yang, M. Kohgi, K. Iwasa, H. Sugawara and H. Sato
Magnetic Excitation in a New Type Spin-Peierls Compound TiOBr……………………………………………………237
T. Sasaki, S. Itoh, T. Yokoo and J. Akimitsu
Vibrational Density of States of n-Alkanes Adsorbed on MgO (100) …………………………………………………238
A. Inaba and N. Sakisato
Vibrational Density of States of Two-dimensionally Ordered Ice Formed in a Binary Solution of Water
and Glycerol ………………………………………………………………………………………………………240
A. Inaba and N. Sakisato
Evidence for the Crucial Role of 4f Electron in the Metal-Nonmetal Transition of PrRu4P12 …………………………241
K. Iwasa, L. Hao, T. Hasegawa, K. Horiuchi, Y. Murakami, K. Kuwahara, M. Kohgi, S. R. Saha,
H. Sugawara, Y. Aoki, H. Sato, T. Tayama and T. Sakakibara
Vibrational Excitation Energy of Interstitial Hydrogen Atoms in CaF2-type Metal Hydrides …………………………243
Y. Nakamura, T. Kamiyama and E. Akiba
Relaxation Behavior of Polypropylene Studied by Neutron and Positron Probes ………………………………………245
M. Kawai, S. Itoh and T. Suzuki
Neutron Scattering Studies on Relaxation and Excitation Phenomena in Structurally Aperiodic System by
LAM-40 ……………………………………………………………………………………………………………246
H. Maekawa, H.-Y. Shen, T. Yamamura, K. Shibata, Y. Kawakita and M. Kawai
Crystal Field Splittings in Cubic Pr Compounds of PrInX2 (X = Cu, Ag, Au) …………………………………………249
H. S. Suzuki and T. J. Sato
Magnetic Excitation in Non-magnetic Γ3 Doublet Ground State of PrInNi4 ……………………………………………250
H. S. Suzuki and T. J. Sato
Lattice Dynamics in Ferroelectric Material LiNbO3 ……………………………………………………………………251
K. Yamada and K. Ohoyama
Temperature Evolution of Low Energy Phonons in La2-x Sr xNiO4 (x=0.275) …………………………………………252
K. Yamada, S. Itoh and R. Kajimoto
Dynamics of Water Molecules in Nano-space …………………………………………………………………………253
S. Kittaka, S. Takahara, Y. Kuroda, T. Mori and T. Yamaguchi
Magnetic Excitations in SrRuO3 ………………………………………………………………………………………254― vii ―

S. Itoh, K. Tomiyasu and Y. Endoh
Magnetic Excitations in MgCr2O4 and ZnCr2O4 ………………………………………………………………………255
K. Tomiyasu and S. Itoh
Quasi-elastic Neutron Scattering of Protonic Conductor K3H(SeO4)2 …………………………………………………257
F. Shikanai, K. Tomiyasu, I. Tsukushi, S. Ikeda and T. Kamiyama
Effect of Conduction Electrons on the Crystal Field in Tm0.05LaxYb0.95-xTe ……………………………………………259
T. Matsumura, H. Ishida, T. J. Sato and K. Shibata
Spin Fluctuation of a Heavy-Fermion Compound YbAgGe ……………………………………………………………261
T. Matsumura, H. Ishida and T. J. Sato
Neutron-scattering Study of Magnetism of Na1.8Cu2Mo3O12-δ Using the INC Spectrometer ……………………………263
M. Hase, S. Itoh, T. J. Sato, H. Kitazawa and G. Kido
Neutron-scattering Study of Magnetism of Na1.8Cu2Mo3O12-δ Using the LAM-40 Spectrometer ………………………265
M. Hase, T. J. Sato, S. Itoh, H. Kitazawa and G. Kido
Effects of Chemical Potential on the Neutron Cross Section ……………………………………………………………267
T. Yokoo, K. Iwase, M. Arai and E. Akiba
Possibility of the Electronic Interband Transition by Epithermal Neutrons ……………………………………………270
T. Yokoo and M. Arai
Report on the LAM-D Activities (2003-2005) …………………………………………………………………………273
T. J. Sato

Magnetism
Magnetic Structure of GdGaAl …………………………………………………………………………………………277
T. Hamasaki, T. Yokoo, M. Arai, K. Kuwahara, S. Ohhara and I. Sakamoto
Neutron Diffraction Studies on TbNiSn …………………………………………………………………………………280
Y. Andoh, K. Murogaki, S. kawano, M. Takahashi, M. Kurisu, G. Nakamoto and T. Tsutaoka
Study of Magnetic Structure on the Tb2Ni3Si5 Single Crystal …………………………………………………………282
Y. Hashimoto, K. Murogaki, S. Kawano and M. Takahashi
Magnetic Ordering of Triangular Lattice Diluted Antiferromagnet CuFe1-xAlxO2 ………………………………………283
K. Kitagawa, S. Mitsuda and M. Takahashi
Elastic Neutron Scattering Experiments for Bi2Sr2-xYxCa(Cu, Zn)2Oz (x=0.3) Single Crystals …………………………284
M. Uehara, H. Inoue, K. Fujita and T. Yokoo
Magnetic Structure of a Chiral Molecule-based Magnet, [Cr(CN)6][Mn(S)- pnH(H2O)](H2O) ………………………286
A. Hoshikawa, T. Kamiyama, A. Purwanto, K. Ohishi, W. Higemoto, T. Ishigaki, H. Imai and K. Inoue
Electric Polarization Dependent Change of the Magnetic Structure in Eu0.595Y0.405MnO3 ………………………………289
R. Kajimoto, T. Yokoo, M. Kofu, K. Noda and H. Kuwahara
Epithermal Neutron Diffraction Study of the Magnetic Ordering in Gadolinium Hexaboride …………………………292
K. Kuwahara, M. Sato, R. Yamamoto, S. Sugiyama, M. Kohgi, T. Yokoo, M. Nakamura, Y. Inamura,
M. Arai, K. Iwasa and S. Kunii
The Magnetic Structure of Gd3Ir4Sn13 Studied by EXCED ……………………………………………………………294
C. Nagoshi, K. Kuwahara and T. Yokoo
Intermediate Phase Structure of Ni2MnGa Combining Synchrotron Radiation Diffraction Data ………………………297
T. Ohba, M. Miyamoto, T. Kakeshita, T. Fukuda and M. TakahashI and K. Kato
Pulsed Neutron Single Crystal Diffractometer FOX at KENS …………………………………………………………298― viii ―M. Takahashi

Instrumentation
Test Experiments for TOF-USANS Method ……………………………………………………………………………305
K. Aizawa, T. Yokoo and M. Arai
Thermal Neutron Refraction by Neutron Material Prism ………………………………………………………………306
T. Shinohara, K. Hirota, T. Adachi, K. Ikeda, H. M. Shimizu, J. Suzuki and T. Oku
Development of Position-Sensitive Neutron Detectors Based on Scintillator …………………………………………307
K. Hirota, S. Satoh, M. Furusaka and H. M. Shimizu
Development of π and π/2 Flippers with Steady Current for the TOF-NSE Spectrometer ……………………………309
T. Takeda, N. L. Yamada, K. Katoh, M. Nagao, H. Seto, Y. Kawabata, M. Takeda and N. Torikai
Drabkin Aergy Filters as a Chopper for Pulsed Neutrons ………………………………………………………………312
D. Yamazaki, K. Soyama, T. Ebisawa, R. Maruyama and M. Takeda
Development of High-Qc and Curved Neutron Supermirrors …………………………………………………………314
K. Ikeda, H. Sato, S. Morita, H. Ohmori, T. Oku, J. Suzuki, K. Ohoyama, H. Hiraka and H.M. Shimizu
Neutron Spin Manipulation for Neutron β Decay Dsymmetry and T-violating NeutronTransmission Measurements …315
Y. Masuda, V. R.Skoy, T. Ino, S. J Eong and Y. Watanabe
Neutron Studies of High Boron Carbide Content, Resin Bonded, Neutron Shielding Materials: KENS Original
B4C-resin…………………………………………………………………………………………………………318

K. Suzuya, K. Kusaka, S. Torii, S. Harjo, K. Aizawa, S. Sato, T. Kamiyama and M. Arai
Development of Microwave-Induced Optical Nuclear Polarization ……………………………………………………320
S. Muto, T. Ino, M. Furusaka, H. M. Shimizu, H. Sato, T Adachi1 and M. Iinuma
Neutron Resonance Imaging – an Application of Computer Tomography ……………………………………………321
T. Kamiyama, H. Sato, J. Ito, H. Noda, H. Iwasa, Y. Kiyanagi and S. Ikeda
Measurement of Spatial Distribution of Neutrons Penetrating into a Thick Concrete Shield …………………………324
K. Masumoto, Q. Wang, A. Toyoda, N. Nakao, H. Matsumura, M. Kawai and T. Shibata
Measurement of the 36Cl Production Rates from Cl, K, and Ca in Concrete at the 500-MeV Neutron Irradiation
Facility at KENS ……………………………………………………………………………………………………326
T. Aze, M. Fujimura, H. Matsumura, K. Masumoto, N. Nakao, H. Matsuzaki, H. Nagai and M. Kawai
Production Yields of the Radionuclides Induced in Various Targets Fixed in Concrete Shield at the 500-Mev
Neutron Irradiation Facility of KENS ………………………………………………………………………………329
H. Matsumura, N. Nakao, K. Masumoto, K. Oishi, M. Kawai, T. Aze, A. Toyoda, M. Numajiri, K. Takahashi,
M. Fujimura, Q. Wang, K. Bessho and T. Sanami
Development of Resistant Materials to Beam Impact and Radiation Damage …………………………………………334
M. Kawai, H. Kokawa, H. Okamura, A. Kawasaki, T. Yamamura, N. Hara, M. Futakawa and K. Kikuchi

IV. J-PARC
Toward the State-of-art Neutron Facility ………………………………………………………………………………343
T. Kamiyama, T. Otomo, S. Itoh and N. Torikai
Instruments Design Activity of KEK for J-PARC ………………………………………………………………………346
T. Otomo, T. Kamiyama, S. Itoh and N. TorikaiHigh Resolution Chopper Spectrometer at J-PARC ……………………………………………………………………350― ix ―

S. Itoh, T. Yokoo, K. Ohoyama, T. Kamiyama, O. Yamamuro, K. Kuwahara, T. Otomo, K. Nakajima, R. Kajimoto,
K. Tomiyasu and H. Sagehashi
High Resolution Neutron Powder Diffractometers: from HRP, Vega and Sirius to J-PARC Diffractometers …………353
T. Kamiyama, T. Ishigaki, K. Mori, K. Oikawa, H. Stefanus, M. Yonemura, S. Torii, A. Hoshikawa, F. Shikanai,
T. Wuernisha, K. Iwase and Dyah
A Framework Design of Computing Environment for the Material and Life Science Facility at J-PARC ……………358
T. Otomo, T. Nakatani, J. Suzuki, T. Aoyagi, R. Kajimoto, M. Yonemura, T. Ohhara, K. Kusaka, S. Harjo,
K. Nakajima, S. Satoh, N. Kaneko, Y. Kobayashi, S. Kawabata, A. Manabe, S. Torii, T. Uno and M. Arai
Development of Readout Electronics for 3He Detectors at KENS………………………………………………………362
S. Satoh
Ultra-long MicroStrip Gas Counter for Spallation Neutron Source Facilities …………………………………………366
H. Takahashi, P. Siritiprussamee, K. Fujita, H. Niko, S. Kishimoto, T. Ino and M. Furusaka
Development of Readout Systems for Neutron Scintillator Detectors …………………………………………………369
S. Satoh
Development of 100Hz T0 Chopper ……………………………………………………………………………………371
S. Itoh, K.Ueno, R. Ohkubo, H. Sagehashi, Y. Funahashi, S. Koike, M. Kawai, M. Ishihama and N. Hitomi
Concept for T0 Choppers with Magnetic Bearings ……………………………………………………………………373
K. Ueno, S. Itoh, R. Ohkubo, H. Sagehashi, S. Koike, Y. Funahashi, M. Kawai, T. Yokoo and J. Suzuki
Γ-ray Irradiation Properties of Grease and Magnetic Fluid Used in the T0 Chopper …………………………………375
S. Itoh, Y. Funahashi, K. Ueno, M. Kawai, R. Ohkubo and H. Sagehashi
Neutron Optics …………………………………………………………………………………………………………378
M. Furusaka, S. Satoh, N. Torikai and H. M. Shimizu
Spatial Distribution of Neutron Intensity on a Hydrogen Moderator and Neutronics of Methane Hydrate
Moderator Sudied for JSNS………………………………………………………………………………………380

Y. Kiyanagi, S. Ohnuma, T. Kai, T. Kamiyama and F. Hiraga
Benchmark Study of Neutron Beam-line Shields for J-PARC …………………………………………………………383
M. Kawai, K. Saito, T. Sanami, N. Nakao and F. Maekawa
R&D of Fabricating AG-IN-CD Decoupler and CD Poison Plate for Decoupled Moderators of JSNS ………………387
M. Kawai, M. Teshigawara, M. Harada, S. Saito, F. Maekawa, K. Kikuchi, N. Watanabe, Y. Ikeda,
H. Kurishita and A. Chiba
Geometric Effect of Aluminum Wall on Intensity Distribution of Detected Neutrons …………………………………391
K. Tomiyasu and S. ItohV. APPENDIX
List of Publications ……………………………………………………………………………………………………395
Members of Committees ……………………………………………………………………………………………404

―x―

I.
FACILITY REPORT

2003–2006

Overview of the Progress at KENS
S. IKEDA
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research
Organization, Tsukuba 305-0801, Japan

1. Overview
The KEK Neutron Science Laboratory (KENS)
is the world’s first user-oriented pulsed spallation
neutron source. Its construction was completed in
1980, and the ﬁrst neutron beam was produced fromthe neutron source on June 18 of that year. Pulsed
spallation neutrons are produced using 500 MeV
proton pulses with an 80 ns width from the Booster
Synchrotron. The neutrons are then moderated anddelivered to the experimental area, where 15 neutron
spectrometers are installed. In FY2005, the KENS
operation time was 2,635.5 hours (about 110 days).
The KENS tantalum-clad tungsten target for neutron
production was irradiated by 2.0 x 1012 protons per
pulse (ppp) on average. However, the KENS neutron
source was shut down on March 22, 2006. During
these 26 years, the Booster Synchrotron delivered 7.7
x 1021 protons to the Neutron and Muon Laboratory(NML) facility and KENS received 3.8 x 10 21
protons. The history of the average beam intensity
delivered to the neutron and muon experiments areshown in Fig. 1. The closing ceremony of KENS was
held on March 22, 2006, and the Director Generaloffered the letters of appreciation to four B1 groupleaders (Fig.2).

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Fig. 1 History of the average beam intensity.

����Fig. 2 Letters of appreciation are offered to four B1 groupleaders on March 22, 2006.

Inter-University Research Program in KENS isgoing well, and many excellent results are obtained,
although KENS staff number is small. Researchers
from universities and KENS staffs together organizea “Cooperative Research Group” (B1 group) for
each instrument. Now, there exists 13 B1 groups andabout 110 researchers join into those groups. The B1
groups have been performing their own long-term
research projects using about 50% (about 50 days) of
the total beam time for their respective instruments.
They also have responsibility for developing andmaintaining their own instruments, as well as forsupporting groups of pure users (named B2 groups).
A similar system will be adopted in of the Japan
Proton Accelerator Research Complex (J-PARC).
Because of the shutdown of KENS at the end of
FY2005, it was decided that the long-term research
projects of the B1 groups would be completed using
100% of the beam time in FY2005, and B2 proposals
were not accepted in FY2005. The number of annual
proposals during the past 26 years is summarized
in Fig. 3. The research activities of KENS wereparticularly vigorous in FY2005, with the B1 groups
concentrating on completing their long-term research
projects.
3

KENS hopes to support the scientiﬁc activities of
those 100 powerful members who are professional on
pulsed neutron sciences. The activities are very much
important in J-PARC as well as in the world. The
KENS staffs and Japanese users are now facing theserious problem of how to maintain and develop theiractivities until the start of operation of J-PARC in
2008, because there will be no pulsed neutron source
in Japan after the shutdown of the KENS facility.
We are considering several ways, using this externalfund. As one of these, KENS is working to establish
special arrangements with other pulsed neutron
facilities—the ISIS Facility at Rutherford Appleton
Laboratory, the Intense Pulsed Neutron Source(IPNS) at Argonne National Laboratory, and the Los
Alamos Neutron Science Center (LANSCE) at Los
Alamos National Laboratory—in order to supportscientiﬁc activities during this “no pulsed neutrons”
period. This will be an effective way to ensure thatthe necessary number of young persons are available
when starting the operation of J-PARC in 2008.
The KENS staff and major users have succeeded in
obtaining external funding for the 2004-2008 period(Grant-in-Aid for Creative Scientiﬁc Research). The
aim of this funding is to develop new neutron science
as well as new neutron devices under international
collaborations with existing pulsed neutron facilities.
Neutron scattering techniques are being applied inseveral new ﬁelds such as medicine and archaeology
as well as materials science. Also, A new program of“Noah’s ark” has been approved by MEXT and will
be funded in 2006, in which we support the travel
expenses to ISIS, IPNS and LANSCE, and hope totransfer the KENS activities. New 20-40 Japanese
proposals will be submitted to those facilities in one
year.

Annual variation in the number of proposals
300

Rejected

250

B2 accepted
A/B1 accepted

200

150

100

50

0

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

00

01

02

03

04

05

Fiscal year

Fig. 3

4

Number of annual proposals. “A” indicates
proposals for construction and R&D of a new
instrument. “B1” and “B2” are described in the text

A research collaboration was formally establishedbetween KENS and IPNS in October 2000, andthe memorandum of understanding for a researchcollaboration program on battery materials wasrevised in October 2005. Structural studies on
clean-energy materials are being promoted in thiscollaboration. In addition, a research collaboration
between KENS and the Manuel Lujan Jr. Neutron
Scattering Center at LANSCE was formallyestablished in September 2005. The dynamics ofhigh-superconducting-transition-temperature (highTc) superconductors as well as surface structures arebeing extensively studied in this collaboration.
To promote neutron scattering experiments at
ISIS, we have been maintaining the Japan-UK
Collaboration Program on Neutron Scattering.
The MARI and MAPS chopper spectrometers
were respectively constructed in the first phase(1986-1996) and the second phase (1996-2006) of
this program. These are both now the world’s leading
spectrometers. Through the Japan-UK collaboration,
many Japanese scientists have performed worldclass bright measurements on MARI, MAPS, andother instruments at ISIS. A meeting of the review
committee for the Japan-UK collaboration was heldin December 2005, chaired by Professor Y. Endoh.
The committee reported that the results of researchobtained by this project deserve attention and can begiven a high evaluation, because quantitative studies
with high precision have provided new discoveries
and, as a result, a new field of neutron science has
been created.
2. Highlights of Research Programs at KENSa) M a g n e t i s m i n a d - E l e c t r o n S y s t e m w i t hUnquenched Orbital Angular Momentum
A magnetic moment is generated not only
by a spin angular momentum S, but also by anorbital angular momentum L. Therefore, magnetic
excitations in systems with L should provide themost fundamental knowledge on magnetism. One
treats the exchange interaction, HEX, described by
S only, when L is quenched. If L is unquenched, as
in f-electron systems, the total angular momentum,
J = L + S, namely, J and Jz, are regarded as goodquantum numbers owing to a large spin-orbit
interaction, HLS (Fig. 4 (a)). However, d-electron
clouds spatially spread compared to f-electron clouds,
and therefore it is possible that the approximationof J does not apply to d-electron magnets with

comparable, indicating that these interactions must be
simultaneously considered without an approximationof the total angular momentum, J. The lowest two
dispersion curves in Fig. 5 are interpreted as mixing
and splitting between dispersive excitations of Sz(S-mode) and individual excitations of Lz (L-mode).
The present experiments are the ﬁrst observation ofsuch hybridization of the S-mode and the L-mode.
Magnetic Excitations of CoO at 150 K
[00q]

[qq0]

[qqq]

200

200

150

150

100

100

50

50

0

unquenched L, in which the magnitude of HLS canbe close to HEX (Fig. 4 (b)). Since L is quenched inmany d-electron systems, very few such studies havebeen reported. In a system with quenched L, only
one spin wave branch normally exists when one up
moment is included in a magnetic unit cell. In an
early inelastic neutron scattering experiment on thed-electron system with unquenched L using CoO(NaCl-type crystal structure, TN = 289 K), however,two or more magnetic modes were observed. Thissuggests that the freedom of unquenched L of a Co2+
ion plays an important role in magnetism.
In order to survey the physics of L, inelastic
neutron scattering experiments were performed
using CoO in the high-energy-transfer region on
the inelastic neutron chopper (INC) spectrometerat KENS as well as in the low-energy region ona triple-axis spectrometer installed at a steadystate neutron source. In experiments using a singlecrystal sample, dispersion relations of the twomagnetic excitation modes below 70 meV were
determined along the symmetric directions in the
crystal. Moreover, magnetic excitations around
120 meV were also observed, as shown in Fig. 5.
The energy spectra on a powder sample suggest
the existence of higher order magnetic excitations
spreading up to around 200 meV. The magnetic
modes were analyzed in connection with theexchange interaction through S with the freedom ofan unquenched L of a Co2+ ion. It was found that themagnitude of the spin-orbit interaction and that of theexchange interaction obtained from the analyses are

250

250

Energy (meV)Fig. 4 Energy-level schemes of a single-ion state ofa Co2+ ion for HLS >> HEX (a) and HLS ~ HEX (b).
The twelvefold 4 states (orbital-triplet spinquadruplet) are represented by l = -1 (effective
orbital angular momentum) and S = 3/2. The
degree of splitting on the right side in (a) and (b)depends on the magnitudes of HLS, HEX, and theanisotropy energy.

0

0.1 0.2 0.3 0.4 0.5

0.4

0.3

0.2

0.1

Normalized wave vector

000

0.1

0.2

0

Fig. 5 Dispersion relations of magnetic excitations,
measured along the [001], [110], and [111]directions at 150 K in CoO. The solid lines arecalculated dispersion relations, obtained by ﬁtting
the observed dispersion relations.

b) Proton Conduction in Hydrogen-Bonded
Materials
M3X(YO4)2 (M: K, Rb, Cs, or NH4; X: H or D;
Y: S or Se) type hydrogen-bonded materials havebeen the subject of investigations owing to many
interesting phenomena. Most of these materials
undergo phase transition in the high-temperature
region, and show more than 100 times higher
electric conductivity than at room temperature. It
is considered that the higher conductivity is due
to proton transfer. Therefore, these materials haveattracted much attention as solid electrolytes forfuel cells in recent years. K3H(SeO4)2 (abbreviated
TKHSe) undergoes phase transition at 390 K(TC). TKHSe shows high electric conductivityof about 10-4 to 10-2 S/cm in the high-temperaturephase (phase I), and ferroelasticity in the roomtemperature phase (phase II). The crystal structurein phase II is characterized by an isolated SeO4H-SeO4 dimer including a hydrogen bond, and thedimers construct a layered structure parallel to themonoclinic bc-plane. Neutron powder diffraction
measurements were carried out on TKHSe at 413
K and 298 K using the VEGA time-of-ﬂight (TOF)5detailed mechanism of the hydration process isstill controversial. Recently, we have studied thehydration process of Ca 3SiO 5 using the time-offlight quasi-elastic neutron scattering (TOF-QENS)
technique.
Figure 7 shows a TOF-QENS spectrum of
hydrated Ca 3 SiO 5 collected on the LAM-80ET
latticed-crystal analyzer mirror spectrometer
installed at KENS. TOF-QENS experiments canprovide dynamical information on hydrogen or watermolecules. In our analysis of the QENS data, wewere able to separate the signals of the bound water(BW) and the free water (FW) in the total spectrum.
Finally, the ratio of the signal from the BW to thetotal signal (BW + FW) was calculated as the degreeof hydration. Figure 8 shows the degree of hydration
as a function of the reaction time, t. From this result,the consumption of FW can be estimated to be
more than 30% after about 15 hours of hydration,
after which the hydration rate exhibits an obvious
decrease. Thus, TOF-QENS is an excellent method
for evaluating the hydration rate of cement throughthe dynamics of water molecules in concretematerials.

150
I (arb. unit)

neutron diffractometer. The crystal structures andnuclear density distribution maps were obtained by
the Rietveld method and maximum entropy method(MEM). In phase II, two SeO4 tetrahedra construct
a dimer linked by a hydrogen bond. About 87.3%of the protons are localized around the hydrogenbond region (area A in Fig. 6). On the other hand, inphase I, a SeO4 tetrahedron is linked to the nearest
three equivalent SeO4 tetrahedra with a probability of
1/3. The oxygen atoms are displaced into triangular
positions from their mean structure sites with an
occupancy of 1/3. In terms of interatomic distances
related to the hydrogen bonds and SeO4 tetrahedra,
the arrangements in both phases are almost identical.
This fact suggests that two SeO 4 tetrahedra areconnected by a hydrogen bond even in phase I, andthat the crystal structure in phase II remains locally.
The number of protons for a hydrogen bond declines
from 87.3% to 21.4% with increasing temperature.
It was found that only 64.2% of the protons exist
around the hydrogen bond (in the inside of the layerarea), and that 13.4% of the protons move mainly
into the inter-SeO4 layer space (area B in Fig. 6), in
which the proton never has a place in phase II. These
results show that the crystal has Frenkel defects inphase I, and the protons in the interlayer space areconducting protons. The density of the proton was
estimated as 6.08 x 10-20 cm-3 at 413 K using the unit
cell volume.

~ 14 h

100
50
0

-0.2
0.0
0.2
Energy transfer (meV)Fig. 7 TOF-QENS spectrum of hydrated Ca3SiO5 after
14 h of reaction.

c) Hydration Properties of Cement
Concrete is an important building material due to
its relatively high compressive strength, durability,
and low cost. The properties of concrete strongly
depend on those of hydrated tricalcium silicate(Ca3SiO5), because it is a principal component of
cement. Although extensive studies of hydrated
Ca 3SiO 5 have been performed, it seems that the6

1.0
Degree of hydration

Fig. 6 Proton distributions obtained by MEM analysis: (a)298 K in phase II, and (b) 413 K in phase I.

0.8
0.6
0.4
0.2
0.0
0

40

80
Time (h)120160Fig. 8 Time dependence of hydration rate of hydrated
Ca3SiO5.

d) Dynamics and Structure of Confined Water in
Nanoporous Silica (FSM-16)
Mesoporous silica with a hydrophilic surface,such as FSM-16 or MCM-41, can adsorb and desorb
water molecules into nano-sized pores dependingon the water vapor pressure. The dynamics andstructure of water molecules in confinement havebeen extensively studied both theoretically andexperimentally, because they are believed to strongly
affect the properties of the pore surface such as thesurface form, the surface electric charge density, andhydrogen bonding to the water molecules.
Dynamical and static structural measurements byneutron scattering were performed with our in-situ
measurement system, which can control the amountof water absorption by monitoring the water vapor
pressure. The diffusion constants of water confinedin FSM-16 pores were measured by quasi-elastic
neutron scattering (QENS) measurement using
the AGNES instrument at the University of Tokyo
at JRR-3M. It was found that water confined in apore can be divided into water on the pore surface(monolayer water) and other water near the center ofthe pore (capillary-condensed water); the mobilityof water on the surface is about one-third that of thewater near the center, and the water near the centerhas almost the same mobility as bulk water. Figure
9 shows the water-vapor pressure dependence of
QENS spectra for FSM-16 at Q = 1,67 Å-1. Static
structure measurements by the small/wide-angle
neutron scattering instrument (SWAN) and HIT at

S(Q, ) (arb. unit)

1.0

0.5

0
-2.0

a
b
c
d
e
f
g

P/P0
0.00
0.19
0.43
0.51
0.56
0.60
0.68
vanadium-1.0-1

Q = 1.67 Å

0

1.0

2.0

E (meV)KENS showed clear crystallization of capillarycondensed water to the Ih phase, whereas no
crystallization behavior was observed in monolayerwater. These results suggest that water on the poresurface is different from bulk water. Details of wateralignments including the water density in nanopores
are under investigation.
e) Abnormal Protein Aggregation and Cell Death
The molecular shape of proteins and the formationof polymeric structures of their self-assembled
bodies and aggregates can seriously damage a cell,since the abnormal aggregation of proteins typicallyobserved in Parkinson’s disease (PD) and Alzheimer’s disease (AD) has been suggested to be a cause of
neuroﬁbrillar degeneration and eventually cell death.
In normal neuron cells, tau stabilizes
axonal microtubules, which are the tracks for
intracellular trafﬁc. In AD, tau becomes abnormallyphosphorylated, aggregates into paired helicalfilaments, and loses its ability to maintain the
microtubule tracks. Two types of tau isomers aremainly expressed in neuron cells. One is 4-repeat tau(47KDa) containing two cysteine residues, and theother is 3-repeat tau (43KDa) containing one cysteine
residue, which is often observed on the aggregatesin neuron cells in AD. We synthesized two types ofhuman recombinant human tau. Both tau molecules
aggregate and form a multimetric cluster by selfassembly, and mono-disperse in water without
intermolecular cysteine linkage. The cluster sizeof 4-repeat tau is smaller than that of 3-repeat tau
although the molecular size of 4-repeat tau is larger(Fig. 10). First, we studied these structures in waterby small-angle neutron scattering (SANS), without
the addition of phosphorylation and oxidative stress.
Interestingly, the SANS profiles indicate that a
4-repeat tau cluster consisting of several thousand
monomers may form a rotating rod-like ellipsoid (a =100 Å, b = c = 542 Å), whereas 3-repeat tau may be
a larger aggregate of random coils. We clariﬁed that
normal tau proteins liberated from the microtubule
form a huge cluster in water by self-assembly. The
cluster forms of 4-repeat and 3-repeat tau were quite
different. This structural difference may inﬂuence thevarious modifications, such as phosphorylation andoxidation.

Fig. 9 Water-vapor pressure dependence of QENS
spectra for FSM-16 at Q = 1,67 Å-1. The monolayer
region is P/P0 < 0.45. The width of each spectrum
corresponds to the water mobility.

7Fig. 10 Primary structures of normal type tau (4-repeat)and AD type tau (3-repeat), and their cluster
structures in water.

f) Applications to Archaeology
Studies on archaeology have started under acollaboration between KENS and the National
Museum of Japanese History, opening up a newresearch ﬁeld in interdisciplinary studies on neutron
scattering. The crystal grain orientations of inclusions
in the barrels of matchlock guns in the Edo Period(1603-1867) were investigated using the SIRIUS
neutron powder diffractometer at KENS.
After matchlock guns first arrived in westernJapan in 1543, the number of guns manufactured inJapan drastically increased with the intensificationof wars during that era. Following this time of
conflict, when stability returned to society in the
Edo Period, the manufacturing and use of such guns
continued until the 19th century. From the directionof extended inclusions, which can be observed byscanning electron microscopy (SEM), these guns are
generally divided into two groups. The characteristicof the samples in group 1 is that the inclusions
extend along the long axis of the barrel, while thatof the samples in group 2 is that the inclusions
extend in a direction oblique to the barrel axis. Fromstudies of old documents of some gunnery schools,
the guns in group 1 are thought to correspond tothe manufacturing method called udon-bari, or
lengthways forging. This method involves rolling along and narrow extended iron plate vertically arounda rod, and welding the joint with forging. The gunsin group 2 are thought to correspond to the method
known as maki-bari, or coiled forging, in which longand narrow iron plates are coiled slantwise over acylinder made by the udon-bari method. As a result,
two layers are formed in the maki-bari method tomake the barrel thick and tough.
Texture analyses of such guns were carriedout by neutron diffraction experiments. Figure 11
shows samples of the matchlock guns. By neutron
diffraction, the distribution of the crystal grain
8

orientation can be observed over the inside of thesample. From the texture analysis of a sample gunthat is known to have been made by the maki-barimethod, it was found that the stress distribution
extended in a direction oblique to the barrel axis.
This result was in good agreement with that of
SEM, even over the inside of the barrel. In SEM
experiments, since it is necessary to remove ruston the barrel surface and to polish the surface to amirror surface, there is the problem of harming theappearance of samples. However, neutron diffraction
is completely nondestructive. The present experiment
therefore showed that neutron diffraction is effective
for the investigation of valuable samples that cannot
be investigated by other, conventional techniques.

Fig. 11 Samples of matchlock guns from the Edo Period
studied by neutron diffraction (courtesy of the
National Museum of Japanese History).

3. Highlights of International Collaborationsa) ISIS – High-Energy Spin Fluctuations inElectron-Doped High-Tc Superconductor
Carrier-type symmetry of the pairing mechanism
is one of the central issues in research on high-Tc
superconductivity. A number of experiments in thehole-doped system have revealed an intimate relation
between magnetism and superconductivity in high-Tc
cuprates. Since the electronic phase diagrams of holeand electron-doped systems are similar, magnetism
is now widely believed to play a universal role in thepairing mechanism. To date, however, there has beena lack of key experiments on electron-doped systems
due to the difﬁculty of preparing high-quality single
crystals.
We have recently succeeded in growing large

single crystals of electron-doped Pr1-xLaCexCuO4 andobserving magnetic signals up to
180 meV on the
MAPS chopper spectrometer at ISIS. At all of themeasured values of , a single peak centered at the(, ) reciprocal position was conﬁrmed. Furthermore,as shown in Fig. 12, data analysis revealed a drastic
decrease of ”( ) with increasing , following nowell-deﬁned magnetic signal at 60 meV. However,a magnetic peak reappeared beyond c 100 meV.
On the other hand, below 60 meV, the peak width
broadened as increased, while in the highenergy region above 100 meV, weakly depended
on . The spin excitation spectrum differs fromconventional spin-wave excitation, although thepresent Pr 0.89LaCe 0.11CuO 4 has a phase boundary
located between the antiferromagnetic ordered andsuperconducting phases, but is similar to that ofmetallic antiferromagnets.

Fig. 12 Energy dependence of (a) the resolutioncorrected peak widthand (b) the local
susceptibility ”( ) for Pr0.89LaCe0.11CuO4.

b) LANSCE - Dispersive Spin Excitations in
Underdoped High-Tc Superconductor
Superconductivity appears when carriers are
doped into insulating parent compounds of highTc cuprates, and it coexists with antiferromagnetic
fluctuations. To clarify the mechanism of highTc superconductivity, it is most important tounderstand the motion of carriers and spins. Recent

neutron scattering experiments using the MAPS
chopper spectrometer at ISIS have revealed similar”
hourglass-like” spin excitations in monolayered
La2-xBaxCuO4 (LBCO) and bilayered YBa 2Cu3O6+x(YBCO). The spin excitations are observed asfour incommensurate peaks in a constant energy
plot at low energy and disperse inwards toward an
antiferromagnetic zone center QAF (0.5,0.5,L) as
energy increases. At a characteristic energy, whichcorresponds to 50 meV, a single peak is found at
QAF. At higher energies, the excitations disperse
outwards and form a square-shaped continuum.
These results indicate that such hourglass-like
dispersive excitations might be common to high-Tc
cuprates. However, the microscopic nature of spincorrelations and their contributions to the high-Tc
pairing mechanism are still not clear.
In order to elucidate the interplay between thehourglass-like spin excitation and superconductivity,
we investigated the hole-doping dependence ofspin excitations. We performed neutron inelastic
experiments for underdoped La2-xSrxCuO4 (LSCO)
with x 0.10 (Tc 29 K) using the Pharos chopper
spectrometer at LANSCE and the TOPAN tripleaxis spectrometer at JRR-3M. Large single crystals
were grown using the traveling-solvent floatingzone method, and we mounted crystals with a
total weight of 40 g. As seen in Fig. 13, four clear
incommensurate peaks are observed at
8 meV
and the incommensurability corresponds to
0.1 rlu (reciprocal lattice unit), which is consistent
with the result of our previous study. At higher
energies, these satellite peaks come close together,indicating that the hourglass-like excitations exist
even in underdoped LSCO, and the convergencepoint is estimated to 30 meV. For optimally doped
La1.84Sr0.16CuO4 (Tc 38 K), the gathering point is
expected to correspond to 40 meV or more. These
results suggest that the gathering point becomes
lower with increasing hole doping. Moreover, wefound that the slope of dispersion is almost the samefor both x = 0.10 and 0.16. Thus, the shift of thegathering point is recognized as a consequence of thedifference in incommensurability.
In the present study, we first observed how thespin excitations change with hole doping in LSCO.
As mobile holes are doped, although the period of
the spin density wave becomes small, its velocity
remains almost unchanged. We believe that further
systematic studies will reveal the relation between
spin dynamics and high-Tc superconductivity.

9Fig. 13 (Left) Constant energy plot of incommensurate peaks at = 8 meV. (Right) Dispersion of magnetic excitations in
La2-xSrxCuO4. The red symbols represent our results for underdoped La2-xSrxCuO4 with x = 0.10 using Pharos (solid
circles) and triple-axis (open circles). The black symbols correspond to the data obtained by Christensen et al. for
optimally doped x = 0.16.

10

and cations at the A site (A-O bond) to the averageinteratomic distance between the oxygen and cations
at the B site (B-O bond). This factor is considered
to determine the structural and magnetic phasetransitions of this material. The experiment was
carried out at room temperature and 50 K, with thepressure changed from ambient to 80 Kpsi at eachtemperature. By analyzing the data using the Rietveld
method, it was found that A-O and B-O bonds
contract at the same rate with changing pressure.
That is, the tolerance factor was unexpectedly found
to remain unchanged within this pressure range atboth temperatures.
3.970

0.90

Lattice constant(deoxidizing)
Lattice constant(reoxidizing)
Oxygen occupancy(deoxidizing)
Oxygen occupancy(reoxidizing)

3.968

0.88

Lattice constant(A)

0.86
3.966

0.84

3.964

0.82
0.80

3.962

Oxygen Fractionc) IPNS – Structural Analysis of Clean-Energy
Materials
The perovskite oxide material La0.2Sr0.8Fe0.8Cr0.2O3-δwas studied in a reducing and oxidizing atmosphereby the neutron powder diffraction method using
the general purpose powder diffractometer (GPPD)
at IPNS. This material shows ionic conductivity athigh temperature and is one of the candidates forapplication to an oxygen separation membrane andelectrode for a solid-oxide fuel cell. It was foundthat changes in the oxygen occupancy and thelattice constant with respect to the oxygen partialpressure show hysteresis-like behavior (Fig. 14).
Furthermore, the lattice constant was found tocontract in the region of log(pO2) < -4 as the oxygen
partial pressure is reduced. This behavior is unusualand not understandable by considering the change
in the radii and the oxidization states of the cations.
The nuclear density distribution obtained by the
maximum entropy method revealed unusual trendsof the atomic distributions suggesting the diffusion
paths of the oxygen and the cations (Fig. 15).
A high-pressure experiment was carried out
on Sr 0.7 Ca 0.3 MnO 3 , using a helium gas drivenhydrostatic high-pressure generator system on thespecial environment powder diffractometer (SEPD)
at IPNS. The aim of this experiment was to observe
the pressure effect on the structure and to explore
new phase transitions. One important factor is thetolerance factor, which is deﬁned as the ratio of theaverage interatomic distance between the oxygen

0.78
3.960

0.76

3.958

0.74
-14

-12

-10

-8

log(pO2)

-6

-4

-2

Fig. 14 Change in the lattice constant and oxygen
occupancy with respect to the oxygen partialpressure.

Fe/CrLa/SrO

Fig. 15 Structure of La0.2Sr0.8Fe0.8Cr0.2O3- and the nuclear
density distribution obtained by the maximum
entropy method.

4. JSNS Facility at J-PARC
KEK and the Japan Atomic Energy Agency(JAEA) are constructing 10 instruments for day
one of proton beam injection. KENS has the role ofrealizing instruments for the Inter-University User
Program at J-PARC, and is responsible for building
four of the 10 instruments for day-one operation
at the Japanese Spallation Neutron Source (JSNS).
These four instruments are the super-high-resolution
powder diffractometer (SHRPD), total scattering
instrument (SQI), horizontal reflectometer (REFL),
and high-resolution chopper instrument (HRC).
KENS originally proposed a budget for the neutron
instruments in J-PARC. However, this proposal was
postponed to the second phase of the J-PARC project,and no budget for neutron-related matters has been
allocated to KENS, while a budget for the neutron
target station and facility construction were allocatedto JAEA. This is a serious deﬁciency of the projectbudget scheme. The KENS International Review
took place in June 2004. Regarding this serious
deﬁciency, the committee concluded as follows: The
Proton Synchrotron (PS) complex in KEK was shut
down in March 2006. Along with this shutdown,
KEK should request a new budget to move thepresent KENS activities to J-PARC. By spending apart of this new budget and by utilizing the existing
KENS instruments, KENS should construct the mainparts of the aforementioned four instruments by
the end of 2007. The new budget was successfully
realized in FY2005, and construction of the mainparts of the four instruments has started.
Development work has been continuing on
innovative devices for the realization of the highprecision experiments at J-PARC; namely, the 3He
polarized neutron spin filter, proton spin filter,
sample nuclei polarization device, multigrid typemicrostrip gas counters, and object-oriented analysis
environment for neutron scattering experiments. The
design work for the four instruments as well as thedevelopment of neutron choppers is being performed
under a collaboration between KENS and the KEK
Mechanical Engineering Center. Among these
activities, development of the T0 chopper under thecollaboration is described here.
High-energy neutrons generated when the
proton beam is incident on the neutron target create
background noise by scattering and thermalizationin the spectrometer. A T0 chopper is a device toreduce such background noise by shutting theneutron beam line at the incident time (T0) witha rotor made from a shielding material for highenergy neutrons. It is necessary to synchronize therotation to the repetition of the accelerator (25 Hz for
J-PARC). To utilize higher energy neutrons on the
spectrometer, the time for shutting the neutron beamline needs to be shorter. To utilize 2 eV neutrons
with a beam cross section of 80 mm 80 mm, we
designed and assembled a T0 chopper rotating at
100 Hz with a rotational radius of 300 mm. If thisT0 chopper is installed at a distance of 8.5 m fromthe neutron source, high-energy neutrons up to 2 eV
can be utilized. The dimensions of the chopper blade(shielding part) on the rotor of the T0 chopper were
determined to be 82 mm 82 mm 300 mm (300mm is the length along the beam) with a margin of ±1 mm. This margin corresponds to the phase control
accuracy of ±5 s. The rotor material chosen was
Inconel X750 due to its mechanical properties as wellas radioactivation properties. In the present design,
we assumed a continuous running time of 1,000
hours (corresponding to the length of the beam time)and an annual running time of 4,000 hours at 100
Hz rotation as a reasonable maintenance period. The
observed rotational fluctuations were well satisfied
with the requirement of ±5 s, and the vibrational
level at various parts of the T0 chopper was
reasonably good. In order to conﬁrm the lifetime ofthis device, a dry-run test was performed and a total
running time of 4,648 hours was recorded. Moreover,
1,529 hours of continuous running time was recorded.
However, the lifetime of the magnetic seal, which
is a part that transfers the rotation from the motor
11

outside the vacuum chamber to the inside rotor, waslimited to approximately 2,500 hours during the total
running time. Therefore, only the magnetic seal did
not satisfy the speciﬁcations for the annual running
time. Changes in the magnetic circuit as well as thevapor pressure of the magnetic ﬂuid were proposed
to increase the lifetime of the magnetic seal. Afterinstallation of the improved magnetic seal, thelifetime of the T0 chopper will be confirmed next
year. A control circuit was developed to reduce therotational fluctuations in the synchronization to theexternal timing signals simulating the accelerator
timing. Figure 16 shows the rotational fluctuations
observed with and without the control circuit.
The reduction of the rotational fluctuations was
greatly improved to ±1 s. A mounting/dismounting
mechanism was also designed. The T0 chopper will
be installed in a tiny space under heavy shielding.
The base plate will be ﬁxed on the ﬂoor, and coolingwater and electricity will be supplied to the T0
chopper from the base plate. When the T0 chopper isplaced on the base, cooling water and electricity will
be connected automatically. The important parts arelocated on the rotational axis at a distance of 300 mm
from the neutron beam line. At this position, theray is dominant and the absorption dose is calculated
to be on the order of 1 kGy/yr. An investigation onradiation damage to the parts in the T0 chopper has
started.

1
Number of events

ON
OFF

0

-5

0

5

Deviation from target timing ( s)Fig. 16 Rotational ﬂuctuations in the T0 chopper with (ON)and without (OFF) the control circuit. The numberof events normalized by the maximum number
is plotted as a function of the deviation from thetarget timing.

12

5. Neutron Optics
We are systematically developing neutron optic
devices and their applications with the aim of
opening up new possibilities for neutron scatteringexperiments. One of the straightforward applications
is the “downsizing” of neutron experiments in which
the capability to analyze tiny samples or tiny regionsof samples is achieved by realizing (1) a good
beam with optimal beam focus, beam divergencesuppression, and neutron spin polarization; (2)sophisticated neutron analysis with direct kinetic
energy determination and neutron spin analysis; and(3) instantaneous fine images with time-resolved
neutron imaging detection. The downsizing of sample
sizes will drastically expand the application fields.
A downsized sample makes it possible to shrink the
distance between the sample and the detector whileachieving the same angular resolution, to downsize
the dimensions of the neutron spectrometer, andto reduce the cost and period of development.
Downsizing of the neutron spectrometer requires
better position resolution for the neutron detector.
The improved neutron detector will increase theangular resolution if used in neutron spectrometerswith the conventional dimensions. Such a chain
reaction of R&D will accelerate innovation and open
up new ﬁelds of neutron scattering experiments.

Fig. 17 Refraction by a neutron microprism. The wavelength dependence data shown here were observed at KENS.

13

Beam-line Operation
S. MUTO, H. FUJIMORI, N. KANEKO, T. TAHARA and Y. KOBAYASHIHigh Energy Accelerator Research Organization, Tsukuba 305-0801
Summary of the NML operation

Development of new beam monitors

Figure 1. shows a summary of the NML
beam-line operation from April, 2003 to March,
2006. Total operation time was 16926.3 hours.
The average beam intensity delivered to the neutron
and meson experiments was 2.1 x 1012 particle parpulse (ppp) and number of protons was 1.1 x 1021.

Collaboration with the accelerator division, newtype of beam profile monitors have developing forhigh intensity hadron accelerators, such as J-PARC.
One of these monitors, a 2-dimensional beam profile
is observed by using a dense gas-sheet target. The
profile monitor was installed in the beam-line, andhas checking its specifications.

Total Operation Time:
Beam-line
51.0 hrs
0.30 %

Meson
7905.8 hrs
46.71 %

Beam Stop
1036.2 hrs
6.12 %

Finish of the NML operation

User's Reject229.5 hrs
1.36 %

Since June 18th, 1980, the beam-line has been
operated. In 9 a.m. at March, 31st, 2006, thebeam-line has finished the proton beam transport tothe meson experiments and close its operation.
The beam-line operation results statistics are shownin Table 1 for operation time and in Table 2 fordelivered proton number, respectively.

Beam-line Trouble
53.4 hrs
0.32 %
Accelerator Stop
725.0 hrs
4.28 %

Neutron7933.3 hrs
46.87 %

Others28.3 hrs
0.17 %

Figure 1. Summary of the NML operation time from
April, 2003 to March, 2006.
As for the history of the average proton beam
intensity in Fig.2, it was well keeping the average
beam intensity of 1.8 to 2.1 x 1012 protons par pulse(ppp) from FY1999.

11

Meson Intensity
Neutron Intensity
Total Protons

20

15

4000

18

10
2000
5

0
1980

1985

1990

1995

Year

2000

2005

Meson
39861.0
Medical8826.3
DUMP exp.
156.3
Beam-line
113.2
Beam-line Trouble
576.5
Others5792.5

(%)
100.0
41.93
41.84
9.26
0.16
0.12
0.61
6.08

Total
NeutronMeson
MedicalDUMP exp.
Beam-line

Protons7.7490 x 1021
3.8332 x 1021
21
3.8267 x 10198.8833 x 10
x 10173.25
x 10175.30

0Figure 2. Average beam intensity and total numberof protons delivered to the neutron and meson
experiments.

14

NeutronToatal Time (h)95279.939954.1

Table 2. Summary of protons

6000

Total Protons (10 )Proton Beam Intensity (10 ppp)

25

ScheduledBeam-ON

Beam-STOP

8000

30

Table 1. Summary of operation time

Total beam stop time coursed by beam-line
trouble is 576.5 hours, and is 0.61 % in total
operation of 26 years since 1980.

Scientific Review on KENS,KEK and P3IB, BATAN Research Collaboration
E.KARTINI and T.KAMIYAMA*
Technology Center for Industrial Nuclear Materials, National nuclear Energy Agency (BATAN),
Kawasan Puspiptek, Serpong, Tangerang 15314, Banten, Indonesia.
*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
The research collaboration between the Neutron
Science Laboratory (KENS), KEK, Japan and the
Research Center for Materials Science andTechnology (P3IB), BATAN, Indonesia has been
started since 2001. It was began, when a scientist
from BATAN Indonesia, Dr. E. Kartini was invitedby Prof. Dr. T. Kamiyama to KEK, under the
MOMBUSHO fellowship program for 6 months toperform joint research on the superionic materials.
The neutron measurements were performed by a
HIT-II spectrometer that was dedicated for liquidand amorphous materials. The results were
presented respectively at the International LAM XII
conference, Yokohama, Japan; ICNS 2001, Munich,Germany and at the IPN meeting, Oct.2003, Japanand several international conferences in Indonesia.
The results were published in several international
journals [1-10].
The collaboration has been followed up officially.
A memorandum of understanding [MoU] between
KENS, KEK and P3IB, BATAN, has been officiallysigned in June 2003 by Prof. S.Ikeda, a Head of
KENS and Drs.. Gunandjar SU, a Director of P3IB.
For the implementation of the KEK-BATAN
joint research, several activities have been
performed. (i) A scientist from BATAN, Dr. Agus
Purwanto has been invited to KEK as a visiting
scientist of MOMBUSHO for a year from June 2003
to May 2004. The topic of his visit was onsuperionic conductors, magnetic materials andcrystallographic. VEGA instrument has been used
for the experiments on superionic conductor andmagnetic materials. A second visit, was in February
to March 2005 to develop software of TOF neutron
powder diffraction analysis. There are 5
international publications published during thosevisits [11-15]. The later, was presented at the ICNS
2005, Sydney, Australia. (ii) A student fromBATAN, Dyah Sulistiningtyas, was sent to KEK, topursue a PhD degree at SOKENDAI under thesupervision of Prof. T. Kamiyama. She received a
MOMBUSHO scholarship for 3.5 years, since April
2004. Now she is in the last year of finishing her

PhD thesis. A paper has been presented at the 6th
National Seminar on Neutron and X-ray Scatteringin Serpong, 2005 [16].
(iii) In February 2004, Prof. Susumu Ikeda and Prof.
T. Kamiyama have visited BATAN and discussed
about the collaboration with Prof. Dr.Soedyartomo
Soentono and Dr. Pramudita Anggraita, a Director
General and Deputy of BATAN, respectively.
(iv) In November 2004, Dr. Ridwan, a former headof Advanced Materials Division, BATAN has
visited KEK for a week to discuss the ongoingcollaboration.
(v)A new collaboration on the dynamic properties
on superionic conducting glasses has been started
since 2003 among Prof. Masatoshi Arai from KENS
with his group with, Dr. E. Kartini from BATAN
and also involving scientists from UK and Germany.
Series of neutron inelastic experiments have been
performed several times using a MARI instrument,
ISIS, UK and a V3 time of flight spectrometer,
BENSC, HMI, Berlin, Germany, respectively in
September 2003, March 2005 and June 2005. The
samples were prepared at both BATAN and KENS.
Some of the results have been presented at the
QENS and ACNS in France and USA, respectively
in 2004 [17,18]. Two papers were presented at theInternational Workshop on Complex system, Sendai,
Japan [19,20] and four papers were presented at the
ICNS, Sydney, Australia in 2005 [21-24].
After a highly competitive selection, in 2005, aninternational joint research proposal for IndonesianInternational Joint Research Grant Program (RUTI
IV) entitled “ Research and Development of New
Solid Electrolyte for a Rechargeable Battery ” hasbeen approved by the Ministry Research andTechnology, Indonesia, to support the Indonesian
researcher on performing experiment and attending
the international conference abroad. The RUTI
program is involving all the international members,
and some more Indonesian scientists. Dr. E.
Kartini was assigned as a research coordinator,
while Prof. T.Kamiyama as the international
research coordinator. It can be concluded that the15

KEK-BATAN collaboration has become broaden
and given benefits for all parties. We expect in the
future, more scientists and students can involve inthis joint research.
REFERENCES(publications of Joint Research KEK-BATAN)
1) E.Kartini, S.J. Kennedy, T.Sakuma, K.Itoh,
T.Fukunaga, M.F. Collins, T. Kamiyama, S.
Suminta, A. Sugiharto, E. Musyafaah, P.Bawono,
J. of Non-Crystalline Solids 312-314 (2002)633
2) E.Kartini, M.F. Collins, C.C. Lovekin, E.C.
Svensson, S. Suminta, E. Musyafaah, J. of
Non-Crystalline Solids 312-314 (2002)628
3) E.Kartini, S.J. Kennedy, K. Itoh, T. Fukunaga, S.
Suminta, T. Kamiyama, Applied Physics A(2002)s1236
4) M.F. Collins and E. Kartini, in Book Recent
Research Development of Solid State Ionics
1(2003) 157-174
5) E.Kartini,
S.J.
Kennedy,K.
Itoh,T.Kamiyama,.M.F. Collins, S. Suminta, Solid
State Ionics 167 (2004)65-71
6) E.Kartini, M.Arai, H. Iwase, T.Yoko,
T.Kamiyama, K. Itoh, M. Sonobe, S. Purnama,J.of Neutron Research vol. 13, No. 1-3(2005)145-149
7) E.Kartini, T. Sakuma, A. Purwanto, M.F. Collins,
T. Kamiyama, to appear in Journal of Atom
Indonesia (2005)
8) E. Kartini, S.J. Kennedy, T. Sakuma and M.F.
Collins, in Proc. 2nd Asian Conference on
Materials Science and Technology, August
2005,p.49-63, Jakarta, Indonesia
9) E.Kartini, International Seminar on Microscopy
Electron, September 2005, Bogor, Indonesia.
10) E. Kartini, in Book Toward Bright and Brilliant
Indonesia (2005), 296-331, LIPI, Press, Jakarta.
11) A. Purwanto, E. Kartini, T. Kamiyama, A.
Hoshikawa,S. Harjo, M. F. Collins,
S.
Purnama Solid State Ionics, vol. 171, issues 1-2,
30 June (2004)113-119
12) A. Purwanto,T. Kamiyama,A. Hoshikawa,S.
Harjo,E. Kartini,M. F. Collins,T. Sakuma., J.of
Neutron Research vol. 13, No. 1-3(2005)169-173
13) A. Purwanto, E. Kartini, T. Sakuma, M. F.
Collins, T. Kamiyama, Materials Research
Bulletin, vol. 40, (2005)47-54
14) A. Purwanto, E. M. Fransisika,T. Kamiyama, S.
Harjo, M. Yonemura, ICNS2005, Sydney
Australia and to appear in Physica B

1615) A. Hoshikawa, T. Kamiyama, A. Purwanto, K.
Ohishi, W. Higemoto, T. Ishigaki, K. Inoue, H.
Imai, Journal of the Physical Society ofJapan,Vol. 73,No.10, (2004)2597-2600
16) D. Sulistyanintyas, T. Kamiyama, K. Itoh, S.
Harjo, M. Yonemura, K. Mori, F. Shikanai, R.
Kiyanagi, K. Iwase and T. Wuernisha,
Proceeding The 6th National Seminar on Neutron
and X-ray Scattering, Indonesia (2005) 146.
17) E.Kartini, M. Arai, H. Iwase, S. Bennington, M.F.
Collins, S.J. Kennedy, American Conference on
Neutron Scattering, June 6-10, 2004, Maryland,USA18) H.Iwase, M.Arai, E. Kartini, T. Otomo, K. Itoh,
S.J. Levett and S.M. Bennington, Quasi Elastic
Neutron Scattering Conference, Sept.2004,
France and to appear in Journal of Chemical
Physics19) M. Arai, H. Iwase, E. Kartini, T. Otomo, S.J.
Levett, S.M. Bennington, M. Nakamura,International Workshop on Complex System,
Nov.2005, Sendai, Japan
20) M.Nakamura, M.Arai, E.Kartini, J.W.Taylor,
M.Russina, International Workshop on Complex
System, Nov.2005, Sendai, Japan21) E. Kartini, S.J. Kennedy, K. Itoh, M. Arai, F.
Mezei, M. Nakamura, International Conferenceon neutron Scattering (ICNS), Nov.27-Dec.4,
2005, Sidney, Australia and to appear in PhysicaB22) M. Nakamura, M. Arai, H. Iwase, E. Kartini, J.
Taylor, M.Russina, International Conference on
neutron Scattering (ICNS), Nov.27-Dec.4, 2005,
Sydney, Australia and to appear in Physica B
23) M. Russina, M. Arai, E. Kartini, F. Mezei, M.
Nakamura, International Conference on neutron
Scattering (ICNS), Nov.27-Dec.4, 2005, Sydney,
Australia and to appear in Physica B
24) Rhet Magaraggia, S.J. Kennedy, T. Tedesco, E.
Kartini, M.F. Collins, K. Itoh, International
Conference on neutron Scattering (ICNS),
Nov.27-Dec.4, 2005, Sydney, Australia and to
appear in Physica B

Research and Development of New Solid Electrolyte for Rechargeable Battery

Indonesian International Joint Research Program (RUTI)
E.KARTINI and RUTI TeamTechnology Center for Industrial Nuclear Materials, National nuclear Energy Agency (BATAN),
Kawasan Puspiptek, Serpong, Tangerang 15314, Banten, Indonesia

17Introduction
This report is a review about the‘Research and Development of New
Solid Electrolyte for a Rechargeable
Battery ” that has been developed by theauthor and co-workers. There are twomain objectives of the research, first is to
explore the microscopic behavior of thesuperionic glass by several different
methods, and second is to apply thematerial for a solid state electrolyte in a
rechargeable battery. The basic idea of
why superionic glass is an interestingmaterial for solid state battery will befirst explained, followed by the glass
formation and development of superionicglasses. The glass formation andelectricalpropertyhave
beencharacterized by an X-ray diffraction, and
Impedance spectroscopy, respectively.
The exploration of science behind thismaterial by using neutrons as probe
becomes the key for understanding theionic conduction mechanism. This part
covers the use of neutron in many
international facilities (Canada, Japan,
UK, Germany and Australia). The
development of superionic glass for solid
electrolyte becomes important aspect of
this material. The glass will be used as asolid electrolyte in a rechargeable battery.
For most of the research on superionicglasses have been published by author
and co-workers in many international
journals and presented at many
international conferences all over theworld [1-29].

through their structure, leading to
exceptionally high values of ionic
conductivity whilst in the solid state. Thisbehavior typically occurs at elevatedtemperatures and as common for a first
type superionic, like AgI, Ag2S etc. The
ionic conductivity of AgI increases by
three orders of magnitude whentransform from β at 147 oC [1]. Atroom temperature, -AgI with the FCC
structure is more stable, but it has very
low conductivity of about 10-6 S/cm.
With the idea to depress the  βtransformation or to stabilized -AgI at
room temperature, the material was
mixed with the second component, like insilver iodide silver oxysalt glass AgIAg2O-P2O5. The molten mixture was thenquenched to arrest to high -AgI phase in
the glass framework. Figure 1 shows thesuperionic glasses, resulted from the melt
quenchingmethod.
These
glassyelectrolytes are interested because they
offer
many
advantages
overpolycrystalline or ceramic electrolytes,
including no grain boundaries, easy of
fabrication, low melting point and highionic conductivity at room temperature
and wide compositional ranges [ 1-3].

Superionic Conductors

A glass formation has been confirmedby the X-ray diffraction and occurs forthe mixture with less AgI content, but
above the solubility limit (~ 57 mol%
AgI), it turns to a composite-glass, like in(AgI)0.7(AgPO3)0.3 as shown in Figure 2.

Superionic conductors are of interest
from both a technical and fundamental
point of view. The materials with ionic
conductivity of at least 10-2 S/cm have anumber of possible technologicalapplications ranging from batteries andfuel cells to sensors. The materials allow
the macroscopic movement of ions18

Figure 1.Superionic GlassKinetic Study of Superionic Glass

700
600(AgI)x(AgPO3)1-x

Intensity

500
400
300

x = 1.0200

x = 0.7
x = 0.5100

x = 0.0

0
20

40

30

50

80

70

60

2

Figure 3. The X-ray diffraction pattern of (AgI) x(AgPO3)1-x

Figure 3 shows the ionic conductivityof (AgI)x(AgPO3)1-x for different x andtemperature. The conductivity of theglasses (~10-3 S/cm) are three orders ofmagnitudes compared with the AgI
crystal and undoped AgPO3 (~10-7 and10-6 S/cm, respectively). The ionic
conductivity of the composite glass wasfound higher than in the glassy state [4].

Log Conductivity [S/cm]-1(AgI)x(AgPO3)1-x

 AgI-2-3-4-5
x=0.85x=0.70x=0.50x=0.30x=1.00x=0.00

-6
-7
2.0

2.2

AgI

2.4

2.6
2.8
1000/T [K]

3.0

3.2

3.4

Figure 3. The Ionic Conductivity of Superionic
Glass (AgI)x (AgPO3)1-x [1]INTERNATIONAL JOINT RESEARCH

The international joint research on
development of new solid electrolyte has
been performed with several scientists
from KEK, Japan; Ibaraki University,
Japan; McMaster University, Canada;
ANSTO, Australia and Hahn MeitnerInstitute, Germany. Main purpose of thecollaboration to observe the microscopic
behavior of the superionic glasses such as
the structure and dynamic particularly byusing neutron scattering techniques thatavailable either at a Reactor or Spallation
Neutron Source in the international user
facilities (Canada, Japan, UK, Australia
and Germany).

The experiment on superionic glasses(AgI)x(AgPO3)1-x was performed in 1998
at Chalk River Laboratory, Canada. We
concentrated on the kinetic study by a
High
ResolutionofPowder
Diffractometer (HRPD). The results arevery interesting and have been publishedin Physica B (1999a, 1999b); Solid State
Ionics (2001) and Physical Review B(2001) and also presented in many
international conferences in USA, Europe,
Canada and Indonesia.
Structure Factor of Superionic Glass

In 2001, the neutron experiment was
performed at High Energy Accelerator
Research Organization (KEK), Tsukuba,
Japan. We have been looking at thestructure these glasses by a neutron
scattering instrument (HIT-II) at theSpallation Neutron Source (KEK). X-ray
scattering is not suitable because thescattering is dominated by silver andiodine atoms and does not see thephosphate of sulfur well. The scattering is
usually described by the scatteringfunction S(Q) ( where Q=4πsin(θ)/λ withθ the scattering angle of Bragg’s Law λ=2dsin(θ). This pattern gives the structureof the glass, as shown in figure 4. We cansee that doping gives an extra peak at
about 0.7Å-1 which corresponds to afeature at distance 10 Å. This is the
distance between the chains when silver
iodide put in between. The results were
published in Journal Applied Physics A(2002), J. of non- Crystallography(2002a) (2002b); Solid-State Ionics(2004); also presented at several
international conferences in Japan,
Europe, Australia and USA.

19

S(Q)

2

Figure 5(a) and 5(b) show the AgPO3
and (AgI)0.5(AgPO3)0.5 model producedby the RMCA, respectively. As shown infigure 5, the PO4 tetrahedral form
continuous chains. P atoms are Red, O
atoms are Green, Ag atoms are blue and
the P-O bonds are orange/yellow and theI atoms of Cyan color. For AgPO3 glass,the co-ordination values for P-O and P-P
are as expected for extended chains of
PO4 tetrahedral. The O-O co-ordination
indicates 54% bridging oxygens –alsoroughly as expected. Part of the results
was presented at the ICNS 2005,
Australia.

X=0.0
X=0.09X=0.17
X=0.23
X=0.33

1

T=300K
0

0

2

4

6

8

10

Q ( -1)

Fig.4. Structure factor S(Q) on Superionic
Glass (AgI)x(Ag2S)x(AgPO3)1-2x measured by
HIT-II, KENS, KEK,Japan

Neutron Diffraction
Composite Glasson

Superionic

In 2002, we have come also to the idea ofdeveloping new metaphosphate glasses,
by less expensive materials, to substitutethe Ag+ ions by K+ or Na+, and the newphosphate glasses become NaPO3 andKPO3. From this, we develop new series
superionic glasses, AgI-NaPO3 and AgIKPO3. For the new AgI-NaPO3, we have
performed several neutron experiments
by VEGA and HIT-II instruments at
KEK and the results were published in
Solid State Ionics (2004) and Journal of
Neutron Research (2005).

Reverse Monte Carlo Analysis
The main objective of this work, is toperform the model of superionic glass by
a Reverse Monte Carlo Analysis . The
model was developed based on theneutron experimental result, S(Q) as
shown in Fig.4 . Reverse Monte Carlo
Analysis has been performed on the
AgPO3 and (AgI)0.5(AgPO3)0.5, in orderto generate the model of superionicglasses.

3000

Intensity

2000

1000

0

1.0

1.5

2.0

2.5

3.0

3.5

4.0

d/Å

Figure 5. RMCA produced Model ofSuperionic glass AgPO3 and AgI-AgPO3

20

Figure 5. Neutron diffraction on compositeglass (AgI)0.6(NaPO3)0.4 measured by a
VEGA instrument, KEK,Japan.

4.5

Dynamic study on Superionic Glass
In 2003, a new direction of research was
to observe the dynamic properties onsuperionic glass has been started. The
main observable in the inelastic neutron
scattering experiment is the measurementof a dynamic structure factor S(Q,ω). In
inelastic scattering events, the neutron
either loses energy or gain energy. The
scattering vector is given by
Q = k2 + k’2 + 2|k||k’| cos2θ
and the energy transfer is
E= ħ2/2m (k2-k’2) = hυ = ħω
where m is neutron mass.
The inelastic neutron experiment was
performed by a time-of flight MARI
instrument at the Spallation Neutron
Source ISIS, Rutherford Appleton
Laboratory, UK. The measurements ofthe dynamic structure factor S(Q, ω)cover both space-time correlation
functions. One of the new interesting
results on the dynamic behavior of thesesuperionic glass is the appearance of low
energy excitation at around ~3-5 meV as
shown in Fig.7. The so-called Boson
peak already appears in the insulator
glass AgPO3, and the intensity increases
with increasing dopant salt AgI. The
results have been presented at the Quasi
Elastic Neutron Conference 2004 in
France and American Conference on
Neutron Scattering 2004, USA ,International conference on Complex
System 2005, Japan and International
Conference on Neutron Scattering 2005
in Sydney, Australia.

Fig.7. Low energy excitation of superionicglasses AgI-Ag2S-AgPO3 measured by
MARI, ISIS, UK

Inelastic Neutron Scattering on superionicglass

In mid 2005, series of inelastic neutron
scattering experiments on superionicglasses (AgI)x(AgPO3)1-x and AgI-Ag2SAgPO3 have also been performed by atime-of flight V3-NEAT instrument at
Berlin Neutron Scattering Center, Hahn
Meitner Institute Berlin, Germany. The
measurements have been done atwavelength (λ) 4 Ǻ. Figure 15 shows the
3-dimension of Time-of-flight data or
corresponding dynamic structure factor
and
S(Q,
ω)
from
AgPO3
(AgI)0.5(AgPO3)0.5 . The different
between those spectra are the existing ofa first sharp diffraction peak or a prepeak
for the doped glass (AgI)0.5(AgPO3)0.5 .
Some of the results have been presented
at the ICNS, Sydney, Australia (20005).

50

X=0.00
X=0.17
X=0.23
X=0.33

40

S(E)

30

20

Figure 8. 3-D TOF data of AgPO3 and(AgI)0.5(AgPO3)0.5 measured by NEAT
spectrometer at HMI, Berlin

10

0

0

2

4

6

8

10

E (meV)21

Re-crystallization Study of Superionic
Glass

In November 2005, series of neutron
diffraction experiments have been
performed at the Lucas Height Reactor,
Bragg Institute, ANSTO, Australia. The
superionic glasses AgPO3, Ag2S-AgPO3
and AgI-AgPO3 have been re-crystallized
at 200oC, and the growth of the crystal
has been observed for several hours. The
data analysis is now in progress.

Figure 9. Recrystallization Process of Ag2SAgPO3 measured by MRPD, ANSTO,
Australia
EXAFS Measurement on Superionic GlassIn March 2006, a series of EXAFS
measurements on superionic glasses andcrystals have been performed at theAustralian National Beam line Facility,
Photon Factory, KEK, Japan. By using a
Ag-K edge target, the measurements weredone to observe the local structure orneighboring atom of Ag atom in thesample. The data analysis is now inprogress.
Research
CoordinatorofIndonesianInternational Joint Research Program (RUTI IV)

22

Development of New Solid State Battery
Batteries have many advantages over otherpower sources. They are efficient, convenient, andreliable, need little maintenance, and can be easily
configured to user requirements. As a result,batteries are used in an extremely wide range andvariety of sizes and applications-from as small as 3
mAh for watches and memory backup to as large as
20,000 Ah for standby power supplies [1].
One cell battery consists of three major
components: (1) the anode or negative electrode, (2)the cathode or positive electrode, and (3) the
electrolyte-the ionic conductor-which provides themedium for transfer of electrons, as ions, inside thecell between the anode and cathode. Most of theconventional batteries based on liquid electrolyte(for example, the lead-acid and nickel-cadmium
battery). The disadvantages of liquid electrolyte arelimited life time due to corrosion, leakage which
requires special sealing. Another problem is the useof material for electrodes (i.e. Ni, Cd, Hg, Li, etc.)that are hazardous, toxic and environmentally notfriendly. Thus, the concept of all solid state batteries
with solid electrolyte attracted renewed interest
every time a new solid electrolyte and newelectrodes were discovered.
ee

AgI-AgPO3
e

e

e

e

e
Ag

Ag+

e

I

Figure 10 . Silver Solid State Battery

The solid electrolyte is a relatively newcomponent in a solid state battery compared toliquid electrolyte batteries. The solid statebatteries are expected to have high energy
density, wide range temperature and long shelflife. One of the most important criteria for thesolid electrolyte is to have high ionic
conductivity at room temperature. Due to thesereasons, this research was continued to develop
a new solid state battery.
The use of solid electrolyte based
superionic glasses for a rechargeable battery
will be the main goal of the present research.
One cell battery that consists of two electrodes
and one electrolyte Ag/AgI-AgPO3/I2 has been
designed and fabricated. A first test of the open

circuit voltage has been made and gives the
OCV ~ 0.68 Volt, that is in agreement with thetheoretical calculation. Further work needs tobe performed to test battery performance bycharge-discharge equipment also for optimizing
the result.

Figure.11. (a) A first prototype of Superionicsolid state Battery (b) Voltage testing
Battery Simulation and Modelling

A development of software for battery modelingis currently being performed and has been
compared with the existing SONY cell battery.
The simulation has also been compared with thecommercial and prototype battery.
Conclusion
It has been shown that the superionic glass(AgI)x(AgPO3)1-x has an ionic conductivity
much larger than its corresponding glass
AgPO3 and its doping salt AgI. With this highionic conductivity it is expected that the glasscan be used as a solid electrolyte for a
rechargeable battery. Further development of
the new rechargeable battery will be importantfor both scientific and technology aspects, aswell as for industry in the future.
Acknowledgement

The author thanks to all the international RUTI
members :Prof. M.Collins (McMaster U., Canada),Prof. T.Kamiyama (KENS,KEK, Japan),Prof. M. Arai (JAEA, Japan),Prof. T. Sakuma (Ibaraki U., Japan),Prof. F. Mezei (BENSC, HMI, Berlin),
Dr. S.J. Kennedy (ANSTO, Australia),
Dr. K. Itoh (KURRI, Japan),
Dr.M. Nakamura (JAEA, Japan),
Dr. M. Russina (BENSC, HMI)
and the Indonesian battery teamDr. Pratondo Busono (BPPT),23

Dr.A. Purwanto, Dr. Mardiyanto, Drs.Gunawan
MSc, Drs. S. Suminta MSc, Drs. A.Hindasyah,Drs. M. Ihsan (BATAN) for all supports andhaving good collaboration.
Thank to the international and national facilities
for the use of instruments.
This work was partly supported by theIndonesian International Joint Research
Program (RUTI IV) under the contract No.
6D/Perj/Dep.III/RUTI/PPKI/II/2005, 1
February 2005
REFERENCES (General)
1. David Linden, Handbook of Batteries,
McGraw-Hill. Inc., New-York, USA, 1995,
411-419.
2. M.Z.A. Munshi Ph.D, Handbook of Solid
State Batteries & Capacitors, World
Scientific, Singapore, 1995
3. D.A.Keen, J.Phys.Condens. Matter
14(2002) R819
4. R.J. Cava et al., Solid State Commun.
24(1977)411
5. Tatsumisago et al., Solid State Ionics (1998)

Selected Publications of Author and Co-workers
1) E.Kartini et al., Physica B 241-243 (1998) 909911
2) E. Kartini, M.F. Collins, E.C. Svensson and N.
Indayaningsih, Solid State Ionics, 138, 2000,
115-121.
3) E.Kartini, Final Report of RUT-VI, National
Research Council, Indonesia (2000).
4) E. Kartini, M.F. Collins, S. Yusuf, T. Priyanto, N.
Indayaningsih, E.C. Svensson, S.J. Kennedy,
Phys. Rev. B Vol.61, 2000,1036-1042.
5) E.Kartini, S.J. Kennedy, T.Sakuma, K.Itoh,
T.Fukunaga, M.F. Collins, T. Kamiyama, S.
Suminta, A. Sugiharto, E. Musyafaah, P.Bawono,
J. of Non-Crystalline Solids 312-314 (2002)633
6) E.Kartini, M.F. Collins, C.C. Lovekin, E.C.
Svensson, S. Suminta, E. Musyafaah, J. of NonCrystalline Solids 312-314 (2002)628
7) E.Kartini, S.J. Kennedy, K. Itoh, T. Fukunaga, S.
Suminta, T. Kamiyama, Applied Physics A(2002)s1236

248) M.F. Collins and E. Kartini, in Book Recent
Research Development of Solid State Ionics
1(2003) 157-174
9) E.Kartini,
S.J.
Kennedy,K.
Itoh,T.Kamiyama,.M.F. Collins, S. Suminta, Solid
State Ionics 167 (2004)65-71
10) E.Kartini, M.Arai, H. Iwase, T.Yoko,
T.Kamiyama, K. Itoh, M. Sonobe, S. Purnama,J.of Neutron Research vol. 13, No. 1-3(2005)145-149
11) S.J. Kennedy, T.Tedesco, R.Magaraggia,
E.Kartini, “Progress report on RMCA of HIT-II
neutron diffraction on AgI-AgPO3 superionicglasses“,RUTI-IV Progress Report 2005.
12) E.Kartini, T. Sakuma, A. Purwanto, M.F. Collins,
T. Kamiyama, to appear in Journal of Atom
Indonesia (2005)
13) E. Kartini, S.J. Kennedy, T. Sakuma and M.F.
Collins, in Proc. 2nd Asian Conference on
Materials Science and Technology, August
2005,p.49-63, Jakarta, Indonesia
14) E.Kartini, International Seminar on Microscopy
Electron, September 2005, Bogor, Indonesia.
15) E. Kartini, in Book Toward Bright and Brilliant
Indonesia (2005), 296-331, LIPI, Press, Jakarta.
16) A. Purwanto, E. Kartini, T. Kamiyama, A.
Hoshikawa,S. Harjo, M. F. Collins,
S.
Purnama Solid State Ionics, vol. 171, issues 1-2,
30 June (2004)113-119
17) A. Purwanto,T. Kamiyama,A. Hoshikawa,S.
Harjo,E. Kartini,M. F. Collins,T. Sakuma., J.of
Neutron Research vol. 13, No. 1-3 (2005)169173
18) A. Purwanto, E. Kartini, T. Sakuma, M. F.
Collins, T. Kamiyama, Materials Research
Bulletin, vol. 40, (2005)47-54
19) E.Kartini, M. Arai, H. Iwase, S. Bennington, M.F.
Collins, S.J. Kennedy, American Conference on
Neutron Scattering, June 6-10, 2004, Maryland,USA20) H.Iwase, M.Arai, E. Kartini, T. Otomo, K. Itoh,
S.J. Levett and S.M. Bennington, Quasi Elastic
Neutron Scattering Conference, Sept.2004,
France and to appear in Journal of Chemical
Physics21) M. Arai, H. Iwase, E. Kartini, T. Otomo, S.J.
Levett, S.M. Bennington, M. Nakamura,International Workshop on Complex System,
Nov.2005, Sendai, Japan22) M.Nakamura, M.Arai, E.Kartini, J.W.Taylor,
M.Russina, International Workshop on Complex
System, Nov.2005, Sendai, Japan23) E. Kartini, S.J. Kennedy, K. Itoh, M. Arai, F.
Mezei, M. Nakamura, International Conferenceon neutron Scattering (ICNS), Nov.27-Dec.4,
2005, Sidney, Australia and to appear in Physica
B24) M. Nakamura, M. Arai, H. Iwase, E. Kartini, J.
Taylor, M.Russina, International Conference on
neutron Scattering (ICNS), Nov.27-Dec.4, 2005,
Sydney, Australia and to appear in Physica B
25) M. Russina, M. Arai, E. Kartini, F. Mezei, M.
Nakamura, International Conference on neutron
Scattering (ICNS), Nov.27-Dec.4, 2005, Sydney,
Australia and to appear in Physica B
26) Rhet Magaraggia, S.J. Kennedy, T. Tedesco, E.
Kartini, M.F. Collins, K. Itoh, International
Conference on neutron Scattering (ICNS),
Nov.27-Dec.4, 2005, Sydney, Australia and to
appear in Physica B
27) E.Kartini, M.F. Collins, S. Purnama, A.
Hindasyah, Presented at the Conference of
Neutron and Energy for the Future, June 2-5,
2004, Washington DC, USA.
28) P.Busono, E. Kartini and M.F. Collins, Presented
in 7th-Asean Science and Technology Week,
Mathematical Simulation of the Silver Battery,
Jakarta, August 2005.
29) E.Kartini (Research Coordinator), Final Reportof RUTI –IV. “ Research and development of
new solid electrolyte for a rechargeable battery”,
Ministry Research and Technology, December
2005.

25

II.
SCIENTIFIC HIGHLIGHT

2003–2006

Spin-Lattice Coupling of Multiferroic (Lu,Y)MnO3
SEONGSU LEE1, MISUN KANG1, F. SHIKANAI2, T. KAMIYAMA2, and J.-G. PARK1,3
1

Department of Physics and Institute of Basic Science, Sungkyunkwan University, Suwon 440-746, Korea
Institute of Materials Science, KEK, Tsukuba-shi, Ibaraki 305-0801, Japan
3
Center for Strongly Correlated Materials Research, Seoul National University, Seoul 151-747, Korea
2

10000

Intensity(arb. units)

Hexagonal manganites have attracted a lot of
attentions recently because of their interesting
multiferroic behavior and two dimensional
triangular Mn network. In order to understand theunderlying physics of this new class of materials, it
is highly important to unravel how the spin degreeof freedom is coupled to the other degrees of
freedom, in particular the electric dipole moment.
According to our previous structure studies of thehexagonal YMnO3 [1], all the structural parameterschange abruptly at TN, which is strong and direct
evidence of a spin-lattice coupling. We believe thatthrough this spin-lattice coupling is the electric
dipole moment coupled to the magnetic moment.
In the hexagonal RMnO3 with space group P63cm,
there are six formula units per unit cell. Each Mn
atom is coordinated by five oxygen atoms in abipyramid configuration. One O(3) atom and two
O(4) atoms are in the equatorial plane of the
bipyramid, whereas the O(1) and O(2) atoms are at
the apexes. R atoms occupy two crystallographic
positions, R(1) and R(2), and both of them arebonded to seven oxygen atoms. The capping
oxygens are O(3) for R(1) and O(4) for R(2). Alongthe z axis, the structure consists of the layers ofcorner-sharing MnO5 bipyramids separated by thelayers of edge-sharing RO7 polyhedra.
The magnetic structure of YMnO3, LuMnO3, andLu0.5Y0.5MnO3 can be descried by Γ1/ Γ3 , Γ2/ Γ4, andΓ1+Γ2 mixed magnetic structure, respectively [2,3].
The spin configuration of the Mn atoms in all
hexagonal manganites form a 120 structure withthe moments in the ab-plane in a triangular lattice,
showing ferromagnetic or antiferromagnetic
coupling between the z=0 and z=1/2 layers.
In order to further understand our findings of
YMnO3, we have carried out new neutron
diffraction experiments on Lu1-xYxMnO3 (x= 0.5,0.0) using SIRIUS.
Fig. 1 displays the neutron data of Lu1-xYxMnO3
together with the refinement results obtained using
the RIETAN-2001T program [4].

8000
6000
4000 LuMnO
2000 3Lu0.5Y0.5MnO3
0

YMnO3

0.6

0.8

1.0

1.2

1.4
d (Å)

1.6

1.8

2.0

2.2

Fig. 1
Neutron diffraction data (symbols) of Lu1-xYxMnO3
taken at 10 K. The solid line represents the results of Rietiveld
refinement with the hexagonal (P63cm) symmetry. The line at
the bottom shows the difference curve.

The summary of our refinement results is given in
Table 1. According to our refinement results, all the
crystal structure parameters of Lu1-xYxMnO3 (x=1.0,
0.5, and 0.0) show a clear anomaly at theantiferromagnetic transition temperature (see Fig. 2).
For example, the z-positions of R(1), R(2), O(3), andO(4) atoms move along the positive direction of thec-axis with decreasing temperatures while thez-positions of the apical oxygens O(1) and O(2)move along the negative direction of the c-axis withdecreasing temperatures. Of particular interest is thatthe movement of the Mn atom in the ab-plane has
not only large temperature dependence but alsochanges the direction of its displacement as we vary
the Y atomic concentration from YMnO3 to
LuMnO3. On the other hand, all the other atoms
expect for the Mn atom have the same displacement
at TN for Lu1-xYxMnO3. We still do not understandthe origin of this unusual doping dependence of Mn
displacement.

29

Structure
YMnO3
Parameters 10 K
300 K
a (Å)
6.12049(7) 6.13838 (5)c (Å)
11.4076(1) 11.3962(1)Vol.(Å3) 370.081(7) 371.877(5)R(1)z0.2773(7)0.2727(8)R(2)z0.2318(6)0.2320(7)Mnx
0.3423(13) 0.3330(17)O(1)x0.3007(4)0.3076(4)O(1)z 0.1606(7) 0.1625(7)O(2)x0.6399(4)0.6414(4)O(2)z 0.3339(6) 0.3360(7)O(3)z 0.4804(8) 0.4754(9)O(4)z 0.0193(7) 0.0163(8)
6.29
4.19
Rwp(% )
4.89
3.42
Rp(% )

LuMnO310 K
300 K
6.02683(11) 6.04171(5)11.3646(2) 11.3619(1)357.487(11) 359.169(6)0.2788(11) 0.2723(9)0.2319(9) 0.2297(7)0.3299(14) 0.3321(13)0.3012(5) 0.3058(4)0.1632(9) 0.1638(7)0.6409(6) 0.6380(4)0.3363(9) 0.3369(7)0.4774(13) 0.4734(10)0.0211(10) 0.0187(8)
5.12
3.19
3.72
2.61

0.280
0.233

0.276

LuMnO3

0.232
0.231

0.274

0.230

0.272

0.229

0.165

0.228

0.164

0.338

0.163

0.337

0.162

0.336

0.161

0.335

0.160

0.334

0.480

0.333
0.022

O3_z

0.478

O2_z

O1_z

YMnO3

Y0.5Lu0.5MnO3

R2_z

R1_z

0.278

0.020

0.476

YMnO3 : dMnO(3)- dMnO(4)0.08

Y0.5Lu0.5MnO(3) : dMnO(3)- dMnO(4)LuMnO3 : : dMnO(4)- dMnO(3)

0.06
0.04
0.02
0.00
0

50

100
150
200
Temperature (K)

250

300

Fig. 3
The temperature dependence of the difference
between Mn-O(3) and Mn-O(4) bond distances.

This drastic temperature dependence of the Mn
atoms near TN is an unmistakable piece of evidence
suggesting that there is a strong coupling between
the lattice and the Mn spin. Another interesting pointis that when we calculated the electric dipole
moment using nominal charge valences, R (3+), Mn(3+), and O (2-), we also found a similarly strong
temperature dependence of the electric dipole
moment as in YMnO3 [1]. That is, the drastic
displacement of all the atoms along the z-axis at TN
produces an additional change to the electric dipole
moment at TN.
To summarize, we found that there is clear
experimental evidence suggesting a coupling amongspin, lattice and electric dipole moments for
Lu1-xYxMnO3. We have been working to understandits microscopic mechanism.

0.016

0.472
0

50 100 150 200 250 300
Temperature (K)50 100 150 200 250 300

0.014

Temperature (K)Fig. 2The temperature dependence of the z-positions of R1,
R2, O1, O2, O3, and O4 obtained from Rietveld refinements of
Lu1-xYxMnO3 data (x=1.0, 0.5, and 0.0).

This different Mn displacement leads to opposite
behavior in temperature-dependent Mn-O bonddistance for YMnO3 and LuMnO3. In the case of
Lu0.5Y0.5MnO3 the displacement of Mn atom has anintermediate value between LuMnO3 and YMnO3.
30

0.10

O4_z

0.018

0.474

An interesting point is that the bond distances follow
more or less the same temperature dependence ofthe magnetic moment obtained from our previous
neutron diffraction experiments [2,3].

/dMnO(3)- dMnO(4)/Table 1. Atomic parameters of YMnO3 and LuMnO3
determined from high-resolution neutron diffraction patterns
taken at 10 and 300 K. The crystal symmetry is hexagonal
P63cm and the wave vector is k=0 with following atomic
positions: R(1) and O(3) at 2a (0,0,z); R(2) and O(4) at 4b(1/3,2/3,z); Mn, O(1), and O(2) at 6c (x,0,z) with Mn z=0.

References
1) Seongsu Lee, A. Pirogov, Jung Hoon Han, J.-G.
Park, A. Hoshikawa, and T. Kamiyama Phys.
Rev. 71, 180413(R) (2005).
2) Seongsu Lee et al., to be published (2006).
3) Junghwan Park Unggul Kong, A. Pirogov, S. I.
Choi, J.-G. Park, Y. N. Choi, Changhee Lee, and
W. Jo, Appl. Phys. A 74, S796 (2002).
4) T.Ohta, F. Izumi, K. Oikawa, and T. Kamiyama,
Physica B 234–236, 1093 (1997).

In Situ Neutron Diffractions for Austenite Transformation during Heating and Ferrite
Transformation during Cooling
P.G. XU1, Y. TOMOTA1, M. YONEMURA1, T. SHINOZAKI2 and T. KAMIYAMA3
1-Institute of Applied Beam Science, Graduate School of Science and Engineering, Ibaraki University,
Hitachi, Ibaraki, 316-8511 JAPAN
2-Graduate Student of Institute of Applied Beam Science, Ibaraki University, Hitachi, 316-8511 Japan
3-Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801 JAPAN1. Introduction
Advanced
thermomechanicallycontrolled
processing (TMCP) combining severe deformation
just above the onset temperature of static
austenite-to-ferrite transformation (Ar3) and rapid
cooling has recently been emphasized as a method
to produce modern high-strength low-alloy steelswith a uniformly ultrafine-grained multiphasemicrostructure. Much attentions has been paid on
the in situ study about phase transformation kinetics
of low-alloy steel during the TMCP because it isexpected to clarify the influencing mechanism ofsevere deformation on the grain refinement.
The austenite-to-ferrite transformation in
low-alloy steels during the TMCP has been recently
investigated by using the neutron diffraction withthe angle dispersive method, and the carbon
enrichment in austenite during ferrite transformation
was confirmed [1]. However, due to the limited
neutron diffraction time at each step and the weak
beam, the diffracted profiles are of relatively low
signal/noise (S/N) ratio, which leads to a certain
statistic error to the quantitative characterization of
ferrite transformation kinetics.
Here, C-Mn low-alloy steel was step-by-stepheated and cooled in a specified vacuum furnace,
and a series of neutron diffraction profiles withcomplete spectra were obtained by collecting theTime-OF-Flight back-scattering diffraction neutrons
for a long diffraction time at each step. The results
reported in this paper can help us make a further
understanding about the austenite transformation,
ferrite transformation as well as the thermal
expansion behavior.
2. Experimental proceduresAs-quenched Fe-2Mn-0.2C steel was employed
as the initial material in this study. The columnar
specimen with 7mm in diameter and 48mm in length
was shielded with vanadium foil, allowed free
expansion of the specimen in all directions, andheated/cooled in a specified vacuum furnace kept at
2.6 10-4Pa within a temperature error about 0.5 .
The diffracted neutron counts for each profile
measurement were larger than 70000 to ensure agood profile quality. The temperature points formeasurement were well considered to cover the
single phase regions of austenite and ferrite formonitoring their thermal expansion behavior andalso to cover the austenite/ferrite dual phase region
for characterizing the transformation kinetics.
The whole-pattern Rietveld refinement of above
TOF neutron diffraction profiles without partial
profile relaxation was carried out by using
RIETAN-20001T software [2] to analyze theaustenite transformation, ferrite transformation andthermal expansion behavior.
3. Results and discussion
Figure 1 shows the change in normalized neutron
diffraction profiles during specimen heating andcooling. At 25 C, the ferrite (110) peak ofmartensite starting microstructure is much broad.
With the increment of temperature up to 600 C, theferrite (110) peak becomes more and more sharp aswell as strong, which suggests that the microscopic
residual strain in the BCT martensite weakens little
by little during the tempering. The ferrite peak
begins to weaken again at 700 C and disappears at
810 C due to the start and finish of austenitetransformation. The peak shift of ferrite (110) in the
single phase region during specimen heating is moreevident than that in the dual phase region, while theaustenite (111) peak shows a non-linear peak shift
due to the carbon diffusion in austenite.
On the other hand, during specimen cooling, theferrite (110) peak begins to appear at about 700 C,
and then intensifies little by little. In the single phaseferrite region, the maximum intensity of ferrite
peaks continues to increase due to the temperatureeffect of neutron scattering. However, the sharp
ferrite peak shape shows little change during
31

step-by-step cooling, which suggests that the
microscopic residual strain in the ferrite formed
during specimen cooling is very small whencompared with that in the martensite starting
microstructure.

previous study [1], the corresponding temperatures
here are about 700 C and 590 C, which suggeststhat the latter ensures the well carbon diffusion andis more approximate to the equilibrium ferrite
transformation.
Meanwhile, during the step-by-step cooling, theprecipitation of cementite as a component phase of
pearlite was found to appear at 560 C. No cementite
precipitation can be found from the martensite
during heating.

CoolingHeating

Fig. 1

Fig.2

Change in Time-Of-Fligth neutron diffraction
profiles of a C-Mn low-alloy steel during heating
and cooling.

Changes in volume fractions of component
phases in a C-Mn low-alloy steel during heating(black marks) and cooling (red marks).

Figure 2 exhibits the changes in phase volume
fractions of transformation products as a function oftemperature. It is easy to find that the austenitetransformation onset/finish temperatures during
heating are much higher than the corresponding
ferrite transformation onset/finish temperaturesduring cooling. Compared with the ferrite
transformation onset/finish temperatures (about
640 C and 500 C, respectively) obtained in our
32

Fig.3

Changes in lattice parameters of austenite andferrite/martensite in a C-Mn low-alloy steel during
heating (black marks) and cooling (red marks)

Figure 3 confirms that the much higher carbon
concentration in austenite occurs at the beginning ofaustenite transformation and at the end of ferrite
transformation, which leads to the evident deviationof austenite lattice parameter from the lineal thermal
expansive relationship. It is very interesting to pointout that the deviation of austenite lattice parameteris more evident during heating than that duringcooling though the reason is not clear.
Since the specimen was here allowed free
expansion in all directions and was isothermal held
about 3.6ks for each step, the linear thermal
expansion coefficient analyzed from the complete
diffraction spectrum should be more suitable for thefurther modeling of phase elastic stress. For example,
the ferrite lattice expansion formula is as follows:(1)a (T)=2.87762 [1+1.501 10-5 (T-250)]
The deviated ferrite lattice parameter in theaustenite/ferrite dual phase region confirms that thecompressive strain really exists during the phasetransformation, which is consistent with ourprevious research [3]. The residual strain inmartensite starting microstructure was also
confirmed. It is found from the ferrite latticeparameters at 250 C, 300 C, 400 C and 500 C
during heating and cooling that the above
macroscopic residual strain in low-alloy martensite
microstructure can be well relaxed by 250 C
tempering for 3.6ks. However, the peak broadening
effect due to the ultrafine martensite substructure
was found to still exist at 250 to a certain extent
and to weaken little by little during heating.
4. Conclusions
The
austenitetransformation,
ferritetransformation and thermal expansion behavior in a
C-Mn low-alloy steel were in situ investigated by
TOF neutron diffraction, and the following results
were found or confirmed:(1) 250 C tempering for 3.6ks can well relax theresidual lattice plane strain in low-alloy martensite
though the ultrafine martensite substructure exhibits
no evident change.
(2) The ferrite compressive strain in ferrite/

austenite dual phase region was found during bothheating and cooling.
(3) The carbon enrichment in austenite during
dual phase region results in the non-linear thermal
expansion behavior of austenite and ferrite.
(4) The free thermal expansion behavior of theferrite and austenite in all directions is wellcharacterized, which is valuable to the further
modeling of phase stress evolution duringtransformation.
References
1) P.G. Xu, Y. Tomota, O. Muransky, P. Lukas, Y.
Adachi, submitted to Materials Science andEngineering A.
2) T. Ohta, F. Izumi, K. Oikawa, T. Kamiyama,
Physica B (Amsterdam), 234-236 (1997) 1093.
3) P.G. Xu, Y. Tomota, P. Lukas, Y. Adachi,

Iron Steel 40 (2005) Suppl. 234.

33

Nanostructure of Ionic Amphiphilic Diblock Copolymer Monolayer on the Water Surface
H. MATSUOKA, E. MOURI*, P. KAEWSAIHA, Y. FURUYA, Y. SUETOMI
Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510, JAPAN*Present Address: Department of Applied Chemistry, Kyushu Institute of Technology,
Kitakyushu, Fukuoka 804-8550, JAPAN34

layer".[1,2] Figure 2 is the density profiles evaluated by
NR and XR. The nanostructure of carpet layer andpolymer brush is highly quantitatively presented. Whatinteresting is the fact that the thickness of the carpet layer
is about 15Å independent the hydrophilic chain lengthand surface pressure. This constancy might be a
10

Air

0

Hydrophobic
Layer
Hydrophilic"Carpet"10 -1

Et 2 SB

MAA

Polyelectrolyte"Brush"

10

Water

-2

Reflectivity

poly(d-Et 2 SB) 23-b-poly(MAA) 49
10 -3

XR
10 -4

10

-5

NR

10 -6

10

NR (D O) by ARISA
2
XR (D O) by RINT-TTR-MA

-7

2

0

0.05

0.1

0.15

Q (Å -1)

0.2

0.25

0.3

Fig.1 XR and NR profiles for poly(d-Et 2 SB)23 -bpoly(MAA)49 monolayer on water surface. Surface
Pressure=35mN/m. Inset:Nanostructure ofmonolayer evaluated.
(d-Et 2 SB) 23 -b-(MAA)

549

Monolayer on Water

0.000350.0003

4

XR
0.00025NR

0.0002-6

 (x10 )320.000150.0001

1

PMAA Brush+ Water

Air
0

PMAA Dense Layer("Carpet")

Water Subphase0

SB Layer

-1
-100

-50

5 10 -5

0

50

100

150

-5 10 -5
200

z (Å）

Fig.2 Density profiles for poly(d-Et2SB) 23 -bpoly(MAA) 49 monolayer on water surface
evaluated by NR and XR .
Surface Pressure=35mN/m.

Scattering Length Density (A -2 )Amphiphilic
diblock
copolymers
show
self-assembling behavior such as micelle formation inwater and monolayer formation on the water surface.
Precise molecular design and synthesis of amphiphilicpolymers enable us to control self-assembling behavior
and nanostructure of the assemblies, which will result in
the development of novel functional polymer materials.
For example, a polymer brush, which can be constructedby monolayer formation of amphiphilic diblock
copolymer on the water, is an interesting system, which is
directly correlated to surface technology such as
water-repelling and oil-repelling behaviors, wetting,adhesion, tribology and biocompatibitily. In this study,
we have investigated nanostructure of monolayer ofamphiphilic
diblock
copolymer
consistedbypoly(diethylsilacyclobutane) (PEt2SB) as a hydrophobic
chain and poly(methacrylic acid) (PMA) as a hydrophilic
segment on the water by in-situ neutron reflectivity (NR)measurement. Since the hydrophilic segment is a weakpolyacid, the hydrophilic layer under the water is
expected to form polyelectrolyte brush. NR
measurements were performed by ARISA reflactometerat KENS, which can be applied to water surface systems.
ARISA has an LB trough at sample stage, which makes
us possible to study monolayer nanostructure as afunction of surface pressure, i.e., brush density.
Figure 1 shows NR profile for monolayer on thewater at surface pressure 35mN/m. For comparison,
X-ray reflectivity (XR) profile is also shown. Clear
fringes with long period are due to a smooth and uniform
hydrophobic layer on the water. A small fringe at
Q=0.05Å-1 is due to polymer brush structure under thewater surface. It is obvious that this small fringe is moreclearly observed in NR profile. By model fitting analysis,
the nanostructure of monolayer could be determined asshown in the inset of Fig.1. The monolayer does not havea simple double layer structure with hydrophobic andhydrophilic layers, but it has a dense hydrophobic layer inbetween these two layers as the third layer. This is quite
novel finding, which became possible by NR techniquefor water surface. We call this dense layer as "carpet

requirement to minimize the interfacial free energy. [3,4]Figure 3 shows the salt concentration
dependence. [5] The NR profiles and the normalized
density profiles for hydrophilic layer (i.e., carpet+brushdouble layer) are shown as a function of added NaBr
concentration from 0M to 0.1M. As is clear from thedensity profile, the brush first stretched with increasing
salt concentration and shrunk up again with further
increase of salt. The maximum is located at about 0.1M
NaBr. This behavior, which looks strange at first sight,
can be explained by the balance of an increase ofeffective charge on the brush chain and enhanced
electrostatic screening effect with increasing salt
concentration. The slight increase of effective charge (inother words, an increase of degree of dissociation) is the
typical and unique behavior for weak acid systems. For
strong acid system in our separated study, different
behavior was observed. Another interesting observation isan increase of roughness of the top of the brush chain (i.e.,
the roughness of brush layer/water interface). We have no

10 1
1M NaCl (D O)
2

1M NaBr (D O)
2

1M Na Cl (D O:H O=8:2 )

10 -1

2

2

fit.
fit.

10 1

Reflectivity [-]NaBr/D O
2salt-free
0.01M
0.1M
1M
fit.

10 -1

10 -3
Reflectivity [-]idea for explanation of this curious observation at thisstage, but such behavior was not reported for strong acidbrush systems.
In Figure 3, the data with NaCl as an added salt
are also shown. However, the data is only for 0.01M and
0.1M NaCl conditions but not for 1M NaCl. We certainly
measured 1M NaCl systems but the NR profile obtained
could not be fitted by 3-box model, which consisted ofhydrophobic, carpet and brush layers. Since 1M NaBr
system could be well fitted by 3-box model, this factmeans that small Cl ions in 1M NaCl system contribute to
the whole density profile.
Figure 4 shows thecomparison of NR profiles for 1M NaCl, 1M NaBr
systems in D2O and 1M NaCl system in D2O/H2O=8/2

10 -3

10 -5

10 -5

10 -7

10 -7

10 -9
0

0.05

0.1

0.15

0.2

0.25

0.3

-1

q [Å ]

10 -9

10 -11
0

0.05

0.1

0.15

0.2

0.25

Figure4
NR profilesforpoly(Et2SB-d10)23-b-poly(MAA)49 monolayer monolayer
at 35mN/m on various subphase.

0.3

-1

q [Å ]
1

0.8

NR
0.6

f [-]

salt-free
0 .01M NaBr
0.1 MNaBr
1MNaBr
0.01M Na Cl
0 .1M NaCl

0.4

0.2

0
0

50

100

150

200

Z [Å]

Figure 3 NR profiles and PMAA fraction forpoly(Et2SB-d10)23-b-poly(MAA)49 monolayer monolayer onsubphase with different salt concentrations at 35mN/m.

system. NR profiles for 1M NaCl and NaBr is largely
different. This observation certainly supports ourinterpretation above. In the system of mixture of heavy
and light water, the contrast of solvent is just matched to
Cl ions. The NR profile obtained was almost the same asthat for 1M NaBr system. From these observations, wehave concluded that the contribution of Cl ions are
significant in D2O system while that of Br ion is not.
Hence, we should take into account the contribution of Cl
ions in the fitting model in addition to polymer layers. In
other words, we can estimate the small ion distribution in
the ionic polymer monolayer system by NR.
Figure 5(a) shows NR profiles in 1M NaCl in35

D2O system with fitting curves with and without thecontribution of small ions in the model. The model withsmall ion distribution in addition to hydrophobic, carpet
and brush layers well reproduced the NR profile. Figure5(b) is the scattering length density profile normal to thewater surface thus obtained. The well-fitted model has ahigh Cl ion density layer just beneath the carpet layer.
This is quite unexpected result for us, so we have no clear
interpretation for this matter at this stage.

100

1M NaCl (D O)
2

Reflectivity [-]fit. with small ion distribution
3-box model fit.

10-2

10-4

10-6

10-8

0

0.1

0.2
q [Å

]

7

Cl- ion6

Nb [10-6 Å-2]

0.3

-1

5
4

Without small ion distribution

3

35mN/m2

1M NaBr (D O)

1

1M NaCl (D O)

2

0
-100

2

-50

0

50

z [Å ]

100

150

200

Figure 5 (a) NR profile for 1M NaCl system and fitting curves
with and without small ion distribution. (b) Scattering lengthdensity profiles thus estimated.

By NR technique with ARISA instrument, thenanostructure of the monolayer of ionic amphiphilic
diblock copolymer on the water surface. The existence of"carpet" layer was quite unexpected but interesting since
an existence of this layer should contribute to the surface
properties of polymer brush. It should be emphasized that
this observation became possible only by in situ
experiment of NR to water surface systems. In addition to36

the detailed information for nanostructure of hydrophobic
and brush layers, the distribution of small ions could bealso evaluated. NR technique, which can be applied toliquid surface systems, certainly has large possibility fordevelopment in the surface and interface sciences.

References[1] E.Mouri, K.Matsumoto, H.Matsuoka, J.Polym.Sci.,B,
41(16), 1921-1928 (2003).
[2] E.Mouri, K.Matsumoto, H.Matsuoka, N.Torikai,
Langmuir, 21(5), 1840-1847 (2005).
[3] E.Mouri, Y.Furuya, K.Matsumoto, H.Matsuoka,
Langmuir, 20(19), 8062-8067 (2004).
[4] H.Matsuoka, Y.Furuya, P.Kaewsaiha, E.Mouri,
K.Matsumoto, Langmuir, 21(15), 6842-6845 (2005).
[5] E.Mouri, P.Kaewsaiha, K.Matsumoto, H.Matsuoka,
N.Torikai, Langmuir, 20(24), 10604-10611, (2004).

Low Energy Excitation of Polymer Thin Films
R. INOUEA, T. KANAYAA, K. NISHIDAA, I. TSUKUSHIB, K. SHIBATACa

Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japanb
Chiba Institute of Technology, Narashino, Chiba-ken 275-0023, Japanc
Japan Atomic Energy Research Institute, Tokai, Ibaraki-ken 319-1195, Japan

0.05

1000
T=230K
T=150K
T=80K
T=11K

S(Q, ) (arb. units)

0.04
0.03
0.02
0.01
0.00

Fig. 1

-2

0

2

4

6

8

Energy transfer (meV)10

Dynamic scattering law S(Q, ) of 1000 Å PS
thin film as a function of temperature.

Figure 1 indicates the dynamic scattering law S(Q, of 1000Å thin films at T=11, 80, 150 and 230 K andthe spectrum changes from inelastic-like toquasielstic-like with increasing temperature. A
very broad peak called boson peak was observed ataround 1.5 meV at a low temperature region. Thisis the first observation of boson peak of polymer
thin films. We first evaluated the mean squaredisplacement <u2> from the Q2 dependence ofelastic intensity Iel(Q) through the relation
Iel(Q)~exp[-<u2>Q2]. The temperature dependence
0.06

0.05

2

)

0.04

<u > (

0.03

2

The mechanical and thermal properties ofpolymer thin films are very different from those ofbulk state and one of the most interesting topics isthe glass transition behaviour of polymer thin films.
In the case of polystyrene (PS) glass transition
temperature (Tg) decreases with film thickness as
revealed by ellipsometry, X-ray or neutronreflectivity [1]. However, the definite mechanismof Tg behaviour of thin films is still unknown. We
considered that the dynamical studies on polymer
thin films were essential for the understanding ofabove mentioned unusual phenomenon. For thispurpose, inelastic neutron scattering method issuitable because we can obtain information on
dynamics from molecular level. Recently someworks on the dynamics of polymer thin films were
performed using inelastic neutron scattering
methods [2,3], however these data were mainly
limited to the elastic scattering due to the very weaksignal from samples. In this work, we studied theinelastic scattering from the glassy PS thin films
1000 and 400Å in thickness in meV rergion, mainly
focusing on the low energy excitaion, the so-calledboson peak using inverted geometry time of flight
spectrometer LAM-40 at KEK and discuss the effectof film thickness on boson peak.

0.02

bulk
1000
400

0.01

0.00
0

Fig. 2

50

100

150

200

250

Temperature (K)Temperature dependence of <u2> for 3 different
film thickness.

of <u2> is shown in Fig.2 for bulk, 1000Å and400Å thin films. <u2> surely decreases with film
thickness, indicating the decrease of mobility withfilm thickness. In this temperature range, <u2> isalmost proportional to temperature, indicating thatthe vibration is harmonic. The slope of <u2>
versus T is inversely proportional to the force
constant f. From Fig.2, the increase of f wasobserved with decreasing film thickness. The
estimated values of f were almost comparable to thef for the interaction potential between non-bonded
atoms. In order to clarify the decrease in <u2> inthe temperature range investigated and observe theeffect of hardening on inelastic scattering, we
focused on the inelastic scattering for bulk and thinfilms. The observed S(Q, ) was converted todensity of phonon states G() after subtracting theelastic component and correcting for the
Debye-Waller factor. Thus obtained G() are
shown in Fig.3. From Fig.3, the decrease in G()37with film thickness are clearly observed. Therefore
the decrease of <u2> is attributed to the decrease ofG(�) with film thickness.
0.0007

bulk
1000A
400 A

0.0005bulk
1000A

0.000220.0004

Boson peak mode
Debye mode

0.0001

Debye contribution

1

0.00060.0002400A

0.0001

3

4

Energy transfer (meV)5

6

Density of phonon states G(w) divided by w2 forbulk and thin films at 80K and the solid lines
were drawn by eye. The dashed liens show thelevel of Debye contribution.

In the energy range examined, there exist at least
two modes from previous work. One is Debye
mode and the other is the boson peak mode. In
order to clarify the cause of decrease of G(�) withfilm thickness, we evaluated the contribution fromboth modes. If the hardening affected the boson
peak mode, the shift of peak position would beobserved. The peak position of boson peak isalmost constant regardless of film thickness within
experimental error. We assumed that the boson
peak mode was not so affected by hardening.
Rather the effect of hardening would be observedfor Debye mode. We evaluated the level of the
Debye mode under the assumption that theamplitudes of both modes were independent of thefilm thickness and the estimated Debye mode clearlydecreased with film thickness, meaning that thehardening mainly affected the Debye mode. Fromthe evaluated values of Debye mode, we also
evaluated the contribution from boson peak mode
assuming that the total G(�) was expressed by theaddition of Debye mode and boson peak mode.
Thickness dependence of both modes is indicated in
Fig.4. Both Debye mode and boson peak mode
decrease with film thickness. The decrease ofG(�) was attributed to the decrease of both modes.
As for boson peak, the peak position was notdependent on film thickness though the decrease of
intensity was observed with film thickness. It was
assumed that the number of the modes boson peakdecreased with film thickness.
How can weunderstand these results?
What we have toconsider is the why both modes decreased with film
thickness. Although we don’t have any definite
idea concerning this problem, there exist some
38

0.00080.00030.0003Fig. 30.00100.00040.00040.00000.00120.0005Intensity (arb. units)

G(ω)/ω2 (arb. units)

0.0006

probabilities. One possibility is the existence of
hard immobile layer “dead layer” at the interface
between thin film and substrate. The hard “deadlayer” is supposed to be harder than normal bulk

0.00020.00000.0000
10

2

10

3

10

4

Film thickness (�)

10

5

10

6

Fig. 4 Thickness dependence of Debye mode andboson peak mode for 3 different film thicknesses at 80K.

layer.
The contribution from “dead layer”
increases with decreasing film thickness. Assuming
the existence of such a dead layer, the average force
constant f would increase with decreasing film
thickness. Such a hard layer is supposed to be
more dense than that of bulk layer, resulting in theincrease of sound velocity v. G(�) from Debye
mode was related to v through the relation Gd(�)~v-3.
The Debye mode would decrease with film
thickness. In the case of boson peak, the situation
is somewhat difficult. The origin of boson peak initself is still under discussion. However, somemodels were deduced from the experimental results.
If the origin of the boson peak came from thedefects or voids, the number of them in such hard“dead layer” is probably smaller than normal bulk
layer. As stated above, the effect of “dead layer”
becomes larger with decreasing film thickness.
This situation results in the decrease of G(�) fromboson peak without affecting the nature of the modeof boson peak (peak energy). As the result of theincrease of contribution from “dead layer” with film
thickness, the decrease of the intensity of bothmodes was observed.
At the present stage, the “dead layer” is likely tobe suitable for the explanation for the observed
results, however the final conclusion is still underdiscussion.
References
1) J. L. Keddie, R. A. L. Jones, and R. A. Cory,
Europhys. Lett. 27(1994) 59.
2) B. Frick, K. Dalenoki-Veress, J. A. Forrest, J.
Dutcher, C. Murray and A. Higgins, Eur. Phys. J.
E 12, s01 (2003) 93.
3) C. L. Soles, J. F. Douglas, W. Wu and R. M.
Dimeo, Phys. Rev. Lett. 88 (2002) 037401.

Magnetic Excitations in CoO
K. TOMIYASU and S. ITOH
Neutron Science Laboratory (KENS), Institute of Materials Structure Science,High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, 305-0801
An orbital angular momentum L, not only a spin
angular momentum S, generates a magnetic moment.
Therefore, magnetic excitations in systems with Lshould provide the most fundamental knowledge
about magnetism. One treats the Hamiltonian
Hex= i,j Jij Si Sj, without L, when L is quenched. If L
is unquenched, like in f-electron magnets, the totalangular momentum, J=L+S, namely J and Jz, areregarded as good quantum numbers owing to a large
spin-orbit interaction. However, d-electron clouds
spatially spread compared to f-electron clouds, andthe constant of the spin-orbit coupling,  is roughly
proportional to r-3, where r is the distance between
an electron and an atomic nuclear. Therefore, it ispossible that the approximation of J is not applied
for d-electron magnets with unquenched L, in which
the magnitude of the spin-orbit interaction can beclose to that of the exchange interaction. In such
systems, we must directly consider the Hamiltonian
Hso+Hex= i I Li Si + i,j Jij Si Sj, therefore, it isprospective that the effect of L explicitly appears[1,2].
Approaches to remove the approximation of J
were tried early only on three collinear
antiferromagnets of CoO (NaCl-type crystalstructure, TN=289 K), KCoF3 (Perovskite-type
crystal-structure, TN=114 K) and CoF2 (Rutile-type
crystal-structure, TN=38 K) by inelastic neutron
scattering [3–7], as far as we know. Although one up
moment is included in a magnetic unit cell in theseCo compounds, two or more magnetic modes wereobserved owing to the freedom of unquenched L ofa Co2+ ion. However, the results present no evidence,
which the quantities, J and Jz, are not understood as
good quantum numbers in the modes [5]. Since CoO
exhibits the largest value of TN among the materials,
suggesting a strongest superexchange interaction,
the magnitude of the exchange interaction canbecome closest to that of the spin-orbit interaction.
In addition, magnetic excitations in CoO were
measured with dispersion relations of phonons
around the point of a lattice in earlier studies [3].
Therefore, it will be worth determining thedispersion relations of magnetic excitations in CoO
around a magnetic
point, in order to study theeffect of L.
In a series of our recent researches, we haveconsidered magnetic excitations in CoO below TN,
by the extensive inelastic neutron scatteringexperiments on single-crystal specimens and a
powder sample of CoO on triple axis spectrometer,
PONTA, installed at a steady state neutron sourceand direct geometry chopper spectrometer, INC,
installed at a pulsed neutron source [8]. In this report,
only a part of the data of the single crystal on INC
and the results of analyses are introduced.
Figure 1(a) shows the energy spectra integrated
in the range of 5.00<2 <9.17 deg, 8.58<2 <9.17
deg and 6.19<2 <7.98 deg measured at Ei=101, 152
and 201 meV, respectively, as the typical data of Ei<
or ~200 meV. Figure 2(a) shows the energy spectra
integrated in the range of 5.00<2 <9.17 deg
measured at Ei =506 meV and ki //[110], as a part ofthe data of Ei ~500 meV. Figures 1(b) and 2(b) show
the corresponding scan-loci in the four-dimensional(Q, E) space projected on the scattering plane. The
spectra of several detectors are merged within sharp
sectors, shown in Figs. 1(b) and 2(b), for higher
statistics. The peak intensities are obtained atintersections or close points between dispersion
curves and the scan-loci, and their positions in the(Q, E) space are roughly represented by ellipsoids in
Figs. 1(b) and 2(b). Magnetic excitations in 50 to 60
meV in Fig. 1(a) and broad inelastic-magneticscattering around 120 meV in Fig. 2(b) are
observed.

Figure 1. (a) Energy spectra measured with ki //[001] at T=150
K on INC by using a single-crystal specimen. The intensities

39

measured at Ei =101, 152 and 201 meV were integrated in therange of 5.00<2 <9.17 deg, 8.58<2 <9.17 deg and6.19<2 <7.98 deg, respectively. Zero points of the intensity are
shown as broken horizontal lines. The solid lines are drawn witha triple-Gaussian or quadruple-Gaussian fitting including anelastic part. (b) Scan-areas projected on the scattering plane. The
open squares indicate magnetic points, and the numbers (0, 50,
100, 150 and 200) mean the values of energy transfer. The
spectra in (a) are integrated within the sharp sectors in (b).

Figure 2. (a) Energy spectra integrated in the range of
6.19<2 <9.17 deg and 5.00<2 <7.98 deg in the single-crystal
data on INC. These data were measured at E i =506 meV, ki//[110] and T=150 K. (b) Scan-areas projected on the scattering
plane. In both (a) and (b), details are the same as those in Figs.
1(a) and 1(b).

Figure 3. Dispersion relations of magnetic excitations in CoO,
determined along the [001], [110] and [111] directions at 150 K.
The solid circles and squares were obtained in single-crystal
experiments on PONTA, and the open circles, squares andtriangles were obtained in single-crystal experiments on INC.
The solid lines show calculated dispersion-relations, obtained byfitting the positions of the plots with Hso+Hex. The broken lines
show the appearance before splitting of the two lowest modes.

40

Figure 3 shows dispersion relations along thesymmetric directions, obtained by plotting the solid(PONTA) or open (INC) marks at the positions of
the peak-tops on the energy spectra in all of thesingle-crystal data. The error-bars attached with thesolid symbols are vertical along loci of constant-Q
scans. Similarly, the diagonal error-bars are written
along projections on the (0, 0, q, E), (q, q, 0, E) and(q, q, q, E) planes of scan-loci running in the fourdimensional (Q, E) space.
In the sense of a transformation in the shapes ofelectron clouds, the L-mode is common with anorbital wave and a quadrupole wave. However, theL-mode comes from the antiferromagnetic order of
L coupled with S. Since a Co2+ ion is characterized
by a non-degenerate ground state, CoO will exhibit
ferro-orbital ordering. The L-mode should be
distinguished from the orbital and quadrupole
waves.
We are now investigating magnetic excitationsin the higher energy region, which is still new fieldin the neutron science, because a steady state reactor
neutron source is difficult to reach such energy
region. It is hoped that our researches develop thephysics of L.
References
1) J. Kanamori: Prog. Theor. Phys. 17 (1957) 177
and 197.
2) K. Motizuki: (private communications) at Kansai
University, haru no bunkakai JPS, 2000.
3) J. Sakurai, W. J. Buyers, R. A. Cowley and G.
Dolling: Phys. Rev. 167 (1968) 510.
4) T.M.Holden, W. J. L. Buyers, E. C. Svensson, R.
A. Cowley, M. T. Hutchings, D. Hukin, and R.
W. H. Stevenson: J. Phys. C 4 (1971) 2127.
5) W. J. L. Buyers, T. M. Holden, E. C. Svensson,
R. A. Cowley and M. T. Hutchings: J. Phys. C 4(1971) 2139.
6) R. A. Cowley, P. Martel and R. W. H.
Stevenson: Phys. Rev. Lett. 18 (1967) 162.
7) P. Martel, R. A. Cowley and R. W. H.
Stevenson: Canadian. J. Phys. 46 (1968) 1355.
8) K. Tomiyasu and S. Itoh: J. Phys. Soc. Jpn.
(submitted).

Spin-dependent Quantum Renormalization Factor in One-dimensional Heisenberg
Antiferromagnets
S. ITOH, Y. ENDOH1, K. KAKURAI2 and H. TANAKA3
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, 305-0801
1
International Institute for Advanced Studies, Kyoto, 619-0225
2
Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195
3
Research Center for Low Temperature Physics, Tokyo Institute of Technology, Tokyo 152-8551
Quantum effects in the spin dynamics in onedimensional (1D) Heisenberg antiferromagnets arestrongly dependent on the spin quantum number (S)of the magnetic atoms. One of the remarkable
quantum effects is the quantum renormalization inmagnetic excitation energies: the classical Néel state
is not the ground state, and then the excitationenergies from the ground state to the first excitedstate are enhanced. The enhancement factor(quantum renormalization factor, R) has been
predicted to be R = /2 for S = 1/2 [1]. The zone
boundary energy is expressed as EZB = 4SJ forclassical systems, whereas EZB = 4SJR for quantum
systems with R depending on S, where J is theexchange constant. It was long time ago confirmedthat R = /2 for S = 1/2 by the inelastic neutron
scattering experiment on CuCl22N(C5D5) [2].
An inelastic neutron scattering experiment candetermine EZB. The value of R can be estimated fromthe observed EZB using J determined from anotherexperiment. In the case of S = 1/2, since thetemperature (T) dependence of the magnetic
susceptibility, (T) [3] was in good agreement with
the quantum theory [4], J was determined from (T)exactly. For S = 1, since the quantum theory
describing (T) has been developed very recently[5], J can be determined from (T) [6]. However, forsystems with larger S, the quantum theory for (T)has not been developed, also the observed (T) are
not fitted to the classical model very well [7,8].
We performed the inelastic neutron scatteringexperiments in CsNiCl3 (S = 1), CsVCl3 (S = 3/2)
and CsCrCl3 (S = 2) [9-12], in order to try to
determine the quantum renormalization factor, R, as
a function of S experimentally. These systems havebeen known to be the quasi-1D Heisenberg
antiferromagnets which order three-dimensionallyat TN = 4.8 K (CsNiCl3), at TN = 13 K (CsVCl3) andat TN = 16 K (CsCrCl3). We try to determine J fromthe T dependence of the inverse magnetic
correlation length, (T), independently on thedetermination of the excitation energies, because(T) is described as a function of J only [13].
Experiments on CsNiCl3, CsVCl3 and CsCrCl3
were performed at KENS and ISIS. We measured
the dispersion relation of magnetic excitations, E(q),as well as (T). In CsNiCl3, E(q) and (T) were
measured on INC at KENS. In CsVCl3, E(q) and(T) were measured on the chopper spectrometer
MARI and the crystal analyzer spectrometer
PRISMA, respectively. In CsCrCl3, E(q) and (T)were measured on INC and PRISMA, respectively.
As shown in Fig. 1, the entire magnetic
excitations in CsVCl3 were clearly observed [9]. In
principle, S(q) can be deduced by the dynamical
structure factor, S(q, ), integrating over . The q
resolution ( q) was 0.2 Å-1 in this experiment with
Ei = 123 meV, and it was too coarse to determine .
Then, on PRISMA, we measured S(q, ) with q =0.02 Å-1, S(q) was deduced by S(q, ) integratingover , finally was determined by fitting S(q) to a
Lorentzian scattering function convoluted by the
instrumental resolution. Similarly, in CsCrCl3, E(q)and (T) were measured on INC and PRISMA,
respectively. In CsNiCl3, since q = 0.05 Å-1 for Ei =20 meV on INC, E(q) and (T) were determined byusing the same data.

Fig. 1

Magnetic excitations in CsVCl3 measured at T =40 K (>TN) with Ei = 123 meV on MARI.

41

S=1 CsNiCl3

S=3/2 CsVCl3

8

T=6K
R = 1.6 ± 0.2
Rtheo = 1.37

6

E (meV)100

S=2 CsCrCl3

T = 40 K
R = 1.45 ± 0.27
Rtheo = 1.21

80

T = 20 K
R = 1.15 ± 0.06
Rtheo = 1.14

30

60

4

the excitation energies were in good agreement with
the quantum renormalization factors predicted by
the quantum Monte Carlo calculation [14] within theexperimental errors.

40

20

40
2

INC
0
0.0

0.1

0.2

0.3

0.4

10

20

0.5

MARI

0
0.0

0.1

q (rlu)
0.5

0.2

0.3

0.4

INC
0.5

0
0.0

0.1

0.2

0.3

0.4

q (rlu)q (rlu)J = 100 ± 19 K

J = 28.1 ± 1.2 K

0.5

0.2

J = 11.0 ± 1.4 K

Table 1. The zone boundary energy (EZB) and theexchange constant (J) were determined at present. The
renormalization factors (R) were deduced from EZB and J.
The values of R have been predicted by the quantum
Monte Carlo calculation (QMC) are also listed.

(rlu)

0.4

0.1
0.2
0.1
0.0

INC
0

10

20

T (K)

Fig. 230

PRISMA
40

0.0

0

50

100 150 200 250

T (K)PRISMA
0.0

0

40

80

T (K)

Dispersion relation of the magnetic excitations,
E(q), and the T dependence of the inverse
correlation length, (T), in CsNiCl3, CsVCl3 andCsCrCl3. The solid lines are the fitted curves. The
sine curves with bars in the upper figures are theclassical dispersion relation estimated by J from(T), and the bars are the experimental errors.

The measured E(q)’s were plotted in the upper
figures in Fig. 2. In the present experiments, at thetemperatures where the dispersion relations were
measured, T = 6 K for CsNiCl3, T = 40 K for
CsVCl3 and T = 20 K for CsCrCl3, the condition for
low temperatures, T/(2S(S+1)J) << 1, is satisfied.
Also, the measurements were performed above TN inorder to discuss the 1D nature.
The determined (T) for each system was wellfitted to that predicted by the quantum theory which
is described as a function of J for each S [13], asshown in the lower figures in Fig. 2. Then, the valueof J for each system was determined. The sine
curves with bars in the upper figures are the classicaldispersion relations expected from J determinedfrom (T).
In the relation, EZB = 4SJR, by using J
determined from (T), R can be determined, and thevalues are listed in Table I. The dispersion relationof the magnetic excitations has been calculated as afunction of S by the quantum Monte Carlocalculation [14]. In the calculation, we can know theratio of the zone boundary energy to that for theclassical limit. The theoretical value of the ratio,
which is the quantum renormalization factor in thepresent definition, is also listed in Table I. The
presently obtained values of enhancement factors in

42

CsNiCl3

CsVCl3

CsCrCl3

S

1

3/2

2

EZB [meV]J [K] from

6.1 ± 0.1

75.0 ± 0.7

22.2 ± 0.2

11.0 ± 1.4

100 ±1928.1 ± 1.2

J[K] from

12

115

27.8

R (=EZB/4SJ)

1.6 ± 0.2

1.45 ± 0.27

1.15 ± 0.06

R (QMC)

1.37

1.21

1.14

0.1

0.3

120

References
1) J. des Cloizeaux and J. J. Pearson, Phys. Rev.
128 (1962) 2131.
2) Y. Endoh, G. Shirane, R. J. Birgeneau, P. M.
Richards and S. L. Holt, Phys. Rev. Lett. 32(1974) 170.
3) K. Takeda, S. Matsukawa and T. Haseda, J. Phys.
Soc. Jpn. 30 (1971) 1330.
4) J. C. Bonner and M. E. Fisher, Phys. Rev. 135(1964) A640.
5) S. Yamamoto, J. Phys. Soc. Jpn. 64 (1995) 4051.
6) T. Asano, Y. Ajiro, M. Mekata, K. Kamishima,
K. Koui, T. Goto, M. Furusawa and H. Hori, J.
Phys. Soc. Jpn. 66 (1997) 460.
7) M. Niel, C. Cros, G. le Flem, M. Pouchard and P.
Hagenmuller, Physica 86-88B (1977) 702.
8) Y. Tazuke, H. Tanaka, K. Iio and K. Nagata, J.
Phys. Soc. Jpn. 53 (1984) 3191.
9) S. Itoh, Y. Endoh, K. Kakurai and H. Tanaka,
Phys. Rev. Lett. 74 (1995) 2375.
10) S. Itoh, Y. Endoh, K. Kakurai, H. Tanaka, S. M.
Bennington, T. G. Perring, K. Ohoyama, M. J.
Harris, K. Nakajima and C. D. Frost, Phys. Rev.
B 59 (1999) 14406.
11) S. Itoh, H. Tanaka and M. J. Bull, J. Phys. Soc.
Jpn. 71 (2002) 1148.
12) S. Itoh, Y. Endoh, K. Kakurai and H. Tanaka, J.
Phys. Soc. Jpn. 73 (2004) 269.
13) N. Hatano and M. Suzuki, J. Phys. Soc. Jpn. 62(1993) 1346.
14) S. Yamamoto, Phys. Rev. Lett. 75 (1995) 3348.

Structure and Absorption Mechanism of Carbon Materials for High Capacity Secondary
Battery
M. NAGAO, C. PITTELOUD, T. KAMIYAMAA, T. OTOMOA, K. ITOHB, T. FUKUNAGAB,
K. TATSUMIC, R. KANNO*Tokyo Institute of Technology, Dpt. of Electronic Chemistry, Interdisciplinary Graduate School of
Science and Engineering, Yokohama, Nagatsuta-cho, Midori-ku, 226-8502
a
Neutron Science Laboratory, Institute of Materials Structure and Technology, High Energy
Accelerator Research Organization, Oho, Tsukuba, 305-0801b
Kyoto University, Research Reactor Institute, Kumatori-cho, Sennan-gun, 590-0494
cNational Institute of Advanced Industrial Science and Technology, Ikeda, Osaka, 653-8577

indicating a similar local structure. Figure 1 shows
the radial distribution function RDF(r) calculated
from the total neutron scattering data measured atroom temperature for the hard carbon and lithiatedcarbon.
40

RDF(r)The lithiation mechanism of the hard carbon has
been studied to clarify its higher lithium capacity
and as a material design tool to develop and improvethe capacity of future materials. Two structuralmodels are fairly accepted to explain the structure:
the “card house” model, and the “wave” model.
Card house model is based on small domain size ofgraphene layer, and each domain is situated towards
each other in a different orientation so as to form
small void between these domains. The other modelis basically formed by graphene layer, in someregion of the graphene layer, the distance between
the layers is much larger than other domains, whichmakes nano-size space with flat shape [1]. Lithium
may insert into these nano-size space so as to form asurface lithium layer similar to the lithium adsorbedon the graphite surface.
The lithiation mechanism has been discussed
based mainly on the NRM data, and no conclusive
information was obtained due to the lack ofstructural details. We used neutron scattering
technique, efficient to obtain structure information
for compounds containing light element such aslithium, and it was done with two different kind ofexperiments: small angle neutron scattering (SWAN,
will be presented in another report) and total neutron
scattering (HIT-II, presented here).
Carbon fiber used in the present study was
prepared by heat-treatment at 1200°C of an isotropic
petroleum pitch as a precursor. Electrochemicallithium insertion was performed in a three-electrodecell. The fully lithiated carbon (LiC5) was preparedby short-circuiting the cell after 24h. The partiallylithiated carbons were prepared by a charge to
0.01V.
It is worth to note first that the hard carbon
shows almost the same pattern as the graphite,C
LiC 15.6
LiC 7.8
LiC 5

20

0
0

1

2

3

4

r (Å)

Fig. 1

Radial distribution function of the carbons withvarious lithium content

The first peak at r  1.4 Å corresponds to thenearest neighbor of C-C distance in the graphene
layer. The second peak r  2.4 Å is related to thefirst peak with r2 = 3 x r1; this corresponds to thesecond nearest neighbor of the C-C distance in thegraphene layer. Similar relationships were found
for the other peaks with larger r values. The hardcarbon is composed of regular six-member ring andis basically composed of two-dimensional graphene
layer similar to the graphite.
Table. 1 Distance, rc-c and coordination number for the
hard carbon and the lithiated hard carbon

C
LiC15.6
LiC7.8LiC5First neighborCNrc-c (Å)
1.418
3.0
1.418
3.0
1.426
3.1
1.433
2.8

Second neighborrc-c (Å)
CN
2.456
6.0
2.456
5.9
2.469
5.8
2.480
5.3

43

The C-C distances increased in the deep
lithiation region of x  15.6 (in LiCx)、see table 1
and figure 2. The increase in the C-C distancecorresponds to the lithiation process into the void.
The coordination number of the non-lithiated hardcarbon found was 3.0.
1.435

(a)
distance r / Å

1.430

1.425

1.420

1.415

C

LiC 15. 6

LiC 7. 8

LiC 5

LiC 15. 6

LiC 7. 8

LiC 5

2.480

(b)

distance r / Å

2.475
2.470
2.465
2.460
2.455

C

Fig. 2C-C distances as a function of Li/C ratio. The
nearest neighbor (a), and the second nearest
neighbor distance (b).

Lithium intercalation
between graphite layera = 2.456 Å
La = 23.8 Å
First neighbor (C-C)
rC-C = 1.418 Å
CNC-C = 3.0
Fig. 344

References
1) R.E. Franklin, Proc. Roy. Soc. A209 (1951) 196
2) R. Kanno and al., J. Eletrochem. Soc. 153 (2006)
A914

c = 7.480 Å-1
QO = 1.680 Å
 = 3.04
P = 3.62

c = 7.192 Å
Lc = 13.8 Å-1
QO = 1.747 Å
 = 3.19
P = 4.00
24Å

For the lithiated sample coordination number of
3 was also found, indicating that the structure in two
dimensional graphene layers has only few edges
similar to the graphite structure.
The values
obtained for the second nearest neighbor show a
gradual decrease during the lithium insertion and noaccurate values could be obtained. Nevertheless,this is a direct evidence for the first Li-C
contribution to the RDF(r), which gives a negative
peak due to the sign of scattering length for lithium.
The bond length for the Li-C is comparable to thatfound in carbon nanotubes by first principle
calculations.
When the present results are combined withthose obtained from X-ray and small angle neutron
scattering, a model for the lithium insertion can beproposed as shown in figure 3. The structure of thehard carbon is composed of two-dimensional
stacked graphene layer and the disorderedarrangements of the layers or “wrinkled” sheets
form voids on the nano-size. Lithium intercalates
into the periodically layered region in the shallow
lithiation region and then inserts into the void [2].

a = 2.456 ÅFirst neighbor (C-C)
rC-C = 1.418 Å
CNC-C = 3.0

c = 7.656 Å-1
QO = 1.641 Å
 = 3.26
P = 3.18
Lithium insertion intovoids

a = 2.469 ÅFirst neighbor (C-C)
rC-C = 1.426 Å
CNC-C = 3.1

a = 2.480 Å
First neighbor (C-C)
rC-C = 1.433 Å
CNC-C = 2.8

Schematic drawing of the structures and lithiation mechanism for the hard carbon

Local Structure of β-V2D: Pair Distribution Function Analysis and Reverse Monte Carlo Modeling
K. ITOH and T. FUKUNAGA
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
Pair distribution function (PDF) analysis ofneutron or X-ray diffraction data havs been used foran observation of short-range structure in
non-crystalline materials but has recently begun tobe applied to the study of crystalline materials. The
conventional approach to the structural study on
crystalline materials by diffraction is done using the
Bragg peaks. This yields information on the average
structure. By contrast, PDF analysis yields direct
information on the local structure.
There has been a number of earlier studies of thestructure of β-V2D. Figure 1 shows the average
structure of β-V2D at room temperature [2,3], where
the V atoms form b.c.t. lattice and the D atoms
occupy the octahedral sites. In this work, PDF
analysis and reverse Monte Carlo (RMC) simulation[1] using X-ray and neutron diffraction data wasused to elucidate the local structure of β-V2D.
The X-ray diffraction measurement was carriedout by using the horizontal two-axis diffractometeron BL04B2 beam line at SPring-8. The neutron
diffraction measurement was carried out in the HITII spectrometer. The structure factor was derived byapplying various kinds of corrections to thebackground, absorption and multiple scattering, andnormalizing with a incident neutron beam profile.
RMC simulation was carried out through fitting to
the X-ray and neutron pair distribution functions. To
ensure a physically realistic configuration, theclosest distances and coordination numbers between
two atoms (V-V, V-D and D-D) allowed to approacheach other were determined from the experimental
total distribution functions.
Fig. 2 shows an average density distribution of
deuterium and vanadium atoms in the (001) planesof the b.c.t. vanadium lattice derived from a 0.04 nm
thick slice of the RMC configuration. It should be
noted that there are very few deuterium atoms in thecentre of the octahedral sites, but in the arias
displaced from the center.
References
1) R. L. McGreevy, L. Pusztai, Molec. Sim. 1(1988) 359-367.

2) D. G. Westlake, M. H. Meuller and H. W. Knott,
J. Appl. Cryst., 6 (1973) 206.
3) H. Asano and M. Hirabayashi, phys. stat. sol. (a)15 (1973) 267
A

B

c0
b0

a0
C

Fig. 1 Structure of β-V2D at room temperature [2,3].
Large spheres are the V atoms, forming b.c.t. latticeindicated by thin lines. The D atoms are located at
the octahedral sites depicted by small spheres.

V
D

b0
a0
Fig. 2 Average density distribution of deuterium andvanadium atoms in the (001) planes of the b.c.t.
lattice45

Pulsed-neutron Diffraction Investigations of Long-period Commensurate
Modulation of TbRu 2Ge2 in an External Magnetic Field
S. KAWANO, K. MUROGAKI*, M. TAKAHASHI** and T. SHIGEOKA***
Research Reactor Institute, Kyoto University, Kumatori, Sennan, Osaka 590-0494, Japan*Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan**Institute of Materials Science, University of Tsukuba, Ibaraki 305-8573, Japan***Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, JapanThe ternary rare-earth compound, TbRu 2Ge2
shows temperature- and field-induced magnetictransitions, as shown in Fig. 1 [1]. Previous single
crystal neutron diffraction studies [2] have revealed
that the magnetic structure of the phase I (zero-fieldhigh temperature phase) is described by the magnetic propagation vector Q=(4/17 0 0) with an arrangement of ferromagnetic and paramagnetic (2 00)/(1 0 0) planes in the one-dimensional sequence
along the a-axis of 0444404444 , where ‘0’, ‘4’, and‘ 4 ’ denotes a paramagnetic plane, and four con-Fig. 1. (H, T) magnetic phase diagram of TbRu2Ge2
determined from magnetization measurements [1].

secutive ferromagnetic planes with the moment parallel, and anti-parallel to the c-axis, respectively, inthe magnetic unit cell of 17a×a×c , where a and c
are lattice constants of the original chemical cell. On
the other hand, the magnetic structure of the phase II(zero-field low-temperature phase) becomes
two-dimensional with the same Q arrangement of4444 4444 , where ‘ ’ and ‘ ’ represents two
antiferromagnetic (2 0 0)/(1 0 0) planes with thephase difference , containing one frustrated paramagnetic Tb ion at corner and body-centered positions, respectively [2]. These planes are a kind of
discommensuration comparing with normal ferromagnetic (2 0 0)/(1 0 0) planes, and should be called
mixed planes after Garnier et al. [3].
46

In the present note we report results ofpulsed-neutron diffraction studies of single crystal
TbRu2Ge2 in an external magnetic field to determine
the magnetic structures of field-induced phases of I’
to VI.
Single crystal pulsed-neutron diffraction experiments were carried out using KENS-FOX diffractometer [4]. The c-axis of the single crystal was vertically oriented in a liquid helium cryostat with asuperconducting magnet. Magnetic fields, therefore,
were applied along the magnetization easy c-axis.
The temperature was kept below the lower transition
point Tt’=4.3 K.
Figure 1 gives distribution of neutron intensities
in the a*-b* reciprocal plane of a zero-field phase II(a) and field-induced phases I’ (b) to V (e). No clear
difference of the diffraction patterns between phases
V and VI was observed. The diffraction patterns
from phase II to IV are very similar, and show
strong Bragg reflections on the high-symmetry lines
and weak ones on the low-symmetry lines, but thepattern of phase I’ indicates an existence of weak
spots at (13/17 1±4/17 0) on low-symmetry (1-4/17
k 0) and (4/17 k 0) lines, which are rather diffusive.
A very similar (H, T) phase diagram has been foundin TbRu2Si2 [5] and DyRu2Si2 [6], showing themodulation to be one-dimensional. In the present
TbRu2Ge2, therefore, the observed weak spots above
mentioned would be a residue of two-dimensional
modulation of phase II, and the spin modulation
would be considered to be one-dimensional.
From magnetization measurements Garnier et al.
[1] have reported that the magnetization values ofzero-field phase II, field-induced phase I’, III, IV to
V are 0.0MS, 0.076MS, 0.13MS, 0.17MS and 0.49MS
at 1.5 K, respectively, where MS is the saturation
magnetization of MS=8.94μB. Thus, a reproducible
spin structure of the distribution of magnetic intensities in Fig. 1 is proposed as shown in Fig. 2 forzero-field phase II, field-induced phase I’, III, IV, tophase V, whose structures give the magnetization
values of 0MS, 0.06MS, 0.13MS, 0.15MS, and 0.50MS,

(a)

(b)

(d)

(e)

0

17
16
15

6 7

8 9 10 11 12 13 14 15 16 17[1 0 0](b) Phase I’

14
13

6
5
4

[0 1 0]

12
11

10
9
8
7

[0 1 0][0 1 0]2 3 4 5

17
16
15

14
13
12
11

10
9
8
7
6
5
4

3
2
1
0

0 1

3
2
1

0 1

2 3 4 56 7

8 9 10 11 12 13 14 15 16 17[1 0 0](a) Phase II

0

17
16
15

17
16
15

14
13
12
11

14
13
12
11

10
9
8
7

10
9
8
7

6
5
4

6
5
4

3
2
1

3
2
1

0
0 1

2 3 4 56 7

8 9 10 11 12 13 14 15 16 17[1 0 0](c) phase III

Fig. 1. Distribution of neutron intensities of the phases of II (a), I’ (b),III (c), IV (d) and V (e) in the a*-b*
reciprocal plane. The broad arcs inthe figures are Debye-Scherrer rings
from scatterings of the Al windows in
the He-cryostat.

[0 1 0]

1

(c)

0 1

2 3 4 56 7

8 9 10 11 12 13 14 15 16 17[1 0 0](d) phase IV00 1

2 3 4 56 7

8 9 10 11 12 13 14 15 16 17[1 0 0](e) phase V

Fig. 2. Proposed magnetic structures of the zero-field low-temperature phase II (a), I’ (b), III (c), IV (d), and V (e) ofTbRu2Ge2, projected on the c-plane. The circles and squares denote the corner and body-centered positions of thechemical cell, while open and solid symbols represent the Tb spins parallel and anti-parallel to the c-axis, respectively.
The crossed-circles in phase II (a) give frustrated paramagnetic Tb ions. The smallest parallelogram indicates the original chemical cell.

based on the models, respectively. These values areclose to the measured ones above mentioned.
The diffraction patterns of phase II, III and IV
are similar, showing that the magnetic satellites arestrong on the high-symmetry lines, and weak on the
low-symmetry lines, so that the modulations arenearly one-dimensional. On the other hand, the pattern of phase V gives strong satellites on the
low-symmetry lines as well as on the high-symmetrylines, suggesting the symmetry to be higher than theothers.
The modulation of phase I’ is one-dimensionaldescribed by the sequence of 54445444 without
any mixed plane, using the notation mentioned before. On the other hand, the two-dimensional modulation of the phase III contains one ferrimagnetic (20 0)/(1 0 0) plane (mixed plane) for every 17 ferromagnetic (2 0 0)/(1 0 0) plane, described by the47

3544 3544 sequence with two ferrimagnetic (2 00)/(1 0 0) planes of and , so that this modulation is very close to one-dimensional one but definitely two-dimensional. Similarly the modulation ofphase IV is described by the sequence of
53 4 353 4 3 . The modulation of phase V is tetragonally symmetric, and shows no one-dimensional
character. Calculated magnetic structure factors forthe models are, as a whole, reproducible of the distribution of the magnetic intensities in Fig. 2.
References[1] A. Garnier, D. Gignoux, D. Schmitt, T. Shigeoka, Physica B 212 (1995) 343.
[2] S. Kawano, T. Kosugi, M. Takahashi, T. Shigeoka, N. Iwata, J. Phys. Soc. Jpn. 70 (2001) Suppl.
A p. 209.
[3] A. Garnier, D. Gignoux, D. Schmitt, T. Shigeoka, J. Phys.: Cond. Matter 10 (1998) 3919.
[4]
M.
Takahashi,
KEK
Proc.
2000-22/JAERI-Conf. 2001-002 (2001) Vol. 1, P.
492.
[5] S. Kawano, M. Takahashi, T. Shigeoka, N.
Iwata, M. Shiimoto, B. Lebech, Physica B (2006)
in Press.
[6] S. Kawano, M. Takahashi, T. Shigeoka, N.
Iwata, M.J. Bull, Physica B 346-347 (2004) 99.

48

III.
EXPERIMENTAL REPORT

2003–2006

CRYSTAL STRUCTURES

2003–2006

Hydration Kinetics of Tricalcium Silicate
K. Mori, Y. Shiraishi, *K. Iwase, **M. Yonemura, *F. Shikanai, *T. Wuernisha, *D. Sulistyanintyas,
K. Itoh, M. Sugiyama, *T. Kamiyama, ***K. Oishi, *M. Kawai and T. Fukunaga
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennnan-gun, Osaka, 590-0494*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization,
Tsukuba, Ibaraki, 305-0801** Institute of Applied Beam Science, Graduate School of Engineering and Science, Ibaraki University,
4-12-1 Nakanarusawa-cho, Hitachi, Ibaraki 316-8511***Institute of Technology, Shimizu Corporation, 3-4-17 Etchujima, Koto-ku, Tokyo 135-8530

Tricalcium silicate (Ca3SiO5) is the mostprincipal component of Ordinary Portland Cement(OPC) clinkers. The hydration process of Ca 3SiO5
can be represented as follows: Ca 3SiO5 +(3+y–x)H2 O(CaO)x(SiO2)(H2O)y + (3–x)Ca(OH)2,
where first and second terms on the right-hand side
indicate calcium silicate hydrate gel (C-S-H gel) anda calcium hydroxide (Ca(OH)2), respectively. In
this work, time-of-flight neutron powder diffraction(TOF-NPD) experiments have been carried out
using the hydrated Ca3SiO5 with heavy water (D2O)[1]. In particular, we focus on the degree ofhydration, x(t), in the early hydration process of
Ca3SiO5 and evaluated the n– and A–values on afour-parameter equation [2,3]:

four-parameter equation. The n- and A-values
were estimated as 2.6 and 0.34, respectively [1].
It is widely recognized that the n-value reflects
the nature of phase transformation through the threeparameters: P, S and Q, where P is thedimensionality for growth product, S is the type ofgrowth, Q is the nucleation rate [2]. The hydrationof Ca3SiO5 may show the interfacial growth (S = 1)
and the site-saturated nucleation (Q = 0) in the
nucleation and growth period, that is, n ~ P.
Presumably, the n-value indicated the fractal
nucleation and growth mainly depends on thegrowth form of C-S-H gel such as tobermorite andjennite.
6000
2 months of hydration

ln k,where k is the nucleation and growth reaction rate
constant, ti is the induction time, n is the exponent
which characterizes the hydration process, A is theasymptotic value of the amount of bound water thatcan be formed as t.
The hydration properties of Ca3SiO5 up to 2
months were studied by the neutron powder
diffractometer, Vega, installed at KEK-KENS [4].
The D2O to Ca3SiO5 mass ratio (D2 O/Ca3SiO5) is 0.5.
In order to quantify the x(t), we applied the standard
addition method with Si. The Rietveld analysis
program, RIETAN-2001T, developed for Vega wasutilized in the multi-phase Rietveld refinements [5].
Figure 1 shows the final Rietveld refinement
pattern of the hydrated Ca3SiO5 for 2 months ofhydration (Rwp = 3.12% and S = 1.3463). The
multi-phase Rietveld analyses of the hydrated
Ca3SiO5 were carried out assuming three phases:
unhydrated Ca3SiO5, Ca(OD)2 and Si. Eventually,
these results of multi-phase Rietveld refinements
gave us the x(t). As can be seen in Fig. 2, thestraight line fit to this data was obtained using theIntensityn ln t t i

4000
2000

0
Ca3SiO5Ca(OD)2
Si
Obs. – Cal.
1.0

1.5

2.0

2.5

3.0

3.5

4.0

d/Å

Fig. 1.

Rietveld refinement pattern of hydrated Ca 3SiO5.
2ln[-ln(1 - x(t)/A)]x t
ln ln 1A

observation
calculation

0
-2
-4
-6
0.0

Fig. 2.

0.5

1.0

1.5
2.0
ln(t - 6)

2.5

3.0

3.5

A plot of the logarithmic form based on thefour-parameter equation.

References
1) K. Mori et al., Trans. Mater. Res. Soc. Jpn., in press.
2) R. A. Livingston, Cem. Con. Res. 30 (2000) 1853.
3) S. A. FitzGerald et al., Cem. Con. Res. 32 (2002) 409.
4) T. Kamiyama et al., Physica B 213&214 (1995) 875.
5) T. Ohta et al., Physica B 234&236 (1997) 1093.

53

TOF Neutron Powder Diffraction Study on the Time Dependence of Phase Transition at Room
Temperature of Quenched La1.5Pr0.5CuO4
T. WUERNISHA, M. YONEMURA*, Y. IKEDA**, M. AZUMA**,Y. SHIMAKAWA** and T. KAMIYAMA
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan* Institute of Applied Beam Science, Graduate School of Science and Engineering, Ibaraki University,
Hitachi, Ibaraki 316-8511, Japan** Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, JapanThe study of ternary phase diagram of the
La2O3-Pr6O11-CuO system by Ikeda et al.
revealed the T’ phase of La2-xPrxCuO4 in thex0.65 besides the Pr-richrange of 0.5
T’ phase in the range of 1.1
x
2 [1].
A polycrystalline sample of La1.5Pr0.5CuO4
is used for this study, and details of the sample
preparation are given in another paper [1]. Prior
to the neutron powder diffraction measurements,
the sintered pellet of La1.5Pr0.5CuO4 washeat-treated at 1000C for several hours thenquenched to RT in air. The sample breaks easily
into fine powder during the quenched process[1]. The obtained powder sample was put in acylindrical vanadium cell and immediately
mounted in the neutron powder diffractometer
VEGA [2]. Data collection started about 10 min
after the sample was quenched. Sequential TOF
neutron powder diffraction data sets werecollected with collecting times at RT. In total,
22 data sets were collected with slowly rotating
the sample (vanadium cell), for a total elapsed
time of ~ 25 hours. Powder XRD measurements
have been performed in the temperature range
RT ~ 1000C at intervals of 100C using a
MAC Science MXP21 diffractometer with Cu
K radiation in the 2 range of 20 ~ 60.
All of the TOF diffraction data in the dranges from 0.47 to 5.0 Å were analyzed by the
Rietveld method with RIETAN-2001T program[3]. We carried out refinements based on the
two-phase model: T phase structure with spacegroup Cmca and T’ phase Nd2CuO4 structurewith space group I4/mmm. The T phasestructure with space group Cmca is the54

orthorhombic modification of the K2NiF4
structure (space group I4/mmm), which appears
at low temperatures in the hole-doped
superconductor La2-xAxCuO4 (A=Ca, Sr,and Ba).
In the refinements both for T and T’ phases, therefined parameters included the lattice
parameters, all variable atom positions, theoccupancies of the oxygen sites, g(O1) and g(O2),and the isotropic displacement parameters, B,
for all the metal and oxygen atoms. Whereas theoccupancies of the La, Pr site, g(La, Pr), and of theCu site, g(Cu), were set to 1. And the refinements
gave good fits with low R as well as almost thesame values and small standard deviations forall of the data.

Fig. 1. Time dependence of mass fraction of T
(Cmca) and T’ (I4/mmm) phases of the quenched
La1.5Pr0.5CuO4 at RT.

Mass fraction of the T and T’ phases isshown as a function of time in Fig. 1. The
as-quenched sample is composed mainly of theT phase, and as elapsed time the T’ phasebecomes dominant. In the final stage of 1436
min, the sample consists almost of the T’ phase.
Figure 2 shows a typical Rietveld
refinement pattern obtained with the two-phasemodel of T and T’ structures for the quenchedsample of La1.5Pr0.5CuO4. The corresponding
lattice and structure parameters, final R factors
are listed in Tables 1 and 2.
Although we refined the occupation factorsof the O(1) and O(2) sites of both T and T’phases, we did not obtain the result to indicate
the deficiency at these sites. Therefore, theoxygen stoichiometry is 4. In the refinement
results, the O(2) atom in the T phase showed aslightly large isotropic displacement parameter.
It can be considered to be due to a large thermal
vibration of this site.
Refinement results revealed that all thelattice parameters and unit cell volumes of both
T and T’ phases do not change significantly withtime. And final stable structure ofT’-La1.5Pr0.5CuO4 with lattice parameters of a =3.9915(8) and c = 12.467(3) Å.
Table1. Structural parameters of
La1.5Pr0.5CuOy at RT determinedfromtwo-phase
Rietveldrefinement of TOF neutron
powder diffraction data of Fig. 2(a). Rwp = 5.58%, Rp = 4.37%, Re= 5.10%, S = 1.09% First phase(T phase): RI = 1.11%, massfraction 72.9%. Unit cell (Å): a =5.34219(8), b = 13.0652(2), c =5.41132(9).
Second phase (T’ phase): RI =1.00%, mass fraction 27.1%. Unit
cell (Å): a = 3.99123(15), c =12.4675(6).
Occupation factors, g, for all sites
are fixed at unity because we do
not obtain the result to indicate
the deficiency.

Fig. 2. The typical Rietveld refinement pattern ofneutron diffraction data for the quenched sample ofLa1.5Pr0.5CuO4 analyzed with a two-phase mixture of
T (Cmca) and T’ (I4/mmm): (a) T phase dominantand (b) T’ phase dominant.

Space group: Cmca
Atom Sitexyz

B (Å2)

g

La

8f

0

0.36134(9)0.0082(3)0.36(3)

0.75

Pr

8f

0

0.36134(9)0.0082(2)0.36(3)

0.25

Cu

4a

0

0

0

0.25(3)

1

O(1)

8e

1/4 0.00888(15)1/40.59(3) 1.01(1)

O(2)

8f

0

0.18435(14) -0.0400(3) 1.15(4) 1.00(1)Space group: I4/mmm

Atom

Site

x

y

z

B (Å2)

g

La

4e

0

0

0.35188(2)0.27(6)

0.75

Pr

4e

0

0

0.35188(2)0.27(6)

0.25

Cu

2a

0

0

0

0.31(7)

1

O(1)

4c

0

1/2

0

0.53(7)1.01(0)

O(2)

4d

0

1/2

1/4

0.46(7)1.01(1)55

Table 2. Structural parameters of
La1.5Pr0.5CuO4 determined fromtwo-phase Rietveld refinement of
TOF neutron powder diffraction
data of Fig. 5 (b). Rwp = 5.59%,
Rp = 4.33%, Re = 4.91%, S =1.14% First phase (T phase): RI =
1.28%, mass fraction 28.6%. Unit
cell (Å): a = 5.34120(2), b =13.0644(6), c = 5.4121(3).
Second phase (T’ phase): RI =0.99%, mass fraction 71.4%.
Occupation factors, g, for all sites
are fixed at unity because we do
not obtain the result to indicate
the deficiency.

Space group: Cmca
Atom

Site

x

y

z

B (Å2)

g

La

8f

0

0.3618(2)0.0084(7)0.43(7)

0.75

Pr

8f

0

0.3618(2)0.0084(7)0.43(7)

0.25

Cu

4a

0

0

0

0.30(8)

1

O(1)

8e

1/4

0.0094(4)1/4

0.56(8)1.01(1)

O(2)

8f

0

0.1847(3)-0.0381(7)1.15(9)1.00(1)

Space group: I4/mmmyz

B (Å2)

g

Atom

Site

x

La

4e

0

0

0.35221(7)0.27(2)

0.75

Pr

4e

0

0

0.35221(7)0.27(2)

0.25

Cu

2a

0

0

0

0.30(3)

1

O(1)

4c

0

1/2

0

0.51(3)1.00(1)

O(2)

4d

0

1/2

1/4

0.53(3)1.00(3)

To conform the structure phase transitionwithtemperature,measurementofhigh-temperature powder XRD was carried out
for this sample. The measurement was started at
RT after the sample was subjected to a complete
transformation to the T’ phase. The lattice
parameters and the unit cell volumes as afunction of temperature calculated by using a
Rietveld method with RIETAN-2000 [4]. In thetemperature range of RT ~800 C, all the XRD
data were fitted with the structure model of T’(I4/mmm). The T phase with the K2NiF4
structure (space group I4/mmm) starts to appear
at about 900 C, the structural phase transition
from T’ to T occurs in the temperature range of
900 C ~ 1000 C, and finally the structure is T at
1000 C.
In summary, we have performed neutron
powder diffraction measurement at RT for thequenched sample of La1.5Pr0.5CuO4. The phasetransition from the T (Cmca) to T’ (I/4mmm)
structure occurred with time. And the final stable56

structure of T’-La1.5Pr0.5CuO4 with lattice
parameters of a = 3.9915(8) and c = 12.467(3) Å.
The high-temperature XRD study showed thephase transition from the T’ (I4/mmm) to T
(I4/mmm) phase in the temperature range of
900 C ~ 1000 C and finally the structure is T at
1000 C.
References[1] Y. Ikeda, K. Yamada, Y. Kusano and J.
Takada, Physica C 378-381 (2002) 395.

[2] T. Kamiyama, K. Oikawa, N. Tsuchiya, M.
Osawa, H. Asano, N Watanabe, M. Furusaka, S.
Satoh, I. Fujikawa, T. Ishigaki and F. Izumi
Physica B 213-214 (1995) 875.
[3] T. Ohta, F. Izumi, K. Oikawa and T. Kamiyama,
Physica B 234-236 (1997) 1093.
[4] F. Izumi and T. Ikeda, Mater. Sci. Forum
312-324 (2000) 198.

Crystal Structure of A-site Deficient Superconductor Ca2-xCuO2Cl2
I. YAMADA, M. AZUMA, A. A. BELIK, S. HARJO*, T. KAMIYAMA*, Y. SHIMAKAWA
and M. TAKANOInstitute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011*Institute for Materials Science, High energy Accelerator Research Organization, 1-1 Oho, Tsukuba,
Ibaraki 305-0801

Superconductivity in copper oxides occurs whenadequate numbers of hole or electron carriers are
introduced into an antiferromagnetic insulator with
CuO2 planes. La2CuO4 becomes superconducting
when the La3+ ions are partially substituted bydivalent alkaline earth ions like Sr2+. Hole doping
can, however, be done in another way. It is wellestablished that the injection of excess oxygen into
interstitial sites works as well. We have found in thecase of Ca2CuO2Cl2, deficiency of the counter cation,
Ca2+, also works.
Copper oxychloride Ca2CuO2 Cl2 shown in Fig. 1
has a single CuO2 plane, the same as La2CuO4. Holedoping by substituting Na for Ca to make thiscompound superconducting was accomplished using
high-pressure (HP) synthesis at 6 GPa.
Ca2-xNaxCuO2Cl2 has the highest TC=28 K at x=0.20.
The ease of sample preparation with a lightly
hole-doped composition, an absence of structuralchanges at low temperature, an absence of structuralmodulation, and excellent single crystal sample
cleavage are ideal for surface sensitive
measurements. Investigations into this compound’s
electronic state using angle-resolved photoemission
spectroscopy
andscanning
tunneling
microscopy/spectroscopy are attracting great
attention.

highest TC was 38 K, 10 K higher than that of
Ca2-xNaxCuO2Cl2. Structure analysis based on
neutron powder diffraction pattern taken by using
the Vega diffractometer at KENS revealed that the
Ca deficiency was the origin of the hole carrier(Fig.
2). This compound has two structural features ascompared to Ca2-xNaxCuO2Cl2; fewer defects and ashorter Cu-Cl bond length. Postannealing at 773 K
led to a further increase of the TC to 43 K. This
superconductor with a flat CuO2 plane might form
the basis for future discussions about the factors that
determine the TC of single-layer cuprates[1].

Fig. 1

Fig. 3

Crystal structure of Ca 2CuO2Cl2.

We havefound anew oxychloride
superconductor
Ca 2-x CuO2Cl2 without cation
substitution by using high-pressure synthesis. The

Fig. 2 Neutron
powderCa2-xCuO 2Cl2 (xn =0.20).

diffraction

pattern

for

TC

in

Carrier number dependence ofCa2-xCuO 2Cl2 and Ca2-xNa xCuO2Cl2.

References
1) I. Yamada et al., Phys. Rev. B, 72 (2005) 224503.
57

High Temperature Phase of Fe-doped Lanthanum Gallate
K. MORI, K. SHIBATA, T. FUKUNAGA, K. ITOH, M. SUGIYAMA,*K. IWASE, **S. HARJO, **A. HOSHIKAWA, **T. ISHIGAKI and *T. KAMIYAMA
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennnan-gun, Osaka, 590-0494*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization,
Tsukuba, Ibaraki, 305-0801**Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195

58

Recently, a diffusion pathway of an oxygen ion wasshown as an arc of a circle above edges ofcorner-sharing [GaO6] octahedra for Sr/Mg-doped
LaGaO3 systems [5]. For our samples, the oxygenions are localized in the rhombohedral perovskite
structure due to the slight oxygen deficiency and the
low temperature, nevertheless this result probably
suggests the direction of the diffusion pathway ofthe oxygen ions around M.
12000

LaGa0.9Fe0.1O3-

10000
8000

Intensity

Lanthanum gallate (LaGaO3) based compounds
have attracted much attention, because they can beutilized as solid oxide fuel cells (SOFCs) andoxygen separation membranes at intermediate
temperatures (600 ~ 800ºC). It was found that the
Fe-doped (La,Sr)GaO3 shows a large oxygen
permeation rate in addition to a high chemical
stability at a wide range of oxygen partial pressures,
while excessive Fe-doping decreases the ionic
conductivity rather than increases [1]. However,
the origin for this complicated phenomenon is still
controversial. In this work, we have prepared
powder samples of LaGa1-xFexO3- (LGF) withvarious Fe-content and carried out neutron powder
diffraction (NPD) experiments at room and hightemperatures [2].
Four polycrystalline samples of LGF (x = 0, 0.1,
0.25 and 0.5) were synthesized by a conventional
ceramics processing. The NPD data of LGF at RT
and 380ºC were collected on the time-of-flightneutron powder diffractometer, Vega, installed at
KEK–KENS [3].
In the Rietveld analyses [4], their crystal
structures at RT could be refined on the basis ofPnma symmetry (Orthorhombic phase), and then the
NPD experiments on LGF with x = 0, 0.1 and 0.25
at 380ºC were carried out in order to study theprecise structure of the high-temperature phase.
The structure parameters were refined on the basisof 3 c symmetry(Rhombohedral phase). It isR
noteworthy that the NPD experiment on
LaGa0.5Fe0.5 O3- was not performed, since no O–R
transition appears below 400ºC for this sample.
Figure 1 shows the final Rietveld refinement
patterns of LaGa0.9Fe0.1O3- . An excellent fit was
obtained between the calculated and the observed
patterns (Rwp = 3.49% and S = 1.1829). The crystal
structure of LaGa0.9Fe0.1O3- in the rhombohedral
high-temperature phase is shown in Fig. 2. Atomic
displacements of atoms are shown as an ellipse.
Especially, it is most likely that oxygen ions on thevertex of [MO6] octahedron (M = Ga/Fe) expand
toward the nearest-neighbor oxygen ones.

6000
4000
2000
0
0.5

1.0

1.5

2.0

2.5

3.0

d/Å

Fig. 1.

Rietveld refinement pattern of LGF at 380ºC.

O

La

Ga/Fe
c
a

Fig. 2.

aCrystal structure of LGF at 380ºC.

References
1) T. Ishihara et al., Solid State Ionics 135 (2000) 631.
2) K. Mori et al., Physica B 352 (2004) 147.
3) T. Kamiyama et al., Physica B 213&214 (1995) 875.
4) T. Ohta et al., Physica B 234&236 (1997) 1093.
5) M. Yashima et al., Chem. Phys. Lett. 380 (2003) 391.

Development of Rietveld-PDF Collaboration Analysis System on Vega
K. MORI, T. FUKUNAGA, K. IWASE*, T. WUERNISHA*, M. YONEMURA**,D. SULISTYANINTYAS*, F. SHIKANAI*, K. ITOH, M. SUGIYAMA,
T. ISHIGAKI*** and T. KAMIYAMA*
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennnan-gun, Osaka, 590-0494*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801**Institute of Applied Beam Science, Graduate School of Engineering and Science, Ibaraki University,
4-12-1 Nakanarusawa-cho, Hitachi, Ibaraki 316-8511***Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195§1. Introduction
Since 1993 Versatile Neutron Diffractometer(Vega) installed at the pulsed neutron source of
Neutron Science Laboratory (KENS) in HighEnergy Accelerator Rersearch Organization (KEK)
has considerably contributed in physics, chemistry
and material science fields through the structure
analysis [1]. The structural investigations would
have mainly focused on crystal structure refinementsof powder samples by taking advantage of the
Rietveld method [2,3]. These days, the Ibaraki
Prefecture Materials Design Diffractometer has been
constructed in the J-PARC project, performing theatomic pair distribution function (PDF) analysis andsmall angle neutron scattering (SANS) experimentin addition to the Rietveld analysis. For one of the
major reasons, recent material science will strongly
demand to get simultaneously more insight of thecrystal, short-range and nano-structures.
In this work, the fundamental development of the
PDF analysis system has been carried out using theVega. The goal of this work is to achieve theRietveld and PDF collaboration analysis from one
time-of-flightneutronpowderdiffraction(TOF-NPD) pattern.
§2. Rietveld–PDF collaboration analysis system
The TOF-NPD data are obtained by on-the-fly
time-focusing method [1,4]. The resolution of theVega, d/d, is 0.25% at a back-scattering detectorbank with 2 between 140 º and 175 º. The rangeof d-spacing is covered up to 5 Å (~ 1.3 Å–1). The
TOF-NPD data can be utilized to refine the crystal
structure through the Rietveld analysis. On theother hand, the PDF software, which derives S(Q),

G(r) and RDF(r) from the TOF-NPD data, has beendeveloped by IGOR Pro, version 5.0 (HULINKS
Corporation) on a Macintosh computer, where S(Q),
G(r) and RDF(r) are the normalized structure factor,
the reduced pair distribution function and the radial
distribution function, respectively. For this system,
we referred to data correction process forbackground, absorption, multiple and incoherent
scattering on the HIT-II [5–7]. The RDF(r) is
derived from the Fourier transformation of the S(Q)measured up to Q = 25 Å-1. Eventually, we cancompare the crystal structure with the short-range
one, as shown in Fig.1.

TOF–NPD data

Rietveld analysis

PDF analysis

Crystal structure

Short-range
structure

Real structure

Fig. 1.

Rietveld–PDF collaboration analysis system.

§3. Examples
3.1 NIST-Si
First of all, the developed PDF analysis system
was evaluated by measuring NIST-Si of which thelattice parameter is guaranteed to be 5.43119 Å.
Figure 2 (a) shows a TOF-NPD pattern of NIST-Si

59

collected on the Vega.
After correcting the
TOF-NPD data, the RDF(r) was derived from theS(Q), as shown in Fig. 2 (b) and (c). In frame (c),the peak position for each correlation of Si–Si,
which was calculated from the known lattice
parameter and atomic coordinates, is indicated as avertical mark under the RDF(r). Even thoughripples slightly appear at short distances, thecoordination number was close to 4 in the nearest
neighbor distance.

was estimated as 6.04916(7) Å. As illustrated inFig. 3 (b), the number of the equivalent atomic sitesof Cu is 16, and occupy for each Cu-site is 0.25.
The peak positions of Cu–Cu correlations estimatedfrom the result of Rietveld analysis are demonstrated
in Fig. 3 (d), but the unrealistic correlation length (=0.32 Å) is also displayed. Actually, in the RDF(r),the Cu–Cu correlations are obviously converged ataround 4.3 Å. Furthermore, it seems that Cu ionsexist stably around I atoms in ~ 2.6 Å.

(a)

(a)

(b)

(b)

(c)

(c)
(d)

Fig. 2.

TOF-NPD pattern (a), S (Q ) (b) and RDF (r ) (c) of
NIST-Si. In frame (c), vertical marks below theRDF indicate the peak position for eachcorrelation of Si–Si.

3.2 –CuICuI is a very famous material, because copperionic conductivity is considerably high above 400ºC[8,9]. Figure 3 (a) shows a Rietveld refinement
pattern of –CuI at RT (Rwp = 3.23% and S = 1.5).
The crystal structure has F 43m space groupsymmetry (cubic phase), and the lattice parameter
60

Fig. 3.

Rietveld refinement pattern (a), crystal structure(b), S(Q ) (c) and RDF(r ) (d) of -CuI. In frame(d), vertical marks below the RDF indicate peak
positions for correlations of Cu–Cu, Cu–I and I–I
estimated from the result of Rietveld analysis.

3.3 –Ca2SiO4
It is well known that –Ca2SiO4 is a principal
component of cement. As shown in Fig. 4 (a), thecrystal structure was refined on the basis of P21 /nspace group symmetry (monoclinic phase) [10,11].
The lattice parameters, a, b, c and were estimatedas 5.50842(6) Å, 6.75038(7) Å, 9.30618(10) Å and94.5854(6) º (Rwp = 2.28% and S = 1.7). In thisstructure, there are two different types of Ca sites;
Ca(1) and Ca(2), respectively. In our previous
work, it was found that the correlation length
distribution of Ca(1)–O is broader than that ofCa(2)–O [11]. Especially, the existence of theshortest Ca(1)–O correlation (~ 2.23 Å) was
suggested from the result of the Rietveld analysis.
Therefore, the Fourier transformation of S(Q) was
carried out to observe the shortest Ca(1)–O in
RDF(r).
Figure 4 (c) shows the RDF(r) of–Ca2SiO4. We could confirm that the Ca–O
correlation distributes up to ~ 2.2 Å. In addition,
the number of oxygen atoms around Si wasestimated ~ 4 from the area of the first peak ataround 1.6 Å which corresponds to Si–O
correlations in a [SiO4] tetrahedron.
(a)§4. Summary
In the present work, the back-scattering detectorbank on the Vega was utilized in order to collect the
TOF-NPD data with the high Q-resolution. This isbecause it has been gradually recognized that to use
a high Q-resolution is really important to determine
the PDF over a large distance range [12].
Eventually, the fairly good RDF could be obtainedby the developed PDF analysis system.
Simultaneously, the Rietveld analysis was
performed using the same TOF-NPD data, and thenwe could demonstrate how to check the structure
model from two points of view; crystal andshort-range structures.
Recently, in three-dimensional visualization of
the crystal and amorphous structures, two advanced
techniques have attracted much attention; theMaximum Entropy Method (MEM) and the Reverse
Monte Carlo (RMC) method, respectively. These
analyses must be performed through the Rietveld
and PDF ones.
In the J-PARC project, the
MEM-RMC collaboration analysis method would be
a promising alternative to the Rietveld and PDF
methods, leading us to the more detailed andvaluable insight of structure for novel materials.
References

(b)

(c)

Fig. 4.

Rietveld refinement pattern (a), S(Q ) (b) andRDF(r ) (c) of -Ca2SiO 4.

1) T. Kamiyama et al., Physica B 213&214 (1995)
875.
2) H. M. Rietveld, J. Appl. Crystallogr. 2 (1969) 65.
3) T. Ohta et al., Phys. B 234&236 (1997) 1093.
4) T. Kamiyama et al., Mater. Sci. Forum 321-324(2000) 302.
5) T. Fukunaga et al., KENS Report-IX (1993) 16.
6) H. H. Paalman and C. J. Pings, J. Appl. Phys. 33(1962) 2635.
7) I. A. Blech and B. L. Averbach, Phys. Rev. 137(1965) A1113.
8) D. A. Keen et al., J. Phys.: Condens. Matter 7(1995) 5793.
9) S. Hull et al., J. Phys.: Condens. Matter 10(1998) 10941.
10) W. G. Mumme et al., N. Jb. Miner. Abh. 169(1995) 35.
11) K. Mori et al., to be submitted.
12) T. Egami and S. J. L. Billinge, Underneath the
Bragg Peaks: Structural Analysis of Complex
Materials, Vol. 7 (2003), Pergamon.

61

Ferroelectric Property and Crystal Structure of (Bi,La)4(Ti,Si)3O12
as a Bulk Ferroelectric Material
Y. IDEMOTO, T. MIYAHARA, N. KOURA, and T. KAMIYAMA*
Department of Pure and Applied Chemistry, Faculty of Science and Technology,
Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, 278-8510* Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
Bi3.25La0.75Ti3O12 (BLT), which is currently used
as capacitor material in ferroelectric memory, hashigh remanent polarization, Pr, low coercive field,
Ec, and good fatigue characteristics, and thus has
been the subject of intensive research[1]. However,this material has problems with the degradation ofcharacteristics when formed into thin films for use
in memory. Kijima et al. reported results obtainedby the formation of a thin film using a sol-gel
solution produced by mixing in arbitrary ratios ofBi3.25La0.75Ti3O12 and Bi2SiO5 and then carrying out
heat treatment at high oxygen partial pressure[2].
We reported that effect of La substitution in BLT
was investigated by comparing its electricalproperties, using a bulk sample, the relation between
properties and crystal structure, as determined byneutron diffraction analysis, was investigated. As aresult, Pr showed a maximum at x= 0.75. Ec showed
the same tendency of Pr, however, its change wassmall. The dielectric constant also showed the sametendency of Pr. Tc decreased with increasing La
substitution content. As a result of crystal structure
analysis, a rotation of TiO6 octahedra in the a-b
plane and a distortion of TiO6 octahedra in the a-cplane moved the cell to a position of tetragonal
system with increasing La substitution content.
Polarization increased with the movement from theposition of ferroelectric phase to the position oftetragonal system, and a suitable flatness of Ti-O 6
octahedra[3].
In this paper, we investigated the crystal
structure and ferroelectric performance of bulk
material obtained by mixing and sintering
Bi3.25La0.75Ti3O12 and bismuth silicates, such as
Bi4Si3O12 or Bi2SiO5, for use as a novel ferroelectricmaterial for ferroelectric memory.
With regard to the synthesis of Si-substituted
BLT, Bi3.25La0.75Ti3O12 and Bi4Si3O12 (raw material(I)) or Bi2SiO5 (raw material (II)) were used, andwet-mixing was carried out at the prescribed ratio.
62

After wet-mixing, the materials were heated for 2 h
at 1000°C in air. The sample was then molded into
pellets, and fired for 2 h at 1100°C in air. The
material was then ground, and reformed into pellets,
followed by heating for 1 h at 1025°C in air toobtain sample (I) and sample (II). The resulting
material was identified as a structure whereby all of
the peaks, as determined by powder X-ray andneutrondiffraction,
were
the
same
as
Bi3.25La0.75Ti3O12, and thus a single phase wasobtained. Moreover, the crystal structure wasdetermined by neutron powder diffraction using
VEGA of KEK. The data were refined via the
Rietveld technique using the Rietan 2001t
program[4].
The crystal growth was superior in the Si
substitution product relative to Bi3.25La0.75Ti3O12
based on SEM observation of the surface
morphology. Based on P-E hysteresis loop
measurement, carried out in order to evaluate theferroelectriccharacteristics,
revealed
animprovement in ferroelectric characteristics,
whereby the remanent polarization, Pr, increased
with both of the Si substitution products (Bi, La)4(Ti,Si)3O12 (I) and (Bi, La)4(Ti, Si)3O12 (II) relative toBi3.25La0.75Ti3O12, and the coercive field resistance,
Ec, decreased in (Bi, La)4(Ti, Si)3O12 (I). From thetemperature dependence of dielectric constant andtan values, the Curie temperature Tc was 404°C for
Bi3.25La0.75Ti3O12, 426°C for (Bi, La)4(Ti, Si)3O12 (I),and 389°C for (Bi, La)4(Ti, Si)3O12 (II). The
dielectric constant for (Bi, La)4(Ti, Si)3O12 (I) was
higher than that of Bi3.25La0.75Ti3O12. With regard totan values, there was no significant variation
among samples when compared near room
temperature.
In addition, as a result of structural analysis
using the powder neutron diffraction method, it was
postulated that in Bi3.25La0.75Ti3O12 (I), La wassubstituted at the Bi sites, and that Si was present atsome of the sites. The best fitting was obtained
when investigations were carried out using a modelin which Si was present at the Ti2” site. It was
thus concluded that in Bi3.25La0.75Ti3O12 (I), Si wassubstituted at the Ti2” site. These results indicatethat a new bulk ferroelectric material having highnovelty, due to its vastly superior crystal structure
characteristics, was obtained[5].
References
1) B. H. Park et al., Nature 401 (1999) 682.
2) T. Kijima et al., Jpn. J. Appl. Phys. 41 (2002)
L1164.
3) Y. Idemoto et al., Material Technology 23 (2005)
182.
4) T. Ohta, F. Izumi et al., Physica B, 234-236(1997) 1093.
5) Y. Idemoto et al., Solid State Commun. 128(2003) 255.

63

Impurity Induced Insulator-Metal Transition in Sr3(Ru1-xMnx)2O7
T. ARIMA1,2, R. MATHIEU 1, J. P. HE 1, Y. ONOSE 1, Y. KANEKO 1, Y. TOKURA1,3
1

2

ERATO-SSS, Japan Science and Technology Agency, c/o AIST, Tsukuba 305-8562
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577
3
Department of Applied Physics, University of Tokyo, Tokyo 113-8656

The Ruddlesden-Popper-type Srn+1RunO3n+1
series show metallic properties, as well as exotic
superconductivity and spin/orbital order. Sr3Ru2O7(Ru4+, 4d4) is essentially paramagnetic although
there is some controversy in the literature related tothe presence of ferromagnetic SrRuO3 and
Sr4Ru3O10 impurities. A metamagnetic transition isobserved at low temperatures in large magnetic
fields, indicating the presence of quantum criticality.
Another signature of this phase competition is foundin hydrostatic pressure experiments or Sr-site doping
by Ca of Sr3Ru2O7, which stabilizes theantiferromagnetic (AFM) state. Here we report theeffects of the Mn substitution for Ru in Sr 3Ru2O7.
A metal-to-insulator transition is observed as the Mncontent increases. Neutron diffraction experiments
show that the low temperature insulating state is
associated with a peculiar antiferromagnetic spinarrangement, which suggests some complex orbital
order.[1]Single crystals of Sr3(Ru1-xMnx)2O7 (x=0, 0.005,
0.025, 0.05, 0.075, 0.10, and 0.20) were grown by afloating zone method. The Mn composition x was
checked by inductively coupled plasma (ICP)
analysis. Resistivity measurements were carriedout by a standard four-probe method. While all thesamples show a metallic behavior at room
temperature, only the crystals with x<0.05 remain
metallic at low temperatures. We observed a clear
kink in the resistivity curves of the crystals with
x>=0.05, accompanied by an insulating behavior
below the temperature.
Importantly, for the
crystals with x>=0.05, a peak is observed in the heat
capacity in the vicinity of the resistivity jumptemperature.
The powder neutron diffraction patterns of thecompound with x=0.05 were collected using atime-of-flight (TOF) diffractometer VEGA, KEK,
Japan. The single crystal was pulverized for thispurpose. The obtained powders were sealed withhelium gas in a vanadium cell with a diameter of 9.2
mm. TOF diffraction patterns for a wide d-range(1~20Å) were obtained at a 30-degree scatteringbank to detect magnetic reflections.

64Fig. 1 Upper panel: intensity of the (1/4,1/4,0) and(1/4,3/4,0) magnetic peaks observed in the neutron
diffraction pattern, as shown in the inset. Lower panel:tetragonal a- and c-axis lattice parameters obtained from
x-ray diffraction.

As shown in the upper panel of Fig. 3, themagnetic peaks corresponding to antiferromagnetic
ordering show up below the metal-to-insulatortransition temperature. Interestingly, the indices ofthe magnetic reflections imply a complex spin
structure with the magnetic wave vector of (1/4 1/40), suggesting some long-range order in t2g orbital
sector. Furthermore, synchrotron x-ray diffraction
measurements on BL-1A at KEK-PF show thataround the same temperature the c-axis lattice
parameter decreases, as seen in the lower panel ofFig. 3. This indicates that the RuO 6 octahedra arecompressed along the c-axis, in a Jahn-Teller likefashion, or that the buckling occurs. The results
illustrate how the impurity doping (replacing only afew percents of Ru) allows the phase control of themulticritical layered ruthenates.
References
1) R. Mathieu et al., Phys. Rev. B 72, (2005)
092404.

Structure Phase Transition in Fe-heavily-substituted Copper Oxide Superconductor
FeSr2YCu2O
T. MOCHIKU1, Y. HATA2, K. IWASE3,4, M. YONEMURA5, S. HARJO6,
A. HOSHIKAWA6, K. OIKAWA6, T. ISHIGAKI6, T. KAMIYAMA4,
H. FUJII1, F. IZUMI7, K. KADOWAKI8 and K. HIRATA1
1

Superconducting Materials Center, National Institute for Materials Science,
Tsukuba, Ibaraki, 305-0047
2
Department of Applied Physics, National Defense Academy, Yokosuka, Kanagawa, 239-8686
3
School of High Energy Accelerator Science, Graduate University of Advanced Studies,
Tsukuba, Ibaraki, 305-0801
4
Institute of Materials Structure Science, High Energy Accelerator Research Organization,
Tsukuba, Ibaraki, 305-0801
5
Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, 316-8511
6
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195
7
Quantum Beam Center, National Institute for Materials Science, Tsukuba, Ibaraki, 305-0044
8
Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki, 305-8573
There were many reports on the substitution ofhigh-Tc
Fe for Cu in the Ba2YCu3O6+
superconductor to investigate the behavior of themagneticFe
elements
inthehigh-Tc
superconductors. These reports show that the
T c,superconducting
transition
temperature,
decreases drastically with increasing the substituted
Fe content. The neutron powder diffraction study
for the Fe-substituted Ba2YCu3O6+ indicates that the
Fe atoms, which are substituted for the Cu atoms inthesuperconducting
CuO2
sheets,affectsuperconductivity [1].
Recently, we havediscovered superconductivity around 50 K in thecompoundFe-heavily-substituted FeSr2YCu2O
with the Ba2YCu3O6+ -type structure, when it isproperly annealed in N2 atmosphere andsubsequently in O2 atmosphere under ambient andhigh pressure [2]. The neutron diffraction study
shows that the N2-annealing causes atomic orderingof Cu and Fe to prevent the substitution of Fe for Cu
on the superconducting CuO2 sheets, and that theO2-annealing supplies carriers on the CuO2 sheets to
exhibit superconductivity. We have analyzed the
crystal structure of FeSr2YCu2O6+ during theN2-annealing by in-situ high-temperature neutron
powder diffraction measurements to understand themechanism of the atomic ordering of Cu and Fe.
The samples were prepared by the solid-state
reaction of stoichiometric mixture of Fe2O3, SrCO3,
Y2O3 and CuO powders. The mixture was calcinedat 900 oC for 24 h in air, and sintered at 1000 oC for
24 h in air. The neutron powder diffraction data
for FeSr2YCu2O6+ were taken with the Sirius

diffractometer at KENS. The intensity data werecollected by 90o detector bank at 300, 500, 600, 650,
700, 750, 800 oC and room temperature in N2.

Fig. 1. Crystal structures of FeSr2YCu2O6+ with (a)tetragonal cell (P4/mmm) and (b) orthorhombic cell
(Ima2).

The crystal structure of FeSr2YCu2O6+ wasrefined using the Rietveld analysis program
RIETAN-TN on the basis of the tetragonal

65

Ba2YCu3O6+�-type structure model (space group
P4/mmm)[3]
andtheorthorhombic
CoSr2YCu2O7-type structure model (space groupIma2) [4]. The crystal structures are shown in Fig.
1. In the present refinement, four sites wereassigned for Cu and Fe: 1a site for Cu(1) and Fe(1),and 2g site for Cu(2) and Fe(2) in P4/mmm; 4b site
for Cu(1) and Fe(1), and 8c site for Cu(2) and Fe(2)in Ima2 [5].

Fig. 2. Change of (a) the lattice parameters, a, b and c, theoccupation factors of Cu at the Cu(1) and Cu(2) sites, gCu(1) andgCu(2), and the oxygen content, 6+�, and (b) the selectedinteratomic distances along the annealing process in N2. The
lattice parameters of the orthorhombic cell were converted tothose corresponding the tetragonal cell.

Fig. 2 shows that the lattice parameters, a, b andc, oxygen content, 6+�, and interatomic distances
are strongly correlative to the annealing process in
N2. As temperature increases, all lattice parameters
increase and the crystal structure transforms fromthe tetragonal structure to the orthorhombic structure
at 750 oC. The refinements of the occupation
factors, gCu(1) and gCu(2), show that the atomicordering of Cu and Fe has been already almost
completed at 300 oC.
However, the atomicordering degenerates when temperature returned
from 500 oC to room temperature.
The oxygen content, 6+�, decreases during theannealing process to decrease the occupation factorof oxygen at the O(1) site.
The atomic
displacement at the O(1) site also becomes
extremely large between 650 oC and 700 oC.
Therefore, these indicate that the transformation
begins from the FeO6 octahedron to the FeO4

66

tetrahedron since the oxygen deficiency in the FeO6
octahedron increases with increasing temperature.
The atomic ordering of Cu and Fe is promoted by
the formation of the FeO4 tetrahedron since Cu canbe not substitute for Fe in the FeO4 tetrahedron.
The arrangement of the FeO4 tetrahedron begins
from 750 oC, and it causes the formation oforthorhombic superstructure with the unit cell of 2c
x √2a x √2a as compared with tetragonal structurewith the unit cell of a x a x c. The temperature
above 750 oC fixes the superstructure due to forming
the arrangement of the FeO4 tetrahedron. Since thesuperstructure remains until temperature returns
from 800 oC to room temperature, the phasetransition from tetragonal to orthorhombic structureis irreversible.
Fig. 2 (b) shows that the Sr–O(1) andCu(2)–O(2) distances are much more influenced by
the N2-annealing than other distances. Decreasing
the oxygen content strongly affects the interatomic
distances around the O(1) atom, especially theSr–O(1) distance, and also influences the valence of
the Cu(2) atom. Therefore, decreasing the valenceof the Cu(2) atom causes increasing the Cu(2)–O(2)distance. Although the change of all distances is
continuous in the region between 300 oC and 700 oC,
the change of the distances around the Fe(1) andO(1) is discontinuous when the crystal structuretransforms from tetragonal to orthorhombic structure.
This is correlated with the irreversible transition
from tetragonal to orthorhombic structure.
References
1) A. M. Balagurov, et al., Physica C 158 (1989)
265. .
2) T. Mochiku, et al., J. Phys. Soc. Jpn. 71 (2002)
790.
3) F. Izumi, et al., Jpn. J. Appl. Phys. 26 (1987)
L1214.
4) Q. Huang, et al., Physica C 193 (1992) 196.
5) T. Mochiku, et al., Physica C 400 (2003) 43.

Neutron Powder Diffraction Study of Y2C3 Superconductor
T. MOCHIKU1, T. NAKANE1, H. KITO2, H. TAKEYA1, S. HARJO3,
T. ISHIGAKI3, T. KAMIYAMA4, T. WADA2 and K. HIRATA1
2

National Institute for Materials Science, Tsukuba, Ibaraki, 305-0047
National Institute of Advanced Science and Technology, Tsukuba, Ibaraki, 305-8586
3
Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195
4High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801

The Y2C3 compound exhibits superconductivity
around 6-11.5 K [1]. The Tc value is strongly
dependent on the synthesizing conditions.
Recently, there were the reports [2,3] that Tc could
be increased to 18 K by the synthesis at higher
pressure than that of the previous reports [1]. In
spite of simple binary system, Y2C3 has the wide
range of Tc between 6 K and 18 K. We have
performed the neutron powder diffraction study toinvestigate the detailed crystal structure of thiscompound with different Tc [4].
The samples were synthesized at ultra highpressure of 3.5-5.0 GPa and at high temperature of
1400-1600 oC for 30 minutes. Neutron powder
diffraction data for two samples with Tc of 14.9 K
and 9.1 K, which are called as the high-Tc andlow-Tc samples, respectively, were taken with the
VEGA diffractometer at KENS.

occupancy.
This indicates that the present
compounds have the stoichiometric composition of
Y2C3. While the lattice parameter, a, does notchange between both samples, the interatomic
distances change, except for Y-Y* along the [111]direction. The Dl/l value of Y-Y* is much lower
than other rates, and is almost the same as that of thelattice parameter, a. This suggests that the size ofthe unit cell depends on Y-Y*. The C-C distance isshorter than the other distances, and changes
significantly between both samples, compared withthe other distances. There is possibility of strong
correlation between superconductivity and the C-C
distance. The YC2 superconductor with the C-C
bond also exists in the Y-C system. This suggeststhat the C-C bond is characteristic of the structure of
the superconductors in the Y-C system.
Table 1. Selected interatomic distances, l, and the rate of changeof the distances between both samples, Dl/l. For comparison,
the lattice parameter, a, is also listed.

Fig. 1.

Crystal structure of Y2C3 (cubic, I-43d, Z = 8).

The structure of the samples was refined using
the Rietveld refinement program RIETAN-TN on
the basis of the Pu2C3-type structure model (see Fig.
1). This model is supported by very low R factors(high-Tc sample: Rwp = 3.37%, S = 1.11, low-Tc
sample: Rwp = 3.10%, S = 1.26). Table 1 shows theselected interatomic distances, l.
According to the refinements of the occupation
factors at all sites, we have obtained the full

Y–C
Y–C

high-Tc
0.2510(1)0.2641(2)low-Tc0.2507(1)0.2647(2)Dl/l
1.20 x 10-3
-2.27 x 10-3

Y–C
Y–Y
Y–Y*
C–C
a

0.2810(1)0.3391(2)0.35668(1)0.1298(4)0.82372(3)0.2806(1)0.3395(1)0.35669(1)0.1290(4)0.82374(3)1.43 x 10-3-1.18 x 10-5-2.80 x 10
-3
6.20 x 10-5-2.43 x 10

-3

References
1) M. C. Krupka, et al., J. Less-Common Met. 19(1969) 91.
2) G. Amano, et al., J. Phys. Soc. Jpn. 73 (2004)
530.
3) T. Nakane, et al., Appl. Phys. Lett. 84 (2004)
2859.
4) T. Mochiku, et al., Physica C 426-431 (2005)
421.

67

Crystal Structure Analysis of Hydrogen Absorbing Ti-Cr-Mo Alloys
K. IWASE *1, T. KAMIYAMA 1 , Y.O NAKAMURA 3,3
K. MORI 4, M. YONEMURA 1,*2, S. HARJO 1 and E. AKIBA
1
3

High Energy Accelerator Research Organization (KEK), Tsukuba, 305-0801, Japan

National Institute of Advanced Industrial Science and Technology (AIST),AIST Central-5, Tsukuba, 305-8565, Japan

4

Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494,
Japan

Introduction

temperature. High resolution neutron powder

Neutron diffraction can directly determine

diffraction data were collected at roomhydrogen atomic positions in metal hydrides.

temperature (RT) on a time-of-flight (TOF)

Using neutron powder diffraction, Nakamura

neutron diffractometer, Sirius2), at Neutron

et al. showed that Ti-Mn-V bcc solid solution

Science Laboratory (KENS) of High Energy

alloys exhibit two hydride phases withAccelerator Research Organization (KEK).

1)

NaCl-type and CaF2-type structure and theForcrystal structure changes from bcc todeuterides were used instead of hydrides

CaF2-type with increasing hydrogen content.

because of the large incoherent scattering

From the result of Rietveld refinement, the Dcross section of H.

neutrondiffraction

experiments,

atoms occupy the octahedral (O) sites in the
NaCl-type phase and the T sites in the

Result and discussion

CaF2-type one. In this study we will focus on

In Ti0.45Cr0.35Mo0.20D1.9, all reflections inthecrystalstructure

absorption-desorption

duringhydrogen

X-ray and neutron diffraction data could beprocessofindexed with a CaF2-type structure model.

theTi-Cr-Mo bcc solid-solution alloy. We haveNo

investigated the crystal structure and theindicating that transition metals, Ti, Cr andhydrogenhydrogenMo, are not ordered in the long-range scale.

absorption-desorption process using XRD

Then, in the Rietveld refinement, Ti, Cr andand neutron powder diffraction.

Mo were assumed to be located at the 4a site

occupation

site

in

superlatticereflection

isobserved,(hereafter M site) with the ratio of 0.45 :ExperimentThe

68

samples,

0.35 : 0.20. D atoms were found to be locatedTi0.45Cr0.35Mo0.20D1.9,

wereat the tetrahedral site. Figure 1 shows theinvestigated by neutron diffraction at room

Rietveld refinement pattern of neutronpowderdiffraction

data

for

Ti0.45Cr0.35Mo0.20D1.9 sample.

[1] Y. Nakamura and E. Akiba: J. Alloys

theComp. 316 (2001) 284.

The refinedlattice and structural parameters are listed in[2] S. Torii, T. Kamiyama, K. Mori, K.

Table 1, D atoms occupy the tetrahedral site

Oikawa, S. Itoh, M. Furusaka, S. Satoh, S.

with an occupancy of g(D)=0.95(1).

Ikeda, F. Izumi and H. Asano: J. Phys.
Chem. Solids 60 (1999) 1583.

References

10000

Intensity

8000
6000
4000
2000
0
0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

d/Å

Fig. 1

Rietveld refinement pattern of Ti0.45Cr0.35Mo0.20D1.9.

Table 1 Refined structure parameters of the Ti0.45Cr0.35Mo0.20D1.9 phase: space group Fm-3m. B
is the isotropic displacement parameter and g is the occupation factor of each site.

Atom Site

g

x

y

z

B(10-2nm2)

M

4a

1.0

0

0

0

0.50(2)D

8c

0.95(1) 1/4 1/4 1/4

1.01(1)

Rwp = 2.74, Rp = 2.36, S = 1.66.

Lattice parameter a = 0.432153(3) nm.

69

Microstructure Studies of Hydrated Ca3SiO5
K. Mori, *S. Takata, **I. Tsukushi, *T. Otomo, K. Itoh, M. Sugiyama,***K. Oishi, *M. Kawai and T. Fukunaga

Research Reactor Institute, Kyoto University, Kumatori-cho, Sennnan-gun, Osaka, 590-0494*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization,
Tsukuba, Ibaraki, 305-0801** Departoment of Physics, Chiba Institute of Technology, 2-1-1, Shibazano, Chiba 275-0023, Japan***Institute of Technology, Shimizu Corporation, 3-4-17 Etchujima, Koto-ku, Tokyo 135-8530

Concrete is an important building material
because of its relatively high compressive strength,
durability and low cost.
Tricalcium silicate(Ca3SiO5) is a principal component of cement.
Therefore, it is expected that the properties ofconcrete strongly depend on those of the hydrated
Ca3SiO5.
Although extensive studies of thehydrated Ca3SiO5 have been performed, it seems thatthe detailed mechanism for the early hydration
process is still controversial. In this work, we havestudied the early hydration process of Ca3SiO5 using
time-of-flight (TOF) quasi-elastic neutron scattering(QENS) and TOF small-angle neutron scattering(SANS) experiments [1].
The polycrystalline sample of Ca3SiO5, made in
Taiheiyo Consultant Co., Ltd., was hydrated withlight water (H2O) in air. The H2 O to Ca3SiO5 mass
ratio (H2 O/Ca3SiO5) was fixed at 0.5.
The
TOF-QENS experiments were carried out at RT (~23ºC) on the LAM-80ET installed at KEK-KENS.
The TOF-SANS data at RT were collected on the
SWAN at KEK-KENS [2].
In analyses of the QENS data, the signals of thebound water (BW) and the free water (FW) in the
total spectrum were separated, as shown in the inset
of Fig. 1. Eventually, the ratio of the signal fromthe BW to the total signal (BW+FW) was calculated.
Figure 1 shows the degree of hydration as a functionof reaction time, t. The result indicates that theconsumption of FW can be estimated to be morethan 30% after about 15 h of hydration, and then thehydration rate decreases obviously.
Figure 2 shows SANS spectra of the hydrated
Ca3SiO5 with H2 O after 1, 5, 10, 14 and 25 h ofhydration. The slope of the SANS curve at low
Q-regions is lowest at early hydration times.
However, it is worth noting that the SANS spectrum
does not change appreciably after 14 h of reaction.
In order to quantify the slope of the SANS curve, all
SANS spectra were analyzed by the following
equation: I(Q) = CQ– + BG, that is, the slope of the
SANS curve is directly reflected in the -value.
The-value deviates from –4 and rises

70

monotonically with increasing t in the early
hydration period, while it seems that the -value
maintains a constant value after 15 h of reaction [1].
From this result, we point out that the change of-value represents the variation of the surface
roughness arising from the formation of hydration
products, as suggested by J. J. Thomas et al. [3].
However, more detailed investigations are necessary
to evaluate exactly the -value.

Fig. 1.

Time dependence of hydration rate for thehydrated Ca3SiO5.

Fig. 2.

SANS spectra of the hydrated Ca3SiO 5.

References
1) K. Mori et al., Physica B, in press.
2) T. Otomo et al., J. Phys. Chem. Solids 60 (1999)
1579.
3) J. J. Thomas et al., J. Am. Ceram. Soc. 84[8] (2001)
1811.

Study on Ferromagnetism and Oxygen Incorporation of Diluted Magnetic Semiconductor(Ga,Mn)N
T. TAKEDA, S. OHTAKI, S. KIKKAWA, and T. ISHIGAKI*
Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido, 060-8628*Department of Materials Sciences and Engineering, Muroran Institute of Technology, Muroran,
Hokkaido, 050-8585
Dilute magnetic semiconductor has been focusedon as a new class of devices that show special
properties such as spin transistor, magnetic random
access memory, optical isolator and magnetic
sensor[1,2]. Especially, Mn doped GaN has beenstudied because of its high Curie temperature above
room temperature (300~940K)[3,4]. They havebeen synthesized by thin film method; molecularbeam epitaxy and ion implantation.
Wesynthesized Mn doped GaN powder by gel
nitridation. In this method, a metal-citrate gel isnitrided in ammonia flowing.
Although the
product showed no apparent ferromagnetic behavior,
ferromagnetic slope change around 150~180K andnegative Weiss temperatute were observed. In thisexperiment, (Ga,Mn)N powder by gel nitridation
was studied by neutron diffraction and its structure
at low temperature was studied. By gel nitridation,oxygen derived from precursor can be incorporated
into the product and affect physical properties.
Oxygen incorporation into the product was alsostudied.
The metal-citrate gel from gallium nitrate andmanganese nitrate in the molar ration of 0.95:0.05
was fired in ammonia flowing at 850°C. Neutron
diffraction measurements were performed by VEGA
at KENS at 12~300K.
There was no apparent difference in patterns
between 12K and 300K. All patterns could be
refined by a hexagonal lattice isostructural with GaN.
Both a and c lattice parameters linearly decreased
with decreasing temperature and showed a slightslope change around 180K as shown in Fig. 1. It
corresponded to the magnetic measurement.
Oxygen and nitrogen content was determined to be
0.3 and 0.7, respectively. Much amount of oxygen
was incorporated into the product shown as Ga(O,N).
To check a presence of long-range order due tooxygen-nitrogen or gallium-manganese order in the
structure, the pattern in high d region wasinvestigated by 30° bank data. There was noapparent peak corresponding to a superstructure.

In another measurement for short range order, amanganese-oxygen cluster in Ga(O,N) structure has
been proposed. Both manganese oxide Mn2O3 andMnO have antiferomagnetic property. In magnetic
measurement, both ferromagnetic slope changearound 150~180K and negative Weiss temperature
were observed. Mn might occupy the site in bothmanganese-oxygen cluster with antiferromagnetic
property and Ga(O,N) with ferromagnetic property.
Small size of manganese-oxygen cluster and a small
amount of Mn distribution into Ga(O,N) make it
difficult to observe the ferromagnetic andantiferromagnetic behavior in neutron diffraction.
(Ga,Mn)N by gel nitridation showed different
anion composition and properties from (Ga,Mn)N
by thin film method.

Fig. 1

Temperature dependence of lattice parameters
a and c for (Ga,Mn)N by gel nitridation.

References
1) Y. Ohno et al., Nature, 402 (1999) 790.
2) X. Liu et al., Appl. Phys. Lett., 79 (2001) 2414.
3) S. Sonoda et al., J. Cryst. Growth, 237-239(2002) 1358.
4) G.T. Thaler et al., Appl. Phys. Lett., 80 (2002)
3694.

71

Sr substitution effect on Pr(Ba, Sr)2Cu3Oy : Structural, Electrical and Magnetic Properties
Y. TAKAHASHIA*1, T. WUERNISHAA*2, F. SANOA, M. YONEYAMAB, S. HARJOB,
Y. TAKANOA , T. KAMIYAMAB and K. SEKIZAWAAaDepartment of Physics, College of Science & Technology, Nihon University,
1-8, Surugadai, Kanda, Chiyoda-ku, Tokyo 101-8308
b
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
Introduction
The suppression of superconductivity by Pr ionsin a family of cuprate superconductors, particularly
the absence of superconductivity in PrBa2Cu3Oy
has attracted much attention in the field of high-Tc
superconductivity. [1]. It is believed that the
hybridization of Pr 4f electrons and O 2p orbitals in
the CuO2 conduction plane play an important role tosuppression of superconductivity
Since Sr doping at Ba site will lead to theincrease of the Pr-O bond length and modify the
distribution of oxygen in the CuO plane, theclarification of correlation between crystal structure
and physical properties in Pr(Ba, Sr)2Cu3Oy is
relevanttounderstandtheabsenceofsuperconductivity in the PrBa2Cu3Oy.
Experimental
Polycrystalline samples of Pr(Ba1-xSrx)2Cu3Oy，(x= 0～0.5) were prepared by the solid state reaction
method which is described in detail elsewhere [2].
Neutron diffraction data at room temperature weretaken on the high-resolution TOF neutron powder
diffractometer VEGA at KENS. The data were
1.0

analyzed and the structure parameters were refinedwith the RIETAN program [3] The electricalresistivity (t) of the samples was measured using
the four probe method. The dc magnetization wasmeasured in the temperature range 3-303 K using aphysical property measurement system PPMS
(Quantum Design) under the magnetic field of 1T.
Results and Discussion
Though the crystal structure of PrBa2Cu3Oy is
known as orthorhombic with space group Pmmm,
the orthorhombicity (b-a)/(b+a) decreases from9 10-3 (x = 0) to 1 10-3 (x = 0.5) with increasing Srconcentration x, and the structure becomes nearlytetragonal at x = 0.3. In relation to this, the oxygen
occupation factors gO(4) of (0, 1/2, 0) site and gO(5) of(1/2, 0, 0) site are changed as shown in Fig.1. The
disorder of O(4) and O(5) site is observed above x =0.3. The gradual increase of distance between Pr
ion and CuO2 plane with x is also confirmed.

gO(4)

0.8

gO(5)

gO(4) and gO(5)

0.6
0.4
0.2
0.0
0.0

0.1

0.2

x

0.3

0.4

0.5

Fig. 1 Occupation factors of oxygen at (0, 1/2, 0)site (O(4)) and (1/2, 0, 0) site (O(5))*1 yumikot@shotgun.phys.cst.nihon-u.ac.jp*2 Present address: KENS, KEK Tsukuba, Ibaraki, 305-0801, Japan

72

Fig. 2 Temperature dependence of theelectrical resistivity

Fig. 3 Néel temperature as a function of Srcontent x

Figures 2 and 3 show the temperaturedependence of the electrical resistivity and Néel
These results
temperature TN,, respectively.
indicate that the hybridization and thus TN increase
with x below 0.3. In contrast, the TN and electricalresistivity decrease in x > 0.3 because therandomness introduced by Sr substitution and slightincrease of Pr-O length reduce the hybridization
between Pr 4f and O2p orbitals.
References
1) H. B. Radousky Mater. Res. Bull. 7 (1992) 1917.
2) T. Wuernisha et al. Physica C 434 (2006) 178.
3) T. Ohta et al. Physica B 234-236 (1997) 1093.

73

Thermal Expansion Behavior of Cementite Polycrystals- Effect of Curie Point on Thermal Expansion S. HARJO, T. KAMIYAMA1, Y. SHIOTA2, Y. TOMOTA2, T. SUZUKI2 and M. UMEMOTO3
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195
1
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
2
Ibaraki University, Hitachi, Ibaraki, 316-8511
3
Dept. Production System Engineering, Toyohashi Univ. of Technology, Toyohashi, Aichi, 441-8580
Iron Carbide Fe3C (called ”cementite”) is an
important phase for engineering steels.1) The amountand shape of cementite determine mechanical andthermal properties of the steels. Cementite is alsosuggested as the major phase in the inner core of thecentre of the earth. However, since the cementite
single phase specimen was so difficult to prepare, its
physical properties have not been examined well.
Ones usually used the extracted cementite frompearlite steel, or used cementite in pearlite steel as
the secondary phase.
Recently, the preparation of cementite bulky
specimen has been performed by using plasma
sintering with mechanical milling.2) The lattice
parameters of pure cementite and Mn-alloyedcementite were determined with the Rietveld
analysis for diffraction profiles obtained by a neutron
powder diffractometer on heating from RT to 673 K.
Subject points of this study are neutron diffraction
with time-of-flight (TOF) method during heating forlower temperatures, to clarify effect of Curie
temperature, TC, measurement was conducted using
bulky sintered sample and effect of Mn addition on
thermal expansion behavior of cementite is also
investigated.
Bulky samples of stoichiometrical cementite andMn-alloyed one were prepared by plasma sinteringfrom mechanically milled powders of Fe, Mn andgraphite. The details of specimen preparation havebeen reported in ref. 2). The neutron powder
diffraction experiments were conducted at a time offlight (TOF) neutron diffractometer Vega3) installedat the pulsed spallation neutron facility KENS, HighEnergy Accelerator Research Organization (KEK).
Coarse powder samples with diameters of about 2-3
mm were filled in vanadium cans and powder
diffraction spectra were firstly measured todetermine the crystallographic structure of cementite.
The vanadium cans filled with the samples were
subsequently set at the center of furnace which wasplaced at the sample position of Vega. Diffraction
patterns were collected at back-scattering bank (2 =140-175º). At first, the samples were measured at RT74

and then were heated in a step-by-step manner up to
673K. The diffraction pattern at each temperature
was measured for about 5.4-10.8ks.

Fig. 1. Neutron powder diffraction and Rietveld
refinement patterns for (a) stoichiometrical and (b)Mn-alloyed cementites measured at RT. Observed
intensity data are shown by crosses, and solid line
overlying them is the calculated intensity. Markers below
the patterns indicate positions of possible Braggreflections. Differences between the observed andcalculated intensities are plotted at the bottom.

Fig. 2. Crystallographic structure of cementite refined by
the Rietveld refinements.

Figure 1 shows diffraction patterns observed for
stoichiometrical and Mn-alloyed cementites. Besides
cementite with space group of Pnma,  Fe andmagnetite were also used as crystal structure models

Table 1 Crystallographic parameters refined from theRietveld refinements

4.57
4.56
4.55
4.54
4.53
4.52

200

300

400

Stuart and Ridley
this study :a

5.13

Lattice parameter of a / Å

4.58

Temperature / °C

100

5.12

red : pureblue: Mn-added

5.11

6.78

b
c

b

6.77
6.76
6.75

5.10

a

5.09

6.74

c

5.08

6.73

Lattice parameter of b / Å

0Lattice parameter of c / Åin the Rietveld analyzes. It is seen in Fig. 1 that, theresiduals between the measured patterns and theRietveld calculated patterns showed mostly straightlines, showing good reliability of the Rietveld
analyzes. The refined crystal structure andparameters for cementite are shown in Fig. 2 andTable 1. Lattice parameters or unit cell volume of
Mn alloyed cementite are smaller thanstoichiometrical one due to the smaller atomic radiusof Mn. The Rietveld refinements showed low R
values not only due to adapting crystal structure
models besides cementite, but also due to adapting asimple magnetic structure to the cementite with themagnetic moment of Fe atoms parallel to b axis. The
mass fractions of cementite in stoichiometricalsample and in Mn alloyed one are 91.6(4) % and95.5(4) % respectively, showing that Mn addition
may stabilize the cementite structure.

6.72

5.07
273

373

473

Temperature / K

573

673

Fig. 4 Lattice parameters as a function of temperature

Figure 3 shows neutron diffraction pattern as afunction of temperature for the stoichiometricalcementite sample. Similar results were also obtained
for the Mn alloyed cementite sample. There are no
intensity changes and no new reflections appeared in
Fig.3. There results show that during heating for
RT-673K, there are no phase transformation and only
little mass fraction change. Lattice parameterschanges during heating are plotted in Fig. 4. The
lattice parameters do not continuously increase withincreasing temperature. Inclination of lattice
parameter change for the stoichiometrical sample
occurs at a knick point of about 490 K. The
phenomena appear more significantly at a and c axes.
Meanwhile, the TC of the cementite is known to beabout 480 K, and it is very close to the knick point.
The knick point may have strong correlation to the
TC. The knick point of Mn alloyed one appears at alower temperature, showing that Mn addition may
decrease TC. It is shown in Fig. 4, knick points are
not clearly observed in the results obtained by Stuart
and Ridley4). This is may be due to a fact that theyused cementite samples extracted from pearlitic
100

Temperature / °C
150
200
250

300

350

400

-6

Thermal expansion coefficient,  × 10 / K

20

50

15

 -Fe

10
a
b
c

5

0

black : Hartmann et al. (X-ray)
red : stoichiometrical cementite
blue : Mn-alloyed cementite-5323

Fig. 3 Neutron diffraction pattern as a function oftemperature for the stoichiometrical cementite sample.

373

423

473
523
Temperature / K

573

623

673

Fig. 5 Linear thermal expansion behavior as a function oftemperature for the stoichimetrical and Mn alloyedcementite.

75

Fe1 of stoichiometrical cementite
Fe2 of stoichiometrical cementite
Fe1 of Mn-alloyed cementite
Fe2 of Mn-alloyed cementite

Magnetic moment,  / B

3.0

2.5

2.0

1.5

1.0
300

350

400

450
500
550
Temperature / K

600

650

Fig. 6 Magnetic moments of Fe atoms in cementites as afunction of temperaturesteels, which may contain many impurities.
Figure 5 shows coefficients of linear thermal
expansion for both samples, obtained by normalizing
to the lattice parameters at RT and the temperatureintervals. It is shown in Fig. 5, the coefficients fortemperatures lower than TC are small but those fortemperatures higher than TC are large to be similar tothe coefficients of Fe. The coefficients of cementite

76

are the lowest near TC. Moreover, those for a axes
show minus values. These results are in good
agreement with those obtained by Hartmann et al.5).
Figure 6 shows changes of magnetic moments of Fe
atoms in cementites with temperature. It is shownthat the magnetic moments rapidly decrease withincreasing temperature up to TC, and then slowly.
The results may have very strong correlations withthe thermal expansion behaviors of cementites. Thatis, the magneto striction below TC are large
depressing the lattice expansion during heating. It
seems the magneto striction is significant in the axes
perpendicular to the magnetic moment.
References
1) M. Umemoto and K. Tsuchiya: Tetsu-to-Hagane,
88 (2001) 117.
2) Umemoto et al., Metall. Mater. Trans. A, 32A(2001) 2127.
3) T. Kamiyama et al., Physica. B + C 213 and 214(1995) 875.
4) N Ridley and H Stuart, 1968 J. Phys. D: Appl.
Phys., 1 (1968) 1291.
5) S. Hartmann and H. Ruppersberg, Mat. Sci. Eng.,
190A (1995) 231-239.

Structure and Mecanical Behavior of Heavily Drawn Pearliteand Martensite in a High Carbon SteelY. SHIOTA, Y. TOMOTA*, and T. KAMIYAMA**
Graduate Student of Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki,316-8511*Institute of Applied Beam Science, Graduate School of Science and Engineering, Ibaraki University,
Hitachi, Ibarki,316-8511**Institute of Materials Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho,
Tsukuba, Ibaraki, 305-0801
Introduction
Fig. 1 exhibits the tensile strength of wires as afunction of true strain given by cold drawing [1]. As
is found, the strengthening rate with respect to given
strain is larger in pearlite steel than in ferrite steel inthe beginning. Furthermore, the strength of pearlite
increases very drastically beyond a true strain of 3.0.
It has been reported that the dissolution of cementite
starts to occur at higher strains larger thanapproximately 3.0 [2-6]. When cementite is detectedby neutron diffraction, the flow stress of pearlite is
attributed to higher stress loading in cementite; theferrite matrix is plastically deformed to hold lower
stress. Such stress partitioning behavior is dependent
on morphology and volume fraction of cementite,which can be investigated by using in situ neutron
diffraction during deformation [7-9]. From such
experiments, the maximum stress that cementite
plates can hold is estimated to be approximately
5GPa which agrees well with the compressive
strength observed in bulk cementite made byplasma-sintering for mechanically milled powders[10]. After cementite is mostly dissolved, thestrength of a wire with 4GPa class is achieved by thestrength of ferrite itself showing the nonlinear elasitc
stress versus strain behavior at higher stresses [11].
From an engineering point of view, the delamination
has to be overcome when a wire is strengthened[12-13]. The mechanism and suppression method of
the delamination is unclear and the influence of
cementite dissolution has been suspected [14]. In
this study, an angler dispersion (AD) method and atime of flight (TOF) method of neutron diffraction
were used for drawn pearlite specimens as well as
martensite specimens in which carbon atoms exist in
the lattice interstitially.
Experimental
The chemical compositions of a steel used in thisinvestigation are shown in Table 1. Hot-rolled roundbars with 1.5mm in diameter are patented through an

industrial process to obtain fully pearlitic structure.
The bars were then cold-drawn to 0.20mm indiameter, i.e., true strain of 4.0. Some bars with
1.5mm were austenitized at 1173K followed by
quenching into water. Neutron diffraction
measurements were performed with powder
diffractometers, VEGA, at KENS/KEK by the TOF
method.

Fig. 1 Tensile strength of steel wire as a function of truestrain given by cold drawing (after Tashiro[1]).
Table 1. Chemical compositions of a pearltitic steel used (mass%)
C

Si

Mn

P

S

Cr

Al

N

0.88

0.16

0.51

0.009

0.005

0.03

0.001

0.0029Results
If cementite plates disappear in a pearlite steel,one may suspect the similarity to martensite. Then,the as-quenched marensite was prepared from thepatented 1.5mm bars. As shown in Fig. 2, themicrostructure consists of martensite and theretained austenite. The as-quenched martensite is
typical bct martensite with the c/a of approximately
1.04 which agrees with the reference datum in the
textbook [15].
The detailed comparison between as-patented
pearlite, drawn wire and martensite is presented inFig. 3 (a part of Fig. 2 is magnified). The profile forthe drawn pearlite is much different from that for77martensite. When the c/a was estimated from curve
fitting, the c/a is less than 1.01 meaning that most ofcarbon atoms do not exist inside the ferrite lattice.
According to the empirical equation by Roberts [16],the carbon concentration in the ferrite matrix in thedrawn wire (0.2 mm diameter) is estimated to be
0.1-0.2 mass% from the c/a determined, which is thesame with the result reported by Taniyama et al.
used synchrotron X-ray [6]. It is, however,
speculated the influence of residual stress
distribution must be overlapped in the relevant
diffraction profiles. In fact, Shiota et al. have foundthe appearance of asymmetrical diffraction profileby the AD method in a heavily drawn ferrite steel
wire as well as in a pearlite steel wire [17]. The
ferrite steel wire examined was almost carbon freeand residual intergranular stresses were observed, sothat there remains a possibility that inhomogeneous
plastic flow brings the asymmetry in diffraction
profile bringing the confusion of precise
determination of c/a caused by solute carbon atoms.

pearlite specimens were annealed, the c/a changed
as shown in Fig. 5. The c/a decreases rapidly withincreasing the tempering temperature in martensite
while small change is observed in drawn pearlite.
The residual intergranular stress has been found to
be relaxed when annealed at a temperature above
700K [7]. Hence, it is not clear the real reason forthe decrease in c/a with annealing is attributed tocarbide precipitation or the relief of residualintergranular stress in case of drawn pearlite.

Fig. 4 Change in diffraction profiles with tempering formartensite.

Fig. 2 Neutron diffraction profiles for as-patented , drawn
by true strain of 4.0 and as-quenchedspecimens.
Fig. 5 The c/a ratio determined from diffraction profiles asa function of tempering or annealing
temperature.

Fig. 3 Comparison of diffraction profiles from as-patented
pearlite, drawn pearlite and as-quenchedmartensite

Fig. 4 presents the influence of tempering on the
profile shape for martensite. As is seen, the the c/aof tetoragonality decreases with tempering, which isalso consistent with the textbook. When, the drawn
78

Conclusion
Neutron diffraction profiles were analyzed under
the assumption of body centered tetoragonal crystal
with unknown c/a ratio. It is found that the c/a ofmartensite changes with tempering showing good
agreements with references and that small value of
c/a was determined for a heavily drawn pearlite wire
indicating a little concentration of carbon within theferrite lattice. Moreover, the influence ofheterogeneous plastic deformation leading to theresidual stress distribution is suggested to affect thec/a so that the convert from c/a to solute carbon
concentration may have some uncertainty.
References

[1] H.Tashiro, Ph.D. Thesis, p.58, Tohoku
University, Japan (1992).
[2] H.G.Read, W.T.Reynolds Jr., K.Hono andT.Tarui, Scripta mater. 37, 1121 (1997).
[3] K.Makii, H.Yaguchi, M.Kaiso, N.Ibaraki,
Y.Miyamoto and Y.Oki, Scripta mater., 37, 1753
(1997).
[3] K.Makii, H.Yaguchi, M.Kaiso, N.Ibaraki,
Y.Miyamoto and Y.Oki, Scripta mater., 37, 1753
(1997).
[4] M.H.Hong, W.T.Reynolds, Jr., T.Tarui and
K.Hono, Metall.Mater.Trans. A, 30A, 717(1999).
[5] Y.Daito and T.Hamada, Tetsu-to-Hagane, 86,
105 (2000).
[6] A.Taniyama, T.Takayama, M.Arai and
T.Hamada, Scripta mater. 51, 53(2004).
[7] Y.Tomota, P.Lukas, D.Neov, S.Harjo and
Y.R.Abe, Acta mater., 51, 805(2003).
[8] Y.Tomota, O.Watanabe, A.Kanie, A.Moriai,

Technology, 19, 1715 (2003).
[9] A.Kanie, Y.Tomota, S.Torii and T.Kamiyama,
ISIJ Int., 44, 1961 (2004).
[10] T.Terashima, T.Suzuki, Y.Tomota and
M.Umemoto, CAMP-ISIJ, 16, 477 (2003).
[11] Y.Tomota, T.Suzuki, A.Kanie, Y.Shiota,
M.Uno, A.Moriai, N.Minakawa and Y.Morii,
Acta mater., 53, 463 (2005).
[12] H.Tashiro, Materia Japan, 44, 495 (2005).
[13] M.Nagao and T.Kuroda, Tetsu-to-Hagane, 90,
583 (2004).
[14] T.Tarui and N.Maruyama, Tetsu-to-Hagane, 90,1031(2004).
[15] For instance, Z.Nishiyama, Martensitic
Transformation., p.13-15, Maruzen-press,(1971).
[16] C.S.Roberts, Trans, AIME 197,203 (1950).
[17] Y.Shiota, Y.Tomota, A.Moriai, and Y.Morii,
unpublished work at JAERI (2004).

79Effect of Lamellar Spacing on Deformation of a Pearlite Steel
T.Shinozaki*1, S.Morooka*1, T.Suzuki*2, M.Yonemura*3, Y.Tomota*3 and T.Kamiyama*4*1Graduate Student of Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511 Japan*2 Superplasticity Research Center, Ibaraki University. 4-12-1 Nakanarusawa, Hitachi, Ibaraki
316-8511 Japan*3Graduate School of Science and Engineering, Institute of Applied Beam Science, Ibaraki University.
4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511 Japan*4 Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho,
Tsukuba, Ibaraki, 305-0801 Japan
Introduction
In a pearlitic steel, phase and intergranular
stresses are yielded due to inhomogeneous plastic
flow between ferrite and cementite and among
differently oriented ferrite blocks, respectively. Suchinternal stresses must be dependent on
microstructural factors. In previous studies, we havereported the influences of cementite volume fraction,
morphology and texture with drawing on stresspartitioning behavior by using neutron diffraction
techniques [1-4]. In this study, we examined theeffect of lamellar spacing on stress partitioning
behavior during tensile deformation by means of insitu neutron diffraction.
Experimental Procedure
The chemical compositions of a steel used are
0.801C-0.01Mn-0.01Si-0.01P-0.01S in mass%.
Specimens were austenitised at 1173K followed byholding at 673K (specimen A), 748K (B), or 823K
(C) for 3.6 ks to complete isothermal transformationfrom austenite to pearlite. The average lamellar
spacing (S0) determined from SEM micrograph are
68nm(A), 71nm(B) and 101nm(C).
Cylindrical tensile specimens with 3mm indiameter and 32mm in gauge length were machined.
In situ neutron diffraction experiments during tensile
test were performed by using a high resolution
powder diffractometer (Sirius) at KEK. The applied
load was kept constant during the measurement.
Peak shifts of ferrite and cementite diffractions withtensile straining were converted to elastic strains(εhkl) byd d0(1)
 hkl  hkl 0 hkl
d hkl
where dhkl and d0hkl refer to (hkl) spacing, andreference spacing (stress-free spacing), respectively.
Strains were measured both along the axial andtransverse directions using 90 banks.

80

Results and Discussion
The overall diffraction profile for the pearlitic
steel obtained by a time-of-flight (TOF) neutron
diffraction is shown in Fig. 1. Although the intensityof cementite peaks is weak compared with those of
ferrite, the peak position can be will determined. Fig.
2 shows the change in ferrite 110 diffraction profile
with the applied stress. As seen, the peaks shift
towards wider lattice spacing with increasing of theapplied stress. The increasing rate becomes ofnegligible order at above 800MPa that is close to the
0.2% proof stress, suggesting that stress in the ferrite
matrix hardly changes with increasing of the appliedstress.

Fig. 1 Diffraction profile obtained by the TOF method.

Fig. 2 Change in ferrite (110) diffraction profiles in theaxial direction with the applied stress obtained.

Elastic phase strains measured parallel to theapplied stress, as determined by the Rietveld
refinement, are plotted as a function of the appliedstress in Fig. 3. Both ferrite and cementite strains in
the axial direction increase with increasing of theapplied stress linearly in the beginning. After the
onset of plastic flow, i.e., yielding, lattice planestrain in ferrite hardly changes or slightly decreases
with increasing of the applied stress. On the other
hand, lattice plane strain in cementite increases
greatly with increasing of the applied stress after theyielding. These results show good agreements withthe predictions by a simple two-phase material
model; the strong cementite bears higher stress after
the yielding, resulting in high work-hardening of thepearlite steel. As seen in Fig. 3, the elastic strain in
the ferrite matrix after the onset of plastic flow isincreased with decreasing of S0.
Fig. 4 shows the residual lattice plane strain in
the axial direction versus macroscopic plastic strain
in ferrite and cementite for specimen A and C. The
plots represent the residual lattice strain measured
after unloading. As seen, cementite holds tensile
strain while ferrite compressive. The absolute value

for cementite is nearly 6 times larger than that for
ferrite. This must stem from stress balance between
cementite and ferrite, where the volume fraction of
cementite is approximately 12.3%. To be noted hereis that the residual strain is influenced by S0,
corresponding to load sharing in Fig. 4.

Fig. 4 Residual lattice strain as a function ofmacroscopic plastic strain.

It is claimed that the use of Rietveld refinementfor overall diffraction profiles is of use in Fig. 3.
However, the elastic strains of individual hkl planes
are influenced by elastic anisotropy of individual
grain. Hence, single peak fitting was employed here
to determine the elastic strains for individual
diffraction planes. The details in the curve fitting
procedure were already reported; a convolution
curve consisting of three functions were used [5].
The residual lattice strains observed in theindividual hkl ferrite matrix after unloading from atensile strain of 5.0% are shown in Fig. 4, as afunction of the elastic anisotropy factor (Ahkl) [6].
Here, the elastic anisotropy factor is given by( h2 k 2 h 2l 2 k 2 l 2 )(2)
Ahkl 
( h2  k2  l 2 ) 2
The strain obtained using the Rietveld refinementis plotted at Ahkl = 0.2 [7]. As is seen in Fig. 4, theresidual lattice strains are all compressive in theaxial direction while all tensile in the transverse
direction. It is again noted that the influence of S0 on
the residual block strain is found from comparison
between specimens A and C.

Fig. 3 Change in lattice plane strain during tensile
deformation; (a) ferrite, (b) cementite.

81

spacing where the degree of stress partitioning
becomes larger with decreasing of the spacing.

Fig. 5 Residual stress in the ferrite matrix as afunction of elastic anisotropy factor (Ahkl).

Conclusions
The effect of lamellar spacing on the stresspartitioning during tensile deformation in a pearlite
steel was investigated. The followings areconclusions obtained.
1. The absolute value of phase stress isincreased with decreasing of lamellar spacing.
2. The block stress is also affected by lamellar

82

References
1) A. Kanie, Y. Tomota, T. Suzuki, S. Torii, A.
Moriai, N. Minakawa, Y. Morii and T.
Kamiyama, J. Soci. Mater. Sci., Japan, 53(2004)
pp.772-775
2) Y. Tomota, O. Watanabe, A. Kanie, A. Moriai, N.
Minakawa and Y. Morii, Materi. Sci.
Technology, 19 (2003), pp.1715-1720
3) Y. Tomota, P. Lukas, D. Neov, S. Harjo and Y.
R. Abe, Acta mater., 51(2003), pp.805-817
4) S. Morooka, T. Suzuki, Y. Tomota, Y. Shiota
and T. Kamiyama, Tetsu-to-Hagane 91(2005),
pp816-821
5) S. Torii, Y. Tomota, T. Suzuki, J. H. Park, K.
Oikawa and T. Kamiyama, Bull.JSME, 68(2002),
pp.1540-1546
6) M. E. Fitzpatrick and A. Lodini, Analysis of
Residual Stress by Diffraction using Neutron and
Synchrotron Radiation, Taylor & Francis, 2003,
pp.47-pp.59
7) F. Bollemath, V. Hank and E. Z. Muller,
Metallkd, 58, 1967, pp.76-82

Tensile Behavior of a TRIP-DP Steel by In Situ Neutron Diffraction
A. Narui1, S-C.Chen1*, S.Morooka1, K.Ikeda1, 2, M.Yonemura3, Y.Tomota3 and T.Kamiyama4
1

Graduate Student of Ibaraki University, 4-12-1 Nakanarusawa-machi, Hitachi,Ibaraki 326-8511,
Japan
2
Sumitomo metal industries LTD, Hikari, Kashima, Ibaraki 314-0047, Japan
3
Graduate School of Science and Engineering, Institute of Applied Beam Science, Ibaraki University,
4-12-1 Nakanarusawa-machi, Hitachi,Ibaraki 326-8511, Japan
4
National Laboratory for High Energy Physics, 1-1 Oho, Tsukuba-shi, Ibaraki 305
1. Introduction
TRIP-DP(Transformation Induced Plasticity-Dual
Phase) steels are characterized by their excellent
strength-ductility combination and favorable
response to high-speed deformation, and hence
expected to be used in the automobile industry. The
strain-induced martensitc transformation of theretained austenite contributes to such mechanicalproperties, but transformation behavior underloading has not been made clear. Tomota et al. haveclaimed that the enhancement of uniform elongation
by TRIP is caused mainly by the second phasehardening not by the transformation strain [1].
In this study, we examined the stress partitioning
and strain-induced martensitc transformation
behavior during tensile deformation in a TRIP-DP
steel by means of in situ neutron diffraction.
2. Experimental procedures
A commercially produced TRIP-DP steel (590T)
was used in this investigation. The chemicalcomposition of the steel is 0.19C-1.58Mn-1.29Si0.10P-0.010S in mass%. The steel consists of theretained austenite, ferrite and bainite. The tensile
properties and volume fraction of the retained
austenite are tabulated in Table 1.

spacing of (hkl) crystal planes with respect to theapplied stress. The lattice plane spacing wasdetermined for individual diffraction peaks by thesingle peak fitting, the details of which werereported [2]; a convolution curve consisting of threefunctions were used. Assuming the stress free latticespacing, d0hkl, the lattice plane strain, εhkl, can becalculated from dhkl commonly measured as thecenter of corresponding diffraction peak according
to Eq.(1).
d d 0(1)
 hkl  hkl 0 hkl
d hkl
3. Results and Discussion
An example of diffraction obtaineed by atime-of-flight (TOF) neutron diffraction is shown in
Fig. 2. Diffractions from ferrite, bainite andstress-induced martensite are overlapped each otherand hardly distinguished. So the peak center for a
combined profile from ferrite, bainite and martensite
was determined to evaluate lattice plane strain in thematrix.

Table 1 Tensile properties and volume faction of the retained
austenite of the steel used.
0.2%
Proof
stress(MPa)380

Tensilestrength
(MPa)

626

Uniform
elongation
(%)

24.2

Total
elongation
(%)

37.7

Vol.frac.ofaustenite
(%)

7.02

In situ neutron diffraction experiment during
stepwise tensile test was performed by using a highresolution powder diffractometer (Sirius) at KEK.
The sharp and dimensions of the specimen used areplate with 1.4mm in thickness, 5mm in width and
32mm in gauge length. Lattice strains in crystalline
materials are determined by the precise
measurement of the deviation of lattice plane

Fig.1. Diffraction profile obtained by the TOF method

Fig. 2 shows the change in relative diffraction
intensity of austenite and ferrite as a function of theapplied stress. These changes are caused not only by
the stress-induced martensitc transformation but also
grain rotation with slip deformation. As seen, the83intensities of (110) and (200) ferrite increase withincreasing of the applied stress. The intensity change
becomes obvious after 360MPa which is indicatedby a dash line labeled P1 in Fig.2, suggesting theonset of plastic flow in the ferrite matrix. This stressis a lower than 0.2% proof stress listed in Table 1.
On the other hand, the intensities of (200) and (111)austenite decrease with increasing of the appliedstress after 360MPa. The decrease must be ascribedof the stress-induced transformation. Therefore, theonset stress for stress-induced transformation
labeled by P2 is consistent with P1
The change in (111) and (200) austenite latticeplane spacings was measured along the longitudinal
direction with respect to the applied stress, and thatwas converted to strain by Eq. (1). The results are
depicted in Fig.3 (a). Both (111) and (200) austenite
lattice plane strains increase with increasing of theapplied stress linearly below approximately 360MPathat is corresponding to yielding indicated by P1.
Here, P1, is almost identical with P2 determined inFig. 2. This correspondence indicates that, thetrigger of yielding is stress-induced transformation.
After the yielding, the lattice plane strain (111) and(200) in austenite increase rapidly in Fig. 3(a).
Contrary to this, the (110) and (200) lattice planestrain in ferrite decrease after P1 in (b). The present
results reveal that the retained austenite is stronger
than the ferrite matrix, i.e., the austenite grains playas the harder phase grains. This is consistent withthe conclusion obtained in our previous work withthe angler dispersion method [1]. After P2, anotherkink is observed in (a); the increasing rate of latticeplane spacing with the applied stress changes at P3.
In the regime from P2 to P3, the internal stress inaustenite is increased leading to the onset of plastic
flow or stress-induced martensitc transformation.

Fig.3. Change in lattice plane strain .during tensile deformation:(a) austenite; (b) ferrite

Thus after P3, plastic flow is believed to occur
almost equally amng the constituents.
Conclusions
Tensile behavior of a TRIP-DP steel was studied
by in situ neutron diffraction experiment. The
followings are conclusions obtained;
1. Martensite is stress-induced during tensile
deformation. The onset of transformation is
speculated to be the trigger of plastic flow in theferrite matrix.
2. High carbon bearing retained austenite isplastically harder than the ferrite matrix.
References[1] Y. Tomota, H.Tokuda, Y.Adachi, M.Wakita,
N.Minakawa, A.Moriai Y.Morii, Acta Mater,
52(2004), pp.5737-5745.
[2] S. Torii, Y. Tomota, T. Suzuki, J. H. Park, K.
Oikawa and T. Kamiyama, J JSME, 68(2002),
pp.1540-1546.

.
Fig.2. Change in diffraction intensity with tensile staining.

84

Tensile Behavior of an Austempered Ductile Cast Iron
Studied by In Situ Neutron Diffraction
H.Ogawa1, S.Morooka1, T.Shinozaki1, M.Yonemura2, Y.Tomota2 and T.Kamiyama3
1

Graduate Student of Ibaraki University. 4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511 Japan
Graduate School of Science and Engineering, Institute of Applied Beam Science, Ibaraki University.
4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511 Japan
3
Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba,
Ibaraki 305
2

1. Introduction
The austempered ductile cast iron (ADI) exhibits
the most excellent balance of strength and toughness
in the various kinds of cast irons. The ADI is
produced by the isothermal transformation fromaustenite to bainite. Because high Si concentrationin the ADI prevents the formation of cementite(Fe3C), a large amount of austenite is retained, tobring high ductility and toughness. The deformation
and/or transformation behavior of the retained
austenite upon loading is however not made clear
sufficiently. Hence, in this study, stress-induced
martensitic transformation of the retained austenite
and deformation behaviors of constituent phases, i.e.,
ferrite, austenite and graphite are firstly examinedby using in situ neutron diffraction during tensile
testing.
2. Experimental procedures
The chemical compositions of a steel used are
3.5C-2.7Si-0.3Mn in mass%. The cast ingot wasfor 1h and then austempered
austenitized at 900
for 3ks followed by water quenching.
at 310Cylindrical tensile specimens with 3mm in diameterand 28mm in gauge length were machined. In situ
neutron diffraction experiment during tensile test
was performed by using a high resolution powder
diffractometer (SIRIUS) with a time of flight (TOF)
method at KENS/KEK. The applied load was kept
constant during the diffraction measurement. Peakshifts of ferrite and austenite, graphite reflections
with tensile straining were converted to lattice plane(elastic) strain, ε hkl by eq. (1),
d d0
(1)
 hkl  hkl 0 hkl
d hkl
where dhkl and d 0hkl refer to (hkl) spacing andreference spacing (stress-free spacing), respectively.
Strains were determined both along the axial and thetransverse directions using two 90° detector banks.

3. Results and Discussion
3.1 Microstructures and mechanical properties
The microstructure observations with a lightmicroscope reveal that the ADI consists of ferrite,
bainite, graphite and the retained austenite. The
results of the conventional tensile test indicate thatthe 0.2% proof stress, tensile strength, and uniform
elongation are 940MPa, 1380MPa and 4.9%,
respectively. The results of micro-Vickers hardness
tests performed aiming at the inside of ferrite,
austenite, and graphite grains were 450HV, 510HVand 80HV, respectively. It should be noted that thehardness of austenite seems to be higher than theferrite matrix although the hardness indent was notexactly limited inside the austenite grains.
Diffraction profiles
The overall diffraction profile obtained is shownin Fig. 1. The reflections from ferrite, austenite andgraphite are observed. In particular, the (002)graphite peak is clearly detected.

Fig. 1 Neutron diffraction profile obtained before loading.

3.2 Elastic strains of constituent phases under thethe applied stress
Figure 2 shows the lattice plane strains in theconstituents as a function of the applied stress,
where YS in the figure means 0.2% proof stress. The
lattice plane strain of graphite is extremely small
compared with those from the other two phases,85

indicating that graphite bears little stress even uponloading.
The lattice plane strains of ferrite (110) and
austenite (111) are very similar in the elastic as wellas the plastic deformation regimes. The strain
increases linearly before YS and deviates from theline lower side after YS with increasing of theapplied stress. On the other hand, the strains offerrite (200) and austenite (200) are similar anddeviated higher side after YS. These results suggestthat the [200] oriented family grains are harder than[110] oriented ones commonly for the ferrite matrix
and the retained austenite and that the flow stress ofthese two constituents are nearly identical. The
strains in graphite after YS become almost zerosuggesting the graphite would fracture easily.

Fig. 3 Changes in lattice plane strain of ferrite with the appliedstress; (a) axial, (b) transverse direction.
Table 1

Diffraction elastic moduli, E andα (110)α(200)α(211)γ(111)γ(200)γ(220)γ(311)
Fig. 2 Changes in lattice plane strains of the constituent phaseswith the applied stress.

3.3 Intergranular strains in ferrite and austenite
under the applied stressFig. 3 shows the (hkl) lattice plane strains in theferrite matrix as a function of the applied stress. As
seen in (a), the strains in the axial direction increases
linearly with the applied stress in the beginning. The
slope, i.e., the diffraction Young modulus, isdependent on (hkl) measured, which is tabulated inTable 1. Although the deviation from the linear line
after YS is subtle, the (200) strain looks to move
upper side while the (110) lower side, meaning thatthe former is harder than the latter for plastic flow.
Fig. 3(b) shows the lattice plane strain observed in
the transverse direction. In the elastic regime, thestrain decreases linearly with the applied stress andthen the Poisson's ratio can be determined from theslope that is tabulated in Table 1, in which thevalues in brackets are after the Kroner model forsingle phase polycrystal free from texture. As seen,
86

E (GPa)209 [226]
146 [173]
203 [226]
217 [248)
149 [149]
196 [213]
178 [184]ν
0.28 [0.28]
0.33 [0.33]
0.29 [0.28]
0.23 [0.23]
0.26 [0.34]
0.27 [0.28]
0.28 [0.31]

ferrite: austenite
values in [ ] are estimatedones by Kroner model for single phase polycrystal.

the measured values are commonly lower than thecalculated ones, indicating the influence of graphite.
After YS, the deviation from the linear line is
obviously found in (200) strain. Although the data at
higher stresses are helpful to study the plastic
deformation behavior, the present specimen is brittle
so that the test was stopped at a low stress. The data
after fracture will be shown later. The change inaustenite volume fraction in Fig. 2 was little, i.e., 5 10% of the retained austenite was transformed tomartensite.
Figure 4 shows the lattice plane strains in theaustenite as a function of the applied stress. The
overall behaviors are quite similar to those observed
for ferrite in Fig. 3. The diffraction Young modulus
and Poisson’s ratio determined in the elastic
deformation regime are tabulated in Table 1. The
trends of the lattice plane strain after YS are alsosimilar to those in the ferrite matrix in Fig. 3. That is,
the intergranular stresses are apparently found but

the difference between ferrite and austenite is notlarge. When examined in details, the deviation fromthe linear relation between the (hkl) lattice planestrain vs. the applied stress is remarkably observedin the retained austenite as is found in Fig. 4(b).

Fig. 5 Residual lattice plane strains measured by neutron
diffraction after tensile deformation.

Fig. 4 Changes in lattice plane strain in the retained austenitewith the applied stress; (a) the axial and (b) thetransverse direction.

3.4 Residual lattice plane strains in ferrite andaustenite after tensile fracture
The stress partitioning, i.e., phase stresses,
between ferrite and austenite is not clearly found in
Figs. 3 and 4. When a higher tensile stress is applied,a specimen fractured in a quasi-brittle manner. Then,the lattice plane strains generated by uniform plastic
elongation were examined by using the fractured
specimen. That is, the residual phase andintergranular strains were determined by comparison
between before and after fracture. The results arepresented in Fig. 5.
As is observed in Fig. 5, the compressive strains
remain in the ferrite while tensile in austenite in theaxial direction. In the transverse direction, strains inferrite are commonly tensile showing the reversefeatures in the results in the axial direction. However,
the austenite strains in the transverse direction are alittle complicated. The (111) strains show
compressive while the other (200), (220) and (311)tensile. The overall trend indicates that the austenite
is stronger than the ferrite matrix.

4. Conclusions
Tensile deformation behavior of ADI was studied
by In situ neutron diffraction. The followings
include concluding remarks:
1) The stress partitioning among the constituents areclearly found, where graphite bears very little
stress even after yielding.
2) The diffraction elastic moduli are dependent on(hkl) adopted but not so different between ferrite
and austenite. Young modulus is smaller than theprediction from the Kroner model for single phasealloy. This is because Young modulus of graphite
is extremely small.
3) The onset of plastic flow in ferrite and austenite
are nearly the same, meaning that the yieldstrengths of both phase are similar.
4) When the residual intergranular stresses aremeasuredafter
fracture(largerplastic
deformation), it is found the austenite is a little
stronger than ferrite.
5) The change in volume fraction of the retained
austenite is small during uniform plastic
deformation. So, the martensitic transformationmust take place obviously during tensile fracture.
References
1)A.Kanie, et al.: ISIJ Int., 44(2004), 1955.
2)K.Ikeda, et al.:TETSU-TO-HAGANE, 91(2005),
825.
3)Y.Tomota et al.: Acta Mater., 52(2004), 74)M.T.Hutchings et al INTRODUCTION TO THE
CHARACTERIZATTION OF RESIDUAL STRESSBY NEUTRON DIFFRACTION, pp.228-231,
Taylor & Francis, 2005

87

In Situ Neutron Diffraction with a Time of Flight Method during Tensile Deformation for a
Heavily Drawn Pearlite SteelY.SHIOTA, Y.TOMOTA*, S.HARJO** and T.KAMIYAMA***
Graduate student of Ibaraki University, Hitachi, Ibaraki, 316-8511 Japan* Institute of Applied Beam Science, Graduate School of Science and Engineering, Ibaraki University,
Hitachi, Ibarki,316-8511** Japan Atomic Energy Research Institute, Tokai, Ibaraki, 319-1196, Japan*** Institute of Materials Science, High Energy Accelerator Research Organization (KEK), Oho,
Tsukuba, 305-0801
Introduction
The work-hardening of
pearlite has been
revealed to stem mainly from the load shearing
between the ferrite matrix and cementite plates byrecent studies with in situ neutron diffraction during
tensile deformation [1-3]. On the other hand,
cementite plates are dissolved into the ferrite matrix
with sever drawing and the drawn wire shows
nonlinear elastic deformation behavior at theexternal stresses above 3GPa, where the ferrite
matrix itself is strengthened [4]. Since the previous
in situ neutron diffraction measurements were
performed by the angler dispersion (AD) method for(110) planes along the tensile direction, much has
been remained unclear. Hence, diffractions fromseveral (hkl) planes both in the tensile and thetransverse directions were observed with the time offlight (TOF) method in this study. The influence of
annealing to work-hardening mechanism was also
examined.

Fig.1 Schematic illustration of in situ neutron diffraction
during tensile loading.

Experimental procedures
The chemical compositions of a steel used in thisinvestigation are shown in Table 1. Hot-rolled roundbars with 1.5mm in diameter were patented throughan industrial process to obtain fully pearlitic
structure. The bars were then cold-drawn to 0.20mm
in diameter, i.e., true strain of 4.0. Tensile behaviorof the drawn pearlite steel wire was investigated by
the in situ neutron diffraction during tensile loading.
The schematic illustration of the measurement with
the TOF method is presented in Fig 1. A pulsed
neutron beam generated from a spallation source isdiffracted by an overall portion of a tensile specimen
under the applied stress. The diffracted beams aremonitored at the two 90-degree detector banks,
which provide the lattice plane strains in the axial
and the transverse direction. The lattice planespacing was determined by a single peak fitting
method and then the lattice plane strains were

Results and discussion
Figure 2 shows diffraction profiles obtained in
the axial and the transverse direction. As seen,
cementite peaks are not detected. Because the strong<110> fiber texture is evolved along the drawing,i.e., axial direction, diffraction intensity except
ferrite (110) is extremely weak. Here, the peak
positions of (110), (211), and (220) ferrite
reflections in the axial direction were determined,
while (110), (200), (211) and (220) in the transverse
direction.
Figure 3 shows the shift of (110) diffraction
profiles with tensile loading in both of the axial andtransverse directions.
The lattice plane strains are plotted as a functionof the applied stress in Fig. 4. As is consistent withthe previous results by the AD method [4], nonlinear
elastic deformation behavior is observed above theexternal stress of 3GPa. When diffraction Young

88

calculated taking the spacing before loading as theinitial gauge length.
Table 1 Chemical compositions of a steel used (mass%).
C

Si

Mn

P

S

Cr

Al

N

0.88

0.16

0.51

0.009

0.005

0.03

0.001

0.0029-3

20x10

(110)
(200)

15

(211)

Axial direction : (220)

Lattice plane strain

modulus is calculated from the beginning regime
below 2.5GPa, 237 and 214 GPa were obtained for(110) and (220), respectively, which should be thesame.
In Fig. 5, the (110) lattice plane strain in thetransverse direction is compared with a single Fe
crystal. As can be seen, the present wire with astrong <110> fiber texture is found to behave nearly
like the single crystal. To be noted here is that the
Poisson’s ratio is strongly dependent on [hkl]: to be
noted here is that the value with respect to [110] isvery small.

10

5

0

-5

Transverse direction : 22 or 33
-10
0

500

1000

1500

2000

2500

Applied stress / MPa

3000

3500

Fig.4 Lattice strains as a function of the tensile stress.

Fig. 5 Features of elastic response in the transverse
direction for the [110] oriented single crystal andthe present result.
Fig.2 Diffraction profiles obtained: (a) the axial and (b)the transverse direction.
(110) at transverse direction

2500MPa
1500MPa

Intensity / countIntensity / count(110) at axial direction

2500MPa
1500MPa

200MPa

0.190

0.195

0.200

0.205

0.210

0.215

Lattice plane spacing / nm

0.220200MPa

0.190

0.195

0.200

0.205

0.210

0.215

Lattice plane spacing / nm

0.220

References[1] Y.Tomota, P.Lukas, D.Neov, S.Harjo and .R.Abe,
Acta mater., 51, (2003), 805.
[2] Y.Tomota, O.Watanabe, A.Kanie, A.Moriai,
N.Minakawa and Y.Morii, Materi.Sci.
Technology, 19, (2003), 1715.
[3] A.Kanie, Y.Tomota, S.Torii and T.Kamiyama,
ISIJ Int., 44, (2004), 1961.
[4] Y.Tomota, T.Suzuki, A.Kanie, Y.Shiota, M.Uno,
A.Moriai, N.Minakawa and Y.Morii, Acta
mater., 53, (2005), 463.

Fig.3 Shift of diffraction profiles with tensile loading: (a)the axial and (b) the longitudinal direction.

89

Crystal Structure of Li(MnyFe1-y)PO4 and Its Delithiated Phases
A. YAMADA*1, Y. TAKEI1, M. YONEMURA2
1

Department of Electronic Chemistry, Interdisciprinary Graduate School of Science and Engineering,Tokyo Institute of Technology
24259 Nagatsuta, Midori, Yokohama, 226-8502 Japan

Institute of Materials Structure Science, High Energy Accelerator Research Organization

1-1 Oho, Tsukuba 305-0801 Japan

LiFePO4 (triphylite) and LiMnPO4 (lithiophilite)
form a solid solution series isomorphous with olivine,with an orthorhombic unit cell and space group Pnma
(see Fig. 1). This class of compounds, particularly
LiFePO4, has been the subject of intensive researchover the past four years. The low cost, nontoxicity,
superb thermal stability, and the position of the
Fe3+/Fe2+ redox couple at 3.4 V vs. Li/Li+, make
LiFePO4 the most likely candidate for use in a
rechargeable lithium battery electrode designed forlarge-scale applications such as electric/hybrid
vehicles and load leveling systems. The position of
the Mn3+/Mn2+ redox couple in the olivine frameworkhas been reported as 4.1 V vs. Li/Li+. However,despite the higher voltage, the current durability in
LixMnPO4 is many orders of magnitude inferior tothat of LixFePO4, and the effective energy density of
LiMnPO4 has turned out to be much smaller than thatof LixFePO4.
One of the key aspects of this important class ofmaterials is that major structural anomalies, such as
anisotropic deformation, significant loss oflong-range order, and local phase segregation, havebeen exclusively detected in the Mn3+ phases. This isreasonable, as Mn3+ is a typical Jahn-Teller ion, andindicates the importance of acquiring various
essential data from the (MnyFe1-y)PO4 solid solution.
However, previous studies have been limited tostructural analysis of the minerals (heterosite: y ~ 1/3,
purpurite: y ~ 2/3), and usually present the specificmanganese content of samples which containstructural disorder and impurities due to their natural
origin.
A series of synthetic heterosite-purpurite,(MnyFe1-y)PO4 (y<0.8), with negligible disorder andimpurities was obtained by chemical oxidation of thewell-crystallized isotypic tryphillite-lithiophilite
series, Li(MnyFe1-y)PO4 (ordered olivine structure,space group Pnma). Comparative magnetic and
X-ray/neutron powder diffraction investigations of
the two solid-solution lines were performed as afunction of Mn content to increase understanding of90

the electrochemical activity loss of Mn3+/Mn2+ in theLix(MnyFe1-y)PO4 electrode system. Introducing Mnions into the 4c site did not cause significant change
in the local geometry of M2+O6, and PO4 polyhedra,
while the M3+O6 octahedra became severely distortedwith an increase in the number of Jahn-Teller (JT)
active Mn3+ ions. The edge-sharing geometry of
M3+O6 and PO4 polyhedra fixed the shared O3’-O3’
inter-atomic distance, causing selective strong
elongation of the M3+-O3’ distance with small
shrinkage of other M3+-O1, M3+-O2, and M3+-O3bond lengths. The overall distortion of the MO6octahedra with M = Mn3+ was much larger than thecorresponding change in the unit-cell orthorombicity
and significantly increased asymmetry in the M-O-M
superexchange interaction. All samples exhibited
antiferromagnetism; however, the trivalent series had
more than a seven-fold larger decrease in Neeltemperature TN (ca. 130 K at y = 0 to ca. 50 K at y =0.8) compared to the divalent series (ca. 52 K at y =0 to ca. 35 K at y =1) as a function of Mn content y.

Fig. 1 Rietveld refinement pattern of the X-ray andneutron diffraction data for Li(Mn0.6Fe0.4)PO4 atroom temperature.

Atom
Li
Fe,Mn
P
O1
O2
O3

Site
4a
4c
4c
4c
4c
8d

g
1
1
1
1
1
1

x
y
z
0
0
0
0.28195(8) 0.25
0.9731(2)0.0936(1)0.25
0.4131(3)0.0965(4)0.25
0.7395(7)0.4559(4)0.25
0.2117(7)0.1630(2) 0.0493(4) 0.2900(4)

B (Å)
1.0
0.6
0.6
1.0
1.0
1.0

PO4 Tetrahedra

(a)

O3’

a=10.4031(1) Å, b=6.06424(8) Å, c=4.72377(7) Å
Rwp=7.28, Rp=5.16, S=Rwp/Rp=1.3589, RI=1.83, RF=0.94
Atom
Li
Fe,Mn
P
O1
O2
O3

Site
4a
4c
4c
4c
4c
8d

g
1
1
1
1
1
1

x
y
z
0
0
0
0.2834(6)0.25
0.967(1)0.0934(2)0.25
0.4131(3)0.0970(1)0.25
0.7356(4)0.4567(1)0.25
0.2083(4)0.1632(1) 0.0479(2) 0.2799(3)a=10.3983(1) Å, b=6.0625(7) Å, c=4.72324(6) Å
Rwp=2.60, Rp=2.21, S= Rwp/ Rp=1.2610, RI=1.00, RF=0.52

Table 1. Rietveld refinement results forLi(Mn0.6Fe0.4)PO4 with X-ray and Neutron diffraction
data.

M-O3



O3
Fe

B (Å)
1.1(1)
0.5(1)
0.34(3)0.38(3)0.50(3)0.46(2)

c

(b)

b

M-O3’

O1

O2
O3

O3’

unit cellFig. 3 (a) Local networking geometry of theequatorial O3(2)-M-O3’(2) plane in MO6 octahedra
and three PO4 tetrahedra in LiMPO4 in projection
perpendicular to he plane. (b) Edge-sheared
networking geometry of MO6 octahedra in LiMPO4
in projection along [100]. The shared oxygen is O3
for one octahedron but is O3’ for the otheroctahedron. The bond lengths M-O3 and M-O3’ andthe bond angle
related to the neighboring
superexchange interaction J1 are denoted.
O1

Li(MnyFe1-y)PO4
y=0

O3
O3’
O3

y=1

O3’

(Mn yFe1-y)PO 4

O2

y=0

M-O1
M-O2
M-O3
M-O3'

1.6

1.8

y=0.8

2.0

2.2

2.4

M-O distance /Å

Fig. 4 Interatomic bond lengths obtained by Rietveld
refinement for LiFePO4, FePO4, LiMnPO4, and(Mn0.8Fe0.2)PO4. The M-O3 and M-O3’ bond lengths
are related to the superexchange interaction and areconnected by dashed lines to show the significant
change in asymmetry.

Fig. 2 Temperature dependence of the inverse
magnetic susceptibility (zero field cooling) for (a)Li(MnyFe1-y)PO4 and (b) (MnyFe1-y)PO4

References
1) A. Yamada*, Y. Takei ， H. Koizumi, N.
Sonoyama, and R. Kanno, Appl. Phys. Lett., 87,252503（2005）
2) A. Yamada*, Y. Takei, H. Koizumi, N.
Sonoyama, R. Kanno, K. Ito, M. Yonemura, and
T. Kamiyama, Chem. Mater., 18, 804(2006)

91

Room Temperature Miscibility Gap in LixFePO4
A. YAMADA*, H. KOIZUMI, and S. NISHIMURA
Department of Electronic Chemistry, Interdisciprinary Graduate School of Science and Engineering,Tokyo Institute of Technology

4259 Nagatsuta, Midori, Yokohama, 226-8502 Japan

State of the art of LiFePO4 technology forlithium battery cathode is already in the commercial
development not only as a main electrode material
but
also
as
an
additiveforanovercharge/overdischarge protection and/or safety
buffer. A key feature of the LixFePO4 cathode is its
extremely flat charge/discharge profile at 3.4V
versus Li+/Li. Conventional belief based on the
Gibbs phase rule was that the reaction proceeds
varying the FePO4/LiFePO4 ratio throughout therange of x in LixFePO4. However, carrier (mobile
electron or hole) densities in the monovalent
stoichiometric end members should be negligible andthis evidently accounts for the very low electronic
conductivity of < 10-9 S/cm in LiFePO4. To
overcome this problem, Chung et al. attempted lowlevel doping with aliovalent ions (e.g., Mg2+, Al3+,
Ti4+, Zr4+, Nb5+) into Li 4a site and reported that theelectronic conductivity increased by a factor greaterthan 108. by introducing p-type and n-typeconductivity at the fully discharged and charged state,
respectively. However, debate exists concerningwhether the observed increase in electronic
conductivity is a true lattice doping effect or is due tothe surface conducting percolation.
In this work, we took a closer look at the phasechange of LixFePO4 at room temperature to
determine if the creation of charge career isspontaneous
duringtheelectrochemicalcharge/discharge process (i.e., does lithium orlithium defect function as a carrier-doping impurity).
As in many binary systems, thermodynamics
suggests there are two solid solution regions outside
the miscibility gap at finite temperatures. This is
typically seen in spinodal decomposition in binary
liquid systems with an inverse-parabolic phaseboundary in the temperature - composition diagram.
For intercalation solid electrode materials, thisbehavior was intensively studied in the 1980s. Onset
temperature of the miscibility gap varies from ca.
270 K for metallic Cheverel LixMo6Se8 (0 < x < 1) to
ca. 1200 K for insulating NASICON-type
Na1+xTi2(PO4)3 (0 < x < 2). Analogous to thesecompounds, the intermediate phase in the LixFePO492

cathode at room temperature may be described as the
mixture of the Li FePO4 and Li1_ FePO4 phases withthe two monophase regions, 0 < x < and 1_ < x <1.

Fig. 1 Rietveld refinement pattern of the neutron
diffraction data measured for Li0.5 FePO4, at room
temperature. The observed intensity data are shownby dots, and the solid line overlying them is theintensity calculated using RIETAN software. Verticalmarkers below the diffraction patterns indicate
positions of possible Bragg reflections. Differences
between observed and calculated intensities areplotted in the same scale.
Here we show the first direct evidence forpartial lithium occupancy and partial lithium defectin the 4a site in the two separated phases in LixFePO4
at room temperature. Time of flight (TOF) neutron
powder diffraction data were obtained for FePO4,
Li0.5FePO4, and LiFePO4 at room temperature, andthe results of Rietveld refinement for Li0.5FePO4 aresummarized in Fig. 1 and Table 1 Both FePO4 and
LiFePO4 were refined to stoichiometric compositions
with ideal atomic distributions under the space group
Pnma and excellent agreement with the previous
report. For a two-phase analysis of Li0.5FePO4, all of
the refined orthorhombic lattice constants in eachphase had values intermediate between those of
stoichiometric FePO4 and LiFePO4, with a systematicdeviation direction. These values agree well with ourrecent X-ray diffraction results and are known to be
independent of x in the wide range of x in LixFePO4.
Therefore, the neutron diffraction profile forLi0.5FePO4 does represent the crystallographic natureinside the miscibility gap. The best fit was realized
by setting partial lithium occupancy= 0.05 andlithium defect = 0.11 in each phase. They are muchlarger than the values indirectly estimated from thedeviation of orthorhombic lattice constants, ’ = 0.03
and ’ =0.04, implying Vegard’s low is not valid forregular solution systems involving strong interaction
between atoms.

Table 1. Rietveld refinement results for Li0.5
FePO4 with neutron diffraction data. Data for the
sample with nominal composition Li0.5FePO4 wereanalyzed as a mixture of Li FePO4 (47.7 %) and Li1FePO4 (52.3 %). Values of and obtained fromthe refined occupation numbers of the Li 4a site ( =0.07, = 0.10) were larger than those estimated by
the lattice constants with Vegard’s law ( ’ = 0.03, ’= 0.04). Different values ofandmight haveresult in changes in the mole fraction of each phase,
instead of equal amounts of the two phases; all of thenumerical values are self-consistent.
References
1) A. Yamada, H. Koizumi, N. Sonoyama and R.
Kanno, Electrochem. Solid State Lett.., 8, A409
(2005)
2) A. Yamada, H. Koizumi, S. Nishimura, N. Sonoyama,
R. Kanno,
M. Yonemura,
T. Nakamura,
Y. Kobayashi, Nature Materials, 5, 357(2006)

93

Structure Refinement of Barium Titanate BaTi2O5
M. YASHIMA,1 R. TU,2 T. KAMIYAMA, 3
K. MORI,4 T. GOTO,2 H. YAMANE 5
1

Department of Materials Science and Engineering, Interdisciplinary Graduate School of Science andEngineering, Tokyo Institute of Technology, Nagatsuta-cho 4259-J2-61, Midori, Yokohama,226-8502
2
Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku
Sendai, 980-8577
3
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
4
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494
5
Institute of Multidisciplinary Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai,
980-8577

Recently two research groups independently
discovered a new ferroelectric barium titanate
BaTi2O5. The crystal structure of the BaTi2O5 has
been investigated by some researchers. Here we
report a neutron powder diffraction study of the
BaTi2O5.
The BaTi2O5 pellets were melted and solidified
by an arc-melting method. Polycrystalline BaTi2O5
was obtained and then crushed into powders. The
powder was isostatically pressed into a rod andheat-treated at 1100 oC for 12 hours in air. The rodof 6 mm in diameter was used for the diffraction
experiment with the VEGA diffractometer at the
KENS, KEK, Japan. The experimental data wereanalyzed by Rietveld method. A computer program
RIETAN-TN was used for calculations [1].

Fig. 1

Rietveld pattern of the barium titanate
BaTi2O5.
The existing phase was identified to be themonoclinic C2 symmetry [2,3]. Figure 1 shows the
Rietveld pattern of the monoclinic C2 BaTi2O5.

94

Calculated profile agreed well with the observed
intensity. Table 1 shows the refined crystallographic
parameters in the Rietveld analysis. Most of refinedparameters in the present study agreed with those in
the single-crystal X-ray analysis [2].
Table 1. Crystallographic parameters and reliability
factors of the barium titanate BaTi2O5.
Atom
x
y
z
B / Å2Ba1 0.3693(3) -0.00011 0.0172(6) 0.29(7)Ba20.0
0.500(6)1/2=
B(Ba1)
Ti1 0.0404(5) 0.029(6) 0.2102(9) 0.26(7)Ti2 0.2050(5) 0.018(6) 0.3705(8)=B(Ti1)
Ti3 0.3333(4) 0.502(6) 0.3052(8)=B(Ti1)
O1
0.0362(3) 0.534(4) 0.2082(6) 0.26(2)O20.1081(3) 0.025(4) 0.4281(6) = B(O1)O3
0.1533(3) -0.003(5) 0.1851(6) = B(O1)O4
0.1751(3) 0.516(5) 0.6623(5) = B(O1)O5
0.2356(3) 0.508(5) 0.3954(6) = B(O1)O6
0.2882(3) 0.482(5) 0.1245(6) = B(O1)O7
0.4418(3) 0.522(5) 0.2857(6) = B(O1)O8
0.0
0.015(6)0.0= B(O1)
Spacegroup:
C2,
Unit-cellparameters:
a=16.8928(2), b=3.93150(4), c=9.4054(4) Å,= =90 deg., =103.105(1) deg.; Rwp=2.12 %,Goodness of fig = 1.48, RI=2.43 %, RF=1.42 %.
References
1) T. Ohta et al., Physica B 234-236 (1997) 1093.
2) T. Kimura et al., Acta Cryst. C 59 (2003) i128.
3) M. Yashima et al., Appl. Phys. Lett. 87 (2005)
101907.

Evaluation of the Residual Strain for the Practical Composite Nb3Sn Wires with Pre-bending
Treatment
S. AWAJI, H. OGURO, G. NISHIJIMA, P. BADICA, K. WATANABE, F. SHIKANAI*,
T. KAMIYAMA* and S. HARJO**High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku
University, Sendai 980-8577*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801**Japan Atomic Energy Agency, Ibaraki 319-1195
Residual strain in practical composite Nb3Sn
wires generates serious problems in development
and application of theses wires. The reason is highsensitivity of the technologically important criticalparameters such as critical current density Jc, upper
critical field Bc2 and critical temperature Tc withresidual strain [1]. Generally, residual strains of thepractical Nb3Sn wires are about 0.2-0.4 % and thesevalues produce a decrease of the critical current
densities.
We found that the repeated bending loads atroom temperature can reduce the residual strain and,hence, can drastically improve the critical current
density [2]. This phenomena is called “pre-bending”
effect. In order to understand the mechanism of the
pre-bending treatment, we tried to measure theresidual strains for the practical Nb3Sn composite
wires by the neutron diffraction at room and low
temperatures.
Samples are high strength Nb3Sn composite
wires with and without pre-bending treatments. The
specifications and the cross sectional view of thesample used in this study are shown in Table 1 andFig. 1, respectively. The pre-bending treatment wasapplied using 10 pulleys with a bending strain of
0.8 %. For the neutron diffraction measurement, thewire was cut into 100 short pieces with 10 mm inlength and stacked parallel into a cubic shape with
10 mm on the side. The neutron diffraction
measurements were conducted at a time of flight(TOF) neutron diffractometer Sirius. Obtained data
were compared with the X-ray diffraction data of the
Nb3Sn filaments. This allowed calculation of theresidual strain. Filaments were extracted from thesame wire by acid etching.
Figure 2 shows the axial tensile strain
dependence of critical current Ic at 14.5T and 4.2 K.
The tensile strain dependence of Ic is changed
drastically, after the pre-bending treatment. The
peak shifts to a lower tensile strain value and the
maximum Ic enhances after the pre-bending
treatment. In is suggested that the peak shift is dueto the reduction of the axial residual strain but theincrease of the Ic maximum may arise from thechange of the transverse strain. It means that not
only the longitudinal but also transverse residualstrains of the Nb3Sn are changed by the pre-bending
treatment, and both influence Jc. Please note that the
behavior of Ic is equivalent with that of Jc for thesame wire architecture, qualitatively.
Figures 3 and 4 summarize the diffraction results
for the composite wires with and without
pre-bending treatment. From measurements at 7K,
we found that for the pre-bending with 0.8 % strain
the axial (longitudinal) residual strain was reduced
Table 1. Specification of the Nb3Sn wires.

Fig. 1

Cross sectional image of the Nb3Sn wire.

95

250

CuNb/Nb3Sn (IS2) 4.2K 14.5T

CuNb/(Nb, Ti)
T=7K

Intensity (arb. unit)

150
100
50
0

as reactedpb=0.8%
0

0.5

1

1.5

axial tensile strain (%)
Fig. 2 Axial tensile strain dependence of Ic at 4.2 K and
14.5 Tby about 0.2% and the lateral (transverse) strain
increased by about 0.03 %. The residual strainchange behavior measured at 7 K and room
temperature was similar. It is considered that both of
the axial and lateral strains influence thesuperconducting properties via deviatric strain.
According to the deviatric strain model proposed byten Haken [3], the maximum of the axial strain
dependence of the superconducting parameters is
obtained at the strain where the deviatric strain is
minimum. The minimum value of the deviatricstrain is dependent on the wire architecture and theelastic-plastic deformation properties of thecomposed materials. Hence, the improvement of theaxial strain dependent Ic properties as shown in Fig.
2 can be qualitatively described by the reduction of
the deviatric strain. Consequently, the next stepwould be measurement of the in-situ strain under
tensile deformations. These measurements are
expected to give rise to the extra necessary data for abetter understanding of the Jc-improvement vs. strain.
Since the variation of Jc with pre-bending is closely
related to the general mechanism of the Jc strain
dependence in the composite superconducting wires,
we believe that the proposed study is of highinterest; it is important not only from fundamental,
but also a practical point of view targetingsuperconducting applications such as ITER and
NMR.
Acknowledgements
Strain dependence of Ic was measured by Prof
Katagiri from Iwate University. We would thank forhis help. A part of this study was supported byIndustrial Technology Research Grant Program in96

filaments
as heat treated
pre-bent with pb = 0.8 %

2.14

2.16

2.18

d (Å)
Fig. 3 Diffraction patterns at 7K of Nb3Sn 210 peaks foraxial direction

CuNb/(Nb, Ti)

3 Sn lateral direction

T=7K

filaments
as heat treatedprebent with pb = 0.8 %Intensity (arb. unit)

Ic (A)

200

3 Sn axial direction

2.14

2.16

2.18

d (Å)
Fig. 4 Diffraction patterns at 7K of Nb3Sn 210 peaks forlateral direction'04 from New Energy and Industrial Technology
Development Organization (NEDO) of Japan and
the Ministry of Education, Science and Technology,
Japan
References
1) J. Ekin, Filamentary A15 Superconductors, ed.
M. Suenaga and A. Clark, Plenum Press, pp187,
1980.
2) S. Awaji, H. Oguro, G. Nishijima, K. Watanabe,
S. Harjo, T. Kamiyama and K. Katagiri,
Supercond. Sci. Techn., 18 (2005) S313.
3) B. ten Haken, A. Godeke, and H. H. J. ten Kate,
J. Appl. Phys. 85 (1999) 3247.

Variation of Hydrogen Occupation in LaNi4.78Sn0.22Dx Along the P-C Isotherms Studied by in
Situ Neutron Powder Diffraction
Y. NAKAMURA,† R. C. BOWMAN, JR.,‡ E. AKIBA††

National Institute of Advanced Industrial Science and Technology (AIST)
AIST Tsukuba Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki, 305-8565‡
Jet propulsion laboratory
California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109-8099, USA

Metal hydrides are regarded as one of key
materials for hydrogen storing technology.
Hydrogen absorbing and desorbing properties ofmetal hydrides are closely related to the crystal
structure, particularly hydrogen occupation in theinterstitial sites. Hydrogen site occupation, thepositions and the occupancies, can be directly
determined only by neutron diffraction. In particular,in situ neutron powder diffraction is a powerful
technique to investigate hydrogen (i.e., deuterium)
occupation in various hydriding states. This kind of
measurements needs a special setting, particularly
for the sample holder. It needs to be pressurized bydeuterium (D2) gas, and connected to the Sieverts
apparatus when diffraction data is collected along
the P-C (Pressure-Composition) isotherms. It is of
critical importance that the diffraction from theholder itself does not disturb the diffraction from thesample, but in real it is difficult to achieve. Recently,
we demonstrated measurements of LaNi4.9Al0.1Dx
along the desorption P-C isotherm using a newly
designed sample holder for 90° banks of a TOF
diffractometer [1]. From the obtained data variationin hydrogen occupancy of each site during
desorption were successfully analyzed.
In this study, we have investigated hydrogen
occupation in LaNi4.78Sn0.22Dx during bothabsorption and desorption by in situ neutron powder
diffraction along the P-C isotherms. Dependence ofhydrogen occupation on hydriding state wasanalyzed for the hydride-phase region and thetwo-phase region.
LaNi4.78Sn0.22 alloy was prepared by arc melting
high purity metals (i.e., 99.8%La, 99.99%Ni, and99.95%Sn) at the Materials Preparation Center,
Ames Laboratory, Iowa State University (USA).
These ingots were annealed at 1223K for ~100h in apurified Ar atmosphere.
6.00 g of the sample powder ranging between 20- 200 mesh was put into a sample holder speciallyfabricated for in situ neutron diffraction
measurements[1],
mainlycomprisingastainless-steel tube with 10-mm outer diameter and
0.3-mm wall thickness. The sample was activated by
evacuating at 353 K for 1 h, pressurizing with D2
gas up to 1.0 MPa at 298 K, and then dehydrided by
evacuation at 353K. The sample holder was set on
the diffractometer and connected with a Sieverts
apparatus. Absorption and desorption reaction with
D2 gas was conducted along the P-C isotherms atroom temperature controlled at ~295K. Hydrogencontent of the sample was calculated by thevolumetric method. The obtained hydrogen content
for the full-hydride (a7 in Fig. 1) was 1.02 D/M =6.12 D/f.u. (f.u.: formula unit, D/f.u. =D/[LaNi4.78Sn0.22])
Neutron powder diffraction data was collected ina TOF (time of flight) diffractometer (Sirius, KENS)
using two 90° detector banks. A cadmium maskwith 3-mm-wide beam windows was used toeliminate diffraction caused by stainless steel fromthe sample holder. Weak diffraction of γ-Fe wasstill observed, but we could analyze the data taking
the γ-Fe phase into the model as the second or thethird phase. The observed intensity of the γ-Fe
corresponds to 0.4–1.3% of the sample in massfraction.
Diffraction data was collected at seven states(a1-a7) in absorption and seven states in desorption(d1-d7) on the P-C isotherm at ~295K indicated inFig. 1. The P-C isotherm was measured directly
using a Sieverts apparatus. The obtained diffraction
profiles indicate that the states a5-a7 and d1-d3 arein the single hydride-phase region. The states a2-a4
and d4-d7 are in the two-phase region, where thesolid solution phase and the hydride phase coexist.

97

The Rietveld refinement program for TOF
neutron diffraction, RIETAN-TN [2-4], was used toanalyze the diffraction data. That program employs
a combination of exponential and Gaussianfunctions for expressing the peak profile.
Coefficients of the functions contain primary profile
parameters, each of which is a function of spacing d.
Selected diffraction peaks were fit using ‘primary
profile parameter relaxation method’ [3,4] without
the d-dependence of the primary profile parameters.

Diffraction data measured in the two-phaseregion was analyzed with a model containing boththe hydride phase and the solid solution phase. The
same structural model with the P6mm symmetry
was used for the hydride phase. Analysis of the solid
solution phase elucidated a structural model in a
P6/mmm symmetry, which was reported for
LaNi5Dx (x=0.1, 0.4) [6] with two hydrogen sites, 3f(1/2, 0, 0) and 6m (x, 2x, 1/2). An example of therefined pattern is shown in Fig. 3.

Fig.1 P-C isotherm of LaNi4.78Sn0.22 in D2
simultaneously measured with in situ neutron
powder diffraction. a1–a7 (absorption) and d1–d8(desorption) indicate the states where diffraction
data were collected.

Fig. 3 Rietveld refinement of the in situ neutron
powder diffraction pattern for LaNi4.78Sn0.22D2.7 (d6)in the two-phase region. Tick marks: the hydride
phase (upper), the solid solution phase (middle), theg-Fe (bottom). Rwp = 3.15%, Rp = 2.53%, RI(hydride) = 1.31%, RI (solid solution) = 1.92%, S =2.33.

The diffraction data of the full-hydride single
phase LaNi4.78Sn0.22D~6 (a5-a7, d1-d3) was analyzed
using a structural model with a P6mm symmetry,containing four hydrogen sites, 3c, 6e1, 6e2 and 2b.
Sn atoms occupy only the 3c sites on the internal
plane (z = 1/2), which is similar to that used for
LaNi4.8Sn0.2 [5]. This model provided a good fit asshown in Fig. 2.

Fig. 2 Rietveld refinement of the in situ neutron
powder diffraction pattern for full-hydride
LaNi4.78Sn0.22D6.1 (a7). Tick marks below the profile
indicate positions of all allowed diffraction for thehydride phase (upper) and the g-Fe (bottom).

98

The full-hydride LaNi4.78Sn0.22D6.1 has a P6mm
structure with four hydrogen sites (Fig. 4). This is
the same structure as LaNi4.9Al0.1D6.1 reported bysome of the authors [1]. Hydrogen occupation sites
comprise one O site near the basal plane and three T
sites near the internal plane: 3c (O[La2Ni4]), 6e1(T[La2Ni2]), 6e2 (T[La1Ni3]), and 2b (T[Ni4]),
denoted as D1–D4, respectively.

Fig. 4 Crystal
structureoffull-hydride
LaNi4.78Sn0.22D6.1. Large sphere: La, sphere at acorner of a polyhedron: Ni (or Sn), small sphere in apolyhedron: D. D1: 3c, D2: 6e1, D3: 6e2, D4: 2b.
Occupancy of the D1 sites was 0.98(2),indicating that they are fully occupied. The otherthree sites, D2, D3, and D4, located close to one
another, were partially occupied with occupancies
0.17–0.34. The analysis indicated that the totalhydrogen content obtained equals 6.5(2) D/f.u.,which agrees with the hydrogen content measured
by the volumetric method.
Hydrogen occupancy for each site in the hydride
phase changed with the total hydrogen content asshown in Fig. 5. Occupation change greatly
depended on the hydrogen sites. The D1 site was
fully occupied during both absorption anddesorption over the whole region. Occupancy of theD2 site was constant around 0.33, except for a slightincrease up to ~0.37 in the two-phase region fordesorption. Occupancies of the D3 and D4 sites
increased (absorption) and decreased (desorption) in
the single-phase region. In the two-phase region theD3 site gradually decreased in the occupancy during
desorption.
The occupancies of the D2, D3 and D4 sites
showed hysteresis between aorption and desorption
in the two-phase region. The D2 site has larger
occupancies for desorption than for absorption,
while the D3 and D4 sites have the opposite
tendency. The hydrogen occupation among the three
T sites are rearranged around the boundary between
the hydride-phase region and the two-phase region
during desorption.Hysteresis was not observed in the
single-phase region for all of the sites.
The total hydrogen content in the hydride phase,
calculated from the occupancies of D1–D4
decreased along the desorption P-C isotherm, evenin the two-phase region. This is considered to be
reduction of the miscibility limit relating to latticestrain formation.

Fig. 5 Occupancy of each site in the hydride phaseduring absorption (open mark) and desorption(closed mark).
Acknowledgements
The authors thank Dr. F. Izumi for providing andmodifying the Rietveld refinement software,
RIETAN-TN. The authors thank Prof. K. Kamiyamaof the High-Energy Accelerator Research
Organization, Dr. T. Ishigaki of Japan Atomic
Research Institute and Mr. K. Iwase of the Graduate
University of Advanced Studies for technicalassistance in neutron diffraction measurements.
A part of this research was financially supportedby the Ministry of Economy Trade and Industry(METI) of Japan.
This research was partially performed at the Jet
Propulsion Laboratory, which is operated by the
California Institute of Technology under contract
with the U.S. National Aeronautics and Space
Administration (NASA).
References
1) Y. Nakamura, T. Ishigaki, T. Kamiyama, E.
Akiba, J. Alloys Compd., 384 (2004) 195.
2) F. Izumi, The Rietveld Method, International
Union of Crystallography, R.A. Young (Ed.),
Oxford University Press, 1993, Ch.13.
3) F. Izumi, Rigaku J. 17, No. 1 (2000) 34–45.
4) F. Izumi, http://homepage.mac.com/fujioizumi/5) J.-M. Joubert, M. Latroche, R. Cerny, R.C.
Bowman Jr., A. Percheron-Guégan, K. Yvon, J.
Alloys Compd. 293–295 (1999) 124.
6) J.L. Soubeyroux, A. Percheron-Guégan, J.C.
Achard, J. Less-Common Met. 129 (1987) 181.

99

Neutron Powder Diffraction Study of Protonic Conductor K3H(SeO4)2
F. SHIKANAI, R. KIYANAGI1, M. YONEMURA2, K, IWASE, D. SULISTYANINTYAS,
T. WURNISHA, K. MORI3, T. ISHIGAKI4, S. IKEDA and T. KAMIYAMA
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801
1
Intense Pulsed Neutron Source Division, Argonne National Laboratory, USA.
2
Graduate school of Engineering and Science, Ibaraki University, Hitachi, Ibaraki, 316-8511
3
Research Reactor Institute, Kyoto University, Sennan-gun, Osaka, 590-0494
4
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Ibaraki, 319-1195
M3X(YO4)2 (M: K, Rb, Cs, or NH4; X: H or D,
Y: S or Se) type hydrogen-bonded materials havebeen the subject of investigations owing to many
interesting phenomena. Most of the materials
undergo phase transition in the high-temperature,and show over 100 times higher electric
conductivities than those at the room-temperature[1]. It is considered that the higher electric
conductivity is due to the proton transfer.
K3H(SeO4)2 (abbreviated as TKHSe) undergoes
phase transition at 390 K (TC). The crystal showshigh electric conductivity about 10-4 to 10-2 S/cm inthe high-temperature phase (phase I), andferroelastic in the room-temperature phase (phase II).
The crystal structure is characterized isolated
SeO4-H-SeO4 dimer including a hydrogen bond, andthe dimers construct the layered structure parallel tothe monoclinic bc-plane [2].
Single crystals of TKHSe were grown at 313 K
by slow evaporation method from aqueous solution.
The crystals were powdered and 3.89 g of themwere used for measurements. Neutron powder
diffraction data were collected using a time-of-flight(TOF) neutron diffractometer VEGA at KENS
pulsed spallation neutron facility. Measurement
were done at 298 K, 385 K, 393 K and 413 K,
Rietveld
analysis
wereperformed
by
RIETAN-2001T modified for VEGA. Protondensity distribution maps were obtained from the
maximum entropy method (MEM) using 935
reflections for phase II and 227 refractions for phase
I. The integrated intensities I and their standard
deviations σI for MEM calculations were adopted
from general using Rietveld equation [3].
Figure 1(a) and Fig. 1(b) show the Rietveld
diffraction fitting of TKHSe at 298 K and 413 K,
respectively. Good agreement between the observedand calculated patterns were obtained with theagreement factors and goodness-of-fit (GOF)
indicator of Rwp = 0.010, RI = 0.004 and S = 1.23 for100

phase II, and Rwp = 0.014, RI = 0.019 and S = 1.77
for phase I.

Fig. 1

Rietveldrefinement
patterns
K3H(SeO4)2. (a) 298 K (b) 413 K

forFigure 2 shows proton distribution maps of
TKHSe in each phases obtained from MEM
calculations. In the phase II, the two SeO4 tetrahedra
construct a dimmer linked by a hydrogen bond. The
proton is localized in a hydrogen bond marked as A
in the figure. On the other hand, in the phase I
oxygen atoms displaced in to triangular positions
with the occupancy of 1/3 from their mean structuresites. This model corresponds to the rotationallydisplacement of SeO4 tetrahedra, and is in the bestagreement with the diffraction pattern. A SeO4
tetrahedron is linked to nearest three equivalent
SeO4 tetrahedra with a probability of 1/3. The proton
occupies the duplicate sites between two oxygen
atoms with the occupancy 1/6. Interatomic distances
related to the hydrogen bonds and SeO4 tetrahedra
arrangements in both phases are nearly equal. This
result suggests that two SeO4 tetrahedra areconnected by a hydrogen bond even in the phase I,
and the crystal structure in the phase II are locallyremains. The proton densities were obtained in theinter-layer space marked as B in the Fig. 2(b). It isstriking contrast with the same part in the phase II.
Amount of the proton in a hydrogen bond were
decline from 87.3 % to 21.4 % with increasing
temperature. Therefore, the proton amounts in theinside of layer space decrease. The decrease of
proton amounts in the inside of layer is roughly
consistent with the increase in the inter-layer space.
This fact shows that the crystal has Frenkel defects
in the phase I, and suggests that the protons in theinter-layer space are conducting proton. About 13 %of protons exist in inter-layer space at 413 K, andthe density of proton was estimated as 6.08×10-20
cm-3 using unit cell volume.
References
1) H. Kamimura et al., Phys. Status Solidi B 241(2004) 61
2) N. O. Yamamuro et al., J. Phys. Condens. Matter
12 (2000) 8559
3) F. Shikanai et. al., ICNS 2005 proceedings,
Physica B (2006) in press
Fig. 2

Proton densities obtained from maximum entropy
method. (a) 298 K (b) 413 K A: in a hydrogenbond B: inter-layer space101

Powder Neutron Diffraction Study of a α,β-Unsaturated Thioamide Derivative
T. OHHARA§, S. IKEDA, T. HOSOYA*§, Y. OHASHI*¶, K. OIKAWA§, A. HOSHIKAWA§
and T. KAMIYAMA
Institute of Materials Structure Science, KEK, Tsukuba, Ibaraki 305-0801, Japan.
*Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo
152-8550, Japan.
Crystalline-state reaction, which proceeds withretention of single crystal form, is one of the mostinteresting topics in crystal chemistry and many
reactions have been analysed mainly by single
crystal X-ray diffraction. Recently, author andco-workers proposed a single crystal neutron
diffraction (SND) analysis of a crystalline-state
reaction as follows; hydrogen atoms in the reactive
part of the reactant molecule are replaced with
deuterium atom as markers, then the crystalline-state
reaction is proceeded, and finally the migration of
the deuterium atoms according to the reaction isobserved by SND. This analytical method is very
powerful to analyse the mechanism of
crystalline-state reaction.[1] However, since SND
requires a very large single crystal, it is much moredifficult to keep the single crystal form during thereaction than single crystal X-ray diffraction study.
So, we proposed to apply powder neutron diffraction(PND) instead of SND. In PND, retention of a large
single crystal form is not necessary. Even though theaccuracy of the structure of an organic molecule
determined by PND is worse than that by SND, we
expected that the distribution of H and D atoms in
the reactive part, which is the most important
information in the analysis of a crystalline-state
reaction, should be clarified. In this work, wedemonstrate that the distribution of H and D atoms
in organic molecule can be clarified by powder
neutron diffraction.
As a target compound, we choose an α β-unsaturated thioamide derivative which is thereactant of the crystalline-state photo-cyclization toform thiolactam.[2] For the PND measurements, weprepared a partly deuterated derivative (Figure 1).
The crystal system is monoclinic, the cell parameter
is a=8.654Å, b=10.156Å, c=10.102Å, β=98.76°,
and the space group is P21. Though the two phenylgroups are not the reactive part, the hydrogen atomsof those phenyl groups were replaced with
deuterium atoms to reduce the background.
§
¶

D
C

H2 C
H2 C

H2
C

C
H2

C
CH

D2 C

C

N

C

CD
C
D
DC

C
D2

C

CD
CD

DC CD
S
Fig. 1 Partly deuterated α,β-unsaturated thioamide derivative

PND patterns were measured by Vega and Sirius
TOF powder neutron diffractometers at KENS with
15K. The measurement time was 28h for Vega and27h for Sirius, respectively. Rietveld analyses werecarried out with RIETAN-2001T[3]. In the initialstructural model of the analysis, the positions andanisotropic
displacement
parametersof
non-hydrogen atoms were determined by single
crystal X-ray diffraction and the position of thehydrogen atoms were calculated with riding model.
In addition, the ratio of H and D atoms at eachhydrogen/deuterium sites were set to 50:50. In the
Rietveld analysis, H/D ratio was refined. The
positions of H and D atoms were also refined withstrong restrain to keep the original position. The
result of the refinement is shown in figure 2. In thecyclohexene ring, the ratio of all H atoms was morethan 75% and at most of them, the ratio of H wasmore than 90%. And at all of other hydrogen sites,
the ratio of D was also more than 75% and at mostof them, the D was more than 90%. This result isreproducing the correct distribution of H and D
atoms in the sample molecule. Figure 3 shows theresults of profile fitting before and after therefinement. The RR-factor was drastically improved
from 45.85% to 13.11% by the refinement. After therefinement, the calculated diffraction pattern showsa good agreement with the observed one.

Current affiliation: Japan Atomic Energy Agency (JAEA).
Current affiliation: Spring-8

102

CD

DC

diffraction patterns detected with the back scatteringbank, the 90° bank, and the 30° bank respectively.
The structure analysis is now in progress. Since thepowder pattern of the back scattering bank hasserious peak overlapping because of the peakbroadening by photo-irradiation, we need to use thedata of all detector banks simultaneously in structurerefinement.
Fig. 2 Distribution of the H/D atoms in the thioamide
derivative determined by PND.

10000

Back-scattering

Fig. 3 Result of the Rietveld analysis. The powder neutron(a)

Rwp:5.08%
RR:45.85%

5000

30°

90°
0
0

2

4

6

8

10

12

Fig. 4 Powder patterns of the thioamide derivative after
photo-reaction measured with all detector banks of the Vega
diffractometer.
(b)

Rwp:1.70%
RR:13.11%

References[1] T. Ohhara, S. Ikeda, H. Imura, H. Uekusa, Y.
Ohashi, I. Tanaka, N. Niimura. (2002) J. Am. Chem.
Soc., 124, 14736-14740.
[2] T. Hosoya, T. Ohhara, H. Uekusa, Y. Ohashi.
(2002) Bull. Chem. Soc. Jpn., 75, 2147-2151.
[3] T. Ohta, F. Izumi, K. Oikawa, T. Kamiyama,(1997) Physica B, 234-236, 1093—1095.

diffraction data was measured by Vega TOF
diffractometer. (a) Before the refinement. (b) After therefinement.

The same analysis was carried out with the Sirius
data. After the refinement, the correct distribution of
H and D atoms was also reproduced. And thecalculated pattern also showed a good agreementwith the observed one. Those results indicates thatthe correct distribution of all H and D atoms inorganic molecules can be determined by PND eventhough the initial model had no information about
the distribution of H and D.
After that, we exposed visible light to thisthioamide derivative by a high pressure Hg lamp for
1 week in order to proceed the crystalline-state
reaction, and measured PND with the Vega
diffractometer. The measurement time was 25h andthe temperature was 10K. Figure 4 shows the103Solid Monolayers of n-Heptane Adsorbed on MgO (100)at Submonolayer and Multilayer Coverages
A. INABA and N. SAKISATO
Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University,
Toyonaka, Osaka, 560-0031

104

monolayer capacity is estimated assuming that themolecule occupies the same area as for graphite(0.427 nm2).
Both the diffraction and incoherent scatteringexperiments were performed on LAM-80ET. A
cylindrical sample can made of aluminum was used.
The diffraction measurements were made at 17 K
and the incoherent scattering experiments were doneat the temperature range between 17 K and 230 K.
1(11)Intensity (arb. units)

Our studies on the structure and dynamics of themonolayers of various molecules adsorbed on thesurface of graphite demonstrate that a number ofmonolayers exhibit interesting phase behavior.
Recent studies also show that the similar solid
monolayers are formed at the interface between thebulk liquid and the graphite surface [1]. Thosemonolayers have been found for various adsorbates
such as n-alkanes, n-alkanols and carboxyl acids[2-7]. This indicates that the phenomenon is rather
general.
The phase behavior of such monolayers depends
not only on the adsorbate-adsorbate interactions but
also on the adsorbate-adsorbent interactions. It istherefore very interesting to study the monolayers
formed on the substrate other than graphite. The(100) plane of MgO is one of the most suitablesurfaces for this purpose because it has quite
different feature from that of graphite (surface
symmetry, potential surface corrugation, etc.). In thepresent study, we have performed neutron
diffraction measurements and incoherent neutron
scattering experiments for n-heptane adsorbed on
MgO (100) to investigate the behavior at
submonolayer and multilayer coverages.
The substrate MgO was prepared by us
according to the procedure reported by J. P.
Coulomb et al. [8]. The specific surface area wasdetermined to be 22.5 m2g–1 by adsorption isotherm
measurements at 77.4 K using nitrogen. It wasdegassed at 950 °C for 12 hours before use.
Deuterated heptane for the diffraction measurements
was obtained from Sigma-Aldrich Co. and theprotonated heptane for the incoherent scatteringexperiments was obtained from Tokyo Kasei Kogyo.
Known quantities of the adsorbates were added tothe adsorbent as liquid using a micro syringe under
an inert atmosphere of helium and annealed at 90 °C.
The amounts of heptane loaded were 0.8 ML for thediffraction measurements and 7 ML for theincoherent scattering experiments. The coverages
are expressed in terms of the number of equivalentmonolayers adsorbed. Since the 2-D structure of theheptane monolayer on MgO (100) is not known, the

(20)
(40)
heptane/graphite (X–ray diffraction)

heptane/MgO(100)00Fig. 110–1
Q / nm20

Neutron diffraction pattern obtained for heptane
on MgO (100) at 0.8 ML at 17 K (bottom). The
X-ray diffraction pattern obtained for heptane ongraphite at 0.8 ML at 10 K (top) is also plotted forcomparison.

Figure 1 displays the neutron diffraction patternobtained for heptane on MgO (100) at 0.8 ML at 17
K. The background contribution from the substrate
as well as the can has already been subtracted. The
subtraction is not satisfactory at Q=8 nm–1 becauseof the burst peak. A step at Q=12 nm–1 isinstrumental. Three Bragg peaks from the heptane
monolayer were observed at Q=15~18 nm–1. The
characteristic 'saw-tooth' line shape [9] indicates that
heptane forms a 2-D crystalline solid on MgO (100).

Since the substrate that we used was isotropicallyoriented (powder), the Braggs peaks from theadsorbed 2-D solid become weaker and broader. In
contrast, the graphite substrate has much advantage
in this respect because the substrate that we used
(Papyex) was fairly oriented adsorbents.
Because of the limited results, we can not say
anything definitely about the detailed structure of
the 2-D solid of heptane on MgO (100). The
comparison between the neutron diffraction pattern
and the X-ray one for heptane on graphite suggeststhat the 2-D solid of heptane on MgO (100) may
have a different structure from that on graphite.

Intensity (arb. units)

1

Tm (Bulk)
Tm (ML at Liquid/Graphite)–1

Q=8.05 nm (004)00Fig. 2–1

Q=11.0 nm (004)

The formation of a solid monolayer above the bulk
melting point is not clear enough. While some solid
component remains, the melting point of themonolayer can not be defined easily. Although theneutron diffraction measurements were performed
simultaneously, we could not find any positive
evidence in favor of the existence of the 2-D solid
formed at the liquid-MgO interface. In this stage,
therefore, we cannot conclude that heptane forms a
2-D solid at the liquid-MgO interface.
References
1) M. A. Castro et al., J. Phys. Chem., B101 (1997)
8878.
2) S. M. Clarke et al., J. Thermal Analysis andCalorimetry, 57 (1999) 643.
3) T. Arnold et al., Phys. Chem. Chem. Phys., 4(2002) 345.
4) T. Arnold et al., Phys. Chem. Chem. Phys., 4(2002) 3430.
5) L. Messé et al., Langmuir, 18 (2002) 4010.
6) L. Messé et al., Langmuir, 18 (2002) 9429.
7) A. Bickerstaffe et al., Phys. Chem. Chem. Phys.,
6 (2004) 3545.
8) J. P. Coulomb et al., J. Phys. Paris, 45 (1984)
1381.
9) J. K. Kjems et al., Phys. Rev. B, 13 (1976) 1446.

Background

100
T/K

200

Incoherent elastic scattering intensity as afunction of temperature for heptane on MgO(100) at 7 ML. The data are normalized to unity
at 17 K. The background level is indicated by thehorizontal dashed line. The vertical solid anddashed lines represent the melting point of bulk
heptane and that for the solid monolayer formedat the liquid-graphite interface, respectively.

Figure 2 illustrates the intensity of incoherent
elastic scattering obtained at Q=8.05 and 11.0 nm–1
from heptane on MgO (100) at 7 ML, where theintensities are normalized at 17 K. The vertical solidline represents the melting point of bulk heptane andthe dashed line for the solid monolayer formed at theinterface between the bulk liquid and the graphite
surface [2]. The initial decrease in intensity at low
temperatures can be ascribed to the effect of the
Debye-Waller factor, whereas the further decreaseindicates premelting of the bulk phase. While thesimilar feature was seen for heptane/graphite at 10
ML [1], the effect observed here is much prominent.
105Neutron Diffraction Measurement of a Layered Cobalt Oxide SrCo6O11
T. SAITO, T. WUERNISHA*, T. KAMIYAMA*, S. ISHIWATA**, Y. TAKEDA,
Y. SHIMAKAWA and M. TAKANOInstitute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801**Department of Applied Physics, Waseda Univ., Shinjuku, Tokyo 169-8555
SrCo6O11 is a layered and pillared cobalt oxidethat exhibits a peculiar two-staged large negative
magnetoresistance coupled to a stepwise change inmagnetization of 0 ↔ Msat/3 ↔ Msat (Msat : saturated
magnetization) below T* = 20 K [1,2]. The crystal
structure of P63/mmc contains three Co sites as
illustrated in figure 1(a); both Co(1) and Co(2) arecoordinated octahedrally, while Co(3) is located at
the center of a trigonal bipyramid. The
Co(1)-octahedra share their edges to form Kagome
layers, while the dimerized Co(2)-octahedra and theCo(3)-bipyramids work as pillars, each forming
triangular lattice in the c-plane. Both the magnetism(shown in figure 1(b)) and magnetotransport arestrongly uniaxial along the c-axis. Similar 1/3
magnetization plateau was found in a triangular spinlattice system Ca3CoRhO6 with a strong uniaxial
anisotropy normal to the triangular plane [3]. Here
2/3 of the Co spins turn up, and the remaining 1/3
turns down, forming a (sqrt3)a × (sqrt3)a
superlattice in the c-plane. We performed neutron
diffraction measurement of SrCo6O11 above andbelow T* without magnetic fields, to study its
magnetic structure.

Figure 2 shows the expanded view of the TOF
diffraction patterns. The pattern at 30 K could bewell reproduced in the Rietveld refinement using thestructure model at room temperature, while newreflections corresponding to a 3-fold superstructure
along the c-axis appeared at 4 K. The absence of
these extra-peaks in the XRD data below T* madeclear that they are magnetic in origin, suggesting theexistence of a long range magnetic order at 4 K. It
should be emphasized here that no extra-peaks
corresponding to any in-plane superstructure were
found at 4K. Considering the result of the NMR
study of our sample that only either Co(2) or Co(3)site is magnetic [4], it is suggested that the spinarrangement in the c-plane is ferromagnetic, having
ferrimagnetic arrangement with 3c periodicity along
the c-axis, unlike the case in Ca3CoRhO6. Further
neutron diffraction measurements were carried out
to determine the magnetic structure of SrCo6O11
under magnetic fields [5].

Fig. 2
Fig. 1(a) Schematic view of the crystal structureof SrCo6O11, and (b) the magnetization
curve of the single crystalline sample of
SrCo6O11 at 5 K.

Powdered sample of SrCo6O11, about 3 g inweight, was prepared by a high pressure technique.
Time of flight (TOF) neutron diffraction patterns
without magnetic fields were collected at 4 K and 30
K on diffractometer VEGA.
106

Expanded view of the TOF diffraction
patterns of SrCo6O11 taken at 4 K and 30 K.
The shaded areas show the magnetic
contributions at 4K.

References
1) S. Ishiwata, et al., in preparation.
2) S. Ishiwata, et al., Chem. Mater. 17 (2005) 2789.
3) S. Niitaka, et al., J. Phys. Soc. Jpn, 70 (2001)
1222.
4) H. Mukuda, et al., in preparation
5) T. Satio, et al., submitted

LIQUID AND GLASSES

2003–2006

Local Structural effect for Fe-doping in LaGa1-xFexO3K. MORI, K. SHIBATA, K. ITOH, M. SUGIYAMA and T. FUKUNAGA

Research Reactor Institute, Kyoto University, Kumatori-cho, Sennnan-gun, Osaka, 590-0494

Lanthanum gallate (LaGaO3) has a distorted
perovskite-type structure with a three-dimensional
network of corner-sharing [GaO6] octahedron.
Recently, it has been reported that the Fe doped(La,Sr)GaO3- shows a large oxygen permeation rate
in addition to a high chemical stability at wide rangeof oxygen partial pressures, while the excessive
Fe-doping reduces the oxygen ionic conductivity [1].
However, the anomalous behavior in the oxygen
ionic conductivity is still poorly understood. In
this work, we carried out time-of-flight neutron
powder diffraction experiments with LaGa1-xFex O3(LGF) [2]. The aim of this investigation is toclarify the local structure of LGF using a total
scattering technique.
Four polycrystalline samples of LGF (x = 0, 0.1,
0.25 and 0.5) were synthesized by conventional
solid-state reaction method, as reported elsewhere[3]. The local structures of LGF were investigatedusing the HIT-II installed at KEK-KENS. The
radial distribution function, RDF(r), was derived
from the Fourier transformation of the structure
factor, S(Q), up to 45 Å–1.
Figure 1 shows the obtained RDF(r)s of LGF.
The vertical marks above the RDF(r) profiles
indicate correlation lengths between atoms. For
the first peak at around 2 Å, to evaluate correlation
lengths of Ga–O and Fe–O we assumed thefollowing equation with two Gaussian distributions;

In the local structure analyses, excellent fits between
the observed and the calculated RDF(r)s wereobtained [2]. Consequently, the first peak of the
M–O correlation could separate into the signals of
the Ga–O and the Fe–O, and it was found that thecorrelation length of the Fe–O is larger than that of
the Ga–O. The refined r Ga–O and rFe–O are plotted vs.
the amount of Fe, as shown in Fig. 2. The rGa–O
remains constant of ~ 1.985 Å at all Fe-contents.
Also, the variation of the rFe–O is fairly slight. The
average rFe–O value is approximately 2.02 Å.
These results mean that the electronic
configuration of Fe3+ has a high-spin state (HS),t2g3eg2. The introduction of Fe3+(HS) induces theincrease in free volume as well as that in unit-cellvolume, while oxygen ions would be localizedaround Fe3+(HS) rather than Ga3+ because of thestrong covalency in Fe3+:eg–O2–:2p.
If moreoxygen vacancies are introduced in Fe doped
LaGaO3, they may concentrate around Ga3+.
Presumably, when the optimum amount of Fe (x ~0.3) exists for the higher oxygen ionic conductivity,
many oxygen ions immigrate to the oxygen
vacancies concentrated around Ga.

Fig. 1.

Fig. 2.

RDF(r)s of LGF at RT.

Variations of Ga–O and Fe–O correlation lengths
as a function of Fe-content, x.

References
1) T. Ishihara et al., Solid State Ionics 135 (2000) 631.
2) K. Mori et al., Trans. Mater. Res. Soc. Jpn., 30[3](2005) 859.
3) K. Mori et al., Physica B 352 (2004) 147.

109

The Local Structure around Lithium Atoms in Lithium Storage Compounds
Studied by Neutron Diffraction
H. SAKAGUCHI, Y. NAGAO, K. ITOH, T. FUKUNAGA,* and T. ESAKA
Department of Materials Science, Faculty of Engineering, Tottori University,
Minami 4-101, Koyama-cho, Tottori 680-8552, Japan*Research Reactor Institute, Kyoto University,
Noda, Kumatori-cho, Sennangun, Osaka 590-0494, JapanRESULTS AND DISCUSSION
Figure 1 illustrates the total radial distributionfunction, RDF(r), of SiO together with that of SiO2
(silica) glass,8 for comparison. These two profiles
are very similar each other. It is well known thatsilica glass has a three-dimensional network
structure consisting of SiO4 tetrahedra. The peaks
corresponding to the interatomic distances of 162
and 263 pm almost coincide with those of Si-O andO-O bonds in SiO4 tetrahedron, respectively. Thissuggests that SiO has the same SiO4 network
structure as silica glass. On the other hand, the peakat 233 pm does not belong to any atomic correlationof silica glass. Therefore, we had to consider thebond between silicon atoms. Cluster-like metallic
silicon could disperse in the matrix ofthree-dimensional SiO4 tetrahedra.
Figure 2 comparatively shows the total radial
distribution functions RDF(r) of Li2.26SiO/Cu, SiO
and Cu. There are some important points in the data
for Li2.62SiO/Cu. Firstly, there are negative signals in
110

28

SiO

24

263pm

162pm

20
16
12

233 pm8
4
RDF(r)INTRODUCTION
The lithium ion battery has a large energy
density in comparison with other secondary batteries,
so it will be used for various purposes in the future.
Recent work indicates that metal monoxides,
such as SnO, SiO, and MnO, are attractive as novel
anode materials. In particular, silicon monoxide(SiO) was reported to have a large charge capacity(over 1400 mA h g-1) compared with other metalmonoxides or carbon materials. Although thisindicates that SiO is a promising anode material, it isnecessary to clarify the mechanism ofelectrochemical lithium insertion/extraction to
improve the electrode performance. However, thereaction mechanism of the SiO electrode is unknown
because of lack of information on the structure of
SiO and its lithiated modification.
In this study, the structures of SiO and lithiated
SiO (LixSiO) were investigated using neutron elastic
scattering.1)

0

28

SiO2

24
20

O-O

Si - O

16
12
8
4
0
0

1

2

3

4

5

2

r / 10 pm

Fig. 1 Neutron total radial distribution functions
RDF(r) of SiO and SiO2 (silica glass).
the RDF(r). As mentioned above, lithium has anegative coherent neutron scattering length, so that anegative peak should appear in the RDF(r) when alithium atom is bonded to atoms with a positive
coherent neutron scattering length. Therefore, theappearance of multiple negative peaks in RDF(r)indicates the lithiation of SiO. Negative peaks areobserved at ca. 200 pm in the top four lithiumcompounds containing oxygen, indicating Li-O
bonding. The corresponding peak was considered to
be present in Li2.62SiO/Cu, which denoted that a part

50
40
30
20
10
0
-10
16

Li2.62SiO

SiO

12
RDF(r)

of inserted lithium formed an oxide. The oxide may
be the cause of irreversible capacity when used as an
anode material in lithium battery. Furthermore, anegative peak of ca. 300 pm on Li2.62SiO/Cu
corresponds to the Li-Si interatomic distance in twolithium silicides, indicating that SiO reacts withlithium to form Li-Si bonds. A small shoulder canbe observed at ca. 230 pm in the RDF(r) of
Li2.62SiO/Cu, which may be interpreted as a Si-Si
atomic correlation in SiO. If the Si-Si correlation
was still remained after lithiation for SiO, the peak
attributed to the correlation would appear in positive
region in the RDF(r). Thus, the Si-Si atomic
correlation at 233 pm in SiO was considered todisappear with electrochemical lithiation, suggestinga decrease in metallic silicon in SiO. The result
supports the above mentioned reaction of lithium, i.e.
the formation of Li-Si alloys. Finally, the intensityof Si-O correlation peak at 162 pm barely changed
after lithium insertion. This indicates that the majorpart of the SiO4 network was maintained in SiO
despite lithium insertion, and, therefore, SiO2 in SiO
does not significantly contribute to the electrodereaction. If only metallic silicon in SiO took part in
the electrode reaction, then the charge (lithium
insertion) capacity should be theoretically 1338
mAh g-1. The charge capacity of SiO used in theneutron scattering experiment was 1594 mAh g-1.
Considering the capacity consumed by forming thesolid electrolyte interface (SEI), the value isreasonable. Therefore, the main reaction of SiO
electrode must be the alloying of lithium withmetallic silicon in SiO on the charge up to thiscapacity.

8
4
0

35
30
25
20
15
10
5
0

Cu

1

1.5

2

2.5

3

3.5

4

r / 10 2 pm

Fig. 2 Neutron total radial distribution functions
RDF(r) of Li2.62SiO/Cu, SiO, and Cu.

REFERENCE
1) Y. Nagao, H. Sakaguchi, H. Honda, T. Fukunaga,
and T. Esaka, J. Electrochem. Soc., 151(10)(2004)A1572-A1575.

111

Structure of Supercooled Water Confined in MCM-41 Porous Silica
T. YAMAGUCHI, M. OTSUJI and K. YOSHIDA
Department of Chemistry, Faculty of Science and Advanced Materials Institute, Fukuoka University,
Nanakuma, Jonan-ku, Fukuoka 814-0180
Structure of water confined in a nanospace ofmesoporous silica has drawn much attention because
these systems can be regarded as a model ofinterfacial water that plays an important role inseparation in chromatography, chemical reaction in
catalysts, sedimentation in soils, and biologicalmembranes. MCM-41 mesoporous silica has highly
controlled cylindrical channels and a very narrow
pore size distribution and thus provides
better-defined nanospace than conventionally used
Vycor glass. It is expected that confined water has
different structural properties from those of bulk due
to both geometrical confinement and interactions
with the pore wall. In particular, in recent years,
supercooled water confined in MCM-41 with a poresize less than ~2.2 nm has been a target of research
since it does not show the homogenous nucleation ina temperature regime of the so-called ‘No man’s
land’ in bulk water [1-3]. Thus, the supercooled
water confined in MCM-41 would be a goodcandidate to investigate the first-order liquid-liquidtransition and the existence of the second
low-temperature critical point of water [4-6].
In the present study, neutron diffraction
measurements of deuterated water (D2O) in
MCM-41 C10 (pore diameter 2.04 nm) were
performed in a temperature range from 298 K down
to 173 K with the HIT-II spectrometer at a pulsed
neutron facility, the Neutron Science Laboratory(KENS) in the High Energy Accelerator Research
Organization (KEK; Tsukuba, Japan).
Micelle-templated mesoporous silica material,
MCM-41, was prepared by an improved Beck’s
method [7]. Properties of pore structure were
defined by powder XRD and TEM observations, andnitrogen adsorption measurements at liquid nitrogentemperature. Thus prepared samples were verified
their durability against damage by water. Deuterated
water was introduced in the pores through vapor
phase up to full filling of pores at the relative
pressures on the basis of the adsorption isotherms.
The adsorption isotherms were measured after
repeated adsorption of D2O vapor to confirm thecomplete deuteration of surface hydroxyls of thesample; thorough exchange of protons with112

deuterium ions was confirmed by FT-IR
measurements. Adsorption isotherms of D2O were
measured gravimetrically at 298 K by use of
Rubotherm (BEL Japan) equipped with a laboratory
made gas dosing system.
A sample cell was made of Ti-Zr null alloy andhas dimension of 8-mm internal diameter, 0.3-mm
thickness, and 85-mm height. Temperature wascontrolled with a helium cryostat and was monitoredwith a thermocouple attached to the upper part of thesample cell. Scattered neutrons were measured with
104 pieces of 3He counters arranged in the scattering
angle range of 10o to 157o. Empty cell and dry
MCM-41 sample were also measured and theirdiffraction data were subtracted as background. All
diffraction data were normalized to absolute units byusing the incoherent scattering from a vanadium rod
with 8-mm diameter and were corrected forabsorption, multiple scattering, incoherent scattering,and recoil effect.
The structure factors S(Q) for D2O in MCM-41
are shown in Fig. 1. The first peak at ~17 nm is
mainly assigned to D-O and D-D correlations [8].
The first peak position Q0 can be considered as anindex of the water structure. The experimentallyobtained Q0 values are plotted against temperature in
Fig. 2. The Q0 value at 268 K (18.9 nm-1) is almost
the same with that at 298 K (18.8 nm-1) and thendecreases with decreasing temperature (18.4 nm-1 at
223 K and 17.8 nm-1 at 173 K). In recent neutron
diffraction measurements on a D2O monolayer inVycor at temperatures ranging between 296 K and
77 K, it has been reported that the Q0 values (18.6
nm-1) are independent of temperature up to 258 K
and suddenly decrease (17.1 nm-1) less than 238 K[2]. In hydrogen-bonded liquids, the Q0 position canbe related to the density of the system and may beconsidered as an index of the structure. Low Density
Amorphous Ice (Q0LDA = 17.1 nm−1) is characterized
by a continuous random H-bond network in which
each water molecule is locally engaged in fourhydrogen bonds. The sudden increase of the Q0
value between 238 K and 258 K suggests a
structural change from a low-density liquid to ahigh-density liquid. In the present study, the Q0

19

Qo /nm-1

values for D2O in MCM-41 pores show a similar
decrease between 268 and 173 K, suggesting afragile-to-strong liquid transition taking place for
D2O in cylindrical channels. Our previous X-ray
diffraction study on water in MCM-41 C10 (2.04nm) and C14 (2.83 nm) has shown that interfacial
water are strongly hydrogen bonded with the surface
silanol groups of MCM-41 with an OH-H2O
distance of ~0.260 nm [9]. It has been reported fromneutron quasi-elastic scattering measurement ofwater in MCM-41 that the dynamics of watermolecules confined in MCM-41 pores are retarded
compared with bulk water [10]. A further study onwater confined in MCM-41 pore is being made byusing a neutron spin echo method to investigate thedetails of dynamics of confined water.

18

17

200

T/K

250

300

Fig. 2 The change of the first peak position Q0 withtemperature
References[1] A. Faraone, L. Liu, C.-Y. Mou, C.-W. Yen, S.-H.
Chen, J. Chem. Phys., 121, 10843 (2004).
[2] J.–M. Zanotti, M.-C. Bellissent-Funel, S.-H.
Chen, Europhys. Lett. 71, 91 (2005).
[3] L. Liu, S.-H. Chen, A. Faraone, C.-W. Yen, C.-Y.
Mou, Phys. Rev. Lett. 95, 117802 (2005).
[4] C.A. Angell, J. Shuppert, J.C. Tucker, J. Phys.
Chem. 77, 3092 (1973).
[5] R. J. Speedy, C. A. Angel, J. Chem. Phys. 65,
851 (1976).
[6] F.X. Prielmeier, E.W. Lang, R.J. Speedy, H.-D.
Lüdemann, Phys. Rev. Lett. 59, 1128 (1987).
[7] T. Mori, Y. Kuroda, Y. Yoshikawa, M. Nagao, S.
Kittaka, Langmuir 18, 1595. (2002)[8] M.-C. Bellissent-Funel, S. Longeville, J.-M.
Zanotti, S.-H. Chen, Phys. Rev. Lett. 85, 3644
(2000).
[9] P. Smirnov, T. Yamaguchi, S. Kittaka, S.
Takahara, Y. Kuroda, J. Phys. Chem. B, 104, 5498
(2000).
[10] S. Takahara, N. Sumiyama, S. Kittaka, T.
Yamaguchi, M.-C. Bellissent-Funel, J. Phys. Chem.
B, 109, 11231 (2005).

Fig. 1 Structure factor S(Q) of deuterated water in
MCM-41 C10 at various temperatures. The solidlines are the fitting results by Gaussian functions todetermine the first peak position.

113

Short-range Structure of Sodium Borate Glasses Containing Al2O3
N. OHTORI, M. TOGASHI, K. TAKASE, K. HANDA*, J. IDE*,
K. ITOH**, T. FUKUNAGA**, and N. UMESAKI***
Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan*
Faculty of Science and Engineering, Ritsumeikan University, Shiga 525-8577, Japan**
Research Reactor Institute, Kyoto University, Osaka 590-0494, Japan***
Japan Synchrotron Radiation Research Institute, Hyogo 679-5198, Japan

Qi(Q)/nm-140

without Al2O3
with Al2O3

20

0

-20

0

100

-1

Q/nm

200

300

Fig. 1 Neutron structure functions, Q·i(Q), for
5Al2O3·29Na2O·66B2O3 glass. The dashed line
denotes Q·i(Q) for 30Na2O·70B2O3 glass.

114

0.7
0.6
0.5
N4

Alkali and alkaline-earth borate mixtures havesome limited glass-forming ranges in theircomposition. Aluminum oxide, Al2O3, has been
empirically known as an effective additive on theextension of the range. The purpose of the present
study on borate glasses containing Al2O3 is to clarify
the role of aluminum in the stabilization of borate
glasses. The compositions of the glass samples
used in the present neutron diffraction study were0.05Al2O3·xNa2O·(0.95-x)B2O3 with x = 0.29, 0.38,
and 0.45. Figure 1 shows obtained structure
functions, Q·i(Q), for 5Al2O3·29Na2O·66B2O3 glass,compared with the result for the sample without
Al2O3. We also performed MD simulation forthese systems and obtained neutron-weighted
structure functions which agreed well with thepresent experimental ones. According to the MD
results, the coordination number of O around Al,
nAlO, was approximately four, regardless of x.
Figure 2 shows the fraction of four-coordinated B,
N4, obtained from the neutron diffraction
experiments. The upper integration limit, rcutoff,used for the evaluation of N4 was 0.170 nm for the

0.4

without Al2O3
without Al2O3
with Al2O3

x/(1-x)

0.3
0.2
0.1
0.0
0.0

0.1

0.2

0.3
x

0.4

0.5

Fig. 2 Fraction of four-coordinated B, N4, obtained
from neutron diffraction as a function of the mole
fraction of sodium oxide content. The values
evaluated using the upper integration limit of 0.170
nm and 0.200 nm are indicated by triangles andcircles, respectively.

glasses with Al2O3 and 0.200 nm for those without
Al2O3, since the B-O correlation cannot be separated
from the Al-O correlation in the former glasses.
The N4 was then also evaluated using a rcutoff of0.170 nm for the glasses without Al2O3. In bothcases, the decrease in N4 resulting from the additionof Al2O3 is seen in a comparison of N4 between theglasses with and those without Al2O3.
On the basis of the analysis of othercoordination numbers and the fraction of
four-coordinated B and Al, it was concluded thatthese Al atoms are present as network-formers of
AlO4 units in the glasses in the same manner as theBO4 unit and causes a decrease of the coordination
number of O around Na. This summary suggeststhat the exclusively formed AlO4 units could
suppress the conversion of the BO3 unit to the BO4
unit caused by an increase of Na2O.
Acknowledgement
This work was supported by a Grant-in-Aid for
Scientific Research from the Ministry of Education,
Science, Sports and Culture of Japan (No.
16560599).

Short-range Structure of Borate Glasses Containing High-content Alkaline-earth Oxides
N. OHTORI, M. TOGASHI, K. TAKASE, K. HANDA*, J. IDE*,
K. ITOH**, T. FUKUNAGA** and N. UMESAKI ***Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan*
Faculty of Science and Engineering, Ritsumeikan University, Shiga 525-8577, Japan**
Research Reactor Institute, Kyoto University, Osaka 590-0494, Japan***
Japan Synchrotron Radiation Research Institute, Hyogo 679-5198, Japan

Q·i(Q)/nm

-1

340
320
300
280
260
240
220
200
180
160
140
120
100
80
60
40
20
0
-20

45MgO·55B2O3
55MgO·45B2O3
20CaO·80B2O3
25CaO·75B2O3

33CaO·67B2O3

40CaO·60B2O3
50CaO·50B2O3
20SrO·80B2O3
25SrO·75B2O3

33SrO·67B2O3
40SrO·60B2O3

45SrO·55B2O3

20BaO·80B2O3

25BaO·75B2O3
33BaO·67B2O340BaO·60B2O3
48BaO·52B2O3

0

100

200

300
-1

Q/nm

400

500

Fig. 1 Neutron structure functions, Q·i(Q), for
MgO-B2O3, CaO-B2O3, SrO-B2O3, and BaO-B2O3
glasses.

0.8
x /(1-x)

0.6
N4

It is well known that the structure and propertiesof borate glasses depend strongly on both the kindand the amount of additives of alkali metal oxides.
Among several parameters describing theshort-range structure of borate glasses, the fractionof four or three coordinated boron atoms, N4 or N3,
is one of the most characteristic parameters. In thepresent study, in order to understand the short-range
structure systematically, pulsed neutron diffraction
experiments were performed on MO-B2O3 (M = Mg,
Ca, Sr, and Ba) glasses with high-content MO of
40-50 mol%. Figure 1 collects together all the total
structure functions, including the previous results [1],0.4

BaO-B2O3
SrO-B2O3
CaO-B2O3

0.2

MgO-B2O3

0.0
0.0

0.1

0.2

0.3
x

0.4

0.5

0.6

Fig. 2 Fraction of four-coordinated B, N4, obtained
from neutron diffraction as a function of the mole
fraction of alkaline-earth oxide content

obtained from the neutron diffraction experiments at
the KENS facility for a series of alkaline earth
borate glasses. On the basis of these structure
functions, the fractions of four coordinated B atoms,
N4, for alkaline earth borate glasses was evaluatedand are illustrated in Figure 2.
These results show that the downward deviationfrom x/(1-x) decreases with increasing cation size,
which is in good agreement with the infrared [2] andour MD results. Therefore, it is concluded that theaddition of MO also converts the BO3 units into BO4
units but the dependence on cation size is positive: itis directly opposite to the case of addition of alkali
metal oxides. These results suggest that only thesimple electrostatic interaction between the metal
cation and O is insufficient to explain the behavior.
References
1) Y. Suzuki et al., Phys. Chem. Glasses, 44(2003) 150.
2) Y. Yiannopoulos et al, Proc. Second Int. Conf.
on Borate Glasses, Crystal and Melts, (1997)
514.

115

Network Structure in Tl2O-TeO2 Glasses and Oxygen Coordination around Tellurium
Y. IWADATE, T. HATTORIa, M. MISAWAb, T. FUKUNAGAc, K. ITOHc, K. FUKUSHIMAa,
S. NISHIYAMAa, Y. ITOH and M. SUZUKI
Graduate School of Science and Technology, Chiba University, Inage-ku, Chiba 263-8522, Japana
Department of Materials Technology, Chiba University, Inage-ku, Chiba 263-8522, Japanb
Department of Chemistry, Niigata University, Niigata 950-2181, Japanc
Research Reactor Institute, Kyoto University, Osaka 590-0494, Japan

116

multiple and incoherent scatterings, and thennormalized with a vanadium rod as a referencematerial. The coherent scattering lengths of theelements were taken from the literature [11]. The
details of the correction procedures have alreadybeen reported elsewhere [12].
The Raman spectra of xTl2O-(1-x)TeO2 glasses
were measured at x=0.00, 0.05, 0.10, 0.15, 0.20,
0.25, 0.30 as shown in Fig. 1. There were typicalRaman bands at about 720cm-1 and 650cm-1 in the
spectra at room temperature. These bands are
ascribed to the stretching mode of the TeO 3 trigonal
pyramidal units (tp) containing terminal Te-O bonds
such as Te=O and Te-O- with non-bridging oxygen
atoms (NBO) and the stretching mode of the TeO4
trigonal bipyramidal units (tbp) with bridging
oxygen atoms (BO), respectively [13].
With
increasing Tl2O content, the amplitude of the
720cm-1 band becomes larger and that of the
650cm-1 band becomes smaller. These results
suggest that the addiction of Tl2O brings about theconversion of the TeO4 tbp units wih BO into the
TeO3 tp units with NBO in xTl2O-(1-x)TeO2 glasses.

x=0.30Intensity/arbitrary Unit

Many studies of the tellurite glasses have beenreported on account of their low melting
temperatures [1.2], large thermal expansion [3], highdielectric constants [4], high refractive indexes, andgood transmission for infrared lights with a wide
range of wavelength [5]. Due to these characteristics,
TeO2-based glasses posses great interests forapplication to optical fibers and non-linear opticalmaterials [6]. The structures of TeO2-based glasses
have often been examined by Raman and IR
spectroscopy, revealing that there are two types ofbasic structural units such as TeO4 trigonal
bipyramid (tbp) with two equatorial, two axial Te-O
bonds and a lone pair of electrons located on thethird equatorial site, and TeO3 trigonal pyramid (tp)[7].
In these structures, the coordination
circumstance of Te changes from TeO4 to TeO3 withincreasing alkali metal ions or a rise of temperature[8]. These spectroscopic measurements were, in fact,
powerful tools for qualitative discussions ofchemical species in glasses since it seemed easy to
distinguish TeO4 from TeO3 in Raman and IR
measurements, but unfortunately semi-quantitativefor evaluation in the fractions of the structure units.
On the contrary, ND provides one-dimensional
interpretation of glass structure through the radial
distribution function (RDF). Te-O and O-O
distances and the coordination number of oxygenaround tellurium are obtained with ease from RDF.
The local structure of Tl2O - TeO2 glasses was thus
analyzed by PND in this study.
The glass samples were prepared from reagent
grade Tl2O and TeO2 through a melting
rapidly-quenchingprocess,
pulverized
andintroduced into the cylindrical vanadium cells (8mm inner diameter, 40 mm in height and 0.25 mm
in wall thickness). PND experiments were carriedout with TOF method using the High Intensity Total
scattering spectrometer (HIT- Ⅱ ) [9,10].
The
structure factor S(Q) was obtained from themeasured scattering data which were corrected forbackground, absorption by the sample and the cell,x=0.25x=0.20x=0.15x=0.10x=0.05

1000

800

600

400

Raman shift / cm-1

x=0

200

Fig. 1 Raman spectra for xTl20-(1-x)TeO2 glasses.

Total structure factors S(Q)'s of xTl2O-(1-x)TeO2(x=0.10, 0.20, 0.25, 0.30) glasses are shown in Fig.
2, indicating that the glass with x = 0.10 is partiallycrystallized. The so-called prepeaks related to themedium-range order in network forming glass
structure were observed as small peaks or shoulders
at 15.0 nm-1. The following equation is applicable tothis type of peak, Qp･rp=2π, where Qp and rp are
the wave vector Q and the correlation distance r
corresponding to the pre-peak, respectively, hence rp
become 0.42 nm according to the above equation.
The intensity of this peak was changed slightly withcomposition, suggesting that there exists somevariation in intermediate range order in Tl2O-TeO2
glasses.

x=0.301

x=0.25S(Q)1

x=0.201

x=0.10

1

0

100

200
-1
Q / nm300

400

Fig. 3 depicts the radial distribution function
D(r) and the scaled function D(r)/r of
0.20Tl20-0.80TeO2 glasses. The nearest neighborcoordination number is usually evaluated from
integration of the first peak area. The first peak
appeared at about r = 0.20nm which was thought tobe due to the overlapping of nearest neighbor Te-O
correlations in TeO4 and TeO3 units as observed inother tellurite glasses, since the peak in D(r)/r curve
was asymmetric. The first peak in the correlation
functions G(r) appeared at around r = 0.20 nm,
which was thought to be due to the overlapping ofsome types of Te-O correlations, since Taking the
crystallographic data [14] and their ion radii [15]into consideration. The second peaks at around r =0.28 nm was thought to correspond to the nearneighbor Tl-O and O-O correlations and the peak ataround r = 0.38 nm was some Te-Te correlations.
In order to refine the short-range structure of theglasses, structural parameters such as the averagecoordination number, the scattering length, thetemperature factor, and the average interatomic
distance were optimized in Q-space by thecorrelation method, because of the difficulty inr-space analysis [16]. The initial values of thestructural parameters were preset to be equal tothose obtained from D(r) and G(r) analysis or takenfrom the crystallographic data. Further we referred
to NMR-data of alkali tellurite glasses [17] to decide
the most probable parameters reproducing the real
structure of the glasses. The interference functions
Q･i(Q)'s of Tl2O-TeO2 glasses are illustrated in Fig.
4.

Fig. 2 Total structure factors S(Q) for xTl20-(1-x)TeO2
glasses.

10○○○

Observed
Calculated0
x x=0.30

-10
400

10

D(r) / nmD(r) r -1/nm-2

-1

300

Q・i(Q) / nm-1

4000

200

0

0.5

r/nm

0
x=0.25

-10
10
0

1

x=0.20

-10
10

100

0
x=0.10

-10
0
0

0.2

0.4

0.6

0.8

r / nmFig. 3 Radial distribution function D(r) and the scaled
function D(r) / r for 0.20Tl20-0.80TeO2 glasses.

100

200

Q / nm-1

1

Fig. 4

Interference functions Q･i(Q) for xTl20-(1-x)TeO2
glasses.

117

As described before, there were two types of nearneighbor Te-O distances, i.e., one was at around
0.19nm and the other around 0.23nm. This trend wasconsistent with those of the alkali tellurite glasses
having two sorts of Te-O pairs in the TeO4 trigonal
bipyramids (tbp) [3]. And these Te-O distances ataround 0.19nm would be due to Te-O bonds in TeO3
trigonal pyramids (tb).
According to therefinement of structural parameters, the third Te-O
pair was observed at about 0.23nm. This would be
due to that the Te-O bonds in the TeO4 trigonal
bipyramids (tbp) were broken partly into TeO3
trigonal pyramids with increasing Tl2O. The total
coordination number of O around Te (in the firstcoordination shell) decreased with increasing Tl2O
content. The results suggest that the tellurite
glasses having lower Tl2O content had networks
composed of mainly TeO4 trigonal bipyramids (tbp).
This finding was almost consistent with that in alkali
tellurite glasses.
The conclusions of this work are summarized in
the following manner.
According to pulsed
neutron diffraction and Raman spectroscopy, theshort-range structure of Tl2O-TeO2 glasses has been
investigated. The results obtained was that thestructure of silver tellurite glasses consisted of the
TeO4 trigonal bipyramids (tbp) and the TeO3
trigonal pyramids (tp), and the TeO4 trigonal
bipyramids were converted to the TeO3 trigonal
pyramids with increasing modifier Tl2O content.
In the TeO4 trigonal bipyramids (tbp), there were
two sorts of near neighbor Te-O distances. The
shorter was at around 0.19nm and the longer ataround 0.23nm. The shortest bond at around
0.19nm was due to TeO3 trigonal pyramids (tp).
Furthermore, the longest bond was thought to be
ascribed to intermediate TeO3+1 appearing when the
Te-O bonds in the TeO4 trigonal bipyramids (tbp)were broken partly into TeO3 trigonal pyramids withincreasing Tl2O.
References
1) J. E. Stanworth, J. Soc. Glass Technol., 36 (1952)
217.
2) J. E. Stanworth, J. Soc. Glass Technol., 38 (1954)425.
3) K. Tanaka, T. Yoko, H. Yamada, T. Kamiyama, J.
Non-Cryst. Solids, 103 (1988) 250.
4) J. E. Stanworth, Nature, 169 (1952) 581.
5) H. Burger, W. Vogel, V. Kozhukharov, Infrared
Phys., 25 (1985) 395.
6) M. Tatsumisago, T. Minami, Ceram., 28 (1993)

118

1227.
7) T. Sekiya, N. Mochida, A. Ohtsuka, M.
Tomokawa, J. Non-Cryst. Solids, 144 (1992)
128.
8) Y. Kowada, K. Habu, H. Adachi, Chem. Express,
7 (1992) 965.
9) H. Ushida, Y. Iwadate, T. Hattori, S. Nishiyama,
K. Fukushima, M. Misawa, T. Fukunaga,
J. Alloys Comp., 327 (2001) 121.
10) H. Kenmotsu, T. Hattori, S. Nishiyama, K.
Fukushima, Y. Iwadate, M. Misawa, T.
Fukunaga, T. Nakazawa, K. Noda, J. Phys. Chem.
Solids, 60 (1999) 1461.
11) V. F. Sears, Neutron News, 3 (1992) 29.
12) K. Suzuki, M. Misawa, K. Kai, N. Watanabe,
Nucl. Instrum. Methods, 147 (1977) 519.
13) B. V. R. Chowdari, P. P. Kumari, Mater. Res.
Bull., 34 (1992) 327.
14) R. W. G. Wyckoff, Crystal Structures, Vol. 1,
Interscience, New York, 1964, p. 332.
15) R. D. Shannon, Acta. Cryst, A32 (1976) 751.
16) A. H. Narten, J. Chem. Phys., 56 (1972) 1905.
17) S. Sakida, S. Hayakawa, T, Yoko, J. Non-Cryst.
Solids, 243 (1999) 13.

Analysis of Local Structure in Semiconductive B2O3-SnO Glasses
Y. IWADATE, T. HATTORIa, M. MISAWAb, T. FUKUNAGAc, K. ITOHc, K. FUKUSHIMAa,
S. NISHIYAMAa, K. SUZUKI, T. MICHII and T. MURAYOSHI
Graduate School of Science and Technology, Chiba University, Inage-ku, Chiba 263-8522, Japana
Department of Materials Technology, Chiba University, Inage-ku, Chiba 263-8522, Japanb
Department of Chemistry, Niigata University, Niigata 950-2181, Japanc
Research Reactor Institute, Kyoto University, Osaka 590-0494, Japan
Fig. 1. The peak height at about 810cm-1 decreased
with addition of SnO and new peaks appeared ataround 770cm-1. This is due to the breaking-up ofboroxol rings by changing BO3 triangles to BO4
tetrahedra.

Intensity / Arbitararyunit

x=0.40x=0.30x=0.20x=0.10x=0.00
1400

1200

1000

800

600

-1
Raman shif t / cm

Fig. 1 Raman spectra of (1-x)B2O3-xSnO glasses

x = 0.40

1

x = 0.30

1
G(r)SnO is expected to be a candidate of negativeelectrode material with high capacity, when it isused as a negative electrode in Li+ battery [1]. As
for B2O3-SnO glasses, not only electrochemical
properties but also structures have so far beenstudied by NMR, XPS and so on, and theirvariations with composition have started to bereported [2]. 3-fold coordination of oxygen aroundboron in borate glass is well known to form a planer
triangle structure and then the triangles are chained
together to build a boroxol ring. A part of triangles
are changed into tetrahedra by adding modifier
oxides to matrix glasses [3, 4].
In the present work, techniques such as pulsed
neutron diffraction and Raman spectroscopy wereapplied to B2O3-SnO and B2O3-SnO-Li2O glasses inorder to estimate structural parameters such as aninteratomic distance, a coordination number, and atemperature factor and finally to analyze local
structure of the glasses.
The glass samples were prepared from reagent
grade H 3 11 BO 3 , SnO, and Li 2 O through a melting
rapidly-quenching process under N2 atmosphere,
pulverized and then introduced into the cylindrical
vanadium cells (8 mm inner diameter, 40 mm inheight and 0.25 mm in wall thickness). PND
experiments were carried out with TOF method
using the High Intensity Total scattering
spectrometer (HIT-Ⅱ) [5, 6]. The structure factor
S(Q) was obtained from the measured scattering
data which were corrected for background,absorption by the sample and the cell, multiple andincoherent scatterings, and then normalized with avanadium rod as a reference material. The detailsof the correction procedures have already beenreported elsewhere [6].
A laser Raman
spectrophotometer of the type NR1800 (JASCO,Tokyo) was used with the light of wavelength514.5nm to study bonding nature and vibrationalmodes in the glasses.
The Raman spectra of B 2 O 3 -SnO glasses in
the range of 500 cm-1 to 1500 cm-1 are shown in

x = 0.20

1

x = 0.10110

x = 0.05

0.2

0.4

0.6

0.8

1

nm
rr//nmFig. 2 Correlation function G(r) of(1-x)B2O3-xSnO glasses

119

The correlation function G(r) was illustrated inFig. 2. Little variation of phase in G(r) was
observed with composition. The small shoulder
appeared at about r = 0.2nm, which was thought tocorrespond to Sn-O pair. This peak shoulders werelarger than that in B2O3-SnO-Li2O glasses, reflectingthat in the latter glasses the negative natLi-O
correlation and the positive Sn-O correlation wereclose to each other and both contributions werecanceled out [7].
Peak assignments were made for other atomic
correlations by taking into account ionic radii suchas B3+= 0.01nm, O2-= 0.138nm, and Sn4+= 0.55nm[8]. The peak at around r = 0.14nm is attributed tothe atomic correlation of B-O pair, the peak at aboutr = 0.25nm being an overlap of B-O and O-O
correlations.
In the scaled function D(r)/rdeconvolution was made for the peak at r = 0.14nm
with D(r) being the radial distribution function.
The degree of peak symmetry became greater withincreasing SnO content, especially centered at r =0.147nm. This would be due to that a part oftriangles are changed into tetrahedra by adding
modifier oxides to matrix glasses, as mentioned
before.
According to the above information, thestructural models were established and more precise
analyses, that is the optimization of structuralparameters, were performed in the reverse lattice
space using the correlation method in which a
non-linear least squares regression was applied to
the Debye scattering equation [9].
In thecomposition range of this work, the network
structure consisting of B-O bondings was found to
be changed with addition of SnO. As demonstratedin G(r)’s, the peak at about r = 0.14 nm is in fact
assigned to both B-O correlations with 3-fold and
4-fold coordination, the interatomic distances ofwhich were determined to be 0.137 nm and 0.148
nm, respectively.
The oxygen coordination
number around tin atom was about 4 on averageover the entire range of SnO, but it decreasedslightly with increasing SnO content, reflecting thedistortion of coordination polyhedra.
Thesebehaviors were caused by the fact that B-O
networkings such as boroxol-type linkages werebroken by the addition of SnO and/or Li2O, andfurther randomness was introduced into the glasses.
References
1) M. Winter, J. O. Besenhard, Electrochim. Acta,
45 (1999) 31.
2) A. Hayashi, Comp. Rend. Chim., 5 (2002) 751.

1203) R. L. Mozzi, B. E. Warren, J. Appl. Crystallogr.,
3 (1970) 251.
4) W. L. Konijnendijk, J. M. Stevels, J. Non-Cryst.
Solids, 18 (1975) 307.
5) H. Ushida, Y. Iwadate, T. Hattori, S. Nishiyama,
K. Fukushima, M. Misawa, T. Fukunaga, J.
Alloys Comp., 327 (2001) 121.
6) H. Kenmotsu, T. Hattori, S. Nishiyama, K.
Fukushima, Y. Iwadate, M. Misawa, T. Fukunaga,
T. Nakazawa, K. Noda, J. Phys. Chem. Solids, 60(1999) 1461.
7) V. F. Sears, Neutron News, 3 (1992) 29.
8) R. D. Shannon, Acta. Cryst., A32 (1976) 751.
9) A. H. Narten, J. Chem. Phys., 56 (1972) 1905.

Structure and Intercalation Mechanism of Electrolytic MnO2
M. NAGAO, C. PITTELOUD, T. KAMIYAMAA, T. OTOMOA, K. ITOHB, R. KANNO*Tokyo Institute of Technology, Dpt. of Electronic Chemistry, Interdisciplinary Graduate School of
Science and Engineering, Yokohama, Nagatsuta-cho, Midori-ku, 226-8502
a
Neutron Science Laboratory, Institute of Materials Structure and Technology, High Energy
Accelerator Research Organization, Oho, Tsukuba, 305-0801b
Kyoto University, Research Reactor Institute, Kumatori-cho, Sennan-gun, 590-0494

r.t.
150°C
300°C
400°C
500°C

RDF(r)

Research and development in new low cost andlow toxicity cathode materials led to the preparationof compounds such as manganese dioxide, forexample -MnO2, used actually in lithium or zincprimary battery. The structure of -MnO2 iscomposed by an intergrowth of ramsdellite(R-MnO2) and pyrolusite (-MnO2), the structure
also contains twinning planes.
The vacancies model [1] was proposed todescribe the protons inside the structure and implied
the existence of two different kinds of protons: (i)the ‘Ruetschi’ protons which compensate the Mn4+
vacancies, and (ii) the ‘Coleman’ protons which areassociated with the Mn3+. Experiments such as
inelastic neutron scattering studies [2] showed theexistence of these different protons but information
is limited to the dynamics of these protons and toobtain pure structural information, another approachis needed.
To activate -MnO2 as insertion electrodes,
heat-treatment process is necessary, which causes
both the dehydration and the changes from theramsdellite to the pyrolusite type structures. The
void size also changes during that treatment and thismay affect the lithium storage capacity. The total
angle neutron scattering provides the local structure
including the positions of the protons.
Electrolytic manganese dioxide composition wasdetermined by chemical titration and TG
measurements to be MnO1.974x0.286H2O. Thechanges from ramsdellite to pyrolusite during theheat treatment was followed by X-ray and thediffraction patterns were calculated based on themodels containing stacking faults using a program
DIFFaX [3]. The total neutron scattering was taken
on HIT-II and the datas were corrected forbackground, adsorption, multiple scattering andnormalize with a vanadium rod.

1

Fig. 1

2

r/Å

3

4

5

Radial distribution functions RDF(r) for -MnO2 atvarious temperatures

The host structure of HEMD (heat treatedelectrolytic manganese dioxide) at 300°C wasdetermined to be the ramsdellite type by X-ray andthe structure change to the pyrolusite at 400°C. The
decrease in the peak at r=2.8 Å (oxygen-oxygen
interactions), figure 1, corresponds to thedehydration at 300°C, while the structure remains at
the ramsdellite. The splitting at 400°C indicates the
structure changes from the ramsdellite to thepyrolusite, consistent with the X-ray data.
Table. 1 Coordination numbers of Mn and molar raito for
H deduced from the 1 Å peak.

nOMn (2Å)nO
H

CH for

R.T.
7.12

150°C 300°C 400°C 500°C
6.79
6.05
6.01
5.92

0.101

0.085

-

-

-

=1
at 1 Å
Table 3 su7mmarizes the coordination number(CN) of manganese ions with oxygen at 1.89 Å. The
CN was calculated assuming that the peak was dueto the Mn-O correlations, and the values obtained
exceeded 6.0. This might be due to the overlappingof the H-O correlation to the peak at r = 1.9 Å. For
the sample heat at 300°C and more (no morestructural protons), the coordination number found121was six in accordance with a MnO6 octahedra. For
the coordination of oxygen around hydrogen at 1 Å,
we assume a coordination number of one andcalculate the percentage of hydrogen to satisfy thisvalue. We found that 67% of hydrogen coordinates
an oxygen within 1 Å, indicating the presence of adifferent hydrogen inside the structure, 33% notdirectly bound to oxygen.
The positions of the protons determined from theRDF(r) data situate in or close to the VMnO6
octahedra with a direction towards the center of thevacant cation site and with an H-O distance of 1 Å,or Ruetschi protons. These protons havehydrogen-bond with the next closest oxygen
neighbor with 1.6  r  2 Å distance. Because nocorrelations except 1, 1.9 and 2.2 Å were observedin the RDF(r), only one proton situates in the vacantoctahedra , and other three protons exist with the
charge compensation of one Mn4+ vacancy situate
outside of the VMnO6 octahedra. The VMnO6
octahedra situate next to the vacant O6 octahedrathat form the 1 x 1 or 1 x 2 tunnel in the -MnO2.
The other protons related to the Mn3+ are situated in
the 1 x 1 and 1 x 2 tunnel and are centered inside an
O6 octahedra as deduced from the Mn-H and H-Ocorrelations.
However to ascertain their position undoubtedly,
we need to calculate the exact coordination numberof this proton from the peak at 1.89Å by separating
Mn-O and H-O correlations. It is also important tonote that we cannot differentiate if the proton issituated in the 1 x 1 or 1 x 2 tunnels with ourexperiment
Our structure, see figure 2, results on the RDF(r)calculations indicated that the “Ruetschi” proton
situate near the vacant Mn4+ site, and this vacantsite should be connected by the 1 x 1 of 1 x 2tunnels in the structure. The dehydration of the
Ruetschi protons might cause the collapse of thecluster of the vacant sites and this provides a part ofthe changes from the ramsdellite to the pyrolusite.
The complete transformation from the ramsdellite to
the pyrolusite proceed above 300°C, which is thechange from 1 x 2 tunnel to the 1 x 1 tunnel
structure.
References
1) P. Ruetschi, J. Electrochem. Soc. 131 (1984)
2737
2) F. Fillaux, and al., Solid State Ionics 125 (1999)
69
3) R. Kanno, and al, J. Eletrochem. Soc. 152 (2005)
E230

Fig. 2 Schematic drawing of the model structure and the position of the protons by the RDF(r): (a) position of the Ruetschi
protons reported previously [2], (b) position of the Coleman protons and, (c,d) position of the Ruetschi protons determined in
the present study

122

Structure and Intercalation Mechanism of Chemical Treated Electrolytic MnO2
C. PITTELOUD, M. NAGAO, K. ITOHA, R. KANNO*Tokyo Institute of Technology, Dpt. of Electronic Chemistry, Interdisciplinary Graduate School of
Science and Engineering, Yokohama, Nagatsuta-cho, Midori-ku, 226-8502
a
Kyoto University, Research Reactor Institute, Kumatori-cho, Sennan-gun, 590-0494

10
8
6
4
g(r)

Research and development in new low cost andlow toxicity cathode materials led to the preparationof compounds such as manganese dioxide, forexample -MnO2, used actually in lithium or zincprimary battery. The structure of -MnO2 iscomposed by an intergrowth of ramsdellite(R-MnO2) and pyrolusite (-MnO2), the structure
also contains twinning planes.
The vacancies model [1] was proposed todescribe the protons inside the structure and implied
the existence of two different kinds of protons: (i)the ‘Ruetschi’ protons which compensate the Mn4+
vacancies, and (ii) the ‘Coleman’ protons which areassociated with the Mn3+. Experiments such as
inelastic neutron scattering studies [2] showed theexistence of these different protons but information
is limited to the dynamics of these protons and toobtain pure structural information, another approachis needed.
The neutron first-order difference method wasused first to overcome the difficulty to analyze
solutions in order to obtain ion salvation andcomplexation informations. This method was thenimplemented by Soper and al. [3] by includinghydrogen isotope substitution directly to the solvent.
It is known that the structure of -MnO2 changes
during the de-intercalation of the proton by heat
treatment that happens ate relatively low
temperature. This treatment is nevertheless used toprepare hydrogen free manganese dioxide cathodefor primary lithium battery. A direct exchange
between H and D is not possible at room
temperature and we developed a new method to
remove the proton by chemical oxidation using
NO2BF4 without any structural change observed.
The neutron diffraction measurement was
performed on the HIT-II diffractometer for sample
with different isotopic compositions and the firstorder difference was applied after correction of thedatas. The isotopic purity of the samples wascontrolled prior experiment by a combined TG-MS
measurement. The real-space first-order differencefunction GH(r) for -MnO2 is presented in figure 1.

2
0
-2
-4
-6
0

Fig. 1

1

2

3
r/Å

4

5

Real-space first order difference function GH(r)for -MnO2

The protons are of two different types, one
situated close to the Mn4+vacancy, ‘Ruetschi’ proton,
and are covalently bonded to oxygen and formedhydrogen-bond with the next nearest oxygen. Those
protons are proposed with an external configuration,and six positions are available for them. The second
type, ‘Coleman’ proton, lies close to the Mn3+ inside
the tunnel of the manganese dioxide centered inside
an octahedron formed by six oxygens.
The neutron scattering experiment done gave
structural results when compared to experiments
such as MAS-NMR or inelastic neutron scattering,and our results must be looked as significant toassess the position of the different protons.

References
1) P. Ruetschi, J. Electrochem. Soc. 131 (1984)
2737
2) F. Fillaux, and al., J. Electrochem. Soc. 140(1993) 585
3) A.K. Soper, J. Phys. C 10 (1977) 1793

123

Structure and Absorption Mechanism of Carbon Materials for High Capacity Secondary Battery
M. NAGAO, C. PITTELOUD, T. KAMIYAMAA, T. OTOMOA, K. ITOHB, T. FUKUNAGAB,
K. TATSUMIC, R. KANNO*Tokyo Institute of Technology, Dpt. of Electronic Chemistry, Interdisciplinary Graduate School of
Science and Engineering, Yokohama, Nagatsuta-cho, Midori-ku, 226-8502
a
Neutron Science Laboratory, Institute of Materials Structure and Technology, High Energy
Accelerator Research Organization, Oho, Tsukuba, 305-0801b
Kyoto University, Research Reactor Institute, Kumatori-cho, Sennan-gun, 590-0494
cNational Institute of Advanced Industrial Science and Technology, Ikeda, Osaka, 653-8577

124

in the structure. The peak at 1.8 Å-1 corresponds tothe 002 Bragg peak.

C
LiC10.4
LiC51000

Intensity

The lithiation mechanism of the hard carbon has
been studied to clarify its higher lithium capacity
and as a material design tool to develop and improvethe capacity of future materials. Two structuralmodels are fairly accepted to explain the structure:
the “card house” model, and the “wave” model.
Card house model is based on small domain size ofgraphene layer, and each domain is situated towards
each other in a different orientation so as to form
small void between these domains. The other modelis basically formed by graphene layer, in someregion of the graphene layer, the distance between
the layers is much larger than other domains, whichmakes nano-size space with flat shape [1]. Lithium
may insert into these nano-size space so as to form asurface lithium layer similar to the lithium adsorbedon the graphite surface.
The lithiation mechanism has been discussed
based mainly on the NMR data, and no conclusive
information was obtained due to the lack ofstructural details. We used neutron scattering
technique, efficient to obtain structure information
for compounds containing light element such aslithium, and it was done with two different kind ofexperiments: small angle neutron scattering (SWAN,
presented here) and total neutron scattering (HIT-II,
will be presented in another report).
Carbon fiber used in the present study was
prepared by heat-treatment at 1200°C of an isotropic
petroleum pitch as a precursor. Electrochemicallithium insertion was performed in a three-electrodecell. The fully lithiated carbon (LiC5) was preparedby short-circuiting the cell after 24h. The partiallylithiated carbons were prepared by a charge to
0.01V.
Figure 1 shows the small angle neutron
scattering of the hard carbon and lithiated hardcarbon. The broad peaks found around 0.2 Å -1
corresponds to the scattering from the void existing

100

10

0.01

Fig. 1

0.1
Q / Å-1

1

Small angle scattering patterns of C, LiC10.4 and
LiC5The scattering intensity, I(Q), is related to thegyration radius Rg, and a correlation length can be
determined by fitting the data. During the lithium
intercalation, the lithium inserted firstly into theperiodically layered region in the shallow lithiation
region, which is indicated by the increase of d-value
and then insertion into the void started,
corresponding to the increase in the correlation
length. A porosity P = 10.7% and the number ofvoid per volume n = 2.75x1019 cm-3 were also
obtained from the data.
To determine the shape of the void in the hardcarbon, the SANS date were fitted and the
Debye-Bueche contribution is replace using an
theoretical scattering function composed by a
combined random branching and ellipsoid formsuggesting that the nano-voids spread out in all
directions with irregular intervals. The fit to the datais presented in figure 2 with a schema of the modelused. The equation used for the new to model thedata is as follows:( Debye  Bueche) 

1
2(1  Q 2 R / 18)

3(3 v  v 2 1)
v7(sin Qa  Qa cos Qa ) 2(Qa) 5(1)

When the present results are combined withthose obtained from X-ray and total angle neutron
scattering, a model for the lithium insertion can beproposed as shown in figure 3.
The structure of the hard carbon is composed of
two-dimensional stacked graphene layer and thedisordered arrangements of the layers or “wrinkled”
sheets form voids on the nano-size. Lithium
intercalates into the periodically layered region in
the shallow lithiation region and then inserts into thevoid [2].

2References
1) R.E. Franklin, Proc. Roy. Soc. A209 (1951) 196
2) R. Kanno and al., J. Eletrochem. Soc. 153 (2006)
A914

+

1
7
6
5

Intensity

43

observed
fitting

2

0.1
7
6
5
4
3
7 8 9

2

0.1

3

4

5
-1

Q/Å

6 7 8 91

2

3

Fig. 2Fitting pattern of the small angle
scattering data for the hard carbon. The total fitting isbased on voids with ellipsoid shapes and random
branching formc = 7.192 Å
Lc = 13.8 Å-1
QO = 1.747 Å= 3.19P = 4.00
24Å

c = 7.480 Å-1
QO = 1.680 Å= 3.04
P = 3.62

Lithium intercalation
between graphite layera = 2.456 Å
La = 23.8 Å
First neighbor (C-C)
rC-C = 1.418 Å
CNC-C = 3.0

a = 2.456 ÅFirst neighbor (C-C)
rC-C = 1.418 Å
CNC-C = 3.0

c = 7.656 Å-1
QO = 1.641 Å= 3.26
P = 3.18
Lithium insertion intovoids

a = 2.469 ÅFirst neighbor (C-C)
rC-C = 1.426 Å
CNC-C = 3.1

a = 2.480 Å
First neighbor (C-C)
rC-C = 1.433 Å
CNC-C = 2.8

Fig. 3 Schematic drawing of the structures and the lithiation mechanism for the hard carbon

125

Network Structure in the Ionic Conducting Chalcohalide Glasses
T. USUKI, T. FURUKAWA, K. NAKAJIMA, Y. KAMEDA
Department of Material and Biological Chemistry, Faculty of Science,
Yamagata University, Yamagata 990-8560, Japan

Appropriate amounts of CuI, As and Se, withthose compositions expressed as (CuI)x(As2Se3)1-x
with x  0.6, were sealed within an evacuated quartz
ampoule and thoroughly mixed in a rocking furnace
at 700 C. Then, the melts were quenched rapidly inan ice-water mixture.
Time of flight neutron diffraction measurements
for samples sealed in an evacuated quartz cell (7.0mm in inner-diameter and 0.5 mm in thickness)were made using the HIT-II apparatus installed at
the pulsed spallation neutron source of KEK-KENS.
Scattered neutrons were counted by 104 pieces of3
He counters, which covered the scattering angle
region of 10  2  157. The data accumulation
time was about 8 h for each run. Diffraction
experiments were done in advance for the
background, empty cell and vanadium rod with thesame dimension of the sample. Scattering intensities
from the vanadium rod were applied to theconversion of observed count rates to absolutescattering cross section. The procedure andcorrections of intensity data were similar to thosedescribed elsewhere [2].
According to our previous study of physicalproperties for (CuI)x(As2Se3)1-x glasses, anincorporation of CuI into As2Se3 glass is responsible
for a pronounced increase in the total electrical126

conductivity, which varies exponentially withincreasing CuI content [3]. The electronic
conductivity for the present glasses with x  0.4 hasa value of about 10-9 Scm-1. The ion transportnumber is, then, almost unity, i.e., the contributionof electronic conduction seems to be negligibly
small [3].
As shown in Fig.1, the structure factor S(Q) for
As2Se3 glass has a first sharp diffraction peak
(FSDP) at around 1.2 Å-1 which is a signature of theintermediate-range
atomicordering(IRO)
constructed by AsSe3/2 pylamidal units. The additionof CuI leads to a decrease of the FSDP height.
However, the FSDP clearly remains for glasses withhigh CuI content, together with a gradual shift in thepeak position from 1.2 (x = 0) to 1.0 Å-1 (x = 0.60).
This can be interpreted to means that theincorporation of CuI into As2Se3 glass causes a
disturbance of the AsSe3/2 network, and then createsa new IRO in highly doped glasses.

2.5

60(CuI)40(As2Se3)
2.0

40(CuI)60(As2Se3)
1.5

S(Q)

Superionic conducting glasses containing Ag andCu ions have received much attention because ofscientific interests in their conduction mechanism aswell as their application in solid stateelectrochemical devices. Although extensive studies
have been carried out to investigate their ionictransport mechanism in silver oxysalt systems, suchas AgI-Ag2O-MxOy [1], an obvious explanation of
the conduction mechanism has not yet emerged fromthe literature. In addition, there has been a lack of
information concerning physical properties anddetailed microscopic structure for CuI doped
non-oxide glass systems. This paper will present
results of neutron diffraction studies in CuI-As2Se3
glasses and discuss the conduction mechanism in
CuI doped non-oxide glasses.

As2Se3

1.0

0.5

0.0

0

5

10

15

20

25

30

-1

Q / A

Fig. 1 Structure factors S(Q) for (CuI)x(As2Se3)1-x
glassesA well-defined first peak is found at 2.42 Å ing(r) for As2Se3 glass. With increasing CuI content,
the first peak shifts toward larger r side from 2.42 to
2.49 Å, and at the same time, a new component of
the second peak grows at about 4.3 A. Thesechanges correspond to the formation of the local
atomic ordering constructed by Cu and I atoms,
similar to the case in crystalline CuI (rCu-I  2.6 andrI-I  4.3 Å in  and  phases of CuI).
7

6

5

4

g(r)

60(CuI)40(As2Se3)
3

40(CuI)60(As2Se3)

2

As2Se3

1

0

0

5

10

r / A

Fig. 2 Pair distribution functions g(r) for (CuI)x(As2Se3)1-x
glasses.

It has been reported that there is a distinct
diffuse scattering peak at around 1.0 Å-1 in the
structure factor of crystalline -CuI, which isstrongly related to the existence of short-distance
Cu-Cu correlations at ~2.4 Å in the Cu-Cu partial
distribution function of -CuI. For the present(CuI)x(As2Se3)1-x glasses with high CuI content, the
FSDP is clearly observed at 1.0 Å-1 (x=0.60) in S(Q)as same as crystalline -CuI. Moreover, it isinteresting to note that nearest neighbour interatomic
distances of Cu-I and Cu-Cu, obtained in our Cu
K-edge EXAFS analysis, occurs closer to those in
crystalline -CuI. Therefore, it is reasonable toassume that the Cu ion environment in the present(CuI)x(As2Se3)1-x glasses with high CuI content may
be similar to that in crystalline -CuI, where Cu+
ions occupy randomly 32(f) sites which represents
one corner of the tetrahedrally distorted 8(c) sites(8(c) sites are tetrahedrally coordinated by I-).

Structural parameters for nearest neighbour
correlations can be determined by the least squares
analysis for the total S(Q) using a model function
under an assumption that the first coordination shellof the present glasses is composed of As-Se, Cu-I
and Cu-Cu correlations.
As summarised in the Table, the nearest
neighbour environment of As does not change andthe pyramidal AsSe3/2 units remain essentially intact
on introducing CuI, i.e., the network matrix in theglass is made by covalent AsSe3/2 pyramidal units at
any composition. On the other hand, Cu atoms havethree iodine nearest neighbours at 2.60 Å and one
copper nearest neighbour at 2.42 Å. These results
suggest that a significant number of Cu occupy thetrigonal sites in the tetrahedral units constructed by
I- ions, which correspond to the 32(f) sites incrystalline -CuI. Therefore, the structure model for(CuI)x(As2Se3)1-x glasses can be proposed as thepseudo-binary mixture of the AsSe3/2 network matrix
and dispersed -CuI clusters, where the addition ofa large amount of CuI does not significantly affect
the SRO of both the network former and modifier
units. This feature may enable the present glass
system to form sufficient pathways allowing for thehigh ionic conduction of Cu ions. The difference inionic conductivity between CuI- and AgI-As2Se3
systems may be related to the cluster size of metal
halide units, that is to say, CuI in CuI-As2Se3 system
is dispersed in the glass network at rather molecularlevel than AgI system.
Table 1. Structural parameters of As-Se, Cu-I and Cu-Cu
correlations for (CuI)x(As2Se3)1-x glassesx
rAs-Se(Å)
lAs-Se(Å)
nAs-SerCu-I(Å)
lCu-I(Å)
nCu-I
rCu-Cu(Å)
lCu-Cu(Å)
nCu-Cu02.41(2)0.111(5)3.1(2)
-

0.4
2.41
0.093
3.0
2.60(2)
0.113(5)3.0(2)
2.43(2)0.099(6)1.0(5)

0.6
2.41
0.105
2.9
2.59
0.121
3.0
2.41
0.105
1.0

References[1] see for example, T. Minami, K. Imazawa, M.
Tanaka, J. Non-Cryst. Solids 42 (1980) 469.
[2] K. Abe, O. Uemura, T. Usuki, Y. Kameda, M.
Sakurai, J. Non-Cryst. Solids 232-234 (1998)
682.
[3] T. Usuki et al., J. Non-Cryst. Solids 312-314(2002) 570.
[4] L.W. Strock, Z. Phys. Chem. B25 (1934) 441.

127

Network Structure and Conduction Pathways in AgBr-doped Chalcogenide Glasses
T. USUKI, Y. ONODERA, T. FURUKAWA, Y. MURAKAMI, Y. KAMEDA
Department of Material and Biological Chemistry, Faculty of Science,
Yamagata University, Yamagata 990-8560, Japan

Appropriate amounts of AgBr, As and Se, withthose compositions expressed as (AgBr)x(As2Se3)1-x
with x  0.6, were sealed within an evacuated quartz
ampoule and thoroughly mixed in a rocking furnace
at 650 C. Then, the melts were quenched rapidly inan ice-water mixture.
Time of flight neutron diffraction measurements
for samples sealed in an evacuated quartz cell (7.0mm in inner-diameter and 0.5 mm in thickness)were made using the HIT-II apparatus installed at
the pulsed spallation neutron source of KEK-KENS.
Scattered neutrons were counted by 104 pieces of3
He counters, which covered the scattering angle
region of 10  2  157. The data accumulation
time was about 8 h for each run. Diffraction
experiments were done in advance for the
background, empty cell and vanadium rod with thesame dimension of the sample. Scattering intensities
from the vanadium rod were applied to theconversion of observed count rates to absolutescattering cross section. The procedure andcorrections of intensity data were similar to thosedescribed elsewhere [3].
According to our previous study of physicalproperties for (AgBr)x(As2Se3)1-x glasses, anincorporation of AgBr into As2Se3 glass is
responsible for a pronounced increase in the total
128

electrical conductivity, which varies exponentiallywith increasing AgBr content [4]. The electronic
conductivity for the present glasses with x  0.4 hasa value of about 10-9 Scm-1. The ion transportnumber is, then, almost unity, i.e., the contributionof electronic conduction seems to be negligibly
small [4].
Structure factors S(Q) for the present glasses
shown in Fig. 1 have a first sharp diffraction peak
(FSDP) at around 1.2 Å-1 which is a signature of theintermediate-range
atomicordering(IRO)
constructed by AsSe3/2-pyramidal network units. The
addition of AgI leads to a decrease of the peakheight without measurable changes in the position of
the FSDP.
2.5

60(AgBr)40(As2Se3)
2.040(AgBr)60(As2Se3)
1.5

S(Q)

Many kinds of studies for ionic conducting
glasses, especially for AgI-doped glass systems,
have been carried out from academic and practicalpoint of view [1]. The fast ion conduction in the
AgI-doped glasses is attributed to their uniquestructure, which can be modeled as a mixture of
conduction pathways similar to the fast ion
conducting phase of crystalline AgI and rather rigid
chalcogenide networks [2]. On the contrary, there
are few reports on the glass systems containing othersilver halides, such as AgBr and AgCl, in which arock salt structure is stable under atmosphericpressure. This paper will present results of neutron
diffraction studies in AgBr-As2Se3 glasses anddiscuss the conduction mechanism in AgBr doped
non-oxide glasses.

As2Se3
1.0

0.5

0.0

0

5

10

15

20

25

30

-1

Q / A

Fig. 1 Structure factors S(Q) for (AgBr)x(As2Se3)1-x
glassesFig. 2 gives pair distribution functions g(r). A
well-defined first peak is found at 2.42 Å in As2Se3
glass. With increasing x, the intensity of an hump at
about 2.7 Å increases maybe due to the formation of
longer Ag-Br bonds. In addition, the intensity of thesecond and third peaks in g(r) systematicallydecreases with increasing x, suggesting that the IRO
in the present glasses changes gradually with x. This
seems to be associated with the disappearance of the
FSDP in S(Q) mentioned above.
6

5

60(AgBr)40(As2Se3)
440(AgBr)60(As2Se3)

g(r)

3

2

As2Se3

Table 1. Structural parameters of As-Se and Ag-Br correlationsfor (AgBr)x(As2Se3)1-x glasses

1

0
2

4

6

8

has three Se nearest neighbours at 2.42 Å. Thissuggests that the network matrix in the glass is madeby covalent AsSe3/2 pyramidal units as same as theparent glass. On the other hand, a significant numberof Ag have the tetrahedral coordination with Br,
strongly differ from the case in crystalline AgBr
which has a lock salt structure with the coordination
number of nAg-Br = 6. Therefore, the structure modelfor (AgBr)x(As2Se3)1-x glasses can be proposed as thepseudo-binary mixture of the AsSe3/2 network matrix
and tetrahedral AgBr units, where the addition of alarge amount of AgBr does not significantly affectthe short-range order of the covalent network matrix.
These results are reasonably supported by our
EXAFS data for the present glasses. This feature
may enable the present glass system to form
sufficient pathways allowing for the fast ionic
conduction of Ag ions.

10

r / A

Fig. 2 Pair distribution functions g(r) for (AgBr)x(As2Se3)1-x
glasses.

It is reasonable to assume that the firstcoordination shell of the present glasses is composedof As-Se and Ag-Br correlations. Structuralparameters for both correlations can be determinedby the least squares analysis for the total S(Q) using
a following model function,

where ri-j, li-j and ni-j denote the interatomic distance,root mean square displacement of i-j pair andnumber of j atoms around a given atom i,
respectively. The least squares fitting was performedat Q  8 Å-1. As summarised in Table 1, the additionof AgBr to As2Se3 glass results in the concentration
independence of all structural parameters, where Asx
rAs-Se(Å)
lAs-Se(Å)
nAs-SerAg-Br(Å)
lAg-Br (Å)
nAg-Br02.42(2)0.090(5)3.0(2)
-

0.4
2.42
0.094
2.8
2.70(2)0.12(5)3.9(2)

0.6
2.43
0.095
2.8
2.70
0.13
3.8

Superionic conducting glasses were obtained in
the AgBr doped As2Se3 system. Their ion transport
properties are strongly associated with the local
structure proposed as the pseudo-binary mixture of
AsSe3/2 network matrix and tetrahedral AgBr units.
References[1] see for example, T. Minami, K. Imazawa, M.
Tanaka, J. Non-Cryst. Solids 42 (1980) 469.
[2] T. Usuki et al., J. Non-Cryst. Solids 312-314(2002) 570.
[3] K. Abe, O. Uemura, T. Usuki, Y. Kameda, M.
Sakurai, J. Non-Cryst. Solids 232-234 (1998)
682.
[4] Y. Onodera et al., submitted to Solid State
Ionics.

129

Structure Determination of New Superionic Composite Glass (AgI)x(NaPO3)1-x
E.KARTINI, A.PURWANTO and T.KAMIYAMA*
Technology Center for Industrial Nuclear Materials, National nuclear Energy Agency (BATAN),
Kawasan Puspiptek, Serpong, Tangerang 15314, Banten, Indonesia.
*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
Superionic conductors are of interest from both atechnical and fundamental point of view. The
materials with ionic conductivity of at least 10 -2
S/cm have a number of possible technologicalapplications ranging from batteries and fuel cells tosensors. The materials allow the macroscopic
movement of ions through their structure, leading to
exceptionally high values of ionic conductivity
whilst in the solid state. This behavior typicallyoccurs at elevated temperatures and as common fora first type superionic, like AgI, Ag2S etc. The ionic
conductivity of AgI increases by three orders ofmagnitude when transform from β at 147 oC [1].
At room temperature, -AgI with the FCC structure
is more stable, but it has very low conductivity of
about 10-6 S/cm. With the idea to depress the  βtransformation or to stabilized -AgI at room
temperature, the material was mixed with the second
component, like in silver iodide silver oxysalt glass
AgI-Ag2O-P2O5. The molten mixture was thenquenched to arrest to high -AgI phase in the glass
framework [2]. The glass formation occurs for the
mixture with less AgI content, but above thesolubility limit (~ 57 mol% AgI), it turns to acomposite-glass, like in (AgI)0.7(AgPO3)0.3 and 80
mol% AgI in AgI-Ag2O-B2O3 [3-4]. The ionic
conductivity of the composite glass was foundhigher than in the glassy state [4].
This work reports the structural studies of thenewcomposite-glass
AgI-Na2O-P2O5
or(AgI)x(AgPO3)1-x with x=0.6, 0.7 and 0.8 [5-7].
NaPO3 glass was chosen as a glass framework due
to economical reason for the application. Na+ that
substitutes the Ag+ is much cheaper and easy to be
produced. The ionic conductivity is ~ 10-3 S/cm atambient temperature and it increases up to ~ 0.2
S/cm at 480 K. The sample was prepared by mixing
and grinding all the components, then it was melted
at 850 oC and quenched into the brass-mould thatwas cooled by liquid nitrogen as described
elsewhere [8-10]. Here we report the powder
measurements on these composite-glasses in order130

to determine the structure and to understand more
about the ionic conduction mechanism.
The neutron diffraction experiment was
performed by using a VEGA instrument at the
Neutron Science Laboratory (KENS), High Energy
Accelerator Research Organization (KEK), Japan.
The powder sample was put inside the vanadiumtube under vacuum condition and the measurement
was done at room temperature. The refinement wasdone for the neutron data using RIETAN2000T,
which uses profile function optimized for VEGA
and SIRIUS diffractometers [6].

Fig. 1

Portion of the refined neutron diffractograms of(a) (AgI)0.8(NaPO3)0.2 and (AgI)0.7(NaPO3)0.3 [ 6].

Figure 1 shows the neutron diffractograms of(AgI)x(NaPO3)1-x with x=0.7 and 0.8 with therefinement results. The pattern shows some Bragg
peaks in the composite indicating that the AgI
composition passes the solubility limit so that the
crystalline AgI precipitates in the NaPO3 glassyframework. Similar AgI precipitates was also
observed in the corresponding (AgI)0.7(AgPO3)0.3
glass [4]. The pattern of (AgI)0.8(NaPO3)0.2 isqualitatively
different
from
that
of
(AgI)0.7(NaPO3)0.3
as shown by several small
peaks at d(Å)=3.52 and 2.73 appear at higher
composition. Another small peaks at d(Å)=3.61 and3.43 only appear at (AgI)0.7(NaPO3)0.3. The
background of this composition is higher due tolarger amount of the glassy part (NaPO3). The small
peaks d(Å)=3.61, 3.43 and 3.98 correspond to thepentasilver iodide diphosphate (V) Ag5IP2O7 [11]which might have been arisen from cutting
phosphate chains by oxidation [5]. The massfraction of AgI and Ag5IP2O7 is 53% and 47%. In(AgI)0.8(NaPO3)0.2 it contains 70% of -AgI and 30%
β-AgI. Table 1 shows the refinement results of(AgI)0.8(NaPO3)0.2 at room temperature with each
atom site having 100% occupancy.

melt-quenched AgI glass [3], possibly due to thefast-cooling that makes the coagulation before thenuclei starts to grow.

REFERENCES
1) D.A.Keen, J.Phys.Condens. Matter 14(2002) R819
2) R.J. Cava et al., Solid State Commun. 24(1977)411
3) Tatsumisago et al., Solid State Ionics (1998)
4) M.F. Collins and E.Kartini, Physica B 213&214(1995) 875
5) A.Purwanto et al., Solid State Ionics 171 (2004)113
6) A. Purwanto et al., J.of Neutron Research (2005)
7) E.Kartini et al., J.Materials Science 4(3) (2003)19
8) E.Kartini et al., Applied Physics A (2002)s1236
9) E.Kartini et al., Phys.Rev. B 64 (2000) 875
10) E.Kartini et al., Solid State Ionics 167 (2004)
11) S.Adam et al., Cryst.Struc.Commun.55(1999)1741

Table 1. Refined parameters of (AgI)0.8(NaPO3)0.2.
-AgI
Cubic F -4 3 m
Ag atoms-AgI
Hexagonal P 63 m c(0,0,0)(1/3, 2/3, 0.61(1))

I atoms(1/4,1/4,1/4)(1/3, 2/3, 0.0)

Lattice parametersa(Å)=6.494(1)Mass fraction

70%

Reliability factors

Rwp=4.30%

a(Å)=4.588(1)c(Å)=7.518(1)30%
R=3.22%The distortion of the hexagonal unit cell due to a
A slightly mismatched line between the hexagonaltilings with respect to the orthorhombic unit cell,caused a distortion of hexagonal unit cell and thebondlength connecting Ag atoms are no longer
constructing perfect hexagons []. The orthorhombic
in unit cell in bc-plane of Ag5IPO7 can be though as
a distorted hexagonal unit cell. Ag5IPO7 has bigger
unit cell than that of the -AgI which is occupied
mostly by oxygen, indicating that -AgI in has been
oxidized.
Though, there was no sign of -AgI phase appears
in the composite-glass (AgI)0.8(NaPO3)0.2 and(AgI)0.7(NaPO3)0.3 but the ionic conductivity is muchhigher compared with the pure crystalline -AgI. The
increase of ionic conductivity in these composites are
due to the distortion to the low phase that causes a
defect in crystal. The existence of defect increases themobility of Ag ions and the diffusive motion among
the cluster (precipitates), thus increasing the ionic
conductivity. Another possible effect, that the particle
size of the precipitates on the glassy framework is in
the order of nanometers. The size is similar to the other131

Local Structural Analysis of LixMPO4 (M = Fe, Mn, x = 0, 1)
A. YAMADA*1, H. KOIZUMI1, and K ITO2
1

Department of Electronic Chemistry, Interdisciprinary Graduate School of Science and Engineering,Tokyo Institute of Technology

4259 Nagatsuta, Midori, Yokohama, 226-8502 Japan
2
Research Reactor Institute, Kyoto University
Kumatori-cho, Senna-gun, 590-0494 JapanThe Mn3+/Mn2+ redox couple in the olivine
framework is positioned at 4.1 V vs. Li/Li + but
possesses much slower kinetics compared toFe3+/Fe2+. Despite the higher open circuit voltage(OCV), the current durability in LixMnPO4 is ordersof magnitude inferior to that in LixFePO4, and theeffective energy density of LiMnPO4 is much smaller
than that of LixFePO4. This has led battery engineers
to concentrate on improving LiFePO4 rather thanusing the Mn3+/Mn2+ redox couple in olivines; morethan 170 papers on this subject have been publishedin the past four years. On the other hand, literature
with promising perspectives for LixMnPO4 cathodes
is very limited. In addition, the OCV of 3.4 V vs.
Li/Li+ in LixFePO4 provides a large overvoltage“margin” to oxidative electrolyte decomposition.
Long-term stable operation as well as enhanced
charging kinetics under acceptable anodic
overvoltage are important technical advantages of
LixFePO4 cathodes.
The key aspect in this important class ofmaterials is that the major structural anomalies, suchas anisotropic deformation, significant loss oflong-range order, and local phase segregation, havebeen detected in the phases with Mn3+. This isreasonable because Mn3+ is a typical Jahn-Teller ion,
indicating the importance of the acquisition of
accurate structural, magnetic, and transport data
along the (MnyFe1-y)PO4 solid solution line forunderstanding the origin of the loss ofelectrochemical activity. However, previous studies
have been limited to structural analyses of minerals(heterosite: y ~ 1/3, purpurite: y ~ 2/3), which usuallypresent the specific manganese content withstructural disorder and impurities due to their natural
origin. Difficulties in synthesizing phase-pureLi(MnyFe1-y)PO4 and hence its oxidized form
(MnyFe1-y)PO4 also have been discussed in terms of
the unexpected segregation of oxidized or reduced
impurities. Although recent studies demonstrate thatpure (MnyFe1-y)PO4 phases with any manganesecontent of y<0.8 can be obtained by chemicaldelithationfromhigh-quality
synthetic132

Li(MnyFe1-y)PO4, only the orthorhombic latticedimensions were provided. Systematic, accurate, anddetailed structural and magnetic analyses on theandsynthetic
phase-pureLi(MnyFe1-y)PO4(MnyFe1-y)PO4 solid solutions have to our knowledge
not documented before.

Fig. 1. Interatomic distances for (a) M-O and (b) P-O
for Li(MnyFe1-y)PO4 and (MnyFe1-y)PO4.
The analysis was performed for the twosolid-solution lines of trivalent (MnyFe1-y)PO4 anddivalent Li(MnyFe1-y)PO4. Changes in the M-O bondlengths in MO6 octahedra and the P-O bond lengths
in PO4 tetrahedra are summarized in Figure 1.
Introducing Mn ions into the 4c site did not
significantly change the local geometry of M2+O6
octahedra and PO4 tetrahedra. The M2+-O bondlengths showed isotropic linear increase as a functionof manganese content y and can be explained simply
by the difference in the ionic radii of the high-spin
Mn2+ (0.97 Å) and high-spin Fe2+ (0.92 Å). The rigid
small PO4 polyanion with covalent P-O bond is not
surprising. While, M3+O6 octahedra become severely
distorted with an increase in the Jahn-Teller (JT)
active Mn3+ ions.

Usually, the Jahn-Teller distortion of MO6
octahedra (Oh symmetry) shows an elongation of thetwo axial (c-direction) bond lengths and shrinkage ofthe four equatorial (a-direction) bond lengths, to givea general expression as c/a > 1. However, theJahn-Teller effect in the MO6 octahedra with barely
ionized M ions tends to yield an equatorial/axial ratio
inversion of c/a < 1, where the two axial bondlengths shrink and another four equatorial bondlengths expand. Such an inversion is typicallyobserved for strongly ionized epidote or perovskite
materials, where the metastable c/a<1 configurationis stabilized in a crystal to prevent the penalty inenergy required to distort the structure from themetastable c/a <1 structure to the stable c/a >1. The(MnyFe1-y)PO4 series evidently belongs to the lattercase of c/a < 1 because the transition metals arestrongly ionized by the M-O-P inductive effect.
The radial distribution functions (RDF) for
LiFePO4, FePO4, LiMnPO4, and amorphous MnPO4
obtained by neutron total diffraction are given in
Figure 2. These functions aid the understanding of
the overall trend in the change in local geometry of
the Lix(MnyFe1-y)PO4 system. Due to the differenceof the sign in the neutron scattering length, i.e.,
Fe(+9.45), Mn(-3.73), P(+5.13), O(+5.803), negative
peaks for Mn-O correlation and positive peaks for
P-O and Fe-O correlations are observed at thecorresponding bond distances. To demonstrate this,bond lengths obtained by the Rietveld refinement of
X-ray diffraction data for LiFePO4, FePO4, and
LiMnPO4 are denoted as vertical bars in Figure 14.
Since no experimental crystallographic data are
available for the metastable pure MnPO4 with aPnma structure, we inferred the bond lengths inamorphous MnPO4 from the optimized geometries
obtained by the first principle calculation kindly
supplied by D. Morgan and G. Ceder. Note that thebond lengths based on the calculated optimized
geometry are coincident with the line extrapolation
toward y = 1, as shown in Figure 1. Even in theamorphous phase, local coordination around Mn3+
appears to be influenced by the Jahn-Teller effect.
Among the four types of M-O bonds in the MO6octahedra, the equatorial M-O3 and M-O3’ bonds
contribute to the neighboring superexchangeinteraction. The enhanced asymmetry in the M-O-M
superexchange interaction upon oxidation of themanganese system is highlighted by the dashed line
in Figure 2, which should influence theantiferromagnetic ground state.

Figure 2. The radial distribution function (RDF) for
LiFePO4, FePO4, LiMnPO4, and amorphous MnPO4
obtained by neutron total diffraction. Rectangularbars represent the interatomic bond lengths obtainedby the Reitveld refinement for LiFePO4, FePO4,
LiMnPO4, and by first principle calculation foramorphous MnPO4. The M-O3 and M-O3’ bondlengths are related to the superexchange interaction
and are connected by dashed lines to show thesignificant change in asymmetry.
References
1) A. Yamada*, Y. Takei ， H. Koizumi, N.
Sonoyama, and R. Kanno, Appl. Phys. Lett., 87,252503（2005）
2) A. Yamada*, Y. Takei, H. Koizumi, N.
Sonoyama, R. Kanno, K. Ito, M. Yonemura, and
T. Kamiyama, Chem. Mater., 18, 804(2006)

133

Structural and Hydration Properties of Amorphous Ca3SiO5
K. MORI, Y. SHIRAISHI, *K. IWASE, **M. YONEMURA, K. ITOH, M. SUGIYAMA,***T. ISHIGAKI, *T. KAMIYAMA, ****K. OISHI, *M. KAWAI and T. FUKUNAGA

Research Reactor Institute, Kyoto University, Kumatori-cho, Sennnan-gun, Osaka, 590-0494*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization,
Tsukuba, Ibaraki, 305-0801** Institute of Applied Beam Science, Graduate School of Engineering and Science, Ibaraki University,
4-12-1 Nakanarusawa-cho, Hitachi, Ibaraki 316-8511***Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195****Institute of Technology, Shimizu Corporation, 3-4-17 Etchujima, Koto-ku, Tokyo 135-8530

For further improvement in cement (or concrete)
properties, many extensive studies have been carriedout from various viewpoints. In the meantime,mechanical milling has been paid much attention forsynthesizing amorphous or metastable alloys. This
process is also well known to promote the reactivityof various materials: biomaterials and energy
storaged materials. Therefore, it can be easily
expected that the application of the mechanicalmilling to the hydration process of cement will
improve the concrete properties. In the present
research, we studied the hydration process from thestructural viewpoint by taking advantage oftime-of-flightneutronpowderdiffraction(TOF-NPD) by focusing on Ca3SiO5 of the major
component of Portland cement clinkers, and byusing mechanical milling technique for the
improvement of concrete properties [1].
Polycrystalline Ca3SiO5 was synthesized byconventional ceramic processing. The mechanicalmilling was conducted dry at 200 rpm for 30 h underargon gas atmosphere using a planetary ball millapparatus (Fritsch Pulverisette 5). The TOF-NPD
data for each sample were collected on the Vega andthe HIT-II, installed at KEK-KENS [2].
Figure 1 shows the comparison between RDF(r)sof unmilled and milled Ca3SiO5. In the RDF(r),the first peak at around 1.6 Å indicates the Si–O
correlation in a [SiO4] tetrahedron, because thecoordination number of Si–O was calculated to be 4
oxygen atoms around a Si atom from the area of thefirst peak. The second and third peaks can berecognized to correspond to the Ca–O correlation (~2.4 Å) and the O–O (~ 2.7 Å), respectively. As
shown in Fig. 1, the peak profiles of Si–O and O–O
correlations of the milled Ca3SiO5 do not change incomparison with those of the unmilled Ca3SiO5 ,whereas the peak broadening of Ca–O correlation isconspicuous. This result leads us to understandthat the structural distortion took place around Ca
atoms due to various kinds of defects was inducedby mechanical milling.
134

To evaluate the improvement of the early
hydration properties (< 24 h of hydration) subjectedby mechanical milling, the intensities for the 101
reflection (d ~ 2.63 Å) of Ca(OD)2 were estimatedfor all TOF-NPD data of the unmilled and milled
Ca3SiO5. Figure 2 shows the time dependence ofintensities for the 101 reflection of Ca(OD)2 for eachsample. In particular, the induction time of thehydrated milled Ca3SiO5 is approximately one half
shorter than that of the hydrated unmilled one.

Fig. 1.

Fig. 2.

RDF(r)s of unmilled and milled Ca3SiO 5.

Time dependence of intensities for 101 reflectionof Ca(OD)2 for each sample.

References
1) K. Mori et al., Cem. Con. Res, in press.
2) T. Kamiyama et al., Physica B 213&214 (1995) 875.

Structural Study on Amorphous Cu-Ta Alloys Prepared by Mechanical Alloying
under Ar and D 2 Atmospheres
K. ITOH, K. YOSHIMURA *, H. T. TAKESHITA*, K. MORI, M. SUGIYAMA
and T. FUKUNAGA
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan* Faculty of Engineering, Kansai University, Suita, Osaka 564-8680, Japan

4

X-ray diffraction
RMC

3
2

Cu32Ta 68

S(Q)

1
0
4
3
2

(Cu33Ta 67)D0.33

1
0
0

50

100

150

200

-1

Q (nm )

Fig. 1 Experimental structure factors, S(Q), observedby X-ray diffraction and RMC fits for amorphous
Cu0.32Ta0.68 and amorphous (Cu0.33Ta0.67)D0.33.
5
Cu32Ta 68(Cu33Ta 67)D0.33

4
3
g(r)

The heat of mixing of a Cu-Ta system is positive andhence the Cu-Ta system is typically immiscible in thesolid state [1]. However, amorphous Cu-Ta alloy has
been reported to be synthesized by mechanical alloying[2-4]. The formation of the amorphous phase has been
confirmed not only by thermodynamic and structural
analysis based on DSC, neutron diffraction and EXAFS[2,3] but also by the electronic studies through changes insuperconducting transition temperature and XPS valenceband structure [4]. It is interesting to investigate thelocation of hydrogen (deuterium) atoms in the systemwith a positive heat of mixing. In this work, the X-ray andneutron diffraction techniques were complementary
employed to clarify the structure of amorphous Cu-Ta
alloys prepared by mechanical alloying under Ar and D2
atmospheres, respectively. Moreover, reverse Monte
Carlo modeling method was employed to clarify the local
environments around the deuterium atoms and thearrangements of metal atoms in amorphous Cu-Ta alloys.
Cu (99.99%) and Ta (99.9%) powders were mixed at
the atomic ratio 3 : 7 and put into a zirconia vial with 10
zirconia balls (10 mm in diameter). After the evacuationfor 12 h below 10-4 Pa by a turbomolecular pump,high-purity Ar gas (99.999%) of 0.1 MPa or high-purity
D2 gas (99.999%) of 1 MPa as an initial pressure wereintroduced into the vials, respectively. Mechanicalalloying was carried out by a planetary ball mill apparatus(Fritsch P-5) with 300 rpm for 50 h. Composition analysis
was done by the induction coupled plasma (ICP) method
for Cu, Ta. The concentration of deuterium in the sample
prepared by mechanical alloying under D2 atmosphere
was determined at the Center for Organic Elemental
Microanalysis, Kyoto University. The compositions of
the alloys prepared by mechanical alloying under Ar andD2 atmospheres were Cu0.32Ta0.68 and (Cu0.33Ta0.67)D0.33,
respectively. The high-energy X-ray diffraction
measurement was carried out with a photon energy of
113.68 keV at the high-energy X-ray diffraction beamline
BL04B2 in the SPring-8. The neutron diffraction
measurements were carried out by using the HIT-II. The
S(Q) were obtained from the scattering intensity after
various corrections. Reverse Monte Carlo (RMC)

2
1
0
0

0.2

0.4

0.6

0.8

1

r (nm)

Fig. 2 Pair distribution functions, g(r), observed by
X-ray diffraction for amorphous Cu0.32Ta0.68 andamorphous (Cu0.33Ta0.67)D0.33 .

simulation [5] was carried out through fitting to both
X-ray and neutron diffraction data. Starting
configurations of 4200 and 5000 atoms for amorphous
Cu0.32Ta0.68
andamorphous(Cu0.33Ta0.67)D0.33,
respectively, with appropriate composition, randomly
distributed in a cube box, was used. To ensure aphysically realistic configuration, the closest distances
between two atoms allowed to approach each other were
determined from the experimental total distributionfunctions.
Figure 1 shows the structure factors, S(Q), foramorphous Cu0.32Ta0.68 and amorphous (Cu0.33Ta0.67)D0.33

135

4

neutron diffraction
RMC

3
2

Cu32Ta 68

S(Q)

1
0
4
3
2

(Cu33Ta 67)D0.33

1
0
0

50

100

150

200

-1

Q (nm )

Fig. 3 Experimental structure factors, S(Q),observed by neutron diffraction and RMC fits forandamorphous
amorphous
Cu0.32Ta0.68(Cu0.33Ta0.67)D0.33.
5
Cu32Ta 68(Cu33Ta 67)D0.33

4

g(r)

3
2
1
0
0

0.2

0.4

0.6

0.8

1

r (nm)

Fig. 4 Pair distribution functions, g(r), observed byneutron diffraction for amorphous Cu0.32Ta0.68 andamorphous (Cu0.33Ta0.67)D0.33.

observed by X-ray diffraction, respectively. There are no
significant differences between the X-ray S(Q)s. This
result suggests that the arrangements of metal atoms forthe two samples are hardly different. The pair distributionfunctions, g(r), for amorphous Cu0.32Ta0.68 and amorphous(Cu0.33Ta0.67)D0.33 observed by X-ray diffraction are
shown in Fig. 2. The X-ray g(r)s also show slightdifferences between the two samples. Especially, thepositions of the peak for amorphous (Cu0.33Ta0.67)D0.33 arealmost in agreement with those for amorphous
Cu0.32Ta0.68. This result is of great interest because theshifts of peaks in g(r) with the absorption of hydrogen(deuterium) were observed in other amorphous materials[6, 7]. The remarkable lack of differences in the X-ray
data between amorphous Cu0.32Ta0.68 and amorphous(Cu0.33Ta0.67)D0.33 are strong evidences that the absorptionof deuterium hardly causes a dilatation in the amorphous
Cu-Ta alloy system.
Fig. 3 shows the S(Q)s for amorphous Cu0.32Ta0.68 andamorphous (Cu0.33Ta0.67)D0.33 observed by neutron
diffraction, respectively. The corresponding g(r)s areshown in Fig. 4. The neutron S(Q)s and g(r)s show some136

differences between the two samples, reflecting aabsorption of deuterium. The neutron g(r) for amorphous(Cu0.33Ta0.67)D0.33 shows a well-resolved first peak around0.20 nm. Since the corresponding X-ray g(r) shown in Fig.
2 has no peak in this region, this peak can be recognized
to be metal–deuterium correlations. If a hard spheremodel with Goldschmidt radii for Cu and Ta atoms isapplied, this peak is expected to be Ta-D correlations.
Under the assumption that the first peak corresponds to
the Ta-D correlations, the coordination number of Ta
atoms around a deuterium atom was calculated to be 3.8
atoms. This result suggests that the deuterium atoms
occupy 4Ta tetrahedral sites in amorphous Cu0.32Ta0.68.
In order to get information about the occupationalsites of the deuterium atoms and the arrangement of metal
atoms, we used the reverse Monte Carlo (RMC) modelingmethod. Calculated total structure factors from the RMC
models for amorphous Cu0.32Ta0.68 and amorphous(Cu0.33Ta0.67)D0.33 are shown together with theexperimental S(Q)s in Figs. 1 and 2, respectively.
Excellent fitting with the experimental S(Q) by both
X-ray and neutron diffraction were obtained. From the
RMC model for amorphous (Cu0.33Ta0.67)D0.33 we foundthat about 91 % of the D atoms locate in the 4Ta
tetrahedral sites and the others locate in the 2Cu+2Ta and
Cu+3Ta tetrahedral sites. This is a really interesting result
because the occupation sites of deuterium atoms aredifferent from those in other amorphous materials [8-11].
Recent X-ray and neutron diffraction studies on
a-TbFe2D3.0 [9] and a-HoFe2D3.0 [10] have shown thatabout 40 % of the D atoms occupy the tetrahedral sites
consisting of rare-earth metal atoms.
The partial pair correlation functions, gi-j(r), calculated
from the RMC models for amorphous Cu0.32Ta0.68 andamorphous (Cu0.33Ta0.67)D0.33 are presented in Fig. 5.
Distinct differences in the structure between amorphous
Cu0.32Ta0.68 and amorphous (Cu0.33Ta0.67)D0.33 can befound in the Cu-Cu pair correlations. For instance theshape of the first peak in the SCu-Cu(Q) are different
between the two samples. Moreover, the intensities of thefirst peak in the gCu-Cu(r) for amorphous (Cu0.33Ta0.67)D0.33
are lower and the dip around 0.35 nm is shallower incomparison with those of amorphous Cu0.32Ta0.68. The
nearest neighbor coordination numbers, Ni-j, which havebeen derived from the RMC models for amorphous
Cu0.32Ta0.68 and amorphous (Cu0.33Ta0.67)D0.33 aresummarized in Table 1. NCu-Cu (NCu-Ta, NTa-Ta) stands forthe coordination number of the nearest neighbor Cu (Ta,Ta) atoms around a Cu (Cu, Ta) atom. The nearest
neighbor coordination numbers also show significant
differences in the Cu-Cu pair correlations between
amorphous Cu0.32Ta0.68 and amorphous (Cu0.33Ta0.67)D0.33.
Namely, the NTa-Ta of the two samples are almost theTable 1 The nearest neighbor coordination number
derived from the RMC models for amorphous Cu0.32Ta0.68
and amorphous (Cu0.33Ta0.67)D0.33.

Cu32Ta 68(Cu33Ta 67)D0.33

4
2

D-D

0
4
2

Cu-D

a- Cu0.32Ta0.68
a- (Cu0.33Ta0.67)D0.33

04
gi-j(r)

2

Ta-D

0
4
2

Cu-Cu

0
4
2

Cu-Ta

0
4
2

Ta-Ta

0
0

0.2

0.4

0.6

0.8

1

r (nm)

Fig. 5 Partial pair distribution functions, gi-j(r), foramorphous

Cu0.32Ta0.68(Cu0.33Ta0.67)D0.33

calculated

and

amorphous

from

the

RMC

models.
Cu32Ta 68(Cu33Ta 67)D0.33

angle distribution

Cu-Cu-Cu

NCu-Cu3.7
4.4

NCu-Ta7.3
6.9

NTa-Ta8.1
7.9

amorphous Cu0.32Ta0.68, extending to smaller angles.
Consequently, we can conclude that there are slightdifferences in the arrangement of Ta atoms but there are
significant differences in the arrangement of Cu atoms
between amorphous Cu0.32Ta0.68 and amorphous(Cu0.33Ta0.67)D0.33.
In the previous paper [1], Fukunaga and Mizutani
concluded that amorphization process in the Cu-Ta
system is characterized by a penetration of smaller Cu
atoms into BCC Ta crystallites. When the tetrahedral sites
consisting of Ta atoms are occupied by the deuterium
atoms, the penetration of the Cu atoms is thwarted by thepresence of the deuterium atoms. This causes not only thedecrease of the NCu-Ta but also the increase of the NCu-Cu. It
is expected that there are a lot of vacancies in an
amorphous phase. Therefore, the deuterium atoms enter
into the sites consisting of Ta atoms without remarkablechanges in the arrangement of Ta atoms.

Ta-Cu-Cu

Ta-Cu-Ta

Cu-Ta-Cu

Ta-Ta-Cu

Ta-Ta-Ta

0

50

100

150

angle (degree)

Fig. 6 Experimental structure factors, S(Q),observed by neutron diffraction and RMC fits forandamorphous
amorphous
Cu0.32Ta0.68(Cu0.33Ta0.67)D0.33.

same but the NCu-Cu and the NCu-Ta of amorphous(Cu0.33Ta0.67)D0.33 are larger and smaller, respectively,
than those of amorphous Cu0.32Ta0.68.
The angle distributions give us more detailed
information concerning the arrangements of metal atoms.
Fig. 6 shows the angle distributions of metal atoms whichhave been derived from the RMC models. These curves
have peaks around 60 and 110 degrees which areobserved characteristically in metallic glasses. The angle
distribution of Ta-Ta-Ta for amorphous (Cu0.33Ta0.67)D0.33
is similar to that of amorphous Cu0.32Ta0.68 except forslight broadening. However, the peaks in the angle
distributions of Cu-Cu-Cu and Ta-Cu-Cu for amorphous(Cu0.33Ta0.67)D0.33 are much broader than those ofReferences
1) T. B. Massalski: Binary Alloy Phase Diagrams, 2nd ed.,ASM international, (1990)
2) T. Fukunaga and U. Mizutani, Tantalum, 1996
3) C. H. Lee, M. Mori, T. Fukunaga, K. sakurai and U.
Mizutani, Material Science Forum, 88-90 (1992) 399.
4) U. Mizutani, C. H. Lee, T. Fukunaga, M. Takaki and K.
Tanaka, Material Science Forum, 88-90 (1992) 407.
5) R. L. McGreevy, L. Pusztai, Molec. Sim. 1 (1988) 359.
6) K. Aoki, X-G.Li, T. Hirata, E. Matsubara, Y. Waseda
and T.Masumoto, Acta Metall. Mater.,41(1993)1523.
7) M. Saito, Y. Waseda, E. Matsubara, X.-M. Wang, T.
Aihara, K. Aoki and T. Masumoto, J. Non-cryst. Solids
205-207 (1996) 721.
8) K. Suzuki, N. Hayashi, Y. Tomitsuka, T. Fukunaga, K.
Kai and N. Watanabe, J. Non-cryst. Solids 61-62 (1982)
637.
9) K. Itoh, K. Kanda, K. Aoki and T. Fukunaga, J. Alloys
Comp., 348 ( 2002) 167.
10) K. Itoh, Y. Miyajima, K. Aoki and T. Fukunaga, J.
Alloys Comp., 376 ( 2004) 9.
11) K. Itoh, T. Sawada, K. Aoki and T. Fukunaga, J.
Alloys Comp., 392 ( 2005) 6.

137

Structural Study on Nano-crystalline FeTiD0.97: Local Environment around Deuterium in the Grain Boundary
K. ITOH, K. H. SASAKI *, H. T. TAKESHITA*, K. MORI, M. SUGIYAMA and T. FUKUNAGA
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan* Faculty of Engineering, Kansai University, Suita, Osaka 564-8680, Japang(r ) � 1 �

1

�

2

0

Q�S (Q) � 1�sin QrdQ, � � (1)2� r� �where � is the average number density of atoms.

138

10

S(Q)

5

(a)

0
10
5

(b)

0
0

50

100

150

200

-1

Q(nm )
Fig. 1 Structure factors, S(Q), observed by X-ray
diffraction with a photon energy of 113.68 keV for: (a)FeTi after 5 h of milling, and (b) the deuteride(nano-crystalline FeTiD0.97).

(a)
(b)

4
g(r)

FeTi alloys have considerable potential fortechnological application as a hydrogen storage material.
A large number of investigations have been performed
not only on hydrogen absorption properties of thesealloys [1-5] but also on the structure of these hydrides(deuteride) [3, 6-8]. Recently interest has been focused on
nano-crystalline FeTi hydrides as a consequence of their
excellent properties [9-11]. It is very important toinvestigate the structural change with the decrease ofgrain sizes and make clear the local environments aroundhydrogen (deuterium) atoms in grain boundary of
nano-crystalline materials. In this work, neutron and the
X-ray diffraction techniques were complementary
employed to clarify the structure of nano-crystalline FeTi
produced by mechanical milling and the location of
deuterium atoms in the deuteride (nano-crystalline
FeTiDx).
FeTi powder of 3 g (High purity chemistry research
institute, 99.9%, average size 25µm) was put into a steel
vial (80 cc volume) with 10 steel balls (10 mm indiameter). After evacuating for 12 h below 10-4 Pa by aturbomolecular pump, high-purity Ar gas (99.999%) was
introduced into the vial. A planetary ball mill (FritschP-5) was used with 300 rpm for milling. FeTi after 5 h ofmilling was reacted with high purity deuterium(99.999%) at the pressure of 1 MPa for 24 hours. The
concentration of deuterium in the sample was measured at
the Center for Organic Elemental Microanalysis, Kyoto
University.
The X-ray diffraction measurements were carried out
by the horizontal two-axis diffractometer with a photon
energy of 113.68 keV on BL04B2 beam line at SPring-8.
The neutron diffraction measurements were carried out by
using the High Intensity Total Scattering spectrometer(HIT-II). The S(Q) was obtained from the scattering
intensity after various corrections of the background,absorption and multiple scattering, and normalization
with a vanadium rod. The pair distribution functions, g(r),can be derived from the Fourier transformation of S(Q) as
follows,

2
0
0.1

0.2

0.3

0.4

0.5

0.6

r (nm)
Fig. 2 Pair distribution functions, g(r), observed by
X-ray diffraction with a photon energy of 113.68 keV
for: (a) FeTi after 5 h of milling, and (b) the deuteride(nano-crystalline FeTiD0.97).

Because of much lager scattering factors of metal
atoms than that of deuterium atom, the arrangement ofmetal atoms can be selectively visible by X-ray
diffraction. The S(Q)s observed by X-ray diffraction for
FeTi after 5 h of milling and the deuteride(nano-crystalline FeTiD0.97) are shown for comparison in
Fig. 1. The corresponding g(r)s are also shown in Fig.2.

S(Q)

6
4
2
0
0

100

200

-1

Q(nm )
Fig. 3 Structure factors, S(Q), observed by neutron
diffraction for nano-crystalline FeTiD0.97.

4
2
0
4
2
g(r)

The Bragg peaks of nano-crystalline FeTiD0.97 were
found to shift to smaller Q in comparison with those of
FeTi after 5 h of milling, which indicates the lattice
expansion due to the deuterium absorption. The g(r) of
FeTi after 5 h of milling shows clear first peak at 0.256
nm. This peak is attributed to the Fe-Ti nearest neighbour
correlation. The remarkable change in the g(r) after the
deuterium absorption strongly indicates the evidence ofthe rearrangement of metal atoms in the grain boundary
as well as the lattice expansion of the crystalline grains.
This leads us to anticipate the existence of a newoccupation site of deuterium different from a
polycrystalline �-FeTiD.
Since the coherent neutron scattering length for
deuterium atom is comparable to those for metal atoms,
the neutron diffraction experiment gives an insight about
the location of deuterium atom from a different point ofview. Figs.3 and 4 show S(Q) and g(r) for
nano-crystalline FeTiD0.97 observed by neutron
diffraction, respectively. The g(r) shows a positive peakaround 0.17 nm and a negative peak around 0.21 nm.
There is no peak in this region in the g(r) observed by
X-ray diffraction (in Fig.2), so that these peaks can berecognized to correspond to correlations in connection
with deuterium. Since titanium has a negative coherent
neutron scattering length, it is clearly understood that thepositive and negative peaks are attributed to the Fe-D and
Ti-D correlations, respectively. In the polycrystalline
�-FeTiD deuterium atoms occupy octahedral sites with
two iron atoms and four titanium atoms and the mean
Fe-D and Ti-D distances are 0.172 and 0.214 nm,
respectively [7]. Hence the positive and negative peaks in
the g(r) are mainly attributed to the Fe-D and Ti-D
correlations in the grain. It should be noted that there is ashoulder at the left side of the positive peak, whichindicates another correlation. The position of the shoulder
is similar to the Fe-D distances observed in other kinds ofamorphous alloys [12, 13]. Consequently, this shoulder
can be identified as arising from the Fe-D correlation in
the grain boundary.
To understand the local environments around
deuterium atoms in the grain boundary, the g(r) for
nano-crystalline FeTiD0.97 was fitted by approximatingwith Gaussian distribution function. The Fe-D and Ti-D
distances and the coordination numbers in the grains werereferred from the previous work on the polycrystalline
�-FeTiD [7].� The components of the fit for Fe-D and
Ti-D correlations in the grains and those of the grainboundary are plotted in Fig 4, respectively, together withthe residual. The peak at 0.22 nm in the residual can be
identified as arising from D-D correlation and its position
is in good agreement with that for the polycrystalline
�-FeTiD [7] and amorphous metal hydrides [12,13]. Fromin grain02

in grain boundary

0
2
0
0.1

residual

0.15

0.2

0.25

0.3

r (nm)
Fig. 4 Pair distribution functions, g(r), observed byneutron diffraction for nano-crystalline FeTiD0.97 andthe components of the fit for the Fe-D and Ti-D
correlations in the grain and those in the grainboundary. The dashed line is the residual.

the fitting result, it was found that about 50% of
deuterium atoms are situated in the grain boundary. The
nearest neighbour coordination number, Ni-j, and theinteratomic distance, r1, which were derived from theareas and peak positions of the Gaussian distributionfunctions are summarized in Table 1. It is noteworthy thatthe value of ND-Fe+ND-Ti in the grain boundary is about
four. The value of which indicates that the deuterium
atoms are situated in the tetrahedral sites. This result isobviously different from that in the grains but consistent
with previous work on the structural change of the Ni-V
powder [14]. The paper proved that octahedral units in
FCC crystal structure were destroyed and transformed
into tetrahedral ones when the amorphization due tomilling proceeded. Namely, a large number of tetrahedral

139

sites are expected to exist in the disordered region of thegrain boundary.
It is of interest to note that the ND-Ti in the grainboundary is considerably larger than the ND-Fe. This result
Table 1 Nearest neighbour coordination numbers, Ni-j, and interatomic distances, r1, in the grains and thegrain boundary for nano-crystalline FeTiD0.97 calculated from the g(r) observed by neutron diffraction.

polycrystalline �-FeTiD [7]in grainin grain boundary

ND-Fe
2
2.1
0.7

D-Fe

r1(nm)
0.172
0.178
0.165

indicates that deuterium atoms occupy the tetrahedral
sites consisting mainly of Ti atoms, i.e. 4Ti and 3Ti+1Fe
tetrahedral sites. This is because of the strong affinity
between deuterium and titanium atoms.

References

1) J. J. Reilly and R.H.Wiswall, Jr., Inorg. Chem.,
13(1974)218-222.
2) L. Schlapbach, A. Seiler, F. Stucki, Mat. Res. Bull., 13(1978) 697-706
3) J. Schefer, P. Fischer, W. Hälg, F. Stucki, L.
Schlapbach,A. F. Andresen, Mat. Res. Bull., 14 (1979)
1281-1294
4) H. Wenzl and E. Lebsanft, J. Phys. F: Metal Phys., 10(1980) 2147-2156
5) T. Schober and D. G. Westlake, Scr. Metall., 15 (1981)
913-9186) P. Thompson, M. A. Pick, F. Reidinger, L. M. Corliss,
J. M. Hastings, J. J. Reilly, J. Phys. F: Metal Phys., 8(1978) L75-L80
7) P. Fischer, W. Hälg, L. Schlapbach, F. Stucki, A. F.
Andresen, Mat. Res. Bull., 13 (1978) 931-946
8) W. Schäfer, G. Will, T. Schober, Mat. Res. Bull.,
15(1980) 627-634
9) K.Aoki, H Aoyagi, A. Memezawa, T. Masumoto, J.
Alloys Comp., 203 (1994) L7-L910) H Aoyagi, K.Aoki, T. Masumoto, J. Alloys Comp.,
231(1995) 804-809
11) L. Zaluski, A. Zaluska, J. O. Ström-Olsen, J. Alloys
Comp., 253-254 (1997) 70-79
12) K. Itoh, K. Kanda, K. Aoki and T. Fukunaga, J.
Alloys Comp., 348 ( 2002) 167-172
13) K. Itoh, Y. Miyajima, K. Aoki and T. Fukunaga, J.
Alloys Comp., in press.
14) T. Fukunaga, Y. Homma, M. Misawa, K. Suzuki, J.
Non-cryst. Solids 117-118 (1990) 721-724.

140

ND-Tb
4
4.0
3.4

D-Ti

r1(nm)
0.214
0.215
0.184

ND-Fe + ND-Ti
6
6.1
4.1

Structural Observation of Amorphous LaNi5D3.3
K. ITOH, T. SHOUMURA, K. MORI, M. SUGIYAMA and T. FUKUNAGA
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan3
neutrons
RMC

2
1
0
S(Q)

Recently amorphous LaNi5D3.3 has beenreported to be synthesized by mechanical alloying
under D2 atmosphere [1]. It is important toinvestigate their structure and make clear thelocation of deuterium atoms. In this work, in situ
neutron and X-ray diffraction measurements havebeen performed on amorphous LaNi5D3.3 preparedby mechanical alloying under D2 atmosphere.
Moreover, reverse Monte Carlo (RMC) modelingmethod [2] was employed to get a three-dimensional
atomic arrangement by using combined neuron and
X-ray diffraction data.
Amorphous LaNi5Dx was prepared bymechanical alloying under D2 atmosphere. The
neutron diffraction measurement was carried out by
using the HIT-II spectrometer. The X-ray diffraction
measurement was carried out by the horizontal
two-axis on BL04B2 beam line at SPring-8. The
LaNi5Dx sample was kept in pressure-resistantcontainers at a constant D2 presser of 1MPa. The
S(Q) was obtained from the scattering intensity after
various corrections of the background, absorption
and multiple scattering, and normalization with avanadium rod. Reverse Monte Carlo (RMC)
simulation [2] was carried out through fitting to theneutron and X-ray S(Q)s. A starting configuration of
5000 atoms with appropriate composition, randomly
distributed in a cube box of length of 3.86 nm, wasused. To ensure a physically realistic configuration,
the closest distances between two atoms (D-D, D-La,
D-Ni, La-La, La-Ni and Ni-Ni) allowed to approacheach other were determined from the experimental
total distribution functions.
Fig. 1 shows neutron and X-ray total structure
factors calculated from the RMC model for
amorphous LaNi5D3.3, compared with theexperimental S(Q)s .The RMC configuration shownin Fig. 2 (a) gave detailed information about theoccupational sites of the deuterium atoms. It was
found that over 90% of the deuterium atoms locate
in the tetrahedral sites consisting of La and/or Ni
atoms. The fraction of the deuterium atoms in thetetrahedral sites (4La, 3La+1Ni, 2La+2Ni, 1La+3Ni
and 4Ni) was obtained. It was found that about 80%of the deuterium atoms occupy tetrahedral sites
consisting of 3La+1Ni and 2La+2Ni.

3
X-rays
RMC

2
1
0
-1
0

50

100

150

200

Q(nm -1)

Fig. 1 Neutron and X-ray total structure factors
calculated from the RMC model (dashed lines) for
amorphous LaNi5D3.3, together with the experimental
S(Q)s (solid lines).

(a)

(b)

(c)

Fig. 2 (a) Atomic arrangements of the RMC model for
amorphous LaNi5D3.3. Large spheres are La, medium
spheres are Ni atom and small spheres are D atoms.
Local environments around Ni atoms: trigonal prisms(b) and Archimedian antiprisms (c), respectively.

Voronoi polyhedral analysis has been performedon the RMC configuration of metal atoms. It was
found that trigonal prisms and Archimedian
antiprisms, which are shown in Fig. 2 (b) and (c),respectively, are dominant around Ni atoms inamorphous LaNi5D3.3.
References
1) H. Fujii, S. Munehiro, K. Fujii and S. Orimo, J.
Alloys Comp., 330-332 (2002) 747-751
2) R. L. McGreevy, L. Pusztai, Molec. Sim. 1(1988) 359-367.

141

Structural Observation of Li2S-GeS2 Glasses
K. ITOH, K. M. SONOBE, K. MORI, M. SUGIYAMA and T. FUKUNAGA
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, JapanT ( r ) � 4�r� �

2� Q �S (Q ) � 1�sin QrdQ ,
� 0
�

(1)

where � is the average number density of atoms.
Figure 1 shows the total correlation functions,T(r), for (Li2S)x(GeS2)100-x glasses derived from theFourier transformation of the structure factors. The
T(r) for x=0 has the strong positive peak at 0.223 nm
and this peak can be identified as arising from Ge-S
nearest-neighbour correlations through comparing
with the structure of GeS2 crystal [12]. The
coordination number of S atoms around a Ge atom,which was calculated from the area under the peak,
was estimated to be 4.0 atoms. This result agrees
well with that in previous neutron diffraction study

142

1000
500

x=0

0
1000
500

x=20

T(r) (nm-2)

0
1000
500

x=30

0
1000
500

x=40

0
1000
500

x=50

0
0

0.1

0.2

0.3

0.4

0.5

0.6

r (nm)

Fig. 1 The total correlation functions, T(r), for(Li2S)x(GeS2)100-x glasses
2000(Li2S)50(GeS2)50 glass

1500
1000

T(r) (nm-2)

Li-containing sulfide glasses with high lithium
ion conductivity are of technological importancebecause of their potential application in solid-statelithium secondary batteries. A lot of studies havebeen performed on these glasses [1-9]. In order tounderstand the transport mechanism, it is important
to investigate their structure and make clear theenvironment of mobile Li ions. In this work, we
tried to synthesize Li2S-GeS2 glasses by mechanicalalloying (MA) and investigated their structure by thetime-of-flight neutron diffraction technique.
(Li2S)x(GeS2)100-x glasses were prepared withcompositions of x=0, 20, 30, 40 and 50. Li2S powder(Furuuchi Chemicals, 99.9%) and GeS2 powder(Furuuchi Chemicals, 99.999%) were mixed at thedesired composition and put into a stainless steel
vial with 30 SUS balls (10 mm in diameter). The
MA treatment was carried out by a planetary ballmill (Fritsch, P-5) under high purity argon gas
atmosphere.
The neutron diffraction measurement was
carried out using HIT-II spectrometer. Each sample
was put into a TiZr zero-alloy cell of inner diameter
8.0 mm with 0.3 mm wall in thickness under argon
gas atmosphere. The structure factor, S(Q), wasderived through applying various kinds ofcorrections to the background, absorption [10] andmultiple scattering [11], and normalizing with aincident neutron beam profile. The total correlation
function, T(r), can be derived from the Fouriertransformation of S(Q) as follows,

500

1000
500
0
0

0.1

0.2

0.3

0.4

0.5

0.6

r (nm)

Fig. 2 The peak fit to the total correlation functionfor (Li2S)50(GeS2)50 glass and its residual. The
positive peak and the negative peak correspond to
the Ge-S and Li-S correlations, respectively.

[13] and indicates that GeS4 tetrahedra form thefundamental framework of GeS2 glasses, in which
there are edge-sharing and corner-sharing GeS4
tetrahedra. The position of the Ge-S correlation peakslightly decreases with increasing Li2S content.
The positive peak at 0.294 nm in the T(r) for the
GeS2 glass, which corresponds to the Ge-Ge
correlations of the edge-sharing GeS4 tetrahedra,
drastically disappeared with increasing Li2S content.
Moreover, the shoulder peak around 0.34 nm
corresponding to the Ge-Ge correlations of thecorner-sharing GeS4 tetrahedra gradually decreased
in intensity with increasing Li2S content. The
disappearance of the Ge-Ge correlations leads us toanticipate a break of the connections of the GeS4
tetrahedral network.
The negative peak appears and grows around 0.25
nm with increasing Li2S content. Since Li has anegative coherent neutron scattering length and the
Li-S distance in a Li2S crystal is 0.247 nm [12], thisnegative peak can be recognized to be Li-S
nearest-neighbour correlations.
The shoulder peak around 0.36 nm in the T(r) for
x=0 is attributed to S-S correlations of the GeS4
tetrahedra judging from the structure of GeS2 crystal[12]. This peak exists apparently even in(Li2S)x(GeS2)100-x glasses. This result indicates thatthe skeleton structure is built up by the GeS4
tetrahedra in (Li2S)x(GeS2)100-x glasses.
The T(r) for (Li2S)50(GeS2)50 glass has the
positive peak at 0.222 nm and the negative peak at
0.25 nm. These can be recognized to correspond to
the Ge-S and Li-S nearest-neighbour correlations,
respectively. However, the right side of the positive
Ge-S correlation peak overlaps with the left side of
the negative Li-S correlation peak. Then, in order toseparate these peaks, the peak fitting was performedon the T(r) by approximating with Gaussian
distribution functions through a least square fitting
method. The fitting result is represented in Fig. 2.
The coordination number of S atoms around a Ge
atom, NGe-S, and that of S atoms around a Li atoms,
NLi-S, which were calculated from the area under theGaussian peaks, are 3.9 and 3.2 atoms, respectively.
The NGe-S indicates that Ge atoms are tetrahedrally
coordinated by S atoms. That is, we can recognizethat GeS4 tetrahedra form the fundamental
framework of the structure of (Li2S)x(GeS2)100-x
glasses. However, the Ge-Ge correlations of theedge-sharing and corner-sharing GeS4 tetrahedra,
which are observed at 0.294 nm and around 0.34 nm
in the T(r), respectively, disappeared and decreased
in intensity with increasing Li2S content. Therefore,

the results allow us to recognize that the connectionof the GeS4 tetrahedral network were broken byalloying Li2S by GeS2 and non-bridging S atoms
located at the corner of GeS4 tetrahedral unit
increased in number. For example, assuming thatevery S atom is bonded to at least one Ge atom, two
non-bridging S should be created by adding one
Li2S unit into the GeS4 tetrahedral network. Hence
GeS4 tetrahedra consist of 33% with bridging S and
66% with non-bridging S in the composition of
x=0.5. Thus corner-sharing GeS4 tetrahedra with alarge amount of non-bridging S atoms are dominant
in the structure of (Li2S)x(GeS2)100-x glasses. The
NLi-S apparently indicates that Li ions arecoordinated by three S atoms, which are mostly
non-bridging S.
References
1) M. Ribes, B. Barrau, J. L. Souquet, J. Non-Cryst.
Solids, 38-39 (1980) 271-276
2) J. L. Souquet, E. Robinel, B. Barrau, M. Ribes,
Solid State Ionics, 3-4 (1981) 317-321
3) A. Pradel, T. Pagnier, M. Ribes, Solid State
Ionics, 17 (1985) 147-154
4) D. L. Price, A. J. G. Ellison, J. Non-Cryst. Solids,
177 (1994) 293-298
5) J. H. Lee, A. Pradel, G. Taillades, M. Ribes, S. R.
Elliott, Phys. Rev. B56 (1997) 10934-10941
6) S. R. Elliott, Solid State Ionics, 105 (1998) 39-45.
7) H. Morimoto, H. Yamashita, M. Tatsumisago, T.
Minami, J. Am. Ceram. Soc. 82 (1999) 1352-1354
8) A. Hayashi, S. Hama, H. Morimoto, M.
Tatsumisago, T. Minami, J. Am. Ceram. Soc. 84(2001) 477 -479
9) M. Tatsumisago, S. Hama, A. Hayashi, H.
Morimoto, T. Minami, Solid State Ionics, 154-155(2002) 635-640.
10) H. H. Paalman and C. J. Pings, J. Appl. Phys. 33(1965) 2635-2639
11) I. A. Blech and B. L. Averbach, Phys. Rev. 137(1965) 1113-1116.
12) P. Villars and L. D. Calvert : Person’s
Handbook of Crystallographic Data for Intermetallic
phases (American Society for Metals, 1985).
13) I. Petri, P. S. Salmon, J. Non-Cryst. Solids,
293-295 (2001) 169-174

143

Atomic Configuration of Metal Atoms in Amorphous (Ti0.676Zr0.324)D0.31 Studied by
Reverse Monte Carlo Modeling
K. ITOH, K. AOKI* and T. FUKUNAGA
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan* Kitami Institute of Technology, Koencho-165, Kitami, Hokkaido 090-8507, Japan

144

6
4
neutrons

2

g(r)

0
-2

4
X-rays200

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
r (nm)

Fig. 1 The pair distribution functions, g(r), foramorphous (Ti0.676Zr0.324)D0.31 observed by neutron
and X-ray diffraction.
6
neutrons
RMC

4
2
0
S(Q)

Both Ti and Zr are important elements forhydrogen storage materials because of their strong
affinities for hydrogen. A Ti-Zr alloy system isisomorphous and its structure is hexagonalclose-packed (h.c.p) [1] where Ti and Zr atoms are
distributed randomly [2]. In this work, the reverse
Monte Carlo (RMC) modeling method was applied
to the neutron and X-ray diffraction data in order todetermine the atomic configuration of metal atoms
in amorphous (Ti0.676Zr0.324)D0.31 synthesized bymechanical alloying under deuterium gas
atmosphere. It is noteworthy that a neutronzero-scattering alloy can be obtained withcomposition Ti0.676Zr0.324 because of negative andpositive coherent scattering length of Ti and Zr,
respectively. Additionally, X-ray diffraction has agreat advantage in observing the arrangement of Ti
and Zr atoms because of much lager scatteringfactors of Ti and Zr atoms than that of D atom.
Therefore, combined use of the neutron and X-ray
diffraction data in the RMC modeling will allow us
to obtain the three-dimensional atomic configurationof amorphous (Ti0.676Zr0.324)D0.31.
Amorphous (Ti0.676Zr0.324)D0.31 was synthesized bymechanical alloying under deuterium gas
atmosphere. The neutron diffraction measurement
was carried out by using the HIT-II spectrometer.
The X-ray diffraction measurement was carried out
by the RIGAKU RINT-Ultima with Mo-K�
radiation. After various corrections, the scattering
intensity was converted to the total structure factor,
S(Q). The pair distribution functions, g(r), can bederived from the Fourier transformation of the S(Q).
Reverse Monte Carlo (RMC) simulation [3] wascarried out through fitting to the neutron and X-ray
S(Q)s. A starting configuration of 4000 atoms withappropriate composition, randomly distributed in a
cube box of length of 3.95 nm, was used. To ensurea physically realistic configuration, the closest
distances between two atoms (D-D, D-Ti, D-Zr,
Ti-Ti, Ti-Zr and Zr-Zr) allowed to approach eachother were determined from the experimental total
distribution functions.
Fig. 1 shows the pair distribution functions, g(r),6
4

X-rays
RMC

2
0
0

50

100

150

-1

Q (nm )

Fig. 2 Neutron and X-ray total structure factors
calculated from the RMC model (dashed lines) for
amorphous (Ti0.676Zr0.324)D0.31, together with theexperimental S(Q)s (solid lines).

0around Ti

Voronoi index

Voronoi index

0 4 4 5 0 0
0 5 2 5 0 0
0 3 6 0 0 0
0 2 8 0 0 0
0 4 4 2 0 0
0 1 10 2 0 0
0 0 12 0 0 0
0 3 6 1 0 0
0 4 4 4 0 0
0 3 6 4 0 0
0 3 6 2 0 0
0 4 4 3 0 0
0 3 6 3 0 0
0 2 8 2 0 0
0 2 8 1 0 0

0.05

0.1

0.15

fraction

0 5 2 6 0 0
0 4 4 6 0 0
0 2 8 0 0 0
0 2 8 4 0 0
0 4 4 5 0 0
0 3 6 2 0 0
0 2 8 3 0 0
0 4 4 3 0 0
0 0 12 0 0 0
0 4 4 4 0 0
0 3 6 3 0 0
0 1 10 2 0 0
0 2 8 1 0 0
0 3 6 4 0 0
0 2 8 2 0 00around Zr

0.05

0.1

0.15

fractionFig. 3 Fractions of Voronoi polyhedra around Ti and Zr atoms obtained from the RMC configuration of metal atoms foramorphous (Ti0.676Zr0.324)D0.31.

for amorphous (Ti0.676Zr0.324)D0.31 observed byneutron and X-ray diffraction. The neutron g(r)shows a negative peak around 0.18 nm and apositive peak around 0.20 nm. Since the X-ray g(r)has no peak in this region, these peaks can berecognized to be metal–D or D-D correlations.
Moreover, it is clearly understood that the negative
peak is attributed to Ti-D correlations and thepositive peak attributed to Zr-D and D-D
correlations, respectively, because of the negative
coherent neutron scattering length of Ti. A negative
peak was again observed in the vicinity of 0.30 nm
in the neutron g(r). In the X-ray g(r) a first peak isdefinitely observed at same distance. Therefore, we
can easily recognize that this peak is attributed to
Ti-Zr correlations. Positive peaks which locate theleft side and the right side of the negative peak in theneutron g(r) can be concluded to be attributed toTi-Ti and Zr-Zr correlations through theGoldschmidt radii of Ti and Zr atoms, respectively.
Calculated total structure factors from the RMC
model(dashedlines)
foramorphous(Ti0.676Zr0.324)D0.31 are shown in Fig. 2, together withthe experimental S(Q)s (solid lines). Excellent fitswith both neutron and X-ray diffraction wereobtained. Voronoi polyhedral analysis has been
performed on the RMC configuration of metal atoms.

Fig. 3 shows the fraction of Voronoi polyhedra
around Ti and Zr atoms. Icosahedral polyhedra (00
12 000) and isosahedron-like polyhedra (028100),(028200), (01 10 200) and (036300) are observed
both around Ti and Zr atoms. The sums of thefractions of these polyhedra are more than 40%. The
result indicates the presence of a lot of
icosahedral-like clusters in the configuration of
metal atoms.
References
1) P. Villars and L. D. Calvert : Person’s Handbookof Crystallographic Data for Intermetallic phases(American Society for Metals, 1985).
2) T. Fukunaga, S, Shibuya, K. Suzuki, J. Mat. Sci.
Lett., 6 (1987) 1435
3) R. L. McGreevy, L. Pusztai, Molec. Sim. 1(1988) 359-367.

145

Neutron Scattering Studies on Relaxation and Excitation Phenomena in Structurally Aperiodic
System by LAM-40
� Study of low frequency protein dynamics on LAM-40 at KENS; hydration, boson peak and �
dynamical transition �
H. NAKAGAWAA, Y. JOTIB, A. KITAOB, K. SHIBATAA, N. GOA and M. KATAOKAA,Cab

Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195
Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi, Tokyo, 113-0032
cGraduate School of Materials Science, Nara Institute of Science and Technology, Nara, 630-0192

Protein works in solvated condition in a cell.
Hydration environment affects the protein dynamics
as well as its biological function [1]. To understandthe molecular mechanism of the protein function,
the hydration-related dynamical properties should beclarified. The boson peak and the dynamicaltransition are two characteristic features of protein
dynamics. The previous extensive theoretical andexperimental studies showed that these phenomena
are dependent on hydration [2,3,4,5].
In 2005, our group has examined thehydration-related protein dynamics with LAM-40.
The beamtime assigned was 35 days in total. The
major subjects we pursued are as follows,
1, Protein boson peak2, Protein dynamical transition
3, Hydrated water dynamics at the protein
dynamical transition
The low energy neutron spectroscopy has beenmeasured with dehydrated and hydrated powder
proteins of Staphylococcal nuclease (SNase), which
has been used for neutron scattering experiment inour group [5]. The purified protein was dialyzed
against pure water and lyophilized. This lyophilized
powder was used as the dehydrated sample. In orderto prepare the hydrated powder sample, thelyophilized powder was equilibrated with a D2O
solution saturated by KCl to ensure hydration. The
hydration level (g D2O/g protein) of the hydrated
samples were h=0.28. The neutron scattering spectra
were collected at an inverted geometry
time-of-flight (TOF) spectrometer LAM-40. Theenergy resolution from the full width of the elastic
peak is �0.2meV and the energy window is below
16meV. The scattering angles were every 16°
between16.3° and 112.3°. The length of thescattering vector Q at the elastic position ranged
from 0.4 to 2.5 Å-1. 700mg of the sample were held
in an aluminum cylinder that was 140 mm high and
14 mm in diameter. After correcting for the146

background, counter efficiency, and the incident
neutron spectrum, the observed TOF spectrum wasconverted to a differential scattering cross section
and then the dynamical structural factor S(2�,�) was
calculated. The dynamical structural factor was
symmetrized and corrected by the Bose occupation
factor and by the Debye-Waller factor [6]. Eachinelastic data was collected for 8�12 hours for eachtemperature.
1, Protein boson peak [7]Fig.1 shows the INS spectra of the dehydrated
and the hydrated proteins at 100K and 300K. These
spectra were plotted by summed up 7 spectra and theaverage Q value at the elastic scattering is 1.5 Å-1.

Fig. 1

Dynamical structural factor of dehydrated (�)and hydrated (�) SNases at 100K and 300K.
The data is corrected by the Bose-factor and the
Debye-Waller factor. The data at 300K is shiftedby 0.01 to easily compare them.

The strong peak at �=0 is the elastic scattering. At
100K an elastic peak and inelastic scattering are
observed. The protein boson peak is clearlyobserved for both samples in the inelastic region.
The peak positions are different, ~3meV for thedehydrated protein and ~4meV for the hydrated
protein. The intensity of the hydrated protein is lesspronounced. These differences were observed in
ref.1 and 8, but not fully discussed. Both samples
show almost identical spectra in the higher
frequency range, suggesting that the solvent slightly
affects the vibrational modes, while the hydration
environment significantly influences the lower
frequency modes.

Fig. 2Temperature dependence of the mean-squaredisplacement of the hydrated (�) and dehydrated (�)SNase. Solid and dashed lines indicate the linear
regression of the data between 30K and 140K (below
the transition near 150K) for the hydrated and thedehydrated SNases, respectively. The slope of the line
gives the effective force constant [10].

The Q-dependence of the elastic scattering givesa mean-square displacement of an observed protein[5]. Fig.2 shows the temperature dependentmean-square displacements. Up to approximately
150K, the mean-square displacements increaselinearly as the temperature increases. This feature
indicates that the motion is almost harmonic. In thislower temperature region, the mean-squaredisplacement of the hydrated protein is smaller thanthe dehydrated protein, which indicates that thefluctuation of the protein is suppressed by hydration.
The slope of the harmonic line gives an effective
environmental force constant, which was introducedby G. Zaccai [9]. The estimated effective force
constants of the hydrated and the dehydrated
proteins are 3.6±0.1 N/m and 3.2±0.2 N/m,respectively. The force constant for the hydrated
protein is larger than the dehydrated protein,indicating that the energy potential of the hydrated
protein is more resilient than that of the dehydrated.
A theoretical study indicated that the low frequency
collective modes dominantly contribute to the total
mean-square displacement [10, 11], and have shownthat the solvent environment makes the energy
landscape along the collective modes more rugged[2,12,13]. The present experimental results showedthat the vibrational motions of the hydrated protein
are trapped in the local minima of the rugged energy
potential at the cryogenic temperature. Consequently,
hydration shifts the boson peak position toward ahigher energy. We conclude that the low frequency
modes with the multiple minima energy landscape
are a plausible origin of the boson peak.
2, Protein dynamical transition
Above ~150K, the mean-square displacement
slightly deviates from the harmonic line, which is
independent of hydration [Fig.2]. This corresponds
to the onset of a new motion. At the higher
temperature around 240K, the mean-squaredisplacement of the hydrated protein differs from thedehydrated protein, suggesting that the additional
new motion is hydration-dependent. This isconsistent with the result that the quasielastic
scattering at 300K of the hydrated protein is moresignificant than the dehydrated [Fig.1]. A molecularsimulation with explicit water molecules shows thatwater suppresses the low frequency motion, whilewater only slightly affects the high-frequency
motion [14,15]. The Jumping-Among-Minima
model depicts the stochastic jumping motion among
several harmonic potential wells [11]. Quasielastic
scattering is observed in the energy region lower
than the boson peak, suggesting that the low
frequency modes below the boson peak are closely
related to the relaxation and/or stochastic motions,which are thought to be essential for the proteinfunction at physiological temperatures. To
characterize these motions, a quantitative analysis of
the quasielastic scattering is highly required.
3, Hydration water dynamics at the protein
dynamical transition
As mentioned above in two topics, the protein
dynamics is strongly affected by hydration. The
dynamical properties of the hydration water should147

give an essential insight into the physical pictures of
the hydration-related protein dynamics. In thissection, we report the dynamics of the hydrationwater at the protein dynamical transition. The
scattering data of the hydration water were estimatedby the subtraction of the scattering profile of a
D2O-hydrated protein from that of a H2O-hydrated
protein as follows, Swater(Q,�)= SH2O(Q,�)SD2O(Q,�). Fig.3 shows the temperature dependent
Elastic Incoherent Structural Factor (EISF) of theprotein and its hydration water. The notable point isthe deviation of the hydration water data from theprotein at around 240K, where the protein
dynamical transition appears as observed in fig.2.
The hydrated water displacement is larger than theprotein. This difference implies that water molecules
are released from the protein surface and undergo akind of diffusive motions. The previous simulation
study showed that at ambient temperature thehydration water has translational diffusive motion
on the protein surface [16], which is consistent with
our implication. Such dynamics of the hydrationwater should be closely correlated with the protein
dynamical transition. To further characterize thediffusive dynamics of the hydration water, thequasielastic scattering experiment with the higher
energy resolution is required.

Fig. 3Temperature dependent Elastic incoherent structural
factor (EISF) of protein (�) and its hydration water(�) at Q=1.5 Å-1.

In conclusion, our group has studied a series ofthree topics about the hydration-related protein
dynamics. In accordance with theoretical prediction[2], it can be shown experimentally that the protein

148

boson peak originates in the protein low frequency
modes. The boson peak is also observed withsynthetic polymers and glassy materials, which has
been studied for a long time but the origin is still
under argument. Our picture for the protein would
give an insight for the origin of the Boson peak. The
hydration dependent dynamical transition wasobserved at 240K. Some protein functions have been
observed to cease with the loss of diffusive
dynamics as the protein is cooled down below the
dynamical transition temperature [17]. So thistransition phenomenon is thought to be related withthe protein biological function. The hydration water
dynamics should be highly coupled with protein low
frequency dynamics at the dynamical transition.
The sufficient beamtime of LAM-40 was
assigned to our group in 2005 to produce fruitfulresults. This has greatly promoted our projects of thehydration-coupled protein dynamics. But thequantitative analysis of the neutron incoherent
scattering with especially high resolution is required
to analyze the remaining problems. In J-PARC
projects, we are proposing a plan to construct theinelastic neutron scattering instrument forbiomolecules. We expect this instrument contributes
to our understanding of the physical bases of life
through the elucidation of the physical anddynamical properties of various biomolecules aswell as proteins. Such studies will open the frontierof the neutron biology.
References
1) V.Kurkal et al., Biophys.J. 89 (2005) 1282.
2) Y.Joti et al., J.Am.Chem.Soc.127 (2005) 8705.
3) M.Tarek et al., J.Chem.Phys. 115 (2001) 1607.
4) M.Kataoka et al., J.Phys.Chem.Solids. 60 (1999)
1285.
5) H.Nakagawa et al., J.Phys.Soc.Japan 73 (2004)
491.
6) S.Cusack et al., Biophys.J. 58 (1990) 243.
7) H.Nakagawa et al., PhysicaB (in press)
8) M. Diehl et al., Biophys.J. 73 (1997) 2726.
9) G. Zaccai. Science 288 (2000) 1604.
10) A.Kitao & N.Go, Curr.Opin.Struct.Biol. 9 (1999)
164.
11) A. Kitao et al., Proteins. 33 (1998) 496.
12) A. Kitao et al., Chem.Phys. 158 (1991) 447.
13) A. Kitao et al., J.Phys.Chem. 97 (1993) 10223.
14) A. Kitao et al., J.Phys.Chem. 97 (1993) 10231.
15) A. Kitao et al., Chem.Phys. 158 (1991) 447.
16) M.Tarek et al., Biophys.J. 79. (2000) 3244.
17) B.F.Rasmussen et al., Nature 357 (1992) 423.

Neutron Scattering Study on Relaxation and Excitation Modes in Condensed Matters Using
LAM-D
Vibrational Excitation of Liquid GeTe mixture at the Eutectic Composition
Y. KAWAKITA, H. SHIGETA*, Y. KATO*, S.TAKEDA

2. Experimental Procedures
Inelastic neutron scattering experiments of liquid
Ge15Te85
were
performed
using
LAM-D
spectrometers also installed at KENS, which isinverted-geometry time-of-flight spectrometer withthe final neutron energy of 4.59meV by Blagg
reflection with PG002 mirrors and the energy
resolution about 0.5meV. The sample was shield ina thin-walled quartz glass tube with an innerdiameter of 10mm, a coaxial length of 100mm and awall thickness of 0.3mm. High temperatures weregeneralized v–DOS (arb. u.)

1. Introduction
Binary alloy system between Ge and Te shows
an eutectic-type phase-diagram around thecomposition of 15 at.% Ge. At this composition, thestatic structure has strong temperature dependency[1-3]. Neutron diffraction [2] and EXAFS [3]measurements suggest that Ge-Te bonding iselongated and the number of atoms covalently
bound to a Ge atom decreases with increasing
temperature from the melting point. This structuralchange is accompanied by volume contraction [4] inspite of the loose bonding of Ge atom and causes astrong temperature dependence of viscosity [5]. Thistendency may be related to the conformation of Te
atoms,
since,
inpure
liquidTe,semiconductor-to-metal transition accompanied byvolume contraction occurs around the similar
temperature range[6,7].
Following the investigation on this structuralchange for the eutectic liquid Ge15Te85 using HIT-II[3], quasi-elastic and inelastic neutron scatteringexperiments by using LAM-40 and LAM-D
spectrometers were performed in KENS. The
vibrational density-of-states were deduced from thespectra measured by LAM-D and the dynamical
structure factors were obtained from LAM-40
experiments. The results of quasi-elastic neutron
scattering experiment by LAM-40 spectrometer arepresented as B1 report elsewhere in this volume.

0.003

generalized v–DOS (arb. u.)

Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu
Chuo-ku,Fukuoka 810-8560*Department of Condensed Matter Chemistry and Physics, Graduate School of Sciences, Kyushu
University , 4-2-1 Ropponmatsu Chuo-ku,Fukuoka 810-8560

0.002

liquid Ge 15 Te85 480C in SiO 2 cell

0.002

solid Ge 15 Te85 R.T. in SiO 2 cell
SiO 2 cell 480C

0.001
0
0

10

20

30

E(m eV)

0.001

0
0

liquid Ge 15Te85 in SiO 2 cell
560C
480C
440C
400C

20

40

E(m eV)

Fig.1 (a)(Top) Generalized vibrational densityof state for Ge15Te85 in the solid phase at theroom temperature (denoted by violet dots) andthe liquid phase at 480ºC (denoted by red dots)
obtained from 80º scattering from the sample
containing into the quartz cell. The cell
contribution has not been subtracted yet. The
cell spectrum at 480ºC is also plotted by blackdots.
(b) (Bottom) Generalized vibrational densityof state for liquid Ge15Te85 obtained from 40º
scattering from the sample containing into thequartz cell. The cell contribution has not been
subtracted yet.

149

achieved by using electrical heater. The measured
temperature points were five from 400 to 560ºC witheach 40ºC interval. In addition of this experiment,
3. Results and discussion
Figure 1 shows the generalized vibrational
density of state, gv-DOS, of liquid Ge15Te85. In the
figure (a), the spectra obtained from 80º scatteringfrom the sample containing into the quartz cell in thesolid phase at the room temperature and the liquid
phase at 480ºC are shown together with thespectrum of the cell. For the solid phase, one can see
three peaks around 7, 11 and 17 meV which are
different from the cell contribution. Those are very
similar to gv-DOS of the pure liquid Te [7] where
the three peaks are assigned as tortional-, bendingand stretching modes in the covalently bonding Te
chain molecule. For the supercooled liquid state ofpure Te, such three modes persist in gv-DOS,
however above the melting temperature after
occurring semiconductor-to-metal transition, thestretching mode goes remarkably down in the
excitation energy to 16meV and rather smearing [7].
In the case of liquid Ge15Te85, the stretching mode
persists in the all temperature from the 400 to 560ºC
and slightly decreases in the excitation energy withincreasing temperature, as shown in the figure (b). It
should be noticed that the bending mode which isobserved around 10 meV in the supercooled liquid
Te disappears in the spectra of liquid Ge 15Te85. Thisshould be strongly related to the conformation of Te
chain if exists in the liquid Ge15Te85, although wecannot construct structural model for liquid Ge15Te85
in the present stage
References150

Neutron Scattering Studies on Relaxation and Excitation Phenomenain Structurally Aperiodic
System by LAM-40—— Dynamics of molten Cuprous halides ——Y. KAWAKITA, Y. KATO*, H. FUJII, S. TAKEDA and K. SHIBATA#
Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuoku,Fukuoka 810-8560*Department of Condensed Matter Chemistry and Physics, Graduate School of Sciences, Kyushu
University , 4-2-1 Ropponmatsu Chuo-ku,Fukuoka 810-8560#Pulsed Neutron Instrumentation Research Group,Neutron Technology Development ResearchCenter,Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA),Tokai-mura, Naka-gun,Ibaraki-pref 319-1195, Japan
CuBr and CuI is well-known to exhibit thesuperionic behaviour in the high temperature solidstate, where the mobile Cu ions migrate between thesites in the sublattice of immobile halogen ions [1].
As for the static structure factors of molten cuprous
halides, several workers have reported for theinteresting structural properties on these molten state[2-6]. The most significant feature in the partial
structure factors of molten CuCl [2,3] and CuBr
[5,6] is a structureless profile in Cu-Cu pairs
correlation, which is different from the cation-cation
correlations in typical molten salt such as alkali
halides. However, Waseda et al. [6] reported that
Cu-Cu partial structure of molten CuI, obtained byanomalous X-ray scattering measurements and withaid of the Reverse Monte Carlo (RMC) simulation,
has a first sharp diffraction peak at 0.9 Å-1. In thereal space, the Cu-Cu distribution significantly
penetrates into the nearest neighboring shell which
is mainly contributed by Cu-I correlation. Recently
Shimojo et al. [7] pointed out that there is somepossibility of covalent character between Cu-Cu
pairs in addition of Cu-I pairs in molten CuI fromtheir ab initio molecular-dynamic simulations. We
also suggest the structure model of molten CuI using
RMC simulation based on neutron diffraction
spectra measured utilizing HIT-II spectrometer andhigh-energy X-ray by BL04B2, SPring-8 [8]. Fig
1(a) shows the atomic arrangements for molten CuI,
generated by RMC structure modelling procedure.
The only Cu distribution in the same model is shownin Fig.1(b). Large density fluctuations of Cu ionsexist and Cu ions bonded with each other look form
one-dimensional streams, which may be consistent
with the reaults of the ab initio MD simulation by
Shimojo et al [7], although they showed much larger(a)(b)
Fig.1 Structure model obtained by RMC simulation
using neutron and x-ray diffraction data. (a) CuI
structure model where Cu ions are denoted by small
particles and I are done by large particles. (b) Cu
distribution is extracted from the model (a). Sticks areattached to the Cu-Cu pairs within 3.0Å distance.

Fig.2 Dynamical structure factors for molten CuI at
650ºC.
fluctuations in the Cu distribution.
The bonding character of Cu-I and Cu-Cu pairs
appears intermediate between ionic and covalentbonds, which may affect on ionic motion. We have
performed quasielastic neutron scattering (QENS)

151

measurements of molten CuI at 650ºC using
inverted geometry TOF spectrometer, LAM-40
installed at KENS. The energy of final neutron was
4.59meV by Blagg reflection with PG002 mirrors
and the achievable wavenumber space was from 0.2
to 2.6Å-1 with energy resolution of about 0.2meV.
The sample was shield in a thin-walled quartz glass
tube with an inner diameter of 10mm, a coaxial
length of 100mm and a wall thickness of 0.3mm.
High temperature was achieved by using electricalheater with Nb foil heater-element.
To extract the dynamic structure factor, S(Q,E),
from the TOF-spectra for LAM-40, a backgroundcontribution was carefully removed and thescattering contribution from the container material

4
3
2

total

1
Lorentz 1

S(Q)magnitude (arb. u.)

5

0.5

1
Lorentz 2
0
0

1

0

2

–1

Q(A )
Fig 3. The results (magnitude) of curve-fitting
procedure using two Lorentz functions withnaroow (solid circle) andbroad (opentriangles) widths. The open circles denote the sumof them and solid line describes static structure
factors by neutron diffraction. Closes is the resultsof one Lorenzian fitting.
3
2

S(Q)

0.5

S(Q)

HWHM (meV)1

1
Lorentz 1
0
0

1

–1

2

0

Q(A )

Fig.4 Energy width (HWHM) of the narrow
Lorentz function in the curve-fitting procedureshown in Fig.3.

152

was subtracted taking into account an absorption
correction due to the sample and the cell. Counter
efficiency was considered using the spectra of
vanadium standard sample. Each spectrum was
normalized to the incident intensity.
Fig. 2 shows the dynamical structure factors ofmolten CuI. One can see the large elastic
contribution at around 0.9 Å-1 due to Cu-Cu
correlation. The reason for absence of spectra in the
Q region from 1.5 to 2 Å-1 is that 4th detector andamplifier were affected by large white electricalnoise.
Preliminarily, curve-fitting procedure of quasielastic peaks has been performed using two Lorentz
functions with narrow and broad widths. The
magnitude of narrow function shows Q-dependence
similar to that of the static structure factor while thatof broad function almost shows no Q-dependence.
The latter might be largely contaminated bymultiple-scattering process, which is estimated as
about 20% of total scattering. From the knowledgeof partial structure factors, narrow Lorentz function
is mainly contributed by Cu-Cu correlation. Theenergy width of this function does not exhibit any
narrowing around the maximum of the prepeak in
S(Q) at 0.9 Å-1, although it is already quite narrowcomparable to energy resolution of 0.2meV.
On the other hand, dynamical structure factors
obtained by inelastic X-ray scattering (IXS)
measurements [9] exhibit a cusp-like shape of quasielastic scattering at around 1.8 Å-1 where a strong
peak can be seen in x-ray diffraction spectrum. Thiscusp shape cannot be reproduce by single Lorentzianor Gaussian. For neutron scattering, the coherent
scattering cross section of Cu is about twice larger
than that of I (Cu;7.49 barns, I;3.50barns), sothat the scattering intensity emphasises thecorrelation including Cu ions. On the other hand, thenumber of electrons in I atom is about twice larger
than that of Cu atoms (I;53, Cu; 29), so that
the X-ray scattering emphasizes the correlation
including I ions. One can see a broad peak in a
relative high Q region beyond 2 Å-1 in QENS.
Mutual diffusion of I-I correlation may be muchslower than that of Cu-Cu one as ab-initio
simulation exhibits [7]. Therefore, delta-function
like contribution of I-I correlation may superimpose
the broad quasi-elastic scattering of Cu-Cu. For IXS,
the former has much strong intensity and then total
scattering possibly looks cusp-like shape withcoupling by energy resolution (1.8meV for IXS).
We have already partial static structures ofmolten CuI by using ND and XRD with the help of

RMC simulation and two dynamical structure
factors by QENS and IXS. We will proceed
quantitative calculation of partial dynamical
structures with the help of dynamical simulation
methods such as ab-initio MD and traditional MD to
make clear the ionic motions in molten CuI where
essential dynamical properties for super-ionic
conduction phenomena still remains in the molten
state.

References[1] J.B. Boyce et al., Phys.Rev. B23 (1981) 2876.
[2] D. I. Page and K. Mika, J. Phys. C: Solid State
Phys. 4 (1971) 3034-3044.
[3] S. Eisenberg et al., Phil. Mag. A46 (1982) l95.
[4] Y. Shirakawa et al., J. Phys. Soc. Jpn. 60 (1991)
2678.
[5] D. A. Allen and R. A. Howe, J. Phys.: Condens.
Matter 4 (1992) 6029-6038.
[6] Y. Waseda et al., J. Phys. Soc. Phys. Condens.
Matter 12 (2000) A195.
[7] F. Shimojo et al., J. Phys. Jpn. 73 (2004) 2148.
[8] S. Takeda, H. Fujii, Y. Kawakita, Y. Kato, S.
Kohara and K. Maruyama, Physica B 385-386(2006) 249-251.
[9] S. Takeda, Y. Kawakita, T. Enosaki, K. Ohshima
and S. Hosokawa, SPring-8 User Experiment Report,
No.8(2001B) p.143 / Y. Kawakita, S. Takeda, S.
Hosokawa, T. Enosaki, K. Ohshima, W.-C. Pilgrim,
A.Q.R. Baron, Y. Tanaka and S. Tsutsui in
preparation

153

Possible Observation of Local Structure by Neutron Resonant Scattering in Single Crystal AgCland AgBr
M. KOFU, T. YOKOO and Y. KAWAKITA*
Neutron Science Laboratory, Institute of Materials Structure Science,High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801*Graduate School of Science, Kyushu University, Fukuoka, 810-8560
Neutrons are resonantly absorbed by someatomic nucleus at characteristic resonant energies.
The lowest resonant energy of 109Ag corresponds to~5eV and neutron scattering cross section isenhanced as well as absorption cross section. (SeeFig.1), which is generally called “anomalous
dispersion” (AD). Utilizing AD in the compoundcontaining neutron absorbing atoms such as silver,
gold, cadmium and so forth, the observation of local
structure of those atoms was attempt. Scatteredneutron intensity from the compounds is expected tofollow the scattering cross section of absorbing
material (NA) because most of the scattering from
non-absorbing atoms might be absorbed by NAs.
Thus, we can see the diffraction only from enhanced
scattering cross section of NA atoms.
Anomalous scattering of 109Ag using single
crystals of binary compound AgCl and AgBr were
measured. Neutron measurements were performedon the EXCED, which is the diffractometer utilizing
epithermal neutron.
Both AgCl and AgBr have NaCl-type structure
and reflections appear at (hkl) (h,k,l = all even orodd).; the structure factor of even reflection isdifferent from that of odd one. For (111) and (222),
we calculate energy dependence of expected
observed intensity. Note that we take into accountthe absorption effect due to sample configuration inthis calculation. As seen in Fig.2, the calculated
intensities just above the resonant energy enhance,
indicating the anomalous dispersion. We also show
the energy dependence of observed intensities in Fig.
2. Here the scale is adjusted. To estimate intensities,
we carried out the following procedures. (i) We
choose 1 pixel among position sensitive detectors,
which shows the highest intensity. (ii) We read theintensities at the certain energy that is derived fromthe values of scattering vector Q, flight path length
L and scattering angle 2 . (iii) The intensities are4
corrected by Lorentz factor/sin2 . In both
AgCl and AgBr cases, the observed intensities
around ~6 eV is higher than those around ~4 eV as
expected, although the differences are lied withinerror bars.
154

Fig. 1 Energy dependence of cross sections of 109Ag

Fig. 2 Calculated intensities (lines) and observed intensities(circles) for (111) and (222) reflections

We note that the correction by Lorentz factor we
performed is not exactly correct. This formula4/sin2 is applied to the integrated intensities overwavelength for fixed single crystal. In the present
analysis, we do not integrate intensities. As neutronenergy increases, the energy resolution E becomeslarge. We consider that the intensities below 2 eVfor (222) reflection of AgBr deviate upwards due tothis inadequate Lorentz correction.

155

QENS Study of Amorphous Poly(vinyl acetate) below Tg
I. TSUKUSHI and T. KANAYA*
Faculty of Engineering, Chiba Institute of Technology, 2-1-1 Shibazono, Narashino, Chiba, 275-0023*Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011
Amorphous atactic poly(vinyl acetate) (aPVAc) shows a quesielastic scattering (QENS)
such a low temperature at 75 K. We haverevealed the QENS due to the methyl rotation
motion. In this study, we compared the methyl
hydrated a-PVAc with methyl deuterated one by
neutronscatteringexperiment.
Themeasurement was carried out with LAM-80ET
at KEK, Tsukuba in an energy range between
0.01 and 0.5 meV.

motion was not observed in the methyl
deuterated a-PVAc.

1.0

a-PVAcel

I (T) / el (10K)

0.90

0.80

0.70

0.60

= 15eVQ = 1.2 Å -1

0.50

a-PVAc(-CD )Fig. 2

3

a-PVAc(-CH )Dynamic scattering law of a-PVAc.

3

0.40
0

50

100

150

200

250

300

350

T /K

Fig. 1 Temperature dependence ofelastic scattering intensity of a-PVAc.
Fig. 1 shows the temperature dependence ofelastic scattering intensity of a-PVAc. The
elastic scattering intensity at T K (Iel(T)) was
divided by Iel(10 K) to reduce the effects ofcoherent scattering.
The elastic scattering
intensity of the methyl hydrated a-PVAc began
to deviate from the linear relation above 50 K
and re-deviate from above 270 K. On theother hand, the deviation from linear relation
was only at around 250 K for the methyl
deuterated one. These deviations show thatsome new pico-second order motions occur ataround 50 K and 250-270 K, respectively. In
a-PVAc, the new motion at around 50 K is dueto the methyl rotational motion because this156

Fig. 2 shows the dynamic scattering law S(Q,)
of a-PVAc hydrated methyl anddeuterated methyl at 75 K. The QENS wasobserved in hydrated methyl sample but not thedeutrated methyl one. In the methyl hydrated
a-PVAc, we observe molecular motion
including methyl groups motion. On the other
hand, the methyl groups motion is not observedin methyl deuterated one. This shows that the
methyl rotation motion occurs in the time scale
for pico-second order which is observed in=15 eV). We have also
LAM-80ET (confirmed the QENS at 75K due to the methyl
rotation motion. On the basis of the data
fitting, the estimated activation energy of themethyl rotation motion is 3.7 kJ/mol. This value
is consistent with the results from othermeasurement techniques such as NMR et. al.

Low-Energy Dynamics in Typical and Untypical Network Silicate Glasses:
Silica (SiO2) and Forsterite (Mg2SiO2)
K. SUZUYA, S. KOHARA* and K. SHIBATA
Quantum Beam Science Directorate, Japan Atomic Energy Agency,
Tokai-mura, Naka-gun, Ibaraki, 319-1195*Japan Synchrotron Radiation Research Institute, Sayo-cho, Sayo-gun, Hyogo 675-5194
v-SiO2 andtemperature.

v-Mg2SiO4

obtainedatambient0.25
Q = 0.23 - 2.09 Å-1

Silica glass
Smoothing
Forsterite glass
Smoothing

0.2

S(Q, E) (a.u.)

Vitreous forsterite (v-Mg2SiO4) is an important“prototypical” orthosilicate for earth’s magmas in
the upper mantle and a model system for
non-equilibrium low-silica-content binary melts.
The structure of v-Mg2SiO4 results entirely fromconnectivity of Mg-O polyhedra (mainly distorted
MgO5 polyhedra) that provide the networks with no
SiO4 chains or closs-linked networks suggested byreverse Monte Carlo (RMC) modelling using a
combination of neutron and high-energy X-ray
diffraction data [1]. The low-energy dynamics
termed the Boson peak, universal feature for glasses,
is expected to reflect the unusual nature of the Mg-O
network structure.
An aim of this experiment is to investigate thelow-energy vibrational spectra, dynamical structure
factors, S(Q, E) in a typical network silicate glass,vitreous silica, v-SiO2 and an unusual network glass
v-Mg2SiO4 by means of inelastic neutron scattering(INS). The primary goal is to relate the behavior ofthe dispersion relation or the localization feature,found in the INS experiments for v-SiO2, to thestrength of the Boson peak.
The INS experiments of v-SiO2 and v-Mg2SiO4
have been performed using LAM-40 spectrometer
installed at KENS, KEK, Tsukuba, Japan. LAM-40
is an inverted geometry time-of-flight spectrometerwith 7 analyzer- and detector-arms. Pyrolytic
graphite (PG) 002 reflections were employed foranalyzers to fix final energy at Ef = 4.59 meV. Glass
samples (small grains) were put into a aluminum
cylindrical container [1]. The dynamic structure
factors were deduced from the measured
time-of-flight spectra by a usual method including
normalization by incident neutron spectrum,
subtraction of background and absorption-correctionof aluminum cell and glass samples. The energy
resolution function of LAM-40 spectrometer was
estimated from vanadium standard and the FWHM
at the elastic position was E ~ 200 eV for PG 002
analyzer mirror.
Figure 1 shows the dynamical structure factors of

0.15

系列4
0.1

0.05

0
-2

0

2

4

6

8

10

12

E (meV)

Fig. 1

Dynamical structure factors S(Q, E) of SiO2
and Mg2SiO4 glasses.

The Boson peak of v-SiO2 is clearly observed at
the position of about 5 meV, this is consistent to theprevious report [2]. On the other hand, a very weak
low-energy excitation is observed at around 7 meVfor v-Mg2SiO4 and the peak position is larger thanthat of silica glass. These differences in low-energy
dynamics between v-SiO2 and v-Mg2SiO4 have been
assigned to the effects of the confinement for
network structure from open structure (SiO4
tetrahedra corner sharing network for v-SiO 2 [3]) toclosed structure (MgOX [x=4~6] polyhedra cornerand edge sharing network for v-Mg2SiO4 [1]).
References
1) S. Kohara et al., Science 303 (2004) 1649.
2) Y. Inamura et al., Physica B 284-288 (2000)
1157.
3) S. Kohara et al., J. Phys. : Condens. Matter 17(2005) S77.

157

Influence of Polytypic Structure on Low-Frequency Vibrational Mode of n-Alkanes
F. KANEKO AND H. KUBOTA
Department of Macromolecular Science, Graduate School of Science, Osaka University,
Toyonaka, Osaka, 560-0043
Aliphatic long-chain compounds such as nalkanes and fatty acids solidify into layered
structures. Depending on crystallization conditions
and their thermal history, most of these compounds
show the structural variation within a molecularlayer in terms of the lateral packing, conformation,and inclination manner of hydrocarbon chains.
Such structure variation is called polymorphism.
Besides ordinary polymorphism, some long-chain
compounds show another kind of structural variation
caused solely by a difference in the stacking mannerof molecular layers called polytypism, which is ahigher-order structural variation caused solely by adifference in the stacking manner of molecularlayers.
It has been revealed that polytypicstructures affect various solid-state properties suchas thermodynamic stability, melting point,mechanical property and so forth.
Two kinds of polytypic structures, Mon and OrthII have been found in the M011 modifications of nalkanes. Mon is a single layered structure and OrthII is a double layered one, as shown in Fig. 1.

Fig. 1.

Two polytypic structures in n-alkanes.

Recently, we investigated the thermodynamic
stability of the two polytypes by solubility
measurements and inelastic neutron scattering (INS).
The solubility measurement revealed that Orth II is
more stable than Mon, and the neutron scatteringexperiments showed that the high density state ofvibrational modes in low-frequency region mainly
contributes to the stability of Orth II [1].
In order to study the influence of polytypicstructure on vibrational modes in more detail, we
carried out inelastic neutron scattering (INS)experiments using single-crystal-mat samples of the
Mon and Orth II polytypes of n-C 36H74 M011
modification. INS spectra were measured with

158

RAC in KEK.
in Fig. 2.

Fig. 2.

The spectra obtained are reproduced

INS spectra for Orth II and Mon polytypes of nC36H74 taken with two different geometries.

In the region of 0-200 cm-1, there is no
significant difference between Mon and Orth IIconcerning the spectra with the geometry of Q // the(001) plane, whereas a clearly larger scattering
intensity is observed for Orth II with the geometrythe (001) plane. Since the (001) planeof Q
corresponds to the lamellar interface, the above
results mean that polytypism has an influence
mainly on the low-frequency modes having a large
displacement component perpendicular to thelamellar interface, which is consistent with the
crystal structures of Mon and Orth II.
Bothpolytypes have an identical structure within lamellae
and they are different only in lamellar stacking
manner.
We infer that the large INS intensity at thegeometry of Q the  plane is ascribed to thesmaller stiffness C33 component [2].
References
1) H. Kubota, F. Kaneko, T. Kawaguchi, J. Chem.
Phys. 122 (2005) 024903
2) Y. Itoh, M. Kobayashi 95 (1991) 1794.

Effects of Structural Change at Eutectic Composition in Liquid Ge-Te Mixture on the
Relaxation Process
S. TAKEDA, Y. KAWAKITA, Y. KATO*
Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu
Chuo-ku,Fukuoka 810-8560*Department of Condensed Matter Chemistry and Physics, Graduate School of Sciences, Kyushu
University, 4-2-1 Ropponmatsu Chuo-ku,Fukuoka 810-8560
Binary alloy system between Ge and Te shows
an eutectic-type phase-diagram around thecomposition of 15 at.% Ge. In the liquid state at thiscomposition, various physical properties show
anomalous temperature dependences. After melting,molar volume decreases as increasing temperatureand has a minimum at around 50ºC above themelting point, and then it starts increasing [1]. Suchvolume contraction near the melting point isobserved in pure liquid Te [2], where the electricaltransition from a semiconducting phase in thel–Ge 15Te85

S(Q)

1

390C
440C
600C

0
0

2

3

–1

Q(A )

4

supercooled liquid region to a metallic one above
the melting temperature occurs. This electricaltransition is accompanied by structural change fromlong two-fold chain molecule to short chain withstrong interchain interaction [3]. Since viscosity ofliquid Ge15Te85 decreases abruptly from a large
value at the melting point [4], the large temperaturedependence of this liquid alloy is strongly related tothe properties of liquid Te.
Of particular interest, liquid Ge15Te85 shows thestrong temperature dependence in the static structure
as reported in our previous paper [5,6] (see Fig.1).
Neutron diffraction[5] and EXAFS[6] measurementssuggest that Ge-Te bond is elongated by 0.1Å andthe nearest neighbor distribution coordinating to a
Ge atom becomes more asymmetric with increasing
temperature by only 100ºC from the melting point.
To observe this structural change from the
dynamical points of view, we have performed
inelastic neutron scattering experiments.
Quasielastic neutron scattering experiments ofliquid Ge15Te85 were performed using inverted

6

390C
440C
600C

g(r)

2

l–Ge 15Te 85 400C

S(Q,E) (arb. u.)l–Ge15Te85–1

Q (A ) at E=0
2.5
2.0

1

1.5
1.0

0
0

2

4
r(A)

6

0.5
0.25

8

Fig.1 Static structure factors (upper figure) andpair distribution functions (lower figure) of
Ge15Te85 at 390, 440 and 600ºC obtained byneutron diffraction using HIT-II soectrometer in
KENS.

–5

0
E(meV)

5

10

Fig. 2 S(2θ, E) of liquid Ge15Te85. Q values in the
figure are the momentum transfer at the elastic
position, E=0meV.

159

S(Q,E) (arb. u.)

geometry TOF spectrometer, LAM-40 installed at
KENS. The energy of final neutron was 4.59meV byBlagg reflection with PG002 mirrors and theachievable wavenumber space was from 0.2 to
2.6Å-1 with energy resolution of about 0.2meV. The
sample was shield in a thin-walled quartz glass tube
with an inner diameter of 10mm, a coaxial length of
100mm and a wall thickness of 0.3mm. The
measured temperature-points were five from 400 to
560ºC with each 40ºC interval, which were achievedby using electrical heater with Nb foil
heater-element.
To extract the dynamic structure factor, S(Q,E),
from the TOF-spectra for LAM-40, a backgroundcontribution was carefully removed and thescattering contribution from the container material
was subtracted taking into account an absorption
correction due to the sample and the cell. Counter
efficiency was considered using the spectra of
vanadium standard sample. Each spectrum was
normalized to the incident intensity. Since surface
spline interpolation on the constant Q trajectory has
not been carried out yet, and therefore we will
present the S(2θ, E) spectra in this report and denote
representative Q-value at the energy transfer of zero,
E=0.
Fig. 2 shows the dynamical structure factors ofliquid Ge15Te85 at 400ºC just above the melting point.
The static structure factor of this eutectic liquid hasa relatively large value in a low Q region below the
first peak position. There can be seen significant
quasi-elastic contribution in S(2θ, E) in a low Q
region. The elastic component of QENS has amaximum at around 2.0Å-1, where the first peak of–1

Q=2.099A

l–Ge15Te 85 560C
l–Ge15Te 85 520C
l–Ge15Te 85 480C
l–Ge15Te 85 440C
l–Ge15Te 85 400C

–50
E(meV)

5

10

Fig. 3 The temperature dependence of dynamical
structure factors for liquid Ge15Te85 at 2.0990Å-1,
near to the first peak position in S(Q).

160

S(Q) locates. One can see the narrowing of energy
width in S(2θ, E) at this Q position, called as deGennes narrowing.
To see the temperature dependence of dynamical
structure factor, the QENS spectra at 2.099Å-1,
nearest to the first peak position, are shown in Fig.3.
As increasing temperature from 400 to 520ºC, theheight becomes lower and the width becomes
broader, however, the spectra at 520 and 560ºC are
almost similar each other. This is consistent with thetemperature dependence of the static structure where
significant structural change occurs in thetemperature range from the melting point to 500ºC.
Chalcogen liquids such as Se and Te consists ofchain molecules whose length changes at thesemiconductor to metal transition. The first peak of
S(Q) of liquid chalcogen is largely contributed byinterchain correlation as well as intrachain one. Just
above the melting point, Ge atom has a relatively
high coordination from 4 for solid to 3 at 400ºC.
With increasing temperature, the coordination of Ge
atoms decreases until about 2. This means that Ge
atoms play a role of a linker for Te chain molecule
at a relatively low temperature near the melting
point, and that, with increasing temperature, Ge-Te
covalent bond weakens and interchain coupling ofTe chain molecules strengthens. The temperaturedependence of QENS may show that this breakingof network structure occurs at this temperaturedependence. Such aspect is detected by generalized
vibrational density-of-state obtained by using
LAM-D spectrometer in KENS.
References
1) Y. Tsuchiya; J. Phys. Soc. Jpn. 60 (1991), 227.
2) H. Thurn and J. Ruska; J. Non-Cryst. Solids 22(1976) 331.
3) T. Tsuzuki, M. Yao and H. Endo; J. Phys. Soc.
Jpn. 64 (1995) 485.
4) H. Neumann, F. Herwig, W. Hoyer; J.
Non-Cryst. Solids 205 (1996), 438.
5) Y. Kawakita, K. Maruyama, S. Takeda; J. Phys.
Soc. Jpn., 70 Suppl. A, (2001), 265.
6) S. Yoshioka, Y. Kawakita, M. Kanehira, S.
Takeda; Jpn. J. Appl. Phys. 38-1, (1999), 468.
7) P. G. de Gennes; Physica 25 (1959) 825 /Physics 3 (1967) 37.
8) H. Endo, T. Tsuzuki, M. Yao, Y. Kawakita, K.
Shibata, T. Kamiyama, M. Misawa and K.
Suzuki; J. Phys. Soc. Jpn. 63 (1994) 3200.

Mixing State of DMF-FA Solutions Studied by Small-Angle Neutron Scattering Technique
T. TAKAMUKU,a K. FUJII,b Y. UMEBAYASHI,b S. ISHIGURO,b and T. OTOMOca

Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering,
Saga University, Honjo-machi, Saga 840-8502, Japanb
Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki, Higashi-ku,
Fukuoka 812-8581, Japanc
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki 305-0801, Japan
with each other in the entire range of DMF mole
fraction studied. This suggests that hydrogen bonds
between DMF and FA molecules more significantly
act on the mixing state of the solutions thanself-aggregation of FA ones, as seen in DMF-NMF
solutions. Thus, DMF molecules can be embedded
into FA clusters by hydrogen bonds between theamino protons of FA molecule and the carbonyl
oxygen atom of DMF one. The homogeneous
mixing of both FA and NMF with DMF in spite ofthe different proton donating abilities of themolecules may arise from strong proton accepting
ability of DMF molecule.
1
0.1
0.01

xDMF = 0.8

1
0.1
0.01

xDMF = 0.7

1
0.1
0.01

xDMF = 0.6

1

Icorr.(Q)/ barns

An N,N-dimethylformamide (DMF) molecule
involves a proton acceptor of the carbonyl oxygen
atom (C=O), but not any proton donor. Our previous
study on DMF–N-methylformamide (NMF) binary
solutions has revealed that DMF molecules arehomogeneously mixed with NMF ones, which
involve a proton donor of the imino proton (NH) anda proton acceptor of the carbonyl oxygen atom, overthe entire range of DMF mole fraction due to ahydrogen bond between DMF and NMF molecules[1]. A formamide (FA) molecule involves two
proton donors of the amino protons (NH2) and thecarbonyl oxygen atom. Hence, FA molecules form
cyclic dimers and chain-like clusters by hydrogenbonding in the liquid, while NMF ones form only
chain-like clusters, i.e., the former may significantly
self-aggregates than the latter. It is thus interesting
how more proton donors of FA molecule effect on
mixing with DMF molecules. In the present study,
small-angle neutron scattering (SANS) experiments
were made on DMF-FA solutions at 298 K to clarify
the mixing state of them at a mesoscopic scale.
DMF-FA binary solutions at various DMF mole
fractions xDMF were prepared by mixing deuterated
DMF-d7 and undeuterated formamide. Neutron
scattering intensities of sample solutions at 298 K
were measured on SWAN, which can cover the
Q-range of 0.01-12 Å-1. The observed intensities
were corrected for background, absorption, and cell
scattering. The correction for detector efficiencies
and normalization to absolute units were made by
dividing the intensities of each solution by those of
vanadium. All the parameters required for the data
treatment were taken from the literature [2].
Figure 1 shows the normalized SANS intensities
for the DMF-d7–FA binary solutions at various xDMF.
This figure shows no significant SANS intensities
for the solutions in the Q-range from 0.05 to 0.4 Å-1,
revealing that sizable clusters among solvent
molecules are not formed in the solutions. Thus,
DMF and FA molecules are homogeneously mixed

0.1
0.01

xDMF = 0.5

1
0.1
0.01

xDMF = 0.4

1
0.1
0.01

xDMF = 0.3

1
0.1
0.01

xDMF = 0.2

1
0.1
0.01
0.001

xDMF = 0.1

0.1

Q/Å

-1

0.4

Fig. 1 SANS spectra for DMF-d7–FA solutions at
various DMF mole fractions xDMF.

References[1] K. Fujii et al., J. Phys. Chem. A, 110, 1798(2006).
[2] V. F. Sears, Thermal-Neutron Scattering
Lengths and Cross Sections for Condensed-Matter
Research; Chalk River Lab.: Ontario, 1984.

161

Temperature Dependence of Microheterogeneity for Acetonitrile-Water Mixtures
Investigated by Small-Angle Neutron Scattering Technique
T. TAKAMUKU,a Y. NOGUCHI,a H. IWASE,b and T. OTOMOca

Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering,
Saga University, Honjo-machi, Saga 840-8502, Japanb
Advanced Science Research Center, Japan Atomic Energy Agency,
Tokai, Ibaraki 319-1195, Japanc
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki 305-0801, Japan

162

intensities Icorr(Q)-1 against Q2 by using aleast-squares refinement procedure with Icorr(Q)-1 =I(0)-1[1+2Q2], where  is the Ornstein-Zernikecorrelation length. Figure 1 shows the  values forthe mixtures at each temperature as a function of xAN.
The  values for the mixtures at xAN = 0.3 and 0.4
extremely rise with decreasing temperature, while
those at xAN = 0.2 and 0.6 slightly increase. Thus,
the microheterogeneity of the mixtures at xAN = 0.3
and 0.4 is most drastically enhanced with decreasing
temperature among the mole fractions investigated.
This is consistent with the mole fraction (xAN = 0.38)
at the UCST. The present SANS experiments clearlyshow the process of phase separation of theacetonitrile-water
mixtureswithdecreasing
temperature.

50
279 K
287 K
298 K
307 K

40
30
/Å

At a room temperature acetonitrile (AN) is
miscible with water at any ratio. However, phaseseparation of their mixtures occurs by cooling; anupper critical solution temperature (UCST) for the
mixture is found at 292 K when the acetonitrile mole
fraction is xAN = 0.38 [1]. Our previous investigation
has shown that acetonitrile and water molecules areheterogeneously mixed with each other at themolecular level and the microheterogeneity ofacetonitrile-water mixtures at 298 K is mostenhanced at xAN  0.35 [2] in the entire mole
fraction range. In the present investigation, to reveal
temperature dependence of the microheterogeneity,
small-angle neutron scattering (SANS) experiments
were made on acetonitrile-water mixtures at various
xAN in the temperature range from 279 to 307 K.
Acetonitrile-D2O mixtures at xAN = 0.2, 0.25, 0.3,
0.4, 0.5, and 0.6 were prepared in a nitrogen-filled
glove box. Neutron scattering intensities for the
mixtures at 279, 287, 298, and 307 K were measured
on SWAN, which can cover the Q-range of 0.01-12
Å-1. The sample solutions were kept in a quartz cellof 22 mm in width, 25 mm in height, and 2 mm insample thickness. The temperature of sample
solution was controlled within 0.5 K. The
scattering intensities were accumulated for 4 h per
sample. The observed intensities were corrected forbackground, absorption, and cell scattering. The
correctionfordetector
efficiencies
andnormalization to absolute units were made by
dividing the intensities of each solution by those of
vanadium.
The normalized SANS intensities for theacetonitrile-D2O mixture at each mole fraction were
strengthenedwithdecreasing
temperature,suggesting that the microheterogeneity of the
mixtures is gradually enhanced by cooling. To makea quantitative analysis, Ornstein-Zernike fits were
performed on plots of the reciprocal SANS

20
10
0
0

0.2

0.4
xAN

0.6

0.8

Fig. 1 The  values for acetonitrile-D2O at 279, 287,
298, and 307 K as a function of xAN.

References[1] D. A. Armitage et al., J. Trans. Faraday Soc.,
64, 1193 (1968).
[2] T. Takamuku et al., J. Phys. Chem. B, 105,
6236 (2001).

Pressure-Induced Remixing of 1-Propanol-Water-KCl Mixture
M. MISAWA, A. ONOZUKA, S. TAKATA*, T. SATO†, M. SUGIYAMA† and T. OTOMO*
Institute of Science and Technology and Department of Chemistry, Niigata University, Niigata
950-2181*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801†Research Reactor Institute, Kyoto University, Kumatori-cho, Sennann-gun, Osaka 590-0494,
Mixtures of 1-propanol and water exhibit
peculiar phase behaviors [1]: by the addition of asmall amount of salts such as KCl into the mixturesof some range of alcohol concentration, a re-entrant
phase-separation appears in a phase diagram oftemperature-salt concentration at ambient pressure;
however, when the pressure is applied to thephase-separated mixtures, they mix again. The latter
behavior is schematically shown in Fig. 1. It seems
that an increase of salt content and an increase ofpressure act in an opposite direction.
We have studied the salt effect on the mesoscale
structure of the current solution and reported that themesoscale structure of the solution wascharacterized by poly-disperse mass-fractals [2-4].
The purpose of the present study is to examine thepressure effect on the mesoscale structure of thecurrent solution.

1-propanol (the mole ratio of 1-propanol/water =1/5) as a function of pressure using thesmall/wide-angle neutron diffractometer SWAN.
The amount of KCl was kept constant at a value of0.0208 in mole fraction. The pressure cell withsapphire windows of large opening speciallydesigned for the SWAN diffractometer was used.
The thickness of the sample was 2 mm. At first the
sample was pressed up to 27 MPa, where a single
phase is attained irrespective of temperature asshown in Fig. 1, then the neutron scattering
measurements were made as a function of pressure
by decreasing pressure at each of a fixed
temperature of 50 or 24 °C as shown in Fig. 1 by thetwo arrows (a) and (b). The scattered intensities
I(Q)'s measured under several pressures at aconstant temperature 50 °C are compared in Fig.2.

100

12.8 MPa100

one phase(a)two phase

60

I(Q) / a.u.

T / °C

80

40

(b)
20

27 MPa

10

1

0
0

5

10

15

20

25

30

P / MPa

0.1

Fig. 1

Schematic
diagramofpressure-induced
re-mixing of 1-propanol-water-KCl mixture.
SANS measurements were made in one-phaseregions at (a) 50 °C and (b) 24 °C by decreasingpressure.

In order to examine the pressure effect on themesoscale structure of the solutions, we have carriedout the small angle neutron scattering experiment on
the salt-added mixture of 1-propanol (C3H7OD) andheavy water (D2O) with a fixed content of

6

8

0.01

2

4

6

8

2

0.1

Q /A
Fig. 2

4

6

8

2

1
-1

Upper seven curves are scattering intensities
I(Q)'s of 1-propanol-water-KCl mixture measured
at 50 °C under pressures of 27, 23,
20,18,15,13,12.8 MPa. Note that the intensity
increases with decreasing pressure. The lowest
curve shows I(Q) of salt-free mixture measured
at 24 °C and 27 MPa for reference.

163

The scattering intensity at low Q region
increases with decreasing pressure from 27 MPa to12.8 MPa. We found that the intensity became
maximum at about 12.8 MPa and decreased again
below 12.8 MPa. This implies that at 50 °C thephase separation occurs at around 12.8 MPa.
The I(Q) curves are analyzed in terms of fractal[2]. They are fitted very well by a scatteringfunction given by a fractal model. The fractal
dimension df and the persistence length  obtainedby the fitting are shown in Figs. 3 and 4,
respectively.

50 C
24 C

2.2

df

2.0

1.8

1.6

0

5

10

15

20

25

30

P / MPa
Fig. 3Fractal dimension df as a function of pressure at
fixed temperature of 50 or 24 °C

300

50 C
24 C

250

 / A

200

150

100

50

0
0

5

10

15

20

25

30

P / MPa
Fig. 4

Persistence length  as a function of pressure at
fixed temperature of 50 or 24 °C

The results strongly suggest that the mesoscale
structure under pressure is also characterized bypoly-disperse mass-fractals. The comparison of the164

salt effect and the pressure effect on the structure isunder way.
References
1) G. M. Schneider and C. Russo, Ber. Bunsenges.
Physik. Chem. 70 (1966) 1008.
2) K. Yoshida, M. Misawa, K. Maruyama, M. Imaiand M. Furusaka, J. Chem. Phys 113 (2000)
2343.
3) M. Misawa, J. Chem. Phys. 116 (2002) 8463.
4) M. Misawa, I. Dairoku, A. Honma, Y. Yamada,T. Sato, K. Maruyama, K. Mori, S. Suzuki and T.
Otomo, J. Chem. Phys. 121 (2004) 4716.

Study of Dffusion Dynamics of Supercritical Aqueous Solution
using Neutron Quasielastic Scattering
M. NAKAHARAa), N. MATUBAYASIa), Y. KAMEDAb),
H. IWASEc), T. OTOMOc), and S. IKEDAc)a) Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011
b) Faculty of Science, Yamagata University, Koshirakawa, Yamagata 990-8560c) Neutron Science Laboratory, Institute of Materials Structure Science,High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801
Recently, super- and subcritical water attracts
much attention as a novel and clean solvent that
freely dissolves nonpolar organic compounds.
Various kinds of new organic reactions have beenfound to be induced in hot water. Owing to thecharacteristic hydration in supercritical water,organic reactions in it can be controlled withoutcatalyst by tuning inhomogeneous and anisotropic
structure around the solutes. The static structure ofwater is characterized by the hydrogen bonding. It isshown recently that the hydrogen bonding persists
even in supercritical water and that its number issensitive to the density variation. The temperature
involved in supercritical water is then not too high inthe sense that a “specific” effect of intermolecularinteraction does not vanish. Supercritical water is
not a simple fluid, and its interaction with the solute
may act as a key to control a chemical process in it.
For designing supercritical reactions, it is necessary
to understand the dynamic properties of water.
Especially, the translational diffusion is importantsince reactive species cannot collide with each otherwithout diffusion. However, the method to observetranslational dynamics in supercritical water has
been limited to the electric conductivity
measurement. Recent progress in supercritical water
reactions increases the necessity of ourunderstanding of the translational dynamics ofneutral molecules, such as water and organic
molecules that cannot be observed by electric
conductivity. The neutron quasielastic scattering
method meets this necessity as well as the NMR [1].
The purpose of the present project is to probe theeffect of added compounds on the translationalmotion of water at elevated temperatures.
The sample holder is made of aluminum. It has
cylinder form with inner and outer diameters of 15.6
and 20 mm, respectively, with capped end. The
samples prepared are pure H2O, 1 M NaCl aqueous
solution, and 1 M CsCl aqueous solution. They weresealed into quartz capillaries with inner diameter of

1 mm. About 30 capillaries were introduced into thesample holder. The vacant quartz capillary served as
the reference.
In Fig. 1, the neutron quasielastic scatteringprofile is shown for pure water (H2O) at 300 and
423 K and its 1 M NaCl and CsCl solutions at 423 K.
The result of pure water at 300 K shows that ourapparatus, the quartz capillary in the aluminum
sample holder used for LAM40, works well. The
data are of high enough quality to determine thediffusion constant in hot water. According to Fig. 1,
the effect of salt on hot water diffusion is welldetectable and the ability of the neutron quasielastic
scattering method to probe the dynamics in hot
water is demonstrated.

Fig. 1. Neutron quasielastic scattering profile for
hot water and its NaCl and CsCl solutions.
References
1) K. Yoshida, C. Wakai, N. Matubayasi, and M.
Nakahara J. Chem. Phys. 123, 164506 (2005).
165

Structure of the Ionic Liquid 1-Butyl-3-methylimidazolium Hexafluorophosphate
M. KANAKUBO,1 Y. HIEJIMA,1 K. MINAMI,1 T. AIZAWA,1 H. NANJO,1
Y. AMO,2 T. USUKI,2 and Y. KAMEDA2
1National Institute of Advanced Industrial Science and Technology (AIST), 4-2-1 Nigatake,Miyagino-ku, Sendai, 983-8551
2
Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, 1-4-12
Kojirakawa-machi, Yamagata, 990-8560
Room temperature ionic liquids (RT-ILs) haveattracted much attention as green solvents in a wide
range of applications such as reaction and separation
chemistry, electrolyte devices, and material
syntheses owing to a negligibly small vapor pressure,high thermal and chemical stability, sufficientelectrochemical competence, and desirable solvent
properties adjusted by modifications of cation andanion structures. There have been a number ofstudies on physical properties of RT-ILs; however,
little is known of the liquid structures of RT-ILs.
Hardacre and coworkers have recently carried out
neutrondiffraction
experimentsfor1,
3-dimethylimidazolium salts, [MMIM]X, withchloride and hexafluorophosphate anions, of which
the cation has C2 symmetry [1-2]. In the present
study, we investigate the liquid structure of
1-butyl-3-methylimidazolium hexafluorophosphate,[BMIM]PF6 (Fig. 1). This IL has been used andstudied more extensively as a typical example
because the asymmetric alkyl substituents at the 1,
3-positions of imidazolium cation generally decrease
the melting point.
Five deuterated samples (I-V) with different H/Disotopic ratios in the ring hydrogen atoms were used
for the neutron diffraction measurements. First,
isotopically natural [BMIM]PF6 was synthesized
and purified as described previously [3]. Then, thedeuterated samples were prepared from [BMIM]PF6by the partial deuteration of the ring protons with thealkyl hydrogen atoms being natural. In the sample
I, all the ring hydrogen atoms in the imidazolium
ring were deuterated by mixing [BMIM]PF6 with
CD3OD in the presence of K2CO3 at 50 oC for 1 day.
In the sample II, the 2-positioned ring hydrogen
atom was partially replaced by deuterium without
K2CO3 in the similar manner. The sample III was
prepared by mixing the sample I with CH3OH,
which gave the 2-protonated and 4,5-deuterated[BMIM]PF6. The samples IV and V were theequimolar mixtures of the samples (I and II) and (Iand III), respectively. The isotopic compositions
166

H(2)
H3C

N + N

H(4)

C4H9

PF6-

H(5)

Fig. 1 Structure of 1-butyl-3-methylimidazolium
hexafluorophosphate with the numbers specified
for the ring hydrogen atoms.
Table 1 Deuterium isotopic ratios of the ring hydrogenatoms of [BMIM]PF6 used for the neutron diffraction
measurements
Sample2-hydrogen
4, 5-hydrogen
I (all D)
II (2-D)
III (4,5-D)
IV (2-D-4,5-D/2)
V (2-D/2-4,5-D)

0.98
0.98
0.02
0.98
0.50

0.98
0.0
0.98
0.49
0.98

of the samples were determined by the signal
integrals of 1H NMR as listed in Table 1.
The neutron diffraction measurements werecarried out at 25 oC using the HIT-II spectrometer[4] installed at the High Energy Accelerator
Research Organization (KEK), Tsukuba, Japan.
The sample cell was made from Ti-Zr null-alloy (8mm inner diameter with 0.3 mm thick). The dataacquisition time was approximately 12 h for eachsample solution. Diffraction measurements weremade in advance for an empty cell, instrumental
background, and vanadium rod (8 mm outer
diameter), respectively. The scattering intensities
observed for each sample were corrected for the
instrumental background, absorption of both thesample and cell, and for multiple and incoherent
scatterings. The effect of inelastic scattering due toresidual protons was eliminated on the basis of theexperimental results of null-H2O as described
previously [5].
The first-order difference functions, i(Q), arederived from the numerical differences between the
fully corrected scattering cross sections of thesamples (I and II), (I and III), (I and IV), and (I and
V), which are represented by 4,5-H(Q), 2-H(Q),4,5-H’(Q), and 2-H’(Q), respectively. Subtracting
the intramolecular contributions in [BMIM]+ from
i(Q), we can obtain the interionic differencefunction, iinter(Q), and its Fourier transformed
distribution function, Giinter(r). Figure 2 shows
iinter(Q) and Giinter(r) around 2- and 4,5-hydrogenatoms. It is apparent that the first peaks in Giinter(r)are quite different; r = 2.6 Å for 2-H and 3.2 Å for
4,5-H.
The second-order differences between ( 2-H(Q)and 2-H’(Q)) and (4,5-H(Q) and 4,5-H’(Q)) can be
related to the partial structure factors, a2-H, 2-H(Q) anda4,5-H, 4,5-H(Q), for the 2-H and 4,5-H autocorrelations,
respectively. The a2-H, 2-H(Q) and a4,5-H, 4,5-H(Q) andthe corresponding distribution functions, g2-H, 2-H(r)and g4,5-H, 4,5-H(r), are given in Fig. 3. On theassumption that the partial structure factor is divided
into the short-range H...H and long-range
contributions, the least-squares fits to theexperimental a2-H, 2-H and a4,5-H, 4,5-H were carried out.
The H...H distances, r(H...H), and the coordination
numbers, n(H...H), were obtained together with theroot-mean-square displacement, l(H...H), as well as
the averaged distance, r0, and displacement, l0, in thelong-range contribution (Table 2). The r(H...H) for
2-H is much smaller than those for 4,5-H, whereasn(H...H) ≈ 1. In the case of the symmetric 1,
3-dimethylimidazolium cation with Cl-, the firstpeaks in gi, i(r) appear at ~2.8 and 3.0 Å for 2-H and4,5-H, respectively [1]. This is reasonable because
the present PF6- anion is larger than Cl-. Moreover,these results imply that the asymmetric replacementof longer butyl chain would bring about more
remarkable difference between the r(H...H) values
for 2-H and 4,5-H.
The other second-order differences between(2-H(Q) and a2-H, 2-H(Q)) and (4,5-H(Q) and a4,5-H,
4,5-H(Q)) can provide to the partial structure factors,
a2-H, X(Q) and a4,5-H, X(Q), around the 2-H and 4,5-H,
respectively (Fig. 4).
These partial structure
factors are expressed by the sum of interactions ofFig. 2 The difference functions iinter(Q) (a; exp= dots and back Fourier transforms of Giinter(r) =solid lines) and the distribution functions Giinter(r)(b) around 2- and 4,5-hydrogen atoms in[BMIM]PF6.

Table 2 Results of the least-squares refinements for thepartial structure factors a2-H, 2-H(Q) and a4,5-H, 4,5-H(Q) of 2-H
and 4,5-H autocorrelations in [BMIM]PF6ainteraction
parametera2-H, 2-H(Q)a4,5-H, 4,5-H(Q)r(H...H) / Å
3.40(2)3.80(2), 5.32(3)short-rangel(H...H) / Å
0.13(3)0.31(1), 0.38(7)H...Hn(H...H)
0.89(4)0.92(3), 1.1(4)4.51(3)5.7(4)
r0 / Å
long-range
l0 / Å
0.2(1)
0.7(4)a
Estimated standard deviations are given in parentheses.

Fig. 3 The partial structure factors ai, i(Q) (a; exp= dots and best-fitted = solid lines) and the
distribution functions gi, i(r) (b; exp = thin dots andbest-fitted = thin solid lines) for the 2-H and 4,5-H
autocorrelations in [BMIM]PF6. The residualfunctions (Q) are shown below in (a) and theshort- and long-range contributions are
represented respectively by the dashed and dottedlines in (b).

aiinter(Q)2-H (+2)

4,5-H

Q / Å-1b

Giinter(r)2-H (+1)

4,5-H

r/Å

a

2-H (+2)

ai, i(Q)-1

(Q) for 2-H (+1)
4,5-H

(Q) for 4,5-H (-1)

Q / Å-1bgi, i(r)2-H (+5)

4,5-H

r/Å

167

References
1) C. Hardacre, J. D. Holbrey, S. E. J. McMath, D.
T. Bowron, A. K. Soper, J. Chem. Phys. 118(2003) 273.
2) C. Hardacre, S. E. J. McMath, M.
Nieuwenhuyzen, D. T. Bowron, A. K. Soper, J.
Phys. Condens. Matter 15 (2003) S159.
3) T. Umecky, M. Kanakubo, Y. Ikushima, Fluid
Phase Equilib. 228-229 (2005) 329.
4) T. Fukunaga, M. Misawa, I. Fujikura, S. Satoh,
KENS REPORT-IX (1993) 16.
5) Y. Kameda, M. Sasaki, T. Usuki, T. Otomo, K.
Itoh, K. Suzuya, T. Fukunaga, J. Neutron Res. 11(2003) 153.

168

ai, X(Q)-1a

2-H (16.109[a2-H, X(Q)-1]+9)

(Q) for 2-H (+3)
4,5-H (29.588[a4,5-H, X(Q)-1])

(Q) for 4,5-H (-6)

Q / Å-1b

2-H (+2)

gi, X(r)the hydrogen atoms with other interionic atoms. In
order to obtain more detailed information aboutliquid structure around the hydrogen atoms in theimidazolium ring, we first attempt to refine theexperimental a2-H, X(Q) and a4,5-H, X(Q) by taking
account of only the nearest-neighbor short-range
interactions with PF6- anions in a single state. Thisapproach can reproduce the first peaks in gi, X(r),which appear at ~2.6 and 3.0 Å for 2-H and 4,5-H,
respectively. However, there will be still anotherpeaks at longer r = ~3.9 and 4.2 Å for 2-H and 4,5-H,
respectively. This suggests that the PF6- anions
around the ring hydrogen atoms are not in a single
state and/or the nearest-neighbor [BMIM]+ cations
make contributions to g2-H, X(r) and g4,5-H, X(r). The
results of the least-squares refinements for a2-H, X(Q)and a4,5-H, X(Q) are given in Table 3 by assuming
another short-range H...F’ interaction arbitrarily.
In this work, we have investigated the liquid
structure of [BMIM]PF6 by means of the H/Disotopic substitution technique. It is very simple
and practical to deuterate only the hydrogen atoms
in the imidazolium cations. The present results
indicate that the 2-hydrogen atom in [BMIM]+ has
the peak at shorter distance in the distributionfunction, probably due to PF6-, than 4,5-hydrogenatoms. The favorable interaction of 2-hydrogen
atom with the anion is in harmony with more acidic
nature of 2-H than 4,5-H.

4,5-H

r/Å

Fig. 4 The partial structure factors ai, X(Q) (a;exp = dots and best-fitted = solid lines) and the
distribution functions gi, X(r) (b; exp = thin dots
and best-fitted = thin solid lines) around the 2-H
and 4,5-H in [BMIM]PF6. The residual functions
(Q) are shown below in (a) and the short- andlong-range
contributionsarerepresented
respectively by the dashed and dotted lines in (b).
Table 3 Results of the least-squares refinements for thepartial structure factors a2-H, X(Q) and a4,5-H, X(Q) around 2-H
and 4,5-H in [BMIM]PF6ainteraction
parametera2-H, X(Q)a4,5-H, X(Q)r(H...1F) / Å
2.56(1)2.95(3)l(H...1F) / Å
0.22(1)0.15(1)l(H...2F) / Å
0.21(1)0.14(1)l(H...3F) / Å
0.25(1)0.23(3)l(H...4F) / Å
1.8(1)
0.4(1)
short-rangel(H...5F)/
Å
0.39(1)0.5(2)
H...PF6l(H...6F) / Å
0.49(1)0.5(2)l(H...P) / Å
0.31(1)0.26(3)
109(1)
110(1)
 b/ o
b o
47(1)
39(1)
 /
n(H...PF6-)

1.15(1)0.70(8)r(H...F’) / Å
3.91(1)
4.18(9)l(H...F’) / Å
0.23(1)0.38(4)n(H...F’)
1.44(2)4.4(7)
r0 / Å
4.45(1)4.4(1)
long-range
0.76(1)0.55(6)l0 / Å
a
Estimated standard deviations are given in parentheses.
b represents the angle of H...F1-P and  the dihedral angle
between the H...F1-P plane and the F1-P-F2 plane in PF6-.

short-range
H...F’(arbitrary)Coherent Quasielastic Neutron Scattering of Liquid Sn
T. KAMIYAMA, T. MASAKI* and T. ITAMI**
Graduate School of Engineering, Hokkaido Univ., Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628, Japan*Japan Aerospace Exploration Agency (JAXA), 2-1-1 Sengen, Tsukuba 305-8505, Japan**Graduate School of Science, Hokkaido Univ., Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, JapanThe diffusion in liquids is very sensitive to thestructure. In the IVB group (Si, Ge, Sn, Pb) the
structure varies between simple one to complex one,and their diffusive nature are changed with thisvariation. The solid state Sn shows an intermediatecharacter between the metallic and thesemiconducive one. It is metallic at the hightemperatures while it is semiconducting with adiamond structure at the low temperatures. Its
diffusive motions must be changed with thisvariation.
The neutron inelastic scattering is a powerful tool
to investigate the microscopic dynamics of atoms inliquids. The quasielastic scattering in the part of theinelastic neutron scattering comes from the diffusion
or structural relaxation phenomena of the matters. In
this study we have carried on the S(Q,E)
measurement for liquid Sn near its melting point. At
such a temperature the liquid Sn may still have theresidue of the crystal structure. Then the structural
relaxation caused from the atomic motion may
reflect the diffusion dynamics.
The inelastic scattering measurements werecarried out by using the direct-geometry typespectrometer INC installed in KENS at High Energy
Accelerator Research Organization (KEK) in Japan.
The liquid Sn sample had a cylindrical shape of 8
mm diameter and 50 mm height. The shape was
decided from the estimation to decrease the multiple
scattering of scattered neutron. The sample cell was
made by quartz with wall thickness of 0.2 mm. The
sample was enclosed in the cell and set into thefurnace. For the date accumulation, the sample was
kept at 573K during 3 days.
The example of the obtained spectrum is shownin figure 1. The evaluation of the width of thequasielastic peak has been performed under theassumption that the spectrum is composed of thesingle Lorentzian component. This assumption may
be plausible because the liquids like Sn arecomposed of a single particle and it is sufficient for
the analysis of the quasielastic line to take accountof the long range translational motion.

Fig. 1

An example of quasielastic spectrum of liquid Sn-1(573 K).(Q = 4.2 Å )The Q2 dependence of the half width at half
maximum (HWHM) of the quasielastic peaks isshown in figure 2 The experimental results areindicated by circles. The HWHM becomes smallerwith decreasing Q, while it has a trend to go to a
specific value asymptotically at large Q. Under thecontinuous diffusion behavior in simple liquids the
HWHM of the incoherent quasielastic line is in
proportion to Q2 deduced from Fick’s law [1].
If the quasielastic peak contains the coherent
scattering component, the HWHM oscillates aroundthe Q2 law, such as the case of liquid Ar [2]. The
result of liquid Sn deviates from such continuous
diffusion model and resembles the diffusive motion
in light water [3]. For the analysis of the water
spectrum Singwi and Sjölander assumed a residence
time 0, which indicates the oscillatory motion ofmolecules on their equilibrium positions [4]. The
water molecules are bound each other by hydrogenbonds. The translation of a molecule to the next
position for diffusion requires a large jump andreforming its shell around the new position. The
long-range diffusive motion is a pile of such jumps.
This jump-diffusion model leads to the equation for
the HWHM of quasielastic line,

HWHM

1

0

1

exp 2W 
1  Q 2 D 0

(1)

where W corresponds to the Debye-Waller factor
and D indicates the diffusion coefficient. Equation

169

(1) is deduced by an assumption that the particle
oscillates in its equilibrium position for a much
longer time than the time for its diffusive motion.
30

5cm 2/s

Sn 573K

E(meV)

D=3.74E-

20

10HWHM (INC)
Jump-Diffusion Model00Fig. 2

5

-1

Q(Å )

10

Half width at half maximum, E, of quasielastic
line (Circles are obtained by INC. Solid line iscalculated with the jump-diffusion model. Broken
line indicates the model of continuous diffusion).

The fitted line of eq. (1) to experimental HWHM
is shown as a solid line in Fig. 4. The fitting results
are 0 = 0.16 ps, D = 0.68×10-5 cm2/s and meansquare displacement <l2> = 0.065 Å2 for W. The
agreement between the fitted line and theexperimental HWHM is good. This means that, on
the whole, the particle dynamics in liquid Sn shows
the similar behavior to that of the water molecule.
The different point between Sn and light water isthat the former is a coherent scatterer and the latteris almost an incoherent scatterer due to extremely
large inelastic scattering cross section of H nuclear.
The interpretation of the coherent quasielastic
scattering is a little bit complex, but this case could
be explained with the jump-diffusion model. In thecase of the liquid Sn at low temperature theresidential time 0 is longer than the diffusion timeto the next site. The coherent quasielastic line widthreflects the structural relaxation time of thesurrounding particle shell around the new site. The
shell is reconstructed by correlated slow motion ofparticles in the small region. In contrast the diffusive
motion is the rapid jump to the outside of thesurrounding shell. The Sn atom stays in the shellwith relaxation time 0, then jumps out to anothershell. The latter process corresponds to the diffusive
motion. In Fig.2 the broken line shows thecontinuous diffusion model in which themacroscopic diffusion coefficient of liquid Sn at 573
K was inserted. The diffusion coefficient deduced
from the jump-diffusion model is smaller compared170

with this macroscopic value. As mentioned above
this may be caused by the difference between the
single particle motion and the coherent motion ofparticles which reflects the slow surrounding shell
motion.
Figure 3 shows the whole quasielastic line
reproduced by the experimental structure factor S(Q)[5] and the jump-diffusion model. The characteristic
oscillation is shown on the all Q-E space. This
complex feature is caused by the coherent scattering
effect, that is, the microscopic structure of the liquid.
For precise analysis of the coherent quasielastic
scattering it needs the information of S(Q,E) on thewide Q-E space. The high-resolution inelastic
neutron scattering experiment with direct-geometry
spectrometer is useful for this purpose.

Fig. 3

Quasielastic line of liquid Sn at 573 K reproduced
from experimental S(Q) and the jump-diffusion
model. The numbers attached to colors indicate-1
the magnitude of S(Q, E) in unit of meV .

References[1] M. Bée, Quasielastic Neutron Scattering (Adam
Hilger ; Bristol and Philadel phia, 1988).
[2] B. A. Dasannacharya and K. R. Rao, Phys. Rev.,
137A (1965) 417.
[3] J. Texeria, M. C. Bellissent-Funel, S. H. Chen
and A. J. Dianoux, Phys. Rev., A31 (1985) 1913.
[4] K. S. Singwi and A. Sjölander, Phys. Rev., 119(1960) 863.
[5] S. Munejiri, T. Masaki, Y. Ishii, T. Kamiyama, Y.
Senda, F. Shimojo, K. Hoshino and T. Itami, J.
Phys. Soc. Jpn. Suppl. A, 70 (2001) 268.

Hydration Structure of Carbonate Ion Studied by Neutron Diffraction with 12C/13C Isotopic
Substitution Method
Y. KAMEDA, M. SASAKI, S. HINO, Y. AMO and T. USUKI
Department of Material and Biological Chemistry, Faculty of Science, Yamagata University,
Yamagata 990-8560
Hydration structure of the carbonate ion hasreceived much attention because of its importance inextensive fields of fundamental and appliedchemistry. However, direct information on the
structure of hydrated carbonate ion has not yet beenreported.
In the present paper, we report results of the TOF
neutron diffraction measurements on aqueous 10
mol% K2CO3 solutions in D2O in which 12C/13C
isotopic ratio has been changed.
Weighed amounts of isotopically enriched
K213CO3 (98.8%, 13C) and natural K2natCO3(98.9%, 12C) were dissolved into D2O (99.9%, D)
to prepare two 10 mol% K2CO3 heavy water
solutions with different isotopic composition of the
carbon atom within the carbonate ion. The sample
parameters are listed in Table 1.
TOF neutron diffraction measurements of thesample solution contained in a Ti-Zr null-alloy cell
(8mm in inner diameter and 0.3mm in thickness)were carried out at 25 °C using the HIT-II
spectrometer installed at the spallation neutron
source (KENS) of the High Energy Accelerator
Research
Organization,
Tsukuba,
Japan.
Measurements of an empty cell, background, andvanadium rod of 8 mm, were made in advance.
After corrections for the background scattering,absorption of both sample and cell, multiple andincoherent scatterings, the observed count rate of thesample was converted to the absolute scatteringcross section scaled at the stoichiometric unit,(K2*CO3)0.1(D2O)0.9, by the use of corrected
scattering intensities from the vanadium rod.
The first-order difference function [1], C(Q),was obtained from the numerical difference in the
scattering cross section between sample solutions I
Table 1 Isotopic composition, mean scattering length bC for
the CO32-, total cross section t (at  = 1.0 Å) scaled at thestoichiometric unit, (K2*CO3)0.1(D2O)0.9
SampleI(K2natCO3)0.1(D2O)0.9

II(K213CO3)0.1(D2O)0.9

13C

bC

t

and II. The C(Q) scaled at the stoichiometric unit,(K2*CO3)x(D2O)1-x, can be written as a linear
combination of partial structure factors relating thecarbon atoms as follows:C(Q) = A[aCO(Q)-1] + B[aCD(Q)-1]+ C[aCK(Q)-1] + D[aCC(Q)-1],
(1)
where
A = 2x(2 + x)bCbO, B = 4x(1 - x)bCbD,
C = 4x2bCbK, and D = (bnatC2 – b13C2),and bC = bnatC – b13C. Values of the weighting
factors, A-D, are numerically listed in Table 2. The
contribution from the C-O and C-D pairs occupies
94% of the observed C(Q) in the present
experimental condition, C(Q) can be regarded as
involving information on the hydration structurearound the carbonate ion.
The distribution function, GC(r), around thecarbon atom of the carbonate ion was evaluated by
the following Fourier transform:
GC(r) = 1 + (A + B + C + D)-1(22r)-1
Qmax

  QC(Q) sin(Qr) dQ
0= [AgCO(r) + BgCD(r) + CgCK(r)+ DgCC(r)](A + B + C + D)-1.

The upper limit of the integral, Qmax, was set to be
20 Å-1.
The intramolecular contribution within the CO32-,
ICintra(Q), was estimated by the following equation:
ICintra(Q) = 6cCbCbOexp(-lCO2Q2/2)
 sin(QrCO)/(QrCO), (3)where, cC is the number of the carbon atom in the
stoichiometric unit. Calculated ICintra(Q) was thensubtracted from the observed C(Q) to deduce theintermolecular difference function, Cinter(Q):Cinter(Q) = C(Q) - ICintra(Q).

(4)

Table 2 Values of the coefficients (in barns) of aij(Q) in
Eq. (1)(10-14m(barns)1.1

0.664613.657

A

B

C

D

98.8

0.6196

13.5880.01100.01080.00070.0006

(%)

(2)

171

In order to obtain structural parametersconcerning the first hydration shell of the CO 32-, theleast squares fitting analysis was applied to theobserved Cinter(Q) employing the model function
which involves contributions from the short-range
interactions associated with the nearest neighbor
C...D2O pair and the long-range correlation:
2cC bCb exp(-lC 2Q2/2)
sin(QrC )/(QrC ) + IClong(Q). (5)Ccalc(Q) =Fig. 1. a) C(Q) observed for aqueous 10 mol% K2CO3
solutions in D2O (dots). Back Fourier transform of GC(r)(solid line) in Fig. 2a. b) Observed C(Q) (dots) andintramolecular contribution (solid line). c) Intermoleculardifference function Cinter(Q) (dots) and the best-fit of thecalculated Ccalc(Q) (solid line). d) Residual functions(dots).

The observed C(Q) is shown in Fig. 1a. The
calculated intramolecular C-O contribution,
ICintra(Q) (Fig. 1b), was subtracted from theobserved C(Q). The normalization factor, ,defined by ICintra(Q) =C(Q) (in the range of 5
-1
Q 20 Å ), was determined to be = 0.97 ± 0.06
from the least squares fit.
The total and intermolecular distribution function,GC(r) and GCinter(r), are represented in Figs. 2a andb, respectively. A dominant first peak at r = 1.3 Åin the GC(r) is assigned to the intramolecular C-O
interaction within the carbonate ion. Partiallyresolved second peak at r 3 Å is attributable to the
C...D2O interaction in the first hydration shell of
CO32-. The second peak involves the C…DW andC…OW interactions (DW: water deuterium, OW:
water oxygen atom) that are overlapping each other.
An indication of the second and third hydration
shells of CO32- appears as more broadened
intermolecular peaks at r 6 and 9 Å.

IClong(Q), was evaluated by the inverse Fouriertransform of the observed GCinter(r) in the range ofr 4.2 Å. The fitting was performed in the rangeof 0.6 Q 12 Å-1.
The best-fit result is compared with the observedinter(Q) in Fig. 1c. The final results of allC
independent parameters are summarized in Table 3.
In the present solution, D2O molecules in the firsthydration shell of the CO32- are found to take aconfiguration that one of the deuterium atoms in
D2O faces towards the carbon atom of the CO 32-,
which may suggest the formation of hydrogen bonds
between the O atom of CO32- and DW1 atom of theD2O. The present value of number of watermolecules in the first hydration shell, nC...DW1(9.1(5)) is much larger than that reported for NO3(5.0(5)) [2], which has similar size as the CO32-.
The fact suggests that the hydration number of thepolyatomic anion is strongly affected by its own
charge. The present value of nC...DW1 suggests
thatthesolvent-sharedion
pairing(CO32-...D2O...K+) is extensively formed in thepresent solution.
Table 3 Results of the least squares refinement forinter(Q) observed for aqueous 10 mol% K CO in D Oa
C
2
3
2
i...j
C...D

W1

C...OW
C...D

a)
b)
c)

d)
e)

rij (Å)lij (Å)nij

 (°)b (°)c2.68(1)0.21(4)9.1(5)

126(8)

64(20)(3.35)d0.29(2)(9.1)eW2 (3.44)d 0.31(5) (9.1)eEstimated standard deviations are given in parentheses.
Bond angle C...DW1-OW.
Dihedral angle between the plane involving C...DW1-OW
atoms and the molecular plane of D2O
Calculated from values rCW1, , and .
Fixed to the nCW1.

References
Fig. 2. a) Total distribution functions around the carbon
atom of CO32-, GC(r), observed for aqueous 10 mol%b) Observed
K2CO3 solutions in D2O (solid line).
intermolecular distribution function GCinter(r) (solid line).
Fourier transform of the calculated Ccalc(Q) is shown by
broken lines.

172

1) J. E. Enderby and G. W. Neilson “Water, A
Comprehensive Treatise”, Plenum Press, New York,(1979) Vol. 6, p. 1.
2) Y. Kameda, H. Saitoh and O. Uemura, Bull.Chem. Soc.
Jpn. 66 (1993) 1919.

Environmental Structure around the Amino Group of Glycine Molecule in Concentrated
Aqueous Solutions Absorbing CO2
Y. KAMEDA, Y. INOUE*, M. SAKANO*, M. SASAKI, Y. AMO and T. USUKI
Department of Material and Biological Chemistry, Faculty of Science, Yamagata University,
Yamagata 990-8560*Advanced Technology Research Center, Mitsubishi Heavy Industries, Ltd., Yokohama 236-8515
In recent years, there has been a growing interestin concentrated aqueous solutions involving aminecompounds to separate CO2 from industrial gases.
However, detailed reaction mechanism to form theamine-CO2 complex has not yet been known.
In the present report, we describe results ofTime-of-Flight neutron diffraction measurements on
14N/15N isotopically substituted aqueous alkaline 2
mol% glycine heavy water solutions absorbing CO2,
I (natND2CH2COOD)0.02(KOD)0.02(D2O)0.96(CO2)0.012 andII (15ND2CH2COOD)0.02(KOD)0.02(D2O)0.96(CO2)0.012.
Sample parameters are listed in Table 1. Neutron
diffraction measurement on the sample solution
sealed in a cylindrical Ti-Zr null-alloy cell (8 mm in
inner diameter and 0.3 mm in thickness) was carriedout at 25 °C using the HIT-II total scattering
spectrometer installed at KENS. Measurements onan empty cell, a vanadium rod (8 mm in diameter),and instrumental background, were made inadvance.
The first-order difference function [1], N(Q)(Fig. 1a) was obtained from the numerical differencein the scattering cross sections between sample
solutions I and II. The N(Q) scaled at thestoichiometricunit,*( ND2CH2COOD)x(KOD)x(D2O)1-x(CO2)y, can be written
as a linear combination of partial structure factors
relating to the nitrogen atom,
N(Q) = A[aNO(Q)-1]+B[aND(Q)-1]+C[aNC(Q)-1]+D[aNH(Q)-1]+E[aNK(Q)-1]+F[aNN(Q)-1],
where
Table 1. Isotopic composition, mean scattering length bN, total
cross section t (at  = 1.0 Å) scaled at the stoichiometric unit,(*ND2CH2COOD)x(KOD)x(D2O)1-x(CO2)y.
15N

bN

t

(natND2CH2COOD)0.02/%
0.4/10-12cm
0.936/ barns
14.562(15ND2CH2COOD)0.02

98.0

0.650

14.508SampleI(KOD)0.02(D2O)0.96(CO2)0.012

II(KOD)0.02(D2O)0.96(CO2)0.012

Table 2. Values of the coefficients of aij(Q) in Eq. 1(in mbarn).
A
6.93

B
15.25

C
0.39

D
-0.25

E
0.08

F
0.18

A = 2x(1+x+2y)bNbO, B = 4xbNbD,
C = 2x(2x+y)bNbC, D = 4x2bNbH,
E = 2x2bNbK, F = x2(b14N2 – b15N2),(1)

and bN = b14N – b15N. Values of the weighting
factors A - F listed in Table 2 indicate that thepresent N(Q) is dominated by the contribution
from the N…D2O interaction. The distributionfunction, GN(r), around the amino-nitrogen atom
was evaluated by the Fourier transform,
GN(r) = 1+(A+B+C+D+E+F)-1(22r)-1
Qmax

  QN(Q)sin(Qr)dQ.

(2)0

The upper limit, Qmax, was set to be 20 Å-1.
Since the fraction of CO2-bound glycine molecule
was estimated to be 46 % from 1H NMR spectra of
the methylene hydrogen atoms within the glycine
molecule, the intra- and intermolecular contributions
from “free” glycine was evaluated by 0.54 times thedifference function N(Q) observed for the aqueous
alkaline 2 mol% glycine solutions [2] and thensubtracted from the present N(Q) to obtain the
difference function, ’N(Q). The ’N(Q) involves
information on environmental structure around the
N atom within the glycinecarbamate molecule asshown in Fig. 1b. The hydration structure aroundthe amino-nitrogen atom of the carbamate wasdetermined from the least squares fitting analysis of
the intermolecular ’Ninter(Q) (Fig. 1d) derived bysubtracting the intramolecular contribution of thecarbamate molecule, which was estimated by themolecular orbital calculation (Fig. 1c).
The total and intermolecular distribution functions,G’N(r) and G’Ninter(r), around the nitrogen atom of173

the glycinecarbamate molecule are shown in Figs.
2a and b, respectively.
Intramolecular peaks
appearing in the total G’N(r) in the range of r < 2.5Å are successfully subtracted in the present
G’Ninter(r).
Final results of the least squares fit are listed inTable 3. The present value of the nearest neighbor

N(-D)…O distance, rNO = 2.95(2) Å, is in good
agreement with that determined for the aqueous
alkaline glycine solution in which D2O molecules
form hydrogen bonds of the N-D…OD2 type (rNO =2.92(3) Å) [2]. The tilt angle between the N…Oaxis and the molecular plane of the nearest neighbor
D2O was calculated to be 64(3)° by employing thenearest neighbor N…D distance of rND = 3.35(1) Å.
The coordination number of the nearest neighbor
N…O interaction was obtained to 2.0(1). The
second and third nearest neighbor N…D2O distanceswere determined to rN…D2O(II) = 3.60(1) Å andrN…D2O(III) = 4.18(2) Å, respectively. These D2O
molecules are considered to form hydrogen bonds
with oxygen atoms of the carbamate group within
glycinecarbamate molecule.
Table 3. Results of the least squares fitting refinement of’Ninter(Q),the intermolecular difference function,observed for the aqueous alkaline 2 mol% glycine solution
absorbing CO2, (*ND2CH2COOD)x(KOD)x(D2O)1-x(CO2)y.a)Fig. 1 a) N(Q) observed for the aqueous alkaline 2
mol% glycine solution absorbing CO2 (dots).
N(Q) forthe aqueous alkaline 2 mol% glycine solution [1] is shownby the solid line. b) ’N(Q) for the glycinecarbamate
molecule (dots). The inverse Fourier transform of thesolid line in Fig. 2a is denoted by the solid line. c) ’N(Q)for the glycinecarbamate molecule (dots). The solid line
indicates the intramolecular interference contribution of theglycinecarbamate molecule.
d) The intermoleculardifference function, ’Ninter(Q) (dots). The best-fit of themodel function (solid line). e) The residual functions(dots).

Interaction
Short N…D2O(I)b)-range

i…j
…
N O

N…D
N…D2O(II)d) N…D2O
N…D2O(III)e) N…D2O

Long
N…Xf)
-range

rij/Å

lij/Å

nij

2.95(2)0.16(4)2.0(1)

3.35(1)3.60(1)0.25(2)0.31(1)(4.0)c)1.6(1)

4.18(2)0.34(2)

3.3(3)r0/Å

l0/Å

4.07(1)0.84(2)a) Estimeted errors are given in parentheses. b) The firstnearest neighbor N(-D)…D2O interaction. c) Fixed to the value
2nNO. d) The second nearest neighbor N…D2O interaction. e)
The third nearest neighbor N…D2O interaction. f) X: O, D, H, N,
C and K.

References
J. E. Enderby and G. W. Neilson, “Water, A
Comprehensive Treatise”, Plenum Press, New
York, (1979), Vol. 6, p. 1.
2) K. Sugawara, Y. Kameda, T. Usuki, O. Uemura,and T. Fukunaga, Bull. Chem. Soc. Jpn., 73(2000) 1967.

1)

Fig. 2 a) The total distribution function, G’N(r), around thenitrogen atom of the glycinecarbamate molecule. b)
Intermolecular distribution function, G’Ninter(r) (solid line).
The short- and long-range contributions are shown by
broken- and dotted lines, respectively.

174

Stractual Study of Liquid GexSb4-xS6 Alloys

175

Structural Study of Liquid Sb-S Mixtures
F. KAKINUMA and T. FUKUNAGA*
Niigata Institute of Technology, 1719 Fujihashi, Kashiwazaki 945-1195*Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka, 590-0494

176

Figure 1 shows the structure factor, S(q), forliquid SbXS100-X with x = 40, 44,and 90. The
structure factors of Sb40S60 and Sb44S56 havefollowing characteristic features. i) The structure
factor of these mixtures has a prepeak at 1.2 Å -1.
This peak is so-called first sharp diffraction peak
(FSDP), which indicates the existence of the middle
range order. ii) The height of first peak at 2.35 Å -1
is slightly smaller than that of second peak at 3.35
Å -1. iii) The oscillation in S(q) persists at higher q
values ( q > 20 Å -1). The characteristic features ofthe structure factors for these liquid Sb-S mixturesare similar to those for liquid As-Se, As-S and Sb-Se
systems. These aspects observed in the structure
factors seem to be common feature of the liquid
semiconductor with chalcogen atoms as one
component.
On the other hand, the structure factor of liquid
Sb90S10 shows somewhat different features. The
prepeak disappears. The first peak becomes large
and the second peak becomes small, which aspects
are similar to that for metallic liquids like as liquid7
S b 90 S 10 at 1073 K
6
S b 90S 10 at 993 K
5
S b 44S 56 at 1073 K
4S(q)The liquid metal-chalcogen binary alloys have been
widely investigated because their physico-chemical
properties exhibit drastic change with temperatureand composition [1,2]. Most of those systems havecompounds such as M2X and M2X3 (M: metal, X:
chalcogen) compositions in the solid state [3]. It
has been known that these alloys partially preserve
their chemical short-range order after melting andshow the semiconducting behaviour. With raisingtemperature and/or increasing metal composition, theelectronic properties change from a semiconducting
to a metallic state. The non-metal-metal transition
observed in these liquid systems was closely related
to the structural change associated with change ofthe physico-chemical parameters.
The Sb-S system has two-phase region in both sideof the stoichiometric composition of Sb2S3. It
indicates that the electronic property of liquid
Sb40S60 is quite different from those of liquid Sband Sb-rich Sb-S mixtures. The electronic propertyof liquid Sb40S60 exhibits semi-conducting behaviour.
The Sb-S system exhibits the non-metal-metaltransition with increasing metal concentration.
The electronic properties of ternary glasses suchas Ge-Sb-S systems were widely investigatedbecause of the application for optical devices [4].
Although the glassy As2S3 is easily obtained, theglassy Sb2S3 is relatively difficult to synthesize [5].
The structural study of the liquid Sb-S mixtures
gives the basic information for the design of glasses.
A neutron diffraction study is one of the most useful
methods for direct observation of liquid structure.
In this paper, we report the analyses of liquid
SbXS100-X mixtures and discuss the liquid structure
and its variation caused by the change ofcomposition and temperature.
Pulsed neutron scattering experiments on liquid
Sb-S mixtures were carried out using the highintensity total scattering spectrometer (HIT II)
installed at High Energy Accelerator Research
Organization (KEK) at Tsukuba. The measured
sample temperatures were liquid Sb40S60 at 630 C
and 800 C, Sb44S56 at 720 C and 800 C and
Sb90S10 at 720 C and 800 C.

Sb 44S 56 at 993 K3
S b 40S 60 at 1073 K2
S b 40 S 60 at 903 K
1

0

0

5

10

15

20

q (Å -1)

Fig. 1 Structure factors for liquid Sb-S mixtures.

25

30

6

3

5
S b 44 S 56 a t 1 0 7 3 K

S b 90 S 10 a t 1 0 7 3 K

4

2

g(r)

g(r)

S b 44 S 56 a t 9 9 3 K
3
S b 40 S 60 a t 1 0 7 3 K

S b 90 S 10 a t 9 9 3 K

21
S b 40 S 60 a t 9 0 3 K
1

0

0

1

2

3

4

5

6

7

8

9

10

r(Å )

Fig. 2 Total correlation functions of liquid Sb40S60 and Sb44S56
mixtures.

Te. The period of oscillation in S(q) for Sb90S10 isquite different from those for Sb40S60 and Sb44S56.
Figures 2 and 3 show the g(r) for Sb-S mixtures
calculated from Fourier transforms of the structure
factors truncated at about 30 Å -1. Distinct two peaks
are observed between 2.0 and 3.0 Å in g(r) for liquid
Sb40S60 and Sb44S56. The parameters used in theanalysis and peak positions in g(r) are listed in Table.
The results of S(q) suggest that the chemical
short-range order and middle-range order exist in theliquid Sb40S60 and Sb44S56. It has been suggested
that the As-S and Sb-S systems in the glass state
have the AsS3 and SbS3 pyramidal unit [7]. The
S-S bond length in liquid sulfur is 2.06 Å and the
Sb-Sb bond length in liquid Sb is 3.30 Å. The
difference between the S-S and Sb-Sb bond length islarge enough to distinguish respective peak positions
with sufficient accuracy. In the crystalline Sb40S60,
the average Sb-S bond distance is about 2.57 Å.
The study of As-Sb-S ternary glasses suggests the
local structure of SbS3 pyramidal unit with an Sb-S
bond distance of about 2.45-2.50 Å. Then the firstpeak observed at r = 2.42 Å in g(r) for Sb40S60 can bereasonably assigned to be Sb-S bonds. The bonddistance of Sb-S in liquid Sb40S60 is shorter thanthose in crystalline and glassy states. The second
peak at 2.86 Å seems to mainly reflect the Sb-Sb and
S-S correlations as a second neighbor. Distinct two
peaks in g(r) suggest that the SbS3 pyramidal units
linked by the sulfur atoms exist in liquid Sb40S60
and Sb44S56. The correlation between the pyramidal
units would be mainly responsible to the FSDP [8].
The profile of g(r) suggests that the liquid structureof Sb90S10 seems to be quite different from those of

0

0

1

2

3

4

5

6

7

8

9

10

r(Å )

Fig. 3 Total correlation function of liquid Sb90S10 mixture.

liquid Sb40S60 and Sb44S56. The intensity of the firstpeak in g(r) for Sb90S10 becomes small, which isrelated to the small concentration of S, and theposition of first peak slightly shifts to the lower side.
Thus the bond distance of Sb-S becomes short in
Sb-rich Sb-S mixtures. The electronic properties ofliquid Sb90S10 is metallic while liquid Sb40S60 and
Sb44S56 are semiconducting. The non-metal-metaltransition occurs at intermediate composition. The
observed difference in the structural parameterssuggests that the change in the electronic property
and the existence of two-phase region in the Sb-S
system seems to be closely related to the differencein the local atomic structure.
References
1) M. Cutler, Liquid Semiconductors, Academic
Press, New York, 1977.
2) Y. Tsuchiya, J. Phys. Soc. Jpn. 60 (1991) 227.
3) T. B. Massalski, H. Okamoto, P. R. Subramanianand L. Kacprzak, Binary Alloys Phase Diagrams(AMS International, Metals Park, OH, 1992) 2nded.
4) J. Ledru et al., J. Non-Cryst. Solids 232-234(1998) 634.
5) E. Bychkov et al., J. Non-Cryst. Solids 159 (1993)
162.
6) K. Suzuki et al., Nucl. Instrum. and Meth. 147(1977) 519.
7) M. Raghni et al., J. Non-Cryst. Solids 192 & 193(1995) 191.
8) L. Červinka et al., J. Non-Cryst. Solids 150(1992) 132.

177

Hydrogen-Bonded Structure of Concentrated Aqueous Solutions Involving
DL- and L-Alanine Molecules
Y. KAMEDA, M. SASAKI, M. YAEGASHI, Y. AMO, and T. USUKI
Department of Material and Biological Chemistry, Faculty of Science, Yamagata University,
Yamagata 990-8560
The optical activity of amino acid molecules plays
an important role in various fields of chemistry andbiology.
Although the chemical properties ofL-amino acids and the DL-racemic mixture(equimolar mixture of D- and L-amino acidmolecules) are identical, the solubility in water isknown to be slightly different between L- andDL-compounds.
This solubility difference isenhanced when the solvent is substituted by heavy
water. However, an experimental study on theeffects of the different optical activity of solute
molecules on the intermolecular hydrogen bonds
among solvent molecules has not yet been reported.
In order to deduce information on the intermolecularhydrogen bonds in solution, neutron diffraction is
one of the most suitable experimental techniques.
In the present paper, we describe the results ofneutron diffraction measurements on aqueous 2.5
mol% DL- and L-alanine solutions in D2O in order
discuss the effects of differences in the opticalactivity of amino acid molecules on theintermolecular hydrogen-bonded structure inaqueous solution [1]. The difference interferencefunction, i(Q), was determined from the difference
between the scattering cross sections observed for
DL- and L-alanine solutions in which 96.1 % of theexchangeable hydrogen atoms have been substituted
by deuterium atoms. The difference distributionfunction, g(r), was obtained from the Fouriertransform of the observed i(Q).
DL-CH3CH(NH2)COOH
and
L-CH3CH(NH2)COOH (natural abundance, Nacalai
Tesque, guaranteed grade) were dissolved in D2O(99.9 % D, Aldrich Chemical Co., Inc.) to prepare
aqueous 2.5 mol% alanine solutions with different
optical activities. Sample solutions were sealed
into cylindrical Ti-Zr null alloy cells (8.0 mm in
inner diameter and 0.3 mm in thickness). TOF
neutron diffraction measurements were carried out at

178

25°C using the HIT-II spectrometer installed at theHigh Energy Accelerator Organization (KEK),
Tsukuba, Japan. Scattered neutrons were detectedby 104 3He counters covering a scattering angle of
10  2  157°.
The observed scattering intensities corrected forthe instrumental background, absorption of both thesample and cell, were converted to the absolute scaleby the use of corrected scattering intensities fromthe vanadium rod. The difference function, i(Q),between the scattering cross sections observed for
DL- and L-alanine solutions in D2O is obtained asfollows:
i(Q) = (d/d)obs (for DL-alanine solution)- (d/d)obs (for L-alanine solution).

(1)

The intramolecular interference term and theinelasticity contribution arising from the H and D
nuclei is expected to cancel out in the present i(Q)function. Since the i(Q) from the 64 sets ofFig. 1a) Circles: Observed difference interferencefunction, i(Q), between the DL- and L-alanine solutions.
Solid line: The best-fit of the calculated interference termin Eq. 3. b) The difference between observed andcalculated i(Q).

forward angle detectors located at 10 251°agree well within the statistical uncertainties, they
were combined at the Q-interval of 0.1 Å-1, andemployed for the subsequent analysis.
Theg(r), wasdifference distribution function,
evaluated by the Fourier transform,g(r) = (2Qmaxr2)-1 Q i(Q) sin(Qr) dQ.

(2)0

The upper limit of the integral was set to Qmax = 20
Å-1. Since the sum of contributions from the
O-Hex and Hex-Hex partial structure factors
corresponds to 86 % of the observed totalinterference term in the present experimental
conditions, the present g(r) reflects the differencein the intermolecular hydrogen-bonded structure
between the DL- and L-alanine solutions.
In order to obtain quantitative information on thepresent i(Q) observed from the TOF neutron
diffraction measurement, a least squares fitting
analysis was adopted. In the refinement procedure,
the following model function was employed:
imodel(Q) =(2- ij) ci nij bi bj
exp(-lij2Q2/2)sin(Qrij)/(Qrij),(3)

where ij = 1, (i = j) and ij = 0, (i j). ci denotes
the number of atoms i in the stoichiometric unit,
nij stands[CH3CH(N*H2)COO*H]x(*H2O)1-x.
for the difference in the coordination number
between the DL- and L-alanine solutions.

Parameters nij, lij, and rij, were determined by
the least squares fit of Eq. 3 to the observed i(Q).
The fitting was performed in the range of 2.5 Q
Parameters for the nearest neighbor
15 Å-1.
O...Hex and Hex...Hex interactions were refinedindependently. The positive peak appearing at r ~3.5 Å was assumed to be a single interaction in orderto reduce the number of independent parameters andalso to improve the fit in the lower-Q region.
The imodel(Q) calculated from the best-fit
model was compared with the observed i(Q) in Fig.
1. A satisfactory agreement is obtained between
the observed and calculated difference functions.
The corresponding distribution function g(r) isrepresented in Fig. 2. The final values of all
independent parameters are summarized in Table 1.
The values of the nearest neighbor intermolecular
O...Hex and Hex...Hex distances were slightly larger
than those determined from the partial structure
factors for the DL-alanine solution. This suggeststhat the average intermolecular hydrogen bonded
O...Hex and Hex...Hex distances in the L-alanine
solution might be slightly longer than those in the
DL-alanine solution.
The difference in thecoordination number for the nearest neighborintermolecular O...Hex interaction nOHex was
obtained to be –0.031(5), which corresponds to
1.9 % of the value of nOHex = 1.64(2) obtained forthe DL-alanine solution [1]. The magnitude of thepresent nHexHex ( = -0.072(5) ) is 2.5 % of thecoordination number for the nearest neighborHex...Hex interaction. These results suggest thatthe intermolecular hydrogen bonds in the L-alanine
solution are ca. 2 % stronger than those in the
DL-alanine solution.
Table 1. Results of the Least-Square Refinement for the
Difference Interference Function, i(Q), between 2.5 mol%DL- and L-Alanine Solutionsa)
i...j
r /Å
l /Å
n
O...Hex(I)H ...Hij

ij

1.99(3)0.170(8)-0.031(5)2.54(2)0.23(5)-0.072(5)O...Hex(II)b)

3.57(1)0.32(2)0.052(4)

ex

a)
b)

Fig. 2 Circles: Observed difference distribution function,g(r), truncated at Qmax = 20 Å-1. Solid line: The Fouriertransform of the solid line in Fig. 1a. Contributions fromthe short-range interactions are denoted by broken lines.

exij

Estimated standard deviations are given in parentheses.
Involving contributions from O...Hex, Hex...Hex, and O...Ointeractions.

Reference
1) Y. Kameda, M. Sasaki, M. Yaegashi, Y. Amo
and T. Usuki, Bull. Chem. Soc. Jpn., 77 (2004)
1807.

179

Low Energy Excitations for the Binary Glass of Water and Glycerol
A. INABA and N. SAKISATO
Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University,
Toyonaka, Osaka 560-0043

180

data collection for each measurement was 9~10
hours.
Fig. 1 illustrates the dynamic structure factor forthe glycerol/water solutions obtained at 10 K. All of
the data obtained from different scattering angles are
summed to improve the statistics. The data arenormalized by the number of protons present in thecell.

S(Q, )

40%
20%
H2O

S(Q, )055% (as quenched)

00Fig. 155% (crystallized)

H2O

0S(Q, )Our recent neutron diffraction measurements forthe binary system of water and glycerol demonstrate
the formation of a two-dimensionally ordered ice in
the initial stage of crystallization from the solution[1]. We also made heat capacity measurements on
this system [2]. The binary mixtures with glycerol
contents more than 55% w/w yielded homogeneous
glassy states, of randomly mixed water and glycerol
molecules, with glass transition temperatures thatextrapolate well to that for pure water (135 K).
Mixtures in the range 0-50% w/w glycerol,
crystallized partly on cooling, yielding threeanomalies in the temperature drift rate measured onheating, and these are associated with: (i) the onsetof reorientational motions of the H2O molecules inhexagonal ice, which increases from 107 to 120 K
with increasing glycerol concentration, (ii) the glasstransition of the maximally freeze-concentrated
solution at 164 K and, tentatively, (iii) ice
devitrification followed by ice dissolution yields
anomalies in the range 185-202 K. A sample with
60% w/w glycerol content exhibited two
distinguishable crystallization peaks on heatingwhere the initial one is large and apparently
associatedwithcrystallization
intoa
two-dimensionally ordered structure and the second
is due to a further transformation into hexagonal ice.
The purpose of the present study is to investigate
the glassy behavior of the glycerol/water systemwith different concentrations by means of incoherent
inelastic neutron scattering at low temperature. The
low energy excitation (Boson peak) may be thesignature to characterize the glass.
The neutron scattering experiments were
performed on LAM-40 spectrometer. The samples
studied were all protonated, C3H5(OH)3 and H2O.
The concentrations explored were 0, 10, 20, 40, 55,
80, and 100 w/w%. After the sample was quenchedwith liquid nitrogen outside of the cryostat, it wasplaced in the cryostat (at 100 K) and cooled further
down. All of the measurements were performed at
10 K. Also performed was the measurement for the
sample with 55 w/w% after completion of
crystallization of ice at 220 K. The time spent for the

80% 55% (as quenched)
Glycerol5

E / meV10

Dynamic structure factors for glycerol/water
solutions obtained at 10 K.

The spectra obtained for the solutions withhigher concentration than 55 % (quenched) showeda typical low energy excitation as seen in the glass.
The spectra obtained for the solutions with lower
concentration than 55% (crystallized) showed thepresence of crystalline ice as well as some glass
mixture.
References
1) A. Inaba et al., J. Neutron Research 13 (2005)
87.
2) A. Inaba and O. Andersson, to be published.

Formation of 2-D Ice at the Initial Stage of Crystallization
in a Binary Solution of Water and Glycerol
A. INABA and N. SAKISATO
Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University,
Toyonaka, Osaka 560-0043
diffraction patterns obtained for the 40 % w/w
solution. The background contribution has alreadybeen subtracted. The reflection indices are given
based on the ice Ih structure. The pattern at 150.1 K
shows two prominent Bragg peaks. The one is at
Q=17 nm–1 with a small shoulder at Q=16 nm–1, thefeature of which is essentially the same as thatobserved at the initial stage of crystallization for the
55% w/w solution [1]. This demonstrates that theD2O crystallizes in 2-D like ice at low temperature.
At higher angles, the Bragg peaks with (H0L)
reflections do not appear at 150.1 K and 190.8 K,
where the first crystallization occurs. The results
obtained here, therefore, demonstrate that ourinterpretation of the diffraction pattern [1] is valid.
260.2 K
100 002101
250.0 K

Intensity (arb. units)

Our recent neutron diffraction measurements forthe binary system of water and glycerol demonstrate
the formation of a two-dimensionally ordered ice in
the initial stage of crystallization from the solution[1]. We also made heat capacity measurements on
this system. The binary mixtures with glycerol
contents more than 55% w/w yielded homogeneous
glassy states, of randomly mixed water and glycerol
molecules, with glass transition temperatures thatextrapolate well to that for pure water (135 K).
Mixtures in the range 0-50% w/w glycerol,
crystallized partly on cooling, yielding threeanomalies in the temperature drift rate measured onheating, and these are associated with: (i) the onsetof reorientational motions of the H2O molecules inhexagonal ice, which increases from 107 to 120 K
with increasing glycerol concentration, (ii) the glasstransition of the maximally freeze-concentrated
solution at 164 K and, tentatively, (iii) ice
devitrification followed by ice dissolution yields
anomalies in the range 185-202 K. A sample with
60% w/w glycerol content exhibited two
distinguishable crystallization peaks on heatingwhere the initial one is large and apparently
associatedwithcrystallization
intoa
two-dimensionally ordered structure and the second
is due to a further transformation into hexagonal ice.
The purpose of the present study is to investigate
the dynamics of glycerol and the structure of D2O
simultaneously at lower concentrations.
The solutions were made from partiallydeuterated glycerol, C3H5(OD)3, in D2O. The
concentrations were 25, 40 and 55 w/w%. After
quenched into a liquid nitrogen bath, the samples
were set into a cryostat which had been cooled
beforehand at 100 K. The neutron scatteringexperiments were performed on the LAM-40
spectrometer. The measurements were made at thetemperature between 10 and 280 K. The data werecollected for 2~3 hours at each measurement.
The 25% w/w solution was found to form ice I h
at low temperature, whereas the 40% w/w solution
was found to show different behavior from othertwo solutions. Figure 1 illustrates the neutron

102

110

103 200

230.8 K
210.9 K
200.7 K
190.8 K

0

Fig. 1150.1 K

20

–1

Q / nm30

Neutron diffraction patterns for 40% w/w glycerol
solution of D2O obtained with the diffraction
counter installed on LAM-40.

However, this can be understood by considering thatcrystallites of ice Ic are also formed and the numberof the crystallites are considerably larger than that of
the 2-D like ice crystallites since the 220 d-spacingof ice Ic is the same as the 110 d-spacing of ice Ih. It
181

182

25% Glycerol/D2O
40% Glycerol/D2O
55% Glycerol/D2O

2

4

2

–4

<u > / 10 nm

should be noted here that the transition from 2-D ice
to ice Ih in 40% solution begins at 200 K lower by
about 10 K than that for 55% solution.
Figure 2 shows the mean square displacement ofglycerol in the aqueous solutions derived from the Q
dependence of incoherent elastic intensity at eachtemperature. Because the spectra contain thecontribution from coherent scattering as well as
incoherent scattering, the calculation of the meansquare displacement has been done taking accountof the coherent scatting contribution. Above 240 K
quasielastic broadening appears which prevent us toapply this calculation. The results for the 25%
solution are close to those reported for pure glycerol[3], indicating that the system is separated into twophases, the glycerol rich phase and the ice Ih phase,at low temperature. For the 40% solution, the meansquare displacement of glycerol is larger than thatfor the 25% solution, although the temperaturedependence is qualitatively similar to each other.
This suggests that the glycerol phase contains a
number of D2O molecules which affect fast
vibrational motions of glycerol molecules. The
results for 55% solution show another behavior.
Below 150 K, i.e., below Tg confirmed by DSC
measurement (Tg ~ 160 K), the temperaturedependence is qualitatively different from the others.
This indicates the formation of glass of thehomogeneous mixture of glycerol and D2O. At the
beginning of ice crystallization, the mean squaredisplacement jumps to higher values close to thosefor the 40% solution. It is interesting to note that thevalues at the temperatures where the transition from
2-D ice to ice Ih begins (200.7 K for the 40%
solution and 209.2 K for the 55% solution) aresimilar to each other. This may suggest that fast
dynamics of glycerol play a role for crystallization
process of ice Ih in the glycerol/water mixture.

200
Fig. 2

100
T/K

200

The mean square displacement of glycerol inaqueous solutions derived from incoherent
elastic scattering.

References
1) A. Inaba et al., J. Neutron Research 13 (2005)
87.
2) J. K. Kjems et al., Phys. Rev. B, 13 (1976) 1446.
3) J. Wuttke et al., Phys. Rev. E, 52 (1995) 4026.

Small Angle Neutron Scattering of Two-dimensionally Ordered Ice
Formed in a Binary Solution of Water and Glycerol
A. INABA and N. SAKISATO
Research Center for Molecular Thermodynamics, Graduate School of Science
Osaka University, Toyonaka, Osaka 560-0043
180 K (17 h)
180 K (54 h)
185 K

190 K
195 K
200 K

205 K
210 K
220 K

I(Q)

0.1

175 K
180 K
180 K (6 h)

0.08

0.1
I(Q)

Our recent neutron diffraction measurements forthe binary system of water and glycerol demonstrate
the formation of a two-dimensionally ordered ice in
the initial stage of crystallization from the solution[1]. We also made heat capacity measurements on
this system. The binary mixtures with glycerol
contents more than 55% w/w yielded homogeneous
glassy states, of randomly mixed water and glycerol
molecules, with glass transition temperatures thatextrapolate well to that for pure water (135 K).
Mixtures in the range 0-50% w/w glycerol,
crystallized partly on cooling, yielding threeanomalies in the temperature drift rate measured onheating, and these are associated with: (i) the onsetof reorientational motions of the H2O molecules inhexagonal ice, which increases from 107 to 120 K
with increasing glycerol concentration, (ii) the glasstransition of the maximally freeze-concentrated
solution at 164 K and, tentatively, (iii) ice
devitrification followed by ice dissolution yields
anomalies in the range 185-202 K. A sample with
60% w/w glycerol content exhibited two
distinguishable crystallization peaks on heatingwhere the initial one is large and apparently
associatedwithcrystallization
intoa
two-dimensionally ordered structure and the second
is due to a further transformation into hexagonal ice.
The purpose of the present study is specificallyto investigate the crystallization behavior by meansof small angle neutron scattering. The two-step
crystallization is identified.
The sample investigated was partially deuterated
glycerol, C3H5(OD)3, in D2O with a concentration of
55% w/w. A flat aluminum can (28×26×2 mm3) was
set in a conventional refrigerator to cool the sample
from room temperature to 150 K (cooling rate ~1.6
K min–1). The neutron scattering experiments were
performed on the SWAN spectrometer. The
measurements were performed at 11 temperatures
between 150 K and 220 K. The sample wasannealed at 180 K for 54 hours in total to investigate
the annealing effect on the crystallization. The data
were collected for about 4 h at each temperature.

0.08

1.5
–1
Q/Å
Fig. 1

2

1.5
–1
Q/Å

2

Neutron diffraction patterns for 55% glycerol
solution in D2O obtained with high angle
detectors. The annealing time is indicated.

Figures 1 illustrates neutron diffraction patterns
obtained with the detectors installed at the highangle detector bank. The result at 175 K shows apattern characteristic of some disordered state. This
demonstrates that the conventional cooling was stillenough to realize a homogeneous glass. A Bragg
peak started to appear at 180 K, as seen in theprevious neutron diffraction measurements [1]. Ashoulder at Q=1.6 Å–1 strongly suggests that 2-D
like ice crystallites are formed at 180K. It is clearthat the pattern obtained at 180 K after annealing forsome time (17 h) did not change very much byfurther annealing (54 h). The 2-D like ice is quite
stable at 180 K. The crystallization process above
190 K observed here is essentially the same as
observed in the previous structural study [1].
Fig. 2 illustrates the SANS spectra. The intensity
substantially increases between 175 K and 180 K
where 2-D ice appears. This shows that a large
number of micro crystallites of 2-D ice are formed at
the initial stage of nucleation. The intensity
increases further at 190 K and then gradually
183

2

I(Q)

10

180 K (17 h)
180 K (54 h)
185 K

175 K
180 K
180 K (6 h)

10

10

8

6

4

2
0

2

0
0

205 K
210 K
220 K

190 K
195 K
200 K

Fig. 3I(Q)10from the fact that the Porod region gradually shifts
to lower angle side with temperature increase. It isnoted here that the lowest angle side of the spectra at
180 K before annealing curves upward, preventing
us to apply the Guinier approximation. This may be
due to interference among 2D ice crystallites.

ln(I(Q))

decrease, indicating that the ice crystallites growsuccessively. It is evident that the SANS spectra do
not change significantly above 200 K where thetransition from 2D ice to ice Ih occurs. It should be
noted here that the slope at the Q region of the orderof 10–2 for the spectra above 180 K can be welldescribed by Porod law [2], showing that the system
was separated into two phases between which theinterface is sharp. The spectrum at 180 K before
annealing has, however, another regime between the
Porod and the Guinier region (see below) where theslope is proportional to Q–1.7~ Q–1.9, indicating thatsome fractal structure appears at the initial stage ofcrystallization.

010
Fig. 2–2–1

0

10 –1 10
Q/Å

–2

10

–1

10 –1 10Q/Å

0

Small angle neutron scattering spectra obtainedfor 55% glycerol solution in D2O.

Fig. 3 shows Guinier plot of the spectra obtained
at 180 K. The radius of gyration Rg for eachannealed sample at 180 K is estimated using the data
where QRg < 1.7, 137 Å for the 6 h annealed sample,
139 Å for the 17 h annealed sample and 161 Å forthe 54 h annealed sample. If we assume a simple
uniform geometrical body of a sphere of radius R,
this enables us to estimate the radius R using therelation Rg2=3R2/5. The resulting values are 177, 179,
and 208 Å, respectively. This shows that the mean
particle size of ice crystallite formed at the initialstage of crystallization extends over 350 Å. At thehigher temperatures, the slopes of the spectra in the
Guinier regime is so steep that the Guinier
approximation cannot be applied, indicating that theice crystallite size becomes considerably larger withtemperature increase. This can also be seen in Fig. 2
184

180 K
180 K (6 h annealed) (Rg = 137 Å)
180 K (17 h annealed) (Rg = 139 Å)
180 K (54 h annealed) (Rg = 161 Å)
185 K
0.00022–2
Q /Å0.0004

Guinier plot of the spectra for 55% glycerol
solution in D2O.

References
1) A. Inaba et al., J. Neutron Research 13 (2005)
87.
2) G. Porod, Kolloid-Z., 124 (1951) 83.

Local Structure and Dissolution Characteristics of CsCl-NaCl Melts
Y. IWADATE, N. UMESAKIa, M. MISAWAb, T. FUKUNAGAc, N. OHTORIb, K. ITOHc,
K. FUKUSHIMA, A. KAJINAMId, H. MATSUURAe, M. MYOCHINf, H. KOFUJIf,
K. SUZUKI, T. MICHII and T. MURAYOSHI

Graduate School of Science and Technology, Chiba University, Inage-ku, Chiba, 263-8522
a
JASRI, bNiigata Univ., cKyoto Univ., dKobe Univ., eTokyo Inst. Techn., fJAEA
The most distinctive property of ionic liquids
consists in huge Coulombic interactions amongcharged species in comparison with other liquids
such as molecular liquids and so on. The ionicinteraction between unlike ion pair, even formonovalent ion pair, amounts to some hundreds kJ
Thus, this strong attractive
mol-1 at maximum.
interaction is thought to give some characteristic
effects of mixing and pressure to translational
dynamics such as electrical conductivity, diffusion
coefficient, and internal mobility [1]. Even in most
simple alkali halide liquids, the situation issomewhat complicated. In molten salts including
divalent or trivalent ions, the phenomena may be
still more complex. In the present work, shortrange structure of alkali chloride binary melts werestudied by time of flight pulsed neutron diffractionin order to make clear their solvent features.
The chemicals with reagent grade were dried
under vacuum at temperatures lower than therespective melting points for 8h, melted, and rapidly
quenched.
Accurately weighed samples weremixed and installed into the diffraction cell made of
fused silica. Diffraction experiments were madewith HIT-Ⅱat High Energy Accelerator Research
Organization, Tsukuba.
The structure factor S(Q) was obtained from themeasured scattering data which were corrected forbackground, absorption by the sample and the cell,
multiple and incoherent scatterings, and thennormalized with a vanadium rod as a referencematerial. The peak positions in S(Q) were nearly
independent of alkali chloride composition with asmall variation of intensity. There was no prepeakin S(Q) of CsCl-NaCl melts, as was often the casewith amorphous materials. On fusion of thesematerials, there appeared no medium and /or longrange orderings. The correlation functions G(r)’sof CsCl-NaCl melts are shown in Fig. 1. Taking
the ionic radii [2] into consideration, the peaks in
G(r)’s at about r =0.34nm, 0.28nm, and 0.40nm
were assigned to the correlations of Cs-Cl, Na-Cl,

and Cl-Cl ionic pairs, respectively. Analyses ofionic correlations, that is the optimization of
structural parameters, were made in the reverse
lattice space using the correlation method in which a
non-linear least squares regression was applied to
the Debye scattering equation [3]. The interferencefunction Q・i(Q) of molten CsCl-NaCl reproduced
from the optimized structural parameters are
depicted in Fig. 2 together with the experimental Q・i(Q).
Coordination numbers and interionicdistances of the respective ionic correlations wereclose to those of pure component melts reported in
the literature [4]. According to neutron diffraction
study on LiCl-CsCl melts [5], the nearest neighbor
Li-Cl distances were reported to decrease withincreasing CsCl concentration. This is because theinternal mobility of Li+ ion decreased withincreasing number of Cs+ ion so that the ionicbonding of Li-Cl became more restrained than ever.
Similar phenomena were expected to occur in
CsCl-NaCl, RbCl-NaCl, and LiCl-NaCl melt
systems, even CsCl-NaCl system possessing a large
difference between cation radii like LiCl-CsClbehaved unlikely in LiCl-CsCl system. CsCl-NaClmelts was thought to have good solvent properties
with large polarities.
Conclusions were summarized as follows. The
short-range structure of CsCl-NaCl melt as well as
RbCl-NaCl and LiCl-NaCl melts has been
investigated by a time-of-flight pulsed neutron
diffraction. The structural parameters for eachatomic pair were optimized in the Q-space, and thenear neighbor Cs-Cl, Rb-Cl, and Li-Cl correlations
were estimated at about r =0.34, 0.31, and 0.24nm,
respectively.
Coordination numbers andinteratomic distances of each correlation were close
to those of pure component melts reported in theliterature. According to Raman spectroscopy little
complex ion exists in molten CsCl-NaCl,
RbCl-NaCl, and LiCl-NaCl systems, and thus the
mixture melts are thought to be dissociated into
discrete ions.
185

2
3 C s C l- N a C l

G(r)

1
0
2
2 C s C l - Na C l

1
0

0.2

0.4

r / nm

0.6

0.8

1

Fig. 1 Correlation function G(r) ofmolten CsCl-NaCl at 893K

Ob s e r v e d
Ca l c ul a t i o n

Q·i(Q)

3 C s C l - Na C l

2 C s C l - Na C l

0100

Fig. 2200
Q / nm -1

Ob s e r v e d
Ca l c ul a t i o n

300

400

Interference function Q・i(Q) of
molten CsCl-NaCl at 893K

References
1) S. Okazaki, I. Okada, Kikan Kagaku Sosetsu,
1995, No. 25., PP.111-123.
2) R. D. Shannon, Acta. Cryst., A32 (1976) 751.
3) A. H. Narten, J. Chem. Phys., 56 (1972) 1905.
4) H. Ohno, K. Igarashi, N. Umesaki, K. Furukawa,“X-Ray Diffraction Analysis of Ionic Liquids”,
Trans Tech Publications, 1994, p.19.
5) Y. Miyamoto, S. Okazaki, O. Odawara, I. Okada,Mol. Phys., 82 (1994) 887.

186

Analysis of Dissolution Characteristics of Rare Earth Chlorides and Oxychlorides
Y. IWADATE, N. UMESAKIa, M. MISAWAb, T. FUKUNAGAc, N. OHTORIb, K. ITOHc,
K. FUKUSHIMA, A. KAJINAMId, H. MATSUURAe, M. MYOCHINf, H. KOFUJIf,
K. SUZUKI, T. MICHII and T. MURAYOSHI

Graduate School of Science and Technology, Chiba University, Inage-ku, Chiba, 263-8522
a
JASRI, bNiigata Univ., cKyoto Univ., dKobe Univ., eTokyo Inst. Techn., fJAEA
One of the nuclear spent fuel reprocessing, that isoxide electrodeposition in molten salts, is promising
for reduction of nuclear wastes and collection of
UO2 and PuO2 as mixed oxides (called MOX) sincethistechnique is indispensable for nuclear
nonproliferation. However, there are problemｓ tobe solved for practical use such as improvement ofstability on system operation. In order to operate
the system safely and successively, it is of necessity
to eliminate ions interfering with electrolysis, todetermine the conditions such that UO22+and PuO22+
ions coexist stabilized, and to produce UO2 andPuO2 with a constant quality. The stability of
UO22+and PuO22+ ions in molten salts is thought tobe strongly dependent on the melt structure in thevicinity of their own.
For this purpose,
2CsCl-NaCl system has so far been regarded as a
candidate melt, but neither best set of salts nor
compositions after considering the operation
temperatures has not been determined yet. In thiswork, pulsed neutron diffraction was made for alkali
chloride binary melts and their mixture melts with
LaCl3 melt so as to predict the melting behavior of
actinyl ions. The structural information of molten
salts would be benefit of both innovation of theelectrodeposition processing and task-surmounting.
The alkali chloride chemicals with reagent gradewere dried under vacuum at temperatures lower than
the respective melting points for 8h, melted, andrapidly quenched. Since lanthanum trichloride isvery hygroscopic and the wetted LaCl3 is easily
converted into LaOCl at elevated temperature,anhydrous LaCl3 was prepared according to thefollowing reaction, La2O3 + 6NH4Cl → 2LaCl3 +6NH3 + 3H2O. The mixed sample was heated at
623K for 2h under vacuum, and then purified bysublimation under reduced pressure at 1300K for 8h
in order to remove oxychlorides as well as NH 4Cl
and La2O3 unreacted. Accurately weighed samples
were mixed, installed into the diffraction cell madeof fused silica, and sealed. Diffraction experiments
were made with HIT-Ⅱspectrometer at HighEnergyAccelerator
Research
Organization,
Tsukuba.
The structure factor S(Q) was obtained from themeasured neutron scattering data which werecorrected for background, absorption by the sample
and the cell, multiple and incoherent scatterings, andthen normalized with a vanadium rod as a referencematerial. The peak positions in S(Q) were hardly
dependent on the composition of component saltwith a small variation of intensity. There was noprepeak in S(Q), as was the usual case with solid
amorphous materials. On fusion of these materials,
there appeared no medium and /or long rangeorderings. The correlation functions G(r)’s ofmoltenCsCl-NaClsystemandmolten(2CsCl-NaCl)-LaCl3 system are demonstrated in
Figs. 1 and 2, respectively. Taking the ionic radii[1] into account, the peaks in G(r)’s of Fig. 1 at
about r = 0.34nm, 0.28nm, and 0.40nm wereassignable to the correlations of Cs-Cl, Na-Cl, and
Cl-Cl ionic pairs, respectively. The peaks in Fig. 2
were observed at around r = 0.28nm and 0.34nm,
which were thought to assigned to La-Cl pair andCs-Cl pair, respectively.
Analyses of ionic correlations, that is the
optimization of structural parameters, were made in
the reverse lattice space using the correlation
method in which a non-linear least squares
regression was applied to the Debye scattering
equation [2]. As for molten CsCl-NaCl system,
coordination numbers and interionic distances of therespective ionic correlations were close to those ofpure component melts reported in the literature [3].
According to neutron diffraction study on LiCl-CsClmelts [4], the nearest neighbor Li-Cl distances werereported to decrease with increasing CsCl
concentration.
This is because the internal
mobility of Li+ ion decreased with increasing
number of Cs+ ion so that the ionic bonding of Li-Cl
became more restrained than ever. Similar
phenomena were expected to occur in CsCl-NaCl,
RbCl-NaCl, and LiCl-NaCl melt systems, even187

CsCl-NaCl system possessing a large difference
between cation radii like LiCl-CsCl behaved
unlikely in LiCl-CsCl system. CsCl-NaCl melts
was thought to have good solvent properties withlarge polarities. According to Raman spectroscopy
little complex ion exists in molten CsCl-NaCl
system as well as molten RbCl-NaCl and LiCl-NaCl
systems, and thus the mixture melts are thought tobe dissociated into discrete ions.
It was expected from the structural parameters
precisely optimized for molten (2CsCl-NaCl)-LaCl3
system that the octahedral structure of complex ionof the type LaCl63- was stabilized by mixing LaCl3
with alkali chloride mixture melts. This wasinferred from the finding that the coordination
number of La-Cl pair in the mixture melt was closer
to 6 than that in the LaCl3 pure melt [5]. The
above information would be very useful to carry out
the simulation of electrolysis for actual actinyl
species.
Cs-Cl
Na-Cl

3CsCl-NaCl

G (r)

1

2CsCl-NaCl
1

0

0.2

0.4

0.6
r / nm0.8

1Fig. 1 Correlation function G(r)of molten CsCl-NaCl at 893K
Cs-Cl

0.8(2CsCl-NaCl)-0.2LaCl3

1
Na-Cl

G (r)

La-Cl

0.9(2CsCl-NaCl)-0.1LaCl3

1

0

0.2

0.4
0.6
r / nm0.8

1Fig. 2 Correlation function G(r) ofmolten 2CsCl-NaCl-LaCl3 at 973K
188

Remarks:
Since the solubility of rare earth oxychlorides was
too small to be detected by diffraction study, thedescription on this matter was deleted in this report.
References
1) R. D. Shannon, Acta. Cryst., A32 (1976) 751.
2) A. H. Narten, J. Chem. Phys., 56 (1972) 1905.
3) H. Ohno,K. Igarashi, N. Umesaki, K. Furukawa,“X-Ray Diffraction Analysis of Ionic Liquids”,
Trans Tech Publications, 1994, p.19.
4) Y. Miyamoto, S. Okazaki, O. Odawara, I. Okada,Mol. Phys., 82 (1994) 887.
5) J. C. Wasse, P. S. Salmon, J. Phys., 11 (1999),1381.

LARGE SCALE STRUCTURES

2003–2006

Basic Study on Estimation of Surface Roughness by Neutron Reflectometry
T. HIRAYAMA, K. INOUE*, T. EBISAWA**, S. TASAKI***, M. HINO****, N. TORIKAI*****
Dept. of Mechanical Eng., Doshisha Univ., Kyotanabe, Kyoto 610-0394, Japan
Dept. of Mechanical and Systems Eng., Ryukoku Univ., Seta, Shiga 520-2194, Japan**
Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan***
Dept. of Nuclear Eng., Sakyo-ku, Kyoto 606-8501, Japan****
Kyoto University Research Reactor Institute, Kumatori, Osaka 590-0494, Japan*****
KEK, Tsukuba, Ibaraki 305-0801, Japan

Introduction
Tribological phenomena usually occur at asolid-solid interface. To examine a tribologicalphenomenon at a lubricated or unlubricated interface,
information on the state at the interface must first be
obtained[1]. Observations of a state between metals,
however, are considered to be difficult because astandard electron beam cannot penetrate into eitherof the metal. Accordingly, the authors haveproposed a new observation method applying a‘neutron beam’ to such a metal-metal interface. It is
well known that a neutron beam can penetrate into
many kinds of common metals. The final purpose of
the study is to establish a new observation method of
metal interface by neutron scattering for depthful
discussion on tribology studies.
As a first impression, all mechanical surfaces
have roughness more or less. Effects of surface
roughness to tribological phenomena have beenmuch examined in past studies. However, for thecase of metal-metal interface, we have no effective
techniques to in-situ estimate its roughness. By theway, reflectometry, which is one scattering method,
is a way to get information through the reflectivityof a sample surface or the interface between
samples[2]. It is generally utilized for analysis ofvertical structures, especially for multi-laminar films.
Based on these studies, we firstly examined apossibility of the estimation of regular surface
roughness by neutron reflectometry in this paper.
Procedure of Experiment
Experimental apparatus
The experimental apparatus ‘ARISA’, which isone of a few neutron reflectometers, was used. It isan energy dispersive X-ray analyzer, installed in
KEK. The neutron beam naturally reflects from amaterial surface when the scattering vector q is
below a critical one q c . The q and q c are given
as follows:

(1)
(2)

q  4 sin  0 

q c  4 sin  0  cwhere the  0 is constant as set along the kind ofsample. Reflectometry is a method to grasp a
structure at surface or interface through a reflectivity
profile. The reflectivity is defined as a ratio ofintensity of a reflecting beam against that of anincidence beam[3].
Samples for surface roughness model
Most surfaces of solids used for tribology areusually rough, at least on a microscopic scale,especially those of engineering materials.
Roughness of a surface is one cause of friction inany case, and there are a lot of cases in which it isnecessary to grasp the state at the interface fortribological studies, such as in the process of“running in” or to “seizure” of two bodies. Firstly,
we focus on a regular surface roughness as a basic
study.
To confirm a reflectivity profile from a material
surface with periodical roughness, a well-defined‘grating’ sample, as shown in Figure 1, wasprepared. The grating sample was made by standard
photo lithography; namely, a nickel-grating film wasdeposited on a silicon-plane. The averaged film
thickness was 105 nm, the grating width was 10 µm,
and its pitch was 20 µm.
Nickel film
Silicon plate

Thickness

Width
Height [nm]

*

1200
1000
800
600
400
200
0
-200

0

50

100

Pitch

150

200

Position [µm]Fig. 1

Nickel grating sample for roughness model.

191

Experimental conditions
In the experiment, the constant incident angle
 0 was set as 0.34 degree. The divergence angle ofthe incident beam against  0 , which was estimatedby the optical alignment, was about 3 %.
Results and Discussion
Reflectivity from grating sample
Firstly, we obtained the reflectivity profiles fromthe above grating sample with rotating the grating
direction against the beam direction. The obtainedreflectivity profiles are shown in Figure 2. It is notedthat this reflectivity is ‘absolute’ figure, that is, theabsolute ratio of the intensity of detected beam
against the one of incident beam. We can see thatthe critical scattering vector q c becomes smallerwhen the grating angle against the beam, expressedas  g , becomes larger. Now, the reason for thechange of q c can be discussed with classifying into
three types focusing on  g .
10

Critical scattering vector

Reflectivity

1
0.1
0.01

0 deg.
18 deg.
30 deg.
45 deg.
60 deg.
90 deg.

almost agrees with q c of ‘one’ material having
average scattering length of silicon and nickel. It
indicates that the neutron can not recognize twomaterials when the interval of grating is extremely
narrow.
In all profiles, any Kisseig fringes were notshown. The reason will have to be examined in thenext step.
Reflectivity from the other grating sample
For much discussion, the other grating sample,
which is ‘silicon grating’, was prepared. The grating
was manufactured by etching technology on siliconplate; the averaged film thickness was 75 nm, thegrating width was 10 µm, and its pitch was 20 µm.
The obtained reflectivity profiles are shown in
Figure 3, where the red line show the result forparallel setting of the grating direction to theincident beam, while the blue one does for
perpendicular setting. For the only case of
perpendicular setting, we can see clear Kisseig
fringes in the profile. The experimental profiles wellagree with the theoretical ones; especially for theperpendicular setting, the theoretical profile iscalculated with the model of type (iii) in theprevious section.
100.0001

0

0.01

0.02

0.03

0.04

0.05

0.06

q [Å-1]

Fig. 2

Reflectivity profiles from grating sample.

(i) At the range  g  3 degree
When  g is extremely small, in short, when thegrating direction is parallel to the incident beam, thereflectivity at q =0 is almost 1.0, and the profiles
have two critical scattering vectors; one is due to thecritical vector of silicon, while the other is due toone of nickel. They agree with the theoreticalvalues.
(ii) At the range 3   g  50 degree
When  g is in this range, the critical scatteringvector is about 0.02 Å-1. This value almost agrees
with the average between the critical scatteringvector of silicon and one of nickel. It indicates thatthe neutron can recognize two materials even if
obscurely.
(iii) At the range 50   g  90 degree
When  g becomes large, in short, when thegrating direction is perpendicular to the incident
beam, the scattering vector is about 0.018 Å-1. It

192

Reflectivity (at free scale)

0.001

Exp. (parallel)
Theor. (parallel)Exp. (perpendicular)
Theor. (perpendicular)

1
0.1
0.01
0.001
0.00010.00001

0

0.01

0.02

0.03

0.04

0.05

0.06

q [Å-1]

Fig. 3

Reflectivity profiles from silicon grating sample.

Conclusion
To investigate an effect of surface roughness toneutron reflectivity profiles, two kinds of regulargrating samples were prepared. According to thegrating direction to incident beam, reflectivity
profiles were changed along the model type wesubmitted.
References[1] B. N. J. Persson, Sliding friction, Springer, 2000.
[2] R. Feidenhans’l, Surf. Sci. Rep., 10 (1989) 105.
[3] J. Daillant et al, X-ray and Neutron Reflectivity:
Principles and Applications, Springer, 1999.

Reflectometric Investigation of Hybrid Langmuir Films Consisting of a
Perfluorinated Fatty Acid and a Block Copolymer with Hydrophobic andPerfluoroalkyl Side Chains
K. MITAMURA,1) T. IMAE,1,2) N. TORIKAI,3) E. MOURI,4)and H. MATSUOKA 4)
1) Graduate School of Science, Nagoya University, 2) Research Center for Materials Science,
Nagoya University, 3) KENS, KEK, 4) Faculty of Engineering, Kyoto University
It was referred from the obtained depth - density curvethat the monolayers were explicitly separated into
dendron block, perfluorinated, and carboxyl acid layers.
Furthermore, the SLD of dendron layer was decreased
withincreasing
themixingratio
ofperfluorooctadecanoic acid, indicating the decrease in
the occupation of dendron moiety. These experimental
facts are consistent with the expectation of layer model
described above and supported the structure oflongitudinally phase-separated hybrid film. The layer
formation is resulted not only from the intermolecularinteraction between perfluorinated fatty acids and block
copolymers but also from the geometry or shape of themolecules.
12108Depth / nm

Controlling morphology of a thin film is
indispensable for optimizing physical characters such as
wetting and tribology of the film. A block copolymer,
poly (3,5-bis(3,5-bis(benzyloxy) -benzyloxy)benzyl
methacrylate-random-methacrylicacid)-block-poly(2-perfluorooctylethyl
acrylate)(M2den3) form spherical micelles in solutions.1)
However, its Langmuir film at air/water interface
displays unique morphology of the strip-like aggregates,
because the polymer consists of hydrophobic andsolvophobic side chains.2) If an amphiphile familiar toboth polymer and water is mixed the polymer, themodification of the film morphology can be expected.
In the present work, hybrid Langmuir films of aM2den3 and a perfluorooctadecanoic acid at different
mixing ratios were investigated by neutronreflectometry, and the structures of the hybrid films
were examined.
At air/water interface, a perfluorooctadecanoic acidarranges with the molecular orientation, wherehydrophilic carboxylic acid moiety anchors in water andalkyl chain moiety locates at air phase owing to its
solvohobicity.3) Then the perfluorinated block inM2den3 is expected to localize in the perfluolinatedalkyl chain domain of fatty acids. Thus, the hybrid
Langmuir films should consist of three layers, that is,layers of hydrophobic (dendron), solvophobic(perfluorinated) and hydrophilic (carboxylic acid)moieties, as inserted in Fig 1.
Neutron reflectivity measurement was carried out onan ARISA of KEK in Tsukuba, Japan. Hybrid Langmuirmonolayers prepared at air/D2O interface wascompressed up to a surface pressure of 15 mN/m andused for the measurement. Based on the Fresnel
equation and the five layer (including air and waterlayers) model, the carve fitting of calculated one withobserved one was carried out, and the optimum set ofthe parameters was determined. Depth – scattering
length density (SLD) profile at a mixing ratio 4 of fatty
acid to M2den3, which was illustrated from theparameters at optimum condition, is shown in Figure 1.

dendron6

fluorocarbon

4

COOH
2

D 2O

0
0.0

-4

1.0x10-4

2.0x10-4-4

3.0x104.0x10-4

5.0x10-4

6.0x10-2

SLD / nmFig.1. The depth – SLD profile where a mixing ratio ofperfluorinated fatty acid to M2den3 is 4. Insert:
illustration of phase-separated hybrid Langmuir film
structure.

References
1) Takahashi, M; Hamaguchi, S.; Ito, H.; Imae, T.;
Nakamura, T., Progr. Colloid Polym. Sci., 2004. 128,68.
2) Mitamura, K.; Takahashi, M.; Hamaguchi, S.; Imae,T.; Nakamra T., Trans. Mat. Res. Soc. J., 2004, 289,
255.
3) Imae, T.; Takeshita, T.; Kato M., Langmuir 2000, 16,
612.

193

Neutron Reflectometric Investigationof a Dendrimer/Nanoparticle Hybrid Film at Air/water Interface
K. MITAMURA,1) M. UJIHARA,1) N. TORIKAI, 2)
and T. IMAE*,1),3)
1)

Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan, 2)Neutron Science
Laboratory (KENS), High Energy Accelerator Research Organization, Oho, Tsukuba 305-0801, Japan, and3)
Research Center for Materials Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan

194

Accelerator Research Organization (KEK) in Tsukuba,
Japan.
-1

Type 2-2-3-4

observed

-5
-6
-7
0.0

0.5

1.0 1.5-1q (nm )

2.0

2.5

10

depth (nm)Type 10log (reflectivity)

Poly(amido amine) dendrimers with azacrown coreand hexyl spacers (aza-C6-PAMAM dendrimer) are
amphiphilic
andflexibleinstructure.1)
Amine-terminated aza-C6-PAMAM dendrimers wereadsorbed on gold and 3-mercaptopropionic acid
(MPA) self-assembled monolayer (SAM) substrates,
and multiadlayers were constructed.2) Langmuir films
at air/water interface were fabricated fromester-terminated dendrimers.3) Although silver
nanoparticles in subphase were adsorbed on
dendrimers with face-on conformation in Langmuirfilms, the adhesion was less and the adsorbed
nanoparticles were disordered.
In the present work, ester-terminals of aza-C6-PAMAM dendrimer were replaced to octyl groups inorder to intensify the amphiphilicity, and thedendrimer/nanoparticle hybrid films at air/waterinterface were investigated. Gold nanoparticles(Au-NP) were adsorbed on Langmuir films ofdendrimers and displayed fractal-like network texture
at low surface pressure. When the hybrid films werecompressed, the morphology of nanoparticle
aggregates was changed to monolayer, where
nanoparticles were uniformly dispersed and partly
ordered. The nanoparicles in the hexagonal latticearray are located on hydrophilic azacrown center inthe ordered lattice arrangement of dendrimers in
face-on conformation. Fourteen dendrimer molecules
were adsorbed on a nanoparticle but the location ofdendrimers on a nanoparticle was not elucidated.
The determination of dendrimer distribution on
nanoparticle surface was carried out using neutronreflectometry.
A
chloroform
solutionofoctyl-terminated aza-C6-PAMAM dendrimer was
spread on an Au-NP suspension subphase. After 1 hr,
the film was compressed until the surface pressure
reached to 5 mN/m and neutron reflectivity wasmeasured on an ARISA (Advanced Reflectometer forInterface and Surface Analysis) of High Energy

8dendrimer

6

Au-NP

4
2
0

-2

roughness of
Au-NP region

0

1

2

3

4

5

6

7 *1 0 -4-2
scattering Slength
L D (ndensitym ) (SLD)

Fig.1 (Left) An observed neutron reflectivity curve ofdendrimer/Au-NP hybrid Langmuir film and fitting curves
based on Type 1 and 2 models, which were inset in figure.
(Right) A depth vs. scattering length density profile ofdendrimer/Au-NP hybrid Langmuir film (based on Type2).

The observed neutron reflectivity curve in Fig. 1
displayed no characteristic fringes. Two types ofmodels were applied for the simulation analysis using
a theoretical equation. That is, (Type 1) dendrimers
surround fully the surface of the Au-NP and (Type 2)
dendrimers cover only the upper-half surface of
Au-NP. From the comparison with observed one, it
was indicated that only half of Au-NP surface iscapped by dendrimers. The scattering lengthdensity-depth profile evaluated from best-fit
parameters is shown in Figure 1. The calculated
depths of Au-NP and dendrimer layers werereasonable in consistency with their evaluated sizes.
References
1) Yemul, O.; Ujihara, M.; Imae, T. Trans. Mater. Res.
Soc. Jpn., 2004, 29, 165.
2) Ujihara, M.; Imae, T. J. Colloid Interface Sci.,
2006, 293, 333.
3) Ujihara, M.; Orbulescu, J.; Imae, T.; Leblanc, R. M.
Langmuir, 2005, 21, 6846.

Structural Observation of Block Copolymer Thin Films with Transmission Electron
Microtomography and Neutron Reflectivity
K. NIIHARA*, N. TORIKAI**, U. MATSUWAKI*, Y. NISHIKAWA* and H. JINNAI**Department of Polymer Science and Engineering, Kyoto Institute of Technology, Matsugasaki,

Sakyo-ku, Kyoto 606-8585, Japan**Neutron Science Laboratory, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba,
Ibaraki 305-0801, Japan
Introduction
Block copolymer thin films are particularimportance in many technological areas, including
microelectronics, coatings, lubricants, and adhesives[1]. Thus, phase-separated morphologies in the thinfilm have been investigated extensively in terms of
their orientation, periodicity etc. as a function offilm thickness, and/or surface energy. Surface
morphology can be observed by Atomic ForceMicroscopy (AFM), while concentration profile ofconstituent blocks along the film normal, i.e. along
depth direction, can be investigated either by crosssectional transmission electron microscopy (TEM)or, more statistically, by neutron reflectively (NR)measurement. It should be noted that none of theseexperimental techniques gives both lateral and depth
structural information at the same time. NR
measurement is widely used in a structural study ofthe block copolymer thin film, and gives a lot ofimportant results [2]. However, NR measurement
includes the hypothesis and model fitting on themorphologies, and thus this technique is limited torathersimplemorphology,e.g.,lamellarmorphology parallel to the substrate. Recently, thetransmission electron microtomography (TEMT) has
been extensively used in polymer society and foundto be a very effective tool for structural observation
as well as analysis [3]. TEMT directly provides thethree-dimensional (3D) image of the internal
structures of a block copolymer thin film [4]: Nanoscale morphology both lateral and depth directions
were successfully imaged. In this study, we try toestablish a novel methodology by utilizing the NR
coupled with TEMT (NR + TEMT), which enables
the structural analysis of nano-scale morphologies inthin films without any hypothesis and models. Thismethod will be further extended so as not only to
study lamellar-type simple morphology but also to
study more complicated morphologies such as
cylindrical morphology.

Experiments
Poly(deuterated styrene-block-2-vinylpyridine)(Mn(dPS)=10,2000,(dPS-b-P2VP),
Mn(P2VP)=37,000, Mw/Mn=1.10) thin films wereused for TEMT and NR. The equilibrium
microphase structure of the dPS-b-P2VP in bulk
state is lamellar. The thin films were prepared byspin-coating on a Si substrate from 4.0 wt % 1, 4dioxane solution, and then annealed at 170 ˚C for 10
days under vacuum. Then, the thin films were
stained by I2 vapor for 3 hours and coated withcarbon on free surface of thin films in order toenhance charge and heat transfer by vacuum
deposition . Ultra thin cross-sectional sections of thedPS-b-P2VP thin films for the TEMT experiments
were prepared by a focused ion beam (FIB)
instrument (JEM-9310FIB, JEOL, Co., Ltd., Japan)[5]. The cross-sectional sections were put on the Cumesh grid for TEMT experiments. Prior to TEMT
observations, the gold particles of 5 nm diameter
were placed on the ultrathin sections using the gold
colloidal solution (GCN005, BBInternational Ltd,UK). The gold particles were used as fiducial
markers for the alignment of the tilt series of the
TEM images. The TEM and TEMT observations
were carried out on JEM-2200FS (JEOL, Co., Ltd.,
Japan). A series of the TEM images were acquired
at tilt angles ranging from -50˚ to +50˚ in 1˚
increments. The tilt series of the TEM images werealigned by fiducial marker method and thenreconstructed on the basis of the filtered-backprojection method [6].
NR measurement was carried out with the PORE
neutron reflectometer at KEK using the same thinfilms observed by TEMT. In this study we observed
specular reflection, where the light source waspulsed neutrons with the wavelength, , range of
0.3-1.6 nm. Also, the incident angle, , was fixed tobe 0.4, 1.0, 2.0 deg, and the angle resolution,/ ,was kept at 5% by adjusting the width of two
incident slits.
Reflectivities were calculated from model

195

scattering length density (b/v) profiles along thedirection perpendicular to the film surface by using
an algorithm of Parratt based on a recursive
calculation method [7,8], and fitted to the measured
reflectivities.
Results
Fig. 1 shows the crossed-sectional TEM image ofthe dPS-b-P2VP thin film. Dark phase corresponds
to the P2VP phase. Small dark spots are thecolloidal gold particles attached on the surface of theultrathin section for fiducial marker method. The
dPS and P2VP form alternating layers (lamellar
morphology) parallel to the substrate surface, whichis rather standard morphology to be studied by NR.

Fig. 2 3D image of the dPS-b-P2VP thin film. White
phase corresponds to the P2VP phase. Box size is
401 nm x 546 nm x 77 nm.
(a)

0

10

-1

data poins of NR
profile calculated by TEMT (RTEMT )best fitted profile ( Rbest )Fig. 1 The crossed-sectional TEM image of thedPS-b-P2VP thin film. Dark phase corresponds to
the P2VP phase.

Reflectivity

10

-2

10

-3

10

-4

10

-5

196

10

0.04

0.08
-1
qz (Å )(b) 7x10-6

0.12

6
5
b/v (Å-2)

Fig. 2 shows a part of 3D image of the dPS-b-P2VP
thin film obtained from TEMT. White phasecorresponds to the P2VP phase. It cleared that theP2VP phase and the dPS phase are completely
wetting the substrate surface and the free surface,respectively. Fig. 3 (a) shows NR profile (opencircles) of the dPS-b-P2VP thin film as a function ofwavenumber, qz; =(4 / ) sin . The scattering lengthdensity (b/v) along the direction perpendicular to thefilm surface is also shown in the Fig.3 (b). Since wehave TEMT data, it is now possible to calculate theconcentration profile of dPS ( dPS-TEMT) from the 3D
image. The concentration profile obtained from the
TEMT data was used to calculate scattering lengthdensity (b/vTEMT, solid line in Fig.3 (b)) and its
reflectivity was also calculated (RTEMT, solid line in
Fig. 3 (a)). The positions of the Bragg-peaks in thereflectivity profile calculated by TEMT werereasonably reproduced. However, the intensity of
the RTEMT was somewhat off from NR data,

4
3
2
1
0

profile calculated by TEMT ( b/v TEMT )best fitted profile (b/v best )

0

1000

2000
Z (Å)

3000

Fig. 3 The crossed-sectional TEM image of thedPS-b-P2VP thin film. Dark phase corresponds to
the P2VP phase.

especially at high qz region . This means that the NR
captures more detail structural features than TEMT.
Therefore it is appropriate to use the b/vTEMT as an
initial guess to fit the NR data. The dashed line in
FIG. 3 shows the best-fitted reflectivity profile thus
obtained from the fitting procedure (Rbest shown by adashed line). Corresponding b/vbest is shown in Fig. 3(b) (dashed line). It was found that the NR
reflectivity was well reproduced, much better thanthe RTEMT did. Interestingly, the scattering lengthdensity, b/vTEMT and b/vbest, were not too muchdifferent. It is very important, however, to point out
that the b/vbest has strong support from the real-space
data, i.e. TEMT image in this case. The present
protocol can easily be extended to the block
copolymer thin film having cylindrical and sphericalmorphologies that were difficult to study by NR
alone so far. Such experiments are currently under
way and will be presented in the near future.
References[1] I. W. Hamley, Nanotechnology, 14 (2003) R39R54.
[2] Naoya Torikai, Macromolecules, 30 (1997)
2907-2914.
[3] H. Jinnai, Y. Nishikawa, T. Ikehara, T. Nishi,
Adv. Polym. Sci., 170 (2004) 115-167.
[4] K. Niihara, Y. Nishikawa, T. Nishi and H. Jinnai,
Trans.Mater.Res. Soc. Jpn., 30 (2005) 617-622.
[5] Ken-ichi Niihara, Takeshi Kaneko, Toshiaki
Suzuki, Yasuhiko Sato, Hideo Nishioka, Yukihiro
Nishikawa, Toshio Nishi, and Hiroshi Jinnai,
Macromolecules, 38 (2005) 3048-3050, 2005
[6] M. Radermacher, “Electron Tomography”, Ed.
by J. Frank, Plenum, New York, (1992) pp. 91-116[7] Parratt, L. G. Phys. Rev., 95 (1954) 359.
[8] Russell, T. P. Mater. Sci. Rep., 5 (1990) 171.

197

Neutron Scattering Studies on Relaxation and Excitation Phenomena
in Structurally Aperiodic System by LAM-40-Dynamics of Polymer thin filmsR. INOUEA, T. KANAYAA, K. NISHIDAA, I TSUKUSHIB, K. SHIBATAC
Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japanb
Chiba Institute of Technology, Narashino, Chiba-ken 275-0023, Japanc
Japan Atomic Energy Research Institute, Tokai, Ibaraki-ken 319-1195, Japan198

temperature region, <u2> is almost proportional to T,
indicating that the vibrational motion is harmonic
With increasing temperature, <u2> deviates from the
0.12

bulk
1000Å
400Å

0.10
0.08

2
2

The physical properties of polymer thin films
were very different from those of bulk state andutilized in the various field of industry, and hence
Polymer thin films were studied actively not only
from scientific point of view but also from industrial
point of view. Among them, the glass transition
behavior is the one of the most interesting
phenomenon. Keddie et al. first reported that glasstransition temperature (Tg) decreased with film
thickness for polystyrene (PS) thin films [1].
However, definite model of Tg behavior of thin films
has not yet been suggested in spite of continuous
study by many researchers. Glass transition is not
the thermodynamical phenomenon but relaxation
process. Therefore the research from the dynamics
is indispensable for the understanding the glasstransition of polymer thin films.
Especiallyinelastic and quasielastic neutron scattering canoffer information on local and fast dynamics
compared to other methods like NMR or dielectricrelaxation.
Therefore, we can observe thedynamics from molecular level. Some works on
dynamics of polymer thin films using inelastic
neutron scattering were reported recently, however
most of them were mainly focused on elastic
scattering due to extremely week intensity from thinfilms [2,3].
In this work, we studied thequasielastic scattering from PS thin films mainly
concentrated on the so-called fast process [4], whichis universal feature for glass-forming materials, withinverted geometry time of flight geometry LAM-40
at KEK and discuss the effect of the spatialconfinement on the local relaxation process.
First, we studied the thickness dependence ofelastic scattering before discussing the effect of film
thickness on quasielastic scattering. Fig.1 indicates
the thickness dependence of mean squaredisplacement <u2>.
As seen in Fig.1 <u2>
decreases with film thickness in the temperature
range examined and the temperature dependence of<u2> becomes weaker with film thickness. At low<u > (Å )

a

0.06
0.04
0.02

bulk Tg

0.00
0

100

200

300

Temperature (K)400Fig. 1 Temperature dependence of <u2> for bulk, 1000Å
and 400Å.

solid lines and increases somewhat steeply. It
indicates the onset of relaxational process called fast
process. The deviation starts at around 150~200K
for bulk and the onset temperature seems to shift tohigher temperature with decreasing film thickness
though definite values of onset temperature cannot
be estimated from this result at present stage.
In order to study the characteristic nature of fast
process in more detail, we fitted the model function
to the observed S(Q, ) after convoluted with theresolution function of the spectrometer. The model
function employed is indicated below
S(Q, )=C(Q)[{1-Afast(Q)} ( )+Afast(Q)L( , )]+B(Q), where B(Q), C(Q) are constants and Afast(Q)indicates the fraction of fast process and ( ) andL( , ) are the -function, and Lorentzian with half
width at half maximum (HWHM) . One example
of curve fit for 1000Å is shown in Fig. 2 and themodel function seems to be a good approximation
for the observed data. We found that the fast
process was well described by the single Lorentzian
regardless film thickness as is the case for bulk.
The relaxation rate
and the fraction of the fast
process is shown on Fig.3.
The temperaturedependence of was not observed formeV)

0.0

1

1

fast processboson peak

S(Q,

1000Å
T=408K-1
Q=2.47Å

0.5

Afast (Q) (arb. units)

0.004

0.003

0.002

0.00080.4

0.00060.3

0.00040.2
0.1

fast processboson peak

0.0
2

0.001

10

-1

0

1

Energy transfer (meV)2

3

Fig. 2 Results of curve fitting to the LAM-40 spectra of1000 Å at T = 408K and Q = 2.47Å-1.
0.5
0.4

(meV)

Afast(Q) (arb. units)

1

0.3
0.2
-1

bulk Q=2.21Å

0.1

0.1
0.5

(meV)

0.4
0.3
0.2
-1

0.1

1000Å Q=2.21Å

0.1

(meV)

0.4
0.3
0.2
-1

0.1

400Å Q=2.21Å

0.00240.00260.1
0.0028
-1
-1

T

(K )

0.0030Afast(Q) (arb. units)

0.5
1

Afast(Q) (arb. units)

1

3

10

4

10

5

10

Film thickness (Å)

0.00020.0000

6

10

Fig. 4 Thickness dependence of intensity and peak
position or of fast process and boson peak.

0.000
-2

Gb( ) (arb. units) (arb. units)

0.005

boson peak (meV)

0.2

0.0032

Fig. 3 Temperature dependence of G and Afast(Q) for 3
different film thickness.

all the samples, indicating that fast process is the
motion within the cage of potential (cage motion).
The was also independent of Q although the data
were not shown here.
From the T and Q
dependence of , the fast process is localized mode.
On the other hand, the Afast(Q) decreases with film
thickness, suggesting that the decrease of the mode
number or the amplitude of fast process.
In addition to the fast process, the boson peak isalso the universal feature of glass-forming materials
and we would like to consider the relation between
fast process and boson peak from the thickness
dependence of both modes. In Fig.4, we compare
the thickness dependence of and the Boson peak
position, and that of the fraction Afast(Q) and thedensity of states Gb( ). Thickness dependence ofAfast(Q) and Gb( ) is almost the same and peak
position andvalues are close to each other, andnot dependent on film thickness.

Considering these observations, these two modes
are supposed to derive from the same origin. We
would like to discuss this problem from the boson
peak. The origin of boson peak is not clear yet,even in the case of bulk. Some models concerning
the origin of boson peak were constructed fromexperimental observation or theory. Among them,
we adopt the idea that the boson peak mode wascaused by the defects or voids [5]. The decrease in
the number of the defects or the voids is supposedwith decreasing film thickness. In such a situation,
only the number of the mode supposed to decrease
without affecting the characteristic frequency ( orpeak position).
One candidate is like these.
Polymer chains tend to form oriented structure or
the layering at the interface. With the existence ofsuch ordered layer, the number of voids or thedefects becomes smaller than that of the normal bulk
layer.
With decreasing film thickness, thecontribution from such ordered layer increases.
This results in the decrease of the number of thedefects or the voids, indicating the decrease of theintensity of the modes without changing the peak
position or .
References
1) J. L. Keddie, R. A. L. Jones, and R. A. Cory,
Europhys. Lett. 27 (1994) 59.
2) C. L. Soles, J. F. Douglas, W. Wu and R. M.
Dimeo, Phys. Rev. Lett. 88, 037401 (2002).
3) B. Frick, K. Dalenoki-Veress, J. A. Forrest, J.
Dutcher, C. Murray and A. Higgins, Eur. Phys. J.
E 12, s01 (2003) 93.
4) T. Kanaya, T. Kawaguchi and K. Kaji, J. Chem.
Phys. 104, (1996) 3841.
5) Y. Inamura, M. Arai, M. Nakamura, T. Otomo,
N. Kitamura, S. M. Bennington, A. C. Hannonand U. Buchenau, J. Non Cryst. Solids. 293(2001) 389.

199

Molecular Recognition of Human Killer Cell Immunoglobulin-like Receptor (KIR/CD158) Family
K. MAENAKA, D. KOHDA, T. TAIDA and I. TSUKUSHI*
Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku,
Fukuoka 812-8582*Faculty of Engineering, Chiba Institute of Technology, 2-1-1 Shibazono, Narashino,
Chiba, 275-0023

200

Figure 1 is the dynamic scattering law S(Q,ω) of
KIR2DL3 (20 mg) after 24 hours measurement atroom temperature. A broad peak about 3~4 meV
was observed, though statistical precision was not
good. The dynamic scattering law is easier tocompare with the theoretical results including
spectrum intensity than the infrared and Raman
spectra which are usually to use the assignment of
the mode of molecular motion. In this stage, wehave not reached the specific understanding of thisdynamic scattering law. We wish to get the new
information comparing S(Q,ω) with the molecularsimulation (specially normal vibration analysis).

0.00020.00015

S ( Q, ) (a.u.)

Cell surface receptors of immune system survey
unusual situations by finding non-self molecules
expressed on microorganisms, viruses or cancer
cells to avoid harmful infections and tumorigenesis.
Thus these receptors have pivotal roles in regulationof various diseases. The clarification of their
non-self ligand recognition mechanism will have big
impact on not only basic life sciences but also on
medical treatments. For latest decades, we haveinvestigated immune cell surface receptors from awide range of scientific views including a genome
science, protein engineering, structural biology,
bioinformatics, and cell biology. Especially wefocus on human immune cell surface receptors,
killer cell immunoglobulin(Ig)-like receptors (KIRsor CD158), which regulates the activation of naturalkiller (NK) cells by recognizing major
histocompatibility complex class I molecules(MHCIs). Our preliminary result of kinetic andthermodymanic analyses of KIR-MHCI interactions
demonstrated the entropically favorable binding
with some conformational changes, which isdifferent either from rigid-body or induced-fit
interactions (refs. 1, 2). It indicates that KIR-MHC
interactions include unique dynamical events, which
are functionally important. In this study, we carriedout the inelastic neutron scattering to measure theslow motion modes in order to reveal the dynamical
characteristics of KIRs.
The extracellular domain of immune receptor
KIR2DL3, an inhibitory member of the
KIR(CD158) family, was expressed in E. coli as
inclusion bodies (50mg per 10l culture). The
functionally active KIR2DL3 protein was preparedby the dilution refolding method using the inclusion
bodies (ref. 2). Because LAM-D spectrometer is low
background level and can apply to wide energy
transfer range, and became high intensity byinserting the super-mirror guide, the inelastic
neutron scattering can be measured in the so muchalso with a small amount of sample. The
measurement was carried out by using about 20mgof the sample. The sample was made in the paste on
the aluminum foil by spontaneous drying.

300 K

0.0001

5 10

-5

0
0

5

10
 E / meV15

Fig. 1 Dynamic scattering law S(Q, ω )KIR2DL3 at room temperature.

20ofReferences
1. Shiroishi M, et al. Entropically driven MHC class
I recognition by human inhibitory receptor
leukocyte Ig-like receptor B1 (LILRB1/ILT2/
CD85j). J Mol Biol. 2006 355(2):237-48.
2. Maenaka K, et al. Killer cell immunoglobulin
receptors and T cell receptors bind peptide-major
histocompatibility complex class I with distinct
thermodynamic and kinetic properties.
J Biol Chem. 1999 274(40):28329-34.

Small-angle Characterization of Multimetric Variants Related to Parkinson’s Disease of
Ubiquitin Carboxyl-terminal Hydrolase L1 in Water by Small-angle Neutron Scattering
S. NAITO1,2, H. MOCHIZUKI2, T. YASUDA2, Y. MIZUNO2, M. FURUSAKA3, S. IKEDA1,
H. M. SHIMIZU1, T. ADACHI4, J. SUZUKI5 , S. FUJIWARA5, S. AOKI6, K.WADA6
1

KEK, Tsukuba, Ibaraki 305-0801, 2Dept. of Neurol., Juntendo Univ. Sch. of Med., 3Dept. of Mech.
Intell. Eng., Grad. School of Eng., Hokkaido Univ., Kita 13, Nishi 8, Kita-ku, Sapporo 060-8628,
4
RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, 5 Japan Atomic Energy Research Institute, Ibaraki
319-1195, 6Dept. of Degen. Neurol. Diseases, Natl. Inst. of Neurosci., Natl Centr. of Neurol. andPsych., 4-1-1 Ogawa Higashi, Kodaira, Tokyo 187-8502.
UCH-L1 is a neuro-specific multiple functional
enzyme. The disfunction of UCH-L1 is closely
associated to Parkinson’s disease (PD)(Fig.1). To
examine the relationship between PD and theconfiguration of UCH-L1 variants [wild-type, I93M
(linked to familial PD), and S18Y (linked to reduced
risk of PD)],

Fig. 1 The crystal structure of UCH L-1 wasmodeled after the crystal structure of human UCH
L-3 using Swiss-Model protein modeling.
The structure of purified recombinant human
UCH-L1 variants were examined using small-angle
(Å)<16.1)]. The
theoretical SANS profile of UCH-L1 was estimatedby Rg value calculated from the crystalline structureof UCH-L1 (Fig. 1) by Svergun [1]. We assumed thedispersion of monomeric and dimeric and rotating
ellipsoidal particle (short axis, a; and long axis, band c, a≤b=c or short axis) and obtained theoretical
SANS curves by applying the following equation of
Debye [2] based on the scattering intensity fromcorrelations between non-spherical body:sin(qrij )I (q) fi f jqrij
jiFig. 2 The theoretical SANS profiles of UCH-L1(wild type) monomer and dimer, and theexperimental profile.
The relation between the configuration of UCH-L1
variants and their functions are summarized in Fig. 3.
The progressive deformation of the ellipsoidal formby the I93M mutation simultaneously impaired thehydrolytic activity. This configurational defect could
cause impairment of dynamic flexibility, which isnecessary for enzymatic functions by theenlargement of the hydrophobic region. The
restoration of globularity of monomeric UCH-L1 by
S18Y substitution augmented the hydrolytic activity.



where rij is the distance between any two points inthe protein molecule and fi and fj are the scattering
length at each point. In the q range of the SANS
measurement, we assumed a constant scatteringfactor in the UCH-L1 variants, and thus divided therotating ellipse by the resolution of a 5 Å cube. The
wild-type was a rotating ellipsoidal dimer although
the crystal structure predicted from the UCH-L3 wasglobular (Fig. 2)[3].

Fig. 3 Schematic speculative models of therelationship between the configuration of UCH-L1s
in water and the multi-enzymatic activities.
References
1) D.I. Svergun et al., J. Appl. Cryst. 28 (1995)
768-773.
2) P. Debye et al., Ann. Phys. 46 (1915) 809.
3) S. Naito et al., B. B. R. C. 339 (2006) 715
201

Surface Swollen Layer in Polymer Films Induced by Sorbed Gas Molecules
Y. FUJII1, K. TANAKA1, T. NAGAMURA1 and N. TORIKAI2
1

Department of Applied Chemistry, Faculty of Engineering, Kyushu University
744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan2
Neutron Science Laboratory, High Energy Accelerator Research Organization
1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan

Polymers are often used as key materials for gas
separation
becauseof
theirsuperior
permeability-selectivity balance. In this case, aninteraction between polymer surface and gas
molecules should be understood at first so that thefunctionality is promisingly improved. At a highpressure, such studies have been widely made.
However, this is not the case at a gentle pressure likeatmospheric pressure. In this study, we chosepoly(methyl methacrylate) (PMMA) as a sample.
As environmental gases, carbon dioxide (CO2) andnitrogen (N2) were used. Aggregation states at the(PMMA/gas) interface were examined by neutronreflectivity (NR) with a high temperature cell.
Polymer films were spin-coated from toluene
solutions onto Si substrates. They were dried
under the ambient atmosphere at room temperature
for more than 24 h, and then, annealed undervacuum at 423 K for 24 h. The film thickness
evaluated by ellipsometry was approximately 110
nm. NR measurement was performed using theadvanced reflectometer for interface and surface
analysis (ARISA).
The incident neutrons
wavelength band was 0.05 – 0.4 nm.
Fig. 1 shows the schematic illustration of the
set-up for the NR measurement in a gas atmosphere.
The neutron beam is transmitted through a series ofquartz windows. The sample is heated from thesubstrate side. The gas pressure is regulated to be
0.1 MPa. Fig. 2(a) shows the scattering vector(q=(4 )•sin , where  is the incident angle ofneutron beams) dependence of reflectivity for
dPMMA films under CO2 atmosphere. The data
for the dPMMA film under vacuum is also shown asa reference.
The data for the (dPMMA/CO2) films are offset
by a decade for the sake of clarity. Solid lines
denote the best-fit calculated reflectivity, to theexperimental data, on the basis of model scattering

202

gas

VacuumneutronquartzFig. 1. Schematic illustration of the experimental set-up
for the NR measurement.

Fig. 2. (a) Neutron reflectivity profiles for (dPMMA/vac)and (dPMMA/CO2) films. Circles are experimental data,and solid lines depict reflectivity calculated on the basis ofmodel scattering length density profiles. The data for the(dPMMA/CO2) is offset by a decade for clarity. (b)Model scattering length density profile for the(dPMMA/vac) film.

length density (b/V) profiles, as shown in Fig 2(b).
Since the calculated curves are in good agreementwith the experimental data, it can be claimed that themodel (b/V) profiles well reflect the realcomposition through the films.

Fig. 3 shows the model (b/V) profile, which isenlarged from the (PMMA/CO2) interface down to 5
nm depth, at various temperatures. The (b/V) value
at the (PMMA/CO2) interface was smaller than thatof the (PMMA/vacuum). The (b/V) values used for
dPMMA and CO2 were 6.61x10-4 and 4.91x10-6
nm-2, respectively, meaning that a decrease in the(b/V) value corresponds to an increase in the CO2
fraction at the dPMMA interface. Moreover, the(b/V) decreased with increasing the temperature.
These results indicate that (dPMMA/ CO2) interface
was swollen by sorbed CO2 molecules.
We have used the following expression for the(b/V) variation in the swollen dPMMA,
where z and are distance from the interface anddecay length for the (b/V) value, respectively. The
panel (a) and (b) of Fig. 4 show the temperaturedependence of under various atmospheres. As ageneral trend, the value increased with increasing
temperature. In the case of the dPMMA films, thevalue for the dPMMA film under CO2 was larger
than that for the dPMMA film under N2 at a given
temperature, indicating that the (dPMMA/gas)interface became thicker when it was placed under
CO2 than N2. This can be explained in terms of gas
solubility to PMMA.[1] In the case of dPS films,
the value was smaller in comparison with dPMMA
films except the data set at 403 K, being higher than
the glass transition temperature. This trend is also
understandable by taking into account gas solubility
to dPS.
Gas solubility to polymers generally decreases
with increasing temperature. Nevertheless, the gas
fraction at the interface increased with increasing
temperature, as shown in Fig. 4.[2] This means
should bethat the temperature dependence ofinterpreted by thermal molecular motion of polymer
interface in addition to gas solubility.
More
conclusive report will be published in the near
future.

Fig. 3. Model scattering length density, which is enlarged
from the (PMMA/CO2) interface down to 5 nm depth, atvarious temperatures.

Fig. 4. Temperature dependence of decay length ( ) forthe (b/V) value; (a) dPMMA and (b) dPS films.

References
1) K. E. Min and D. R. Paul, J. Polym. Sci., Part B;
Polym. Phys., 1988, 26, 1021.
2) A. R. Manninen, H. E. Naguib, A. V. Nawaby,
and M. Day, Polym. Eng. Sci., 2005, 45, 904.

203

Structural Study on Concentrated Block-Copolymer Brushes in Dry State
by Neutron Reflectometry
K. OKAYASU1, S. YAMAMOTO1, Y. TSUJII11, T. FUKUDA1, N. TORIKAI2, M. TAKEDA3
1

2

Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011
High Energy Accelerator Research Organization, Oho, Tsukuba, Ibaraki 305-0801
3
Japan Atomic Energy Institute, Tokai-mura, Naka-gun, Ibaraki 319-1195

Living radical polymerization (LRP) has been
Neutron Reflectometry
applied to surface-initiated graft polymerization,
allowing controlled grafting of well-definedzpolymers from various solid surfaces with
2nd block
1,2
dramatically high surface densities.
The surface
boundaryst blocklayer
1
density  was more than 1 order of magnitude
Siliconwafer
higher than those of typical “semi-dilute” brushes,dgoing deep into the “concentrated brush” regime
Figure 1 Neutron reflectivity measurement of
which had previously been little explored
block-copolymer brushes on silicon wafer.
systematically because of the unavailability of suchbrush samples. Recent studies revealed that these
the anisotropic structure of such concentrated
concentrated brushes have structure and properties
brushes in dry state. For this purpose, concentrated
quite different and even unpredictable from those ofblock-copolymer brushes were prepared on a siliconsemi-dilute brushes1: most strikingly, thewafer by the surface-initiated atom transfer radical
concentrated brushes of poly(methyl methacrylate)block-copolymerization technique: the 1st block was(PMMA), swollen in a good solvent (toluene),
the deuterated PMMA (PMMAd), and the 2nd one
exhibited an equilibrium film thickness as large as
was hydrogenated PMMA or poly(styrene) (PS).
80-90 % of the full (contour) length of the graft
Table I shows the characteristics of the samples. The
chains, indicating that the chains are extended to a
specular NR data was collected at room temperaturesimilarly high degree.3
on a PORE time-of-flight reflectometer at Nuetron
The surface density of 0.7 chains/nm2 for a
Science Laboratory (KENS), High Energy
PMMA brush, for example, also means that the
Accelerator Research Organization and analyzed bythickness of the dry film reaches about 40% of thethe three-layer model assuming the 1st and 2nd
full length of the chains, which is much larger thanblock layers and their boundary (interfacial) layer
the mean size of the chains ina random-coil (or so-called
Table I Characteristics of Concentrated Blockcopolymer Brushes“mushroom”) conformation.
1st block2nd blockblock
Presumably reflecting this(duetrated)(hydrogenated)
efficiency
characteristic conformational-PMMAdfeatureofconcentrated
Mn = 68000
brushes, dry PMMA brushes
Mw/Mn = 1.08－－
 = 0.56 chains/nm2
had
a
glass
transition
L1st = 53 nm
temperaturesignificantly
4-PMMAd-b-PMMA
higher,andaplate
Mn = 70000
Mn = 68000
compressibility
markedly
Mw/Mn = 1.12
M
/M
=
1.08
w
n
91%
 = 0.51 chains/nm2
smaller,5 than those of the = 0.56 chains/nm2
L2nd = 50 nm
L1st = 53 nm
equivalent cast films andimmiscibility
even
with
-PMMAd-b-PS
Mn = 55000
Mn = 68000
homologous free PMMA of
Mw/Mn = 1.07
Mw/Mn = 1.19
an oligomeric chain length.697%
 = 0.56 chains/nm2
 = 0.55 chains/nm2
In this study, we haveL1st = 53 nm
L2nd = 50 nm
appliedtheneutronreflectometry (NR) to analyze204(see Figure 1). Figure 2 shows reflectivity data
(R/R0) and the best fits plotted against neutron wave
vector q. The experimental data was well fitted bythis model, giving the segmental density profile( 1st) of the 1st dueterated block, which was plottedagainst z/L1st, where z and L1st being the distancefrom the substrate surface and the average thicknessof the 1st layer, respectively.
The PMMAd brush (without a 2nd block) gavea step-like profile with a sharp boundary, suggesting
surface homogeneity of the dry brush. Figure 3
also revealed that the chemically identical but
partially
dueterated“homo”polymer(PMMAd-b-PMMA) brush gave nearly the same
boundary profile between the dueterated andhydrogenated layers as compared with theThus, weincompatible PMMAd-b-PS one.
concluded that the graft density was so high as tostretch graft chains to a high extent even in the dry
state, giving a layered structure corresponding to the

(a)

0
-2
-4
0

monomer-sequence distribution along a chain.
Another interesting point to be noted is that theincompatible PMMAd-b-PS brush had a broader
boundary profile as compared with the boundary inthe microphase-separated structure of the ungraftedblock-copolymer. This was reasonably ascribed to achain length distribution, the effect of which wasenhanced by the highly stretched conformation ofgraft chains, even thought the polydispersity index
was as low as 1.1. The detailed boundary structureis under investigation.
References
1) Tsujii, Y.; Ohno, K.; Yamamoto, S.; Goto, A.;
Fukuda, T. Adv. Polym. Sci., in press.
2) Ejaz, M.; Yamamoto, S.; Ohno, K.; Tsujii, Y.;
Fukuda, T. Macromolecules 1998, 31, 5934.
3) Yamamoto, S.; Ejaz, M.; Tsujii, Y.; Matsumoto,M.; Fukuda, T. Macromolecules 2000, 33, 5602;
Yamamoto, S.; Ejaz, M.; Tsujii, Y.; Fukuda, T.
Macromolecules 2000, 33, 5608.
4) Yamamoto, S.; Tsujii, Y.; Fukuda, T.
Macromolecules 2002, 35, 6077.
5) Urayama, K.; Yamamoto, S.; Tsujii, Y.; Fukuda,T.; Neher, D. Macromolecules 2000, 35, 9459.
6) Yamamoto, S.; Tsujii, Y.; Fukuda, T.; Torikai,N.; Takeda, M. KENS Report 2001-2002, 14,204.

log(R/R0)(b)-2(a)PMMAd

1.0(b)PMMAd-b-PMMA(c)PMMAd-b-PS

0

(c)

1st

-4

0.5

-2
-4
0.00

0.05

0.10
-1

q/A

Figure 2 Reflectivity data (symbols) and best fits(solid curves) plotted against q for (a)PMMAd, (b) PMMAd-b-PMMA, and (c)PMMAd-b-PS brushes grafted on siliconwafers.

0.0
01

z / L1st

2

Figure 3 Density profiles of PMMAd plotted against
z/Ld for (a) PMMAd, (b) PMMAd-b-PMMA,
and (c) PMMAd-b-PS brushes grafted on
silicon wafers.

205

Structure of Lipid Nanotube by Small-angle Neutron Scattering
K. YOSHIDA, T. YAMAGUCHI, and S. LEE
Advanced Materials Institute and Department of Chemistry, Faculty of Science, Fukuoka University,
8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180
Recently, lipid nanotubes have drawn
attention in the nano-technology field. They aresynthesized within 1 day in a buffer solution byadding an amphiphilic peptide to liposome [1].
Interestingly, the pore size of lipid nanotubes iseasily controllable by changing the hydrophilic andlipophilic balance of a peptide in contrast with carbon
nanotubes [2]. Therefore, a wide use of lipid
nanotubes is expected. So far, the size of lipid
nanotubes has been measured with TEM. The
dimater and length of nanotubes are ~50 nm and afew m, respectively, whereas the diameter ofspherical liposome is around 80 nm [3]. However, themechanism of formation of lipid nanotubes, i.e. how
the peptide interacts with liposome, is not clear. In
this study, small-angle neutron scattering (SANS)
was measured for lipid nanotubes that areisotopically substituted.

was 0.015~2 Å-1. The neutron beam size was 20 x 20mm2, and the wavelengths were = 1~16 Å. Neutron
scattering intensities were accumulated up to 6 x 107
counts; it took 8 ~ 10 hr. The correction for detector
efficiency and normalization to an absolute unit wasmade by using the intensities of vanadium plate.
Incoherent scattering cross section was subtracted
from the total scattering cross section. All samples
were measured at room temperature.

Experimental
Two kind of isotope substituted liposomes
made of DMPC (1,2-dimysteroyl-sn-glycero-3-phosphocholine) were prepared by an ultra
sonication method. One is DMPC-d13 where only thehead group was deuterated. The other is a mixture(DMPC-h/d) of protonated DMPC (DMPC-h),DMPC-d13, and DMPC-d67 (all hydrogen atoms are
deuterated) where the contrast of both tail and headgroups of the liposome is adjusted to that of thepeptide. An amphiphilic peptide, Hel 13-5 (thenumber of residues is 18), was synthesized by an
F-moc solid phase method [1]. The liposome andpeptide solutions were mixed at a molar ratio[peptide]/[DMPC]= 1:5 and was aged for 24 hr.
SANS measurements were performed on the
SWAN spectrometer at a pulsed neutron facility(KENS) of High Energy Accelerator Research
Organization (KEK) (Tsukuba, Japan). The
momentum transfer Q (=41sin) range covered

where d and  are the thickness of the flat plate andthe contrast between the plate and medium,
respectively. The scattering intensity from the plate is
described as follows:

206

Results and Discussion
To analyze the scattering data, the following
primitive model for a plat plate was introduced:dThe layer of the nanotubes can be regarded asa flat plate because the curvature of the nanotube ismuch larger than neutron wave length. Hence, themodel can be applied to the present system in orderto determine the thickness of the nanotubes.
At first, the thickness of the liposome wasdetermined from the intensity of DMPC-h/d sample
without the peptide using the above equation. The
contrast was fixed to -6.13×1010 cm-2 that istheoretically obtained [4, 5]. The value of d for2

Q I(Q)
10 -4

0

0.1
Q / Å-1

0.2

Fig. 1, The scattering intensity of the lipid nanotube
consisting of HEL13-5 and DMPC-d13.

10 -3

2

Q I(Q)

DMPC-h/d sample without the peptide was 32.5 Å.
Next, the same equation was applied to the sample of
DMPC-h/d with the peptide. It has been found thatthe value of d for DMPC-h/d with the peptide was
27.2 Å. The thickness of the lipid bilayer would
become smaller when the lipid nanotube is formed.
The thickness of the hydrophobic core of thepeptide-liposome complex was determined from thescattering intensity of DMPC-d13 with the peptide in
the same way. Assuming that the scattering densityof the head group of the DMPC is equal to that of thebulk, the value of d corresponds to the thickness ofthe complex of the tail group of DMPC and the
peptide. The values of d and  obtained from thefitting were 20.0 Å and -4.90 ×1010 cm-2, respectively.
On the other hand, the thickness of the tail group of
DMPC in the lipid bilayer without the peptide was
20.7 Å under the condition that the contrast value
was fixed to -4.73 ×1010 cm-2, which is theoreticallycalculated [4, 5]. The d value of the peptide-liposome
complex is close to the thickness of the tail group of
the lipid bilayer.
Therefore, the peptide isconsidered to be embedded to the lipid bilayer asshown in Fig.3.

10 -4
0

0.1
Q / Å-1

0.2

Fig. 2, The scattering intensity of the lipid nanotube
consisting of HEL13-5 and DMPC-h/d

References[1] T. Kiyota, S. Lee, and G. Sugihara, Biochemistry35, 13196 (1996).
[2] A. Kitamura, T. Kiyota, M. Tomohiro, A. Umeda,
S. Lee, T. Inoue, G. Sugihara, Biophys. J. 76, 1457
(1999).
[3] S. Lee, T. Furuya, T. Kiyota, N. Takami, K.
Murata, Y. Niidome, D. E. Bredesen, H. M. Ellerby,
G. Sugihara, J. Biol. Chem. 276, 41224 (2001).
[4] P. Balgavy, M. Dubnickova, N. Kucerka, M.A.
Kiselev, S. P. Yaradaikin. D. Uhrikova, Biochim.
Biophys. Acta 1512, 40 (2001).
[5] V. F. Sears, Neutron News 3, 26 (1992).

27 Å

20 Å

Fig. 3, The schematic structure model of the lipid nanotube
obtained from SANS.
.

207

In-Situ Neutron Reflectivity Studies of DNA Adsorption by Cationic Lipid Monolayer at
Different Calcium Ion Concentrations
TSANG-L. LIN 1, JUI-C. WU 1, U-S. JENG 2, and N. TORIKAI 3
1

Department of Engineering and System Science,
National Tsing Hua University, Hsinchu 300, Taiwan
2
National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan
3
Neutron Science Laboratory, High Energy Accelerator Research Organization,
Tsukuba, Ibaraki, 305-0801, Japan

Abstract We have studied the effect of divalention on the DNA adsorption by the cationic DC-Chol
monolayer at the air-water interface by in-situ
neutron reflectivity. It was found that in thepresence of calcium ions, other than the dense layerof a single ordered DNA array, there is a loose DNA
layer formed in adjacent to the dense DNA layer.
The thickness of the loose DNA layer increases
roughly in proportional to the square root of thecalcium ion concentration.
Since the charge
screening length constant is inversely proportional
to the square root of the calcium concentration, it issuspected that the DNA condensation is closely
related to the charge screening length constant andthe charge screening effect. The enhanced DNA
adsorption could be attributed to the bridging effectof the divalent ions between the adjacent adsorbed
DNA molecules. The existence of the well ordered
and compact first adsorbed DNA layer could also be
critical to the enhanced DNA adsorption.
Introduction Cationic lipid-DNA liposomes arewidely studied as the gene delivery system for genetherapy [1]. There were several studies on the
structure and interaction of DNA with lipid bilayers
in the presence of divalent salts [2-5]. As for theeffect of adding salts on the DNA-lipid monolayerinteraction at air-liquid interface, it is still not muchstudied. Langmuir-Blodgett (LB) technique is a
useful tool to study the cationic lipid-DNA
interaction at the air-water interface [6-12]. The
DNA molecules adsorbed onto a supported cationicbilayers could form aligned two dimensional
structure of regular spacing as revealed by AFM[13]. Surface charge density can also affect the
DNA adsorption [14]. Kago et al. found by in-situ
X-ray reflectivity that a two-DNA layer model wasneeded in order to fit the reflectivity data. Other thanthe dense first layer beneath the lipid monolayer,
there is a second layer of about 11 Å containing lessDNA [6].

208

It is important to understand the structure andinteraction of DNA with the lipid monolayer, which
simulates the interaction of DNA with the surface of
membrane. It was found that adding divalent salts
at above certain critical concentration would induce
DNA condensation with the bilayer [3]. It is notclear whether similar condensation effects will occur
in the interaction of DNA with lipid monolayer.
In our previous studies, it was found that cationiclipid DC-Chol can form a uniform film at the
air-liquid interface and can adsorb one layer of DNA[15]. In this study, we studied the structure andinteraction of DNA adsorbed to the cationic lipid
monolayer with the addition of calcium ions byin-situ neutron reflectivity.
Experimental Linear DNA-type XIV fromherring testes was purchased from Sigma and usedwithout further purification. The size of the DNA isbetween 400 and 1000 base pairs with a center of
distribution at 700 bps (Dias et al., 2000). DC-Cholwith molecular weight of 537.3 was purchased from
Sigma and used without further purification. The
DNA solution was prepared at the concentration of 1
μM in H2O and the solution was sonicated for 30
minutes for completely dissolving. The in-situ
neutron reflectivity measurements were carried out
at the KENS, KEK, by using the ARISA
reflectometer.
Results and Discussions The surfacepressure-area isotherms of pure DC-Chol and
DC-Chol/DNA added with different amounts of
CaCl2 were shown in Figure 1. For the cases with
DNA in the subphase, the surface pressure increases
right from the beginning of compression. Without
DNA in the subphase, the surface pressure will not
rise in the beginning of compression. This is dueto that the DC-Chol molecules dispersed at thesurface interact with the DNA in the solution toform a condensed network at the air-water interface.
As for the cases added with the CaCl2 at 1, 10, 50,
100, and 200 mM, their isotherms are similar but

with slightly higher surface pressure rise with higher
calcium ion concentrations at the beginning ofcompression. With higher calcium concentration,
the repulsion between the DNA adsorbed to the
DC-Chol at the surface is reduced and more DNA
can be adsorbed to the surface to form more dense
surface networks.

10

-2

10

-3

1x10

-4

1x10

-5

10

-6

20

10

-7

10

10

-8

Surface Pressure (mN/m)DC
DC/ DNA
DC/ DNA + 1 mM CaCl2
DC/ DNA + 10 mM CaCl2
DC/ DNA + 50 mM CaCl2
DC/ DNA + 100 mM CaCl2
DC/ DNA + 200 mM CaCl2

40
30

0
30

Reflectivity-150

DC / DNADC / DNA + 1 mM CaCl2
DC / DNA + 10 mM CaCl2
DC / DNA + 30 mM CaCl2

0.01
40

50

60

2

70

80

Area (Å /molecule)90-1qZ (Å )

100

The �-A isotherms of pure DC-Chol and
DC-Chol/DNA added with different amounts of
CaCl2.

Fig. 300.1

The in-situ neutron reflectivity curves of pure
DC-Chol and DC-Chol/DNA added with different
amounts of CaCl2. The solid curves are fitted results.
The plots are shifted in scale to show better clarity.
-7

10

10

Reflectivity*q

10

DC / DNADC / DNA + 1 mM CaCl2
DC / DNA + 10 mM CaCl2
DC / DNA + 30 mM CaCl2

4

DC / DNADC / DNA + 1 mM CaCl2
DC / DNA + 10 mM CaCl2
DC / DNA + 30 mM CaCl2-1

Reflectivity

0

10

60

Fig. 1

10

-2

10

-3

10

-8

10

-4

1x10

-5

1x10

0.00

0.05

0.10

-1

0.15

0.00

0.20

Fig. 4The in-situ neutron reflectivity curves of pure
DC-Chol and DC-Chol/DNA added with different
amounts of CaCl2. The solid curves are fitted
results.

0.10

-1

0.15

0.20

qZ (Å )qZ (Å )

Fig. 2

0.05

The in-situ neutron reflectivity curves of pure
DC-Chol and DC-Chol/DNA added with different
amounts of CaCl2 plotted in a reflectivity times q4.
The solid curves are fitted results.

The in-situ neutron reflectivity curves of
DC-Chol/DNA added with different amounts of
CaCl2 were showed in Fig. 2. Figure 3 shows theplots shifted in scale for better clarity. The
reflectivity curves are also plotted in Fig. 4 as thereflectivity times q4. The reflectivity curves show
209

more pronounced dips around qz=0.05 and 0.12 Å-1
as more calcium ions added in the subphase. This
indicates the adsorbed DNA layer becomes thicker
as more calcium ion is presence in the solution.
The Parratt32 software (developed by
Hahn-Meitner Institute) was used in the Neutronreflectivity data analysis. The fitted curves are alsoplotted in Figs. 2-4. The reflectivity data can bereasonable fitted with the proposed structural model.
The parameters determined from the fitting are listed
in Table 1. For the cases added without calcium
ions, a three-layer model was used in the fitting.
The first layer consists of the hydrophobic tails of
DC-Chol and the second layer contains the headgroups and par of the adsorbed DNA that penetrates
partially into the head group region. The thirdlayer contains the adsorbed DNA. The thickness ofthe third layer is around 12 with a neutron scattering-2

length density (NSLD) around 5  10 6 Å asdetermined from the fitting.
The NSLD of DNA

and the adsorbed DNA layer becomes thicker. The
enhanced DNA adsorption is due to the charge
screening by the added calcium ions that reduces therepulsive forces between DNA molecules. The
divalent calcium ions act as the bridging glue tocondense the DNA. The existence of the ordereddense DNA array adsorbed directly to the DC-Chol
monolayer also play an important role in this surface
condensation phenomena. An ordered DNA arrayis critical to induce the further adsorption of DNA in
the presence of calcium ions. The thickness of thisloose DNA layer increases with calcium ion
concentrations. It is roughly linearly proportional
to the square root of the calcium concentration.
Since the charge screening length constant isinversely proportional to the square root of thecalcium concentration, it is suspected that the DNA
condensation is closely related to the charge
screening length constant the charge screening
effect.

-2-2order to have an average NSLD of 5  10 6 Å .
It is expected that a single array of DNA molecules
be adsorbed to the lipid monolayer. The diameterof DNA is around 2 nm. Part of the DNA
penetrates into the head group region.
For the cases added with 1, 10 and 30 mM
calcium ions, a four layer model is used to fit thereflectivity data. An extra layer containing DNA atlower NSLD is needed in the modeling of thereflectivity data. For the top three layers, the layer
thickness and NSLD are the same as that for thecase without adding calcium ions. The difference
is in the appearance of the additionally adsorbed
loose DNA layer. The layer thickness of thisadditional loose DNA layer is 8, 43 and 60 Å,
respectively, for the case of 1, 10 and 30 mM
calcium cases. Adding calcium ions will induce
DNA condensation on the dense DNA arrayadsorbed to the DC-Chol monolayer. The NSLD

Scattering Length Density ( 10-6 Å -2)

is around 4  106 Å , which means about 50%
volume of this DNA layer is occupied by DNA in

7
6
5
4
3
2

DC / DNADC / DNA+1 mM CaCl2
DC / DNA+10 mM CaCl2
DC / DNA+30 mM CaCl210-10 0 10 20 30 40 50 60 70 80 90 100

Length (Å)
Fig. 5 NSLD profiles according to the parameters
determined from fitting the reflectivity data.

-2of this loose DNA layer is around 5.7  106 Å .
The amounts of DNA within this loose layer can be
estimated from the NSLD. It is found that about
15% volume of this loose DNA layer is occupied by
DNA. This value is about one third of the value
for the dense DNA layer. It is possible that the
DNA molecules are in a more disordered state inthis loose layer as compared with the more ordereddense layer.
Adding calcium ions enhances the DNA
adsorption to the cationic DC-Chol lipid monolayer
210

Figure 5 shows the NSLD profiles according to
the parameters determined from fitting thereflectivity data.
A dense DNA layer existed at
the depth of 14 to 26 Å. The loose DNA layer is in
adjacent to the dense DNA layer. The interface
roughness between the loose DNA layer and thebulk water is around 5 to 8 Å. This interface
roughness indicates some heterogeneous of the
DNA adsorption.

Table 1. The parameters determined from fitting thereflectivity data.
DC/DNA +0 mM CaCl2

Layer

neutronThickness

Neutron SLD

�

(Å)

-6

( ×10 Å )(Å)-2

1 (tail)

10

1.5

2

2 (head+D2O)

4

2.5

2

3 (DNA+D2O)

12

5

2

D2O

--

6

8

1 (tail)

10

1.5

2

2 (head+D2O)

4

2.5

2

1 mM CaCl2 3 (DNA+D2O)

12

5

2

4 (DNA+D2O)

8

5.7

3

D2O

--

6

5

1 (tail)

10

1.5

2

2 (head+D2O)

4

2.5

2

10 mM CaCl2 3 (DNA+D2O)

12

5

2

4 (DNA+D2O)

43

5.7

5

D2O

--

6

5

1 (tail)

10

1.5

2

2 (head+D2O)

4

2.5

2

30 mM CaCl2 3 (DNA+D2O)

12

5

2

4 (DNA+D2O)

60

5.7

5

D2O

--

6

8

Conclusions We have studied the effect ofdivalent ion on the DNA adsorption by the cationic
DC-Chol monolayer at the air-water interface byin-situ neutron reflectivity. It was found that in thepresence of calcium ions, other than the dense layerof a single ordered DNA array, there is a loose DNA
layer formed in adjacent to the dense DNA layer.
The thickness of the loose DNA layer increases
roughly in proportional to the square root of thecalcium ion concentration.
Since the charge
screening length constant is inversely proportional
to the square root of the calcium concentration, it issuspected that the DNA condensation is closely
related to the charge screening length constant andthe charge screening effect. The enhanced DNA
adsorption could be attributed to the bridging effectof the divalent ions between the adjacent adsorbed
DNA molecules. The existence of the well ordered
and compact first adsorbed DNA layer could also be
critical to the enhanced DNA adsorption.

References
1) Song Li and Zheng Ma, Curr. Gene Ther. 1(2001) 201.
2) Ilya Koltover, Tim Salditt, Joachim O. Rädler,
and Cyrus R. Safinya, Science 281 (1998) 78.
3) Ilya Koltover, Kathrin Wagner, and Cyrus R.
Safinya, Proc. Natl. Acad. Sci. U.S.A. 97(2000) 14046.
4) Jennifer J. McManus, Joachim O. Rädler, andKenneth A. Dawson, Langmuir 19 (2003) 9630.
5) Barbara Wetzer, Gerardo Byk, Marc Frederic,Marc Airiau, Francis Blanche, Bruno Pitard, andDaniel Scherman, Biochem. J. 356 (2001) 747.
6) Keitaro Kago, Hideki Matsuoka, Ryuji
Yoshitome, Hitoshi Yamaoka, Kuniharu Ijiro,
and Masatsugu Shimomura, Langmuir 15 (1999)
5193.
7) Yoshio Okahata, Takuya Kobayashi, andKentaro Tanaka, Langmuir 12 (1996) 1326.
8) Xiaodong Chen, Lin Li, and Minghua Liu,
Langmuir 18 (2002) 4449.
9) Murali Sastry, Vidya Ramakrishnan, Mrunalini
Pattarkine, Anand Gole, and K. N. Ganesh,
Langmuir 16 (2000) 9142
10) Christian Symietz, Marc Schneider, Gerald
Brezesinski,
andHelmuthMö1hwald,
Macromolecules 37 (2004) 3865.
11) D. McLoughlin,R. Dias, B. Lindman, M.
Cardenas, T. Nylander, K. Dawson, M. Miguel,and D. Langevin, Langmuir 21 (2005) 1900.
12) Marité Cárdenas, Tommy Nylander, Bengt
Jönsson, and Björn Lindman, J. Colloid Interface
Sci. 286 (2005) 166.
13) Ye Fang and Jie Yang, J. Phys. Chem. B 101(1997) 441.
14) Hauke Clausen-Schaumann and Hermann E.
Gaub, Langmuir 15 (1999) 8246.
15) Tsang-Lang Lin, Jui-Ching Wu, U-Ser Jeng, andNaoya Torikai, accepted for publication in
Physica B (2006).

Acknowledgements We would like to thank the
KENS of KEK for neutron reflectivity
measurements using ARISA and the supports during
the measurements. This research is supported by
the National Science Council, Taiwan, ROC, grant
No.
NSC93-2113-M-007-018
andNSC94-2623-M-007-014, and the Ministry of
Education, ROC, grant No. 91- I 0037-J4.
211

In-Situ Neutron Reflectivity Studies on the DNA Adsorption by the Lipid Monolayer at the
Air-Liquid Interface at Different pH Values
TSANG-LANG LIN1, JUI-CHING WU1, U-SER JENG2, and NAOYA TORIKAI3
1
Department of Engineering and System Science,
National Tsing Hua University, Hsinchu 300, Taiwan
2
National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan
3
Neutron Science Laboratory, High Energy Accelerator Research Organization,
Tsukuba, Ibaraki, 305-0801, Japan212

neutron reflectivity was carried out at the
time-of-flight reflectometer ARISA, KENS, KEK,
Japan. The Langmuir trough was used in the in-situ
reflectivity measurements at ARISA. The
temperature of the trough for all measurements is
controlled at 20±0.1oC by external water circulation.
The reflectivity data were analyzed using theParratt32 software (developed by Hahn-MeitnerInstitute).
Results and Discussions Figure 1 shows thesurface pressure-area isotherm at different pH values.
Comparing the isotherms for the same lipid
composition of d62-DPPC:DC=1:1 at pH 2 and pH
3, the isotherm at pH2 has higher pressure rise thanthe case at pH 3. This indicates that at lower pH
values there is stronger DNA-lipid interaction. The
DNA-lipid monolayer interaction is also stronger for
higher ratios of DC-Chol/d62-DPPC. At the same
pH 2, the d62-DPPC to DC-Chol of 1:1 case hashigher surface pressure rise than the 4:1 case.
Higher percentage of cationic DC-Chol lipid means
higher surface charge density and stronger chargeinteraction with the negatively charged DNA.
45

Surface Pressure (mN/m)

Abstract In this study, the effect of pH values on
the DNA interaction with the mixed d62-DPPC and
DC-Chol monolayer at different pH values wasinvestigated by in-situ neutron reflectivity. It was
found that mixed lipid monolayers with higher
DC-Chol ratios interact stronger with the DNA in
the subphase. By changing the pH value of thesolution, significant effect on the DNA adsorption
was observed. The thickness of the adsorbed DNA
layer becomes larger and larger as the pH is changed
from neutral to 3, then to 2. It can be concluded
that pH value is an important factor in regulating the
DNA-lipid monolayer interaction.
Introduction Due to the fast development ingene therapy researches, DNA adsorption by lipid
bilayers and monolayers has been widely studied.
The cationic lipid-DNA complex is a promisingvehicle for the gene therapy. It was found thatDNA formed ordered arrays between the lipidbilyars. Furthermore, the inter DNA distance isreduced when multivalent ions are added in thesolution [1]. Although there are several studies on
the structure and interaction of lipid-DNA complex
in solution [1-3], there are still limited studies of
their interaction at the air-water interface.
Recently, there are some studies using LB technique
to investigate the DNA-lipid interaction at the
air-water interface [4-5]. In this study, the effect ofpH values on the DNA adsorption by the mixed
d62-DPPC
andDC-Cholesterol(DC-Chol)monolayer at the air-liquid interface was studied byin-situ neutron reflectivity. HCl was added to thesolution to change the pH value of solution.
Experimental Linear DNA-type XIV fromherring testes was purchased from Sigma and usedwithout further purification. The size of the DNA isbetween 400 and 1000 base pairs with a center of
distribution at 700 bps (Dias et al., 2000). DC-Cholwith molecular weight of 537.3 was purchased from
Sigma and used without further purification. The
DNA solution was prepared at the concentration of 1
�M in H2O and the solution was sonicated for 30
minutes for completely dissolving. The in-situ

40
35
30
25

dDPPC/DC(1:1) DNA pH2dDPPC/DC(1:1) DNA pH3dDPPC/DC(4:1) DNA pH2dDPPC DNA pH2dDPPC/DC(1:1) DNA D2O(60%) pH2
dDPPC DNA D2O(60%) pH2

20
15
10
5
0
35 40 45 50 55 60 65 70 75 80 85 90 95 100 105
2Area (Å /molecule)Fig. 1The surface pressure-area isotherm.

The measured in-situ neutron reflectivity curves
were showed in Figure 2 in together with model
fitted curves. Some of the reflectivity curves areplotted in Fig. 3 in reflectivity time qZ4.

0

-4

10

Reflectivity

4

-2
-6

-2

10

-6

10

-8

10

-10

10

-12

10

-14

10

-16

10

-18

10

-20

10

Fig. 20.01-7dDPPC /DNA pH2dDPPC:DC(1:1)/DNA pH2
DC/DNA pH2

10

-8

10

-9

Fig. 3

Scattering Length Density (�10 Å )10

10

Reflectivity Times qz

Pronounced oscillations in the reflectivity curves
can be clearly observed in Fig. 3. It indicates there
is a thick film at the air-water interface. The
neutron scattering length density profiles as
determined from fitting the reflectivity data areshown in Fig. 4.
In our previous study, it was found that mixed
lipid monolayers with higher ratios of DC-Cholwould adsorb more DNA. Therefore, for theconditions of the same pH value, the mixed lipid
monolayer of d62-DPPC:DC=1:1 has more dense
adsorbed DNA layer than the d62-DPPC:DC=4:1
case. It is consistent with the isotherm results.
For the same lipid monolayer composition of
d62-DPPC:DC=1:1, the lower pH value induces
more DNA absorption and the thickness of theadsorbed DNA layer becomes much larger for thepH2 case than for the pH3 case. The pH effect is
an important factor in regulating the DNA-lipid
monolayer interaction.

0.00

0.05

0.10

-1

q Z (Å )0.15

The in-situ neutron reflectivity plotted as reflectivity
times qZ4 verse qZ.

7
6
5
4
3

dDPPC:DC(1:1)/DNA pH2dDPPC:DC(1:1)/DNA pH3dDPPC:DC (4:1)/DNA pH2dDPPC/DNA pH2dDPPC:DC (1:1)/DNA D2O(60%) pH2
dDPPC/DNA D2O(60%) pH2

2
1
0
-50

0

50

100

150

200

250

300

Length (Å)
D2O
dDPPC/DC(1:1) DNA pH2dDPPC/DC(1:1) DNA pH3dDPPC/DC(4:1) DNA pH2dDPPC DNA pH2dDPPC/DC(1:1) DNA D2O(60%) pH2
dDPPC DNA D2O(60%) pH2-1

q Z (Å )0.1

The measured in-situ neutron reflectivity curves.
The solid curves are the model fitting results.

Fig. 4

The neutron scattering length density profiles
determined by fitting the reflectivity data.

Conclusions In this study, the effect of pH
values on the DNA interaction with the mixed
d62-DPPC and DC-Chol monolayer at different pHvalues was investigated by in-situ neutronreflectivity.
It was found that mixed lipid
monolayers with higher DC-Chol ratios interact
stronger with the DNA in the subphase. Bychanging the pH value of the solution, significant
effect on the DNA adsorption was observed. The
thickness of the adsorbed DNA layer becomes larger
and larger as the pH is changed from neutral to 3,
then to 2. It can be concluded that pH value is an
important factor in regulating the DNA-lipid
monolayer interaction.

213

Acknowledgements We would like to thank the
KENS of KEK for neutron reflectivity
measurements using ARISA and the supports during
the measurements. This research is supported by
the NSC, grant No. NSC93-2113-M-007-018 and
NSC94-2623-M-007-014, and the Ministry of
Education, ROC, grant No. 91- I 0037-J4.
References
1) Ilya Koltover, Kathrin Wagner, and Cyrus R.
Safinya, Proc. Natl. Acad. Sci. U.S.A. 97(2000) 14046.
2) Jennifer J. McManus, Joachim O. Rädler, andKenneth A. Dawson, Langmuir 19 (2003) 9630.
3) Barbara Wetzer, Gerardo Byk, Marc Frederic,Marc Airiau, Francis Blanche, Bruno Pitard, andDaniel Scherman, Biochem. J. 356 (2001) 747.
4) Xiaodong Chen, Lin Li, and Minghua Liu,
Langmuir 18 (2002) 4449.
5) Christian Symietz, Marc Schneider, Gerald
Brezesinski,
andHelmuthMö1hwald,
Macromolecules 37 (2004) 3865.

214

Neutron Reflectivity Study on TAT Peptides and Proteins at the Charged Lipid Monolayers
A.

FARHAN1, C. LEE1, G. TAE1, K. SHIN1, N. TORIKAI2

1

2

Gwangju Institute of Science and Technology, Gwangju, 500-712, Korea
Neutron Science Laboratory, High Energy Accelerator Research Organization, Tsukuba, 305-0801

Cell-penetrating
peptides(CPPs)
orprotein-transduction domains (PTDs) are the short
peptides that can traverse cell membranes efficiently,
thus translocate the attached cargo into the cytosolof the cells. They are short in size (less than 30
amino acids), and typically have strong net positive
charge [1]. Their translocation ability is very
efficient and universal; they can cargo into the mostof cell types, from small peptides to massive
particles up to 200 nm, regardless of the attachment
method with cargo [2] or the attachment position(N-terminus, C-terminus, or center) [3]. Therefore,
the attachment of CPPs can be a versatile tool for
intracellular drug delivery systems, especially forbiological drugs such as peptides, proteins, or genes.
Adsorption process of cell-penetrating peptides(CPPs) in biological systems is very important, since
the CPPs provides cell transport activities to mostimmunodeficiency virus, causing lethal diseases.
Lipid monolayer at the air/water interface is used toinvestigate the binding mechanism of trans-acting
activator of transduction (TAT) peptides, whichwere known as a protein transduction domain ofhuman immunodeficienty virus, into lipid
membranes. The adsorption of cell-penetrating
peptides on phospholipid monolayers and HIV entry
inhibitors (Roche Ltd.) at the air-water interface wasinvestigated as a function of surface charge densityand packing density using Langmuir techniques. The
surface charge density of the monolayers were
controlled bymixing negatively
chargedphospholipids (DPPS) with neutral phospholipids(DPPC).

Fig.1 Schematic structure of DPPC and DPPS
monolayers at the air/water interface

The pronounced adsorption was occurred when
30 % of DPPS molecules were mixed with DPPC.
We measured the adsorption dynamics, bymonitoring the area change due to inter-penetrationof TAT peptides into the phospholipid layer. At
various stages of adsorption, the domain
morphology was monitored using Brewster angle
microscopy, florescence microscopy and in situ
neutron ray reflectivity.

Fig.2 In situ Neutron Reflectivity Curves
measured at ARISA, KEK, for i) deuterated PBS
buffer, ii) TAT peptides on 7:3 of d-DPDC/d-DPPS
mixed monolayer, and iii) HSA on 7:3 ofd-DPDC/d-DPPS mixed monolayer.
In detail, neutron reflectivity measured at ARISA,
KENS (Tsukuba, Japan) was used to confirm
structural change in a nanometer scale during theadsorption process. For comparison, adsorption
kinetics of human serum protein (HSA) andfibrinogen were also studied.
Fig. 2 shows the neutron reflectivity before andafter adsorption and penetration of the TAT peptides
and HSA adsorbed on the 7:3 DPPC: DPPS mixed
monolayer. The changes in the reflectivities areclear; the first minimum appears at ~ 0.1 Å-1.
Since alkyl tail groups of both phospholipids, DPPC
and DPPS are fully deuterated, the contrast is
originated at the interface of headgroup andadsorbed non-deuterated molecules (HSA and TAT
peptides). For the HAS adsorbed layer, the firstminimum of the Kissieg fringe was located at the215lower q-region, indicating the total thickness
measured from the contrasting interface (HSA
adsorbed layer) to the end of tail group, became
thicker. The reflectivity at high q-region (0.1 ~ 0.25
Å-1) was bounding back to d-PBS normal surface,indicative of negligible change of density profile attail group. In contrast, the intensity of the TAT
adsorbed layer shows a significant reduction at highq-region. These characteristics shown in Fig.2 canbe explained; i) the tail layer of phospholipids was
highly disturbed upon TAT adsorption. Note that thesurface status of the phospholipid layer was nearly asolid phase, meaning that the tail molecules arehighly compressed. Therefore, the disturbance dueto the TAT adsorption, should occur when the TAT
molecules penetrated into the tail molecules. ii) The
first minimum of the Kissieg fringes is linearlycorresponding to the size of adsorbed molecules.
Therefore, the adsorption of HAS molecules shows
thicker layer, forming at the headgroup ofphospholipids, while as the TATs are much smaller
in size. The fact that HSA molecules were adsorbed,
does not induce the density reduction of tail layer,
indicating the HAS molecules were hardly
inter-penetrating into the phospholipid layer.
The fitting was performed by including an
additional layer on the headgroup layer, keeping the(tail/headgroup/additional layer) floating during therefinement. Fig. 3 shows the depth profiles of
those two adsorbed layers, and the schematic models
are showing in the inset to the figure. In contrast to
the HSA system, the adsorbed TAT molecules dohighly disturb the tail/headgroup interface,indicating that most of the adsorbed TAT only fitted
into the inter-molecular space.
In summary, the results indicate; (i) TAT peptide
can effectively adsorb and penetrated into the 30%
DPPC monolayer. (ii) The net charge of the DPPS
head group might be responsible for the entrapped
TAT layers near the head group layer. The
relationship between the highest adsorption
phenomena, which were shown for the 30% DPPS
layer and the surface charge effects are currently
being investigated by other methods (X-ray
reflectivity, and Brewster angle microscopy).[4]216Fig.3 The corresponding scattering lengthdensity profiles from the fitting of the reflectivity
spectra shown in Fig.2.
References[1] M. Zorko, U. Langel, Adv. Drug Del. Rev. 57(2005) 529.
[2] B. Albarran, R. To, P.S. Stayton, Protein Eng.
Des. Sel. 18 (2005) 147.
[3] H.Brooks, B. Lebleu, E. Vives, Adv. Drug Del.
Rev. 57 (2005) 559[4] G. Tae, K. Shin, S. Satija, and N. Torikai, J.
Appl. Crystal, submitted.

Neutron Reflectivity Measurement of the Gibbs Monolayerof Ionic Liquid [BMIM]BF4 Aqueous Solution
T. TOHYAMA, K. KANAI, Y. OUCHI, K. SEKI, D. KIM*, and N. TORIKAI**
Department of Chemistry, Graduate School of Science, Nagoya University,
Furo-cho, Chikusa-ku, Nagoya 464-8602* Department of Physics and Interdisciplinary Program of Integrated Biotechnology, Sogang
University, Seoul 121-742, Korea**Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
In this study, we, for the first time, performed
neutron reflectivity measurement for [BMIM]BF4 /D2O aqueous solution at a concentration of c=0.016
to elucidate a thickness of a Gibbs monolayer.
[BMIM]BF4 was purchased from C-Tri in Korea andwas used without further purification. The
measurements were conducted on ARISA
reflectometer at KENS facility, KEK. The data
were taken at = 0.3993 ° and 1.289 ° with/ of about 6 %. Figure 2 shows a typical
specular reflectivity profile of [BMIM]BF4 / D2O
aqueous solution at a concentration of c=0.016.
Reflectivity calculation with use of a standard
optical matrix method clearly indicates that the
profile is better fitted with an assumption of a 13.5
Å thick monolayer floating on the aqueous solution.
Considering the size of the ionic liquid, it is quite
reasonable that the Gibbs monolayer consists of not
only cations but anions, which may weakly boundtogether to form an electric double layer.
0

10

Reflectivity

Room-temperature ionic liquid (RIL) is a saltconsisting of certain organic cation and anion, and isin liquid phase at room temperature. Because theseionic liquids are nonvolatile, nonflammable, and aregood solvent for many chemicals, they are gaining
interest as environment-friendly solvents for a rangeof chemical processes or as possible constituents inelectrochemical applications. As the mixture of RIL
with water is expected to have interesting properties,
several experimental studies about the bulk
properties of the mixture were performed. Recently,
we investigated the surfaces of room-temperature
ionic liquid (RIL)+water binary mixtures of varying
concentrations using a surface tension measurement(as shown in Fig. 1) and IR-Vis sum-frequency
generation (SFG) vibrational spectroscopy [1].
Rapid drop in the surface tension followed by aslight increase allowed us to draw an idea about thechemical composition and the density of the surface
molecules with the increase in the bulk RIL
concentration. The result from SFG was inagreement with the above findings. However, theactual dimension of the monolayer is still not known
from these techniques, and hence the detailed
understanding is still lacking

surface tension  / (mN/m)

70
70

65

65

-1

10

-2

10

-3

10

-4

10

-5

60

60

55
50

55

45
40
0.00

50

0.04

0.08

0.12

0.16

0.20

45
0.00

40
0.0

0.2

0.4

0.6

0.8

0.05

0.10

0.15

qz/Å-10.20

1.0bulk mole fraction of RIL

Fig. 110

D2O_[BMIM]BF4_0.016molefrac.
Reflectivity
Reflectivity_fitting(Bulk model)-6-2
b_v=4.58×10 Å
Reflectivity_fitting(Monolayer model)-6-2b_v(m)=2.42×10 Å , d=13.5Å-6-2
b_v=4.83×10 Å

Surface tension of [BMIM]BF4 aqueous solution. The
inset shows the same data at lower concentration in
more detail.

Fig. 2

Specular reflectivity profile of [BMIM]BF4 / D2O
aqueous solution at a concentration of c=0.016

References
1) J. Sung et al. Chem. Phys. Lett., 406(2005)496

217

Analysis of Structure of Poly(2-Methacryloyloxyethyl Phosphorylcholine) Brush at the
Aqueous Interface by Neutron Reflectivity
M. KOBAYASHI１, K. MIYAMOTO2, N. HOSAKA2, K. ISHIHARA3, A. TAKAHARA*1,2
1

Institute for Materials Chemistry and Engineering, 2Graduate School of Engineering, Kyushu
University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581, Japan3
Department of Materials Engineering, School of Engineering, The University of Tokyo

1. Introduction
Polymer brush is a system formed by densely
tethered polymers on a solid surface, of whichchains are stretched away from the surface [1]. The
behavior of polymer brushes in solvent has
important technological implications for various
applications. Polymer brush in good solvent ispredicted to adopt a fairly extended conformation
due to the high osmotic pressure caused by highlocal density of polymer chains [2]. However, it isindeed difficult to measure the thickness of theextended brush because a continuous layer ofsolvated chains will be formed. Neutron reflectivity(NR) measurements are, therefore, appropriate forthe study of the influence of solvent on polymer
brush structure. In this work, the authors used superhydrophilicpolymerbrush
preparedby
2-methacryloyloxyethyl phosphorylcholine (MPC)
polymer, which has well-designed chemical
structure for the improvement of biocompatibility of
medical devices [3].
2. Experimental
The poly(MPC) brush was prepared bysurface-initiatedatomtransfer
radicalpolymerization of MPC from the surface of a quartz
plate (75  75  10 mm) and a silicon wafer (10  40
 0.5 mm) at the same time. In advance ofpolymerization, both of substrates were immobilizedwith alkyl bromide monolayer as a surface
initiator.[4,5] The number-average molecular weightof the obtained polymer was estimated to be 59500(degree of polymerization was ca. 200) by GPC
analysis of linear polymer, which was grown fromco-existed free initiator during surface-initiatedpolymerization. Thickness of polymer brush on
silicon wafer under the dry state was found to be 25
nm by an imaging ellipsometer. The polymer brushon quartz plate should have the same thickness. The
grafting density was calculated to be 0.20
chains/nm2 from the thickness, molecular weight of218

brush, and bulk density of poly(MPC).
NR measurements were performed on theadvanced reflectometer for interface and surface
analysis (ARISA). As shown in Figure 1, neutron
beam irradiated from quartz glass to the interface
between D2O and immobilized poly(MPC) brush.
Incident angles were fixed to 0.3 and 0.6 thatcovered q range of 0.11~0.55 nm1 and 0.2~1.1 nm1,respectively. The angular resolution, /, was kept
at 5%. The NR profiles were analyzed by fitting a
selection of theoretical scattering length density
profiles to the data, using a Parratt32 software.
CH2
3C

Poly(MPC) brush

C COO(CH
H 2)2OPO3(CH2)2NMe3nIncident neutron
beam
Quartz
D2O

Reflected neutron
beam
Polymer brush
Teflon base

Figure 1. Schematic view of the liquid cell used inexperiment.

3. Results and discussion
A critical angle was clearly observed at q = 0.11
nm-1 in Figure 2 owing to the difference in scattering
length density between quartz (3.8010-4 nm-2) andD2O (6.410-4 nm-2). The reflective profile arisingfrom polymer brush interface (Figure 2(b)) shifted
downward compared with that from bare quartz(Figure 2(a)). This result indicated that thepoly(MPC) chains were stretched up to 60~70 nm,
and formed concentration gradient of D2O underswelling states. The full length of the graft chain in
the all-trans conformation is calculated to be 50 nm,
assuming the length per monomer unit as 0.25 nm
and 200 of repeating units. The observed thickness
by NR is acceptable value, since polymer brush has
distribution in chain length, corresponding withmolecular weight distribution (Mw/Mn = 1.5).[6]Nb (10-4 nm-2)

Therefore, the tethered polymer chains would havefairly extended conformation along the direction
normal to the quartz surface.
On the other hands, thickness of poly(MPC) brushdecreased to 30~40 nm in deuterated ethanol/D2O(68/32, v/v), as shown in Figure 2(c). Ishihara andhis coworkers already reported that poly(MPC) was
soluble in pure water and pure ethanol, while it was
insoluble in a water/ethanol mixture, containing
70~90% of ethanol.[7] Hence the polymer brush is
expected to shrink in a mixture of deuterated ethanol
and D2O.
6.0
5.0

Brush / D2OBrush / C2D5OD+D2O

4.0

increases in a poor solvent for polymer. Interestingly,
however, opposite results were obtained in the caseof poly(MPC) brush. The authors supposed thatswollen and extended poly(MPC) brush chains inpure water and ethanol should have increased actual
contact area between brush and glass probe to resultin higher friction coefficient, compared with theshrinking brush in the poor solvent.
In conclusion, NR measurement revealed that thestructure and the thickness of poly(MPC) brush at
the aqueous interface were sensitive to content of
ethanol in water mixture. The authors will continue
to investigate the relationship between the interface
structure of polymer brushes and their tribologicalproperties.
0.3

100

(a): Bare quartz / D2O(b): Brush / D2O(c): Brush / C2D5OD+D2O

10-1

Reflectivity

10-2
10-3

(a)

10-4
10

Friction coefficient

0
20
40
60
Distance from quartz surface / nm

Glass ball

0.2

0.1

(b)

-5

0

10-6
10

-7

10

-8

(c)

0.1

0.2

0.3 0.4
q / nm-1

0.5

0.6

Figure 2. Experimental NR profiles of bare quartz (a),poly(MPC) brush in D2O (b), poly(MPC) brush in a
mixture of deuterated ethanol / D2O (68/32, v/v) (c),and their corresponding fits. Assumed scattering lengthdensity profiles for (b) and (c) are shown above.

The authors have been studied the tribologicalproperties of hydrophilic polymer brush surface
using a conventional ball-on-disk type friction tester
in water.[5] In this work, dynamic friction test werecarried out by sliding a glass ball (d = 10 mm) onpoly(MPC) brush on silicon wafer in water, ethanol,and their mixture under the normal load of 0.49 N atroom temperature. As shown in Figure 3, friction
coefficient decreased with ethanol content in water
ranging from 65 to 85%, and increased again in pureethanol (100%). Generally, the friction coefficient ofpolymer brush decreases in a good solvent and

0

65
75
85
100
EtOH content in water /%Figure 3. Friction coefficient of poly(MPC) brush inethanol/water solution by sliding a glass ball over awidth of 20 mm at a sliding velocity of 90 mim/min
under loading of 0.49 N at 298 K.

References[1] W. J. Brittain et al, Polymer Brushes,
Wiley-VCH, Weinheim (2004).
[2] T. Fukuda et al., Macromolecules 33, 5602
(2000).
[3] K. Ishihara et al., J. Biomed. Mat. Res. 26, 1543
(1992).
[4] A. Takahara et al., Polym. J. 37, 767 (2005).
[5] M. Kobayashi et al., Chem. Lett. 34, 1582 (2005)[6] S. T. Milner et al., Macromolecules 22, 853(1989).
[7] K. Ishihara et al., J. Biomater. Sci. Polym. Ed. 13,
214 (2002).

219

Neutron Reflectivity
for the Structural Analyses of the Silsesquioxane-filled Polymer Thim Films
N. HOSAKA, K. MIYAMOTO, N. TORIKAI* and A. TAKAHARA
Institute for Materials Chemistry and Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku,
Fukuoka, 812-8581*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, 1-1 Oho, Tsukuba, Ibaraki, 305-0801
PolyhedraloligomericR
O Si ROSi
silsesquioxane(POSS),RSi O SiOR
O
O
which is one of nanosized
ORSiOmaterials with a silica core
O Si
O
O R
Si
O Si RR
and organic groups on thesurface, meets increasing
R = Cyclopentyl
interest as a building unit for Fig. 1 C h e m i c a linorganic-organic
hybrid structure of CpPOSS.
materials. In our previous
study, the authors reported that the incorporation of
cyclopentyl- substituted POSS (CpPOSS, Fig. 1) tothe polystyrene (PS) thin films led to a great
inhibition of dewetting of the films [1]. In this paper,the dispersion state of CpPOSS and PS with POSS
end group (PS-POSS) in the PS films wasinvestigated. Furthermore, the relationship between
the structure and dewetting property of the hybrid
films is discussed.
POSS/PS hybrid films were prepared byspin-coating method onto acid-cleaned silicon
substrates from toluene solution of the mixture of
POSS and PS with specific compositions. PS(number average molecular mass Mn = 2100, andpolydispersity value Mw/Mn = 1.06; PS2k) was used
as a matrix polymer to observe the dewetting
behavior of the film in experimental time scale. PS(Mn = 44000, Mw/Mn = 1.04; PS44k) was used forstructural analyses. Deuterated-PS (Mn = 38500,
Mw/Mn = 1.07; d-PS38k) was used for neutronreflectivity (NR) measurements to make a contrast
to POSS nanofillers in scattering length density. NR
measurement was performed at an advanced
reflectometer for interface and surface analysis(ARISA) on H5 beamline of Neutron Science
Laboratory, High Energy Accelerator Research
Organization. NR data was analyzed with Paratt 32
software from HMI Berlin.
Fig. 2 shows the optical micrographs of purePS2k film and CpPOSS/PS (15/85 w/w) hybrid film
annealed at 393 K for 3 h. PS2k film was completely
dewetting as shown in Fig. 2 (a), On the other hand,no appreciable dewetting was observed in
220

CpPOSS/PS2k hybrid film after the annealing
treatment.
(a)

(b)

Fig. 2 Optical micrographs of (a) 53 nm thick pure PS2k filmand (b) 56 nm thick CpPOSS/PS2k (15/85 w/w) hybrid film
nm.

Surface and interfacial structures are important tounderstand the stability of the polymer thin films ona certain substrate. Interfacial roughness was known
to pin the contact line of the dewetting front andinduce the wetting process [2]. Surface energetics is
also an important factor to describe the dewetting ofpolymer thin films. The key to whether a film isstable or not on a certain substrate is given by
Young’s equation for the spreading coefficient [3],SB A 

AB

(1)where A, B are the surface free energies of thepolymer film, substrate, and AB is the free energy ofpolymer-substrate interface, respectively. PS2k thinfilm on the silicon substrate has negative spreading
coefficient, so the film is unstable and caused thedewetting.
The dispersion state of CpPOSS in the PS films,
especially at the surface and interface of the films,
was investigated by NR measurement. NR profile
for CpPOSS/d-PS38k (10/90 w/w) hybrid film wasshown in Fig. 3. The solid curve in Fig. 8 is theresult of model fit corresponding to the depth profileof the scattering length density, (b/V), shown in theinset. Since (b/V) of the d-PS38k matrix is muchlarger than that of CpPOSS nanofiller, thedistribution of the nanofiller in the film can bestudied. At the surface of the hybrid film, as shownin the inset of Fig. 3, the boundary of the air and the

10

-2

10

4
2
0
-10 0 10-3

10Measured
Calculated-410100110120

Depth / nm

-5

10

0.1

0.2

0.3

0.4

0.5
-1

0.6

0.7

0.8

q / nm

Fig.3 NR profile and fitting curve of the CpPOSS/d-PS38k(10/90 w/w) hybrid film. Solid curve is the result of model fit
corresponding to the depth profile model of (b/V) shown in theinset.

The segregation of CpPOSS to the film surface
was originated from the lower surface free energy of
CpPOSS than PS matrix. The segregation of lower
surface free energy component to the surface
affected the surface energetics of the film andbrought the increase of spreading coefficient, S,
which can reduce the dewetting of the films. The
segregation of the film-substrate interface can alsochange the energetics at the interface, and affect thedewetting behavior of the film, Furthermore, theCpPOSS enrichment layer roughened the interfacial
structure, expected to cause the pinning of thedewetting front. The driving force of the segregationof CpPOSS at the film-substrate interface has notbeen proved yet, nevertheless, it can be attributed tothe enthalpic effect. Polymer chains existing in theinterface should be in a confined state. The enthalpic
penalty of interface segregation for the low
molecular weight component, like CpPOSS, issmaller than polymers, and often segregates to thefilm interface.
Due to the low affinity of CpPOSS with PS, thefilm surface was roughened by the aggregation of
CpPOSS in the CpPOSS/PS hybrid films. Therefore,
the authors synthesized PS with POSS end group(Mn = 2500, Mw/Mn = 1.11; PS-POSS) throughnitroxide-mediated radical polymerization
as

O

N
O

R
O
Si O Si Si
O
R Si O Si O
R O
O
O R
O
O Si O Si R
Si O Si O
R
R

125 oC

N
O

O
N
H

O

n

R = cyclopentyl

Scheme 1. Synthesis of PS-POSS.

shown in Scheme 1 to improve the dispersibility of
POSS in PS thin films and reduce the surface
heterogeneity of the film.
Atomic force microscopy revealed that
PS-POSS2.5k/PS44k hybrid film possessed thesmall
surfaceroughness,compared
with
CpPOSS/PS44k hybrid film. This result is indicativeof the improvement in the dispersibility of POSS in
PS thin films by the introduction of PS. The
incorporation of PS-POSS2.5k into PS thin films
brought a great inhibition of dewetting. NR
measurement
wascarriedout
forthe
PS-POSS2.5k/d-PS38k thin films. The result isshown in Fig.4. As shown in the inset of the Fig. 4,
The PS-POSS2.5k also had the tendency tosegregate to the film surface and film-substrateinterface. The dewetting inhibition by the additionof PS-POSS to the PS thin films can be attributed tothe modification of the film surface and interface by
the segregation of PS-POSS just like CpPOSS
nanofiller.
1

10

-2

-2

(b/v) / 10 cm

Reflectivity

-1

10

6

O
N
H

0

10

10

0

10

R
O
Si O Si SiOOR Si O Si R
O
O
O R
O
O Si O Si R
O
Si
O Si
R
R

(b/v) / 10 cm

1

10

OMe

OMe

-1

Reflectivity

film was broadend du to the segregation of CpPOSS
to the film surface and morphological roughness ofthe surface. (b/V) of the hybrid film was lower thanpure d-PS38k in the middle part of the film becauseof the existence of CpPOSS, and extensively
decreased near the polymer-substrate interface. At
the interface, the roughness of the substrate can beignored, so the result means the formation of
CpPOSS enrichment layer at the interface.

10

-2

10

6
4
2
0
-10 0 10

-3

-4

10

-5

10

0.0

100110120

Depth / nm

10

Measured
Calculated
0.2

0.4

-1

q / nm

0.6

0.8

Fig. 4 NR profile and fitting curve of the PS-POSS2.5k/d-PS38k(28/72 w/w) hybrid film. Solid curve is the result of model fit
corresponding to the depth profile model of (b/V) shown in theinset.

References
1) N. Hosaka, K. Tanaka, H. Otsuka, A. Takahara,
Composite Interfaces, 11, (2004) 297.
2) R. R. Netz, D. Andelman, Phys. Rev. E, 55,(1997) 687.
3) G. Krausch, J. Phys.: Condens. Matter., 9, (1997)
7741.

221

Effects of NaI Salt on Structure of a Spin-Coated DMPC Lipid Film
N. L. YAMADA and N. TORIKAI
Neutron Science Laboratory, Institute of Materials Structure Science,High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801
It has been well known that phospholipid
molecules, the basic constituent molecules ofbiomembranes, usually form multi-lamellar vesicles(MLVs) in water. These mimic biomembranes
produced by phospholipids have been extensively
studied to understand the actual behavior of real
biomembranes. Such vesicles are typically obtainedby hydrating a dry lipid film on a solid surface. [1]
In contrast, effective methods to create uni-lamellar
vesicles (ULVs) with the phospholipids were also
pursued since living cells and their organelle exist as
the ULVs. [2-6] It has been recently shown that theaddition of sugar or salt promotes the formation of
ULVs only when they are mixed with lipid films
before hydration. [7] The mechanism of the ULVformation induced by additives, however, has notbeen clarified yet.
To understand the mechanism of vesicle
formation through hydration of lipid film, it isimportant to investigate the stacking structure of
bilayers for the lipid film before hydration. Hishida
et al. have observed the structure of pure lipid films
before hydration and the hydrated products byphase-contrast microscopy and atomic-force
microscopy. Their results indicated that the vesicle
formation strongly depends on initial structure of thelipid film on a substrate.[8] Since the vesicles can be
hardly fused or split once they are formed, thehydration process from the lipid film could govern
the vesicle formation. In this study, we investigated
the structure of lipid thin films with and without anadditive on solid substrates by neutron reflectivity
measurement to clarify the mechanism of the ULVformation induced by additives.
Two lipid thin films with and without an additive
were prepared on Si substrates by spin-coating: apure dimyristoylphosphatidylcholine (DMPC) lipid
with fully-deuterated hydrocarbon chains and its
mixture with NaI salt at equi-molar fraction. NaI
was chosen because it is easily soluble in the organic
solvent used for spin-coating the lipid films.
Neutron reflectivity measurement was performed on
the ARISA neutron reflectmeter in KEK, Japan.
Figure 1 shows the reflectivity profiles of thepure DMPC and the DMPC/NaI mixture films at

222

Fig. 1 Neutron reflectivity profiles of DMPC lipid films withand without NaI.

different temperatures in a vacuum. In the profile ofthe pure DMPC film at 30°C, there are small fringes
and a Bragg peak around q=0.125 Å-1 reflecting thetotal film thickness and the lipid bilayer stacking,respectively. For the DMPC/NaI mixture film at
30°C, the fringes disappeared and the Bragg peakwas shifted to lower-q than that observed in the purelipid film. This implies that the addition of NaI
induced the uneven structure on the surface, andincreased the repeat distance of the bilayer stacking.
Since no or little water can exist in a vacuum, theincrease of the repeat distance reflects theintercalation of NaI molecules between the bilayers.
The experiments were also performed at 80°C,
which is higher than a chain-melting transition
temperature, around 60°C, of a pure dry DMPC. The
Bragg peak for the pure DMPC film was slightly
shifted to higher-q with increasing temperature. Thismeans that the bilayer thickness is decreased
because the straight hydrocarbon chains could bepartially bent at high-temperature phase. On theother hand, a new Bragg peak for the DMPC/NaI
mixture film appeared around q=0.155� Å-1, and it
possesses a shoulder around the q-position
corresponding to the Bragg peak in the
low-temperature phase. This change in the Bragg
peak position by temperature for the DMPC/NaI
mixture film is too much to be explained by thechain-melting transition even if the hydrocarbon
chains of the lipid molecules are fully bent. Further,
the apparent bilayer thickness, about 40 Å, evaluatedfrom the new Bragg peak is consistent with that in
an “interdigitated phase”, which was previously
reported in the aqueous solution with ethanol andwas characterized by an alternative alignment ofhydrophilic head-groups and hydrophobic tails ofphospholipid molecules as the schematic illustrationin Fig. 2. [9] Therefore, we concluded that the new
Bragg peak observed at 80°C for the DMPC/NaI
mixture film is originated from the interdigitatedphase.
The experimental results suggested that the salt
is located between the lipid bilayers. This isconsistent with the previous results on the aqueous
solution prepared from the lipid/additive mixture
film: the osmotic pressure due to the NaI molecules
between lipid bilayers would result in the formationof the ULV.[10] Also, the addition of NaI induced
the phase transition to an interdigitated phase at hightemperature. Although it is known that amphiphilicmolecules such as alcohol induce the phasetransition to the interdigitated phase in water
solution, it has not been reported that the addition ofsalt causes this kind of phase transition even inaqueous solution as far as we know.

Fig. 2 Schematic illustration of a phase behavior in lipid
films with and without NaI.

1)

J. P. Reeves and R. M. Dowben, J. Cell.
Physiol. 73 (1969) 49.
2) A. Darszon, C. A. Vandenberg, M. Schonfeld,
M. H. Ellisman, N. C. Spitzer, and M. Montal,
Proc. Natl. Acad. Sci. USA 77 (1980) 239.
3) S. Kim and G. M. Martin, Biochim. Biophys.
Acta. 646 (1981) 1.
4) M. I. Angelova, S. Soléau, Ph. Méléard, J. F.
Faucon, and P. Bothorel, Progr. Colloid Phlym.
Sci. USA 89 (1992) 127.
5) N. Magome, T. Takemura, and K. Yoshikawa,Chem. Lett. (1997) 205.
6) K. Akashi, H. Miyata, H. Itoh, and K.
Kinoshita Jr., Biophys. J. 74 (1998) 2973.
7) K. Tsumoto and T. Yoshimura, in preparation.
8) M. Hishida, H. Seto, and K. Yoshikawa, Chem.
Phys. Lett. 411 (2005) 267.
9) H. Seto, H. Nobutou, N. L. Yamada, T. Takeda,
D. Ihara, M. Nagao, and K. Inoue , J. appl. cryst.
36 (2003) 607.
110) N. L. Yamada, M. Hishida, H. Seto, K.
2 Tsumoto, and T. Yoshimura, in preparation.

References

223

Study on Surface Segregation in Miscible Polymer Mixture of Poly(4-Trimethylsilylstyrene) /Polyisoprene Based on Neutron Reflectivity
D. KAWAGUCHI1, M. OHYA1, N. TORIKAI2, A. TAKANO1 and Y. MATSUSHITA1*
1)

Department of Applied Chemistry, Nagoya University, Nagoya, Aichi, 464-8603
2)
Neutron Science Laboratory, Institute of Materials Structure Science,High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801

We have already found that a blend ofpoly(4-trimethylsilylstyrene) (PTMSS), which is apolystyrene (PS) derivative, and 1,2- and 3,4polyisoprene (PI) is a miscible polymer blend though PS
and PI are a typical immiscible polymer blend.[1]Based on the small-angle neutron scattering measurement
and microscopic observation, the polymer blend exhibitsa lower critical solution temperature (LCST) type phase
diagram. This result indicates that incorporation oftrimethylsilyl (TMS) group into phenyl ring on PS can
induce drastic change in miscibility of the blend.
However, aggregated structure of the present blend at thesurface has not been clarified yet. In most miscible
polymer blends composed of glassy and rubbery
components, a rubbery one is enriched at the surface. It isconceivable that low density of the rubbery component isrelevant to the low cohesive energy density and low
surface free energy. The objective of this study is toinvestigate surface segregation phenomena in PTMSS/PI
blend by neutron reflectivity (NR).
Monodisperse deuterated PTMSS (dPTMSS) and PI
with weight-averaged molecular weights of 34k and 11k,
respectively, were used in this study. Glass transition
temperatures, Tgs, of dPTMSS and PI are 403 and 283 K.1 and 37.4
and their surface free energi
mJ·m-2, respectively. dPTMSS/PI blend film mixed at
the ratio of 1:1 in volume was prepared by spin-coating
method from the toluene solution onto Si wafer withnative oxide layer. The film was annealed at 403 K for
120 h, the annealing temperature being above the Tg andbelow the LCST of the blend. NR measurement was
carried out using Advanced Reflectivity for Interface andSurface Analysis (ARISA)[2] at Neutron Science
Laboratory, High Energy Accelerator Research
Organization. Angular resolution was set to be 5.0 %.
The reflectivity was calculated on the basis of thescattering length density, (b/V), profile along the depth
direction by SERF. [3]We examined the surface composition of thedPTMSS/PI blend film based on contact angle
30.4 mJ·m-2 which was almost equivalent to that ofdPTMSS homopolymer film of 31.1 mJ·m-2. Thismeans that the blend film surface is completely covered
with dPTMSS. Figure 1 shows the scattering vector, q,
dependence of NR for the dPTMSS/PI blend film
annealed at 403 K. Experimental data set is shown by

224

circles. A solid curve denotes the best-fit calculated
reflectivity to the experimental data based on the model(b/V) profile as shown in the inset of Figure 1. Since thecalculated curve was in good agreement with theexperimental data, it is regarded that the model (b/V)
profile corresponds well to the composition profile in thefilm along the depth direction. In this calculation, the(b/V) values of 3.63 x 10-4 and 0.27 x 10-4 nm-2 were used
for dPTMSS and PI, respectively. The (b/V) value atthe surface is higher than that in the bulk region, whereas
the (b/V) value of approximately 1.0 x 10-4 nm-2 in theinterfacial region is lower than that in bulk region. Thus,
it is apparent that dPTMSS and PI were enriched at thesurface and interface, respectively, to minimize total freeenergy. Here, it should be noted that a glassy componentof dPTMSS was preferentially segregated at the surface.
This phenomenon could be achieved due to the peculiar
segregation of TMS groups at the surface.

Figure 1. Neutron reflectivity profile for dPTMSS/PI
blend film annealed at 403 K. Solid curve denotes thebest-fit calculated reflectivity to the experimental data
based on model (b/V) profile shown in the inset.
References
1) Harada, et al. Macromolecules, 38, 1868 (2005).
2) Torikai, et al. Appl. Phys. A, 74 (Suppl.), S264(2002).
3) Welp, et al. J. Neutron Res., 8, 37 (1999).

Surface Segregation of Water-soluble Block in Fluctuating Block Copolymer Melts
H. YOKOYAMA,1 S. HAN,2 T. ISHIZONE2 and N. TORIKAI3
Nanotechnology Research Institute, National Institute of Advanced Industrial Science andTechnology, Central 5, Higashi, 1-1-1, Tsukuba, Ibaraki 305-8565
2
Department of Organic and Polymeric Materials, Tokyo Institute of Technology,
2-12-1, Ohokayama, Meguro-ku, Tokyo 152-8552
3
Institute of Materials Structure Science,High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801

Spontaneous segregation of hydrophobic blockin amphiphilic block copolymers is common andproduces a hydrophobic surface. Hydrophilic (ormore specifically water-soluble) blocks withrelatively high surface energy tend to be repelledfrom the surface and embedded in bulk. The
methacrylates with EO side chains without methyl
terminationsuchaspoly(2-hydroxyethyl
methacrylate), poly[(diethylene oxide) methacrylate]and poly[(triethylene oxide) methacrylate] are
known to stay away from the surfaces.[1] We
report a block copolymer of deuterated polystyrene(dPS) and 2-[2-(2-methoxyethoxy)ethoxy]ethyl
methacrylates (PME3MA) spontaneously exposes
the PME3MA block, which is soluble in water, tothe surface in a vacuum.[1,2] This surprising
surface segregation of water-soluble block tovacuum and air surfaces is observed even influctuating dPS-PME3MA block copolymer
disorder melts. Neutron reflectivity (NR) revealed
that dPS-PME3MA fluctuates in the direction
normal to the surface and enriches PME3MA
fraction at the surface. The fluctuation wavelength
in the thin film agreed very well with that in bulk
measured by small angle X-ray scattering (SAXS).
Shown in Fig. 1 is the small angle scatteringprofile of dPS-PME3MA annealed at 140 ºC for 10hours and quenched to room temperature. SAXS
profiles were obtained using an X-ray diffractometer(Rigaku Ultrax 4153A 172B). A Cu K radiation
q isdefined as q
between the incident and scattered X-rays. A
broad single peak in the profile clearly indicates thatdPS-PME3MA is in a disorder phase withcompositional fluctuation, and the value of q at thepeak top, qmax, is inversely proportional to thewavelength of the fluctuation. We attempt to
extract the Flory   parameter from the fluctuation
peak using a random phase approximation (RPA)
introduced by Leibler[3]. A fit of the RPA isshown as a solid line in Fig. 1, in which only thehigher q side of the peak is used for the fit to avoid
the influence of the tail of direct beam. For the
total number of segments N = 131 and volume
fraction f = 0.41,   is estimated to be 0.079. The  is surprisingly small despite the difference of thesolubility of PME3MA and PS in water. It seems
that the interaction of PME3MA with PS is screenedby the presence of the methyl termini: PS may nothave a direct contact with the EO in the interior of
the side chains while a small molecule like watercan easily penetrate into the interior of the side
chains and interact with the EO.

SAXS Experiment
Random Phase Approximation

Intensity, a.u.

1

0.0

0.2

0.4

0.6

1

0.8

1.0

q / nmFig. 1

Small
angle
X-ray
scatteringprofileofdPS-PME3MA block copolymer.
Intensity isplotted in an arbitrary unit against q defined by q
points, and the line is the fit by random phaseapproximation.

It is known that a block copolymer even in adisorder phase forms a layered structure induced by
the difference in the surface energies of the blocks.
Therefore, dPS-PME3MA in a disorder phase may
not have a homogeneous composition at the surface.
We measured a depth profile of a dPS-PME3MA
thin film using neutron reflectivity (NR) to reveal a225

reflected neutron beams respective to the surface
plane. The reflectivity of the film is shown in Fig.
2. The periodic Kiessig fringes corresponding to
the total thickness of the film appear, and the broad
peak at 0.43 nm-1 overlaps. Since qmax of the
SAXS profile in Fig. 1 agrees very well with thevalue of the weak Bragg peak maximum in thereflectivity, the layered structure was induced by thesurface and substrate with the same length scale offluctuation in bulk.
0

Reflectivity

10

Fig. 2

10

-1

10

-2

10

-3

10

-4

10

-5

0.0

0.1

0.2

0.3

0.4

q / nm

0.5

1

0.6

0.7

0.8

Neutron reflectivity of the neat dPS-PME3MA block
copolymer on a silicon substrate. The reflectivity isplotted against q defined by q
solid line is a fit using a model depth profile ofneutron scattering length density b/V shown in theinset.

The profile of a scattering length density, b/V, inwhich dPS has a higher value of b/V, clearly shows
decaying oscillation from the surface and the silicon
substrate. The depletion layer of b/V at the surface
clearly indicates that the PME3MA blockpreferentially covers the surface.
Despite thedPS-PME3MA block copolymer in a disorder phase,the surface is sufficiently covered by thewater-soluble PME3MA blocks.

226

2

7

4

b / V x 10 /nm

surface induced structure. NR measurements werecarried out using Advanced Reflectometer forInterface and Surface Analysis (ARISA) on H5beam line of Neutron Science Laboratory, HighEnergy Accelerator Research Organization.
A
neutron beam with a range of wavelengths from 0.12
to 0.4 nm was used. The corresponding q (=q < 1 nm-1

6
5
4
3
2
1
0
0

20

40

60

80

100

Depth / nm
Fig. 3

A depth profile of neutron scattering length density(b/V) representing the concentration profile of dPS.

References
1) T. Ishizone, S. Han, M. Hagiwara and H.
Yokoyama Macromolecules 39 (2006) 962-970.
2) H. Yokoyama, T. Miyamae, S. Han, T. Ishizone,
K. Tanaka, A. Takahara, and N. Torikai,
Macromolecules 38 (2005) 5180-5189.
3) L. Leibler, Macromolecules 13 (1980) 1602.

Temperature Dependence of Interfacial Structures of Microphase-Separated Block Copolymers
N. TORIKAI, A. NORO*, D. KAWAGUCHI*, A. TAKANO*, Y. MATSUSHITA*
Neutron Science Laboratory (KENS), High Energy Accelerator Research Organization,
Tsukuba, Ibaraki, 305-0801*Department of Applied Chemistry, Nagoya University, Chikusa, Nagoya 464-8603
So far we have intensively studied
microphase-separated interface of block copolymers
by neutron reflectivity (NR) measurment at room
temperature, to understand their phase-separated
structure at the molecular level. The interfacial
structures of diblock and two-component triblock
copolymers, with poly(styrene-d8) (D) andpoly(2-vinylpyridine) (P), showing lamellar
microdomain in spin-coated thin films werecompared [1, 2]. Their interfacial thicknesses
evaluated by specular reflectivity measurement wereapparently larger than the predictions of amean-field theory. This discrepancy between theexperimental
andtheoreticalresults
wasquantitatively explained by considering theexistence of thermal fluctuations on polymer
interface. These results suggest that apparent
interfacial thickness could be affected by changing
the magnitude of the Flory-Huggins interaction
parameter �, that is, changing temperature. In thisstudy the interfacial structure for DP diblock
copolymer thin films with different film thicknesses
was examined by changing temperature (R.T.~
about 200 C) in NR measurement.
Thesampleused
hereisstyrene-d8-2-vinyl-pyridine(DP)
diblock
copolymers with 90k and 124k for total molecularweight and 0.50 for the volume fraction of D-blockchain. The glass transition temperatures (Tg) for boththe components are around 110 C. It was confirmedthat DPs exhibit a lamellar structure in bulk. A few
thin film specimens with slightly different film
thicknesses were prepared by changing the rotation
speed of spin-coating on cleaned Si wafers from thesame DP solutions in p-dioxane, and then annealed
at 170 C for one week in a vacuum. Among thosefilms thus prepared from the same solution, the best
one with the least island or hole formation on thefilm surface was selected for NR at high temperatureby using optical microscopy and X-ray
reflectometry. NR measurements were performed on
ARISA [3] at different temperatures using ahigh-temperature cell in a vacuum. The sample was
first heated up to 200 C from R.T. to remove its

thermal history, and then cooled down gradually. At
each temperature sample alignment was made after
no changes in the reflectivity profile was observed.
Mostly, it took about 1 hour after temperaturereached at the desired values.
Fig. 1 compares specular neutron reflectivity
profiles for a thicker DP film measured at different
temperatures as a function of neutron momentum
transfer, qZ (=4�sin�/�), in the vertical direction. All
the profiles exhibited a few distinct Bragg peaks
originating from the lamellar structure preferentiallyoriented parallel to the film surface, and their basic
shape in the profile was not changed except for theshift of peak position. It indicates that the DP film isstill in the well-ordered state even at the hightemperature up to 200 C. Further, it was found thatthe position of the Bragg peaks is shifted to lower
qZ-region, i.e., lamellar domain spacing increases,
with increasing temperature, as observed in bulk. On
the other hand, thinner DP film with 110 nm inthickness, corresponding to 2.5 lamellar repeating
units, exhibited opposite temperature dependence ofdomain spacing, that is, the domain spacing has alower value at high temperature.

With

Fig. 1 Specular neutron reflectivity profiles for a thicker
DP diblock copolymer film measured at different
temperatures.

References
1) N. Torikai et al., Physica B, 283 (2000) 12.
2) N. Torikai et al., J. Phys. Soc. Jpn., 70 Suppl. A(2001) 344.
227

Magnetic Structure of Exchange-biased Fe/Cr Thin Film
KI-YEON KIM1, YO-SUN HWANG2, J. -G. PARK2, N. TORIKAI3, M. TAKEDA4,
S. -W. HAN5, and SUNG-CHUL SHIN1
1

Department of Physics and Center for Nanospinics of Spintronic Materials,
Korea Advanced Institute of Science and Technology, Deajeon 305-701, Korea
2
Department of Physics and Institute of Basic Science, Sungkyunkwan University, Suwon 440-746,
Korea
3
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801, Japan
4
Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
5
Department of Physics Education, Chonbuk National Univerisity, Jeonju 561-756, Korea

228

10

(a)

R+
R-

0.1

1E-3
1E-5
1E-7

0.00

0.04

0.08

-1

0.12

Reflectivities

process. Interestingly enough, there is no exchange
bias in the M-H loop taken at 3 K after FC using a
SQUID magnetometer.

Reflectivities

0.16

1

1

(b)

R+
R-

0.01

1E-4

1E-6

q z (A )

0.00

0.04

0.08

0.12

0.16

-1

q z(A )(c)( R/R)FC -( R/R)ZFC

When ferromagnet(FM)/antiferromagnet(AFM)
thin films in atomic contact with each other are
field-cooled through the Néel temperature of the
AFM layer under a saturation magnetic field or
deposited under a magnetic field during film growth,
the magnetic hysteresis (M-H) loop of the FM layer
is shifted away from its origin along the field axis.
This unidirectional anisotropy discovered by
Meiklejohn and Bean [1] in 1956 is called theexchange bias.
Although a satisfactory theoretical picture still
remains elusive, it is commonly believed that thisphenomenon is associated with an interfacialexchange interaction between FM spins anduncompensated AFM spins in a FM/AFM bilayer.
This uncompensated spins at the FM/AFM interface
is considered to originate from several reasons: e.g.
an epitaxial relationship at the interface, chemicallyinter-diffusion, and various structural defects
including interface roughness and grain boundary.
We carried out spin-polarized neutron reflectivity(SPNR) experiments (#2004-B2-207) using atime-of-flight reflectometer PORE at the highenergy accelerator research organization (KEK) in
Japan [2]. The SPNR has its unique capability todetermine the depth profile of absolute vector
magnetization along the surface-normal with 1 nm
resolution.
It is found in our spin-dependent reflectivity
results of Fe/Cr thin films for ZFC (zerofield-cooling) and FC (field-cooling) with 3 kOe that
there is a definite difference between the ZFC andFC cases. This can be seen clearly from spin
asymmetry curves, ΔR/R = 2(R+ -R-)/(R++R-). Basedon the results, we can conclude that this difference
between the ZFC and FC results is clear evidence of
surplus uncompensated AFM Cr spins induced
along the cooling field direction during the FC

+

T =3K
Hext=3 kOe

-

0

-1
0.02

0.04

0.06

-1

0.08

0.10

q z (Å )Fig. 1
Spin up (R ) and spin down(R ) reflectivitiies
measured at 3 K after (a) zero-field cooling (ZFC) and (b) fieldcooling (FC) with 3 kOe. The difference between the twocorresponding asymmetry curves is shown in (c)In conclusion, our studies using both the SPNR
and the SQUID magnetometer found that pinned anduncompensated spins are induced in the sputtered
Fe/Cr thin films after field cooling. We conclude
that all the pinned and uncompensated spins may not
be necessarily involved in the exchange bias but
rather contribute to enhancing the coercivity too.
References
1) W. H. Meiklejohn and C. P. Bean, Phys. Rev.
102, 1413 (1956).
2) M. Takeda and Y. Endoh, Physica B 267-268
185 (1999).

Observation of Electrode Surface for Lithium Batteries
K. SAKAMOTO 1, W. CHO 1, M. YOSHIOKA1, H. KONISHI 1,
N. SONOYAMA 2, M. YONEMURA3, N. TORIKAI 4, A. YAMADA1,
R. KANNO 1*
Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering,Tokyo Institute of Technology, 4259 Nagatuta-cho, Midori-ku, Yokohama, 226-8502, Japan
2
Graduate School of Engineering, Department of Environmental Technology and Urban Planning,
Nagoya Institute of Technology, Gokiso-cyo, Syouwa-ku, Nagoya 466-8555
3
Institute of Applied Beam Science,Graduate School of Science and Engineering, Ibaraki University
4-12-1 Nakanarusawa, Hitachi, Ibaraki, 316-8511
4
Neutron Science Laboratory, High Energy Accelerator Research Organization, 1-1 Oho, Tsukkuba,
305-0801, Japan

Table 1 The orientation of LiNi0.8Co0.2O2 epitaxial thin film
deposited on the SrTiO3 substrates.
LiNi0.8 Co 0.2 O2 (110) on STO(110)

LiNi0.8 Co 0.2 O2 ( 003) on STO(111)

out of plane

LiNi0.8Co0.2O2 ( -1 -1 0) // SrTiO3 (1 1 0)

LiNi0.8Co0.2O2 (0 0 3) // SrTiO3 (1 1 1)

in plane

LiNi0.8Co0.2O2 [0 0 1] // SrTiO3 [1 -1 1]

LiNi0.8Co0.2O2 [1 1 0] // SrTiO3 [1 -1 0]<-1 -1 0><0 0 3>Structure

We used LiNi0.8Co0.2O2 (110) as an electrode, thesurface of which corresponds to the intercalation
lattice plane.
Figure 1 shows ex-situ neutronreflectivity curves of before (a) and after (b) the
electrochemical experiment. The pattern changed
with the electrochemical charge-discharge process,which indicates a formation of surface film. In
order to observe the film-formation process, wedeveloped our in-situ electrochemical-cell forneutron reflectivity.
The in-situ cell was composed of the electrodefilm on the STO substrate, the electrolyte,

10

-1

10

-3

10

-5

(a) Before 1cycle(b) After 1cycle

0.04

0.08
-1

0.12

q/Å
Fig. 1 Neutron reflectivity curve for the Li Ni0.8Co0.2O2 (110)of before (a) and after (b) the electrochemical test.

EC/DEC+LiPF6, and a counter Li electrode. The
neutron beam was passed through 20mm-long pathof the substrate to have an access to the buriedinterface between the substrate and the liquid
electrolyte.
This cell-configuration reduces theneutron absorption by the electrolyte. Figure 2
shows the in-situ neutron reflectivity curve of
LiNi0.8Co0.2O2(110) at 3.0 V.
The two-layered
model (SrTiO3 and LiNi0.8Co0.2O2) was used forfitting the data. Due to the intensity is rather week,
it was difficult to observe the oscillation pattern.
To improve the data intensity, we are developing
new cell arrangements with Si substrates. The insitu technique for neutron reflectivity might be a
powerful tool to clarify the electrochemical
reactions at the electrode surface.
-1

Experimental
Fitting

10

Intensity

A comprehensive understanding of the electrodereaction at the electrode/electrolyte interface is an
important subject for activating electrode reaction
process and for designing new electrode materials
suitable for high power-density battery operation.
We tried to clarify the electrochemical process using
ideal electrode surface with epitaxial film electrodes.
In the present study, surface changes during theelectrochemical reaction were observed by neutronreflectivity measurements on PORE.
LiNi0.8Co0.2O2 films were synthesized by pulse
laser deposition (PLD) method. Single crystals of
conductive SrTiO3 (STO: 1wt% Nb) were used as
the substrates.
The orientation of the films
characterized both by XRD measurements of out-ofplane and in-plane are summarized in Table 1.

Intensity

1

-2

10

-3

10

-4

10

0.02

0.04

0.06 0.08 0.10
-1q/ÅFig. 2 Neutron reflectivity curve of LiNi0.8Co0.2O2 (110)
together with fitting data.

229

Recent Research Activities on a Polarized Neutron Reflectometer (PORE)
N. TORIKAI, M. TAKEDA1, H. ASAOKA1, T. HIRANO2, H. HAYASHIDA3, M. HINO3, M.
KITAGUCHI3, M. MIZUSAWA4, K. SAKURAI4, R. CUBITT5, K. IKEDA6, K. HIROTA6, H. M.
SHIMIZU, M. YONEMURA7, M. YOSHIOKA8, K. SAKAMOTO8 and R. KANNO8
Neutron Science Laboratory (KENS), High Energy Accelerator Research Organization, Tsukuba,
Ibaraki, 305-0801
1
Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195
2
Hitachi Research Laboratory, Hitachi, Ltd., Omika, Hitachi 319-1292
3
Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494
4
National Institute for Materials Science, Tsukuba, Ibaraki 305-0047
5
Institut Laue Langevin (ILL), 6 Jules Horowitz, 38000 Grenoble, France
6
RIKEN, Wako, Saitama 351-0198
7
Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki 316-8511
8Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology,
Nagatsuta, Yokohama 226-8502
The PORE (POlarized neutron REflectometer)[1] is only one spectrometer at the KENS using
polarized neutrons for material structural science. It
adopts a vertical-sample geometry, and the polarized
neutrons are produced with a wide wavelength bandof 3-15 Å by using Fe/Si supermirrors. The PORE
has been intensively utilized for the developments ofneutron devices and new experimental techniques aswell as the studies on hard materials such as
magnetic thin films and artificial lattices. Also, a
new field of research required making full use ofcomplementary information of neutron and X-ray
was searched. Here, recent research activities
developed on the PORE are summarized.
A multilayer structure is indispensable to key
components of magnetic recoding devices. In suchdevices the functions for the performance ofmagnetic recording are strongly connected to thedetailed magnetic structure near the interfaces. It is,however, difficult to investigate such magnetic
structures by using the conventional methods
because the interfaces are embedded inside themultilayers. Polarized neutron reflectometry (PNR)
with polarization analysis is the most powerful andnon-destructive way to investigate such buriedinternal magnetic structures. On the other hand, thistechnique requires rather brilliant neutron sources.
Thus, the polarization analysis of PNR has not been
intensively performed on PORE. Before the KENS
shutdown we did this kind of trial PNR
measurements of NiFe/PtMn/FeCo/Ru/FeCo multilayers synthesized for the TMR read heads. Fig. 1

shows the results under the external magnetic fieldsof 40 and 10 kOe. In this figure three kinds ofreflectivity, R++, R--, and Rsp, are displayed. Here thefirst sign of the subscript represents the spin state ofincident polarized neutrons, and the second one thatof reflected neutrons. Rsp expresses the reflectivity
with spin-flip process. The spin-flip reflection takes
place under the condition that there is a normalcomponent of the magnetization to the spin in thesample plane. This figure indicates that even under
the large magnetic field of 10 kOe the normalcomponent of magnetic moments still remains, and
it is not sensitive to the external magnetic fields.
Although the origin of this component is still
unknown, we successfully measured the PNR
profiles with polarization analysis. We are now
convinced that this kind of measurements will
become the mainstream of industrial use ofreflectometers for the development of magnetic
devices in the J-PARC.

Fig. 1 The PNR profiles of a TMR read head.

230

clarify the electrochemical process. LiNi0.8Co0.2O2(110) was used as an electrode, of which surface
corresponds to the intercalation lattice plane. Fig. 3
shows ex-situ neutron reflectivity curves before (a)and after (b) the electrochemical reaction. The
profile changed with the electrochemicalcharge-discharge process, indicative of a surface
film formation. In order to observe the filmformation process, an in-situ electrochemical cell forneutron reflectivity was prepared.

Intensity

When the surface of Si substrate is terminated byhydrogen, Sr or SrO films can epitaxially grow on
this special substrate in spite of a quite large latticemismatch [2]. It is, however, still an open question
how interfacial monoatomic layer can accommodate
such large lattice mismatch. The orthodox methods
like XPS and RHEED is not so effective to elucidate
the interfacial structure because these methods do
not directly see the H atoms. The probing such aninterfacial monatomic layer of H is essential toreveal the new mechanism of crystal growth. It isnevertheless to say, the neutron reflectometer has norival as a non-destructive tool to investigate the Hmonatomic layer buried in theses epitaxial films. We
performed neutron reflectivity measurements ofSr/SrO films on H- and D-terminated Si (111)substrates in order to confirm the existence of themonatomic layer using the contrast variation. The
result of the film with D-terminated substrate isshown in Fig. 2. The experimental data are plottedwith horizontal error bars and the solid line is thebest-fit curve. The difference of H- and Dterminated substrate clearly appears in thereflectivity profiles one of which is not shown here.
This obviously shows that the H and D monatomic
layers exist between the films and the substrates.
Combined with the results of XPS and RHEED themechanism of relaxation of the lattice mismatch is
expected to be clear. The result will be reported
elsewhere in the near future.

(a) Before 1cycle(b) After 1cycle

-1

10

-3

10

-5

10

0.04

q /Å

The in-situ cell was composed of the electrode film
on SrTiO3 (STO) substrate, the electrolyte EC/DEC+LiPF6, and a counter Li electrode. The neutron
beam passes through inside the substrate to approach
the interface between the electrode film and theelectrolyte. This cell-configuration reduces neutron
absorption by the electrolyte. Fig. 4 shows thein-situ NR curve of LiNi0.8Co0.2O2(110) at 3.0 V.
The two-layered model (STO and LiNi0.8Co0.2O2)
was used for fitting the data. Although the intensity
is rather weak, we could observe the oscillation
pattern from the in-situ cell. To improve the dataintensity, we are developing new cell arrangementswith Si substrates. The in-situ technique for NR
might be a powerful tool to clarify theelectrochemical reactions on the electrode surface.
-1

A comprehensive understanding of the electrodereaction at the electrode/electrolyte interface is an
important subject for activating electrode reaction
process and for designing new electrode materials
suitable for high power-density battery operation.
Here, the changes on electrode surface during theelectrochemical reaction were observed by NR
measurements with epitaxial film electrodes to

0.12

-1

Fig. 3 Neutron reflectivity curves for the Li Ni0.8Co0.2O2(110) before (a) and after (b) the electrochemical test.

Experimental
Fitting

Intensity

10
Fig. 2 Neutron reflectivity profile of SrO epitaxial film on
D-terminated Si(111) substrate.

0.08

-2

10

-3

10

-4

10

0.02

0.04

0.06 0.08
-1
q /Å

0.10

Fig. 4 The in-situ neutron reflectivity
LiNi0.8Co0.2O2 (110) together with fitting data.

curve

of

A polarizing supermirror is one of most usefuldevices to control polarized slow neutron beam. It is231

a stack of magnetic multilayer with gradually
increasing value of the d-spacing and thesupermirror with large-m is desirable to enlarge
utilization. Hino et al. have fabricated a several
kinds of magnetic multilayer, for example, Fe/Si,
Fe/Ge,
Fe50Co50/V,
Supersendust(Fe87Si7.5Al4Ti1)/Ge and so on. These multilayers
have been fabricated by using ion beam sputtering(IBS) technique. At PORE, we measured polarizing
efficiency of such multilayers as a function ofmagnetic field in which the strength was up to 1T.
As a result, it is not so easy to magnetize and does
not work as a remanent polarizing mirror after
applied strong magnetic field of 1T. Therefore we
improved a magnetic sputter target for IBS. It is welldeoxidized iron target by heating it in hydrogen
atmosphere. The pre- treatment was carried out by
OHTAMA Co. We have succeeded in fabricating
m=5 Fe/Ge polarizing neutron supermirrors which
work under magnetic field of 45mT as shown in Fig.
5 [3].

m=

1

2

1.0

4

5
40

0.8

30

0.6
20
0.4
10

0.2

Flipping ratio

Reflectivity

3

The measured FWHM of  spread is shown in Fig. 7
when  =-0.25 deg., where the neutron refracts frominside the MgF2 to air. The spread in  can be
estimated by differentiating the above equation(d)2={ (/)}2+{ (/)}2
where  is determined from the angular resolutionof the incoming beam, defined by slit collimation,and the flatness of the MgF2 surface, and  is thespatial resolution of a detector. Throughout theexperiment the beam divergence was fixed at 0.007
deg., and the flatness of the well-machined MgF2
was characterized to be 0.002 deg. The fitting ofexperimental data with  as a free parameter yields
0.038 deg. (0.94 mm). This demonstrates that thepresent arrangement is limited by the detector
resolution. The same experiment was tested with asingle-crystal Al2O3 plate on the reflectometer D17
of ILL, and suggested the possibility of using thissimple prism to encode neutron wavelength without
intrinsic loss by choppers at a reactor [4].

Fig. 6 A schematic illustration of an experimental setup
using a MgF2 plate.

0.0

0
0.6
0.8
1.0
1.2
-1
Q nm
Fig. 5 Measured reflectivities of up (red) and down (blue)
spin neutron for m=5 Fe/Ge supermirror (1875 bilayers).
The black line is reflectivity of NiC monolayer with 60nm inthickness.
0.2

0.4

The resolving power of a simple single-crystal
MgF2 plate (100mm60mm4.9mm) as an energy
analyzer was demonstrated using white neutrons at apulsed-neutron source. The basic idea behind theexperiment originated from Dr. R. Cubitt of ILL,
and was tested during his stay at the KENS in 3
months. The experimental setup is schematicallyillustrated in Fig. 6. The wavelength  of neutron
after the sample is given as a function of the incident
angle , the scattering length density b of the MgF2
with 5.1310-6 Å-2, and the deflection angle  fromthe beam direction.
=(2/b){1-cos/cos(-)}1/2

232

Fig. 7 The measured FWHM of  spread as a functionof  when =-0.25 deg. The solid line is the fitting resultwith  as a free parameter.

References
1) M. Takeda and Y. Endoh, Physica B 267-268(1999) 185.
2) H. Asaoka, K Saiki, A Koma, H Yamamoto, Thin
Solid Films 369 (2000) 273.
3) M. Hino et al., Physica B, 385-386 (2006) 1187.
4) R. Cubitt, H. M. Shimizu, K. Ikeda, N. Torikai,
Nucl. Instr. and Meth. A 558 (2006) 547.

DYNAMICS

2003–2006

Inelastic Neutron Scattering from Kondo Semiconductor CeOs4Sb12
C.P. YANG1, M. KOHGI1, K. IWASA2, H. SUGAWARA3 and H. SATO1
Department of Physics, Tokyo Metropolitan University,
1-1 Minami-Osawa, Hachioji, Tokyo 192-0397
2
Department of Physics, Tohoku University, Sendai 980-8578
3
Faculty of Integrated Arts snd Sciences, The University of Tokushima,
1-1, Minamijosanjima-cho, Tokushima 770-8502
1

Rare-earth filled skutterudites of the formula
RT4X12 (R = rare earths, T= Fe, Ru, Os, X = P, As
and Sb) are formed in a body-centered cubic
LaFe4P12 structure with a space group of Im3 [1, 2].
These compounds have been the focus of extensive
efforts recently owing to their various electrical andmagnetic properties, particularly, a novel mechanism of superconductivity observed in this series [3].
Among them, although most Ce-containing RT4X12
compounds are typical semiconductors, CeRu4Sb12
shows non-Fermi liquid anomalies [4], andCeOs4Sb12 is regarded as a Kondo semiconductorfrom many interesting physical features determinedby transport measurements, such as metal–insulatortransition, magnetic moment markedly decreasing at
low temperatures [5]. It shows also an unclear transition occurring below 0.86 K [6]. These notablefeatures are attributed to the freedom and instabilityof 4f electrons of Ce3+ ion in CeOs4Sb12, whichstrongly correlate with on-site and inter site electrons or ions of its surroundings. In addition to thefeatures of the magnetic 4f electrons, the lattice dynamics of filled skutterudites is also particularlyinteresting and vital because incoherent phonons,
resulting from the unique rattling vibration mode ofrare earth atoms, was claimed to have been observedin some skutterudite structures [7, 8]. In this work,
we performed inelastic neutron scattering on the
CeOs4Sb12 compound in order to study the 4f electron state as well as phonon state to understand theabove-mentioned features.
Single crystal samples were synthesized by the
Sb-self-flux growth method. Inelastic neutron scattering measurements of a powder sample preparedfrom single crystals with a weight of 60.7 g were
performed using the spectrometers INC and LAM-D
installed at the pulsed neutron scattering facility of
KEK (High Energy Accelerator Research Organization) at Tsukuba, Japan.
Figure 1 shows the inelastic neutron spectrum ata low angle detector bank (2 = 5°–9°) measured
using the chopper spectrometer INC of KEK with

Fig. 1 Neutron spectra of CeOs4Sb12 powder measured
using INC at a constant incident energy of 60 meV. The
dash line denotes calculated CF intensities based on themodel in ref. 5 (see text).

the incident neutron energy of 60 meV for the
CeOs4Sb12 powder sample. The spectrum is shownon the absolute scale of the cross section after calibration by the cross section of a standard vanadium
sample. The dashed line shows the calculated crosssection of crystal field (CF) excitations at 28.2 meV
for CeOs4Sb12 based on the model of the groundstate of doublet 7 and excited-state of 8 quartet
proposed in ref. 5. It can be clearly seen from thefigure that there is no such inelastic intensity except
for a broad spectrum below about 30 meV which
can be ascribed to the phonon scattering as discussed below. It means that no well-defined CF excitation was found for the CeOs4Sb12 compound aroundthe expected energy position. This fact contradicts
the assumption that CF splitting occurs at 28.2 meV
for CeOs4Sb12 filled skutterudite proposed in ref. 5
by fitting magnetic susceptibility.
On the other hand, the rattling vibration behaviorof rare earth ions in a filled skutterudite structure isdiscussed to be exotic and vital [7–9]. To further
study the inelastic response from CeOs4Sb12, we also
performed neutron scattering measurements using
LAM-D spectrometer of KEK, in which a final en235

Fig. 2
Neutron spectra of polycrystalline CeOs4Sb12
measured using LAM-D of KEK at several temperatures for
scattering angles of 85° and 40°. The final neutron energy
is 4.6 meV.

ergy of 4.6 meV was maintained for outgoing neutrons. Fig. 2 shows the spectra of polycrystalline
CeOs4Sb12 measured at several temperatures for boththe low (40°)- and high (85°)-scattering angle detectors after subtracting the background. It is clearlyseen that the intensity of the spectra increases withincreasing temperature at low transfer energies andthe intensities at the high scattering angle is higher
than those at the low scattering angle, indicating thephonon origin of the spectra. In order to determine
the origins of scattering intensities, we divided theobtained spectra by the temperature factor{exp( h /kBT) - 1}-1 + 1, where h is the energy
transfer, kB the Boltzmann constant and T the temperature. The results are shown in Fig. 3. From Fig.
3 we can see that they decrease weakly with increasing temperature at high energies above 5 meV.
It indicates that the intensity above 5 meV of thespectra reflects the character of phonon excitations
because phonon scattering cross-section is proportional to the Debye-Waller factor. It should be notedthat no well-defined CF excitation exists in the finite
energy transfer range from the data obtained using
the LAM-D spectrometer in Fig. 2, consistent withresult obtained using the INC spectrometer discussed earlier. Moreover, there is a clear peak at about 4
meV observed at high temperatures in the spectra in

236

Fig. 2
Intensity of inelastic neutron scattering for
CeOs4Sb12 after dividing it by temperature factor (see text).

Fig. 2. Similar inelastic neutron scattering peaks
were also found for Tl0:8FeCo3Sb12 at approximately
5 meV [7], and for LaFe4Sb12 with two peaks at approximately 7 meV in the density of state curves [8].
The peaks were regarded as resulting from incoherent vibrations of rare-earth ions rattling in the skutterudite structure. Therefore, the peak at about 4
meV observed for CeOs4Sb12 is also thought to be
the evidence for the rattling motion of the Ce ions in
the compound.
References
1) W. Jeitschko and D. Braun: Acta Crystallogr.,
Sect. B 33 (1977) 3401.
2) D. J. Braun and W. Jeitschko: J. Less-Common
Met. 72 (1980) 147.
3) Y. Aoki et al.: Phys. Rev. Lett. 91 (2003)
067003.
4) N. Takeda and M. Ishikawa: Physica B 259–
261 (1992) 92.
5) E. D. Bauer et al.: J. Phys.: Condens. Matter 13(2001) 449.
6) T. Namiki et al.: Acta Phys. Pol. B 34 (2003)
1161.
7) R. P. Hermann et al.: Phys. Rev. Lett. 90 (2003)
135505.
8) V. Keppens et al.: Nature 395 (1998) 876.
9) T. Goto et al.: Phys. Rev. B 69 (2004) 180511.

Magnetic Excitation in a New Type Spin-Peierls Compound TiOBr
T. SASAKI, S. ITOH*, T. YOKOO* and J. AKIMITSU

Intensity [arb.units](a)Energy transfer [meV]TiOX (X = Cl and Br) has been suggested to be aquasi-one-dimensional (1D) S = 1/2 spin system due
to a ferromagnetic dxy orbital along the b-axis [1].
TiOX has a FeOCl-type crystal structure, where the
TiO bilayers separate from each other along thec-axis. It is believed that the chains are composed ofedge-shared TiO4X2 octahedra. The temperaturedependence of susceptibility showed two successive
phase transitions at Tc1=27K and Tc2=47K for X = Br.
The two-fold superlattice reflections appear below
Tc1, which indicates that there is a spin-Peierls lattice
distortion along the chain-axis (b-axis). The mostinteresting phenomenon was realized between Tc1
and Tc2 (intermediate region), in which the spin
modulation transforms to the incommensurate
structure along the a- and b-axes. Although
Rückamp et al. suggested that the incommensurate
modulation is caused by the magnetic competitive
interaction between intra- and inter-chains [2], wesuggest the different scenario which is that the local
spin-Peierls lattice distortions propagate from thenearest-neighbor (NN) to next-nearest-neighbor(NNN) chains, because the chain shares the same
oxygen atoms with NN and NNN chains [3].
Polycrystalline TiOBr (27g) was prepared by achemical vapor transport technique. We performed
inelastic neutron scattering experiments to determine
the spin excitation spectrum using Ei=128 meV at
4K and 60K in a novel spin-Peierls system TiOBr.
The magnetic excitation below Tc1 was measured on
the chopper spectrometer INC installed at the pulsed
spallation-neutron source, KENS, at the HighEnergy Accelerator Research Organization (KEK).
We take a particular note of the spin gap reported
for TiOCl [4]. 1/T1T behavior is qualitatively similar
to the pseudo-gap phase observed in the underdoped
high Tc cuprates. Below Tc2, TiOCl undergoes a firstorder phase transition to a fully gapped state with an
extraordinarily large energy gap Eg = 430K.
Although the energy gap of TiOBr was not reported
by any other measurements, it is almost 230K whichis estimated by comparing the intra-chain interaction
J in case of TiOCl and TiOBr, which is not inagreement with the NMR data. Fig.1 shows the

Intensity [arb.units]

Department of Physics and Mathematics, Aoyama-Gakuin University,
5-10-1 Fuchinobe, Sagamihara, Kanagawa 229-8558*
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
8060

 /b* 3 /b*

5 /b*

40
20
0

1

2

3-1
q [A ]

4

5

11K
150K

(b)

11K-150K

0 10 20 30 40 50 60 70 80
Energy transfer [meV]Fig.1 (a) Excitation spectra near antiferromagnetic zone
center q=π at 11K and 150K. Inset shows a region of

integrated intensities which is surrounded by two radialline. (b) the spectrum was obtained by subtracting theintensities at 150K from ones at 11K.

excitation spectrum near antiferromagnetic zone
center q=π at 11K and 150K. Although thespectrum does not have an enough amount ofstatistics, it is confirmed that spectrum is different
between 11K and 150K (Fig.1(a)). Fig.1 (b) showsthat the spectrum obtained by subtracting theintensities at 150K from ones at 11K. The spectrum
indicates existence of two peaks at 25.4 and 39.2
meV which is fitted by a Lorentzian function.
Although half width of peak at 25.4 meV is in good
agreement with resolution function, one at 39.2 meVis larger than that of the resolution function. The
peak at 39.2 meV has a tail towards higher energy,
which is possible to be existence of successive
excitation above 39.2 meV.
In summary, we detected two excitation spectra
which are possible to be spin gaps at 25.4 and 39.2
meV below Tc1.
References
1) A. Seidel et al., Phys. Rev. B 67 (2003)
020405(R).
2) R. Rückamp et al., Phys. Rev. Lett. 95 (2005)
097203
3) T. Sasaki et al., Phys. Rev. B ; submitting4) T. Imai and F. C. Chou, cond-mat/0301425

237

Vibrational Density of States of n-Alkanes Adsorbed on MgO (100)A. INABA and N. SAKISATO
Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University,
Toyonaka, Osaka 560-0043
Our studies on the structure and dynamics of themonolayers of various molecules adsorbed on thesurface of graphite demonstrate that a number ofmonolayers exhibit interesting phase behavior.
Recent studies also show that the similar solid
monolayers are formed at the interface between thebulk liquid and the graphite surface [1]. Thosemonolayers have been found for various adsorbates
such as n-alkanes, n-alkanols and carboxyl acids[2-7]. This indicates that the phenomenon is rather
general.
The phase behavior of such monolayers depends
not only on the adsorbate-adsorbate interactions but
also on the adsorbate-adsorbent interactions. It istherefore very interesting to study the monolayers
formed on the substrate other than graphite. The(100) plane of MgO is one of the most suitablesurfaces for this purpose because it has quite
different feature from that of graphite (surface
symmetry, potential surface corrugation, etc.). In thepresent study, we have performed inelastic neutron
scattering experiments for n-heptane and n-octane
adsorbed on MgO (100) at submonolayer andmultilayer coverages to investigate the vibrational
properties.
The substrate MgO was prepared by us
according to the procedure reported by J. P.
Coulomb et al. [8]. The characterization by SEM
demonstrated that the cube-shaped particles with(100) surfaces were typical with a side ofapproximately 0.2 µm. We used two MgO samples
from different batches. The specific surface areas
were determined to be 10.7 and 11.7 m2g–1,
respectively, by adsorption isotherm measurements
at 77.4 K using nitrogen. For the present study,
those two specimens were add together. The
substrate thus obtained was degassed at 950 °C for
12 hours before packed into a sample can. Heptane
and octane were obtained from Tokyo Kasei Kogyo
and Wako Pure Chemical Industries, respectively.
Known quantities of the adsorbates were added tothe adsorbent as liquid using a micro syringe under
an inert atmosphere of helium and annealed at 90 °C.
The amounts of the adsorbates loaded were 0.6, 2, 3
and 7 ML. The coverages are expressed in terms of238

the number of equivalent monolayers adsorbed.
Since the 2-D structure on MgO (100) is not known
for either adsorbates, the monolayer capacities arecalculated assuming that the molecule occupies thesame area as for graphite (0.427 nm2 for heptane and0.524 nm2 for octane).

Fig. 1

Vibrational density of states obtained forn-heptane adsorbed on MgO (100) at thecoverages 0.6, 2, 3, and 7 ML. The one obtained
for n-heptane on graphite at 0.8 ML is alsoplotted for comparison (gray line). Upward
arrows indicate the torsions of the methyl andmethylene groups and downward ones thevibrations due to the carbon skeletal bending.

The inelastic neutron scattering experiments
were performed on LAM-D. The scattered neutrons
were collected at Q = 9.0 and 20.0 nm–1 to obtain thedensity of states. The measurements were performed
at 17 K for all the samples.
Figures 1 and 2 illustrate the vibrational densityof states obtained for n-heptane and n-octane,
respectively, adsorbed on MgO (100). The spectra
are normalized by the amount of adsorbate loaded.
The results clearly demonstrate that the spectra
obtained at 7 ML are significantly different fromthose at 0.6 ML, particularly at E < 10 meV where
the lattice vibrations are responsible for thevibrational density of states. This suggests that thebulk solid is formed at 7 ML, whereas a 2-D solid isformed at 0.6 ML. A prominent peak was observed
around 6 meV for both adsorbates at 0.6 ML. Thiscan be ascribed to vibration of the whole molecule
perpendicular to the surface.

Fig. 2Vibrational density of states obtained forn-octane adsorbed on MgO (100) at thecoverages 0.6, 2, 3, and 7 ML. The one obtained
for n-octane on graphite at 0.8 ML is also plottedfor comparison (gray line). Upward arrows
indicate the torsions of the methyl and methylenegroups and downward ones the vibrations due tothe carbon skeletal bending.

The arrows in the figures indicate theintramolecular vibrational modes assigned byinelastic neutron scattering studies and normal mode
calculations [9]; the upward arrows for thevibrational modes due to the torsional motions of themethyl and metylene groups and the downward
arrows for those due to the carbon skeletal bending
motions. A hump for heptane and a peak for octane
both at 17 meV, which appeared at all the coverages,
can be attributed to the librational mode of thewhole molecule. It is interesting to note that thepeak position of the carbon skeletal bending mode
agrees rather well with the reported values at all thecoverages, whereas the position of the torsionalmode depends on the coverage. This may suggestthat the molecules are adsorbed on the surface withan orientation of the carbon skeleton parallel to thesurface.
Also plotted in the figures is the vibrational
density of states obtained for n-heptane and n-octanemonolayers adsorbed on graphite. The results
demonstrate that the vibrational mode perpendicular
to the (100) plane of MgO (6.3 meV for heptane and6.5 meV for octane) has lower frequencies thanthose on the graphite surface (8.3 meV for heptane
and 10 meV for octane). This suggests that themolecules on MgO (100) are weakly bound to thesurface. The result also shows that the density ofstates below 2 meV is essentially zero. This may beconnected with the gap in the phonon dispersion
curves at the center of the Brillouin zone, which
may exist for a commensurate phase owing to thecorrugated potential of the substrate [10-12]. A
structural study is necessary to confirm this.
References
1) M. A. Castro et al., J. Phys. Chem., B101 (1997)
8878.
2) S. M. Clarke et al., J. Thermal Analysis andCalorimetry, 57 (1999) 643.
3) T. Arnold et al., Phys. Chem. Chem. Phys., 4(2002) 345.
4) T. Arnold et al., Phys. Chem. Chem. Phys., 4(2002) 3430.
5) L. Messé et al., Langmuir, 18 (2002) 4010.
6) L. Messé et al., Langmuir, 18 (2002) 9429.
7) A. Bickerstaffe et al., Phys. Chem. Chem. Phys.,
6 (2004) 3545.
8) J. P. Coulomb et al., J. Phys. Paris, 45 (1984)
1381.
9) K. W. Logan et al., J. Chem. Phys., 59 (1973)
2305.
10) G. Cardini et al., Surf. Sci. 154 (1985) 231.
11) L. W. Bruch et al., Phys. Rev. B 37 (1988) 6658.
12) T. M. Hakim et al., Phys. Rev. B 37 (1988) 974.

239

Vibrational Density of States of Two-dimensionally Ordered Ice
Formed in a Binary Solution of Water and Glycerol
A. INABA and N. SAKISATO
Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University,
Toyonaka, Osaka 560-0043

240

20

Intensity (arb. units)

Our recent neutron diffraction measurements forthe binary system of water and glycerol demonstrate
the formation of a two-dimensionally ordered ice in
the initial stage of crystallization from the solution[1]. We also made heat capacity measurements on
this system [2]. The binary mixtures with glycerol
contents more than 55% w/w yielded homogeneous
glassy states, of randomly mixed water and glycerol
molecules. Mixtures in the range 0-50% w/w
glycerol, crystallized partly on cooling, yielding
three anomalies in the temperature drift ratemeasured on heating, and these are associated with:(i) the onset of reorientational motions of the H2O
molecules in hexagonal ice, (ii) the glass transitionof the maximally freeze-concentrated solution at 164
K and, tentatively, (iii) ice devitrification followedby ice dissolution yields anomalies in the range
185-202 K. The samples with 55% or 60% w/w
glycerol content exhibited two distinguishable
crystallization peaks on heating where the initial one
is large and apparently associated withcrystallization into a two-dimensionally orderedstructure and the second is due to a furthertransformation into hexagonal ice.
The main purpose of the present study was toinvestigate the vibrational DOS of the “2D ice” tosee whether it is different from the one for the
hexagonal ice.
The neutron scattering experiments were
performed on CAT spectrometer. The sample was asolution of C3H5(OH)3 and H2O with concentrationof 55% w/w. After the sample was quenched withliquid nitrogen outside of the cryostat, it was placedin the cryostat (at 100 K) and cooled further. Afterthe first measurement was made at 39 K, where thesample was in a homogeneous glassy state, thesample was warmed up to 179 K. At thistemperature, the first crystallization of ice should
occur. After the measurement at 179 K, the sample
was warmed up to 220 K and annealed for 4 hours atthat temperature to complete the crystallization,
where we should have hexagonal ice. The sample
was cooled down again to the same temperature(179 K) to measure it.

1000Fig. 140

E / meV80

120Incoherent inelastic neutron scattering spectra
obtained for glass (filled symbols), 2-D ice (blackline) and hexagonal ice (gray line).

Figure 1 illustrates the spectra obtained, where
the background is included, to compare to each other.
The translational modes are involved in the energy
below 45 meV and a peak at 70 meV is due tolibrational modes of H2O molecules [3]. While the
DOS of the glass is significantly different fromthose of the crystals, the spectra from two crystals
are essentially identical over the whole energy
region, indicating that the local structure of the 2D
ice is similar to that of the hexagonal ice. The factthat the peak at 70 meV is slightly shifted to thelower energies in the glass may suggest that theglass is rather homogeneous.
References
1) A. Inaba et al., J. Neutron Research 13 (2005)
87.
2) A. Inaba and O. Andersson, to be published.
3) D. Eisenberg et al., in “The Structure andProperties of Water” (Oxford University Press,
Oxford, 1969), Chap. 3.

Evidence for the Crucial Role of 4f electron in the Metal-Nonmetal Transition of PrRu4P12
K. Iwasa, L. Hao, T. Hasegawa, K. Horiuchi, Y. Murakami, K. Kuwahara1, M. Kohgi1,
S. R. Saha, H. Sugawara2, Y. Aoki1, H. Sato1, T. Tayama3 and T. Sakakibara3
Department of Physics, Tohoku University, Sendai 980-8578
Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397
2
Department of Mathematical and Natural Sciences, Faculty of Integrated Arts and Sciences, The
University of Tokushima, Tokushima 770-8502
3
Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581
1

Various physical properties in rare-earth filled
skutterudites RT4X12 (R = lanthanide and actinide
elements, T = transition metal, X = pnictogen) havebeen attractive topics in the field of strongly
correlated electron systems. Since R ions are
surrounded by twelve X atoms forming an
icosahedron in the cubic crystal structure (Im-3), it
is suggested that the hybridization between p state of
X and f state of R is responsible for the heavy
electron behaviors in Pr-based compounds, Kondo
semiconductors of Ce-based ones and so on [1].
PrRu4P12 exhibits a metal-nonmetal transition at
TM-I = 63 K [2]. The electrical resistivity turns up
below TM-I, and electron and X-ray diffraction
studies revealed a superlattice (Pm-3) characterized
by the wave vector q0 = {1, 0, 0} below TM-I [3,4].
The band calculation study proposed the Fermi
surface nesting condition with q0, so that this phasetransition is thought to be a formation of charge
density wave (CDW) [5]. On the other hand,
LaRu4P12 that has the same Fermi-surface geometryas PrRu4P12 does not show any transition with gap
formation. Moreover, in PrRu4P12, an isotropic
magnetic moment of about 1B/Pr is induced under amagnetic field at lower temperature, which cannot
be explained by a single crystal-field (CF) level
scheme of Pr3+ ion [2,6].
To investigate a 4f-electron role on the transtion,
we performed an inelastic neutron scatteringexperiments at the time-of-flight analyzer-mirrortype spectrometers LAM-D and LAM-40 installedin the pulsed neutron facility KENS in KEK, Japan.
Figure 1 represents typical measured magnetic
response functions S(E) from the polycrystalline
sample of PrRu4P12. Distinct peaks are seen at 3.2,
9.3, 13.9 and 23 meV at 5 K, whose widths are very
close to the instrumental resolution. Since thescattering-angle dependence of peak intensity is
consistent with that of magnetic form factor of Pr3+,
they are attributed to CF excitations. It is noticeable

that with increasing temperature the peaks shift by
about 3 meV and become very broad near TM-I.

Fig. 1

Symbols are magnetic response function S(E) of
PrRu4P12 measured at LAM-D. The origins ofordinate of each temperature are shifted by 0.1.

The CF Hamiltonian for 4f electrons for both Im3 and Pm-3 is represented as HCF = A4(O40 + 5O44) +A6c(O60 - 21O64)+ A6t(O62 - O66) [7]. We carried out aleast-squares fitting procedure of CF excitation
spectra calculated from HCF to the data of S(E). We
took as free parameters the CF coefficients, a scale
factor for a ratio of calculated cross section to theexperimental result, and a peak width. It is notablethat the observed spectra at low temperature cannot
be reproduced by a single CF scheme, since weobserved more excitation peaks than those expected.
Finally, we succeeded in obtaining the satisfactory
fitting by the two inequivalent schemes, which isconsistent with the superlattice formation of thecrystal lattice below TM-I. The resultant CF schemes241as a function of temperature is shown in Fig. 2. We
obtained 1 ground states for both CF schemes of
Pr1 and Pr2 near TM-I. On the other hand, the groundstate of Pr2 switches to a magnetic triplet 4(2) while
Pr1 keeps a non-magnetic ground state 1. Such two
schemes reproduce the total magnetization of about
1B/Pr at low temperature. In addition, the verylarge peak width near TM-I suggests the strong
interaction between 4f electron and carrier.

Fig. 2

Two CF schemes Pr1 and Pr2 deduced from themagnetic spectra S(E) of PrRu4P12.

We also carried out the polarized neutron
diffraction experiment at triple-axis spectrometers at
JRR-3M to investigate the spatial arrangement of
Pr1 and Pr2 [8]. The experimental result is
consistent with that they also align periodically with
q0 as the structural superlattice. Figure 3 represents
schematically the superlattice including not only the
crystal structure but also the CF schemes. This fact
clearly indicates the long-range order of 4f electronstate is responsible for the metal-nonmetaltransition.

Fig. 3

242

Schematic view of the superlattice of crystal
structure and CF alignment with q0 in PrRu4P12.

The drastic evolution and the periodic alignmentof inequivalent of CF schemes can be explained by
the p-f hybridization effect between Pr3+ 4f2 andcarrier originated from the pnictogen au band [9].
The strong hybridization as seen in the broad
magnetic spectrum indicates that 4f electrons
contribute to enhance the density of state at the
Fermi surface, so that the energy gain due to the gap
formation with nesting can occur. The alignment of
CF schemes with q0 below TM-I is recently
interpreted as the antiferro-hexadecapole ordering[10,11]. Within the j-j coupling model considering
p-f hybridization between 4f2 and au band, thecoupling between the 4f–electron hexadecapole andcarrier charge modulation is deduced. Owing to thenesting condition with q0, the antiferro-hexadecapole
ordering gives rise to the charge modulation byforming the gap at the Fermi surface. It is interestingthat the responsible hexadecapole is represented by
the operator Jx4 + Jy4 + Jz4 – 236 that is equivalent to
the first term of HCF. Therefore, the ordering of
hexadecapole provides the change of CF splitting
without any symmetry breaking.
We conclude that the metal-nonmetal transitionin PrRu4P12 is a new type of CDW formation by thestrong p-f hybridization and hexadecapole degree of
freedom.
This work was partially supported by MEXT,
Japan through the Grants-in-Aid for Scientific
Research (No. 15740219, No. 15072206 and No. 16
04659) and Yamada Science Foundation.
References[1] H. Harima and K. Takegahara, J. Physics:
Condens. Matter 15 (2003) S2081.
[2] C. Sekine et al., Phys. Rev. Lett. 79 (1997) 3218.
[3] C. H. Lee et al., J. Phys.: Condens. Matter. 13(2001) L45, J. Magn. Magn. Mater. 272-276(2004) 426, Phys. Rev. B 70 (2004) 153105.
[4] L. Hao et al., J. Magn. Magn. Mater. 272-276(2004) e271.
[5] H. Harima and K. Takegahara, Physica B 312313 (2002) 843.
[6] K. Iwasa et al., Phys. Rev. B 72 (2005) 024414.
[7] K. Takegahara et al., J. Phys. Soc. Jpn. 70 (2001)
1190, ibid. 70 (2001) 3468, ibid. 71 (2002) 372.
[8] K. Iwasa et al.: J. Phys. Soc. Jpn. 74 (2005)
1930.
[9] J. Otsuki et al., J. Phys. Soc. Jpn. 74 (2005) 200.
[10] Y. Kuramoto et al., Prog. Theor. Phys. Suppl.
160 (2005) 134.
[11] T. Takimoto, J. Phys. Soc. Jpn. 75 (2006)
034714, to appear in Physica B (2006).

Vibrational Excitation Energy of Interstitial Hydrogen Atoms in CaF2-type Metal Hydrides
Y. NAKAMURA †, T. KAMIYAMA ‡ and E. AKIBA††

National Institute of Advanced Industrial Science and Technology (AIST)
AIST Tsukuba Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki, 305-8565‡
Graduate School of Engineering, Hokkaido University
Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-8628

Ti or V based solid solution alloys with BCC
structure are known as good hydrogen storage
materials which are reversibly hydrogenated underambient conditions [1,2]. Their hydrogen
absorption-desorption properties are closely relatedwith the local structure of hydrogen atoms, which
are located in the tetrahedral or octahedral sites ofthe metal sublattice.
Incoherent Inelastic Neutron Scattering (IINS)
spectra of metal hydrides provide the vibrational
excitation energy of the hydrogen atoms. The data
reflect the local structure surrounding the interstitialhydrogen atoms. We have started IINS studies
with hydrides of Ti-V-Cr and Ti-V-Mn alloys [3,4].
Their di-hydrides with a CaF2 type structure showed
spectra similar to TiH2 [5], which is described by aharmonic oscillation model.
The vibrational
excitation energy for the Ti-V-Cr hydride washigher than the Ti-V-Mn hydride. This seems
reasonable if considering the relation that thesmaller hydrogen occupation site has the narrower
vibrational potential. In this study, we investigatedhydrides of a new type of BCC alloys, Ti-Cr-Mo [6]containing Mo.
Ti1.1Cr1.4Mo0.3 alloy was prepared by arc melting.
The ingot was annealed at 1743K for 60s followed
by water quench. It was crushed into powder andhydrogenated at 5 MPa and 298K. About 5g of thepowder was put into an aluminum flat cell. The
thickness of the sample layer was around 1.0 mm.
The IINS data were collected in He atmosphereat 10–25K using the TOF type crystal analyzer
spectrometer, CAT at KENS.

Fig.1

IINS spectrum of di-hydride of TiCr1.4Mo0.3.

The relation between metal-hydrogen distance R
and vibrational excitation energy E was reported in aseries of CaF2-type binary metal hydrides, MH2 byRoss et al [7]. E was considered to be proportional
to R-1 or R-2/3 [7,8]. Our results for di-hydrides of
Ti1.0Mn0.9V1.1, Ti0.7Cr1.1V1.2 and Ti1.1Cr1.4Mo0.3 areplotted with the reported data in Fig. 2. All three ofour data are located under the curve for the binary
metal hydrides. Among the three we investigated,
however, the plot of Ti1.1Cr1.4Mo0.3 hydride islocated closest to the curve, particularly close to thatof TiH2. This indicates that this hydride has asmaller lattice than TiH2 but the local circumstanceof H atoms is similar to that in TiH2.

Figure 1 shows the IINS spectrum of Ti-Cr-Mo
di-hydride. The pattern is basically similar to that ofTiH2 although that in the higher energy region is not
so clear. The first and second excitation energy is E1~148 meV and E2 ~280 meV. E1 is higher than thatobserved for Ti-V-Cr and Ti-V-Mn di-hydrides,~140 meV and 133.0 meV, respectively [3].

243

Acknowledgements

The authors thank Mr. K. Kubo and Dr. H. Itoh ofJapan Steel Works, Ltd. for preparation of the
Ti-Cr-Mo alloy.

Fig.2
Relation beween metal-hydrogen distance andvibrational excitation energy of CaF2-type di-hydrides.
Square plots are data of binary hydrides (e.g. TiH2, etc.)
taken from ref.7.

The hole size of the interstitial sites is considered
to more closely relate to the vibrational potential
than the metal-hydrogen distance. A smaller holesize would make the potential curve narrower. The
hole size for the three hydrides were calculatedusing average Goldschmidt radii: 0.048 nm(Ti0.7Cr1.1V1.2), 0.051 nm (Ti1.0Mn0.9V1.1), 0.048 nm(Ti1.1Cr1.4Mo0.3). The Ti-Cr-Mo and Ti-Cr-V
hydrides have a similar hole size, but have a
difference in the vibrational excitation energy. It
suggests that chemical properties of each element
affect the vibrational potential more than the size
factor in this case. Ti has a deeper potential curvethan V, Cr. Ti-Cr-Mo containing more Ti than
Ti-Cr-V would be more affected by the potential ofTi.

Table1 Vibrational excitation energy and average holesize for CaF2-type di-hydrides

Vibrational
excitationenergy E/ meV

Average Hole
size / nm

Ti1.1Cr1.4Mo0.3

148 a

0.048

Ti0.7Cr1.1V1.2

133 b

0.048

Ti1.0Mn0.9V1.1

140 b

0.051

TiH2

149 c

0.045

a) this sudy, b) ref.3, c) ref.7

244

References
1) E. Akiba, H. Iba, Intermetallics, 6 (1998) 461.
2) Y. Nakamura, E. Akiba, J. Alloys Compd., 311-2(2000) 317.
3) Y. Nakamura, T. Omura, K. Kamiyama, E. Akiba,
KENS report XIII (2002).
4) Y. Nakamura, T. Omura, K. Kamiyama, E. Akiba,
KENS report XIV (2004).
5) S. Ikeda, N. Watanabe, J. Phys. Soc. Jpn., 56(1987) 565.
6) K. Kubo, H. Ito, T. Takahashi, T. Ebisawa, T.
Kabutomori, Y. Nakamura, E. Akiba, J. Alloys
Compd., 356-357 (2003) 452.
7) D. K. Ross, P. F. martin, W. A. Oates, R. Khoda
Bakhsh, Z. Phys. Chem. N.F. 114 (1979) 221.
8) Y. Fukai, H. Sugimoto, J. Phys. F: Metal Phys.,
11 (1981) L137.

Relaxation Behavior of Polypropylene Studied by Neutron and Positron Probes
M. KAWAI, S. ITOH, and T. SUZUKI*
Neutron Science Laboratory, Institute of Materials Structure Science,*
Radiation Science Center,
High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801
Although there are many methods to measurerelaxation behavior of polymers, neutron scatteringand positron annihilation lifetime spectroscopy(PALS) are unique approaches to study therelaxation from the nano-scale level. PALS canmeasure relaxation behavior as a secondary effectthrough the interaction of positron and trappedelectrons: neutron scattering
gives the direct
information of the motion of polymer structures
through the interaction with the constituent atoms
and molecules. Comparing these methods, neutron
scattering is quite important to determine therelaxation behavior and PALS results must be
verified by the neutron scattering. In this research,
relaxation behaviors of polypropylene (PP) werestudied by PALS and neutron scattering.
Positrons injected in polymer usually form ahydrogen-like atom, positronium (Ps), composed of
one positron and one electron. Although ortho-Ps(o-Ps) has a long life time of ca. 140 ns in vacuum,
it shortens its lifetime to a few ns in polymer
through a pick-off interaction with electrons. The
o-Ps lifetime (τ 3) and intensity (I3) reflect thechange of state of polymer as shown in Fig. 1.

groups. But this is only the interpretation and these
discussions must be proved by the neutron scattering,which may give the direct information of therelaxation temperature of –CH3 groups.
Intheneutronscatteringexperiment,
non-irradiated PP with a size of 50×50×2 mm3 wasused at the INC beam line. To investigate thetemperature dependence, neutron elastic scatteringexperiments using neutron energies of 50 and 200
meV were conducted at eight different temperatures(6, 30, 50, 70, 100, 150, 200, 300K). The results areshown in Fig. 2 and 3.

Fig.2, Neutron elastic scattering for 200meV.

Fig.3, Neutron elastic scattering for 50meV.
Fig.1, Temperature dependence of lifetime (τ3) andintensity (I3) for irradiated and non irradiated PP.
The decrease of I3 above 50k for non-irradiatedand 180K for irradiated PP is explains by thedecrease of trapped electrons in shallow potentials,
which disappear by the commencement of –CH 3
groups and –C–C– axis motion during the heatingof the PP samples. When these potential disappear,
trapped electrons are ejected, resulting in thedecrease of Ps formation with these electrons. Hence,
the temperature of the commencement of decrease isconsidered to be the relaxation temperature of –CH 3

Two modes with energies of 180 and 170 meVwere observed, which correspond to activationenergies of rotation of –CH3 groups: the former isrelated to –CH3 attached to the main chain axis andthe latter to the end of the chain. There is a mode of
30 meV, which is related to the motion with low
energy like vibrational mode of –C–C– axis andsmall torsional vibration of –CH3 groups. The
former rotations affect shallow potential, however
the latter vibration does not affect it. These results
support the explanation of PALS results.
Reference
T. Suzuki, et al.,Mat. Res. Innovat. 7(2003) 31

245

Neutron Scattering Studies on Relaxation and Excitation Phenomena in Structurally Aperiodic
System by LAM-40
Qasielastic neutron scattering measurement of mesostructured composite ionic conductor
H. MAEKAWA123, H.-Y. SHEN123, T. YAMAMURA13, K. SHIBATA4,
Y. KAWAKITA5 and M. KAWAI6
1

Graduate School of Engineering, Tohoku University, Sendai, 980-8579
PRESTO, Japan Science and Technology Corporation, Kawaguchi, 332-0012
3
Center for Interdisciplinary Research, Tohoku University, Sendai, 980-8578
4
Neutron Scattering Research, JAERI, Tokai-mura, 319-1195
5
Graduate School of Science, Kyushu University, Fukuoka, 810-8560
6
KENS, Institute of Materials Structure Science, Tsukuba, 305-0801

2

Solid-state electrolytes that allow high-speed
ionic migration within a solid serve as a very
important key material for a high efficiency fuel cell,and a highly reliable all solid-state secondary battery.
Fabrication of ionic conductor composites having
mesoscale interface and restricted geometry by
artificial structure-directing methods is attractive
approach for the development of high ionic
conductor both in fundamental and application pointof view. The enhancement of conductivity is
expected by using interfacial phenomena such as
space-charge effect and a formation of surface
specific conduction paths.
A dispersion of insoluble dielectric oxide particles
such as Al2O3 in certain ionic conductors is known
to increase total electrical conductivity. In case thedistance between two interfaces is comparable to the
Debye length, a further conductivity enhancement
due to “size effect” was predicted, as a result of an
overlapping space-charge layer [1-6]. The purposeof the present investigation is to preparenano-channeled ceramics including Al2O3 withvarious pore sizes by means of sol-gel synthesis, andto investigate conductivity and diffusive propertiesof lithium ions confined within mesosized space.
Powdered mesoporous alumina with various poresizes was prepared by the sol-gel method utilizing
neutral surfactants as structure-directing agents[7-9]. Pore size, pore volume and BET surface
area were obtained by N2 adsorption and desorption
isotherms at 77 K by Micrometrics ASAP2010.
Mesoporous alumina and anhydrous lithium iodide
beads (Aldrich, 99.999%), were mixed and pressed
into a pellet under the globebox atmosphere (< 1ppm v H2O). The pellet was sealed into a glassand heated at 773 K for 15 h. Dc conductivity was
obtained from the diameter of a single arc observedon the Cole-Cole plot of the ac impedance
measurement.
246

7

Li diffusion coefficient of the composite wasdetermined from quasielastic neutron scattering(QENS) and pulsed field gradient (PFG)-NMR.
QENS was measured by LAM40 spectrometer at
KENS, Tsukuba, Japan. Scattering intensity frommetallic vanadium was used as a window functionof the spectrometer. PFG-NMR was measured byChemagnetics CMX Infinity 300 spectrometer withhigh temperature probe operated up to 800K and thefield gradient strength of 600 G/cm. Samples used
for PFG-NMR measurements were prepared byimpregnation of molten LiI into cold isostatic press(CIP) mesoporous alumina pellet (4 mm ).
The N2 adsorption and desorption isotherms ofthe mesoporous-Al2O3 were Type IV, with a small
hysteresis that indicates a minor deviation from a
regular array of cylinders. The pore diameter
distribution curve was obtained by the BJH methodfrom the adsorption branch of the N 2 adsorption
isotherm.
A sharply peaked distribution wasobserved reflecting a uniform mesopore size
ranging from 3 to 22 nm. A linear relationshipbetween pore size and [solvent]/[surfactant] ratio of
the sol-gel solution suggest size controllingmechanism is a swelling of micelles. The 27Al
MAS-NMR spectra show that smaller pores have alarge amount of distorted coordination of aluminium
ions (5-ccordinated), reflecting thinner pore walls.
Figure 1 shows an example of QENS analysis
for 0.5LiI-0.5mesoporous-Al2O3 composite at-1
479K and Q =1.22 Å . A Lorentzian function,
Sc (Q,ω),was used for the QENS component. In the QENS
spectra of the composite, a broad component at thebase of the intense elastic scattering was observed.
Convolution of a Lorentzian function to thevanadium window function yields simulated
7
pattern of the total neutron scattering.
Li
diffusion constant was obtained by the slope of the
Q-dependence of the width of the Lorentzianfunction.
0.5
0.3
0.2

2

0.1

Diffusion Coefficient (cm /s)

S(Q, )

0.4

diffusion coefficients obtained from PFG-NMR are
shown. The increase of Li ion diffusion coefficientfor the composite compared to pure LiI wasobserved. The pore size dependence was also
observed for the composites.
The diffusion
constant increased from 15 nm to 4.2 nm withdecreasing pore size. Decrease in Li diffusion
coefficient was observed for sample with 2.8 nm
pore size. These results are in agreement withelectrical conductivity behaviors as described
previously.

0-0.1-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
Energy (meV)
Figure 1 QENS analysis for 0.5LiI-0.5mesoporous-Al2O3(pore size = 4 nm) composite observed at 479K
-1
and Q=1.22 Å(dotted line): neutron scattering from metallic
vanadium used as a window function of thespectrometer; (solid bold line): Lorentz functionused for the convolution to the window function;(solid hairline): fitted spectrum.
4

10
Intensity (a.u.)

D =5.62x10 -8 cm2/s

10

-4

10

-6

10

-8

pore size=15 nm
4.2 nm9 nm
2.8 nmm.p.
(446℃)
pure LiI

-10

10
7

1

1.5
2
-1
1000/T (K )2.5

Figure 3: Li diffusion coefficients obtained by PFG-NMR
for pure LiI, and LiI-mesoporous-Al2O3
composites with different averaged pore size.

In Figure 4 diffusion coefficients obtained from
QENS, PFG-NMR and the measured conductivity
were compared.

3

10

0

1 10

7

7

2 10

3 10

7

Figure 2 Magnetization decay of PFG-NMR as increasing
field gradient strength (g) at constant pulseintervals ( and ), observed for pure LiI at 643K.

Figure 2 shows an example of 7Li NMR peakintensity plotted against pulsed field gradient
2 2 2
strength ( g（ - /3）). An exponential decayof the intensity follows the theoretical equation,
2

S( , ) = S0exp[- g2

2

D( - /3)].

(2)

Diffusion coefficient was obtained from the slope ofsemi-log plot of the 7Li NMR intensity plottedagainst the field gradient strength (g) with constantpulse delays ( and ). D =5.62x10-8 cm2/s was
obtained for pure LiI at 643K. In Figure 3

Figure 4.

7

Li diffusion coefficients and dc electricalconductivities for pure LiI, and 0.5LiI-0.5
mesoporous-Al2O3 (4.2 nm pore) composites
plotted against 1/T. (solid line): Dc electricalconductivity of pure LiI [2]; (●): 7Li diffusion
coefficient for pure LiI obtained by PFG-NMR;
7(■): Li diffusion coefficient for the composite
obtained by PFG-NMR; (□): 7Li diffusion
coefficient for the composite obtained by
QENS; (Δ): Dc conductivity of the composite.

247

The diffusion coefficient of pure LiI show
excellent agreement with the measured conductivity[2] by using Einstein equation,=Z 2F 2DC/RT,(3)

assuming a carrier concentration, C, equals to an
overall concentration of lithium in LiI. In equation(3), Z is a charge, F is a Faraday constant, D is adiffusion coefficient, respectively. On the other
hand, the diffusion constant of LiI-mesoporousAl2O3 composite measured by QENS showedalmost one order higher than that of PFG-NMR.
Due to limited conductivity data, comparison withthe calculated conductivity could not be made forthe composite electrolyte, although the diffusion
constant by PFG-NMR exhibit close relation withthe measured conductivity.
Table 1: Comparison of activation energies of ionicmigration of mesoporous-alumina-LiI composite
measured by various methods.
MethodActivation Energy(kJ/mol)

PFG-NMR- 43

Electrical Conductivity, T

- 41

QENS

- 17

7

- 18

Li NMR T1

In Table 1, activation energies obtained byvarious techniques used in the present investigation
were summarized. A similarity of activationenergies was observed between the electricalconductivity and PFG-NMR. On the other hand,activation energies obtained by 7Li NMR T1 and
QENS were similar and almost 3 times smaller
than that of PFG-NMR and the conductivity.
These differences in activation energies can be
explained by the heterogeneous migration
mechanism in the composite electrolytes.
For electrical conductivity and PFG-NMR, ionicmigration processes that have a distance greaterthan microns in order have been observed, which
include conduction both in mesopores and the grainboundary region between the mesoporous alumina
particles. On the other hand, T1 and QENS canmonitor local ion motion in atomistic region. The
anomalously low activation energies for local ionicmotion observed by QENS and 7Li NMR T1 mightsuggest an increased ion migration of LiI confinedwithin mesopores.
In the present investigation, it was found that the
conductivity of LiI-mesoporous alumina composites
248

systematically depends on the pore size of alumina
particles. An order of higher conductivity wasobserved for the LiI-mesoporous alumina
composites prepared in this investigation comparedto the previously reported ones. Lithium ion
migration mechanism was examined by various
techniques including PFG-NMR, 7Li NMR T1 and
QENS.
A difference of activation energies
betweendifferent
techniquesuggestaheterogeneous conduction of the composite and apossible enhancement of the conductivity inmesoscopic region.
References
1) C.C. Liang, J. Electrochem. Soc. 120,
1289(1973).
2) F. W. Poulsen et al., Solid State Ionics, 9/10,
119(1983)
3) S. Pack, B. Owens, and J.B. Wagner, Jr., J.
Electrochem. Soc. 127, 2177(1980).
4) J. Maier, Prog. Solid St. Chem. 23, 171 (1995).
5) H. L. Tuller, Solid State Ionics 131 143 (2000).
6) J. Maier, Solid State Ionics 23, 59(1987).
7) H. Maekawa, R. Tanaka, T. Yamamura, MRS
Symposium Proceedings, 756,
EE6.18.1(2003)
8) H. Maekawa, R. Tanaka, T. Sato, Y. Fujimaki
and T. Yamamura, Solid State Ionics, 175,
281(2004).
9) H. Maekawa et al., Mater. Res. Soc. Symp.
Proc. 835(2005)K3.8.1
10) H. Maekawa, J. Esquena, S. Bishop, C. Solans,
BF. Chmelka, Adv. Mater., 15 (7-8): 591-596(2003)
11) Y. Daiko; T. Kasuga and M. Nogami, Chem.
Mater, 14, 4624(2000).
12) W. Y. Hsu and T. D. Gierke, J. Membr. Sci., 13,
307(1983)
13) H. Maekawa, R. Tanaka, H. Shen, Y. Fujimaki,
T. Yamamura, K. Shibata, M. Kawai Solid
State Ionics: The Science and Technology ofIons in Motion, Eds. B.V.R.Chowdari,
H.-L.Yoo, G.M.Choi, J.-H.Lee, pp.851-857(2004).
14) H.Shen, H.Maekawa, Y.Fujimaki, K.Kawata,
and T.Yamamura, Solid State Ionics: The
Science and Technology of Ions in Motion,
Eds. B.V.R.Chowdari, H.-L.Yoo, G.M.Choi,
J.-H.Lee, pp.187-193 (2004)
15) H Maekawa, H Shen, J Kawamura, T.
Yamamura, Solid State Ionics, Articles inpress16) K. Kawata, H. Maekawa, T. Yamamura, Solid
State Ionics, Articles in press

Crystal Field Splittings in Cubic Pr Compounds of PrInX 2 (X = Cu, Ag, Au)
H. S. SUZUKI and T. J. SATO*
National Institute for Materials Science, Tsukuba, Ibaraki, 305-0047*Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581
Systems including non-Kramers rare-earth ion
under cubic symmetry are of special interest fromtheviewpointof
theircharacteristic
crystalline-electric-field (CEF) states. For example,
the Hund's rule ground state for 3H4 of Pr3+ ion splits
in a cubic CEF into one singlet, 1, one doublet, 3,
and two triplets, 4 and 5. Here, it is noted thatthe non-Kramers doublet of 3 is non-magnetic but
has quadrupolar moments. When 3 ground statewith a relatively large CEF splitting is realized, it issuited for the investigation of a pure quadrupolarsystem. They are, however, rare cases, for example,
PrPb3 [1], PrInAg2 [2] and PrPtBi [3].
In this research, we have investigated the CEF
level scheme systematically by substitution of aligand atom in the cubic Pr compounds with the 3
ground state. Inelastic neutron scattering is mostpowerful for this purpose. We focus on ternarycompounds taking advantage of the two kinds ofthe ligand atom for the substitution. For thisexperiment, we have prepared the samples of PrInX2(X = Cu, Ag, Au) series. In this substitution, thenumber of the outer electrons of the ligand X atom
dose not change.
The experiments were performed at LAM-D.
The samples of single crystals were crushed into
powder. To minimize absorption by In and Ag in the
scattering, the powder was filled into a gap between
two Al cylinders with different radii.
Shown in figure are the inelastic scattering
spectra at representative temperatures for PrInAg2
and PrInCu2. For PrInCu2, the main structure of thespectra is similar to that of PrInAg2 and all the peaks
can be indexed as in the figure. These results
indicate that the CEF level scheme of PrInCu2 is thesame, i.e. the ground state is 3, and its splitting islarger compared with those of PrInAg2. Consideringthat the lattice constant of PrInCu2 is smaller thanthat of PrInAg2, the larger splitting of PrInCu2 isconcerned with the volume effect. The line width of
PrInCu2 is found to be larger than that of PrInAg2. In
specific heat measurements, a broad peak was
observed around 2 K and 0.4 K in PrInCu 2 and
PrInAg2, respectively. The origin of the peak of
PrInAg2 has been discussed concerning with the

Kondo effect between the local quadrupolar
moments and the conduction electron. Such a
correlation would be the origin to broaden the
inelastic lines and stronger in PrInCu2 due to thevolume effect.

FigureInelastic neutron spectra of PrInAg2 and PrInCu2.

We have observed the CEF excitations in
PrInAg2 and PrInCu2 and PrInAu2 (the result of
PrInAu2 are not shown). The CEF ground state of
PrInCu2 is 3 and its level scheme is the same witha larger splitting compared with that of PrInAg2,
resulting from the volume effect.
References
1) W.Gross, K.Knorr, A.P.Murani, K.H.J.Buschow,
Z. Phys. B 37 (1980) 123.
2) R.M.Galera, J.Pierre, E.Siaud, A.P.Murani, J.
Less-Common Met. 97 (1984) 151.
3) M.Kasaya, H.Suzuki, D.Tazawa, M.Shirakawa,
A.Sawada, T.Osakabe, Physica B281-282 (2000)
579.

249

Magnetic Excitation in Non-magnetic

3

Doublet Ground State of PrInNi4

H. S. SUZUKI and T.J. SATO*
National Institute for Materials Science, Tsukuba, Ibaraki, 305-0047*Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581
Singlet-ground-state ferromagnet of rare earth
compound, such as fcc Pr and Pr3Tl, had beenstudied well in the 1960s-1970s because, in such amaterials, the crystal field and exchange field arenearly balanced and their magnetic properties wereconsidered to differ from those of conventional
magnets [1]. Inelastic neutron scattering [2] had
revealed the dispersion of the crystal field singlettriplet excitations, which were discussed comparing
with theories, mainly, in terms of the molecular field.
Recently, the polycrystalline sample of PrInNi4 withthe cubic MgSnCu4-type structure has been preparedand its physical properties have been reported [3].
The magnetic susceptibility and the magnetization
curve have revealed a non-magnetic doublet groundstate of 3, a ferromagnetic transition at Tc = 0.9 K
and a field-induced ferromagnetic transition at low
temperatures.
The purpose of this research is to investigate themagnetic excitation in the induced ferromagnet
PrInNi4 with non-magnetic doublet ground state.
The experiments were performed at LAM-40. The
samples of polycrystalline were crushed into powder.
To minimize absorption by In in the scattering, thepowder was filled into a gap between two Al
cylinders with different radii.
In a previous inelastic neutron experiment [4],two excitations at E = 1.7 and 14 meV wereobserved at T = 1.5 K. The lower-energy excitationis considered to correspond to a splitting between
the ground state 3 and the 1st excited state 4, andthe higher one to 2nd excited state 5. The inelastic
line of the higher one is relatively broad comparedwith the lower one, implying a strong Q-dependenceof the excitation.
The inelastic neutron spectra at T = 0.4 K( below Tc) are shown in Figure with the variation of
Q. The inset shows the Q-dependence of the peakaround 1.7 meV, corresponding to the lower-energy
excitation. It is shown that the Q-value decreases
toward E = 0, reflecting the ferromagnetic
interaction. This dispersion of the CEF excitation
was also observed above Tc. On the other hand, Qdependence of the higher-energy excitation was not250

observed or extremely small if any (not shown)
against expectations.

FigureInelastic neutron spectra of PrInNi4 at T = 0.4 K.
The intensity of the spectrum is shifted with a-1constant from Q = 0.2(the lowest one) to Q
-1
= 2.6
. The inset shows the Q-dependenceof the inelastic line around 1.7 meV.

We have observed the dispersion of the crystal
field excitation from the non-magnetic ground state
to the 1st excited state below and above Tc. The
dispersion reflects the ferromagnetic interaction.
More quantitative analyses in terms of a mean-fieldapproximation model are now in progress.
References
1) See for example, B.R. Cooper, Phys. Rev. B. 6
(1972) 2730.
2) R.J. Birgeneau et al., Phys. Rev. Lett. 27 (1971)
1530.
3) N. Tsujii, et al., J. Phys. Soc. Jpn. 71 (2002)
1852.
4) H.S. Suzuki, et al., to be publishedLattice Dynamics in Ferroelectric Material LiNbO3
K. YAMADA, K. OHOYAMA
Institute for Materials Research, Tohoku Univ. Katahira 2-1-1, Sendai 980-8577
observed at e~50meV and 80meV. These peak ofthe density decreases with increasing temperature;
the peak at 50meV disappears at T=521K. As
shown in fig.1, no region where the density of stateincreases in this temperature range was observed.
This probably suggests that the density of state
above 90meV must increase with increasing
temperature because of conservation of density.
To clarify the relation between lattice dynamics andthe charge emission, observation of higher energy
response is needed.
30
G(e)= INT /(n+1) /(Kf/ki)*(hw)^2
25

20
G(e) (a.u.)

The ferroelectric Material LiNbO3 has attracted
much interest because of the strange charge
emission[1]. The most important character of thecharge emission is that it only occurs when thesample temperature increases or decreases in therange between 300K and 500K; on the other hand,the charge emission never occurs when thetemperature is stable even in the same range.
Though the mechanism is still an open question, thischarge emission has been used as a very compact
X-ray source on a commercial basis. In thismeaning, LiNbO3 is interesting from a point of viewof engineering as well as of solid state physics.
LiNbO3 has a hexagonal lattice with R3c spacegroup. In our previous neutron powder diffraction
experiments, we have found that Li atoms movealong the c-axis by 1.5% in the temperature range
where the charge emission is observed; note that thepowder diffraction experiments were performed atstable temperatures. This result probably suggeststhat lattice distortion plays an important role on the
charge emission.
We expect that the lattice
distortion gives large influence against latticedynamics; therefore, observation of characters oflattice dynamics in the temperature range where thecharge emission is observed is indispensable tounderstand the mechanism of the strange charge
emission behaviour.
Since LiNbO3 includes Li and O atoms, that is,
the phonon energy must be relatively higher,
chopper spectrometers are suitable for this study incomparison with triple axis spectrometers. We
performed,
therefore,
inelastic
scatteringexperiments on a powder sample of LiNbO3 on the
chopper spectrometer installed at KENS-KEK.
The powder sample, which was obtained bycrushing singlecrystalline samples, was set in a Al
cylindrical cell of a furnace. Incident neutronenergy was 150meV to observed higher energy
response. We measured lattice dynamics fromroom temperature up to 520K. Each spectrum was
obtained at a stable temperature.
Figure 1 shows temperature dependence ofdensity of state of phonon of LiNbO3 which was
obtained form spectra observed by INC. At room
temperature (open circles), peaks of the density were

15

10
292K
343K+-10K'387K+-20K
430K+-25K
475K+-30K
521K+-30K

5

0

0

20

40

60

80

100

120

140

Energy Transfer (meV)Fig. 1

Temperature dependence of phonon density of
LiNbO3 estimated from energy spectra obtainedby INC. Incident energy was 150meV.

The authors would like to thank Dr. S. Itoh and
Dr. T. Kamiyama for their kind support for theexperiments.
References
1) J.D. Brownridge and S. Raboy, J. Appl. Phys. 86(1999) 640.)251Temperature Evolution of Low Energy Phonons in La 2-x Srx NiO4 (x=0.275)
K. YAMADA, S. ITOH* and R. KAJIMOTO*
Institute for Materials Research, Tohoku University*National Laboratory for High Energy Physics, 1-1 Oho, Tsukuba-shi, Ibaraki 305
Strong coupling between doped holes and lattice
vibration of metallic oxides has been attracting acontinuous attention due to the possible origin forthe pairing interaction of high-Tc superconductivity.
These coupling can be studied through phonons byboth neutron and X-ray inelastic scattering
techniques.
In La1.725Sr0.725NiO4, a charge stripe order and an
Fig.1. Energy spectra by an X-ray inelastic
scattering. Triangles show the Bose factorcorrected intensities at 20K(closed) and300K(open).

energy resolution of less than 5meV. Two single
crystalline rods of La1.725Sr0.725NiO4 (~6mm indiameter and ~40mm in length) were co-aligned.
The angle of the crystal axis with respect to theincident neutron was set so as to perform a quasiconstant q scan by time-of-flight method. To obtain
the data up to 50meV we utilized an incident energyof 60 mev. The energy spectra were taken at T=20K,
60K, 110K and 300K with the same configuration.
The obtained intensities by different detectors arenormalized by a vanadium scattering intensities andthe elastic intensities are subtracted by using theenergy spectrum of vanadium. An example of theresult is shown in Fig.2 for the data at 20K and
300K.
The obtained energy spectrum clearly exhibits amore detailed structure compared to the spectra by
x-ray scattering. The data after thermal-factor
correction still show a deviation between the data at
20K and 300K. However, the deviation is seen in theFig.1. Constant-q energy spectra by an x-ray
inelastic scattering. Triangles show the Bosefactor-corrected intensities at 20K(closed) and300K(open). The q-position approximately
corresponds to the q-vector of the charge stripe
order.

antiferromagnetic spin order start to develop below
around 190K and 100K, respectively[1]. The bondstretching phonons and their softening with theenergy above ~50 meV were studied by neutron
scattering. Recently, to study the effect of charge
stripe fluctuations on phonons below 50meV weperformed an X-ray inelastic scattering experimenton the single crystalline La1.725Sr0.725NiO4 with theenergy resolution of ~6meV[2]. As shown by anarrow in Fig.1, the observed energy spectra exhibit
an anomalous temperature dependence. At low
temperature, the intensities in a wide energy range
between 20 and 40 meV are clearly suppressedcompared to those of at high temperature.
In order to confirm such anomalous thermal
evolution we performed a neutron inelastic
scattering by the INC spectrometer with better
252

Fig.2. Energy spectra by INC. The open andclosed circles show the Bose-factor-corrected
intensities at 20K and 300K, respectively. Notethat the q-position is slightly different from that of
x-ray scattering.

energy region below around 25meV which isdifferent from that of x-ray scattering.
References[1] H. Yoshizawa et al., Phys. Rev. B61, R854
(2000) and references therein.
[2] T. Fukuda et al., unpublished data.

Dynamics of Water Molecules in Nano-space
S. KITTAKA, S. TAKAHARA, Y. KURODA,* T. MORI,* and T. YAMAGUCHI**
Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1 Ridaicho,
Okayama 700-0005, Japan; *Department of Chemistry, Faculty of Science, Okayama University,
Tsushima, Okayama 700-8530, Japan; **Advanced Materials Institute and Department of Chemistry,
Faculty of Science, Fukuoka University, Nanakuma, Jyonan-ku, Fukuoka 814-0180, Japan
Water confinned in mesopores of MCM-41,
which are uniform nano-space, have lately attachedattantion as a model system for interfacial water
which plays important roles in many fields. We haveinvestigated the structure and dynamics of water
confined in MCM-41 samples by using quasi-elastic
neutron scattering [1-4]. In the present study, wemeasured inelastic neutron scattering spectra of waterin MCM-41 to investigate the strength of hydrogenbond between the confined water molecules.
Two kinds of siliceous MCM-41 samples (C10and C18) were prepared by the method of Beck et al[5]. The pore diameters determined from the N2
adsorption isotherms were 2.14 (C10) and 3.74 nm(C18). For the neutron scattering measurements, weprepared three kinds of samples having different
amounts of adsorption for each MCM-41 sample. (1)capillary-condensed (cc) sample: the mesopores werefilled with the water molecules; (2) surface -adsorbed(sa) sample: the pore walls are covered with the watermolecules; (3) dry sample: physisorbed molecules
were removed by evacuation at room temperature.
Inelastic neutron scattering spectra were measured in
the temperature range 50-275 K with spectrometer
LAM-D ( = 4.22 Å) installed at KEK, Tsukuba.
According to our DSC measurements, cc water in
C18 sample freezes at low temperatures (melting
point: ~230 K), but cc water in C10 sample and sa
water are the non-frozen water.
Figure 1 shows inelastic neutron scattering
spectra of water in MCM-41 at 50 K and 2 = 85°.
Peak energy of libration band of sa water in C18
sample at 50 K was shifted to lower energies thanliterature value of bulk amorphous ice [6]. Thisconfirms that breaking and/or distortion ofintermolecular hydrogen bonds in sa water. cc watersin C10 and C18 samples had similar peak energy tobulk amorphous ice but intensities on the low energy
side of the peak become larger, indicating thatintermolecular hydrogen bonds in cc water are
partially broken and/or distorted. For cc water in C18
sample, discontinuous change in spectra due tomelting of the confined water was observed between
the temperature 225-250 K, which is consistent withthe result of DSC measurement.

Figure 1. Inelastic neutron scattering spectra of
the capillary-condensed (cc) and surface adsorbed (sa) water in MCM-41 at 50 K and 2= 85°.
References
1) S. Takahara et al., J. Phys. Chem. B, 109 (2005)
23162.
2) S. Takahara et al., Adsorption, 11 (2005) 479.
3) P. Smirnov et al., J. Phys. Chem. B, 104 (2000)
5498.
4) S. Takahara et al., J. Phys. Chem. B, 103 (1999)
5814.
5) J. Beck et al., J. Am. Chem. Soc., 114 (1992)
10834.
6) O. Yamamuro et al. J. Chem. Phys. 115 (2001)
9808.

253

Magnetic Excitations in SrRuO 3
S. ITOH, K. TOMIYASU and Y. ENDOH *Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801* International Institute for Advanced Studies, Kyoto, 619-0225

254

rapidly dropped as the scattering angle increases.
Also, paramagnetic scattering spectrum wasobserved above TC in which the energy widths areextended to as high as 20 meV, as shown in Fig. 1.
These observed spectra are of magnetic origin fromsuch Q and T dependences. The magnetic peakintensities at around 20 meV and at T = 5 K became
weaker for Ei = 50 meV, and was not detected for Ei= 20 meV. This indicates that the scan locus for Ei =100 meV is closer to the dispersion curve of the spinwaves in SrRuO3 in consideration with theresolutions, and the dispersion curves should be
estimated from these results. However, it is
supposed that the magnetic peak could be detectedby the resolution ellipsoid only just grazing thedispersion curve. In order to detect the magnetic
peak clearly and to determine the parametersdescribing the magnetic scattering, lower scattering
angles are required.
0.8
SrRuO3 on INC
Ei = 100 meV
= 5°
5K
159 K
300K

0.6
intensity

Very recently, both theoretical and appliedinterests are directed to the spin dynamics of thestrong ferromgnets, which is challenged only byinelastic neutron scattering (INS) experiments using
spallation pulsed neutrons. In this respect, such INS
experiments from various manganites have been
performed on several instruments such as chopper
spectrometers and even triple axis spectrometers.
Since these materials of manganites are available insingle crystal samples, INS spectra can be readily
obtained by the conventional scanning modes.
However, many of these materials are at present
only available as polycrystalline or powder samples.
However, if we can use the novel technique of thesmall angle INS, namely Magnetic Brillouine
Scattering, it is possible to be focused on the spin
fluctuations from (000). A dispersion relation can be
determined uniquely below TC if the spectrometer
configuration is suitable to cover wide energies.
One example for such studies is SrRuO3 in the
cubic perovskite. This material shows a ferromagnetic long range ordering below TC = 160 K.
Then we expect isotropic dispersion relation withthe relatively large stiffness constant. It also attracts
us as a realistic candidate for searching the magnetic
monopole ascribed to the special band structure [1].
As a result, thermo-power is enhanced at lower
temperatures. Besides, the ferromagnetism might beoriginated by the strong electron correlations. In
order to understand the magnetic behavior in thismaterial, the determination of the parametersdescribing the spin dynamics, such as the exchange
constant, the gap energy, the critical exponents, andso on, is indispensable. Normally, such quantities
can be determined by measuring magnetic
excitations by using a single crystal sample. Since
growth of the single crystal is not easy, we tried tomeasure spin excitations from a powder sample.
In the first attempt on the chopper spectrometer
INC, we observed magnetic excitations in SrRuO3.
At T = 5 K well below TC, we observed a magnetic
peak at around 20 meV at the lowest scattering angleof 5° on INC with the incident neuron energy of Ei =100 meV, as shown in Fig. 1. The peak intensity was

0.4
0.2
0.0
0

Fig. 120

40
60
E (meV)

80

100

Inelastic spectra in SrRuO3 observed on INC. TC
is close to 159 K.

References
Z. Fang, N. Nagaosa, K. S. Takahashi, A.
Asamitsu, R. Mathieu, T. Ogasawara, H.
Yamada, M. Kawasaki, Y. Tokura and K.
Terakura, Science 302 (2003) 92.

1)

Magnetic Excitations in MgCr2O4 and ZnCr2O4
K. TOMIYASU and S. ITOH
Neutron Science Laboratory (KENS), Institute of Materials Structure Science,High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, 305-0801
MgCr2O4 and ZnCr2O4 are the normal spinel
antiferromagnets, in which non-magnetic Mg2+ and
Zn2+ ions occupy A sites and magnetic Cr3+ ionsoccupy B sites. Related to the fact that the B sites
form the corner sharing tetrahedra, the materials
exhibit the characteristic magnetic diffuse scattering
along the second Brillouin zone boundary, which isthe sign of the magnetic geometric frustration, above
TN=13 K [1,2]. In MgCr2O4, a partial magnetic orderoccurs at TN’=16 K [3]. According to the third law,
the frustration is released by the slight tetragonallattice distortion with the magnitude of the order of
0.1% at TN [4], and all of the spins compose
antiferromagnetic long-range order.
It seems to be believed that the properties of thefrustration completely disappear below magnetic
ordering temperature. However, there is thefollowing report on the powder specimen of
ZnCr2O4 below TN in the earlier inelastic cold
neutron scattering experiments in the range of Q of 0
to 2.5 Å-1 and E (energy) of 0 to 12 meV [5]. The
dispersive spin wave mode with the gap energy of
below 1.5 meV appears under 3.5 meV. Anothermode, which is expected to show the same Q
correlation as that of the frustration, still remains
around 4.5 meV. An unknown mode with almost
constant energy also exists around 9.0 meV.
In order to extend our knowledge on theabnormal magnetic excitations in those systems to
the higher energy region, we performed the inelastic
thermal neutron scattering experiments on the
powder specimens of MgCr2O4 and ZnCr2O4 in theenergy range of 0 to 25 meV by using the direct
geometry chopper spectrometer INC installed at thepulsed spallation neutron resource of KENS. The
incident energy is fixed at 30 meV. The powder
specimens were synthesized from a stoichiometricand that of
mixture of MgO and Cr2O3 at 1200
ZnO and Cr2O3 at 1150
in air, repsectively. No
extra lines, which cannot be explained by the spinel
structure, are observed in X-ray powder diffraction
patterns of the present samples at room temperature.
The samples of 50 g were enclosed in squarealuminum folders with a shape of 5 5 cm2 with 4He
exchange gas, which were mounted on the cold headof a closed-cycle He refrigerator.
Since there is no appreciable difference between
the present data of MgCr2O4 and ZnCr2O4 within thestatistical errors, we give only the data of MgCr2O4
below. Figures 1(a), 1(b), 1(c) and 1(d) show theintensity maps on the Q and E plane at 5 K (LTphase: T<TN), 15 K (HT-phase: TN<T<TN’), 100 and
300 K (P-phase: T<TN), respectively. As well as thereport on ZnCr2O4 [5], the two magnetic modes
centered by 1.5 Å-1 are also observed around 4.5 and
9.0 meV in the LT-phase in MgCr2O4, andtransforms
toparamagnetic-like
quasielastic
scattering in the HT- and P-phases. The pattern in
the HT-phase is almost the same as that at 100 K in
the P-phase. In addition, we newly found themagnetic scattering around 1.0 Å-1 and 12 meV,which is almost independent of the temperature. To
clear the feature of the magnetic scattering, we also
extract the energy spectra integrated over the
scattering angle from 5 to 12 degrees and from 17 to
28 degrees, respectively, as shown in Figs. 2(a) and2(b). In Fig. 2(a), with increasing the temperature,
the sides of the modes around 4.5 and 9.0 meV in
the LT-phase disappear in the HT-phase, andbecome quasielastic. The scattering around 12 meVdoes not almost change even at the room
temperature. In Fig. 2(b), the strong two modes losttheir structures above in the HT-phase, and theintensity shifts to Q=0 side (Fig. 2(a) side).
Since the two modes dramatically alter aboveand below TN, they will be assigned to be collective
fluctuations with regard to the antiferromagnetic
long-range order in the LT-phase. The spin wave
analysis might be useful. The new mode around 12
meV is seems to be an individual excitation becauseof the temperature independence.
In these experiments, we found the following
facts. MgCr2O4 exhibits the same two abnormal
magnetic excitations as ZnCr2O4. Another mode
exists around 12 meV. The magnetic geometricfrustration already appears in the HT-phase in
MgCr2O4 as well. The measurements on a singlecrystal specimen are required to further clarify themagnetic excitations.

255

Figure 1. Temperature dependence of neutron scattering intensity, measured on the Q andE plane on MgCr2O4. The data with the scattering angle between 5 to 40 degrees are shown.

Figure 2. Temperature dependence of energy spectra integrated over the scattering angle from 5 to 12 degrees (a)and from 17 to 28 degrees (b) on MgCr2O4.

References
1) S. -H. Lee, C. Broholm, W. Ratcliff, G.
Gasparovic, Q. Huang, T. H. Kim, and S. -W.
Cheong, Nature (London) 418, (2002) 856.
2) H. Suzuki, M. Toki, and K. Tomiyasu, JPS 61st
annual meeting (Ehime university), (2006)
28pPSB-47.
2563) H. Ehrenberg, M. Knapp, C. Baehtz, and S.
Klemme, Powder Diffraction 17, (2002) 230.
4) H. Shaked, J. M. Hastings, and L. M. Corliss,
Phys. Rev. B. 1, (1970) 3116.
5) S. -H. Lee, C. Broholm, T. H. Kim, W. Ratcliff II,
and S-W. Cheong, Phys. Rev. Lett. 84, (2000)
3718.

Quasi-elastic Neutron Scattering of Protonic Conductor K3H(SeO4)2
F. SHIKANAI, K. TOMIYASU, I. TSUKUSHI , S. IKEDA and T. KAMIYAMA
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, 1-1 Oho, Tsukuba, Ibaraki, 305-0801
1
Faculty of Engineering, Chiba Institute of Technology, Narasino, Chiba, 275-0023
M3X(YO4)2 (M: K, Rb, Cs, or NH4; X: H or D,
Y: S or Se) family of hydrogen-bonded materials
have attracted a lot of attention due to the interesting
phenomena in the high-temperature. Most of thematerials show over 100 times higher electric
conductivities than those at room-temperature [1]. It
has been considered that the higher conductivities
were due to the proton transfer in the crystal.
Therefore, these material expected as the solid
electrolytes for fuel cell in recent years. In this study,
we selected K3H(SeO4)2 (abbreviated as TKHSe) as
the sample. TKHSe undergoes phase transition at
390 K (TC) and show high electric conductivity
about 10-4 to 10-2 S/cm in the high-temperaturephase (denoted as phase I).
In order to examine the proton dynamics, we
performed quasi-elastic neutron scattering (QENS)
measurements using high-resolution spectrometer
LAM80-ET installed at KENS pulsed spallation
neutron facility. Cylindrical powdered sample of
3.64 g were enclosed with Ar gas in an aluminumcell. The measurements were carried out on coolingprocess at varying temperature of 433 K, 413 K, 393
K, and 388 K in the phase I, and 383 K and 298 K in
the phase II. Energy resolution of _E = 6.5 _eV and
17 _eV are corresponding to reflections (004) and(006) of mica analyzer with a effective Q range 0.17
to 1.65 _-1. Prior to these experiments, we carriedout neutron powder diffraction experiments toinvestigate the detail of structural change, andperformed maximum entropy method (MEM) toobtain proton distribution maps in each phases. The
proton densities estimated from MEM calculations
as 6.08 _10-20 cm-1 at 413 K and 4.26_10-20 cm-1 at
393 K, respectively [2].
Figure 1 shows the temperature dependence of
QENS spectra. The phase transition temperature isabout 385 K because of the cooling processexperiment. The data in the phase I are shown by
filled characters, and those in the phase II are shownby outline characters in the figure. As seen in the
figure, the QENS spectra appear only above TC, thatis, those spectra are due to the conduction protons.
To separate QENS spectra as elastic and quasi-

elastic scattering components, we use the wellknown jump-diffusion model. The half width at thehalf maximum (HWHM) of QENS spectra is givenas

HWHM 

DQ 2
1  DQ 2

where D is diffusion constant and _ is relaxation
time. The typical QENS spectrum is shown in theFig. 2. Small quasi-elastic broadening was observedin the phase I. The HWHM values of QENS spectra
are about 5.2 _eV to 10.4 _eV with the range of Q =, and these values were same order of the
1.65
energy resolutions. Fitting parameters for eachtemperatures are listed in Table 1. As temperature
increase, the diffusion constant D increases while
the relaxation time _ decreases. The relaxation times
were consistent with those values of Rb3H(SeO4)2
reported by Lechner [3]. Activation energy Ea wasestimated from temperature dependence of D using
Arrhenius relation;

D  D0 exp

Fig. 1

Ea.
RT

Quasi-elastic neutron spectra of K3H(SeO4)2 at
dependence temperature.

257

The activation energy was estimated as 172(48)meV.
Thus we obtained proton densities from MEM
calculations and the diffusion constants from QENS
measurements at the same temperature at 393 K and
413 K. The electric conductivities _ can be
estimated using Nernst-Einstein relation;Ne 2 Dk BT

where N is the density of mobile proton, e is proton
charge, kB is Bolzmann constant. The electric
conductivities were estimates as 5.8(8)_10-3 S/cm at
413 K and 3.6(2)_10-3 S/cm at 393 K, respectively.
These values are good agreement with those values
obtained from macroscopic measurement.
Fig. 2

References
1) H. Kamimura et al., Phys. Status Solidi B 241(2004) 61
2) F. Shikanai et. al., ICNS 2005 proceedings,
Physica B (2006) in press
3) R. E Lechner; Solid State Ionics 145 (2001) 167.

Table 1. Fitting parameters for QENS spectra ofK3H(SeO4)2 at different temperatures with their standard
deviations in the parentheses.
Temperature [K]
388
393
413
433

258

Typical QENS spectrum separated elastic andquasi-elastic components.

D _10-10 [m2/s]
1.3(2)
1.9(1)
2.1(3)
2.6(3)_ _10-11 [s]9.0(8)
5.8(2)
5.2(4)
4.9(3)

Effect of Conduction Electrons on the Crystal Field in Tm0.05LaxYb0.95-xTe
T. MATSUMURA, H. ISHIDA T. J. SATO* and K. SHIBATA**
Department of Physics, Graduate School of Science, Tohoku University, Sendai, 980-8578*Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, Tokai, 319-1106**Neutron Science Research Center, Tokai Research Establishment, JAERI, Tokai, 319-1195
The origins of crystalline electric field (CEF)
splittings in 4f electron systems is usually attributed
to ligand anion charges. However, it is difficult topredict CEF parameters that are determined
experimentally. The point charge model is usually
too crude to explain the actual CEF parameters.
Although the role of the conduction electrons has
been considered to be important[1,2], there havebeen no good experimental example.
TmxLa1-xTe, with NaCl structure, is a system wefound recently in which a clear CEF splitting
appears by introducing conduction electrons by
substituting divalent Tm with trivalent La [3].
Further, the CEF level scheme of 7- 8(10 meV)6(17.6 meV) that was determined for x=0.95 in
Ref. [3] is opposite to the prediction of the point
charge model. TmTe and TmxYb1-xTe, which are
divalent insulators, do not exhibit such large CEF
splittings. This is a clear experimental result thatshows the conduction electrons play an importantrole in determining the CEF.
In order to study the effect of conduction
electrons, we have examined Tm0.05LaxYb0.95-xTe
system, where the Tm concentration is kept dilute at
5 % and only the number of conduction electrons isvaried by substituting divalent Yb with trivalent La,
both of which are non-magnetic.
Neutron inelastic scattering experiment has been
performed using the LAM-D spectrometer at the
KENS puled neutron source. A collection of small
pieces of crystals with total mass about 18 g was
enclosed in an aluminum container and was attached
to a closed-cycle refrigerator.
Fig. 1 shows the magnetic part of the neutron
scattering function as a function of La concentration
x, the density of the conduction electrons. The
spectrum for x=0.95 indicates the CEF excitation of7
8(10 meV). The peak splits because of thediffernce in the local environment of the Tm ions;the number of other divalent Tm ions in its nearest
neighbor sites varies from ion to ion when theconcentration is 5 %. This situation is shown in Fig.
2, and the experimental peak intensities are
consistent with the calculated probabilities of theFig. 1

Magnetic part of the Neutron scatteringfunction of Tm0.05La0.95Yb0.95-xTe as a funcionof La concentration. Solid lines are fits withLorentzian or Gaussian spectral functions.
Dashed line at E=0 represents the resolutionfunction.

local environments. The experimental spectrum canbe well reproduced if we consider the
8 levelcomes down by 1.56 meV by one substitution of
La3+ with a 2+ ion.
With decreasing the concentration of condcution
electrons by substituting La3+ with Yb2+, the CEF
excitations are collapsed soon. At x=0.75 acontinuous broad excitation is observed. The line in
the figure is a rough fit with a Gaussian spectral
function centered at 4 meV with FWHM=9 meV.
The center of the peak seems to be shifted to around
6 meV because of the temperature effect. This
broadened exitations can be understood on the samefooting as for x=0.95. The spectrum is consistent
with the calculated distribution of La3+ ions in Fig.
2 if we assume the 1.56 meV reduction of the8259

resistivity of this system at room temperature.
Judging together with the temperature dependence,
it is metallic above x=0.3 and metal-insulatortransition takes place around x=0.2. It is insulating
at x=0.15. Although the transport property changes
abruptly between x=0.3 and 0.15, the neutron
excitation spectrum do not vary very much as shownin Fig. 1. This shows that although the local densityof the conduction plays an important role for the
CEF splitting but it is not such sensitive to themobility of the carriers. The critical concentration of
conduction electrons for the CEF levels seems to bearound x=0.5, while the critical concentration for themobility of the conduction electrons is around x=0.2.
Fig. 2 Calculated distribution of La ions in the firstnearest-neighbor rare-earth sites around a Tm
ion.

level by one replacement of La3+ with a 2+ ion.
However, at concentrations below x=0.55, thissimple interpretation is not valid. At x=0.55, a quasielastic scattering is clearly observed followed by abroad excitation up to 10 meV. From the calculated
distribution in Fig. 2 and 1.56 meV reduction for
one loss of La3+, we expect that the G8 level iscollapsed to energy zero for more than half of the
Tm ions. We consider that the quasi-elastic
scattering arises from such Tm ions and the broad
excitations up to 10 meV arises from Tm ions thatstill have more than six La3+ ions, where the local
density of the conduction electron is relatively high.
At x=0.3 and x=0.15, the CEF excitations arealmost collapsed and only a quasi-elastic scattering
can be observed. This result is quite similar to thatof TmTe. The
8 level came down to the zeroenergy. These low energy excitations can beinterpreted as the damped CEF excitations between
7 and
8 as in TmTe or the spin fluctuations
caused by the valence instability.
The collapse of the CEF excitation between
x=0.75 and x=0.55 is relfected to the lowtemperature specific heat. At x=0.75, there appears a
Schottky type behavior, which indicates that there isan energy gap between the ground state and the 1st
excited state. At x=0.55, however, the behavior
changes from the Schottky-type to the T-linear type,incicating that the gap has been closed and theground state has a continuous distribution in energy.
The low energy excitation that appears below
x=0.55 is related to this T-linear specific heat.
It is also interesting to compare our excitation
spectrum with the resistivity. Fig. 3 shows the260

Fig. 3

Resistivity of Tm0.05LaxYb0.95-xTe attemperature. Line is a guide for the eye.

room

In conclusion, this experiment demonstrates thatthe 4f state of a Tm ion strongly depends on thelocal environment of conduction electrons. When
there is a lot of trivalent ions in the NN sites, thelocal environment becomes metallic and a large CEF
appears. When the number of divalent ions increase,the local environment becomes insulating and the
CEF vanishes.
References
1) D. Schmitt, J. Phys. F: Met. Phys. 9 (1979) 1745.
2) M. S. S. Brooks et al., Phys. Rev. Lett. 79 (1997)
2546.
3) T. Matsumura et al., Phys. Rev. B 66 (2002)
11410.

Spin Fluctuation of a Heavy-Fermion Compound YbAgGe
T. MATSUMURA, H. ISHIDA and T. J. SATO*
Department of Physics, Graduate School of Science, Tohoku University, Sendai, 980-8578*Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, Tokai, 319-1106
roughly be extracted from the seven sets of detectors
placed at angles ranging from 8 to 120 degrees.
Figure 1 shows the inelastic excitation spectra
obtained at T=0.4 K, well below the magnetic
ordering temperature. Broad quasielastic scattering
is observed for every detectors. It is noticed that thelineshapes differ from one detector to another,indicating that there is a significant wave-vector
dependence. The broad peak around 12 meV is the
CEF excitation as observed in Ref. 3. Lines in the
figure are fits with Lorentzian spectral functions.
The low energy excitation spectrum cannot be
described by a single Lorentzian, which also
indicates the wave-vector dependence of the spin
fluctuation. With respect to the wave-vector
dependence, a detailed study using a single crystal
has been reported recently [4].

25x10

-3

YbAgGe (LAM-40)
T=0.4 K
20
S(�,�) [arb. units]

YbAgGe has recently been attracting interest as a
new Yb-based heavy-fermion compound [1]. A
major point of interest is the coexistence of the
Kondo effect and geometrical frustration of the
kagome-lattice-like triangular coordination of Ybions in the ZrNiAl-type crystal structure. Effective
mass of about 400 mJ/mol K2 is observed at 2 K in
the specific heat measurement, followed by twomagnetic phase transitions at 0.8 K and 0.65 K.
Another aspect of importance is the field-induced
non-Fermi liquid behavior. The lnT dependence ofthe magnetic specific heat is observed in a wide
temperature range from 10 K to below 1 K [2].
Although YbAgGe is close to the quantum criticalpoint, various physica properties reminds us local
moment behavior. Existence of the crystalline
electric field (CEF) levels is one of such properties.
Schottky-type specific heat anomaly is observed ataround 60 K, and the CEF excitation is also
observed in inelastic neutron scattering [3].
Previous measurement of inelastic neutron
excitation spectrum in Ref. 3 clarified the existenceof large quasi-elastic scattering, which is ascribed tothe spin fluctuation by the Kondo effect. At hightemperatures the spectral function could be
described by a single Lorentzian. However, withdecreasing temperature down to the lowest
temperature of 1.5 K, the spectral function deviatedfrom the Lorentzian. Although this has been
ascribed to the wave-vector dependence of the spin
fluctuation that becomes more significant at low
temperatures, detailed measurement has not beendone.
In order to investigate the wave-vector
dependence of the low energy part of the excitation
spectrum in YbAgGe, we have performed aninelastic neutron scattering experiment down to 0.4
K using the same sample as in Ref. 2. We used theLAM-40 spectrometer at the KENS pulsed neutron
source. A collection of small pieces of polycrystals
with a total mass of 14.2 g were sealed in analuminium container and were attached to a
3He-cryostat. Although the sample is polycrystalline,
information on the wave-vector dependence can�=
15 120°102°
10 83°
64°
5

46°
27°

0

8.3°
0

5

10

15

Energy [meV]Fig. 1

Neutron scattering functions of YbAgGe as afunction of the scattering angle at the lowest
temperature of 0.4 K. Solid lines are fits with a
Lorentzian spectral function.

261

-3

χ'(φ,0)P(φ,ω) [arb. units]

8x10

YbAgGe (LAM-40)
φ=8.3°
0.4 K
1.2 K
5K
10 K
20 K
40 K

6
4
2
0

0

2

4

6

8

Energy [meV]Fig. 2Temperature dependence of the spectral
function multiplied by the real part of themagnetic susceptibility as measured for thedetector at �=8.3°.

In order to look this behavior in more detail, we
compare in Fig. 3 the temperature dependence of thespectral intensity in Fig. 2 at E=1 meV and themagnetic
susceptibility.
The
temperaturedependence of the spectral weight as measured byneutron scattering is roughly consistent with themagnetic susceptibility for H//a. This could be
because the magnetic moments are almost confinedin the ab-plane by the strong crystal field anisotropy
and the fluctuation occurs within the ab-plane.

262

χ'(φ,0)P(φ,E=1meV) [arb. units]

-3

7x10

100x10

6

H//a

5

80

4

60

3

40

2

0
0.1

20

H//c

1
1

-3

χ [emu/mol]Figure 2 shows the temperature dependence ofthe spectral function of the low energy excitation
multiplied by the real part of the magnetic
susceptibility, which is obtained from S(�,�) bycorrecting for the Bose factor and multiplying withthe energy. The overall decrease in intensity withincreasing temperature is due to the reduction in themagnetic susceptibility that is represented by aCurie-Weiss law. However, the spectral weight at
low energy decreases abruptly with decreasing
temperature from 1.2 K to 0.4 K across the magnetic
ordering temperature. This indicates that the low
energy spin fluctuation became static because of themagnetic ordering. However, there still remain asignificant low energy quasi-elastic excitation.

10

0
100

Temperature [K]Fig. 2(left axis, filled circles) Temperature dependenceof the spectral intensity at E=1 meV as
measured for the detector at �=8.3°. (right axis,
open circles) Temperature dependence of themagnetic susceptibility measured for a single
crystal.

In conclusion, we have measured the low energy
part of the inelastic excitation spectrum of aheavy-fermion compound YbAgGe for apolycrystalline sample. The spectral line shapedeviates from Lorentzian at low temperatures, whichsuggests an existence of a significant wave-vector
dependence. The quasi-elastic scattering can be
ascribed to the spin fluctuation caused by the Kondo
effect. The temperature dependence of the intensity
is roughly proportional to the bulk magnetic
susceptibility, which is quite a normal behavior.
Detailed measurements using a single crystal isstrongly required.
References
1) K. Katoh et. al., J. Magn. Magn. Mater. 268(2004) 212.
2) S. L. Bud'ko et al., Phys. Rev. B. 69 (2004)
014415.
3) T. Matsumura et al., J. Phys. Soc. Jpn. 73 (2004)
2967.
4) B. Fak et. al., J. Phys: Condens. Matter 17, 301(2005).

Neutron-scattering Study of Magnetism of Na1.8Cu2Mo3O

Using the INC Spectrometer

M. HASE, S. ITOH1, T. J. SATO2, H. KITAZAWA, and G. KIDO
National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba Ibaraki 305-0047, Japan1
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki 305-0801, Japan2
Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata,
Tokai, Ibaraki 319-1106, Japan
Magnetism provides research fields of quantum
mechanics. Various magnetic phenomena are notexplainable by classical physics. An example isspin-singlet ground state with spin gap. This statecannot be explained by a classical picture wherespins are treated as vectors. In these decades, manyspin systems (spin-gap systems) are recognized tohave spin-singlet ground state with spin gap such as
the spin-Peierls system [1] and the orthogonal-dimer
system [2]. The spin-gap systems form an importantfield in magnetism. Recently, we have found a new
insulating cuprate having a spin-gap system,
Na1.8Cu2Mo3O12- , and report magnetism of thiscuprate.
We made small single crystals of this cuprate by
a flux method. The composition Na1.8Cu2Mo3O12was determined by a chemical analysis. To ourknowledge, this cuprate is a new material andtherefore atomic positions in this cuprate areunknown. The x-ray powder diffraction pattern ofpulverized crystals is similar to that of Li2Fe2Mo3O12
whose space group is orthorhombic Pnma (No. 62).
The diffraction pattern of Na1.8Cu2Mo3O12- could be
reproduced using atomic positions in Li2Fe2Mo3O12
and using lattice constants a = 5.136 Å, b = 11.193Å, and c = 17.839 Å.
In Na1.8Cu2Mo3O12- , only Cu2+ ions have
localized spin-1/2. Figure 1 shows schematically Cu
positions. Three kinds of short Cu-Cu bonds exist.
The first-shortest, second-shortest, and third-shortest
bonds are indicated by solid, dashed, and dotted bars,
respectively. Cu-Cu distances and Cu-O-Cu angles
are 3.20 Å and 97.5° in the first-shortest bond, 3.21
Å and 91.1° in the second-shortest bond, and 3.94
Å and 124.0° in the third-shortest bonds. Exchangeinteractions are expected to exist in the three Cu-Cu
bonds. The respective parameters of theirinteractions are defined as J1, J2, and J3. From the
Cu-O-Cu angles, probably, the J1 and J3 interactions
are antiferromagnetic (AF) and the J2 interaction is
ferromagnetic (F) [3]. In contrast, Cu-Cu distances

a

c

J2

J1

J3

J2

J1

b

Fig. 1 Schematic drawing of positions of Cu in
Na1.8Cu2Mo3O12- . Solid, dashed, and dotted bars
represent the first-shortest, second-shortest, andthird-shortest Cu-Cu bonds, respectively.

in the other bonds are greater than 5.14 Å .
Therefore, exchange interactions in these bonds areprobably much weaker than the J1, J2, and J3
interactions.
The open circles in Fig. 2 show the temperature
T dependence of magnetic susceptibility in 0.1 T of
Na1.8Cu2Mo3O12- powder ( exp) measured using a
superconducting quantum interference device(SQUID)
magnetometer(Quantum
Design,MPMS-5S). A broad maximum is observed around
60 K and indicates that Na1.8Cu2Mo3O12- is a
low-dimensional antiferromagnet. The susceptibility
increases rapidly below 20 K. Magnetic phasetransition is not seen above 2 K. We fitted theformula C/(T + ) + 0 to the measured
susceptibility below 10 K, where C, , and 0 are aCurie constant, Weiss temperature, and a constantterm, respectively. The solid curve in the inset of Fig.
2 represents the fitted curve. Values of theparameters are evaluated as C = 0.0334 emu K/Cu
, and 0 = 1.56×10-4 emu/Cu mol.
mol,
We determined independently the g value of Cu2+
spins as g = 2.09 in an X band electron spinresonance (ESR) measurement at room temperature.

263

Na Cu Mo O

Susceptibility (emu/Cu mol)

1.8

2

3

0.003

12-

H = 0.1 T

0.002
0.02
0.001

0.01

0
0

0
0

5
10
150
Temperature (K)

300

Fig.
2
Magnetic
susceptibility(exp)
ofNa1.8Cu2Mo3O12- (the open circles), cor ≡ exp - C/(T +  )(the solid circles), and the calculated susceptibility of thespin-1/2 AF dimer with exchange interaction of 114 K(9.82 meV) plus the constant term 1.56×10-4 emu/Cu mol(the solid curve). The inset shows T dependence of exp of
Na1.8Cu2Mo3O12- (the open circles) and the fitted curve
C/(T + ) + 0 below 10 K (the solid curve).

The evaluated values of C and  suggest that nearly
free spins of about 8 % exist. At present, origin of
this Curie term is unsolved. The closed circles
represent cor ≡ exp - C/(T +  ). The susceptibilitycor has a board maximum around 70 K, decreases
rapidly below 50 K, and becomes a small value at
low temperature. This temperature dependence
indicates that the spin system in Na1.8Cu2Mo3O12-
has spin-singlet ground state with spin gap. The
solid curve in Fig. 2 shows calculated susceptibilityof the spin-1/2 AF dimer with exchange interactionof 114 K (9.82 meV) plus the constant term
1.56×10-4 emu/Cu mol. The calculated susceptibility
resembles cor. Thus, we consider that main origin of
0.025

0.025

300 K

4K

0.02

0.02

5

0.015

4

0.01

3
2

0.005

Intensity (arb. units)

Intensity (arb. units)

5

4

0.015

3

0.01

2
0.005
1

1
0

0

5
10
Energy (meV)

15

0

0

5
10
Energy (meV)15

Fig. 3 Neutron-scattering intensity versus energy inNa1.8Cu2Mo3O12- at 4 and 300 K. The initial neutronenergy is 20.1 meV. The curves 1, 2, 3, 4, and 5 indicate
summation of intensities at detectors with scattering
angles of 4.85 to 8.58°, 9.17 to 11.56°, 17.00 to 27.73°,
29.52 to 40.24°, and 48.58 to 66.81°, respectively. The
vertical positions of the intensities of the curves 2, 3, 4,
and 5 are shifted by 0.004, 0.008, 0.012, and 0.016,
respectively.

264

the spin gap is the AF dimer and that weakinterdimer exchange interactions also exist andcause inconsistency between cor and the calculated
curve of the dimer model.
In order to confirm directly existence of the spin
gap, we measured neutron scattering of
Na1.8Cu2Mo3O12- using the INC (inelastic neutron
chopper) spectrometer. Since the single crystals are
too small for neutron-scattering measurements, we
synthesized
crystalline
powderof
Na1.8Cu2Mo3O12- by solid-state reaction method andused the powder in neutron-scattering measurements.
Figure 3 shows neutron-scattering intensities versus
an energy transfer at 4 K and 300 K. The initial
neutron energy is 20.1 meV. We can see excitations
between 5 and 12 meV at 4 K but not at 300 K. Thus,
these excitations are magnetic excitations from thesinglet-ground state. The excitation energy in theneutron-scattering measurements and the spin gap
estimated in the magnetic susceptibility are notmutually contradictory. Because the spectra at 4 K
depend weakly on the scattering angle, probably
dispersion of the magnetic excitations is small. This
result is consistent with the inference that the spin
system is considered to be the AF dimer with weakinterdimer interactions. Since the J1 and J3
interactions are antiferromagnetic, the dominant
intradimer interaction is the J1 or J3 interaction. In
future study, we should investigate temperaturedependence of the magnetic excitations in detail.
References
1) M. Hase, I. Terasaki, and K. Uchinokura, Phys.
Rev. Lett. 70 (1993) 3651; M. Hase, I. Terasaki,
Y. Sasago, K. Uchinokura, and H. Obara, Phys.
Rev. Lett. 71 (1993) 4059; M. Hase, I. Terasaki,
K. Uchinokura, M. Tokunaga, N. Miura, and H.
Obara, Phys. Rev. B 48 (1993) 9616.
2) H. Kageyama, K. Yoshimura, R. Stern, N. V.
Mushnikov, K. Onizuka, M. Kato, K. Kosuge, C.
P. Slichter, T. Goto, and Y. Ueda, Phys. Rev.
Lett. 82 (1999) 3168.
3) M. Hase, M. Kohno, H. Kitazawa, N. Tsujii, O.
Suzuki, K. Ozawa, G. Kido, M. Imai, and X. Hu,
Phys. Rev. B 73 (2006) 104419.

Neutron-scattering Study of Magnetism of Na1.8Cu2Mo3O12- Using the LAM-40 Spectrometer
M. HASE, T. J. SATO1, S. ITOH2, H. KITAZAWA, and G. KIDO
1National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba Ibaraki 305-0047, Japan
Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata,
Tokai, Ibaraki 319-1106, Japan2
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki 305-0801, Japan

Low-dimensional quantum spin systems show
various interesting magnetism. One example isspin-singlet ground state with spin gap. Recently, we
have found that Na1.8Cu2Mo3O12- has spin-singlet
ground state with spin gap [1]. The space group isinferred to be orthorhombic Pnma (No. 62) withlattice constants a = 5.136 Å, b = 11.193 Å, and c= 17.839 Å. In this cuprate, only Cu2+ ions have
localized spin-1/2. Figure 1 shows schematically Cu
positions. Three kinds of short Cu-Cu bonds exist.
The first-shortest, second-shortest, and third-shortest
bonds are indicated by solid, dashed, and dotted bars,
respectively. A Cu-Cu distance and Cu-O-Cu angle
are 3.20 Å and 97.5° in the first-shortest bond, 3.21
Å and 91.1° in the second-shortest bond, and 3.94
Å and 124.0° in the third-shortest bond. Exchangeinteractions are expected to exist in the three Cu-Cu
bonds. The respective parameters of theirinteractions are defined as J1, J2, and J3. From the
Cu-O-Cu angles, probably, the J1 and J3 interactions
are antiferromagnetic (AF) and the J2 interaction is
ferromagnetic (F) [2]. In contrast, Cu-Cu distancesin the other bonds are greater than 5.14 Å .
Therefore, exchange interactions in these bonds are

a

c

J2

J1

J3

J2

J1

b

Fig. 1 Schematic drawing of positions of Cu in
Na1.8Cu2Mo3O12-. Solid, dashed, and dotted bars represent
the first-shortest, second-shortest, and third-shortest Cu-Cu
bonds, respectively.

probably weaker than the J1, J2, and J3 interactions.
We measured the temperature T dependence ofmagnetic susceptibility (exp) of Na1.8Cu2Mo3O12-
powder synthesized using solid-state reaction
method. The susceptibility increases rapidly below
20 K. We fitted the formula C/(T + ) + 0 to themeasured susceptibility below 10 K, where C, , and0 are a Curie constant, Weiss temperature, and aconstant term, respectively. Evaluated values of theparameters suggest that nearly free spins of about
8 % exist. At present, origin of this Curie term is
unknown. The susceptibility cor defined as exp C/(T + ) has a board maximum around 70 K,
decreases rapidly below 50 K, and becomes a smallvalue at low temperature. This temperaturedependence indicates that the spin system inNa1.8Cu2Mo3O12- has spin-singlet ground state withspin gap. From comparison between cor andcalculated susceptibility of the spin-1/2 AF dimer
with exchange interaction of 114 K (9.82 meV), we
consider that main origin of the spin gap is the AF
dimer and that weak interdimer exchangeinteractions also exist.
We also measured neutron scattering of
Na1.8Cu2Mo3O12- powder using the INC (inelastic
neutron chopper) spectrometer. We observed
excitations between 5 and 12 meV at 4 K but not at
300 K. Thus, these excitations are magnetic
excitations from the singlet-ground state. The
excitation energy in the neutron-scattering
measurements and the spin gap estimated in themagnetic
susceptibilityarenotmutually
contradictory. Because the spectra at 4 K depend
weakly on the scattering angle, probably dispersionof the magnetic excitations is small. This result is
consistent with the inference that the spin system isconsidered to be the AF dimer with weak interdimer
interactions. Since the J1 and J3 interactions are
antiferromagnetic,thedominant
intradimer
interaction is the J1 or J3 interaction.

265

(b)
116.3

56.3

112.3

52.3

108.3

44.3
40.3
36.3
32.3
28.3

5000

0

104.3
100.3
96.3
92.3

5000

24.3

0

10000

50
40

20

80.3

1.5 K

1.5 K

12.3

68.3

8.3

64.3

00

5
10
Energy (meV)15

Fig. 2 Neutron-scattering intensity versus energy inNa1.8Cu2Mo3O12-��at 1.5 K. The numbers in the figuresindicate the scattering angles (2�) in degrees. The vertical
positions of the intensities are shifted at intervals of 1000.

In next step, we should investigate temperaturedependence of the magnetic excitations in detail.
Thus, we measured neutron scattering of
Na1.8Cu2Mo3O12-��powder using the LAM-40(lattice-crystal analyzer mirror spectrometer)
spectrometer. Figure 2 shows neutron-scattering
intensities versus an energy transfer at 1.5 K. We
can see clearly the magnetic excitations between 4
and 12 meV. Although the spectra depend on the
scattering angle, the energy region of the magnetic
excitations is almost independent of the scattering
angle. The results are consistent with theabove-mentioned
results
obtainedinthemeasurements of the INC spectrometer. Figure 3
shows neutron-scattering intensities versus anenergy transfer at various temperatures for two
scattering angles. The magnetic excitations areclearly seen at low temperatures. The region of theexcitations is independent of the temperature, while
the excitations are not observed as a peak structure
at 200 K. Figure 4 shows the temperaturedependence of integrated intensities between 4 and
12 meV. The integrated intensities are normalized
by the value at 1.5 K. The integrated intensity
decreases with increasing temperature. Although themagnitude of the magnetic excitations must decrease
with increasing temperature, the spectrum at 200 K
has larger scattering intensities below 5 meV than
the spectrum at 1.5 K. This result suggests existenceof phonon excitations that prevents us fromcomparing the temperature dependence of theintegrated intensities with theoretical curves. We

266

40

60
5000

20

72.3

0

50

80

84.3
76.3

0

100

30

16.3

15

150

100

60

(b) 24.3

200

150

80
5000

10000

88.3

20.3

5
10
Energy (meV)(a) 8.330

510Energy (meV)

15

00

5
10
Energy (meV)15

Fig. 3 Neutron-scattering intensity versus energy inNa1.8Cu2Mo3O12-� for 2� = 8.3° (a) and 24.3° (b) at various
temperatures. The vertical positions of the intensities are
shifted at intervals of 1000.

1
Integrated intensity

48.3

10000

200

10000

Intensity (arb units)

60.3

Intensity (arb units)

15000

(a)

Intensity (arb. units)

Intensity (arb. units)

15000

0.5

0

0

50

100
150
Temperature (K)200

Fig. 4 Normalized integrated intensity versus temperature
in Na1.8Cu2Mo3O12-� for 2� = 8.3° (circle), 24.3° (square),and 40.3° (cross).

have to consider a method to subtract contribution ofphonon excitations. Besides, we should make large
single crystals of Na1.8Cu2Mo3O12-� and investigate
the magnetic excitations by neutron scattering
measurements in future studies.
References
1) M. Hase, I. Terasaki, and K. Uchinokura, Phys.
Rev. Lett. 70 (1993) 3651; M. Hase, I. Terasaki,
Y. Sasago, K. Uchinokura, and H. Obara, Phys.
Rev. Lett. 71 (1993) 4059; M. Hase, I. Terasaki,
K. Uchinokura, M. Tokunaga, N. Miura, and H.
Obara, Phys. Rev. B 48 (1993) 9616.
2) M. Hase, M. Kohno, H. Kitazawa, N. Tsujii, O.
Suzuki, K. Ozawa, G. Kido, M. Imai, and X. Hu,
Phys. Rev. B 73 (2006) 104419.

Effects of Chemical Potential on the Neutron Cross Section
T. YOKOO, K. IWASE, M. ARAI and E. AKIBA*
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801*National Institute of Advanced Industrial Science and Technology, AIST Central-5, Higashi 1-1-1,
Tsukuba, Ibaraki 305-8565

where A is an atomic mass of the scattering atoms, sf
and sb correspond to a scattering CS of free atoms
and fully bound atoms, respectively. The total CS isgenerally written as [1]H (n=0,1,2)

4

sigmaT(0)sigmaT(1)sigmaT(2)
sum

3

2

Sigma

t

where,

omitted). This fact is, of course, crucial for thediffraction experiment with light atoms. Reported
effects on these chemical binding of zircon hydride
indicates theoretically predicted oscillating CS curve[2]. In zircon hydride the isotropic harmonic
potential and a set of energy levels equally spaced
are indicated. It is also suggested that the resulting
curve will be too complicated if the potential well isanisotropic or involving possibly several types ofharmonic motions. However, we believe that a
precise elastic measurement have the possibility ofdetermining the three dimensional potential shapewith comparing a model calculation, and the specificvalue of potential well energy levels at least, without
performing any inelastic experiments.

[Unit of Sigma]

The neutron total cross section (CS) of free
atoms is known to be less than that of fully boundatoms. This is because of the energy dependence of
CS. Hydrogen, for example, shows a CS whichdrops off quite rapidly to a roughly constant value
with neutron energy. This is the change in the
scattering CS from a bound state of atoms at low
energy to a free state at energy high compared withthe binding energy of hydrogen atoms in thematerial. The ratio of these cross sections is givenby,The energy ‾h w0 is chemical binding (potential)
energy. In the case of hydrogen atoms, the ratio sb/sf
equals to 4 as shown in Fig. 1. The total CS falls
rapidly due to the recoil effects with increasing
incident neutron energy. This is drawn by a black
symbol and line in the figure, and it is the case n=0
in the equation above. In general, atoms are
chemically bound in materials with some binding
energy or harmonic potential of specific energy w0.
Therefore, CS has a sharp minimum value s=sf at thethreshold of the first potential level (n=1; blue line),and returning to the sf at the threshold of each level(n=2; green line). Thus, the sum of these processes
is expressed by red line (higher order processes are

1

0

Fig. 10

1

2

3Reduced Neutron Energy

45Calculated relative hydrogen cross section as afunction of incident neutron energy.

Utilizing relatively higher energy of pulse
neutron, energy dependence of deuterium (D) CS
was tested. The materials containing D, namely,
Ti0.45Cr0.45Mo0.1D1.8 (TCMD) and Ti0.48Cr0.32V0.2D1.8(TCVD) known as metal hydrides were used [3,4].
These are quite good for diffraction measurement
since sum of scattering amplitudes from metals is267

almost zero. Hence, it is possible to deduce thereflection contributed only by D atoms. Powder
samples were prepared of about 3-4 grams andsealed in a vanadium sample can to avoid thebackground from the sample can. CCR was used not
only for getting low temperature also for excluding
an air scattering by pumping the CCR chamber. The
neutron experiments were performed using
epithermal neutron diffractometer EXCED installedat KENS neutron facility in KEK [5,6]. From thediffraction pattern and its temperature dependence(T=24 K and 200 K), the observed peak wereconfirmed that from the sample.
In Fig. 2, the observed diffraction pattern of
TCMD at 24 K is shown. Suppose the specificenergy of this system is around 40 meV (This value
is roughly estimated from the hydrogen desorption
temperature), the peak at Q=4 Å-1 can be thecandidate to see the energy dependence of peakintensity with EXCED detector bank condition. In
order to see the energy dependence, the peak at Q=4
Å-1 was time focused by 5 PSD pixels as shown in
the inset of Fig. 2. The curve is the fitted result by
linear background and double Gaussian.

dip clearly observed at around 30 meV seems tocorrespond the specific potential energy of thesystem. In TCMD, moreover, an oscillating behavior
is also seen implying higher order energy states. But
it looks somewhat smeared and its statistics is notenough to confirm the second and higher dip energy.
In TCVD, on the other hand, energy dependence ismuch more enhanced. The �w0 goes to higher
energy than that of TCMD resulting the higher
potential energy are not covered by thisexperimental condition.

Fig. 3Fig. 2

Diffraction pattern of TCMD time-focused with full
PSD segments of EXCED detector bank. Inset:-1
The peak profile at Q=4 Å time-focused by 6
pixels.

Thus, the integrated peak intensity (II) was
obtained. Since the ratio sb/sf~2 for the case of D
from the Eq. (1), which is a half of hydrogen, still it
is observable. The II as a function of neutron energy
on TCMD and TCVD are shown in Fig. 3. The first

268

Neutron energy dependence of integrated peakintensity on TCMD (above) and TCVD (below).
Intensity minimum at 29 meV (TCMD) and 35
meV (TCVD) has been observed.

In general, harmonic potential of hydride is an
incoherent process and its energy level is order of
100 meV. Taking into account the doubled mass of
D atoms, obtained �w0 is relatively small. The
difference of �w0 between TCMD and TCVD might
be related to the difference of hydrogen desorption

energy, which is roughly expected as 30 meV for
TCMD and 40 meV for TCVD.
It is interesting to note that here an II of Bragg(elastic) reflection is analyzed with subtracting alinear background. This can also subtract incoherent
scattering contribution. Assuming it is ideallysubtracted, quite visible energy dependence of theneutron CS exists even in the elastic reflection.
References
1) S. W. Lovesey, Theory of Neutron Scatteringfrom Condensed Matter, Oxford Science
Publications.
2) W. L. Whittemore and A. W. McRevnolds, Phys.
Rev. 113 (1959) 806.
3) T. Kabutomori, H. Takeda, Y.Wakisaka, K.
Ohnishi, J. Alloys Compd. 231 (1995) 528.
4) T. Tamura, T. Kazumi, A. Kamegawa, H.
Takamura and M. Okada, J. Alloys Compd.�
356-357 (2003) 505.
5) K. Kuwahara, et al., Applied Physics A 74
(2002) S302.
6) T. Yokoo et al., Neutron News 15 (2004) 18.

269

Possibility of the Electronic Interband Transition by Epithermal Neutrons
T. YOKOO and M. ARAI
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801
Neutrons have been known as a good probe forthe study of lattice and magnetic moment because of
their interactions in-between. Thus, some ofphysical degrees of freedoms in condensed matter
have been elucidated by means of neutron scattering
technique. Neutrons, on the other hand, areinefficacious for the study of electron properties thatare also quite significant for interpreting themechanisms of physical properties. Those electronic
band structures, particularly observation of Fermi
surface and electron density is mainly done by X-ray
photoelectron spectroscopy (XPS) and angleresolved photoemission spectroscopy (ARPES) so
far [1]. It is, however, also true that spins and orbital
angular momentum of band electrons interact toneutron spins even though its interaction is weak.
This fact enables us to expect the possibility of band
electron excitations using high-energy (epithermal)
neutrons.
The neutron cross section (CS) by an electron
can be written as the sum of spin and orbital parts
assuming nonmagnetic system (spin-up and spindown bands are equivalent) in the one-electron
approximation.

d2
d dE

d2
d dE spind2
d dE orbital

The spin part of the cross section is given byd2
d dE spin

e2
mc 2

f nk

f mk Q2kf
ki n, m

(S )
Fnm
k,Q

2

k

E

E mk Q .

E nk

(s)

F denotes the spin form factor and fnk is the Fermi
occupation number. The corresponding orbital
contribution is written as,d2
d dE orbital

e2
mc 2
f nk

(o)

2

f mk Qkf1
2

k i 2 Q n, m

(O)
Fnm
k,Q

2

k

E E nk

E mk Q ,where F is the orbital form factor [2,3]. It might bestill difficult to obtain the total electronic band
structure due to its weak coupling and low flux ofneutrons particularly at epithermal region. However,270

comparing with theoretical calculation with a model
band, one can expect that the band structure and gap
energy can be determined. Thus, the challenging
attempts to measure the electronic inter bandtransition (IBT) through a neutron-electron spin
(orbital) channel was tested using epithermal
neutrons.
EXCED is the spectrometer optimized tomeasure elastic diffraction at eV order neutronenergy range [4,5]. Therefore, filter-method utilizing
Au neutron absorption was adopted to perform theenergy selection. The 60mm Au-foil was inserted
just after the sample. The scattered neutron by the
sample is observed as an elastic signal at TOF
corresponding to the Au absorption (resonance)energy (5 eV) going through the filter. The band gap
energy of ordinary semiconductors is well known as
the order of eV, which is much adequate for
EXCED spectrometer conditions. 20 20 30 mm3 Si
single crystal was used. The band gap of Si is 1.14
eV of X band [6]. Our attempt is directly observing
the electron excitation at G-X point direction with 1
eV energy transfer apart from elastic Au resonanceenergy. The (H, H, 0) plane of the crystal was set ina horizontal scattering plane, and the reflection of X
point by 5 eV neutrons is detected with scattering
angle of 1.2 degrees.
The observed Au absorption curve bypolyethylene incoherent scattering is shown in Fig. 1.
The background (empty scan) is subtracted from thedata and the intensity is normalized by the signal
without Au foils, namely I=(P-E)/{(PAu)-(EAu)},
where P corresponds to the intensity with
polyethylene without Au foils, E stands for theempty signal and the notation "Au" means the datameasured with Au foils. The clear peak at w0=5.01
eV with its width G=0.48 eV is the Au resonancepeak. In the vicinity of the peak (inelastic channel),the base line is quite flat.

RF (Au) absor pt ion cur ve

3

Fig. 2(PE-Empty)/{(PEAu)-(EmptyAu)}

Normalized Intensity [a.u.]

w 0 =5.014 eV=0.48 eV
2

1
0

2

4

6

8

10

Neutron Energy [eV]Fig. 1

The neutron absorption curve measured with
polyethylene sample. The peak at 5 eVcorresponds to the resonant energy of Au.

In Fig. 2, the measured Si (H, 0, 0) data are
depicted. The scattering of neutron energy loss
process has positive neutron energy in the figure andthe elastic energy (5 eV) is shifted to zero. The
smooth red line is a simple Lorentzian curve. The
data (blue line) is a sum of PSD pixels foraccumulating the intensity, which is the range of
0.95˚< 2q < 10.3˚ in the scattering angle. Weak (andbroad) signal from 2 eV up to 8 eV were observed.
This summation of data treatment could have theinelastic signal broad, but again the expected signal
is too weak to detect by only several pixels.

Obtained scattering spectrum of silicon Q=(H, 0,0) direction. The peak at zero energy is theelastic scattering absorbed by Au foils.

The data summation will cause the "Qambiguity". Schematic concept of this ambiguity isillustrated in Fig. 3. As indicated by blue area, someQ region will be summed up by pixel summation
shown as dQ2 in a Q space. The comparison withmodel calculation, therefore, is required to deduce
the physical properties as mentioned above. Such amodel calculation by Ref. [3] reproduces the samemanner of observed clue by this experiment. Here,as an example, the calculated results of spin andorbital (total) contribution at Q=(4, 0, 0) is shown in
Fig. 4. The abscissa is in unit of energy eV. Total
scattering is almost contributed by the orbital
scattering in this direction. Intensity (in unit of
mb/sr/eV) starts increasing at 2-3 eV, similar tosilicon data.
It is not quite sure that the result is the inelastic
channel coming from silicon IBT. Much higher
neutron intensity is desired to investigate this type ofexperiments.

Si (H00)

1

Normalized Intensity

Normalized Intensity [a.u.]

0.8

Fitted Lorentzian

0.6

Fig. 30.4

0.2

Diagram of detecting area by EXCED PSD bankin reciprocal space. Red line: line measured bysingle PSD pixel as a TOF, Blue area: areasummed up by picked pixels.

0
-2

0

2

4

6

8

10

12

14

Neutron Energy [eV]271

Fig. 4

Calculated total scattering (solid curve) intensity
for silicon with Q=(4, 0, 0). Spin (dashed curve)
and orbital (dotted curve) scattering are shown as
well, cited from Ref. [3].

References
1) A. S. Kheifets, et al., Phys. Rev. B 68 (2003)
233205.
2) J. F. Cooke and J. A. Blackman, PhysicalReview B 26 (1982) 4410.
3) T. Morgan, J. A. Blackman and J. F. Cooke,
Phys. Rev. B 33 (1986) 7154.
4) K. Kuwahara, et al., Applied Physics A 74
(2002) S302.
5) T. Yokoo et al., Neutron News 15 (2004) 18.
6) M. L. Cohen and T. K. Bergstresser, Phys. Rev.
141 (1966) 789.

272

Report on the LAM-D Activities (2003-2005)
T. J. SATO*
Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata,
Tokai, Ibaraki 319-1106, Japan*also at SORST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanAs a typical and representative result, we herereport on magnetic excitations in the ternary 4f
CeB2C2 crystallizes incompound CeB2C2.
tetragonal structure with the space group P4/mbm,
where the magnetic Ce ions form a square lattice inthe c plane. It has been reported that CeB2C2
exhibits long-range magnetic order at TN = 7.3 K
where incommensurately modulated structure withthe modulation vector qM = (0.161, 0.161, 0.100) is
stabilized [6]. The magnitude of the orderedmoment is inferred to be very small. With appliedmagnetic field of about 1 T in the a-b plane,
CeB2C2 is known to exhibit metamagnetic behavior,
recovering the magnetic moment of more than 1�B.
The small ordered moment at zero field is puzzling,
since spin fluctuations must be suppressed at thezero temperature for well-localized moments. In
this work, to elucidate the origin of the smallordered moment and associated metamagnetictransition, we have performed the neutron inelastic
scattering study using the powder samples of
Ce11B2C2.
Shown in Fig. 1 are the inelastic scattering
spectra at several temperatures from 4.7 K to 20 K.
At high temperatures (T > TN), the spectrum
consists of broad quasielastic peak centered at �� =0 meV and broad inelastic peak at �� = 8 meV.

The broadness of the peak indeed confirms thestrong interaction and/or hybridization effectbetween the Ce 4f electrons and conduction
electrons. A prominent change can be seen in the
spectrum at the lowest temperature T = 4.7 K; thesharp inelastic peak at �� = 2.5 meV manifests
instead of the broad quasielastic signal. This
clearly indicates that the strong spin fluctuations
are suppressed by the magnetic ordering, eventhough the ordered moment is small. Detailed
analysis is now under progress and will be
published in near future [5].

0.12

Ce11B2C2
LAM-D
2� = 35deg.
Ef = 4.59meV
T=20 K

0.10
S(Q, � E) (a.u.)

Activities at the LAM-D inverted-geometry
time-of-flight spectrometer during the period of
2003-2005 may be summarized as follows:
1. Dynamics of spins and atoms in quasicrystals[1,2].
2. Effect of conduction electrons on crystalline
electric filed splitting [3].
3. Microscopic dynamics of liquid metals [4].
4. Boson peaks in amorphous polymers.
5. Relation between structural change and boson
peak in oxide glasses.
6. Super ionic conductors.
7. Dynamics in forsterite glasses.
8. Magnetic excitations in novel magnetic materials
[5].

0.08

T=10 K

0.06

T=8.7 K

0.04

T=4.7 K

0.02
0.00

-5

0

5
10
� E (meV)15

20

Fig. 1: Inelastic excitations in Ce11B2C2 observed at
LAM-D.
This work has been done by T. Onimaru, I.
Nakanowatari and T. J. Sato (ISSP).
References[1] T. J. Sato, Acta Cryst. A61 (2005) 39.
[2] T. J. Sato et al., Phys. Rev. B 73 (2006) 054417.
[3] T. Matsumura et al., J. Phys. Soc. Jpn. 73(2004) 2967.
[4] Y. Kato et al., Physica B (submitted).
[5] T. Onimaru, I. Nakanowatari, and T. J. Sato (inpreparation).
[6] K. Ohoyama et al., J. Phys. Soc. Jpn. 72 (2003)
3303.

273

MAGNETISM

2003–2006

Magnetic Structure of GdGaAl
T. HAMASAKI, T. YOKOO*, M. ARAI*, K. KUWAHARA**, S. OHHARA***and I. SAKAMOTO***
Physics Department, Kyushu Sangyo University, Matsukadai, Higashi-ku, Fukuoka, 813-8503*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801**Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397***Department of Electrical and Computer Engineering, Nagoya Institute of Technology, Gokiso,
Showa-ku, Nagoya, 466-8555
GdGa2 crystallizes in the AlB2-type hexagonal
structure and orders antiferromagnetically at 23.6 K.
A second magnetic phase transition is reported at 5K
below Néel temperature [1]. Below Néel
temperature, the metamagnetic transitions areobserved. Thus GdGa2 exhibits the complex
magnetism though its magnetocrystalline anisotropy
is negligible due to the S character of Gd3+. The
powder neutron diffraction measurement on thiscompound at 2K shows that GdGa2 has anincommensurate magnetic structure with apropagation vector (0.39, 0.39, 0) and the magnetic
moments are in the (1-10) plane [2]. The neutron
diffraction experiment on the single crystal GdGa2clarifies the existence of the spin reorientation at 4.6
K [3].
GdGaAl also crystallizes in the AlB2-type
hexagonal structure but the ratio c/a of the lattice
parameters is 0.83 which is smaller than 0.98 of
GdGa2 [4]. GdGaAl orders antifferomagnetically at
49.3 K. There is no magnetic transition below Néel
temperature. The magnetic structure of GdGaAl isquite different from that of GdGa2. There is noreport on the magnetic structure of GdGaAl. Then
we have a plan to determine the magnetic structureof GdGaAl by the neutron diffraction experiment. It
will give rise to a well understanding of the complex
magnetism of GdGa2.
Single crystal was grown by the Czochralski
method using a tri-arc furnace from 99.99% Gd(natural abundance), 99.9999% Ga and 99.999% Al
and cut in the orientation of [110]-[1-10]-[001](corresponding dimensions 2×3×1 mm3). The
neutron diffraction was measured by use of theepithermal neutron diffractometer (EXCED)
installed at KENS neutron facility, High Energy
Accelerator Research Organization, in Tsukuba. The
single crystal was installed in a cryostat andmounted on the goniometer. At first the crystal wasaligned with the [110] axis vertical and [1-10] axis
parallel to the incident beam.
In this situation, we could observe the magneticreflection by the upper detector. In order todetermine the accurate index of this reflection, we
observed this reflection with the goniometer tilted.
Finally the observed magnetic reflection was
indexed as (-1/3, 2/3, 3/2). In order to confirm thesymmetry of this index, we observed several
magnetic reflections while rotating the crystal. All
observed reflections are shown in Figure 1. In theregion of this crystal rotation, another magneticreflection was not observed.
������
2 1 1��� � 1 , ,1 �
3 3 2�
�

1 2 1��� � 1 , ,1 �
3 3 2�
�

1 2 1�
�
��1 , , �
3 3 2�
�������
� 2 1 1��� , , �� 3 3 2�

� 2 1 1�� � , ,1 �
� 3 3 2�

� 1 2 1�� � , ,1 �
� 3 3 2�

�����

�����
�2 2 1�� , , �
�3 3 2�c*�2 2 1�� , ,1 �
�3 3 2�

a*Fig. 1

Observed magnetic reflections projected on
the a*-c* plane.

Especially, in order to confirm a sixfold
symmetry on the c axis, we scanned the reflections
carefully with the index of L=1.5. As shown in Fig.
2, we observed the reflections at the expected
positions. Although we did not have enough time toscan the whole reciprocal space, because of the highneutron absorption of Gd, we believe the277

propagation vector in GdGaAl is only (1/3, 1/3, 1/2).
This propagation vector is commensurate andtriangular and is the same as one of two propagation
vectors in the low temperature phase of HoAlGa [5].
The similar propagation vectors of the type of (1/3,
1/3, �) are reported in TbGa2 (�=0.189) [6] andErGaAl (�=0.472) [7], which are incommensurate.

� 1 2 1�� � 1 , ,1 �
� 3 3 2�

� 1 2 1�� � , ,1 �
� 3 3 2�
� 2 1 1�� � , ,1 �
� 3 3 2�

�2 2 1�� , ,1 �� 3 3 2�a*������������������

���
���
���
���

�

����������������������������

b*

�
���

���
���
���

�������
���
���
�

��

��

��

��

��

��

���������������

Figure 3 shows the temperature dependence of
the intensity of (-1/3, 2/3, 3/2) magnetic reflection.
Figure 4 shows the temperature dependence of (101)reflection, which is observed with (-1/3, 2/3, 3/2)
magnetic reflection simultaneously. There is notemperature dependence of the intensities of (101)reflection above Néel temperature and below Néel
temperature. Therefore, it is concluded there is no
ferromagnetic component in GdGaAl.
As the conclusion, we have observed themagnetic reflection in GdGaAl single crystal andobtained the propagation vector (1/3, 1/3, 1/2). In
account of the results of the magnetic susceptibility
measurements, it is concluded that the magnetic
moments lie in the c plane and have the cycloidal
structure. The calculations of the exchangeinteraction energies of the various magnetic
configurations of GdGaAl in the RKKY modelshows that the obtained configuration is most stable.
But, by the same calculation on GdGa2 it is
impossible to explain the stability of the observed
magnetic configuration. GdGa2 has a very complex
magnetic structure, in comparison with the simple
magnetic structure of GdGaAl. In order tounderstand the magnetic structures of thesecompounds, the theoretical calculation of the band
structures is desired.

278

Fig. 3Temperature dependence of the intensity of(-2/3, 1/3, 1/2) magnetic reflection.
����������

���

���

���

���

�

Observed magnetic reflections in the a*-b*
plane with the index L=1.5.

����������������������������

Fig. 2

���

���

���

���
�

��

��

��

��

��

��

���������������

Fig. 4Temperature dependence of the intensity of(101) reflection.

References
1) S. Ohara, I. Sakamoto, Y. Aoki, H. Sato, I.
Oguro, T. Sasaki, G. Kido and S. Maruno,
Physica B 223&224 (1996) 379.
2) J.
M.
Barandiaran,D.
Gignoux,J.
Rodriguez-Fernandez and D. Schmitt, Physica B
154 (1989) 293.
3) T. Hamasaki, T. Yokoo, M. Arai, S. Ohara, I.
Sakamoto, J. Magn. Magn. Mater. 272-276(2004) e465.
4) F. M. Mulder, R. C. Thiel, K. H. J. Buschow, J.
Alloys Compounds 203 (1994) 97.
5) D. Gignoux, D. Schmitt, A. Takeuchi, F. Y.
Zhang, J. Magn. Magn. Mater. 98 (1991) 333.
6) J. A. Branco, D. Gignoux, J. C. Gomez Sal, J.
Rodriguez-Fernandez and D. Schmitt, Physica B
175 (1991) 349.
7) O. E. Martin, K. Girgis, P. Fischer, J. Magn.
Magn. Mater. 37 (1983) 231.

279

Neutron Diffraction Studies on TbNiSn
Y. ANDOH, K. MUROGAKIa, S. KAWANOb, M. TAKAHASHIc, M. KURISUd, G. NAKAMOTOd
and T. TSUTAOKAe
Faculty of Regional Sciences, Tottori University, Tottori 680-8551, Japana
Graduate School of Science, Kyoto University, Kyoto 606-8502, Japanb
Research Reactor Institute, Kyoto University, Osaka 590-0494, Japanc
Institute of Materials Science, University of Tsukuba, Ibaraki 305-8573, Japand
Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japane
Graduate School of Education, Hiroshima University, Hiroshima 739-8524, Japan
TbNiSn crystallizes in the orthorhombic TiNiSi
type. Its magnetic properties are characterized by thefour successive magnetic transitions and multi-step
metamagnetic transitions along the b-axis: TN = 18.5
K, T3 = 7.6 K, T2 = 6.0 K, and T1 = 2.2 K; four
critical fields of 6.5, 20, 43 and 53 kOe at 1.5 K[1,2]. Neutron diffraction study has revealed that themagnetic structure is of a square-wave with Q =(0.600, 0.345, 0) for T < T2 (phase II), Q = (0.665,
0.330, 0) for T2 < T < T3 (phase III) and of asine-modulated type with Q = (0.685, 0.330, 0) forT3 < T < TN (phase IV) [3]. In the present note, wereport more detailed results of neutron diffraction
studies of not only zero-field structure but also
field-induced structure of a TbNiSn single crystal
and propose possible magnetic structures for theobserved phases in which the antiferromagnetic
modulations are mostly incommensurate.
The single crystal of TbNiSn was grown by the
Czochralski method using a penta-arc furnace. The
pulsed-neutron diffraction measurements were
performed in the a*–b* and a*–c* reciprocal planes
for the field-induced phases at low temperaturesusing the KENS-FOX diffractometer in Tsukuba,
Japan. The magnetic field was applied along theb-axis of the easy magnetization direction for the
a*–c* plane.
Figure 1 shows the pulsed-neutron diffraction
patterns in the a*–b* reciprocal plane at 3, 6.5 and12 K. At 3 K, first order magnetic reflections andthird order ones appear at (3.39 1.67 0) and (2.17
0.95 0) on the dotted line, respectively. Furthermore,
the fifth order magnetic reflection is found at (1 0.25
0). Therefore, a square-wave magnetic structure at 3
K is proposed with the magnetic wave vector Q =(0.61, 0.35, 0). At 6.5 K, third reflections overlap at(210) nuclear reflection and the fifth reflection is not
visible. It is concluded that the wave vector changes
to (2/3, 1/3, ~0) at T2 . At 12 K, the third reflection is
not observed.

280

Fig.1 Pulsed-neutron diffraction of TbNiSn in
the a*–b* plane at T = 3, 6.5 and 12 K.
Figure 2 shows the pulsed-neutron diffraction
patterns in the a*–c* reciprocal plane at T = 5, 6.5
and 12 K, respectively. At 5 K, the weak magneticreflections are found at Q = (h�q1 0 l) with q1 =0.2a* for h + l = odd, but there is no magneticreflection on the a*-axis. These weak satellites
observed in the a*–c* plane are considered to be thethird satellites from the main magnetic reflections in
the a*–b* plane, for instance, (1.8 0 1) appears as athird harmonic of the main reflection with magnetic
wave vector Q = (0.60, 0.33, 0). Considering that themagnetic satellites in the a*–c* plane come from themain reflections in the a*–b* plane, one can explainthat there is no magnetic reflection on the a*-axis in
the a*–c* plane, although the easy axis ofmagnetization is the b-axis. At 6.5 K ( > T2), thereflection is not found around (302). There is nodifference in the pattern between 6.5 and 12 K.

Fig.2 Pulsed-neutron diffraction of TbNiSn in the
a*–c* plane at T = 5, 6.5 and 12 K.
Figure 3 shows the distribution of pulsed-neutron
intensities under magnetic field up to H = 5 Tesla
along the b-axis in the a*–c* reciprocal plane at T =1.6 K. The third magnetic reflection is not observed
and the nuclear one at (h 0 l) (h + l = even) is
increased at H = 1 Tesla. Under H = 2 Tesla, newmagnetic reflections with Q = (0.7, 0, 0) are
observed at (0.7 0 2) and (1.3 0 2). With further
increasing field, the intensity of these magneticreflections is increased. The wave vector is given by
Q = (2/3, 0, 0) at 5 Tesla.
In summary, we have demonstrated the existenceof higher order magnetic scatterings in thispulsed-neutron experiment. Furthermore, thefield-induced magnetic transitions are observed,
which is in consistent with the observation in theprevious reactor-based neutron measurements [3].

Fig.4 Pulsed-neutron diffraction of TbNiSn undermagnetic field in the a*–c* plane at T = 1.6 K.
References[1] M.Kurisu et al., Physica B, 201, 107 (1994).
[2] M.Furusawa et al., J.Magn.Magn.Mater.,
140-144, 877 (1995).
[3] Y.Andoh et al., Physica B, 237-278, 575 (1997).

281

Study of Magnetic Structure on the Tb2Ni3Si5 Single Crystal
Y. HASHIMOTO, K. MUROGAKI*, S. KAWANO*, M. TAKAHASHI**
Department of Physics, Fukuoka Univ. of Education, Fukuoka, Munakata, 811-4192*Research Reactor Institute, Kyoto University, Kumatori, Osaka, 590-0494** nstitute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573
It is known that Tb2Ni3Si5 compound takes theU2Si3Ni5 type structure. In our previous studies on
the Tb2Ni3Si5 single crystal showed that the single
crystal takes modulated structure containing two
orthorhombic lattices, the U2Si3Ni5 type and the
CeNiSi2 type1). Both structures are known asderivative structures of the BaAl4-type structure2).
These contain so-called BaAl4 slabs. In this single
crystal the two lattices unite with each other, as thea-axis of the U2Si3Ni5 type lattice coincides to theb-axis of the CeNiSi2 in direction. Neutron
diffraction studies on the single crystal indicatedmagnetic Bragg reflections observed for each twolattices. Spin configuration of each lattice wasdescribed by multi-wave vectors and showedtemperature dependences corresponding to magnetic
phase transitions.
The modulated lattice of the single crystal istransformed to the U2Si3Ni5 type homogeneous
single phase by annealing operation. The homogeneous single crystal is prepared by annealing thesingle crystal that is grown by pull-up method.
X-ray investigation on powder sample, which is
produced from the annealed single crystal, showed
U2Si3Ni5 type single phase. Magnetic properties ofthe single crystal are alternated distinctly by thisannealing operation. Magnetism of the modulated
Tb2Ni3Si5 single crystal showed Néel temperature at
34.2 K and two antiferromagnetic transition
temperatures at 8.3 K and 3.8 K. These magnetic
characteristics are changed to an antiferromagetismof TN = 13.8 K by annealing. Also metamagnetic
characteristics and anisotropic behavior inmagnetization process become to be clearly.
The difference of magnetic character between
modulated and homogeneous Tb2Ni3Si5 single
crystal is considered mainly to the change ofsurrounding condition of the Ni atom. Studying themagnetic characteristic of homogeneous Tb2Ni3Si5
single crystal is available to consider the effects ofenvironmental effects of the Ni atom.
We have performed pulsed-neutron diffraction
investigation on the homogeneous single crystal byusing four-circle neutron diffractometer of a single
282

crystal (FOX) installed at High Energy Accelerator
Research Organization (KENS) at Tsukuba.
Measurements were made for the reciprocal b*-c*plane at below and above the Néel temperature. The
neutron diffraction pattern at paramagnetic range
represented nuclear scattering respecting in an
orthorhombic system representing the U 2Si3Ni5 typestructure. Other nuclear peaks corresponding to the
TbNiSi2 lattice did not appear. Observed magneticreflections of the U2Si3Ni5 type lattice in themodulated Tb2Ni3Si5 single crystal were explainedby multi-propagation vectors, as (0, 0, 0.5), (0.5, 0,0.283), (0.25, 0, 0.5) and (0, 0, 0.25). We could notobserve magnetic Bragg reflections that correspondto these propagation vectors. In this experiment, weobserved magnetic components on the nuclear peaks
respecting in an orthorhombic U2Si3Ni5 typestructure. And also magnetic reflections wereobserved (0, k, l) (k+l = odd, l = 2n). Former
reflections indicate that the magnetic spin
configuration has magnetic component in the aplane. And the latter peaks suggest that spin
configuration in an a-plane has an antiferromagnetic
combination with the neighboring plane each other.
The latter magnetic reflections do not coincide withthose observed in the modulated single crystal. We
could not get more magnetic reflections in thisexperiment. The used homogeneous single crystal
showed a clear powder X-ray diffraction pattern of
the U2Si3Ni5 type structure, though the diffraction
pattern of the single crystal influenced by some twin
structure a little. It made it difficult to investigate
weak magnetic reflections moreover. Neutron
diffraction studies for the other reciprocal lattices onmore homogenized single crystal are necessary toconfirm the spin structure.
References
1) Y. Hashimoto, S. Kawano and T. Kosugi, J. Phys.
Soc. Jpn. 70 (2001) Suppl. A 215-217
2) E. Parthe, B Chabot, H. F. Brun and N.Engel,
Acta Cryst. B39 (1983) 588-595

Magnetic Ordering of Triangular Lattice Diluted Antiferromagnet CuFe1-xAlxO2
K. KITAGAWA, S. MITSUDA and M. TAKAHASHI*
Department of Physics, Faculty of Science, Tokyo University of Science, Tokyo 162-8601*National Laboratory for High Energy Physics, 1-1 Oho, Tsukuba-shi, Ibaraki 305
As one of model materials of triangular lattice
antiferromagnet, magnetic oxide CuFeO2 has been
extensively investigated to study geometrical spin
frustration effects on magnetic phase transition [1].
With a small amount of substitution, various
magnetically ordered phases compete with eachother on x-T magnetic phase diagram of CuFe1xAlxO2 up to x~0.05 reflecting partial release offrustration [2], and the only oblique-partiallydisordered (OPD) phase shows up as themagnetically long-range ordered phase in x=0.05
sample. With further dilution, the ZFC and FC
magnetic susceptibility exhibit spin-glass (SG)-likebehavior at low temperature, suggesting reentrant
SG state characterized by co-existence of long-range
magnetic Bragg scattering and short-range magnetic
diffuse scattering. In present experiments, we havestudied magnetic ordering of CuFe1-xAlxO2 with
x=0.2 using KENS-FOX (four circle neutron
diffractometer for single crystal).
Fig.1 (b) shows the high-temperature(50K)-datasubtracted diffraction patterns at T=3K of x=0.2
sample in (h h l) zone, where magnetic Braggreflections with magnetic propagation wave number
q~0.183 can be seen at (h h l) ± (q q 0) with l=±n/2(n=3, 9, 15, 21, …) while magnetic diffuse
scattering widely distributed in reciprocal lattice
space was not found within experimental accuracy.
This suggests that OPD magnetic ordering is still
survived for further dilution and that typicalreentrant SG state, namely co-existence of longrange magnetic Bragg scattering and short-range
magnetic diffuse scattering, is not realized in thissystem where geometrical spin frustration initiallyexists and randomness is introduced with
substitution.
To investigate the origin of the SG-like behavior,
we performed additional profile analysis ofmagnetic Bragg scattering using triple-axis
spectrometer HQR at JRR-3M, and found thatmagnetic Bragg scattering function is not delta
function but squared-Lorentzian with anisotropic
width dominating at low temperature. This indicatesthat the domain state in the prototypical randomfield Ising model is realized even in zero-external

magnetic field as zero-field random-field effect has
been reported in the critical scattering study on
CsCo0.83 Mg0.17 Br3 [3]. We would like to emphasizethat simultaneous measurement over wide reciprocallattice space using FOX is effective for search ofdiffusive scattering, whereas triple axis spectrometeris complementary in line-shape measurement formagnetic scattering function close to Bragg delta
function but with finite width.

Fig.1 Diffraction pattern of x=0.2 sample in (HHL) zone at
T=3K.

References
1) S. Mitsuda, M. Mase, K. Prokes, H. Kitazawa
and H. Aruga Katori: J. Phys. Soc. Jpn.69 (2000)
3513.
2) N. Terada, S. Mitsuda, T. Fujii, K. Soejima, I.
Doi, H. A. Katori and Y. Noda:J. Phys. Soc. Jpn.
74 (2005)2604.
3) J. van Duijn, B. D. Gaulin, M. A. Lumsden, J. P.
Castellan and W. J. L. Buyers:Phys. Rev. Lett 92(2004)077202.

283

Elastic Neutron Scattering Experiments for
Bi2Sr 2-xYxCa(Cu,Zn) 2O z (x=0.3) Single Crystals
M. UEHARA, H. INOUE, K. FUJITA and T. YOKOO*
Department of Physics, Faculty of Engineering, Yokohama National University,
Hodogaya-ku Yokohama 240-8501*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization

284

The analysis of actual Zn content was very difficult,owing to small amount of remnant Zn ion in thesample. Typical size of crystals is 3 x 7 x 0.2 mm3for a, b and c axes, respectively and 10
crystallographyically aligned crystals are used forthe experiments. EXCED spectrometer was used forthe measurements. Crystals were mounted so thatscattering plane would be (h, h, l) plane. The (h, h,0) Bragg diffraction peaks were observed by
PSD#40 with segments 110 and 111 (average
scattering angle 2_=79°). The diffraction peaks
coming form the static stripes are expected to appear
at (h/2± , h/2, l) or (h/2, h/2± , l) ( ~ 0.125).
Utilizing the arrangement of PSD detector, which
cover -5°< 2_ver <10° for vertical direction from thescattering plane, the diffractions around (h/2, h/2, 0)in (h, k, 0) plane were investigated. Scattering vector
Q is chosen as indicated in fig.1. Measurements
were done at 200 and 9 K.

PSD33

3

PSD37
PSD40
PSD42

k (r. l. u)

Static charge stripe in CuO2 plane has been
observed in La1.48Nd0.4Sr0.12CuO4 (LNSCO) and La2(LBCO) [1,2]. Static charge stripe
xBaxCuO4
strongly suppresses the suprconductivity and thishad been an enigma known as 1/8-carrier
concentration problem until the exsistence of static
stripe was unveiled. Static charge stripe turns into be
dynamical when the pinning potential by a particular
crystal sturucture is removed.
Antiferromagnetic spin fluctuations possibly
associated with dynamical stripe are widely believedto play a key role in the mechanism of high-Tc
superconductivity. Indeed, extensive neutron
scattering measurements on La2-xSrxCuO4 and
YBa2Cu3Oy have revealed the close relation between
superconductivity and characteristic features in thespin fluctuations [3,4].
However, it is not clear that charge stripe is acommon phenomenon in high-Tc cuprate because
clear static charge stripe has been observed only in
LNSCO and LBCO. Therefore, investigation of
charge stripe in the system beyond LNSCO andLBCO is now quite significant for the clarificationof the common origin of superconducting
mechanism.
In Bi2Sr2-xYxCaCu2-yZnyOz (x~0.3, y=0.05) system,
there have been reports that the existence of static
stripe or its precursor is suggested by resistivity and SR measurements [5,6]. According to the reports,
Zn impurity works as the pinning center for
dynamical stripe and the pinning of stripe is themost stabilized at the sample that the Cu formal
valence is tuned to be ~2.125 by Y-substitution forCa.
In order to clarify if the charge stripe in Bi2Sr2Y
CaCu
x x
2-yZnyOz really exists or not, we have
performed the elastic neutron scattering experiments
for Bi2Sr2-xYxCa(Cu,Zn)2Oz (x=0.3) single crystal
with Tc of ~20 K.
Single crystals are grown by traveling solvent
floating zone method. Due to high volatility of Zn,
extra ZnO powder was added for crystal growth andthe nominal composition of Cu and Zn is Cu1.95Zn0.5.

2
PSD48

1

0

0

1

2
h (r. l. u.)

3

Fig. 1 Schematic picture of (h, k, 0) plane in reciprocal
space. Scattering vector Q is chosen on the solid lines in(h, k , 0) plane. It is also shown what PSD is used for dataacquisition of each Q -directions. Black circles are
expected super-lattice spots from static stripes.

In fig.2, summed scattering intensities taken by
segments 110 and 111 as a function of Q at various
directions in (h, k, 0) plane around (3/2, 3/2, 0) are
shown for 200 and 9 K measurements. Each dataassigned with used PSD number corresponds to a Qdirection indicated in fig. 1. As can be recognized byreferring to fig. 1, these scans cover the expectedsuper-lattice positions. In the figure, the expectedsuper-lattice positions of Q=3.32 and 3.61 Å -1 are
indicated with broken vertical lines. As seen in the
figure, no clear extra diffractions at (3/2± , 3/2, 0)
and (3/2, 3/2± , 0) ( ~0.125), and no systematic
temperature-dependent
intensitychanges areobserved. The peaks around 3.5 Å-1 are the known
background of EXCED spectrometer.

Intensity (a.u.)

PSD#379K
200 K

ion due to its tiny amount in the sample (~ a few %of Cu ion). Therefore, there may be chemical
inhomogeneity especially for Zn ion. The
improvement of the sample is the most crucial
subject and now in progress.
References
1) J. M. Tranquada et al., Nature 375 (1995) 561.
2) M. Fujita et al., Phys. Rev. Lett. 88 (2002) 16700.
3) M. Yamada et al., Phys. Rev. B 57 (1998) 6165.
4) J. Rossat-Mignod et al., Physica B 169 (1991) 58.
5) M. Akoshima et al., Phys. Rev. B 57 (1998) 7491.
6) I. Watanabe et al., Phys. Rev. B 60 (1999) 9955.

PSD#38

PSD#39

PSD#40

PSD#41

PSD#42

3.3 3.4 3.5 3.6 3.7 3.3 3.4 3.5 3.6 3.7
Q ( -1 )Fig. 2 Neutron scattering intensities as a function of Q atvarious directions in (h, k , 0) plane at 9 and 200 K. The
data are collected by PSD#37-42 with segments 110 and
111. The intensities are calculated by summing the data of
two segments. Broken lines at Q =3.32 and 3.61 Å -1 showsthe expected super-lattice positions.

From this experiments, the static charge stripe
has not been detected for Bi2Sr2-xYxCa(Cu,Zn)2Oz(x=0.3). At present stage, the result is not definite
because the sample volume seems to be insufficientfor this kind of experiment and the sample quality
has not been perfectly guaranteed. Actual chemicalcomposition and homogeneity were checked byenergy dispersive x-ray analysis (EDX). It wasdifficult to know the content and homogeneity of Zn

285

Magnetic Structure of a Chiral Molecule-based Magnet, [Cr(CN)6][Mn(S)- pnH(H2O)](H2O)
A. HOSHIKAWA1, T. KAMIYAMA2, A. PURWANTO3, K. OHISHI1, W. HIGEMOTO1, T.
ISHIGAKI1, H. IMAI4, K. INOUE5
1

Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba,
305-0801, Japan3
R & D Center for Materials Science and Technology, National Nuclear Energy Agency, Serpong,
Tangerang 15314, Indonesia
4
Department of Applied Molecular Science Institute for Molecular Science, Okazaki 444-8585, Japan
5
Faculty of Science, Hiroshima University, Higashihiroshima 739-8526, Japan2

The magneto-chiral dichroism (MChD) effect has
been theoretically predicted in optically active
magnetic materials [1]. Rikken and Raupachsuccessfully observed a small MChD effect in achiralparamagnetic
material[2].
Since
molecule-based magnets offer advantages indesigning molecular building blocks and controlling
structural dimensionality as well as opticaltransparency, it is highly likely that molecule-basedmagnets with MChD will be designed. Using thisstrategy, several chiral magnets were newly
synthesized as optically active magnetic materials[3]. One of them is a two-dimensional (2D) chiralmagnet of a green needle-shaped crystal,((S)-pn=[Cr(CN)6][Mn(S)-pnH(H2O)](H2O)(S)-1,2-diaminopropane). Inoue et al. reported on
the crystal structure (Fig. 1) and physical propertiesof this crystal; it was orthorhombic (space group
P212121) with lattice constants of a = 7.6280, b =14.510 and c = 14.935 Å at room temperature, andthe critical temperature Tc = 38 K with the saturation
magnetization of 2µB, which is in consistent with thetheoretical value of antiferromagnetic coupling
between Cr3+ (S = 3/2) and Mn2+ (S = 5/2) ions [3].
Magnetic circular dichroism (MCD) spectra were
measured, and MCD is enhanced at around Tc. Since
the magnetic structure has not been obvious yet, wehave carried out neutron powder diffraction (NPD)
using samples of [Cr(CN)6][Mn(S)-pnH(H2O)](H2O),
and have analyzed the magnetic structure of thismaterial.
NPD data were measured between 4 K and 300 K
on a time-of-flight (TOF) neutron diffractometer,
Vega [4], at the pulsed spallation neutron facility
KENS. In order to collect high quality data for themagnetic reflections, a thin plate-like specimen
holder was chosen so that neutron attenuation due tothe incoherent scattering from protons was reduced
at the detectors of the low angle bank.
As shown in Fig. 2, anisotropic temperaturedependence of the unit-cell parameters wasobserved; with increasing the temperature above 50
K, b decreases and c increases where as a varies
negligibly up to 300 K. Below 50 K, a decreases
slightly while both b and c vary negligibly. Crystal
structural study in a wide temperature range is
�����

a
b
c

����

�����

�����
�����

a/Å

c/Å

b/Å

����

�����
�����

����

Fig.1
Crystalstructureof[Cr(CN)6][Mn(S)-pnH(H2O)](H2O). Magnetic atoms
Cr and Mn are marked with Arabic and Roman
numerals, respectively.

286

�����
�����
����
��

���

���

T/K

���

���

���

Fig.2 Temperature dependence of unit-cell parameters.

c
Cr

Mn

Cr

C3
C2
C1

6.0

d/Å

6.5

7.0

7.5

100

5.5

002
020

5.0

101
110
012
021

I020/I002

Mn

111

Normalized intensity / arb. unit

C3

b
Cr

102
120
022

����

C2
Mn

4.5

����

a

112
121

��������

C1

013
031

����

Cr and Mn magnetic moments. Three directions foreach of the Cr and Mn spins, parallel to the a-, band c-axes, can be chosen for each of the Shubnikov
groups. Accordingly, there are 24 possible models
for the magnetic structure. The 24 diffraction
patterns were simulated, and they were comparedwith the difference pattern in Fig. 3. A number ofthe simulated patterns based on the magnetic spacegroup P2121’21’ are shown in Fig. 4, where thecorresponding collinear spin directions areillustrated. The simulated pattern C1 in Fig. 4 agrees
well with the difference pattern in Fig. 3, whereas
other models do not reproduce the pattern. Although
the statistics in the difference pattern in Fig. 3 isrelatively poor because of the high background fromthe incoherent scattering of protons, it is safely
concluded that theC1 model with the collinear
antiparallel alignments of the Cr and Mn spins along
the a-axis with P2121’21’ is most probable. It is notedthat the spin direction is along neither the b- nor
c-axis.

Normalized Intensity / arb. unit

indispensable for clarifying the origin of theanisotropic behavior of the unit-cell parameters.
Parts of diffraction patterns collected at 50 K (aboveTc) and 4 K (below Tc) and their difference pattern
are shown in Fig. 3. All peaks in the difference
pattern are ascribed to the magnetic Braggreflections. Since the positions of those reflections
agree with those of the chemical indices and nosatellite peak is observed, it is most likely that themagnetic structure is commensurate within theexperimental error. The strongest magnetic 020
reflection is located at d = 7.3 Å in the difference
pattern. As shown in the inset of Fig. 3, its intensity
ratio to the 002 nuclear Bragg reflection, I020/I002,
decreases with increasing temperature in accordancewith the magnetization measurement. A similar
temperature dependence is observed in othermagnetic reflections.
The magnetic structure was determined bycomparing the observed magnetic intensities withthe simulated intensities using a Rietveld refinement
program, GSAS [5]. The effective magnetic
moments used for the simulation were 3.84µB (Cr3+)
and 5.88µB (Mn2+: high spin state) [6]. Owing to themagnetic symmetry requirement imposed by the
space group P212121, four possible magnetic spacegroups (Shubnikov groups), P212121, P21’21’21,
P21’2121’ andP2121’21’ were examined.
We first consider the collinear structure models
with a parallel or antiparallel alignment between the

8.0

����

Fig.4
Simulated
NPD
patternsof[Cr(CN)6][Mn(S)-pnH(H2O)](H2O)
withthe
Shubnikov group P2121'21'. Three collinear models
and corresponding NPD patterns are shown: C1, C2and C3.

����
����
��

��

4K

��

T/K

��

��

50 K
4 K - 50 K difference curve

���

���

002
020

���

101
110
012
021

���

111

���

102
120
022

112
121

013
031

���

���

d /Å

Fig.3 Neutron diffraction patterns at 4 K (below
Tc) and 50 K (above Tc), and their difference
pattern of [Cr(CN)6][Mn(S)-pnH(H2O)](H2O).
The difference pattern shows the magnetic
contribution only. Intensities are normalized by
the incident spectrum. The inset shows thetemperature dependence of the intensity ratio of
the 020 magnetic Bragg reflection to the 002
nuclear Bragg one, I020/I002.

Subsequently, we examine the noncollinear
magnetic structure models based on the Shubnikov
group P2121’21’. The new models were deduced fromthe collinear model C1 by tilting Cr and Mn spins
along the b- or c-axis. Figure 5 shows several
noncollinear models, N1–N4, and the corresponding
diffraction patterns simulated by GSAS. In the
figure, the tilting directions are along the b-axis in
N1 and N2 and along the c-axis in N3 and N4. The
angles between Cr and Mn spins are smaller than
180 degrees in N1 and N3, while they are 180
degrees in N2 and N4. Each model agrees with C1
when the tilting angle is zero. The diffraction

287

C1

N1
Mn

Mn

a

a

Mn

Mn

b

b

c

Cr

Cr

002
020

Cr

Mn

c

101
110
012
021

Cr

N4

N3

a

a

a

Normalized Intensity / arb. unit

N2

Cr

N4
N3
N2
N1
C1

6.0

d/Å

6.5

7.0

7.5

100

5.5

111

5.0

102
120
022

112
121

013
031

4.5

8.0

Fig.6
Simulated
NPD
patternsof[Cr(CN)6][Mn(S)-pnH(H2O)](H2O)
withthe
Shubnikov group P2121'21'. A collinear case (C1)and four noncollinear cases (N1, N2, N3 and N4)
are shown. The C1 pattern is the same as that inFig. 5. The NPD patterns are calculated for thetilting angles fixed at 20 degrees.

patterns in Fig. 5 are calculated for N1–N4 when thetilting angles are fixed at 20 degrees.
In both the N1 and N2 models, the intensity of the111 Bragg reflection was found to become stronger
as the tilting angle became larger. At the tilting
angle became larger than 20 degrees, the simulated
intensity no longer agreed with the difference
pattern in Fig.3 despite its large statistical errors. In
the N3 model, the 120 Bragg reflection becomesstronger as the tilting angle along the c-axis
becomes larger. In the N4 model, the 100 and 021
Bragg reflections were found to become stronger as
the tilting along the c-axis became larger. Both theN3 and N4 models can reproduce the difference
pattern in Fig. 3 as long as the tilting angle is nolarger than 20 degrees.
On the basis of the above consideration, it isconcluded that the magnetic moments point in the
direction of the a-axis within 20 degrees. Thismeans that the magnetic structure might be collinearwith the magnetic moments along the a-axis, or it
might be noncollinear and conical with the magnetic
moments nearly along the a-axis and the apex of thecone being less than 20 degrees. The model of thenoncollinear magnetic structure with a helicalalignment of spins was excluded from our results.
In the conical alignment of spins, a long-period
magnetic structure is anticipated. However, nomagnetic satellite reflection expected from such along-period magnetic structure was observed in thepresent work. This finding is ascribable to the weakintensities of the satellite reflections compared withlarge statistical errors in the diffraction data. Or if
288

the period of the magnetic structure is large, thesatellite peak position is so close to the fundamental
one that the satellite reflection may be hindered by
the fundamental one. In order to determine themagnetic structure in detail, diffraction studies using
a single crystal are urgently required. In this work,themagnetic
structureof[Cr(CN)6][Mn(S)-pnH(H2O)](H2O) was studied by
NPD. The magnetic moments of Cr (III) and Mn (II)are found to be nearly antiparallel to each other, andboth the spins are likely to point in the direction of
the a-axis, within 20 degrees. The magnetic structureis either collinear with spins aligned nearly along thea-axis, or conical with spins directed nearly along
the a-axis and the apex of the cone being less than20
degrees. The helical alignment model of magnetic
moments is excluded.
References
1) G.Wagniere and A. Mejer: Chem. Phys. Lett. 110(1984) 546.
2) G.L.J.A. Rikken and E. Raupach, Nature 390(1997) 493.
3) K. Inoue, K. Kikuchi, M. Ohba and H. ¯Okawa:Angew. Chem. Int. Ed. 42 (2003) 4810.
4) T. Kamiyama, K. Oikawa, N. Tsuchiya, M.
Osawa, H. Asano, N.Watanabe, M. Furusaka, S.
Satoh, I. Fujikawa, T. Ishigaki and F. Izumi: Physica
B 213&214 (1995) 875.
5) A.C. Larson and R.B. von Dreele, GSAS: General
Structure Analysis System, Report LAUR 86-748,
Los Alamos Laboratory, Los Alamos, NM, USA,1986.
6) B.N. Figgis and J. Lewis: Progress in Inorganic
Chemistry (Interscience Publishers, New York,1964), Vol. 6.

Electric Polarization Dependent Change of the Magnetic Structure in Eu0.595Y0.405MnO3
R. KAJIMOTO, T. YOKOO*, M. KOFU*, K. NODA** and H. KUWAHARA**
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki 305-0801**Department of Physics, Sophia University, Chiyoda-ku, Tokyo 102-8554
Distorted cubic perovskite RMnO3 with R = La,
Pr, Nd are famous as mother compounds ofmaterials that show the colossal magnetoresistancewhen holes are doped on Mn sites. In thesecompounds, magnetic moments of Mn3+ ions show alayered (A-type) antiferromagnetic structure at a lowtemperature. On the other hand, when R has asmaller ionic radius, such as Gd, Tb, and Dy, thespin ordering becomes sinusoidally and spirally
modulated structures with a wave vector (0,qs,1) inthe orthorhombic (Pbnm) cell [1–3]. Recently, thesesmall R manganites are attracting much attention,
because spontaneous ferroelectric polarization andlarge magnetoelectric effect have been found [4].
For example, TbMnO3 shows a sinusoidally
modulated spin structure below TN = 42 K, and themagnetic structure becomes an elliptically distorted
spiral structure below TC = 28 K [2]. The
spontaneous ferroelectric polarization is observed
below TC, and the direction of the polarization canbe switched by applying a magnetic field. Recent
theories claimed that the spontaneous ferroelectric
polarization is induced by the spin supercurrent or
the inverse Dzyaloshinsky-Moriya (DM) interaction[5–7]. This suggests that the direction of thepolarization is determined by the spin structure andvice versa. Therefore, clarifying the relation
between the ferroelectric polarization and the spin
structure is important to understand themagnetoelectric effect in RMnO3. Accordingly, we
performed a neutron diffraction study on
Eu0.595Y0.405MnO3 to investigate its magnetic
structure.
In a typical compound TbMnO3, the magnetic
structure should be much affected by a large internal
field induced by the ordering of 4f moments of Tb3+
ions. By choosing Eu3+ or Y3+ as the R ion, we wereable to avoid the ambiguity coming from 4f
moments, because Eu3+ has no 4f moments and Y3+
has no 4f electrons. The ratio of Eu and Y wasdetermined so that the average ionic radius is sameas that of Tb3+ [8]. The sample shows
antiferromagnetic transition below TN = 47 K. A

spontaneous ferroelectric polarization P along the caxis appears below TCc = 25 K. The direction of P
then switches to the a direction below TCa = 23 K.
The temperature induced switching of the directionof P is a distinct difference from TbMnO3, which isanother point that makes the present compound
adequate for the study of the relation between the
ferroelectric polarization and the magnetic structure.
However, the large absorption cross-section of Eu
for thermal neutrons (4530 barns at 25 meV) makes
a neutron diffraction study with a conventional
diffractometer at a reactor source difficult. Therefore,
we utilized ~150 meV neutrons at a pulsed source,
where the absorption cross-section of Eu shows alocal minimum.
A single crystal of Eu0.595Y0.405MnO3 was grownby the floating-zone method. The crystal has the
Pbnm symmetry with lattice constants a = 5.31 Å, b
= 5.86 Å, c = 7.41 Å. Details of the sample
preparation and characterization have been
described elsewhere [8]. The neutron diffraction
measurement was performed using the epithermal
neutron diffractometer EXCED installed at KENS
spallation neutron facility of High Energy
Accelerator Research Organization (KEK). The
crystal was aligned so that the [010] axis and the[001] axis lie on the scattering plane. The sample
was encapsulated in an aluminum can filled withhelium gas, and was attached to the cold finger of aclosed-cycle helium refrigerator.
In TbMnO3, strong magnetic peaks are observedat (h,k�qs,l) with qs ~ 0.28. Peaks with h + k = evenand l = odd (“A type”) have strong intensity, but
peaks with other conditions (“G type”, “C type”, and“F type”) have only weak intensity [9]. Figure 1
shows intensity maps in Eu0.595Y0.405MnO3 aroundpositions of “A-type” magnetic Bragg points on the(0,k,l) plane measured at 6 K (see also inset of Fig.
2).� Peaks due to the antiferromagnetic spin ordering
are clearly observed at (0,qs,1) and (0,2�qs,1) with qs= 0.31. The value of qs is slightly larger than that of
TbMnO3 (qs = 0.28). We also measured intensity
around a “G-type” position, (0,1�qs,1), but found no289

Eu0.595Y0.405MnO3
1.2

(a)

1.0
0.8

l (r.l.u.)

1.1

0.6

1.0

0.4
0.2

0.9

0

0.8
0.1
1.2

0.2

0.3

0.4

0.5

(b)

0.5
0.4

l (r.l.u.)

1.1

0.3

1.0

0.2
0.1

0.9

0

0.8
1.5

1.6

1.7

1.8

1.9

k (r.l.u.)
Fig. 1Figure 2 shows temperature dependences of theintegrated intensities of the (0,qs,1) peak and the(0,2�qs,1) peak. The scattering vector Q of theformer point is almost parallel to c* and that of thelatter point is almost parallel to b*, as illustrated in
the inset of Fig. 2. Since a magnetic structure factor
depends on the component of magnetic moment �that is vertical to Q, a change of the magnetic
structure can be detected by difference intemperature profiles of the intensities between thesetwo peaks. And we were able to observe thedifference clearly both at TCc and at TCa, indicating
the magnetic structure changes concomitantly withthe change of the direction of P.
Decreasing temperature, both of the magnetic
peaks appear at TN = 47 K. In a magnetization
measurement, the magnetization along the b axis
steeply decreases below TN, while those along the aaxis and the c axis remains almost constant [8],suggesting that the magnetic ordering below TN is a290

Eu0.595Y0.405MnO3
0.7
0.6

12

TCc

0.5

8

TN

0.4
(0,2-qs,1)(0,qs,1)0.3
0Fig. 2

16

TCa

10

BG
20

30

40

Temperature (K)4Integrated Intensity (a. u.)

Intensity maps on the (0,k,l) plane around (a)(0,qs,1), (b) (0,2�qs,1) measured at 6 K. The
intensity is normalized by that of a vanadium
sample. The peak profiles are elongated along
the radial direction due to the shape of theresolution function.

longitudinally sinusoidal wave along the b axis like
TbMnO3 [2]. In the present neutron diffraction
measurement, the (0,2�qs,1) peak has much weakerintensity compared with (0,qs,1), which is consistent
to that � is parallel to the b axis. Below TCc = 25 K,
slopes of both the temperature profiles increase, but
the (0,2�qs,1) peak shows a much steeper increase.
This indicates the appearance of the component of �that is perpendicular to the b axis. If the newcomponent of � was parallel to the a axis, theincreases in the slopes would be almost identical forboth the peaks. Therefore, the new component
should be dominated by that along c. On the other
hand, the development of the (0,2�qs,1) peak
becomes moderate below TCa = 21 K. The slope
becomes almost identical to that of the (0,qs,1) peak.
This suggests that the component of � along the baxis vanishes, whereas the component along the aaxis appears below this temperature. The
temperature TCa of 21 K is slightly lower than TCa =23 K in Ref. 8 which is defined as the temperature atwhich P along the a axis (Pa) starts to develop, but it
corresponds to the temperature at which P along thec axis (Pc) vanishes [8]. This difference should be
due to the coexistence of Pc and Pa between 21 K
and 23 K.

Integrated Intensity (a. u.)

peak. This suggests that the weak G-, C-, F-typemagnetic peaks in TbMnO3 are induced by the
influence of Tb 4f moments.

50

Temperaturedependencesof
integrated
intensities of (0,qs,1) (closed symbols) and(0,2�qs,1) (open symbols) magnetic peaks. For
both peaks, the measurements were done onelevating temperature. Inset shows scatteringvectors Q corresponding to these reciprocal
points on the (0,k,l) plane.

TbMnO3 shows a spiral magnetic ordering on thebc plane and the spontaneous ferroelectric
polarization along the c axis below TC. According to
the recent theories that interpret the ferroelectric
polarization in spiral magnets by the spinsupercurrent or the inverse DM interaction predictthat both P and qs lie on the same plane where themagnetic moments form a spiral ordering [5–7]. The
present results on Eu0.595Y0.405MnO3 can beinterpreted as follows in accord with the theories: At
TCc < T < TN, the magnetic structure is alongitudinally sinusoidal structure along the b axis,
and the compound does not show the spontaneouselectric polarization. At TCa < T < TCc, where P
along the c axis exists, the magnetic moments showa spiral structure on the bc plane. On the other hand,at T < TCa, the magnetic moments show a spiralstructure on the ab plane, and this magnetic structure
induces P along the a axis.
In summary, we have performed a neutron
diffraction study on a 4f-moment-free perovskite
manganite Eu0.595Y0.405MnO3 to elucidate therelation between the spontaneous ferroelectric
polarization and the magnetic structure. We havesucceeded in observing the change of the magnetic
structure at temperatures where the ferroelectric
polarization appears and changes its polarization
direction. Our observations can be interpreted asformation of a spiral spin structure and change of its
easy plane corresponding to the change of thedielectric properties, which is in accord with recent
theories.
References
1) T. Kimura et al., Phys. Rev. B 68, 060403(R)(2004).
2) M. Kenzelmann et al., Phys. Rev. Lett. 95,
087206 (2005).
3) T. Arima et al., Phys. Rev. Lett. 96, 097202(2006).
4) T. Kimura et al., Nature (London) 426, 55(2003).
5) H. Katsura et al., Phys. Rev. Lett. 95, 057205(2005).
6) I. A. Sergienko and E. Dagotto, Phys. Rev. B 73,
094434 (2006).
7) M. Mostovoy, Phys. Rev. Lett. 96, 067601(2006).
8) K. Noda et al., J. Appl. Phys. 99, 08S905 (2006).
9) R. Kajimoto et al., Phys. Rev. B 70, 012401(2004).

291

Epithermal Neutron Diffraction Study of the Magnetic Ordering in Gadolinium Hexaboride
K. KUWAHARA1, M. SATO1, R. YAMAMOTO1, S. SUGIYAMA1, M. KOHGI1,
T. YOKOO2, M. NAKAMURA3, Y. INAMURA3, M. ARAI3, K. IWASA4 and S. KUNII4
1

Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
IMSS, High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
3
Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
4
Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan2

292

moments. In order to obtain further information
about the magnetic structure of GdB 6, especially
focusing attention on the direction of the orderedmoments, we have performed the epithermal neutron
diffraction measurements on GdB6 under magnetic
fields.
A large single crystal of GdB6 was grown by afloating zone method, where natural abundant Gd
isotopes and 99.52% enriched 11B were used. The
single crystal has the shape of a parallelepiped of
3. The epithermal neutron diffraction
measurement has been done using EXCED installedat KENS. Magnetic fields up to 6.8 T along the[0,-1,1] direction were obtained in the Oxford
Instruments superconducting split pair magnet. The
sample was set inside this magnet with the [0,-1,1]
axis vertical to the (h k k) scattering plane. The
measurements were performed at incident energy of~1 eV and at the beam collimation of

3

Intensity (arb. units)

Rear-earth hexaborides RB6 (R: rare-earth) with the
CaB6-type crystal structure (space group Pm-3m)
have been attracting much interest because of richvarieties of low-temperature properties in this series.
Especially, an antiferroquadrupolar ordering in a
typical dense Kondo compound CeB6 ion has been
extensively studied by many researchers, where theorbital degree of freedom of 4f electron of Ce3+
plays the important role in this ordering. For
Gadolinium hexaboride GdB6, on the other hand, it
might be expected that it is a simple Heisenberg
magnet with S = 7/2 since the 4f electrons of Gd3+
ion have no orbital degree of freedom. However themagnetic phase diagram is complex, similar to thatin CeB6 [1]. It undergoes a first-orderantiferromagnetic (AF) phase transition at a Neeltemperature TN = 16 K. In addition to the phasetransition at TN, another anomalies indicating aphase transition have been observed around T* ~ 10
K in some measurements such as magnetic
susceptibility, electrical resistivity and x-ray
diffraction experiments [1-5]. Thus, the magnetic
phase diagram is divided to three phases:
paramagnetic phase above TN, the high-temperatureordered phase between T* and TN and the
low-temperature ordered phase below T*. In
previous
epithermal
neutrondiffraction
measurements on GdB6 in zero magnetic field, we
found that GdB6 has the complex magnetic structurewith the wave vector kord = [1/4,1/4,1/2] in bothordered phases below T* and TN for the first time[6]. Interestingly, this is the same wave vector that
other rear earth hexaborides CeB6, PrB6, and DyB6
[7-9] have in the AF ordered phase. This may be
important in a description of physical properties in
the whole rear earth hexaborides. Regarding thispoint, it has been pointed out that this magnetic
structure with kord = [1/4 1/4 1/2] originates fromtheir common Fermi surface of all RB6 which
consists of three nearly spherical pieces at the X
points in the Brillouin zone [10, 11]. The effect of
the orbital degrees of freedom on the magnetic
structure may appear in the direction of the ordered

T*

TN

2

GdB6

1

(1/4,1/4,1/2)
0

0

5

10
T (K)

15

Fig. 1 Temperature dependence of the integrated
intensity at the (1/4 1/4 1/2) antiferromagneticreflection. Arrows denote the transition temperatures
TN = 16 K and T* = ~10 K.

Figure 1 shows the temperature dependence of theintegrated intensity of the (1/4 1/4 1/2) AF magneticreflection, where the data were obtained byincreasing temperature after cooling the sample tothe lowest temperature. The intensity shows a slightanomaly around T* ~ 10 K and rapidly vanishes at
TN as increasing temperature. This rapid decrease isconsistent with the first-order nature of the phasetransition at TN. The slight anomaly around T* maybe due to the rotation of the ordered moments, sinceno magnetic reflection has been observed except forthe (1/4 1/4 1/2) reflection below T*.
Figure 2 shows the magnetic field dependence of theintegrated intensity of AF magnetic reflections inboth ordered phases below T* and TN. The
experimental configuration between the wave
vectors and the direction of the applied magnetic
field in the reciprocal space is also shown. By
applying magnetic field, the (1/2 1/4 1/4) AF
magnetic peak vanishes above 1 T, while theintensity of the (1/4 1/4 1/2) AF magnetic peakincreases and shows the hysteresis in both orderedphases. It should also be noted that the intensity ofthe (1/4 1/4 1/2) AF magnetic peak above 1 T is 1.5
times larger than that in zero field. These results

Intensity (arb. units)7(1/4,1/4,1/2) T=1.6K

65

References(1/4,1/4,1/2) T=12K

4
3
2(1/2,1/4,1/4) T=1.6K

10(1/2,1/4,1/4) T=12K

0

1

2

3
4
B (T)

[0,-1,1]

5

6

suggest that AF magnetic domains with twice period
structure parallel to the applied magnetic field
increase and the domains with twice period structure
perpendicular to the applied magnetic field vanish.
Therefore, the direction of the ordered AF magnetic
moment mord is not parallel to the direction of twice
period structure, that is, mord // [mx, my, 0] in the AF
magnetic domain with kord = [1/4,1/4,1/2], because�� is���  below a Neeltemperature. Furthermore, we examined whether the
direction of the ordered moment of GdB 6 is a planar
xy-type with ordered moments along the [1,1,0]
direction such as CeB6 and PrB6. As shown in Fig. 2,
the intensity of the (1/2 1/4 1/4) AF magneticreflections vanish under magnetic field 1 T along the[0,-1,1] direction. This indicates that the direction of
the ordered moment is not the [0,1,1] direction�� ����� below TN. Within high symmetrycase of the direction of ordered moment, therefore,
mord = [1,0,0] in the AF magnetic domain with kord =[1/4,1/4,1/2] may be most likely to realize in thissystem. The present study revealed that the magnetic
structure of GdB6 has the same wave vector as CeB6
and PrB6, but has not the same direction of theordered moments. The direction of the orderedmoments clearly reflects the orbital state of 4f
electrons in RB6 series.

7

B// [0,-1,1](1/4,1/4,1/2)[0,1,1](1/2,1/4,1/4)[1,0,0]Fig. 2 Magnetic field dependence of the integrated

intensity of AF magnetic reflections. The experimental
configuration in the reciprocal space is also shown.

1) S. Kunii, K. Takeuchi, I. Oguro, K. Sugiyama, A. Ohya, M.
Yamada, Y. Koyoshi, M. Date and T. Kasuya, J. Magn.
Magn. Mater. 52 (1985) 275.
2) R. M. Galera, P. Morin, S. Kunii and T. Kasuya, J. Magn.
Magn. Mater 104-107 (1992) 1336.
3) D. F. McMorrow, K. A. McEwen, J-G. Park, S. Lee, D.
Mannix, F. Iga and T. Takabatake, Physica B 345 (2004)
66.
4) K. Kuwahara, R. Yamamoto, M. Kohgi, H. Nakao, K. Ishii,
K. Iwasa, Y. Murakami, S. Kunii, H. Sagayama, Y.
Wakabayashi and H. Sawa, Physica B 359-361 (2005) 965.
5) M. Amara, S. E. Luca, R.-M. Galera, F. Givord, C. Detlefs
and S. Kunii, Phys. Rev. B 72 (2005) 064447.
6) K. Kuwahara, S. Sugiyama, K. Iwasa, M. Kohgi, M.
Nakamura, Y. Inamura, M. Arai and S. Kunii, Appl. Phys.
A 74 (2002) S302.
7) J.M. Effantin, J. Rossat-Mignod, P. Burlet, H. Bartholin, S.
Kunii and T. Kasuya, J. Magn. Magn. Mater. 47&48 (1985)
145.
8) P. Burlet, J. Effantin, J. Rossat-Mignod, S. Kunii and T.
Kasuya, J. de Phys. C 8 (1988) 459.
9) K. Takahashi, H. Nojiri, K. Ohoyama, M. Ohashi, Y.
Yamaguchi, M. Motokawa and S. Kunii, J. Magn. Magn.
Mater. 177-181 (1998) 1097.
10) Y. Kuramoto and K. Kubo, J. Soc. Jpn. 71 (2002) 2633.
11) Y. Kuramoto and K. Kubo, Physica B 328 (2003) 135.

293

The Magnetic Structure of Gd 3Ir4Sn13 Studied by EXCED.
C. NAGOSHI, K. KUWAHARA, and T. YOKOO*.
Department of Physics, Faculty of Science, Tokyo Metropolitan University, 1-1 Minami-Oosawa,
Hatioji, Tokyo, 192-0397*
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
The crystal structure of R3T4X13 is cubic with ainvolving twolattice constant of about 9.7
chemical formulas per unit cell and the space groupis Pm-3n. By connecting the nearest neighbor R
atoms, three one dimensional (1D) chains are formed
parallel to the x, y, and z axes, and by connecting thesecond nearest neighbor R atoms, regular triangles
which bond three 1D chains are formed as shown in
Fig. 1. Thus, it is expected that R3T4X13 exhibits
competition or coexistence of 1D and frustrated
magnetism in some conditions.

Fig. 1 Arrangement of R atoms in R3T4X13, Only R atoms
are shown. Thick and thin lines show the nearest andsecond nearest neighbor bonds between R atoms in theunit cell, respectively.

We report about the epithermal neutron ( 1eV)
diffraction experiments at EXCED (EXtreme
Condition Epithermal neutron Diffractometer) to
study the magnetic structure of Gd3Ir4Sn13 in thismunuscript. Eu3Ir4Sn13 had already been studied [1].
We succeeded to grow single crystals of Gd3Ir4Sn13
by molten Sn flux method for the first time, and it
was clear that the susceptibility of Gd3Ir4Sn13 showsan antiferromagnetic (AFM) like phase transition at
10 K (T1). Gd3+ and Eu2+ ions in R3Ir4Sn13 have same
4f electron state [4]S=7/2, L=0, and J=7/2
which is attributed purely to spin component.
However, Gd3+ state is very stable, and Eu2+ one isnot. Therefore, Gd3Ir4Sn13 and Eu3Ir4Sn13 can be key
materials to study the general magnetic properties of
R3T4X13.
Generally, it is impossible to perform neutron294

diffraction experiment on Gd compounds by ahindrance of the large absorption of Gd nucleus for
30 meV). Especially, inthermal neutrons (Gd3Ir4Sn13, Ir has also a large absorption for theneutrons. Now, we define the effective path length ofis the linear
Gd3Ir4Sn13 Reff as 1/ , here,
coefficient of it, the calculation of Reff is shown in
Fig. 2 as a function of neutron energy. There exist a
broad peak around 0.41eV. We used the scattered
beam with energy around 0.41eV, which is notthermal but epithermal neutron. Therefore, we
needed the scattering experiment at EXCED
spectrometer designed for a small scattering angle
diffractometer using epithermal neutrons. The best
size for the beam is about 3mm [6]. We performed
the diffraction experiments on two samples with theshapes on the experimental diffraction plane, 3mm
2.5mm (Sample 1) and 2.8mm 2.0mm (Sample 2).
The sizes of Sample 1 are rough, those of Sample 2
are exact, as expressed by the significant figures.
We can evaluate the absorption effect for Sample 2,of which sizes were determined by the experiment on
Sample 1.

Fig. 2 The neutron energy dependence of Reff of Gd3Ir4Sn13.

We will discuss the results obtained from Sample 1,
mainly. The spectra in the directions of [100], [011],
and [111] at 4K by using the epithermal neutron
beam are shown in Figs. 3, of which x axis represent
the scattering vector length Q. To detect (100) Bragg
scattering by using the neutrons of 0.41eV, we used

scattering angle near 2 =2.66 in PSD (Position
Sensitive Detector) installed at EXCED. The Reff
translated into the dependence of Q [7] aresuperposed in (A) of Figs. 3. The spectra in the
directions of [011] and [111] in Figs. 3 (B) and (C)were obtained near 2 =3.76 and 4.60 in the PSD,
respectively. These angles are chosen to detect themagnetic Bragg scattering of (011) and (111) by theneutrons of 0.41eV. The Bragg peaks at (100) and(111) in Figs. 3 are forbidden reflections for the
crystal phase of Pm-3n, and the (100) Bragg peak
disappears completely above T1 (=10K) as shown in
Fig. 4. Therefore, they are ascribed to the magnetic
scattering. The temperature dependence of spectra in[100] direction are displayed in Figs. 5. Note that thedata in Figs. 3 and Figs. 5 are raw data. Figs. 3 andFigs. 5 indicate that the magnetic Bragg scattering of(1/n, 0, 0), where n is an integer and more than 2,
does not exist. Therefore, we can conclude that theanomaly at T1 (10K) is ascribed to the AFM phasetransition characterized by the magnetic propagation
vector of (100) and use the crystal unit cell as themagnetic unit cell.

The chains extending x , y, and z directions arecalled x, y, and z chain, respectively. The Gd ions on
x chain are located at (1/4, 1/2, 0) and (3/4, 1/2, 0) in
both the crystal and magnetic unit cell, and Gd ionson the y chain are at (0, 1/4, 1/2) and (0, 3/4, 1/2),
and Gd ions on the z chain are (1/2, 0, 1/4) and (1/2,, Gd6,
0, 3/4). We call these Gd ions as Gd1,
respectively. Each Gd ion’s magnetic moment iswritten as Mn (n=1 6). The (200) scattering in Figs.
5 shows no temperature dependence, whereas (100)shows a temperature dependence, which indicate thatthe magnetic scattering does not exist on (200) andexists on (100). These experimental results suggestthat the possible magnetic structure should have therelations of M1= - M2, M3= - M4, M5= - M6 (1), andMn must have the perpendicular component to thechain which the moment locates. The detailed andstrict discussions are exhibited in the doctoral thesis
written by C. Nagoshi [3].

Figs. 5 The temperature dependence of spectra in [100]direction.

Figs. 3 The spectra of Gd3Ir4Sn13 in the directions of [100],[011], and [111] at 4K by using epithermal neutrons.

Fig. 4 The temperatue
dependence of (100)magnetic Bragg
scattering intensity of
Gd3Ir4Sn13.

Equation (1) leads to the important result that the
1D AFM arrangement realizes in Gd3Ir4Sn13. We
obtain the interesting structural feature; thesummation of the magnetic exchange field from Gd
ions on the different chains always becomes zero. It
indicates that the magnetic structure of Gd3Ir4Sn13 isdivided into three sub-lattices with antiferromagnetic
structure, each of them is formed by either x, y, or z
chains, and independent with each other. Theinteraction between the Gd pairs on the different
chain with the same direction may be the origin of295

the three dimensional ordering, though their distanceis large.
To compare the magnetic propagation vector of
Gd3Ir4Sn13; (1, 0, 0) with that of Eu3Ir4Sn13; (1/2, 1/2,1), we notice that the chain arrangement differs
conserving the relations of Eq. (1). That is, thenearest neighbor chain between parallel chains isequivalent in Gd3Ir4Sn13, is inverse regards as themagnetic moment directions in Eu3Ir4Sn13. Each
chain arrangement exhibits in Fig. 6.

Fig. 6 The diagram of the moments arrangement on a chain
in Gd3Ir4Sn13 and Eu3Ir4Sn13. The black and white circles
means anti-parallel moments each other.

The magnetic moment of a Gd ion in Gd3Ir4Sn13
must have the perpendicular component to the chainthat the moment locates, as stated above. For another,
the powder neutron diffraction on Eu3Ir4Sn13
suggested that the magnetic moments of Eu2+ are
perpendicular to the chain that the moment locates[3]. Judging from the above, we propose themagnetic structure model as follows. The magnetic
moments on the x chain have direction in y axis, thedirection of magnetic moments on other chains isgiven by the cyclic permutation of xyz shown in Fig.
7 [8]. This magnetic structure can explain theobserved diffraction intensities; (010), (110) and(120) on Sample 2 as shown in Fig. 7. They were
measured by using the neutrons of 0.41eV andLorents and absorption factors are corrected. Because
the observed magnetic Bragg scattering are only
three in this experiment, the strict discussion isremained. Observing more scattering such as the(210), (130), and (310)which are the observable
scattering in our diffraction geometry in Sample 2 inwill
spite of small angle scattering of EXCED
make clear the magnetic structure of Gd3Ir4Sn13.
However, we can show the probability of thequantitative handling of the intensities by using
epithermal neutron beam.
We suggest an unique and reliable magnetic
structure of Gd3Ir4Sn13 in AFM phase by theepithermal neutron experiment at EXCED. We showthat EXCED is the powerful tool for the magnetic
structure studies of Gd compounds.

296

We thanks Prof. O. Sakai and Prof. Y. Noda for
his valuable discussions. We express thanks to Prof.
M. Kohgi for his suggestion of EXCED experimentof Gd compound with the form of R3T4Sn13. We
express thanks to Prof. M. Arai and Mr. R.
Yamamoto for EXCED experiments. We express
special thanks to Dr. H. Sugawara, Dr. Y. Aoki, andProf. H. Sato for growing the Gd3Ir4Sn13 single
crystal.

Fig. 7 The observed(Sample 2) and calculation diffraction intensities. The
magnetic structure model is shown in this figure. All
corrections are performed on the observations.

References
1) The susceptibility of Eu3Ir4Sn13 shows an AFM
like phase transition at 10 K and obeys CurieWeiss law of Eu2+ ions [2], and it exhibits an AFM
phase with the magnetic characterized vector of (1/2,
1/2, 1) below 10K [3].
2) Y. Aoki et al., J. Phys. Soc. Jpn. Vol 65, No. 4,
April, 1996, 1005.
3) C. Nagoshi, Doctoral Thesis, Tokyo Metropolitan
University, 2006.
4) The temperature dependences of resistivity andHall coefficients of Gd3Ir4Sn13 and Eu3Ir4Sn13 arequite different each other, they will reflect thedifference of band electron number due to thedifference of valence, Gd3+ and Eu2+ [5].
5) C. Nagoshi et al., J. Phys. Soc. Jpn. Vol 75, No. 4,
April, 2006.
6) The best size is given as Reff.
7)The translation equation between Q and E is Q=2/dhkl=4 sin/. Here, dhkl and are theinterplanar spacing and the Bragg angle of (h k l)
Bragg scattering.
8) The magnetic structure model that the magnetic
moments on the x chain have direction in z axis, thedirection of magnetic moments on other chains isgiven by the cyclic permutation of xyz is equivalent
with the model in text, if the crystal structure is the
cubic of which space group is Pm-3n. They commute
each other by the symmetry operation of Pm-3n.

Intermediate Phase Structure of Ni2MnGa Combining Synchrotron Radiation Diffraction Data
T. OHBA1, M. MIYAMOTO1, T. KAKESHITA2, T. FUKUDA2 and M. TAKAHASHI3, K. KATO4
1

Shimane university, Department of Materials Science,
Osaka University, Materials Science and Engineering,3
University of Tsukuba, Institute of Materials Science
3
Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1, Kouto, Mikazuki-cho, Sayo-gun,
Hyogo, 679-5198, Japan
2

Intensity[arb.unit]

Ferromagnetic shape memory alloys are one of
topics these days. NiMnGa alloy system is one ofthose alloys and attracted many researchers becauseof large magnetic strain. The large strain is related
to the martensitic transformation. Thus the alloy
interests us not only an application, but also a
fundamental purpose. Standing on the fundamental
aspect, the transformation mechanism of themartensitic transformation has not been solved yet.
Incommensurate to commensurate transformation
was sometimes reported prior to the martensitic
transformation, such as TiNi.[1]Magnetic susceptivility of Ni2MnGa against
temperature were measured and slight change wasobserved at 260 K. Further cooling indicatessudden drop of the susceptivility, which corresponds
to the martensitic transformation, around 224 K.
Precise diffraction experiments were performed withsynchrotron radiation and are shown in Fig. 1.
These correspond to intermediate phase in magnetic

30.5

31

31.5

2� [degree]

32

230K
235K
240K
245K
250K
255K
260K
265K
270K
280K

susceptivility. [2]Neutron diffraction experiments were performed
at FOX with using single crystal for observing detailchanges in diffraction patterns. Figure 2 shows hk0
plane at 250 K, corresponding to the intermediatephase. There are satellite reflections around 1/3 of[110]. Precise observation of synchrotron radiation
data indicated that weak reflections appeared aroundfundamental reflections. It is difficult to index
those reflections as commensurate reflections.
Thus the intermediate structure has incommensurate
structure with approximately three times of [110]with orthorhombic symmetry. Detailed analyses
have been undertaken.
References
1) C. M. Hwang, M. Meichle, M. B. Salamon and C.
M. Wayman, Phil. Mag., A47, (1983), 9, 31.
2) T. Ohba, N. Miyamoto, K. Fukuda, T. Fukuda, T.
Kakeshita and K. Kato, Smart Material and
Structures 14, 2005, S197-S200.

32.5

Fig. 1.
Diffraction profiles at various
temperatures around 31.5° in 2�, measured bysynchrotron radiation. The arrow indicatesmartensitic peak position. The peak splittingof (620)p was clearly observed. This indicatesthat the cubic symmetry was broken in theintermediate phase.

250K
Fig. 2. Neutron diffraction pattern observed at
250 K. Satellite peaks were observed.

297

Pulsed Neutron Single Crystal Diffractometer FOX at KENS
M. TAKAHASHI
Institute of Materials Science, University of Tsukuba, Tsukuba 305–8573, Japan§1.

Pulsed neutron single crystal diffractometerFOX

FOX installed at H1 thermal neutron line on KENS
was a single crystal diffractometer using a time-of-ﬂight(TOF) Laue technique by combining the TOF methodwith white neutrons and a multidetector system of 36 linearly placed 3 He detectors. The spectrometer enables
us to observe a large area of two-dimensional reciprocal
space with a single measurement. It was initially a fourcircle single crystal diffractometer with 128 scintillator
detectors and mainly used for studies of structural analysis. However, four-circle diffractometer limits the observable reciprocal space and is not suitable for the measurement with white neutrons, we have improved FOX
as a Laue type diffractometer with the purpose of measuring low intensity scattering spread over the large reciprocal space such as diffuse scattering and superlattice
peaks. The overview of FOX is shown in Fig.1. Though
the system is quite simple, a large two-dimensional reciprocal space is observed effectively with high S/N rateon the renewed FOX.
Mult i-Channe lTime-Ana lyzer
0

Amp

cm

In this report, we have reviewed selected examples ofscientiﬁc results obtained at FOX and also show the possibility of quantitative analysis with the TOF Laue technique.
§2.

Studies at FOX

2.1 Secondary ordering in Pt-Mn and CuMnPt6 alloys
The phase diagram for Pt-Mn alloys with the Mn composition less than 17 at.% had remained unclear though
the stoichiometric composition Pt 3 Mn has the Cu 3 Au
type ordered structure, one of the common ordered structures in binary alloy system. With the observation of Lpoint diffuse scattering in the disordered Pt-8.8 at.%Mnalloy 1) and Cu 3 Au type ordered Pt-12.5 at.%Mn alloy(MnPt 7 ), it was expected that new ordered phase with
the ABC 6 type ordered structure exists as a secondary
ordered phase at low temperature in the alloy. The
ABC6 type structure is unique in that the unit cell is
as large as 2 × 2 × 2 the fundamental fcc cell, the largest
cubic unit cell found in the ordered fcc alloy. The unit
cell is divided into three sublattices A, B and C, as shownin Fig.2.

Ma c
G3
3

36 He Detectors
Detector
Bank Shield
Sl it2
Neutro nbe amColl imator
Slit 1A
SamplePositi on

Fig. 1.

Sample Tab leOutline of FOX di?ractometer.

The TOF Laue technique has signiﬁcant advantages
in the observations of
1. diffuse scattering which spreads over the reciprocal
space with anisotropic distribution,
2. reﬂections whose reciprocal position is unpredicted,
3. phase transitions under the extreme ﬁeld,
4. time-dependent reﬂections such as kinetics of phasetransition,
5. reciprocal space with very large wave number q.

298

Fig. 2.

B

C

Structure of the ABC6 type order.

In the reciprocal space, superlattice reﬂections appear
at both X- and L-points of the fcc Brillouin zone in theABC6 type ordered structure, while they appear onlyat X-point in the Cu 3 Au type ordered structure. The
atomic arrangement of the ordered structure is describedwith two independent order parameters, S 1 , related tothe degree of the Cu 3Au type order and S 2 , related tothat of the layered order of the alternate (111) planes. It
was ﬁrst proposed for the model of ordered structure in
Pt-72.5 at.% Cu. 2)
Khachaturyan, with his static concentration wave theory, predicted that the structure is a secondary ordered
superlattice and arises from the non-stoichiometric hightemperature superlattice with the Cu3 Au type structurewhich is regarded as the ABC6 type structure with one ofthe order parameters S 2 being zero. 3) In order to investigate the ordered structure and phase diagram in the Ptrich Pt-Mn alloys, in-situ measurements were performed
at FOX.
Figure 3(a) shows a result of in-situ measurement with
the MnPt 7 single crystal at FOX.4) It shows temperature variations of the intensities for the X-point (100)and L-point (3/2 1/2 1/2) superlattice reﬂections up to1050 o C. Temperatures at which superlattice reﬂections
vanish are different for the X- and L- point reﬂections;792 o C for the former and 668 o C for the latter. Since
superlattice reﬂections only at the X-points correspondto a Cu 3 Au type ordered structure, the former temperature is the transition temperature between the disorderedfcc phase and the Cu3 Au type ordered phase and designated here as Tc . The latter temperature is the transition
temperature between the Cu3 Au type ordered phase andABC6 type, a new ordered phase, and designated as Tcl .
(a)-2

5.0x10
0.14
4.0

0.10
3.0

0.08
0.06
0.04

2.0

MnPt7
100
3/2 1/2 1/2

1.0

0.02
200

(b)

400

600

800
o

Temperature ( C )-2

5.0x10

0.7
0.6

4.0

0.5
3.0

0.4
0.3
0.2
0.1
0.0

2.0
CuMnPt6100
3/2 1/2 1/2
200

400

Intensity (arb.units)

Intensity (arb.units)

Intensity (arb.units)

Intensity (arb. units)

0.12

1.0

600

800

1000

o

Temperature ( C )Fig. 3. Temperature dependences of the intensities of (100) and(3/2 1/2 1/2) superlattice reﬂections for (a) MnPt 7 and(b)CuMnPt 6 . The arrows indicate T cl and T c , respectively.

The ordered structure is also investigated at FOX for
Pt-14.5 at. % Mn and the double-step ordering with
Tc = 969 o C and Tcl = 682 o C was also observed. 4)
These observations clearly show the secondary ordering
as fcc → Cu 3 Au type → ABC6 type in the Pt-rich Pt-Mn
alloys. They are the ﬁrst binary alloys that exhibit thesecondary ordering with the fcc-based lattice. we regard
the ordered structure forming at temperatures below Tcl
as PtMnPt 6 for the MnPt 7 alloy.
Since the ABC 6 type structure consists of the threesets of cubic sublattice, it is more appropriate to regard
it as the ordered structure proper to the three component
system. With this idea, ordered structure in the ternary
alloy CuMnPt 6 was investigated. Figure 3(b) shows temperature dependences of the intensities at the X-point(100) and the L-point (3/2 1/2 1/2) of the CuMnPt 6
single crystal measured at FOX. 5) The intensity at (100)disappears at 968 o C while that at (3/2 1/2 1/2) disappears at 746 o C. The result shows that he ABC 6
type secondary ordered structure is formed in a real threecomponent system of the CuMnPt 6 ternary alloy.
From the observed neutron intensities at fundamental reﬂections and superlattice reﬂections at the X-pointand L-point, the two order parameters S1 and S 2 were
estimated for the present alloys. They are S 1 = 0 .9 andS 2 = 0.7 for MnPt 7 and S 1 = 0.9 and S 2 = 0.3 for
CuMnPt 6 . The low value for S 2 in the ternary alloy is
due to diffculties in the interchange of Mn and Cu atoms
which are next-nearest neighbors to each other. In thebinary alloy the interchange is only between Mn and Pt
atoms, which makes the secondary ordering mach easier.
The formation of the ABC 6 type order in these alloys
are the ﬁrst examples of a secondary ordering for the alloys with fcc-based lattice. The clear observations of the
double step ordering at FOX show that the diffractometer is quite suited for the studies of phase transitions
under the external ﬁeld.
2.2 Magnetic scattering in Pt-Mn spin-glass alloys
The disordered Pt-rich Pt-Mn alloys have been known
as one of the prototype spin-glass alloys. From neutronscattering measurements on metallic spin-glass alloys of
Cu-Mn, Pd-M and Pt-M (M; 3d element), it is now
commonly interpreted that the spin-glass-like behavior
in these disordered alloys arises from dynamical ﬂuctuations of short-ranged spin correlations originating by aspin-density wave (SDW).6) due to a Fermi surface nesting effect. Since the atomic disorder causes the ﬂuctuations, change in magnetic behavior is expected in theordered Pt-Mn alloys. In order to study the relation
between magnetic and atomic order in the Pt-Mn and
CuMnPt6 alloys, diffraction patters for these alloys were
measured at low temperature.
Figure 4(a) shows the magnetic diffuse scattering in(hk0) plane at 4 K from a single crystal of ordered Pt 7 Mn
alloy with the ABC 6 type structure. 7) In the imaged
diffraction patterns in Fig 4, logarithmic intensities areplotted to emphasize weak scattering. At 1/2, 1/2, 0,
the characteristic fourfold splitting of the diffuse scattering appears. Its origin is considered to be the SDW
formation because the magnetic susceptibility shows thesimilar spin-glass-like behavior in this ordered alloy. In
the disordered state, the SDW diffuse peaks appear at
1/2, 0, 0 and its equivalents of fcc lattice due to the
Fermi nesting vector of Q = 1 / 2, 0, 0. In the orderedstate with the ABC 6 type structure, the SDW peaks appear at 1/2, 0, 0, and its equivalents of the ABC 6 typestructure, such as at 1/2, 1/2, 0. Its intensities become
stronger than in the disordered alloys because the nesting
effect is enhanced for the crossing of the nesting vector in
the narrowed Brillouin zone of the ABC 6 type structure.

299

Integrated intensity (a.u.)

0.6
CuMnPt6(1)= 0.08

0.5

0.4

0.3

0.2

0

100

200

300

Temperature (K)Fig. 5. Temperature dependence of the magnetic diffuse intensities near 1 0 0 reciprocal point.

difference in magnetic scattering was completely unpredicted. The result shows that FOX has advantage of
observing unpredicted reﬂections.
2.3

Fig. 4. Magnetic scattering on the (001) scattering plane measured at FOX for the ABC 6 type ordered Pt-Mn alloys of (a)12.5
at.% Mn (Pt 7 Mn) at 4 K and (b) 14.4 at.% Mn at 12 K.

The origin of the four-fold splitting is not explained up
to now and the detailed information on the structure ofnesting Fermi surface is necessary for understanding themechanism of splitting.
Figure 4(b) shows the magnetic scattering in the same(hk 0) plane at 12 K from a single crystal of ordered
Pt-14.5 at.% Mn alloy with the ABC6 type structure.
The fourfold splitting at 1/2, 1/2, 0 is completely disappeared and instead, magnetic superlattice peaks appear
at 1/ 2, ± 1/4, 0, 1/ 2, 0, ± 1/ 4 and their equivalent points
in the ABC 6 type structure. These magnetic peaks indicate that the alloy forms long-rang order of type-II
anti-ferromagnetic structure.
Though the magnetic susceptibility also shows spinglass -like behavior in the ordered CuMnPt6 with theABC6 type structure, neither the SDW peaks nor theanti-ferromagnetic peaks appear in the alloy. Instead,measurements revealed increasing intensities around 1 0
0 superlattice point for lower temperature, showing ferromagnetic short-range order develops at low temperaturein the ordered CuMnPt 6 . The temperature dependenceof the diffuse intensities near 1 0 0 is plotted in Fig. 5.
These results show that the magnetic structure in thepresent alloys is sensitively dependent on the atomic order. It is indicated that not only the magnetic moment
on Mn atoms at A(B) sublattice but also that lies on the
Pt atoms at B (A) sublattice, the nearest site to the Mn
atoms, plays an important role on the formation of thelong-ranged magnetic structure in the Pt-Mn alloys.
It should be mentioned that these alloys with theABC6 type ordered structure show similar spin-glasslike behavior in the susceptibility measurement, thus the300

Quantitative analysis with standard samples
Since the TOF Laue technique gives extremely rapid
measurement of large volumes of reciprocal space to highwave vector q, it has also advantageous for the studies ofstructural analysis. Integrated intensities for hundredsof Bragg reﬂections are given rapidly and directly by
the integrated counts underneath the one TOF scan. To
examine the possibility of quantitative analysis with the
integrated intensities at FOX, standard samples of NaCland Al were measured.
−1
Figure 6 shows (Å ) dependence of integrated
Bragg intensities for NaCl single crystal at room temperature (R.T.), plotted together with the calculated intensities. The sample was sizes of 2.0 × 2.5 × 5.5 mm andintensities of about a hundred Bragg reﬂections were integrated from ﬁve diffraction patterns observed with ﬁve
different sample orientations in the measurements. The
integrated intensities are normalized by monitor counts
and vanadium incoherent intensities to remove time andwave-length dependence of the incident intensities, anddue corrections have been made for absorption, extinction and counter effciency. As for the extinction correction, wave-length and 2 dependences were taken into
account and in the case of the NaCl measurement, modelof the secondary type II extinction with Lorentzian approximation was found to explain the observed intensities well. The resultant values of Debye parameter B for2
Na and Cl atoms are both 2.0 Å , which agree well with2
the value 1.5 Å calculated from the Debye characteristic
temperature(Θ D ) for NaCl.
In the measurement of Al, single crystal of rod-shapesample with 7 × 20 mm was used. Intensities of Bragg
reﬂections were measured at four different temperatures,
R.T., 200 K, 100 K and 4 K. For each temperature, 100~ 200 reﬂections were integrated from the ﬁve diffraction patterns measured with ﬁve different sample orientations and the same corrections were applied as in theanalysis for NaCl. In the case of Al measurement, model
dependence of the extinction was very little though theobserved intensities spread over very wide range of 10 3 .

§3.
Intensity (arb.units)

1000

100
NaCl R.T.
I (obs.)I (calc.)

10

1

4

6

8

10

12

14

16

-1

q(A )
−1

Fig. 6. Observed intensities (open circles) verses Q ( Å ) for
NaCl single crystal at R. T.. The stars show calculated intensities.
4

Intensity (arb.units)

10

3

10

2

10

1

10

Al 200K
I(obs.)
I (calc.)

0

10

5

20

15

10

25

-1

q(A )

Remarks

The TOF Laue type diffractometer FOX has demonstrated satisfactory performance on the measurementsof weak scattering spread over the reciprocal space under an external ﬁeld and surveying the reciprocal space.
It is shown that quantitative analysis for the integrated
Bragg intensities is also possible with the di?ractometer. The number of reﬂections analyzed in the present
studies were less than 200 points and only debye temperature factor was examined as the structural parameter. For the structural studies with actual more complicated system, larger number of reﬂections should be measured in the three-dimensional reciprocal space by using
two-dimensional detectors with high count rate. Sucha diffractometer, though ideal for the Bragg scatteringstudies, is usually not suitable for the weak scatteringstudies such as diffuse scattering and superlattice reﬂections. For much developed studies on both weak diffuse
scattering and strong Bragg peak reﬂections, construction of a new type diffractometer at a powerful neutron
source is expected to revolutionize single-crystal neutron
diffraction.
I am grateful to Prof. M. Arai for his many advices
on FOX improvement, and to Prof. K. Ohshima for his
support on the experiments at FOX. I am also gratefulto the staff of KENS for their assistance in many aspects
at KENS.

−1

Fig. 7. Observed intensities (open circles) verses Q ( Å ) for Al
single crystal at 200K. The stars show calculated intensities.

2

Debye parameter (A )

0.9
0.8
0.7
0.6
0.5
0.4
0.3

0

100

200

1) M. Takahashi, S. Yoshimi, K. Ohshima, and Y. Watanabe,
Phys. Rev. B 61 , 3528 (2000).
4 , 377(1951).
2) Y. Tang, Acta Cryst.
3) A. G. Khachaturyan: Progress in Materials Science 22, 24(1978) .
4) M. Takahashi, T. Sembiring, M. Yashima, T. Shisido and K.
Ohshima, J. Phys. Soc. Jpn.
71 , 681 (2002).
5) M. Takahashi, A. K. Das, R. Nakamura, H. Iwasaki, T.
Shishido and K. Ohshima, J. Phys. Soc. Jpn.75, 13601(2006).
6) Y. Tsunoda, J. Magn. Magn. Matter 177-181, 1337 (1998).
7) M. Takahashi, T. Sembiring, Y. Noda, T. Shishido and K.
Ohshima, Phys. Rev. B 70 , 14431(2004).

300

Temperature (K)Fig. 8. Temperature dependence of the Debye parameter obtainedfor Al single crystal.

This may be because the mosaic in the Al sample is−1rather large. Figure 7 shows q(Å ) dependence of integrated Bragg intensities for Al measured at 200K together with the calculated intensities. The observed andcalculated intensities ﬁt well up to very large q values−1of 25 Å . In Fig. 8, temperature dependence of the
Debye parameters obtained with the present analysis forfour temperatures are plotted. They are consistent to2
the values calculated from the Θ D for Al: 0.92 Å at
2
2
293 K, 0.39 Å at 93 K and 0.28 Å at 20 K.
The present results of NaCl and Al reveal capabilityof quantitative analysis at pulsed neutron single crystal
diffractometer with TOF Laue technique.

301

INSTRUMENTATION

2003–2006

Test Experiments for TOF-USANS Method
K. AIZAWA, T. YOKOO* and M. ARAI
Quantum Beam Science Directorate, Japan Atomic Energy Agency, 2-4 Shirakata Shirane,
Tokai-mura, Ibaraki, 319-1195* Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
TOF-USANS method based on double crystal
diffractometer with perfect single crystals, which isconsists of the first (monochromator) and the second(analyzer) crystals, has possibility to extend q-range
compared with reactor based USANS method,
because it can effectively use higher orderreflections in addition to fundamental reflection by
TOF scan [1]. According to this method, it isexpected that characterization of the hierarchicalstructure from the nanometer to the several hundred
micrometer length-scale becomes possible by one
instrument.
To development TOF-USANS method, firstly,
we performed diffraction experiments for the first
crystal at EXCED instrument. We used two types of
FZ-Si crystals. One is the flat Si crystal and theother is the 3-bounce channel-cut crystal. Figure1(a) shows the diffraction patterns from a flat Si
crystal. The (111) fundamental reflection withneutron wavelength of 0.443 nm and higher orderreflections up to (555) reflection were detected.
Figure 1(b) shows the diffraction patterns from the
3-bounce channel-cut Si crystal with same opticalcondition for the flat Si crystals. Note that detectedpeak positions shift toward low detector channel
number due to 3-bounce reflections. For simplicity,
the correction of the incident neutron flux was not
performed in these figures. It is found that whole
diffraction peaks for the channel-cut crystal is
sharper than those of the flat Si crystal. This
character is especially pronounced in higher orderreflections.
Now, we will plan an experiment for double
crystal arrangement at CHOP instrument in JRR3
reactor. The CHOP instrument has a disk chopper
for producing the pulsed neutron beam from thewhite neutron beam. The rocking curve of thesecond crystal will be measured in TOF method.

Fig. 1(a) Diffraction patterns for the flat Si crystal. (b)Diffraction patterns for the 3-bounce channel-cut
Si crystal.

References
1) K. Aizawa, J. Neutron Res. 13, 113-118 (2005)

305

Thermal Neutron Refraction by Neutron Material Prism
T. SHINOHARA, K. HIROTA*, T. ADACHI**, K. IKEDA*, H. M. SHIMIZU***,
J. SUZUKI and T. OKU
Quantum beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195*Radiation Laboratory, RIKEN, Wako, Saitama, 351-0198**Daiichi Kiden Co. Ltd., Chofu, Tokyo, 182-0034***Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
Neutron refractive optics, such as neutron lenses
and prisms, are very powerful tools for the beamfocusing or beam bending, because of their large
effective apertures compared to the reflective opticaldevices. Through the recent developments ofneutron optics, two kinds of neutron refractive
optics have been achieved, i.e., magnetic lenses [1,2] and material lenses [3, 4]. These are mainly used
to focus cold neutron beams, and lead to someexperimental advantages such as better resolution
for small-angle neutron scattering or increase in theincident neutron intensity. However, use of theserefractive optics remains restricted only to the cold
neutron range, because neutron refraction angle
decreases with shorter wavelengths. In this work, wehave developed a material prism, called microprism,
applicable to thermal neutron beams andexperimentally confirmed the refraction of thermal
neutron beams at the thermal neutron port H-8(PEN) of KENS.
The neutron material prism was fabricated using
a commercial perfluoropolymer “CYTOP” (ASAHIGLASS Co., Ltd.). This neutron prism wascomposed of several hundred thin sheets, each ofwhich has a large number of grooves on the top
surface (Fig. 1). The design and preparation
procedure of the prism are described in elsewhere [5,6].

Fig. 1306

Illustration of microprism.

Experimental results are shown in Fig. 2. The leftof Fig. 2 shows the result without prism, and theright shows that obtained using a microprism by 200
sheets. This figure clearly demonstrates the evidenceof thermal neutron refraction for neutrons with thewavelengths longer than ~1 Å. This is the first
confirmation of thermal neutron refraction using amaterial prism. The refracted angle almost replicatesthe simulation result, and the distribution ofdivergent neutrons also shows good agreement withthe simulation.
In conclusion, we have developed a material
prism for thermal neutron beam bending. Thermal
neutron refraction was clearly observed using thisprism and the refracted angle was well reproduced
by a computational simulation.

Fig. 2

Neutron wavelength dependence of refracted
angle. Left is the result without prism, and right iswith prism composed of 200 sheets.

References
1) H. M. Shimizu et al., Phys. B 241-243 (1998)
172.
2) H. M. Shimizu et al, Nucl. Instr. and Meth. A
430 (1999) 423.
3) M. R. Eskildsen et al., Nature 391 (1998) 563.
4) T. Oku et al., Nucl. Instr. and Meth. A 462(2001) 435.
5) T. Shinohara et al., Nucl. Instr. and Meth. A 529(2004) 134.
6) T. Shinohara et al., Phys. B (accepted).

Development of Position-Sensitive Neutron Detectors Based on Scintillator
K. HIROTA, S. SATOH*, M. FURUSAKA**
and H. M. SHIMIZU*
Radiation Laboratory, RIKEN, Hirosawa2-1, Wako, Saitama351-0198*Neutron Science Laboratory, High Energy Accelerator Research Organization, Tsukuba, 305-0801* Faculty and Graduate School of Engineering, Hokkaido University, Sapporo, 060-8628
Introduction
Neutron Optical devices such as neutron
magnetic and material lens have been developed
recently [1]. These devices need good spatial
resolution of less than 1 mm for the detector. We are
therefore developing two kinds of scintillating
detectors. One is RPMT detector and another iscalled Flatpanel called Anger detector. The RPMT
detector [2, 3] has good spatial resolution, highsignal-to-noise ratio and user friendliness. The
flatpanel Anger detector has also good spatial
resolution and large effective area. The neutron
detection point is calculated by center of the lightyield of the scintillator in both detectors, but themethod is different. The RPMT detector uses charge
division method in the PMT and the flatpanel Anger
detector uses light dispersing method.
RPMT detector
The RPMT has three major components; theneutron sensor, DAQ system and monitoring system.
The neutron sensor consists of a scintillator and aposition-sensitive photomultiplier tube (PSPMT). A
ZnS(Ag)/6LiF plate is used for a neutron scintillator.
The light yield must be sufficiently large value forgood spatial resolution. This scintillator has a large
light yield, more than ten thousand photons for acold and a thermal neutron detections. The PSPMT
has a 12-stage coarse mesh dynode structure andmultiple anode wires crossing one another in the X
and Y directions. Output signals from each anodewire are divided in two by registers. The detection
position is calculated by the ratio of these two
signals for each coordinate. In total only five lines,
four signal lines and a high-voltage line, are used.
The DAQ system used of this system is a revised
version of a PSD2K module [4, 5]. There are two
types of detention area in the PSPMT. The effective
area of the larger detector is �90 mm (5 inch PMT),and smaller one is �50 mm (3inch PMT).
Fig.2 shows the two-dimensional image of the
RPMT detector. This figure shows a cold neutron
beam passing through a 0.3 � 20 mm2 cadmiumslit, at 1 mm increments. The spatial resolution isless than 1 mm and the detection efficiency, which
is about 30 % for the cold neutron, is almost same inall effective area, but this image has strong
distortion. To reduce the image distortion, we createa distortion correction table and use it to transformthe image.

Fig. 1 Apparatus of RPMT detector

Fig. 2
Two-dimensional image of cold
neutron beam by the RPMT detector
Flatpanel Anger detector
The flatpanel Anger detector also consists ofneutron sensor, DAQ system and a PC. A
64-channel flatpanel PMT (FPMT), Hamamatsu

307

H8500 and ZnS(Ag)/6LiF scintillator are used forthe sensor. The data taking system is constructedusing 10-bit 100 MHz FADC and Xilinx FPGA
chips. The 64 anodes and a dynode output signals
are pulse-shaped by amplifier and then digitalizedby FADC chips in parallel. The trigger timing isused by the dynode signal. The effective area of thisdetector is around 25 cm2, and it is easy to expand
larger area with small dead space by multi-FPMT’s
system. A ‘center of light yield position’ calculation
is used on the pulse height data of 9 pixels of the
FPMT including the brightest central pixel and its
surrounding 8 pixels. In the case of the brightest
pixel is in peripheral of the FPMT, the position isdecided by the ratio of the brightest pixel and thenext pixel.
The two-dimensional image of cold neutron
beam is shown in fig. 3. This figure shows
collimated neutron beam with a 5 mm-gap-combshaped cadmium slit. Neutron detecting counts ofthe central region is the highest because the neutron
beam is not uni-field.
The spatial resolution was measured using a
cadmium collimator with a diameter of 0.5 mm.
This measured spatial resolution is originated fromboth collimator size and detector resolution. The
neutron beam wavelength was 0.95 nm. The
measured spatial resolution is typically 0.8 mm
FWHM in central region and getting worse toaround 1.5 mm in the peripheral pixel region. This isbecause the calculating method is not so good inperipheral pixel region, and we should develop new
analyzing method.

Fig. 3 Two-dimensional image of cold neutron beam by
the flatpanel Anger detector.

References3081) H. M. Shimizu et al.: Physica B311 (2002) 23.
2) K. Kuroda : Nucl. Instr. Meth. Phys. Res. A 277(1989) 242.
3) Katsuya Hirota et al.: Phys. Chem. Chem. Phys.
7 (2005) 1836.
4) S. Satoh et al. : KEK Report 2001-9 (2001)
5) S. Satoh et al. : Nucl. Instr. Meth. Phys. Res A
529 (2004) 421

Development of � and �/2 Flippers with Steady Current for the TOF-NSE Spectrometer
T. TAKEDAa, N. L. YAMADAb, K. KATOHb, M. NAGAOc,
H. SETOd, Y. KAWABATAe, M. TAKEDAf and N. TORIKAIgab

Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521
Graduate School of Bio-Sphere Science, Hiroshima University, Higashi-Hiroshima, 739-8521
c
NSL, ISSP, The University of Tokyo, Tokai, Ibaraki, 319-1106d
Department of Physics, Kyoto University, Kyoto, 606-8502
eFaculty of Science, Tokyo Metropolitan University, Hachioji, 192-0397
f
ASRC, Japan Atomic Energy Research Institute, Tokai, Ibaraki, 319-1195g
NSL, IMSS, High Energy Accelerator Research Organization, Tsukuba, 305-080

We carried out performance tests of a tiny
time-of-flight neutron spin echo (TOF-NSE)
machine with the new-type � and �/2 flippers using
a pulsed white neutron beam at the polarized
neutron reflectometer (PORE) [1] of Neutron
Science Laboratory (KENS), High Energy
Accelerator Research Organization (KEK) and we
observed the TOF-NSE signal pattern, which gave
direct evidence that the flippers worked for a pulsed
white neutron beam.
The neutron spin echo
spectroscopy (NSE) proposed by Mezei[2] provides
an extremely high energy resolution without aneutron intensity loss from a corresponding
monochromatization, since the resolution of energychange on scattering is decoupled with thewavelength resolution. The NSE technique using
the time-of flight method (TOF-NSE) provides ahigh NSE energy resolution together with an
ordinary momentum resolution using a wide neutron
wavelength band (nearly white beam)[3]. IN15 at
ILL has been operated for the first time in TOF-NSE
mode[4] and proves the feasibility of the NSE
technique on a pulsed source. However, the flipper
system of IN15 needs synchronizing and tuning formany coils. We designed � and �/2 flippers which
operate with steady current for a white neutron
beam[5] and proposed TOF-NSE spectrometers[6]especially at a pulsed spallation neutron source(JSNS) in High Intensity Proton Accelerator Project(J-PARC)[7].
The new-type � flipper with thefirst type modified current sheet which was made bywinding Al-conductor wires operated well as a �flipper in the previous test experiment[8].
Wereported another design of a new-type �/2 flipper
and the results of performance tests of the new-type
� and �/2 flippers with the second type modified
current sheet which was made of Al alloy plates[9].
Performance tests of the spin flippers with themodified current sheet made newly were carried out
using ISSP-NSE[10] at C2-2 port of JRR-3M inJapan Atomic Energy Research Institute (JAERI).
We replaced all of the Mezei-type � and �/2 flippersof ISSP-NSE with the new-type ones and observed
the NSE signal of neutrons scattered elastically froma stacked graphite sheet (grafoil).
The result
showed that the new-type � and �/2 flippers operate
well as a flipper system for a NSE spectrometer[11].
Recently, ISSP-NSE was relocated to the C2-3-1
port of JRR-3M, graded up and renamed iNSE[12].
As the � flipper of iNSE, the new-type � flipper isinstalled and runs well[13]. We present the resultof performance tests of a tiny TOF-NSE set with the
new-type � and �/2 flippers using PORE, where weobserved the TOF-NSE signal pattern[11].
The principle of the new-type spin flippers witha modified current sheet which operate with steadycurrent for a white neutron beam is as follows. The
new-type spin flippers which consist of a modified
current sheet and Helmholtz coils. The modified
current sheet produces magnetic fields BS parallel tothe sheet surface without magnetic fields
perpendicular to the sheet at the surface of the sheet
for a large neutron beam cross section. For the �
flipper, the correction field from Helmholtz coils BC
perpendicular to the current sheet cancels out theperpendicular component of the magnetic field fromthe precession coils B0 at the current sheet[8]. For
the �/2 flipper, the correction field from Helmholtz
coils BC perpendicular to the current sheet modifies
the magnetic field from the precession coils B0 sothat |B0+BC| = |BS | at the sheet[9]. Outside thecurrent sheet at both flippers, the direction of themagnetic field B = BS + B0 + BC as seen from amoving neutron rotates slowly enough, so that theneutron spin state follows the change of B
adiabatically.
Crossing the current sheet, the309

direction of B turns by � and �/2 suddenly withoutchange in the neutron spin direction at the � and the�/2 flipper, respectively. As a result, this coilsystem operates as a � or �/2 flipper without extra
tuning independently of the neutron wavelength.
The third and the fourth type modified current
sheets were made of Al alloy(5052) plates inthickness of 3 mm, which were cut at intervals from
14/6 to 14 mm and from 10.5/6 to 10.5 mm in areaof 336w x 334h mm2 and 168w x 167h mm2 byelectrospark machining, respectively.
We
constructed a compact NSE set with the length of 68
cm for the performance tests of the new-type � and�/2 flippers with the modified current sheet using apulsed white neutron beam at PORE. Before theexperiment at PORE, we set it on the sample table of
ISSP-NSE and observed the NSE signal in order tofind the appropriate conditions of the coil system
which should be independent of the neutron
wavelength when the new-type flippers are used.
Performance tests of the spin flippers with themodified current sheet made newly were carried out
using the polarization analysis system of PORE for apulsed white neutron beam from a spallation neutron
source in KEK. We replaced the magnetic guides
between the sample site and the analyzer of PORE
with the above tiny NSE set as shown in Fig. 1.

CS1(�/2)P

magnetlarger than a limit. The large 2� reduced theneutron flux at the NSE set extremely. In order toreduce 2�, the NSE set was made as close as
possible to the analyzer of PORE. The stray fieldfrom the analyzer magnet which provided thevertical magnetic field of about 0.1 T for the
analyzer was more than 5 mT at the second �/2flipper of the NSE set. In order to reduce thestrong stray field from the analyzer down to 0.05
mT, we put a temporary magnetic shield made ofiron plates between the analyzer and the NSE set.
The magnetic shield caused a little depolarization.
Figure 2 shows TOF profiles obtained fromperformance tests of the new-type � flipper with thethird type current sheet using a pulsed white neutron
beam, where the current sheets for the �/2 flippersof the NSE set were removed in order to reduce 2�.
The profile obtained when both flippers of PORE
and of the NSE set were operated is little different
from that when both flippers were not run. This
result shows that the new-type � flipper operated
well without tuning independently of the neutron
wavelength. We used the fourth type current
sheets for the new-type � and �/2 flippers of the
NSE set in order to reduce 2� and to observe a
TOF-NSE signal pattern.

CS0(�) CS2(�/2)
PC

PC

MS

A

D

SF
grafoil2�

CCduct of SWAN

Fig. 1 Set-up of performance tests of the flippers at
PORE.
P; polarizer, SF; spin flipper, magnet; magnet atthe sample site, A; analyzer, D; detector. They areprovided for PORE. NSE set consists of the following
parts: PC; precession coil, CC; correction coils, MS;magnetic shield, etc. CS0, CS1 and CS2 are current
sheets for �, 1st �/2 and 2nd �/2 flipper, respectively.

Polarized neutrons scattered from grafoil at the
sample site are provided to the NSE set. Since
PORE is installed at C1 cold neutron beam port
which is shared with a small/wide-angle neutron
diffractometer (SWAN), the current sheet wasinterfered with the duct of SWAN as shown in Fig. 1
and the scattering angle 2� at the sample site was
310

Fig. 2
TOF profiles obtained from performance tests of
the new-type � flipper using a pulsed white neutron beam
at PORE. OFF-ON; ( SF:off & CS:on ), OFF-OFF;( SF:off & CS:off ), OFF-ON; ( SF:off & CS:on ), ON-ON;( SF:on & CS:on ). SF is the spin flipper of PORE andCS the new-type �flipper with the modified current sheet.

Fig. 3 TOF-NSE signal pattern observed using a pulsed
white neutron beam at PORE. The channel number is
proportional to the neutron wavelength. The tones of grays
correspond to the neutron intensity.

Fig. 4 NSE signal profiles of the above TOF-NSE signal
pattern for Channel Nos. 190, 210 and 230 whichcorrespond to the neutron wavelength � = 6.54, 7.22 and7.91 Å, respectively. The profiles for Channel Nos. 210
and 230 are shifted 10 and 20 arbitrary units for better
visualization, respectively.

Figure 3 shows a TOF-NSE signal pattern observed
using a pulsed white neutron beam at PORE. The
channel number is proportional to the neutron

wavelength. The tones of grays correspond to the
The NSE signal profiles forneutron intensity.
Channel Nos. 190, 210 and 230 are also shown in
Fig. 4. The intensity IC of the profiles was given
by IC = 1000ID/IM, where ID and IM are the count of
the main detector and the monitor counter of PORE,
respectively.
The normalized NSE signal
amplitude PNSE is 0.76 for Channel No. 210 whichcorresponds to � = 7.22 Å. The values of PNSE
observed at PORE are smaller than that at
ISSP-NSE, which is mainly because ofdepolarization by the magnetic shield. The highspeed of the rotation of the magnet field direction as
seen from a moving neutron spin which is originatedin the magnetic shield causes the wiggles whichappear at the lower channel number (shorter
wavelength) in the TOF-NSE signal pattern as well
as depolarization. The discontinuity in the pattern
and the profiles which appears at zero in thesymmetry coil current is originated in poor
calibration on offset of the power supplies. Only
by one shot try, we could observe the TOF-NSE
signal pattern shown in Fig. 3, which gave direct
evidence that the flippers worked for a pulsed white
neutron beam. This result shows that the new-type
� and �/2 flippers operated well without tuning
independently of the neutron wavelength. The
operation is very easy, that is, one has to tune only
the correction field from Helmholtz coils for a given
precession field.
References[1] M. Takeda et al.; Physica B 267-268 (1999) 185.
[2] F. Mezei, Z. Phys. 255 (1972) 146.
[3] F. Mezei; Nucl. Instr. and Meth. 164 (1979) 153.
[4] B. Farago et al., ILL Yellow Book 2000, P.79.
[5] T. Takeda et al., Int. Workshop on Neutron Spin
Echo Spectroscopy, Berlin, Oct. 2000.
[6] H. Seto et al., Proc. ICANS-XV, JAERI-Conf
2001-002 (2001) 390.
[7] S. Nagamiya, Nucl. Instr. Meth. In Phys. Res. B
214 (2004) 216.
[8] T. Takeda et al., Appl. Phys. A 74 (2002) S177.
[9] T. Takeda et al., Physica B 335 (2003) 211.
[10] T. Takeda et al., J. Phys. Chem. Solids 60(1999) 1599.
[11] T. Takeda et al., to be published in J. Neutron
Research.
[12] M. Nagao et al., Proc. International Symposium
on Research Reactor and Neutron Science, (2005)
762.
[13] M. Nagao et al., to be published in Physica B.

311

Drabkin Aergy Filters as a Chopper for Pulsed Neutrons
D. YAMAZAKI, K. SOYAMA, T. EBISAWA, R. MARUYAMA and M. TAKEDA
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Ibaraki, 319-1195
A chopper-mode of the Drabkin energy filter was
proposed and demonstrated at PORE, KENS.
The Drabkin energy filters extract monochromatic
neutrons. It is composed of a polarizer, a Drabkinelectromagnetic resonator [1], a spin �-flipper and apolarization analyzer. The Drabkin resonator, which
generates a uniform magnetic field and a
periodically alternating field perpendicular to theuniform field, flips the spin of neutrons with aresonant wavelength �*. The polarization analyzer
then extracts the spin-flipped neutrons. The resonant
wavelength �* (i.e. the wavelength of the extracted
neutrons) depends on the field strength in theresonator and is therefore variable electronically.
Drabkin energy filters could be a powerful tool for
pulsed neutron experiments. One of possible
applications of the Drabkin energy filters is pulse
shaping [2,3]. By varying the resonant wavelengthin accordance with the time-of-flight of neutrons(�*(t) = �pulse(t)), delayed neutrons are eliminatedand neutron pulse widths can be sharpened.
In this study, it was proposed and demonstrated
that the Drabkin energy filter could be used as achopper for pulsed neutrons [4]. By sweeping theresonant wavelength fast, neutrons are extracted
only when the resonant wavelength and neutron
wavelength are equal (see Fig. 1). Even if �* wasfixed, the Drabkin energy filter act like a chopper.
But, the faster �* is swept, the shorter the“opening-time” we obtain.

Fig. 1

Traces of the resonant wavelength in three
chopper-modes and the static mode are shownin gray regions together with the trace of neutron
pulse peak. Arrows with a couple of dotted lines
show the “opening-time”.

The chopper-mode was demonstrated, using a
Drabkin resonator whose wavelength resolution is312

17%, at PORE of KENS. The experimental setup is
shown in Fig.2. The space was too restricted to placea Drabkin resonator in the direct beam-line becauseof the neighboring beam tube for SWAN. A NiC/Ti
supermirror was therefore placed to reflect neutrons
away from the SWAN beam tube.

�

Fig.2 Experimental setup at PORE.

The Drabkin resonator was composed of a zig-zag
folded current sheet of pure aluminum which
generates alternating horizontal magnetic-field and a
Helmholtz coil which generates vertical field. Bychanging the currents for the current sheet and theHelmholtz coil, the resonant wavelength arecontrolled.
The Drabkin resonator was driven by varying thecurrents as schematically shown in Fig.3. At time t res(the “resonance point”) in the rise-time �t, theresonant wavelength gets equal to the pulsed neutron
wavelength and neutrons are extracted. The shorter
the rise-time is set, the shorter “opening time” weobtain.
�

Fig.3 Current sweeping in a chopper-mode.

Figure4 shows TOF profiles measured at achopper-mode with rise-time �t=2.46ms and at thestatic mode together with the incident profile. The
position of the extraction peaks is about 13.5 mscorresponding to wavelength about 5Å.

Gaussianopening time. Higher S/N ratio could be achieved byinstalling two or more Drabkin energy filters insequence [3].

fittings to the extraction peaks showed that FWHM
of the peaks are 0.21 ms for the chopper-mode and1.08 ms for the static-mode. Subsidiary peaks are
attributed to the field configuration in the resonatorand could be reduced by modulating the alternating
field strength [5] or using two or more Drabkinfilters [3].
Neutron Counts /25�s/2����pulses

2500

References
1) G.M.Drabkin, Sov.Phys.JETP 16 (1963) 282.
2) A.A. Parizzi et al., Appl. Phys. A 74 (Suppl.)(2002) S1498, S1607.
3) D. Yamazaki et al., Nucl. Instr. Meth. A 529(2004) 204.
4) D. Yamazaki et al., Physica B 356 (2005) 174.
5) M.M. Agamalyan et al., Phys. Rep. 168 (1988)
265.

2.46msstaticIncident
flipped

2000

1500

1000

500

0

11.5

12

12.5

13

13.5

14

14.5

15

15.5

Time (ms)Fig.4 Extracted neutrons from Drabkin energy filters in achopper-mode of �t=2.46ms ( ○ ) and in thestatic mode (●). Incident profile and spin- flipped
profile are represented by △ and ▲.

Measurements were also carried out for
chopper-modes with �t=4.10 ms and 8.20 ms. The
obtained time widths are compared with a calculated
curve in Fig.5 which shows a good agreement
between them. The small discrepancy is attributed tothe pulse width of neutrons at PORE.

Opening time (ms)

1

0.1

0.01

0

2

4

6

8

10

Rise time (ms)Fig.5 Relation between rise time �t and obtained openingtime.

In conclusion, we proposed a chopper-mode of
Drabkin energy filters and carried out ademonstration experiments at PORE, KENS.
“Opening time” of 0.21 ms was realized with a
low-resolution (����*=17%) Drabkin resonator.
Narrower opening time will be available by shorter
rise or fall time as shown in Fig.5. Resonators withhigher resolution are also effective for shorter

313

Development of High-Qc and Curved Neutron Supermirrors
K. IKEDA, H. SATO, S. MORITA*, H. OHMORI*, T. OKU**, J. SUZUKI**,
K. OHOYAMA***, H. HIRAKA*** and H.M. SHIMIZU****
Radiation Laboratory, RIKEN, Wako, Saitama, 351-0198*Materials Fabrication Laboratory, RIKEN, Wako, Saitama, 351-0198**Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195***Institute for Materials Research, Tohoku University, Sendai, Miyagi, 980-8755****Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
Neutron supermirrors with a parabolic orparaboloidal surface are suitable for focusing
neutrons transported by some guide tubes from aneutron source, because mirrors in guide tubes selectneutrons with the divergence of not more than thecritical reflection angle of them. Two kinds ofprototypes of devices with curved supermirrors were
proposed for focusing of thermal and cold neutrons.
One is a focusing mirror with multiple-parabolic
surface (mPRB, Fig.1) designed for thermal
neutorns of wavelength of 1.8Å. The mPRB wasconstructed by thirty-two pieces of 3Qc Ni/Ti
supermirrors deposited on Borate float glass of
150mm x 100mm x 0.4mm. These pieces were linedwith parabolic wedge-shaped acrylic-resin spacers
so that they were formed into four pieces of
1200mm long mirror and constituted 3 channels
with parabolic shapes. It converged 2.8 times as
many neutrons of 1.8Å as would arrive without it on
the area of 1mm width by one-dimensionallyfocusing of beam with 20mm width at T1-3 beam
port (HERMES) in JRR-3M, JAEA. The amount ofdetected neutrons had good agreement with that
expected by the Monte Carlo simulation.

The other is with paraboloidal surface (PRB,
Fig.2) for cold neutrons of 8.8Å. The PRB consistedof four pieces of quartz glass substrates with aquarter of a paraboloidal surface. The curved
surfaces of these pieces were coated by 3Qc Ni/Ti
supermirror, 1.5Qc Ni/Ti supermirror, Ni monolayer,
and no material. The total length and focal distancewas 165mm and 54mm, respectively. It converged
6.9 times as many neutrons of 9.5Å on the area of
1mm2 by two-dimensionally focusing of beam with
20mm in diameter at NOP beam port in JRR-3M,
JAEA. The amount of detected neutrons was about
14% in comparison with what is expected by theMonte Carlo simulation, because of extensively
peeling off of 3Qc supermirror.
A supermirror with higher-Qc and higher
reflectivity makes devices with curved supermirrors
smaller and more efficiently. The accuracy in shapeof parabolic and paraboloidal surface decreases lossof neutrons to be focused. The studies of bothcoating of supermirrors on curved surfaces andfabricating of curved surface are in progress.

Fig. 1

Fig. 2314

A focusing mirror with multiple-parabolic surfaces
for thermal neutrons.

A focusing mirror with a paraboloidal surface forcold neutrons.

Neutron Spin Manipulation for Neutron Decay Dsymmetry and T-violating Neutron
Transmission Measurements
Y. MASUDA, V.R. SKOY, T. INO*, S. JEONG and Y. WATANABE
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization, Tsukuba,
Ibaraki, 305-0801*Institute of Material Structure Science, High Energy Accelerator Research Organization, Tsukuba,
Ibaraki, 305-0801
We have succeeded in pulsed neutron Ramsey
resonance.
Ramsey resonance is a precession
nuclear magnetic resonance (NMR), which has beenused for atomic clocks and electric dipole momentmeasurements. In the Ramsey resonance, Larmor
precession in a static field between two
radiofrequency (RF) coils is observed as an
oscillation as a function of RF frequency. Thisoscillation term is call Ramsey fringe, which
increases the sensitivity of the NMR. We haveapplied the Ramsey resonance to a pulsed neutron
beam, and then succeeded in precise neutron spin
manipulation, which will be used for a neutron b
decay asymmetry measurement and a time reversal
experiment on polarized neutron transmission
through a polarized nuclear target.
In Fig. 1, the apparatus for the Ramsey
resonance, which comprises a neutron spin polarizerof polarized 3He, two RF coils, and a neutron spin
analyzer of polarized 3He in their respective
solenoids, is shown. The apparatus is placed in apulsed neutron beam line. The principle of theRamsey resonance is shown in Fig. 2. Neutrons
from a pulsed neutron source are polarized in theneutron beam axis, z-axis upon transmission throughpolarized 3He nuclei. The two RF coils produce
rotating fields of H1eiwt. If the frequency w is w0 =gH0, the neutron spin sees only H1 as a static field ina rotating frame with frequency w. H0 is the static
field induced by the solenoid. In the first RF coil,the neutron spin rotates from z- to x-axis in therotating frame, when gH1t = p/2. t is a neutron
time of flight in this coil. After the first RF coil,the neutron spins rotate with the frequency w0
around the static field H0, and then enter the second
RF coil, which produces a coherent field with thefirst rotating field.
Here, the phase relation
between the rotating field and the neutron spinrotation does not change. The phase angle of H1with respect to the neutron spin is always p/2. As aresult, in the second RF coil, the neutron spins
continue to rotate around the field H1 from the x- to

Fig. 1 Apparatus for Ramsey resonance315

Fig. 2

Pulsed neutron Ramsey resonancethe –z direction in the rotating frame. And finally,
the neutrons pass through the neutron spin analyzer.
When the rotation phase angle of the neutron spin isdeviated from p/2 by q, a cosq component of theneutron spin is analyzed. Neutrons from the pulsed
neutron source enter the RF coils in order of velocity.
We have applied the rotating field synchronized theneutron arrival times in a neutron energy region
from 23.6 to 80 meV. We have modulated theamplitude of H1 as a function of the neutron arrival
time so that the equation, gH1t = p/2 is satisfied.
At the resonance, w = w0, the deviation angle q
becomes 0. We have calculate a ratio R, which isrepresented as R = Ton/Toff – 1. Here, Ton and Toffare the neutron counts with and without the rotating
fields, respectively. The result is shown in Fig. 3

as a function of the neutron energy.
We have estimated the ratio by mean of a density
matrix formalism. The red curve is the theoreticalcurve which fits the result. The slope in Fig. 3
arises from the neutron energy dependence of thepolarization cross section of (n, a) reaction. We
have also modulated the phase of the second rotating
field from o to 2p as a function of the neutron arrival
time. The result is shown in Fig. 4.
We will apply the present result to neutron spin
manipulation in the measurement of the b decay
asymmetry rand rthe P-odd and T-odd spin correlationrr
term, (s I ) rk , between the neutron spin s , thernuclear spin I , and the neutron momentum k .
The neutron spin should be precisely controlled in
the b decay asymmetry measurement, since theFig. 3 Neutron transmission at Ramsey resonanceFig. 4 Ramsey resonance with phase modulation

Fig. 3 Neutron transmission at Ramsey resonance316

Fig. 4 Ramsey resonance with phase modulationprecision of the measurement is limited by theneutron polarization error.
In the T-violation
experiment, the neutron spin should be vertical to
the nuclear spin which is polarized in a magnetic
field.
The neutron spin rotates around thismagnetic
field. In order to hold the direction ofr rs I vertical to the neutron momentum, the Larmor
precession is cancelled by the pseudo magnetic
precession which is induced by a spin dependent
strong interaction. We will use the pulsed neutron
Ramsey resonance for the measurement of apseudomagnetism in a polarized nuclear target andthen for the neutron spin control.
In addition,
we can also apply the pulsed neutron Ramsey
resonance to the measurement of the neutron
velocity. The oscillation shown in Fig. 4 depends
on the neutron velocity.

317

Neutron Studies of High Boron Carbide Content, Resin Bonded, Neutron Shielding Materials:
KENS Original B4C-resin
K. SUZUYA, K. KUSAKA, S. TORII, S. HARJO, K. AIZAWA, S. SATO*, T. KAMIYAMA**
and M. ARAI
Quantum Beam Science Directorate, Japan Atomic Energy Agency,
Tokai-mura, Naka-gun, Ibaraki, 319-1195*High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801** Division of Quantum Science and Engineering, Graduate School of Engineering,
Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810
Boron carbide (B4C) has been used in many
forms for neutron shielding because of the large
thermalandepithermal
neutroncapturecross-section of 10B and because it is an inert
material. However, boron carbide is difficult tomachine due to the hardness so other methods ofshaping it for neutron shielding have been used.
Boron carbide grit can be poured into a containersuch as an aluminum can or a thin polyethylene bag,it can be sintered to form sheets, or it can be bonded
together with a binder.
Because powder-metallurgically sintered boron
carbide (sintered-B4C) is expensive and the forms of
the products are limited, the resin bonded boron
carbide (B4C-resin) tiles, have been widely used forneutron shielding. Resins have small neutron capture
cross-sections and contain hydrogen which isefficient at thermalising neutrons, but if the resin
content is minimized the composite materials has alarge neutron capture to scatter ratio for both
thermal and epithermal neutrons, Prof. N Watanabeand his co-workers of KENS Japan have developeda recipe and technique for producing a composite
with a resin content of 6-10 wt% [1]. In attempting
to repeat these results in ISIS, Pugh et al have found
two optimal compositions of the B4C-resin that havegood mechanical properties, fairly uniform density
and allow for simple fabrication techniques [2].
An aim of this study is to investigate the neutron
scattering background from the surface of the
B4C-resin shielding tiles to achieve the highest
possible signal-to-noise ratio with the lowest
possible cost. For comparison with other B4C
products, the sintered-B4C tile (EaglePitcher, size
100 mm x 100 mm, and 1 mm thickness) is used as astandard. Neutron diffraction experiments have been
performed using RAC spectrometer installed at
KENS, Tsukuba, Japan. We set a sample and a 3He
detector with the flight paths L1 = 13 m
(moderator-sample), L2 = 0.35 m (sample-detector)
318

and the scattering angle 2� = 45 deg. The B4C
sample plate was set at the sample position insymmetric � -2� (45°–90°) reflection geometry as
shown in figure 1. We investigate two compositionsof B4C-resin tile. “Crisp-type” tile has thecomposition of 3 wt% epoxy resin (Grout-type,
Sho-Bond) and 97 wt% B4C grit (Wacker Ceramics).
The B4C grit consists of three particle-sizes: F20(course) 38 wt%, F40 (medium) 56 wt%, F60 (fine)
3 wt%. Another type of B4C-resin, “Flexible-type”,
is composed of 10 wt% epoxy resin and 90 wt%
B4C grit (F20: 35 wt%, F40: 52 wt%, F60: 3 wt%).
The mix was cast in an open mold (size 100 mm x
100 mm, and 1 mm thickness) and was oven cured
at 120 C° for 2 hours.

Sintered-B4C (sample)
Detector box(B4C-resin)

Neutrons

Fig. 1

Layout of neutron diffraction measurements of
B4C tiles at RAC spectrometer, KENS.

Figure 2 shows neutron time-of-flight diffraction
profiles of the B4C-resin tiles and the sintered-B4C
tile with background profile. (The backgroundprofile was measured by a detector located in theclosed B4C-resin detector box.) In the profiles there
are many broad peaks that can be assigned to theBragg peaks of B4C crystal (R3m, rhombohedral)
[3].
10000
B4C-resin Flexible-type Back-side
B4C-resin Crisp-type Face-side
Sintered B4C

Intensity

B.G. (Shielded detector)

5000

0
0

5000

10000

15000

TOF (micro sec)

Fig. 2Time-of-flight neutron scattering spectra of two
type B4C-resin materials and a sintered-B4C.

The scattering intensity from the back-side(resin-rich side) of the flexible-type B4C-resin tile ishigher than those of other samples because of thelarge incoherent scattering from hydrogen atoms in
the resin-rich surface layer. On the other hand, thescattering intensity from the face-side (B4C-grit-richside) of crisp-type B4C-resin tile is relatively low
and is almost identical to that from the surface of thesintered-B4C tile.
These data show that the crisp-type B4C-resin isa good candidate for low cost shielding materials
covered inside the scattering chamber of neutron
scattering instrument instead of costly sintered-B4C
tiles.
References
1) N. Watanabe, private communication.
2) V. T. Pugh and B. W. Hendy, ICANS-VIII(1985) proceedings, Report RAL-85-110 (1985)
670.
3) H. L. Yakel, Acta Cryst. B31 (1975) 1797.

319

Development of Microwave-Induced Optical Nuclear Polarization
S. MUTO, T. INO, M. FURUSAKA, H. M. SHIMIZU1, H. SATO1, T ADACHI1 and M. IINUMA2High Energy Accelerator Research Organization, Tsukuba 305-0801
The Institute of Physical and Chemical Research (Riken), Wako 351-0106
2
Photon Physics Laboratory, ADSM, Hiroshima University, Higashi-Hiroshima 739-8530
1

For the spin dependent neutron scatteringexperiments, we have been developing a techniqueTheof proton spin polarization in samples.
neutron scattering cross section is depending on
neutron and nuclear spin. In neutron scatteringexperiments, a manipulation of neutron spin is welldone by using various method in neutron spinpolarizers. On the other hand, nuclear spin insample materials are not still well controlled. We
try to control spin of sample nuclei and to observe inneutron scattering.
As a method of nuclear proton polarization, amicrowave induced optical nuclear polarization(MIONP) technique has been used[1].
The
MIONP is applicable in a low magnetic field and at
a rather high temperature.
A scenario of
naphthalene proton polarization is as follows. A
single crystal of pentacene doped naphthalene isused for a sample. An excited triplet state ofpentacene is aligned in decay sequence of following
optical pumping, as shown in fig. 1. During a life
time of the excite state, an electron alignment istransferred to a proton spin polarization by dynamic
nuclear polarization (DNP) using electron spinresonance (ESR) technique. A pentacene proton
polarization, then, is transferred to naphthalene
proton by nuclear dipole-dipole interaction.
S’
12%

S1

microwave (DNP)
T0
optical pump

76%
12%

~20�s

electron+proton spin

S0electron spin

Fig. 1 Energy levels of pentacene.
The H8 beam-line was used for an experiment.
The MIONP system consisted of equipments of amagnet and a micro-wave generator for the ESR, axenon flash lump for optical pumping, a magnetic
field sweep controller for DNP, as shown in fig. 2.
320

Neutron were detecting in two ways, one is atransmission counting for normalizing for neutron
beam intensity. And PSD counters are counting
scattered neutron[2]. The samples of naphthalene
were cooled by liquid nitrogen blowing, and kept
under a temperature of -40oC.
50Hz
Polarization transfer(ISE)

Photo Excitation
Pulsed Light

F.G.

Xenon Flash Lamp 60W
AC P/S
PSD

Monitor Counter
BMOD Coil ~10G

Cavity Q~1000

Neutron Source
B0, BMOD

B0 Magnet ~3kG

Transmission Counter

naphthalene crystal
B0

Gunn diode~ 9.5 GHz
ESR

Oscilloscopepentacene~10 m

Fig. 2 Schematic view of the experimental setup
Preliminary results of the experiment have nosignificant change of count rate at bragg spot in PSD
counters. The reasons of the result maybe caused
by insufficient optical power in absorb wave lengthof pentacene, which make low polarization
production, and relatively high sample temperature,
which make low relaxation time.
Inaddition to the experiment at the H8 beam-line,
a preparation for an experiment at the FOX
spectrometer has be preformed with collaboration of
the FOX group. The FOX spectrometer can find a
crystal axes precisely so that easily identify intense
bragg spot. The result of the FOX experiment israther good, but difficulty is due to the fact that the
sample of pentacene doped naphthalene, apolarization axis of pentacene x-axis and c-axis ofsingle crystal naphthalene host is not same direction.
References
1) M. IInuma et al., Phys. Rev. Lett. 84 (2000) 171.
2) S. Satoh et al., KEK Report 2001-9.

Neutron Resonance Imaging – an Application of Computer Tomography
T. KAMIYAMA, H. Sato, J. ITO, H. NODA, H. IWASA, Y. KIYANAGI and S. IKEDA*
Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628*Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba,
Ibaraki, 305-0801
Neutron resonance absorption spectroscopy(N-RAS) has been applied in the field of thematerial science, such as to layer compounds [l] orionic conductors [2], because the technique candistinguish the dynamics of individual nuclides
having resonance peaks. We can identify the
motions of a particular nuclide with its resonanceenergies of neutron absorption, and analyze thedynamics of nuclides from the Doppler broadeningof the resonance peaks due to their thermal motion.
Some of the resonance absorption cross sections
have very large values, for example, 73Ta has 13,000
barns at 4.28 eV, and then N-RAS has very highsensitivity.
In the spectrometer DOG at KENS, theresonance absorption spectrum is recorded with theprompt gamma ray from the absorption phenomenon.
From the line shape analysis of the spectrum, we candeduce a parameter that is called the effective
temperature, Teff, which has an asymptotic trendwith the actual local temperature of the target
nuclide over room temperature. Using this character,we can measure the local temperature on the nuclide.
That is they work as a thermal sensor of the atomicsize.
In actual measurements, the obtained spectrum isseen to include internal information of the target
object, since neutrons have high penetration power.
The internal information can be reconstructed as thetemperature distribution over a planar cross-section
With CTusing computed tomography (CT).
analyses of the N-RAS spectra we deduce at thesame time the nuclide distribution and temperature
distribution on the cross-section of an object. The
development of this neutron resonance imaging(NRI) method has links to new industrial
applications for neutrons, namely remote-sensing
and non-destructive analysis for mechanicalequipment or new material; in future, neutron
spectroscope.
The measurements were carried out on theneutron resonance absorption spectrometer DOG
installed at KENS at the High Energy Accelerator
Research Organization (KEK) in Japan [1, 2]. DOG
is set up at the light water moderator port and its

flight path length to the sample is 9.53 m. The
sample absorbs neutrons with a resonance energy ER
and then emits the prompt gamma ray by (n, )
reaction. Plastic scintillation detectors installed on
both sides of the sample detect the gamma rays andthe events are recorded by time analyzers, whichhave time channel widths of 31.25 ns and 16000
channels. The absorbed neutron energy isdetermined from the neutron flight time between themoderator and the sample.

Fig. 1 Reconstructed result of temperatures for the
homogeneous object obtained by N-RAS with CT.
Sample objects have a cylindrical shape of 17
mm diameter and 100 mm height. The homogeneous
type object contains Al2O3 and TaC powders

321mixture. The inhomogeneous type consists of Al2O3
powder and 4 Cu pipes (4 mm outer diameter, 3 mm
inner diameter), including a homogeneous mixtureof Al2O3 and TaC. The Ta concentration wasdetermined to avoid deformation of the spectral
shape by excess absorption [1]. Inside the object
there was a thermal gradient from the center to therim. The temperature at the center was around
140 °C and at the rim 40 °C. The finite element
method was used to estimate the actual temperature
distribution. We obtained the resonance spectra fromthe object through an incident slit of 2 mm width.
The slit was moved 10 times in 2 mm steps. At eachslit position for the inhomogeneous object the object
was rotated between 3 angles,  =0,  /8 and /4.
The spectra of the other positions were substituted
for them because of the object symmetry. With thespectrum for the all combinations of the slit
positions and the rotation angle  the CT
calculations were carried out using the Fouriertransformation or maximum entropy methods.

Fig. 2. Reconstructed result of temperatures for the
inhomogeneous object obtained by N-RAS with
CT. The upper figure shows the planarcross-section of the object; the bright area
implies the existence of Ta and indicates its
temperature. The lower shows a comparison
between the reconstructed (the circles) andestimated (the line) temperature distributions
along the A axis. The shaded areas correspondto the Ta rods positions.

322

Figure 1 shows the reconstructed result for the
homogeneous object (lower). The result haveobtained by reconstruction with the Teff values
deduced all combinations of the slit positions andthe rotation angle. The upper figure shows theestimated temperature distribution calculated by thefinite element method. The experimental andcalculated distributions are well coincide with eachother except the center area. This disagreement
comes from the coarse resolution of the moving
neutron slit.
Figure 2 shows the experimental results for the
inhomogeneous object. The spatial distribution wasreconstructed by CT technique with the Teff values
deduced from the 2 mm slit and the 12 angles. The
upper 73Ta distribution map shows the planarcross-section of the sample object. The color scalecorresponds to the local temperature of 73Ta. The
bright area shows the existence of 73Ta, and anincrease in brightness indicates that it is a higher
temperature. The outer circle corresponds to theobject rim, and the 4 small circles to the Ta rods
positions. The Ta positions are all bright in the
figure; the result agrees with the actual object
structure. The lower figure shows the temperature
distribution along cross-section A on the upper map.
The temperature reconstructed by CT is shown ascircles. The temperature at the area where Ta wasnonexistent could not be obtained, but was assumed
as 0 °C for convenience. The broken line shows theestimated temperature distribution and that Ta exists
within the shaded areas. The reconstructed Ta
temperature is well close to the estimated one and its
areas of interest (not 0 °C) are limited inside the Ta
position.
The results of figs. 1 and 2 are reconstructed
ones with the series of fitted parameters of Teff forthe each slit and angle position spectrum. There isanother approach to make the tomograph, that isreconstruct the each time channel intensity data.
Figure 3 shows the reconstructed spectrum with thisway for the inhomogeneous object. In the uppergraph the energy axis is corresponds to the 73Ta
resonance region and there are looking 4 colored
region inside the space. The color means theabsorption intensity, then it shows the 4 absorption
peaks appear corresponding to the 73Ta resonanceabsorption. These intense areas are agreed with the 4
Ta rod positions in the object. The middle and lower
figure are absorption intensity distributions along
the anises A and B shown in the upper figure. The
axis A passes through the center at one of Ta rods

and the axis B through the center of the object where
no Ta exists. The Ta resonance peak appears in theintensity distribution along the axis A, but no peaks
are shown on the axis B. This result shows thepossibility of the spectrum reconstruction with thismethod.

is considered the same origin within the fig. 1.) This
well agreement implies that the spectral shapes are
kept in this method, and the method can be said
reliable.

Fig. 4. Position dependence of effective temperature Teff
from the resonance peak shape analysis of thereconstructed
intensity
spectraforthehomogeneous object. The red line shows thecalculated results with the finite element method.

References[1] K. Kaneko, T. Kamiyama, Y. Kiyanagi, T.
Sakuma and S. Ikeda, J. Phys. Chem. Solids, 60(1999) 1499.
[2] K. Tokuda, T. Kamiyama, Y. Kiyanagi, R.
Moreh and S. Ikeda, Jpn. J. Appl. Phys., 40 Part
1 (2001) 1504.

Fig. 3. Reconstructed result of each time channel intensity
forinhomogeneous
object(upper);A
reconstructed intensity spectrum along the axis A
is shown in the middle, and along the B in thelower. The axis A is along the center of the Ta
rod, and B along the center of the object.

To confirm the accuracy of the reconstructed
spectrum, we got the parameter Teff with fitting fromthe homogeneous object result. Figure 4 shows thecomparison the Teff and estimated sample
temperature. The position dependency of thetemperature is well agreed with each other, except
for the object center. (The disagreement in the center
323

Measurement of Spatial Distribution of Neutrons Penetrating into a Thick Concrete Shield
K. MASUMOTO, Q. WANG, A. TOYODA, N. NAKAO, H. MATSUMURA, M. KAWAI*
and T. SHIBATA
Radiation Science Center, Applied Research Laboratory, High Energy Accelerator Research
Organization, Tsukuba, Ibaraki, 305-0801
Neutron Science Laboratory, Institute of materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
Recently, high intensity and high energy
accelerators are constructed. In case of theirfacilities, neutron shielding and activation are mostimportant concern in the field of radiation protection.
To study the behavior of high-energy neutrons, anexperiment was performed at the KENS spallation
neutron source facility.
The Fig.1 shows the vertical cross sections of thehigh-energy neutron beam course of KENS arranged
for our experiment. The neutrons produced in theforward direction from a tungsten target bombarded
by 500MeV-5μA protons are available at 2.5-mfrom the target center, and ordinary concrete shields
of 4-m-thickness were newly assembled in contact
with the beam exit.

Fig. 1 Cross-sectional views of the KENS high energy
neutron beam course

In this work, small circular gold foil (10mmφand 0.05mm in thickness) and small square Al foil
(10×10mm2 and 0.1mm in thickness) were selected
to monitor the thermal neutron flux and fast neutron
flux, respectively. The gold foils with and without
Cd cover (10mmφ and 0.05mm in thickness) werealso set to measure the epithermal and thermal
neutron flux ratio on the beam axis by cadmium
ratio method.
In order to obtain the two-dimensional
distribution of the neutron flux inside the 4-m
concrete shield, activation detectors (Au and Al foil)
were fixed on the beam axis, 40-, 80- and 120-cm
off the axis at 7 slots of various depths of concrete
shield. The detectors were also set horizontally andvertically on the end surface of the 4-m concrete
shield.

324

The radioactivity of 198Au induced by the 197Au(n,γ)198Au reaction with 98 barn for thermal and 1550
barn for epithermal capture cross-section and 27Al(n,α)24Na and 27Al(n, sp)22Na reactions induced in Al
were also monitored. After one week irradiation, theactivation detectors were collected and pasted on across sectional plan of the irradiation setup, whichcorrespond to monitoring points of each detector.
The IP (BAS-SR2025, Fuji Photo Film Co.) was
overlaid with the plan to measure the activities ofthe detectors simultaneously for an appropriate
exposure time. The IP was scanned with abio-imaging analyzer (BAS-1800II, Fuji Photo FilmCo.). A color image of the activity of the activation
detectors was obtained as a two-dimensional map by
the software (MacBAS, provided by FUJIX Co.).
The intensity of the photo-stimulated luminescencein the unit of PSL was calculated automatically forthe position of each activation detector. The image
data was superimposed on the plan of the concrete
shield on a computer display.
In order to obtain the conversion factor from PSL
intensity to the activity of 198Au in Bq, someselected gold foils were measured. An automatic
gamma-ray spectrometer, which comprises a
Ge-detector (Ortec GEM-20195), a multi-channel
analyzer (TRUMP, SEIKO EG&G) was used for
γ-ray measurements. The counting time waschanged from 2000 to 10000 sec for each activation
detector. Each foil was set on a Ge-detector surface
during measurements..
It was confirmed that the PSL values linearly
increased in proportion to the activity of 198Au. An
empirical relation for 198Au, PSL=0.09 × (activity,Bq) × (exposure time, min), could be obtained
within 3 to 6% RSD for exposure times of 5 to 60min.
By using same method, the empirical relationsfor 24Na and 22Na were also obtained to be
PSL=0.129 × (activity, Bq) × (exposure time, min),and PSL=0.0993 × (activity, Bq) × (exposure time,min), respectively.

Exp.

Cal.
on the beam axis
40cm off the beam axis (x 10 -1)

The observed depth profiles of reaction rates of
197
Au(n, γ)198Au is shown in Fig. 2. It was found thatreaction rates are exponentially decreased withthickness and reaction rate become constant at every
hight outside of the shield (4m).

80cm off the beam axis (x 10 -2)
-4

10

-19

10

-21

10

-23

10

-25

10

-27

10

-29

-1

-1

Reaction Rate [atom �C ]120cm off the beam axis (x10 )

10

-15

on the beam axis
40cm off the beam axis
80cm off the beam axis
120cm off the beam axis

10-16
10

-17

x 10-1x 10-2x 10-4

10-18
10-19

0

Fig. 4 Comparison of the reaction rate of 27Al(n, α)24Na-21

between experimental and calculated results.

10-22

0

50

Fig. 2 Reaction rates of 197Au(n,γ)198Au in concrete shield

As shown in Fig.3, the reaction rate of Au
activation detector by epithermal neutrons in
concrete shield surface were about 2 times larger
than that caused by thermal neutrons beyond a depthof 50cm because epithermal neutrons were gradually
thermalized to thermal neutrons. The thermal andepithermal neutron flux ratio on the beam axis was
about 30 and almost constant for every slot except
for slot-1 which faces the target.
-15

10

7

10

6

10

-16

10

-17

10

5

10

-18

10

4

10

-19

10

3

10

-20

10

2

10-21

101

10

-22

10
0

50

Thermal/Epithermal Flux Ratio

Reaction Rate [atom -1 �C-1]

Epithermal
ThermalT/E flux ratio

In this work, reaction rates at beam axis of
Au(n, γ)198Au, 27Al(n, α)24Na and 27Al(n, x)22Na
are exponentially decreased. Therefore, the intensityof thermal and fast neutrons exponentially attenuate
through the 4-m thick concrete shield. Moreover, it
was found that the distribution of thermal neutronsin irradiation room behind concrete shield was
almost uniform.
The combined use of activation detectors and IP
was very useful, because the activity of many pieces
of detector can be measured simultaneously without
any efficiency correction and decay correction. The
high detection sensitivity and good linearity werealso obtained. This technique was utilized in the
KENS shielding experiment, and the attenuation
profiles and spatial distribution of thermal to few
MeV neutrons inside the concrete shield could begrasped at a glance as the two-dimensional map.
On the other hand, the obtained experimental
data will be useful to understanding the neutron
propagation in the concrete shield and designing aneffective shielding of neutrons.
Our work has been published as follows.

197

100 150 200 250 300 350 400

Concrete Shield Thickness[cm]10100 150 200 250 300 350 400

Concrete Shield Thickness [cm]

10-20
10

50

0

100 150 200 250 300 350 400

Concrete Shield Thickness (cm)Fig. 3 Depth profiles of thermal and epithermal neutronsFig.4 shows a comparison of reaction rates ofAl(n, α)24Na between the experiments andsimulation using the MARS14 Monte Carlo code.
The results show a good agreement.

References
1) N. Nakao et al.; J. Nucl. Sci. Technol. Suppl.
4,22-25, 2003
2) Q. Wang et al,; J. Nucl. Sci. Technol. Suppl.4.
26-29,2004
3) K. Masumoto et al.; J. Radioanal. Nucl. Chem.
271, 2007(in press)

27

325

Measurement of the 36Cl Production Rates from Cl, K, and Ca in Concreteat the 500-MeV Neutron Irradiation Facility at KENS
T. AZE1, M. FUJIMURA2, H. MATSUMURA3, K. MASUMOTO3,
N. NAKAO3, H. MATSUZAKI4, H. NAGAI5, and M. KAWAI3
1

2

Graduate School of Science, the University of Tokyo, Bunkyo-ku, Tokyo 113-0033
Graduate School of Integrated Basic Sciences, Nihon University, Setagaya-ku, Tokyo 156-8550
3High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801
4
Graduate School of Engineering, the University of Tokyo, Bunkyo-ku, Tokyo 113-0033
5College of Humanities and Sciences, Nihon University, Setagaya-ku, Tokyo 156-8550

Introduction
In high-energy accelerator facilities, concrete
walls and floors, beam ducts, targets, and beam
dumps are exposed to secondary neutrons of various
energies during machine operation. In the case of
concrete, the neutrons produce various long half-liferadionuclides, such as 3H, 36Cl, 60Co, and 152Eu.
Since most of the nuclides are mainly produced bythermal neutron-capture reactions, estimating their
specific activities or the neutron fluence producedby the primary beam is important for releasing theconstruction components into the environment after
a facility is decommissioned. In order to investigate
the specific activity of 36Cl at various accelerator
facilities, Bessho et al. developed the 36Cl-AMS
technique for activated concrete, and measured theratios of 36Cl to 35Cl at various depths of concretecore samples obtained from the SF-cyclotron room[1]. The SF-cyclotron mainly provided protons(maximum energy, 40 MeV) for a 20-year operation
period. The maximum 36Cl/35Cl ratio was observed
at a depth of around 10 cm from the surface, and its
value was approximately 1 × 10–9. This depth profile
is similar to those of other nuclides produced bythermal neutrons. Therefore, it was found that 36Cl
in the concrete was mainly produced by thethermal-neutron capture of 35Cl. Furthermore, it wassuggested that measuring 36Cl in the concrete would
be useful for accurately monitoring thethermal-neutron fluence, which would enableestimation of the activities of other nuclides
produced by thermal neutron-capture reactions.
In the case of accelerators that provide
high-energy particles (over several hundred MeV),
especially downstream of the beam dump, 36Cl, in
addition to its production from the thermal-neutron
capture of 35Cl, can be produced in a considerablylarge amount by high-energy neutrons via spallation
reactions of other concrete components, such as K
and Ca. However, the production rates of 36Cl
produced from these elements by high-energy
326

neutrons have not yet been measured. Therefore, inorder to reveal the characteristics of 36Cl productionin the concrete of high-energy accelerator facilities,
we measured the production rates of 36Cl from Cl, K,
and Ca at various depths in concrete downstream of
the tungsten target, which completely stopped the
500-MeV protons. In this study, we showed depth
profiles of the production rates of 36Cl from Cl, K,
and Ca, and considered whether the monitoring ofthermal neutrons using the 36Cl measurement in
concrete is applicable to high-energy accelerator
facilities.
Experimental
The irradiation was performed at the high-energy
neutron-irradiation course of the Neutron Science
Laboratory (KENS), High Energy Accelerator
Research Organization (KEK). Secondary neutrons
were produced by the bombardment of primary
500-MeV protons on tungsten targets. The neutrons
were collimated along the beam axis using a neutron
beam guide, and passed through the shield concrete.
This course has seven irradiation positions, referred
to as slots 1 to 7, that irradiate at various thicknessesof the shield concrete. The depths from the concretesurface to slots 1 to 7 were 0, 40, 80, 130, 185, 250,
and 320 cm, respectively. This irradiation course isdescribed in detail in Refs. [2, 3].
Powders of NaCl, K2CO3, and CaCO3, whichwere sealed in individual polyethylene bags, wereused as targets and placed into each slot on thebeamline. The chemical purities of NaCl, K2CO3,
and CaCO3 were 99.99%, 99.9%, and 99.99%,
respectively. Approximately 15 mg of the NaCltarget was placed in each slot, while the weights of
the K2CO3 and CaCO3 targets were approximately
0.5, 0.5, 0.5, 1.0, 2.0, 5.0, and 5.0 g for slots 1–7,
respectively. The irradiation time was 12710 min
and the average current of the primary protons was
6.447 μA.
After irradiation, each irradiated target was

10-16

Cl target
K targetCa target

36

-1

-1

Cl Production rates (atom ・�C )

10-17

10-18

10-19

10-20

10-21

10-22

10-23

0

100

200

300

Concrete thickness (cm)400

Fig. 1 Production rates of 36Cl from Cl, K, and Ca
targets in each slot. The vertical axis represents the
production rate per target atom per μC of the
primary proton. The circles, triangles, and squares
indicate the production rates of 36Cl from Cl, K, andCa, respectively. The error bars indicate the 1σ valueof the statistical error and the 3.2% of the scatteringof the repeated measurements in the AMS.
1000Cl Production rate ratio, Cl/Ca

Results and discussion
The production rates of 36Cl from Cl in slots 1–7;
K, slots 1–4; and Ca, slots 1–7 were obtained. The
errors associated with these results include statisticalerrors in the AMS counting, errors introduced at thebackground subtraction, and error due to systeminstability, which is estimated from repeatedmeasurements of standard samples.
Figure 1 shows the depth profiles of the
production rates of 36Cl from Cl, K, and Ca. The
vertical axis represents the production rate per target
atom per μC of primary proton. All of the
production rates decreased exponentially by fourorders of magnitude with an increase in the depth
from the concrete surface, and the profiles were very
similar to each other. However, a slight bow shapearound the surface was observed in the profile forthe production from Cl on the semi-log graph. From
the reaction threshold energies and expected
excitation functions, the reactions of K(n, 2pxn)36Cl
and Ca(n, 3pxn)36Cl are induced by fast neutrons(less than several ten MeV) and that of 35Cl(n, γ)36Cl
is induced by thermal neutrons. Therefore, the depth

profiles indicated that the thermal-neutron flux had
slightly built up around the surface.

800

600

400

200

36

dissolved in 20 ml of water and a few ml of 16 M
HNO3 in a beaker. In the case of K and Ca samples,
1–4 mg of Cl– carrier was added to the solution. A
few ml of a 1.5% AgNO3 solution (equivalent of Cl–
in the solution) was added to the sample solution inorder to precipitate AgCl, which was thencentrifuged and dissolved in a few ml of 15 M
NH4OH. In this step, the radioactivities, such as 7Be
and 22Na can be eliminated from Cl. A few ml ofwater and 16 M HNO3 were added to the samples toprecipitate the AgCl again. The AgCl wascentrifuged and thoroughly rinsed three times with
10 ml of water. Finally, it was rinsed with 5 ml ofethanol and dried at 110?C in an electric oven for six
hours. It was then pressed into a sample holder madeof aluminum for accelerator mass spectrometry(AMS).
The ratios of 36Cl to Cl were measured by AMS at
the Micro Analysis Laboratory, Tandem accelerator(MALT) of the University of Tokyo. The basic
measurement procedure is described in Ref. [4];however, in this study, the injection system for theaccelerator and the detector system were improvedin order to enhance the detection efficiency. A gas
ionization chamber placed behind a gas-filled
magnet was employed as the final ion detector in the
AMS system for ΔE–E detection. The typical beam
current of 35Cl– extracted from the ionizer wasaround 25 μA and the ratios of the samples were
determined by a comparison with the count rates ofstandard samples (36Cl/Cl = 7.98 × 10–11).

0

0

100

200

Concrete thickness (cm)

300

400

Fig. 2 Variation in the 36Cl production rate ratio(Cl/Ca) as a function of the depth from the concretesurface.
In order to clarify the build-up effect, the ratios of
the production rate from Cl to that from Ca wereplotted as a function of the depth from the concretesurface in Fig. 2. The production rate ratios
increased up to a depth of around 150 cm, after
which they became constant. It was observed thatthe thermal-neutron flux increased to a depth of327

around 150 cm, at which it attained equilibrium.
The production rates from Cl were higher by twoorders of magnitude when compared with thosefrom K and Ca over the entire depth observed in thisstudy. In general, however, the concentration of Cl
in concrete is considerably lower than that in K and
Ca. On the basis of NUREG/CR-3474 [5], theconcentrations of Cl, K, and Ca are obtained as 45
mg·kg–1, 0.75%, and 28.3%, respectively. From theconcentrations and the measured production rates,
we were able to estimate the contribution ratios of36
Cl productions from Cl, K, and Ca in concrete. For
example, the estimated contribution ratios of Cl, K,
and Ca in slot 4 were shown in Fig. 3. In the case ofslot 4, the contribution from Ca in the concrete wascomparably greater than that from Cl and K becauseof the abundance of Ca, and the contribution from K
was comparable with that from Cl. As a result, it
appears that the majority of 36Cl in concrete is
produced from Ca. We obtained unfavorable results
concerning the usefulness of 36Cl as an indicator of
the thermal-neutron fluence; however, theconcentrations of Cl, K, and Ca in concrete dependon the source of rocks. Therefore, when the thermal
neutron fluence is estimated from the 36Cl
concentrations in the concrete, it is necessary toconsider the concentrations of Cl, K, and Ca in
concrete.
6.7%
6.8%

Ca
K
Cl
86.5%

Fig. 3 Estimation of 36Cl production contribution
rate in the concrete from Cl, K, and Ca targets at theslot 4.
Conclusions
The neutron-induced production rates of 36Cl
from Cl, K, and Ca targets in shield concrete atvarious depths were measured by AMS. All of the
production rates decreased exponentially by fourorders of magnitude with an increase in the depth
from the concrete surface to 320 cm. The production
328

rates from Ca and K targets were two orders lower
than that from a Cl target at the same concrete depth.
According to our estimations, the contribution of36
Cl production from the Ca target was considerably
greater than that from the Cl and K targets because
Ca is a major component in concrete. Moreover, thecontribution of K was almost equal to that of Cl.
Since the contribution of the spallation from Ca isconsiderably greater at high-energy accelerator
facilities, it is essential to consider the concentrationof not only Cl, but also Ca and K in the shieldconcrete for estimating the thermal-neutron fluence
from 36Cl in shield concrete.
References
1) K. Bessho et al., Radiochim. Acta, to be
published (2006).
2) N. Nakao et al., Proc. The 2ns iTRS International
Symposium on Radiation Safety and Detection
Technology (ISORD-2), July 24-25, 2003,
Tohoku University, Sendai, JAPAN, J. Nucl. Sci.
Technol. Suppl. 4, 26 (2004)
3) N. Nakao et al., Radiat. Prot. Dosim., 116, 553(2005).
4) S. Hatori et al., Nucl. Instrum. Method in Phys.
Res. B172, 211 (2000)
5) Evans, J. C. et al., NUREG/CR-3474, PacificNorthwest Laboratory for the Nuclear Regulatory
Commission, Washington, DC (1984).

Production Yields of the Radionuclides Induced in Various Targets
Fixed in Concrete Shield at the 500-Mev Neutron Irradiation Facility of KENS
H. MATSUMURA1, N. NAKAO1, K. MASUMOTO1, K. OISHI2, M. KAWAI1, T. AZE3, A. TOYODA1,
M. NUMAJIRI1, K. TAKAHASHI1, M. FUJIMURA4, Q. WANG5, K. BESSHO1, T. SANAMI1
1High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
2
Institute of Technology, Shimizu Corporation, Tokyo, Japan
3
Graduate School of Science, The University of Tokyo, Tokyo, Japan
4
Graduate School of Integrated Basic Sciences, Nihon University, Tokyo, Japan
5
The Institute of High Energy Physics (IHEP), Beijing, China
Introduction
In high-energy proton accelerator facilities,
high-energy neutrons are secondarily produced uponbombardment with a proton beam. Such neutrons
have high penetrability, and induce activation of thesurrounding materials. The spectra of the neutrons
and activation of the materials are generally estimatedusing Monte-Carlo simulation codes. It is very
important to confirm experimentally their confidence
from the benchmark.
However, only few experiments for thebenchmark have been performed so far. In particular,
there are no experimental data pertaining to theconditions of “high energy neutron”, “0 degree
direction”, and “thick concrete shield.” We therefore
constructed a high-energy neutron-beam course at
KEK Neutron Science Laboratory (KENS) at theHigh Energy Accelerator Research Organization(KEK) [1, 2]. The course has seven irradiation slots
inside a 4-m-thick concrete shield. High-energy
neutrons were guided to the shield through acollimator of 2.19-m length from a tungsten-target
assembly which completely stopped 500-MeV
primary protons.
Using this course, we have been accumulating
experimental data for following: (1) the spectrum andattenuation characteristics of the neutrons in theconcrete shield and (2) the activation products
induced by high-energy neutron irradiation in thewell-known system at KENS. With regard to the firstpoint, an activation method is most suitable fordetecting neutrons in the limited spaces in theconcrete. Therefore, we have measured the yields ofthe radioactive products from various targets andobserved the attenuation profiles of the neutrons. The

yields obtained from the various nuclear reactions
with different Q-values can indirectly provide
information on the energy spectra of the neutrons andtheir intensities. With regard to the second point, wemeasured many yields of the spallation products fromvarious targets induced by high-energy neutrons.
Following this, charge distributions and mass yield
curves were elucidated from the yields. In this paper,
we introduce a part of our experimental data [1-7],
including the preliminary data, obtained using thehigh-energy neutron-beam course at KENS.
Experimental procedure
The 500-MeV neutron irradiation facility of KENS
The high-energy neutron-beam course of KENS
was designed for this shielding experiment. Figure 1
shows the cross-sectional views of the KENS
high-energy
neutron-beamcourseandthearrangement of the shielding experiment. Secondary
neutrons were produced by bombarding with
500-MeV protons on four tungsten blokes placed in
the tungsten-target assembly. Since the total thicknessof the tungsten blocks was 11.68 cm, the primary
protons were completely stopped in the tungsten
blocks. The produced secondary neutrons werepassed through a 10-cm stainless-steel block placeddownstream in the target assembly, and collimatedwith an iron beam guide to lead in zero-degree
direction. The collimated beam finally reached to abeam exit of 20 cm width × 15 cm height located in a
distance of 250 cm from the target assembly andirradiated on an ordinary concrete of 4 m thickness
which borders on the beam exit. The concrete has
eight irradiation positions referred to as “slot 1” to“slot 8”. They are positioned along the neutron beam329

direction in the concrete shield. The slots 1, 2, 3, 4, 5,
6, 7, and 8 were located on 0, 40, 80, 130, 185, 250,
320, and 400 cm depth from the surface of theconcrete shield, respectively. The more details of thiscourse were described in [1, 2].
Irradiation
The targets of Na2CO3, MgO, Al, Si, KCl,
K2CO3, CaCO3, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn,
In, Au, Au covered with Cd, and Bi were irradiated at
slots 1, 2, 3, 4, 5, 6, 7, and/or 8. The targets wereindividually sealed in polyethylene bags. Plastic
capsules containing the targets were fixed at thebottom of the shield plugs and inserted into the 8 slots,
and set on the beam axis. Nine irradiations werecarried out. The irradiation duration was typically 1
week. The average current of the primary protons was
typically 6-7 μA. The fluctuation of the primary
proton current was monitored during the irradiation.
The beam fluctuation was corrected for radioactive
decays if necessary.
Beam shutter

Detector insertion plugs

1000

Uncontrolled area
Heavy concrete

25 0
x80

Φ15 0

Φ15 0

1500

Ordinary concrete
Iron
590

p

600

700

300

2530

Soil

550

Φ1 0 62 10
x 45

Neutron beam line
400 400

500

550

650

700

2080

800

4000

1500
W target450

assembly

2530
1200

Neutron Irradiation Room

4500

2500

6000

1500

1200

Ordinary concrete

2500

Shield door
4500

6000

Soil

4000

W targetassembly
Neutron beam linepIron

12 3 4 5
Slot-No
5000

6

7

Heavy
concrete

8

5000

3000

Neutron Irradiation Room
Ordinary concrete

Cold Neutron Lab.

Fig.1 Cross-sectional views of the KENS high-energy neutron-beamcourse and the arrangement of the shielding experiment

Measurements of the radioactive products
Spallation products from 197Au
After irradiation, γ-ray spectrometry was
performed with HP Ge detector systems. The
radioactivities of 196Au, 194Au, 192Au, 188Pt, 189Ir, 185Os,
330

183

Re, 181Re, and 175Hf were determined
non-destructively. On the other hand, 173Lu, 171Lu,
169
Yb, and 167Tm could not be detected directly
because of their low activity and high activity of198
Au and neighbor spallation products. Therefore,
they
were
measuredafter
radiochemicalgroup-separation of rare-earth elements. The
radioactivity measurements of target set in the
backward from slot 5 were more difficult than that set
at front side due to their attenuation. For the targets ofslots 5 to 7, low background γ-ray counting was
performed with an anti-Compton and/or X-γ
coincidence system which HP Ge detector coupledwith 3 NaI scintillation counters. All of the yields
were cumulative for the respective β+-decay and/or
electron-capture chains. The details of the samples forthe targets of slots 1 to 5 and the chemical procedure
were described in [5]. Since the details of the samples
and data analysis for the targets of slots 5 to 7 arepreliminary, they have not published yet.
Chlorine-36
After irradiation, chlorine was chemicallyseparated from each irradiated target and finallyprecipitated as AgCl. The amount of the 36Cl was
determined by accelerator mass spectrometry (AMS)
in the Micro Analysis Laboratory, Tandem
Accelerator (MALT) at the Research Center for
Nuclear Science and Technology, the University ofTokyo. The details were described in [6].
Other products
After irradiation, γ-ray spectrometry was
nondestructively performed with HP-Ge detectors todetermine the radioactivities of the products from thevarious targets. The yields of 22, 24Na from Cl wereobtained by subtracting the yields in K2CO3 fromthose in KCl. In order to detect 198Au from Au and Au
covered with Cd, the irradiated gold foils were also
simultaneously exposed to an imaging plate (IP). The
exposed IP was scanned with a bio-imaging analyzer.
The details of the activity determination with the IP
were described in [3]. The yields induced byepithermal neutrons were measured from the Au
targets covered with Cd. We could obtain the yields
induced by thermal neutrons by subtracting the yields
in the Cd-covered Au from those in the non-coveredAu.

10-15

10-15

10-16

10-16

10-17

10-17

-18

10-18

10

10-19
Au
-1
Au 96(x 1-1900
Au 4(x 5 )
0
- 19
2(x )
Pt20)
18
Ir -1 8 (x20)
8O s- 9(x7185 )Re (x5)-1 8
Re 3(x3 )
-18
Hf- 1
175
(x2
Lu
)
-17
3

10-20
10-21
10-22
10-23

(a)

10-24
10

-25

10-26
0

40

80

Yields (1/atom/ C)

Yields (1/atom/ C)

120

160

200

240

Lu
-1 7
Yb 1(x1/2 )-1
Tm 69(x-16 1/3)
7( x
1/ 5
)

280

320

360

10-19
10-20

Bi
-20
5 (x

10-22

10-24
10

-25

10-26
0

400

10-15

10-16

10-16

Au
- 19
8 fr
om
Au
Au
- 19
-19
8 fr
7
om
Au
Au
-19
-19
7 [t
8f
he r
r om
ma
Au
l] (x
-19
1 /3
7 [e
)
C lpith er
36
ma
C l- from
l] (x
36
C
1/3
f r o l (x1/1)
m
K (x 0)
C l36
5)
fr o
m
Ca

10-19
10-20
10-21
10-22

In -

10-23

115
m

(c)

10-24
10-25
-26

0

40

80

fro
m

Bi -2
03(
x

(b)
40

80

Bi202
(x

120

-11
5 (x

10-19
10-20
10-21
10-22

10-24

1/1
00)

10-25

120

160

200

240

280

320

360

400

160

200

240

280

1/1
0)
1/1
00
)

320

360

400

320

360

400

Na
-24
fro
m
Na
Na
- 22
( x1
000
N a from
)
- 22
Na
( x1
N a from- 24
Mg 000)
fro
(x 4
m
00)
M
g
Na
(x 2
-24
00)
fro
m
Na
Al
- 22
(x5
fro
0)
m
Na
Al
- 22
(x3
0)
N a from-24
fro S i ( x
5
m
Na
Si )
- 24
(x3
)
N a from
- 22
Cl
fro
(x2
m
)
Na
Cl
-24
fro
m
Na
K
-22
(x1
/3
fr
)
o
Na
-22 m K
( x1
fr o
Na
/7)
-24
m
Ca
fro
(x1
m
/30
Ca
)
( x1
/8 0
)

10-18

10-23
In

10
)

Bi
-20
4

10-17

10-17
10-18

100
)

Depth of the concrete shield (cm)Depth of the concrete shield (cm)
10-15

10

Bi -2
06(
x

10-21

10-23

Yields (1/atom/ C)

Attenuation profiles of the neutrons obtained by theactivation method
In the activation method, the detectable energyof the neutrons depends on the reaction thresholdenergy. Using the energy dependence, we canindirectly derive information on the spectrum profile,intensity, and attenuation of the neutrons from theproduct yields in the various reactions. Accordingly,
at the slots 1-8, we measured the yields of thefollowing products:(1) 13 spallation products from a 197Au target,(2) 202 - 206Bi in 209Bi(n, xn) reactions,(3) 198Au from a 197Au target and a 197Au target
covered with Cd,(4) 115mIn from 115In,(5) 36Cl from natCl, natK, and natCa targets, and,(6) 24Na and 22Na from 23Na, natMg, 27Al, natSi, natCl,
nat
K, and natCa targets.
The effective energies of the yields are estimatedat to be 8-500 MeV for (1), 10-100 MeV for (2),thermal and epithermal reactions for (3), and 1-10
MeV for (4), and thermal to several 100 MeV for (5)and (6). In particular, the threshold energy in the Au
spallation products covers the widest energy range
among the measured targets in this work. The
threshold energy of 197Au(n, 2n)196Au is 8.1 MeV,
which is the lowest among the (1) products. The
effective neutron energy for this reaction is estimatedat around 10 MeV. On the other hand, the thresholdenergy of 197Au(n, 10p21n)167Tm is 202.9 MeV,
which is the highest among the measured reactions.
The effective neutron energy for this reaction isestimated to be in the range of 350 to 500 MeV [5].
As the results, the effective energies of the 13 Au
spallation products are in the range of 10 to 500 MeV.
Furthermore, whole neutron energies were completely
covered using all the productions of (1) to (6).
In Fig. 2, the measured yields of (a) the

Yields (1/atom/ C)

Results and discussion
Many yields were collected in this work. The
unit of the yield is atom-1μC-1, which indicates the
production probability per target atom and per μC of
the primary protons. We explain the measured yields
in following two separate sections.

spallation products from 197Au, (b) the products of the209
Bi(n, xn) reactions, (c) 198Au from 197Au, 36Cl from
Cl, K, and Ca, and 115mIn from 115In, and (d) 24Na and22
Na were plotted as a function of the depth from thesurface of the concrete shield. The open and theclosed symbols joined by solid lines represent thereported ([1, 5, 6]) and preliminary experimental
yields, respectively. All the yields are exponentiallyattenuated in the concrete shield and their slopes
appear similar regardless of the reactions.

10

-26

0

(d)
40

80

120

160

200

240

280

Depth of the concrete shield (cm)Depth of the concrete shield (cm)Fig.2 Measured attenuation profiles of the various yields of (a) the
spallation products from
(c)

198

Au from197

197

Au, (b) products of

209

36

Bi(n, xn) reactions,24

Au, and Cl from Cl, K, and Ca, and (d) Na and22

Na from various targets

In order to compare the details of the relative
yield variations, the ratios of the yields at each slot tothose at slot 2 are plotted in Fig. 3. The open symbols
denote the experimental values published in [1, 5, 6],
while the closed symbols denote the preliminary
values. The solid lines indicate the average for the Au
spallation products. This figure shows the relativechange in the energy spectra of the neutrons passing
through the concrete shield. The ratios are almost
constant except in the low-energy reactions such as
35
Cl(n, γ)36Cl, 197Au(n, γ)198Au, 197Au(n, 2n)196Au, and
331

100

Bi-206 from Bi
Bi-205 from Bi
Bi-204 from Bi
Bi-203 from Bi
Bi-202 from Bi

Cl-36 from Cl
Cl-36 from K
Cl-36 from Ca

Au-198 from Au
Au-196 from Au
Au-194 from Au
Au-192 from Au
Pt-188 from Au
Ir-189 from Au
Os-185 from Au
Re-183 from Au
Re-181 from Au
Hf-175 from Au
Lu-173 from Au
Lu-171 from Au
Yb-169 from Au
Tm-167 from Au

slot 1/slot 2
slot 2/slot 2
slot 3/slot 2

10-1

10-2

slot 4/slot 2
slot 5/slot 2
slot 6/slot 2

10-3

slot 7/slot 2
10-4

10-5

Fig.3 Ratios of the yields at slots 1, 3, 4, 5, 6, and 7 to those at slot 2

Production yields of radioisotopes from various
targets
The yields obtained from the Au target are alsoavailable for the benchmark of the residual products
from heavy targets. All the yields are cumulative forthe respective �+-decay and/or electron-capture chains.
Since the measured nuclides are closed to stable
isotopes, the yields can be approximately regarded as
mass yields according to the spallation characteristics.
In Fig. 4, the yields from Au target are plotted as afunction of the product mass number. The open
symbols denote the experimental values published in[5], while the closed symbols denote the preliminary
experimental values. The solid lines drawn throughthe points are provided as a visual guide. On thesemi-log graph, it is evident that each mass yield
curve decreases steeply in an arc with a decrease in
the product mass number.
For the benchmark of the residual products frommedium targets, we measured the yields of thespallation products from the 45Sc, natTi, natV, natCr,
55
Mn, natFe, 59Co, natNi, natCu, and natZn targets at slot
2. Although the charge distribution characteristics
332

10-17

slot 110-18

slot 2slot 310-19

slot 410-20

slot 5-1

Yield ratios (slot x/slot 2)

101

Na-24 from Al

102

In-115m from In

103

were unclear for the neutron-induced spallation, we
attempted to fit the spallation yields to an empiricalfive-parameter formula derived by Rudstam [9] thatwas successfully applied to photospallation reactions[8]. Rudstam’s formula (CDMD formula) for charge
distribution (CD) and mass yield distribution (MD) is�PR2/3exp[PA-R | Z-SA+TA2 | 3/2]
Y(Z, A) = ����������������������,1.79{exp(PAt)-1}, where Y(Z, A) indicates the independent yield of a
nuclide (Z, A) obtained from the target (Zt, At) and P,
�, R, S, and T are free parameters. The parameter P
defines the slope of the MD; �, the total inelastic
cross section; R, the width of the CD; and S and T, thelocation of the CD through the most probable charge
Zp = SA-TA2. Figure 5 shows the CD of the spallation
products from the 45Sc, natTi, natV, natCr, 55Mn, natFe,
59
Co, natNi, natCu, and natZn targets. The open squares
indicate independent yields (I); reverse triangles,
cumulative ones for �+ and/or electron-capture decay(C+); and triangles, cumulative ones for �- decay (C-).
The solid lines indicate the CD obtained by the fitting,and the dashed and dotted lines represent the
cumulative yields for C+ and C- estimated using the
CDMD formula, respectively. As shown in the figure,the results of these fittings are very good for all the
products and targets. Therefore, it was confirmed that
the CDMD formula was useful for the yields of theneutron spallation residues obtained at KENS.

-1

In(n, n’)115mIn where the threshold energy is lower
than approximately 10 MeV. The ratios of the yieldsof the low-energy reactions are slightly higher thanthe others at slots deeper than slot 3. Therefore,
without changing the profile of the neutron spectrum
in the range of 10 to 500 MeV, the intensity is
exponentially attenuated with an increase in the depthof the concrete, although there was a small build-up
of low-energy neutrons at depths below 40 cm.

Yields (atom �C )115

slot 610-21

slot 7

10-22

10-23

10-24

10-25

10-26
160

165

170

175

180

185

190

Product mass number

195

200

Fig.4 Mass yields of the spallation products from

197

Au

10-2

nat

2

1

0

Z-Zp

-1

-2

-3

10-2

10-3
5
4
Neutron deficient-4-5
Neutron rich

101

Fe

C�

C+
�

10-1

10-2

3

2

1

0

-1

Z-Zp

-2

-3

2

1

0

Z-Zp

-1

-2

-3

C+
�

10-1

10-2

59

100
C�

C+
�

10-1

10-2

3

nat

2

1

0

-1

Z-Zp

-2

3

2

1

0

Z-Z p

-1

-2

-3

101

Mn

C+
�

10-1

10-2

10-3
5
4
Neutron deficient-4-5
N eutron rich

Ni

100
C�

C+
�

10-1

10-2

10-3
5
4
N eutron deficient

3

2

1

0

-1

Z-Zp

-2

100
C�

C+
�

10-1

10-2

I
�

-3

nat

3

2

1

0

Z-Zp

-1

-2

I
�

-3

10-3
5
4
Neutron deficient-4-5
N eutron rich

101

nat

Cu

100
C�

C+
�

10-1

10-2

I
�
-4
-5
N eutron rich

55

Cr

C�

101

I
�
10-3
5
4
Neutron deficient-4-5
Neutron rich

nat

100

I
�
10-3
5
4
N eutron deficient-4-5
N eutron rich

101

I
�
3

C�

Co

100

10-3
5
4
N eutron deficient

100

Fraction of isobaric yields

10-1

Fraction of isobaric yields

Fraction of isobaric yields

101

3

V

C+
�

I
�

I
�
10-3
5
4
N eutron deficient

101

51

Ti

C�

Fraction of isobaric yields

10-1

101

nat

100

Fraction of isobaric yields

C+�

Fraction of isobaric yields

Fraction of isobaric yields

Fraction of isobaric yields

ScC�

Fraction of isobaric yields

101

45

100

Fraction of isobaric yields

101

3

2

1

0

Z-Zp

-1

-2

-4
-5
N eutron rich

10-3
5
4
Neutron deficient

3

2

1

0

Z-Zp

-1

-2

-4
-5
Neutron rich

100
C�

C+
�

10-1

10-2

I
�

-3

-3

Zn

I
�

-3

10-3
5
4
Neutron deficient-4-5
N eutron rich

3

2

1

0

Z-Zp

-1

-2

-3

-4
-5
Neutron rich

45

Fig.5 Charge distributions of the spallation products From the Sc,
nat

Ti,

10-18

45

Mass yields (1/atom/�C)

10-19

nat

V,

nat

55

nat

Cr, Mn,

10-18

Sc

nat

10-19

59

Fe, Co,

10-18

Ti

nat

Ni,

nat

10-19

nat

Cu, and

10-18

V

10-20

10-20

10-20

10-21

10-21

10-21

10-21

10-22

10-23
20
10-18

55

10-19
10

25

30

35

40

45

50

55

10-22

10-23
60
20
10-18

25

nat

Mn

10-19

-20

35

40

45

50

59

Fe

10-19

-20

25

30

35

40

45

50

55

10-23
60
20
10-18

10

10

10-21

10-21

10-22

-23

-23

-23

nat

10-19

30

35

40

45

50

55

10-18

Cu

10-19

10-20

25

nat

30

35

35

40

45

50

55

60

30

35

40

45

50

55

60

10-22

40

45

50

55

10
60
20

50

55

60

65

70

25

30

35

40

45

50

55

10-23
60
20

25

Zn

10-20

10-21

10-21

10-22
10-23
30

10
60
20

30

Ni

-20

10-22
25

25

10-19

10-21

20

Cr

nat

Co

-20

10-22

10-18

Zn targets

10-22

-23
6010 20
10-18

55

10-21

10

10

30

nat

10-19

10-20

10-22

nat

Conclusion
Applying an activation method, we successfully
investigated the spectrum profile, intensity, andattenuation of the neutrons in the concrete shield at
KENS. The profile of the neutron spectrum ranging
from 10 to 500 MeV was kept and the intensity was
exponentially attenuated with an increase in the depthof the concrete, although there was a small build-up
of low-energy neutrons at depths below 40 cm.
Furthermore, the CDMD formula was demonstrated
to be suitable for the neutron spallation at KENS.
Using this formula, the charge distributions of theyields and mass yield curves of medium targets wereobtained. Furthermore, mass yield curves in an Au
spallation are available to the benchmark the residual
products of heavy targets. In addition to the data, wewill provide the further data in the near future.

10-22
35

40

45

50

55

60

65

-23
7010 30

35

40

45

45

Product mass number

Fig.6 Mass yields from Sc,
nat

nat

Ti,

Cu, and

nat

V,

nat

55

Cr, Mn,nat

59

Fe, Co,

nat

Ni,

nat

Zn targets

Mass yield curves were calculated using the
CDMD parameters. Figure 6 shows the MD for the
45
Sc, natTi, natV, natCr, 55Mn, natFe, 59Co, natNi, natCu, andnat
Zn targets. The solid lines represent the calculated
mass yields. The squares indicate the experimental
mass yields compensated with estimated yields of
unmeasured products. We were able to obtain the MD
for a wide range of product mass number.
Furthermore, we have been measuring the yieldsof the spallation products from other targets such as
89
Y. Systematic measurements of fixed products, suchas 7Be, 10Be, 24Na, and 22Na, from various targets arealso useful for benchmark. The yields will be reported
in the near future, some of them have already been
published in [7].

References
1) N. Nakao et al., Radiat. Prot. Dosim., 116, 553(2005).
2) N. Nakao et al., Proc. 2nd iTRS International
Symposium on Radiation Safety and Detection
Technology (ISORD-2)”, July 24-25, 2003, Tohoku
University, Sendai, JAPAN., J. Nucl. Sci. Technol.
Suppl.4, 26 (2004)
3) Q. Wang et al, Proc. The 2nd iTRS International
Symposium on Radiation Safety and Detection
Technology (ISORD-2), Tohoku University, Sendai,
JAPAN, July 24-25, 2003.
4) K. Oishi et al., Radiat. Prot. Dosim., 115, 623 (2005).
5) H. Matsumura et al., Radiat. Prot. Dosim., 116, 1(2005).
6) T. Aze et al., KEK Preprint 2005-99.
7) H. Matsumura et al., Radiochim. Acta 93, 497 (2005).
8) S. R. Sarkar et al., Radiochim. Acta 55, 139 (1991).
9) G. Rudstam et al., Naturforschg. 21a, 1027 (1966).

333

Development of Resistant Materials to Beam Impact and Radiation Damage
M. KAWAI*1, H. KOKAWA2, H. OKAMURA2, A. KAWASAKI2,
T. YAMAMURA2, N. HARA2, M. FUTAKAWA3 and K. KIKUCHI3
1) Institute of Materials Structural Science, High Energy Accelerator Research Organization, 1-1
Oho, Tsukuba-shi, 305-0801 Japan
2) Graduate School of Engineering, Tohoku University, 6-6-02 Aramaki-aza-Aoba, Sendai
980-8579, Japan
3) Japan Atomic Energy Research Institute, Tokai-mura, Ibaraki-ken, 319-1195 Japan

Materials which have strong resistance to bothbeam impact (or shock-wave) and radiation damage
are required for the beam target of an intense accelerator and space applications. Recently, spallation
target engineering groups discovered pitting damage
under the pulse irradiation of liquid-metal targets[1],and have studied the phenomenon and countermeasures. Futakawa et al. [2] derived the following
observation in their pitting experiments for total
impact cycles above 1 million: Kolsterising specimens have a stronger resistance to pitting than SS316
CW. A similar effect can be expected for other
hardening treatments, and new material development
is hopeful. Recently, we have organized a project
team to develop high-performance materials that arestrong against shockwaves and radiation. The team iscomposed of scientists from KEK, JAERI and universities (Tohoku, Kyoto, Hokkaido, Kobe, Kyushu
and Okayama University of Science).
The project scope is as follows:(1) Development of new materials and cladding
techniques by means of grain boundary engineering(GBE), powder metallurgy and new ceramics, surface treatment with nitriding and laser peening etc.
and surface coating with electro-deposit using
molten salt and the PVD method etc.
(2) Evaluation of newly developed materials, such as
microscopic observations with TEM/SEM, neutron,
synchrotron orbital radiation (SOR) and positron,mechanical tests and residual stress measurementsby neutrons, impact tests with high-speed camera
observations, post-irradiation experiments for the334

STIP-2 samples for tungsten alloys, ion-beam irradiation tests and FEM analyses for impact tests,
thermal stress etc.
In the present paper, recent topics are introduced.
1. Tpopics
1.1 Grain boundary engineering
In constructing a structure, welding is required.
Intergranular corrosions (IGC), resulting in weld
decay, is frequently observed in the heat affected zone
(HAZ) of austenitic stainless steel. The optical micrograph of the weld decay region shows a mixed
structure of grooved and non-grooved boundaries by
10% oxalic acid electro-etching[3]. IGC is initiallycaused by Cr23C6 precipitation in the grain boundary.
Chromium carbide precipitation leads to sensitizationby chromium depletion. Recent studies on the grainboundary structure have revealed that the sensitization
depends strongly on the crystallographic nature andthe atomic structure of the grain boundary, and that
low-energy grain boundaries, such as CSL (coincidence site lattice) boundaries, have strong resistanceto intergranular corrosion [4]. The concept of ‘grainboundary design and control’ has been developed
through GBE [5] to inhibit sensitization by increasing
the frequency of CSL boundaries. GBEed materials,
which are characterized by high frequencies of CSL
boundaries, are resistant to intergranular deteriorationof materials, such as intergranular corrosion. In thepresent work, Kokawa of Tohoku University tried to
produce a GBEed austenitic stainless-steel possessing
a strong resistance to weld decay using an identical304 steel.
(Experimental)
A commercial type-304 austenitic stainless-steel
was used throughout this study. The chemical composition (wt%) was 18.28 Cr, 8.48 Ni, 0.60 Si, 1.00
Mn, 0.055 C, 0.029 P and 0.005 S. A base material
plate of 9x50x 150 mm3 was welded by bead-on-plategas-tungsten-arc (GTA) welding at a welding currentof 300A in direct current electrode negative (DCEN),a travel speed of 4 cm/min, and an arc length of 1 mmwithout filler materials in a welding chamber filledwith argon gas.
The specimens were solution-heat treated at 1,323
K for 0.5 h. A thermomechanical treatment was performed by cold-rolling and subsequent annealing. The
roll reduction ratio in thickness resulted in as
pre-strain from 0 to 60%. The pre-strained specimens
were annealed at various temperatures from 1,200 to
1,600 K and quenched in cold water. The GBCD
(grain boundary character distribution) was examinedby OIM (orientation imaging microscopy). The intergranular corrosion resistance was evaluated by adouble loop electrochemical potentiokinetic reactivation (DL-EPR) test after sensitization treatment at 923
K. The tested specimens were observed by SEM. The
as-received and the GBEed (thermomechanicallytreated) materials of the 304 steel were GTA welded
and the weld HAZs were observed by SEM and TEM,
and examined by a corrosion test and OIM.
(Corrosion test)
The DL-EPR test results reflect the fractional areaof chromium depletion near sensitized grain boundaries on the test surface. The actual intergranular corrosion propagates along grain boundaries from thesurface into the material, and causes mass-loss due tofalling off the specimen surface. The corrosion (massloss) rate during the ferric sulfate-sulfuric acid test is
shown in Fig. 1 for the BM, r5%- and r5%-1200K
specimens after sensitization. The strain-annealed
specimens have much lower corrosion rates than the

BM for every test duration. The difference in mass-

Fig. 1
Corrosion mass-loss of the BM and thestrain-annealed specimens during a ferric sulfate-sulfuric acid test [6].
loss is much more than that expected simply 1300K
from differences in the DL-EPR test results and CSL
boundary frequencies, because the improvement in
GBCD can strongly affect the mass-loss. The
r5%-1200 K-72 h specimen with the optimized GBCD
(Fig. 2d) indicated the smallest corrosion rate, which
was less than one-fourth that of the BM, and less thanhalf that of the r5%-1300 K-0.5 h specimen.
(Effect of GBE)
In order to examine the effect of GBE on the weld
decay in 304 austenitic stainless steel, the r5%-1200
K-72 h specimen with the optimized GBCD and theas-received 304 base material were GTA-welded. The
HAZ of each weld was observed after electro-etchingin an oxalic acid solution. In the HAZ, distributed
between 0 mm and 12 mm away from the fusion lineof the as-received base material, most of the grainboundaries are grooved in the areas far away (about 8mm) from the fusion line, as generally seen in weld
decay. In contrast, almost none of grain boundaries aregrooved through the HAZ of the GBEed material.
Both the degree of sensitization by the DL-EPR test
and the corrosion rate during the ferric sulfate-sulfuric
acid test were much lower in the weld of GBEed material than in that of the as-received 304 steel basematerial.

335

1.2 TiN-AlN fine-grained ceramics composite
Titanium nitride (TiN) has been widely used asa coating of cutting tool because of its high hardness
and low friction coefficient. In order to improve its
mechanical toughness, composites of TiN and otherceramics, such as AlN or Al2O3 etc., have beenstudied. In the present work, TiN-AlN composites
have been prepared, using a mechanical alloying
technique based on an in situ chemical reaction with
NH3 which was produced from the disintegration ofammonium carbonate during mechanical alloying:
Ti + NH3 ---> TiN [7].
The microstructure and mechanical properties of thecomposite were investigated.
(Experimental)
Two different synthesis routes were employedwith the same designed compositions (TiN : AlN =1:1 (mole ratio)): one is to ball-mill AlN and TiN
powders in ethanol (composite A). The other was
TiN-AlN composite powders synthesized in situ
from powders of AlN, Ti and ammonium carbonate
as initial materials, by taking advantage of thechemical reaction between Ti and ammonium carbonate during 32 h mechanical alloying and a heat
treatment of heating at 1,200oC for 2 h. Synthesized
powders were pressed by 100 MPa into a green pellet
and CIP’ed at 200MPa (composite B). X-ray diffraction showed that Ti in the composite B diminished through a 32 h-milling and 2 h-heating process.
In both cases, HIP was made under the condition of
1,750oC, 180 MPa for 2 hours as a sintering process
in order to obtain full-densified bulk materials. The
microstructure was observed with SEM and TEM.
Vickers hardness and fracture toughness were
measured by the indentation method.
(Results)
Considerably fine powder of below 50 nm was
obtained by mechanical alloying with the following
parameters: 32 h-milling of AlN, Ti and ammonium
carbonate. The values of the Vickers hardness andfracture toughness are compared in Table 1. The

336

values of synthesized sample are higher than those ofball-milling of AlN and TiN powders, and TiN. A
microstructural observation showed that different
phases were mixed by nano-scale in synthesized
sample, while they were mixed by a scale of several
micrometers in TiN+AlN.
Table 1 Comparison of the mechanical properties.
SampleSynthesized
TiN+AlN
TiN

Density(kg/m3)
4,690
4,230
5,260

Hardness
(GPa)
19.6
16.0
12.1

Toughness(MPa/m 1/2)
5.1
2.48
3.9

1.3 Ta cladding on tungsten by electrodeposition
with a molten salt bath method
Tantalum exhibits a high corrosion resistanceover a wide range of aggressive media, but has weak
points of reduced neutron production compared totungsten and high decay heat resulting from highradio activities induced by thermal neutrons [8]. It
will be required to minimize any decay heat for exchanging a used target into a new one by reducing
the amount of tantalum clad on tungsten. Electro-deposition is extremely useful due to high flexibility for big size complicated shape of the objects tobe coated, and has an advantage of low cost. Molten
salt electrolysis has been successfully applied for thedeposition of valve metals and their alloys. In thepresent work, Yamamura group of Tohoku University investigated two possibilities for the electro-deposition of tantalum on tungsten.
At first, a dense and compact coating of tantalumon nickel was pursued to attain a Ta coating on atungsten substrate mediated by a thin Ni layer. The
electrolyte consisted of 55%LiF-35%NaF-10%CaF2
in which 1% K2TaF7 was added. (Percentage is given
in mole percent.) The cell consisted of a graphite
crucible. A electrodeposition of tantalum on nickel
wire (1-mm diameter) was performed at a current
density of 0.2 kA.m-2 and at 700oC. A continuous andrather smooth coating on the nickel layer was obtained.
Additional attempts to prepare coatings directly

on tungsten were performed. The chronopotentiometry showed that the current efficiency increased
at higher current densities. Hence, attempts weremade to prepare coatings on tungsten at higher current densities, which proved to be successful, andcomplete coverage was obtained on tungsten. Finally,
it can be summarized that the cladding of tantalumon tungsten is possible by electro-deposition in a
LiF-NaF-CaF2 melt containing 2% K2TaF7 at a current density of ~ 1-1.5 A.m-2.
1.4 CrN cladding on tungsten plate
Nio et al.[8] and Takenaka et al.[9] pointed out,
based on their neutronics and thermal calculations on
0.5mm thick-tantalum-clad tungsten target for MW
class spallation neutron source, that there were severe
problems of high gamma-ray dose and decay heatfrom activated tantalum during maintenance of thetarget. On the other hand, CrN has a high hardness anda high resistance against corrosion, wear and oxidization. Nio et al. also showed that CrN cladding would
become a solution of problems involving a tantalum-clad tungsten target because CrN was much lessactivated compared to tantalum.
Since the surface properties of CrN film are likely
depend on the film formation technique, we tried tomake a CrN cladding on a tungsten plate with different
techniques. One is an arc-plasma type PVD techniqueat Japan Coating Center Co. Ltd. and Japan ITF Co.
Ltd. This method is very popular, and film formation
process is standardized in the former company. The
film thickness was controlled by the deposition time tobe 5 and 8 m. In Japan ITF Co. Ltd, the ion-platingprocesses were made twice and the film thickness wasmeasured with a spherical abrasion test method to be
2.4 m and 2.0 m (total 4.4 m).
The other was ion-beam-enhanced deposition(IBED) at Tohoku University. In the IBED, a film wasdeposited on a substrate by the ion-beam sputtering oftarget material and, at the same time, the film wasbombardedbyanother
ion-beamsource~enhancement source. By this method, it was possible
to increase the mobility of the depositing chemical
species and cause reactions between the depositing
film and the bombardment ions. A dual ion-beam

sputtering apparatus was employed. The deposition
time was 480 min. The film thickness of the specimen
produced with the IBED process was measured by astylus-based surface profiler to be 350 nm to 400 nm.
Surface status and electoro-chemical properties of
CrN film ware investigated. The results are as follows:(1) X-ray diffraction revealed that the film due to the
AIP method contained mainly CrN and the film by the
IBED method CrN and Cr2N.
(2) XPS analysis clarified that a ratio of CrN and Cr2N
contents is not so much difference between both films.
(3) SEM photographs of specimen surface given in
Fig. 2 shows that the surface of the CrN thin film
formed by IBED is very smooth, while that of the film
formed by ion plating displays pronounced microparticles (droplet) and pinhole-like defects.
(4) Density of pin hole defects of CrN film wasmeasured with the critical polarized current density
method. In case of thick AIP-CrN film, its average
was 0.017% but dispersion was large, while average
was 0.045%.with small dispersion in case of thin filmby the IBED method.

Fig. 2 Comparison of SEM photographs of CrN cladtungsten plates.
An investigation of CrN cladding is also progressing by means of the molten salt bath method at
Kyoto University together with radiation damage ofthese CrN clad tungsten samples with electron or
proton bombardment from accelerators.
1.5 Investigation on pitting damage
In a mercury target under pulsed-irradiation conditions, the pitting of the target vessel and the window
from cavitation erosion is so severe that it can limit
our ability to determine the lifetime of a target. Recent
experiments clarified that the treatment to the surface
to increase the hardness was effective for increasing337

the materials resistance against impact erosion. The
following techniques can be applied for the surface
treatment: kolstelize (a registered trademark ofBodycote International plc., i.e., carbonate), nitride
and cladding or film formation with hard materials
such as TiN and CrN. Fig. 3 shows a comparison of
the impact erosion resistances as a function of thehardness between the 316-type austenite stainlesssteel and surface-treated materials [11]. Here, theimpact erosion resistance is defined to be an inverse of
fraction of the eroded area. It is strongly correlatedwith the hardness, as shown in the figure. Therefore,
harder materials provide better to give a higher resistance against pitting damage.

Fig. 4 Micrographs of indents at 4.9N.
of the indent thickness, and found that it decreased
with the depth in the case of surface-treatment materials, while austenite stainless steel did not have such athickness dependence of the hardness. The surface of a
micro-vickers-hardness-tested specimen was observed, as shown in Fig. 4. In the case of a TiN and
CrN clad material, we can observe a micro-cracks
around the indentation at 4.9N. Accordingly, the impact erosion resistance against multi-cycle (beyond
108 cycles) stresses depends not only on the hardness,but also on the impact propagation between the coating and the base material. Accordingly, a complex
structure to mitigate propagated impact is promising.
Further investigation to clarify pitting mechanism

Fig. 3 Relationship between the hardness and impact
erosion resistance.
However, if the pitting damage penetrates througha hard material, which is obtained by a surface-treatment, damage will abruptly proceed. In addition, these surface may be less ductile. Accordingly,
the layer thickness will be limited. Recently, Futakawa
et al. measured the hardness of materials as a function

Fig. 5 Bubble formation observed by high-speed
camera after input of impact by MIMTM. camera.
are .also progressed by using super high speed ob-

338

serving a glass window contacted with mercury on
which controlled impacts generated by the electro-magnetic high-frequency impact generator
MIMTM are given. Typical result of bubble formationon the surface of glass window after impact is shownin Fig. 5. Computer simulation describes that when
the bubble collapse, micro-jets is emitted and pitting
on the material science is occurred.

[8] D.Nio,et al.,J. Nucl. Mater., 343 (2005) 163.
[9] M. Mehmood,et al. Material Transactions, 44-2,
pp.259-267 (2003).
[10] N.Takenaka,et al.,J. Nucl. Mater., 343 (2005)
169.
[11] M. Futakawa, et al., Int. J. Imp. Eng., 28 (2003)
123.

2. Conclusion
We are investigating ways to develop materials
that have strong resistance against impact shock andirradiation for spallation targets and aerospace.
There are 5 topics reported as a result of recent activities. Pitting phenomena in mercury target is also
investigated.
In the next stage, material development andcharacterization will be promoted. As for material
development, cladding or film coating on SS isneeded by using a more improved method, such as
laser peening, as well as an optimized condition,even for the conventional method. Presently, CrN
film formation with the molten salt method is being
performed at Kyoto University..
The characterization of materials and the material
behavior under impact condition and radiation isvery important to certify new materials and improvethem. We will continue this work.
Acknowledgements
The present work has been made by the High
Performance Material Developing Team under the
support by 2004 - 2006 Grand-in-Aid for Science
Research (A) by JSPS
References:[1] K. Kikuchi, et al, J. Nucl. Mater., 318 (2003) 84.
[2] M. Futakawa, et al, J. Nucl. Mater., 343 (2005)
70.
[3] H. Kokawa, et al., JOM, 52 (2000) 34.
[4] P. H. Pumphrey, in “Grain Boundary Structure
and Properties,” edited. by G. A. Chadwick and D.
A. Smith (Academic Press, London, 1976) p. 139.
[5] G. Palumbo, et al., JOM, 50 (1998) 40.
[6] M. Shimada, et al., Acta Mater., 50 (2002) 2331.
[7] M. Krasnowski et al, Nanostruct. Mater., 12(1999), 455.

339

IV.
J-PARC

2003–2006

Toward the State-of-art Neutron Facility
T. KAMIYAMA1, T. OTOMO1, S. ITOH2 and N. TORIKAI2
1

J-PARC Project Office, High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801
2
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801

In Material life science facility (MLF), 1MW
spallation neutron beam will be available when
proton current reaches the designed value of 333µA
at 3GeV. The repetition rate of 25Hz is muchsmaller than that of the first target station at ISIS (50Hz) and SNS (60 Hz), resulting in the uniqueness ofthe first neutron instruments at J-PARC where awide dynamical range is attained with limited loss ofneutron.
The completion of the MLF building
construction will be scheduled in December 2006.
The first beam is scheduled to be supplied on May
2008, and the stable beam supply in 100 kW isexpected to start in the beginning of 2009. In July
2006, more than 80 % of MLF building has been
completed. 23 shutter gates have been installed,
and inserts of the Helium vessel beam windows
were placed by using a remote handling device.
The temporary opening at the central section will beclosed after finishing all scheduled heavy
components installation. Both of the extended
buildings for a residual stress analysis diffractometer(JAEA) and a super high-resolution powder
diffractometer (KEK) are funded and under design.

Fig.1 MLF building. The construction will be completed
in December, 2006.

After long term discussion with users [1], we
decided to have three cryogenic super-criticalhydrogen moderators: a coupled, decoupled andpoisoned-decoupled moderators.
The prototype
fabrication test of the MLF moderator was carriedout with reasonable performance.
Uniquecharacteristic of the MLF moderators is that half ofbeamlines are looking at a high intensity coupledmoderator.
This decision was made after
discussion with potential instrumental scientists. It
is significantly different as main moderators of ISIS
and SNS are decoupled moderators.
In the decoupled moderator, the tails of pulse
peaks are removed by the decoupler. Demands on
S/N above 100 meV to be better than 1.5 – 2 orderlead to the preferred decoupling energy of 1 eV with
Ag-In-Cd (AIC), which later found its R&D wastough. Compared with the coupled moderator,
integrated intensity decreases by 1/2 (l = 1 Å) to
1/10 (l = 8 Å), but peak intensity does not sodecrease: 4/5 (1 Å) to 1/3 (8 Å) [2].
In the decoupled poisoned moderator, thepoisoning material was one of discussion points.
Cd (0.4 eV) has higher cut-off energy comparedwith Gd (0.35 eV) but not exceeds B4C (1.6 eV),which cannot be used because of radiation damage.
The choice of Cd results in the shift of symmetricalregion to the shorter wavelength region, and thenarrow and symmetrical Dt at l > 1 Å will beattained by selecting 20 mm depth in average(25mm at the deepest). Although poisoning energy
is larger in Cd, peak intensity is not so different.
Compared with decoupled non-poisoned moderator,
integrated intensity decreases by 2/3 (l = 1 Å) to 1/3(l = 8 Å), but peak intensity does not so decrease:
4/5 (1 Å) to 1/2 (8 Å) [3].
The call for "Letters of Intent" of neutron
instruments has been continued every year since
2002 [4]. Each proposal has been reviewed twiceby the neutron instrument planning committee under
the J-PARC director; after the first review, each
proposal was re-examined in terms of theirappropriateness in installing in MLF beam lines inearly stage. The approved proposals wereencouraged to proceed to funding procedure. After
proposals of two project instruments, SuperSirius (a343

versatile powder diffractometer) and BIX-P1 (a highintensity single crystal diffractometer for protein
crystals), were accepted, similar instruments were
financed by Ibaraki prefecture. Although these twoare almost identical to SuperSirius and BIX-P1, theaim of Ibaraki prefecture is primarily the promotionof industrial uses. Then, the proposals of Ibaraki
prefecture were submitted separately. Which werelater approved in 2004.
Since, to date, more than 20 proposals have been
approved without specifying the MLF beam lines
and only 23 beamlines (11 coupled, 6 decoupled and6 poisoned-decoupled moderators) are available, thespecification procedure is now discussed.
At
present, following eight instruments are fully or
partly funded, and will be commissioned in 2008[see figure 2]: high resolution powder diffractometer(HRPD) of KEK, Engineering diffractometer (JED)
and low energy chopper spectromenter (CNDCS) of
JAEA, versatile powder diffractometer and single
crystal protein diffractometer of Ibaraki prefecture,very high intensity chopper spectromenter(4SEASONS), Nuclear data engineering instrument,
Neutronics validation instrument of JAEA. HRPD,
JED and CNDCS are three of 10 project instruments
which will be constructed by KEK or JAEA.
Designs for project instruments including delayed
ones have been in progress. The technical reviews
for the two instruments of Ibaraki prefecture wererepeated often.
To fulfill the users’ requirement for an MLF
computing environment, a framework of an
integrated system was designed based on a dataacquisition and control network that are an assemblyof multiple computers. Along with this hardware,data analysis software is incorporated. A prototypeof the software was tested using SWAN and Sirius
of KENS.
The Neutron Group Board (KEK-JAEA neutron
working group) which was formulated under the
MLFG leader worked on showing the 'Impact ofneutrons on both science and industry' to getfinancial support from the Government. It thendiscussed the organization of the neutron and muongroups after the neutron beam would be operational.
The beamline working group (BLWG) was alsoorganized under the J-PARC steering committee todiscuss the treatment of instruments being
developed by organizations outside the project team,including two instruments of Ibaraki prefecture.
The hot issue is the charging scheme for theirproprietary use. These discussions have been
continued by the deliberative team (task force) and344

will be concluded before autumn of 2006. The
deliberative team will also formulate a general ruleof neutron beam line installation and discuss
conditions for a third party instrument.
The budget profile for the MLF operation wasinvestigated; the present summary was reviewed by
the international experts as a part of the whole
J-PARC operation scheme review in 2005. A costof the neutron beam use was studied with respect tothe total operation cost for the neutron beam
production. This value is used to formulate thecharging scheme for the third party instruments
especially for proprietary use.
Technical support to both third party instrument
teams and general users is quite important toestablish a user-friendly facility.
User accessand the flow of general use, viz. writing proposals,
sample preparation, travel support, accommodation,
radiation safety and other safety education,
experiments, analyses, reports, etc. has been
examined to optimize scientific output. It must be
sufficiently simple and flexible so as to meat user
demands although two organizations are responsible
about J-PARC and there are several third-party
instruments.
It is also important to allocate
research coordinators to help new users. User
proposals should be evaluated by appropriately
constituted review committees, which is directly
related with the mission of both KEK and JAEA.
Table 1. Project instruments were selected by the project teamof KEK and JAEA. �: commissioning in 2008.
Elastic Instruments
High Resolution Powder Diffractometer
KEK�
Versatile Powder Diffractometer
JAEA
Engineering Diffractometer
JAEA �
High Intensity Total Scattering Diffractometer KEK
Single Crystal Diffractometer for Proteins
JAEA
High Intensity SANS
JAEA
Reflectometer with Horizontal Sample Geometry KEK
Inelastic Instruments
High-Resolution Chopper Spectrometer
KEK�Low Energy Chopper Spectrometer
JAEA
Protein Dynamics Analysis Spectrometer
JAEA

References
1) M. Arai, T. Kamiyama, K. Oikawa, T. Otomo, N.
Torikai, K. Soyama, K. Aizawa, K. Suzuya, I.
Tanaka, A. Moriai, J. Suzuki, K. Shibata and S.
Itoh, KENS report, XIV, 47(2003).

2) M. Harada, M. Teshigawara, N. Watanabe, T.
Kai and Y. Ikeda, Proc. ICANS-XVI. , M.
Harada, S. Saito, M. Teshigawara, M. Kawai, K.
Kikuchi, N. Watanabe, Y. Ikeda, Proc.
ICANS-XVI.

Fig.2 Day-one instruments in MLF.

3) T. Kamiyama andICANS-XVI.
4) See http://j-parc.jp/

K.

Oikawa,Proc.

All eight instruments are fully or partly funded and scheduled to be commissioned in 2008.

345

Instruments Design Activity of KEK for J-PARC
T. OTOMO, T. KAMIYAMA, S. ITOH* and N. TORIKAI*
J-PARC Project Office, High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801

KEK, JAEA and university researchers arecollaborating to design neutron instruments for
J-PARC. KENS is responsible to four instruments
below and has promoted their conceptual andengineering design. The engineering design work
including R&D has been performed under thecollaboration with KEK Mechanical Engineering
Center.
(1) High-Performance Neutron Reflectometer with
Horizontal Sample Geometry
It has been widely recognized that neutronreflectometry is a powerful and essential technique
for studies on surface and interface of materials. The
reflectometer proposed for the J-PARC adopts
horizontal sample geometry, so that it can be applied
for any kinds of material interfaces including freeinterfaces such as liquid surface or liquid/liquidinterface, which are not measured by using thevertical reflectometer. The two downward beamlines
with different angles, 5.71 and 2.22, relative to thehorizontal were guided viewing moderator surface
directly for the measurements on free interfaces. The
well-designed beamline makes it possible tomeasure specular reflectivity up to 0.5Å-1 in neutron
momentum transfer, Qz, along the direction verticalto the sample surface. The estimated neutron flux at

Fig. 1 Schematic view of high-performance neutronreflectometer with horizontal sample geometry.

346

the sample position is about 200 ~ 900 times higher
than ARISA of KENS. The weak intensity fromlow-contrast sample or off-specular scattering canbe precisely measured with high resolution during ashort period of time.
Table 1 Specifications of high-performance neutronreflectometer with horizontal sample geometry

Moderator
Source-sample distanceSample-detector distance
Guide tube
QZ-range
QZ resolution
Band width
Glancing Angle

Coupled liquid-H2
15.0 m
2.5 m
3Qc supermirror
0.008QZ(Å-1) 0.5
< 10 %
2.5 – 9 (18) Å
5.71 and 2.22
(straight), 0.86 and0.34 (with bender)

The reflectometer is equipped with a polarized
neutron option, so that the spatial distribution ofmagnetic moment can be detected for magnetic thinfilms or artificial lattices. Also, the polarized
neutrons are used to distinguish incoherent
scattering. This is very effective especially for the
samples containing many hydrogen atoms, such as
polymer, bio-membrane, etc., since it reduces the
background intensity from incoherent scattering sothat structural information can be obtained more
precisely and reliably. Further, another two uniqueand challenging options, i.e., grazing-incidence
diffraction (GID) or small-angle scattering (GISAS),and spin-echo options, are introduced. So far, there
has been no precedent for installing these techniques
at pulsed-neutron source. The GID or GISAS option
is favorable to observe the detailed surface structurewith a scale of nm. The spin-echo option is effective
for the studies on dynamics of interface with neVorder, and is expected to develop new science using
a neutron reflectometer. Here, a neutron resonancespin-echo method using radio-frequency flippers is
adopted.
Currently, a secondary shutter system (so-calleda “revolver”) with several optical devices, which
could be located at the position of about 12 m far
from the moderator, is intensively designed forselecting and producing the beamlines with different
downward angles. Also, a sample table is carefully
designed for meeting different requirements, i.e., afree interface and a heavy load. The free interfaces
can not be inclined, so that they should be moved
vertically to adjust the sample height to eachbeamline with keeping the sample surface very still.
(2) Super-High-Resolution Powder Diffractometer
Synchrotoron
Radiation
powderX-ray
diffractometers (SR-XRD) and advanced analysis
methods have developed rapidly in the past five
years. In SR-XRD, the use of high luminosity andshort wavelength X-ray results in the best statistic
data and wide Q range of measurements.
Advanced analysis methods based on high-precision
analysis methods like maximum entropy method
enable us to extract structural information from tinychanges in diffraction patterns. The combination ofthese high quality data from SR-XRD and theirhigh-precision analysis often give us information oflight elements. Then, newly developed materials
with small amount tend to be studied only by
SR-XRD which is supported by high-precision
analysis methods.
The high-precision analysis methods are inprinciple applicable to neutron powder diffraction(NPD) data, but the limited statistics and resolutionof existing instruments impede the breakthrough of
NPD. These confinement would be removed infuture NPD in the upgraded ISIS, SNS and J-PARC.
We are proposing a high resolution powder
diffractometer with ∆d/d = 0.03 %, which iscompatible with the best SR diffractometer. We
have carefully designed a decoupled hydrogenmoderator (off-center poisoned by Cd anddecoupled by Al-In-Cd) to achieve the designed
resolution within 100m flight path. Figure 2 shows
resolution comparison between KENS-Vega and the
new high-resolution powder diffractometer.

Fig. 2 Resolution comparison between KENS-Vega and the newhigh-resolution powder diffractometer.

Precise structural analysis of newly developedmaterials will be done with the powder
diffractometer with similar amount of sample as in
the laboratory X-ray.

Fig. 3 Schematic image of super-high-resolution powder
diffractometer.

Table 2. Specifications of super-high-resolution powder
diffractometer.

Moderator

Source-to-sample distanceSample-to-detector
distance
Guide tube
Detector coveraged-ranged-resolution ∆d/dBand width

poisoned decoupledmoderator
92 m
1.9 - 4.5 m
supermirror(3Qc)
10° 100°,150° 170°
0.5  d(Å)  60
0.03% at d < 4 Å
1.6Å

(3) High Intensity Total Scattering DiffractometerWe designed a high intensity total diffractometer
which can allow us to obtaine scattering intensity ofvarious materials over a large range of wave-vector
change Q (0.01 Å-1 < Q < 100 Å-1). The
diffractometer will be a gateway of structural
analysis and should be a high through-put
instrument with high accuracy and reasonable
resolution.
A total diffractometer gives strcutural
informations by the Fourier transformation ofdiffraction patterns and accuracy of resulted
real-space correlation function depends on statisticalaccuracy on the higher Q-side. For this reason,
intensity is the first priority to determine instrument347

parameters and then the primary flight pass length,
L1, should be short as possible. It should beemphasize that this total diffractometer is not only
for glasses and liquids; nano-scale order/disorderand fluctuation are special interest of this
instrument. These topics are thought to be important
to investigate structural origin of material’sfunctions such as ionic conducting materials,
hydrogen storage materials, and so on. Therefore,
this instrument should realize enough resolution as apowder diffractometer and also small-angle detectorbank. The best resolution, ∆d/d, of backscatteringbank should be better than 0.5 % for the Rietveld
analysis. By taking into account the pulse width,
total flight pass length was estimated to be longer
than 15 m. Based on these considerations, L1 is set
to 15 m to balance the intensity and resolution
required for the high intensity total diffractometer aswell as spaces for neutron beam shaping devices andneutron & gamma-ray shielding. The bandwidth of
this instrument is 8.8 Å at 25 Hz repetition rate andestimated neutron flux at sample position is about
109 neutron/sec viewing a decoupled hydrogenmoderator (non-poisoned). Figure 4 shows current
design of the total diffractometer. Green plates
correspond to neutron detectors.

Fig. 4(4) High-Resolution Chopper Spectrometer
Chopper
spectrometers
arestandard
spectrometers studying dynamics in materials byusing an intense pulsed neutron source. Three typesof chopper spectrometers are considered: highresolution type, low energy type and high intensity
type. In this project, we will construct the chopper
spectrometer of high resolution type among the three
types, and promote the dynamical studies onstrongly correlated electron systems, non-uniform
magnetic systems, liquids, random systems andsuper molecules, where the dynamics spreads over awide dynamical range in Q- space. Since the highresolution chopper spectrometer covers the wideQ-  space with high resolutions, it enables us toperform systematic studies in these systems. This
spectrometer will be installed facing the decoupledliquid hydrogen moderator, and be realized by aproven technique using a Fermi chopper tomonochromate neutron energy. We aim to have thehighest resolution in the similar type of chopper
spectrometers in the world, and the Q resolution
should be matched to the energy resolution. This
spectrometer efficiently employs a detecting systemof a large solid angle to measure coherent inelastic
scattering. We aim to design this spectrometer sothat a large counting rate can be realized.

An engineering design of the high-intensity total
scattering diffractometer.

Table 3. Specifications of high-intensity total diffractometer

Moderator
Source-to-sample distanceSample-to-detector
distance
Q range
Q resolution
Band width

decoupled moderator
15 m
1.4 - 4 m
0.01Q(Å-1) 100
0.25-30%
8.8 ÅWe are now carefully examining wavelength
dependence of neutron-focusing devices because
348

corrections of wavelength dependence are key issues
to obtain accurate results.

Fig. 4A schematic image of High-resolution chopper
spectometer.

Instruments, such as the high-resolution chopper
spectrometer, high-resolution powder and the total
scattering diffractometer need large area windows
made with thin Aluminum plate (~ 1mm) in theorder of 1 m2. Mock up test of large window was
performed and it was concluded that such large
vacuum window is feasible by modifying edges of
the window frame to round shape. Further

engineering design including safety are on going.
Table 4. Specifications of high-resolution chopper
spectrometer

Moderator
Source-to-sample distanceSample-to-detector
distance
Guide tube
Detector coverage
Ei range
E-resolution ∆E/Ei

decoupled moderator
15 m
4m
supermirror(3Qc)-30<-1, 1<130
1Ei(meV) 2000
1%

349

High Resolution Chopper Spectrometer at J-PARC
S. ITOH, T. YOKOO, K. OHOYAMA1, T. KAMIYAMA2, O. YAMAMURO3, K. KUWAHARA4,
T. OTOMO, K. NAKAJIMA5, R. KAJIMOTO5, K. TOMIYASU and H. SAGEHASHI
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
1
Institute for Materials Research, Tohoku University, Sendai 980-8577
2
Graduate School of Engineering, Hokkaido University, Sapporo 060-8628
3
Institute for Solid State Physics, University, University of Tokyo, Tokai 319-1106
4
Graduate School of Science, Tokyo Metropolitan University, Hachioji 192-0346
5
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai 319-1195
A major approach in the modern material scienceis to try a description of properties in materials by
not only a simple and single interactions but also
complex interactions. Recent studies in materialscience have suggested the existence of phenomena
originated from multiple interactions such as spin,
charge, lattice and so on, also phenomena driven bysome interactions in different scales in space andtime. In such phenomena, since the dynamics
spreads over wide dynamic range in space and time,
experiments with high resolutions in wide Q� space
are required. Chopper spectrometers are one of thestandard ways of studying dynamics in materials byusing an intense pulsed neutron source. The High
Resolution Chopper Spectrometer (HRC) at J-PARC
will be installed at the cold neutron source(decoupled moderator), and high resolution
experiments will be realized in the wide Q� space.
HRC is the best spectrometer to study the dynamics
in materials, in the key word, “universality on
hierarchical correlations in space and time”.

Fig. 1
Schematic drawing of the High Resolution Chopper
Spectrometer.

350

The basic performance of HRC is summarized[1]. A schematic drawing of HRC is shown in Fig. 1.
HRC is designed based on a technology using asingle Fermi chopper. We have chosen as L1(moderator-sample distance) = 15 m and L2(sample-detector distance) = 4 m. The detectors
cover scattering angles from –30° to 130°
horizontally, and ±30° vertically. It consists ofthousands of pieces of 1/2 inch position sensitive
detectors (PSD’s) with approximate 1 m long, whichcorresponds to 40 m2 area. We are aiming to realize
�E/Ei = 1% at the elastic scattering. The Q
resolution will be matched to the energy resolution
in the high resolution condition. Since neutrons with
Ei = 1 meV – 2 eV will be utilized with �E/Ei = 1 %,an energy range of 10 �eV – 2eV can be covered. Alarge counting rate will be realized with the large
area of the detecting system as well as thesupermirror guide tube. In comparison with the
chopper spectrometers installed at ISIS, if �E/Ei =2.5 % is realized on HRC, which is the same
resolution as those of the chopper spectrometers at
ISIS, the intensity gain at the energy region ofepithermal neutrons will be 15 times, because theproton beam power of J-PARC (1MW) will be 6
times, the solid angle of the detector system of HRC
will be 5 times, but a larger L1 will reduce theintensity to be half. At low energies, HRC will havea much more gain, because of the cold neutron
source as well as the supermirror guide tube. In thesecond phase of the construction of HRC, a small
angle bank for utilizing lower Q region, a double
chopper system for a higher resolution than 1 %, andpolarizers for precise experiments will be installed.
One of the key points on HRC, the realization of
the 1% resolution, is described [1]. HRC exhibits
�E/Ei = 2.5% for the optimum condition of �tch =�tm, where �tch and �tm are the chopper opening

time and the pulse width, respectively. For tch <tm, the energy width (E) becomes narrower, but
the peak intensity decreases. On the other hand, fortch > tm, E increases and the peak intensity isalmost unchanged. In Fig. 2, the peak intensity isplotted as a function of tch/tm. The resolution
E/Ei = 1% can be realized at tch/tm = 0.4. To
obtain a higher resolution, the peak intensity is lost,but, for the 1% resolution, it is still 75 % of that at
the optimum condition. The pulse width tm for thedecoupled moderator is proportional to Ei-1/2 down to
Ei = 20 meV [2], and we assumed tm(s) =2.5/{Ei(eV)}1/2. Therefore, this discussion can beapplied to a wide energy range. It is noted that only
timing structures were included in this discussion.
To realize E/Ei = 1% at Ei = 2 eV, tch is required
to be 0.7 s. In a Fermi chopper, tch = w/2Df,
where w is the slit width, D is the chopper diameterand f is the rotational frequency. To minimize thebeam loss at the Fermi chopper, the collimation w/D
should be larger than the beam divergence (5 mrad).
The parameters of w = 0.5 mm, D = 100 mm and f =1 kHz satisfy the required tch with a collimationcomparable to the beam divergence.

peak intensity

1.0

0.5

single chopper
double chopper
0.0
0

1

tch/tm

2

3

Fig. 2
Shaping neutron pulses and intensities simulated for
HRC. The peak intensities of the elastic scattering at thechm.

One expectation in dynamical studies to be
carried out on HRC is described. The neutron is aunique probe for surveying energy space andmomentum space simultaneously. In neutron
spectroscopy, since the energy transfer between two
states is measured directly, it is possible todetermine the band structure of unoccupied bands aswell as occupied bands. Moreover, in neutron
scattering, there is no forbidden transition between
orbitals, contrary to the severe selection rule in the

optical process in photon scattering. Although theneutron has such advantageous properties, it has notbeen playing the role, because the interaction
between neutrons and electrons is very small due tochargeless particles and it was difficult to control
neutrons with energies of eV order. There exists
interactions between neutron spin and electron spin
undeniably, and it is predicted by theories thatcharge excitations are observable through theseinteractions in neutron scattering [3]. The neutron
flux available at any existing neutron source is too
weak to detect charge excitations, and therefore, theneutron has been recognized as a probe effective forlow energy region of meV order only and has beenused for observing magnons and phonons only. That
is underestimation of the role of the neutron. The
MW-class intense pulsed neutron source, J-PARC,
may enable us to observe charge excitations for the
first time. By establishing the technique for the
direct observations of charge excitations, the neutron
is expected to become the essential probe
elucidating novel physical phenomena driven bymultiple freedoms such as spin, charge, lattice andso on in strongly-correlated electron systems. Also,
the observation of the interband transitions insemi-conductors is possible.
One example in such investigations is described.
Halogenbridgedmetal
complexes
arestrongly-correlated electron systems and exhibit
various electronic properties due to competing
multiple interactions. Among them, the nickel
complex[Ni(chxn)2Br]Br2(chxn=1R,2R-cyclohexanediamine) has been found to be a one-dimensional (1D)charge transfer insulator from the X-ray
photoemission spectroscopy (XPS) studies and so on
and this system has been suggested to be a spin-1/2
1D antiferromagnet with the exchange interaction of
1 eV order [4]. Recently, the 1D extended Hubbard
model has been developed for describing thephysical properties in this system [5,6]. The
absorption spectrum from the XPS at the gap energyof the insulator suggests a coupling of spins to thecharge excitations [5]. Also, a clear spin-charge
separation has not observed in this system [7],whereas it has been clearly observed in the 1D
cuprates [8]. Such behaviors in this system might be
attributed to a coupling between spin and charge,
because the charge excitation energies are reduced
to be comparable to the magnetic excitation energies
resulting from reduction of the on-site Coulomb
repulsion via perturbation of the inter-site Coulomb
repulsion [5,6]. As the result, magnons at low

351

1eV

spin-induced charge excitations

magnonsFig. 3 Dispersion relation of magnetic excitations in
the halogen bridged nickel complex predicted by the 1D
extended Hubbard model [6]. Spin-induced charge
excitations are predicted in the high energy region above
magnons.

energy region as well as spin-induced charge
excitations at high energy region are predicted, as
shown in Fig. 3 [6]. The spin-induced charge
excitations are novel magnetic excitations whichhave not be known experimentally and theoretically.
The detection of the spin-induced charge excitations
will be a direct experiment adding a new knowledge
in physics on the freedoms of spin and charge.
HRC is matched to the observation of such
excitations. In the halogen bridged nickel complex,
the zone boundary energy of magnons and theenergy of the spin-induced charge excitations are
expected to be about 0.3 eV and 0.5 – 0.8 eV,

352

respectively. In the discussion of properties of
elementary excitations, it is necessary to determine
the mass of the quasi-particles by measuring thedispersion relation of the excitations. The Q
resolution on a chopper spectrometer depends on theenergy resolution as �Q/ki = (1/2)��E/Ei, where ki
is the incident wave number. The super lattice pointin many antiferromagnets is at around Q = 1 Å-1, andthe Q resolution of �Q = 0.1 Å-1 at least is required
to determine the dispersion relation at around Q = 1
Å-1. In order to realize �Q = 0.1 Å-1 for Ei = 1 eV,
�E/Ei = 1% is required.
References
1) S. Itoh et al., J. Neutron Research 13 (2005) 59.
2) M. Arai et al., ICANS-XVI (2003) 157.
3) J. F. Cooke and J. A. Blackman, Phys. Rev. B 26
(1982) 4410.
4) H. Okamoto et al., Phys. Rev. B 42 (1990)
10381; Phys. Rev. B 54 (1996) 8438.
5) N. Tomita and K. Nasu, Phys. Rev. B 56 (1997)
3779.
6) N. Tomita and K. Nasu, Phys. Rev. B 61 (2000)
2488.
7) S. Fujimori et al., Phys. Rev. Lett. 88 (2002)
247601.
8) C. Kim et al., Phys. Rev. Lett. 77 (1996) 4054;
Phys. Rev. B 56 (1997) 15589.

High Resolution Neutron Powder Diffractometers: from HRP, Vega and Sirius to J-PARC
Diffractometers
T. KAMIYAMA1, T. ISHIGAKI2,3, K. MORI4, K. OIKAWA3, H. STEFANUS3,
M. YONEMURA5, S. TORII1,6, A. HOSHIKAWA3, F. SHIKANAI1, T. WUERNISHA1,
K. IWASE 1,7 and DYAH1,7
1

Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
2
Materials Science and Engineering, Muroran Institute of Technology, Muroran, 050-8585
3
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195
4
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494
5
Institute of Applied Beam Science, Graduate School of Science and Engineering, Ibaraki University,
Hitachi, Ibaraki 316-8511
6
Nihon Advanced Technology,
7
Department of Materials Structure Science, Graduate University for Advanced Studies, 1-1 Oho,
Tsukuba, Ibaraki 305-0801
The accelerator-based neutron powder diffraction(NPD) began in the end of 60’s at Tohoku
University. It was epoch-making because it proved
the electron linac could be an alternative neutron
source.
The diffractometer was later called‘Kimura Sputnik’ by J. Carpenter from its shapewith 90-degree banks and low angle banks. It isregretful that the further development of NPD was
not continued in Japan. It was continued in UK at
Harwell and US at ANL. They had succeeded inestablishing data analysis including Rietveld
analysis which newly appeared at that time, while inJapan powder diffraction data had been
supplemental. The first Rietveld analysis in Japanwas done in JAERI with its original code, but it
could not become popular.
At present, the accelerator-based NPD is takenover by the four spallation neutron facilities with
proton accelerators at the High Energy Accelerator
Research Organization (Japan), Argonne National
Laboratory and Los Alamos Laboratory (USA), andRutherford Appleton Laboratory (UK). It is now
recognized that NPD is indispensable in these large
neutron facilities.
In 1983, a High Resolution Powder
Diffractometer, HRP with d/d = 0.3 - 0.5% and a
Medium Resolution Powder Diffractometer, MRP
were constructed [1]. Their designs were basicallysimilar to the backward banks of IPNS powder
diffractometers. HRP initially aimed at obtaining a
set of high-resolution data within several days; thenit had a couple of normal detectors. But as highresolution is more and more important, number ofdetectors was increased to three sets and finally six
sets.
Soon after structural refinement wasestablished with HRP, the high-Tc fever occurred.
When the famous data on Ba2YCu3O7 was obtained,
it took 48 hours with the 3500 highest peak counts;
it is to be emphasized that better-resolution datawith similar statistics were later obtained within 1
hour by Vega and Sirius.
There were increasing demands for NPD
experiments which required many data-sets:
experiments under special environments or those inpursuit of time-dependent phenomena, etc. It wasalso desirable to measure intensity data for small
amounts of samples, e.g., those containing
expensive elements (isotopes) or those prepared
under special conditions. Collecting intensity datain such kinds of experiments with HRP required
much beam-time. Motivated by these requirements,
we developed a powder diffractometer Vega in 1993
[2].
In order to enhance the efficiency of datacollection in a small facility as KENS, an increase in
the solid angle of detectors of Vega is indispensable.
Arranging many short and long normal detectors
along the Debye-Scherrer rings makes large inactive
region in the backscattering bank, and cannot give
us a sufficient detector solid angle without
sacrificing resolution. Then, we decided to adopt
arrays of one-dimensional 3He position-sensitive
detectors (1D-PSD's) for NPD for the first time;each detector with a 1/2” diameter and an active353

length of 60 cm contains 10 atm of 3He gas +stopping gas and was purchased from Reuter Stokes.
There are increasing demands for high-resolution
NPD at KENS. All Bragg reflections are notnecessarily separated because overlapped patterns
can be analyzed by Rietveld refinement, but highresolution increases the information content of apowder pattern, and permits the access to moredetailed structure differences or the refinement oflarger and complex structures. The necessary
resolution for a specific sample is written as, d/d,
where d is the separation of neighboring Bragg
peaks. By a simple calculation, d/d = d3m/2V,

where m and V are the reflection multiplicity and theunit-cell volume, respectively. For C60 with a = 14
Å, Vega gives resolved Bragg peaks at d > 0.9 Å.
The total number of reflections, N, with d > d0 is
given by N = 2V/3md03, which indicates that

doubling the unit cell volume doubles N andrequires 2-times better resolution.
In order to observe subtle symmetry changes,
required resolution is much higher even for a sample
with a small unit-cell volume. Careful examinationsof fitting patterns sometime enable us to convincethat the reported crystal system which we initiallyassume is incorrect. In such cases, we often findthat the results of the analyses on the basis of therevised models depend on the models one chooses.
For example, YbInCu4 (cubic, V = 370 Å3) exhibits
a first-order phase transition at 40 K from an Yb3+
state to a valence fluctuating state without any
symmetry change.
Change in the latticeWithparameter a is less than 2x103.
medium-resolution data, the result of the Rietveld
analysis depends on the profile model in the region
where the two phases coexists, because diffraction
patterns of both phases have resemblance [3].
Similar situations occur quite often in the studies on
the first order phase transition. Then, higher
resolution is necessary even if the density of Bragg
peaks is small.
Motivated by these requirements, we havedesigned a new high resolution powder
diffractometer, Sirius [3]. Since neutron beam
intensity at KENS is 40 times weaker than that at
ISIS, resolution must not be obtained at the expenseof intensity. This makes it difficult to simply copy
the existing diffractometers. Sirius is situated 38 m
apart from a solid-methane moderator at ca. 20 K.
A long flight path, required from the above
resolution, demands the use of a neutron guide tube
to avoid the loss of intensities.
354

Table 1. Instrumental parameters of Vega and measured
values of resolution. Incident flight path: 18.5 m. L2:
secondary flight path.

L2
No. of PSD2
d-spacing
Solid Angle
resolution

Backward
1m
160
140-175
0.2-5
1.2 str0.25 %

90° Bank
2m
144
80-1000.5-7
0.27 str
0.5 %Low Angle
2m
72
20-40
1-20
0.14 str
0.8 %Table 2. Instrumental parameters of Sirius and measured
values of resolution. Incident flight path: 38 m. L2:
secondary flight path. Figures in paraentheses arenumbers of PSD’s which have been already installed.
28.5 m supermirror guide (m=2.9) with 4 cm x 5 cm islocated between the moderator and the sample position.

L2
No. of PSD2
d-spacing
Solid Angle
resolution

Backward
2m
500(320)150-175
0.2-2.5
1 str
0.09 %

90° Bank
2m
288 (248)
80-1000.3-3.6
0.5 str
0.5 %The guide tube was placed between themoderator and the diffractometer, at 5.5 m apartfrom the moderator, and 0.5 m from a biologicalshield. In order to intensify short-wavelength
neutrons, we use a supermirror guide tube with thelength of 28.5 m and the cross section of 4 cm x 5
cm. If natural nickel is used for the guide coating,the critical wavelength of a guide tube becomes
about 4 Å and transported neutron intensity
drastically decreases at shorter wavelength requiredon Sirius while resolution can be selected mucheasily. Then, we decided to use a guide tube
comprising NiC/Ti-supermirror coated on boron
glasses with a critical wave number triple of that ofnatural nickel, manufactured by Osmic Inc., whichenable high intensity even below  = 1 Å. The
reflectivity, R(Q), of the supermirror limits thetransported intensity. Osmic Inc. presented theR(Q � 0.02 Å–1)
following specification of R(Q):–1� 0.99,R(Q � 0.04 Å ) � 0.95, R(Q � 0.056
Å–1) � 0.90 and R(Q � 0.06 Å–1) � 0.85. Qc,
which is defined as R(Qc)=1/2 and indicates the
wavelength range of transported neutrons, is about
0.063 Å1 [4]. Then, c is given by c = (Qc/4)

= 5.01 mrad, which is 2.9 times as large as that ofnatural-nickel. The critical wavelength for a guidetube, c, is mainly determined by c and ageometrical configuration between the moderator
and the guide tube. The intensity of transported
neutrons as well as the beam divergence at the exitof the guide tube increases quadratically up to  =c where c reaches a visual angle of the moderator
from the entrance of the guide tube. At  > c,they are constants and proportional to the solid angleof the moderator at the entrance of the guide tube.
The intensity and beam divergence (and hence theresolution of the instrument) at the sample position
are controllable by adjusting beam collimation at theexit of the guide tube. Curved guide is preferable
to avoid fast neutron contamination, but 40 m isshort to have both curved section and straightsection. An overall flight path of 40 m introduces
frame overlap that can be eliminated by a tail cutter.
The tail cutter is designed to rotate at 20 Hz with abeam window of 45 ° and gives a wavelength
window of 5 Å that corresponds to a d range of 2.5
Å. A beam shutter and the tail cutter are situatedbetween the end of the biological shield and theguide tube entrance.
A backward bank is situated at 2 m apart from asample position to reduce a cot contribution tothe overall resolution and has a detective area aslarge as 4 m2. To cover this large detector area,
500 one-dimensional 3He position-sensitive
detectors (PSD’s) has been used. Such a uniquedesign was adopted because any arrangement withmany short and long normal detectors along
Debye-Scherrer rings inevitably produces wide
inactive regions. Two-dimensional PSD’s were not
adopted because of their lower counting-rate
limitations and difficulty in maintenance. This
new geometry also makes it possible to increase theefficiency of data collection and to improve
resolution.
Contrary to Vega, the backward bank cannot be
evacuated because its detector area is as large as 3 
3 m. The supporting frame against a vacuum
window produces a large dead area of detectors,
which restricts a detector solid angle in Vega.
Then, the backward bank is separated from thesample chamber and filled with He gas (later
replaced by Ar gas).
The neutron beam istransported through an evacuated collimator tube
which runs through the backward bank to the placenear the sample position. The distance between theexit of guide tube and the sample is 4 m.

A 90 large-area detector bank was also installed
at Vega and Sirius for studies under special
environment such as high pressure with resolution ofd/d=5x10-3. The scattering geometry has
significant advantages for experiments of this kind,because suitable collimation of incident andoutgoing beams can eliminate scattering from thesurrounding of the sample like pressure medium.
Studies of textures and materials strength under
special environment were done with the 90 bank.
A large-area low-angle (20 - 40 detector bank
was also installed at Vega to cover a d-spacing range
up to 20 A with the resolution of 2x10-2. The
obtained data from this bank was used to analyze
magnetic structures and crystal structures with large
unit cells.
Each PSD, manufactured by Reuter-Stokes, inc.,has a diameter of 12.7 mm and an effective length of
607 mm, containing 10 atm of 3He plus appropriate
stopping gases. Eight PSD's are installed in a PSD
unit box with pre- and shaping-amplifier boards [5].
Each amplifier board can be removed/repaired incase of trouble with easy maintenance.
For
position encoding, a charge division method is
employed in PSD boxes; at each end of PSD, aneutron event produces an output charge, which is
amplified and filtered with a 0.5 s shaping constant.
The signals are then sent to an encoding module in a
VME crate and encoded to event data with aneight-bit position, a two-bit detector number in amodule, a six-bit module number and sixteen-bit
time data. The encoded data are recorded into adual-port first-in-first-out (FIFO) memory up to 32
K events per each module and histogrammed by aMacintosh computer in formats specified by several
look-up tables. Based on the look-up tables, we
can concurrently perform several add-one operations
into each histograms including on-the-fly
time-focusing
histograms.
On-the-fly
time-focusing can be performed by the look-up table
which sets up parameters, c0 and c1, in t' = c0t + c1
to obtain the time-focused TOF t' from the raw
time-of-flight, t. Tentatively, c1 's are set to be 0.
c0 's are fixed at geometrically calculated values forevery detector segments. Usually, three types ofhistograms are stored: time-integrated position data
similar to Laue patterns, time-focused data withineach detector, and time-focused data for the wholedetector bank.
The histogrammed data aredisplayed on Macintosh computers.

355

8000
6000
4000
2000
0
1

Fig. 1

2

d (A)

3

4

Diffraction data of YBa265Cu3O7 measured in
1995 with Vega for 1 hr.

The Japanese proton accelerator project, J-PARC,
will start delivering neutron beam from May of 2008.
Three NPD’s with different resolution and intensity
are necessary in the beginning of J-PARC. The
reason is given as follows.
SR powder diffractometers (SR-XRD) andadvanced analysis methods have developed rapidly
in the past 10 years. In SR-XRD, the use of highluminosity and short wavelength X-ray as well as
high resolution results in the best statistic data andwell-resolved structure factors with wide Q range ofmeasurements. Advanced analysis methods likethe maximum entropy method enables us to extract
structural information from tiny changes in
diffraction patterns. It is also emphasized that
more higher resolution XRD’s are being developed.
The combination of high resolution and ab initio
structural calculation opens new opportunity inpharmaceuticals development.
The newly
developed functional materials as the results ofnano-science tend to have large unit cell volumes
which can be fully solved only by high resolution
powder diffractometers. The advanced analyses
realized or will be realized in SR-XRD are inprinciple applicable to neutron NPD data, but thelimited statistics and the instrumental resolution ofexisting instruments impede the breakthrough of
NPD. This confinement will be removed in future
NPD at ISIS, SNS and J-PARC. Then, we areproposing a high-resolution powder diffractometerwith d/d = 0.03 %, which is compatible with thatof the best SR diffractometer.
There are several thousands of laboratory X-ray
diffractometers (XRD) currently running in various
facilities in both academic and commercial institutes.
XRD’s are indispensable tools for characterizing
materials under development. Most usages are‘sample check’ or phase analysis, but some others
are quantitative analysis under ambient condition oreven various in situ conditions. Since advanced

356

materials often contain both heavy and lightelements such as cement, lithium-ion batteries, fuelcell materials, hydrogen absorbing materials,
ferroelectric materials, other oxides, the use of
neuron powder diffraction is strongly recommend.
However, the use of NPD has been avoided, becauseof limited knowledge, hard access, slow to start
actual experiments, amount of sample, limited
opportunity, necessity for secret, etc.
Thissituation would be altered when we could establish asystem of structural evaluation with easy access(including
mail-insystem),quick
start,
secret-guarantee system, accepting several tens of
thousand experiments in a year, routine tutorial
system, etc. Impact on materials development
would be expected. The diffractometer of this kindshould cover wide Q range to examine various
structure types: crystal structure analysis with highintensity and standard resolution (0.15 %), nanostructure analysis and local atomic structure
analysis.

Fig. 2

Resolution and intensity of world powder
diffractometers.
J-PARC diffractometers will
exceed the present frontier.

The reason of the third diffractometer is obvious.
Since D20 in ILL and GEM in ISIS were developedin five years ago, rapid measurements are more andmore popular.
This promotes sciences withkeywords, time-dependent phenomena, chemical
reactions,
phasetransitions,stroboscopic
measurements etc. and stimulates development ofvarious sample environments. This tendency is not
only in NPD as seen from the present topics ofCommission on Powder Diffraction of IUCr to be‘rapid diffractometry’. It is noteworthy the rapidchanges in structures often includes changes
between crystal and glass/amorphous, between local
and average structures and among nano structures.

This implies that the diffractometer of this kindequally emphasizes three structure types: crystal
structure, local structure and nano structure. Then
we are proposing a high-intensity NPD (total
scattering instrument) with d/d = 0.3 % with wide
range of Q.
A high-resolution NPD with d/d = 0.03 %(SHRPD) is now under construction and will becommissioned in 2008. In the light of profile
characteristics, we have chosen a decoupledpoisoned hydrogen moderator (62 mm, 25 Hz) toachieve the designed resolution within 100m-flight
path; hydrogen moderator is better than watermoderator at energy region lower than 100 meV
because narrow & symmetrical pulse region(slowing down region) extends to longer-wavelength
range. Demands on S/N above 100 meV to bebetter than 1.5 – 2 order lead to the preferred
decoupling energy of 1 eV with AIC [6]. As forthe poisoning material, on the other hand, the choiceof Cd results in the shift of symmetrical region to
the shorter wavelength region, and the narrow andsymmetrical t at
> 1 Å will be attained by
selecting 20 mm depth in average (25mm at the
deepest). Although poisoning energy is larger inCd, peak intensity is not so different. Comparedwith decoupled non-poisoned moderator, integrated
intensity decreases by 2/3 ( = 1 Å) to 1/4 ( = 8 Å),
but peak intensity does not so decrease: 4/5 (1 Å) to
1/2 (8 Å). SHRPD covers d range 0.5 < d (Å) < 4
with d/d = 0.03 %, and covers 4 < d (Å) < 45 with
gradually changing resolution. Other choices of drange & resolution and intensity in combination withrepetition rate would be useful. 80 m of ellipticalguide with 30 m curved section (r = 5 km) will
optimize intensities below 100 meV.

Fig. 3prefecture diffractometer (IP-NPD).
The new
design adopts high resolution bank with d/d =0.16 % covering 0.18 < d (Å) < 5.0 at most, two 90
degree banks at 1.6 m, a low angle bank (10 < 2 <40) at 1.1 – 4.5 m and a small angle bank (0.7 < 2< 5). Similar to Sirius, one-dimensional cylindrical
3He PSD’s with 1/2” and 8 mm (20 atms) are being
purchased for IP-NPD. IP-NPD is now underconstruction and will be commissioned in 2008.
A high-intensity NPD with d/d = 0.3 % will be
constructed as a versatile total scattering instrument,
and is described separately.
References
1) N. Watanabe, H.Asano, H.Iwasa, S.Satoh,
H.Murata, K. Karahashi, S. Tomiyoshi, F.Izumi
and K. Inoue, Jpn.J.Appl.Phys.26, 1164 (1987).
2) T. Kamiyama, K. Oikawa, N. Tsuchiya, M.
Osawa, H. Asano, N. Watanabe, M. Furusaka, S.
Satoh, I. Fujikawa, T. Ishigaki, F. Izumi ,Physica B 213&214 (1995) 875.
3) T. Kamiyama, S. Torii, K. Mori, K. Oikawa, S.
Itoh, M. Furusaka, S. Satoh, T. Egami, S. Ikeda,
F. Izumi and H. Asano: Mat. Sci. Forum 321-324(2000) 302.
4) S. Itoh, T. Kamiyama, M. Furusaka and S. Ikeda,
Physica B 241-243, 79 (1998).
5) M. Furusaka, S. Satoh, T. Kamiyama and K.
Oikawa, Proc. Int. Conf. Data acquisition system
in neutron scattering (Dubna, 1997).
6) M. Harada, M. Teshigawara, N. Watanabe, T.
Kai and Y. Ikeda, Proc. ICANS-XVI. , M.
Harada, S. Saito, M. Teshigawara, M. Kawai, K.
Kikuchi, N. Watanabe, Y. Ikeda, Proc.
ICANS-XVI.

SHRPD building and instrument.

An NPD with d/d = 0.15 % is originally planed
as one of J-PARC project instruments (SuperSirius).
However, as Ibaraki prefecture was interested in our
proposal described above, we modified our design
and re-proposed a versatile NPD as an Ibaraki

357

A Framework Design of Computing Environment for the Material and Life Science Facility
at J-PARC
T. OTOMO, T. NAKATANI*, J. SUZUKI**, T. AOYAGI***, R. KAJIMOTO*,
M. YONEMURA****, T. OHHARA*, K. KUSAKA*, S. HARJO*, K. NAKAJIMA*, S. SATOH,
N. KANEKO, Y. KOBAYASHI, S. KAWABATA**, A. MANABE**, S. TORII*, T. UNO*
and M. ARAI*
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801, JAPAN*Quantum Beam Science Directorate, Japan Atomic Energy Agency
Tokai-mura Naka-gun, Ibaraki 319-1195,Japan** Computing Research Center, Applied Research Laboratory, High Energy Accelerator Research
Organization, Tsukuba, Ibaraki, 305-0801, JAPAN***Computational Science Systems Center, Japan Atomic Energy Agency 6-9-3, Higashiueno,
Taito-ku, Tokyo, 110-0015, JAPAN****Institute of Applied Beam Science, Graduate School of Science and Engineering, Ibaraki
University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki, 316-8511
At J-PARC, variety of new opportunities to
explore materials and life science will be
opened. Depending on the purpose of anexperiment, experiment conditions (resolution,
sample temperature and so on) and analysis
scheme should be optimized. Users always needto reconsider the experiment condition during
their experiment according to the collected dataof several Giga-byte. This means that theenvironment should be flexible, high throughput

and highly reliable. Moreover, the computing
environment should be easy to use for “neutron
beginners” since the neutron facility will haveseveral thousands of users per year and many of
the users are expected to be non-specialists ofneutron scattering. Our aim is to design aframework that satisfies above requirements andmake the computing environments the world’s
best as well as instruments hardware and theneutron target system of J-PARC. Based on the

Remote access
Security: Under research

Collaboratory

Network

Working desktop (Python)Analysis

Experiment

Simulation

Visualization

Logging

Devices

DAQ

Analysis
Reduction

GnuPlot

IRIS exp,
Matlab,etc

Ab Initio
Monte-Carloetc

Data File
Admin DB

Experiment DB

SAN / Grid Storage

Figure 1 Schematic diagram of the computing environment.

358

framework, each instrument will be able todevelop specific software and other instrument
will be able to import some parts of the software
easily. Hardware will be replaced in some years
but software should be inheritance andimproved continuously.
Conceptual Design
Software structure of the environment is shownin Fig. 1. Main components are 1) experiment, 2)
data analysis, 3) visualization, 4) simulation(interpretation), 5) database and 6) “working
desktop” which combines these components toenable to use the components as an integrated
environment. Each component works independently
as a server, which replies outputs to requests fromworking desktop.
Experiment component: This component
controls instrument’s hardware such data acquisition
electronics modules, cryostat, furnace, gonio-motors,
collimators, choppers and so on. logs experimentconditions into database.
Analysis component: This component consistsof data reduction part and data analysis part. The
reduction part reduces TOP spectra to scatteringcross section. Such data reduction software is one of
the most important infrastructures of the facility.
The reduction part has been developed with C++
language and named as Manyo-lib. The analysis partwill be also made with C++ or legacy software will
be used.
Visualization component: Data visualization isnecessary at every stage of research process throughinstrument commissioning to data analysis. Also,
visualization software is not necessary to be
dedicated to neutron scattering experiments, i.e.
there are number of useful software of free orcommercial ones. By taking account these aspects,
the visualization component will be independent
component from others. Output data from
Experiment or Analysis component will betransferred via Working Desktop component or as afile. Interactivity, such as mouse drag to choose afitting area on a graph, should be considered.
Simulation (Interpretation) component: This
component reproduces experiment results bysimulating neutron scattering based on models andhas adopters to commercial software and databases
for data interpretations. As simulation software ofneutron scattering, elapsed time of simulation should
be short and simulation software should be easy to
execute. As well as first principle calculations,molecular dynamics calculations and so on, versatile

simulations will be performed on large scalecomputing hardware through this component.
Data-management
component:
User
information, target & moderator information, sample
information,
experiment-log,
analysis-log,
scenario-log, and etc. will be access as database.
These databases log indispensable information fordata analysis not relying on a personal log-note.
Another new important roles of databases arestorages of user-experience and will be used forsharing know-how of experiment, analysis andsimulation. For example, an analysis or an
experiment scheme (scenario) will be stored in the
scenario database and the scenario will be re-usedby the other user. TOF data database is for recording
path of data files: users wouldn’t waste time forlooking for data files even if they may be distributedon different data storage. User interfaces design ofthis component to provide essential and useful
information is the most important.
“Working Desktop”: This is a user interface tocontrol above components and provide an integrated
computing environment. Graphic engine will be
included with this component and will have adopters
to commercial graphic software for users who may
want to use their favorable software to depict results.
Command-line user interface is necessary to realize
flexible system and graphical user interface isnecessary for ‘daily’ usage. We have started R&D torealize the working desktop with “Python”.
Advantages of this object-oriented programming
language are: 1) it has own command line interface,2) it can include (wrap) C++ codes easily, 3) it hasconnection adaptors to various graphic software and4) it has large user community from various fields.
All components work standalone and are consistof software libraries. Definition of interfaces of thecomponents, how and what kind of communications
are made among these components, is important toensure independency and collectiveness of thecomponents. Distributed computing environments
are necessary to obtain enough transaction speed. Incase of off-line analysis, experiment components
will be excluded
Monolithic integration of components will bequite effective but construction of complicate andheavy framework is not a wise direction: simple andclear structure of the framework is necessary to
improve continuously and to let many people join to
improvement works of the environment.

359

Figure 2 Server-Client system of Experiment component.
Current R&D works
We have started R&D work whilst conceptual
design of whole environment is continuing. It isquite unrealistic to complete whole the systembefore J-PARC starts its operation. It is necessary to
pick up software components to be ready for Day-1
experiment.
1) Experiment component
We built two types of prototype based on
existing LabVIEW™ (National Instruments co.)DAQ software and tested at KENS. We choseLabVIEW for the prototyping but it is not limit touse other software. Most essential point of the
prototyping is implementation of server-client modelusing TCP/IP socket. Figure 2 shows theserver-client diagram of DAQ. Hardware dependent
component can be replaced easily.
One of two prototypes is for “histogram mode”
DAQ and the other is “event mode” one. “Histogrammode” means that TOF spectra will be made andstored on DAQ electronics. “Event mode” meansthat DAQ electronics will record a event consists of
TOF time and pixel ID on the memory andaccumurated events on computers will be organized
to make TOF. The histogram mode is reliable but isinflexible about TOF setteings. On the other hand,the event mode is very flexible about TOF setting
360

but there is a risk to miss-accumulation from DAQ
electronics. The histogram mode DAQ was tested on
Small- and wide-angle neutron scattering
diffractometer (SWAN) for 7 month, and the event
mode was tested on High-resolution and highintensity powder diffractometer (Sirius) for 6 monthof actual user program. Both prototypes worked
successfully used by normal users of KENS who are
not familiar with the DAQ system.
Remained major issues of Experiment
component are: 1) to confirm that the server-clientsystem works with more than 10 computers, 2) todevelop sample environment control platform, 3) tofix data format of instrument parameters and 4) todevelop logging system of instrument parameters.
2) Analysis component
Manyo-lib
implements
basic
spectramanipulations like four arithmetic operations, error
propagation, ribinning and so on. Manyo-lib will becommonly used by instruments at J-PARC neutron
facility but it was found out that there is a problem;
units system and axis coordination may be different
depends on instruments, even on users. Our current
solution is to fix one unit system and axis
coordination within Manyo-lib and conversion
mechanism will be implement within Working
Desktop, i.e. within Python. Also, data container ofFigure 3

Integration scheme of Experiment and Analysis components.

Manyo-lib was modified to be able to store unit ofeach data.
NeXus file format, which will be supported at
ISIS, SNS and other neutron and synchrotron
facilities, can be used from Manyo-lib.
Server-client function was also implemented toAnalysis component using Python and C++. The
implementation is not same as Experiment
components but, now, both components can becontrolled through Working Desktop as shown in
Figure 3. Actual integration of Experiment, Analysis
and Visualization component will be completed by
FY2007. Currently, the integration has been realized
as shown in Fig. 3.
Remained major issues of Analysis component
are: 1) to check consistency with instrument
dependent software, 2) to develop an fault tolerant
server-client system, 3) to implement unit
conversion mechanism, 4) to fix format of input
parameters.

inconsistency and problems will come up before weare really ready for Day-1 experiments.
Data management and Visualization components
are still under research. Basically, visualizationengine can be chosen by a user but it may be wise tochose default visualization software. Security
control is always delicate and difficult problem. Not
only network securities but also definitions of accessprivileges to database should be solved carefully.
As a conclusion, the software environment
design progressed step by step even though there arestill many items to be developed and issues to besolved.

Summary
Prototyping of the computing environment for
the Material and Life science facility at J-PARC has
been progressed. So far, minimum softwareenvironment for Day-1 experiment in FY2008 was
implemented. However, instrument dependent
software will be start in FY2006 and then361

Development of Readout Electronics for 3He Detectors at KENS
S. SATOH
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
Readout electronics for a linear position-sensitive
He gas detector (PSD) has been developed. It was
widely used for neutron-scattering instruments at
KENS.
In J-PARC, because many PSDs are scheduled to
be used, the possibility that the PSD2K system [1,2,3]
developed at KENS will be used is high. In addition,
because some new types of PSD are being developed
for J-PARC, tests of those performances are urgently
needed.
In this article, the several readout systems and the
PSD tests are mentioned.

3

KENS electronics for the neutron detectors
The electronics have been developed at KENS:
following.
1980~1995: Electronics for a normal 3He detector
without position information has been developed. Its
main function is a time analysis (TA) function and apulse height analysis (PHA) function.
1990~2002: Electronics for the PSD has beendeveloped. In the beginning, an analog processing PSD
system was developed for detecting the positions ofneutrons. However, the system did not have sufficientperformance. Because ADC and FPGA technology
have been remarkably developing in the world after
that, the PSD2K system, which adopts fully digitalprocessing, has been developed. It has good feature.
The position FWHM of a 60cm-PSD is about 5 mm,
for example.

other computers

SCSI-VME module
TA17XC module

Data
Acqusition
Software(Lab View)
Macintosh or windows95

SCSI

He3 detectors
VME power rack
Kicker pulse
AMP module

Fig. 1.

high voltage 500V ~ 2000V

TA system for normal He-3 gas detectors.

Fig. 2 shows the PHA distribution data of the 3He
detector. Separation of the noise and the neutron signal
is facilitated by this data. This PHA function iscomposed of one VME module, and it is combinedwith the TA module and used. These devices are very
useful for evaluating other detectors.

Fig. 2.

PHA data of 3He detector.

Fig. 3 shows a general view of the PSD2K system,
which consists of an amplifier and an encode-module.

2002~: Several electronics for neutron scintillators
have been developed. Most of them are 2-dimensions
position detector systems.
Fig. 1 shows a general view of the TA system,
which consists of an amplifier and a TA
encode-module.
Fig. 3.

PSD2K system, PSD amplifier unit and PSD2K
encode-module.

Fig. 4 shows a block diagram of the PSD2K
encode-module, which is a VME 2U 1-span module. It
has 4 ADC-cards, and each of them has 4 ADCs and a
50k-gate FPGA, which also takes care of time-stamp
information. The module has a 150k-gate FPGA and362

handles data from the ADCs, and makes histograms
into the on-board 16M-byte D-RAM.

Fig. 5.
Fig. 4.

Block diagram of the PSD2K encode-module.

These analogue signals from each end of the PSD(Q1, Q2) are directly converted to digital data by the
12bit 20MHz ADCs. Fig. 5 shows the ADC digitalform data obtained by them; the method of peakdetection uses the digital waveforms. The FPGA-1
detects the waveforms pedestal and the peak height.
When both ADCs detect the peaks at the same timewithin 800 ns, these pulse heights and the time arerecorded.
The main logic board has an Electrically Erasable
Programmable Read-Only Memory (EEPROM), which
has scaling data and discriminator-level information
for all of the inputs. By using the scaling data in the
EEPROM, the heights of the peaks are scaled, and theposition of the neutron is obtained by the
charge-division method. All of the processing data are
executed by the FPGA-2 by digital.
The FPGA-2 checks the ADC daughter cards, andcollects a neutron event within 500 ns. It becomes 4
micro-second at the worst collecting time of 8 PSDs.
Therefore, each dead time is adjusted to the same 4
micro-second. The FPGA-2 has two FIFO buffers
before and after the encoding calculation.
The event data consist of Q1 and Q2, the time, and
the PSD number. After a position calculation, theFPGA-2 makes a histogram based on information of
the detected position (8~16bit), the time (11~13bit),and the PSD number (3bit) in the D-RAM (16M-byte).
At any time a control-PC can read the histogram data
through the VME bus.

Digital peak detection method using ADCs.

60cm 3He PSD test
The standard PSD size at KENS is 1.27 cm indiameter and about a 60 cm active length cylinder. Fig.
6 shows the test data obtained at the EZO beam line.
The upper graph is position data that was irradiated on
a 1 mm wide neutron beam. The PSD was irradiated at
12 points located 50 mm from each other by a moving
goniometer. The lower graph is the pulse-height
distribution of the same data. The average FWHM of
the 11 peaks is 4.77 mm.

Fig. 6.

Upper is position data collected on a 1mm neutron
beam at 12 points with 50mm distance; lower ispulse-height data.

Fig. 7 shows position-peak channel data obtained fromthe upper graph of Fig. 6, and the error position fromthe least-squares line. The linearity is within+1.0mm/-1.5mm. The linearity of a peak near bothends is worse than that of the peak in the vicinity of thecenter.

363

Fig. 7.

Position-channel data obtained from Fig. 6.

Fig. 8 shows the time data. The horizontal axis of
the graph is the past time from the generation of thepulsed neutron. The PSD position is about 28 m fromthe pulsed-neutron target. Therefore, a 0.5 eV point is
at around 4 ms. One PSD has 19 atm 3He gas; the otherhas 10 atm 3He gas. Their difference can be seen
sufficiently at the left side, which is thethermal-neutron area. The ratio of the neutron count isin proportion to the 3He gas pressure.

Fig. 8.

Time data of the 60cm PSD.

2.5m 3He PSD test
The 2.5m 3He PSD will be used at J-PARC. Fig. 9shows a picture of the PSD. Since the length of the
PSD is too long, it has to be used in the verticaldirection. A test was with an up and down goniometer.

Fig. 9.

Fig. 10 shows testing data at the MUSASI beamline of JAEA. The neutron wavelength is about 2
angstroms. The graph has 23 peaks. The detector
moves at 23 points, which are located 100 mm fromeach other by the up and down goniometer. The
average FWHM of the 23 peaks is 15.8 mm.

Fig. 10.

364

2.5m PSD.

position data collected on a 2 mm neutron beam at 23
points with 100 mm distance.

Fig. 11 shows position-peak channel data that was
obtained from the graph of Fig. 10; and the error
position from the least-squares line. The linearity is
within +3.0mm/-3.0mm.

Fig. 11.

Position-channel data obtained from Fig. 10.

Another new type PSDs, which are an elliptical PSD,a small-diameter PSD and other one, etc., will be used
at J-PARC. It is necessary to test them as soon as
possible.
References
1) S. Satoh et al., Development of readout systems
for neutron detectors, Nuclear Inst. And Meth. A;
529/1-3 (2004) 421-424
2) S. Satoh et al., Development of Position
Sensitive Detector, PSD2K system for Neutron
Scattering Experiment, KEK Report 2001-9.
3) S. Satoh, Development of readout technology for3
He gas detector, JSNS Hamon 2005-1.

365Ultra-long MicroStrip Gas Counter for Spallation Neutron Source Facilities
H. TAKAHASHI, P. SIRITIPRUSSAMEE, K. FUJITA, H. NIKO, S. KISHIMOTO*,
T. INO* and M. FURUSAKA**
Department of Nuclear Engineering and Management, The University of Tokyo,7-3-1, Hongo,
Bunkyo-ku, Tokyo 113-8656, Japan*Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801** Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan
Recently novel spallation neutron sources arebeing constructed in the US, Japan, and Europe.
Japan Proton Accelerator Research Complex(J-PARC) requires very high counting rate forneutron detectors in excess of 10 6 n/s. Wire
proportional counters have long sensitive length andare widely used in the current neutron facilities.
However, they are not tolerable at such a highcounting rate over 100 kHz. To make the most of the
new source, conventional 3He tubes are notsufficient. We investigate for a new fast detector. In
this paper, we consider the use of MSGC [1] as aproportional counter tube with one dimensional
position information.
MSGCs have several attractive properties such as
good uniformity over the entire sensitive area, very
high counting rate operation, high spatial resolution
etc. However, surface discharge [2-3] severely
restricts MSGC’s gas gain. Also, the surface charge
accumulation brings many difficult problems in thistype of detectors. One solution to this problem is amulti-grid-type MSGC (M-MSGC) [4], which is a
new generation of MSGC that is stabilized byintermediate grid electrodes between the anode andthe cathode. The grid electrodes realize favourable
electric field and effectively remove surface charge
for avoiding the streamer development that causes afatal damage to the electrodes. We are now trying to
use this structure as an alternative gas amplification
element in the conventional 3He tube. We call this
M-MSGC tube an MSTube.
First, simple replacement of the resistive anodewire with M-MSGC structure is considered,however, this structure leads to two problems. One
is the slow signal due to detector’s time constant.
The other problem is the very high gas gain
requirement to achieve the high position resolution.
Therefore, we have modified the position readout
scheme for our MSTubes. To realize a fast andhigh-resolution MSTube, a new geometrical charge
division method is developed. We alreadyintroduced a new GLG method [5] for our366

multilayer two-dimensional M-MSGC. The idea is
to divide the total charge Q into two parts, QG and
QL , and further divide QG and QL into two parts
according to the incident position. From QG , weobtain a rough position of incident radiation andfrom QL, we obtain detailed position of the radiation.
This charge division makes the readout front-end
electronics somewhat complicated but the benefit of
the method makes it acceptable. Simple analysis of
the charge division method is shown below.
Suppose the detector’s signal to noise ratio and thesensitive length are A and L, respectively. Then theposition resolution is expected to be L/A in theconventional charge division method. However, if
we divide the total charge into equally weighted twoparts, the expected signal to noise ratio at this
divided charge is A/2. Therefore we could achieve
the position resolution of 2L/A only using a half
portion of the signal. Then we can still utilize halfcharge and we could achieve the position resolutionof L (2/A)2 in the ideal case. We name this double
charge division as a GL (Global-Local) charge
division. Let us assume some practical values of
L=640 mm, A=100. The simple charge division only
provides the resolution of 6.4 mm but the GL charge
example, this method is greatly dependent on thesignal-to-noise ratio of the system, therefore,
compatibility of the method and proportionalcounters are quite good. Fig. 1 shows therelationship in above case.

Fig. 1 Relationship between the signal-to-noise
ratio and the achievable position resolution.

Grids

Anode

Grids

GlobalPixel N

Fig. 3 Distribution of pulse height spectrum foran 8keV synchrotron radiation
GlobalPixel N+1

EnergyLocal＋HV

GlobalP

iti

Fig.2 Principle of 1-D GL M-MSGC
Fig.2 schematically shows the geometricallyweighted GL charge division plate. In order tomodulate charge density along the incident position,
we have used a quite similar technique used in thegraded-density cathode [6]. Since the microstrip
plate is fabricated by a photolithography technique,very accurate structure of the electrode pattern isrealized. Thus we further divided the cathode andchanged the density of two sub cathodes along theanode strip. In the microstrip counter, one anodestrip is surrounded by two cathodes and positive
ions produced near the anode strip return to thesetwo cathodes at almost equal weight. We now
discriminate one side of the cathode from the otherside and form two sets of “global” and “local”
cathodes. On the global cathode, we have two
readout lines connected to the pads. The stepwisechange of pad density provides the different
probability to accept the positive ions (see Fig.2).
This approach was used for defining the position.
On the local cathodes, we use the same method as
global but the pads density is changed in a periodic
pattern which can provide the fine position
information within the global pitch. The ratio ofcollected charge on the cathode can be used to locate
the position.

Fig. 4 The results from X-ray beam scan test.
The test plate, which has 640 mm of active
length, has been designed and fabricated. The test
plate has two anode strips and four-grid electrodes
inserted between the anode and the cathode. Global
and local cathode pitches were 32 and 0.4mm,
respectively. The test detector was operated in Ar
70% + CH4 30% gas mixture (1 atm). The
experiments were performed at KEK, Photon
Factory, BL-14A. The detector was irradiated with
8keV synchrotron radiation. The detector was tested
at a gas gain of 6000. The pulse height spectrum isshown in Fig.3. The energy resolution was 13.3%(FWHM). The detector was scanned with thecollimated X-ray beam. Fig.4 shows the result of thebeam scan test. We observed periodic peaks fromthe local cathode signal. These peaks corresponded
to the periodic pattern of local cathodes. These
results confirmed that the GL geometrical charge
division method was successfully operated although
unfortunately the resistivity of the anode strip washigh in the first lot and therefore we have observed
global position dependence in the signal modulation.

367

and we are planning to characterize the detector indetail.
Conclusions

Fig. 5 Measured position resolution. Collimatedbeam was incident on the detector with a pitch of 8mm.

A new one-dimensional multi-grid-type MSGC
has been developed for the new spallation neutron
source, J-PARC. To achieve a high spatial resolution,
GLG method has been applied to the new detector.
A test plate with 640 mm of sensitive length has
been designed, fabricated and tested. The gas gain
was 6000 for the Ar 70% and CH4 30% gas mixture
and 300 for the 3He(0.5bar) and CF4(2.5bar) gas
mixture. The results confirmed that the GLG method
was successful. Measured global and local position
resolutions for neutrons were 32 mm and 1.6 mm,
respectively.
References

Fig. 6 Typical waveform obtained for both theanode and the cathode: Rise time is less than 200 ns.

Fig. 7 Measured position resolution obtainedwith neutron beam. The best resolution was 1.2 mm
FWHM for 64 cm long neutron tube.
Fig. 5 shows a result from a local position scan
test. The averaged position resolution was 2.4 mm(FWHM). A neutron beam test was performed andthe result was quite satisfactory. Fig. 6 shows
waveform data obtained for 3He (0.5 bar) and CF4(2.5 bar) gas mixture at the gas gain of 300. The
global and local resolutions were 32 mm and 1.2-1.6
mm (see Fig.7), respectively. The position resolution
includes the poor collimation of the neutron beam

368

1) A. Oed, Nucl. Instr. and Meth. A263, (1988) 351.
2) V. Peskov, B. D. Ramsey and P. Fonte, Nucl.
Instr. and Meth., A392, (1997) 89.
3) S. Keller, U. Werthenbach, G. Zech and T.
Zeuner, Nucl. Instr. and Meth. A419, (1998) 382.
4) H. Takahashi, K. Mori, et al., Nucl. Instr. andMeth. A477, (2002) 13.
5) H. Takahashi, P. Siritiprussamee, et al., Nucl.
Instr. and Meth. A529, (2004) 348.
6) E. Mathieson, G.C.Smith, and P.J.Gilvin, J. of
Phys. E; Sci. Instrum., Vol. 13, (1980) 792.

Development of Readout Systems for Neutron Scintillator Detectors
S. SATOH
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
In recent years, the requirement for a twodimensional (2D) detector system with a relatively
good positional resolution has become more crucial
for neutron-scattering instruments. Especially, thedemand by J-PARC is keen.
A detector that uses the neutron scintillator isused to obtain a positional resolution of a 3 mm or
less. It is too difficult for a 3He detector. Several
versatile readout systems have been developed at
KENS.
Fig. 2.

2D charge division detector readout system[1,2]Fig. 1 shows a 5-inch PMT (R3292) and a 3-inch
PMT (R2486) of Hamamatsu Photonics Co. Theyare 2-dimension detectors with high positional
resolution if a neutron scintillator is put on them.
The 5-inch PMT detects a round area of about 10 cm,
and neutrons can be detected with a positional
resolution of 0.8 mm. The 3-inch PMT detects around area of about 5 cm, and neutrons can bedetected with a positional resolution of 0.5 mm.

Fig. 1.

5 inch PMT and 3-inch PMT.

Fig. 2 shows 2D neutron image data that is
obtained by narrow wide neutron-beams located 1
mm from each other on the 3-inch PMT. The
positional resolution is about 0.5 mm, though there
are some distortions according to the location.

2D neutron image data.

These detectors employ the charge-division
method. Since a center-of-gravity calculation is doneby analog networks in the charge-division method,high position resolution is obtained with few
electronics. Since the position is obtained by the
relational expression x/L=Q2/(Q1+Q2) as well as
the PSD2K system, the same system is used.
Coincidence is taken, respectively, of the X axis andthe Y axis for Q2/(Q1+Q2), and preserves it in a
DRAM of 16MB on the board. The time information
can take only 16ch at a positional resolution of thehighest 512ch*512ch. Other modes can be chosenfrom 64ch of 256ch, 256ch of 128ch*128ch, and1024ch of 64ch*64ch.
When ZnS/6Li is used for the neutron scintillator,
a detection efficiency of about 30% is obtained
compared with the 3He detector at a cold-neutronarea. When 1mm thick 6Li glass is used, a detection
efficiency of about 100% is obtained.
2D-8x8 6Li glass detector readout system[2]Fig. 3 shows the 2D-8x8 6Li glass detector thathas been developed for a high count rate. Thisdetector has 64 6Li-scintillators directly on the frontof it, and is a multi-anode PMT (H7546) byHamamatsu Photonics Co. Each 6Li-scintillator is asquare of 1.7 mm * 1.7 mm of 1 mm in thickness.
Each anode of the PMT is arrayed by 2.3 mm pitch.

369

Fig. 3.

2D-8x8 6Li glass detector.

Fig. 4 shows a block diagram of one channel. The
time analyzing function is composed independently
in each channel.

Fig. 4.

Block diagram of one channel.

It irradiates during a fixed time, and ameasurement that raises the LLD little by little isperformed. Fig. 5 shows the PHA distribution graph,
which is made from the difference in each data. The
above graph shows the PHA on the horizontal axis,
the channel on the vertical axis, and the number ofcounts in light and shade. The lower graph shows
the PHA on the horizontal axis, the number ofcounts on the vertical axis. Since 6Li glass is used as
the neutron scintillator, separation of the noise andthe neutron signal is easy.

Fig. 5.

PHA distribution graph.

Fig. 6 shows a cadmium mark put on the detector,
and the acquired data in the H9 beam line at KENS.
The detector obtained 15 Mcps as the maximum
count rate.

Fig. 6.

370

2D detector by flat panel type PMT[2]The neutron scintillator is put directly on a flat
panel-type 64ch multi-anode PMT(H8500) made by
Hamamatsu Photonics Co. The flat panel-type PMT
detector (FPMT) can combine with little dead space,and has a possibility that the detection area can bechanged according to the usage since it is rimless.
Fig. 7 shows the detector. The glass for optical
diffusion is put between the FPMT and thescintillators, and light of the scintillator is diffusedby it. This light is received with three or morechannels of the FPMT, and the neutron attainment
position is obtained by a center-of-gravity
calculation. However, since the range of thecalculation is not unrestrictedly expanded, theposition is obtained from the maximum channel and,its surrounding 4 channels.

Cadmium mask, and 2D neutron image data.

Fig. 7.

FPMT detector.

Fig. 8 shows a cadmium mark put on the detector,
and the acquired data in the EZO beam line at
KENS. The positional resolution is about 1mm.

Fig. 8.

Cadmium mask, and 2D neutron image data.

References
1) S. Satoh et al., Development of Position
Sensitive Detector, PSD2K system for Neutron
Scattering Experiment, KEK Report 2001-9.
2) S. Satoh, Development of readout systems forneutron detectors, JSNS Hamon 2005-1.

Development of 100Hz T0 Chopper
S. ITOH, K.UENO, R. OHKUBO, H. SAGEHASHI, Y. FUNAHASHI, S. KOIKE, M. KAWAI,
M. ISHIHAMA* and N. HITOMI**High Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801*Department of System Design Engineering, Kanagawa Institute of Technology, Atsugi 243-0292**Innovation Plaza Miyagi, Japan Science and Technology Agency, Sendai 989-3204
rotational frequency of the motor of 50 Hz was
doubled by a belt, and an encoder was mounted on
the shaft of the rotor. The base timing of 100 Hz is
generated by the same function generator. The
difference between the rotational pulse from theencoder and the base timing was observed, as shownin Fig. 1. The fluctuations of 3 ms in peak to peakwere initially observed without any control device.
To reduce the fluctuations, we mounted a stabilizer,
which is a sort of a dynamic break, on the rotational
shaft. By using the stabilizer, the fluctuations weresuccessfully reduced to 1.5 ms in peak to peak. Thisis satisfied with the specification for the phase
control accuracy of ±5 ms.
The vibration levels are evaluated by thevibration amplitude. For 100 Hz, the excellent levelis defined for the amplitude less than 7.95 mm in theJapanese Industrial Standard. The vibrations weremonitored at both bearing housings at the motor sideand the encoder side, and at the encoder base. The
amplitudes in the stable operation at 100 Hz were
measured to be 2.0 mm, 2.7 mm and 1.9 mm at thebearing housing at the motor side, at that at theencoder side and at the encoder base, respectively.
The vibration levels were in the excellent level.
FUNCTION
GENERATOR

MORTOR

12 MHzPULSE
GENERATOR

409.6 kHz SERVO AMP
8192 pulses/turn

COUNTERbase timing

50 Hz
BELT 100 Hz
ENCODER(100 Hz)(100 Hz)DATA
TAKING

fluctuations (s)Requirements for T0 choppers at J-PARC varyagainst the instruments, dependently on the beam
size as well as the neutron energy range utilized on
the instruments. We started the development of T0
choppers for the severest mechanical condition [1,2].
To utilize 2 eV neutrons with the beam cross sectionof 80 mm 80 mm, we designed and assembled a
T0 chopper running at 100 Hz. This beam size isutilized on an instrument having a large guide tube
transporting higher energy neutrons, such as achopper spectrometer. The cross section of the
chopper blade (shielding part) on the rotor of the T0
chopper was determined to be 82 mm × 82 mm witha margin of ±1 mm. This margin corresponds to thephase control accuracy of ±5 ms. The length of theblade of 300 mm was chosen to be the same as thatat ISIS, and the same signal-to-noise ratio is
expected. The rotational radius of the rotor is 300
mm. If this is installed at 8.5 m from the neutron
source, neutron energies up to 2 eV can be utilized.
The rotor shape was designed on the basis ofstress analysis calculations. The rotor was made in abody including rotational axis, and the material waschosen to be Inconel X750 from the mechanicalproperties as well as the radioactivation properties.
As the result, the maximum stress could be reduced
less than half of the proof stress. Almost all of theparts were designed on the basis of the JapaneseIndustrial Standard. However, there does not exist a
standard product for the bearings. The rotor and thebearings are mounted inside the vacuum. We used
the mechanical bearings of 45 mm in the diameter ofthe rotational axis, which is the maximum diameterfor 100 Hz rotation in the products available
commercially. Since the vacuum is at around 1 Pa
not too high, we used the bearings for theatmosphere, but the grease was changed to that for
the vacuum. In the present design, we assumed thecontinuous running time of 1000 hrs (corresponding
to the length of the beam time) and the annual
running time of 4000 hrs at 100 Hz of the rotation,
as a reasonable maintenance period.
For the rotation, a servo motor was driven by thepulses generated from the function generator. The

Fig.1

5

0

-5
0

10

20

time (sec)30

40

Circuit for monitoring the rotational fluctuations andthe rotational fluctuations in the best case.

371

Fig. 2

10

 t

5

0
50

100

time (sec)

t

5

0
50

100

150

time (sec)200

Typical rotational fluctuations. The fluctuation
amplitude Dt is defined as shown in each figure.

During the dry run test, we observed two types ofrotational fluctuations, as shown in Fig. 2. The
origin of these fluctuations is unknown, however, it
might be related to the condition of the bearings. We
recorded the number of events for these types offluctuations. The fluctuation amplitude was found tobe almost less than 5ms, that is satisfied with thespecification for the control accuracy of ±5ms. The

372

1

200

150

10

control circuit was developed to reduce therotational fluctuations. The deviation of therotational phase was reduced by comparing therotational pulse from the encoder with the basetiming shown in Fig. 1 and by sending pulses
necessary for the correction to the servo amplifier.
Figure 3 shows the rotational fluctuations observedwith and without the control circuit. The reductionof the rotational fluctuations was greatly improved
to almost ±1 ms in peak to peak. To realize suchexcellent mechanical properties, it was found to be
essential that the mechanical parts on the rotational
axis are assembled in a reasonably good accuracy.
Based on these results, we designed a model of
the T0 chopper for the actual experiment, where thetotal length of the device along the neutron beam
was reduced. The mount/dismount mechanism wasalso designed. The T0 chopper will be mounted in atiny space under the heavy shielding. The base will
be fixed on the flour, and cooling water andelectricity will be supplied to the T0 chopper fromthe base. When the T0 chopper is mounted on thebase, cooling water and electricity will be connected
automatically.
The important parts are located on the rotational
axis at 300 mm from the neutron beam line. At thisposition, g ray is dominant and the absorption dosecan be calculated in the order of 1 kGy/yr. The
investigations on the radiation damage on the partsin the T0 chopper have been started.

ONOFF

number of events

fluctuations (s)fluctuations (s)Since the excellent mechanical properties wereconfirmed, we started a continuous dry run test toinvestigate the life time of this T0 chopper. An
unmanned system was also designed with
monitoring vibrations, temperatures, water flows,
vacuum, electric currents and so on, at the key parts
for the system. We defined a threshold value foreach monitoring item, and the system will be
stopped automatically in emergency case. The
monitoring items were selected for the actual
operation in the future. In the dry run test, the total
running time of 4648 hours was recorded, also, thecontinuous operation time of 1529 hours wasrecorded. However, the life time of the magnetic
seal, which is a part to transfer the rotation from the
motor outside the vacuum chamber to the insiderotor, was limited around 2500 hours during the total
running time, and therefore, only the magnetic seal
did not satisfy the specifications for the annual
running time. By changes in the magnetic circuit tohold the magnetic fluid as well as the magnetic fluid
material with higher vapor pressure, an increase in
the life time of the magnetic seal was suggested. By
installing the improved magnetic seal, the life timeof the T0 chopper will be confirmed.

0

-5

0

5

deviation from target timing (s)Fig. 3

The rotational fluctuations in the T0 chopper with(ON) and without (OFF) the control circuit. Numberof events normalized by the maximum number isplotted as a function of the deviation from the target
timing. The deviation corresponds to Dt in Fig. 2.

References
1) S. Itoh et al., ICANS-XVI (2003) 423.
2) S. Itoh et al., ICANS-XVII (2006) in press.

Concept for T0 Choppers with Magnetic Bearings
K. UENO, S. ITOH, R. OHKUBO, H. SAGEHASHI, S. KOIKE, Y. FUNAHASHI, M. KAWAI,
T. YOKOO and J. SUZUKIHigh Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801
The collaboration on the development of T0
choppers between the Mechanical Engineer Center(MEC) and the Neutron Science Laboratory (KENS)
started at KEK in 2002 [1]. We here summarize thecurrent development of the T0 chopper and present a
new concept using magnetic bearings.
Requirements for T0 choppers to be installed at
J-PARC vary against the neutron instruments,
dependently on the beam size as well as the neutronenergy range utilized on the instruments. The
requirements of the T0 chopper for the current
development, which are the severest conditions forT0 choppers for instruments utilizing high energy
neutrons with a large beam cross section, are listed
in Table 1. We designed and built up the T0 chopper
based on these requirements by using ball bearings,
an electric motor, an stabilizer, an belt and so on.
We have been investigating the performance of theT0 chopper for over two years by improving its
properties. In Table 2, the elementary issues in thedevelopment of the T0 chopper are listed.
Table 1. Requirements of the T0 chopper.

Available Maximum Neutron Energy: 2 eV
Beam Cross Section: 80 mm x 80 mm
Blade Cross Section: 82 mm x 82 mm
Blade Length along the Beam: 300 mm
Rotational Radius: 300 mm
Rotational Frequency: 100 Hz
Distance from Neutron Source: 8.5 m
Diameter of Rotor Shaft: over 45 mm
Rotor Material: Inconel X 750
Rotor Weight: 120 kg
Rotor Inertia: 4.7 kgm2
Annual Running Time: 4000 hours
Continuous Running Time: 1000 hours
Outer Size of T0 Chopper:
1300 mm(L) x 1300 mm(H) x 990 mm(W)
Atmosphere of Rotor: 1 Pa
Temperature around T0 Chopper: 25°C
Driving Functions:control signals, electric power,
cooling water and vacuum

Table 2. Elementary issues in development of the T0 chopper.

(corresponding to the margin between theblade and the beam)
Lubrication: in vacuum at 1Pa
Irradiation Properties:
shielding and replacement of countermeasureparts
Maintenance : using standard and long-life parts
Semi-Auto Installation:
auto connection to the driving functions
We tested and confirmed the continuous running
time of 1000 hours (corresponding to the length of
the beam cycle) and the annual running time of 4000
hours at 100 Hz of the rotation, as a reasonable
maintenance period [2]. As the result of the longrunning test, we estimate that this T0 chopper willpass the first trial at J-PARC. During the runningtest, we made sure the several issues in Table 3 forthe countermeasure of the safety operation. Also,
issues listed in Table 4 have been watched during
the running test.
Table 3. Countermeasure of safety issues during the running testof the T0 chopper.

Safety Cover: first and second double cover(walls of test room and vacuum chamber)
Rotor Kinetic Energy at Destruction: 1.1MJ
Monitoring Internal Test Room: video system
Earthquake: auto stop over revel 6 EQTable 4. Watching issues of the T0 chopper status.

Vibration: housing of bearings and motor
Temperature: bearings, motor, cooling water
Vacuum: inside of the chamber
Electric current: servo motor
Video with Sound: outside view of T0 chopper
Earthquake: seismometer

A radiation damage of parts mounted on the T0
chopper is possible to be a factor determining the
lifetime of the T0 chopper. Main parts, which are373

bearings, magnetic seals, an encoder and a belt, arelocated on the rotational axis at the distance of 300
mm from the neutron beam line. We haveparts for presenting a reasonable maintenancesenario [3]. It is important to reduce the number ofparts and use parts stronger for irradiation.
By using the ball bearings, we achieved goodmechanical properties such as control accuracy,
rotational fluctuations, vibrational properties andlifetime. The obtained properties were satisfied withthe requirements and the essential issues listed inTables 1 and 2. The lifetime of the T0 chopper islimited by the lifetimes of the mechanical parts
mounted on the T0 chopper, however, it is expected
to be more than the annual running time in thecurrent development. In fact, in the running test, it issatisfied for the T0 chopper with ball bearings to run
for over one year.
We here present a new concept for the T0
chopper, in order to keep maintenance free forbearings, by putting on magnetic bearings instead ofball bearings in both sides of the rotor shaft. If theengineering of magnetic bearings is applied for the
T0 chopper, it is good not only the long lifetime but
also the size reduction of the T0 chopper. Since amagnetic bearing system includes the motor system,a wide range of the control of the rotationalfrequency is available with reasonably small
rotational fluctuations. We expect that the length of
the T0 chopper with magnetic bearings is 80% ofthat with ball bearings, due to the elimination ofseveral parts such as ball bearings, an electric motor,a stabilizer, a belt, magnetic seals. A conceptual
drawing of the T0 chopper with magnetic bearings is374

illustrated in Fig. 1. It is noted that we can evaluate
the difference between the performance of the T0
chopper with magnetic bearings and that with ballbearings, since we have already taken a lot of data
during the running test with ball bearings as
mentioned above.

Figure 1. The T0 chopper with magnetic bearings (crosssectional view).

References
1) S. Itoh, K. Ueno, R. Ohkubo, H. Sagehashi, Y.
Funahashi, N. Sato, M. Kawai, M. Ishihama and
N. Hitomi, ICANS-XVII (2005).
2) S. Itoh, K. Ueno, R. Ohkubo, H. Sagehashi, Y.
Funahashi, S. Koike, M. Kawai, M. Ishihama
and N. Hitomi, in this issue of KENS Report.
3) S. Itoh, Y. Funahashi, K. Ueno, M. Kawai, R.
Ohkubo and H. Sagehashi, in this issue of
KENS Report.

-ray Irradiation Properties of Grease and Magnetic Fluid Used in the T0 Chopper
S. ITOH, Y. FUNAHASHI, K. UENO, M. KAWAI, R. OHKUBO and H. SAGEHASHIHigh Energy Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801
We are developing a T0 chopper running at 100
Hz for a reduction of a background noise generated
by high-energy neutrons on neutron spectrometers to
be installed at J-PARC, assuming its lifetime to be
more than one year [1]. A radiation damage of parts
mounted on the T0 chopper is possible to be a factor
determining the lifetime of the T0 chopper. Mainparts, which are bearings, magnetic seals, an
encoder and a belt, are located on the rotational axis
at the distance of 300 mm from the neutron beamline. The spatial distribution and the material
dependence of the absorbed dose around the T0
chopper has been calculated [2], and it has beenfound that the absorbed dose at the distance of 300
mm from the neutron beam line just at the outside of
the bulk shielding is approximately 1 kGy/yr at theoperating proton beam power of 1 MW and that theperformed irradiation experiments on the parts on
the rotational axis. The samples, the grease in therotor bearings and the magnetic fluids in themagnetic seals, were irradiated by high-energy
60
Co at the Cobalt 60
Irradiation Facilities, Takasaki Advanced Radiation
Research Institute, Japan Atomic Energy Agency(JAEA). The dose irradiated to the samples wascontrolled to be 1 kGy, 10 kGy and 100 kGy. Afterthe irradiation, properties of the materials were
investigated. The results are summarized below.
Grease in rotor bearings (SEM and 19F-NMR)
Grease consists of a puffing agent and a base oil.
The puffing agent is a solid component to make thebase oil gel-like by configuring a three-dimensional
structure and increasing viscosity. We investigatedthe DEMNUM grease, L65 (Daikin Industries, Ltd.),
which is used in the rotor bearings. The puffing
agent consists of particles of polytetrafluoroethylene(PTFE) and the base oil is DEMNUM (fluoric oil).
These two components were separated bysupersonic wash in C6F14. The puffin agent wasobserved by scanning electron microscopy (SEM)
and the base oil was investigated by 19F-NMR. The
samples of the grease were irradiated with the doseof 1 kGy, 10 kGy and 100 kGy. Figure 1 shows theparticle size distribution of the puffin agent in theunirradiated and irradiated samples observed by
SEM. It was found from the SEM photographs thatthe particle size distribution and the particle
connection are almost unchanged in the dose range
from 0 to 100 kGy. The observed 19F-NMR spectra
were almost unchanged in the dose range from 0 to
10 kGy, but a small change in the molecular field
was observed at 100 kGy. The averaged molecularweight of the base oil deduced from the NMR
spectrum is listed as a function of the dose in Table
1. The molecular weight was almost unchanged up
to 100 kGy.

unirradiated

1 kGy

10 kGy100 kGy

Fig. 1 SEM photographs of the puffin agents in the
DEMNUM grease, L65. The width of the scale in eachphotograph is 1.5 m.
Table 1. Molecular weight of the base oil in the DEMNUM
grease, L65, determined by 19 F-NMR as a function of theirradiation dose.
dose(kGy)
molecular
weight04500 –
4800

14500 –
4700

104600 –
4800

100
4500 4600

375

376

friction coefficient measured in this experiment andthe lifetime are summarized in Table 3, where thelifetime is normalized by that of the unirradiatedsample. However, the friction coefficient for theunirradiated sample seems to be much smaller thanthose of the other irradiated samples. Further
investigations to clarify the accuracy of thisexperiment are required.

D (mm)

Grease in rotor bearings (four-ball method)
Lubricating properties of grease can beinvestigated by the four-ball method. Four steel ballsof 1/2 inch diameter are located on the corners of atetrahedron with the closed-pack configuration, andthe grease is inserted among the balls. The bottom
three balls are fixed, and the load is applied to the
top ball and the top ball is rotated in an appropriate
time with an appropriate frequency. After therotation, the diameters of the scars on the threebottom balls are measured and the averaged value isdetermined. Also, during the rotation, the torque inthe grease can be measured. We investigatedlubricating properties of the DEMNUM grease, L65.
First, we performed the loading test [3]. After therotation with 1760 rpm and 10 sec, the scar
diameters (D) were measured as a function of theload (L), as shown in Fig. 2. The unirradiated grease
was not burned out up to the load of 800 kgf, but thegrease irradiated with 100 kGy was burned out at
620 kgf (welding load, WL). From the linear regionin Fig. 2, the load wear index (LWI) is estimated as
the averaged value of LD0/D, where D0 is the scar
diameter for a static load and is given by anempirical formula [3]. The obtained parameters arelisted in Table 2. It is said that the accuracy of LWI
is 17% for the tests under the same condition using
the same instrument by the same trier. LWI
represents an extreme pressure property of grease. It
was found from this loading test that the acceptableload is reduced at the irradiation dose of 100 kGy.
Next, we performed the defacement test [4].
After the rotation with 1200 rpm and 1 hour under
the application of the load of 40 kgf, the scar
diameters were measured. Also, during the rotation,
the torque in the grease was measured. The load of
40 kgf in this standard is comparable to the actualload in the rotor bearings in the T0 chopper (therotor of 120 kg is supported with two bearings). The
scar diameter was almost unchanged up to 100 kGy.
The torque measured during the rotation is
proportional to the friction coefficient via an
constant related to the instrument. The friction
coefficient measured during the rotation is shown in
Fig. 3. The lifetime of a bearing is inversely
proportional to the cube of the load. Assuming thatthe load is proportional to the friction coefficient in
the bearing and that the contribution of the frictionof the grease to the overall friction of the bearing is
dominant, the lifetime is inversely proportional tothe cube of the friction coefficient of the grease. We
estimated the lifetime of the bearing as a function of
the irradiation dose. The scar diameter and the1

0.1

unirradiated100 kGy
D0(L)
100

1000
L (kgf)Fig. 2 The scar diameter (D) as a function of the load (L) inthe loading test by the four-ball method, for the
DEMNUM grease, L65. The solid lines on the marks
are fitted lines. The slope is related to LWI in Table 2.
The dashed line is the empirical load-dependence ofthe scar diameter for a static load, D0 (L).

unirradiated100 kGy

Fig. 3

Friction coefficient of the DEMNUM grease, L65,
converted from the torque measured during therotation in the defacement test by the four-ballmethod. The friction coeffi cients for the horizontal
solid lines were used for the analysis in Table 3.

Table 2. Result of the loading test by the four-ball method. WL(welding load) and LWI (load wear index) of the DEMNUM
grease, L65, are listed as a function of the irradiation dose.
0
> 800
141

dose (kGy)
WL (kgf)
LWI (kgf)

100
620
99

Table 3. Result of the defacement test by the four-ball method.
The scar diameter and the friction coefficient are measured.
The friction coefficient is of the DEMNUM grease, L65. The
lifetime of the bearing is estimated from the friction coefficientof the grease.
dose (kGy)scar diameter (mm)friction coefficient
lifetime

0
0.73
0.091
1

1
0.68
0.113
0.52

10
0.69
0.114
0.51

100
0.70
0.117
0.46

Table 4. Viscosity coefficient at 20°C and evaporation speed at
80°C and 0.7 Pa in the magnetic fluid, FV-42. (*The value on
the inspection sheet of the product.)dose (kGy)viscosity coefficient (Ns/m2)
evaporation speed (g/cm2h)00.3251
1.2 x 10-4100
0. 3565 (0.313*)
1.2 x 10-4

Magnetic fluids in magnetic seals
The properties of magnetic fluids can becharacterized by density, viscosity, magnetization,
concentration and size distribution of magnetic
particles, out-going gas, vapor pressure andsegregation. The radiation damage of magnetic
thought to make a change in the chemical propertiesof the solvent and the surfactant. If so, the radiation
damage might reflect to viscosity and vapor pressure.
We measured the viscosity coefficient at 20°C andthe evaporation speed at 80°C and 0.7 Pa in themagnetic fluid, FV-42 (Rigaku Corporation), whichis consist of ferrite particles dispersed in an alkylic

solvent and is used in the magnetic seals on the T0
chopper. The result is listed in Table 4. The
viscosity coefficient and the evaporation speed were
almost unchanged between the unirradiated sample
and the sample irradiated with 100 kGy.
grease in the rotor bearings and magnetic fluids inthe magnetic seals in the T0 chopper were
investigated. Remarkable damages in the following
properties were not observed: the size distribution
and the connection of the puffin agent of the rotor
bearing grease, the molecular weight of the base oilof the rotor bearing grease, and the viscosity and theevaporation speed of the magnetic fluids in themagnetic seals. However, a change in lubricating
properties of the rotor bearing grease was observed.
The accuracy of the change should be investigated.
Moreover, irradiation properties of grease in themagnetic seals, an encoder and a belt will be
investigated. Also, we are planning an experiment todirectly determine the lifetime of bearings mounting
irradiated grease.
We are grateful to Dr. J. Kusano (JAEA) for
arranging the beam time at the Cobalt 60 Irradiation
Facilities. The SEM and NMR measurements were
performed at Daikin Industries, Ltd., the four-balltests were performed at Japan Lubricating Oil
Society, and the properties of the magnetic fluids
were measured at Rigaku Corporation.
References
1) S. Itoh, K. Ueno, R. Ohkubo, H. Sagehashi, Y.
Funahashi, S. Koike, M. Kawai, M. Ishihama
and N. Hitomi, in this issue of KENS Report.
2) M. Tamura, private communications (2004).
3) Japan Petroleum Institute Standard, JPI-5S-4093.
4) Japan Petroleum Institute Standard, JPI-5S-3290.

377

Neutron Optics
M. FURUSAKA, S. SATOH, N. TORIKAI and H. M. SHIMIZU
Neutron Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, Tsukuba, Ibaraki, 305-0801
The neutrons deliverable to samples andcontributing scientific data are limited in number
compared with X-rays and visible photons. One of
the reasons is that the neutron production requires
nuclear reactions. Another is the low density in thephase space, which leads to a large beam crosssection and divergence in order to obtain acceptable
flux. We thus need to prepare large samples andthe instrument dimension is chosen as large as the
sample size does not adversely affect the angularresolution of scattered neutrons. A research anddevelopment of neutron optics is in progress forovercoming these difficulties and moreover for
activating new possibilities of neutron scatteringexperiments.
One of possible results is the increase of the‘efficacy’ of the neutron use, which involves thedevelopment of neutron optical devices, imaging
detector, sample environment, data reduction andanalysis. Another is the downsizing the instrument
dimension at the same performance.
A stack of thin compound refractive opticalsheet (microprism) was characterized using the H8378

beam line of KENS. We observed the neutron
refraction up to E=0.1eV using 300-sheet and 500sheet stacked microprisms made of perfluoropolymer[1,2]. The neutron beam profile was
acquired as a function of time using a scintillation
imaging detector with a resistive-wire connected
position sensitive photomultipler[3].
The bending power of compound refractive
optics is proportional to E-1, which implies that thecold neutron beam can be refracted very strongly
without decreasing the effective aperture.
The imaging detector used in the measurement
has the position resolution of about half millimeter.
Its counting capability allows us to acquire theprofile of the direct beam in a reactor-based small
angle neutron scattering with focusing geometry,
which has enabled us to minimize the accessible qregion and has achieved the enhancement of neutron
beam ‘efficacy’ by two orders of magnitude.
The R&D activities are being expanded to
involve reflective optics, magnetic refractive optics,
micropattenedelectrodegaseousdetectors,
mechanical choppers, data acquisiton electronics,

on-line data acquisition framework, sample nuclear
polarization out of thermal equilibrium etc. forfurther activation and expansion of new possibilitiesof neutron science [4].
References
1) T. Shinohara et al., Nucl. Instrum. Methods
A529 (2004) 134.
2) T. Shinohara et al., Physica B (in press as theProc. of ICNS2005).
3) K. Hirota et al., Phys. Chem. Chem. Phys. 7(2005) 1836.
4) H. M. Shimizu et al., Physica B (in press as theProc. of ICNS2005)379

Spatial Distribution of Neutron Intensity on a Hydrogen Moderator and
Neutronics of Methane Hydrate Moderator Sudied for JSNS
Y. KIYANAGI, S. OHNUMA, T. KAI*, T. KAMIYAMA and F. HIRAGA
Graduate School of Eng., Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, 060-8628, Japan*Proton Accelerator Facility Unit, Quantum Beam Science Directorate, JAEA, Tokai-mura, Naka-gun,Ibaraki-ken,319-1195, Japan
1. Introduction
As moderators for the Japan Spallation Neutron
Source (JSNS) we decided to use the hydrogenmoderators since radiation damage of hydrogen issimple and therefore easy to handle even under thehigh radiation field. However, difficulty of hydrogenis that the neutronic performance strongly depends
on the ortho/para ratio. We already experimentallystudied change of the spectral intensity and the pulse
shape depending on the ortho/para ratio[1-2]. The
effect of the ratio became very large withapproaching para 100%, which indicated again thatthe stability of the ratio was very important for theneutron scattering experiments, since we will use
about para 100% moderator because of its highneutronic performance.
Furthermore, the spatial distribution of neutron
intensity on the surface of the para hydrogenmoderator is expected to be different from a normalhydrogen moderator from the result of simulation
calculation[2]. However, it has not been
experimentally confirmed.
On the other hand, methane hydrate has been
expected to be a new moderator material for the
future spallation neutron sources, since it includes amethane molecule in each ice cage. In the moderator
development program in the ESS project, thismoderator was one of the most important
moderators. We are also interested in this material
and have performed measurements to study theneutronic performance of this material.
Here, we present the results of the measurementsof the spatial distribution on the hydrogen moderator
surface, and the neutronic performance of themethane hydrate moderator.

the hydrogen moderator is shown in Fig. 1. The
flight path length is 6m and the pinhole of 2mm wasset at middle of the flight path to apply pin-holecamera principle. Eight of 1-D position sensitive
detectors were used. The moderator size was 12cm x
12cm x 5cm, which is different from the size used at
JSNS, since the aim of this measurement was to see
the characteristic spatial distribution of thepara-hydrogen moderator compared with that of theortho-rich hydrogen moderator. Ortho/para ratio wasmeasured by Raman spectroscopy.
For the measurements of the methane hydrate
moderator we used a different system similar to thisbut there was no pinhole. The content of themethane molecules in methane hydrate was 80% andthe packing rate of methane hydrate in themoderator chamber was 58%, since the sample wasminute particles. Methane hydrate is unstable atambient circumstance, so we packed the sample into
the moderator chamber cooled by liquid nitrogen.

Fig. 1 Experimental setup for the spatial distribution
measurements for the hydrogen moderators.

2. Experimental

3. Results and discussion
3.1 Spatial distribution of neutron intensity on
the surface of the hydrogen moderators

The experiments were performed at the
Hokkaido linac facility. The moderator system used
was almost the same as the system used in theprevious measurements[3]. The experimental setup
for the measurements of the spatial distributions of

The 2-D image of the spatial distributions of thetwo moderators are shown in Fig.2 for ortho-rich(about 35% para) moderator (lower figure) andpara-rich (about 99%) moderator (upper figure). The

380

differences between the energy spectra are not solarge in the case of the para-hydrogen moderator but
in the ortho-rich case the spectrum in the center has
highest cold neutron intensity while the intensity
above about 10 meV is lower than the “Near” andthe “Edge” cases.

Neutron Intensity (arb./eV)

notation “Near” indicates the position near the target,and others are similar to this. It is indicated that theintensity of neutrons of the para-moderator is higher
around the periphery than that around the center part.
On the other hand ortho-rich moderator the intensity
around the center is higher than the periphery as
observed in other hydrogenous moderators. From
the results it was confirmed that the characteristic
distribution of the para-hydrogen moderator that theintensity around the periphery is higher than thecenter.

10

2

10

1

10

0

10

-1

10

-2

10

-3

10

-4

P a ra ric h

O rth o ric h (x 0.0 1 )C ro s s: F a r
C ircle : C en ter
S q u are: N e a r
T rian g le: E d g e
1

10
N eu tro n E n erg y (m e V )100

Fig. 3 Spatial dependent energy spectra at various
positions for the two hydrogen moderators.

Fig. 2 Spatial distribution on the hydrogenmoderators
The energy spectra at the positions indicated bycircles in the Fig. 2 are shown in Fig. 3. The

3.2 Neutronic performance of the methane
hydrate moderator
We have measured the spectral intensity and thepulse shapes from the methane hydrate moderator ina decoupled and a coupled moderator systems.
Figure 4 shows the spectral intensity from a
decoupled methane hydrate moderator comparedwith the liquid-hydrogen moderators and the solid
methane moderator. Para ratio of the hydrogenmoderators are 35% and 99%, respectively. The
temperature of the methane hydrate moderator is
32.5 K and the others are about 18 K. The
temperature of the methane hydrate was higher thanthe other moderators since connecting the moderator
top to the cold head of the cooling system at low
temperature in the air would make the thermal
conductivity worse than other cases. The spectral
intensity of the methane hydrate moderator is lower
than the methane and the hydrogen moderators in
the energy region below about 5 meV, but higher
above this energy. This result indicates that themethane hydrate moderator gives relatively medium
intensity spectrum over the wide energy range.

381

��

However, there exists some ambiguity in thenormalization of relative intensity.
From these results methane hydrate is not as good�������������������������������

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The pulse widths in full width at half maximum of
the emission times of each moderator are shown in
Fig. 5. In the low energy region around 2 meV thelowest value is from the decoupled para-hydrogenmoderator, next the decoupled 35% para-hydrogenmoderator, and the third the decoupled solid
methane moderator. The forth is the coupled
para-hydrogen moderator, and next is the methane
hydrate. Therefore, the pulse width of the methane
hydrate is between the 99% and the 35% coupledpara hydrogen moderator. This wide pulse width
may be due to the ice in methane hydrate since themethane molecule rotate freely in the ice cage.
������������������
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�������������������������

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Fig. 5

Pulse widths in full width at half maximum.

In the case of the coupled moderator, we got thesimilar tendency of the spectral intensity ofmethane hydrate. The intensity at cold region is nothigher than the others but higher at higher energy.

382������������������
����������������������

Fig. 4 Energy spectra of the methane
hydrate moderator as well as the methaneand the hydrogen moderators.

���

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������

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Fig. 6 Spectral intensity of the coupledmethane hydrate moderator as well as themethane and the hydrogen moderators.

as methane from the neutronic point of view, since
the neutronic characteristics would be mainly
governed by ice. Methane hydrate is not so easy tohandle and the neutronic characteristics is not sogood compared with methane.
So, future
development of the high performance cold
moderator should be based on methane.
4. Conclusion
It is confirmed experimentally that the special
feature of the para-hydrogen moderator in the spatial
distribution of the neutron intensity, that is the low
intensity around moderator center and higher around
periphery. Furthermore, neutronic performance ofthe methane hydrate moderator was studied and it
was found that the performance is not as good as thehydrogen moderator. This result suggests thatmethane hydrate will not be a good candidate for the
future cold moderator at high power neutron
sources.
References[1] M. Ooi, H. Ogawa, H. Iwasa, and Y. Kiyanagi,
Proc. ICANS-XVI, Dusseldorf-Neus, Germany,
2003, p791.
[2] T. Kai, M. Harada, M. Teshigawara, N.
Watanabe, and Y. Ikeda, Nucl. Instr. Meth., A539,
345 (2005).
[3] M. Oi, M. Konno, H. Iwasa, T. Kamiyama, M.
Furusaka and Y. Kiyanagi, J. Nucl. Sci. and Tech.,
Vol.41, No.12, 1138 (2004).

Benchmark Study of Neutron Beam-line Shields for J-PARC
M. KAWAI1, K. SAITO2, T. SANAMI2, N. NAKAO2 and F. MAEKAWA3
1) Neutron Science Laboratory, Institute of Materials Science, High Energy Accelerator Research Organization, 1-1, Oho, Tsukuba-shi, Ibaraki-ken, 305-0801
2) Radiation Research Center, High Energy Accelerator Research Organization, 1-1, Oho,
Tsukuba-shi, Ibaraki-ken, 305-0801
3) Japan Atomic Energy Agency, 2-4, Shirakata Shirane, Tokai-mura, Naka-gun, Ibaraki-ken,
319-1195

The JSNS[1] is a spallation neutron source of the J-

shielding design criteria.

Sometimes, neutrons andPARC (JAERI-KEK Joint Project of the High Intensity

gamma-rays from the neighboring beam line may influent

Proton Accelerator) which will be driven by a pulsedon the data measured by neutron detectors as a noise.

proton beam at 1 MW power with an energy of 3 GeV

Thick shields of one NBL may interfere the neighboring

and a beam current of 333 micro-ampere. It has 23 neu-

NBL shields because of limited space of the JSNS ex-tron beam lines with a length from about 10m to 100m as

perimental hall against many NBLs. It is necessary toshown in Fig. 1. Neutron beam-line (NBL) shield is very

optimize the NBL shields for saving a construction cost ofimportant since the neutron intensity is extremely highthe facility. In the present work, we made base data forand over all length of NBLs is so long. The amount of theshields such as iron, concrete etc. becomes several hun-

optimum shielding design with a new method for the
NBL shielding calculation [2] by using the MCNP-X

dred tons per one NBL at least in order to reduce radiation

code /3/.

dose rates to below 1 mSv/hr which is a
1. Calculation method
The NBL shielding calculation can be divided into
two kinds of problems: radiation streaming through a duct
space of NBL and the bulk shields around the NBL. Accordingly, the present benchmark shielding calculation is
also divided into two steps.
(1) First Step calculation
Components inside the biological shield of JSNS
such as a target-moderator-reflector-assembly and NBLs
were modeled:. Cross section area of straight NBL ducts
Fig. 1 Model of source calculation for NBL shielding

was 100 x 100 mm, and ducts began at 1.5 m from thecalculation for JSNS

moderator. The most forward directed NBL was selected
for calculation. Many surface crossing estimators of 100 x

383

neutrons decreased in every interval of surface crossing
estimators, is called “neutron wall load” to the NBL ducts.
The calculated wall loads became single differentiation of
the fitting curves for the neutron current in the ducts.
(2) Second step calculation for bulk shield aroundneutron beam line
The calculated neutron current distribution for the
NBL duct was tabulated in a file. Because the DXTRAN
sphere was used in the first step calculation, neutron current spectra above 150 MeV could not be calculated. The
spectra above 150 MeV were extrapolated assuming thatthe spectral shape in the beam duct was similar to that near
the TMRA where neutron spectra above 150 MeV could
be calculated with a real estimator. Asource subroutine for
MCNPX that sampled source neutrons according to theFig. 2 Model of NBL shielding calculation

tabulated neutron current distribution, J(E,li), was created.

x 100 mm were distributed in the duct as shown in Fig. 1,

2. Benchmark Calculation

and a neutron current distribution J(E,li) was calculated

For the benchmark calculation, the bulk shield ma-

where li is a distance of the i-th surface crossing estimator

terials around NBL were a single layer of iron and heavy

from the moderator. Two DXTRAN spheres were used toconcrete, multi-layers of constant thick iron and concrete,

obtain results with good statistical accuracy: one at a position at 1.7 m close to the entrance of the duct and anotherpolyethylene or concrete and colemanite mixture withtotal thickness shields of 3m. Finally, Iron thickness wasin the duct at 3.4 m. The position of the DXTRAN spherepartially changed as a function of distance from moderator

in the duct was changed to 8.6 m and 21.0 m, and repeat

by taking account of dose rate reduction. Fig. 3 shows. a

the calculation to obtain the current distribution up to 50 mmodel of typical 25m long NBL having a various combi-

from the moderator.

nation of iron and concrete-colemanite mixture shields: In

Here, we call shield region around the NBL ducts

worse case, reducing iron thickness may bring fast neu-

extending in l > 1.5 m as ‘collimator shield’. In the calcu-

tron enhancement, which can be suppressed by increase

lation, importance values for the collimator shield regionsof concrete shield around the iron shield. Accordingly,

were set to zero. This means that neutrons coming directly

nearly constant shield can be expected to maintain a uni-

form the TMRA region to the estimators of J(E,li) areformly distributed dose rates.

counted but all neutrons scattered at least once in the collimator shield are not counted. This treatment is needed toseparate clearly the direct component and the in-scattercomponent otherwise the in-scatter component is counted
doubly in the source term and the second step calculation.
The direct component is treated as a source for the second
step calculation while scattering in the collimator shield isconsidered in the second step calculation. The distribution
for the straight duct is well fitted[2] by an equation J(l) =65(1/l)2 where 65 is a normalization factor. Number of384

Fig. 3 Configuration of typical 25 m long NBLshields.

2.1 Single layer Iron or magnetite concreteFig. 4 shows the radial distribution of total dose rate

Benchmark calculation for NBL shield configura-at Z=20m. It indicates that 2m thickness of the magnetite

tions was made with MCNPX. In simple geometry with aconcrete is needed to reduce dose rate to the design crite-

single layer, radial dose rate distributions at different dis-

ria even at Z=20m. In case of the polyethylene shield, ittances from the moderator have a very similar shape to

was found that insert location is important to determine

each other. It means the dose rates strongly depend on thethe dose rate in the outside region of the shields. In thesource intensities at the duct wall. It is also found that thefigure, 150R case, finally gave the lowest dose rate.

magnetite concrete is more effective to reduce dose rates

Coleminite concrete is the most effective to save shieldthan iron.

thickness..

In the NBL shield, fast neutrons from the spallation
neutron target make play a very important role on dose
rate outside of the shield. Iron is effective to reduce fast

3.3 Effect of iron shield thickness in case of composite
shields

neutron fluxes. In case of the iron shield, fast neutrons

Iron shield is much expensive compared to normal

show very small contributions which are lower than those

concrete and even colemanite concrete. In order to reduceof the magnetite concrete, while the contributions of neu-

the NBL shield construction cost, iron shield saving istrons in the energy below 1 MeV are very high and ex-much effective. In the present work, we tried to take aceeds a design criteria of dose rate: 1 mSv/h even atneutron dose rate as a parameter determining the iron

Z=50m. These high contribution are said to be caused byshield thickness. This means that the iron shield thickness

the window effects at the valley of the total cross sections

decreased with a distance from the center, i.e., Z, asin the resonance energy region below about 1 MeV. The

shown in Fig. 3. Fig. 5 shows the results of the radial dose

magnetite concrete effectively suppressed those contribu-

rate distributions for various iron shield thickness: Fe-tions by large neutron slowing-down power of hydrogen.

Con1micro is denoted to the case of iron was cut at the

Accordingly, hydrogeneous materials are inevitable to the
NBLshields.

position where fast neutron dose rate became 1 mSv/h or
smaller. The larger cutting dose rare means thinner shieldthickness. In case of 100mSv/h cut, neutron moderation

3.2 Multi-layered shield with constantly thick ironeffect reduced dose rate in the inner region but remained

It is interested in which of homogeneous or hetero-fast neutrons gave a slow decaying curve in the outergeneous shields composed of iron and hydrogeneous

region. This trend resembles that of the magnetite con-material is more effective to the NBL shields. The form-

crete. The cases of the cutting parameter of 10mSv/H ander shields are heavy concrete containing magnetite and

30mSv/h show different trend but gives nearly the same

steel ball. The latter are considered to be composite ones

shielding thickness to satisfy the design criteria. 10%

such as polyethylene, normal concrete or some special

weight-abundant coleminte concrete and iron shields ofconcrete with iron.

1.0E+06
Comparison of Neutron Dose at Z=20m

Dose Rate Distribution at Z = 20m

Fe
Heavy Con
Fe+Poly 100R
Fe+Poly120R
Fe+Poly150R
Fe+Conc
Fe+5%B Conc
Fe+10%B Con

Dose Rate ( Sv/h)

1.0E+06

1.0E+04

Neutron Dose Rate (mSv/hr)

1.0E+08

1.0E+02

1.0E+00

FE2M
FE-Con1micro
FE-Con10micro
FE-Con30micro
FE-Con100micro
FE-Con10micro+B

1.0E+04

1.0E+02

1.0E+00

1.0E-02

0

50

100

150

200

250

300

350

R (cm)

1.0E-02
0

50

100

150
200
R (cm)

250

300

Fig. 4 Radial dose distributions at Z=20m

350

Fig, 5 Neutron dose distribution for various configuration of shield varying iron thickness385

10mSv/h cutting parameter effectively reduced the doseshield thickness is very sensitive to final dose rates at therate and the shield thickness satisfying the criteria wereshield surface. Colemanite concrete is very effective to

170 cm and 140cm at Z=10m and 20m, respectively.

reduce shied thickness.
The present importance reduction procedure ofsource sampling was coped into the PHITS code[4] by

4. Concluding remarks

Niita. At the present, NBL shielding designs of each neu-

NBL shielding design studies for the spallation

tron spectrometer of J-PARC are progressed by using theneutron source, JSNS, has been performed with the new

PHITS code and the source data calculated with themethod using the MCNP/X code. Shielding properties of

MCNP-X code, taking account of the present results.. .

various shielding materials were investigated. Iron showed good performance against fast neutrons above 1 MeV
but could not reduce the contribution of neutrons below 1

References:1). Y. Ikeda: Proc. of ICANS-XVI, Vol. 1, pp.13-24

MeV. The hydoreogenoeous shields such as concrete and(2003) Forschungszentrum Juelich.

polyethylene turned out effectively reduce the dose con-2). F. Maekawa, et al. , ibid. Vol. 3, pp.1247 - 1255 (2003).

tributed by such neutrons. The heterogeneously composite

3). L.S. waters (Ed.): MCNPX User’s Manual, TPO-E83-

shields of iron and polyethylene or concrete seems to be

G-UG-X-00001 (1999), Los Alamos National Laboratory.

more effective to the NBL shields than the heavy concrete,4). Niita,

since the latter showed higher decay of the dose rate nearsource and became slower decay far from the source. Iron

386

R&D of Fabricating AG-IN-CD Dedoupler and CD Poison Plate for Decoupled
Moderators of JSNS
M. KAWAI1, M. TESHIGAWARA2, M. HARADA2, S. SAITO2, F.MAEKAWA2,
K. KIKUCHI2, N. WATANABE2, Y. IKEDA2 H. KURISHITA3, and A. CHIBA4
1)Neutron Science Laboratory, Institute of Materials Structure Science, High Energy
Accelerator Research Organization, Tsukuba, Ibaraki, 305-0801
2) JAEA, Tokai-mura, Naka-gun, Ibaraki-ken, 319-1195
3)Insititute for Materials Research, Tohoku Univ., Oarai-machi, Ibaraki-ken, 311-1313
4)Shock-wave and Condensed Matter Research Center, Kumamoto-Univ., Kumamoto-shi,
860-8555

The Japanese Spallation Neutron Source,
JSNS,[1] is one of the worldwide intense pulsed neutron sources and is now being constructed under the
JAERI-KEK Joint Project of the Intense Proton Accelerator Facility whose acronym is J-PARC (Japan
Proton Accelerator Research Complex) [2]. The purpose of the installation is to carry out research on
material structures and life-science by means of neutron scattering methods. The TMRA (i.e., target-moderator-reflector assembly) of JSNS is composed of a mercury target, liquid hydrogen moderators,
and composite reflectors of beryllium and iron[3]. It
has 23 neutron beam lines for neutron spectrometers.
For neutron scattering experiment using thetime-of-flight method, moderator performance ischaracterized by the pulse characteristics: intensity,
pulse width (FWHM, full width at half maximum)and its decay time. The moderators of JSNS were
designed to provide a high performance as follows.
Three kinds of liquid hydrogen moderators (i.e., coupled, decoupled and poisoned moderators) are adopted
for the individual research objectives. The decoupledand poisoned moderator system consists of multilayers of aluminum (Al) alloy containers, hydrogen(20K), vacuum, helium (He) and of cooling. The
thermal neutron absorbing materials (so called “decoupler” and “poison”) were also adopted to obtainnarrow neutron beam pulses. The decoupler is arranged in Al alloy between the He and cooling waterlayers except for the neutron beam extraction surface.
Higher decoupling energy is very effective for reducing decay time. Boron carbide (B4C) is alreadyutilized for this purpose in KENS, IPNS and ISIS.
aHowever, He gas generation due to 10
shorten the decoupler life time in MW class system. In
JSNS, new material of Ag-In-Cd (abbreviated as AIC)
alloys with a high decoupling energy of about 1 eV isdeveloped to provide a long life-time usage even in thevery intense neutron field[4].
A poison brings about narrow pulse widths which
are controlled by moderator thickness. Gd was widely
utilized for a poison material in various pulsed neutron
sources. However, it has many resonances above 1 eV
and they reduce the slow neutron intensity. On theother hand, the neutron capture cross section of Cd isvery low above 0.4 eV. Neutronic calculation[4] of
JSNS showed that a shape of neutron pulse from a
Cd-poisoned moderator near the cut-off energy wasbetter than that of a Gd-poisoned system. The design
requirements for a Cd poison are 1.3 mm in thickness
giving 6 years life time and to be asymmetrically inserted 2.5 cm from the viewed surface. Both the AIC
decoupler and the Cd poison sheet should be covered
with the Al clad because of fabricating the moderator

387

system. It is important to obtain a tight bonding between the AIC or Cd and the Al clad because of thethermal stresses between deformation and exfoliation
due to the thermal shrinkage and radiation damage, etc.
The experiments of trial fabricating them with themethods of the HIP and explosion welding etc. werereported at the ICANS-XVI[4,5]. In the present time,
the further experiments by improving the processing
conditions and by measuring a rupture stress ofbonded AIC materials are reported.

2. Experiments fabricating AIC decoupler
At the first, the AIC plate was divided into Ag-In(15wt%) and Ag-Cd (35wt%) plates within the solubility limits of In and Cd in Ag in order to extend thelife time by considering the irradiation effects studied
to develop the AIC thermal neutron absorber [17, 18]
for the control rod of nuclear reactors. Secondary, the
Ag-In-Cd (70wt%Ag-2.5wt%In-29.5wt%Cd) plate
was attempted in order to make a fabrication processes
reduced. We performed bonding tests by HIP (HotIsostatic Pressing) to establish the bonding condition.
Mechanical tests of the Al alloy and AIC were also
performed to determine the basic properties after HIP.
Small specimens of the AI, AC and AIC wereprepared by cutting a rod with a diameter of 20 mm
that had been made by melting constituent materials
at about 1373 K in an electric furnace into the ones
with the thickness of 2, 2 and 3 mm, respectively. they
were stored in Al alloy (A6061-T6) housing capsule(shape : cylindrical, size : approximately 22 mm inouter diam. x 5 mm in height with thickness of 1 mm)
sealed by using electron beam welding, where theevacuated pressure was about 10-3 Pa for each ofsample. Before storing, samples and Al capsules were
polished by an emery paper with up to 800 grit andcleaned in acetone using ultra sonic waves. After HIP
treatment, we cut and polished the sample to observe
micro structures of the interfaces between the Al alloy
and AI/AC or AIC and to measure mechanical properties such as Vicker’s micro hardness, the mechanical strength, tensile and shear tests.
Figures 1 is micrographs showing the HIP temperature dependence for the case of Ag-In (AI)/Ag-Cd (AC). Bonding tests were performed at388

temperatures from 440oC to 560oC with 100 MPa
and 1 hour holding time. The sample HIPed at 530oC
was the only one successfully bonded. AI and AC
were basically bonded up to 530oC in all cases. The
Temperature

440�

470�

500�

530�

560�

Al alloy

Ag-In
Ag-Cd

A6061

Melted

Ag-In

100�m

100�m

100�m

100�m

Ag-Cd

*
Al alloy

Bonding

100�m�Pressure : 100 MPa, Holding time : 60 min.

100�m

�

100�m

�

100�m

�

�

*Cracking were occured during remounting process.

Fig. 1 Results for small size HIP’ing in case of AgIn/Ag-Cd and A6061-T6.
sample HIPed at 560oC was melted. Even the unsuccessful bonding, the reaction layers of both AI Al alloy and AC - Al alloy were recognized as shownin Fig. 2. The thickness of reaction layers of AI - Alalloy and AC - Al alloy increased with increasing
temperature. This result shows that a relatively thickreaction layer is needed for successful bonding. The
thickness of reaction layer of AC and the Al alloy
was about 3.5 times thicker than that of AI and Al
alloy. In the case of successful bonding at 530oC, thethickness of reaction layer of AI and Al alloy, andAC and Al alloy were about 570 and 175 micrometers, respectively. We also examined the effect on the
HIP treatment of varying the holding time from 10,
30 and 60 min. at 530oC. It was found that the reaction layer thickened with increasing holding time
and the holding time of 60 min was the best in caseof Al-6061 so far. The strength of the Al alloy(A6061-T6) was reduced about 1/3 after HIP treatment.
The bonding test of AIC samples by means of the
HIP clrified that the optimum temperature was
530oC as like two phase samples (Ag-Cd, Ag-In)
and the optimum holding time was 60 min. for
Al6061 and 10 min for Al5083. HIP treatments affected the strength of Al alloy. In case of Al-6061,
heat treatments called T62 were made in order torecover the rupture strength of the HIP’ed sample

and we observed the sample strength became about
50 MPa as like Al5083.
Therefore, we proceeded the experiments for thelarge scale samples of 200 mm x 200 mm x 3mm t ofA6061-T6 and A5083 using AIC. The optimum HIP
conditions which were observed in the small specimen tests were applied to the tests. The HIP’ed
samples were examined by means of the ultrasonicdiagnostics. The typical results in case of A5083
were shown in Fig. 3. It was found that from thefigure that nearly perfect bonding was found for bothecho from the upper and lower interfaces of the AIC
and the A5083 plates in the figure. Tensile strengths
of small cylindrical specimens cut from the sample
were shown to be more than 20 MPa. On the other
hand, A6061 sample showed good bonding after HIP
but peel off on the bottom interface after the heat
treatment which recovered the tensile strength tomore than 50 MPa.

propagation velocity oscillates, the joint interface ofboth metal that is welded by the explosion method
shows a wave form.
Tests were performed using 40mmW x 90mmL x
1mm Cd plates with a different geometrical configuration of Al plate to find the optimum explosion conditions. Fairly good result was obtained by using inthick Al plate with 5 mm and the PAVEX thickness of
30 mm: SEM picture showed good bonding as
shownFig.4. However, this case happened to break atail part of Al and made a deform of sample. Accordingly, the improvement of the experimental conditions
was made for the Al and PAVEX thicknesses. Al plate
was divided into two plates keeping total(a) Photograph of exploded small sample of
Cd poison sheetA(a) Upper interface echo (b) Lower interface echo
Partially unbonded.
Fig. 2 Results of supersonic diagnostics for large
scale sample of A5083 and AIC

3. Experiments fabricating Cd poison plate
3.1 Explosive Welding
In an explosive welding method, a plate of an intermediate cladding material is located in parallel witha base plate and at a distance so as to be accelerated
enough by explosion toward the base plate. After firing a detonator, explosion waves propagate and force
the cladding plate towards the base plate. Both plates
strongly collide and generate a metal jet. The metal jet
cleans up the surfaces of both plates and exposes apure metal. As the result, both plates can make a rigid
metal bond with each other. Since the metal jet

C

C
1
A

(b)SEM of cross section(c) SEM of cross section(35 times)(400 times)
Fig. 4 Results of small sample of Cd poison plate of 5mm thick Al after explosion(a) Photograph of sample (b) transmitted echo
Fig. 5 Results of small sample of Cd poison plate of
two-layered Al after explosion
thickness of 4mm and the PAVEX thickness was reduced into about 10 mm which was distributed as a389

function of the distance from the Cd edge. Fig. 5
shows the result for the small sample. Fig. 5(b) shows
the supersonic echo transmitted through the sample:
Gray zone means good bonding and black does someproblems absorbing the super sonic in the sample or its
surface.
The explosion test for the real sized Cd poison
plate of 116mm x 106 mm x 1mmt was made under
the optimum condition. The result is shown in Fig. 6.
Thin Al was bent near the edges and transmitted echoshows that perfect bonding was not obtained. Unbonded part is concentrated on the lower interface
between Cd and Al behind the detonator and the
PAVEX.

(a) Photograph of sample (b) transmitted echo
Fig. 6 Results of real sized sample of Cd poison plateof two-layered Al after explosion

3.2 HIP method
Another promising method fabricating the Cd
poison sheet is the HIP method. However, good result
has not been obtained without any kind of contact
material such as Zn which has a good compatibility toboth material of Cd and Al. At the present time, a test
using the Zn contact was made at low temperature
below 300oC, considering the low melting point of Cd.
The result showed good bonding as we expected, but
encountered to a problem that the Al capsule wascracked because of making the intermediate metalalloy of Al-Zn and Cd leaked out the Al capsule.
The perfect bonding of the Cd poison plate has notbeen obtained with the explosion welding nor the HIP
method. Recently, Kinoshita analyzed the thermal
stress of the Cd poison plate of the JSNS. He foundthat thermal stress was fairly low and that partial
bonding would not bring problem on thermal stressbut may do a problem on bend of the Cd plate. Accordingly, bonding or loose contact of Al and Cd is an
390

issue of the argue.
4. Summary
We have made the R&D to fabricate the hydrogenmoderator system of the JSNS to obtain good performance with an intense, narrow width and shorter
tail by means of the new AIC decoupler and the Cd
poison sheet which have long life of 6 years. the main
conclusions are as follows:
HIP method is adoptable to the AIC decoupler witha comnation of A5083 so far. However, A6061 encountered a problem of partial peeling-off after T6
process to recover the fracture strength which is lost
during the HIP process. Further investigation isneeded.
As for the Cd poison plate, the explosive welding
produced partially bonding and bending of Al plate
which was prominent near the edges of the Al plate.
The HIP method using Zn as a contact resulted in goodbonding and a problem of melting a partial Al capsuleand leaking Cd from it. recent thermal analysis[18]clarified that a thermal stress of the Cd poison plate
was not so high. Then, loose or partial bonding may be
applicable.
References:[1] Y. Ikeda, Proc. of 16th Meeting of the Int. Collaboration on Advanced
Neutron Sources(ICANS-XVI), May 12 - 15, 2003, Duesseldorf-Neuss,
Germany, Vol. 1, pp.13 - 24 (July 2003) Forschungszentum Juelich, Germany.
[2] The Joint Project Team of JAERI and KEK, “The
Joint Project for High-Intensity Proton Accelerators,”
KEK Report 99-4 (July 1999).
[3] N. Watanabe, et al., Journal of Neutron Research,
Vol. 11 (1-2), pp. 13-23 (2003).
[4] M. Harada et al. Proc. of ICANS-XVIVol. II,
pp.697 - 706 (July 2003)[5] M. Teshigawara, et al., Proc. ICANS-XVI, pp.689- 696 (July 2003)

Geometric Effect of Aluminum Wall on Intensity Distribution of Detected Neutrons
K. TOMIYASU and S. ITOH
Neutron Science Laboratory (KENS), Institute of Materials Structure Science,High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, 305-0801
geometric effect of the honeycomb. Meanwhile, Fig.
3 shows the results on the surface reflection on thehoneycomb depth plane for the wavelength of 10
Angstrom. The loci of the neutrons with the incident
angle below the critical angle of 0.047 degree arechanged with the reflectivity of 100%. The surfaceof aluminum near the boundaries of pixels transfers
the neutrons into the next pixel. The effect leads tothe severe spurious peaks in the real experiments.

a point sample

1 pixel

0

40

40

20

Y [mm]The integrated intensity of secondary scatteringfrom aluminum, which supports the vacuum
scattering chamber between a sample and detectors,
should be reduced as much as possible on neutron
scattering instruments with detectors outside thevacuum. Nevertheless, it is ideal to set the detectors
inside the vacuum, but the method is accompaniedwith the technical difficulties on leak paths andelectric circuits around the detectors. On the other
hand, if the aluminum forms honeycomb internal
structure, the volume of the aluminum can be
drastically cut down retaining its mechanicalstrength. The aluminum density of the honeycomb
structure, proposed by the Mechanical Engineering
Center in KEK, realizes the neutron transmission T
over 99%. In this paper, we consider the effect of
the honeycomb shape on detected signals by
numerical calculations.
In our calculations, only the broad scatteringover the large solid angle, such as incoherent
scattering from vanadium and light hydrogen,coherent diffuse scattering and inelastic scattering,were supposed. The signal with the ring shape,
which caused by the small angle scattering,
diffraction and total scattering from soft matters andpowder samples, were not taken into account. The
Bragg reflections from single-crystal samples were
not also included.
The calculations were performed along thefollowing conditions and procedures. The sample isassumed as a point. The honeycomb, which iscomposed of hexagons with 3 mm on a side and 15
mm depth, is resolved into many finite elements, as
shown in Fig. 1. The squares indicate the pixels with
1/2 inch on a side on the position sensitive detectors.
The scattering from all of the finite elements issummed for all of the elements.
Figure 2 shows the summation of the secondary
scattering rings arising from the honeycomb for the
wavelength of 1.0 Angstrom. The finite element isassumed to generate the uniform Debye rings ofaluminum with the FWHM of 1 degree. The
integrated intensity is the order of or below (1T)~1%. The rings are smoothed, and the intensity on
the four ends relatively decreases. There is no

0

-20

-40

-40

-20

X [mm]

20

Figure 1. Projection on the XY plane, perpendicular to theline from the sample to detectors. The point
sample, honeycomb wall and the pixels on thedetectors are shown together. The distance
between the sample and the honeycomb and thatbetween the honeycomb and the detectors are
390 and 10 cm, respectively.

391

40

Y [mm]

20

0

-20

-40

-40

-20

0

20

40

X [mm]

Figure 2. Summation of Debye rings arising from all offinite elements on honeycomb. The intensity is
described in arbitrary units.

40

References
1) S. Itoh, J. Suzuki, K. Ueno, S. Takata, K.
Tomiyasu, and T. Otomo, ICANS-XVII (2005)
at Santa Fe.

Y [mm]

20

0

-20

-40

-40

-20

0

20

40

X [mm]
Figure3. Surface reflection of the neutrons withwavelength of 1.0 Angstrom, coming fromhoneycomb planes. The intensity is described inarbitrary units.

We also estimated the small angle scattering by
the isotropic Gunie plot. The radius of inertia isassumed as over 10 nm. The geometric effect ofhoneycomb was not found within the approximation.
The hexagonal-like pattern and the streak in the dataon SWAN [1] is interpreted as the random grains of392

aluminum, which make the small angle scatteringexperiments and the capture of low S/N signals
troublesome.
In summary, since the total superficial area canbe large with decreasing the total volume of thealuminum, the honeycomb column structure gives
rise to the spurious peaks by the surface reflection.
To avoid the effect, the depth should also form
zigzag-like or truss-like structures so that the tilt
angle of the surface becomes larger the critical angle,
though the techniques to produce such structures
without glue are required. The other strong
scattering from the aluminum is the small angle
scattering, the coherent Bragg reflection and theincoherent scattering. The geometric effect of thehoneycomb on the scattering can be smeared if thehoneycomb size is enough smaller than the pixel
size. Meanwhile, the total volume of the aluminum
increases with decreasing the honeycomb size.
Therefore, it is needed to optimize the honeycomband pixel sizes for each neutron instruments. In
addition, we would like to emphasize that the small
angle scattering from the grain causes the limitationof detection of signals, which is the common weak
point for all of the neutron scattering instrumentswith detectors outside the vacuum.

V.
APPENDIX

2003–2006

List of Publications
1. General
Present status of KENS
S. Ikeda, M. Kawai, M. Arai, M. Furusaka, T. Kamiyama, S. Itoh, T. Otomo, N. Torikai and T.Ino
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003

2.Target
Development of Hydrogen Cold Moderator Systems for a Spallation Neutron Source
Y. Kiyanagi, M. Ooi, H. Ogawa, and M. Furusaka
J of Neutron research 11 2003
Compact Coating of Tantalum on Tungsten Prepared by Molten Salt Electrodeposition
M. Mehmood, N. Kawaguchi, H. Maekawa, Y. Sato, T. Yamamura, M. Kawai, K. Kikuchi, M. Furusaka
Material Transactions 44 2003
Electro-Deposition of Tantalum on Tungsten and nickel in LiF-NaF-CaF2 Melt Contaning K2TaF7-Electrochemical Study
M. Mehmood, N. Kawaguchi, H. Maekawa, Y. Sato, T.Yamamura, M. Kawai, K. Kikuchi, and M. Furusaka
Materials Trans 44 2003
Cryogenic System Design for Cryogenic Hydrogen Moderator of the Spallation Neutron Source in J-PARC
T. Kato, T. Aso, M. Furusaka, T. Takahashi, I. Ushijima, N. Watanabe, R. Hino, Y. Ikeda
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss
Solid Spallation Target Materials Development
Masayoshi Kawai, Michihiro Furusaka, Jing-Feng Li, Akira Kawasaki, Tsutomu Yamamura, Mazhar Mehmood, Hiroaki Kurishita, Kenji Kikuchi, Nobuyuki Takenaka,
Yoshiaki Kiyanagi, Tadashi Igarashi, and Masahiro Katoh
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
Target Station Design of 1 MW Spallation Neutron Source at the High Intensity Proton Accelerator Facilities J-PARC
H. Takada, F. Maekawa, S. Honmura, K. Yoshida, T. Teraoku, S. Meigo, A. Sakai, Y. Kasugai, S. Kanechika, H. Ohtake, M. Furusaka, R. Hino, Y. Ikeda, N. Watanabe
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
Development of a solid target for a 1 MW spallation neutron source
Y. Kiyanagi, D. Nio, N. Takenaka, M. Furusaka, M. Kawai, and K. Mishima
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
Shielding Experiment for Neutron Beam Lines at LANSCEY. Kasugai, F. Maekawa, H. Takada, T. Ino, M. Ooi, Y. Kiyanagi, G. J. Russell, E.J. Pitcher, G. Muhrer, M. Furusaka, Y. Ikeda, N. Watanabe
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
A New Method for Neutron-Beam-Line Shielding Calculation
F. Maekawa, M. Tamura, M. Kawai, M. Furusaka, N. Watanabe
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
R&D of A MW-class solid-target for a spallation neutron source
Kawai, M.; Furusaka, M.; Kikuchi, K.; Kurishita, H.; Watanabe, R.; Li, J.-F.; Sugimoto, K.; Yamamura, T.; Hiraoka, Y.; Abe, K.
Journal of Nuclear Materials 318 2003
Neutronic Studies on Reﬂector Materials of the Target-Moderator-Reﬂector System in the Japan Spallation Neutron Source
Motoki Oi, Hirotatu Ogawa, Yoshiaki Kiyanagi, Tetsuya Kai, Makoto Teshigawara, Fujio Maekawa, Noboru Watanabe, Yujiro Ikeda, Masayoshi Kawai,Michihiro Furusaka
International Conference on Nuclear Engineering (Tokyo, JAPAN, April 20-23, 2003 ICONE11-36090) 2003

3. Instrumentations
A resonance neutron-spin ﬂipper for neutron spin echo at pulsed sources
Maruyama R, Ebisawa T, Tasaki S, Hino M, Takeda M, Kawai T, Kawabata Y, Sakai K
Physica B 335 2003 TOP (PORE)
The Current Design of a Neutron reﬂectometer with Horizontal Sample Geometry Proposed for the J-PARC
N. Torikai, H. Matsuoka, K. Soyama, H. Takahashi, M. Takeda, S. Tasaki, D. Yamazaki, T. Ebisawa, T. Sakuma, and M. Furusaka
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
Development of a Halbach-type permanent sextupole magnet for neutron beam focusing
T. Oku, J. Suzuki, T. Adachi, K. Sakai, K. Ikeda, T. Morishima, Y. Kiyanagi, M. Furusaka, T. Tsuzaki and H.M. Shimizu
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
Neutron Spin Flip Chopper with very high S/N Ratio for Pulsed Source
K. Soyama, T. Ebisawa, D. Yamazaki, S. Tasaki, R. Maruyama, M. Hino, K., Sakai, T. Oku, K. Shibata, M. Arai, M. Furusaka, N. Watanabe
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
Fully Asymmetric Diffraction Geometry of a Bent Perfect Crystal Silicon Analyzer for High-Resolution TOF Spectrometry
P. Mikula, M. Vr_a, M. Furusaka, Y. Yasushige
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003

395

Magnetic Focusing Devices for Pulsed Neutrons
J. Suzuki, T. Oku, T. Adachi, H. M. Shimizu, Y. Kiyanagi, and M. Furusaka
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
Recent Development of a Position-Sensitive Scintillator Detector Employing Wavelength-Shifting Cross-Fiber
K. Sakai, T. Adachi, T. Oku, K. Ikeda, T. Morishima, H.M. Shimizu, M. Furusaka,T. Ino, S. Sato, Y. Kiyanagi, N. Sakamoto, T. Sakuma, J. Suzuki, K. Littrell,
C.-K. Loong, R. Goyette, S. Hosoya, M. Ishii
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
Monte Carlo Simulation of Magnetic- and Refractive-Neutron Optical Components
S. Suzuki, T. Otomo, M. Furusaka, H. M. Shimizu, K. Niita, M. Misawa
Proc. ICANS-XVI, May 12 - 15, 2003, Dusseldorf-Neuss 2003
Development of charge integrating multi-grid type MSGC
Takahashi, H.; Ishitsu, T.; Hagai, C.; Yano, K.; Nakazawa, M.; Kishimoto, S.; Furusaka, M.; Ino, T.; Hasegawa, K
Nucl. Instrum. Methods A 513 2003
Development of a multi-grid-type microstrip gas chamber for synchrotron radiation applications and spallation neutron sources
Takahashi, H.; Hagai, C.; Yano, K.; Fukuda, D.; Nakazawa, M.; Kishimoto, S.; Ino, T.; Furusaka, M.; Hasegawa, K.,
Nucl. Instrum. Methods A 513 2003
Development of Drabkin energy ﬁlters for JSNS project
Yamazaki, D.; Soyama, K.; Ebisawa, T.; Tasaki, S.; Furusaka, M.; Arai, M.
Physica B 335 2003
Development of a spin ﬂipper for an application of a neutron magnetic device
Oku, T.; Sakai, K.; Adachi, T.; Ikeda, K.; Shimizu, H.M.; Maruyama, R.; Hino, M.; Tasaki, S.; Kiyanagi, Y.; Kamiyama, T.
Physica B 335 2003
Design for 100 Hz background suppression chopper
S. Itoh, R. Ohkubo, H. Sagehashi, K. Ueno, Y. Funahashi, M. Kawai, T. Kume, H. Sakuraba and N. Hitomi
ICANS-XVI (Proceedings of the 16th Meeting of the International Collaboration on Advanced Neutron, Forschungzentrum Julich GmbH, ISSN 1433-559X, 2003)
Monte-Carlo simulation codes development and their applications to neutron optical devices and neutron scattering instruments
M. Furusaka, K. Nitta, S. Suzuki, K. Fujita, J. Suzuki, T. Oku, H. M. Shimizu, T. Otomo, M. Misawa
Nucl. Instrum. Methods A 529 2004
Investigation on possibility of neutron electric optical devices based on piezoelectric single crystals
J. H. Kaneko, Y. Otake, H. Fujimoto, S. Kawamura, M. Watanabe, F. Fujita, T. Sawamura, P. Mukula, M. Furusaka
Nucl. Instrum. Methods A 529 2004
Preliminary results on development of a thin GSO scintillator for neutron science
J. H. Kaneko, N, Susa, S. Tsuchida, M. Watanabe, S. Miura, T. Mizuno, Y. Yamauchi, M. Hashiba, T. Oku, A. Homma, F. Fujita, T. Ino, M. Furusaka, T. Sawamura,
H. M. Shimizu, Y. Kiyanagi
Nucl. Instrum. Methods A 529 2004
Bragg diffraction optics in neutron diffractometry
P. Mikula, M. Vrana, M. Furusaka, V. Wagner, Y-N. Choi, M-K. Moon, V. Em, C-H. Lee
Nucl. Instrum. Methods A 529 2004
Feasibility study on application of a megnetic neutron lens to SANS ecperiments
T. Oku, J. Suzuki, H. Sasao, T. Adachi, T. Shinohara, K. Ikeda, T. Morishima, K. Sakai, Y. Kiyanagi, M. Furusaka, H. M. Shimizu
Nucl. Instrum. Methods A 529 2004
Development of position-sensitive neutron detector based on scintillator
K. Sakai, K. Hirota, T. Adachi, K. Ikeda, T. Morishima, H. M. Shimizu, M. Furusaka, S. Sato, Y. Kiyanagi, N. Shamoto, T. Sakuma, T. Oku, J. Suzuki, K. Littrell,
C-K. Loong, J. B. Czirr, T. K. McKnight
Nucl. Instrum. Methods A 529 2004
Development of readout systems for neutron detectors
S. Satoh, T. Ino, M. Furusaka, Y. Kiyanagi, N. Shamoto, K. Sakai
Nucl. Instrum. Methods A 529 2004
Neutron optics and a superconducting magnetic lens for smaii-angle neutron scattering with focusing geometry
H. M. Shimizu, T. Adachi, M. Furusaka, Y. Kiyanagi, T. Oku, H. Sasao, T. Shinohara, J. Suzuki
Nucl. Instrum. Methods A 529 2004
Development of a magnetic focusing device for pulsed neutrons
J. Suzuki, T. Oku, T. Adachi, H. M. Shimizu, Y. Kiyanagi, T. Kamiyama, F. Hiraga, H. Iwasa, K. Sato, M. Furusaka
Nucl. Instrum. Methods A 529 2004
Development of a two-dimensional multi-grid-type microstrip gas chamber for spallation neutron source
H. Takahashi, P. Siritiprussamee, M. Kai, M. Nakazawa, T. Ino, M. Furusaka, S. Kishimoto, M. Taniguchi, S. Ito, M. Kanazawa
Nucl. Instrum. Methods A 529 2004
Current activities and plans for polarized neutron instruments of the JSNS/J-PARC project
M. Furusaka
Physica A, in press 2004
A demonstration study of focusing geometry SANS using a magnetic lensT. Oku, J. Suzuki, H. Sasao, S. Yamada, M Furusaka, T Adachi, T. Shinohara, K. Ikeda, H.M. Shimizu
Physica A, in press 2004

396

Development of polarized neutron optics
Hirohiko M. Shimizu,Takayuki Oku, Jun-ichi Suzuki, Michihiro Furusaka,Yoshiaki Kiyanagi
Physica A, in press 2004
The Design of the Neutron Total Scattering Spectrometer for Hydrogenous Materials at J-PARC-JSNS
K. Suzuya, Y. Kameda, T. Otomo, K. Yoshida, K. Itoh, T. Fukunaga and M. Misawa
J. Neutron Research 13 2005
Designed Performance of High Resolution Chopper Spectrometer at J-PARC
S. Itoh, K. Ohoyama, T. Otomo, K. Nakajima, K. Kuwahara, R. Kajimoto, T. Kamiyama and O. Yamamuro
J. Neutron Research 13 2005

4. Crystal Structures
Neutron diffraction study of thermal residual strain in three layered materials made by self-propagating high-temperature synthesis
K. Inoue, T. Tsujikami, M. Ohyanagi, M. Kawagai, M. Komatsu, M. Sugimoto, N. Minakawa, A. Moriai, T. Kamiyama and K. Oikawa
Mater. Sci. Res. Int. 9 2003 SIRIUS
Structural Distortion on Metal-Insulator Transition in Ordered Double Perovskite Ca2FeReO6
Kenichi Oikawa, Takashi Kamiyama, Hisato Kato and Yoshinori Tokura
Journal of Physical Society of Japan 72 2003 SIRIUS
Neutron Diffraction Study of Thermal Residual Strain in Three Layered Materials Made bySelf-propagating High-temperature Synthesis
K. Inoue, T. Tsujikami, M. Ohyanagi, M. Kawagai, M. Komatsu, M. Sugimoto, N. Minakawa, A. Moriai, T. Kamiyama and K. Oikawa
MATERIALS SCIENCE RESEARCH INTERNATIONAL 9 2003
Local structure of BaFeO3-δ studied by neutron scattering
K. Mori T. Kamiyama H. Kobayashi K. Itoh T. Otomo S. Ikeda
Physica B 329-333 2003 HIT
Neutron Diffraction Study on Lanthanum Gallate Perovskite Compound Series
M. Kajitani M. Matsuda A. Hoshikawa K. Oikawa S. Torii T. Kamiyama F. Izumi M. Miyake
Chemistry of Materials 15 2003 SIRIUS
Structural Evidence for the Charge Disproportionation of Fe4+ in BaFeO3-δ
K. Mori T. Kamiyama H. Kobayashi T. Otomo S. Ikeda
Jounal of the Physical Society of Japan 72 2003 VEGA
High-temperature phase transition in lanthanum titanate perovskite La0.64(Ti0.92,Nb0.08)O3
Masatomo Yashima, Mizuki Mori, Takashi Kamiyama, Ken-ichi Oikawa, Akinori Hoshikawa, Shuki Torii, Koh Saitoh, Kenji Tsuda
Chemical Physics Letters 375 2003
Crystal structure analysis of β-tricalcium phosphate Ca3(PO4)2 by neutron powder diffraction
Masatomo Yashima, Atsushi Sakai, Takashi Kamiyama and Akinori Hoshikawa
Journal of Solid State Chemistry 175 2003
Contribution of local atomic arrangements and electronic structure to high electrical resistivity in the Al82.6-xRe17.4Six(7 ≪ x ≪ 12)1/1-1/1-1/1 approximant
T. Takeuchi, T. Onogi, T. Otagiri, U. Mizutani, H. Sato, K. Kato, T. Kamiyama
PHYSICAL REVIEW B68 2003 VEGA
X-Ray and Neutron Studies of Antiferroelectric Phase Transition in Cu(HCOO)2/4H2O
T. Omura, K. Yoshizumi, C. Moriyoshi, K. Itoh and S. Ikeda
Ferroelectrics 285 2003 RAC
Structure and dynamics of hexaﬂuoroisopropanol-water mixtures by X-ray diffraction, small-angle neutron scattering, NMR spectroscopy, and mass spectrometry
K. Yoshida, T. Yamaguchi, T. Adachi, T. Otomo, D. Matsuo, T. Takamuku and N. Nishi
J. Chem. Phys 119 2003 SWAN
Atomic ordering in Fesr2LnCu2O6+δ system (Ln=Nd, Y and Er)
T. Mochiku, Y. Nakano, K. Oikawa, T. Kamiyama, H. Fujii, Y. Hata, J. Suzuki, I. Kanaya, K. Kadowaki, K. Hirata
Physica C 400 2003 SIRIUS
Defect Structure od LiMn2O4 after High-Temperature Storage
M. Yonemura, T. Kohigashi, A. Yamada, N. Sonoyama, H. Kobayashi, T. Kamiyama and R. Kanno
Electrochemistry 71 2003 SIRIUS
Cation Composition and Oxygen Content Dependence of Crystal Stucture and Tc for Tl2-xBa2Ca2Cu3+zOy
Yasushi Idemoto,Kentarou Yamawaki, Nobuyuki Koura, Takashi Kamiyama, Kenichi Oikawa and Fujio Izumi
Journal of the Ceramic Society of Japan 111 2003 VEGA
Crystal structure and ferroelectric properties of (Bi, La)4(Ti, Si)3O12 and as a bulk ferroelectric material
Yasushi Idemoto, Takahiro Miyahara, Nobuyuki Koura, Takeshi Kijima, Hiroshi Ishiwara
Solid State Communications 128 2003 VEGA
Crystal Structure, Property, and Ferroelectric Performance of Si Substituted Ferroelectric Oxides
Yasushi Idemoto, Nobuyuki Koura
Tech. Report of IEICE SDM2002-270 2003 SIRIUS
Phase Transitions and Low-temperature Structure of Lithium Manganese Oxide Spinel
M. Yonemura, T. Kamiyama, Y. Kawamoto and R. Kanno
Materials Transactions 45 2004 SIRIUS VEGA

397

Synthesis, structure, and phase relationship in lithium manganese oxide spinel
M. Yonemura, A. Yamada, H. Kobayashi, M. Tabuchi, T. Kamiyama, Y. Kawamoto and R. Kanno
J. Mat. Chem. 14 2004 VEGA
Structural and magnetoelectric properties of Ga2-xFexO3 single crystals grown by a ﬂoating zone method
T. Arima, D. Higashiyama, Y. Kaneko, J.P. He, T. Goto, S. Miyasaka, T. Kimura, K. Oikawa, T. Kamiyama, R. Kumai, Y. Tokura
Physical Review B 70 2004 VEGA
Elastic Strains of Cementite in a Pearlite Steel during Tensile Deformation Measured by Neutron Diffraction
A. Kanei, Y. Tomota, S. Torii, T. Kamiyama
ISIJ International 44 2004 SIRIUS
Structural Properties of Fe-doped lanthanum gallate
K. Mori, T. Fukunaga, K. Shibata, K. Iwase, S Harjo, A. Hoshikawa, K. Itoh, T. Kamiyama, T. Ishigaki
Physica B B 2004 VEGA
Elastic Strains of Cementite in a Pearlite Steel during Tensile Deformation Measured by Neutron Diffraction
A. kanie, Y. Tomota, S. Torii, T. Kamiyama
ISIJ International 44 2004 SIRIUS
Crystal structure of Fe-doped LaGaO3-σ
Kazuhiro Mori, Koji Shibata, Hidenori Sagehashi, Toru Ishigaki, Akinori Hoshikawa, Stefanus Harjo, Takashi Kamiyama, Keji Itoh, Toshiharu Fukunaga
PHYSICA B 350 2004 VEGA
Spin Fluctuation and Crystal Field Excitation of Heavy-Fermion Compound YbAgGe Studied by Inelastic Neutron Scattering
Takeshi Matsumura, Hideaki Ishida, Taku J. Sato, Kenichi Katoh, Yuzuru Niide and Akira Ochiai
Journal of the Physical Society of Japan 73 2004 LAM
Stress Measurement of Rolled Steels Using Pulsed Spallation Neutron Diffraction
Masahide Gotoh, Toshihiko Sasaki, Takashi Kamiyama and Yukio Hirose
International Offshore and Polar Engineering Conference 2004 SIRIUS
Crystal structure and hydrogen occupation of LaNi4.9Al0.1Dx (5.0 ｲ x ｲ 6.1) on the desorption isotherm studied by in situ neutron powder diffraction
Yumiko Nakamura, Toru Ishigaki, Takashi Kamiyama, Etsuo Akiba
J. Alloys Compd. 384 2004
Structural Analysis of Pure and Electrochemically Lithiated SiO Using Neutron Elastic Scattering
Yasutaka Nagao, Hiroki Sakaguchi, Hitohiko Honda, Toshiharu Fukunaga and Takao Esaka
J. Electrochemical Society 151 2004
Relation between the crystal structure and ferroelectric propertoes of Bi4-xLaxTi3O12-d(x=0.25, 0.5, 0.75, 1.0) ferroelectric material by changing La substitution content
Yasushi Idemoto, Naoto Yokoyama, Nobuyuki Koura, Takashi Kamiyama
Material Technology 23 2005 SIRIUS
Dependence of properties, structure and conductivity on composition and heat treatment of La2-xRExCuOy(RE=Y, Tb)
Yasushi Idemoto, Tohru Miyabe, Nobuyuki Koura
Material Technology 23 2005 SIRIUS
Direct observation of a coupling between spin, lattice, and electric dipole moment in multiferroic YMnO3
Seongsu Lee, A. Pirogov, Jung Hoon Han, J.-G. Park, A. Hoshikawa, and T. Kamiyama
Phys. Rev. B 71 2005 SIRIUS
Multiferroic Behavior andTwo Dimensional Magnetism of Hexagonal Manganites
Seongsu Lee, Misun Kang, Changhee Lee, A. Hoshikawa, M. Yonemura, T. Kamiyama J.-G. Park
Physica B 2005
Hydrogen absorption. Vdesorption properties and crystal structure analysis of Ti-Cr-Mo alloys
K. Iwase, Y. Nakamura, K. Mori, S. Harjo, T. Ishigaki, T. Kamiyama, E. Akiba
Journal of Alloys and Compounds 404-406 2005
Single-layer oxychloride superconductor Ca2-xCuO2Cl2 with A-site cation deﬁciency
I. Yamada, A. A. Belik, M. Azuma, S. Harjo, T. Kamiyama, Y. Shimakawa and M. Takano
Phys. Rev. B 72 2005
In situ X-ray and neutron powder diffraction study of LaNi5-xSnx-H systems
Yumiko Nakamura, Robert C. Bowman, Jr., Etsuo Akiba
Mater. Res. Soc. Symp. Proc 837 2005
In situ X-ray and neutron powder diffraction study of LaNi5-xSnx-H systems
Yumiko Nakamura, Robert C. Bowman, Jr., Etsuo Akiba
Mater. Res. Soc. Symp. Proc. 837 2005
Average and Local Structures in Hydrogen Absorbing Ti-Cr-Mo Alloy
Kenji Iwase, Takashi Kamiyama, Yumiko Nakamura, Kazuhiro Mori, Masao Yonemura, Stefanus Harjo, Toru Ishigaki and Etsuo Akiba
Materials Transactions 47 2006
Variation of hydrogen occupation in LaNi4.78Sn0.22Dx along the P-C isotherms studied by in situ neutron powder diffraction
Yumiko Nakamura, Robert C. Bowman, Jr., Etsuo Akiba
J. Alloys Compd 2006
Secondary Ordering in Ternary Alloy CuMnPt6
M. Takahashi, A. K. Das, R. Nakamura, H. Iwasaki, T. Shishido and K. Ohshima

398

J. Phys. Soc. Jpn. 75 2006 FOX
Secondary ordering in Pt -rich Pt-Mn binary alloys and CuMnPt6 ternary alloy
M. Takahashi, A. K. Das, T. Sembiring, H. Iwasaki and K. Ohshima
Physica B: Condensed Matter 2006

5. Amorphous
Large-Angle X-ray Scattering, Small-Angle Neutron Scattering, and NMR Relaxation Studies on Mixing States of 1,4-dioxane-Water, 1,3-dioxane-Water, andTetrahydrofuran-Water Mixtures
Toshiyuki Takamuku, Akira Nakamizo, Masaaki Tabata, Koji Yoshida, Toshio Yamaguchi, and Toshiya Otomo
J. of Mol. Liq. 103/104 2003 SWAN
Hydration Structure of Alanine Molecule in Concentrated Aqueous Solutions
Y. Kameda, K. Sugawara, T. Usuki and O. Uemura
Bull. Chem. Soc. Jpn 76 2003
Local structure of liquid Te studied by neutron diffraction and EXAFS
H Endo, K Maruyama, H Hoshino, and H Ikemoto
Z. Phys. Chem. 217 2003
The network-chain transformation in the liquid As-Te mixtures near the semiconductor-metal transition
H Hoshino, H Endo, and K Maruyama
Z. Phys. Chem. 217 2003
Neutron scattering on a re-entrant binary liquid mixture
A. Maira-Vidal, M. A. Gonz_ez, C. Cabrillo, F. J. Bermejo, M. Jim 始 ez-Ruiz, M. L. Saboungi, T. Otomo, F. Fayon, E. Enciso and D. L. Price
Chemical Physics 292 2003 SWAN
Cluster formation in 1-propanol aqueous solution revealed by a reverse Monte Carlo analysis of neutron small angle scattering
M. Misawa
J. Phys. soc. Jpn 72 2003
Annion Effect of the Structure of Ag2S-AgPO3 Superionic Glasses
E. Kartini, S.J. Kennedy, K. Itoh, T. Kamiyama, M.F. Collins, and S. Suminta
Solid State Ionics 2003
A Review Article ﾒ Recent Research Development of Superionic Phosphate Glasses
M.F. Collins and E. Kartini
Recent Development of Solid State Ionics 2003
Colloidal silver iodide: synthesis by a reverse micelle method and investigation by a small-angle neutron scattering study
Sanae Tamura,Ken Takeuchi, Guomin Mao, Roseann Csencsits, Lixin Fan, Toshiya Otomo, Marie-Louise Saboungi
Journal of Electroanalytical Chemistry 559 2003 SWAN
The local structure of hydrogen storage nanocrystalline graphite by neutron scattering
K. Itoh, Y. Miyahara, S. Orimo, H. Fujii, T. Kamiyama and T. Fukunaga
Journal of Alloys and Compounds 2003 HIT, RAC
Inelasticity Effect on Neutron Scattering Intensities of the Null-H2O
Y.Kameda, M. Sasaki, T. Usuki, T. Otomo, K. Itoh, K. Suzuya, T. Fukunaga
Journal of Neutron Research 11(3) 2003 SWAN
Disappearance of βAgI in (AgI)0.7-(NaPO3)0.3 composite at room temperature
A. Purwanto, E. Kartini, T. Kamiyama, A. Hoshikawa, S, Harjo, M.F. Collins, S. Purnama
Solid State Ionics 171 2004
Network Structure of B2O3-PbO and B2O3-PbO-PbBr2 Glasses Analyzed by Pulsed Neutron Diffraction and Raman Spectroscopy
H. Ushida, Y. Iwadate, T. Hattori, S. Nishiyama, K. Fukushima, Y. Ikeda, M. Yamaguchi, M. Misawa, T. Fukunaga, T. Nakazawa, S. Jitsukawa
J. Alloys and Compds. 377[1-2] 2004
Structural Approach to Nanoscience: A Case Study of Complex and Cluster Formation in ZnBr2-ZnCl2 Melts
Y. Iwadate, K. Fukushima, Y. Seki, K. Itoh, T. Fukunaga, M. Misawa, H. Matsuura, A. Kajinami, N. Ohtori, N. Umesaki, H. Kofuji, M. Myochin
Sci. Techn. Adv. Mater 5[5-6] 2004
Structural analysis for crystalline and amorphous RFe2Dx(R: Ho, Tb) by X-ray/neutron diffraction and reverse monte Carlo modeling
Keiji Itoh, Yoshinobu Miyajima, Kiyoshi Aoki, Toshiharu Fukunaga
J. Alloys and Compounds 376 2004
Structure of Nano-crystalline FeTiDx by Neutron and X-ray Diffraction
K. Itoh, H. Sasaki, H. T. Takeshita, K. Mori, and T. Fukunaga
Journal of Alloys and Compounds 404-406 2005
Evolution of Local Structure in Ag2O-TeO2 Glasses with addition of Ag2O Analyzed by Pulsed Neutron Diffraction and Raman Spectroscopy
Y. Iwadate, M. Suzuki, T. Hattori, K. Fukushima, S. Nishiyama, M. Misawa, T. Fukunaga, K.Itoh, T. Nakazawa, A. Iwase
J. Alloys and Compds. 389[1-2] 2005
Local Structure of Lead Halide Melts Analyzed by Pulsed Neutron Diffraction
Y. Iwadate, Y. Seki, K. Fukushima, M. Misawa, T. Fukunaga, T. Nakazawa, Y. Okamoto, H. Matsuura and N. Umesaki
J. Phys. Chem. Solids 66[2-4] 2005

399

Structure of Amorphous TbNi2D2.4 observed by X-ray and neutron diffraction
Keiji Itoh, Tomohiro Sawada, Kiyoshi Aoki, Tohiharu Fukunaga
J. Alloys and Compounds 392 2005 HIT

6. Magnetism
In-plane Anisotropy and Temperature Dependence of Oxygen Lattice Modes in YBa2Cu3O6.95
J.-H.Chung, T.Egami, R.J.McQueeney, M.Yethiraj, M.Arai, T.Yokoo, Y.Petrov, H.A.Mook, Y.Endoh, S.Tajima, C.Frost and F.Dogan
Phys. Rev. B 67 14517 2003
Incommensurate Dynamical Properties of Optimally Doped YBa2Cu3O6.9
T.Yokoo, M.Arai, Y.Shiohara, S.Tajima, C.D.Frost and Y.Endoh
Journal of Low Temperature Physics 131 2003 EXCED (MRP)
Two-dimensional high-order commensurate structure in DyRu2Si2
N. Iwata, K. Hattori, M. Kadota, M. Takahashi, S. Kawano, T. Shigeoka
J. Magn. Magn. Mater 256 2003
Magnetic Excitations in the Heavy-Electron and Antiferro-Quadrupolar-Ordering System PrFe4P12
K. Iwasa, L. Hao, M. Nakajima, M. Kohgi, H. Sugawara, Y. Aoki, H. Sato, T. D. Matsuda
Acta Physica Polonica B 34 2003 LAM
In-plane anisotropy and temperature dependence of oxygen phonon modes in YBa2Cu3O6.95
J.-H.Chung, T.Egami, R.J.McQueeney, M.Yethiraj, M.Arai, T.Yokoo, Y.Petrov, H.A.Mook, Y.Endoh, S.Tajima, C.Frost and F.Dogan
Physical Review B 67 2003 EXCED (MRP)
Complimentary Use of Neutron and X-ray Reﬂection in Study on a Giant magnetoresistance (GMR) Effect of Magnetic Multilayers
Takeda M, Endoh Y, Kamijo A, Langridge S, Dalgliesh R, Her J H, Lee K BTrans. Mater. Res. Soc. Jpn. 28 2003 TOP (PORE)
Spin dependent quantum renormalization factor in the one-dimensional Heisenberg antiferromagnetic systems determined by inelastic neutron scattering experiments
S. Itoh, Y. Endoh, K. Kakurai and H. Tanaka
J. Phys. Soc. Jpn. 73 2004 INC
Magnetic excitations in halogen bridged nickel complex, [Ni(chxn)2Br]Br2
S. Itoh, S. Takaishi and R. Ikeda
J. Magn. Magn. Mat. 272-276 2004
Time-of-Flight Neutron Powder Diffractin Studies on a Chiral Two-dimensional Molecule-based Magnet
A. Hoshikawa, T. Kamiyama , A. Porwanto, K. Ohishi, W. Higemoto, T. Ishigaki, H Imai, K. Inoue
Journal of the Physical Society of Japan 73 2004 VEGA
Spin Dynamics in One-Dimensional and Percolating Systems Studied under UK-Japan Collaboration Program on Neutron Scattering
S. ItohJ. Neutron Research 12 2004
Magnetic Correlations in CuGeO3
R. Kajimoto, S. Itoh, M. J. Bull, K. Kakurai, I. Harada, M. Arai, M. Fujita and M. Nishi
J. Neutron Research 12 2004
Magnetization measurements of Rb2CoF4 in megagauss ﬁelds
M. Motokawa, S. Itoh, A. Kirste, S. Hansel and M. von Ortenberg
Proceedings of the Xth International Conference on Megagauss Magnetic Field Generation and Related Topics (Humboldt University, Berlin, 2004) 2004
Neutron diffraction studies on modulated Tb2Ni3Si5 single crystal
Y.Hashimoto, S.Kawano, M.Takahashi
Journal of Magnetism and Magnetic Materials 272-276 2004
Frustration and two-dimensional spin ordering in TbRu$2Si2, TbRu2Ge2 and DyRu2Si2
S. Kawano, B. Lebech, M. Takahashi, T. Shigeoka, N. Iwata, T. Kosugi
J. Magn. Magn. Mater. 272-276 2004 FOX
Pulsed-neutron diffraction studies of ﬁeld-induced two-dimensional magnetic modulations in DyRu2Si2
S. Kawano, M. Takahashi, T. Shigeoka, M.J. Bull, N. Iwata
Physica B : Condensed Matter. 346-347 2004 FOX
Neutron diffraction studies of two-dimensional ordering of the low temperature phase in TbRu2Si2
S. Kawano, M. Takahashi, T. Shigeoka, N. Iwata, B. Lebech
Physica B 350 2004 FOX
Neutron Diffraction Studies on Modulated Tb2Ni3Si25Single Crystal
Y. Hashimoto , S. Kawano and M. Takahashi
J. Magn. Magn. Mater 272-276 2004 FOX
Magnetic structures and spin--glass ﾑ like behavior in ordered and disordered Pt-rich Pt-Mn alloys
M. Takahashi, T. Sembiring, Y. Noda, T. Shishido and K. Ohshima
Phys. Rev. B 70 2004 FOX
High energy resolution inelastic neutron scattering experiment on fracton dispersion in near-percolating three-dimensional Heisenberg antiferromagnet, RbMn0.4Mg0.6F3
S. Itoh, R. Kajimoto and M. A. Adams
J. Phys. Soc. Jpn. 74 2005

400

Neutron diffraction investigations of zero-ﬁeld and ﬁeld-induced magnetic structures of DyNiSn single crystal
K. Murogaki, S. Kawano, Y. Andoh, M. Takahashi, M. Kurisu and G. Nakamoto
Journal of Alloys and Compounds 408-412 2006 FOX
Formation of the ABC6type ordered structure in fcc alloys
K. Ohshima, M. Takahashi, H. Iwasaki
Z. Metallkd. 97 2006 FOX
Two- and one-dimensional magnetic modulations of low-ﬁeld-induced phases in TbRu2Si2 at low temperatures
S. Kawano, M. Takahashi, T. Shigeoka, N. Iwata, M. Shiimoto and B. Lebech
Physica B: Condensed Matter 2006

7. Dynamics
Inelastic Neutron Scattering and Low-energy Excitation of Amorphous SF6-hydrate Prepared by Vapor-deposition TechniqueO. Yamamuro, T. Matsuo, I. Tsukushi and N. Onoda-Yamamuro
Can. J. Phys. 81 2003
Absence of the Rotator Phase and Evolution of Dynamical motions in cluster monolayers
R. Mukhopadhyay, S. Mitra, B. Nair, T. Pradeep, I. Stukushi and S. Ikeda
J. Chem. Phys 118 2003 LAM
Dynamical properties of vitrous silica around the ﬁrst sharp diffraction peak
M. Nakamura, M. Arai, Y. Inamura, T. Otomo and S.M.Bennington
Physical Review B 67 2003 EXCED (MRP)
Appearance of the crystal ﬁeld levels with conduction electrons in Tm0.05LaxYb0.95-xTe
H. Ishida, T.Matsumura, K. Shibata
Journal of Magnetism and Magnetic Materials 272-276 2004 LAM
Inelastic neutron scattering from CeOs4Sb12
C.P. Yang, M. Kohgi, K. Iwasa , H. Sugawara and H. SatoJ. Phys. Soc. Jpn. 74 2005

8. Materials Science
R&D of MW-class Solid-Target for Spallation Neutron Source
M. Kawai, M. Furusaka, K. Kikuchi, H. Kurishita, R.Watanabe, Jing-Feng Li, K. Sugimoto, T. Yamamura, Y. Hiraoka, K.Abe, A. Hasegawa, M.Yoshiie, N. Takenaka, K.
Mishima, Y. Kiyanagi, T. Tanabe, N.Yoshida and T. Igarashi
J. Nuclear Materials 318 2003
Preparation and Characterization of (Ca, La)Ti(O,N)3 Perovskite Oxynitride
S. Kawata, T. Gotoh, F. Utsuno, I Yasui
Journal of the Ceramic Society of Japan, Supplement Supplement112-1 2004 VEGA
Hydration Structure Around the Carboxyl Group Studied by Neutron Diffraction with 12C/13C and H/D Isotopic Substitution Method
Yasuo Kameda, Motoya Sasaki, Masahiro Yaegashi, Kosuke Tsuji, Shingo Oomori, Shuji Hino and Takeshi Usuki
Journal of Solution Chemistry 33 2004
Hydration Structure around the Carboxyl Group Studied by Neutron Diffraction with12C/13C and H/D Isotopic Substitution Methods
Y. Kameda, M. Sasaki, M. Yaegashi, K. Tsuji, S. Oomori, S. Hino and T. Usuki
J. Solution Chem. 33 2004
On the so-celled "semi-ionic" C-F bond character in ﬂuorine-GIC
Yuta Sato, Keiji Itoh, Rika Hagiwara, Toshiharu Fukunaga, Yasuhiko Ito
Science Direct Carbon 42 2004 HITPrebending effects in bronze route Nb3Sn wires
Satoshi Awaji, Hidetoshi Oguro, Gen Nishijima, KazuoWatanabe, Stefanus Harjo, Takashi Kamiyama and Kazumune Katagiri
Supercond. Sci. Technol. 18 2005
SiC-Based Ceramic Fibers Prepared via Organic-to-Inorganic Conversion Process - A Review
K. Okamura, T. Shimoo, K. Suzuya and K. Suzuki
Journal of the Ceramic Society of Japan 114 2006 LAM, WINK

9. Polymers
Small-Angle Neutron Scattering Investigations of Layer-Block Dendrimers in Aqueous Solutions
Katuya Funayama, Toyoko Imae, Keigo Aoi, Kaname Tsutsumiuchi, Masahiko Okada, Michihiro Furusaka, and Michihiro Nagao
Physical Chemistry B 107 2003
Fast and Slow Dynamics of Water-Soluble Dendrimers Consisting of Amido-Amine Repeating Units by Neutron Spin-Echo
Katsuya Funayama, Toyoko Imae, Hideki Seto, Keigo Aoi, Kaname Tsutsumichi, Masahiko Okada, Michihiro Nagao, and Michihiro Furusaka
Physical Chemistry B 107 2003
Neutron Reﬂectivity study of Surface and Interfacial Structure in Polymer Thin Films
Takahara A, Tanaka K, Kawaguchi D, Tasaki S, Takeda M, Torikai N, Kajiyama T
Trans Mater Res Soc Jpn 28 2003 ARISA

401

Short-range structures of poly(dicarbon monﬂuoride) (C2F)n and poly(carbon monoﬂuoride) (CF)nYuta Sato, Keiji Itoh, Rika Hagiwara, Toshiharu Fukunaga, Yasuhiko Ito
Science Direct Carbon 42 2004
Two-dimensional Solids Formed at Interface
A. Inaba, N. Sakisato, A. K. Bickerstaffe and S. M. Clarke
J. Neutron Research 13(1-3) 2005
Structure and phase behavior of two-dimensional solids formed at interfaces
Akira Inaba
Pure Appl. Chem. 78 2006

10. Proceedings of Workshops
第 4 回核破砕中性子源材料の科学技術研究会
M. Kawai and K. Kikuchi
KEK Proceedings 2003
Workshop on Science for the High Resolution Chopper Spectrometer
S. Itoh
KEK Proceedings 2003

11. KENS-Report
KENS Report-XIV(2001/2002)
Itho S and Muto S
KEK Progress Report 2003-6 M 2003

12. Proceedings of Conference
Icommensurate properties of high-Tc superconductor YBa2Cu3O6.93
Tetsuya Yokoo, Masatoshi Arai, Yu Shiohara, Setsuko Tajima, Chris D. Frost, Yasuo Endoh
Physica C 388-389 2003 EXCED (MRP)
Strength proof evaluation of diffusion-jointed W/Ta interfaces by small punch test
J.-F. Li, M. Kawai, K. Kikuchi, T. Igarashi, H. Kurishita, R. Watanabe, A. Kawasaki
Journal of Nuclear Materials 321/2-3 2003
Summary of Third Workshop on Materials Technology for Spallation Neutron Sources at KEK
M. KawaiJ. Nuclear Materials 318 2003

13. Liquid
Experimental Evidence of Differences in the Hydrogen-Bonded Structure of Concentrated Aqueous Solutions Involving DL-and L-Alanine Molecules
Yasuo Kameda, Motoya Sasaki, Masahiro Yaegashi, Yuko Amo and Takeshi Usuki
Buttetin of the Chemicl Society of Japan 77 2004 HIT
Neutron diffraction studies on the liquid Te and As-Te mixtures
K.Maruyama, H.Hoshino, H.Ikemoto and H.Endo
J. Phys. Soc. Jpn 73 2004
Mass-fractal clustering and power-law decay of cluster size in 1-propanol aqueous solution
M. Misawa, I. Dairoku, A. Honma, Y. Yamada, T. Sato, K. Maruyama, K. Mori, S. Suzuki and T. Otomo
J. Chem. Phys. 121 2004
The structure of binary zinc phosphate glasses
K. Suzuya, K. Itoh, A. Kajinami and C.-K. Loong
Journal of Non-Crystalline Solids 345&346 2004 HIT
Hydration Structure around a Formyl-Hydrogen Atom Studied by Neutron Diffraction with H/D Isotopic Substitution Method
Yasuo Kameda, Atsunari Sayama, Motoya Sasaki, Yuko Amo and Takeshi Usuki
Bulletin of the Chemical society of Japan 78 2005 HIT
Neutron diffraction study of concentrated aqueous lithium benzoate solutions
Yasuo Kamed, Kazuhide Mochiduki, Masahiroo Imano, Hisashi Naganuma, Motoya Sasaki, Yuko Amo, Takeshi Usuki
Journal of Molecular Liquids 119 2005 HIT
Local structure of liquid Rb-Se mixtures: chain- and interstitial void- structures near the miscibility gap
K.Maruyama, H.Hoshino, H.Endo, M.Yamazaki and T.Miyanaga
J.Phys.:Condens.Matter 17 2005
Short- and Intermediate-Range Structures of Liquid Rb-Se Mixtures
K.Maruyama, H.Endo, H.Hoshino
J. Phys. Soc. Jpn. 74 2005
Observation of Mesoscale Structure of 1-propanol Aqueous Solution and its Visualisation
M. Misawa, I. Dairoku, A. Honma, Y. Yamada, T. Sato, K. Maruyama, K. Mori, S. Suzuki and T. Otomo

402

J. Neutron Research 13 2005
Structure and Dynamics of Halogenoethanol-Water Mixtures Studied by Large-Angle X-ray Scattering, Small-Angle Neutron Scattering, and NMR Relaxation
T. Takamuku, T. Kumai, K. Yoshida, T. Otomo, and T. Yamaguchi
J. Phys. Chem. A 109 2005
Pulsed Neutron Diffraction of Phosphorous Acid and Its Aqueous Solution with Inactivation Capability of Activated Oxygen
Y. Iwadate, Y. Tani, K. Fukushima, M. Misawa, T. Fukunaga, T. Nakazawa
J. Neutron Research 13[1-3] 2005
Concentration ﬂuctuations and cluster dynamics of 2-butoxyethanol-water mixtures by small-angle neutron scattering and neutron spin echo techniques
Koji Yoshida, Toshio Yamaguchi, Toshiya Otomo, michihiro Nagao, Hideki Seto, Takayoshi Takeda
J Molecular Liquids 119 2005
Structure of Highly Concentrated Aqueous Lithium Alaninate Solutions Studied by Neutron Diffraction with 14N/15N, 6Li/7Li, and H/D Isotopic Substitution Methods
Y. Kameda, M. Sasaki, Y. Amo and T. Usuki
Bull. Chem. Soc. Jpn. 79 2006
Thermal Properties and Mixing State of Ethylene Glycol-Water Binary Solutions by Calorimetry, Large-Angle X-ray Scattering, and Small-Angle Neutron Scattering
M. Matsugami, T. Takamuku, T. Otomo, and T. Yamaguchi
J. Phys. Chem. A. 2006
Theemal Properties and Mixing State of Ethylene Glycol-Water Binary Solutions by Calorimetry, Large-Angle X-ray Scattering, and Small-Angle Neutron Scattering
M. Matsugami, T. Takamuku, T. Otomo, and T. Yamaguchi
J. Phys. Chem. B 110 2006 SWAN

403

Members of Committee
Neutron Scattering Program Advisory Committee (2003.4.1~)
AKIBA, Etsuo

AIST

MATSUSHITA, Tadashi

KEK

ASAHI, Koichiro

Tokyo Inst. of Tech.

IKEDA, Susumu

KEK

KANAYA, Toshiji

Kyoto Univ.

NAGAMINE, Kanetada

KEK

FUKUNAGA, Toshiharu

Kyoto Univ.

IIDA, Atsuo

KEK

MISAWA, Masakatsu

Niigata Univ.

NISHIYAMA, Kusuo

KEK

MORII, Yukio

JAEA

KAWATA, Hiroshi

KEK

YAMADA, Kazuyoshi

Tohoku Univ.

SATOH, Kotaro

KEK

YOSHIZAWA, Hideki

Univ. of Tokyo

ITOH, SHINICHIKEK

FURUSAKA, Michihiro

Hokkaido Univ.

KAMIYAMA, Takashi

KEK

ARAI, Masatoshi

JAEA

KAWAI, Masayoshi

KEKJapan-UK Steering and Program Advisory Committee (2003.4.1~)
AKIBA, Etsuo

AIST

KOMA, Atsushi

KEK

ASAHI, Koichiro

Tokyo Inst. of Tech.

MATSUSHITA, Tadashi

KEK

KANAYA, Toshiji

Kyoto Univ.

IIDA, Atsuo

KEK

FUKUNAGA, Toshiharu

Kyoto Univ.

NISHIYAMA, Kusuo

KEK

FURUSAKA, Michihiro

Hokkaido Univ.

KAWATA, Hiroshi

KEK

MISAWA, Masakatsu

Niigata Univ.

IKEDA, Susumu

KEK

MORII, Yukio

JAEA

NAGAMINE, Kanetada

KEK

YAMADA, kazuyoshi

Tohoku Univ.

ITOH, Shinichi

KEK

YOSHIZAWA, Hideki

Univ. of Tokyo

KAWAI, Masayoshi

KEK

ARAI, Masatoshi

JAEA

SATOH, Kotaro

KEK

KAMIYAMA, Takashi

KEK404