Preface
This Activity Report covers scientific and technological activities carriedout using the UVSOR-III Synchrotron in FY2021 (April 2021 - March
2022). We present scientific examples of how the users study at the UVSOR
Synchrotron Facility.
The present UVSOR-III Synchrotron is one of the most advanced lowenergy SR facilities of the 3rd generation SR in the world and is now one of
the critical resources to accelerate the investigation of molecular science.
The UVSOR-III Synchrotron has a small electron storage ring but has
powerful 6-undulator beamlines (3 VUV and 3 in-vacuum soft X-ray
undulators) with 8-dipole beamlines. We continue improving and upgrading
our micro- and nano-scale photoabsorption and photoemission approaches
and in situ/operando measurements in the IR, VUV, and soft X-ray regions,based on our strategic international collaboration program in molecularscience. We are grateful to all the people who use our facility and support our eﬀorts.
UVSOR operates for 40 weeks/year (ca. 2,200 h user time for 36 weeks), accepts ~230 proposals, about ~600
individual researchers counting total ~5,000 people*day/year. Most users stay for one or two weeks for experimenting.
To continue high-level achievements in science and technology at the UVSOR-III Synchrotron, our in-house staﬀ isconstantly committed to maintaining and improving high-performance accelerators and beamlines.
In terms of personnel, Assitant professor, K. Sugita left UVSOR. The support technical staﬀ, T. Horigome retired,
who has been dedicated manufacturing and equipment development for a long time since the early days of UVSOR.
A senior researcher, beamline scientist, T. Araki joined to UVSOR from January 2022. He will promote life scienceand biology field using BL4U and BL3U.
On the experimental side, technological development never stops, hence we will make a progress on the operando
and/or imaging-related techniques to inspire advanced molecular science. We have started to construct the new
endstation at the undulator-based soft X-ray beamline BL6U since 2020. The new instrumentation of the photoelectron
momentum microscope (PMM) is developing and you may find the final whole picture of the apparatus in FY2022,
which consists of a double-hemispherical analyzer with spin detector. In FY2023, it will be connected to anotherbeamline BL7U for doing normal-incident geometry experiments. In the beamline BL1U, we have conducted indeveloping the novel light sources, including novel experiments using twin-Undulator configuration to demonstrateatto-second interference experiments. The advanced SR-related instrument will oﬀer opportunities in characterizing
the electronic structure of surface atomic sites, thin films, molecular adsorbates, bulk crystals, and so on.
We have discussed to construct the post-UVSOR-III as a long-term plan for sustainable development since 2019.
The idea would partly be seen in the IOP journal we submitted, a special issue of Electron Structure. We lookforward to receiving your feedback and suggestions on the continuing evolution of the UVSOR Synchrotron Facility.
In the FY2023, the UVSOR conglutinates the 40th-year ceremony, hence the cover design of Activity Report isrevised as a memorial issue of 50th. We hope many users will perform excellent work by fully utilizing the UVSORIII Synchrotron as a unique international hub for the SR research in advanced molecular science.
April 2023
Satoshi Kera
Director of the UVSOR Synchrotron Facility

News
2022
The 10th JSSRR Achievement Award Given to Mr. Eiken Nakamura
Mr. Eiken Nakamura, Chief Engineer in UVSOR, has been awarded “the 10th Achievement
Award” from the Japanese Society for Synchrotron Radiation Research (JSSRR). The award
is given by JSSRR to persons who made a significant contribution to support for synchrotron
radiation research and technology for many years.

Among his many achievements, Mr. Nakamura’s development of an L-shaped watercooled four-quadrant slit drive mechanism is worthy of special mention. He developed adrive mechanism that can control an aperture in both vertical and horizontal directions,while the pulse motor shafts for the drive are all located in the vertical direction, achieving
the same performance as conventional systems at a fraction of the size. This technology is
indispensable for a compact synchrotron light source such as UVSOR.

The award was presented in the award ceremony in the 36th Annual Meeting of JSSRR in
January, 2023.

UVSOR ACTIVITY REPORT 2022
Preface
S. KeraNews
I Organization and Staff List

1

II Current Status of Light Sources and Beamlines

9

Light Source in 2022（Y. Taira）

11

Beamlines in 2022（F. Matsui）

14

III-1 Accelerators and Instruments

33

III Research Activities

Spectral Phase Interferometry for Direct Electric- ield
Reconstruction of Undulator Radiation [1U]

T. Fuji, T. Kaneyasu, M. Fujimoto, Y. Okano, E. Salehi,
M. Hosaka, Y. Takashima, A. Mano, Y. Hikosaka, S. Wada and
M. Katoh

35

Construction of Laser Transport Line and Light Measurement Setup
for Coherent Harmonic Generation Experiment at BL1U [1U]36

Impact of the Temperature on the Non-Destructive Nuclide Assay in
the Transmission NRF Method [1U]

37

Basic Study on Compton Camera for Detection of Polarized gammarays [1U]38

Development of gamma-ray-induced Positron age-momentum
Correlation [1U]39

F. Sakamoto, H. Zen, T. Tanikawa, Y. Taira, Y. Okano, H. Ohta,
J. Yamazaki, K. Hayashi, Y. Takashima, A. Mano and M. Katoh

M. Omer, T. Shizuma, M. Koizumi, Y. Taira, H. Zen, H. Ohgaki and
R. Hajima

K. Shimazoe, M. Uenomachi, T. Ueki, Q. Shu, A. Takeda, K. Magata,
K. Nagayanagi and Y. TairaY. Taira, Y. Okano and T. Hirade−i−Study on Generation of F-LCS Gamma-rays for Absolute Cross-section
Measurement of NRF using BL1U Undulator [1U]40

Double-Pulsed Light Wave Packets Emitted from a Tandem Undulator
[1U]

41

Progress in Single Electron Storage Experiment [1U]42

H. Ohgaki, H. Zen, T. Kii, T. Hayakawa, T. Shizuma, M. Fujimoto and
Y. Taira

T. Kaneyasu, M. Hosaka, A. Mano, Y. Takashima, M. Fujimoto, E. Salehi,
H. Iwayama, Y. Hikosaka and M. Katoh

A. Asai, M. Shimada, H. Miyauchi and M. Katoh

Calibration of the Soft X-ray Response Matrix of CMOS Detector Usedin Sounding Rocket Experiment FOXSI-3 [2A]

43

N. Narukage, R. Shimizu, Y. Sato and S. Kashima

Development of a Transfer Vessel for NEXAFS Spectroscopy [2A]
E. Kobayashi and A. Inoishi

Soft X-ray Transmission Measurements of Polymer Films for Soft X-ray
Absorption Spectroscopy of Liquids in Low-Energy Regions [3U]44
45

M. Nagasaka, S. Fujikawa, H. Takaya and Y. Uozumi

Dissociation Channels of Molecules for a Use of Plasma Etching
Processes [3B]46

T. T. Nguyen, K. Ishikawa and H. Iwayama

Study of Luminescence Characteristics of Diamond Scintillator for
Dark Matter Search [3B]47

A. Umemoto

Current Photon Flux and Focus Size of BL4B [4B]
H. Iwayama

Low Radiation Damage XAFS Measurements at BL4B [4B]
H. Iwayama

Transmission Characteristics of an Optical Filter for UV Observations
[5B]

48
49
50

A. Yamazaki, K. Goda, T. Matsumoto, S. Teramoto and K. Yoshioka

Evaluation of the Pressure Dependence of the Krypton Absorption Cell
[5B]

51

M. Kuwabara, K. Kato, K. Arakawa and M. Taguchi

XUV Polarization Measurement using Visible Fluorescence from Neon
Atoms [5B]52

T. Kaneyasu, K. Hosaka and J. Adachi

A Position-sensitive Microchannel Plate Detector with Resistive Anode
[5B]

53

S. Matoba, S. Kanda, H. Ohshita, K. Hirata, H. Iwayama and T. Kaneyasu

Progress of Photoelectron Momentum Microscopy for Revealing
Complex and Detailed Electronic Structures of Materials [6U]
S. Suga and F. Matsui− ii −

54

Low-frequency Photocarrier Response in Semiconductors Based on
ns-visible-pump broadband-infrared-probe Spectroscopy [6B]55

J. Nishida and T. Kumagai

Study on the Re lective Properties of Black Coatings Used in UV
Observation Equipment. [7B]56

T. Matsumoto, K. Goda, A. Yamazaki, K. Inoue, S. Liu and K. Yoshioka

Complex Refractive Index Measurement by Re lectance Spectra in
Different Polarization Con igurations (II) [7B]57

K. Shinkai, K. Fukui, K. Yamamoto and T. Saito

Performance of the Refreshable Large Crystal Nuclear Emulsion for
the NINJA Experiment [Others]

58

T. Fukuda, H. Kobayashi, Y. Hirobe, Y. Morimoto and M. Nakamura

Lattice Design of the UVSOR-IV Storage Ring [Accelerators]

59

III-2 Material Sciences

61

E. Salehi, Y. Taira, M. Fujimoto and M. Katoh

Observation of Charge Separation Reaction in a Ti-Mn
Electrolyte for Redox Flow Batteries by STXM [4U]63

Temperature-dependent Electronic Band Structure ofOrganic Molecular Semiconductor [7U]64

Gamma-induced Positron Annihilation Lifetime Spectroscopy of
β-SiAlON:Eu Phosphor [1U]65

In-situ Measurement of Defects Dynamics in Stress Applied Bulk Iron
by Means of Gamma Ray Induced Positron Annihilation Spectroscopy
[1U]

66

E. Hosono, D. Asakura, A. Ohira, H. Yuzawa and T. Ohigashi

K. Fukutani, F. Nishino, P. I. Jaseela, D. Okaue, K. Fukui,
S. Makita, K. Tanaka and S. Kera

M. Kitaura, S. Watanabe, H. Masai,Y. Taira, K. Takahashi, T. Takeda,
N. Hirosaki, M. Tansho, K. Deguchi, S. Ohki and A. Ohnishi

F. Hori, S. Araki, S. Hirayama and Y. Taira

Gamma-ray Induced Positron Annihilation Lifetime Measurement ofCeO2 Catalyst Placed in a Quartz Tube [1U]

67

S. Dohshi, K. Maeda, Y. Taira and T. Hirade

Formation of the stress-induced Vacancies in Iron by in situ Positron
Annihilation Lifetime Spectroscopy [1U]68

M. Fujinami, R. Awaji, A. Yabuuchi, T. Hirade, N. Oshima and Y. TairaIn-situ Measurements of Vacancies Formed in Pure Iron by
Electrolytic Hydrogen Charging using gamma-ray-induced Positron
Annihilation Lifetime Spectroscopy [1U]

A. Yabuuchi, T. Hirade, M. Fujinami, R. Awaji, N. Oshima, K. Takai and
Y. Taira− iii −

69

Formation of Catalytically Active Mo2C Species on H-MFI for Methane
Aromatization Studied by Mo L-edge XANES [2A]70

Local Environment of Dopants in (M, Nb) co-doped TiO2 (M=Fe, Ni)
[2A]

71

K. Kuramochi, Y. Sonobe, H. Shimura, Y. Kinoshiro, R. Yamazaki,
Y. Uchimura and H. Aritani

H. Murata, T. Nishio, Y. Nagatomo and A. Nakahira

XAFS Study of MgAl2O4 - MgGa2O4 Solid Solutions [2A]
S. Yoshioka, K. Yasuda, E. Kobayashi and K. Okudaira

NEXAFS Spectroscopy of Battery Materials Using a Transfer Vessel
[2A]

72
73

A, Inoishi and E. Kobayashi

Direct Observation of Electrochemically Generated High Valent IronOxo Species of μ-Nitrido-Bridged Iron Phthalocyanine Dimer
Deposited on Graphite Surface by Soft X-ray Absorption Spectroscopy
[3U]

74

Y. Yamada and M. Nagasaka

Structural Analysis of luoro-polymers Using Resonant Soft x-ray
Scattering [3U]75

K. Yamanoi, M. Yamashita, Y. Yamamoto, H. Iwayama and M. Noumi

Structure Analysis on Chiral Dark Conglomerate of Achiral Liquid
Crystal Trimers by Resonant Soft X-ray Scattering (RSoXS) at UVSOR
[3U]

76

Y. Takanishi, F. Araoka and H. Iwayama

Measurements of Fluorescence Lifetimes of Scintillators Adopted for a
New in-beam Detector of the ‫ܭ‬௅଴ Rare Decay Experiment at J-PARC
[3B]

77

Material Search of Li-Containing Halide Scintillators for Neutron
Detection [3B]78

K. Shintate, R. Abe, Y. Hayashi, T. Naito, S. Sakano, J. Ohashi,
Y. Tajima and H.Y. Yoshida

C. Fujiwara, S. Kurosawa and A. Yamaji

Optical Properties of Cs2IrCl6-CsCl Composite Phosphor [3B]

S. Kodama, S. Omiya, N. Shimoyama, T. Saito, I. Yanase and H. Takeda

79

Visible-to-Ultraviolet Spectral Change with the Current-Induced
Local-to-Nonlocal Transition of SmS [3B, 6B]

80

Exciton States of Cesium Silver Iodide Crystals [3B]81

H. Watanabe, S. Tatsukawa, K. Imura, H. S. Suzuki, N. K. Sato and
S. Kimura

S. Ibuki and T. Kawai

Temperature Dependence of Excitation Spectra in Er-doped La2Zr2O7[3B]
M. Yoshino and M. Ito− iv −

82

Analysis of Cathode Materials for Li-Ion Batteries by STXM [4U]83

Unraveling the Origin of Irreversibility between the First and Second
Charging Process in Primary Conversion Anode Particle [4U]84

E. Hosono, D. Asakura, H. Yuzawa, T. Ohigashi, W. Zhang,
M. Kobayashi, H. Kiuchi and Y. Harada

J. Kim, J. Chung, T. Ohigashi, H. Yuzawa and J. Lim

Chemical Bonding Structures of SBR/BR Interfaces [4U]
T. Ejima and Y. Tamura

Observation of Distribution of Sulfur and cross-linking Reagent in
Vulcanized Rubber by Using STXM [4U]85
86

T. Ohigashi, F. Kaneko, H. Yuzawa and H. Kishimoto

Scanning Transmission X-ray Microscopy of Hydrogen Evolution
Electrocatalysts on Graphene Oxide Membranes [4U]87

Examination of Methods for Inner Structures of Magnetic Thin Films
at UVSOR BL4B by Re lection XMCD Measurement Setup [4B]88

C. O. M. Mariano, J. S. D. Rodriguez, R. H. Clemente, T. Ohigashi,
H. Yuzawa,W. H. Hsu, J. Shiue and C. H. Chuang

K. Yamamoto, H. Iwayama, O. Ishiyama and T. Yokoyama

L2,3-edge X-ray Absorption Spectra of Transition Metal in Wurtzite-AlN
[4B]

89

S. Imada

C K-edge XAFS Measurement of Carbon Containing Porous Silica [4B]
S. Dohshi

90

Evolution of the Electronic States by Electron Doping in a Kagome
Superconductor KV3Sb5 [5U]91

Evolution of Electronic Correlations and Excitonic Properties Near
semiconductor-excitonic Insulator Transition [5U]92

T. Kato, K. Nakayama, Y. Li, Z. Wang, S. Souma, K. Tanaka,
T. Takahashi, Y. Yao and T. Sato

K. Fukutani, K. Kiyosawa, C.I. Kwon, J.S. Kim, K. Tanaka and S. Kera

Polarization-dependent Angle-resolved Photoemission Study of MAX
Phase Compound Zr3SnC2 [5U]93

M. Mita, D. Pinek, M. Nakatake, K. Tanaka, T. Ouisse and T. Ito

Electronic Structure of a Layered Magnetic Semiconductor
CeTe1.83Sb0.17 [5U, 7U]

94

Synchrotron ARPES Study of Nodal Dirac Semimetal Candidate LaTeBi
[5U]

95

T. Nakamura, H. Murakawa, Y. Chen, H. Sugihara, K. Tanaka,
N. Hanasaki and S. Kimura

R. Saitou, N. Kataoka, H. Kageyama, R. Kondo and T. Yokoya

Re-examination of the Phase Diagram of the high-Tc Cuprate
Superconductor Bi2Sr2CaCu2O8+δ Studied by ARPES [5U, 7U]

Y. Tsubota, Y. Miyai, S. Nakagawa, S. Ishida, S. Kumar, K. Tanaka,
H. Eisaki, T. Kashiwagi, M. Arita, K. Shimada and S. Ideta

−v−

96

Alkaline-metal-dependent Electronic States in V-based Kagome Metals
[5U]

97

Veri ication of the Intrinsic Electron Doping Effect in T’-type Cupratehigh-temperature Superconductors [5U]98

Polarization Dependent Orbital States in Mn3-xGa Studied by angleresolved Photoemission Spectroscopy [5U]99

T. Kato, K. Nakayama, Y. Li, Z. Wang, S. Souma, K. Tanaka,
T. Takahashi, Y. Yao and T. Sato

M. Miyamoto, M. Horio, K. Moriya, A. Takahashi, K. Tanaka, Y. Koike,
T. Adachi and I. Matsuda

J. Okabayashi, Y. Miura, K. Tanaka, K. Z. Suzuki and S. Mizukami

Impact of Electron Scattering on Seebeck Coef icient [5U]
K. Kandai, K. Kuga, M. Matsunami and T. Takeuchi

Temperature Dependence of the Band Folding in TiSe2 [5U]
S. Tanaka, K. Ueno, K. Fukutani and K. Tanaka

Doping-Dependent ARPES Study of Nodal Dirac Semimetal Candidate
LaTeSb and LaTeBi [5U]

100
101
102

R. Saitou, N. Kataoka, T. Wakita, H. Kageyama, R. Kondo and T. Yokoya

Symmetry Reduction of the Electronic Structure in Heavily Overdoped
Pb-Bi2201 Observed by Angle-resolved Photoemission Spectroscopy[5U, 7U]

103

Far- and Mid-infrared Absorption on the Single-crystal Pentacene [6B]104

Y. Miyai, T. Kurosawa, M. Oda, M. Arita, K. Tanaka, S. Ideta andK. Shimada

Y. Nakayama, K. Yamauchi, Y. Baba and J. Miyamoto

ARPES Study of a chalcopyrite-type Topological Insulator Candidate
[7U]

105

Electronic Structure of the ive-fold oxygen-coordinated Cuprate
Superconductor [7U]

106

Angle-Resolved Photoemission Study of Solid Electrolytes
Li3xLa2/3-xTiO3 Bulk Single Crystal [7U]107Electronic Structure of Layered Nitride Chloride ZrNCl by ARPES [7U]108

T. Iwaya, A. Honma, K. Nakayama, K. Sugawara, S. Souma, K. Tanaka,
T. Takahashi, K. Segawa and T. Sato

M. Horio, M. Miyamoto, X. Peiao, K. Tanaka, T. Taniguchi, M. Fujita and
I. Matsuda

S. Koyama, M. Nakatake, S. Takakura, K. Tanaka, Y. Fujiwara, T. Taishi,
H. Moriwake, Y. Iriyama and T. Ito

N. Kataoka, R. Saitou, M. Tanaka and T. Yokoya

Low-Energy ARPES Study on the Electronic Structure of Cr2Se3 [7U]

109

Polarization-Dependent Photoemission from the Folded Band of TiSe2
[7U]

110

C.-W. Chuang, T. Kawakami, T. Kato, K. Sugawara, K. Nakayama,
S. Souma, K. Tanaka, A. Chainani, T. Takahashi, K. Segawa and T. Sato

S. Tanaka, K. Ueno, K. Fukutani and K. Tanaka− vi −

Momentum Dependence of the Spectral Weight in the Single Layer
High-Tc Cuprate Bi2Sr2CuO6+δ Studied by ARPES [7U]111

Excitation Spectra of Plastic Scintillators in the Vacuum Ultraviolet
Region [7B]112

Y. Onishi, Y. Miyai, Y. Tsubota, S. Kuma, M. Atira, K. Tanaka, H. Eisaki,
S. Ishida, K. Shimda and S. Ideta

M. Koshimizu, Y. Fujimoto and K. Asai

Mineral Analysis for Resource Exploration by Deep Ultraviolet
Spectroscopy [7B]113

T. Shimizu, K. Shinohara, K. Yamanoi and N. Sarukura

Optical Re lectivity Study of Au-Al-Yb Quasicrystals [7B]114

III-3 Chemistry117

H. Okamura, A. Kamiki, K. Namba, S. Hirokawa and K. Deguchi

Ligand Field in Fe-based spin-crossover Coordination
Polymer Revealed by Soft x-ray Absorption Spectroscopy
[4B]

119

K. Yamagami

Monitoring Phase Difference between Magnetic Substates in Helium
Atom [1U]120

T. Kaneyasu, Y. Hikosaka, M. Fujimoto, H. Iwayama and M. Katoh

High-Resolution Measurement of State-Resolved Photoelectron
Circular Dichroism with Varied Photoionization Energies [1U]

121

M4,5-edge XANES Spectra of La and Nd Complex Oxides [2A]122

H. Kohguchi, Y. Hikosaka, T. Kaneyasu, S. Wada, H. Ota, M. Katoh and
Y-I. Suzuki

H. Asakura, M. Konno and K. Nanakarage

O K-edge XAS of Photoreactions in Dissolved Oxygen on Lipid Bilayer
[3U]

123

Carbon K-edge X-ray Absorption Spectra of Liquid Ethanol
Reproduced by Quantum Chemical Calculations and Molecular
Dynamics Simulations [3U]124

F. Kumaki, M. Nagasaka, Y. Kinjo, R. Tero, Y. Okano, M. Fujimoto and
J. Adachi

M. Nagasaka

Observation of the Behavior of Sumanene in Organic Solvents by C
K-edge XAS Experiment [3U]125

Y. Uetake, K. Sugimura, R. Ihsan, M. Nagasaka and H. Sakurai

Operando Observation of Adsorbed Anions on the Surface of Nickel
Catalysts by Soft X-ray Absorption Spectroscopy [3U]126

A. Sakai, Z. Li, K. Harada, S. Tsunekawa, M. Nagasaka and M. Yoshida

Temperature Effects on the X-ray Absorption Spectrum of Aqueous
Ca(NO3)2 Recorded at the Ca L-edge [3U]
D. Céolin, T. Saisopa, Y. Rattanachai, H. Yuzawa and N. Kosugi− vii −

127

Self-Assembled Hierarchical Nanosegregated Chiral Intermediate
Phases Composed of Two Different Achiral Bent-Core Molecules [3U]128

F. Araoka, Y. Takanishi, S-W. Choi and H. Iwayama

X-ray Absorption Spectra of Metal Carbonyl Solutions [3U]
T. Sasaki and H Xu

Soft X-ray Absorption of Photocatalysts for Arti icial Photosynthesis:
Ultraviolet Light Irradiation in Water [3U]

129
130

H. Onishi, Yi Hao Chew, K. Matsui, N. Ichikuni and T. Yoshida

Hydration of Dimethyl Sulfoxide Probed by Liquid-Phase Soft X-ray
Absorption Spectroscopy [3U]131

C. Sugahara, K. Okada and H. Iwayama

Multielectron-ion Coincidence Spectroscopy of I 4d inner-shell
Photoionization of CH3I and CH2I2 Molecules [4B]132

M. Fushitani, Y. Hikosaka and A. Hishikawa

Quadruple Auger Decay from Xe 4s Core-Hole State Studied by MultiElectron−Ion Coincidence Spectroscopy [4B]133

Y. Hikosaka

Metastable OCS3+ States Investigated by Multi-Electron−Ion
Coincidence Spectroscopy [4B]134

Y. Hikosaka

Soft X-ray Absorption Study of Semiconductor Photocatalysts forHighly Ef icient Oxidation of Water [4B]135

T. Yoshida, N. Ichikuni, H. Onishi and Yi Hao Chew

High-Resolution Photoelectron Spectroscopy of Unexplored Chiral
Systems for Demonstration of the Photoelectron Circular Dichroism
[7B]

136

H. Kohguchi, Y. Hikosaka, T. Kaneyasu, S. Wada and Y-I. Suzuki

The Challenge of Photoionization Plasma Generation Using
Synchrotron Radiation Source for Study of Plasmas in Interstellar
Space and in Nuclear Fusion Devices [7B]
M. Kobayashi, H. Iwayama, J. Takahashi, S. Yoshimura, H. Ota,
K. Kobayashi, M. Katoh, H. Nakamura, I. Sakon, K. Sawada and
Y. Kebukawa

III-4 Surface, Interface and Thin Films
Fermiology of a Kagome Superconductor Cs(V1-xNbx)3Sb5
Revealed by Momentum Microscope [6U]

T. Kato, K. Nakayama, Y. Li, Z. Wang, S. Souma, F. Matsui,
T. Takahashi, Y. Yao and T. Sato

Mg K-edge NEXAFS of MgO, Mg(OH)2 and MgCO3 [2A]
E. Kobayashi, S. Yoshioka and K. K. Okudaira

Structural Analyses of Silicon Atoms in a Zero-dimensional Metalatom Encapsulating Silicon Cage Clusters by X-ray Absorption
Spectroscopy [2A]
A. Nakajima and T. Inoue− viii −

137

139

141

142

143

Annealing Effects on Surface Electronic Structure of MoO3
Nanoparticles by UPS [2B]

144

K. K. Okudaira and S. Ishii,

X-ray Absorption Spectroscopy Study of 4-MBA and Cysteine on Gold
Surfaces [3U]145

F. Sato, I. Sakaida, S. Ohno and M. Nagasaka

Evaluation of Growth Orientation and Crystallinity of Deep UVEmitting Zinc Aluminate Thin Films [3B]

H. Kominami, K. Inoue, N. Uesugi, K. Nie, A. Adachi, R. Isihara, K. Yabe,
J. Kamikawa, T. Sadamori, D. Takeya, N. Miyazaki, A. Dorokhina andS. Kurosawa

146

Application of atomically-thin Graphene to X-ray Astronomy: Soft
X-ray Transmission Measurements [4U]147

Tuning Magnetic Properties of Atomic Layer Materials by organicinorganic Interfacial Magnetic Coupling [4B (XMCD)]

148

X-ray Magnetic Circular Dichroism Study of Chiral Antiferromagnetic
Co2-xPdxMo3N Thin Films [4B (XMCD)]

149

Controlling Magnetic Anisotropy of Magnetic Thin Film
Heterostructures [4B (XMCD)]

150

X-ray Photoemission Spectroscopy and X-ray Absorption Spectroscopy
Measurement of the Chiral Molecule on the Metal Substrate [4B]151

I. Mitsuishi, K. Kashiwakura, Y. Niwa, T. Ogawa, M. Hirota, Y. Tawara,
R. Kitaura, H. Yuzawa, T. Ohigashi and K. Tanaka

H. Ono, Y. Umeda, K. Yamamoto, O. Ishiyama, T. Yokoyama,
M. Mizuguchi and T. Miyamachi

B. Qiang, M. Togashi, T. Fukasawa, T. Hajiri, M. Kuwahara,
H. Asano and T. Ito

Y. Umeda, H. Ono, K. Yamamoto, O. Ishiyama, T. Yokoyama,
M. Mizuguchi and T. Miyamachi

F. Nishino, K. Fukutani, P. I. Jaseela, H. Iwayama, S. Makita and S. Kera

Observation of Heat Treatment Effects of Amorphous Selenium Thin
Film by Vacuum Ultraviolet Transmission Spectrum [4B]152

K. Hayashi

UV-X-ray Transmission Measurements of Atomically Thin Graphene
Astronomical Applications [4B]153

Si L-edge NEXAFS Spectra of Native Oxide Si Wafer with Different
Crystal Surface [4B]154

I. Mitsuishi, K. Kashiwakura, Y. Niwa, T. Ogawa, R. Kitaura,
E. Nakamura, M. Nagasaka and K. Tanaka

K. K. Okudaira, S. Yoshioka and E. Kobayashi

ARPES from Si{111} ξ3 × ξ3 -Ag ultra-thin Film on Arti icially Designed
three-dimensional Si facet-line Structure with {111} Facet Surfaces on
Si(001) Substrates [5U]
K. Hattori, Niʼmatil Mabarroh, Juharni, Y. Ida, W. Imayama, Y. Kimoto,
Y. Kitagawa, S. Tanaka, A. N. Hattori, S. Suga and K. Tanaka− ix −

155

Sizable Rigid Shift of the Valence Band of h-BN by Cs-doping [5U]

S. Ichinokura, A. Hemmi, H. Cun, K. Tanaka, T. Greber and T. Hirahara

Growth of Transition Metal Phosphide Thin Film on Au(111) [5U]
N. MaejimaK. Inaoka and K. Edamoto

156
157

Heavy-Fermion in a Mono-Atomic Layer YbCu2/Cu(111) [5U, 7U]

158

Region and Element-speci ic Surface Observation of CVD Graphene on
Ir(111)/α-Al2O3(0001) by Photoelectron Momentum Microscopy [6U]159

H. Sugihara, T. Nakamura, Y. Chen, K. Nishihara
M. F. Lubis, K. Tanaka and S. Kimura

E. Hashimoto, Y. Onuma, F. Matsui and S. Koh

High-resolution angle-resolved Photoemission Study on MnBi2Te4/
MnBi2Te4/Bi2Te3 Heterostructure [7U]

160

Electrochemical Attenuated Total Re lectance Ultraviolet (EC-ATR-UV)
Spectroscopy Applied for Organic Semiconductor / Ionic Liquids
Interface [7B]161

III-5 Life, Earth and Planetary Sciences

163

X-ray Absorption Spectra of Lipid Bilayer Membranes in
Aqueous Solutions [3U]165

K. Ishihara, H. Nishimichi, K. Ide, S. Ichinokura, K. Tanaka and
T. Hirahara

I. Tanabe, Y. Hanamori and K. Fukui

R. Tero, Yu Kinjo and M. Nagasaka

Study on Chirality Emergence of Amino Acid Molecules Induced by
Circularly Polarized Lyman-α Light Irradiation [1U]

166

Attempts at Structural Analysis of Biological Macromolecules Using
Resonant Soft X-ray Scattering [3U]167

M. Kobayashi, J. Takahashi, H. Ota, G. Fujimori, K. Kobayashi,
K. Matsuo, Y. Taira, M. Katoh, H. Nakamura and Y. Kebukawa

Y. Sugimoto and H. Iwayama

Water-Ion Interactions in Natural Lake Brines [3U]168

Drug Administration Concepts Involving Redox Nanocarriers Affect
the Spatial Distribution of Topically Applied Formulations in Human
Skin [4U]

169

Absorption- Image and Spectra of Apoptosis Nuclei in P-L Edge [4U]170

Y. Hao, N. Fauré, Y. Qiu, M. Nagasaka, E. Thomson, S. Wang and
X. Kong

G. Germer, T. Ohigashi, H. Yuzawa, K. Rajes, R. Haag, F. Rancan,
A. Vogt and E. Rühl

T. Ejima and S. Tone−x−Embracing Natural and Anthropogenic Aerosol Particle Complexity
[4U]

171

STXM in Characterizing Lysosomal Storage Materials in a Mouse
Model [4U]

172

Determination of Spectral Changes in NEXAFS of Biomolecules Causedby Radiation Effects for Molecular Mapping of Biological Specimens
[4U]

173

Attempt to Constrain the Initial Condition of Aqueous Alteration on
Cometary Organic Matter [4U]174

P. A. Alpert, L. Li, L. F. Escusa Dos Santos, F. Mahrt, M. Ammann, L. Wu,
W. Hu, P. Fu, M. Hallquist, E. Thomson and X. Kong

T. Mansikkala, T. Ohigashi, H. Yuzawa, I. Miinalainen, S. M. Kangas,
M. Salo, N. Kosugi, J. Uusimaa, M. Huttula, R. Hinttala and M. Patanen

A. Ito, K. Shinohara, A. Matsuura, S. Toné, K. Tohya, H. Yuzawa and
T. Ohigashi

H. Yabuta, N. Nishii, T. Araki and H. Yuzawa

Organics in Asteroid Ryugu Samples: Analytical Approach Utilizing
Micro and Multi Beam Techniques. [4U]

M. Ito, N. Tomioka, M. Uesugi, A. Yamaguchi, N. Imae N. Shirai,
T. Ohigashi, M. Kimura, M-C, Liu, R.C. Greenwood, K. Uesugi, A. Nakato,
K. Yogata, H. Yuzawa, Y. Kodama, A. Tsuchiyama, M. Yasutake,R. Findlay, I.A. Franchi, J.A. Malley, K.A. McCain, N. Matsuda,
K.D. McKeegan, K. Hirahara, A. Takeuchi, S. Sekimoto, I. Sakurai,
I. Okada, Y. Karouji, T. Yada, M. Abe, T. Usui, S. Watanabe and
Y. Tsuda

Chemical Morphology of Biomass-Burning Particles Generated fromDifferent Fuels under Varied Burning Conditions [4U]

175

176

J. Chen, N. Faure, Y. Hao, Z. Kanji, E. S. Thomson, S. Wang and X. Kong

Heat Resistance of SiC/Mo/Si Multilayer Mirrors at 30.4nm [5B]177

Synchrotron-radiation Infrared Microspectroscopy Analysis of
Persistent Organic Compounds [6B]178

S. Teramoto, K.Inoue, A.Yamazaki, T.Matsumoto, S. Liu, K. Yoshioka andI. Yoshikawa

T. Kawasaki, F. Teshima and K. Tanaka

Development of an Infrared Spectro-Microtomography Using a Mid-IR
Supercontinuum Laser: Preliminary Report [6B]179

IV List of Publications

181

H. Yabuta, Y. Ikemoto, F. Teshima and K. Tanaka− xi −

V Workshops

187

UVSOR Symposium 2022

189

The 5th workshop on prospects and construction plan of the next
generation synchrotron radiation facility: Cooperation between
facilities II
IMS Symposium“Resonant Soft X-ray Scattering and Re lectivity”

IMS Symposium“Symposium on Generation and Advanced Use of Various Quantum
Beams in UVSOR-III”

Facts and Figures− xii −

191
192
193

197

პ

Organizationand Staff List

Ⅰ Organization and Staﬀ List

UVSOR Synchrotron Facility Organization

IMS

WATANABE, Yoshihito (Director General)

UVSOR Steering Committee

Department

Photo-Molecular Science III
KERA, Satoshi

Technical and Engineering
Departments

Electronic Structure
YOKOYAMA, Toshihiko
KIMURA, Shin-ichi (Cross Appt.
Osaka Univ.)

Research Center

Visiting Professor:
MASE, Kazuhiko (KEK)UVSOR

KERA, Satoshi (Director)

Advanced Accelerator Research:
KATOH, Masahiro (Cross Appt. Hiroshima Univ.)
Beam Physics and Diagnostics Research:
MATSUI, Fumihiko, TAIRA, Yoshitaka, ARAKI, Tohru
Advanced Solid State Physics:
TANAKA, Kiyohisa
Advanced Photochemistry:UVSOR Users Association−3−

Mar. 2023

Ⅰ

Ⅰ

Staﬀ List

Mar. 2023

UVSOR Staﬀ
Director
KERA, Satoshi

Professor

kera@ims.ac.jp

Division of Advanced Accelerator Research
KATOH, Masahiro

Project Professor
mkatoh@ims.ac.jp(Cross Appt. Hiroshima Univ.)

SALEHI, Elham

Project Research Staﬀ

elham@ims.ac.jp

Division of Beam Physics and Diagnostics Research
TAIRA, Yoshitaka

Associate Professor

yostaira@ims.ac.jp

OHIGASHI, Takuji

Associate Professor (Cross Appt. KEK)

(until Mar. 2023)

SUGITA, Kento

Assistant Professor

ysugimoto@ims.ac.jp(until Feb. 2023)

MATSUDA, Hiroyuki

Project Research Staﬀ

hmatsuda@ims.ac.jp

Division of Advanced Solid State Physics
MATSUI, Fumihiko

Professor

matui@ims.ac.jp

TANAKA, Kiyohisa

Associate Professor

k-tanaka@ims.ac.jp

HAGIWARA, Kenta

Project Research Staﬀ

k-hagiwara@ims.ac.jp(since Nov. 2022)(since Jan. 2023)

Division of Advanced Photochemistry
ARAKI, Tohru

Senior Researcher

araki@ims.ac.jp

IWAYAMA, Hiroshi

Assistant Professor

iwayama@ims.ac.jp

Research Cooperative Staﬀ
KANEYASU, Tatsuo(Concurrent Appt. SAGA-LS)(since Apr. 2022)

SUGIMOTO, Yasunobu

Specially Appointed Senior Specialist(since May 2022)

Technical Staﬀ
HAYASHI, Kenji

Engineer (Unit Leader)

NAKAMURA, Eiken

Chief Engineer

MAKITA, Seiji

Engineer

YAMAZAKI, Jun-ichiro

Chief Technician

SAKAI, Masahiro

Chief Technician

YANO, Takayuki

Chief Technician

OKANO, Yasuaki

Chief Technician

TESHIMA, Fumitsuna

Chief Technician

KONDO, Naonori

Chief Technician

YUZAWA, Hayato

Technician−4−

Ⅰ Organization and Staﬀ List

OTA, Hiroshi

Technician

HORIGOME, Toshio

Technical Fellow

MIZUKAWA, Tetsunori

Technical Fellow

MINAKUCHI, Aki

Technical Fellow(until Mar. 2023)

Secretary
ISHIHARA, Mayumi
KAMO, Kyoko

Departments in IMS (＊Group Leader)
Division of Photo-Molecular Science III
KERA, Satoshi＊

Professor

NAGASAKA, Masanori

Assistant Professor

FUKUTANI, Keisuke

Assistant Professor

Division of Photo-Molecular Science Ⅳ
MASE, Kazuhiko

Visiting Professor (KEK)

Division of Electronic Structure
YOKOYAMA, Toshihiko＊

Professor

KIMURA, Shin-ichi

Professor (Cross Appt. Osaka Univ.)

KOITAYA, Takanori

Assistant Professor(until Jul. 2022)

YAMAMOTO, Kohei

Assistant Professor(until Mar. 2023)

KURAHASHI, Naoya

Assistant Professor(since Dec. 2022)

Graduate Students
KOYAMA, Shotaro

Nagoya University(until Mar. 2023)

MITA, Manaya

Nagoya University(until Mar. 2023)

OZAWA, Shunnosuke

Nagoya University(until Mar. 2023)

SEMA, Ryota

Nagoya University(until Mar. 2023)

SHIOHARA, Keisuke

Nagoya University(until Mar. 2023)

YAMAUCHI, Saki

Nagoya University(until Mar. 2023)

UVSOR Steering Committee (＊Chair)
KERA, Satoshi＊

UVSOR, IMS

MATSUI, Fumihiko

UVSOR, IMS

KATOH, Masahiro

UVSOR, IMSTANAKA, Kiyohisa

UVSOR, IMSTAIRA, Yoshitaka

UVSOR, IMS

MASE, Kazuhiko

UVSOR, IMS (KEK)

Chair

−5−

(since Apr. 2022)

Ⅰ

Ⅰ

KANEMITSU, Yoshihiko

Kyoto University

KIMURA, Shin-ichi

Osaka University

HARADA, Yoshihisa

University of Tokyo

FUKUSHIMA, Takanori

Tokyo Insititute of Technology

NAKAMURA, Tetsuya

Tohoku University(since Apr. 2022)

YABASHI, Makina

RIKEN(since Apr. 2022)

ITO, Takahiro

Nagoya University(since Apr. 2022)

WATANABE, Yoshihito

IMS, Director General(since Apr. 2022)

YOKOYAMA, Toshihiko

IMS

IINO, Ryota

IMS(since Apr. 2022)

SEGAWA, Yasutomo

IMS(since Apr. 2022)

KURAMOCHI, Hikaru

IMS(since Apr. 2022)

SHIGEMASA, Eiji

IMS

HAYASHI, Kenji

IMS

NAKAMURA, Toshikazu

IMS

UVSOR Users Association (＊Chair)
KITAURA, Mamoru＊

Yamagata University

HIKOSAKA, Yasumasa

Toyama University

ITO, Takahiro

Nagoya University(since Apr. 2022)

MIYAMACHI, Toshio

Nagoya University(since Apr. 2022)

HIRAHARA, Toru

Tokyo Insititute of Technology(since Apr. 2022)

Visiting Scientists
MANSIKKALA, Leo

Oulu University

Jul. 2022

PATANEN, Minna

Oulu University

Jul. 2022

SILLY,Mathieu

Synchrotron Soleil

Aug. 2022

ALPERT, PeterPaul Scherrer InstituteAug. 2022

CEOLIN,Denis

Synchrotron Soleil

Aug. 2022

ESCUSA DOS SANTOS, Luis Filipe
University of Gothenburg

Aug. 2022

LI, Linjie

University of Gothenburg

Aug. 2022

MAHRT, FabianPaul Scherrer InstituteAug. 2022

SAISOPA,Thanit

Rajamangala University of Technology Isan

Aug. 2022

RATTANACHAI,Yuttakarn

Rajamangala University of Technology Isan

Aug. 2022

KONG, Xiangrui

University of Gothenburg

CHUANG, Cheng-Hao

Tamkang University

Sep. 2022

HUANG, Wun-Cin

Tamkang University

Sep. 2022

Aug. 2022, Feb. 2023, Mar.2023

RODRIGUEZ, Jan Sebastian Dominic
Tamkang University
RÜHL, Eckart

Free University of Berlin

Chien-Lin Pan

Tamkang University−6−

Sep. 2022
Sep. 2022, Mar.2023
Dec. 2022

Ⅰ Organization and Staﬀ List

Chung-Li Dong

Tamkang University

Dec. 2022

TA THỊ THÚY NGANational Yang Ming Chiao Tung University

Dec. 2022

Huang Hou-Yi

Tamkang University

Dec. 2022

Mannu PandianTamkang University

Dec. 2022

CHEN, Jie

ETH

Feb. 2023

FAURE, Nicolas

University of Gothenburg

Feb. 2023, Mar.2023

HAO, Yuxin

Northwest University, China

Feb. 2023, Mar.2023

−7−

Ⅰ

Staﬀ

ჟ

Current Status ofLight Sources and Beamlines

Ⅱ Current Status of Light Sources and Beamlines

Light Source in 2022
Yoshitaka TairaUVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, JapanIn FY2022, UVSOR-III was operated for users asscheduled for 36 weeks from end of May 2022 toMarch 2023. Monthly statistics of operation time andintegrated beam current are shown in Fig. 1. From April
1 to May 6 was a shutdown period, during which
periodic inspections were conducted. The two weeks
following the shutdown were allocated to the adjustmentof the accelerator and beamlines.
The weekly operation schedule is as follows.
Mondays are assigned to machine studies from 9:00
AM to 9:00 PM. User operation is assigned Tuesday
through Friday, with Tuesday and Wednesday operatingfrom 9:00 AM to 9:00 PM, and Thursday from 9:00
AM to 9:00 PM on Friday for 36 continuous hours.
Thus, the user’s beam time per week is 60 hours.
July to August is the period when attention should be
paid to instantaneous voltage drops caused by lightning
strikes. Beam dumps due to instantaneous voltage
drops occurred frequently, resulting in loss of operation
time. High voltage application errors in the klystronpulse modulator had been occurring since the fall of
2021 and were still occurring frequently in 2022. The
cause of this event is unknown, but it is not occurring
now. It is possible that the error was corrected
accidentally during an inspection. Regarding vacuumrelated issues, vacuum leakage from the bellows ductof the bending magnet of the booster synchrotron has
occurred frequently. The vacuum level has deteriorated
due to the formation of pinholes in the ducts, but thishas been addressed each time by applying repair
materials. Failures of the beam position monitor moduleand the RF frequency signal generator were addressedby replacing them with alternatives or repairing them.
APPLE-II type tandem undulators are in operational
at BL1U. Until now, they were used only on machine
study days as the standard orbit of the electron beam foruser operation did not pass through the central axis ofthese undulators. From April 2022, the standard orbit
has been changed to one that passed through the center
axis. This improvement allows some users to conduct
experiments on the BL1U undulators during normaluser operation.
We started a design study for the future plan of
UVSOR-IV. As a first step, we have analyzed thepresent magnetic lattice, seeking a possibility to reduce
the emittance more [1]. Although, we did not find asolution to drastically reduce emittance, we have founda few interesting solutions that achieved lower
emittance than the current situation. As the second step,
we have started designing a totally new storage ring,which is close to the diﬀraction limit in the VUV range[2].
The steep rise in electricity prices is a global problem.
Although the rate of increase in electricity prices inJapan is lower than in Europe, the impact is stillenormous. UVSOR’s electricity rates typically range
between 50 - 60 million yen per year, but the estimatedamount for FY2022 is over 80 million yen. The power
consumption of the electron accelerator and beamline
during non-operating periods is 50 kW and 150 kW,
respectively. These are mainly the power used tomaintain a high vacuum, such as vacuum pumps.
During accelerator operation, these increase to 390 kW
and 250 kW, respectively. As power saving measures,
we have begun shortening operation hours outside ofnormal user operation, such as weekend operation,
turning oﬀ unused equipment, and shutting down
vacuum pumps at beamlines with low user utilization.
The light source development and utilization
beamline BL1U, constructed under the support ofQuantum Beam Technology Program by MEXT/JST,
continue to develop new light source technologies andtheir applications such as free electron laser, coherent
harmonic generation, coherent synchrotron radiation,
coherent control [3], laser Compton scattered gamma
rays [4], and optical vortices.

Fig. 1. Monthly statistics in FY2022.
[1] E. Salehi and M. Katoh, Proceedings of IPAC2021(2021) 3970.
[2] E Salehi, Y Taira, M Fujimoto, L Guo, M. Katoh, J.
Phys.: Conf. Ser. 2420 (2023) 012062.
[3] T. Kaneyasu et al., Sci. Rep. 13 (2023) 6142.
[4] Y. Taira et al., Rev. Sci. Instr. 93 (2022) 113304.

− 11 −

− 12 −

Ⅱ Current Status of Light Sources and Beamlines− 13 −

Beamlines in 2022
Fumihiko Matsui
UVSOR Synchrotron Facility, Institute for Molecular Science

UVSOR is one of the highest-brilliance light sourcesin the extreme-ultraviolet region among the synchrotron
radiation facilities with electron energies of less than 1
GeV. The low natural emittance of the UVSOR-III
storage ring, 17.5 nm-rad, was accomplished after the
successful completion of the storage ring upgrade
project (the UVSOR-III project) in 2012. Eight bending
magnets and six insertion devices are available assynchrotron light sources at UVSOR. There are a totalof fourteen operational beamlines. Twelve of them are
the so-called “Public beamlines”, which are open toscientists from universities and research institutes
belonging to the government, public organizations,private enterprises and also those from foreigncountries. The beamline BL6U is the “In-housebeamlines”, and are dedicated to the use of researchgroups within Institute for Molecular Science (IMS).
The beamline BL1U is a partially “Public” and partially“In-house” beamline. There is one tender X-ray (TX)
station equipped with a double-crystal monochromator,
seven extreme ultraviolet (EUV) and soft X-ray (SX)
stations with grazing incidence monochromators, threevacuum ultraviolet (VUV) stations with normal
incidence monochromators, two infrared (IR) stations
equipped with Fourier Transform interferometers, andone direct radiation station located after two tandem
undulators, as shown in the appended table (next page)for all available beamlines at UVSOR in 2022. The
details of the updates for undulator beamlines are thefollowings.
● In BL1U, the development of a new light source
and the utilization of gamma-rays are being carriedout. This beamline is equipped with a tandem
undulators with a buncher section, which can beused for free electron laser in the range fromvisible to deep UV, VUV coherent harmonic
generation, and generation of spatiotemporal
structured light such as an optical vortex beam, avector beam and double-pulsed wave packets.
It is also equipped with a femto-second laser
system synchronized with the accelerator, which
is used for the generation of Compton scatteredgamma-rays. Users are provided with gamma-ray
induced positron annihilation spectroscopy that
can analyze nanometer-order defects in bulk
materials. To increase the counting rate ofannihilation gamma rays, an array detector witheight BaF2 scintillators was developed. The
measurement can be completed in a few hours formetal samples.
● In BL3U, the ultrathin-liquid cell for low-energy
XAS has been developed. The studies of local
structures of several aqueous solutions and various
chemical processes in solution such as catalytic

●

●

●

− 14 −and electrochemical reactions, and laminar flows
in microfluidics by using operando XAS in C, N,
and O K-edges were demonstrated. Moreover, anargon gas window that is eﬀective from 60 to 240
eV with the removal of high-order X-rays, which
will develop chemical research since it includes
K-edges of Li and B and L-edges of Si, P, S, andCl was established.
Resonant soft X-ray scattering (RSoXS) for soft
materials is also applicable. RSoXS is similar tosmall angle X-ray scattering (SAXS) and canprovide information on the mesoscopic structure(1-100nm) of sample. This method has selectivityof elements, functional groups and molecularorientation. Since soft X-ray region include K—edge energies of light element (C, N, O), RSoXS
is a powerful tool to investigate soft matters.
BL4U, which is equipped with a scanningtransmission soft X-ray microscope (STXM), is
actively used not only by academic users but also
by many industrial users. The STXM can beapplied to wide range of sciences, such as polymer
science, material science, cell biology,
environmental science, and so on. In FY2020, it
became possible to image the lithium K-edge witha spatial resolution of 72 nm. Final adjustments
for the airtight sample transport system and thesample transport container were carried out for theorganic substance analysis of the Hayabusa2
returned samples for the summer of FY2021.
In BL5U, high energy resolution angle-resolved
photoemission spectroscopy (ARPES) is available.
Users can now use so-called “deflector mapping”
for all kinetic energies and lens modes by using
the latest version of ARPES analyzer. Users canalso obtain spatial-dependence of the electronic
structure of solid surfaces using micro-focused
beam (50 μm). An alkali-metal deposition system
has been installed. Potassium for example can bedeposited while the sample is still mounted on the
manipulator at low temperatures. As part of thedevelopment of spin-resolved ARPES, a twodimensional image of the spin-resolved spectrumof the Rashba splitting of Au(111) surface has
been successfully obtained.
At BL6U, one of the In-house beamlines,
photoelectron momentum microscope (PMM),
which is a new-concept multi-modal electronic
structure analysis system with high resolution inreal space and momentum space, has been installed
and is in operation. A key feature of the PMM isthat it can very eﬀectively reduce radiationinduced damage by directly projecting a single
photoelectron constant energy contour inⅡ Current Status of Light Sources and Beamlines●

reciprocal space with a radius of a few Å-1 or real
space with a radius of a few hundred μm onto a 2D
detector. Experiments such as valence band
photoelectron spectroscopy on the micrometerscale and resonance photoelectron diﬀraction bysoft X-ray excitation are performed. In FY2023,
we plan to further expand PMM’s capabilities byintroducing an additional 2D spin filter. In addition
to grazing-incidence soft X-ray excitation, normalincidence vacuum ultraviolet (VUV) beam withvariablepolarizations(horizontal/vertical/
circular) became also available at the same focal
position of the PMM via a newly added branchfrom the next BL7U. This highly symmetricalmeasurement geometry completely eliminates thep-polarized linear dichroism eﬀect in the circulardichroism measurements of valence band, making
transition matrix element analysis much simpler
and reliable.
At BL7U, high-energy resolution ARPES isavailable with extremely low energy of photons (6eV~) using the low-temperature 6-axis manipulator
with a sample temperature 4.5-350 K. In FY2021,
the deflector-type detector for the hemisphericalanalyzer was installed to realize an eﬀective 2D
measurement with the automated manipulator
control. Users can perform the measurement of thebulk sensitive electronic structure of solids and thehigh-throughput measurement for molecularmaterials using high-photoionization cross-section
using low-excitation photon energy.
Those wishing to use the open and in-house beamlines
are recommended to contact the appropriate beamline
contact persons (see next page). Applications can besubmitted at NOUS (https:// nous.nins.jp/user/signin).
All users are required to refer to the beamline manuals
and the UVSOR guidebook, on the occasion of
conducting the actual experimental procedures. For
updated information on UVSOR, please see http://
www. uvsor.ims.ac.jp.

− 15 −

Beamlines at UVSOR
Beamline
BL1U

Monochromator /Spectrometer

Energy Range

Targets

Techniques(Irradiation)

Y. Taira

Solid

Reflection
Absorption

K. Tanaka

Solid

Reflection
Absorption

F. Matsui

Solid

Photoemission

S. KeraGas
LiquidSolid

Absorption
Photoemission
Photon-emission
Reflection
Absorption
Photon-emission

Free electron laser

1.6 – 13.9 eV
BL1B

Martin-Puplett FT-FIR

0.5 – 30 meV
BL2A

Double crystal

585 – 4 keV
18-m spherical grating(Dragon)

BL2B

Varied-line-spacing
plane grating(Monk-Gillieson)

BL3U

BL3B

23 – 205 eV

40 – 800 eV

2.5-m off-plane Eagle

Solid

1.7 – 31 eV
Varied-line-spacing
plane grating(Monk-Gillieson)
Varied-line-spacing
plane grating(Monk-Gillieson)

BL4U

BL4B

Spherical grating(SGM-TRAIN†)

BL5U

BL5B

50 – 770 eV

25 eV – 1 keVVariable-included-angle
varied-line-spacing
plane grating

BL6B

40 – 500 eVMichelson FT-IR
10-m normal incidence(modified Wadsworth)

BL7B

Yellow columns represent undulator beamlines.
In-house beamline.

*− 16 −

H. Iwayama
iwayama@ims.ac.jp

F. Matsui
matui@ims.ac.jp

Photoionization
Photodissociation
Photoemission

H. Iwayama

Solid

Photoemission

K. Tanaka

Solid

Calibration
Absorption

K. Tanaka

Gas
Solid

Photoionization
Photodissociation
Photoemission
Reflection
Absorption
IR microscopeohigashi@ims.ac.jp

iwayama@ims.ac.jp

k-tanaka@ims.ac.jp

k-tanaka@ims.ac.jp

F. Matsui
matui@ims.ac.jp

K. Tanaka
k-tanaka@ims.ac.jp

Solid

Photoemission

K. Tanaka

Solid

Reflection
Absorption
Photon-emission

F. Matsui

6 – 40 eV

1.2 – 25 eV

kera@ims.ac.jp

Gas
Solid

Solid

3-m normal incidence

matui@ims.ac.jp

T. Ohigashi

4 meV – 2.5 eV
BL7Uk-tanaka@ims.ac.jp

Absorption(Microscopy)

6 – 600 eV
BL6U*

yostaira@ims.ac.jp

Gas
LiquidSolid

20 – 200 eV

Plane grating

Contact

k-tanaka@ims.ac.jp

matui@ims.ac.jp

BL1U
Light Source Development Station▼Description
BL1U is dedicated for developments and applications of novel light sources. This beamline is equipped with adedicated tandem undulator for variable polarization with a buncher section, which can be used for free electron
laser in the range from visible to deep UV, VUV coherent harmonic generation (CHG), and generation of
spatiotemporal structured light such as an optical vortex beam, a vector beam and double-pulse wave packets. It isalso equipped with a femto-second laser system synchronized with the accelerator, which is used for the generationof CHG, laser Compton scattered gamma-rays, and coherent THz radiation. Nowadays, material analysis by positronannihilation spectroscopy using laser Compton scattered gamma rays is actively used.

Fig. 1. Configuration of the free electron laser

VerticalCircular

Horizontal

Fig. 2. Brilliance of BL1U Apple-II Undulator

Fig. 3. Accelerator synchronized Laser System▼Technical Data of FEL▼Technical Data of Ti:Sa Laser

Wave Length

Wave Length

800 nmPulse Length

130 fsec

199-800 nm-4Spectral Band Width~10

Polarization

Circular/Linear

Oscillator

90.1 MHz

Pulse Rate

11.26 MHz

Pulse Energy

2.5 mJ

10 mJ

50 mJ

Max. Ave. Power~1 W

Repetition Rate

1 kHz

1 kHz

10 Hz

− 17 −

BL1B
Terahertz Spectroscopy Using Coherent Synchrotron Radiation▼Description
Coherent synchrotron radiation (CSR) is a powerful light source in the terahertz (THz) region. This beamline has
been constructed for basic studies on the properties of THz-CSR. However, it can be also used for measurements ofreflectivity and transmission spectra of solids using conventional synchrotron radiation.
The emitted THz light is collected by a three-dimensional magic mirror (3D-MM, M0) of the same type as thosealready successfully installed at BL43IR in SPring-8 and BL6B in UVSOR-II. The 3D-MM was installed in bendingmagnet chamber #1 and is controlled by a 5-axis pulse motor stage (x, z translation; θx, θy, θz rotation). The acceptanceangle was set at 17.5-34 degrees (total 288 mrad) in the horizontal direction. The vertical angle was set at ±40 mrad
to collect the widely expanded THz-CSR.
The beamline is equipped with a Martin-Puplett type interferometer (JASCO FARIS-1) to cover the THz spectral
region from 4 to 240 cm-1 (hν = 500 μeV-30 meV). There is a reflection/absorption spectroscopy (RAS) end-station
for large samples (~ several mm). At the RAS end-station, a liquid-helium-flow type cryostat with a minimum
temperature of 4 K is installed.

Fig. 1. Schematic top view of the beam extraction part of
the THz-CSR beamline, BL1B. The three-dimensional
magic mirror (3D-MM, M0) and a plane mirror (M1) arelocated in the bending-magnet chamber. A parabolic mirror(M2) is installed to form a parallel beam. The straightsection (BL1U) is used for coherent harmonic generation(CHG) in the VUV region.

Fig. 2. Obtained intensity spectra with the
combination of a light source (UVSOR),
interferometer (FARIS-1), and detectors (Sibolometer and InSb hot-electron bolometer).

▼Technical Data
Interferometer

Martin-Puplett (JASCO FARIS-1)

Wavenumber range(Energy range)

4-240 cm-1
(500 PeV-30 meV)

Resolution in cm-1

0.25 cm-1

Experiments

Reflection/transmission spectroscopy

Miscellaneous

Users can use their experimental system in this beamline.

− 18 −

BL2A
Soft X-Ray Beamline for Photoabsorption Spectroscopy▼Description
BL2A is a soft X-ray beamline for photoabsorption spectroscopy. The beamline is equipped with a pre-focusing
mirror and a double-crystal monochromator [1]. The monochromator serves soft X-rays in the energy region from
585 to 4000 eV using several types of single crystals, such as beryl, KTP (KTiOPO4), and InSb. The throughput
spectra measured using a Si photodiode (AXUV-100, IRD Inc.) are shown in Fig. 1. The typical energy resolution(E / ΔE) of the monochromator is approximately 1500 for beryl and InSb.
There is a small vacuum chamber equipped with an electron multiplier (EM) detector. Photoabsorption spectra for
powdery samples are usually measured in total electron yield mode, with the use of the EM detector. In addition, ahemispherical electron analyzer for photoelectron spectroscopy is equipped.
Recently, a new omnidirectional photoelectron acceptance lens (OPAL) has been developed aiming to realize
2π-steradian photoelectron spectroscopy and photoelectron holography [2]. By combining OPAL and the existing
hemispherical electron analyzer, a photoelectron spectrometer with high energy resolution can be realized, and a fullrange (±90°) 1D angular distribution can be measured at once. This upgrade is currently in the commissioning
phase.
[1] Hiraya et al., Rev. Sci. Instrum. 63 (1992) 1264.
[2] H. Matsuda and F. Matsui, Jpn. J. Appl. Phys. 59 (2020) 046503.

Fig. 1. Throughput spectra of the double-crystal monochromator at BL2A.

▼Technical Data
Monochromator
Monochromator crystals:(2d value, energy range)
Resolution
Experiments

Double crystal monochromatorberyl (15.965 Å, 826–2271 eV), KTP (10.95 Å, 1205–3310 eV),InSb (7.481 Å, 1764–4000 eV), Ge (6.532 Å, 2094–4000 eV)
E/ǻE = 1500 for beryl and InSb
Photoabsorption spectroscopy (total electron yield using EM and partial
fluorescence yield using SDD)

− 19 −

BL2B
Photoelectron spectroscopy of molecular solids▼Description
This beamline previously dedicated for experiments in the field of gas phase photoionization and reaction
dynamics. Then, the beamline has been reconstructed for photoelectron spectroscopy of molecular solids with a newend station, and experiments can be performed from May 2014. The monochromator is a spherical grating Dragon
type with 18-m focal length. High throughput (1 × 1010 photons s-1) and high resolution (E/∆E = 2000 - 8000) areachieved simultaneously under the condition of the ring current of 100 mA [1]. The optical system consists of two
pre-focusing mirrors, an entrance slit, three spherical gratings (G1 - G3), two folding mirrors, a movable exit slit,
and a refocusing mirror [2]. The monochromator is designed to cover the energy range of 23–205 eV with the threegratings: G1 (2400 lines mm-1, R = 18 m) at 80–205 eV; G2 (1200 lines mm-1, R = 18 m) at 40–100 eV; G3 (2400lines mm-1, R = 9.25 m) at 23–50 eV. The percentage of the second-order light contamination at hν = 45.6 eV is
23 % for G2 or 7 % for G3.
A UHV chamber is placed downstream of the refocusing mirror chamber and equipped silicon photodiode,sapphire plate Au mesh and filters for absolute photon flux measurement, monitor the photon-beam position, relative
photon flux measurements and attenuate higher order light, respectively.
The new end station consists of a main chamber with a hemispherical analyzer (SCIENTA R3000) and a liquidHe-cooled cryostat (temperature range of 15-400 K) with 5-axis stage, a sample preparation chamber with a fastentry load-lock chamber and a cleaning chamber with LEED, ion gun for sputtering and IR heating unit.
[1] M. Ono, H. Yoshida, H. Hattori and K. Mitsuke, Nucl. Instrum. Meth. Phys. Res. A 467-468 (2001) 577.
[2] H. Yoshida and K. Mitsuke, J. Synchrotron Radiation 5 (1998) 774.

Fig. 2. End station of BL2B for photoelectron
spectroscopy of molecular solids.
Fig. 1. Throughput from Dragon monochromator.

▼Technical Data
Monochromator

18 m spherical grating Dragon-type

Wavelength Range

23-205 eVResolution

2000–8000 depending on the gratings

Experiments

Angle-resolved ultraviolet photoelectron spectroscopy− 20 −

BL3U
Varied-Line-Spacing Plane Grating Monochromatorfor Molecular Soft X-Ray Spectroscopy▼Description
The beamline BL3U is equipped with an in-vacuum undulator composed of 50 periods of 3.8 cm period length.
The emitted photons are monochromatized by the varied-line-spacing plane grating monochromator (VLS-PGM)
designed for various spectroscopic investigations in the soft X-ray range. Three holographically ruled laminar
profile plane gratings are designed to cover the photon energy range from 40 to 800 eV. The beamline has liquid cells
for soft X-ray absorption spectroscopy (XAS) in transmission mode as shown in Fig. 1. The liquid cell is in theatmospheric helium condition, which is separated by a 100 nm thick Si3N4 membrane with the window size of
0.2 × 0.2 mm2 from the beamline in an ultrahigh vacuum condition. The thin liquid layer is assembled by using two
100 nm thick Si3N4 membranes. The thickness of the liquid layer is controllable from 20 to 2000 nm by adjusting
the helium pressures around the liquid cell in order to transmit soft X-rays. Liquid samples are exchangeable in situ
by using a tubing pump. The liquid cell has two types of windows: one is the liquid part to obtain the soft X-ray
transmission of liquid (I), and the other is the blank part to obtain the transmission without liquid (I0). We can obtain
the reliable XAS spectra based on the Lambert-Beer law ln(I0/I). Since the liquid cell is in the atmospheric condition,
we can measure XAS of liquid samples in the real environment. Operando XAS observation of several chemical
reactions such as catalytic, electrochemical reactions are also possible by using our liquid cells developed for these
purposes.

Fig. 1. (a) Schematics of a liquid cell for XAS in transmission mode settled in BL3U. The blowup shows athin liquid layer assembled by two Si3N4 membranes with the thickness of 100 nm. (b) Flux at the sample
position with the resolving power of λ/Δλ=104.

▼Technical Data
Monochromator
Energy Range
Resolution
Experiments

Varied-line-spacing plane grating monochromator
40-800 eV
E / ǻE > 10 000
Soft X-ray absorption spectroscopy of liquid in transmission mode

− 21 −

BL3B (HOTRLU)
VIS-VUV Photoluminescence and Reflection/Absorption Spectroscopy▼Description
BL3B has been constructed to study photoluminescence (PL) in the visible (VIS) to vacuum ultraviolet (VUV)
region. This beamline consists of a 2.5 m oﬀ-plane Eagle type normal-incidence monochromator, which covers the
VUV, UV, and VIS regions, i.e., the energy (wavelength) region of 1.7-31 eV (40-730 nm), with three sphericalgratings having constant grooving densities of 1200, 600, and 300 l/mm optimized at the photon energies of ~20,
~16, and ~6 eV, respectively. The schematic side view and top view layouts are shown in Figs. 1(a) and 1(b),respectively. The FWHM of the beam spot at the sample position is 0.25 mm (V) × 0.75 mm (H). Low energy passfilters (LiF, quartz, WG32, OG53) can be inserted automatically to maintain the optical purity in the G3 (300 l/mm)
grating region (1.7~11.8 eV). Figure 2 shows the throughput spectra (photon numbers at a beam current of 300 mA)
for each grating with entrance and exit slit openings of 0.1 mm (resolving power E / ∆E of ~2000 (G3, ~6.8 eV)).
Since both slits can be opened up to 0.5 mm, a monochromatized photon flux of 1010 photons/s or higher is available
for PL measurements in the whole energy region.
The end station is equipped with a liquid-helium-flow type cryostat for sample cooling and two detectors; one ofwhich is a photomultiplier with sodium salicylate and the other a Si photodiode for reflection/absorption measurement.
For the PL measurements in the wide energy region from VIS to VUV, two PL monochromators, comprising not
only a conventional VIS monochromator but also a VUV monochromator with a CCD detector, are installed at theend station.

Fig. 1. Schematic layout of the BL3B (a) side view and (b)top view.

Fig. 2. Throughput spectra for each grating(G1:1200 l/mm, G2:600 l/mm and G3:300 l/mm) with S1 = S2 = 0.1 mm.

▼Technical Data
Monochromator-2.5 m normal-incidence monochromator

Energy range

1.7-31 eV (40~730 nm)

Resolution ('hQ/ hQ)

t 12000 (at ~ 6.9 eV, 0.02 mm slits, G1 (1200 l/mm)

Experiments

Photoluminescence, reflection, and absorption spectroscopy, mainly for solids− 22 −

BL4U
Scanning Transmission X-ray Microscopy in the Soft X-ray Region▼Description
In the soft x-ray region, there are several absorption edges of light elements and transition metals. The near edge
X-ray absorption fine structure (NEXAFS) brings detailed information about the chemical state of target elements.
A scanning transmission X-ray microscope (STXM) in the soft X-ray region is a kind of extended technique of the
NEXAFS with high spatial resolution. The STXM has a capability of several additional options, for example, in-situ
observations, 3-dimensional observation by computed tomography and ptychography, by utilizing the characteristicsof the X-rays. The STXM can be applied to several sciences, such as polymer science, material science, cell biology,
environmental science, and so on.
This beamline equips an in-vacuum undulator, a varied-line-spacing plane grating monochromator and a fixed exit
slit. The soft X-ray energy range from 50 to 770 eV with the resolving power (E/∆E) of 6,000 is available. The
aperture size of the fixed exit slit determines not only the resolving power but also the size of a microprobe. A
Fresnel zone plate is used as a focusing optical device through an order select aperture and its focal spot size of ~30
nm is available at minimum. An image is acquired by detecting intensities of the transmitted X-rays by aphotomultiplier tube with scintillator with scanning a sample 2-dimensionally. By changing the energy of theincident beam, each 2-dimensional NEXAFS image is stacked. A main chamber of STXM is separated from thebeamline optics by a silicon nitride membrane of 50-nm thickness; therefore, sample folders can be handled in
vacuum or in helium.
M1 mirror andGratingPinholeSlit

M2 mirror

M0 mirror

Fixed exit slit

STXM

Fig. 1. Schematic image of BL4U

Fresnel zone plate
Order Sorting Aperture
SamplePhoto multiplier tube
with scintillator P-43

Monochromatized X-rays

Central stopper

Fig. 2. Schematic image of STXM

▼Technical Data
Energy range (E)50 -770 eVResolving power (E/'E)~6,000

Photon flux on a sample (photons/s)~2u107 @400 eV

Focusing optical element

Fresnel zone plate

Spatial resolution~30 nmExperiments

2-dimensional absorption spectroscopy
standard sample folder in vacuum or in helium,
specially designed sample cell in ambient condition

Measurement environment− 23 −

BL4B
Varied-Line-Spacing Plane Grating Monochromatorfor Molecular Soft X-Ray Spectroscopy▼Description
The beamline BL4B equipped with a varied-line-spacing plane grating monochromator (VLS-PGM) wasconstructed for various spectroscopic investigations in a gas phase and/or on solids in the soft X-ray range. Threeholographically ruled laminar profile plane gratings with SiO2 substrates are designed to cover the photon energy
range from 25 to 800 eV. The gratings with groove densities of 100, 267, and 800 l/mm cover the spectral ranges of
25–100, 60–300, and 200-1000 eV, respectively, and are interchangeable without breaking the vacuum. Figure 1
shows the absolute photon flux for each grating measured using a Si photodiode (IRD Inc.), with the entrance- andexit-slit openings set at 50 and 50 μm, respectively. The maximum resolving power (E/ΔE) achieved for eachgrating exceeds 5000.
There is no fixed endstation on this beamline. A small vacuum chamber equipped with an electron multiplier(EM) detector is available. Soft X-ray absorption spectra of solid samples are usually measured by means of thetotal electron yield method using EM, and the partial fluorescence yield method using a silicon drift detector (SDD).

㻝㻱㻝㻞㻵㼚㼠㼑㼚㼟㼕㼠㼥㻌㻔㼜㼔㼛㼠㼛㼚㼟㻛㼟㻕

㻳㻟
㻝㻱㻝㻝

㻿㼘㼕㼠㻦㻌㻡㻜P㼙㻙㻡㻜P㼙

㻳㻞

㻝㻱㻝㻜

㻳㻝
㻝㻱㻥

㻝㻱㻤
㻜

㻞㻜㻜

㻠㻜㻜

㻢㻜㻜

㻤㻜㻜

㻝㻜㻜㻜

㻝㻞㻜㻜

㻼㼔㼛㼠㼛㼚㻌㻱㼚㼑㼞㼓㼥㻌㻔㼑㼂㻕

Fig. 1. Throughput from the VLS-PGM monochromatoron BL4B.

Fig. 2. Photo of BL4B.

▼Technical Data
Monochromator

Varied-line-spacing Plane Grating Monochromator

Energy range

25-1000 eVResolution

E / ǻE > 5000 (at maximum)

Experiments

Soft X-ray spectroscopy (mainly, photoabsorption spectroscopy for solid targets
by means of total electron yield method using EM and partial fluorescence yield
method using SDD)

− 24 −

BL5U
Photoemission Spectroscopy of Solids and Surfaces▼Description
Since the monochromator of BL5U was an old-style spherical grating type SGMTRAIN constructed in 1990s andthe throughput intensity and energy resolution were poor, the whole beamline has been replaced to state-of-the-art
monochromator and end station. The new beamline has been opened to users from FY2016 as high-energy resolution
ARPES beamline. Samples can be cooled down to 3.8 K with newly developed 5-axis manipulator to perform highenergy resolution measurements. Users can also obtain spatial-dependence of the electronic structure of solids using
micro-focused beam (~ 50 μm). The new electron lens system makes it possible to obtain ARPES spectra without
moving samples. This beamline will also have new capability to perform high-eﬃcient spin-resolved ARPES in the
future.

Fig. 1. Picture and photon flux of BL5U.

▼Technical Data (Expected Performance)
Light source

APPLE-II type undulator (Ȝu = 60 mm, N = 38)
vertical/horizontal, right/left circular (depending on hv)

Monochromator

Monk-Gillieson VLS-PGM

Energy Range

20-200 eVResolution

hv/ ǻE > 10,000 for < 10 ȝm slits

Experiment

ARPES, Space-resolved ARPES, Spin-resolved ARPES

Flux<1012 photons/s for <10 ȝm slits (at the sample position)

Beam spot size

23 (H) x 40 (V) μm

Main Instruments

Hemispherical photoelectron analyzer with deflector scan (MBS A-1
Lens#4),
Liq-He flow cryostat with 5-axis manipulator (3.8 K-350 K)− 25 −

BL5B
Calibration Apparatus for Optical Elements and Detectors▼Description
BL5B has been constructed to perform calibration measurements for optical elements and detectors. This beamline
is composed of a plane grating monochromator (PGM) and three endstations in tandem. The most upstream station
is used for the calibration measurements of optical elements, the middle one for optical measurements for solids, andthe last for photo-stimulated desorption experiments. The experimental chamber at the most downstream station issometimes changed to a chamber for photoemission spectroscopy. The calibration chamber shown in Fig. 2 isequipped with a goniometer for the characterization of optical elements, which has six degrees of freedom, X-Ytranslation of a sample, and interchanging of samples and filters. These are driven by pulse motors in vacuum.
Because the polarization of synchrotron radiation is essential for such measurements, the rotation axis can be madein either the horizontal or vertical direction (s- or p-polarization).

Fig. 1. Throughput spectra for possible combinations ofgratings and mirrors at BL5B measured by a gold mesh.

Fig. 2. A side view of the experimental chamber
for calibration measurements.

▼Technical Data
Monochromator

Plane Grating Monochromator

Energy range

6-600 eV (2-200 nm)

Resolution

E / ǻE ~500

Experiments

Calibration of optical elements, reflection and absorption spectroscopy mainly
for solids− 26 −

BL6U
Variable-Included-Angle / Variable-Line-Spacing Plane Grating
Monochromator for Soft X-Ray photoelectron Spectroscopy▼Description
The beamline BL6U equipped with a variable-included-angle Monk-Gillieson mounting monochromator with avaried-line-spacing plane grating was constructed for various spectroscopic investigations requiring high-brilliancesoft X-rays on solid surfaces. Through a combination of undulator radiation and sophisticated monochromator
design (entrance slit-less configuration and variable-included-angle mechanism), using a single grating, themonochromator can cover the photon energy ranging from 40 to 500 eV, with resolving power of greater than 10000
and photon flux of more than 1010 photons/s. Figure 1 shows an example of the monochromator throughput spectra
measured using a Si photodiode, with the exit-slit opening set at 30 μm, which corresponds to the theoreticalresolving power of 10000 at 80 eV.
A new Momentum Microscope experimental station for photoelectron spectroscopy resolved in 3D momentum
space with a microscopic field of view has been built at BL6U (SPECS KREIOS 150 MM). A momentum resolutionof 0.01 Å-1 in kx/ky as well as kz is achieved. A spatial resolution of 50 nm, an energy resolution of 20 meV at 9 K,
and a field of view of 2 μm for ARPES are successfully demonstrated. This experimental station specializes incharacterizing the electronic structure of surface atomic sites, thin films, molecular adsorbates, and bulk crystals.
This method opens the door to direct observation of the Fermi surface of μm-sized crystals, which was diﬃcult withconventional ARPES-type hemispherical analyzers.

Throughput spectra of the BL6U (Gap=13 mm, Slit=30Pm)

Flux(Photons/s/100mA:PD-AXUV100G)

1E13

3rd

1E12

5th

1st
1E11

DE 168q
DE 170q
DE 172q
DE 174q

1E10
1E9
1E8
1E7
30

100

Photon energy(eV)Fig. 1. Throughput spectra of the BL6U
monochromator at various included angles.

Fig. 2. Photograph of BL6U end station▼Technical Data
Monochromator

Variable-included-angle Varied-line-spacing Plane Grating Monochromator

Energy range

40-500 eV(practical)

Resolution

E / ǻE > 10000 (at maximum)

Experiments

High-resolution soft X-ray spectroscopy (photoelectron spectroscopy for solid
surfaces)− 27 −

BL6B
Infrared and Terahertz Spectroscopy of Solids▼Description
Synchrotron radiation (SR) has good performance (high brilliance and high flux) not only in the VUV and soft
X-ray (SX) regions but also in the infrared (IR) and THz regions. BL6B covers the IR and THz regions. The
previous beamline, BL6A1, which was constructed in 1985, was the pioneer in IRSR research. The beamline wasdeactivated at the end of FY2003 and a new IR/THz beamline, BL6B (IR), was constructed in FY2004. The frontend part including bending duct #6 was replaced with a new part having a higher acceptance angle (215 (H) × 80(V) mrad2) using a magic mirror, as shown in Fig. 1.
There are two Michelson type interferometers in this endstation; with first one (Bruker Vertex70v), which covers
a wide spectral region from 30 to 20,000 cm-1 (hν = 4 meV-2.5 eV), reflection/absorption spectroscopy measurementsof large samples (up to several mm) and IR/THz microscopy measurements of tiny samples (up to several tens ofμm) can be performed. For reflection/absorption spectroscopy measurements, a liquid-helium- flow type cryostat
with a minimum temperature of 4 K is installed. The other interferometer (Jasco FT/IR-6100), which covers 350 to
15,000 cm-1 (hν = 45 meV-1.8 eV), has been available for IR microscopy imaging measurements from FY2014. One
can also perform ATR measurements using diamond ATR prism.

Reflection/absorption
end station

Michelson FT-IR(Jasco FT/IR-6100)

IR microscopy imaging(Jasco IRT-7100)

Michelson FT-IR(Jasco FT/IR-6100)

Fig. 1. Schematic top view of BL6B.

Fig. 2. Obtained intensity spectra with the
combination of a light source (UVSOR),
detector (Si bolometer), and interferometer(Bruker Vertex70v) with diﬀerent
beamsplitters (6 μm Mylar and KBr) .
(Only low energy side is shown).

▼Technical Data
Interferometer

Michelson (Bruker Vertex70v)-1Michelson (Jasco FT/IR-6100)

Wavenumber Range(Energy range)

30-20,000 cm(4 meV-2.5 eV)

350-15,000 cm-1
(45 meV-1.8 eV)Resolution in cm-1

0.1 cm-1

0.5 cm-1

Experiments

Reflectivity and transmission
spectroscopy
THz Microspectroscopy

IR microscopy imaging (JASCO IRT-7000)
ATR spectroscopy− 28 −

BL7U (SAMRAI)
Angle-Resolved Photoemission of Solids in the VUV Region▼Description
Beamline 7U, named the Symmetry- And Momentum-Resolved electronic structure Analysis Instrument(SAMRAI) for functional materials, was constructed to provide a photon flux with high energy resolution and highflux mainly for high-resolution angle-resolved photoemission spectroscopy, so-called “ARPES”, of solids [1]. An
APPLE-II-type variable-polarization undulator is installed as the light source. The undulator can produce intense
VUV light with horizontal/vertical linear and right/left circular polarization. The undulator light is monochromatizedby a modified Wadsworth type monochromator with three gratings (10 m radius; 1200, 2400, and 3600 lines/mm
optimized at hv = 10, 20, and 33 eV). The energy resolution of the light (hv/Δhv) is more than 104 with a photon fluxof 1011-1012 ph/s or higher on samples in the entire energy region. The beamline has a photoemission end-stationequipped with a 200 mm-radius hemispherical photoelectron analyzer (MB Scientific AB, A-l analyzer) with awide-angle electron lens and a liquid-helium-cooled cryostat with 6-axis pulse motor control. The main function of
the beamline is to determine the electronic structure of solids and its temperature dependence in order to reveal theorigin of their physical properties.
[1] S. Kimura, T. Ito, M. Sakai, E. Nakamura, N. Kondo, K. Hayashi, T. Horigome, M. Hosaka, M. Katoh, T. Goto,
T. Ejima and K. Soda, Rev. Sci. Instrum. 81 (2010) 053104.

Fig. 1. SAMRAI beamline [(a), (b)]consisting of an APPLE-II type undulator(U7), a modified Wadsworth type
monochromator (M0-S), and a highresolution photoemission analyzer at the
focal point. The monochromator has five
major optical components: two plane
mirrors (M0 and M1) with water cooling,
one set of three spherical gratings (G), an
exit slit (S), and one toroidal refocusing
mirror (M3). (c) Example of flux
intensity versus photon energy [1]▼Technical Data
Light source

APPLE-II type undulator (Ȝu = 76 mm, N = 36)vertical/horizontal, right/left circular (depending on hv)

Monochromator

10 m normal-incidence monochromator (modified Wadsworth type)

Photon energy range

6 – 40 eV (Ȝ = 30 – 200 nm)

Resolution (hv/ǻhv)E / ǻE > 10000-50000

Photon flux on sample

t 1011-1012 ph/s (depending on hv)

Beam size on sample

200 (H) × 50 (V) ȝm2

Experiments

Angle-resolved photoemission of solids(MV Scientific A-1 analyzer, acceptance angle: ± 18 deg)

− 29 −

BL7B
3 m Normal-Incidence Monochromator for Solid-State Spectroscopy▼Description
BL7B has been constructed to provide suﬃciently high resolution for conventional solid-state spectroscopy,
suﬃcient intensity for luminescence measurements, wide wavelength coverage for Kramers–Kronig analyses, andminimum deformation to the polarization characteristic of incident synchrotron radiation. This beamline consists ofa 3-m normal incidence monochromator, which covers the vacuum ultraviolet, ultraviolet, visible, and infrared, i.e.,
the wavelength region of 50–1000 nm, with three gratings (1200, 600, and 300 l/mm). Two interchangeablerefocusing mirrors provide two diﬀerent focusing positions. For the mirror with the longer focal length, an LiF or a
MgF2 window valve can be installed between the end valve of the beamline and the focusing position. Figure 1
shows the absolute photon intensity for each grating with the entrance and exit slit openings of 0.5 mm. A silicon
photodiode (AXUV-100, IRD Inc.) was utilized to measure the photon intensity and the absolute photon flux was
estimated, taking the quantum eﬃciency of the photodiode into account.
The cooling system for the pre-focusing mirror has been removed, resulting in longer beam settling times.
Currently, BL7B is opened during single bunch mode, but limited use is possible during multi bunch mode.

Fig. 1. Throughput spectra of BL7B measured using asilicon photodiode.

Fig. 2. Photo of BL7B.

▼Technical Data
Monochromator

3 m Normal-Incidence Monochromator

Wavelength Range

50-1000 nm (1.2-25 eV)Resolution

E / 'E = 4000-8000 for 0.01 mm slits

Experiments

Absorption, reflection, and fluorescence spectroscopy, mainly for solids− 30 −UVSOR User 1

UVSOR User 2რ

Accelerators andInstruments

Ⅲ-1 Accelerators and Instruments

BL1U

Spectral Phase Interferometry for Direct Electric-field Reconstruction of
Undulator Radiation
T. Fuji1, T. Kaneyasu2, M. Fujimoto3, Y. Okano3, E. Salehi3, M. Hosaka4,5, Y. Takashima4,
A. Mano4, Y. Hikosaka6, S. Wada7 and M. Katoh8,31

Laser Science Laboratory, Toyota Technological Institute, Nagoya 468-8511, Japan
2
SAGA Light Source, Tosu 841-0005, Japan
3
Institute for Molecular Science, Okazaki 444-8585, Japan
4
Synchrotron Radiation Research Center, Nagoya University, Nagoya, 464-0814, Japan
5
National Synchrotron Radiation Laboratory, University of Science and Technology of China,
Hefei 230029, China
6
Institute of Liberal Arts and Sciences, University of Toyama, Toyama 930-0194, Japan
7
Graduate School of Advanced Science and Engineering, Hiroshima University,
Higashi-Hiroshima 739-8526, Japan
8
Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan

An undulator is a device widely used in modern
synchrotron light sources to produce quasimonochromatic light. The waveform of the electricfield produced by a relativistic electron in the undulator
is primarily determined by the number of magnets andthe gap between them. Although a simple
electromagnetic theory predicts a square-shaped
waveform, it has never been measured due to the lackof a suggested method. Therefore, it is crucial tocharacterize the electric field produced by the undulator
for the development of synchrotron sources.
SPIDER is a femtosecond pulse characterization
method that has been widely used since its invention in1998 [1]. It involves retrieving the spectral phase byanalyzing the fringes of the interferogram between atest pulse and a spectrally sheared replica. At the
UVSOR-III synchrotron light source, a tandem
undulator produces two wave packets whose
wavelengths can be individually adjusted by changing
the gap between the permanent magnets of each
undulator. A phase shifter consisting of three pairs ofelectromagnets forms a small chicane for the electron
beam and controls the delay between the wave packets
in the femtosecond regime with attosecond accuracy.
The twin tandem undulator produces a pair of
wavelength-shifted wave packets with a delay, and theinterferogram between them can be regarded as a
“SPIDER” interferogram. Consequently, we can use
the same algorithm as SPIDER to analyze theinterferogram and reconstruct the electric field
generated by the undulator [2].
The experiment took place at the 750-MeV UVSORIII storage ring, where a tandem undulator was installed
as shown in Figure 1. The undulator consisted of twin
APPLE-II type variable polarization devices that
operated in the horizontal linear polarization mode,with 10 magnetic periods and a period length of 88 mm.
The central photon energy of the fundamental radiation

was adjusted to 35 eV. Figure 2 displays the retrieved
electric field, which shows 10-cycle field oscillations
with a rectangular envelope of the wave packet that are
accurately reproduced.
This method is advantageous for shorter wavelength
synchrotron radiation, including soft and hard x-rays,
as it does not require nonlinear wavelength conversion.
Additionally, it holds potential for the characterizationof FEL pulses.

Fig. 1. Conceptual diagram of the tandem undulator.
ω0 and ω0 +Ω represent the carrier frequencies of the
upstream and downstream wave packets, respectively.

Fig. 2. Waveform of the wave packet retrieved using
the SPIDER algorithm.
[1] C. Iaconis and I. A. Walmsley, Opt. Lett. 23 (1998)
792.
[2] T. Fuji et al., Optica 10 (2) (2023) 302.

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BL1U

Construction of Laser Transport Line and Light Measurement Setup for
Coherent Harmonic Generation Experiment at BL1U
F. Sakamoto 1, H. Zen2, T. Tanikawa3, Y. Taira4, Y. Okano4, H. Ohta4,
J. Yamazaki4, K. Hayashi4, Y. Takashima5, A. Mano5 and M. Katoh4,61National Institute of Technology, Akita College, Akita 011-8511, Japan
Institute of Advanced Energy, Kyoto University, Kyoto 611-0011, Japan
3
Innovation Center for Applied Superconducting Accelerators (iCASA), High Energy Accelerator Research
Organization (KEK) Ibaraki 305-0801, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
Synchrotron Radiation Research Center, Nagoya University, Nagoya 464-8603, Japan
6
HiSOR, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
2

Coherent Harmonic Generation (CHG) is a method
to imprint external laser information to an electron
beam and generate temporally coherent and short VUVradiations from it [1]. Since the properties of the CHG
such as polarization, temporal and spectral distribution
are completely dependent on the external laser [2], they
can be optimized by changing the laser and electron
beam conditions. These features of the CHG havepossibilities for some applied experiments. So far,some experiments on CHG have been performed at
UVSOR-II and important features of CHG wereobserved [3, 4].
We plan to resume detailed studies of CHG using an
optical klystron and an ultrashort Ti:Sapphire laser
pulse at BL1U. The optical klystron of BL1U consistsof two APPLE-II variable polarization undulators and abuncher magnet which is located between the undulators[5]. The laser pulse is injected into the first undulator
and an energy exchange between the laser pulse andelectron beam that circulates in the storage ring occurs.
This leads to an energy modulation inside the electron
beam. In the buncher magnet, the energy modulation isconverted to a density modulation with a period of thelaser wavelength (micro-bunching). Temporally
coherent radiations are generated from the microbunched electrons in the second undulator.
In order to perform the CHG experiment, we have
newly constructed a laser transport line and lightmeasurement setup at BL1U. Schematics of the setup
are shown in Fig. 1. The laser pulse is transported about
10 m from laser hutch and injected to the vacuum tube
connected to the storage ring. The polarization state iscontrolled by a λ/2 waveplate and a polarization beam
splitter (PBS). We also set a monitoring system toadjust spatial and temporal overlaps between the laserand electron beam using CMOS and streak cameras.
After the construction of the setup, we have performed
the first CHG experiment at BL1U.
The experiment was performed with an electron
beam energy of 600 MeV. A resonant wavelength of theundulators was set to 800 nm which corresponds to thewavelength of Ti:Sapphire laser. Figure 2 shows thestreak camera images. From these images, we canconfirm the laser pulse of 1 ps was well overlapped on
the undulator radiation (i.e., electron beam) of 100 ps.

We also observed the spatial overlap by using CMOS
camera that was focused in the first undulator. The firsttarget wavelength for the observation was set to 267 nm
which was 3rd harmonics of the radiation from themicro-bunching. For the purpose, CHG and Ti:Sapphirepulses were separated by using a dichroic mirror and aband pass filter (BPF) at a downstream of undulators. A
photo-multiplier tube (PMT) was used to monitor an
intensity of the CHG signals but unfortunately no CHG
signals was observed. We are considering the spatial
overlap between the laser pulse and electron beam in
the first undulator was not good enough. For the next
experiment, we plan to remodel the alignment optics
for the spatial overlap.

Fig. 1. Schematics of laser transport line and lightmeasurement setup.

Fig. 2. Streak camera images of laser pulse andundulator radiation. The vertical scale corresponds
between right and left images and is synchronized withRF signal of accelerator.
[1] G. Vingnola et al., Nucl. Instrum. Methods Phys.
Res., Sect. A 239 (1985) 43.
[2] H. Zen et al., Proc. FEL2010 TUPB16 (2010) 286.
[3] M. Labat et al., Eur. Phys. J. D 44 (2007) 187.
[4] T. Tanikawa et al., Appl. Phys. Express 3 (2010)
122702.
[5] Y. Uematsu et al., Proc. PASJ 2012 WEPS066(2012) 551.

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Ⅲ-1 Accelerators and Instruments

BL1U

Impact of the Temperature on the Non-Destructive Nuclide Assay in theTransmission NRF Method
M. Omer1, T. Shizuma2, M. Koizumi1, Y. Taira3, H. Zen4, H. Ohgaki4 and R. Hajima2
1
Japan Atomic Energy Agency, Tokai 319-1195, Japan
National Institutes for Quantum Science and Technology, Kizugawa 619-0215, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
Institute of Advanced energy, Kyoto University, Uji 611-0011, Japan
2

Nuclear resonance fluorescence (NRF) is thephotoexcitation of a nuclide using high energy γ-rays.
The resonating levels excited by NRF are a fingerprintof each nucleus. Therefore, NRF can be employed as a
non-destructive assay technique for nuclear materials
such as fissile isotopes. There are two schemes for NRF
measurement. The first one is scattering NRF
measurement, by which the sample is irradiated by a
γ-ray beam, and the scattered NRF photons aremeasured. The second scheme is the transmission NRF
measurement, by which the absorption of NRF photons
by the sample is measured. To realize absorption
measurement, a second target (witness target of thesame sample located downstream the sample target) isused to estimate the amount of γ-ray absorption in thesample. In transmission NRF, γ-ray detector ispositioned close to the witness target. So, themeasurement is possible without the shadow ofbackground radiation from the sample target. [1].
The emission and absorption rate of NRF γ-rays
depend on the temperature of the scattering and witness
targets via the Doppler broadened widths of NRF
levels. Therefore, the temperature of the scattering andwitness targets may aﬀect the time and sensitivity ofthe measurement. Based on the level widths, many
isotopes are possible candidates to study the eﬀect oftemperature on transmission NRF, such as 27Al, 48Ti,
51
V, 206Pb, and 208Pb. In the present measurement, 208Pb
target was irradiated with laser Compton scattering(LCS) γ-ray beam at BL1U of UVSOR. LCS γ-rays of
maximum energy of 5.54 MeV were produced from thecollision of 746-MeV electrons with laser photons of awavelength of 1.98 μm. A lead collimator with 20-cm
thickness and 3-mm aperture size was used to confine
the generated γ-rays energy width to approximately 8%(FWHM). Three 140% HPGe detectors, locatedhorizontally, were used to detect NRF γ-rays. Two ofthem were positioned at a scattering angle of 135° andthe third at a scattering angle of 70° with respect to theincident γ-ray direction, as shown in Fig. 1.
A typical γ-ray spectrum measured using 208Pb isshown in Fig. 2. NRF peaks of 208Pb were observed asindicated in Fig. 2. We also observed substantial
background lines at energies higher than the maximum
energy of the LCS γ-ray beam. These lines probably
originate from the neutron capture interactions withmaterials surroundings the experimental setup. The

neutron capture background aﬀects the accuracy of
NRF peaks. We applied a 10-cm thickness lead shieldaround one detector to decrease the background. As
shown in Fig. 2 (green spectrum), the background was
eﬀectively suppressed. The shielding configuration will
be applied in the planned transmission NRF
experiments. This work is a contribution of the JAEA
to the International Atomic Energy Agency (IAEA)
under the agreement of the coordinated research
program (CRP), J02015 (Facilitation of Safe andSecure Trade Using Nuclear Detection Technology Detection of RN and Other Contraband).

Fig. 1. Photo of the experimental setup used for the
cryo-NRF experiment at BL1U.

Fig. 2. Typical γ-ray spectra observed for 208Pb before(red) and after (green) heavy shield. NRF levels arelabeled with resonance energies. Also, single anddouble escape peaks are labeled. The high energy
background was eﬀectively suppressed.
[1] C.T. Angell et al., Nucl. Instrum. Methods Phys.
Res. B 347 (2016) 11.

− 37 −BL1U

Basic Study on Compton Camera for Detection of Polarized gamma-rays
K. Shimazoe 1, M. Uenomachi2, T. Ueki1, Q. Shu1, A. Takeda3, K. Magata3,
K. Nagayanagi3 and Y. Taira4
1

Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
2
Space Unit, Kyoto University, Kyoto 606-8502, Japan
3
Miyazaki University, Miyazaki 889-2192, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

Compton imaging is a promising technology
visualizing the distribution of gamma-rays by using theCompton kinetics principle. Measuring the energies inscatterer and absorber determines the scattering angleof gamma-rays and enables the localization of radiation
source. Compton imaging is now widely investigated
for the application of astronomy, medical imaging [1]and environmental monitoring [2]. Although the
gamma-ray imaging is possible through Compton
imaging, but the information of polarization in gammaray is not well utilized till now. The polarization
information can be used to improve the image quality
in positron emission tomography (PET) scanners with
its quantum entanglement nature [3].
In the previous research, we have been working on
developing silicon on insulator (SOI) based monolithic
sensor integrating the silicon sensor and readout
electronics in one chip [4]. SOI device can be used todetect the track of Compton recoil electrons for theadvanced Compton imaging. In this research weinvestigated the possibility of extracting the polarization
information of incoming linearly or circularly polarized
gamma-rays through the pattern of electron tracks andCompton scattering angles.
Figure 1 shows the experimental setup for detecting
the polarization of gamma-rays. Two SOI pixel sensor
are used as scatterers and Compton electron trackers.
Eight 8×8 GAGG arrays (pixel size is 3.2 mm andthickness is 9 mm) coupled with SiPM array are used asabsorber. All the detectors are synchronized for
detecting the coincidence events between detectors.
Figure 2 shows the picture of detector setup aligned
to the beam. In this setup 31-47 degree and 45-61
degree scattering events can be acquired for SOI1/
GAGG and SOI2/GAGG coincidence respectively.

Figure 3 shows the expected scattering angle ofpolarized photon with a Monte Carlo simulation code
(GEANT4).
In the first analysis, the coincidence events are
successfully acquired between laser trigger and SOI
and between laser trigger and GAGG as shown in
Figure 4. The more detail analysis is ongoing.
()

Fig. 2. the detector setup in the beamline BL1U

Fig. 3. Simulated scattering angle of polarized photon

Fig. 4. time diﬀerence histogram of SOI and laser

Fig. 1. Two SOI sensors and eight GAGG arrays areused to detect polarized gamma-rays.

[1] M. Uenomachi, M. Takahashi, K. Shimazoe, et al.,Sci Rep 11 (2021) 17933 .
[2] Jianyong Jiang, et al., Journal of Nuclear Scienceand Technology 53.7 (2016) 1067.
[3] D. P. Watts, et al., Nature Communications 12.1
(2021) 2646.
[4] Y. Yoshihara, et al., Journal of Instrumentation 12.01(2017) C01045.

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Ⅲ-1 Accelerators and Instruments

BL1U

Development of gamma-ray-induced Positron age-momentum Correlation
Y. Taira1, 2, Y. Okano1 and T. Hirade3
1
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan
3
Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai, 319-1195, Japan
2

In UVSOR-III, gamma-ray-induced positronannihilation spectroscopy using the ultra-short pulsed
gamma rays is developed. The ultra-short pulsed
gamma rays with a pulse width of ps range are generated
via inverse Thomson scattering with 90 degreecollisions between an electron beam and a laser pulse at
BL1U [1]. Gamma-ray-induced positron annihilation
lifetime spectroscopy (GiPALS) is currently available
to users. In addition to GiPALS, gamma-ray-induced
age-momentum correlation (GiAMOC) is being
developed. GiAMOC is an approach to measure theemission time and the energy shift of annihilation
gamma rays with an energy of 0.511 MeV
simultaneously for observing the time-resolved
momentum distribution of an electron, which is theannihilation counterpart of a positron. For that, one of
the two annihilation gamma rays produced from asample is detected using a barium fluoride (BaF2)
detector with high time resolution and the other isdetected by a high purity germanium detector (Mirion
Technologies, GC4018, 40% relative eﬃciency) withhigh-energy resolution. A BaF2 detector comprises a
BaF2 scintillator and a photomultiplier tube (Hamamatsu
Photonics K.K., H3378-51). GiAMOC using one
detector pair was presented in Ref. [2]. In this report,
we present the results of quartz measurements using
two detector pairs.
The GiAMOC measurement system is shown in
Figure 2 of Ref. [2]. Two sets of this system were used
to improve the counting rate by a factor of two, asshown in the picture in Fig. 1. The measured time
evolution of a fraction of low-momentum annihilation(S-parameter) of synthetic silica glass (Tosoh SGM
Corp., ED-C) is shown in Fig. 2. As shown in Fig. 2,
S-parameter decreased with time. Around time 0, theannihilation process of para-positronium, which has ashort annihilation lifetime and a small energy spread, isdominant, and as time passes, the annihilation processesof free positrons and ortho-positronium, which have
longer lifetimes and larger energy spreads than thepara-positronium, is dominant. The time evolution of
the measured S-parameter is consistent with thatmeasured using a slow positron beam at AIST [3].

Fig. 1. Detector arrangement of GiAMOC.

Fig. 2. The time evolution of S-parameter for synthetic
silica glass.
[1] Y. Taira et al., Nucl. Instr. Meth. A 652 (2022) 696.
[2] Y. Taira et al., Rev. Sci. Instr. 93 (2022) 113304.
[3] Y. Komuro et al., Rad. Phys. Chem. 76 (2007) 330.

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BL1U

Study on Generation of F-LCS Gamma-rays for Absolute Cross-section
Measurement of NRF using BL1U Undulator
H. Ohgaki1, H. Zen1, T. Kii1, T. Hayakawa2, T. Shizuma2, M. Fujimoto3 and Y. Taira3
1
Institute of Advanced Energy, Kyoto University, Kyoto 611-0011, Japan
Tokai Quantum Beam Science Center, National Institutes for Quantum and Radiological Science and Technology,
Ibaraki 319-1106, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

2

Fig. 1. Schematic drawing of the LCS beamline BL1U,UVSOR. PM: power meter, W: window, SM: Spherical
Mirror. A Ge detector was added after the collimator in
the POP experiment.

Fig. 2. LCS gamma-ray energy distribution in thevertical axis with the undulator K-value of K=0.2.
㻝㻚㻞㻝Normalized Count

Laser Compton Scattering Gamma-ray beam
(F-LCS), which has a flat distribution in the energy
spectrum and the spatial distribution with a few mm
diameter beam size, has been developed to study an
isotope selective CT Imaging application in thebeamline BL1U in UVSOR. By using a circular motionof the electron beam which is excited by a helicalundulator installed in a storage ring, and collision withan intense laser beam, an F-LCS beam can be generated.
The principle is that the electron beam divergence
could be enlarged by the undulator field that enlarges
the beam divergence of the Compton backscatteredgamma-ray (LCS) beam. At the same time, the LCS
beam energy is also spread.
An Electron Gamma Shower version 5 (EGS5) [1]simulation study assumed in the LCS beamline BL1U
(Fig.1) with the collimator diameter of 2 mm .has
been carried out. Figure 2 shows the energy spectra of
the LCS beams with K-values from 0 to 0.4. The
boarder energy spread peak is observed with a larger
K-value. The energy spread is widened from 2.7 to
22% (FWHM), and the peak energy is shifted from5.53 MeV to 5.01 MeV by increment of the K-value
from 0 to 0.4 On the other hand, the F-LCS beam yieldat the top energy region decreases with the increase of
the undulator field. Therefore, K-value of 0.2 could berecommended for practical applications in BL1U.
A POP experiment was carried out at the BL1U in
UVSOR. The experimental setup was the same as thatshown in Fig. 2 except for a high-purity germanium(Ge) detector with a relative eﬃciency of 120% wasadded after the 2-mm collimator. The stored electronwith an energy of 746 MeV and a current of about 6 mA
was used. The laser beam from a Tm-fiber laser system(TLR-50-AC-Y14, IPG Laser GmbH) whose
wavelength was 1.896 μm with random polarization
was used at around 1 W CW power. The spectra of the
LCS beams were measured for diﬀerent K-values from
K=0 to 0.3. Although the Ge detector response madecomplicated energy spectra, we observed peak the shift
toward lower energy according to larger K value, as
shown in Fig. 3.
As a result, the larger K-value, the broader energy
bandwidth of the LCS was observed as predicted by
EGS5 simulation. This result supports the successful
generation of the F-LCS beam.

㻜㻚㻤

㻷㻩㻜㻚㻝
㻷㻩㻜

㻜㻚㻢
㻜㻚㻠
㻷㻩㻜㻚㻞
㻷㻩㻜㻚㻟

㻜㻚㻞
㻜

㻠

㻠㻚㻞

㻠㻚㻠

㻠㻚㻢

㻠㻚㻤

㻡

㻡㻚㻞

㻡㻚㻠

㻡㻚㻢

㻡㻚㻤

㻢

Energy (MeV)

Fig. 3. Measured LCS beam spectra with the undulator
K-value of 0, 0.1, 0.2, and 0.3.
[1] H. Hirayama, Y. Namito, A.F. Bielajew, S.J. Wilderman and W.R. Nelson, The EGS5 code system, SLAC
Report number: SLAC-R-730, KEK report number:2005-8 (2005).

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Ⅲ-1 Accelerators and Instruments

BL1U

Double-Pulsed Light Wave Packets Emitted from a Tandem Undulator
T. Kaneyasu1,2, M. Hosaka3,4, A. Mano4, Y. Takashima4, M. Fujimoto2,4, E. Salehi2,
H. Iwayama2,5, Y. Hikosaka6 and M. Katoh2,4,7
1

SAGA Light Source, Tosu 841-0005, Japan
Institute for Molecular Science, Okazaki 444-8585, Japan
3
University of Science and Technology of China, Hefei 230029, China
4
Synchrotron Radiation Research Center, Nagoya University, Nagoya, 464-8603, Japan
5
Sokendai (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan
6
Institute of Liberal Arts and Sciences, University of Toyama, Toyama 930-0194, Japan
7
Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan2

The waveform of electromagnetic radiation from anultra-relativistic electron reflects the motion of theelectron. We report on a fully-optical characterizationof double-pulsed wave packets emitted by individual
relativistic electrons passing through a tandem
undulator in a synchrotron light source [1]. The
experiment was carried out at the undulator beamline
BL1U. The light source of BL1U consists of two
identical APPLE-II undulators, between which a threepole electromagnetic phase shifter is installed (Fig. 1).
The period length and number of periods for each
undulator were 88 mm and 10, respectively. A
relativistic electron passing through the undulators
emits a wave packet with a waveform expected to be
characterized by time-separated 10-cycle oscillations.
The time delay between the double-pulsed components
can be controlled by adjusting the length of electron
orbit between the undulators using the phase shifter
magnet.
Using a Mach-Zehnder interferometer [2] operating
at ultraviolet wavelengths, we measured the
autocorrelation trace for the spontaneous radiationfrom the tandem undulator. The double-pulsed wave
packets were randomly distributed within the overall
300 ps radiation pulse corresponding to the length ofthe electron bunch. Figure 2(a) shows the interferograms
obtained by setting the field strength of the phase shifter
magnet to four diﬀerent values. The central wavelengthof the radiation was 357 nm for both undulators. Theinterferograms measured at a phase shifter current of
10.0 A or more show approximately 20-cycle
oscillations with triangular envelopes in the range of-12 – +12 fs, as well as weaker 20-cycle oscillations
lying on both sides. The side oscillation structuresapproach the central structure as the phase shifter
current decreases, and they are unified at a phase shifter
current of 0 A.
The observed interferograms can be understood as
autocorrelation traces of double-pulsed wave packet.
The calculated autocorrelation trances for a doublepulsed 10-cycle sinusoidal wave packet at 357 nm
wavelength are shown in Fig. 2(b). Over the whole
range of phase shifter currents, one finds excellent
agreement between the experiments and calculations.

This fact confirms that each of the relativistic electron
emits a double-pulsed 10-cycle wave packet which
well reflects the magnetic field in the tandem undulator.

Fig. 1. Schematic illustration of the tandem undulator.
A relativistic electron passing through the undulators
emits a wave packet with a waveform expected to be
characterized by time-separated 10-cycle oscillations.

Fig. 2. Autocorrelation measurements of spontaneousradiation from the tandem undulator at various valuesof the phase shifter current. The wavelength of thefundamental undulator radiation was set to 357 nm. (a)Measurement. (b) Calculation.
[1] T. Kaneyasu et al., Sci. Rep. 12 (2022) 9.
[2] A. Mano et al., UVSOR Activity Report 2020, 48(2020) 38.

− 41 −

BL1U

Progress in Single Electron Storage Experiment
A. Asai 1, M. Shimada 2,3, H. Miyauchi 2,3 and M. Katoh 3,1,4,2
1School of Science, Hiroshima University, Higashi-hiroshima 444-8585, Japan
High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
3
Hiroshima Synchrotron Radiation Research Center, Hiroshima University, Higashi-hiroshima 739-0046, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
2

Single electron storage has been achieved at several
electron synchrotrons, aiming to investigate electron
dynamics in a synchrotron [1,2,3], to investigate
electromagnetic radiation from an electron [4], or toutilize the radiation as a primary standard [5,6,7]. In
FY2021, we have started an experimental study on
single electron storage at UVSOR-III and successfully
demonstrated it [8, 9]. In FY2022, we continued
improving the operation technique for the single
electron storage and also have started some basic
studies on undulator radiation [10]. Here, we report
some preliminary results. The final results will be
published elsewhere in future.
We have established the following procedure for the
single electron storage. First, we accumulate an electron
beam with very low current, typically 0.1 mA. Indeed,this current corresponds to one shot of the injector. At
this low beam current, we could observe and adjust the
optical axis by eye from the undulator at BL1U, which
is tuned at 355 nm wavelength. Then, we reduce thebeam lifetime to several minutes by using beam scraper.
We use a photomultiplier tube (PMT) to measure thesynchrotron radiation intensity. The PMT signal was
analyzed with a counting unit and recorded by a PC.
Single electron storage corresponds to about 1 pA beam
current. Therefore, we have to observe very wide rangeof the intensity for many orders of magnitudes.
Therefore, we set ND filters in front of the PMT toadjust the radiation intensity and remove them as theintensity reduces. To make the operation simpler, we
examined an ultra-wide range PMT and obtained agood result. The details will be described elsewhere in
future.
We could observe step function like changes in theintensity as shown in Figure 1, which corresponds to aloss of one electron. We also observed the timing of the
PMT output relative to the revolution signal provided
by the RF system, as also shown in Figure 1. We could
observe in which RF bucket the electrons exists. We
confirmed that the last electron survives for more than
2 hours after we pulled out the beam scraper to theoriginal position. This allows us to observe some basic
properties of synchrotron radiation. An example ispresented in Figure 2, which shows that the photon
statistics is well represented by Poisson distribution.
Other interesting results will be presented somewherein future.

Fig. 1. Synchrotron radiation intensity

Fig. 2. Photon Statistics observed at BL1U
[1] A. N. Aleshaev et al., NIM A 359 (1995) 80.
[2] I. V. Pinayev et al., NIM A 375 (1996) 71.
[3] A. Romanov et al., 2021 JINST 16 (2021) P12009.
[4] I. V. Pinayev et al., NIM A 341 (1994) 17.
[5] R. Klein et al., Phys. Rev. STAB 11 (2008) 110701.
[6] R. Klein et al., 2010 Metrologia 47 (2010) R33.
[7] T. Saito et al., Bulletin of the ElectrotechnicalLaboratory (in Japanese) (1985) 431.
[8] R. Shinomiya et al., UVSOR Activity Report 2021,(2022) 39.
[9] R. Shinomiya, Bacholor Thesis (Hiroshima University)(in Japanese) (2022).
[10] Y. Asai, Bacholor Thesis (Hiroshima University)(in Japanese) (2023).

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Ⅲ-1 Accelerators and Instruments

BL2A

Calibration of the Soft X-ray Response Matrix of CMOS Detector Used inSounding Rocket Experiment FOXSI-3
N. Narukage 1, 2, R. Shimizu2, 3, Y. Sato1, 2 and S. Kashima3
1
National Astronomical Observatory of Japan (NAOJ), Mitaka, 181-8588, Tokyo, JapanThe Graduate University for Advanced Studies, SOKENDAI, Hayama, 240-0193, Kanagawa, Japan
3
Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA),
Sagamihara, 252-5210, Kanagawa, Japan2

The solar corona is full of dynamic phenomena suchas solar flares. The understandings of these phenomena
have been progressing step-by-step with the evolutionof the observation technology in EUV and X-rays fromthe space. But there are fundamental questions remainunanswered or haven’t even addressed so far. Ourscientific objective is to understand underlying physics
of the dynamic phenomena in the solar corona, coveringsome of the long-standing questions in solar physics
such as particle acceleration in flares and coronalheating. To achieve this objective, we identify theimaging spectroscopy (the observations with spatial,
temporal and energy resolutions) in the soft X-ray
range (from ~0.5 keV to ~10 keV) is a powerfulapproach for the detection and analysis of energetic
events [1]. This energy range contains many lines
emitted from below 1 MK to beyond 10 MK plasmas
plus continuum component that reflects the electron
temperature.
The soft X-ray imaging spectroscopy is realized withthe following method. We take images with a shortenough exposure to detect only single X-ray photon in
an isolated pixel area with a fine pixel Silicon detector.
So, we can measure the energy of the X-ray photons
one by one with spatial and temporal resolutions. When
we use a high-speed soft X-ray camera that can performthe continuous exposure with a rate of more thanseveral hundred times per second, we can count thephoton energy with a rate of several 10 photons / pixel /second. This high-speed exposure is enough to track
the time evolution of spectra generated by dynamic
phenomena in the solar corona, whose lifetimes areabout form several ten seconds to several minutes. For
the first imaging spectroscopic observation of the solar
corona in soft X-ray range, we launched a NASA’ssounding rocket (FOXSI-3) on September 7th, 2018 andsuccessfully obtained the unprecedented data [2] using
a high-speed X-ray camera [3] with a back-illuminated
CMOS detector [4].
Calibration of CMOS detectors is essential forscientific data analysis. For this purpose, a completely
monochromatic X-ray light source is needed. In
addition, the flux must be adjusted so that individual
X-ray photons can be isolated. Therefore, we havedeveloped a mirror-based reflective-type flux reduction
system [5].
In this time, using this system, the response of the
CMOS detector aboard the FOXSI-3 sounding rocket iscompletely calibrated in the energy range of 840 eV to4500 eV in 20 eV intervals (see Fig. 1).

Fig. 1. Measured response matrix of the FOXSI-3
CMOS detector from 840 eV to 4500 eV. In the colormaps, the horizontal axis shows the values of output
signals from the detector, when the detector detects the
monochromatic X-ray photons with the energy shownin the vertical axis. The colors indicate, in log scale,
how frequently each signal value is output. The topright panel shows the number of monochromatic X-ray
photons used to create this matrix.
[1] N. Narukage et al., White paper of the “soft X-ray
imaging spectroscopy”, arXiv:1706.04536 (2017).
[2] N. Narukage and S. Ishikawa, UVSOR Activity
Report 2018 46 (2018) 36.
[3] S. Ishikawa et al., Nucl. Instrum. Methods Phys.
Res., Sect. A 912 (2018) 191.
[4] N. Narukage et al., Nucl. Instrum. Methods Phys.
Res., Sect. A 950 (2020) 162974.
[5] N. Narukage, UVSOR Activity Report 2022, 49(2021) 42.

− 43 −BL2A

Development of a Transfer Vessel for NEXAFS Spectroscopy
E. Kobayashi 1 and A. Inoishi 2
1
2

Kyushu Synchrotron Light Research Center, 8-7 Yayoigaoka, Tosu, Saga 841-0005, Japan
Institute for Materials Chemistry and Engineering, Kyushu University 6-1 Kasuga-koen,
Kasuga-Shi 816-8580, Japan

Battery materials are contaminated with oxygen,carbon dioxide and water when exposed to theatmosphere. Therefore, we developed a sample transfer
vessel that can transport the sample to the analyzer
without exposing it to the atmosphere [1, 2].
Furthermore, in order to perform more precise analysis,
we developed a transfer vessel with a small ion pump[3]. In recent years, analysis of battery materials using
soft X-ray absorption spectroscopy has been performed.
However, it was diﬃcult to analyze across the beamline
without atmospheric exposure. This is because thesample holders are diﬀerent depending on the beamline.
Therefore, we have developed a transfer vessel that canmeasure the soft X-ray absorption spectrum across thebeamline without exposing the sample to theatmosphere, based on the apparatus that we havedeveloped.
The ZrO2 powders was attached to the transfer vessel
in a glove box under an argon atmosphere. NEXAFS
spectra of the ZrO2 powders using both total electron
yield (TEY) and partial fluorescence yield (PFY)
modes were measured at the beamline 2A of the
UVSOR in the Institute of Molecular Science. For
TEY, the drain current of the sample was measured. For
PFY, fluorescence X-rays were collected using anenergy dispersible silicon drift detector (SDD). All
experiments were performed at room temperature.
Fig. 1 shows a photograph of the developed transfer
vessel. The sample is fixed to the lower part of thevessel using carbon tape. The sample current ismeasured using the Bayonet Neill-Concelman (BNC)
connector on the upper part of the vessel. Fig. 2 shows
the Zr L-edge NEXAFS spectra of ZrO2 powder
obtained from TEY and PFY. The shape of the spectrum
measured in the TEY mode was almost the same as thatmeasured in the PFY mode. The TEY is surfacesensitive whereas the PFY is sensitive to the bulk. The
result indicates that the sample could be transported
without air contamination.

Fig. 1. Photograph of the transfer vessel.

Fig. 2. Zr L-edge NEXAFS spectra of ZrO2 powder
obtained from TEY and PFY.
[1] E. Kobayashi, J. Meikaku, T. Okajima, and H.
Setoyama, Japanese Patent No. 5234994.
[2] E. Kobayashi, J. Meikaku, H. Setoyama, T. Okajima,
J. Surf. Anal., 19 (2012) 2.
[3] E. Kobayashi, S. Tanaka, T. Okajima. J. Vac. Soc.
Jpn. 59 (2016) 192.

− 44 −

Ⅲ-1 Accelerators and Instruments

BL3U

Soft X-ray Transmission Measurements of Polymer Films for Soft X-ray
Absorption Spectroscopy of Liquids in Low-Energy Regions
M. Nagasaka1, 2, S. Fujikawa3, H. Takaya1,4 and Y. Uozumi1,2
1
Institute for Molecular Science, Okazaki 444-8585, JapanThe Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
3
International Institute for Carbon-Neutral Energy Research (WPI-I2CNER) and Research Center for Negative
Emissions Technologies, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
4
Department of Life Science, Faculty of Life & Environmental Sciences, Teikyo University of Science,
Main Buld #15-05, 2-2-1 Senjyusakuragi, Adachi-ku, Tokyo 120-0045, Japan
2

Soft X-ray absorption spectroscopy (XAS) is anelement-specific method to investigate electronic
structures of liquids. The soft X-ray regions below 2
keV have chemically and biologically absorption edges
such as K-edges of C, N, and O and L-edges of transition
metals such as Mn, Fe, Co, and Ni. Recently, we havedeveloped a transmission-type liquid cell, where aliquid layer is sandwiched between two Si3N4
membranes with the thickness of 100 nm, and measured
XAS spectra of several liquid samples in transmission
mode by adjusting the liquid thicknesses precisely from20 nm to 2000 nm [1].
The low-energy regions below 200 eV include
absorption edges for the investigation of chemical andbiological phenomena in solutions such as K-edges of
Li and B and L-edges of Si, P, S, and Cl. Since soft
X-ray transmission in the low-energy region isextremely lower than that in the high-energy region
above 200 eV [2], transmitted soft X-rays below 200
eV include many high-order X-rays. Recently, we haveused an argon gas window for removing high-order
X-rays by using the Ar L-edge (240 eV) [3] anddeveloped the soft X-ray detector that removes highorder X-rays [4]. However, the XAS measurements inthe low-energy regions are still diﬃcult since soft
X-rays are strongly absorbed by Si3N4 membranes with
the Si L-edges (100 eV). In this study, we havesynthesized polymer films that include no Si atoms
with the thickness of 100 nm and evaluated the soft
X-ray transmission of the polymer film.
The experiments were performed at BL3U. The
polymer film was settled under an ultrahigh vacuum
condition, which directly connected to the beamline.
The transmitted soft X-rays through the polymer film
were measured by using a photodiode detector.
Figure 1 shows the soft X-ray transmission of thepolymer film in the soft X-ray region from 50 eV to 560
eV. Since the polymer film includes the C=C and C=N
groups, the sharp absorption peaks such as the transition
from C 1s electrons to C=C π* orbitals at the C K-edge
and the transition from N 1s electrons to C=N π*orbitals at the N K-edge are observed. Note that the soft
X-ray beamline BL3U includes three monochromatic
gratings for covering wide photon energy regions. The

photon intensities are also maximized by adjusting theundulator gap. That is why several photon energy
regions are not continuous due to the diﬀerent gratings
and the orders of the undulator gap. Since the polymer
film includes no Si atoms, there is no peaks at the Si
L-edge. Soft X-ray transmission of the polymer filmshows a still high value below 200 eV, indicating thepresent polymer film is suitable to measure XAS ofliquids in the low-energy region.
In the present, we have developed an ultrathin liquidcell to reduce the optical pass length of Ar gas. We will
include the present polymer films to the ultrathin liquidcell for improving the soft X-ray transmission of liquidsamples in the low energy region below 200 eV.

Fig. 1. Soft X-ray transmission of the polymer film.
[1] M. Nagasaka and N. Kosugi, Chem. Lett. 50 (2021)
956.
[2] C. T. Chantler, J. Phys. Chem. Ref. Data 29 (2000)
597.
[3] M. Nagasaka, J. Synchrotron Rad. 27 (2020) 959.
[4] M. Nagasaka and H. Iwayama, Rev. Sci. Instrum.
91 (2020) 083103.

− 45 −

BL3B

Dissociation Channels of Molecules for a Use of Plasma Etching Processes
T. T. Nguyen1, K. Ishikawa1 and H. Iwayama2
1

2
Nagoya Univeersity Center for low-temperature plasma sciences, Nagoya 464-8601,
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

Plasma etching is indispensable for the fabrication ofsemiconductor devices. In recent years, there has been
an urgent need to develop etching gases that meet therequirements for manufacturing three-dimensional
devices and high aspect ratio structures. For the plasmaetching, hydrofluorocarbon molecules are uesd. Plasma
dissociates and ionizes gas molecules. The plasmarelated reactions are complicated significantly, howeverthese reactions of dissociated and ionized fragments ofmolecules should be controlled on the basis of scientificunderstanding. First, we predicted dissociation andionization channels of gas moledules using
computational chemistry. As the results, we calculated
precisely the excited state of perfluorocarbon, c-C4F8[1]. In order to improve the accuracy of the reaction
prediction,
experimental
verificationofphotodissociation is required.
In this study, experimental verification of dissociationof perfluorocarbons, which are not in the database forplasma-etching gases, mainly hydrofluorocarbon
molecules, has been performed with precision andaccuracy using beamlines owned by the Institute for
Molecular Science (IMS). Through this study, we will
pioneer the future development of the world’s best
plasma etching gas by combining coincidence
spectroscopy and computational chemistry.
This study conducted coincidence spectroscopy
experiments on photoionization and photodissociation
using vacuum ultraviolet light region from 40 nm to
400 nm from beamlines of BL3B in the IMS. This lightsource is the only facility in Japan.
In the etching process plasmas, abundances fordissociated ions are reported by C3F5+ > CF3+ > CF+ >C2F4+, which are diﬀerent C2F4+ > C3F5+ > CF+ > CF3+ inmass spectra taken at 70 eV electron energy. The
calculation results showed that a secondary process of
c-C4F8+ to C2F4 + C2F4+ disscociation route is a potential
barrier of 12.05 eV (Fig. 1, Table 1), which is wellcorresponded with the calculated energy barrier of 12.0
eV along the C2F4+ dissociation route [1]. The C3F5+ ion
production channel is the lowest energy barrier due tointramolecular rearrengement reaction, that is
c-C4F8+→C3F5+ + CF3 and additionally c-C4F8+ ions
C2F4+ channel is the second lowest energy barrier. The
other fragments such as C3F5+, CF3+, CF+, are producedbyintermolecularrearrangement
reactions.

Consequently, the ionization process of C3F5+ channel
is abundant due to the lowest potential barrier.

Fig. 1.
Typical mass spectral intensities byphotoionization of c-C4F8 measured vacuum ultraviolet
ranges from 10 to 30 eV.
Table 1. Ionization potential (IP) and appearance
potentials(AP)for c-C4F8.
p
( )
Ions
IP
AP

c-C4F8+c-C4F7+

Potential
Calc. [1]
11.5
15.1

C3F5+

12.0

C2F4+

12.4
12.0*

CF3+

12.5

CF2+

14.8

+

13.6

CF

(eV)
Exp.
11.55
15.45
12.1
11.85
12.35
12.05
14.4
16.6
17.9
18.4
17.1

References
This study
This study
Lifshitz[2]This study
Lifshitz[2]This study
Lifshitz[2]This study
This study
Lifshitz[2]This study* vertical ionization potential[1] T. Hayashi, et al. Jpn. J. Appl. Phys. 61 (2022)
106006.
[2] C. Lifshitz, et al. Int. J. Mass Spectrum Ion Phys. 10(1972) 25.

− 46 −

Ⅲ-1 Accelerators and Instruments

BL3B

Study of Luminescence Characteristics of Diamond Scintillator
for Dark Matter Search
A. Umemoto
Division of Physics, University of Tsukuba, Tennoudai, Tsukuba, Ibaraki, 305-8571, Japan

Direct detection of dark matter is one of the highest
priorities in astroparticle physics. The dark matter inMilky Way Galaxy can be detected via elastic scatteringfrom nuclei in a detector on the earth. For the direct
dark matter search, diamond is one of the promisingdetector. The highest Debye temperature among
crystals (2200 K) and optical centers due to defects andimpurities are unique physical properties of diamond,and they might make good performance of a diamondscintillating bolometer [1][2].
With the goal of developing a diamond scintillating
bolometer for dark matter search, we constructed anexperimental system to measure a photoluminescence
property of synthetic diamond at BL3B in UVSOR.
Usually, the measurements at BL3B are conducted by
the following setup: the excitation light is incident on asample surface at an angle of 45°, and fluorescence is
detected with a CCD placed at right angles to theexcitation light. But this measurement setup will notwork well for diamond due to the total internal reflection
because the refractive index of diamond (n = 2.42) ismuch larger comparing with that of air (also vacuum).
Therefore, a measurement system using a right angle
prism as shown in the schematic diagram of Fig.1 wasdesigned. The excitation deviated a light path by 90°by
entering one side of the prism will be made incident on
the diamond attached on the other side of the prism byvacuum grease. The system makes it possible for the
CCD to detect the photoluminescence of diamond
emitted in a direction perpendicular to the diamondsurface. We used a UV fused silica right angle prismwith length of 10 mm manufactured by Thorlabs, whichtransmits more than 90% of light with wavelengths
more than 185 nm.
Fig.2 shows a photoluminescence spectrum of adiamond excited by ultra violet light with wavelengthof 200 nm. The diamond is a commercially available
synthetic crystal with a size of 3 x 3 x 0.3 mm
manufactured by a method of high-pressure hightemperature. Nitrogen impurities of the diamond is lessthan 200 ppm. Although a peak due to the second-orderdiﬀraction of the excitation light was also observed, theshape of the spectrum detected in the wavelength of

500<λ<700 nm was consistent with our previous resultof X-ray radio luminescence spectrum. It wasdemonstrated that the measurement system is useful for
detecting a photoluminescence of diamond. In FY2023,
we plan to perform low-temperature measurementswith this setup to quantify the luminescence propertiesof diamond scintillators.

Fig. 1. A design of the experimental setup forphotoluminescence measurement of diamond.

Fig. 2. Photoluminescence spectrum of a commerciallyavailable HPHT diamond measured by using the system
shown as Fig.1. Ultra violet light with wavelength of
200 nm was used for photoluminescence excitation.
[1] T.L. Nam et al., Appl. Radiat. Isot. 40 (1989) 8.
[2] L. Canonica et al., J. Low. Temp. Phys, 189 (2020)
606.

− 47 −

BL4B

Current Photon Flux and Focus Size of BL4B
H. Iwayama 1, 2
1
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan2

Beamline BL4B has three holographically ruled
laminar profile plane gratings (G1: 800 lines/mm, G2:
267 lines/mm, G3: 100 lines/mm) and covers soft X-ray
regions ranging from 40 eV to 1000 eV. This soft x-ray
region includes K-edge energies of light elements such
as C, N, and O and L-edge energies of transition metals
such as Mn, Fe, and Co. Since an endstation of BL4B
is not fixed for specific equipment, users can bring intheir equipment and connect them to BL4B. The main
experiments at BL4B are X-ray magnetic circulardichroism (XMCD), angular resolved photoemission
spectroscopy (ARPES), and X-ray absorption finestructure (XAFS) measurements.
The BL4B uses synchrotron radiation from a bending
magnet, and its photon flux and focus size are weak andlarge compared to undulator beamlines. While BL4B isdiﬃcult to measure in tiny samples, it is suitable fororganic molecules, which are fragile against radiation
damage. Thus photon density is an important parameterfor estimating radiation damage on the sample.
This work measured photon flux and focus image at
the focus point. We use a photodiode and Ce:YAG
scintillator for photo flux and focus image
measurements.
Figure 1 shows photon flux curves for each grating.
Entrance and exit slits of the beamline are set to 50 μm.
The photon flux is almost the same as the previous one
measured in 2005, and a photon flux is higher than theprevious one for a high photon energy region of morethan 400 eV. In 2012, our facility improved the optics
of electron storage ring, such as bending magnets, andupgraded from UVSOR-II to UVSOR-III. Whileelectron trajectories in the storage ring were significantly
changed after the major update of UVSOR synchrotron,
the photon flux curves measured this time indicate thatbeamline optics were optimized well and the throughput
and photon flux of the beamline was maintained.
Figure 2 shows a photo of measurement equipment
for a focus image. The equipment comprises Ce:YAG
scintillator, ultra-long working distance lens, and
CMOS camera. The scintillator is in a vacuum chamber
and irradiated by soft X-ray beam of BL4B. The
irradiated scintillator emits ~ 550 nm fluorescence, andwe observed them by the ultra-long working distancelens and CMOS camera. This lens’s working distanceand optical magnification are 305 mm and 0.37 ~ 4.48,
respectively. The highest space resolution is 7 μm.
Figure 3 shows a typical focus image. Photon energy
and flux are 400 eV and 8×109 photons/s. An exposure

time is 30 seconds. This image exhibits a focus size ofφ ~ 500 μm.

Fig. 1. Photon flux curves for G1, G2 and G3.
Entrance and exit slits are set to 50 μm.

Fig. 2. Photo of focus image measurement equipment
at an endstation of BL4B.

Fig. 3. Focus image at the Ce:YAG scintillator. The
photon energy is 400 eV.

− 48 −

Ⅲ-1 Accelerators and Instruments

BL4B

Low Radiation Damage XAFS Measurements at BL4B
H. Iwayama1, 2
1
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan

2

Recent developments in synchrotron radiation andfocusing optics technologies yield highly brilliant lightsources. This high bright synchrotron radiation enables
us to measure tiny samples and perform nano-structure
analysis such as scanning transmission x-ray
microscope (STXM) and photoemission electron
microscope (PEEM). In addition, photon-hungry
experiments such as resonant inelastic x-ray scattering
benefit from the recent higher brightness of synchrotron
radiations.
However, the higher brightness causes severe
problems of radiation damage to the samples. In
particular, soft X-rays has weak penetration power, andonly a several-100 nm thickness of the sample almost
absorbs them. Thus radiation damage problem for soft
X-ray regions is much more severe than that for hard
X-ray regions. If a photon flux, focus size, and photon
energy are 1013 photons/s, 10 μm, and 300 eV, thecorresponding dose is estimated to be at 10 GGy/s forsamples mainly composed of carbon. Critical dose forchemical change are 80, 280, and 1230 MGy forpolymethyl methacrylate, fibrinogen, and polystyrene,
respectively [1]. It means that irradiation of suchbrilliant synchrotron radiation destroys soft mattersamples in a moment.
Low photon flux measurements are also important toavoid radiation damage on fragile samples such as soft
matter. In this case, signals of XAFS measurements are
weak in proportion to the photon flux. For good SN
ratio data, noise levels should be pretty small. A total
electron yield (TEY) measurement is one of the mostpopular X-ray absorption fine structure analysis
methods. In the TEY measurements, we measure
currents in the sample irradiated by soft X-rays. The
current means the total electrons ejected from thesample, corresponding to absorption cross sections.
Thus we measure the sample current for each photon
energy by using a pico-amperemeter. In this case, thenoise of signals mainly comes from electric noise. In
particular, noise from the ground level of theexperimental hall is critical.
In this work, we estimate radiation damages for
XAFS measurements and verify the lower limit ofphoton flux, which is enough to obtain XAFS spectrawith good SN ratios. Our TEY equipment at BL4B issimple. A sample is fixed on a sample holder of analuminum board in a vacuum chamber using carbon
tape. We connect a current output terminal of thevacuum chamber to a pico-amperemeter (Keythleyelectrometer 617) with a low-noise BNC cable. The
sample is FePO4 powders.

Figure 1 shows (a) sample currents and (b) the
histogram of our TEY equipment when no soft X-ray
irradiates the sample. The Full-width half maximum(FWHM) is 2 fA. In this measurement, we observe an
oﬀset of 6 fA. It may be because the ground voltages ofthe pico-amperemeter and sample holder are slightly
diﬀerent. When we use a standard BNC cable instead ofthe low-noise cable, the FHWM of noise levels becomes
2 fA.
Figure 2 shows TEY spectra of FePO4 powders at
diﬀerent photon fluxes. The resolution of photon
energies is set to E/ΔE of 2000, and it takes 8 minutes
to obtain one spectrum. When photon flux is more than
4×107 photons/sec, SN ratios are enough to find finestructure of XAFS spectra. However, at the photon fluxof 8×106 photons/sec, while we observe the prominent
peak at the photon energy of 710 eV, sample current
intensities are about 10 fA, and their fine structures
around 723 eV are drowned in noise. From this, a lower
limit of photon flux is around 4×107 photons/sec at the
Fe L edge, and the corresponding dose is only 20 kGy.
This work demonstrates that our TEY system enables
us to perform low radiation damage XAFS
measurements.

Fig. 1. Noise levels of our TEY equipment at BL4B.

Fig. 2. TEY spectra of FePO4 powders for various
photon fluxes.
[1] J. Wang et al., J. Electron Spectrosc. Relat. Phenom.
170 (2009) 25.

− 49 −

BL5B

Transmission Characteristics of an Optical Filter for UV Observations
A. Yamazaki1, K. Goda1, T. Matsumoto2, S. Teramoto2 and K. Yoshioka2
1

Department of Earth and Planetary Science, Graduate School of Science,
The University of Tokyo, Tokyo 113-0033, Japan2
Department of Complexity Science and Engineering, Graduate School of Frontier Sciences,
The University of Tokyo, Chiba 277-8561, JapanThe hydrogen absorption cell is a unique type of filter
that functions as an optical band-stop filter for hydrogen
Lyman-α. The Lyman-α is absorbed by hydrogencontained in the cell when thermally dissociated into
the atomic state. The shape of this cell is cylindrical(φ35 mm, L40 mm), and the windows on each side are
made of magnesium fluoride (MgF2) for UV lighttransmission. Therefore, the cell simply acts as an
MgF2 filter without hydrogen gas. Overall, the cell isknown for its narrow bandwidth, lightweight, small
size, and thus suited to mount on a small spacecraft. We
plan to use this filter in the ongoing Comet Interceptor
Mission, in which the filter is used to observe theatomic hydrogen coma of the target comet remotely.
However, there is a diﬃculty regarding this filter: thedegradation of MgF2 transmittance. The transmittanceof MgF2 drops over time as it alters by UV lightirradiation, and this filter is no exception. Since wehave been using this filter in past experiments, thecenter of the MgF2 window is more altered comparedto the edges. To better understand the characteristic, inthis experiment, we mainly focused on evaluating theposition dependence of the MgF2 transmittance and thechange in the transmittance after polishing the surface
with ethanol. The latter aims to retrieve the transmittancelost due to alteration. Since the experiments aim tounderstand the characteristics of the filter window, we
did not fill hydrogen gas in the cell and thus was not
functioning as a band-stop filter.
In the experiment, we measured the position
dependence of the filter transmittance. The cell was set
on a motorized stage, and the transmittance wasmeasured at multiple incident positions by moving it
vertically against the beam. Microchannel plates and a
resistive anode encoder were used for the detector. For
each measurement, a wavelength scan was performed
using the G3M5 grating system with the range of 110135 nm at an interval of 1 nm. Later, the samemeasurement was done after polishing the MgF2
surface with ethanol.
Figure 1 shows the transmittance of the cell filter.

The solid and dashed lines show the result before andafter polishing the surface with ethanol. The plots’colors describe the diﬀerent incident positions as shownin the upper right illustration. The area below 116 nm is
shaded since the data in this range has a low S/N ratio
due to the MgF2 cutoﬀ wavelength at 115 nm.
The result implies that the transmittance increases
from the center towards the edge, and also increases bypolishing the MgF2 surface with ethanol. However, theincrease in transmittance varies significantly among theincident positions. At the center of the cell, thetransmittance increases no more than a few percent, butaround the edges, it increases by ~20%. One possible
explanation is that polishing the surface is eﬀective forsurface dust and smears, but not for degradation caused
by intensive UV light irradiation. Since the center ofthe cell has suﬀered irradiation throughout the pastexperiments, the alteration is discernible. Polishing thecell surface proved eﬀective in increasing thetransmissions, but we could not fully retrieve those lost
due to UV-induced alteration.

Fig. 1. Transmission spectra of MgF2 windows on ahydrogen absorption cell.

− 50 −

Ⅲ-1 Accelerators and Instruments

BL5B

Evaluation of the Pressure Dependence of the Krypton Absorption Cell
M. Kuwabara 1, K. Kato1, K. Arakawa1 and M. Taguchi1
1

Department of Physics, College of Science, Rikkyo University, Tokyo 171-8501, Japan

In planetary upper atmospheres, hydrogen atoms
originating from hydrogen molecules in lower
atmospheres expand to an altitude equivalent to several
planetary radii. These hydrogen atoms resonantly
scatter the solar Lyman-alpha radiation (121.567 nm),forming planetary hydrogen coronae. Since thebrightness of the hydrogen coronae depends on thenumber density of hydrogen atoms, the spatial
structures can be obtained by imaging the coronae.
A hydrogen absorption cell is eﬃcient tool for remotesensing of the density and temperature distribution of
the exospheric hydrogen atoms. Additionally, thistechnique has advantages over other techniques interms of geometrical size, weight, and simplicity.
Therefore, this technique is expected to be eﬀectively
used for exploration using ultra-small spacecraft andother applications [1].
One of the drawbacks of the absorption cell techniqueis the diﬃculty of calibration. Since the absorption
linewidth of the hydrogen absorption cell is a few pm at
most, the calibration system must have high wavelengthstability. However, it is revealed that the measurement
wavelength of BL5B beam line drifts as the temperatureof the mirror changes, so it is necessary to know thecorrect wavelength for each measurement. This

problem can be overcome by placing a krypton
absorption cell in front of the hydrogen absorption cell.
This is because krypton has a strong absorption line at
123.584 nm, which is close to the Lyman-alpha line of
the hydrogen atom. By measuring the light transmitted
through both cells, the peak of the absorption of thehydrogen Lyman-alpha line can be determined.
In this experiment, we evaluate the pressure
dependence of the absorption line profile of the krypton
cell to establish a calibration method for the hydrogen
absorption cell. Figure 1 shows the result of theexperiment. The absorption line of krypton is 123.584
nm, but the measurement wavelengths of the calibration
system are oﬀ, and the peaks are seen a little beyond
124 nm. In addition, the positions of the peak vary ineach measurement. Regarding the pressure dependence,as the pressure of krypton gas increases, both the depth
and the width of absorption also increase. The result
will be used to determine the optimum pressure for the
krypton absorption cell needed for the BL5B calibration
system in the future.
[1] M. Kuwabara et al., Rev. Sci. Instrum. 89 (2018)023111.

Fig. 1. Pressure dependence of the krypton cell absorption.

− 51 −BL5B

XUV Polarization Measurement using Visible Fluorescencefrom Neon Atoms
T. Kaneyasu1,2, K. Hosaka3 and J. Adachi4,5
1
SAGA Light Source, Tosu 841-0005, Japan
Institute for Molecular Science, Okazaki 444-8585, Japan
3
National Institutes for Quantum Science and Technology, Takasaki 370-1292, Japan
4
Institute of Materials Structure Science, KEK, Tsukuba 305-0801, Japan
5
The Graduate University for Advanced Studies (SOKENDAI), Tsukuba 305-0801, Japan
2

Polarization is one of the most importantcharacteristics of synchrotron radiation. For accurate
measurements using the polarization properties ofsynchrotron radiation, it is essential to evaluate thepolarization state of light at a sample point. Fluorescencepolarimetry is a useful technique to determine thepolarization state of the extreme ultraviolet (XUV)
radiation. This method is based on the conversion of
XUV radiation to visible light on the atomic resonance[1,2]. The fluorescence preserves the polarization stateof the excitation light when it is observed along thelight propagation axis. Comparing with the opticalpolarimeters [3,4], this method has advantages in its
simple apparatus and easy operation. Up to the present,
however, this method has been only applied to helium
atoms [2,4,5], and the wavelength range is restricted toaround 50 nm. In this study, we show that neon atoms
can be used to measure the polarization state of XUVradiation at 60 nm wavelength.
The experiment was performed at the bending magnet
beamline BL5B. Figure 1 shows the experimental
layout of the present study. The wavelength of
monochromatized synchrotron radiation was set to 59.6
nm. Neon atoms were provided by an eﬀusive beam.
The XUV radiation resonantly excites the neon atom to
the 4d’[3/2]o1 state. This state decays to the 3p[1/2]o1
state with the emission of 511.4 nm fluorescencephoton. The fluorescence photons emitted parallel tothe light propagation axis (z-axis) were detected by aphotomultiplier tube equipped with a polarizer and a
bandpass filter. The fluorescence photon basicallypreserves the polarization state of the XUV radiation.
The only diﬀerence between them is that the polarization
angle of the fluorescence photon is expected to rotate
by 90 degrees with respect to the polarization angle ofthe incident XUV radiation.
Figure 2 shows the fluorescence intensity measured
as a function of the polarizer angle which is defined by
the angle of the polarization axis with respect to thehorizontal axis (x-axis). In accordance with the
expectation, the fluorescence intensity shows asinusoidal modulation reflecting the vertically linear
polarization of the fluorescence photon. Assuming an
elliptical polarization, the experimental data points are

fitted by a theoretical curve. The linear polarization
degree and polarization angle of XUV radiation areevaluated to be 0.67±0.02 and 10±2 degrees,
respectively. This is roughly in agreement with theresults obtained by helium atoms [5, 6], suggesting thecapability of fluorescence polarimeter using neon
atoms.

Fig. 1. Experimental setup. The visible fluorescencephoton emitted along the light propagation axis was
detected.

Fig. 2. Fluorescence intensity measured as a functionof the polarizer angle. The experimental data points are
fitted by a theoretical curve.
[1] V. Bobahev and O. S. Vasyutinkii, Rev. Sci. Isturm.
63 (1992) 1509.
[2] C. J. Latimer et al., J. Electron Spectroscopy Relat.
Phenom. 101-103 (1999) 875.
[3] D. Cubric et al., Meas. Sci. Technol. 10 (1999) 554.
[4] E. Allaria et al., Phys. Rev. X 4 (2014) 041040.
[5] T. Kaneyasu, K. Hosaka and J. Adachi, UVSOR
Activity Report 2020 49 (2021) 46.
[6] Y. Hiosaka, H. Iwayama and T. Kaneyasu, J.
Synchrotron Rad. 27 (2020) 675.

− 52 −

Ⅲ-1 Accelerators and Instruments

BL5B

A Position-sensitive Microchannel Plate Detector with Resistive AnodeS. Matoba1, S. Kanda1, H. Ohshita1, K. Hirata2, H. Iwayama3, 4 and T. Kaneyasu5
1Institute of Materials Structure Science, KEK, Tsukuba 305-0801, Japan
National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology,
1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
3
Editorial Board, UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan
5
SAGA Light Source, Tosu 841-0005, Japan2

A microchannel plate (MCP) is a lead glass detector
with a two-dimensional array of electron-multiplying
pores of about 10 μm in diameter. When charged
particles or short-wavelength photons collide with theinner wall of the pore, secondary electrons are generated
and amplified in the pore to be detected as electron
pulses. MCPs are used in a very wide range of fields
from basic research to industry because of their large
area, high spatial resolution, and high-speed detection
capability.
We are developing a system that enables easymeasurement of imaging techniques using quantum
beams regardless of the beam type and location, which
can be used for trial experiments prior to the use ofadvanced devices. The most common method of twodimensional detectors for MCP anodes is opticaldetection of emission from fluorescent anodes using a
CCD camera or the like. However, the diﬃculty of
inserting a detector in the middle of the beamline andthe upper limit of the frame rate of the camera limit theuse of this method for accelerator beamlines. Anothermajor method, the delay-line anode[1], requires a highspeed circuit that can detect time diﬀerences between
wires, making it expensive and diﬃcult to implementin small-scale experiments.
We are developing a position-sensitive detector using
resistive anodes as a two-dimensional detector forvarious particles such as neutrons, ultraviolet light,
muons, and ions. The advantages of this system are that
position detection can be easily performed by using a
4-channel waveform analyzer and that the resistive
anodes are only about 2 mm thick, so they can beassembled into a compact assembly. Resistive anodes
as two-dimensional detector elements have beendeveloped for a long time[2], but there is no simple
system that can be used by researchers who are notdetector experts, and we are developing one.
In this experiment, the “solid chamber” of BL5B was
removed and a pinhole, a four-quadrant slit, and a lightreducing filter made of aluminum foil and tungsten
mesh were installed to detect the incident position of

the MCP with a wavelength of 130 nm UV light ofapproximately 1 mm in diameter. The charge of theelectron pulses generated by the MCP, which has aneﬀective diameter of 40 mm and consists of two stages,
is dispersed and transferred to the electrodes at the four
corners of the resistive anode. The two-dimensional
position information is calculated from the current
flowing to each electrode as x/d = (I1 + I4) /I, y/d = (I1+ I2) /I (where d is the full width or height of one sideof the resistive anode and I = I1+I2+I3+I4). The current
flowing to each electrode was measured with a
4-channel amplifier, shaper and waveform analyzer.
Figure 1 shows an example of the measured light
positions. In this experiment, the measurement system
was verified and confirmed to be capable of soundposition detection. In the future, the position resolution
and detection eﬃciency distribution will be investigatedusing patterns, etc.

Fig. 1. Position reconstruction on the resistive anode.
[1] S. E. Sobottka and M. B. Williams, IEEE Trans.
Nucl. Sci., 35 (1988) 348.
[2] M. Lampton and R. F. Malina, Rev. Sci. Instrum.,47 (1976) 1360.

− 53 −

BL6U

Progress of Photoelectron Momentum Microscopy for Revealing Complex
and Detailed Electronic Structures of Materials
S. Suga 1, 2 and F. Matsui 3, 4
1

SANKEN, Osaka University, Osaka, 567-0047, Japan
2
PGI-6, Jülich Research Center, Germany
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan

The photoelectron momentum microscope (often
abbreviated as 2D-PMM) is installed already in 2020 at
BL6U of UVSOR in the form of single hemisphericaldeflection electron energy analyzer (HDA) behind the
PEEM type objective lens, which can easily be switchedbetween the real space to the momentum spacedetection mode. EB(x,y) or EB(kx,ky) constant energy
contour (CEC) can be simultaneously detected by a 2D
detector behind the focusing lens optics installed after
the exit of the HDA[1]. The detection eﬃciency of theEB(kx,ky) is very high in comparison with theconventional HDA detection due to the simultaneously
covered wide acceptance angle owing to the use of
PEEM, where the sample rotation is not necessary forEB(kx,ky) detection and excitation light focusing is notnecessary to probe micro-nano regions. Then very
reliable gigantic data set is obtained by this instrument
in rather short measuring time [2−4]. Temperature
down to 10 K can be measured.
Since the best quality sample surface region down to~10 μm can be selected by the proper sized field
aperture in the objective lens, high quality andreproducible data can be obtained by this instrument.
The beam focusing is not necessary in this system byusing the PEEM and several tens of nm resolution canbe realized without noticeable radiation damage.
Detailed behaviors of CECs of graphite are shown in
Fig.1 [3]. Resolutions are ΔE~40 meV and Δk~0.01
Å-1. Band dispersions along any kx-ky direction can be
immediately derived from the big data.
Since 2022 upgrading is progressing. In addition to
68° incidence of light from the surface normal direction, 0° incidence is soon available. HDA is upgraded to
2 HDAs to realize this configuration. 2D spin filter will
be installed within a few months to realize themultichannel figure of merit FoM~102. Then the spin
detection eﬃciency becomes 104 times higher than the
single channel spin detection and 102 times higher thanusing the W (tungsten) 2D spin filter.
Various additional upgrading of the SP-2D-PMM
system in UVSOR will be made in the next few years,
producing the world best heavy data on micro-nanoregions of exotic and/or functional materials supporting
the new device development.

Fig.1. CECs of graphite (0001) at various hν reproduced
from Ref.[3]. Thus EB(kx,ky,kz) as well as band
dispersions along any kx-ky directions can be easily
derived from gigantic data.
[1] S. Suga, A. Sekiyama, C. Tusche, Photoelectron
Spectroscopy, Springer, Springer Series of Surface
Science 72 (2021) 1−503.
[2] F. Matsui, S. Makita, H. Matsuda, T. Yano, E.
Nakamura, K. Tanaka, S. Suga, and S. Kera, Jpn. J.
Appl. Phys. 59 (2020) 067001.
[3] F. Matsui and S. Suga, Phys. Rev. B 105 (2022)
235126.
[4] F. Matsui, Y. Okano, H. Matsuda, T. Yano, E.
Nakamura, S. Kera and S. Suga, J. Phys. Soc. Jpn. 91(2022) 094703.

− 54 −

Ⅲ-1 Accelerators and Instruments

BL6B

Low-frequency Photocarrier Response in Semiconductors Based on
ns-visible-pump broadband-infrared-probe Spectroscopy
J. Nishida 1* and T. Kumagai 1
1

Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki 444-8585, Japan

Optical responses of photoinduced carriers in mid- to
far-infrared encode their scattering times as well as trap
and polaronic states, which are all directly relevant to
the mobility of the carriers. Yet, due to the spectrally
broad nature of such responses, the time-resolved studyof such photoinduced carriers is often diﬃcult andrequires advanced laser sources for ultrafast experiments[1]. While mid-infrared thermal light source with fastelectronics covers important subsets of the spectral
range and time resolution [2], the full characterizationof the low-frequency carrier response has remained
elusive.
An extremely broadband output of a synchrotron
provide unique opportunities to tackle such problems.
With the combination of broad spectrum extending
from mid- (~100 meV) to far-infrared (~ meV), as well
as a reasonable pulse duration of < 1 ns, it may bepossible to address the scattering and polaronicstabilization of photoinduced carriers on the nanosecond
time scale. Such an information is particularly relevant
to address the photoinduced carrier responses in lead
halide perovskites, where the interaction of carriers
with surrounding lattice has been intensely debated [3].
We thus attempted to combine the mid-infraredsynchrotron output at BL6B beam line as a probe pulse
with a 10s-ns visible laser as a pump pulse (Fig. 1a).
We mainly focused on the application in the singlebunch operation (~5 MHz) to enforce the relaxation ofphotoinduced carriers as much as possible. The TTL
output synchronized with the synchrotron laser is used
to trigger our commercial and duration-tunable (6 – 40ns) pulsed nanosecond laser. In collaboration with
Equipment Development Center, we developed timedelay generator and modulator to control the timing
between the visible and broadband mid-infrared pulse,
as well as to modulate the visible pump pulse intensity.
The modulation frequency is used for the lock-in
detection of the photoinduced change in the intensitythat transmits a sample. We implemented a Michelsoninterferometer for spectral measurements.
We first demonstrated the photo-modulation
absorption spectroscopy on the low-frequency responseof silicon. In Fig. 1b, we show an acquired interferogramin the ground-state (I), and its photoinduced change(ΔI). With the average time of ~30 min, we demonstrated
the sensitivity of ΔI/I ~ 10-3. The Fourier transform(Fig. 1c) shows the divergent response toward the lowfrequency side, consistent with the Drude-like behavior

expected for the photo-carriers in silicon.
We then attempted to extend the approach toperovskite quantum dots dispersed in solution. While
we observed a photoinduced change in the transmitted
intensity, the response was strongly dependent on themodulation frequency (Fig. 1d), likely pointing to athermal eﬀect. Such a thermal contribution can bealleviated by modulating the pump pulse rapidly at 100
kHz. We scanned the pump-probe delay to identify any
relaxation processes related to the photoinduced
carriers, but so far could not identify any such responses(Fig. 1d, inset; 5 min average each point).
To observe photoinduced carriers in a broad range ofsemiconductor materials, we estimate another order ofmagnitude improvement is necessary for the signal-tonoise ratio. We confirmed that the current signal-tonoise level is limited by the HgCdTe detector,
potentially due to the large element size. With the
optimization of the electronics, we may attain enoughsensitivity to be combined with the time resolution andspectral range that we demonstrated.

Fig. 1. (a) Timing scheme, (b) photo-modulated
interferogram and (c) spectrum on silicon, (d)modulation-frequency dependence of photo-induced
modulation.
[1] T. T. Yeh et al., Sci. Rep. 7 (2017) 1.
[2] K. Furuhashi et al., J. Phys. Chem. C 117 (2013)
19101.
[3] K. Munson T. et al., Chem, 4 (2018) 2826.

− 55 −

BL7B

Study on the Reflective Properties of Black Coatings Used in UV
Observation Equipment.
T. Matsumoto2, K. Goda1, A. Yamazaki1, K. Inoue1, S. Liu2 and K. Yoshioka2
1

Department of Earth and Planetary Science, Graduate School of Science,
The University of Tokyo, Tokyo 113-0033, Japan2
Department of Complexity Science and Engineering, Graduate School of Frontier Sciences,
The University of Tokyo, Chiba 277-8561, JapanThe emission angle dependence of scattered lightintensity (Experiment 1) and reflectance (Experiment2) were measured for three diﬀerent, black-coatedaluminum plates (Samples A, B, and C) and a mirror.
The reflectance of the samples was determined basedon their relative reflectance to the mirror. This
experiment aimed to optimize the black coating to be
applied to the optics of the hydrogen imager (HI) on
board the Comet Interceptor (CI) mission to be launchedin 2029. To do this, we quantitatively determine theblack coating that minimizes stray light caused byreflections inside the equipment. These measurements
are also crucial for the quantitative estimation of the
expected performance of CI/HI.
The setup for both Experiment 1 and Experiment 2
was the same. Samples A, B, and C and a mirror were
mounted on the inner rotating stage, while the detector
was mounted on the outer rotating stage (Fig. 1). The
detector used was a photodiode with an eﬀective areaof 10 mm × 10 mm. The slit width was adjusted toprevent saturation of the measured values at each
incident angle. A G3 diﬀraction grating was used.
The following g12 measurements were performed.
p

4 targets3 incident angles
×(A, B, C, Mirror)(30°, 45°, 60°)
In Experiment 1, the wavelength was set to 121.4 nm.
The detector was positioned with the direction of theincoming beam as 0° and rightward as positive. Anglescans were performed from 45° to 180° with an intervalof about 13.5°, followed by angle scans near the peakwith an interval of about 2°. In Experiment 2, thedetector was fixed, and wavelength scans were
performed from 112 nm to 133 nm with an interval of 1
nm without summing.
Experiments 1 and 2 are summarized below with
their results (Fig. 2 and Fig. 3.).
The results found that, at any incident angle, thereflectance was A, B, and C from the lowest to thehighest, with Sample A being the most optimal.
However, the reflectance of Samples A and B was
negative only at 45° incident angle, which might havebeen due to the dark noise and the positional accuracyof the detector. Further experiments are needed toconfirm reproducibility and evaluate the consistency of
the incident angle dependence of reflectance withtheoretical values.

Fig.1. The setup of the measurements.

Fig. 2. Experiment 1: The emission angle dependenceof the scattered light intensity

Fig. 3. Experiment 2: Reflectance− 56 −

Ⅲ-1 Accelerators and Instruments

BL7B

Complex Refractive Index Measurement by Reflectance Spectra in Diﬀerent
Polarization Configurations (II)K. Shinkai1, K. Fukui1, K. Yamamoto1 and T. Saito2
1
Department of Electrical and Electronics Engineering, University of Fukui, Fukui 910-8507, Japan
Department of Electrical and Electronic Engineering, Tohoku Institute of Technology, Sendai 982-8577, Japan2

configuration can be easily changed with the system.
These features make the PS method suitable for thissystem. The following are the intermediate results ofcomplex refractive index measurements of fused silica
glass substrate using this PS method.
Figure 1 shows reflectance spectra both in p- ands-polarization configurations. The dots are reference
points which represent the reflectance calculated fromthe complex refractive index obtained from the ES
mode, and the lines are reflection spectra of the OR
mode in p- and s- polarization configurations corrected
for the reference points. Note that the eﬀect of surface
roughness is taken into account in the optical model ofthe ES mode and reflectance calculations. The
dispersion after the band edge is well shown by thecontinuous spectrum.
0.5㻌㻾㻜㼻㻔㻻㻾㻌㼙㼛㼐㼑㻕㻌㻾㻥㻜㼻㻔㻻㻾㻌㼙㼛㼐㼑㻕㻌㻾㻜㼻㻔㻿㻱㻌㼙㼛㼐㼑㻕㻌㻾㻥㻜㼻㻔㻿㻱㻌㼙㼛㼐㼑㻕

0.4

ReflectanceBased on the basic design of the instrument by agroup at AIST [1], a combined refractive index
spectrum measurement system (CRIMS-VUV) [2] hasbeen developed specifically for BL7B, which cancontinuously measure from the visible region (VIS) at
2 eV to the vacuum ultraviolet (VUV) region at 20 eV.
CRIMS-VUV is composed of two measurement modes(spectroscopic ellipsometry measurement (SE) modeand reflection spectrum measurement (OR) mode),both of which can be performed in the sameenvironment.
SE mode has the advantage of measuring the complex
refractive index with high accuracy. However, thismode has the disadvantage that, due to its measurement
principle, it takes time to measure at each measurement
point (photon energy), making it diﬃcult to measure acontinuous spectrum. In this respect, OR mode issuitable for measuring continuous spectrum. The wellknown Kramers - Kronig analysis (KKA) method isused to determine the complex refractive index
spectrum from the reflectance spectrum. However, as
mentioned our previous work [2], KKA method isuseful, for example, for obtaining qualitative complex
refractive index spectrum for limited photon energy
region around the absorption edge, but is not well suitedfor obtaining quantitative complex refractive index
spectrum over a wide photon energy region. Therefore,
we decided to use the method for determining thecomplex refractive index from the reflectance in p- ands-polarization configurations (PS method) as a methodfor determining the complex refractive index from thereflectance for each photon energy. This method
requires the linear polarization of the incident light(Stokes parameter S1), which can be measured from theSE mode of the system. The S1 can be measured fromthe SE mode of the system, and the polarization

0.3
0.2
0.1
0.0

0

2

4

6

8

10 12 14 16 18 20

Photon Energy(eV)Fig. 1. Reflectance spectra in p- and s-polarization
configurations of fused quartz glass[1] T. Saito, M. Yuri and H. Onuki, Rev. Sci. Instrum.
66 (1995) 1570.
[2] M. Horiba et al., UVSOR Activity Report 2021 49(2022) 49.

− 57 −

Others

Performance of the Refreshable Large Crystal Nuclear Emulsion
for the NINJA Experiment
T. Fukuda 1, 2, H. Kobayashi2, Y. Hirobe2, Y. Morimoto2 and M. Nakamura1,3
1

F-lab., Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
2
Institute for Advanced Research, Nagoya University, Nagoya 464-8601, Japan
3
Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8601, Japan

In neutrino oscillation studies, it is important todetect short-range hadrons in the energy range of about
1 GeV in order to understand neutrino-nucleus
interactions. The Emulsion Cloud Chamber (ECC) is asandwich structure consisting of a special photographic
film nuclear emulsion film with sensitivity to minimum
ionizing particles, with a thickness of several hundred
microns (composed of two sensitive emulsion gel
layers each tens of microns thick and plastic baselayer), and a thin target material with a thickness ofseveral hundred microns to several millimeters, stacked
alternately. The NINJA experiment, which uses ECC as
the main detector, has been publishing measurement
data on low-energy hadrons for neutrino-iron andneutrino-water interactions since 2014, while expanding
the scale of the experiment.
This autumn to winter, we plan to conduct a largescale statistical experiment on neutrino-H, O, C, and Fe
nuclear interactions using about 250 square meters of
nuclear emulsion films. The tracks on the nuclear
emulsion films are automatically scanned by the track
selecting device HTS, but 250 square meters is twice
the amount of the previous experimental run that tookapproximately 20 months for track scanning, and weare developing the track selecting device HTS2, which
has five times the scanning speed of HTS. With the
expansion of the field of view, the pixel size of HTS2
has been increased, and it is necessary to increase thesize of the developed silver grains compared to theconventional nuclear emulsion.
We have created a nuclear emulsion with AgBrI
crystal size of 320 nm, which is larger than theconventional 240 nm, and added a group of chemicals
that have a proven eﬀect in suppressing latent image
fading and fogging. After irradiating the emulsion films
with electron beams using UVSOR, we performed arefresh process to eliminate unwanted tracks byexposing it to high temperature and humidity conditions(30℃, 95%RH). We have newly discovered that therefresh which removes unwanted tracks is insuﬃcient(Fig. 1.). The left image of Fig. 1. has a grain density of
53.5±1.5 grains/100 μm and has not undergone arefresh process. The image on the right of Fig. 1. hasundergone a refresh process with a grain density of
29.8±1.7, but the disappearance of tracks due to therefresh process is insuﬃcient.
Based on our experience in the OPERA experiment,
we conducted experiments to determine the appropriate

amount of 5-methylbenzotriazole (5-MBT, Fig. 2.),
which promotes refreshment by oxidizing latent image
nuclei in high humidity conditions. The results ofcomparing the GD of emulsion film samples withvarying amounts of 5-MBT added, using UVSOR to
apply an electron beam and comparing with and without
refresh processing, are shown in Fig. 3. The initial
sensitivity decreased depending on the amount of
5-MBT added to the emulsion. However, when 5-MBT
was added at 1.0×10-3 or more moles per mole of silverin the emulsion, the refresh eﬀect was enhanced. A
suitable amount of balance between the refresh eﬀect
and initial sensitivity was found through this addition.

Fig. 1. Microscopic images of large crystal emulsion
films. (left) unrefreshed film. (right) refreshed film.

Fig. 2. The chemical formula of 5-MBT.

Fig. 3. GD of electron beam tracks. The solid anddashed lines show the data of unrefreshed films andrefreshed films, respectively.

− 58 −

Ⅲ-1 Accelerators and Instruments

Accelerators

Lattice Design of the UVSOR-IV Storage Ring
E. Salehi1, Y. Taira1, M. Fujimoto1,3 and M. Katoh1,2
1
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-hiroshima 739-0046, Japan
3
NUSR, Nagoya University, Nagoya, Japan

2

In this study, we have designed a new lattice for
UVSOR storage ring to provide diﬀraction-limited
light in the vacuum ultraviolet range which requires asmall emittance at least a few nm. UVSOR is a low
energy synchrotron light source. After some major
upgrades [1-4], it is now called UVSOR-III, which has
a moderately small emittance of about 17 nm andprovide vacuum ultraviolet light of high brightness.
In order to provide diﬀraction-limited light, at thefirst step, we have analyzed the present magnetic latticeof UVSOR based on tie diagram to explore thepossibility to get a lower emittance with some minorchanges in the configuration of magnets. We havefound a few optics which has smaller emittance around
10 nm than the present value [5]. To reach the low
emittance around a few nm, we have designed a new
storage ring of 1 GeV electron energy, which is higher
than the present value, 750 MeV. The magnetic lattice
is based on a compact double bend achromat cell. This
cell consists of two bending magnets and four focusing
magnets, all of which are of combined function
magnets. In this lattice two sextupole families arelocated in between two combined dipoles for thechromaticity correction and two harmonic sextupolefamilies are also employed to correct the high ordergeometric aberrations. The circumference is 82.5 m.
This lattice has twelve DBA cells with six long straightsections about 4 m and six short straight sections
around 1.5 m long. Among 12 straight sections, twosections will be used for the injection and RF cavity,
and ten sections will be used for insertion devices.
These lengths are same as those of UVSOR-III. This
may enable us to use the undulators at UVSOR_III in
the new ring. The undulators can radiate nearlydiﬀraction-limited light in VUV.
A tune survey was performed to optimize the magnet
arrangement and the working point by ELEGANT [6].
We found an optic with a small natural emittancearound 4.2 nm in the achromatic condition, whichbecomes lower in the non-achromatic condition.
Occupying three short straight sections with 2T
multipole wigglers in symmetry can reduce theemittance to 3.6 nm-rad. Moreover, these wigglers
provide intense tender X-rays. Figure 1 shows (left) the
lattice functions in the achromatic condition and (right)
the dynamic aperture for on- and oﬀ energy particles atthe straight section after optimizing the strengths of theharmonic sextupoles.
Intra-beam and Touschek scattering which dominate
the lifetime in low emittance storage rings, particularlyof low energy has been studied. Figure 2 shows that
IBS eﬀect increases the Touschek lifetime, while theemittance is increased. One possible technique todecrease the IBS eﬀect is lengthening the bunches byusing harmonic cavity which is routinely used at
UVSOR-III. Our simulation shows that the increasingof the bunch length by 80 mm can reduce IBS eﬀect on
the emittance to an acceptable level with to ߳଴ = 4.3 ݊݉[7].

Fig. 1. (Left)Lattice function of 1 GeV storage ring
whit a small emittance of 4.2 nm for UVSOR-IV, (right)
dynamic aperture of optic for diﬀerent energy deviation.

Fig. 2. IBS eﬀect on Touschek lifetime (top) andlongitudinal emittance (bottom) versus bunch charge.
[1] M. Katoh, K. Hayashi, et al., Nucl. Instr. Meth. A
467 (2001) 68.
[2] M. Katoh, M. Hosaka, et al., AIP Conf. Proc. 705(2004) 49[3] M. Adachi, H. Zen, et al., J. Phys. Conf. Ser. 425(2013) 042013.
[4] M. Katoh, M. Adachi, et al., AIP Conf. Proc. 1234
(2010) 531.
[5] E. Salehi and M. Katoh, in Proc. IPAC’21,
Campinas, Brazil, May 2021, 3970.
[6] M. Borland, APS LS-287 (2000). https://www.aps.
anl.gov/Accelerator-Operations-Physics/Software[7] E. Salehi, Y. Taira, et al., J. Phys. Conf. Ser. 2420
(2023) 012062.

− 59 −UVSOR User 3

რMaterial SciencesⅢ-2 Material Sciences

BL4U

Observation of Charge Separation Reaction in a Ti-Mn Electrolyte forRedox Flow Batteries by STXM
E. Hosono1,2,3, D. Asakura1,2,3, A. Ohira1,2, H. Yuzawa4 and T. Ohigashi4,51

Global Zero Emission Research Center, National Institute of Advanced Industrial Science (AIST),
Tsukuba, Ibaraki 305-8569, Japan
2
Research Institute for Energy Conservation, AIST, Tsukuba, Ibaraki 305-8565, Japan
3
AIST-UTokyo Advanced Operando Measurement Technology Open Innovation Laboratory (Operando-OIL),
Kashiwa, Chiba 277-8565, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan

Redox flow battery (RFB) is one of the candidates oflarge-scale energy storage device to utilize renewableenergy. RFBs use the redox reaction of electrolytes [1],which is diﬀerent from lithium-ion batteries using theredox reaction of the solid-state electrodes. To enhance
the performances of RFBs such as cyclability, chargedischarge capacity, and cost, understanding the redox
reaction is of particular importance. Electronicstructure analysis by synchrotron X-ray spectroscopy isessential to reveal the redox reaction.
In this study we focus on Ti-Mn RFB which involves
sulfuric acid aqueous solution electrolyte with Ti and
Mn ions [2]. The same Ti-Mn electrolyte is used forboth positive and negative electrodes. The redox
reaction has been thought to be
Mn2+ ⇔ Mn3+ + e- (1)in the Ti-Mn electrolyte of the positive electrode and(TiO)2+ + 2H+ + e- ⇔ Ti3+ + H2O (2)in the Ti-Mn electrolyte of the negative electrode [2].
Besides, it has been reported that the Mn3+ ions in the
charged electrolyte of the positive electrode (Eq. (1))
exhibits charge separation reaction as
2Mn3+ → Mn2+ + Mn4+ (3)during the charge process [2]. Moreover, the Mn4+ ionsare changed to MnO2 which precipitates in theelectrolyte of the positive electrode.
Mn4+ + 2H2O → MnO2 + 4H+ (4)This reaction is less reversible that is problematic forthe cyclability. To further understand those reactions in
Ti-Mn RFB, we demonstrate STXM measurements ofthe electrolytes [3]. The high spatial resolution of
STXM is helpful to clarify the formation of precipitation.
To conduct soft X-ray spectroscopic measurementsof liquid samples, we have developed a special cell asshown in Fig. 1 [3]. The Si3N4 thin-film window (100nm) and UV curable resin bond separate liquid sample
from the vacuum. A Ti-Mn electrolyte of the positiveelectrode was investigated by STXM at BL4U of
UVSOR. The electrolyte had been charged up to 50 %of state of charge. The spatial resolution was around
100 nm.
Figure 2(a) shows the STXM image at the Mn L3edge. The bright area corresponds to a precipitate

whose size is approximately 4 μm × 4 μm. The Mn L3edge absorption spectrum of the white area (I) shown in
Fig. 2(b) is mostly attributed to Mn4+ state as comparedwith spectra of reference materials [4]. The surroundingarea in Fig. 2(a) corresponds to the solution whose
spectrum (area (II)) is attributed to Mn2+ state (Fig.
2(b)). Therefore, the charge separation reaction of Eq.
(3) was successfully confirmed by STXM. Similar
STXM experiments of diﬀerent electrolytes will be
performed to obtain strategies to suppress the formationof precipitations.

Fig. 1. A schematic image of the cell for the STXM
measurements [3].

Fig. 2. (a) Mn L3-edge STXM image and (b) spectra of
selected area in the charged Ti-Mn electrolyte of thepositive electrode [3].
[1] For example, T. Shigematsu, Curr. Opin.
Electrochem. 18 (2019) 55.
[2] Y. R. Dong et al., ECS Trans. 69 (2015) 59.
[3] D. Asakura et al., Chem. Asian J. 18 (2023)
e202201047.
[4] For example, R. Qiao et al., Nano Energy 16 (2015)
186.

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BL7U

Temperature-dependent Electronic Band Structure ofOrganic Molecular Semiconductor
K. Fukutani 1, 2, F. Nishino2, P. I. Jaseela2, D. Okaue3, K. Fukui1,3, S. Makita1,
K. Tanaka1,2 and S. Kera1,2
1

Institute for Molecular Science, Okazaki 444-8585, JapanThe Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
3
Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan2

The organic molecular semiconductors are among
the very promising materials in shaping the future of
our electronic device applications in various aspects,
including their physical flexibility, low cost of
fabrication, high biodegradability in the environment,
and the abundance of the constituent elements (mostly
carbon and hydrogen) that are, in principle, inexhaustive.
In fact, the organic molecular semiconductor crystals
already play indispensable roles in our industry, and thecontinuing extensive researches have been ceaselessly
improving their performances.
However, despite the success of organic molecular
semiconductor devices, the knowledge of theirelectronic structure, one of the most fundamentalbuilding blocks for understanding and controlling theirproperties, is far from complete. Among such organic
molecular semiconductors, single crystalline rubrene(C42H28) is known to exhibit exceptionally high carrier
mobility (40 cm2/Vs [1]) and is considered one of themost promising organic semiconductor materials forthe next-generation electronics.
In this regard, we have been extensively investigating
the electronic band structure of rubrene for the purposesof not only elucidating their band structures, but also
for understanding the vibrational eﬀects, arising fromthe intra-molecular and inter-molecular (phonon)
degrees of freedom.
It is well known that many organic semiconductors
exhibit a dual nature in their electronic transport
properties, namely the (coherent) band transport and(polaronic) hopping transport, assisted by the electronic
coupling to the aforementioned vibrations. Rubrene
indeed falls into this category and its transport
properties are believed to originate from the ‘mixture’of both the band and the hopping transports. Since therespective contributions from each mechanism are
believed to depend on temperature, it is clear that thedirect experimental elucidations of the temperaturedependent band structure are essential for the fullunderstanding of the origin of carrier transport inorganic semiconductors.
However, there are very limited number of suchdirect measurements as with angle-resolved
photoemission spectroscopy (ARPES) [2], most likely
due to the numerous experimental diﬃculties, including
the fabrication of large single crystals, removing of thesample charge-up eﬀects and molecular damages
caused by light irradiations.

In our experiments, we have successfully overcome
these obstacles by utilizing BL7U at UVSOR andrevealed the high-resolution temperature-dependent
band structure of rubrene by ARPES. Figure 1 shows
the band structure of rubrene observed at T = 300, 180,
and 80 K along the π-stacking (Γ-Y) direction. Our dataclearly shows the change in the band dispersion width
as the temperature decreases. These data points towards
the discernable change in the carrier eﬀective masses,
which play an important role in the determining thecarrier mobilities. Furthermore, the band dispersion
width appears to be ‘locked’ above T ~ 200 K, which is
the temperature at which the structural anomaly [3] isobserved. Our researches with these experimental
results are expected to provide a key insight into thetransport mechanisms of organic semiconductors.

Fig. 1. Temperature-dependent ARPES data (second
derivative plots) obtained along the Γ-Y direction at (a)T = 300 K, (b) 180 K and (c) 80 K. (d) shows the band
dispersion widths as a function of temperature extracted
from our measurements.
[1] J. Takeya et al., Appl. Phys. Lett. 90 (2007) 102120.
[2] F. Bussolotti et al., Nat. Commun. 8 (2017) 173.
[3] A. van der Lee et al., J. Phys. Chem. Lett. 13 (2022)
406 .

− 64 −

Ⅲ-2 Material Sciences

BL1U

Gamma-induced Positron Annihilation Lifetime Spectroscopy of
β-SiAlON:Eu Phosphor
M. Kitaura1, S. Watanabe2, H. Masai3, Y. Taira4,5, K. Takahashi6, T. Takeda6, N. Hirosaki6,
M. Tansho7, K. Deguchi7, S. Ohki7 and A. Ohnishi1
1

Faculty of Science, Yamagata University, Yamagata 990-8560, Japan
Institute of Innovative Research, Tokyo Institute of Technology, Tokyo 152-8550, Japan3
Department of Materials and Chemistry, National Institute of Advanced Industrial Science and Technology,
Ikeda 563-8577, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
School of Physical Sciences, The Graduate University for Advanced Studies, Okazaki 444-8585, Japan
6
Research Center for Functional Materials, National Institute for Materials Science, Tsukuba,
Ibaraki 305-0044, Japan
7
High field NMR group, National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan2

Eu-doped β-SiAlON (Si6-zAlzOzN8-z; 0 ≤ z ≤ 4.2) iswell-known to be a green-emitting phosphor with highbrightness, narrow line width, and excellent resistanceto thermal quenching [1]. These features areindispensable for the development of next-generation
phosphors to fabricate advanced wide gamut
backlighting device. For this purpose, it is important toinvestigate the nature of lattice imperfections such asvacancies, interstitials, and unexpected impurities,
because they aﬀect adversely as so-called “killer” or“trap” responsible for luminescence quenching andafterglow.
Positron annihilation lifetime spectroscopy (PALS)
is a unique experimental method that can probevacancy-type defects with negative charge. In thepresent study, we investigated such vacancy-type
defects in β-SiAlON:Eu phosphors by gamma-ray
induced PALS (GiPALS) experiment [2]. GiPALS
experiment was performed at the BL1U of UVSOR
synchrotron facility. Positron annihilation lifetimes andrelative intensities were analyzed using the software
LT10 [3]. Positron annihilation lifetimes at the bulk anddefect states were calculated by two-component
density-functional-theory (TCDFT) calculations [4,5].
Figure 1 shows the GiPALS spectrum of aβ-SiAlON:Eu phosphor. The composition was
Si5.97Al0.03O0.03N7.97Eu0.01. The data were obtained atroom temperature. The GiPALS spectrum reproduced
three exponential decay components indicated bybroken lines. The first and second component withshort and middle lifetime are attributed to the positronannihilation at the bulk and defect states in β-SiAlON,
respectively. The third component with long lifetime
originates in the formation of positroniums, which may
arise from amorphous layer covering phosphor particles[6]. The relative intensity of the third component was
negligibly small compared to other two. To estimate
bulk lifetimes using experimental lifetimes and relative
intensities, we adopted two-state trapping model, where
the long lifetime component was not considered. The
experimental bulk lifetime was estimated to be 265±18

ps. This value agreed with the bulk lifetime (= 271 ps)
calculated for the relaxed lattice of a β-SiAlON(Si95Al1O1N127). This fact indicates the validation of ourexperiment and calculation. On the other hand, thelifetime of the middle lifetime component was not
reproduced by DFT calculations for monovacancies atsilicon and nitrogen sites. We suppose that the second
component originates in defect complexes of multiple
vacancies. The origin of the second component is now
in investigation.

Fig. 1. (Upper) GiPALS spectrum of a β-SiALON:Eu
phosphor. (Lower) Residual between the results ofexperiment and curve fit analysis.
[1] X. Zhang et al. Chem. Mater. 29 (2017) 6781.
[2] Y. Taira et al., Rev. Sci. Instrum. 84 (2013) 053305.
[3] D. Giebal and J. Kansy, Phys. Procedia 35 (2012)
122.
[4] P. Giannozzi et al. J. Phys.: Condens. Matter 21(2009) 395502.
[5] X. Gonze et al., Comput. Phys. Commum. 248(2020) 107042.
[6] N. Hirosaki et al., Appl. Phys. Lett. 86 (2005)
211905.

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BL1U

In-situ Measurement of Defects Dynamics in Stress Applied Bulk Iron by
Means of Gamma Ray Induced Positron Annihilation Spectroscopy
F. Hori 1, S. Araki1, S. Hirayama1 and Y. Taira2
Dept. of Quantum and Radiation Eng., Osaka Metropolitan University, Sakai, Osaka 599-8570, Japan
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

hydrogen introduced sample slightly higher than that ofpure Fe. This indicates the formation of vacancy
clusters, such as di-vacancy, and the presence ofhydrogen may facilitate the aggregation of vacancies.
However, this is considered that the τ2 slightly decreases
taking long time afterwards indicates that these initiallyformed di-vacancies dissociate. Also, it found that therelative intensity I2 corresponds to the defectconcentration of τ2 component, and the concentration
change after stress addition also shows a slight decrease
with relaxation time.
㻥㻜㻲㼑㻲㼑 㻨㻙 㻴㻲㼑㻔㼑㻙 㼕㼞㼞㼍㼐㻚㻕 㻨㻙 㻴㻯㼔㼍㼚㼓㼑 㼕㼚 㼟㼠㼞㼑㼟㼟㻘䃢㻔㻹㻼㼍㻕㻵㼚㼕㼠㼕㼍㼘 㼍㼜㼜㼘㼕㼑㼐 㼟㼠㼞㼑㼟㼟 㻦 㻤㻤 㻹㻼㼍
㻤㻡

㻤㻜

㻣㻡

㻣㻜

㻢㻡

㻜

㻝

㻞

㻟

㻠

㻡

㻢

㻣

㼀㼕㼙㼑㻘 㼠 㻔㼔㻕

Fig. 1. Stress change after initial stress applied.
㻡㻜

㻠㻝㻜

㻟㻜
㻟㻢㻜

㻟㻝㻜

㻵㼚㼠㼑㼚㼟㼕㼠㼥㻘 㻵㻞 㻔㻑㻕

The behavior of hydrogen atoms is attracting
attention in a wide range of research fields such as
high-strength structural materials and hydrogen storage
materials. In such materials, hydrogen atom diﬀuses
and has various interaction with defects, consequently
it makes serious characteristic change. In particular, inthe corrosion of metallic materials, it is known that thepresence or absence of lattice defects in the materialaﬀects mechanical and physical properties of materials.
On the point of view, positron annihilation techniques
are useful to detect and estimate the behavior of
vacancy type micro defects in materials. However, inorder to investigate the dynamics of the internal defectbehavior without destructing materials, more thanmega electron volts positron is needed. Recently, thedevelopment of high-energy Gamma-ray induced
positron spectroscopy (GiPS) has developed at somephoton factories. Especially, direct incidence of highenergy gamma rays with the energy more than 1.022
MeV into the target material produces positrons in it
and annihilated there. High-energy gamma rays fromlaser Compton scattering at synchrotron radiation
facilities enables positron experiments to detect defects
in bulk materials without sample destruction. In thisstudy, in-situ positron annihilation lifetime measurement
while applying stress to a bulk specimen have performedon the beam line BL1U at UVSOR.
Positron lifetime measurement has performed onpure iron bulk specimens processed into JIS standard
tensile specimens, irradiated with 8 MeV electron, andirradiated with electron and then hydrogen introduced.
Electron irradiation have done by linear accelerator at
Kyoto University Reactor Research. Hydrogen was
introduced into the sample by immersion in a 20%
ammonium thiocyanate solution at 318 K for 14 days.
Figure 1 shows the results of the stress change after
applying a stress of 88 MPa, corresponding to 90% of
the yield stress, for all samples. It is clear that stressrelaxation is suppressed by the presence of hydrogenand vacancies. In addition, the sample without defects
relaxes greatly in a short period of time and almost nochange can be confirmed after that, but the sample withvacancy and hydrogen shows a small amount ofrelaxation, but it relaxes slowly over a long period oftime. Figure 2 shows the change of positron lifetimes
and their relative intensities during relaxation after
initial stress applied. The long lifetime of positron τ2
increase to more than 170 ps after stress application inall samples, indicating that vacancies were formed
even at stresses below the yield point. Also, τ2 for㻜
W㻞 㻔㻲㼑㻕
W㻞 㻔㻲㼑 㻨㻙 㻴㻕W㻞 㻔㻲㼑 㻔㼑㻙 㼕㼞㼞㼍㼐㻚㻕 㻨㻙 㻴㻕W 㻔㻲㼑㻕
W 㻔㻲㼑 㻨㻙 㻴㻕W㻝 㻔㻲㼑 㻔㼑㻙 㼕㼞㼞㼍㼐㻚㻕 㻨㻙 㻴㻕㻞㻢㻜㻼㼛㼟㼕㼠㼞㼛㼚 㼘㼕㼒㼑㼠㼕㼙㼑㻘 W 㻔㼜㼟㻕

1

㻞㻝㻜

㻙㻝㻜

㻙㻟㻜

W㻞

㻙㻡㻜

㻝㻢㻜
㻙㻣㻜

W㻝

㻝㻝㻜

㻙㻥㻜
㻢㻜
㻜

㻝

㻞

㻟

㻠

㻡

㻢

㻣

㻙㻝㻝㻜

㼀㼕㼙㼑㻘 㼠 㻔㼔㻕

Fig. 2. Positron lifetimes and relative intensity I2change after initial stress applied.

− 66 −

Ⅲ-2 Material Sciences

BL1U

Gamma-ray Induced Positron Annihilation Lifetime Measurementof CeO2 Catalyst Placed in a Quartz Tube
S. Dohshi1, K. Maeda1, Y. Taira2 and T. Hirade3
1

Osaka Research Institute of Industrial Science and Technology
2-7-1, Ayumino, Izumi, Osaka 594-1157, Japan
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
3
Japan Atomic Energy Agency, Ibaraki 319-1195, Japan

In situ observation of the catalyst during catalytic
reactions is very important for elucidating the reaction
mechanism and preparing the highly active catalyst.
Recently, it has been reported that the presence ofoxygen vacancies in CeO2 catalysts aﬀect their catalytic
activity [1]. Therefore, it becomes more and more
important to analyze the behavior of oxygen vacancies
of CeO2 with high sensitivity during catalytic reactions.
Positron annihilation lifetime measurement is a
powerful tool for the detection of lattice defects such as
oxygen vacancies with high sensitivity. However, there
have been no examples of positron annihilation lifetime
measurements with controlling gas atmosphere andtemperature. Typically, the catalytic reaction is
performed in a quartz or alumina tube with controlling
gas atmosphere and temperature. When gamma-ray
induced positron annihilation lifetime measurement isperformed under the same conditions as the catalytic
reaction, positrons generated in the sample can be
annihilated not only in the sample but also in the quartz
tube, because of the presence of the quartz tube between
the sample and the detector.
In this study, the eﬀect of quartz tube on the positronannihilation lifetime of CeO2 was investigated.
The pellet sample with 20 mm in diameter and 10
mm in thickness were prepared using CeO2 nanoparticles
with a primary particle size of ca. 2 nm.
We have set up a gamma-ray spectroscopy system atthe laser-Compton scattering (LCS) beamline of BL1U
at UVSOR-III [2], and measured the lifetime of theannihilation gamma-rays at room temperature using
BaF2 scintillation detector. We used the software
Lifetime9 (LT9) to analyze the spectra.
Table 1 shows the positron annihilation lifetimes andrelative intensities of CeO2 catalyst with various
measurement conditions. In case of the measurement
without quartz tube, the positron annihilation lifetime
was composed of two components (τ1 and τ2). These
lifetimes were attributed to the positron annihilation in
CeO2 bulk and surface. On the other hand, in case of themeasurement with quartz tube, the positron annihilation
lifetime was composed of three components (τ1, τ2 andτ3). The longest lifetime component (τ3) can be attributed
to the annihilation in the quartz tube, with a relative
intensity (I3) of about 1%, regardless of the gamma-ray
beam diameter. Furthermore, the lifetimes and relative
intensities of the other two components derived fromCeO2 (τ1 and τ2) did not change significantly whenmeasured using quartz tubes. These results suggest that
positron annihilation lifetime measurements can be
performed in a quartz tube while controlling the gas
atmosphere and temperature.
Next fiscal year, gamma-ray induced positronannihilation lifetime measurement will be performed
with controlling the gas atmosphere and temperature toclarify the behavior of oxygen vacancies in CeO2.
[1] X. Liu et al., J. Am. Chem. Soc. 131 (2009) 3140.
[2] Y. Taira et al., Rev. Sci. Instr. 84 (2013) 053305.

Table 1 Positron annihilation lifetimes and relative intensities of CeO2 catalyst with various measurement conditions.
measurement
conditions

(ps)

I1
(%)

(ps)

I2
(%)

(ps)

I3
(%)
-

without quartz tube

155

6.5

388.2

93.5

-

with quartz tube
( -ray beam: 2 mm)

159

3.8

367.8

95.0

1386

1.2

with quartz tube
( -ray beam: 3 mm)

142

4.2

362.5

94.4

1290

1.4

− 67 −

BL1U

Formation of the stress-induced Vacancies in Iron
by in situ Positron Annihilation Lifetime Spectroscopy
M. Fujinami1, R. Awaji1, A. Yabuuchi2, T. Hirade3, N. Oshima4 and Y. Taira5
1
Department of Applied Chemistry and Biotechnology, Chiba University, Chiba 263-8522, Japan
Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori 590-0494, Japan
3
Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan
4
National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan
5
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

2

Investigating the formation process of atomic
vacancies by mutual cutting of dislocations is essential
to understand the role of vacancies in the mechanicalproperties of metals. However, such vacancies have yet
to be directly observed. The reason is that vacancies
have a significant diﬀusion coeﬃcient and are unstable.
Positron annihilation lifetime spectroscopy is the
only method that allows direct observation of atomic
vacancies. However, the conventional method using aradioactive isotope such as 22Na as a positron source isdiﬃcult to measure in situ under various conditions dueto the risk of radioactive contamination. If it becomes
possible to measure the vacancies while applying
stress, it will be possible to detect transient vacancies,
which leads to the first detection of transient vacancy
formation. It also provides essential fundamental
knowledge for discussing the behavior of vacancy
stabilization by impurities, including hydrogen. In thisstudy, we attempted to directly detect vacancies formedin pure iron during tensile deformation in situ using theBL1U beamline, where positrons are created in thesample directly.
A 3-mm-thick tensile sample was mounted on a small
tensile tester. The sample was subjected to tensile
deformation up to a nominal strain of over 7% with astrain rate of 2.2×10−5 s−1. Ten samples were measured
under the same tensile deformation conditions to obtainenough counts of positron lifetime spectra.
Figure 1 shows the positron lifetime spectra of pureiron before and after tensile deformation. A longer
lifetime component is observed in the positron lifetime
spectrum when the sample is elongated to a nominal
strain of ~7.3%. Figure 2 shows the change in mean
positron lifetime during tensile deformation. The mean
positron lifetime increases with increasing nominal
strain. However, the change in mean positron lifetime
obtained in this study diﬀers significantly from thetrend reported in an earlier study using the conventional
method [1]. One possible reason for this diﬀerence isthe diﬀerence between the conventional method, whichobserves a depth of about 0.1 mm from the sample
surface, and this method, which observes the entire
sample, including the deeper region. Further detailed
analysis is currently underway.

Fig. 1. Positron lifetime spectra of pure iron before andafter tensile deformation with a nominal strain of~7.3%.

Fig. 2. Change in mean positron lifetime during tensile
deformation.
[1] B. Somieski et al., NDT & E Int. 27 (1994) 235.

− 68 −

Ⅲ-2 Material Sciences

BL1U

In-situ Measurements of Vacancies Formed in Pure Ironby Electrolytic Hydrogen Charging using gamma-ray-induced
Positron Annihilation Lifetime Spectroscopy
A. Yabuuchi1, T. Hirade2, M. Fujinami3, R. Awaji3, N. Oshima4, K. Takai5 and Y. Taira6
1Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori 590-0494, Japan
2
Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan3
Department of Applied Chemistry and Biotechnology, Chiba University, Chiba 263-8522, Japan
4
National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan
5
Department of Engineering and Applied Sciences, Sophia University, Tokyo 102-8554, Japan
6
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

Recently, a fracture mechanism involving vacancies
has been proposed as a new model to explain thehydrogen embrittlement of steels [1]. Therefore, manystudies on hydrogen embrittlement have been performed
using positron annihilation spectroscopy, a vacancy
detection technique. However, the conventional
positron annihilation technique is challenging tomeasure during hydrogen dosing in a liquid. The highenergy pulsed gamma-rays obtained at UVSOR make itpossible to produce positrons directly inside a sample
placed in a fluid and perform positron annihilation
measurements. In this study, we attempted in-situ
positron annihilation lifetime measurements duringhydrogen charging in liquid to investigate hydrogeninduced vacancies in pure iron.
Six well-annealed pure iron plates with a purity of
99.99% and a thickness of 2 mm were arranged in the
beam axis direction with a gap of 2 mm between them.
This measurement geometry was chosen to achieve
suﬃcient hydrogen introduction throughout the sample
and still obtain a suﬃcient count rate of annihilation
gamma-rays. For electrolytic hydrogen charging, thesample was immersed in 0.1 N NaOH solution
containing 5 g/L NH4SCN. A pulsed gamma-ray beamwith a maximum energy of 6.6 MeV was injected tomeasure the positron lifetime.
Figure 1 shows the positron lifetime spectra of pureiron plate samples placed in air and the electrolyte
solution. The spectrum obtained from the in-air
measurement shows almost no lifetime component of
positrons annihilated outside the sample. In contrast, alonger lifetime component originating from positronannihilation in the electrolyte solution appears in the
spectrum obtained from the sample placed in theelectrolyte solution. The change in positron lifetime iniron during hydrogen charging was investigated byanalyzing such spectra. However, it was concluded thateliminating the electrolyte solution component fromthe spectra is essential for a detailed analysis of the ironsample components.
Figure 2 shows the calculated positron flux
distribution when a gamma-ray beam is injected into aniron plate in water. Positrons are mainly produced iniron, which has a high specific gravity, but they are also
produced to some extent in water. In addition, some ofthe positrons produced in iron are emitted out of ironand annihilated in water. Therefore, we consider
improving the measurement geometry for the next
beamtime.

i 1. Positron
i lifetime
lif i spectra of well-annealed
f
ll
l d
Fig.
pure
iron measured in air or an electrolyte solution.

Fig. 2. (a) Geometry of the simulation model.
(b) Calculated positron flux distribution.
[1] M. Nagumo, Mater. Sci. Technol. 20 (2004) 940.

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BL2A

Formation of Catalytically Active Mo2C Species on H-MFI for Methane
Aromatization Studied by Mo L-edge XANES
K. Kuramochi1, Y. Sonobe2, H. Shimura2, Y. Kinoshiro2, R. Yamazaki1, Y. Uchimura2
and H. Aritani2
Advanced Science Research Laboratory, Saitama Institute of Technology, Fukaya 369-0293 Japan
2
Graduate School of Engineering, Saitama Institute of Technology, Fukaya 369-0293 Japanenergy side after the reaction for 10 minutes, indicatingthat further reduction of Mo proceeds to form β-Mo2C
like species with low crystallinity. Since the edgeenergy is kept on after 90 minutes (in the maximum
activity) is exhibited, β-Mo2C like species are possibly
act as a highly active one for methane dehydrogenation.
As the reaction time progresses, only a slight shift ofthe edge to the lower energy side can be seen. Therefore,
it is presumed that the deactivation of reactivity after 30
minutes is caused mainly by carbon deposition on
H-MFI support rather than excess reduction of Mo
species.
1.0

TEY (Normalized Intensity)

As a typical GTL (Gas-To-Liquid) catalyst, supported
molybdenum on H-MFI zeolites show catalyticallyhigh and selective activity to convert methane tobenzene directly. Although the GTL process isextremely innovative, it is an important subject tosuppress deactivation as well as increase the yield ofaromatics. For the Mo/H-MFI catalysts, definite
deactivation due to coke deposition has been a major
problem for enhancement of MTB reactivity. A causeof the deactivation strongly depends on both coke
deposition onto strong acid sites over H-MFI andstructural deactivation of carbonized Mo species. Oneof the most important subjects for catalytically highand durable activity is the elucidation of active Mo
carbide (MoCx) species and their structural stability. In
this study, Mo LIII-edge XANES is applied tocharacterize the active MoCx species on Mo/H-MFI
during the methane aromatization.[1] The change ofactive Mo species during the reaction was investigatedas a time course of XANES spectra.
Mo/H-MFI (Si/Al2=23-30 in H-MFI, 5.0 wt% as
MoO3-loading) catalysts were prepared as described in
the previous paper.[2] The methane dehydroaromatization reactivity was evaluated at 1023 K. Mo
LIII-edge XANES spectra were obtained in BL2A of
UVSOR-IMS in a total-electron yield mode using the
InSb double-crystal monochromator. A REX-2000(Rigaku) software was used for normalization of each
XANES spectra. The edge energy was obtained fromthe maximum of the first derivative of XANES.
Figure 1 shows the LIII-edge XANES of reference
Mo compounds. The energy of the absorption edge
becomes higher according to the higher oxidation stateof molybdenum. For Mo-carbides, the edge energy in
α-Mo2C (fcc: 2526.55 eV) is significantly larger thanthat in β-Mo2C (orthorhombic: 2524.45 eV). Since thediﬀerence of energy value should be due to thecoordination number in Mo-C shells, the edge energy
of XANES can be applied to characterize the local
structure of Mo2C species.
For evaluation of catalytic activity for methane
aromatization at 973 K, it is concluded that Mo/HMFI(Si/Al2=30) shows the maximum benzene yield in
30 minutes as an initial streaming range. On the Mo/HMFI catalysts, time course of L-edge XANES spectra
are shown in Figure 2. Before the reaction (at 0 min.),the Mo/H-MFI catalyst has been pre-reduced with
CO(2%)-He at 1023 K. At this time, Mo species havealready reduced to form Mo4+ (due to MoO2) and/or
Mo2+ (α-Mo2C). The edge of XANES shifts to the low

Mo metal
D-Mo2CE-Mo2C
MoO2
MoO3

0.5

0.0
2515

2520

2525

2530
2535
Energy /eV

2540

2545

Fig. 1. Mo LIII-edge XANES spectra of reference Mo
compounds.
Mo/H-MFI(30)
0 min.
10 min.
30 min.
90 min.
180 min.
D-Mo2CE-Mo2C

1.0

TEY (Normalized Intensity)

1

1.0

0.8

0.6
2525

2526

2527

0.5

0.0
2515

2520

2525
Energy / eV

2530

2535

Fig. 2. Mo LIII-edge XANES spectra of Mo/H-MFI (Si/Al2=30) catalyst after the reaction for each time (0 –180 minutes).
[1] H. Aritani et al., UVSOR Activity Report 2021 49(2022) 58.
[2] H. Aritani et al., J. Environm. Sci., 21 (2009) 736.

− 70 −

Ⅲ-2 Material Sciences

BL2A

Local Environment of Dopants in (M, Nb) co-doped TiO2 (M=Fe, Ni)
H. Murata 1, 2, T. Nishio2, Y. Nagatomo2 and A. Nakahira1, 2
1

Department of Materials Science, Osaka Metropolitan University, Sakai 599-8531, Japan2
Department of Materials Science, Osaka Prefecture University, Sakai 599-8531, Japan

Both of the co-doped TiO2 samples exhibited visible
light absorption. Based on the spin and valence statesof dopants, the visible light absorptions are induced at
diﬀerent origins. The (Fe, Nb) co-doped TiO2 has anarrowed band gap and weak spin forbidden d-dtransitions. On the other hand, the (Ni, Nb) co-doped
TiO2 has a strong spin-allowed d-d transition. These
diﬀerent origins of visible light absorption
fundamentally influence behaviors of excited careersand chromaticity. These results lead to a comprehensive
understanding of the visible light applications such as
photocatalyst and pigments.

Nb-L3
Ti0.50Ni0.33Nb0.17O2
Ti0.60Ni0.13Nb0.27O2

Intensity / arb. units

Titanium dioxide (TiO2) is a typical fine ceramicmaterial used in a wide range of applications, such as
photocatalysts, pigments and transparent conductors.
TiO2 has a several polymorphs with wide band gaps
and absorb only UV light. Numerous studies have been
carried out on cation and anion doping into TiO2 toutilize visible light. However, most of them induce
weak visible light absorption due to their small solid
solubility limits. Co-doping into TiO2 has been
investigated [1] and combinations of dopants such as(Fe, Nb) and (Ni, Nb) significantly increase solid
solubility limits [2-4]. However, local environments ofthe co-doped dopants int TiO2 and their light absorption
mechanism have not been clarified. In this study, local
environments and electronic structures of (Fe, Nb) and(Ni, Nb) co-doped TiO2 were investigated.
(Fe, Nb) and (Ni, Nb) co-doped TiO2 samples wereprepared by a conventional solid-state reaction method
using TiO2, Fe2O3, NiO and Nb2O5 as starting materials.
The stating materials were ground and mixed by analumina mortar and pestle. They were calcined in analumina crucible at 1200 °C for 6 h. The samples wereground and mixed by the mortar and pestle again. Then,they were calcined in an alumina crucible at 1200 °C
for 6 h.
Samples were characterized using X-ray diﬀraction(XRD), UV-Vis, 57Fe Mössbauer spectroscopy, and
X-ray absorption near edge structure (XANES). Ni-L3
and Nb-L3 XANES spectra were collected using thetotal electron yield method with a sample current at
BL2A in UVSOR (Okazaki, Japan). The X-ray beam
was monochromated using beryl and InSb double
crystals for Ni-L3 and Nb-L3, respectively. NiO andNb2O5 was used as reference materials.
XRD patterns of the samples can be assigned torutile-type TiO2 with peak shifts. They confirmed that
(Fe, Nb) and (Ni, Nb) co-doped TiO2 has large solubility
limit over 50 cation%, where the dopants ratios are 1:1
and 1:2 for (Fe, Nb) and (Ni, Nb), respectively. Notethat their lattice parameters increased linearly with theconcentration of dopants.
57
Fe Mössbauer spectroscopy and Ni-L3 XANES
show that Fe and Ni in the samples are high-spin Fe3+
and Ni2+ in octahedral coordination, respectively. Nb-L3
XANES of the samples have typical features of Nb5+ inoctahedral coordination [5], as shown in fig. 1. These
results indicate that large solid solubility limit of theco-doped TiO2 is due to charge compensation between
dopants.

Ti0.80Ni0.07Nb0.13O2
Ti0.50Fe0.25Nb0.25O2

Ti0.60Fe0.20Nb0.20O2
Ti0.80Fe0.10Nb0.10O2
Nb2O5

2360

2370
2380
2390
Photon energy / eV

2400

Fig. 1. Nb-L3 XANES spectra of (Fe, Nb) and (Ni, Nb)
co-doped TiO2.
[1] A. S. M. Nur et al., J. Water Process. Eng. 47 (2022)
102728.
[2] M. A. Tena et al., Mater. Res. Bull. 27 (1992) 1301.
[3] B. Balzer and H. Langbein, Cryst. Res. Technol. 31(1996) 93.
[4] M. Wenger and T. Armbruster, Neues Jahrb.
Mineral. Monatsh. 5 (1993) 225.
[5] Y. Kubouchi et al., X-ray Spectrom. 41 (2012) 259.

− 71 −BL2A

XAFS Study of MgAl2O4 - MgGa2O4 Solid Solutions
S. Yoshioka 1, K. Yasuda1, E. Kobayashi2 and K. Okudaira3
1

Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University,
Fukuoka, 819-0395, Japan
2
Kyushu Synchrotron Light Research Center, Saga 841-0005, Japan
3
Graduate school of Advanced Integration Science, Chiba University, Chiba, 263-8522, Japanenergy of 1330 eV after the removal of the background
intensity. The Mg K-edge XANES of MgGa2O4 wereclearly diﬀerent from that of MgAl2O4. The spectrum
diﬀerence between MgAl2O4 and MgGa2O4 suggests
local structure diﬀerence between two specimens.
Previous study using diﬀraction technique reported
octahedral location of Mg in MgGa2O4 as an inverse
spinel, whereas tetrahedral location of Mg in normal
spinel of MgAl2O4. Detailed analyses on the local
environment of Mg and Al in the MgAl2-xGaxO4 are in
progress by combined use of the XANES and the firstprinciples band structure calculations.
Mg K-edge
MgAl2O4

Intensity (arb. units)

Spinel oxides with the general formula AB2O4 can beformed with various kinds of divalent A and trivalent B
cations. Owing to their unique mechanical, electronic,
and magnetic properties, the spinel oxides have gained
considerable attention not only from the fundamental
research fields but also from the industrial application
point of view. Some spinel compounds accommodate alarge degree of cationic disorder. The cationicdisordering naturally aﬀects the structural properties ofthe spinels. For example, magnesium aluminate(MgAl2O4) and magnesium gallate (MgGa2O4) are
generally known as normal and inverse spinel
structures, respectively. However, their inversion
degrees for synthetic specimens were also reported to
be fluctuating between 0 and 1, respectively, due to the
cationic disordering. Recently, the structure of
MgAl2-xGaxO4 was reported using first principles
calculations and X-ray diﬀraction [1]. X-ray absorption
spectroscopy (XAS) is a powerful structure
characterization method that uses an X-ray probe toreveal local atomic coordination and electronic
structures. In this study, we focus on the local structuresin MgAl2O4 – MgGa2O4 solid solutions, particularly
cationic-disordered structures.
The polycrystalline samples of MgAl2-xGaxO4 (x = 0,0.5, 1.0, 1.5, and 2.0) were synthesized by a solid-state
reaction. They were sintered in air at 1500 ºC for 10 hfollowed by furnace. Mg and Al K-edge XANES
measurements were performed on BL2A beamline at
UVSOR Synchrotron Facility, Okazaki, Japan, using
the partial fluorescence yield method. A KTiOPO4
double-crystal monochromator gives Mg and Al
K-absorption edges in the energy regions 1290–1340
eV and 1540–1610 eV, respectively. The measurementsof Mg and Al K-edge XANES spectra were carried out
in vacuum at a pressure and temperature of 1×10−4 Pa
and 20 ºC, respectively. Fluorescence X-rays of Mg Kα
and Al Kα were collected utilizing an energy-dispersible
silicon drift detector.
The Mg K-edge XANES spectra for MgAl2O4 and
MgGa2O4 are shown in Fig. 1. The intensity of each
spectrum was normalized to a value of 1 at the photon

1310

MgGa2O4

1320

1330

1340

1350

Photon energy (eV)Fig. 1. Mg K-edge XANES spectra of MgAl2O4 and
MgGa2O4[1] G. Pilania, V. Kocekski, J. A. Valdez, C. R. Keller
and B. P. Uberuaga, Commun. Mater. 1, Article number:
84 (2020).

− 72 −

Ⅲ-2 Material Sciences

BL2A

NEXAFS Spectroscopy of Battery Materials Using a Transfer Vessel
A, Inoishi1 and E. Kobayashi 2
1

Institute for Materials Chemistry and Engineering, Kyushu University
6-1 Kasuga-koen, Kasuga-Shi 816-8580, Japan
2
Kyushu Synchrotron Light Research Center, 8-7 Yayoigaoka, Tosu, Saga 841-0005, Japan

To increase capacity in all solid-state lithium-ion
batteries, it is better to remove as much of the solid
electrolyte and conductive carbon contained in theelectrode as possible. Recently, we reported the allsolid-state lithium batteries using electrochemicallithium insertion in some anode materials. We reported
Mg(BH4)2, and MgH2 anode materials.[1,2] In theseconversion-type electrodes, LiBH4 and LiH are
generated as lithium salt during lithiation and ionic
conduction paths are formed during the electrochemical
reaction. Solid electrolyte is not required in theseelectrode mixture and reasonable battery performanceswere observed with the electrode composed of active
material (Mg(BH4)2 or MgH2) and acetylene black,
without electrolyte powder. We call this new concept as“in-situ forming of solid electrolyte”. Recently, we
newly focused on MgCl2 as a new anode active material.
For the case of MgCl2, it is assumed that LiCl is formed
after lithiation as “in-situ formed electrolyte”. In thisstudy, we evaluated the mechanism of electrochemical
reaction of MgCl2 anode by X-ray adsorption
spectroscopy.
Composite powder containing MgCl2 was preparedby mechanical milling of MgCl2 with acetylene black(AB) in a 70:30 mass ratio at 400 rpm for 30 min. Each
all-solid-state cell (Li/LiBH4/MgCl2, AB) was
assembled using an insulating cell die (Poly Ether Ether
Ketone) sandwiched between two stainless steel rods
under Ar. Discharge/charge measurements wereconducted in a vacuum at a current density of 0.05
mAcm-2 and at 120 °C. Ex-situ X-ray absorption
spectroscopy (XAS) data for Mg K-edge and Cl K-edge
were acquired at the BL2A of UVSOR Synchrotron
Facility, Institute for Molecular Science. For thetransportation to XAS, a sample transfer vessel wasused.[3,4]Initial lithiation capacity and delithiation capacity of
the Li/LiBH4/MgCl2 cell were 465 mAhg-1 and 321
mAhg-1, respectively. The initial lithiation capacity was
82 % of the theoretical capacity of MgCl2. In thiselectrode, solid electrolyte is not required in theelectrode mixture. This indicates that lithium
conduction path is formed from MgCl2 by theelectrochemical reaction. Mg K-edge X-ray adsorption
spectroscopy for the MgCl2 electrode before and after
the discharge-charge were measured. MgCl2 showedsharp peaks at 1310 eV. “Initial state” just after cellfabrication was similar spectrum with MgCl2 chemical,

indicating that “initial state” is still MgCl2. After the
initial lithiation, adsorption at 1302 eV was newly
observed. This is also observed in Mg metal.[5]Therefore, MgCl2 is reduced to form Mg metal duringlithiation process. After the following delithiation,
similar spectrum with initial state was observed,
indicating that MgCl2 is reversibly formed after thedelithiation process. Cl K-edge X-ray adsorption
spectroscopy for the MgCl2 electrode before and after
the discharge-charge were also measured. Initial stateand delithiated state were similar spectra with that of
MgCl2. After lithiation, the main intense peak wasslightly shifted to higher energy. This corresponds tothe adsorption observed in LiCl.[6] From these results,
it was confirmed that following reaction is occurred in
the MgCl2 anode as shown in Fig. 1.
MgCl2 + 2Li+ + 2e-→ 2LiCl + Mg (1)Fig. 1. Schematic view of “in-situ forming of solid
electrolyte” in MgCl2 electrode using Li/LiBH4/MgCl2
cell.
[1] H. Sato, R. Sakamoto, H. Minami, H. Izumi, K.
Ideta, A. Inoishi, S. Okada, Chem. Commun, 57 (2021)
2605.
[2] A. Inoishi, H. Sato, Y. Chen, H. Saito, R. Sakamoto,
H. Sakaebe, S. Okada, RSC Advances, 12 (2022) 10749.
[3] E. Kobayashi, J. Meikaku, T. Okajima, and H.
Setoyama, Japanese Patent No. 5234994.
[4] E. Kobayashi, J. Meikaku, H. Setoyama, T. Okajima,
J. Surf. Anal., 19 (2012) 2.
[5] J. W. Chiou, H. M. Tsai, C. W. Pao, K. P. Krishna
Kumar, S. C. Ray, F. Z. Chien, W. F. Pong, App. Phys.
Lett. 89 (2006) 043121.
[6] H. S. Lee, X. Q. Yang, J. McBreen, L. S. Choi, Y.
Okamoto, J. Electrochem. Soc. 143 (1996) 3825.

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BL3U

Direct Observation of Electrochemically Generated High Valent Iron-Oxo
Species of μ-Nitrido-Bridged Iron Phthalocyanine Dimer Deposited on
Graphite Surface by Soft X-ray Absorption Spectroscopy
Y. Yamada 1, 2 and M. Nagasaka3
1

Department of Chemistry, Graduate School of Science, Nagoya University,
Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
2
Research Center for Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
3
Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan

CH4 is expected as a next generation carbon resource
because it is abundant in nature as natural gas ormethane hydrate. Therefore, development of novel
catalysts that convert CH4 into valuable raw chemicals
eﬃciently is strongly desired. However, high chemical
stability of CH4 makes it highly challenging. We
recently reported that a μ-nitrido-bridged ironphthalocyanine dimer closely stacked on a graphite
surface 1/G (Fig. 1a) eﬃciently convert CH4 intomethanol, formaldehyde, and formic acid in an acidic
aqueous solution containing excess H2O2 at atemperature below than 100 °C. It was demonstrated
that 1/G showed especially potent CH4 oxidation
catalyst among a variety of molecule-based CH4oxidation catalysts and its catalytic activity was almost
comparable to that of a natural particulate methane
monooxgenase (pMMO)[1].
In order to advance the chemistry of 1/G, we next
attempted to develop the method for electrochemical
generation of 1oxo/G. It is expected that 1oxo/G could be
generated by oxidation of coordinating H2O on the ironcenter of 1(H2O)/G in an aqueous solution (Fig. 1b).
This method is expected to provide a more economicallyfavored approach for CH4 oxidation.
We first prepared a SiN membrane tip modified by
1/G. A SiN membrane tip modified with 20 nm
thickness of carbon membrane (cmSiN) was treatedwith a pyridine solution of 1, followed by washing withtrifluoroacetic acid and H2O to give a SiN membrane
tip modified by 1/G (1/cmSiN). It was confirmed that 1
was successfully deposited on the carbon surface of
cmSiN (Fig. 2a) by using cyclic voltammogram in an
CH3CN solution containing 100 mM nBu4N+·PF6–.
Electrochemical generation of the high-valent ironoxo species from 1(H2O)/cmSiN (Fig. 2b) wasmonitored by O K-edge XAS spectra in a 100 mM
phosphate buﬀer (pH = 7.0) by using a beamline
equipped with a transmission-type liquid flow cell in
BL3U of UVSOR [2]. The measurements were
performed by changing the applied voltage to 1(H2O)/
cmSiN. The spectra were obtained by the LambertBeer law, ln(I0/I), where I0 is the transmission signals of
the cmSiN in buﬀer and I is those of 1(H2O)/cmSiN at
diﬀerent applied voltage in buﬀer.
It was found that the broad peak around 532 eV wasapparently appeared when applying the voltage of 1.8

V vs. Ag/AgCl (Fig. 2c). Taking that DFT calculation
indicated that the peak of O1s – π* of Fe=O for 1oxoshould appear at around 529 eV, whereas the peaks for
1 having a coordinating H2O should be observed at
higher energy than 534 eV, it is considered that the peak
appeared at around 532 eV is assignable to the excitationof O1s – π* of Fe=O of electrochemically generated
high-valent iron-oxo species of 1(H2O)/cmSiN (1oxo/
cmSiN). We are going to check the CH4 oxidation
activity of electrochemically generated 1oxo/cmSiN.
(a)
O
N
N

N

N

N
N

N

N
N

N

CH4

N

N

N
N

H2O2

FeN4+ NN

N

FeN4+ N
N

N
N

N

0

N
N

FeN3+ N

N

N

N

FeN4+ N
N

CH3OH
HCHO
HCOOH

Graphite

1oxo/G

1/G
(b)
OH2
N
N
N

N

N

N
Fe3+
N

Electrochemical
Oxidation

O
N
N

N

N

N

N
N

N

FeN4+ N
N

N
N

0

N
N

N

–2H+–2e–N

FeN4+ N

N

N
N

N

FeN4+ NN

N

Graphite1(H2O)/G

1oxo/G

Fig. 1. Generation of 1oxo/G from 1/G (a) by using H2O2or (b) by electrochemical oxidation.
(a)

(c)

N
N

N
N

N

FeN3+ N
N

N

N
N

N
N

N

FeN4+ N

1.8 V vs. Ag/AgClN

C membrane~ 20 nmRest potential
SiN membrane

1/cmSiN

(b)

OH2
N
N

N
N

N

FeN3+ N
N

N

N
N

N
N

N

FeN4+ NN

C membrane
SiN membrane

1(H2O)/cmSiN

Fig. 2. Structures of (a) 1/cmSiN and (b) 1(H2O)/
cmSiN. (c) Comparison of O K-edge XAS spectra of1(H2O)/cmSiN at rest potential (blue) and 1(H2O)/
cmSiN at the applied potential of 1.8 V vs. Ag/AgCl.
[1] Y. Yamada, M. Nagasaka et al., JACS Au. DOI :10.1021/jacsau.2c00618.
[2] M. Nagasaka and N, Kosugi, Chem. Lett. 50 (2021)
956.

− 74 −

Ⅲ-2 Material Sciences

BL3U

Structural Analysis of fluoro-polymers Using Resonant Soft x-ray Scattering
K. Yamanoi 1, 2, M. Yamashita1, Y. Yamamoto1, H. Iwayama3 and M. Noumi2
1Institute of Laser Engineering, Osaka university, Suita, Osaka, 565-0871, Japan2
DAIKIN Industries Ltd, Settsu, Osaka, 566-8585, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

Fluoropolymers or sometimes referred to as
fluororesins have been widely used for chemical,
electrical, and medical applications because of theirhigh chemical resistance, mechanical strength,hydrophobicity, heat resistance, low surface energies,
low coeﬃcients of friction, and low dielectric constants[1-3]. These favorable properties stem from theelectronic structure of the fluorine (F) atom, the stablecarbon-fluorine (C-F) covalent bond, and the uniqueintramolecular and intermolecular interactions between
the polymers’ fluorinated segments and main chains[4]. Based on their structure and composition,
fluoropolymers can be classified as partially fluorinatedpolymers or perfluoropolymers. Partially fluorinatedpolymers contain F and hydrogen (H) atoms in theirstructures, while perfluoropolymers only contain F
atoms, i.e., the H atoms are replaced with F atoms. For
example, polyvinylidene fluoride (PVdF) is a very
processable and mechanically strong partiallyfluorinated polymer, whereas polytetrafluoroethylene(PTFE) is a chemically strong and heat-resistant
perfluoropolymer.
Among their diﬀerent applications, modified PTFE
which includes oxygen component in the polymer isused to fuel injectors and as packing and linings ofhigh-pressure vessels. Consequently, the ability todirectly observe the oxygen related microscopic
morphology is very important in revealing polymer
function. As PTFE is known to have semi-crystalline,
lamellar structures consisting of both amorphous andcrystal phases [5], small-angle x-ray scattering (SAXS)
technique is the most appropriate method to study theinternal morphologies of these fluoropolymers within
the 10 to 100-nm range. Additionally, the Resonant
Soft X-ray Scattering (RSoXS) is attractive method toobserve the structure related with specific chemicalbond in mesoscopic region.
Previously, SAXS has been used to investigate themorphology of PTFE and their co-polymers under
supercritical carbon dioxide condition [6]. In thisresearch the RSoXS method was used in BL3U,UVSOR facility on the modified PTFE sample.
The sample was sliced to 1 μm thickness andsandwiched with Si3N4 membrane. Soft x-ray isirradiated on the sample through the Si3N4 membrane
and the scattered soft x-ray is monitored by camera at
the position of 2θ=7.5 and 30°. The x-ray energy istuned at 540 eV which is resonant with oxygen bonging
in polymer.
Figure 1 shows the results of scattering patterns of
540 eV comparing with the 528 eV which is notresonant with oxygen bonding.
We could observe the diﬀerence around the higher
angle corresponding to smaller structure between
resonant and non-resonant x-rays. This result shows theoxygen bonding related structure has the smaller crystal
structure compared with others, however the scattered
x-ray signal was weak since the sample was muchthick. For the detailed discussion of oxygen bonding
related structure, more thinner sample is required.

Fig. 1. Scattering patterns of RSoXS with 540 eV and
528 eV[1] S. Ebnesajjad, P. R. Khaladkar, Fluoropolymer
applications in the chemical processing industries(Second Edition), William Andrew Publishing (2017).
[2] Z. Cui, E. Drioli, Y. M. Lee, Prog. Polym. Sci. 39(2014) 164.
[3] G. Eberle, H. Schmidt, W. Eisenmenger, IEEE
Trans. Dielectr. Electr. Insul. 3 (1996) 624.
[4] H. Teng, Appl. Sci 2 (2012) 496.
[5] A. Marigo, C. Marega, R. Zannetti, G. Ajroldi,
Macromolecules 29 (1996) 2197.
[6] K. Yamanoi, S. Shibuta, A. Shiro, M. Noumi, M. J.
F. Empizo, M. Cadatal-Raduban, N. Sarukura, K.
Nishikawa, and T. Morita, J. Supercrit. Fluids, May
2022 vol. 184 (2022) 105555.

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BL3U

Structure Analysis on Chiral Dark Conglomerate of Achiral Liquid Crystal
Trimers by Resonant Soft X-ray Scattering (RSoXS) at UVSOR
Y. Takanishi1, F. Araoka2 and H. Iwayama3,4
1

Faculty of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto, 606-8502, JapanRIKEN Center for Emergent Matter Science, Hirosawa 2-1, Wako, Saitama 351-0198, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan

2

Spontaneous chiral symmetry breaking in soft matteris one of most attractive topics. Liquid crystal (LC) isa typical one of soft matter, and bent-core molecules
show unique LC phases. The B4 phase is the lowest
temperature phase observed in the bent-core liquid
crystals, and it shows spontaneously chiral separated
domains despite of achiral molecules. Recently it isreported that some kinds of rod-like LC trimers also
show similar DC phase caused by unique molecular
packing by designing intermolecular interactions.
Yoshizawa’s group studied intensively achiral LC
trimers exhibiting DC phase. They systematicallysynthesized LC trimers, and reported that the DC phaseis stabilized in (a) equimolecular mixture of nematicand smectic trimers, (b) binary mixtures of a nematic
trimer with biphenyl units at the center and cyanobiphenyl compound and (c) a single asymmetric trimer.
In resonant X-ray scattering, using X-ray whoseenergy is coincident with a certain atom absorption
edge, the structure factor becomes a tensor instead of
the scalar in conventional X-ray diﬀraction. Carbon
K-edge resonant soft x-ray scattering (RSoXS) has
been applied to study, and successful in obtaining the
precise structures of polymer blends, block copolymer,
and LCs. Recently one of authors (YT) studied thebinary system between a rod-like cholesteric LC
mixture and a bent-core LC showing B4, and found a
new smectic structure that does not appear in only
constituent molecules with wide temperature range was
unexpectedly discovered. Last year, the structure ofhelical nano-filament of B4 phase in the nano phaseseparation of cholesteric liquid crystal mixture and abent-core molecule was analyzed using RSoXS to
study the eﬀect on the nano-helical filament in thismixture. We summarized that the pitch of helicalfilament decreases and coherence of helical structure
increases, which would be caused by the interaction
between bent-core and rod-like molecules.[1]In this study, we report the local nano-structure
analysis of DC conglomerate phase in achiral LC trimer
using resonant soft-X-ray scattering (RSoXS)
technique. Small angle and wide angle scattering were
measured and alkyl chain length dependence of rodlike molecules was discussed.
The experiment was performed at BL3U of UVSOR.
Used achiral liquid crystal trimers are I-(m,n), as shownin Fig. 1. In this study, m is fixed to 9, and n changes

from 7~11. Samples used were filled in the isotropic
phase between two pieces of 100 nm-thick Si3N4
membranes (Norcada). The scattering was detected by
CCD (ANDOR DO940P-BN). Incident X-ray beam
was tuned between 270~300eV. In these compounds,
carbon K-edge energy was 284.5 eV.
Figure 2 shows 2D small-angle RSoXS images of (a)I-(9,7), (b)I-(9,9) and (c)I-(9,11). Resonant scatteringpeaks are clearly observed, and with the increase of
spacer chain length n, the long-range periodicity
corresponding to the peak increases from ca. 900~1300
nm. In I-(9,9), tubercle structures a are seen by STEM
observation, but its diameter was about 200 nm, andhence our results suggest the existence of the longerrange periodic structure.
Figure 3 shows 2D wide-angle RSoXS images of (a)I-(9,7), (b)I-(9,9) and (c)I-(9,11). Even in these images,
clear sharp peaks are observed, and the corresponding
periodicity are ca. 70~80Å, which increases with theincrease in the spacer chain length n. Since the layer
thickness by conventional X-ray scattering are ca.40Å,these results indicate that LC trimers form intercalated
bilayer structure.

Fig. 1. Chemical structure of I-(m,n).
(a)

(b)

(c)

Fig. 2. 2D small-angle RSoXS images of (a)I-(9,7), (b)I-(9,9) and (c)I-(9,11).
(a)

(b)

(c)

Fig. 3. 2D wide-angle RSoXS images of (a)I-(9,7), (b)I-(9,9) and (c)I-(9,11).
[1] Y. Takanishi, Soft Matter, 17 (2021) 563.

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Ⅲ-2 Material Sciences

BL3B

Measurements of Fluorescence Lifetimes of Scintillators Adopted for a New
in-beam Detector of the ࡷ૙ࡸ Rare Decay Experiment at J-PARC
K. Shintate, R. Abe, Y. Hayashi, T. Naito, S. Sakano, J. Ohashi, Y. Tajima and H.Y. Yoshida
Department of Physics, Yamagata University, 990-8560, Japan

J-PARC E-14 KOTO [1] is the experiment ofsearching for the direct CP violating decay‫ܭ‬௅ ՜ ߨ ଴ ߥߥҧ . This decay mode is considered to besensitive to new physics beyond the Standard Model(SM), and its branching ratio is predicted to be 3.0×10-11
in the SM with about 2% theoretical uncertainly.
The cross-sectional view of the KOTO detector isshown in Fig.1. The upper limit currently obtained on
the branching fraction of ‫ܭ‬௅ ՜ ߨ ଴ ߥߥҧ decay is 3.0×10-9
at the 90% confidence level [2].
One of the main backgrounds is caused by ‫ ܭ‬± decays
in the beam. To reduce this background by detecting‫ ܭ‬± , we are planning to install an in-beam charged
particle detector with a scintillator of 0.2 mm thickness
named UCV (Upstream Charged Veto, Fig.2). The
scintillator used for UCV is required to have suﬃcient
light yield and short fluorescence lifetime. We measured
fluorescence spectra and decay curves of the scintillator
to evaluate the performance of UCV as a particle
detector.

Fig. 1. Cross-sectional view of the KOTO detector.
The beam enters from the left. Detector components
with their abbreviated names written in blue (in green
and underlined) are photon (charged-particle) vetocounters. The UCV detector is installed at the upstream(left) end of the KOTO detector.

Fig. 3 shows the 2D fluorescence spectra of the UCV
scintillator. Fig. 4 shows the decay curve for the 432
nm band under excitation at 284 nm. The blue line
indicates experimental data. The red line is the fitting
curve consists of two fluorescence lifetimes andreproduces the experimental data. The fitting results
analyzed by using the data analysis framework named“ROOT” [3] are summarized in Table 1.

Fig. 3. 2D fluorescence spectra of the UCV scintillator.
Y-axis is excitation wave length (nm), and x-axis isemission wave length (nm).

Fig. 4. Decay curve of the UCV scintillator for the 432
nm band under excitation at 284 nm.
Table 1. Fluorescence lifetimes of the UCV scintillator,
determined from our data analysis.

SampleUCV

Fig. 2. The UCV detector. To install in the beam line,
the scintillators are made as thin as 0.2mm thick andscintillating lights are detected by photomultipliertubes (PMTs) using reflector sheets.

ȜEX
[nm]
284

ȜEM
[nm]
432

Ĳ1[ns](Ratio)1.9(91.4%)

Ĳ2[ns](Ratio)20.3(8.6%)[1] J. Comfort et al., Proposal for ‫ܭ‬௅ ՜ ߨ ଴ ߥߥҧExperiment at J-PARC (2006).
[2] J. Ahn et al. (KOTO Collaboration), Phys. Rev.
Lett. 122 (2019) 021802.
[3] R. Brun and F. Rademakers, Nucl. Instrum. Methods
Phys. Res. A 389 (1997) 81.

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BL3B

Material Search of Li-Containing Halide Scintillators for Neutron Detection
C. Fujiwara1,2, S. Kurosawa2,3,4 and A. Yamaji2,31

Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai, Japan
2
Institute for Materials Research (IMR), Tohoku University, Sendai, Japan3
New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai, Japan
4
Institute of Laser Engineering, Osaka University, Osaka, Japan

A remote real-time radiation detector consisting of ascintillator and optical fiber is required to achieve thedecommissioning of the Fukushima Daiichi Nuclear
Power Plant[1]. The scintillator for this application isrequired to have an emission wavelength of 550 nm or
longer and high light output from the viewpoint oftransmission eﬃciency in the optical fiber and reductionof optical fiber-derived noise[2][3]. In addition,neutrons-emitting debris is expected to be present
inside the reactor, and neutron-sensitive scintillationmaterials are needed. Due to the above reason, we havedeveloped Li2HfI6 as a candidate material [4], while
Li2HfI6 contains a heavy element, Hf with a highdetection eﬃciency for gamma rays. Therefore, in thisstudy, Li2ZrX6 (X=Cl, Br, I) was prepared by replacing
Hf with Zr, and its luminescence properties were
investigated.
Li2ZrX6 crystal specimen was synthesized by thevertical Bridgman growth method in our laboratory
using 99.9%-pure LiCl, LiBr and LiI powders, and
99%-pure ZrCl4, ZrBr4 and ZrI4 powders were used. We
measured the photoluminescence excitation andemission spectrum from 50 to 300K at UVSOR BL3B
beam line.
As shown in Fig.1(a), Li2ZrCl6 showed broad
luminescence with a peak at 570 nm at an excitation
wavelength of 300 nm at 50K. Although theluminescence intensity decreased as the temperature
increased, no significant change in both the excitationand emission wavelengths were observed. The emission
wavelength was 580 nm at the excitation wavelength of
300 nm at room temperature. This wavelength range
satisfies the above requirement, and Li2ZrCl6 can be a
candidate material for neutron detection with opticalfiber.
Fig.1(b) showed the emission spectrum of Li2ZrBr6
as a function of temperatures. Li2ZrBr6 shows a broad
emission with a peak at 580 nm at an excitation
wavelength of 305 nm at 50 K. When the temperature
is increased, the emission intensity decreases, and theemission wavelength became shorter.
Fig. 1(c) shows the emission spectrum of Li2ZrI6, and
Li2ZrI6 had red and near-infrared emission with theemission wavelength of 670 nm at an excitation
wavelength of 430 nm at 50 K. However, the emission
intensity decreases significantly as the temperature
increases, and no emission is observed at room
temperature.
From these results, LiZrCl6 was found to be a

candidate material for neutron detection using an
optical fiber. In the future, we plan to investigate thelight output by neutron excitation and conduct a
detection test by connecting the optical fiber.

Fig. 1. Photoluminescence spectrum at each temperaturefor (a) Li2ZrCl6, (b)Li2ZrBr6, (c)Li2ZrI6[1] I. Wakaida, Topic. Fukushima 70 (2015) 1.
[2] C. and H. Ltd, Opt. Quantum Electron 13 (1981) 85.
[3] H. Liu et al., Rev. Sci. Instrum. 89 (2018) 083302.
[4] C. Fujiwara, K. Shunsuke, and Y. Akihiro, UVSOR
Activity Report 49 (2021) 84.

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Ⅲ-2 Material Sciences

BL3B

Optical Properties of Cs2IrCl6-CsCl Composite Phosphor
S. Kodama, S. Omiya, N. Shimoyama, T. Saito, I. Yanase and H. Takeda
Saitama University, Saitama 338-8570, Japan

Cs2HfCl6 was reported as the novel single-crystalline
inorganic scintillator with a high light output and agood energy resolution [1]. Cs2HfCl6 exhibits the strong
intrinsic luminescence at the blue region. Several
luminescence origins were suggested for Cs2HfCl6 [23], however, the detailed mechanism was still unclear.
In this study, we focused on the charge transitiontransfer (CT) phenomena. Inorganic crystals which
consist an isolated anion complex show the CT
luminescence. In order to occur the CT luminescence,the peripheral electron orbital of the center metal ion in
the anion complex should be empty. The crystal
structure of Cs2HfCl6 consists Cs+ ions and isolated[HfCl6]2- anion complexes. In addition, the electron
orbital of Hf 4+ of [HfCl6]2- anion complex is empty, thus
we assumed that the intrinsic luminescence of Cs2HfCl6
can be attributed to be CT luminescence.
To distinguish the CT luminescence from otherluminescence origins such as the self-trappedluminescence or the defect luminescence, therefore inthis study, we synthesized Cs2IrCl6 and compared theoptical properties with Cs2HfCl6. Although Cs2IrCl6 has
the same crystal structure as Cs2HfCl6, the peripheral
electron orbital of Ir4+ of [IrCl6]2- is not empty, therefore,
Cs2IrCl6 must not exhibit the CT luminescence. If someluminescence was observed in Cs2IrCl6, the CT
luminescence should not occur in Cs2HfCl6.
Cs2IrCl6 was synthesized from the starting powdersof CsCl and IrCl4. The melted specimen included
Cs2IrCl6 and CsCl phases, thus we represent theobtained specimen to be Cs2IrCl6-CsCl composite.
Additionally, in order to compare the optical properties,
non-doped CsCl and Ir:CsCl crystals were grown.
Figure 1 shows the photoluminescence spectra ofCs2IrCl6-CsCl composite, CsCl and Ir:CsCl. At 300K,
all specimens showed the single emission peak at ~310
nm excited by 254 nm. In addition to ~310 nm band, allspecimens showed another emission peak at ~420 nm
at 300K. The emission peaks of Cs2IrCl6-CsClcomposite and Ir:CsCl well corresponded to that of
CsCl, therefore, Cs2IrCl6 was concluded to show noluminescence originated from the self-trapped excitons
or defects. Based on the obtained results, theluminescence origin of Cs2HfCl6 might be assumed tobe the CT luminescence.

Fig. 1. Photoluminescence spectra of Cs2IrCl6-CsClcomposite (represented as CIC+CsCl), CsCl and
Ir:CsCl at (a) 300K and (b) 10K.
[1] A Burger et al., Appl. Phys. Lett 107 (2015) 34.
[2] B. Kang and K. Biswas, J. Phys. Chem. C 120(2016) 12187.
[3] R. Král et al., J. Phys. Chem. C 121 (2017) 12375.

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BL3B, 6B

Visible-to-Ultraviolet Spectral Change with the Current-Induced Local-toNonlocal Transition of SmS
H. Watanabe1,2, S. Tatsukawa2, K. Imura3, H. S. Suzuki4, N. K. Sato5 and S. Kimura1,2,6
1
Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
Department of Physics, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan
3
Institute of Liberal Arts and Sciences, Nagoya University, Nagoya 464-8602, Japan
4
Institute for Solid State Physics, The University of Tokyo, Kashiwa 277-8581, Japan
5
Center for General Education, Aichi Institute of Technology, Toyota, 470-0392 Japan
6
Institute for Molecular Science, Okazaki 444-8585, Japan

2

Samarium monosulfide SmS exhibits the phasetransition from a black-colored semiconductor to agolden-colored metal (BGT) by applying pressure
above 0.7 GPa [1,2]. The origin of the BGT is now still
under debate. Among the possible origins, the transition
between Bose-Einstein condensation and BCS state of
excitons is currently being discussed [3,4], but nodefinitive evidence has been obtained. Recently, Andoet al. reported the nonlinear relation between thevoltage (V) and electric current (I) with increasing
current at lower temperatures than 100 K, whichsuggests a drastic change in the electrical resistivity [5].
It is unclear whether the nonlinear V/I relation is related
to pressure-induced BGT. To clarify the origin of thenonlinear V/I curve and its relation to the BGT, we haveinvestigated the current and temperature dependenciesof the reflectivity spectrum in the THz and IR regions.
We have already reported the carrier character change
from the high increasing rate (dN/dI) and the highrelaxation time (τ) of carriers at the region of low
temperature and low current to low dN/dI and low τ athigh temperature or high current regions [6,7].
The origin of the character change of carriers can be
attributed to an electron delocalization, in which thelocalized electrons trapped at Sm sites start moving by
the applied current. In this case, the electronic structure
is modified, and finally, the band gap is expected to beclosed, but it has not been revealed. In the visibleultraviolet region, there are excitations from occupied
4f states to the unoccupied 5d states. It is expected to beable to observe changes in the reflectivity spectrum dueto the modification in the electronic structure, such as aband gap narrowing. To observe the current-induced
spectral change in SmS, we measured the current
dependence of the visible-ultraviolet reflectance at
BL3B.
Single crystalline SmS with a typical sample size of
1×1×1 mm3 was sandwiched by the electrodesconnected to the current source. The sample was cooled
down to 30 K during the experiment.
Figure 1 shows the applied current dependence of thevisible-ultraviolet reflectivity spectrum. With increasing
applied current, the intensity of a peak at 3 eV decreases,
and a shoulder at about 6 eV shifts to low energy. In

addition to the spectral change, an oscillation inreflectivity appeared between 4 to 6 eV, which is
expected to be due to a change in the surface condition,
but the exact origin is not clarified. From these results,
although we observed a slight change in the reflectivity
spectrum in the visible-ultraviolet region due to thecurrent application, these could not suggest a drasticchange in the electronic structure, such as a shift in theoverall band structure due to a change of the band gap.
In summary, the application of electric current gives
energy to the electrons, causing delocalization.
However, the results suggest that the applied current
does not influence the electronic structure far from theFermi level.

Fig. 1. Current dependence of the visible-to-ultraviolet
reflectivity spectrum of SmS at 30 K.
[1] A. Jayaraman et al., PRL 25 (1970) 1430.
[2] T. Mizuno et al., JPSJ 77 (2008) 113704.
[3] B. I. Halperin and T. M. Rice, RMP 40 (1968) 755.
[4] S. Watanabe, JPSJ 90 (2021) 023706.
[5] H. Ando et al., JPS Conf. Proc. 30 (2020) 011132.
[6] H. Watanabe et al, UVSOR Activity Report 2021
(2022) 92.
[7] S. Kimura et al., arXiv: 2302.12998 (2023).

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Ⅲ-2 Material Sciences

BL3B

Exciton States of Cesium Silver Iodide Crystals
S. Ibuki and T. Kawai
Graduate School of science, Osaka Metropolitan University, Sakai 599-8531, Japanߝሺ߱ሻ ൌ ߝ௥ ൅ ݅ߝ௜ൌ ߝ௕ ൅

݂ଵଶ߱௘௫ଵ െ ߱ ଶ െ ݅߱ߛଵ
൅350

where |ε | = (εr2 + εi2)1/2. From the best-fitting analysis,

Wavelength (nm)
250

200

Reflection (arb. units)

CsAg2I3
12 K

4.0

4.5
5.0
5.5
Photon Energy (eV)

6.0

6.5

Fig. 1. Reflection spectrum of the CsAg2I3 crystal at
12K.
340

Wavelength (nm)
330
320

310

CsAg2I3
12 K

3.6

1 ൅ |ߝ| െ ඥ2ሺ|ߝ| ൅ ߝ௥ ሻ
1 ൅ |ߝ| ൅ ඥ2ሺ|ߝ| ൅ ߝ௥ ሻ

300

3.5

݂ଶ
ଶ
߱௘௫ଶ
െ ߱ ଶ െ ݅߱ߛଶwhere εr and εi are the real and imaginary parts of thedielectric constant, respectively, ωex1,2 is the resonancefrequency of the excitons, εb the background dielectric
constant, f1,2 oscillator strength, and γ the damping
constant. The reflectance R is given byܴൌ

which is shown by the broken curve in Fig.2, theresonance energies of the excitons were estimated to be
3.78 and 3.87 eV.
As future works, we are planning to investigate theoptical properties of ternary sliver iodides such as
Cs2AgI3.

Reflection (arb. units)

In the past decade, ternary lead halides have attracted
wide interest in the field of applications, including
scintillator materials, photodetectors, and solar cells[1]. However, the environmental toxicity of the lead isamong the significant concerns in this field. Therefore,
considerable eﬀorts have been devoted to developing
alternative eco-friendly lead-free ternary metal halide.
In this study, we focused on ternary sliver iodides suchas CsAg2I3.
CsAg2I3 compounds were obtained by the Bridgman
method from high purity CsI and AgI powders, whichwere mixed in a stoichiometric ratio. The thin crystals
of CsAg2I3 were prepared by a cell method [2]. The
quartz-cells with the narrow gap are made of a pair of
two quartz plates. The melt of CsAg2I3 compounds was
percolated into the gap of the quartz-cells throughcapillary action and the thin crystals were grown in the
gap by natural cooling.
Figure 1 shows the reflection spectrum of the CsAg2I3
crystal at 12 K in the energy region of 3.5 ~ 6.5 eV. The
sharp dispersion-like structures due to band-edge
excitons are observed around 3.8 eV. Furthermore, thebroad reflection peaks are observed around 4.6 and 5.1
eV. The energy values are consistent with those of theabsorption bands reported in a previous paper [3].
Now, we confine one’s attention to the dispersionlike structures due to the band-edge excitons around 3.8
eV. The reflection spectrum magnified around thedispersion-like structures is shown in Fig.2. Two
dispersion-like structures are confirmed. We attempted
to fit the reflection structures by using the simple
oscillators model with two close-lying resonances.
Then, the dielectric function is represented by thefollowing expression:

3.7
3.8
3.9
Photon Energy (eV)

4.0

4.1

Fig. 2. Reflection spectrum of the CsAg2I3 crystals inthe band-edge exciton region at 12 K. Broken curve isthe fitting result calculated with the two-oscillator
model.
[1] J. Yuan, et. al, Joule 4 (2020)1160.
[2] S. Hashimoto and M. Itoh, Jpn. J. Appl. Phys. 27(1988) 726.
[3] V. K. Miloslavskii, et. al, Solid State Spectro. 80(1996) 577.

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BL3B

Temperature Dependence of Excitation Spectra in Er-doped La2Zr2O7
M. Yoshino and M. Ito
Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan

Based on our first-principles calculations, Er
substituted for La in pyrochlore-type oxide, La2Zr2O7(LZO) has multiple stable positions with significant
displacements from the original La position, and is
expected to spread in a disc shape at room temperature.
This combination of static and dynamic disorderproduces diversity in the Er coordination environment,
and the transition spectrum of Er3+ is expected to havea broad shape due to the overlap of each environment
case. At low temperatures, the transition spectra
become sharper due to the decrease in the dynamic
disorder. Therefore, we measured the excitation spectraof Er-doped LZO from low temperature to room
temperature. For comparison, we also measured Erdoped Y2Ti2O7 (YTO) with pyrochlore-type structure,
Y0.5Zr0.5O1.75 (YZO) with defect fluorite structure, andY3Ga5O12 (YGG) with garnet-type structure. Er in YTO
and YGG have small displacements, and Er in YZO has
static disorder but less dynamic disorder, so thetemperature dependence of their spectral shapes is
expected to be small. Fig. 1 shows the excitation
spectrum of LZO with emission wavelength of 560 nm.
Results from 20 K to 100 K are shown here, but
measurements were also performed up to 300 K. To
examine the temperature dependence of the spectral
shape, we normalized the spectra using the peak withthe maximum intensity at 20 K. Fig. 2 and Fig. 3 show
the results for YZO and YTO, respectively. In eachcase, the spectral shape becomes broader withincreasing temperature. To compare their temperaturedependences, we estimated the change in the height ofthe valley between peaks around 380 nm with respect
to the 20 K case as shown in Fig. 4. It was found that
LZO tends to have a larger change in the height of thevalley than the other samples, resulting in broad spectra.
This indicates that the temperature dependence is larger
for LZO.

Fig. 1. Excitation spectra of La2Zr2O7 : Er( λem = 560 nm ).

Fig. 2. Excitation spectra of Y2Zr2O7 : Er( λem = 560 nm ).

Fig. 3. Excitation spectra of Y2Ti2O7 : Er( λem = 560 nm ).

Fig. 4. Change in the height of the valley between
peaks around 380 nm.

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Ⅲ-2 Material Sciences

BL4U

Analysis of Cathode Materials for Li-Ion Batteries by STXM
E. Hosono1,2,3, D. Asakura1,2,3, H. Yuzawa4, T. Ohigashi4,5, W. Zhang6, M. Kobayashi7,8,
H. Kiuchi6 and Y. Harada3,6,9
1

Global Zero Emission Research Center, National Institute of Advanced Industrial Science and Technology (AIST),
Tsukuba, Ibaraki 305-8569, Japan
2
Research Institute for Energy Conservation, AIST, Tsukuba, Ibaraki 305-8565, Japan
3
AIST-UTokyo Advanced Operando Measurement Technology Open Innovation Laboratory (Operando-OIL),
Kashiwa, Chiba 277-8565, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan
6
Institute for Solid State Physics (ISSP), The University of Tokyo,
5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
7
Department of Electrical Engineering and Information Systems, The University of Tokyo,
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
8
Center for Spintronic Research Network, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo
9
Synchrotron Radiation Research Organization, The University of Tokyo,
7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, JapanThe development of clean energy devices is attracting
attention toward the realization of a low-carbon society
for preventing global warming. Since lithium ion
batteries (LIBs) are expected to be broadly used forsuch as electric vehicles and stationary types for homeuse, their devices are the most actively investigated inboth industry and academia fields. However, the market
demand for improved performance of LIBs is still
extremely high, and the development of innovative
materials for LIBs is essential to exceed significantly
the current performance. To solve this diﬃcult problem,
characterization of component materials for LIBs is
crucially important.
We have been analyzing electrode active materials byabsorption and emission spectroscopy usingsynchrotron soft X-rays in order to clarify the detailed
electronic states of the materials. In addition, we havealso been analyzing them by microscopic photoelectron
spectroscopy using synchrotron soft X-rays. The LIBs
are devices that stores energy by the insertion anddiﬀusion of Li into the host crystal, which is strongly
dependent on the local environment of the active
materials. Therefore, local analysis can provide
important information for understanding the chargedischarge mechanism. Photoelectron spectroscopy is asurface-sensitive method, while scanning transmission
X-ray microscopy (STXM) is a bulk-sensitive method
because of its transmission.
In this study, we applied STXM analysis to most
famous LIB cathode material, LiCoO2 (LCO). Figure 1
shows the Co L3-edge X-ray absorption spectra (XAS)of the initial (dotted line) and charged (solid line)
conditions of LCO. By using STXM, we were able toobtain XAS spectra of selected areas and visualize the
distribution of the oxidation state of LCO. The details
were reported in ref. [1].

Fig. 1. Co L3-edge XAS of the initial (dotted line) andcharged (solid line) conditions of LCO. Panel (a) shows
average spectra of selected particles including area 1-5(circle areas: 300 nm diameter). Panel (b) shows
extracted spectra from area 1-5, which exhibit diﬀerent
charging states (oxidation states) from each other.
[1] W.X. Zhang et al., Sci. Rep. 13 (2023) 4639.

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BL4U

Unraveling the Origin of Irreversibility between the First and Second
Charging Process in Primary Conversion Anode Particle
J. Kim 1, J. Chung1, T. Ohigashi2, H. Yuzawa2 and J. Lim1
Department of Chemistry, Seoul National University; 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

Among the various candidates for rechargeable
lithium-ion battery anode, alpha-hematite (α-Fe2O3)
has been actively investigated due to its high theoretical
capacity (1007 mA∙h/g), low processing cost, abundantremaining source, and nontoxicity. Despite theseadvantages, commercialization of α-Fe2O3 anode ischallenging due to the fast capacity fading, particularly
occurring in first and second charging process. A
previous report proposed the three reaction pathways inthe first charging process of α-Fe2O3 [1]. First step:
monophasic insertion reaction; (1) Fe2O3 + xLi+ →LixFe2O3. Subsequent second and third steps: biphasic
conversion reaction; (2) LixFe2O3 + (2-x) Li+ → 2FeO +Li2O and (3) 2FeO + 4Li+ → 2Fe + 2Li2O. From ourelectrochemistry data (Fig. 1), it shows that the voltage
plateau in the first charging is attributed to (2) and (3)distinct conversion reactions. Since this conversion
reaction produces an (ir)reversible reaction product(i.e., Li2O), we hypothesize that the local reaction
pathway of subsequent electrochemical cycles could be
influenced by the site-specific Li2O formation in firstcycle. The Li2O, well-known insulating material,
increases reaction overpotential which allows the
sluggish reaction kinetics of the host material.
To reveal this degradation mechanism, we note thatthe nanoscale chemical distribution of α-Fe2O3 single
particle at first charged/discharged states should be
identified. The compositional heterogeneity within theintraparticle in first charging process allows us toinvestigate non-uniform intraparticle distribution of
Li2O, which insulates the subsequent electrochemical
reaction. Furthermore, to unravel reaction hysteresis in
first battery cycle in Fig. 1, it is essential for capturing
the chemical distribution of α-Fe2O3 at first discharged
state which are entangled with the first charging
process. Thus, we conducted ex-situ STXM
measurement of first charged/discharged states of
α-Fe2O3 at UVSOR BL4U.
Fig. 2 shows chemical composition maps at pristine,
first charged state, and first discharged state, revealingthat chemical distribution of Fe phases is inhomogeneous
within the single particle. In Fig 2b, fully charged Fephase (Fe0) was partially formed and randomly
distributed, suggesting that insulating Li2O species was
generated in the first charge regardless of any specificlocation. In Fig. 2c, the discharging end phase was not

fully recovered to the pristine state (Fe3+). Thisobservation correlates with some previous reports [2,3], claiming that existence of various discharging
reaction pathways; (4) 2Fe + 3Li2O → Fe2O3 + 6Li+, (5)Fe + Li2O → FeO + 2Li+ and (6) 3Li2O + 2Fe →1.5LiFeO2 + 0.5Fe. From our results, we conclude that
intraparticle heterogeneity evolves in first charging
process (conversion reaction) and this inhomogeneity
could be aﬀected by the distribution of the reaction
product (Li2O), resulting in irreversibility of (dis)charging process.
3.0
2.5
2.0

Voltage (V)1

1.5

Reaction hysteresis
1.0

Capacity loss

0.5
0.0
0

200

400

600

800

1000

1200

Specific Capacity (mAh g-1)

Fig. 1. Charge/discharge profiles of the synthesized α-Fe2O3 at 0.1 C current rate. (Unpublished)ab
Pristine(Fe2O3)cFirrst charging(at 0.05 V)

Fe0

First discharging(at 3.0 V)

Fe3+

Fig. 2. Chemical composition maps at a. pristine, b.
first charged state (0.05 V vs. Li/Li+), and c. firstdischarged state (3.0 V vs. Li/Li+). Scale bars below
each image are 1 um.
[1] A. Banerjee, et al., Nano Energy 2 (2013) 890.
[2] T. C. Christie, et al., Journal of Materials Chemistry22 (2012) 12198.
[3] Su. Qingmei, et al., ACS Nano 7 (2013) 9115.

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Ⅲ-2 Material Sciences

BL4U

Chemical Bonding Structures of SBR/BR Interfaces
T. Ejima1 and Y. Tamura2
1
SRIS, Tohoku University, Sendai 980-8577, JapanENEOS Materials Corp., Yokkaichi 510-0871, Japan

2

Rubber materials used in tires often have multiple
elastomers to achieve desired properties. Combining
styrene-butadiene rubber (SBR) and butadiene rubber(BR) can enhance skid and rolling resistance, but
increasing styrene content can reduce low-temperature
performance. By using high cis-1,4 BR instead of BR
and adding it to SBR, the glass transition temperature(Tg) can be controlled, and low-temperature
performance can improve [1-3]. The study used SBR
and BR to fabricate interface structures with NEXAFS
spectra, clarifying chemical bonding states.
Understanding these states can clarify complex
elastomer properties.
The preparation of the samples involved compounding
SBR-A, SBR-B, and BR with a 75 ml plast mill (ToyoSeiki). The diﬀerence of the types of SBR is thediﬀerence of the crosslink density: The A type SBR(SBR-A) is normal one and the B type has a highcrosslink density (SBR-B). The prepared samples werethen cut into sheet shapes, and these sheets were
subsequently laminated together to form a SBR-A/BR
interface sheet and a SBR-B/BR interface sheet.
Furthermore, a sample SBR-B/BR was kneaded bycompounding SBR-B and BR at a ratio of 70:30. The
resulting SBR-A/BR and SBR-B/BR interface sheets
and kneaded SBR-B/BR sheet were sliced using an
ultramicrotome, placed on an electron microscope grid,
fixed to a dedicated STXM sample holder. The thicknessof the sample was fixed at 100 nm.
The soft X-ray image of the SBR-B/BR interface
sample shows the existence of a region near theinterface that exhibits a spectral structure diﬀerent fromthat of the SBR-B and BR used to prepare the sample
The two-dimensional (2D) soft X-ray absorption
distributions of the SBR-B phase, the BR phase, andthe residual phase are shown in Fig. 1(a). In the figure,the absorption intensity of the BR phase is shown inred, the SBR-B phase in blue, and the residual phase ingreen. The respective absorption intensities are
represented by the respective color gradations. The
simultaneously obtained spectra of the BR phase, the
SBR-B phase, and the residual phase are shown in Fig.
1 (b). The color of the spectra corresponds to the color
in the soft X-ray image of Fig. 1(a). The spectral
intensities are normalized by the background before
and after the absorption edge.

5HVLGXDO

6%5%

%5

D

Fig. 1. (a) Material separation image of S-SBR-B/BR
interface sample, (b) NEXAFS spectra of each material
obtained in (a).
[1] A. J. Marzocca, et al., Polym. Int. 49 (2000) 216.
[2] J. M. Massie, et al., Rubber Chem. Technol. 66(1993) 276.
[3]H. H. Le, et al., Macromol. Mater. Eng. 298 (2013)1085.

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Observation of Distribution of Sulfur and cross-linking Reagent in
Vulcanized Rubber by Using STXM
T. Ohigashi1, 2, 3, F. Kaneko4, H. Yuzawa2 and H. Kishimoto4
1

Institute of Material Structure Science, High Energy Accelerator Research Organization,
Tsukuba 305-0801, Japan
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan3
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Tsukuba 305-0801, Japan
4
Sumitomo Rubber Industries Ltd., Kobe 651-0072, Japan

In recent years, SDGs (Sustainable Development
Goals) is a keyword to represent attitude of our daily
life. Especially, reduction of mass consumption is a
critical issue. Rubber is one of the important resources
and its demand is assumed to increase especiallyaccording to growth of car industries. To reduce its
consumption, establish of LCA (Life Cycle Assessment)of rubber industrialization and further improvement offunctionality of rubbers, such as wear- and destructionresistant, are essential.
Rubber is generally heterogeneous network structure,
which is produced by rubber polymer and cross-linking
agent (vulcanization). Since the remained cross-linking
reagent in this structure is heterogeneously distributed,
it gathers internal stress of rubber deformation to cause
the destruction. Therefore, dispersion of a cross-linking
reagent in the rubber is an important parameter todetermine mechanical character of rubber. However, it
is not easy to observe the dispersion because the crosslinking reagent in rubber is so small amount and isconsisted of light elements.
We have been characterized rubber by using scanningtransmission X-ray microscopy (STXM) at BL4U
[1,2]. STXM is a powerful tool to obtain 2-dimensional
X-ray absorption spectroscopy by near edge X-ray
absorption fine structure (NEXAFS) with high spatial
resolution around 30 nm. Moreover, STXM gives muchless radiation damage to the sample than by electron
microscopy. Therefore, STXM is the best approach forthis study. In this report, the distribution of crosslinking reagent in vulcanized rubber is investigated by
STXM.
The sample is styrene-butadiene rubber with zincoxide, sulfur, N-cyclohexyl-2-Benzothiazolylsulfenamide(CBS), 3-diphenylguanidine (DPG) as cross-linking
reagents. The rubber was cut as 200 nm-thick by
ultramicrotome and was placed on a TEM grid. As
reference
samples,
CBS,
DPG
and
2-mercaptobenzothiazole (MBT) were dispersed in
acetone and were drop-casted onto TEM grids withsupport membrane. X-ray absorption images ofunvulcanized and vulcanized rubbers taken at 400 eV
are shown in Fig. 1. In these images, dark spots show
higher absorption than matrix and are considered as
distribution of cross-linking reagents. By comparing
Figs. 1(a) and 1(b), dark spots decrease in size andbecome more dispersive through a vulcanization
process. Normalized N K-edge NEXAFS spectra ofreference samples of CBS (blue), DPG (green), MBT(red) and the dark spot (black; shown by an arrow in
Fig. 1(b)) are shown in Fig. 2. Although the signal ofthe dark spot is quite low, the dark spot seems to beconsisted of mixture of CBS, DPG and MBT. Especially,
the sharp peak of MBT at 400.8 eV contributes to thatof the dark spot. MBT was produced by vulcanization
process and contributed to the distribution of crosslinking reagent.

(a)

(b)

Fig. 1. X-ray absorption image of (a) unvulcanized and(b) vulcanized rubbers taken at 400 eV. Scale bars are 5
μm.

Fig. 2. N K-edge NEXAFS spectra of CBS (blue),
DPG (green), MBT (red) and a dark spot (shown in Fig.
1 by an arrow). The spectra are normalized by max andminimum.
[1] T. Ohigashi, F. Kaneko, H. Yuzawa and H.
Kishimoto, UVSOR Activity Report 2021, 49 (2022) 73.
[2] T. Ohigashi, et al., J. Electron Spectrosc. Relat.
Phenom. 266 (2023) 147356.

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BL4U

Scanning Transmission X-ray Microscopy of Hydrogen Evolution
Electrocatalysts on Graphene Oxide Membranes
C. O. M. Marianoa, J. S. D. Rodrigueza,b, R. H. Clementea,
T. Ohigashic,d, H. Yuzawac, W. H. Hsue, J. Shiuef and C. H. Chuanga,*a

Department of Physics, Tamkang University, Tamsui, New Taipei City 251301, TaiwanbInstitute of Chemistry, Leiden University, Leiden, 2300 RA, The NetherlandscInstitute for Molecular Science, Okazaki 444-8585, Japand
Photon Factory, Institute of Materials Structure Sciences, High Energy Accelerator Research Organization,
Tsukuba 305-0801, Japane
Institute of Physics, Academia Sinica, Nankang, Taipei 11529, TaiwanfInstitute of Atomic and Molecular Sciences, Academia Sinica, Daan, Taipei 106319, Taiwan
The oxygen functional groups present in GO haveeﬀects on the HER activity of cobalt catalyst (CoxOy)
and should be studied for its specific role thoroughly.
GO has several oxygen functional groups, i.e., carboxyl(-COOH), carbonyl (C=O), hydroxyl (-OH), andepoxide groups (C-O-C). These functional groups areimportant because they can interact with the cobalt
ions, which increases the catalytic activity for the HER.
The oxygen functional groups of GO can be identified
using such as fourier-transform infrared spectroscopy,
raman spectroscopy, and X-ray photoelectron
spectroscopy, but to acquire additional information
about the spatial distribution of these functional groups,
scanning transmission X-ray microscopy (STXM)
must be used [1].
This study aims to understand the relationshipbetween the oxidation state of CoxOy supported on GO
membranes (called as Co/GO), for their catalytic
activities. Fig. 1(a) shows the surface morphology ofthe dropcast GO membranes measured using thetapping mode of AFM. The vertical diﬀerence along
the line profile (red arrow) was noted as 46 nm because
a random flake stacking of the GO on the Au meshbehaves like a rough surface after drying. Fig. 1(b)exhibits a SEM image for the CoxOy grown on GO
membranes, and Fig. 1(c) shows a high magnification
image of Co/GO to display the 3D wrinkle flower
structure of electrodeposited (ED) Co.
To identify the nanoscale distribution of theseheterogeneous materials, STXM was measured in theenergy regions of C K-edge, O K-edge, and Co L-edge
XANES. The area-selected spectra are marked as “1”,“2”, and “3” owing to the prominent contrast in the OD
image at C/O K-edges and Co L-edge, as for the total
absorbance amount of Co/GO membranes. From the C
K-edge XANES of Fig.1(d), the oxygen functionalgroups (C-O-C, C=O of COOH, and C=O) in the GO
membranes were assigned based on our previous result[1]. The feature at 284.9 eV was assigned to theformation of doubly coordinated carbon, because of thering opening and modifying π* bond [2]. The intensive
feature at 288.4 eV is known as HO-C=O (π*)/defectstate and its low-energy shoulder nearby at 287.4 eV is
assigned to C-O-C (π*) state; furthermore, the mostintensive feature and its shoulder are identified as
O-C(O)-O/C=O (π*) of the GO edge at 290.2 eV and
HO-C=O (σ*) state at 289.5 eV [1,2,3]. C-OH (π*) at
286.5 eV appears in the raw GO membranes [1] but isabsent in Co/GO membranes.
Fig. 1(e) exhibits the area-selected O K-edge XANES
spectra of Co/GO and GO. Compared the spectrum Co/
GO with that of GO, the signal of O 2p-Co 3d (π*) andCo-4s (σ*) newly centered at PEs of 531.5 eV and 539.5
eV [3,4]. The surface oxidation (i.e., C=O and C-O-C)of the GO membranes also emerges among the feature
centered at 531.5 eV [1]. Furthermore, it is critical tosee one shoulder at the 534.4 eV, mainly considered awater signal[5]. Fig. 1(f) shows Co L-edge XANES
spectra, which are composed of spectral components of
Co0, Co2+, and Co3+ states. The octahedral (Oct.)symmetrical Co2+ state composes of two features at
775.0 and 776.2 eV. The metal species of cobalt has one
primary absorption at 776.2 eV because its energy
levels are continuous. The Oct. symmetrical Co3+ stateoﬀers two additional features at 777.3 and 779.6 eV,with a higher energy range than the other cobalt
species[3]. The rising shoulder shows the gains ofmetal cobalt and Oct. Co3+ states due to the chemical
reduction and growth along the continuous
electrodeposition process, consistent with the result on
the G membranes (Co/G) in Fig. 1(f) [3].
The Co/GO membranes became a great variety in theoxidation state and lattice structure at the interface,compared to the raw GO surface. The mapping andspectroscopic information at diﬀerent positions helps
us to understand the chances of ED CoxOy growth on
the confirmed GO membranes.

Fig. 1. (a) AFM image of GO membranes and certain
curve of its height line profile along the red dottedarrow. (b)(c) SEM image of electrodeposited Co-GO
membranes. (d)-(f) XANES spectra of selected areas at
C K-edge, O K-edge, and Co K-edge.
[1] J.S.D. Rodriguez et al., Carbon N Y. 185 (2021) 410.
[2] J.J. Vélez et al., Electrochem. Soc. 160 (2013) C445.
[3] J.-J.V. Vélez et al,. Chin. J. Phys. 76 (2022) 135.
[4] J. Wang et al., Energy Environ. Sci. 6 (2013) 926.
[5] J.W. Smith et al., Chem. Rev. 117 (2017) 13909.

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BL4B

Examination of Methods for Inner Structures of Magnetic Thin Films at
UVSOR BL4B by Reflection XMCD Measurement Setup
K. Yamamoto, H. Iwayama, O. Ishiyama and T. Yokoyama
Institute for Molecular Science, Okazaki 444-8585, Japan

Complex depth-structured magnetic thin films/
multilayers exhibit a wide range of magnetic phenomena
due to interlayer interactions[1]. In addition, multilayer
structures are used to achieve useful properties inrecording media, an application area of great importancefor magnetic materials. It has been possible to elucidate
the evolution mechanism of the magnetic structure ofthin films by directly observing the magnetic
distribution in the depth direction of these magnetic
multilayers.
We have installed an experimental setup for thereflection X-ray magnetic circular dichroism (XMCD)
method [2] in the soft X-ray region at BL4B, andexperiments have been performed on test samples. The
sample and detector can be rotated independently toobtain the reflectivity. The magnetic field was about
0.35T and the measurements were performed at room
temperature. The magnetic field was applied by twopairs of opposing Nd magnets. The magnets can berotated and the relative position between the magnetic
field and the sample was kept constant. The setup is
shown schematically in Fig. 1. We used a photodiode(AXUV100G, Optodiode inc.) for our measurements
last year. In order to measure the lower signals in thehigher angle regions and to eliminate the fluorescenceof oxygen from the substrates, we introduced a silicon
drift detector (FASTSDD, Amptek). The detector
temperature was controlled by water cooling and thenoise level was kept constant at lower levels and thedetector and samples can be rotated arbitrary in thevacuum chamber shown in Fig. 2.
We used oﬀ-axis components of X-rays from thebending magnet to obtain circularly polarised light. The
X-rays are elliptically polarised. The intensity of the
XMCD was measured by changing the direction of themagnetic field.
When measurements were performed on a reference
sample, a vibrational structure was observed due tointerference between the cap layer and the underlying
layer. By changing the direction of the magnetic field,
diﬀerences corresponding to XMCD were observed.
The same measurements were also made near theabsorption edge and spectroscopic information was
extracted. However, structural information is not wellobtained compared to hard x-rays. Using an X-ray tube
light source, we also performed hard x-ray reflectometry.

Both soft and hard X-ray results could be reproducedby simulations based on a full-matrix algorithm, taking
into account the magneto-optical eﬀects of ellipticallypolarized X-rays. Although there have been previous
studies using XMCD of reflectance, few have extended
this method to obtain spectroscopic information. In
order to analyze depth-resolved magnetization
information, spectroscopic measurements were
performed to obtain the photon energy dependence andthe reflection angle dependence.
Combining this study with a light source that canarbitrarily modulate polarization would provide amethod to reveal more detailed properties.
Magnetic
Polarized
thin films
X-rays2䃗
䃗

Silicon drift
detector

Fig. 1. The illustration for the XMCD reflectivity
measurements.

Fig. 2. The vacuum chamber for the maeasurements in
UVSOR BL4B.
[1] F. Hellman et al., Rev. Mod. Phys. 89 (2017)025006.
[2] S. Macke and E. Goering, J. Phys. Condens. Matter.
26 (2014) 363201.

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Ⅲ-2 Material Sciences

BL4B

L2,3-edge X-ray Absorption Spectra of Transition Metal in Wurtzite-AlN
S. Imada
Faculty of Electrical Engineering and Electronics, Kyoto Institute of Technology, Kyoto 606-8585, Japan

3d-TM doped AlN (Al1-xTMxN) is promising forlight-emitting, spintronic, and photoelectric conversion
materials [1,2]. For these applications, it is indispensable
to reveal the electric structure, including ligand fieldand charge transfer multiplets. For this purpose, TM
L2,3-edge X-ray absorption structure (XAS) andresonant X-ray emission scattering (RIXS)
spectroscopies are powerful tools. So far, however, acomprehensive and systematic study of these importantsystems still needs to be included.
We synthesised and investigated the band structuresof Al1-xTMxN using Al and N K-edge XAS [2-4]. This
study investigated TM L2,3-edge XAS structures of
Al1-xTMxN films with various TM concentrations(0.02<x<0.08), focusing on Ti, V and Mn for the firsttime. For example, with low concentrations x<0.05, theaverage distance between TMs is larger than 7.5Å; we
expect to observe a well-localised electronic structure.
Looking ahead, we can even prepare films including
other TMs with concentrations well above 0.1 (<6Å) toreveal interactions between TMs, which are necessary
to understand for spintronic and photoelectric
conversion use.
Here we show an example of the TM concentration
dependence of the XAS structure for Al1-xTixN. Our
previous study [2] revealed that the Al1-xTixN films with
x≧0.083 showed photoconductivity under blue-green
light irradiation, while the film with x<0.083 did not.
The Ti L2,3-edge XAS spectra of Al1-xTixN films showed
structural change at x=0.083 (Fig.1). Our previous
study on Ti K-edge extended X-ray absorption finestructure (EXAFS) did not show any evidence of local
crystallographic structure change at the concentration.
Thus, we tentatively conclude that the observed change

in L2,3-edge XAS implies delocalisation of Ti 3delectrons starts at around x=0.083. To reveal the originsof the spectral change in detail, we will conduct L-edge
RIXS measurements and partial RIXS yield (PRIXSY)
analyses, which will give us new insights into XAS
structure interpretation.

Fig. 1. Ti L2,3-edge X-ray absorption spectra of Al1-xTixN
films (x= 0.083, 0.064, and 0.045) These spectra were
measured in partial fluorescence yield (PFY) mode.
[1] S. S. Khludkov et al., Russian Physics Journal 63(2020) 2013.
[2] N. Tatemizo et al., J. Mater. Chem. A 5 (2017)
20824.
[3] N. Tatemizo et al., Sci. Rep. 10 (2020) 1819.
[4] S. Imada et al., Matr. Adv. 2 (2021) 4075.

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BL4B

C K-edge XAFS Measurement of Carbon Containing Porous Silica
S. Dohshi
Osaka Research Institute of Industrial Science and Technology
2-7-1, Ayumino, Izumi, Osaka 594-1157, Japan

Porous silica with only micropores of less than 1 nm
in diameter has been successfully synthesized by using
collagen fibers or denatured collagen as a template [1].
As a result of a detailed study of the process of removing
collagen as a template by calcination, we found that theporous silica with a small amount of carbon (hereafter
denoted as carbon containing porous silica) showed
white luminescence under UV light irradiation [2]. The
emission spectrum of the prepared carbon containing
porous silica under UV excitation shows a continuous
spectrum over the visible light region, and this carbon
containing porous silica is expected to be used as awhite light source material with high color rendering
property. The author investigated the mechanism ofwhite luminescence of carbon-containing porous silica.
Since porous silica without carbon does not show whitelight luminescence property under UV light irradiation,
it is clear that carbon in porous silica contributes toluminescence property. However, the local structure ofcarbon in porous silica has not yet been elucidated
because the carbon content is very low, about 0.1%.
Therefore, in this study, we attempted to elucidate thelocal structure of carbon in porous silica by C K-edge
XAFS measurement using BL4B of UVSOR III. We
optimized the sample preparation method andmeasurement conditions.
Fig. 1 shows the experimental setup at BL4B and thesample holder for C K-edge XAFS measurement. The
powder sample was fitted onto carbon tape or indium
foil. The measurement was performed by fluorescencemode (using SDD detector).
When the sample was fixed on the carbon tape, thespectra derived from the carbon tape were observed,
and almost no spectra derived from the sample wereobserved. On the other hand, when the sample was
fixed on indium foil, the spectra derived sample wasobtained. It was also found that the X-ray irradiation
angle to the sample had a significant eﬀect on theintensity of the spectra.
In the next fiscal year, we will measure the C K-edge
XAFS measurement using pelletized sample under the
optimized conditions.

Fig. 1. The experimental setup at BL4B and the sample
holder for C K-edge XAFS mesurement.
[1] S. Dohshi, J. Soc. Leather Technol. Chem, 95 (2011)
200.
[2] S. Dohshi et al., J. Soc. Mater. Sci., Jpn., 68 (2019)549.

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Ⅲ-2 Material Sciences

BL5U

Evolution of the Electronic States by Electron Doping in a Kagome
Superconductor KV3Sb5
T. Kato1, K. Nakayama1, Y. Li2,3,4, Z. Wang2,3,4, S. Souma5,6, K. Tanaka7,8, T. Takahashi1,
Y. Yao2,3 and T. Sato1,5,6,9
1

Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture andMeasurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, P. R. China
3
Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology,
Beijing 100081, P. R. China
4
Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology,
Jiaxing, 314011, P. R. China
5
Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
6
Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Sendai 980-8577, Japan
7
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
8
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan
9International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University,
Sendai 980-8577, Japan
2

Recent discovery of a new kagome-lattice material
AV3Sb5 (A = K, Rb, and Cs) is attracting great attention.
While most of the kagome-lattice materials studied so
far have been magnetic, AV3Sb5 is unique in that it isparamagnetic and shows superconductivity with Tc of
0.93-2.5 K. AV3Sb5 also undergoes a charge-density
wave (CDW) transition below TCDW = 78-103 K,
accompanied by the unit-cell doubling with the 2×2×2
periodicity. This CDW state shows an intriguinginterplay with the superconductivity and hosts exotic
properties such as strong anomalous Hall eﬀect,
possible time-reversal symmetry breaking, andnematicity. From the electronic structure point of view,
AV3Sb5 is a multiband/multi-orbital superconductor
characterized by the formation of multiple Fermi
surfaces originating from Dirac-cone, saddle-point, andfree-electron-like bands. Given the multiband character,
it is essential to understand which bands/orbitals are
responsible for the CDW and superconductivity. A
useful means to clarify this point is to control the energy
position of bands relative to the Fermi level (EF) by
carrier doping [1] because the CDW andsuperconductivity would be sensitive to the band filling.
In this study, we have performed an angle-resolved
photoemission spectroscopy (ARPES) study on
K-dosed KV3Sb5. We have successfully controlled
electron doping level by K dosing and determined thedoping-induced evolution of the band structure.
High-quality single crystals of KV3Sb5 were grownby the self-flux method. K dosing was carried out by
using K dispenser (SAES Getters) in an ultrahighvacuum. High-resolution ARPES measurements were
performed by using a MBS-A1 spectrometer at BL5U
with linearly-polarized energy-tunable photons.
A comparison of Fermi surfaces in pristine [2] andK-dosed KV3Sb5 [Figs. 1(a) and 1(b), respectively]
shows that a circular-shaped electron pocket at the Γpoint expands with the K dosing, indicative of theelectron doping. We have estimated the amount ofenergy shift for each band and found band/orbitaldependent electron doping eﬀect. In addition, we
determined the evolution of CDW gap size withelectron doping. Our results suggest an important roleof the saddle-point band for the occurrence of CDW.

Fig. 1. (a), (b) ARPES intensity plots at EF in freshly
cleaved and K-dosed KV3Sb5, respectively[1] K. Nakayama et al., Phys. Rev. X 12 (2022) 011001.
[2] T. Kato et al., Commun. Mater. 3 (2022) 30.

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BL5U

Evolution of Electronic Correlations and Excitonic Properties Near
semiconductor-excitonic Insulator Transition
K. Fukutani1, 2, K. Kiyosawa3, C.I. Kwon4,5, J.S. Kim4,5, K. Tanaka1,2 and S. Kera1,2,3
1
Institute for Molecular Science, Okazaki 444-8585, JapanThe Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
3
Graduate School of Science and Engineering, Chiba University, Chiba 263-8522, Japan
4
Center for Artificial Low-Dimensional Electronic Systems, Institute for Basic Science, Pohang, Korea
5
Pohang University of Science and Technology, Pohang, Korea
2

In semiconductors, external stimuli, such as lightirradiations are known to create bound pair of anelectron and a hole. This quasi-particle is known as
excitons, and are known to play principal roles invarious quantum devices, including solar cells, lightemitting diode (LED), and excitonic lasers etc. The
eﬃcient creation of excitons and the manipulations of
their properties are among the central interest in thecurrent semiconductor industry.
Recently, what is called an excitonic insulator has
been experimentally identified. This new class ofmaterials is either a narrow-gap semiconductor or ashallow-overlap semimetal in their normal phase and,at suﬃciently low temperature, the electrons and holes
are spontaneously paired into excitons via quantum
condensation process.
Ta2NiSe5 is one of the most extensively studied
excitonic insulators [1], along with 1T-TiSe2. Whatdiﬀerentiates Ta2NiSe5 from 1T-TiSe2 is the fact that theformer exhibits a direct band gap and does notaccompany the change in the structural periodicities(charge density wave transition). Thus, from the pointof view of excitonic instability, Ta2NiSe5 is ideal
platform to study the nature of excitonic insulator andthe transition to/from the normal phase.
The recent extensive researches have revealed that
Ta2NiSe5 is classified into Bose-Einstein condensate(BEC)-type excitonic insulator, while it is near the
crossover regime between BEC and BCS transitions.
Theoretically, in the BEC-type excitonic insulator,
the excitons are created above the transition temperature(Tc) and as they cool down below Tc, those “preformed
excitons” undergo the condensation and acquire themacroscopic coherence [2]. The temperature (and bandgap) regime where such steady-state excitons exist
without forming a condensate is called “preformed
exciton phase” and its existence has been recently
verified [3].
Such phase of steady-state excitons represents theinverted ground state from the normal semiconductors(i.e., the excitons are formed in the ground state, while
the external stimuli are required to dissociate them into
free carriers) and provides a particularly uniqueplayground for future electronics applications.
The purpose of this research project is to explore theexcitonic insulator phase diagram both in terms oftemperature and the bandgap to evaluate the propertiesof the steady-state excitons, including its binding

energy, Bohr radius and their relative density (comparedto the free carriers), in order to understand the formation
process of this new ground state.
With these goals, we have performed high-resolution
angle-resolved photoemission spectroscopy (ARPES)
at BL5U for the chalcogen-substituted compounds
Ta2Ni(Se1-xSx)5 with particular focus at the compositionx ~ 0.6, where the material is believed to be very close
to the transition between a BEC-type excitonic insulator
and a normal semiconductor. Figure 1 shows thetemperature-dependent ARPES spectra for thiscomposition. It can be seen that at T ~ 120 K, thematerial exhibits a flat-top valence band, characteristicof excitonic insulator phase. As the temperature rises,
at T ~ 200 K, the clear signature of exciton appears near
the valence band maximum and at T ~ 350 K, thevalence band maximum is no longer flat, reminiscent of
the normal semiconductor Ta2NiS5, and the weakened
exciton signal moves towards the Fermi level with thevalence band. These observations possibly indicatesthat as the temperature increases, the electronic
correlations, which are keeping the excitons bound, areweakening at the same time as the exciton binding
energy decreases. The experimental results obtained
here are expected to give new insights into the formation
path of excitons.

Fig. 1. Temperature-dependent ARPES data from
Ta2Ni(Se1-xSx)5 at x ~ 0.6 measured at (a) T ~ 120 K, (b)200 K and (c) 350 K. The second derivative plots from
Γ01 are shown on the bottom panel (d-f).
[1] Y. Wakisaka et al., Phys. Rev. Lett. 102 (2009)026402.
[2] Y.F. Lu et al., Nat. Commun. 8 (2017) 14408.
[3] F.X. Bronold et al., Phys. Rev. B 74 (2006) 165107.
[4] K. Fukutani et al., Nat. Phys. 17 (2021) 1024.

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Polarization-dependent Angle-resolved Photoemission Study of
MAX Phase Compound Zr3SnC2
M. Mita1, D. Pinek2, M. Nakatake3, K. Tanaka4,5, T. Ouisse2 and T. Ito1,6
1

Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan
2
Grenoble Alpes, CNRS, Grenoble INP, LMGP, F-38000 Grenoble, France
3
Aichi Synchrotron Radiation Center, Seto, 489-0965, Japan
4
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
The Graduate University for Advanced Studies, Okazaki 444-8585, Japan
6
Synchrotron radiation Research center, Nagoya University, Nagoya 464-8603, JapanMAX phase compounds, i.e., Mn+1AXn where M is atransition metal, A belongs to groups 13-16 and X is the
C or N element, have recently been attracted muchattention due to their possible application for new classof two-dimensional systems called MXenes byremoving A atoms [1]. On the other hand, the bulk
electronic structure of MAX phase has been studied
mostly by calculations, mainly because of lack of wellestablished single crystalline samples. In this study, we
have performed angle-resolved photoemission
spectroscopy (ARPES) on MAX phase compound
Zr3SnC2, in which relatively higher two-dimensionality
than 211 phase due to the thicker MX layer as well as
the strong spin-orbit coupling eﬀect due to the 4dtransition metal Zr were expected.
ARPES measurements were performed at the
UVSOR-Ⅲ BL5U. Data were acquired at T = 30 K
with hν = 76 eV which enables us to trace around theΓKM plane with inner potential of V0=17.7 eVestimated from the photon energy dependentmeasurement (not shown). With using linear
horizontally (LH), vertically (LV) and circularly right(CR), left (CL) polarized photons, we have obtained
the orbital and orbital-angular-momentum (OAM)
dependent ARPES images. It should be noted that each
ARPES images were obtained without changing thephoton incident angle relative to the sample surface byutilizing two-dimensional mapping lens mode of MBS
A-1 analyzer.
Figure 1 shows the obtained Fermi surface (FS)image on the ΓKM plane. The band structure along theΓM line is shown in Fig. 2 (a) together with the DFT
calculation of Sn-terminated surface. Six-folded
symmetry of hole-pockets α and β has clearly been
observed in consistent with the DFT calculation. In
addition, three-fold symmetry around the K point of thesmall triangular-shape FS γ formed by so-called saddlelike surface state (SS) at the M point also has been
elucidated in Fig.1. With respect to this SS, even orbital
symmetry has been recognized with almost the same
circular dichroism (Fig. 2(b) and (c)). On the other
hand, opposite OAM sign without changing orbital
symmetry with respect to the MK line has been

observed at the high-binding energy region. The results
might suggest the change of chirality of OAM at thehigh-energy bound states at the Sn-terminated surfaceof Zr3SnC2. To elucidate the relation between theobserved anomalies and the spin-orbit coupling eﬀect,
further studies are intended.

Fig. 1. (a) Fermi surface (FS) image on ΓKM plane of
Zr3SnC2.

Fig. 2. (a) Band structure along the ΓM line of Zr3SnC2
obtained by LH polarized photons. Solid lines are DFT
calculation for Sn-terminated surface. (b,c) orbital (b)and OAM (c) dependent ARPES image of Zr3SnC2
along the ΓM line, which is obtained by subtracting the
ARPES results of linearly (LH−LV) and circularly(CR−CL) polarized photons, respectively.
[1] M. Basoum, MAX phases (Wiley, Weinheim 2013).

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Electronic Structure of a Layered Magnetic Semiconductor CeTe1.83Sb0.17
T. Nakamura1,2, H. Murakawa2, Y. Chen2, H. Sugihara2, K. Tanaka3,
N. Hanasaki2 and S. Kimura1,2,3
1

Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
Department of Physics, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan
3
Institute for Molecular Science, Okazaki 444-8585, Japan2

The metal-insulator transition through charge density
wave (CDW) formation has been a central topic ofsolid-state physics. While many materials have beenreported to exhibit CDW, CeTe2, a family of rare-earth
dichalcogenide, has attracted considerable interest due
to its high transition temperature that reaches 1000 K[1,2] as well as magnetic ordering below 4 K [3].
Recently, CeTe1.83Sb0.17, which shows a huge anisotropic
magnetoresistance ratio as high as 7500 thanks to theextremely low carrier density, has been synthesized bya chemical vapor transport technique [4]. Due to thepartial substitution of Te with Sb, an extra charge
carrier removes by hole doping. However, the detail ofthe electronic band structure of this sample has notbeen observed yet. In this study, we have measured theangle-resolved photoelectron spectroscopy (ARPES)of the CeTe1.83Sb0.17 to investigate the electronic
structure.
The single-crystalline CeTe1.83Sb0.17 was cleaved
under ultra-high vacuum conditions. Due to thediﬃculty of cleavage, the ARPES measurable domain
size was less than 100×100 μm2. However, the microfocused beam from UVSOR-III BL5U made it possible
to observe the electronic structure in a piece of domains.
Figure 1 shows the resonant angle-integrated
photoelectron spectra of CeTe1.83Sb0.17, taken with theenergy of 122 eV, corresponding to the resonant energyof the Ce 4d-4f absorption. In contrast to the nonresonant condition (hv = 110 eV), the sharp peak at abinding energy of 1.7 eV originates from the Ce 4f 0
final states after photoexcitation was observed in theresonant condition, indicating that the Ce 4f states are
fully localized.
Figure 2 shows the ARPES intensity plot along Γ-M
at 15 K. Several hole bands near the Γ point are
observed. Among them, the apex of band H1, which isat the outermost part of the measurement range, seems
to be in an unoccupied state, indicating that it exhibits
metallic properties even though extremely low carrier
densities are confirmed in the transport measurements.
Further experimental studies such as polarization
dependence and bulk sensitive measurement using
higher energy photons would help to elucidate theorbital character of bands in the electronic structure of
CeTe1.83Sb0.17.

Fig. 1. Resonant angle-integrated photoelectron spectraof CeTe1.83Sb0.17 at 15 K. The excitation energies of 110
and 122 eV correspond to the oﬀ- and on-resonanceconditions at the Ce 4d-4f absorption edge.

Fig. 2. ARPES intensity plot of CeTe1.83Sb0.17 along
Γ-M taken with 103 eV at 15 K.
[1] J. G. Park et al., Physica B 241-243 (1998) 684.
[2] M. H. Jung et al., J. Phys. Soc. Jpn. 69 (2000) 937.
[3] M. H. Jung et al., Phys. Rev. B 67 (2003) 212504.
[4] H. Murakawa et al., Phys. Rev. Mater. 6 (2022)
054604.

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Synchrotron ARPES Study of Nodal Dirac Semimetal Candidate LaTeBi
R. Saitou1, N. Kataoka1, H. Kageyama1, R. Kondo1 and T. Yokoya1,21Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
2
Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan

point with respect to EF is found to be calculation
dependent. However, an implication from this study isthat the electron concentration is not enough. To
achieve the interesting physical properties originatingfrom the topological electronic structure in the sample,
further electron doping is necessary.

Binding Energy (eV)

E0F

-1
1

-2
2

-3
3

-4
4

-5
5

-1.0

-0.5

0

-1

0.5

1.0

kx (‫) ڣ‬

Fig. 1. ARPES intensity map of LaTe1+xBi1-x measured
with 94 eV photons and at 20 K.

Binding Energy (eV)

LnTe1+xSb1-x (Ln: lanthanides) is a layered material
consisting of alternative stack of a layer of LnTe and alayer of a single Sb square lattice. It is theoretically
predicted as a nodal line semimetal [1]. In addition, by
selecting a magnetic element as Ln, it is possible tobreak the time-reversal symmetry. Therefore, it is amaterial that has the potential to access novel
topological phases [2-5]. Our research group are
making an eﬀort to control the physical properties ofrelated materials by introducing magnetic elements,
substituting Sb with Bi, and changing carrier
concentration [6] for the purpose of observing theexotic transport properties peculiar to Dirac electrons.
In the present study, we have performed synchrotron
angle-resolved photoemission spectroscopy (ARPES)
to clarifying the electronic structure of the nonmagnetic phase and check the relative energy
relationship between the Fermi energy (EF) and Dirac
nodes in a related material, LaTe1+xBi1-x, which
possesses single square lattices composed of Bi atoms,
having a stronger spin-orbit interaction than Sb.
LaTe1+xBi1-x single crystal samples (x = 0.025) wereprepared by a self-flux method. ARPES measurements
were performed at BL5U of UVSOR III. Linear
polarized light of 32-124 eV energies were used. Theenergy resolution was set to ~ 40 meV. All samples
were cleaved in situ on the (001) plane in an ultrahigh4vacuum of less than 5.0 x 10-9 Pa and were measured
at 20 K.
Figure 1 shows the valence band dispersion of
LaTe1+xBi1-x along the Γ-X direction in the Brillouinzone (BZ), measured with the photon energy of 94 eV.
White regions, which are the higher-intensity regions,correspond to band dispersions. The band dispersions
are symmetric with respect to the high symmetry
points: Γ and X of the bulk BZ of LaTe1+xBi1-x. This
indicates that the band dispersions reflect intrinsic
electronic structure of the sample. Importantly, one canobserve weak structures near EF on both sides of the X
points, where Dirac nodal lines are expected to belocated theoretically. To look at the electronic structures
more in detail, an energy and momentum enlarged
intensity map is shown in Fig. 2. We now clearlyobserve two electron-pockets-like structures. Theseband dispersions are consistent with the calculatedband dispersions. However, at the X point, the intensity
at EF is very small, indicating that the starting point of
the theoretically expected Dirac nodal line at the X
point is not located below EF for the measured sample.
The energy position of the Dirac nodal line at the X

EF0
-0.1
0.1
-0.2
0.2
-0.3
0.3
-0.4
0.4
-0.5
0.5

0.4

0.6

0.8

-1

1.0

kx (‫) ڣ‬
Fig. 2. Enlargement of Fig.1 for the region near EF and
the X point.
[1] A. Weiland et al., APL Mater. 7 (2019) 101113.
[2] Y. Wang et al., Phys. Rev. B 103 (2021) 125131.
[3] S. Yue et al., Phys. Rev. B 102 (2020) 155109.
[4] P. Gebauer et al., Chem. Mater. 33 (2021) 2420.
[5] L. M. Schoop et al., Sci. Adv. 4 (2018) eaar2317.
[6] R. Kondo, in preparation.

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Re-examination of the Phase Diagram of the high-Tc Cuprate
Superconductor Bi2Sr2CaCu2O8+δ Studied by ARPES
Y. Tsubota1, Y. Miyai2, S. Nakagawa5, S. Ishida4, S. Kumar2, K. Tanaka3, H. Eisaki4,
T. Kashiwagi5, M. Arita2, K. Shimada1,2 and S. Ideta1,21Graduate School of Advanced Science and Engineering, Hiroshima Univ., Japan
2
Hiroshima Synchrotron Radiation Center (HiSOR), Hiroshima Univ., Japan
3
UVSOR-Ⅲ Synchrotron, Institute for Molecular Science, Japan
4
National Institute of Advanced Industrial Science and Technology (AIST), Japan
5
Graduate School of Science and Technology, Tsukuba Univ., Japan

It has been known that the cuprate superconductors
show a high superconducting (SC) transition
temperature (Tc) and exotic physical properties.
However, the SC mechanism has been unclear yet. In
order to understand the mechanism of high-Tc cuprates,
Bi2Sr2CaCu2O8+δ (Bi2212) is one of the promising
candidates to study the electronic structure and reveal
the physical properties. Bi2212 has two CuO2 planes in
the unit cell and shows the high Tc around 95 K at the
optimally doped sample. Superconductivity occurs
upon hole doping into the CuO2 plane and the amountof hole doping can control Tc, and therefore, carrier
doping (hole/electron concentration) plays an important
key parameter in cuprates [1, 2]. The electronic phase
diagram of hole-doped high-Tc cuprate superconductors
plotted as a function of temperature and carrier
concentration has been reported as an empirical anduniversal phase diagram which is a dome-like shapecentered at ~0.16 of hole concentration [1]. However,previous ARPES experiments suggest that its empiricalphase diagram is not universal and shifted toward
overdoped region [2-4]. Therefore, in the present study,
we have performed an angle-resolved photoemission
spectroscopy (ARPES) measurements to study whether
the phase diagram changes depending on sample
compositions and hole concentration or not.
In this study, we have performed ARPES
measurements systematically to directly investigate theelectronic structure of the underdoped, optimally
doped, and overdoped Bi2212. ARPES experiments
were carried out at BL5U and BL7U. We measured
overdoped sample: Bi2.1- xPbxSr2CaCu2O8+δ (x = 0.66, Tc~ 70 K) in the SC and the normal states at BL7U and
5U. We measured underdoped, optimally doped, andoverdoped samples: underdoped Bi2Sr2CaCu2O8+δ (Tc ~75 K ), optimally doped Bi2Sr2CaCu2O8+δ (Tc ~ 92 K ),overdoped Bi2Sr2CaCu2O8+δ (Tc ~ 74 K ) and optimally
doped Bi2.1- xPbxSr2CaCu2O8+δ (x = 0.66, Tc ~ 97 K) in
the SC and the normal states. High quality single
crystals of Bi2212 were cleaved in-situ in the ultrahighvacuum ~5×10-9 Pa.
Figure 1 (a) shows the Fermi surface taken at hν =17.8 eV and T = 30 K in the SC state for optimally
doped Bi2Sr2CaCu2O8+δ. Fermi surface is clearlyobserved in wide momentum space.

We have analyzed the ARPES spectra from the nodal
to the antinodal region for each sample and determined
the Fermi momentum (kF) for each Fermi surface byfitting of momentum-distribution curves (MDCs) withsingle Lorentzian or double Lorentzian. Around thenodal region, kF is defined at Fermi level (EF) by single
Lorentzian. In the oﬀnodal to the antinodal region, kF is
defined at the momentum which shows the gap
minimum by double Lorentzian. The kF points areplotted as shown by red dots (Fig. 1. (a)). We have fitted
Fermi surface shape (red dots) by tight binding model(white curve) and estimated the hole concentration ofeach sample from the Fermi surface area and comparedthem quantitatively. Figure 1 (b) shows the new phase
diagram re-examined by the present ARPES study. As aresult, the phase diagram (Fig. 1. (b)) is diﬀerent fromthe previous one which was reported by Tallon et al [1].
We have figured out that the phase diagram changes
depending on sample compositions and holeconcentration. As a future work, we continue to study
the electric structure of underdoped and overdoped
samples to make an entire phase diagram of Bi2212.

Fig. 1.
(a) Fermi surface of optimally doped
Bi2Sr2CaCu2O8+δ in the superconducting state (30 K).
(b) The new phase diagram of Bi2212 in the present
ARPES study.
[1] J. L. Tallon et al., Phys. Rev. B 51 (1995) 12911.
[2] I. M. Vishik et al, Proc. Nat. Acd. Sci. 6 (2012)1833218337.
[3] R. Sobota et al, J. Phys. Soc. Jpn. 88 (2019) 064711.
[4] H. Sakamoto et al, J. Phys. Soc. Jpn. 85 (2016)
104710.

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Alkaline-metal-dependent Electronic States in V-based Kagome Metals
T. Kato1, K. Nakayama1, Y. Li2,3,4, Z. Wang2,3,4, S. Souma5,6, K. Tanaka7,8, T. Takahashi1,
Y. Yao2,3 and T. Sato1,5,6,9
1

Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture andMeasurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, P. R. China
3
Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology,
Beijing 100081, P. R. China
4
Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology,
Jiaxing, 314011, P. R. China
5
Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
6
Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Sendai 980-8577, Japan
7
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
8
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan
9International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University,
Sendai 980-8577, Japan
2

Kagome lattice oﬀers a fertile playground to explore
exotic quantum phases such as Weyl semimetals,
density-wave orders, fractional charge, andsuperconductivity, owing to the interplay between
electron correlation eﬀects and unique band structures
such as flat bands, Dirac cone bands, and van Hove
singularities. Recently-discovered AV3Sb5 (A = alkali
metal), in which V atoms form an ideal two-dimensional
kagome lattice, provides an excellent opportunity toinvestigate charge-density wave (CDW) in the kagome
lattice. The CDW state of AV3Sb5 is characterized bythree-dimensional lattice distortions with 2×2×2 or
2×2×4 periodicity depending on the A element. The
transition temperature TCDW varies with the A elementfrom 78 K to 103 K. AV3Sb5 also exhibits
superconductivity in the CDW phase (Tc = 0.92–2.5 K).
Besides the CDW and superconductivity in the bulk,
AV3Sb5 shows an A-element-dependent charge order at
the surface. To clarify the origin of these A-element
dependent physical properties, elucidation of the bulk
and surface band structures is urgently required.
In this study, we have performed high-resolution
angle-resolved photoemission spectroscopy (ARPES)
measurements of a series of AV3Sb5 (A = K, Rb, andCs). High-quality single crystals of KV3Sb5, RbV3Sb5,
and CsV3Sb5 were grown by the self-flux method.
High-resolution ARPES measurements were performedby using a MBS-A1 spectrometer at BL5U withlinearly-polarized energy-tunable photons of 90-150
eV.
Figures 1(a) and 1(b) show the ARPES intensity plotsmeasured along the high-symmetry line of the bulk
Brillouin zone in KV3Sb5 [1] and CsV3Sb5, respectively.
While the band dispersions show overall similarity
between the two compounds, a closer look reveals
A-element dependence in the energy positions of theelectron-like band at the Γ point and the Dirac point at

the K point. High-resolution measurements at low
temperatures show doubling of some energy bands,
indicative of CDW-induced electronic reconstruction.
We performed first-principles band calculations tounderstand the origin of A-element-dependent band
structures and their relationship with physical properties
in AV3Sb5.

Fig. 1. (a) ARPES intensity along the ΓK cut in KV3Sb5
plotted as a function of binding energy and wave vector.
(b) Same as (a) but for CsV3Sb5.
[1] T. Kato et al., Commun. Mater. 3 (2022) 30.

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Verification of the Intrinsic Electron Doping Eﬀect in T’-type Cuprate hightemperature Superconductors
M. Miyamoto1, M. Horio1, K. Moriya2, A. Takahashi3, K. Tanaka4,
Y. Koike3, T. Adachi2 and I. Matsuda1
12Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Department of Engineering and Applied Sciences, Sophia University, Tokyo 102-8554, Japan.
3
Department of Applied Physics, Tohoku University, Sendai 980-8579, Japan.
4
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan.

It is believed that in cuprate high-temperature
superconductors, superconductivity appears when the
carrier is doped by elemental substitution. However, inthe electron-doped cuprates R2-xCexCuO4 (R: rare earth)with a T’-type structure, As-grown samples don’t showsuperconductivity and reduction annealing is essential
for it, regardless of Ce doping level [1,2]. This isprobably due to the presence of excess oxygen on theapical site from the CuO2 plane in As-grown samples. A
crucial role of this reduction annealing has been thought
to remove the apical oxygen [3]. In thin-film samples
with large surface area relative to volume, the apicaloxygen was reduced more eﬃciently, resulting in a
non-doped superconductor [4]. On the other hand,
ARPES measurement performed on Pr2CuO4 thin films
reviled that the carrier concentration was comparable tothat of Ce-doped superconductor samples [5].
Therefore, the nature of the electronic structure in T’type cuprates remains elusive. And it is important toinvestigate the carrier concentration dependence inisolation from the actual crystal structure degrees of
freedom.
In recent years, several studies have shown that thecarrier concentration in cuprate high-temperature
superconductors can be controlled by alkali metal
adsorption [6,7,8]. And our group has previously used asimilar technique for a Mott insulator Ca3Ru2O7 withsuccessful carrier dosing [9]. This method can dope
electrons on the sample’s surface without changing its
crystal structure, Ce concentration, and oxygen amount.
That is, if this method is eﬀective enough, we candistinguish the eﬀects of apical oxygens from that ofcarrier concentration.
We have carried out the ARPES measurement on
Pr1.22La0.7Ce0.08CuO4 As-grown samples at BL5U at 8 K
and dosed K on them. To verify the K deposition, werecorded the core level peaks of K 3p and O 2s (Fig.1).
The figure shows K was dosed eﬀectively. Fig.2 showsthe energy distribution curves at the nodal cut before
and after dosing of K. After 10 minutes of dosing, thequasi-particle spectrum around the Fermi level
enhanced, and the nodal gap looks closing. After
experimenting with various deposition times anddeposition counts, we currently concluded that fewer

and longer depositions lead to more electron electrons
being doped.

Fig. 1. Energy distribution curves around the K corelevel

Fig. 2. Energy distribution curves at nodal cut[1] Y. Tokura, et al. Nature 337 (1989) 345.
[2] H. Takagi et al. Phys. Rev. Lett. 62 (1989) 10.
[3] M. Horio et al. Nat. Commun. 7 (2016) 10567.
[4] O. Matsumoto et al. Physica C 469 (2009) 924.
[5] M. Horio et al. Phys. Rev. B 98 (2018) 020505(R)[6] Q. Gao et al. Chinese Phys. Lett. 37 (2020) 087402.
[7] S. Kunisada et al. Science 369 (2020) 833.
[8] C. Hu et al. Nat. Commun. 12 (2021) 1356.
[9] M. Horio et al. UVSOR activity report 2021 49(2021) 79.

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Polarization Dependent Orbital States in Mn3-xGa Studied by angle-resolved
Photoemission Spectroscopy
J. Okabayashi1, Y. Miura2, K. Tanaka3, K. Z. Suzuki4 and S. Mizukami4
1

Research Center for Spectrochemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
2
National Institute for Materials Science (NIMS), Tsukuba, 305-0047, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585
4
WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8579, Japan

Magnetic ordered alloys have attracted significant
attention for use as spintronics materials because they
are highly likely to exhibit perpendicular magnetic
anisotropy (PMA). Tetragonal Mn3-xGa alloys arewidely recognized as hard magnets which exhibit
highly anisotropic, ferrimagnetic, and metallic
properties [1]. We have investigated the mechanism of
PMA and large coercive fields in Mn3-xGa by x-ray
magnetic circular and linear dichroisms (XMCD /XMLD) [2]. The origin of PMA in Mn3-xGa alloys canbe explained by the quadrupole contribution along thez-axis by the charge distribution. The specific crystalline
structures provide the elongated c-axis direction, which
induces the anisotropic chemical bonding, resulting in
the anisotropy of electron occupancies in 3d states.
However, orbital magnetic moments in the Mn sites arealmost quenched because of the half-filled occupation.
Although the site-specific charge distributions can beaccessed by x-ray absorption spectroscopies, the originof quadrupole-induced PMA from the viewpoint of theband structures in Mn3-xGa alloys is not fully understood.
Here, we employ the angle-resolved photoemission
spectroscopy (ARPES) to unveil the anisotropic band
structures in Mn3-xGa by the comparison with thedensity-functional
theory(DFT)
calculations.
Especially, in order to clarify the anisotropic electronic
structures, the polarization dependent APRES arenecessary.
30-nm-thick Mn3-xGa samples were prepared on
MgO (001) substrate using sputtering technique. On
the surface of Mn3-xGa layer, the Mg and MgO capping
layers were deposited. The MgO layer was removed by
Ar-ion sputtering and the Mg layer was removed byannealing just before the ARPES measurements. We
construct the method to remove the Mg layer which
does not react chemically with Mn atoms at theinterface. Clear low-energy electron diﬀraction (LEED)
patterns were also obtained.
ARPES was performed at BL5U, UVSOR, where thephotoemission chamber is connected to the sample
preparation chamber. The measurement conditions
were set at 15 meV energy resolution and 10 K. Linear
polarized beams of s- and p-polarization were used todetect the orbital symmetry. We employ the photon
energy ranges of 60 – 80 eV to enhance the Fe 3d

photo-ionization cross section, where the Γ-X(M) line
is scanned by the angular mode of ±15°.
Figure 1 shows the Fermi surface mapping taken at
photon energy of 70 eV. Assuming the inner potentialof 10 eV and the work function of 5 eV with the lattice
constant along c-axis as 3.90 Å, Γ point can be accessed
at 70 eV photon energy. Figures 1(a) and 1(b) show thevertical (s-polarized) and horizontal (p-polarized) casesin Mn3Ga. Four-hold symmetric lines are detected.
High intensity spots appear at the Γ point and they havea character of yz orbital because it can be detected by
the s-polarized beam in vertical geometry andreproduced by the density-functional-theory (DFT)
calculations.
We discuss the quadrupole formation. In the DFT
calculations, the virtual spin-flip transitions fromoccupied up-spin yz to down-spin z2 orbitals correspondto the finite matrix element to the PMA in theperturbation. Therefore, occupied yz orbitals detectedby ARPES contribute to spin-flipped yz-z2 oblate
quadrupole charge distribution, resulting in the PMA.
Our finding explains the origin of PMA in Mn3-xGa
comes from not orbital moment anisotropy but
elongated charge distribution through the spin-flipped
transition in specific orbitals [3], whose results are also
supported by XMCD and XMLD [2].

Fig. 1. ARPES images of Mn3Ga taken at hv=70 eV
using (a) s-polarized beam and (b) p-polarized beam.
[1] S. Mizukami et al., Scr. Mater. 118 (2016) 70.
[2] J. Okabayashi et al., Sci. Rep. 10 (2020) 9744.
[3] Y. Miura and J. Okabayashi, J. Phys.: Cond. Mater
34 (2022) 473001.

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Impact of Electron Scattering on Seebeck CoeﬃcientK. Kandai1, K. Kuga1, 3, M. Matsunami1, 2, 3, 4 and T. Takeuchi1, 2, 3, 4
1
Toyota Technological Institute, Nagoya 468-8511, Japan
Research Center for Smart Energy Technology, Toyota Technological Institute, Nagoya 468-8511, Japan
3
CREST, Japan Science and Technology Agency, Tokyo 102-0076, Japan
4
MIRAI, Japan Science and Technology Agency, Tokyo 102-0076, Japan2

The thermoelectric power generation has been
considered as one of the most important technologies
for constructing a sustainable society. The thermoelectric
devices can directly convert heat and electricity using
Seebeck and Peltier eﬀects. The maximum eﬃciency ofthermoelectric generator at an absolute temperature T isexpressed as an increasing function of the dimensionlessfigure of merit ZT = S2T/ρκ, where S, ρ, and κ are theSeebeck coeﬃcient, electrical resistivity, and thermal
conductivity, respectively, of constituent materials [1].
In the research field of thermoelectric materials, thethermoelectric properties, particularly for Seebeck
coeﬃcient, are frequently interpreted and predicted on
the basis of electronic structure calculated with density
function theory (DFT). However, the Seebeck
coeﬃcient of the materials with unconventional
electronic structures, such as strongly correlated
electron systems (SCES), cannot be accurately
described in terms of only the electronic density ofstates obtained with first-principles DFT calculations.
In the theoretical point of view, the main reason is thatthe energy dependence of relaxation time in the
scattering process of conduction electrons is notconsidered [2, 3]. Although the first principles
calculations incorporating dynamical eﬀects are now inprogress, it is still diﬃcult to accurately treat an electron
correlation eﬀect. In any case, it is necessary toexperimentally evaluate the energy dependence of therelaxation time to verify how it aﬀects the Seebeck
coeﬃcient. The strong electron correlation is considered
as one of the key concepts for developing nextgeneration thermoelectric materials because some
SCES materials possess superior thermoelectricperformance. Therefore, for constructing the guiding
principle to develop high-performance thermoelectricmaterials using SCES, it is very important to identify
the origin of the preferable thermoelectric properties.
The main purpose of this research is to establish amethodology for experimentally evaluating the energy
dependence of the relaxation time of conduction
electrons using angle-resolved photoemission
spectroscopy (ARPES). As a first step toward achieving
this purpose, we select the elemental Cu metal as asample because the Cu can be expected to show no
significant energy dependence of relaxation time of
conduction electrons based on its simple electronic

structure and band dispersion.
Clean (110) surface of single crystalline Cu was
prepared by in-situ Ar sputtering and subsequentannealing under ultra-high vacuum condition. The
ARPES measurements were performed in the energy
range of 32-160 eV at the undulator beamline BL5U of
UVSOR facility.
Figure 1 shows the ARPES image of Cu (110) surface
at 9 K measured with the photon energy of 100 eV. The
free electron-like parabolic dispersion of the (bulk)
conduction band is clearly observed in the energy range
down to -3 eV below the Fermi level. The energy
dependent relaxation time of conduction electrons canbe estimated from the peak width both of energy
distribution curves and momentum distribution curves.
As expected, we confirmed that the energy dependenceof the relaxation time shows less significant variation
across the Fermi level.

Fig. 1. ARPES image of Cu (110) surface at 9 K
measured with 100 eV.
[1] T. Takeuchi, J. Thermoelectrics Soc. Jpn. 9 (2012)
1.
[2] Y. Xia et al., Phys. Rev. Applied 11 (2019) 024017.
[3] B. Xu et al., Phys. Rev. B 102 (2020) 155128.

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BL5U

Temperature Dependence of the Band Folding in TiSe2
S. Tanaka1, K. Ueno2, K. Fukutani3 and K. Tanaka3
2

1
Sanken, Osaka University, Ibaraki 567-0047, Japan.
Graduate School of Science and Engineering Saitama University, Saitama 338-8570, Japan.
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan.

Layered material TiSe2 is one of the TransitionMetal-Dichalcogenide (TMDC) and has extensively
studied for decays as a typical system of ChargeDensity-Wave (CDW) transition. Although excitonic
condensation is considered to be the most importantfactor in the CDW transition in TiSe2 thanks to many
experimental and theoretical studies, there are still
many unanswered concerns regarding the electrical andatomic structure upon the CDW transition at ~200K. In
this article, we use angle-resolved photoelectron
spectroscopy (ARPES) to examine how TiSe2’s
electronic structures change with temperature. We
focus on the specifics of the band folding brought on by
the reconstruction of the (2x2x2) superstructure as aresult of the CDW transition.
Figs.1 displays the ARPES spectra at 190K (a) and8K (b) with photon energies of 46eV. The electron
pocket at M-points (commonly referred to as the
conduction band) and the hole pocket at Γ points(commonly referred to as the valence band) combine toform bands close to the Fermi level in TiSe2. As a resultof the CDW transition, where the M point of the originallattice is folded to the Γ point in the rebuilt lattice, ourmeasurements show that the replica of the valence bandat the Γ point is clearly visible at the M point at 8K.
This is in agreement with how the Brillouin zone wasrecreated when the CDW transition created the (2x2x2)
superlattice. The replica of the conduction band at the
M point, on the other hand, is faintly visible even at 8K.
We discovered that this replica’s intensity greatly
fluctuates with photon energy and is quite low athν=46eV. Moreover, the intensity distribution at the M
point significantly changes at two temperatures (see thethird panel from the top). This can be explained by the
Fermi surface modulation along the kz line due to the
CDW transition.
Together with the production of replicas and changes
in the intensity distribution, the energetic profile of theband changes with temperature. At low temperatures,the valence band’s energy location is visibly moved
downward (see the second panel from the top). This isa defining trait of the bigger gap development broughton by the CDW transition’s associated excitonic
condensation. The replica located at M at 9K is alsoenergetically displaced to the original valence band at
the same temperature. Although the specifics are still

being examined, it might also be linked to themodulation of the band along the kz line.
It should be noted that the replica at M can be dimly
detected at 190K, which is considerably lower than thereference’s CDW transition temperature. We looked
more closely at how the ARPES spectra change withtemperature and discovered that the reported
temperature of the CDW transition is around thetransition temperature determined by energetic profile,which is substantially higher than that determined byreplica intensity. Investigations are currently ongoing
to determine the physical cause of this behavior.

Fig. 1. ARPES spectra of TiSe2 taken at 190K (a) and8K (b). Upper two panels for (a) and (b) show theintensity maps along the energy-angle axes. Lower twoshow the iso-energy intensity maps along the x- andy-angles at the binding energies of 0eV and 0.4eV.

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Doping-Dependent ARPES Study of Nodal Dirac Semimetal Candidate
LaTeSb and LaTeBi
R. Saitou1, N. Kataoka1, T. Wakita1, H. Kageyama1, R. Kondo1 and T. Yokoya1,21Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
2
Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan

LnTe1+xSb1-x (Ln: lanthanides) is a layered material
consisting of alternative stack of a layer of LnTe and alayer of a single Sb square lattice. It is theoretically
predicted as a nodal line semimetal [1]. In addition, by
selecting a magnetic element as Ln, it is possible tobreak the time-reversal symmetry. Therefore, it is amaterial that has the potential to access novel
topological phases [2-5]. Our research group are
making an eﬀort to control the physical properties ofrelated materials by introducing magnetic elements,
substituting Sb with Bi, and changing carrier
concentration [6] for the purpose of observing theexotic transport properties peculiar to Dirac electrons.
In the present study, we have performed synchrotron
angle-resolved photoemission spectroscopy (ARPES)
to experimentally observe the electronic structure of
the non-magnetic phase and check whether the carrier
concentration can be controlled by changing the Teconcentration.
LaTe1+xSb1-x (x = -0.1 and 0.2) and LaTe1+xBi1-x (x =0.2) single crystal samples were prepared by a self-flux
method. ARPES measurements were performed at
BL5U of UVSOR III. Linear polarized light of 70-110
eV energies were used. The energy resolution was set
to ~ 40 meV. All samples were cleaved in situ on the(001) plane in an ultrahigh vacuum of less than 5.0 x
10-9 Pa and were measured at 20 K.
Figure 1(a) shows the valence band dispersion of
LaTe1.2Bi0.8 along the Γ-M direction in the Brillouinzone (BZ), measured with the photon energy of 94 eV.
White regions, which are the higher-intensity regions,correspond to band dispersions. The band dispersionsof the two samples are symmetric with respect to thehigh symmetry points: Γ and M of the bulk BZ of
LaTe1+xBi1-x. This indicates that the band dispersions
reflect intrinsic electronic structure of the sample.
Figure 1(b) is the valence band dispersion of
LaTe1.025Bi0.975 measured with the same experimental
condition. Although there are small diﬀerences in theintensity distribution between the two ARPES maps,
which may originate from the diﬀerence in the conditionof the measured surface, the band dispersions of thetwo maps look very similar with each other. On theother hand, from a careful comparison, it was foundthat the energy positions of the structures in the x = 0.2

sample shift to the higher biding energy side by ~ 100
meV. Two guidelines to demonstrate the energy shift ofstructures at the Γ point were shown with orange dottedlines. This indicates that increasing Te concentration
works as electron doping and one can control the
relative energy between the Dirac nodal line and the
Fermi level (EF) by changing the relative concentration
between Te and Bi. Since the energy position of the
Dirac nodal line in the x = 0.025 sample was found tobe located above EF, the Dirac nodal line in the x = 0.2
sample may be located closer to EF or just at EF. Further
ARPES studies along the X-R line in the Brillouinzone, where the Dirac nodal line is expected to islocated by band structure calculations, is planned toconfirm this anticipation.

Fig. 1. Comparison of ARPES intensity maps along theΓ-M direction of LnTe1+xBi1-x between (a) x = 0.2 and(b) x = 0.025, measured with 94 eV photons and at 20
K.
[1] A. Weiland et al., APL Mater. 7 (2019) 101113.
[2] Y. Wang et al., Phys. Rev. B 103 (2021) 125131.
[3] S. Yue et al., Phys. Rev. B 102 (2020) 155109.
[4] P. Gebauer et al., Chem. Mater. 33 (2021) 2420.
[5] L. M. Schoop et al., Sci. Adv. 4 (2018) eaar2317.
[6] R. Kondo, in preparation.

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Symmetry Reduction of the Electronic Structure in Heavily Overdoped PbBi2201 Observed by Angle-resolved Photoemission Spectroscopy
Y. Miyai1, T. Kurosawa2, M. Oda3, M. Arita4, K. Tanaka5, S. Ideta4 and K. Shimada4
1
Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
Fuculty of Science and Engineearing, Muroran Institute of Technology, Muroran, 050-8585, Japan3
Department of Physics, Hokkaido University, Sapporo 060-0809, Japan
4
Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
5
UVSOR-III Synchrotron, Institute for Molecular Science, Okazaki, 444-8585, Japan2

cuprateHightransition-temperature(TC)superconductors have attracted much interest since
their discovery in 1986 for their high superconducting
transition temperature as well as unusual physicalproperties such as a pseudogap state and a nematic
phase [1, 2]. Superconductivity occurs in the CuO2
plane and the Cu 3dx2-y2 state forms the Fermi surface(FS). One can expect a four-fold symmetry of the FS
because the CuO2 plane is tetragonal. However,symmetry reduction of the electronic structure has beenreported in Bi-based cuprate superconductors recently[2, 3]. Similar symmetry reduction or nematicity was
found in iron-based superconductors, the electronic
states break the four-fold rotational symmetry of thelattice [4, 5]. Although nematicity in electron liquids
has attracted much interest, the rotational symmetry
breaking in the electronic states for high-TC cuprate
superconductors has not been clarified yet.
Here, we have examined the symmetry of theelectronic
structureofheavily
overdoped(Bi,Pb)2Sr2CuO6+δ (Pb-Bi2201) (TC < 2.5 K) using highresolution angle-resolved photoemission spectroscopy(ARPES). We selected Bi2201 because it has a single
CuO2 plane and one can exclude the complexity of theelectronic structure such as bilayer splitting derived
from two CuO2 planes. Furthermore, the pseudogap
disappears in the heavily overdoped sample and one
can clearly see the entire FS in the normal state without
Fermi arc.
Figures. 1(a) and 1(b) show the FS obtained byrotating the sample around the two nodal directions
taken at hν = 60 eV and T = 20 K with the s-polarizationgeometry. We have found that the value of 2kF (kF:
Fermi momentum) for the two nodal directions are
diﬀerent; 2kF(1) = (7.996 ± 0.003) × 10-1 Å-1 (Fig. 1(a))
and 2kF(2) = (8.572 ± 0.003) × 10-1 Å-1 (Fig. 1(b)). Thisdiﬀerence independents of temperature from T = 20 K
to 260 K. In addition, we reveal that the energy
dependence of the quasiparticle lifetime broadening is
also diﬀerent for these two nodal directions. The
situation is similar for the samples with TC = 4, 6, and
10 K. Our results indicate C4 symmetry breaking of theelectronic structure in the CuO2 plane in the heavily

overdoped Pb-Bi2201, which might be related to acharge order formation in the heavily overdoped PbBi2201 as observed by resonant inelastic X-ray
scattering [6], and/or the nematic phase associated with
the Pomeranchuk instability as suggested by Raman
scattering measurements on Bi2212 [7].

Fig. 1. (a), (b) Fermi surface mapping obtained byrotating around the two nodal directions taken at hν =60 eV and T = 20 K with the s-polarization geometry.
Red and blue markers indicate the Fermi surface points
determined from the peaks of the momentum
distribution curves. We determine 2kF values (2kF(1) and2kF(2)) for the two nodal directions as shown in the inset
of panel (b).
[1] M. Hashimoto et al., Nat. Phys. 10 (2014) 483.
[2] S. Nakata et al., npj Quantum Mater. 6 (2021) 86.
[3] Y. Zheng et al., Sci. Rep. 7 (2017) 8059.
[4] H. C. Xu et al., Phys. Rev. Lett. 117 (2016) 157003.
[5] J-H. Chu et al., Science 329 (2010) 824.
[6] Y. Y. Peng et al., Nat. Mater. 17 (2018) 697.
[7] N. Auvray et al., Nat. Commun. 10 (2019) 5209.

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Far- and Mid-infrared Absorption on the Single-crystal Pentacene
Y. Nakayama1, 2, K. Yamauchi1, Y. Baba1 and J. Miyamoto1
1

Department of Pure and Applied Chemistry, Tokyo University of Science, Noda 278-8510, Japan
2
Institute for Molecular Science, Okazaki 444-8585, Japan

Electronic coupling with molecular vibrations and/or
lattice phonons is one of the key issues for theconsideration of charge carrier transport in organic
semiconductor solids. In the present work, we
conducted infrared absorption measurements on the
pentacene single-crystal (PnSC) samples as a modelcase of high-mobility organic semiconductors for the
elucidation of the electron-vibration coupling in welldefined solid-state molecules.
Infrared absorption measurements were carried out at
BL6B. A Si bolometer or a HgCdTe detector was used
for the signal detection in a wave number range of
100 – 700 cm−1 (FIR) or 700 – 7000 cm−1 (MIR),
respectively. Details of the PnSC samples andmeasurement geometry were the same as reported
previously [1]. The data were collected by changing thesample azimuthal angle by 180° in 15° and 45° intervals
for the FIR and MIR measurements, respectively. In
this report, angularly averaged spectra were used forthe analyses. Spectra measured through a diamondplate were adopted as blank spectra (I0) to derive theabsorbance of PnSCs.
Figure 1 shows a typical FIR spectrum of PnSC in aregion where prominent peaks were observed. A
persistent background modulation of a “frequency” at(5.9 ± 0.2) cm−1 is filtered out for further analyses. The
spectral feature can be attributed to two vibration
modes predicted to be at 476.9 cm−1 and 491.7 cm−1. In
the present measurements, twenty vibration modes
were assignable in the spectra. Energy deviations of theexperimental vibration peaks with respect to thetheoretical values calculated in the B3-LYP/6-31g(d)level are plotted in Fig. 2, where a recommended “scale
factor” for the calculated wavenumbers [2] is indicatedas a standard. As the vibration mode #88 (in-planescissoring of the backbone) exhibited the best match,
the relative intensity for each spectral peak is derived
with respect to the mode #88 intensity and plotted as afunction of the corresponding calculated relative
intensity in Fig. 3. Further discussion on the results is
yet under consideration.

Fig. 2. Energy deviation of the experimental peak
positions with respect to the calculated values. The sizeof the symbols indicates the peak intensity.

Fig. 3. Experimental relative peak intensity plotted asa function of the calculated magnitudes. The color of
the symbols corresponds to the mode number indicatedin Fig. 2. The inset image shows the mode #88 vibrationof the pentacene molecule.
[1] Y. Nakayama and J. Miyamoto, UVSOR Activity
Report 2020 (2021) 83.
[2] J. P. Merrick, D. Moran and L. Radom., J. Phys.
Chem. A 111 (2007) 11683.

Fig. 1. FIR absorption spectrum on the PnSC.

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BL7U

ARPES Study of a chalcopyrite-type Topological Insulator Candidate
T. Iwaya1,, A. Honma1, K. Nakayama1, K. Sugawara1,2, S. Souma2,3, K. Tanaka4,5,
T. Takahashi1, K. Segawa6 and T. Sato1,2,3,7
1

Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
3
Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Sendai 980-8577, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan
6
Department of Physics, Kyoto Sangyo University, Kyoto 603-8555, Japan
7
International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University,
Sendai 980-8577, Japan
2

Three-dimensional topological insulators (3D TIs)
are a novel quantum state of matter where the bulk
band gap induced by a strong spin-orbit coupling leads
to the appearance of gapless Dirac-cone surface states
protected by time-reversal symmetry. The discovery of
3D TIs has further stimulated the search for novel
topological materials. From the viewpoint of the crystal
symmetry, most of the 3D TIs so far discovered, e.g.,
Bi2Se3, Bi2Te3, and TlBiSe2, have the spatial inversion
symmetry in the crystal. On the other hand, there areseveral theoretical proposals of TI candidates withbroken inversion symmetry. There is a demand to
experimentally discov such symmetry-broken phasebecause a peculiar phenomenon which cannot berealized in inversion-symmetric TIs is predicted toemerge.
Here we focus on CdGeAs2 which crystalizes in achalcopyrite structure with I̅ 42d space group. As seenfrom Fig. 1(a), the crystal consists of a stack of zinc
blend structure and hence breaks the inversion
symmetry. Recent theoretical study predicted CdGeAs2
to be a topological insulator [1]. Owing to the inversion
symmetry breaking, CdGeAs2 can have nontrivial
Fermi arc surface states and lead to a giant
magnetoelectric eﬀect. To establish a material platformof such exotic phenomena, experimental elucidation of
the topological properties in CdGeAs2 is highly desired.
In this study, we have performed high-resolution
angle-resolved photoemission spectroscopy (ARPES)
of CdGeAs2 at BL7U. Single crystals of CdGeAs2 weregrown by the vapor-phase growth method. Clean
surfaces for ARPES were obtained by in situ cleavingof the crystals. By x-ray laue diﬀraction, the cleaved
surface was determined to be (101) plane. ARPES
measurements were performed by using a MBS-A1
spectrometer at BL7U with linearly-polarized energytunable photons.
Figure 1(b) shows the ARPES intensity plot along a
momentum cut crossing the Γ point of the bulk Brillouinzone. We observed several highly dispersive hole-likebands centered at the Γ point. These bands are
reproduced by the band calculations shown by red

curves and attributed to the bulk valence bands withdominant As 4p orbital character. We further performed
detailed measurements over the entire Brillouin zone
with tuning photon energies to find a signature of the
topological surface states.

Fig. 1. (a) Three-dimensional view of the crystal
structure of CdGeAs2. (b) ARPES intensity plotted as afunction of binding energy and wave vector measured
in CdGeAs2. Red curves are the result of first-principles
band structure calculations.
[1] K. Osumi et al., Commun. Phys. 4 (2021) 211.

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Electronic Structure of the five-fold oxygen-coordinated Cuprate
Superconductor
M. Horio 1, M. Miyamoto1, X. Peiao2, K. Tanaka3, T. Taniguchi2, M. Fujita2 and I. Matsuda1
1Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
2
Institute for Materials Research, Tohoku University, Katahira, Sendai 980-8577, Japan
3
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

Structural isomers of so-called 214-type cuprates
provide a unique platform for studying the eﬀect ofoxygen coordination on the electronic structure ofcuprate superconductors. The local oxygen coordination
around copper can be varied from a six-fold octahedron(T-type) to a four-fold square plane (T’-type). It is
known that a decrease in the oxygen coordination
number leads to a decrease in the charger-transfer gap
and hence electron correlation [1]. However, while theT-type cuprates can be doped only with holes, the T’type cuprates do not usually accept hole doping [2],preventing direct comparisons. On the other hand, T*type cuprates with five-fold pyramidal oxygen
coordination can be hole-doped and are directlycomparable to the T-type one [3]. Optical conductivity
studies of the parent compound suggest that T*-type
cuprates have a smaller charge transfer gap than T-type[1]. As-grown samples of the T*-type cuprates are
known to have oxygen defects in the apical site, and inorder to induce superconductivity, post-growth highpressure oxygen annealing is required [3,4]. Recent
oxygen K-edge x-ray absorption spectroscopy (XAS)
studies [5] found a dramatic increase in doped holes
upon oxygen annealing, consistent with compensationof oxygen defects. The Tc of O2-annealed T*-SmLa1xSrxCuO4 (SLSCO) monotonically increases withdecreasing Sr concentration [6], in contrast to thedome-like behavior of the T-type La2-xSrxCuO4 (LSCO).
The diﬀerent superconducting properties between T*and T-type cuprates suggest a significant diﬀerence inthe electronic structure associated with a change in thecoordination number of oxygen. However, theelectronic structure of T*-type cuprates, including its
evolution by annealing, is still largely unknown [7],even 35 years after its discovery. In this work, we
performed angle-resolved photoemission spectroscopy(ARPES) measurements on the T*-type cuprates T*SLSCO.
Single crystals of T*-SLSCO (x = 0.25) were grownby the travelling-solvent floating-zone method. After
post-growth O2 annealing at 500 ℃ and 45 MPa for 72
hours, the sample showed superconductivity below Tc= 17 K. ARPES measurements were performed at
BL7U of UVSOR at T = 7 K and hν = 18 eV.
Fig. 1 presents ARPES spectra obtained from T*SLSCO. While the spectral weight becomesdiminishingly small as approaching the Fermi level,
Fermi crossing is observed for the nodal spectrum (#1).
As moving away from the nodal region, the band
become gapped with a strong suppression of thespectral weight, signifying the opening of a pseudogap.
According to a previously reported phase diagram for
T*-SLSCO, x = 0.25 corresponds to deep in theoverdoped region. This is apparently incompatible withthe present observation of the robust pseudogap, which
is typical of underdoped or optimally doped samples.
The result suggests a potentially unique phase diagramof T*-type cuprates, which deserves further systematicinvestigations with varying hole concentrations.

Fig. 1. ARPES spectra of O2-annealed T*-SLSCO (x =0.25). (a)-(f) Energy-momentum maps from the nodal
to antinodal regions. Cut positions are indicated in (g).
(h) Energy distribution curves at each kF point.
[1] Y. Tokura et al., Phys. Rev. B 41 (1990) 11657.
[2] N. P. Armitage et al., Rev. Mod. Phys. 82 (2010)2421.
[3] J. Akimitsu et al., Jpn. J. Appl. Phys. 27 (1988)
L1859.
[4] F. Izumi et al., Physica C 158 (1989) 440.
[5] S. Asano et al., J. Phys. Soc. Jpn. 89 (2020) 075002.
[6] T. Kakeshita et al., J. Phys.: Conf. Ser. 150 (2009)052089.
[7] A. Ino et al., Physica B 351 (2004) 274.

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Angle-Resolved Photoemission Study of Solid Electrolytes Li3xLa2/3-xTiO3
Bulk Single Crystal
S. Koyama1, M. Nakatake2, S. Takakura3, K. Tanaka4,5,
Y. Fujiwara6, T. Taishi6, H. Moriwake7, Y. Iriyama1 and T. Ito1,3
1

Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan
2
Aichi Synchrotron Radiation Center, Seto, 489-0965, Japan
3
Synchrotron radiation Research center, Nagoya University, Nagoya 464-8603, Japan
4
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
The Graduate University for Advanced Studies, Okazaki 444-8585, Japan
6
Faculty of Engineering, Shinshu University, Nagano 380-8553, Japan
7
Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587, Japan

With the recent expansion of the use of lithium-ion
secondary batteries, development of all-solid-statebatteries using lithium-ion conductive inorganic solid
electrolytes has been progressing to realize further
safety, high energy density, and high output, etc. On theother hand, the valence-band electronic structure,
which is essential to understand the relation between
lithium-ion and electron conductivity in inorganic solid
electrolytes, has not been well elucidated yet, though
the chemical analysis using operand X-ray
photoemission has intensively been applied on thesystem [1,2]. In this study, we have performed angleresolved photoemission spectroscopy (ARPES)
measurements on Li3xLa2/3-xTiO3 (LLTO) bulk single
crystals to clarify the eﬀect of lithium on the electronic
structure of solid electrolytes. The results werecompared with the ARPES study on LixLa(1-x)/3NbO3(LLNbO) in which relatively lower Li ion conductivity
has been reported [3].
ARPES measurements were performed at the
UVSOR-Ⅲ BL7U. Data were acquired with hν = 18 eVat room temperature. To minimize spectral modification
due to photo-irradiation, photon flux was suﬃciently
reduced (<3E+10 photons/s) during all measurements.
Single crystals were cleaved in situ along (100) plane,
where La/Li rich (A1) and La/Li poor layers (A2)appear alternately (inset: Fig.2 (a)).
Figure 1 (a) and (b) show ARPES spectra and band
structure along the ΓX line of LLTO, respectively. The
observed band structure mainly consists of two peaks
around 4 and 7 eV with the band gap about 3 eV. Fromthe comparison with DFT calculation (Fig. 2(a)) [4], wefound that the valence band width (~5 eV) seems to be
similar between the ARPES and calculation.
When we compare the ARPES band structure
between LLTO and LLNbO bulk single crystals [3], wefound that the valence band width of LLTO becomes
about 1 eV narrower than LLNbO, while the band gap
size observed as almost the same. In Fig. 2(a) and (b),the observed diﬀerences of band width as well as the
spectral features between LLTO and LLNbO are
qualitatively reproduced by the DFT calculations. The
results indicate the applicability of ARPES to study theelectronic structure of solid electrolytes single-crystal.

Fig. 1. ARPES spectra (a,c) and band structures (b,d)
along the ΓX line of Li3xLa2/3-xTiO3 (a,b) andLixLa(1-x)/3NbO3 (c,d), respectively. Solid and dashedlines are guides for eyes.

Fig. 2. The partial density of states of Li0.2375La0.5875TiO3[4] (a) and La1/3NbO3 (b), respectively. Inset of eachpanel shows average crystal structures of LLTO andLLNbO, respectively.
[1]K. Hikima et al., Commn. Chem. 5 (2022) 52.
[2]K. N. Wood et al., Nature Commun. 9 (2018) 2490.
[3]Y. Fujiwara et al., J. Cryst. Growth 433, 48-53(2016); Y. Fujiwara et al., Jpn. J. Appl. Phys. 55,
090306 (2016).
[4]K. Dai et al., J. Mater. Sci. 57 (2022) 2825.

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BL7U

Electronic Structure of Layered Nitride Chloride ZrNCl by ARPES
N. Kataoka1, R. Saitou1, M. Tanaka2 and T. Yokoya1,31Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
2
Graduate School of Engineering, Kyushu Institute of Technology, Kitakyushu 804-8550, Japan
3
Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan

spectrum near EF shows a small structure, whose energy
position and spectral shape are similar to the structure
before K deposition (Figure 2), although the intensity
increases after K deposition. Based on previous studies,
the structure before evaporation may be a state causedby hydrogen impurities[5]. Further studies, including
comparison with theoretical studies that also take thesurface state into account, are necessary to understandthese observations.

Fig. 1. 2nd-derivative ARPES intensity maps along
Γ-M of ZrNCl before (a) and after (b) K deposition.

Normalized intensity(arb. units)

Electron-doped layered nitride chloride ZrNCl shows
superconductivity of Tc ~ 16 K by intercalating alkali
metals between the layers[1]. Observed exotic
properties have suggested that its superconducting
properties are diﬃcult to be explained by the BCS
theory[2]. Theoretical studies have proposed a model
mediated by spin fluctuations[2] and a superconducting
mechanism with a BCS-BEC crossover[3]. However,there are no experimental observations of the electronic
structure by ARPES measurements, and thesuperconducting
mechanismhasremainedundetermined. This is due to the fact that alkali metalinserted ZrNCl is easily oxidized in the atmosphere andthat it is diﬃcult to obtain large single-crystal samples.
In this study, we prepare electron-doped ZrNCl bydepositing alkali metals in vacuum on a relatively large
parent material. The electronic structure of ZrNCl
before and after alkali metal deposition is studied by
ARPES.
Samples were prepared by vacuum evaporation oncleaved ZrNCl single crystals at room temperature inultrahigh vacuum using a Potassium(K) deposition
source. The samples were transferred from theevaporation chamber to the measurement chamber.
ARPES measurements were performed at BL7U of
UVSOR III with 28–40 eV photons and an energy
resolution of 15~20 meV. The measurement temperature
was 40 K.
Figures 1(a) and 1(b) show the band dispersion of
Γ-M line in ZrNCl before and after K deposition.
Before deposition, the top of the valence band was
located at ~ 3.0 eV at the Γ point and the bottom of thevalence band was located at ~ 8.3 eV at the M point.
After K deposition, the band near the Γ point, the top of
the valence band, is shifted to the higher binding energy
side by about 100 meV. The energy position of thebottom of the valence band at the M point did notchange significantly. A theoretical study predicted abandwidth of 6.1 eV[4] for ZrNCl and significant
expansion of the valence band width by alkali metalintercalation. This is diﬀerent from nearly the sameband width between before and after K deposition.
Regarding the change of the bandwidth by K
evaporation, it is possible that the result is not an
intrinsic change in electronic structure, but rather
reflect an eﬀect of the surface state formed by thedeposition. For near the Fermi energy (EF), after
deposition, a clear dispersive band was not observed at
the K point, where electron pockets are expected toappear theoretically. On the other hand, angle integrated

1.0

ZrNCl
K deposited ZrNCl
Au

0.8

0.6
0.4
0.2
0
Binding energy (eV)-0.2

Fig. 2. Angle-integrated spectra near EF of ZrNCl
before and after K deposition, compared with Au.
[1] Y. Kasahara et al., Physica C 514 (2015) 354.
[2] K. Kuroki, Phys. Rev. B 81 (2010) 104502.
[3] Y. Nakagawa et al., Science 372 (2021) 190.
[4] Z. P. Yin et al., Phys. Rev. X 3 (2013) 021011.
[5] T. Yokoya et al., Phys. Rev. B 70 (2004) 193103.

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Ⅲ-2 Material Sciences

BL7U

Low-Energy ARPES Study on the Electronic Structure of Cr2Se3
C.-W. Chuang1,, T. Kawakami1, T. Kato1, K. Sugawara1,2, K. Nakayama1, S. Souma2,3,
K. Tanaka4,5, A. Chainani6, T. Takahashi1, K. Segawa7 and T. Sato1,2,3,8
1

Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
3
Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Sendai 980-8577, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan
6
National Synchrotron Radiation Research Center, Hshinchu, 30077, Taiwan ROC
7
Department of Physics, Kyoto Sangyo University, Kyoto 603-8555, Japan
8
International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University,
Sendai 980-8577, Japan
2

Transition metal chalcogenides (TMCs) are a groupof materials that have been intensively studied for longtime because of a wide variety of physical properties
depending on their crystal structure and composition,
including superconductivity, metal-insulator transition,and three-dimensional topological insulators. Recently,
TMCs have attracted even more attention because their
atomic layer films show dramatically diﬀerent
properties from those of bulk counterparts, such as
Ising superconductivity, spin-valley Hall eﬀect, twodimensional topological insulators. To understand andcontrol these exotic properties, an experimental study
on the electronic structure of TMCs is of crucial
importance.
Here we focus on a chromium-based TMC, Cr2Se3
with the two-dimensional rhombohedral crystal
structure (NiAs type; P63/mmc). Bulk Cr2Se3 is known
as a thermoelectric material with a large figure of merit.
This material is attracting attention because of
intriguing magnetic properties; bulk Cr2Se3 exhibits acollinear antiferromagnetic order with TN ~ 45 K,
followed by a successive transition to a non-collinear
antiferromagnetic phase [1], whereas monolayer Cr2Se3
was predicted to be a ferromagnet which potentiallyhosts a half metallic ground state [2]. To clarify theinterplay between these magnetic orders and theelectronic structure, we have performed angle-resolved
photoemission spectroscopy (ARPES) measurementsof bulk and monolayer Cr2Se3.
High-quality bulk Cr2Se3 was grown by flux method.
Monolayer Cr2Se3 was grown on graphene/SiC bymolecular-beam epitaxy method. High-resolution
ARPES measurements were performed by using a
MBS-A1 spectrometer at BL7U with linearly-polarizedenergy-tunable photons.
Figure 1 shows representative ARPES results in theantiferromagnetic state of bulk Cr2Se3, i.e. ARPES
spectra measured along a momentum cut crossing the Γpoint [Fig. 1(a)] and the corresponding intensity plot
[Fig. 1(b)]. We observed several band dispersions in theenergy range of the Fermi level (EF) to 5 eV, such as arelatively flat hole-like band near EF and a highly
dispersive hole-like band topped at 2 eV below EF at theΓ point. Upon increasing the temperature, we found afinite change in spectral intensity across TN, indicativeof magnetism-induced electronic reconstructions. We
also measured the photon-energy dependence of theband dispersion and determined the three-dimensionalbulk band structure. In addition, we found a clear
diﬀerence in the band structure and its temperaturedependence between bulk and monolayer Cr2Se3. The
obtained ARPES results were compared with firstprinciples band structure calculations to understand thetemperature- and thickness-dependent changes in theband structure.

Fig. 1. (a) ARPES spectra in the valence band region of
bulk Cr2Se3 measured at T = 30 K with 21-eV photons,and (b) corresponding intensity plot as a function ofbinding energy and wave vector.
[1] Y. Adachi et al., J. Phys. Soc. Jpn. 63 (1994) 1548.
[2] J.-Y. Chen et al., Adv. Electron. Mater. 6 (2020)
2070001.

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BL7U

Polarization-Dependent Photoemission from the Folded Band of TiSe2
S. Tanaka1, K. Ueno2, K. Fukutani3 and K. Tanaka3
2

1
Sanken, Osaka University, Ibaraki 567-0047, Japan.
Graduate School of Science and Engineering Saitama University, Saitama 338-8570, Japan.
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan.

It is crucial for the creation of symmetry-broken
collective phases, such as charge density waves andtopological and superconducting states of matter, thatcrystalline solids have a momentum-dependent orbital
structure. Measurements with the polarizationdependent angle-resolved photoelectron spectroscopy(ARPES) can provide important details on the material’s
orbital texture. Layered material TiSe2, one of thetransition-metal-dichalcogenide (TMDC) and known
as a model system of the charge-density wave (CDW)
transition, is a good candidate to make such a study,
since TiTe2, which has a similar electronic structure to
TiSe2 but does not exhibit the CDW transition, has been
recently well studied by similar method[1].
Fig. 1 shows ARPES spectra near the Γ point at 10K
taken using the vertically polarized photon of 7eV. The
cutting plane along the kx (at ky=0) and ky (at kx=0)
axes is shown in the lower panels, while the upper
panel displays the photoelectron intensity map along
the kx-ky plane at the Fermi level. The band below theBE~0.07eV is the Se4p/Ti3d valence band, and theband near the Fermi level is the replica of the Ti3dderived conduction band originally located at the M
point, which is caused by the formation of the (2x2x2)
superlattice as a result of the CDW transition. The
assignment can be confirmed by the observation of theextinction of this feature at higher temperatures. The
photoelectron intensity distribution, however, isdiﬀerent from the original Ti3d conduction band at M.
White dot lines represent the replica’s anticipatedtraces, which originate from the six nearby M points,
and only a portion of them have photoelectrons visible.
This must be due to the matrix element eﬀect, which
relates to the orbital texture and also discerning
structural and collective phases of the material in the
CDW transition.
We measure the polarization-dependent ARPES byrotating the sample along the surface normal to provide
information about the matrix element eﬀect (azimuthal
rotation). The vertically-polarized photon was used,
and the polarization vector is always parallel to thesample surface. The variation in the photoelectron
distribution as a result of azimuthal angle is depicted in
Figure 2. Shiny branches shift as the polarization
vector’s angle with the sample axis changes. It makes it
evident that the matrix element is crucial, and the indepth research, currently underway, will yield
information regarding the orbital texture of the replicaband formed by the CDW transition.

Fig. 1. ARPES spectra of TiSe2 at 10K. The photon
energy taken was 7eV of vertical polarization.

Fig. 2. ARPES intensity maps near the Fermi level as afunction of the azimuth rotation. The photon of 7eV
with a vertical polarization is used.
[1] S. Beaulieu et.al., npj Quantum Materials 6 (2021)
93.

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Ⅲ-2 Material Sciences

BL7U

Momentum Dependence of the Spectral Weight in the Single Layer HighTc Cuprate Bi2Sr2CuO6+δ Studied by ARPES
Y. Onishi1, Y. Miyai1, Y. Tsubota1, S. Kuma2, M. Atira2, K. Tanaka3, H. Eisaki4, S. Ishida4,
K. Shimda1,2 and S. Ideta1,21Graduate School of Advanced Science and Engineering, Hiroshima Univ., Japan
2
Hiroshima Synchrotron Radiation Center (HiSOR), Hiroshima Univ., Japan
3
UVSOR-III Synchrotron, Institute for Molecular Science (IMS), Japan.
4
National Institute of Advanced Industrial Science and Technology (AIST), Japan

Spectral weight (SW) directly observed by angleresolved photoemission spectroscopy (ARPES) has theinformation of the electronic structure which is related
to the mechanism of high-transition temperature (Tc)
cuprate superconductivity [1-3]. Nonetheless extensive
experimental and theoretical studies have been reported,the mechanism of high-Tc cuprates have not been clear
yet, why their Tc exceeds above ~40 K which cannot be
explained by the BCS theory [4]. To understand themechanism of high Tc in cuprate superconductivity, oneof the essential physical parameters is superfluid
density (ρs) which plays an important role in determining
Tc and might be proportional to SW observed by
ARPES [1,2,5,6]. In this study, we have performed an
ARPES study to investigate the relationship between
coherent spectral weights (SW) on the Fermi surface
directly and Tc in cuprates, which seem to correspondto the magnitude of ρs and Tc [5].
We measure the electronic structure of the singlelayer Bi-based high-Tc cuprate superconductor,
Bi2Sr2CuO6+d (Bi2201), which has one CuO2 layer inthe unit cell and shows a high Tc of 35-40 K at optimal
doping [7]. We have performed ARPES measurements
systematically to directly investigate the electronic
structure of the optimally doped (Tc ~ 35 K) andoverdoped (Tc ~ 30 K) Bi2201. ARPES were carriedout at BL7U, and temperature was set at ~10 K (< Tc)
and 1.5Tc to measure the electronic structure in the
superconducting and normal states, respectively. The
photon energy was hν = 17 eV. High-quality single
crystals of Bi2201 were cleaved in-situ in the ultrahighvacuum ~5×10-9 Pa.
In this study, We have clearly observed Fermi surface(FS) on Bi2201 in the s polarization above and below

Tc. Energy distribution curves (EDCs) are symmetrized
and we have estimated the Fermi momentum (kF) on theentire FS, where the kF is determined by minimum gap
locus method.
Compared with EDC in the
supercondcuting and normal states, we have successfully
observed diﬀerence of the spectral weight even though
the nodal region in contrast with the previous study [6].
We will systematically measured doping dependence of
SW in the nodal direction. From the present study, we
found that the even in the nodal region which shows thezero sueprconducting gap, the nodal region should
contirbute to the supercondcutivity in cuprates. As anext step ,we will measure the momentum dependence
on the entire FS and discuss the distribution of SW on
FS. We will also study the relationship between
pseudogap and the distribution of SW.

Fig. 1. Symmetrized EDC of OPT35K (a) and OD30K(b).
[1] D. L. Feng et al., Science 289 (2000) 277.
[2] H. Ding et al., Phys. Rev. Lett. 87 (2001) 227001.
[3] K. M. Shen et al., Science 307 (2005) 901.
[4] W. L. McMillan, Phys. Rev. 167 (1968) 331.
[5] Y. J. Uemura et al., Phys. Rev. Lett. 66 (1991) 2665.
[6] T. Kondo et al., Nature 457 (2009) 296.
[7] A. Iyo et al., J. Phys. Soc. Jpn. 76 (2007) 094711.

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BL7B

Excitation Spectra of Plastic Scintillators in the Vacuum Ultraviolet Region
M. Koshimizu1, Y. Fujimoto2 and K. Asai3
2

1
Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8011, Japan
Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan

Plastic scintillators consist of host polymer andorganic phosphor molecules and are widely used owing
to their fast response and easy fabrication at large scale.
The scintillation process in the plastic scintillators isroughly described as initial formation of ionization andelectronic excitation and subsequent transfer of theexcitation energy to the phosphor molecules. In theconsideration of the scintillation process, we have toconsider two kinds of electronic excitations: singlet andtriplet states. The triplet states are formed in two
processes: one is the intersystem crossing from thesinglet to the triplet states, and the other is the direct
formation of the triplet states upon recombination ofionization. To analyze the contribution of the latterprocess, we consider that the excitation in the vacuum
ultraviolet (VUV) light may be a convenient tool,
because the excitation by the VUV light produces
ionization at higher probability with the excitation
photon energy. In this study, we measured the excitation
spectra of the plastic scintillators at 50–200 nm.
Plastic scintillators were fabricated using polystyrene
as the host polymer and DPO and POPOP as theprimary and secondary phosphors, respectively. The
samples having diﬀerent phosphor concentrations were
fabricated. The photoluminescence spectra of thesamples were obtained with VUV excitation at BL7B,
UVSOR. The excitation spectra were obtained as theemission intensity in the photoluminescence spectra asfunctions of the excitation wavelength.
The photoluminescence spectra of the samples arepresented in Figure 1. The emission bands are derived
from the singlet excitation of POPOP. The spectra weresimilar at diﬀerent excitation wavelengths. The
excitation spectra of the samples with diﬀerent DPOPOPOP concentrations are presented in Figures 2 and3. The photoluminescence intensity increased andsubsequently decreased as the excitation wavelength
became shorter. The increase in the intensity down to
150 nm can be attributed to production of secondary
excitation. The decrease in the intensity can be
attributed to the enhanced probability of the triplet
formation.

Fig. 1. Photoluminescence spectra of the plastic
scintillators with excitation at 150 nm.

Fig. 2. Excitation spectrum of the plastic scintillators
having DPO-POPOP concentration of 0.5 wt%.

Fig. 3. Excitation spectrum of the plastic scintillators
having DPO-POPOP concentration of 2 wt%.

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Ⅲ-2 Material Sciences

BL7B

Mineral Analysis for Resource Exploration by Deep Ultraviolet Spectroscopy
T. Shimizu, K. Shinohara, K. Yamanoi and N. SarukuraInstitute of Laser Engineering, Osaka University, 2-6 Yamadaoka Suita, Osaka 565-0875 Japan

Vacuum ultraviolet (VUV) light has important
technological applications in photochemical processing,surface treatment, optical cleaning of semiconductor
substrates, and sterilization. In particular, it has beensuggested that non-contact sterilization, treatment, andprocessing may be advanced by using VUV in thecurrent coronavirus pandemic. To keep pace with therapid progress in VUV research and application, it isessential to develop detectors in the short wavelength
range. Conventional detectors are mainly sensitive only
to visible light, and therefore VUV scintillators basedon rare-earth ions and wide bandgap materials havebeen investigated for the detection of VUV. In our
research group, we have developed scintillators withrare-earth ions doped in fluoride materials using widebandgap materials and have achieved good results.
Currently, there is a need to develop a spectrometerfor two-dimensional analysis of broadband light, whichis required in the fields of industrial technology, energy,
and the environment. Imaging spectroscopy is widelyused for the identification of molecular species of gases
and nondestructive analysis of liquids and solids, and is
beginning to be applied to environmental measurements
and resource surveys. In addition to the sorting by
visible light imaging called color sorting, multiwavelength imaging measurement is becoming a key tosolving social problems in the future. In addition, thenon-destructive nature of the measurement reduces theenvironmental burden, and research that integrates thehumanities and sciences, such as the non-contact
analysis of cultural assets, is also expected. If thisimaging spectroscopic measurement can be performed
in a large space, it is expected to make it possible toestimate the location of buried resources without
digging, and to analyze tiles and paints on the walls ofvaluable old temples and shrines.
In the case of resource survey as one of the goals, thedeep ultraviolet region, such as VUV, is compatible
with the absorption and emission of quartz, the mostcommon mineral on earth, for observation, and its
characteristics are well represented. On the other hand,the practical application of imaging spectroscopy
systems, for which technology has been accumulated in
the visible light region, has not progressed due to thelack of optical elements that are compatible with nonvisible light. The applicant has focused on theapplicability of imaging spectroscopy measurement
and has so far succeeded in developing a lens that canbe applied up to deep UV, also using UVSOR [1][2].

Since the preparation of the elements around themeasurement device has progressed significantly up to
this point, the next step is to start evaluating the VUVproperties of the actual minerals.
Typical minerals are known to exhibit fluorescence.
Minerals contain a variety of impurities, which are theactive factors that give rise to fluorescence. In otherwords, by observing fluorescence, it is possible toevaluate the quality of a mineral, making it a powerfultool for resource exploration and environmental
measurement. However, fluorescence observation
requires excitation in the deep ultraviolet. In this study,
we used UVSOR-BL7B to demonstrate whether typicalmineral impurities can be evaluated by PL (photo
luminescence) spectra and PLE (photo luminescence
excitation) spectra.
Fig. 1 shows the measurement results of fluorite. It isconventionally believed that europium is contained influorite as an impurity. The measurement data this timeshows a peak that is certainly derived from europium.
Although the data shown here are for general fluorite,other minerals were also analyzed in the same way, andimpurities were confirmed. It was found that the deep
ultraviolet analysis technique is eﬀective for mineralevaluation. In the future, we will combine this techniquewith our spectroscopic technology and put it to practicaluse as a new technology for resource exploration andenvironmental measurement.

Fig. 1. PL spectra and PLE spectra of fluorite.
[1] T. Shimizu et al., UVSOR Activity Report 2019, 47(2020) 100.
[2] Y. Minami et al., Phys. Status Solidi B, 257(2020)
1900480.

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BL7B

Optical Reflectivity Study of Au-Al-Yb Quasicrystals
H. Okamura 1, A. Kamiki1 , K. Namba2, S. Hirokawa2 and K. Deguchi2
Department of Applied Chemistry, Tokushima University, Tokushima 770-8506, Japan
2
Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan

Since its discovery, quasicrystals (QCs) haveattracted a lot of interest for their unique properties [1].
For example, they do not have a translational symmetry
in the crystal structure but show a clear rotational orderin the measured diﬀraction pattern. Recently, Ybcontaining QCs have been studied in detail [2,3], andthey have revealed a singular behavior of the average
Yb valence as a function of a6D, a six-dimensionallattice parameter of the QC [3]. Namely, the average
Yb valence of a series of Au-Al-Yb QC samples showeda sudden and steep drop, from 2.82 to 2.31, when a6D of
the sample was increased through a critical value of0.74 nm by about 0.01 nm. Valence transitions or
crossovers have been observed in many Yb-containing
crystalline materials such as heavy fermion andintermediate-valence compounds. It is quite interestingwhether or not the singular behavior of the Yb valence
in QCs shares any common feature with the Yb-based
heavy fermion compounds.
To investigate the interesting electronic structures of
Yb-containing QCs, we have been measuring theoptical reflectivity spectra [ܴ(߱)] of Au-Al-Yb QCs
that show the above-mentioned valence-transition-likebehavior. In our experimental method, ܴ(߱) of asample is measured over a wide spectral range between
infrared and vacuum UV, and the Kramers-Kronig(KK) analysis is used to obtain the dielectric function
߳(߱) or the optical conductivity ߪ(߱) from themeasured ܴ(߱). At BL7B of UVSOR, we havemeasured ܴ(߱) between 40 and 600 nm on the six
samples indicated in Table 1. Note that Sample C has
the critical value of a6D, and that the average Yb valence
rapidly decreases from Sample C to F.
Figure 1 indicates the ܴ(߱) spectra of Samples A-F
measured at room temperature. All the samples show
increase of ܴ(߱) toward longer wavelength, with an
onset at around 150-200 nm. Samples C, D and E also
show a clear minimum of ܴ(߱) at 160-200 nm range.
Samples A, B and F, on the other hand, do not show aclear minimum. Namely, there seems to be somequalitative diﬀerence between the two groups ofsamples. The diﬀerence in the onset wavelength
between Samples B and C is particularly clear, although
they are next to each other in Table 1. An onset of highreflectivity in a metallic compound is usually associatedwith the plasma frequency, and is related with thedensity of free electrons. However, to make a detailed
analysis on the electronic structures, we need to obtain
߳(߱) and ߪ(߱) via the KK analysis of ܴ(߱). To do so,
we are currently extending the measurement to theinfrared range, since a wide spectral range of ܴ(߱) is
required to perform a reliable KK analysis. The spectrain Fig. 1 will be connected to those in the infrared range
to obtain ܴ(߱) in a wide spectral range, and will be
used for the KK analysis.
Table 1. Measured QC samples.

Sample
label
A
B
C
D
E
F

Chemical formula

Average Ybvalence
2.90
2.83
2.82
2.73
2.66
2.31

(Au0.5Cu0.5)49Al34Yb17(Au0.9Cu0.1)49Al34Yb17
Au49Al34Yb17
Au49(Al0.9Ga0.1)34Yb17
Au49(Al0.7Ga0.3)34Yb17
Au56Ga28Yb16

0.6(Au-Al-Yb) quasicrystals

Reflectivity

1

A
B
C
D
E
F

0.4

0.2

297 K
0

0

100

200

300

400

500

600

Wavelength (nm)Fig. 1. Optical reflectivity spectra of Au-Cu-Yb
quasicrystal samples A to F at room temperature
measured at BL7B.
[1] D. Shechtman et al., Phys. Rev. Lett. 53 (1984)
1951.
[2] K. Deguchi et al., Nat. Mater. 11 (2012) 1013.
[3] K. Imura et al., Sci. Rep. 10 (2020) 17116.

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UVSOR User 5რChemistryⅢ-3 Chemistry

BL4B

Ligand Field in Fe-based spin-crossover Coordination Polymer Revealed bySoft x-ray Absorption Spectroscopy
K. Yamagami
Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1, Sayo-cho, Sayo-gun, Hyogo 679–5198, JapanThe 3d transition metal elements have many attractive
physical phenomena in solid-state materials such as
unconventional superconductivity, metal-insulatortransition, and spin transition involving magnetism dueto their high charge, spin, and orbital degrees of
freedom. Since the 3d electronic states in solids arecontrolled by “ligand field eﬀects” due to the type andsymmetry of ligands and “charge transfer interactions”
between transition metal ions via ligands, experimental
exploration of element-specific electronic states
provides fundamental information for understanding
macroscopic properties involving 3d electrons.
In this study, I focus on “spin crossover,” which isstrongly related to ligand field eﬀects and spin degrees
of freedom. Spin crossover is a phenomenon in which achange in the splitting width of the 3d orbital levelcauses an electron spin transition. In particular, the spincrossover transition that appears in transition metal
coordination polymers exhibits thermal hysteresis.
Since the transition temperature and the shape of thehysteresis depend on the guest molecules encapsulated
in the coordination polymer, it is attracting attention asa new adsorption material along with activated carbon
and silica gel. However, spectroscopic element-specificanalysis of the 3d orbital levels associated with thermal
spin-crossover transitions in coordination polymers ischallenging due to their low chemical stability against
light source irradiation.
In this work, I performed the soft x-ray absorption
spectroscopy (XAS) for the Fe-based spin-crossovercoordination polymer Fe(pyrazine)2[Pt(CN)4] toinvestigate the contribution of ligand field eﬀect for
Fe2+ ions under the tetragonal symmetry related to thethermal spin crossover transition.
The XAS measurement was done at UVSOR BL4B.
The Fe L2,3-edge XAS spectra was recorded by the total
electron yield (TEY) and partial fluorescence yield(PFY) modes obtained by the drain current for TEY and
SDD detector for PFY, respectively. The powder
samples were thinly expanded on the carbon tape andits temperature was controlled by the liq.N2 and ceramicheaters. During measurement, the x-ray irradiateddamage of the samples was checked from the position
and irradiation time dependence of the XAS spectra.
The energy calibration was done by the Fe L2,3-edge
XAS spectra of Fe3O4. All XAS spectra were normalized
by the incoming x-ray flux.
In this report, I show the XAS results in PFY mode
since the huge noise was observed in TEY mode. Fig.1
shows the temperature dependent Fe L2,3-edge XAS
spectra. During one cycle of temperature change, I

observed a spectral change corresponding to thetransition between the high-spin (HS) state at hightemperature and the low-spin (LS) state at lowtemperature and found that the transition temperature
diﬀers between the heating and the cooling processes.
According to the simplest Fe2+ ionic model calculations,
the Fe2+ ions have only HS state at 320 K and only LS
state at 240 K. Therefore, I carried out the linear fitting
analysis by the spectra at 320 K and 240 K to estimate
the spin state weight around spin-crossover transition.
The fitting results reproduce the experimental spectra
and plotted as the function of the temperature together
with the macroscopic magnetometry result ofFe(pyrazine)2[Pt(CN)4] (Fig.2). I found that thetransition temperature between XAS spectra andmagnetization is quite diﬀerent, seemingly linking to
the diﬀerent thermal stability between the electronic
state and structural distortion.

Fig. 1. The temperature dependent Fe L2,3-edge XAS
spectraandfittinganalysis
resultofFe(pyrazine)2[Pt(CN)4].

Fig. 2. The spin state wight of Fe2+ ions as the functionof the temperature.

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BL1U

Monitoring Phase Diﬀerence between Magnetic Substates in Helium Atom
T. Kaneyasu1,2, Y. Hikosaka3, M. Fujimoto2,4, H. Iwayama2,5 and M. Katoh2,6
1
SAGA Light Source, Tosu 841-0005, Japan
Institute for Molecular Science, Okazaki 444-8585, Japan
3
Institute of Liberal Arts and Sciences, University of Toyama, Toyama 930-0194, Japan
4
Synchrotron Radiation Research Center, Nagoya University, Nagoya, 464-8603, Japan
5
The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
6
Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
2

Quantum manipulation of populations and reaction
pathways in matter using the coherence properties oflight, so-called coherent control, is currently one of thehottest research areas in optical physics andphotochemistry. We have recently shown thatsynchrotron light is a new tool for achieving coherent
control in the XUV and attosecond regimes [1–3]. Thismethod is based on the use of the longitudinal coherenceof individual light wave packets comprising incoherent
radiation pulses. In all of these experiments, a pair oflight wave packets was used to produce a pair ofelectron wave packets that interfere in a single atom.
The quantum phase diﬀerence between the electron
wave packets determines the behavior of the controlled(or probed) quantum state, and can be precisely
controlled by varying the time delay between the lightwave packets at the attosecond level. In this report, we
present another approach to orbital alignment controlof helium atoms [2] to monitor the phase diﬀerence
between the interfering wave packets. The quantum
phase diﬀerence between coherently excited magnetic
substates is visualized as a quantum beat that appears in
the fluorescence decay curve [4].
The experiment was performed at undulator beamline
BL1U of the UVSOR-III synchrotron. A tandem
undulator consisting of twin APPLE-II type variable
polarization devices was operated in helical mode,
providing pairs of 10-cycle left- and right-circularly
polarized light wave packets. The central frequency of
the fundamental radiation was set to about 24 eV. To
measure the fluorescence decay curve of helium atoms,
the UVSOR-III synchrotron was operated in the single
bunch mode. The fluorescence photons emitted fromhelium atoms were detected by a photomultiplier tube.
A magnetic field of approximately 20 G was applied
parallel to the light propagation axis in the interaction
region to induce Zeeman splitting between the magnetic
substates of helium atoms.
Figure 1 shows fluorescence decay curves of 1s6p
excited state of helium atoms measured at eightdiﬀerent settings of the time delay τ between the lightwave packets. The quantum beat oscillations
superimposed on the exponential decay with a lifetimeof 13.1 ns are visible and the initial phases of theoscillations shift by varying the time delay. The

theoretical curves well reproduce the quantum beatstructures observed in the measurement. Quantum beatmeasurement thus enables visualization of the quantum
phase that has been used as a control knob for quantum
manipulation of atomic systems

Fig. 1. Zeeman quantum beat in fluorescence decay ofhelium atoms [4]. The quantum phase ωτ is set toincrease from 0 to 7π/2 with a step size of approximately
π/2 where ω is the resonance frequency from the groundstate to the 1s6p state. The experimental data points areshown by gray circles and the red curves represent thecalculation results[1] Y. Hikosaka et al., Nat. Commun. 10 (2019) 4988;
ibid. 12 (2021) 3782.
[2] T. Kaneyasu et al., Phys. Rev. Lett. 123 (2019)
233401.
[3] T. Kaneyasu et al., Phys. Rev. Lett. 126 (2021)
113202.
[4] T. Kaneyasu et al., J. Phys.: Conf. Ser. 2380 (2022)
012115.

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Ⅲ-3 Chemistry

BL1U

High-Resolution Measurement of State-Resolved Photoelectron Circular
Dichroism with Varied Photoionization Energies
H. Kohguchi1, Y. Hikosaka2, T. Kaneyasu3, S. Wada1, H. Ota4, M. Katoh1,4 and Y-I. Suzuki5
1

Graduate School of Advanced Science and Engineering, Hiroshima University,
Higashi-Hiroshima 739-8526, Japan
2
Institute of Liberal Arts and Sciences, University of Toyama, Toyama 930-0194, Japan
3
SAGA Light Source, Tosu 841-0005, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
School of Medical Technology, Health Sciences University of Hokkaido, Tobetsu, 061-0293, Japan

Measurements of photoelectron circular dichroism(PECD) require high-quality radiation for ionizing
chiral molecules. One-photon photoionization in thevacuum ultraviolet region provides a fundamental
understanding of the physical origin of PECD. Thus,
we launched the PECD measurements at BL1U on
February 2020. In the beginning of the feasibility test,
the undulator conditions for circularly polarized light
were optimized for a particular electron beam orbit,
which was not used in regular beam time operation. In
2022, the normal electron beam orbit applicable to
BL1U was developed so that the PECD measurements
were possible in regular beam time. With the alternationof the electron beam orbit, the arrangement of theBL1U line was reformed.
We have employed a monochrometer to reduce thespread of photon energy to measure the state-resolved
PECD of chiral systems. The monochrometer line withtwo mirror chambers is inserted between the BL1U
port and our velocity-map imaging (VMI) apparatus(Fig. 1). We also modify the imaging device in thisbeam time. Our original setup used a resistive anodebacked by an MCP detector to obtain the photoelectron
images. We have replaced an imaging system consistingof a phosphor screen and a CCD camera with the anodetype imager. The benefit of the optical camera system isreal-time imaging during the measurement, which is
expected to be advantageous in eﬃcient searching forexperimental conditions. Improved performance due tothe renewal of the electron beam condition and theimaging system is evaluated in comparison with theprevious PECD data [1].
We measured the PECD of methyl oxirane (CH3C2H3O) in the new experimental setup. The PECD
appears as asymmetric forward/backward intensitywith respect to the circularly polarized light propagation.
The result almost reproduced the previous data in thatthe forward-backward asymmetry (red/blue in Fig. 2)
exhibited distinct state-dependence. The quality of the
PECD data is the contrast of the forward/backward
asymmetry, which is presented by blue/red contrast in
the diﬀerence images of the right and left circularpolarization in Fig. 2. The imaging system with thecamera provides an analog (Fig. 2(a)) and a counting(Fig. 2(b)) integration modes. The better PECD data
was obtained by analog integration, although it isgenerally inferior to the counting mode in accuracy.
This can be due to the too-slow counting integration of
the software compared to the photoelectron counting
rate. The renewal of the setup potentially improve our
PECD measurements; however more detailed
examination of several signal properties is necessary.
yFig. 1. New arrangement of the VMI apparatus for
PECD measurements with a monochrometer at theBL1U beamline.

Fig. 2. Photoelectron circular dichroism (PECD)
images of s-methyl oxirane measured with (a) analog
integration mode and (b) counting integration mode.
The propagation direction of the photoionization
radiation is vertical in the figures.
[1] H. Kohguchi, Y. Hikosaka, T. Kaneyasu, S. Wada,
H. Ota, M. Fujimoto, M. Kato and Y-I. Suzuki, UVSOR
Activity Report 49 (2021) 106.

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BL2A

M4,5-edge XANES Spectra of La and Nd Complex Oxides
H. Asakura 1, M. Konno 1 and K. Nanakarage 1
1

Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, Kowakae,
Higashiosaka, Osaka 577-8502, JapanThe areas of the pre-edge region at the lanthanide(Ln) L1-edge XANES spectra and the full with half
maximum of the white line at the Ln L3-edge XANES
spectra have been found to be good indicators of thelocal structure or symmetry of Ln elements in complex
oxides [1-3]. However, it is usually diﬃcult to obtain
detailed electronic and/or geometric information of theLn elements because of the inherent low energy
resolution of Ln L-edge XANES spectra. Then, theM-edge XANES spectra, which are potentially much
more sensitive to electronic structure, are employed toobtain more detailed information on the local structure.
However, there are very few reports on the measurementof M-edge XANES spectra of Ln elements. In thisstudy, we measured the M-edge XANES spectra of La
or Nd complex oxides to investigate whether they canbe used as indicators of local structure.
We prepared various La and Nd complex oxides by apolymerized complex method and confirmed that single
phase polycrystalline powders were obtained by their
XRD patterns. Nd M4,5-edge XANES spectra wereobtained at BL2A, UVSOR using a Beryl doublecrystal monochromator. We put each powder sample
onto indium (In) foil bonded to the sample holder withcarbon tape for total electron yield method measurement.
To the best of our knowledge, there are no wellestablished data analysis procedure on the M-edge
XANES spectra even for basic background removal or
normalization. On the present data, we performed
background removal in the pre-edge region below theM5-edge and normalization in the post-edge region
above the M4-edge with Athena included in the Demeter
package [4].
The Nd M4,5-edge XANES spectrum of Nd2O3,
NdAlO3, NdMnO3, and Nd2CoO4 was very similar toeach other (Fig. 1), which indicated the oxidation stateof Nd was the same, trivalent. By a closer look into thespectra, we found diﬀerence in relative absorbance ataround 1006, 1008, and 1010 eV marked as peak A, B,
and C at the Nd M4-edge XANES region (Fig. 2). The
main contribution for the peak A and B is ascribed tothe transition obeying the selection rule ∆J = 0, andpeak C is to ∆J = −1, respectively [5]. In addition,
theoretical simulation of Pr M4,5-edge XANES of Pr3+,[PrF6]3-, [PrCl6]3-, and [PrBr6]3- indicates possible
sensitivity to the local structure of Pr [5]. However, atpresent, we do not have plausible interpretation of thesecharacteristic features.
On the other hand, there are some questions as towhether the validity of the spectra can be guaranteed.
For example, it is possible that diﬀerences due tocharge-up or slight variations in X-rays may be reflected
into the spectra. In fact, on NdAlO3, significant
diﬀerence was observed at another facility when theenergy sweep direction was from the low energy to thehigh energy and from high to low, and the eﬀect ofcharge-up was suspected. Thus, further careful study isneeded.

Fig. 1. Nd M4,5-edge XANES spectra of Nd complex
oxidesFig. 2. Nd M4-edge XANES spectra of Nd complex
oxides[1] H. Asakura et al., Inorg. Chem. 53 (2015) 6048.
[2] H. Asakura et al., J. Phys. Chem. C 118 (2014)
20881.
[3] H. Asakura et al., Inorg. Chem. 60 (2021) 9359.
[4] B. Ravel, M. Newville, J. Synchrotron Rad. 12(2005) 537.
[5] H. Ramanantoanina, J. Chem. Phys. 149 (2018)054104.

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Ⅲ-3 Chemistry

BL3U

O K-edge XAS of Photoreactions in Dissolved Oxygen on Lipid Bilayer
F. Kumaki1, 2, M. Nagasaka3, 4, Y. Kinjo5, R. Tero5, Y. Okano3, M. Fujimoto3, 4 and J. Adachi1, 2
1

Institute of Materials Structure Science, High Energy Accelerator Research Organization,
Tsukuba 305-0801, Japan
2
School of High Energy Accelerator Science, The Graduate University for Advanced Studies (SOKENDAI),
Tsukuba 305-0801, Japan
3
Institute for Molecular Science, Okazaki 444-8585, Japan
4
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan
5
Toyohashi University of Technology, Toyohashi 441-8580, Japan

Porphyrin dyes form triplet states by thephotoexcitation and relaxation process due to lightabsorption. Singlet oxygen (1O2) is generated by theenergy transfer from the triplet state of the porphyrin to
the surrounding oxygen molecule with ground triplet
state (3O2). Singlet oxygen is highly reactive, and thegeneration of singlet oxygen by photosensitizers suchas porphyrins is used for a cancer treatment as aphotodynamic therapy [1]. The experimentally researchof the elementary processes of singlet oxygen
production in a wet environment like in vivo conditions
or in liquid is important for the development ofchemistry and medicine.
From O K-edge X-ray absorption spectroscopy(XAS), we planned to measure the electronic state ofsinglet oxygen generated in solution directly via laser
excitation of photosensitizers. We have recently
developed and demonstrated the time-resolved XAS
system for optical reactions in liquid samples by asynchronizing synchrotron radiation pulse and a laser
pulse at KEK Photon Factory [2]. At the UVSOR, wehave been developed a similar time-resolved XAS
system by synchronizing soft X-ray pulses (530 eV,
128 ps) and visible laser pulses (400 nm). Since thelifetime of singlet oxygen in liquid is ~3 μs [3], thesynchrotron radiation pulse whose pulse duration isabout 100 ps, is suitable to observe its dynamics. In thisreport, the change of XAS spectra between the groundstate and the state under laser irradiation was measured.
The O K-edge XAS spectra were measured by using
the liquid flow cell at BL3U. The liquid cell consists ofa liquid layer sandwiched between two Si3N4
membranes on which lipid bilayers were prepared. The
buﬀer solution (NaCl 100 mM, HEPES 25 mM)
bubbled with oxygen gas was continuously pumped
into the cell at a flow rate of 100 μl/hr to keep the
dissolved oxygen on the lipid bilayer. The emphasizedpeak of dissolved oxygen on the lipid bilayers can bemeasured by thinning the liquid layer to the limit [4].
For the formation of singlet oxygen with aphotoreaction, the chlorophyll-a was used as aphotosensitizer and was added to the lipid bilayer. By
irradiating the visible laser (400 nm, 0.5mW) which issecond order harmonic generation (SHG) of Ti:sapphirelaser to the cell, the chlorophyll-a was photoexcited.

We attempted to observe singlet oxygen produced from
dissolved oxygen by the energy transfer from the triplet
state of chlorophyll-a caused by the photoexcitationand the relaxation process. The O K-edge XAS spectraof dissolved oxygen in the ground state and during laser
irradiation were compared, and the diﬀerence wasobserved.
Figure 1 shows the O K-edge XAS spectra of lipid
bilayer. The peak around 531 eV is assigned as
dissolved oxygen molecules adsorbed on lipid bilayers.
The spectrum of the state during laser irradiation (laseron) shows the lower photon energy shift compared tothat in the ground state (laser oﬀ). We will discuss theformation mechanism of singlet oxygen from thediﬀerence spectrum with the help of the inner-shell
calculations.

Fig. 1. O K-edge XAS spectra of dissolved oxygen,
whose peak positions are around 531 eV, on lipid
bilayers. The green and blue lines are the ground state(laser oﬀ) and the state under laser irradiation (laseron), respectively.
[1] M. Ethirajan et al., Chem. Soc. Rev. 40 (2011) 340.
[2] F. Kumaki et al., J. Chem. Phys. 158 (2023) 104201.
[3] C. A. Long and D. R. Kearns, J. Am. Chem. Soc. 97(1975) 2018.
[4] F. Kumaki et al., UVSOR Activity Report, 49 (2022)
118.

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BL3U

Carbon K-edge X-ray Absorption Spectra of Liquid Ethanol Reproduced by
Quantum Chemical Calculations and Molecular Dynamics Simulations
M. Nagasaka1, 2
1Institute for Molecular Science, Okazaki 444-8585, JapanThe Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan

2

Liquid ethanol (EtOH) shows complicated liquid
structures with the continuous formation and decay ofhydrogen bond networks including the hydrophobic
interactions between ethyl groups. Soft X-ray
absorption spectroscopy (XAS) has potential toinvestigate the structures of liquid EtOH separating thecontributions of the hydrogen bond interactions andhydrophobic interactions between ethyl groups.
Recently, we have measured C K-edge XAS of liquid
EtOH by using a transmitted-type liquid cell [1].
However, the inner-shell spectra of the model structures
did not reproduce the spectral shapes of liquid EtOH
since the liquid structures reconfigured continuously. In
this study, we have performed C K-edge inner-shell
calculations of liquid EtOH by the summation of thecalculated spectra of excited EtOH molecules withneighbor molecules extracted from the liquid structures
obtained by the molecular dynamics (MD) simulations[2].
MD simulations of liquid EtOH were conducted byusing the program package GROMACS [3]. The
equilibrium structure including one thousand EtOH
molecules were obtained after a simulation time of 101
ns at 25 °C and 1 atm in the isobaric-isothermal
ensemble. The inner-shell calculations were conductedby using the program package GSCF3 [4]. The groundand core excited states were calculated within the
Hartree-Fock method, namely, ΔSCF (self-consistent
field). As shown in the inset of Fig. 1, we have extracted
one thousand small liquid structures that consist of
excited EtOH molecules and neighbor EtOH molecules
within the CH2-CH2 distance of 6 Å from the excited
EtOH molecules. The inner-shell spectrum of liquid
EtOH was obtained by the summation of one thousand
calculated spectra of small liquid structures.
Figure 1(a) shows the experimentally obtained C
K-edge XAS spectrum of liquid EtOH [1]. The
spectrum shows four peaks: The peak at 287.311 eV is
the transition of the CH3 C 1s electron to the 3s-type
Rydberg orbital (CH3 3s). The peaks at 288.025 eV and
288.760 eV are assigned as the transition of the CH3 C
1s electron to the 3p-type Rydberg orbitals (CH3 3p1
and 3p2). The peak at 289.710 eV is assigned to thetransition of the CH2 C 1s electron to the 3s-type
Rydberg orbital (CH2 3s). Figure 1(b) shows thecalculated inner-shell spectrum of liquid EtOH fromthe summation of one thousand calculated spectra ofsmall liquid structures. The calculated spectra well
reproduced four Rydberg peaks and spectra shapes

obtained by the experiments. However, the calculated
higher energy shifts from gas to liquid phases areoverestimated compared to the experimental values. It
is because the induced polarization of the surrounding
EtOH molecules above the CH2-CH2 distance of 6 Å isignored, which causes the lower energy shifts of the
XAS peaks. We have also calculated C K-edge innershell spectra of liquid methanol and confirmed that thecalculated spectra well reproduced the experimental
results [5].

Fig. 1. C K-edge XAS spectra of liquid EtOH from (a)experiments and (b) calculations. The inset shows oneof the liquid structures used for the inner-shell
calculations, where EtOH molecules were extracted
from the liquid structure within the CH2-CH2 distanceof 6 Å from the central EtOH molecule.
[1] M. Nagasaka et al., J. Phys. Chem. B 126 (2022)
4948.
[2] M. Nagasaka, J. Chem. Phys. 158 (2023) 024501.
[3] M. J. Abraham et al., SoftwareX 1-2 (2015) 19.
[4] N. Kosugi, Theor. Chim. Acta 72 (1987) 149.
[5] M. Nagasaka et al., J. Phys. Chem. B 118 (2014)4388.

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Ⅲ-3 Chemistry

BL3U

Observation of the Behavior of Sumanene in Organic Solventsby C K-edge XAS Experiment
Y. Uetake1,2, K. Sugimura1, R. Ihsan1, M. Nagasaka3 and H. Sakurai1,2
1Division of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI),
Osaka University, Suita, 565-0871, Japan
3
Institute for Molecular Science, Okazaki 444-8585, Japan2

0.8

C K-edge XAS

C = C ʋ *0.6
triphenylene

Intensity

Sumanene, a bowl-shaped π-extended molecule, hasbeen found to exhibit a unique columnar packing
structure in the crystalline state due to the intermolecularCH–π interactions between them[1]. Such interactions
are expected to occur in the solution state. Previously,
our group reported the infrared spectroscopy ofsumanene in para-H2 matrix. However, there are still
few reports on the dynamic behavior of π-conjugatedmolecule, including sumanene, in solution state. In thisstudy, we performed solution-phase X-ray absorption
spectroscopy (XAS) of π-extended molecules toinvestigate dynamic behavior, such as intermolecularinteractions, in organic solvents.
The solution-phase C K-edge XAS experiments were
performed at soft X-ray beamline BL3U using atransmission-type liquid flow cell[2]. Sumanene (1),corannulene (2), and triphenylene (3) were dissolved in
tetrahydrofuran, respectively, to give sample solutions(10 mmol/L). The thus-prepared solution was injectedto the cell by syringe. After adjusting the optical path
length by controlling helium pressure, XAS experiment
was conducted.
Fig. 1 shows C K-edge XAS data of sumanene,
corannulene, and triphenylene, respectively. In the caseof sumanene, relatively sharp peak was observed at285.2 eV, which is assigned as the transition of C 1s
electron to C=C π* orbitals. Meanwhile, two peaks
were observed at 284.8 and 285.3 eV. This result
indicated the diﬀerence of the electronic structure
between sumanene and corannulene. Inner-shell
calculations were performed using GSCF3 program[3,4]and it was found that the simulated peak pattern wasmatched with experimental spectra in the case ofsumanene and corannulene, although these calculations
did not reproduce the relative energy value (Fig. 2).
From this calculation, it was found that the peak at
284.8 eV corresponds to the internal carbons of
corannulene. Interestingly, XAS data for triphenylene
showed two split peaks, unlike the case of sumanene.
Since the inner-shell calculations of sumanene andcorannulene exhibited almost the same spectral shape,
the spectroscopic diﬀerence is thought to represent thediﬀerence in the behavior in solution.

0.4
corannulene

0.2

sumanene

10 mmol/L in THF

0.0
283.5

284.0

284.5

285.0

285.5

286.0

286.5

Energy (eV)Fig. 1. C K-edge XAS data of sumanene, corannulene,
and triphneylene.

Fig. 2.
Inner-shell calculations of sumanene,
corannulene, and triphneylene.
[1] H. Sakurai, T. Daiko, H. Sakane, T. Amaya and T.
Hirao, J. Am. Chem. Soc. 127 (2005) 11580.
[2] M. Nagasaka and N. Kosugi, Chem. Lett. 50 (2021)
956.
[3] N. Kosugi and H. Kuroda, Chem. Phys. Lett. 74(1980) 490.
[4] N. Kosugi, Theor. Chim. Acta 72 (1987) 149.

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BL3U

Operando Observation of Adsorbed Anions on the Surface of Nickel
Catalysts by Soft X-ray Absorption Spectroscopy
A. Sakai1, Z. Li1, K. Harada1, S. Tsunekawa1, M. Nagasaka2 and M. Yoshida1,3
1

Yamaguchi University, Tokiwadai, Ube, Yamaguchi 755-8611, Japan
Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
3
Blue Energy Center for SGE Technology (BEST), Ube, Yamaguchi 755-8611, Japan
2

Recently, electrochemical hydrogen production fromwater has been attracting attention to develop asustainable society. In this system, nickel oxides
electrodeposited in carbon electrolyte solution are
known to be one of the eﬃcient electrocatalyst foroxygen production [1-2]. Thus, various operando
spectroscopic analyses have applied to the nickel
catalysts in order to reveal the physical properties andfunctions. However, the role of carbonate anion in theelectrolyte solution is still not fully understood. From
this background, in this study, the role of adsorbed
carbonate anion was investigated for the nickel
electrocatalysts by X-ray absorption fine structure(XAFS) measurements using hard X-ray and soft X-ray
under operando conditions.
The handmade electrochemical cell was used with a
Pt wire counter electrode and an Ag/AgCl referenceelectrode (NaCl). The nickel electrocatalysts wereprepared by electrodeposition on Au thin film in asolution containing Ni2+ and carbonate anion (Ni-Ci
catalyst). The operando Ni K-edge XAFS were carriedout by fluorescence mode in the SPring-8 BL01B1, andthe operando C K-edge XAFS were performed bytransmission mode at BL3U in the UVSOR synchrotron.
First, SEM, EDX, UV-vis and XPS measurements
were also measured to investigate the surface
morphology and chemical states of electrodepositedcatalysts. Next, we tested the electrochemical activityof oxygen evolution reaction (OER), suggesting thatthe prepared Ni-Ci functioned as highly eﬃcient OER
electrocatalyst. Moreover, the electrolyte solution was
exchanged from potassium carbonate solution (K-Ci) topotassium phosphoric solution (K-Pi) during monitoring
the OER activity, indicating that the water splitting
activity of the Ni-Ci catalyst was preserved in the K-Pi
electrolyte solution.
The operando Ni K-edge XAFS measurements were
performed to investigate the electronic state and local
structure of the Ni-Ci catalyst. The result of EXAFS
analysis showed that the peaks of Ni-O and Ni-Nibonds were observed at similar positions compared tothe γ-NiOOH reference sample, suggesting that the
local structure of Ni in the catalyst was consistent withthat of γ-NiOOH. Moreover, the local structure of thecatalyst in the K-Pi solution was also maintained that of
γ-NiOOH.

Finally, the operando C K-edge XAFS measurements
were carried out for the Ni-Ci catalyst under thecatalytic reaction (Fig. 1). The result showed thatcarbonate anions were adsorbed on the catalyst surface.
The adsorbed peak was remained even after exchanging
the electrolyte solution from K-Ci to K-Pi. Thus, thisresult suggests that the carbonate anions are strongly
adsorbed on the Ni-Ci catalyst. The adsorbed carbonate
anions are likely to contribute the stabilize the γ-NiOOH
structure with high oxidation number Ni. On the basisof these discussions, we concluded that the γ-NiOOH
structure stabilized by adsorbed carbonate anions could
eﬃciently decompose water molecule to oxygen gas
due to the high oxidation number Ni of active site.

Fig. 1. Operando C-K edge XAFS spectra for Ni-Ci
electrocatalyst with exchanging the electrolyte solution
between K-Ci and K-Pi by transmission mode at BL3U
in the UVSOR synchrotron. The electrolyte aqueous
solution of potassium carbonate was measured as
reference compounds.
[1] K. S. Joya, Y. F. Joya, and H. J. M. de Groot, Adv.
Energy Mater., 4 (9) (2014) 1301929.
[2] T. Shinagawa, M. T. Ng and K. Takanabe, Angew.
Chem. Int. Ed. Eng., 56 (18) (2017) 5061.
[3] A. C. Garcia, T. Touzalin, C. Nieuwland, N. Periniand M. T. M. Koper, Angew. Chem. Int. Ed. Eng., 58(37) (2019) 12999.

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Ⅲ-3 Chemistry

BL3U

Temperature Eﬀects on the X-ray Absorption Spectrum of Aqueous
Ca(NO3)2 Recorded at the Ca L-edge
D. Céolin1, T. Saisopa2, Y. Rattanachai2, H. Yuzawa3 and N. Kosugi3
1
Synchrotron SOLEIL, l’Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette Cedex, France
Department of Applied Physics, Faculty of Sciences and Liberal Arts, Rajamangala University of Technology
Isan, Nakhon Ratchasima 30000, Thailand
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

2

Calcium dication is frequently studied due to its
abundance in human body and its importance inbiological processes. Thus, its local structure
determination is the subject of number of investigations,both experimental (XRD, EXAFS, MD, etc.) andtheoretical (QM/MM, MD). In aqueous solutions,
X-ray absorption spectroscopy (XAS) was used toprobe the eﬀect of the concentration on e.g., thehydration number, but the influence of the temperature
was not investigated, despite some information wasreported on other techniques [1].
In this context, we performed XAS measurements at
the BL3U beamline on aqueous Ca(NO3)2∙4H2O, using
the liquid cell in transmission mode. The setup oﬀers
the possibility to monitor its temperature (T). We
choose a high concentration close to the solubility limitof this salt in water at 0°C, that is 1050 g/L. The results
are presented in the Figure 1. Each spectrum has its
background removed.
A full attribution of the diﬀerent structures was given
in a previous paper [2]. The 2p-1 spin-orbit contributions
are located below (above) ~351 eV for L3 (L2),respectively. The temperature change from 0 to 60°C
do not influence the splitting between the two mainlines, nor the position of the smaller peaks. The intensity
ratio between peaks 1 and 2, which gives informationon the crystal field 10Dq value, is small. Despite weobserve a slight modification of this ratio with T, we
consider it as not relevant as it does not follow the Tvariation and is attributed to the background removal
procedure.
A more precise analysis shows a slight blue-shift of
the right side of the peaks toward the high photon
energies following the temperature increase (see insert
in Fig. 1 corresponding to a zoom of the main L3 line),
whereas the low energy sides remain quasi-unchanged.
The width of peak 1 for each T is shown in Fig. 2. The
photon bandwidth and the detector contribution are
constant and lead to an experimental resolution of 166
meV, whereas the Lorentzian broadening contribution
shows a slight increase roughly from 200 to 250 meV
within the T going from 0 to 60°C.
Temperature eﬀects were already probed by XAS inelectrolyte aqueous solutions at the O K-edge. For a 5
M LiCl aqueous solution [3], a redshift of the pre-edge
resonance maximum was observed when T increases. It
was attributed to the change of the distance between thebulk water molecules with T, whereas molecules in thefirst hydration shell of lithium ion are more strongly
bonded to it and less sensitive to T variations. In thepresent case, the sample concentration is high and close
to the solubility limit at 0°C. We can argue that thermal
motion at low T is reduced and slightly increases in thisT range. These observations should be confirmed bycomplementary measurements.

Fig. 1. X-ray absorption spectra of a 4.5 M Ca(NO3)2∙4(H2O)
aqueous solution, recorded in the vicinity of the Ca 2p
ionization threshold, for temperatures in the 0-60°C
range.

Fig. 2. Influence of temperature on the width of themain line (full width at half maximum: FWHM). The
Gaussian and Lorentzian contributions are extracted.
[1] A. A. Zavitsas, J. Phys. Chem. B, 109 (2005) 20636.
[2] T. Saisopa et al., J. Electron Spectrosc. Relat.
Phenom., 244 (2020) 146984.
[3] M. Nagasaka et al., J. Phys. Chem. B, 121 (2017)10957.

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Self-Assembled Hierarchical Nanosegregated Chiral Intermediate Phases
Composed of Two Diﬀerent Achiral Bent-Core Molecules
F. Araoka1, Y. Takanishi2, S-W. Choi3 and H. Iwayama4,5
1

RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
2
Faculty of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan3
Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University,
Yongin 17104, Republic of Korea
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
5
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki, Aichi 444-8585, Japan

Chirality is fascinating because of its fundamental
importance in nature. As we presented in the activity
report of the previous year, achiral BC molecules are
well-known for spontaneous chiral resolution at themacroscopic scale despite the chiral-carbon-atom-free(hence, achiral) molecules (Fig. 1a). The so-called B4phase—often the lowest temperature phase of BCs—isone such chiral mesophase in which a helicalnanofilament superstructure is spontaneously selfassembled. In this case, structural chirality, observed as
helical handedness, originates from the layered chiralityof tilted smectic layers twisting along the filaments.
Another very similar type of chiral phase formed byachiral bent-core molecules is the dark conglomerate(DC) phase. The DC also exhibits optically resolved
domains with strong optical activity, but it looks moreisotropic. The fundamental morphology of DCs
comprises disordered sponge-like structures of tilted
smectic layers. Although sponge-like structures do nothave morphological chirality, it is understood that theobserved macroscopic optical activity is attributed to
the layered chirality of the tilted smectic layers.
Recently, we explored some interesting chiralityrelated phenomena in nano-separated intermediatephases composed of two achiral bent-core liquid
crystalline molecules, one of which is circularly
polarized luminescence (CPL) in the nano-separated
intermediate phase blended with a luminescent dye [1].
Following up this work, we further extended thisconcept to realize dual-chiral intermediate phase (asillustrated in the right panel of Fig. 1a) of coexisting B4
and DC phases, using nanophase segregation between
two bent-core molecules and hierarchical selforganization.
Interestingly,
theluminescencedissymmetry factor of CPL from the nano-separated
dual-chiral phase of the B4 and DC was one order ofmagnitude higher than that of the previously reported
chiral phases of the bent-core system [2].
Thus, the present dual-chiral phase system looks
promising. However, its structure has not yet been
confirmed. Since the system is consisting of two
mesophases, direct observation methods such as usingtransmission electron microscope aren’t usable.

Therefore, for this sake, we performed resonant soft
X-ray scattering (RSoXS) experiment to identify thenano-separated phases. Our RSoXS setup was preparedin BL3U of UVSOR at IMS – A homemade vacuum
chamber equipped with a cooled CCD camera (Newton,
Andor) was used for small angle detection (2θ~1-15˚).
In the present study, the X-ray photon energy waschosen as 284.5 eV, corresponding to the carbon K-edge
absorption of the present sample mixtures. The sample
mixture was sandwiched between two SiN membranefilms and then sealed not to exposed to vacuum. The
sample chamber also equips a furnace to heat up thesample.
The RSoXS profile of the dual chiral phase (Fig. 1b)
was compared with those of the only-B4 (Fig. 1c) andonly-DC (Fig. 1d) phases. The RSoXS result clearlyshows that the patterns of two chiral phases aresuperimposed in the dual chiral phase. In addition, we
carefully examined the dual chiral phase with circulardichroism spectroscopy, polarizing light microscopy,
and diﬀerential scanning calorimetry, we concluded
that the model proposed in Fig. 1a is reasonable in thepresent dual chiral system.

Fig. 1. (a) Schematics of the nanoscopic structures of
the B4 and DC phases, and the nano-separated dualchiral phase. (b, c, d) RSoXS patterns obtained for (b)B4, (c), DC, and (d) dual chiral phases. [2][1] Kim et al. Adv. Funct. Mater. 29 (2019) 1903246.
[2] Lee et al. Int. J. Mol. Sci. 23 (2022) 14629.

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BL3U

X-ray Absorption Spectra of Metal Carbonyl Solutions
T. Sasaki and H Xu
Department of Complexity Science and Engineering, Graduate School of Frontier Sciences,
The University of Tokyo, Kashiwa 277-8561, Japan

XAS measurements for liquid samples have beenenabled at UVSOR BL3U, giving new insights forphysicochemical properties of materials [1]. We havestudied O-K edge XAS measurements for cellobiose
aqueous solutions and found that XAS signals can be
simulated with CP2K and hydrogen bonding with watermolecules aﬀect the relative intensity of XAS peaks. In
this study metal carbonyl solutions were examined for
XAS measurements to gain information of metal
carbonyls dissolved in liquid phase, since metal
carbonyls can be regarded as good models for bothhomogeneous and heterogeneous catalysts. Therefore
we can expect XAS method will act as a new
characterization tool for chemical and catalytic
processes in liquid phase. In this study Mo(CO)6 andRu3(CO)12 were chosen as target molecules.
XAS measurements for liquid samples wereconducted at UVSOR BL3U using facilities developed
by Nagasaka et al. [1]. The liquid sample cell with
Si3N4 membranes was adopted, where the thickness of
the liquid layer was controlled by the He gas pressurearound the cell.
Fig. 1 shows O-K XAS spectrum for Mo(CO)6 (40mg) in 10 ml CH3CN at room temperature.
Concentration is 15 mM. This condition is close to thesaturated solution. A sharp peak at 531.25 eV wasobserved and can be attributed to excitation to C=O
1π* level. Broad features above 534 eV can beassociated with sigma bonding of C-O ligand.
Fig. 2 shows O-K XAS spectrum for Ru3(CO)12 (3mg) in 5 ml CHCl3 at room temperature. Concentration
is 0.94 mM. This condition is also close to the saturated
solution. It is noticed that peak intensity for Fig. 2 isweaker than that for Fig. 1, because of the low solubilityof Ru3(CO)12. A peak was found at 531.65 eV and canbe attributed to excitation to C=O 1π* level. Broadfeatures above 534 eV can be associated with sigma
bonding of C-O ligand.
Due to the limitation of rather low concentration C-K
edge measurements are diﬃcult since overlap withabsorption peaks by solvent molecules aﬀect the peaks
associated with CO ligand.
For the precise peak assignments MD calculation for
carbonyl species dissolved in solvent molecules andcore excitation simulation are now in progress. It is
expected to conduct measurements of other metal
carbonyls and observation of ligand exchange. Whether
site discrimination, for example atop coordination andbridging coordination is possible or not is alsointeresting point to be clarified.

Fig. 1. O-K XAS spectrum for Mo(CO)6 (40 mg) in 10
ml CH3CN at room temperature.

Fig. 2. O-K XAS spectrum for Ru3(CO)12 (5 mg) in 5
ml CHCl3 at room temperature.
[1] M. Nagasaka et al., J. Electrosc. Relat. Phenom.
200 (2015) 293.
[2] D. Akazawa et al., J. Chem. Phys. 156 (2022)
044202.

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Soft X-ray Absorption of Photocatalysts for Artificial Photosynthesis:
Ultraviolet Light Irradiation in Water
H. Onishi1,2, Yi Hao Chew1, K. Matsui1, N. Ichikuni3 and T. Yoshida4
1
School of Science, Kobe University, Kobe 657-8501, Japan
Division of Advanced Molecular Science, Institute for Molecular Science, Okazaki 444-8585, Japan
3
Graduate School of Engineering, Chiba University, Chiba 263-8522, Japan
4
Reserch Center for Artificial Photosynthesis, Osaka Metropolitan University, Osaka 558-8585, Japan
2

Sodium tantalate (NaTaO3) and strontium titanate(SrTiO3) provide a class of semiconductor photocatalysts
which produce hydrogen–oxygen mixed bubbles in theoverall water splitting reaction, when properly dopedwith metal cations [1, 2]. We are conducting a series ofstudies to answer the question of why doping withmetal cations raised the quantum yield of the reaction[3]. Here, soft X-ray absorption is applied forcharacterizing the electronic structure of thephotocatalysts in the presence and absence of ultraviolet(UV) light for bandgap excitation.
NaTaO3 particles doped with Sr cations (2 mol%)were prepared through a solid-state reaction, andcharacterized with EDX and XRD in Kobe University.
The particles were suspended with water (5 g l-1) andsent to a liquid film cell for transmission absorption bya syringe pump (Figure 1). To avoid sedimentation of
the particles, pH of the suspension was tuned at 13, farfrom isoelectric point of the particles.
An Hg–Xe lamp (200 W) was used to irradiate UV
light for photocatalyst excitation. The photodiodedetecting transmitted X-ray was capped with a nickel
filter to minimize stray UV light from the lamp andhigher-order X-ray passing through the monochromator.
Figure 2 shows an oxygen K edge absorption
spectrum of Sr-doped NaTaO3 photocatalyst particles
suspended in water. It was not straightforward to placea significant amount of the photocatalyst particles in
the water film pinched with two SiN membranes. An

absorption band appeared at 531.5 eV was ascribed tothe photocatalyst particles but to be further examined,
since the oxidized layer of the membranes may provide
an absorption band at 530–531 eV.
Purin Sathirathai, an undergraduate student ofSirindhorn International Institute of Technology,
Thammasat University in Thailand, assisted us inphotocatalyst preparation under Sakura Science
Exchange Program by Japan Science and Technology
Agency. This study was supported by JSPS KAKENHI(grant numbers 18KK0161 and 22H00344).

Fig. 2. Oxygen K edge absorption spectrum of NaTaO3
photocatalyst particles doped with Sr cations observedin water without UV light irradiation. The absorbance
spectrum is shown in an arbitrary unit as a function of
X-ray energy.

Fig. 1.
Strontium-doped NaTaO3 photocatalyst
particles suspended in water. White suspension in thesyringe was sent to the liquid film cell for transmission
XAFS measurements.

[1] H. Kato, K. Asakura, A. Kudo, J. Am. Chem. Soc.
125 (2003) 3082.
[2] T. Takata, J. Jiang, Y. Sakata, M. Nakabayashi, N.
Shibata, V. Nandal, K. Seki, T. Hisatomi, K. Domen,
Nature 581 (2020) 411.
[3] H. Onishi, ChemSusChem 12 (2019) 1825.

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Ⅲ-3 Chemistry

BL3U

Hydration of Dimethyl Sulfoxide Probed by Liquid-Phase Soft X-ray
Absorption Spectroscopy
C. Sugahara1, K. Okada1 and H. Iwayama2,3
1

Graduate School of Advanced Science and Engineering, Hiroshima University,
Higashi-Hiroshima 739-8526, Japan
2
Institute for Molecular Science, Okazaki 444-8585, Japan3
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan

Soft X-ray absorption spectroscopy oﬀers informationon the local atomic environment of a molecular system
under study by the resonant excitation of the local site.
Diﬀerent characters of water in solution, i.e. bulk andhydrated water, can be detected by the spectroscopy.
The subtle diﬀerences in character, however, prevent us
from clear distinction from one another without a useful
analysis method. We have proposed a new quantity,
called the excess absorption coeﬃcient, for the analysis
of absorption spectra of solutions and applied to theacetone–water binary system [1]. The analysis gives a
successful extraction of the hydrated component.
This study is intended for generalization by theapplication of the method to another solution. The
system of interest for this purpose is dimethyl sulfoxide(DMSO) aqueous solution. The DMSO molecule ismore polarized than acetone. This is shown by thediﬀerence in the values of excess molar enthalpy. The
acetone–water mixture has negative values only in the
dilute region [2], while the DMSO–water mixture has
negative values at all fractions and has greater absolutevalues [3]. We expect that more intensity in theabsorption component of hydrated water for the lattermixture.
The experiments were performed on the soft X-ray
beamline, BL3U. The photoabsorption spectra were
measured in the oxygen K-edge region, with sample
cell windows made of silicon nitride with a thickness of
150 nm. The incident photon energy was calibrated tothe peak at 530.88 eV of a polymer film [4]. The
absorption coeﬃcient was evaluated so as to match thevalue at 547.85 eV to that tabulated in the database [5].
The sample solutions were prepared by mixing liquid
DMSO with purified water to give the molar fraction of
DMSO, xD, in the range 0–0.35.
Observed absorption spectra of DMSO aqueous
solutions are shown in Fig. 1. The spectrum for pure
DMSO (xD = 1) has peaks at 532.6 and 534.0 eV. The
former peak, assigned to the π* ← O 1s transition of
DMSO, is clearly dependent on xD. The 4a1 ← O 1s
absorption peak of water at 534.7 eV seems to shift tolower energies with xD. The behavior is, however, notconclusive due to the overlap with the hump at about

534 eV which is assigned to another resonancetransition of DMSO. This fact indicates that in thissystem the distinction of hydrated water from the bulk
water requires a physicochemical analysis method: The
system is a perfect system for testing our method ofanalysis. The results of the analysis will be publishedelsewhere.

Fig. 1. The soft X-ray absorption spectra of liquidwater and DMSO aqueous solutions measured for aseries of molar fractions of DMSO. The spectrum of
the liquid DMSO is also shown for comparison.
[1] K. Okada, C. Sugahara, H. Iwayama and M.
Nagasaka, UVSOR Activity Report 2021, 49 (2022)
117.
[2] B. Löwen and S. Schulz, Thermochim. Acta 262(1995) 69.
[3] T. Kimura and S. Takagi, Netsu Sokutei 13 (1986)
2.
[4] M. Nagasaka, H. Yuzawa, T. Horigome and N.
Kosugi, J. Elec. Spectrosc. Relat. Phenom. 224 (2018)93.
[5] C. T. Chantler et al., NIST Standard Reference
Database 66 (1995; last update in 2005), available athttps://www.nist.gov/pml/x-ray-form-factorattenuation-and-scattering-tables.

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BL4B

Multielectron-ion Coincidence Spectroscopy of I 4d inner-shell
Photoionization of CH3I and CH2I2 Molecules
M. Fushitani 1, Y. Hikosaka 2 and A. Hishikawa1,3
1
Graduate School of Science, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8602, Japan
Institute of Liberal Arts and Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan
3
Research Center for Materials Science, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8602, Japan
2

Inner-shell photoionization of molecules often leads
to formation of highly charged states followed byfragmentation processes. Identifying which ion species
are generated from which electronic states is of great
importance for the basic understanding of ultrafast
processes associated with inner-shell ionization.
Amongothers,multielectron-ion
coincidence
spectroscopy using a magnetic bottle type electron
spectrometer is a powerful approach to obtain suchinformation [1-3]. Here, we applied it to I 4d innershell ionization of CH3I and CH2I2 molecules toinvestigate fragmentation processes occurring fromdoubly charged states.
Electrons generated by photoionization with asynchrotron radiation at 100 eV were guided from theinteraction region into a time-of-flight (TOF) tube (1.5m) by magnetic fields from a permanent magnet andsolenoid coil while ions were pushed into the tube by
applying pulsed voltages to ion-collecting electrodes[1]. These electrons and ions were detected by amicrochannel plate placed on the opposite side of the
TOF tube.
Figure 1 shows Auger electron spectra obtained incoincidence with I 4d photoelectrons, I+ ions andselected counterpart ions for (a) CH3I and (b) CH2I2.
These Auger peaks provide information on the locationof excited electronic states producing the fragment ion
pairs. In Fig.1(a), the pair of I+ and CH3+ ions are mainly
generated together with Auger electrons having kinetic
energies around 20-30 eV which correspond to doubly
charged states associated with outer-valence
configurations [4,5]. On the other hand, Auger signals
are observed below 20 eV for the (I+, CH2+), (I+, CH+),and (I+, C+) ion pairs, showing that these ion pairs areformed preferentially from higher excited states related
to inner-valence configurations [4].
In the case of CH2I2 (Fig.1(b)), the (I+, CHnI+) ion pairreflecting the single C-I bond cleavage is produced
mostly with Auger electrons having 25-32 eV kinetic
energies. By contrast, Auger signals appear in the lower
energy region for other ion pairs associated with two
C-I bond fissions, indicating the dissociations occur in
excited doubly charged states.
The present study shows a promising approach forapplications and fundamental understanding of
nonlinear inner-shell ionization of iodine-containing
molecules by intense free-electron lasers.

Fig. 1. PEPEPIPICO spectra of I 4d inner-shell
photoionization at 100 eV for (a) CH3I and (b) CH2I2.
[1] Y. Hikosaka, J. Electron Spectrosc. Rel. Phenom.
255 (2022) 147158.
[2] Y. Hikosaka and E. Shigemasa, Int. J. Mass
Spectrom. 439 (2019) 13.
[3] M. Fushitani et al., Phys. Rev. A (Letter) 107 (2023)
L021101.
[4] A. Hult Roos et al., Chem. Phys. 491 (2017) 42.
[5] A. Bodi et al., Phys. Chem. Chem. Phys. 25 (2023)
7383.

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BL4B

Quadruple Auger Decay from Xe 4s Core-Hole State Studied byMulti-Electron−Ion Coincidence Spectroscopy
Y. Hikosaka
Institute of Liberal Arts and Sciences, University of Toyama, Toyama 930-0194, Japan

Emissions of multiple Auger electrons, following
inner-shell photoionization of atoms in the soft X-ray
region, can occur within the permitted limits of theenergetics. Multi-electron coincidence spectroscopyusing a magnetic bottle electron spectrometer is a
powerful means for studying multiple Auger decay.
Discrimination of multiple Auger processes against
dominant single Auger decay can be improved byfiltering multi-electron coincidences with the additional
detection of product ions relevant to the multiple Auger
processes. By adding such ion detection capability to amagnetic bottle electron spectrometer, multi-electron−
ion coincidence measurements can be performed very
eﬃciently [1-3].
In this study, quadruple Auger decay of the Xe 4s
core-hole state is investigated by multi-electron−ion
coincidence spectroscopy with a magnetic bottle
electron spectrometer [4]. Figure 1(a) shows the total
electron spectrum (black curve) and the spectrum
filtered by coincidence with Xe5+ ions (red curve),
where the 4s photoelectron peak is observed around a
kinetic energy of 180 eV. From the net intensities of the4s peaks observed in the total and coincidence spectra,
the fraction of the quadruple Auger path in the 4s decay
was determined to be 16%.
The two-dimensional map in Fig. 1(b) displays thecorrelation between the fastest electron’s energy andthe sum of the energies of the other four electrons,
determined from the six-fold coincidence including
Xe5+ ion. It is possible to recognize structures running
diagonally. The diagonal structures correspond to theformation of Xe5+ levels, resulting from the energy
conservation (photon energy) - (binding energy of the
Xe5+ state) = (fastest electron’s energy) + (the sum of
the energies of the other four electrons). Enhancementof Xe5+ formation is observed at the 4s photoelectronenergy, corresponding to quadruple Auger decay fromthe 4s-1 state.
Figure 2 shows the Xe5+ distribution populated by thequadruple Auger decay from the 4s-1 state. The
distribution is obtained by integrating the coincidence
counts in Fig. 1(b) along the direction (fastest electron’senergy) + (the sum of the energies of the other fourelectrons) = const., where the fastest electrons wererestricted to be of the 4s photoelectron energy range. In
addition to the formation of the 5p-5 levels, both
histograms show substantial formation of excited Xe5+
levels. The final formation fractions of the 5p-5, 5s-15p-4,
and 5s-25p-3 levels by the quadruple Auger decay are
estimated to be 7%, 7% and 2% of the 4s decay,
respectively.

Fig. 1. (a) Inner shell photoelectron spectra of Xe
observed at a photon energy of 391.7 eV, obtained for
total events in the coincidence dataset (black) or byfiltering with the detection of a Xe5+ ion (red). (b) Twodimensional map showing the correlation between thefastest electron’s energy and the sum of the energies ofthe other four electrons.

Fig. 2. Xe5+ distribution populated by the quadruple
Auger decay from the 4s-1 state.
[1] Y. Hikosaka and E. Shigemasa, Int. J. Mass
Spectrom. 439 (2019) 13.
[2] Y, Hikosaka, J. Electron Spectrosc. Relat. Phenom.
255 (2022) 147158.
[3] Y. Hikosaka and S. Fritzsche, Phys. Chem. Chem.
Phys. 24, (2022) 17535.
[4] Y, Hikosaka, Phys. Rev. A 106 (2022) 062814.

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BL4B

Metastable OCS3+ States Investigated by Multi-Electron−Ion Coincidence
Spectroscopy
Y. Hikosaka
Institute of Liberal Arts and Sciences, University of Toyama, Toyama 930-0194, Japan

Triply charged molecular ions are always
energetically unstable due to Coulomb repulsion
between the three positive charges. However, low-lying
trication states in some limited molecules are known to
be stable for more than μs due to the presence of deep
minima on the potential energy surfaces. In this study,
metastability of OCS3+ states populated by the S 2p
double Auger decay has been investigated by multielectron−ion coincidence spectroscopy. A magnetic
bottle electron spectrometer with ion detection
capability [1-4] was employed for this investigation,and the high detection eﬃciencies for electrons enabled
to derive the information of stability of OCS3+ electronic
states.
The double Auger decay of the S2p-1 states in OCS
can be isolated by inspecting electron triple coincidences
including a S2p photoelectron. The two-dimensional
map in Fig. 1 is derived from the electron triple
coincidences, displaying the energy correlation
between the two electrons other than the S2p
photoelectron. On this map, several diagonal stripes are
identified in (faster electron’s energy) + (slower
electron’s energy) =95-115 eV, which are formed bydouble Auger decay. The population of the OCS3+ states
formed by the S2p double Auger decay is revealed byprojecting the coincidence yields on the diagonal axisof (faster electron’s energy) = (slower electron’senergy). The resultant OCS3+ spectrum is shown in Fig.
2 as black curve. Several peaks are observed in the
kinetic energy range of 95-115 eV, corresponding to the
diagonal structures seen on the two-dimensional map in
Fig. 1. Moreover, a broad structure is seen in thebinding energy range of 80-95 eV. These spectral
profiles agree with the previous investigation by Elandet al. [5].
Metastability of OCS3+ states can be investigated byinspecting the ion species detected in further
coincidence with S2p photoelectron and two Auger
electrons. The double Auger spectrum filtered byfurther coincidence with parent OCS3+ ion is presented
in Fig. 2 as red shaded spectrum. Only the peak for the
ground 3π-3 2Π state at a binding energy of 60 eV isexhibited in the spectrum, revealing that the groundstate is metastable in the μs regime. An MRCI/CASSCF
calculation [5] predicts the ground 3π-3 2Π state has apotential surface with a potential well along both
directions lengthening the CS and CO bonds, although
excited OCS3+ states are all unbound to lengthening the

CS bond. The present observation is in consistent withthe calculation results.

Fig. 1. Two-dimensional map showing the energy
correlations between two Auger electrons emitted in
the S 2p double Auger decay of OCS, which wasderived from electron triple coincidence.

Fig. 2. OCS3+ spectra formed by the S2p double Auger
decay of OCS: total spectrum (black solid curve) andthe one filtered with further coincidence with parent
OCS3+ ions (red shaded spectrum).
[1] Y. Hikosaka and E. Shigemasa, Int. J. Mass
Spectrom. 439 (2019) 13.
[2] Y, Hikosaka, J. Electron Spectrosc. Relat. Phenom.
255 (2022) 147158.
[3] Y. Hikosaka and S. Fritzsche, Phys. Chem. Chem.
Phys. 24, (2022) 17535.
[4] Y, Hikosaka, Phys. Rev. A 106 (2022) 062814.
[5] J.H.D. Eland et. al, J. Chem. Phys. 132 (2010)014311.

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BL4B

Soft X-ray Absorption Study of Semiconductor Photocatalysts for HighlyEﬃcient Oxidation of Water
T. Yoshida1, N. Ichikuni2, H. Onishi3,4 and Yi Hao Chew3
1

Reserch Center for Artificial Photosynthesis, Osaka Metropolitan University, Osaka 558-8585, Japan
2
Graduate School of Engineering, Chiba University, Chiba 263-8522, Japan3
School of Science, Kobe University, Kobe 657-8501, Japan
4
Division of Advanced Molecular Science, Institute for Molecular Science, Okazaki 444-8585, Japan

A number of metal oxides including gallium oxide,(Ga2O3), sodium tantalate (NaTaO3) and strontium
titanate (SrTiO3) provide a class of semiconductor
photocatalysts highly eﬃcient for the overall water
splitting reaction, when properly doped with foreign
metal cations. [1-3]. We are conducting a series ofstudies to answer the question of why metal-cation
doping raised the quantum yield of the reaction [4].
Here, soft X-ray absorption is applied for characterizing
the electronic structure of the photocatalysts in thepresence and absence of ultraviolet (UV) light forbandgap excitation.
Sub-micrometer-sized Ga2O3 particles were preparedin Osaka Metropolitan University, while NaTaO3 dopedwith Sr2+ cations and SrTiO3 doped with Al3+ cations
were prepared in Kobe University. Oxygen K edge
absorption spectrum of the photocatalysts particles wasobserved under vacuum in the presence and absence of
UV light provided by a Hg–Xe lamp (200 W).
In XAFS measurement of oxygen K edge, thephotocatalyst particles were molded as disks of 7-mm
diameter. The disks were placed in a vacuum chamber,
irradiated with incident X-ray, and fluorescent X-ray
was detected with a silicon drift detector (SDD). The
detector was capped with a 150-nm-thick aluminum
film (LUXEL, TF110) to minimize contribution ofstray UV light to detector response (Fig. 1).
Figure 2 shows a set of oxygen K edge spectra
observed on Sr-doped NaTaO3 photocatalyst disk. The
low energy band, which was assigned to the electronictransition from the oxygen 1s to oxygen 2p levels
hybridized with tantalum 5d orbitals, appeared at 531.2

eV in the absence of UV light irradiation. The band
shifted by 0.4 eV to the low-energy side under UV
irradiation.
A possible reason of the band shift is the conduction
band partially filled with bandgap-excited electrons.
The density of vacant states, the final states of the Kedge absorption, should have modified with theelectrons excited from the valence band. The oxidation
state of Ta cations decreased from 5+ to 4+ by the
bandgap excitation.
This study was supported by JSPS KAKENHI (grant
numbers 18KK0161 and 22H00344).

Fig. 2. Oxygen K edge absorption spectrum of a Srdoped NaTaO3 photocatalyst disk in the absence (upper
panel) and presence (lower panel) of UV-lightirradiation.

Fig. 1. A devise capping the SDD with the aluminum
filter for fluorescence yield detection of oxygen K edge
absorption spectrum under UV-light irradiation.

[1] Y. Sakata, T. Hayashi, R. Yasunaga, N. Yanaga, H.
Imamura, Chem. Commun. 51 (2015) 12935.
[2] H. Kato, K. Asakura, A. Kudo, J. Am. Chem. Soc.
125 (2003) 3082.
[3] T. Takata, J. Jiang, Y. Sakata, M. Nakabayashi, N.
Shibata, V. Nandal, K. Seki, T. Hisatomi, K. Domen,
Nature 581 (2020) 411.
[4] H. Onishi, ChemSusChem 12 (2019) 1825.

− 135 −

BL7B

High-Resolution Photoelectron Spectroscopy of Unexplored Chiral Systems
for Demonstration of the Photoelectron Circular Dichroism
H. Kohguchi1, Y. Hikosaka2, T. Kaneyasu3, S. Wada1 and Y-I. Suzuki4
1

Graduate School of Advanced Science and Engineering, Hiroshima University,
Higashi-Hiroshima 739-8526, Japan
2
Institute of Liberal Arts and Sciences, University of Toyama, Toyama 930-0194, Japan
3
SAGA Light Source, Tosu 841-0005, Japan
4
School of Medical Technology, Health Sciences University of Hokkaido, Tobetsu, 061-0293, Japan

Photoelectron circular dichroism (PECD) has
attracted attention as a novel molecular chirality
detection method. One of the remarkable attributes of
PECD is that the asymmetric photoelectron angular
distribution is generated from isotropically oriented
molecules in the gas phase. In addition, PECD depends
on the final ionic states so that the PECD data can be
related to the chirality of the molecular orbitals. We
have been conducting state-resolved PECD
measurements with the UVSOR BL1U beam line.
Although the circularly polarized light supplied by the
BL1U undulator is indispensable for detecting thestate-dependence of PECD [1], the narrower photon
energy spread is desired for resolving the electronic
structure of the observed photoelectron spectra. The
width of the experimental photoelectron spectra islimited by our VMI apparatus as well as the lightsource. High-resolution photoelectron spectra provide
unambiguous assignment of the electronic states which
is applicable to the PECD image data. For combining
the narrow band spectra with the PECD results
measured in BL1U, we have developed the VMI
apparatus and inspected the performance in the BL7B
beam line.
We adopt two types of imaging systems in our VMI
apparatus employs: a resistive anode and a CCD
camera. The total resolution was evaluated inmeasurement of Ar photoelectron images in BL7B. The
photoelectron images measured with the resistive
anode imager exhibited suﬃciently high resolution thatthe spin-orbit dual ring was resolved, as shown in Fig.
1 (a)-(d). The same measurement with the camera
system yielded the image data with a comparable
resolution but with a poor signal-to-noise ratio (Fig. 1(A)-(D)). This is because the numerical operation
determining the photoelectron positions of the camera
system was found to be less eﬃcient by 10 % of theresistive anode imager. The performance of these two
imaging systems was directly examined with thenarrow band light source, providing necessary
improvement toward the state-resolved PECD
measurements.
The photoionization experiments of chiral compoundswith a heat nozzle were conducted as another evaluationof the machine developments. An increase of thephotoelectron in a particular photon energy region wasmeasured with the elevated nozzle temperature, which
was ascribed to the vaporized chiral molecules (Fig. 2).
The photoelectron emitted in the shorter wavelengththan 100 nm was regarded to be due to contaminatedwater, which is generally hard to eliminate. This result
indicates that the density of the vapor in the irradiation
volume needed to be increased for the state-resolved
PECD measurements of new chiral systems. The
machine developments should be reconsidered basedon the results of the BL7B measurements.

Fig. 1. Photoelectron images of Ar measured at various
photon energy from 75 nm to 50 nm; (a)-(d) with aresistive anode imager, (A)-(D) with a CCD camera
capturing a phosphor screen image.

Fig. 2. Photoelectron yield spectrum of binaphthol atvarious nozzle temperatures near the ionizationthreshold.
[1] H. Kohguchi, Y. Hikosaka, T. Kaneyasu, S. Wada,
H. Ota, M. Fujimoto, M. Kato and Y-I. Suzuki, UVSOR
Activity Report 48 (2020) 93.

− 136 −

Ⅲ-3 Chemistry

BL7B

The Challenge of Photoionization Plasma Generation Using Synchrotron
Radiation Source for Study of Plasmas in Interstellar Space and in Nuclear
Fusion Devices
M. Kobayashi1, H. Iwayama2, J. Takahashi3, S. Yoshimura1, H. Ota2, K. Kobayashi3,
M. Katoh2,4, H. Nakamura1, I. Sakon5, K. Sawada6 and Y. Kebukawa3
1

National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, JapanUVSOR Synchrotron Facility, Institute for Molecular Science, Myodaiji,Okazaki 444-8585, Japan
3
Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku,Yokohama 240-8501, Japan
4
Hiroshima Synchrotron Radiation Center, Hiroshima University, 739-0046, Japan
5
Department of Astronomy, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan
6
Graduate School of Engineering, Shinshu University, Nagano, Japan2

An interstellar space is filled with interstellar plasmas,
which is generated by ionization by cosmic rays or byinterstellar radiation field [1]. In nuclear fusion devices[2], it is considered that neutral atoms and molecules inthe divertor region are photoionized by a light comingfrom the confinement region and the scrap-oﬀ layers,
where hot plasmas emit light in various energy ranges,
from EUV through visible to infrared ranges.
Characteristics and roles of the photoionized plasmas
are, however, not yet fully understood: What is thedependency of the density and temperature of thephotoionized plasmas on the energy range of the light?
How the plasma transport under an influence of space
magnetic field aﬀects chemical evolution of organic
molecules in the interstellar space? How thephotoionization process aﬀects the atomic/molecular
processes in the divertor region of the nuclear fusion
devices, which plays important roles on a device wallheat load mitigation?
To address these issues, we attempt to generate
photoionized plasmas by using the Synchrotron
Radiation Source UVSOR-III. There has been
substantial works on the photoionization by using laser
light with relatively high power source. In the present
work, however, we are interested in photoionization by
the radiation field (continuum light) in order to mimic
the interstellar radiation field and the radiation in thefusion devices, such as Bremsstrahlung. It is expectedthat the photoionization by the continuum light issignificantly diﬀerent from those by the laser, becauseof the continuous energy distribution that can excite
and ionize at various energy levels simultaneously.
The beamline BL7B is used to generate a continuum
light from 30 to 400 nm with 0th order emission. A gas
cell has been installed inside the irradiation chamber tomaintain high pressure of the sample gas while keeping
a good vacuum condition for the beamline. A high gaspressure is necessary to enhance the photoionization
events through an interaction between the photons andneutral atoms/molecules. Fig.1 shows the gas cell basedon a ICF34 cube. Holes of diameter of 1 to 2 mm are
made for the injection of the light into the cell as well
as for a gas outlet. Optical fibers are installed at the gas

cell for measurements of spectra of VUV, visible andmid infrared range from the photoionized plasmas. The
gas is fed to the cell through the pipe at the top of thecell. An electrode is situated at the bottom of the celland is biased up to +30V with respect to the ground tomeasure electron saturation currents of the plasmas.
As a sample gas, Ar and hydrogen were introduced
respectively. The ionization potentials of the gaseousare 14.5 and 13.6 eV, respectively. The light from theBL7B beamline has a peak intensity at around 50 nm,
which corresponds to a photon energy of 24.8 eV. The
gas pressure inside the gas cell could be increased to anorder of 1 Pa while the ambient pressure outside of thecell was kept at an order of 10-4 Pa and the pressure at
the upstream of the beamline was at an order of 10-6 Pa.
A beam of a few mm diameter could be injected into
the gas cell through the holes. The photon flux of thebeam was measured with a photodiode, and wasestimated at an order of 1011 photons/s/mm2. However,no significant signal of photoionization was obtained
this time. More challenges to come by optimizing thegas cell shape and the measurement system.

Fig. 1. A gas cell for the photoionization experiments.
[1] E.F.van Dishoeck et al., Faraday Discuss 133 (2006)
231.
[2] M. Kobayashi et al., Nucl. Fusion 62 (2022) 056006.

− 137 −UVSOR User 6რ

Surface,
Interface andThin Films

Ⅲ-4 Surface, Interface and Thin Films

BL6U

Fermiology of a Kagome Superconductor Cs(V1-xNbx)3Sb5 Revealed by
Momentum Microscope
T. Kato1, K. Nakayama1, Y. Li2,3,4, Z. Wang2,3,4, S. Souma5,6, F. Matsui7,
T. Takahashi1, Y. Yao2,3 and T. Sato1,5,6,8
1

Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture andMeasurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, P. R. China
3
Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology,
Beijing 100081, P. R. China
4
Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology,
Jiaxing, 314011, P. R. China
5
Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
6
Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Sendai 980-8577, Japan
7
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
8
International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University,
Sendai 980-8577, Japan
2

Recently, AV3Sb5 compounds (where A represents analkali metal K, Rb, or Cs) have been discovered to hostan ideal two-dimensional kagome lattice formed by Vatoms [Fig. 1(a)]. These materials undergo a charge
density wave (CDW) transition below the criticaltemperature (TCDW) of 78-103 K. The CDW transition ischaracterized by lattice distortions with the star-ofDavid or inverse star-of-David patterns. Notably, theCDW phase exhibits intriguing properties, including
the coexistence with superconductivity, time-reversal
symmetry breaking, and nematicity. Understanding theorigin of the CDW in AV3Sb5 and its interplay withother properties is currently a hot topic in condensed
matter physics. One useful approach to study this issue
is to perturb the CDW phase by varying key physicalparameters such as pressure and carrier concentrations.
In this regard, chemical substitution in the crystal,
which can adjust chemical pressure and/or carrier
concentrations, is a promising strategy.
In this study, we performed an angle-resolved
photoemission spectroscopy (ARPES) study on Nbsubstituted CsV3Sb5, Cs(V1-xNbx)3Sb5, with x = 0, 0.03,
and 0.07 [1]. The substitution of V with isovalent Nb
results in a reduction of TCDW, while simultaneously
enhancing the superconducting transition temperature(Tc) [Fig. 1(b)].
High-quality single crystals of Cs(V1-xNbx)3Sb5 weresynthesized by the self-flux method. ARPES
measurements were carried out by using momentum
microscope KREIOS 150 MM (SPECS) at BL6U [2].
In Fig. 1(c), we present the experimentally determined
Fermi surface in the normal state at T = 120 K (above
TCDW) for the highest Nb concentration (x = 0.07). The
use of a momentum microscope allowed to collectphotoelectrons over a wide momentum space, enablinga comprehensive observation of multiple Fermi
surfaces. Specifically, we observed a circular pocket
centered at Γ, which is derived from the p orbital of Sb
atoms embedded in the kagome lattice plane, and alarge hexagonal pocket at Γ and triangular pockets at K,
both of which originate from the 3d orbitals of the V
kagome lattice. A comparison of the Fermi surface at
x = 0.07 with that at x = 0 reveals intriguing trends: thecircular pocket expands with increasing x, while thetriangular pocket shrinks. The significant impact of theobserved band shift is a lifting of the saddle point near
the M point away from the Fermi level. Since TCDW
becomes higher when the saddle point is located atcloser to the Fermi level, a large density of states of thesaddle point plays a key role in stabilizing CDW.
Additionally, our findings suggest that the enhancementof Tc through Nb substitution is partly attributed to the
expansion of the circular pocket.

Fig. 1. (a) Crystal structure and (b) phase diagram ofCs(V1-xNbx)3Sb5. (c) ARPES intensity at the Fermi levelplotted as a function of two-dimensional wave vector.
Red, purple, and blue dashed lines are guides for theeyes to trace the experimental Fermi surfaces.
[1] T. Kato et al., Phys. Rev. Lett. 129 (2022) 206402.
[2] F. Matsui et al., Jpn. J. Appl. Phys. 59 (2020)
067001.

− 141 −BL2A

Mg K-edge NEXAFS of MgO, Mg(OH)2 and MgCO3
E. Kobayashi 1, S. Yoshioka 2 and K. K. Okudaira 3
1
Kyushu Synchrotron Light Research Center, 8-7 Yayoigaoka, Tosu, Saga 841-0005, Japan
Gradiate School of Engineering, Kyushu University, 744 Motooka Nishi-ku Fukuoka 819-0395 Japan
3
Graduate School of Science and Engineering, Chiba University,
1-33 Yayoi-cho Inage-ku, Chiba 263-8522, Japan

2

In recent years, organic photovoltaic (OPV) has been
attracting attention as a low-cost, lightweight battery
that replaces conventional solar cells. Metal oxides
plays an essential role as an electron and a hole transportlayer (ETL and HTL) material. [1,2] In order to further
improve the characteristics of these charge transportlayers, it is necessary to understand the band structure.
Near-edge x-ray absorption fine structure (NEXAFS)
spectroscopy is a powerful tool for investigating theunoccupied state of band structure of materials. When
discussing the band structure, information on theposition of the unoccupied bottom is important. It isnecessary to know the eﬀects on the bottom of theunoccupied band when metal oxides are contaminatedby atmospheric component such as OH and CO2.
Therefore, we measured the unoccupied state of MgO,
Mg(OH)2 and MgCO3・xH2O generated by theadsorption of OH and CO2 on the MgO surface.
NEXAFS spectra of the MgO, Mg(OH)2 and MgCO3・
xH2O powders using both total electron yield (TEY)and partial fluorescence yield (PFY) modes were
measured at the beamline 2A of the UVSOR in theInstitute of Molecular Science. For TEY, the draincurrent from the sample was measured. For PFY,
fluorescence X-rays were collected using an energy
dispersible silicon drift detector (SDD). All experiments
were performed at room temperature.
Figure 1 shows the Mg K-edge NEXAFS spectra of
MgO, Mg(OH)2 and MgCO3・xH2O powder obtained
from TEY mode. The peak positions of MgO, Mg(OH)2and MgCO3・xH2O spectra are diﬀerent. This suggeststhat their structures are diﬀerent. On the other hand, therising positions of the spectra of MgO, Mg(OH)2 andMgCO3・xH2O are very similar. This suggests that thebottom of the unoccupied band is the same. Figure 2
shows the Mg K-edge NEXAFS spectra of MgO,
Mg(OH)2 and MgCO3・xH2O powder obtained from
PFY mode. The rising positions of the spectra of MgO,
Mg(OH)2 and MgCO3・xH2O are very similar. It was

found that the bottom of the unoccupied state of MgO
was not aﬀected by contamination by atmosphericcomponent such as OH and CO2.

Fig. 1. Mg K-edge NEXAFS spectra of MgO, Mg(OH)2and MgCO3・xH2O powder obtained from TEY mode.

Fig. 2. Mg K-edge NEXAFS spectra of MgO, Mg(OH)2and MgCO3・xH2O powder obtained from PFY mode.
[1] I. Ierides et al., J. Mater. Chem. C 9 (2021) 3901.
[2] Y. –J. Lee et al., Adv. Energy Mater. 2 (2012) 1193.

− 142 −

Ⅲ-4 Surface, Interface and Thin Films

BL2A

Structural Analyses of Silicon Atoms in a Zero-dimensional Metal-atom
Encapsulating Silicon Cage Clusters by X-ray Absorption Spectroscopy
A. Nakajima and T. Inoue
Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku,
Yokohama 223-8522, Japanbetween the obtained spectra and the theoreticallycalculated FEFF spectra of structural isomers to obtainthe structural information.

Fig. 1. Photo of the connected chamber transported
from Keio University.

ROI / Photon (a. u.)

Since silicon (Si) element belongs to the same groupas carbon, it has been highly expected to create novel
low-dimensional compounds as fullerene and carbon
nanotube. In zero-dimensional silicon nanoclusters, it
has been found that metal-atom encapsulating siliconcage, M@Si16 superatom (SA), can be generated in a
gas-phase synthesis [1, 2]. In this study, the X-ray
absorption fine structure analysis (XAFS), especiallythe extensive X-ray absorption fine structure analysis(EXAFS), has been applied to thin films of M@Si16 SA
deposited on a solid surface to reveal the structural
information, compared with the structure obtained byquantum chemical calculations.
The Ta@Si16 SA, composed of tantalum (Ta) and Si,
was generated using a pulsed magnetron sputteringsystem, and Ta@Si16 SA cations were deposited on ahighly oriented pyrolytic graphite (HOPG) substratethat was set on a wobble stick, as ten layers with a spotof 6-8 mm in diameter. The deposited substrate was
kept in vacuum with an ion pump and transported from
Keio University to UVSOR, where an ion pump wasused with a nickel hydride battery (pumping speed
20L/s). The battery (24 V, 2000 mA h) can work in 10
hours, which covers the transportation time, and XAFS
measurements of the Si K-edge were performed at theBL2A beamline (Fig. 1). Absorption of Si atoms wasmeasured by the fluorescence method. The structure
was identified by comparing the obtained EXAFS
spectrum with the theoretically calculated FEFF
spectrum of three structural isomers (Td, D4d, and C3v).
For the deposited Ta@Si16 SA samples, XANES and
EXAFS measurements were performed for the Si
K-edge at 1800 to 2400 eV in the soft X-ray region(Fig. 2). For monitoring the incident light intensity, thescattered intensity of the copper mesh was used insteadof gold mesh, because there is no XAFS of copper inthe measurement energy region. However, the optics inthe beamline inevitably contain gold-coated ones, andthen X-ray absorption based on gold appears above
2000 eV; the light intensity decreases, where Si K-edge
signals should be observed from the thin Ta@Si16 SA
films. Although proper normalization of the incident
light intensity had been tried with the scatteredfluorescence from the measurement sample itself, theincident light intensity could not be accurately
evaluated, and then the measurement energy range wassqueezed to 1800-2000 eV (k = 3 - 7 Å-1). The EXAFS
vibrations in the soft X-ray region were compared

Background subtracted
spectrumRaw spectrum

Background signal
1800

2000

2200

2400

Photon energy (eV)Fig. 2. Si K-edge XAFS Spectra for the deposited Ta@
Si16 SA samples. The spectrum in blue was obtained bysubtracting background signal in red from raw spectrumin black. The spectrum in 1800-2000 eV was used forthe structural analyses.
[1] H. Tsunoyama, H. Akatsuka, M. Shibuta, T. Iwasa,
Y. Mizuhata, N. Tokitoh and A. Nakajima, J. Phys.
Chem. C 121 (2017) 20507.
[2] H. Tsunoyama, M. Shibuta, M. Nakaya, T. Eguchi
and A. Nakajima, Acc. Chem. Res., 51 (2018) 1735.

− 143 −

BL2B

Annealing Eﬀects on Surface Electronic Structure of MoO3
Nanoparticles by UPS
K. K. Okudaira1 and S. Ishii2,
1

Graduate School of Engineering, Chiba University, 1-33 Yahoi-cho, Inage-ku Chiba 263-8522, Japan
2
Graduate School of Science and Engineering, Chiba University,
1-33 Yahoi-cho, Inage-ku Chiba 263-8522, Japan

Organic photovoltaic (PV) cells have been the hot
research topic in recent years due to their advantages of
low-cost manufacturing, light weight and good
flexibility. Among these PV cells, solution-processedbulk heterojunction PV cells with donor–acceptor (D–A) blends sandwiched between the anode and cathodeare the most promising alternative to realize large-scale
production. In bulk heterojunction PV cells, the charges
generated in the active layer upon light absorption aretransported via D–A networks and collected by theelectrodes to realize light-electricity conversion.
Recently, the transition metal oxides (TMOs) wereinserted between the electrodes and organic active layer
to prevent the leakage of undesired charged carrier toelectrode as well as to promote the charged carriertransfer. [1] The eﬃciency of these electron transfer
layer (ETL) and hole transfer layer (HTL) largely
depend on the surface electronic structure of the TMO
layer.
In this work we prepared MoO3 nanoparticles (NPs)films with diﬀerent annealing atmosphere and estimatedthe electronic structure of MoO3 NPs by ultraviolet
photoelectron spectroscopy (UPS) measurements toestimate the eﬀect of annealing on the surface electronic
structure and the work function.
UPS measurements were performed at the beam line
BL2B of the UVSOR storage ring at the Institute for
Molecular Science at the photon energy (hν) of 28 eV.
MoO3 NPs were synthesized via solvothermal method.
[2] The thin films of MoO3 NPs were deposited on ITO
by spin casting (denoted as “non”). The films wereannealed at 500℃ in air and hydrogen atmosphere(denoted as “in air” and “in H2”, respectively). The
mean size of synthesized MoO3 NPs was about 10 ~ 30
nm using TEM measurements.
The whole spectral structure of MoO3 thin films byannealing in H2 atmosphere is almost same as that of
non annealing as shown in Fig. 1 (a). On the contrary,by annealing in air, the position of valence band top(VBT) is shifted to higher binding energy by about
0.3 ~ 0.4 eV. It is expected that the Fermi level leaves
from VBT due to the formation of defect states justabove the Fermi level by annealing in air. Furthermore,
the work function of MoO3 films by annealing in air islarger than that of non annealing MoO3 films by about
0.2 eV. This vacuum level shift is considered by theinterfacial dipole formation due to the introducing thehydroxyl group to the surface of the MoO3 film byannealing in air.

a

b

c

Fig. 1. UPS of MoO3 NPs at hν = 28eV (a) in thevalence band region (b) in the secondary cut-oﬀ and (c)in the valence top region.
[1] F. Liu et al., Sol. Energy Mater. Sol. Cells 94 (2010)842.
[2] W.-S. Kim et al., J. Nanopart. Res. 12 (2010) 1889.

− 144 −

Ⅲ-4 Surface, Interface and Thin Films

BL3U

X-ray Absorption Spectroscopy Study of 4-MBA and Cysteine
on Gold Surfaces
F. Sato1, I. Sakaida1, S. Ohno1 and M. Nagasaka2
Graduate School of Engineering Science, Yokohama National University, Yokohama 240-8501, Japan
2
Institute for Molecular Science, Okazaki 444-8585, Japan

It is important to understand the behavior of
biomolecules on solid surfaces for the application to
medical device, biosensor and biocompatible material.
It is essential to study the adsorption and desorption
behavior of biomolecules and their response to theapplied electric fields. It is of particular importance toanalyze the dynamic behavior of biomolecules on asurface in electrolyte solutions, which is close to therealistic condition in the body of living creatures [1,2].
In the present study, potential-dependent adsorption/
desorption behavior of 4-mercaptobenzoic acid (4MBA) and cysteine on Au membrane surfaces havebeen investigated using soft X-ray absorption
spectroscopy (XAS) in the transmission mode. The
experiments were performed on the soft X-ray undulator
beam line at UVSOR-III, BL3U. We used H2SO4 and
KOH as the electrolyte solution. For the adsorption of
4-MBA molecules, the samples were immersed in
1mM 4-MBA/ethanol solution for more than 30 min.
For the adsorption of cysteine molecules, the samples
were immersed in 1mM cysteine/K-OH solution for
more than 1 hour.
In our previous study, we have studied the adsorption/
desorption behavior of 4-MBA on Au films using
surface diﬀerential reflectance spectroscopy (SDRS)
combined with cyclic voltammetry (CV) [3]. The key
issue was the interaction between functional group(-COOH) and Au films through Coulomb interaction
depending on the applied biases and pH conditions.
Redox processes involving charge transfer were clearlyobserved with CV and the relation between the change
in the reflectance spectra and the peaks in CV wasinvestigated in detail. Interestingly, we found some
precursor phenomena to cause significant changes in
the reflectance spectra with no corresponding signal in
CV. This indicates that such changes in the reflectancespectra are not due to the charge-transfer-type reactions
but rather to the subtle change in the orientation/
conformation of 4-MBA molecules. We also observed
similar eﬀects for cysteine.
To our knowledge, there has been no serious eﬀort tostudy the 4-MBA/Au and cysteine/Au systems using
XAS in terms of the aforementioned precursor
phenomena. At the initial stage, we have tried toobserved the eﬀects on Au(111). However, we could
not obtain the clear data showing the adsorption/
desorption behavior of 4-MBA, though they are

confirmed with CV measurements.
Here, we used an Au membrane as the substrate
which has polycrystalline structure. Our CV data revealthat there should be Au(111) part on the surface, andthat clear feature for adsorption/desorption for both
4-MBA and cysteine are confirmed.
In our previous XAS measurements, we havesucceeded in obtaining the absorption peak of calbonylgroup (-COOH) for 4-MBA. In this case, we observed
two distinct features at 532 and 535 eV in the O K-edge
region. These are assigned as due to the transition to theπ* orbital in the C=O double bond. Here, we observed
a rather weak feature at 533 and 536 eV for cysteine, as
shown in Fig. 1. We expect that these are the slightly
shifted components, similarly assigned to the C=O
double bond.
As a result, we could have established themeasurement set up for the transmission mode for both
4-MBA and cysteine. We now plan to investigate aseries of alkanethiol molecules to form self-assembled
monolayer (SAM), and compared their behavior with
4-MBA and cysteine.
The next step should be the observation of the change
in the orientation/conformation depending on theapplied bias to the electrode (Au membrane). We expectthat the precursor phenomena be proved more clearly.
0.5

Cysteine
Absorbance (x102)

1

0.0
-0.5
-1.0
-1.5
-2.0
530

535

540

545

Photon Energy (eV)Fig. 1. O K-edge XAS spectrum for cysteine.
[1] R. LeParc et al., Langmuir 22 (2006) 3413.
[2] C. I. Smith et al., J. Electrochem. Soc. 150 (2003) 1.
[3] N. Ikeda et al., ALC’19 (2019) 22.

− 145 −

BL3B

Evaluation of Growth Orientation and Crystallinity of Deep UV Emitting
Zinc Aluminate Thin Films
H. Kominami1,2,3, K. Inoue1, N. Uesugi1, K. Nie1, A. Adachi1, R. Isihara1, K. Yabe1,
J. Kamikawa2, T. Sadamori2, D. Takeya2, N. Miyazaki2, A. Dorokhina3 and S. Kurosawa4,51

Graduate School of Integrated Science and Technology, Shizuoka University,
2
Faculty of Engineering, Shizuoka University,
3
Graduate School of Science and Technology, Shizuoka University,
1~3
3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8651 Japan
4
New Industry Creation Hatchery Center (NICHe), Tohoku University
6-6-10 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
5
Faculty of science, Yamagata University, 1-4-12, Kojirakawa-machi, Yamagata, 990-8560, JapanThe UV light is used for various applications
depending on the wavelength as well as the sterilization
described above. Recently, from the viewpoint ofconsideration to the environment, the mercury free UVemission devices have been demanded for theapplication of catalyst and medical situations. In ourprevious work, it was clarified that ZnAl2O4 phosphor
was suitable for the UV field emission lamp because of
its stability and luminescent property. It shows strong
UV emission peaked around 250 nm which suitable forsterilization.
In this research, ZnAl2O4 thin film layer wereprepared by thermal diﬀusion of ZnO and sapphire
substrate for new UV devices. In order to evaluate theinside of the film, an etching treatment was performed
using hydrochloric acid.
XRD measurement was performed on the preparedsample. As a result, diﬀraction peaks of (220)(311)(400)(333) were observed. XRD measurement was
performed on the prepared sample. As a result,diﬀraction peaks of (220)(311)(400)(333) wereobserved.
φ scan results of ZnAl2O4(220)(422)(533) andc-Al2O3 (110)(300) where diﬀraction peaks wereobserved in 2θχ/φ scans around the a- and m-planes, a
total of six diﬀraction peaks were observed every 60°.
The results are shown in Fig.1. This is a diﬀraction
peak with six-fold symmetry derived from α-Al2O3,
which is a hexagonal system. ZnAl2O4 is a cubic
substance, and ZnAl2O4 (220)(422)(533) also had atotal of six diﬀraction peaks at intervals of 60°.
In ZnAl2O4{220}{422}, there are 6 planes
perpendicular to ZnAl2O4 (333) every 60°. There is aface. From this, the diﬀraction peaks of ZnAl2O4 (220)(422)(533) with six-fold symmetry in the φ scan are
considered to be the diﬀraction peaks of a crystal inwhich ZnAl2O4 (333) is oriented on the c-plane ofc-Al2O3.
The six planes of ZnAl2O4{220} and {422} eachform an angle of 30°, and the m-plane and a-plane ofc-Al2O3 also form an angle of 30°. ZnAl2O4(220) and(422) are oriented along the m-plane and a-plane ofc-Al2O3, respectively, from the measurement results of2θχ/φ scans around the m-plane and a-plane of c-Al2O3,
so ZnAl2O4{422} and the a-plane of c-Al2O3, and them-plane of ZnAl2O4{220} and c-Al2O3 are parallel toeach other.
From Fig.1, there is a large peak of 6-fold symmetry
and a small peak of 6-fold symmetry at 30° shift (▼).
In addition, ZnAl2O4(220) is also oriented on thea-plane of c-Al2O3 from the measurement result of2θχ/φ scan around the a-plane of c-Al2O3. Thesediﬀraction peaks are thought to be due to crystals
formed by a phase relationship in which ZnAl2O4 isrotated 30° about ZnAl2O4[333], where the planes of
ZnAl2O4 and c-Al2O3 are parallel to each other. Sincealmost no diﬀraction peaks other than the above twomodels are observed, it is considered that the sample isformed by the relationship between the phases ofc-Al2O3 and ZnAl2O4 in these two models.
φ scans of ZnAl2O4(220) samples whose thin film
surface was etched by hydrochloric acid showed thatthe sample etched about 400 nm lost some of its internalorientation, while the sample etched about 450 nm lostits orientation largely. lost part.
From the CL measurement results of this sample, thesample etched about 400 nm maintained the UVemission intensity, but then the emission intensity
dropped sharply, and the sample etched about 450 nm
did not obtain UV emission. From these results, it isconsidered that a uniform ZnAl2O4 thin film is formed
from the sample surface to about 400 nm, but theformation of ZnAl2O4 is insuﬃcient inside.

Fig. 1. φ - scan XRD spectra of ZnAl2O4 and c-Al2O3.

− 146 −

Ⅲ-4 Surface, Interface and Thin Films

BL4U

Application of atomically-thin Graphene to X-ray Astronomy:
Soft X-ray Transmission Measurements
I. Mitsuishi 1, K. Kashiwakura1, Y. Niwa1, T. Ogawa1, M. Hirota1, Y. Tawara1, R. Kitaura2,
H. Yuzawa3, T. Ohigashi 3 and K. Tanaka3
1

Graduate School of Science, Division of Particle and Astrophysical Science, Nagoya University, Furo-cho,
Chikusa-ku, Nagoya, Aichi 464-8602, Japan2
Department of Chemistry, Nagoya University, Nagoya 464-8602, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

20 mm

X-ray

Sample chamber

Graphene sample
on a quartz substrate

Fig. 1. Sample chamber and a close-up view of thegraphene sample on the quartz substrate with a taper
structure.
Single-layer
Five-layer

Transmission

Thin-film devices have been used in a large variety offields including astronomy. In X-ray astronomy, thinfilm devices have been prepared for payloads such asdetectors and telescopes and playing a key role as, e.g.,
optical and contamination blocking filters and thermal
shields [e.g., 1, 2]. For such thin film devices, severe
launch and space environmental tolerance and hightransmission are essential at the same time for highsensitivity space observations in the limited observing
time. Plastic films such as polyimide have often been
adopted as thin films. However, there is still room for
improvement especially in transmission of a soft energy
range below 1 keV. Thus, we have proposed to makeuse of graphene which is an atomically-thin material
but has excellent mechanical strength. Our idea is to
apply graphene to thin film devices in X-ray astronomy[3].
As a first step, we conducted rough X-ray transmission
measurements from 100 to 500 eV and confirmed very
high transmission for both single- and five-layer
graphene sample [3]. As a next step, we performed
detailed X-ray transmission measurements tounderstand systematic errors for the observed values inthis experimental setup and aging degradation as shownin Fig. 1. We used the same quartz substrates with large
tapers with an angle of 30 degrees to avoid the
shadowing eﬀect by the substrate for focused X-ray
photons by the Fresnel zone plate. Consequently, very
high transmission, specifically 94-99% and 95-101%
for single- and five-layer graphene samples in nominal
values except the C K-edge structure, was obtained.
The systematic errors are estimated to be 3% for oursample in this experimental setup considering shortand long-term time variability and spatial dependence
and thus, there is no significant diﬀerences in thetransmission between the samples within the systematic
errors in our current experimental setup. This suggeststhat very high transmission is expected even for fivelayer graphene films with much stronger mechanicalstrength which allows us to fabricate free-standing
structures with larger diameter much easier. The results
are shown in Fig. 2. We confirmed that there is no
significant aging degradation at least for the singlelayer graphene sample for 9 months. The paper
including these results is being prepared (Kashiwakura,
Mitsuishi et al., in prep.).

Energy [eV]Fig. 2. Resultant transmission from 100 to 500 eV forsingle- (filled circle) and five-layer (triangle) graphenesamples (Kashiwakura, Mitsuishi et al., in prep.).
Systematic errors are +/-3%.
[1] P.J. Serlemitos et al., Publ. Astron. Soc. Japan 47(1995) 105-114.
[2] P.J. Serlemitos et al., Publ. Astron. Soc. Japan 59(2007) S9-S21.
[3] I. Mitsuishi et al., UVSOR Activity Report 2021 49(2022) 45.

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BL4B(XMCD)

Tuning Magnetic Properties of Atomic Layer Materials
by organic-inorganic Interfacial Magnetic Coupling
H. Ono1, Y. Umeda1, K. Yamamoto3,4, O. Ishiyama3,4,
T. Yokoyama3,4, M. Mizuguchi1,2 and T. Miyamachi1,21Department of Materials Science and Engineering, Nagoya University, Aichi, 464-8603, Japan.
Institute of Materials and Systems for Sustainability (IMaSS), Nagoya University, Aichi, 464-8601, Japan.
3
Institute for Molecular Science, Myodaiji-cho, Okazaki 444-8585, Japan
4
The Graduate University for Advanced Studies, Myodaiji-cho, Okazaki 444-8585, Japan

2

Organic materials are expected to be useful to
spintronics devices due to their low spin current
dissipation derived from weak spin-orbit interaction.
Organic-inorganic hybrid interface has been studied
because of its controllable interfacial spin state via theproximity eﬀect. Spin-dependent electron transport
properties depend on the electronic interaction between
organic and inorganic materials and local interface
structures. Thus, understanding structural, electronic
and magnetic properties of the organic-inorganicinterface on the level of single molecules is important
for realizing molecular spintronics devices. However,microscopic details of the hybrid interface have notbeen clarified so far.
In this study, we fabricate organic-inorganic hybrid
films and investigate their intrinsic electronic andmagnetic properties on the level of single molecules.
For this purpose, ferromagnetic iron nitride atomic
layers with γ’-Fe4N stoichiometry were chosen as aninorganic material, which uniformly grow and showhigh surface quality on the atomic scale [1,2]. Molecularlayers composed of planer cobalt phthalocyanine(CoPc) were chosen as an organic material. Structural,electronic and magnetic properties of the hybridinterface composed of CoPc with the thickness of 1, 2
and 3 molecular layers and a bilayer γ’-Fe4N were
investigated by scanning tunneling microscopy (STM),
low energy electron diﬀraction (LEED) and x-ray
absorption spectroscopy/magnetic circular dichroism(XAS/XMCD).
A bilayer γ’-Fe4N was prepared by iron deposition on
Cu (001) with N+ ion bombardment and subsequentannealing at 620 K. Then, CoPc/γ’-Fe4N hybrid thinfilms were fabricated by depositing CoPc on the γ’Fe4N at room temperature. In combination with resultsof STM and LEED, the impact of thickness-dependent
structural properties of CoPc layers on the interfacial
Fe and Co spin states were investigated by XMCD.

XAS/XMCD measurements were performed at
BL4B in UVSOR by total electron yield mode at B =0 - ± 5 T and T = 7.3 K. The XMCD spectra are obtainedat the normal (NI: θ = 0°) and the grazing (GI: θ = 55°)
geometries by detecting μ+ – μ–, where μ+ (μ–) denotes
the XAS recorded at Fe and Co L adsorption edges withthe photon helicity parallel (antiparallel) to the sample
magnetization. Note that θ is the angle between thesample normal and the incident x-ray [3].
We confirm the magnetic coupling for
CoPc(1ML)/γ’-Fe4N from the finite of Co XMCD
signal. The perpendicular magnetic anisotropy of γ’Fe4N, which is proportional to the diﬀerence between
out-of-plane and in-plane Fe orbital magnetic moment
obtained by XMCD sum rule, becomes larger after thedeposition of CoPc molecules on the γ’-Fe4N. This
result indicates the magnetic coupling with CoPc
enhances the perpendicular magnetic anisotropy of γ’Fe4N. As for magnetic properties of CoPc, we find that
Co out-of-plane and in-plane XMCD signals show
diﬀerent behaviors with increasing the amount of CoPc.
While the out-of-plane Co XMCD signal gradually
decreases with increasing CoPc thickness, the strong
Co XMCD is maintained in the in-plane direction.
Taking the random stacking of CoPc layers revealed by
STM and LEED, these results indicate that the orbital
dependent magnetic coupling between CoPc layers,i.e., the magnetic coupling via the in-plane Co 3d
orbitals is weak, but that via the out-of-plane Co 3d
orbitals relatively robust.
[1] Y. Takahashi et al., Phys. Rev. Lett. 116 (2016)056802.
[2] Y. Takahashi et al., Phys. Rev. B 95 (2017) 224417.
[3] S. Nakashima et al., Adv. Funct. Mater. 29 (2019)1804594.
[4] P. Bruno, Phys. Rev. B 39 (1989) 865.

− 148 −

Ⅲ-4 Surface, Interface and Thin Films

BL4B (XMCD)

X-ray Magnetic Circular Dichroism Study of Chiral Antiferromagnetic
Co2-xPdxMo3N Thin Films
B. Qiang1,2, M. Togashi3, T. Fukasawa1, T. Hajiri1, M. Kuwahara3,4, H. Asano1,5 and T. Ito61
Department of Materials Physics, Nagoya University, Nagoya, Japan, 464-8603
Department of Materials Design Innovation Engineering, Nagoya University, Nagoya, Japan, 464-8603,
3
Department of Applied Physics, Nagoya University, Nagoya, Japan, 464-8603
4
Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya, Japan, 464-8603
5
Research Department, Nagoya Industrial Science Research Institute, Nagoya, Japan, 464-0819
6
Synchrotron Radiation Research Center, Nagoya University, Nagoya, Japan, 464-8603

2

Dzyaloshinskii-Moriya (DM) interaction-induced
magnetic skyrmions [1,2] have been observed in manychiral magnets with broken space reversal symmetry[3,4]. Recently, filled β-Mn-type Fe2-xPdxMo3N [5] andCo2-xPdxMo3N (CPMN) [6,7] have been reported tohost small size skyrmions at room-temperature, which
are a good playground for skyrmion device applications.
X-ray magnetic circular dichroism (XMCD) is known
as a very powerful tool to detect the element-specificspin and orbital states in each site. In this study, we
have applied XMCD on filled β-Mn-type CPMN toelucidate the relation between its magnetism, especiallyferromagnetic skyrmions at the low-temperature(Spiral-II) phase [6], and spin and orbital magnetic
moment of Co.
CPMN (x=1.01) thin film (30 nm in thickness,without capping layer) was prepared using magnetron
sputtering technique grown on C-sapphire substrates.
Measurements of XAS/XMCD were performed at theBL4B in UVSOR by total electron yield mode at T = 4
K (Spiral-II phase). The external magnetic fields H up
to ±1 T were applied in parallel to the surface normal
axis. The circularly polarized x-ray beam was induced
nearly parallel to H. It should be noted that each Co L2,3
XAS spectra at H = +0.5 ~ +0.1 T (-0.5 ~ -0.1 T) wereobtained after the magnetization due to canted
antiferromagnetism being saturated at H = - 1 T (+ 1 T),
since the magnetic skirmions in this system is expected
to be generated around H = ±0.2 T asymmetrically withrespect to the zero field (see inset of Fig. 1(b))[6].
Figures 1(a) and 1(b) show the magnetic fielddependence of the Co L2,3 edge-XAS spectra of CPMN
(x = 1.01) and the XMCD spectrum obtained bysubtracting XAS spectra between H = +1 T (~ +0.1 T)
and H = -1 T (~ -0.1 T), respectively. It can be seen thata clear XMCD is observed at H = ±1 T, where the spinstate associated with the formation of canted
antiferromagnetism is expected from the magnetic andtransport measurements at the low temperature region.
With decreasing magnetic field, the observed XMCD
intensity gradually decreases, and a opposite sign of the
XMCD intensity near the L3 edge at 778 eV appears in
the region of H < ±0.25 T, where magnetic skirmion

formation is expected from the topological Hall eﬀect
measurement (Fig. 1(b), inset). We expect that theobserved magnetic field dependence of XMCD near the
low-energy edge might suggest the change in themagnetic structure associated with the formation ofmagnetic skirmions on CPMN.

Fig. 1. (a) XAS spectrum at the Co L2,3 edge obtainedby using the photon helicity parallel (μ+, red) andantiparallel (μ-, blue) to the external magnetic field H,
respectively. (b) External magnetic field dependence of
XMCD spectra (μ+−μ-) for CPMN (x=1.01) at T = 4 K.
Inset shows the field dependence of topological Halleﬀect [6].
[1]T. Jo, J. Phys. Soc. Jpn. 62 (1993) 1814.
[2]Y. Teramura, A. Tanaka, and T. Jo, J. Phys. Soc. Jpn.
65 (1996) 1053.
[3]C. Papas et al., Phys. Rev. Lett. 102 (2009) 197202.
[4]V. Kumar et al., Phys Rev B 101 (2020) 014424.
[5]B. W. Qiang et al., Appl. Phys. Lett. 117 (2021)
142401.
[6]B. W. Qiang et al., Jpn. J. Appl. Phys. 61 (2022)
120901.
[7]B. W. Qiang et al., AIP Advances 13 (2023) 025138.

− 149 −

BL4B(XMCD)Controlling Magnetic Anisotropy of Magnetic Thin Film Heterostructures
Y. Umeda1, H. Ono1, K. Yamamoto3,4, O. Ishiyama3,4,
T. Yokoyama3,4, M. Mizuguchi1,2 and T. Miyamachi1,21Department of Materials Science and Engineering, Nagoya University, Aichi, 464-8603, Japan.
Institute of Materials and Systems for Sustainability (IMaSS), Nagoya University, Aichi, 464-8601, Japan.
3
Institute for Molecular Science, Myodaiji-cho, Okazaki 444-8585, Japan
4
The Graduate University for Advanced Studies, Myodaiji-cho, Okazaki 444-8585, Japan2

3d transition metal ordered alloy thin films with L10
crystal structure are attracting attention as rare-earth
free magnetic materials due to their large perpendicularmagnetic anisotropy, large magnetic moment, and highCurie temperature. Using pulsed laser deposition, thegrowth of FeCo thin films with alternating Fe and Co
atomic layers was investigated [1]. Although mucheﬀort has been made to realize uniaxial anisotropy in
the L10-FeCo phase, the L10 structure is a nonequilibrium state of the FeCo phase and hence themethod for achieving the out-of-plane magnetization
has not been established. The main problem could becaused by atomic-scale disorder at the Fe/Co interface
during growth processes, which highlights theimportance of microscopic characterizations of thestructural, electronic, and magnetic properties of L10FeCo. Therefore, we intend to fabricate high-quality
FeCo alloy thin films on Cu(001) substrates by utilizing
the nitrogen surfactant eﬀect of a monatomic layer
nitride. The high surface lattice stability of a monatomic
layer nitride and the nitrogen surfactant eﬀect thateﬀectively suppresses the interdiﬀusion at theheterointerface could lead to the growth of FeCo alloy
thin films with atomically flat and uniform interfaces[2,3]. The important role of the nitrogen surfactant
eﬀect in the preparation of high-quality L10-type alloy
thin films has been demonstrated for FeNi alloy thinfilms [2].
In this study, FeCo ordered alloy thin films in theinitial growth stage were prepared using the nitrogensurfactant eﬀect. The correlation between the structuralchanges at the FeCo interface and magnetic properties
upon sample heat treatment was investigated using
low-energy electron diﬀraction (LEED) and X-ray
absorption spectroscopy/X-ray magnetic circulardichroism (XAS/XMCD). FeCo alloy multilayer thinfilms were grown on Cu(001) using the following
process: (1) a bilayer iron nitride (Fe2N/Fe) was firstgrown on Cu(001), (2) 1 monolayer (ML) of Co was
deposited at a low temperature (~150 K), (3) annealing
was carried out at 300, 570, and 670 K, and (4)additional 1 ML of Fe was deposited at a lowtemperature (~150 K) for samples heated at 570 K(FeN/Co/Fe/Fe).
The
annealing
temperaturedependence of electronic and magnetic properties wasinvestigated by XAS/XMCD.XAS/XMCD measurements
were performed at BL4B in UVSOR by total electron
yield mode at B = 0 - ± 5 T and T = 7.9 K. The XMCD
spectra are obtained at the normal (NI: θ = 0°) and thegrazing (GI: θ = 55°) geometries. Note that θ is theangle between the sample normal and the incident
x-ray. Element specific magnetization curves were also
recorded by plotting the L3/L2 Fe and Co XAS intensities
as a function of the magnetic field.
The XMCD signal of the bilayer iron nitride is greaterin the GI geometry than in the NI geometry, revealing
its strong in-plane magnetic anisotropy as previously
reported [3]. Adding 1 ML Co activates the nitrogensurfactant eﬀect [2], which leads to the formation of
CoN in the topmost layer (CoN/Fe/Fe). Accordingly,
we observed an increase in the out-of-planemagnetization of the Fe layer from Fe magnetization
curves. The perpendicular magnetic anisotropy of the
Fe layer is further enhanced by annealing at 570 K.
However, at an annealing temperature of 670 K, adecrease in the coercivity of the Fe layer is observed.
Taking into consideration the annealing temperaturedependence of the LEED pattern, the enhancement of
the out-of-plane magnetization could be due toimproved ordering of the Co/Fe interface up toannealing temperatures of 570 K. At 670 K, surface N
atoms start to desorb, which induces the interdiﬀusionof interfacial Co and Fe atoms and consequently lowers
the coercivity. In the sample with additional Fe
layers (FeN/Co/Fe/Fe), the perpendicular magnetic
anisotropy of Fe is further enhanced.
[1] H. Ito et al., AIP Adv. 9 (2019) 045307.
[2] K. Kawaguchi et al., Phys. Rev. Mater. 4 (2020)
054403.
[3] Y. Takahashi et al., Phys. Rev. B 95 (2017) 224417.

− 150 −

Ⅲ-4 Surface, Interface and Thin Films

BL4B

X-ray Photoemission Spectroscopy and X-ray Absorption Spectroscopy
Measurement of the Chiral Molecule on the Metal Substrate
F. Nishino1,2, K. Fukutani 1,2, P. I. Jaseela1,2, H. Iwayama1,3, S. Makita3 and S. Kera1,2,3,4
1
Institute for Molecular Science, Okazaki 444-8585, JapanThe Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
Graduate School of Science and Engineering, Chiba University, Chiba 263-8522, Japan
2

Chirality-induced spin selectivity (CISS) is aphenomenon in which the spin of an electron ispolarized/filtered in the process of electron transfer(transmission) in a system with broken mirror
symmetry. The spin polarization by chiral molecular
CISS in the gas phase was studied from 1980’s. Since it
was reported that the spin polarization was less than
0.5%, CISS has not attracted wide attention at this time.
However, in 1999, R. Naaman et al. reported that spinunpolarized electrons that transmitted through thechiral molecular film on solids exhibited spinpolarization as high as 60% at room temperature [1].
While the CISS does not require magnetic materials or
external magnetic fields, it exhibits higher spinpolarization than the spin filters using magnetic metals.
These features are expected to be applied to magnetic
storage media with high storage density. Therefore,
CISS by organic chiral molecules has been actively
studied both theoretically and experimentally toelucidate its mechanism and for the purpose of device
applications. Presently, however, the details of
mechanism why chiral molecular film on solid exhibits
spin polarization larger than 1000 times that of gasphase molecules remains unsolved. For this reason, thegap between the theory and the application research is
growing. In order to elucidate the mechanism, it isnecessary to rigorously observe the interaction between
the travelling electrons and the chiral molecules. In
order to understand the CISS processes in chiralmolecules, it is important to investigate how CISSeﬀect depends on the relative orientations among thechiral molecules, the substrate, and the direction ofelectron transmission. Also, the diﬀerence of electronic
structure and structure between the gas phase and thechiral molecular film on substrate.
In this study, the chiral molecule 2,2’-Bis(diphenylphosphino)-1,1’-binaphthyl (BINAP hereafter) shownin Fig. 1(a) were deposited on a clean Au(111) substrate,and in-situ X-ray photoemission spectroscopy (XPS)
measurements were performed to investigate theinteractions between BINAP molecules and Au(111)substrate.
Figure 1(b) shows the results of XPS from thephosphorus (P) 2p core orbital of BINAP molecules,acquired at the nominal coverages of 0.4 monolayer(ML) and 2 ML of (R)-BINAP on Au(111).
Interestingly, while the molecules at the sub-monolayer coverage (0.4 ML) are expected to interact
more strongly with the substrate than the multi-layer
coverage (2 ML), we find that the P2p core peaks
appear very similar, as can be seen from the peak fitting
results for the two peaks [labelled A and B in Fig. 1(b)].
This likely signifies that the intermolecular interactions
are much stronger (which determines the chemical shiftof the atomic orbitals) than the molecule-substrateinteractions. This view is indeed consistent with thelater measurements in our project using the low-energy
electron diﬀraction (LEED) and scanning tunnelling
microscopy (STM), which clearly reveals the weaklyinteracting incommensurate molecular overlayer
structures.

Fig. 1. (a) Molecular structures of (R)- and (S)BINAPs. (b) P2p core level peaks of (R)-BINAP on
Au(111) measured by XPS at the nominal coverages of
0.4 ML (bottom) and 2 ML (top). The spectra at eachcoverage are fitted with the two spin-orbit doublets[labelled A (green) and B (blue)] with Doniach-Sanjiclineshape.
[1] K. Ray, S. P. Ananthavel, D. H. Waldeck and R.
Naaman, Science 283 (1999) 814.

− 151 −

BL4B

Observation of Heat Treatment Eﬀects of Amorphous Selenium Thin Filmby Vacuum Ultraviolet Transmission Spectrum
K. Hayashi
Department of Electrical, Electronic and Computer Engineering, Gifu University, Gifu 501-1193, Japan

It is well-known that various photoinduced
phenomena [1,2] such as changes in optical band gap,
conductivity, and volume occur in chalcogenide
amorphous semiconductors by light irradiation.
Although many studies have been done on thephotoinduced phenomena of these materials, little is
known about the details of these mechanisms. Thesephenomena were studied by exciting outer coreelectrons with the irradiation of light with the energy
corresponding to the optical bandgap or sub-bandgap.
The interest has been attracted for the change of the
optical properties in the energy region of the visible
light. We are interesting for the changes of the opticalproperties in the higher energy region. To obtain a wide
knowledge of the photoinduced phenomena, it isnecessary to investigate to the photoinduced and heat
treatment eﬀects on wide energy region. In this report,
we report heat treatment eﬀects on the vacuum
ultraviolet (VUV) transmission spectra of amorphousselenium thin film.
Sample used for the measurement of the VUVtransmission spectra was amorphous selenium thin film
prepared onto thin aluminum film by conventional
evaporation technique. The sample thickness was about
180nm. The aluminum film of the thickness of 200 nm
was used to eliminate the higher order light from themonochromator in the VUV region. These
measurements were carried out at room temperature on
the BL4B beam line of UVSOR. The spectrum wasmeasured by using the silicon photodiode as a detector.
Two pinholes of 1.5mm in a diameter were inserted
between the monochromator and sample to remove
stray light. The intensity of the VUV light wasmonitored by measuring the TPEY of a gold mesh. The
positions of the core levels for the samples were
calibrated by referencing to the 2p core level absorptionof the aluminum film. Observation of the heat treatmenteﬀect in the VUV transmission spectrum was carriedout by performing heat treatment for one hour at eachtemperature up to 363K.
Figure 1 shows heat treatment eﬀects on the VUVtransmission spectrum of an amorphous selenium thinfilm. Main absorption peaks around 22nm corresponds
to the 3d core level of Se atom. The absorption spectrum
observed in the amorphous selenium thin film isroughly consistent with the previous report [3].
Although the spin-orbit splitting of the 3d5/2 and 3d3/2
level of Se atom is not clearly resolved in thisamorphous selenium thin film. I don’t know the cause,
but there may be diﬀerences in the preparation

conditions of the film. As can be seen from the figure, asignificant change in the VUV transmission spectrum isobserved by heat treatment at temperatures above
343K. We are also studying the eﬀect of heat treatment
on the photoconductivity of amorphous selenium thinfilms in our laboratory. There is a correlation between
the heat treatment eﬀect on photoconductivity andVUV transmission spectrum, and it is thought that thischange is due to the crystallization of the amorphousselenium thin film. From the VUV transmission
spectrum change of selenium thin films by heat
treatment, it can be seen that the broad peak around
20nm in the VUV transmission spectrum of amorphousselenium thin films is composed of about threeabsorption peaks. It is not clear about the origin ofbroad spectra and several peaks. I think that these
origins are related to the local structures of theamorphous network. The detailed experiments andanalysis will be done in the next step. More detailed
experiments are necessary to clarify the origin of the
VUV transmission spectra.

Fig. 1. Heat treatment eﬀects on the VUV transmission
spectrum of amorphous selenium film.
[1] K. Tanaka, Rev. Solid State Sci. 4 (1990) 641.
[2] K. Shimakawa, S. Inami, and S. R. Elliott, Phys.
Rev. B, 42 (1990) 11857.
[3] J. Bordas and J. B. West, Phil. Mag. 34 (1976) 501.

− 152 −

Ⅲ-4 Surface, Interface and Thin Films

BL4B

UV-X-ray Transmission Measurements of Atomically Thin Graphene
Astronomical Applications
I. Mitsuishi 1, K. Kashiwakura1, Y. Niwa1, T. Ogawa1, R. Kitaura2, E. Nakamura3,
M. Nagasaka3 and K. Tanaka3
1

Graduate School of Science, Division of Particle and Astrophysical Science, Nagoya University, Furo-cho,
Chikusa-ku, Nagoya, Aichi 464-8602, Japan2
Department of Chemistry, Nagoya University, Nagoya 464-8602, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

Thin-film devices have been utilized in a great variety
of uses as not only ground-based but also space-based
applications such as optical and contamination blocking
filters and thermal shields [e.g., 1, 2]. Recently,
polyimide films have often been used as thin films
considering relatively stronger mechanical strength inplastic films. However, there is still room of
improvement in sensitivity of the thin films (=transmission) below 1 keV including UV region
although such energy ranges are very informative forunderstanding, e.g., stellar coronae and large-scale
structure of the Universe [e.g., 3, 4]. Thus, we haveproposed to make use of graphene which is anatomically-thin material but has excellent mechanicalstrength. Our idea is to apply graphene to thin film
devices in X-ray astronomy [5].
As a first step, we measured reflectivity at a soft
X-ray range between 100 and 500 eV successfully forsingle- and five-layer graphene samples at BL4U andconfirmed very high transmission above 90% except C
K-edge structure [5]. Thus, as a next step, we tried tomeasure transmission in UV region below 100 eV andconstruct our original experimental setup at BL4B. Our
experimental setup is shown in Fig. 1 and we prepareda five-layer graphene sample with a diameter of 300
μm on a quartz substrate to obtain larger photon
statistics. To check the consistency of transmission
between the beamlines of BL4U and BL4B, we used
the same sample and measured transmission from 100
to 250 eV as well. Consequently, we measured
transmission from 30 to 100 eV successfully andconfirmed very high transmission from 91 to 101% in
nominal values with systematic errors of 5% due toshort- and long-term time variability. We confirmedthat there are no significant diﬀerences in 100-250 eV
between the results obtained from BL4B and BL4U.
The results are summarized in Fig. 2. A slight decreasing
trend can be seen toward 30 eV even though thesystematic errors are high (5%). This trend is the sameas the expected from a database for bulk carbon. In
order to verify the trend, we need additional
measurements with smaller measurement accuracyof <2% down to 10 eV. The paper including theseresults is being prepared (Kashiwakura, Mitsuishi etal., in prep.).

Fig. 1. Sample chamber and a close-up view of thegraphene sample on the quartz substrate.

Fig. 2. Resultant transmission from 30 to 250 and from100 to 250 eV for five-layer graphene samples measured
at BL4B (filled triangle) and BL4U (filled circle)(Kashiwakura, Mitsuishi et al., in prep.). Systematic
errors are 5% / 3% at BL4B / BL4U.
[1] P.J. Serlemitos et al., Publ. Astron. Soc. Japan 47(1995) 105.
[2] P.J. Serlemitos et al., Publ. Astron. Soc. Japan 59(2007) S9.
[3] I. Mitsuishi et al., Publ. Astron. Soc. Japan 64(2012) 18-1.
[4] S. Takasao, I. Mitsuishi et al., The Astrophys. J. 901(2020) 70.
[5] I. Mitsuishi et al., UVSOR Activity Report 2021 49(2022) 45.

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BL4B

Si L-edge NEXAFS Spectra of Native Oxide Si Wafer
with Diﬀerent Crystal Surface
K. K. Okudaira1, S. Yoshioka 2 and E. Kobayashi3
1

Graduate School of Engineering, Chiba University, 1-33 Yahoi-cho, Inage-ku Chiba 263-8522, Japan
Gradiate School of Engineering, Kyushu University, 744 Motooka Nishi-ku Fukuoka 819-0395 Japan
3
Kyushu Synchrotron Light Research Center, 8-7 Yayoigaoka, Tosu, Saga 841-0005, Japan

2

Silicon dioxide is one of the most popular substrate
for inorganic semiconductor devices as well as organic
devices such as self-assembled monolayers, which isuseful for organic field eﬀect transistors. [1] One
important advantage of the silicon substrate over the
metal substrate is that conductive currents are
eliminated. The leakage current is relatively large byusing native oxide Si wafer as dielectric layer due to thethinness and inhomogeneous of oxide layer of nativeoxide Si wafer. The application of self-assembled
monolayer to SiO2/Si substrate depress the leakage
current. [2] The electrical properties such as insulation
characteristics depends on the structure of surface
silicon dioxides layer, which is considered amorphous.
It is expected that the properties of native oxide layer
on Si substrates would be aﬀected by the underlying
crystalline Si.
In this report, we investigate the eﬀect of crystal
structure of underlying crystalline Si on the surface
structure of silicon dioxide by means of NEXAFS ofnative oxide Si(001) and Si(111) wafers.
NEXAFS spectra of the native oxide Si(001) andSi(111) wafers were measured at the beamline 4B of
the UVSOR in the Institute of Molecular Science. In
the total electron yield (TEY), the drain current of thesample was measured. All experiments were performedat room temperature.
Figure 1 shows the TEY Si L-2,3 edge NEXAFS
spectra of native oxide of Si(111) and Si(001) wafers.
In the observed fine structure two region are identified.
The absorption features observed from 100 to 104 eV
are attributable to Si0 (crystalline Si under native oxide
layer) and those from 104 to 110 eV are associated with
Si4+ (SiO2) [3]
In the hν range from 100 eV to 104 eV due to the Si
crystalline layer, the spectral structure of Si(001) is
identical with the one of Si(111). On the contrary, thespectral feature of native SiO2/SI(001) is diﬀerent fromthat of SiO2/Si(111) in the hν range from 104 to 110 eV,

which is attributed to native oxide layer (SiO2). By
closed comparison the relative intensity of the peak a1
at hv of 106 eV to that of the peak a2 at hν of 106.8 eV
for the SiO2/Si(001) is diﬀerent from that of SiO2/
Si(111). The peak a1 disappears in the observed Si
L-edge NEXAFS of native oxides Si(111) wafer. The
peaks a1 and a2 can be assigned to 2p3/2 and 2p1/2 → theantibonding orbital of Si 3s character. [4] Harp et al.
shows the peak positions of a1 and a2 depend on not
only the oxidation state but also the thickness of nativeoxide layer [5]. These diﬀerences indicate that theproperties of surface native oxide layer such as bonding
structure as well as oxidation states are aﬀected byunderlying crystalline Si layer.

a1 a2Fig. 1. Si L-edge NEXAFS of native oxide Si(001) andSi(111) wafers in TEY mode
[1] M. McDowell et al., Appl. Phys. Lett. 88 (2006)
073505.
[2] M. -H. Yoon et al., PNAS 102 (2005) 4678.
[3] M. Kasrai et al., Appl. Surf. Sci, 99 (1996) 303[4] M. Kasrai et al., J. Vac. Sci, Tech. A11 (1993) 2694.
[5] G. R. Harp et al.,. J. Vac. Sci, Tech. A8 (1990) 2566.

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Ⅲ-4 Surface, Interface and Thin Films

BL5U

ARPES from Si{111} ξ૜ × ξ૜-Ag ultra-thin Film on Artificially Designed
three-dimensional Si facet-line Structure with {111} Facet Surfaces
on Si(001) Substrates
K. Hattori1, Ni’matil Mabarroh1, Juharni1, Y. Ida1, W. Imayama1, Y. Kimoto1, Y. Kitagawa1,
S. Tanaka2, A. N. Hattori2, S. Suga2 and K. Tanaka3
1

Nara Institute of Science and Technology, Ikoma 630-0192, Japan
2
SANKEN, Osaka University, Ibaraki, 567-0047, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

Highly densified device like 3D FET has beenrequired by information society to break the limitationof miniaturizing 2D planar-type devices. Control of 3D
structure device is indispensable to improve thespecification, such as carrier mobilities on any direction
surfaces of the 3D structures.
Recently, our group has successfully created 3D-Si
surfaces by combining lithography and surface
treatment techniques [1-4], and reported a successful
creation of Si{111} 7×7 clean facet surfaces showing
surface and bulk electronic bands on Si(110) substrates
using laboratory based angle-resolved photoelectron
spectroscopy (ARPES) [5], aiming for a future
3D-surface band-engineering. Here, we first
demonstrated the creation of ultra-thin film on 3D Si
clean facet surfaces indicating characteristic film band
structures, essential for the 3D surface control.
In our experiment, 3D Si facet-lined structures with
(111) and (1ത 1ത 1) facet surfaces and [1ത 10]-direction faceedges on (001) substrates with the facet pitch of 4 μm
period, were prepared by using a photo-lithography andwet etching (Fig. 1). After degassing and flashing thesample in ultra-high vacuum, {111} 7×7 reconstruction
was confirmed by low-energy electron diﬀraction(LEED). Subsequently Ag was deposited on the sample
at ~770 K, showing ξ3 × ξ3 reconstruction in bothFig. 1. SEM image of 3D
Si facet-lined structure.

Fig. 2. LEED pattern of{111} ξ3 × ξ3 -Ag facet
surfaces (120 eV).

Fig. 3. ARPES geometry. 60
eV photons (pink) result inelectron emission (purple)
from (111) facet surfaces.

(111) and (1ത 1ത 1) facet surfaces. Note that thesuperposition of the LEED patterns from the two facet
surfaces are seen in Fig. 2.
ARPES was also performed in UVSOR at BL5U.
Valence band dispersion was measured mainly at 70 eV
photons with the (111) facet surface normal to theanalyzer at 6 K, by optimizing the sample orientation(Fig. 3). We obtained the specific band structurescaused by ξ3 × ξ3 -Ag ultra-thin film on the (111)facet surface (Figs. 4a and 4c), which was almost thesame as those of the ξ3 × ξ3 -Ag on a 2D planar
surface (Figs. 4b and 4d) measured under the same
condition.
We confirmed that ARPES under optimizing 3D
geometries informs us band structures of artificiallydesigned 3D structure surfaces and “created films”.
This will shed the light on future band engineering of
3D devices.

Fig. 4. E-k along [1ത 1ത 2] (a, b) and kx-ky near Fermi level(dashed lines in a and b) (c, d) for facet (a, c) and planar(b, d) (111) ξ3 × ξ3 -Ag surfaces.

[1] A.N. Hattori, K. Hattori, et al., Surf. Sci. 644 (2016)
86.
[2] A.N. Hattori, K. Hattori, et al., Appl. Phys. Express
9 (2016) 085501.
[3] A.N. Hattori and K. Hattori, 21st Century Surface
Science (IntechOpen, London, 2020).
[4] S. Nakatsuka, T. Abukawa, A.N. Hattori, K. Hattori,
et al., e-J. Surf. Sci. NanoTechnol. 19 (2021) 13.
[5] K. Hattori, A. N. Hattori, et al., e-J. Surf. Sci.
Nanotechnol. 30 (2022) 214.

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BL5U

Sizable Rigid Shift of the Valence Band of h-BN by Cs-doping
S. Ichinokura1, A. Hemmi2, H. Cun2, K. Tanaka3, T. Greber2 and T. Hirahara1
1
Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan
Physik-Institut, Universität Zürich, Winterthurerstrasse, 190, Zürich CH-8057, Switzerland
3
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

2

Hexagonal boron nitride (h-BN) is a two-dimensional
semiconductor with a wide bandgap. Its gap size ofaround 5.9 eV corresponds to deep ultraviolet light,
making h-BN a promising material for the developmentof energy-eﬃcient optical disinfection devices. To
reduce the working voltage of electroluminescencethrough tunneling carrier injection, it is required todevelop p- and n-doping near the electrodes. However,
the wide gap in h-BN poses a challenge for carrier
doping through conventional substitution methods,
which limits its use in electroluminescence devices.
To address this challenge, we are exploring analternative approach known as chemical gating, which
involves surface adsorption or intercalation of alkali
metals (AMs) to the substrate interface. This creates anelectrical dipole by facilitating charge transfer from theAMs to the substrate. Cs-doping has been shown to
induce the largest electron doping in h-BN/Ir, where thevalence band maximum (VBM), specifically the top of
the π band at the K point, was indirectly estimated to be
at 5.9 eV from the shift of the σ band at the Γ point,
assuming a rigid band shift [1]. However, the limits ofdoping remain unclear until the direct observation of
the band structure in a wide wavenumber range from Γ
to K point.
In the present study [2], we conducted an analysis of
the complete valence band structure of monolayerh-BN on Rh substrate before and after Cs doping via
angle-resolved photoemission spectroscopy (ARPES)
utilizing synchrotron radiation as a light source. The
h-BN/Rh was grown by means of chemical vapor
deposition. The doping of Cs was carried out via
vacuum deposition at room temperature in the
preparation chamber of the BL5U end station, followed
by in-situ measurements of ARPES utilizing linear
polarized light with hν = 72 eV at 200 K. Figures 1(a)and (b) depict the valence band spectra before and afterCs doping obtained by horizontally polarized (H-pol.)light, respectively, whereas Figures 1(c) and (d) show
the same as Figs. 1(a) and (b), respectively, obtained byvertically polarized (V-pol.) light. The uppermost
portion of the π band is located at the K point with ahigher binding energy than the top of the σ band at theΓ point, making it possible for us to evaluate the VBM.
EVBM and E’VBM are defined as the binding energy of the
VBM before and after doping, as denoted by dashedblack lines. The shift of the VBM, ΔE = E’VBM - EVBM is

observable to be 2.5 eV, identical to the σ band at the Γpoint (refer to Figs. 1(c) and (d)). This clearly suggests
a rigid shift of both the π and σ bands. Notably, Cs
doping lowers the VBM to 5.7 eV. Considering the
bandgap of h-BN is known to be 5.9 eV, the conduction
band should lie only 0.2 eV above the Fermi surface.
Thus, h-BN experiences significant electron doping.
As a concluding remark, for both Rh and Ir substrates,
the VBM attained binding energy nearly equated to theband gap. This can be elucidated by the vacuum levelalignment model when Cs is adsorbed on both sides ofh-BN. This indicates that Cs with the lowest work
function is the most eﬃcacious, and this method can be
implemented on an electroluminescence device usingh-BN with any electrode.

Fig. 1. ARPES spectrum of hBN along Γ-K-M line in
the Brillouin zone. Panels (a) and (c) display thespectrum before Cs-deposition, while and (b) and (d)show the spectrum after Cs-deposition. The spectra
were obtained with hν = 72 eV at a temperature of 200
K. Panels (a) and (b) were obtained wiht hollizontallypolarized light, while panels (c) and (d) were obtainedwith vertically-polarized light. In panels (a) and (b), theshift of VBM is indicated by black dashed line andarrow. In panels (c) and (d), the shift of σ band isdenoted by black dashed line and arrow.
[1] J. Cai et al., Phys. Rev. B 98 (2018) 195443.
[2] S. Ichinokura et al., Appl. Phys. Lett. 122 (2023)
071601.

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Ⅲ-4 Surface, Interface and Thin Films

BL5U

Growth of Transition Metal Phosphide Thin Film on Au(111)
N. Maejima 1, 2 K. Inaoka 1 and K. Edamoto1, 2
1Coll. Sci., Rikkyo Univ., Tokyo 171-8501, Japan
Research Center for Smart Molecules, Rikkyo Univ.,Tokyio 171-8501, Japan

2

The Ni12P5@Au core-shell catalyst has attracted
attention because of its high catalytic activity foroxygen evolution reactions [1]. Novel functions ofcore-shell catalysts arise from the interaction between
the core and the shell at the interface [2]. Direct
observation of the electronic states formed through theinteractions between core and shell is diﬃcult, and thus
the fabrication of the Ni phosphide thin film on an Au
substrate is desirable as a model system that allows theinvestigation using photoelectron spectroscopy. In thisreport, we will show that a nickel phosphide thin film
can be grown on Au(111) by Ni deposition on a
P-covered Au(111).
Experiments were performed at BL5U of the UVSOR
facility. The Au(111) surface was cleaned by cycles of
Ar+ ion spattering (0.5 keV) and annealing (750 °C) . P
atoms were deposited on the Au(111) surface at 400℃
(AuP/Au(111)). The prepared Au(111) and AuP/
Au(111) samples showed 1x1 and 5x5 LEED patterns,
respectively. Ni was subsequently evaporated onto
AuP/Au(111) at 400℃ to form a NixP thin film on
Au(111)(NixP/Au(111)). This LEED pattern of thissample consisted of 1x1 spots arising from the Au(111)substrate and the additional 12 spots which are assigned
as the spots from the NixP crystal thin film. Au 4f, P 2p,
Ni 3p and valence band photoelectron spectroscopy(PES) measurements were performed by an MBS A-1
analyzer. The ratio of the amount of Ni and P atoms on
the Au substrate were determined by the ratios of thepeak areas of Ni 3p and P 2p photoelectron spectra to
be Ni : P = 2:1.
Au 4f 7/2 spectra obtained from Au(111) clean surface,
AuP/Au(111), and NiP/Au(111) samples are shown in
Fig. 1. In the Au 4f7/2 spectra of Au(111) clean surface,
two bulk and surface components were observed atbinding energies of 84.0 and 83.7 eV, respectively.[3]The spectrum obtained from P deposited sample containthe bulk and surface Au-P component at 84.0 eV and
84.4 eV, respectively.[4] The surface component
observed in the spectra of Au(111) clean surface hasdisappeared, indicating that the whole surface iscovered with P. In the spectrum of the Ni deposited
sample, peaks of bulk and surface components wereobserved at 84.0 eV and 83.7 eV, respectively. The
disappearance of the peak at 84.4 eV corresponding to
Au-P bonds indicates the cleavage of all Au-P bonds.

Though the P 2p spectrum obtained from NixP/Au(111)contains multiple peak components, the component
that is ascribed to P atoms bonded to Au wasdisappeared. In addition, the surface component
observed in the spectrum of the Au(111) clean surface
reappears in the spectrum of NixP/Au(111). These
results imply that the interaction between the thin film
and the substrate is weak or the nickel phosphide film
congregates to form islands. The Ni 3p peak position in
the spectrum of NixP/Au(111) was higher than thatobtained from Ni2P(10-10) single crystal by 0.3 eV [5],whereas the spectral shape was almost the same. These
results suggested that a Ni phosphide whose
composition was Ni : P = 2:1 can be formed on Au(111).

Fig. 1. Au 47/2 photoelectron spectra of clean Au(111),
AuP/Au(111) and NiP/Au(111) samples.
[1]Lee. Jong-Soo et al., JACS 130 (2008) 9673.
[2]Xu. Yingying et al., Nano research 10 (2017) 3103.
[3]Citrin. Ph. H. et al., Phys. Rev. Lett. 41 (1978) 1425.
[4]Zhang. Wei et al., Small 14 (2018) 1804066.
[5]N. Maejima et al., UVSOR Activity Report 48(2020) 115.

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BL5U, 7U

Heavy-Fermion in a Mono-Atomic Layer YbCu2/Cu(111)
H. Sugihara1, T. Nakamura2,1, Y. Chen1, K. Nishihara1
M. F. Lubis1, K. Tanaka3 and S. Kimura2,1,4
1

Department of Physics, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan
2
Graduate School of Frontier Biosciences, Osaka University, Suita, 565-0871, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
Department of Materials Molecular Science, Institute for Molecular Science, Okazaki 444-8585, JapanThe Kondo eﬀect leads to exotic physical phenomena
due to hybridization between localized f-electrons andconductive carriers at low temperatures. Especially,
heavy-fermion (HF) systems, in which massive
eﬀective carriers appear due to the Kondo eﬀect, havefascinated many researchers [1,2]. Recently, twodimensional (2D) HF systems have been realized using
a molecular beam epitaxy method and it was shownthat dimensionality is also important for the characterof the HF system [3,4]. However, two-dimensionalmono-atomic layer HF material has never beenreported. Here, we have studied the electronic structureof a mono-atomic layer HF material, YbCu2/Cu(111),
which is a novel perfect two-dimensional HF system,measured by angle-resolved photoelectron spectroscopy(ARPES).
Clean Cu(111) substrates were prepared by the cycleof Ar+ sputtering with an acceleration of 0.5 eV andannealing at a temperature up to 800 K. After checking
the sharp peaks and low background of the streakelectron diﬀraction pattern appearing in the reflection
high-energy electron diﬀraction (RHEED), Yb-metal
was evaporated with a homemade Knudsen cell. The
fabricated YbCu2 mono-atomic layer has a fractional
pattern suggesting a small lattice mismatch of YbCu2
from the Cu(111) substrate. VUV-ARPES measurement
was carried out at BL7U (hν = 37 eV) at temperaturesof 7 – 130 K.
Figure 1 shows the ARPES intensity plot of YbCu2/
ഥ of the surface BrillouinCu(111) surface along Ȟത - Kzone of YbCu2/Cu(111). To see the band dispersion
above the Fermi level, the ARPES spectra were divided
by the Fermi-Dirac distribution function convolved
with the instrumental resolution. A flat band near the
Fermi level and several highly dispersive bands arevisible. The flat band is attributed to the Yb2+ 4f7/2 final
state after the photoexcitation process. The highly
dispersive conduction bands are hybridized with theflat Yb 4f band near the Ȟത point suggesting theappearance of the c-f hybridization, which is the
spectral evidence of the appearance of HF. Furthermore,angle-integrated photoelectron spectra of YbCu2/
Cu(111) taken at hν = 37 eV (T = 10 – 130 K) are shownin Fig. 2. The appearing steep peak, pointed by anarrow, is grown and moves to the low energy withdecreasing temperature. The peak can be attributed to a
Kondo resonance peak usually observed in HF materials[5], therefore, the results suggest the HF formation in

the mono-atomic layer YbCu2/Cu(111).

Fig. 1. ARPES band dispersion of YbCu2/Cu(111)
ഥ taken at hν = 37 eV (T = 7 K). The
surface along Ȟത-Kphotoelectron intensities were normalized by the
Fermi-Dirac distribution function convoluted with the
instrumental resolution.

Fig. 2. Angle-integrated photoelectron spectra of
YbCu2/Cu(111) taken at hν = 37 eV (T = 10~130 K).
The allow indicates the Kondo resonance peak.
[1] A. C. Hewson, The Kondo Problem to Heavy
Fermions (Cambridge Univ. Press, Cambridge, 1993).
[2] P. Coleman, et al., J. Phys.: Condens. Matter 13(2001) R723.
[3] L. Fernandez et al., Nanoscale 12 (2020) 22258.
[4] M. Ormaza et al., PRB 88 (2013) 125405.
[5] S. Chatterjee et al., Nat. Commun. 8 (2017) 852.

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Ⅲ-4 Surface, Interface and Thin Films

BL6U

Region and Element-specific Surface Observation of CVD Graphene on
Ir(111)/α-Al2O3(0001) by Photoelectron Momentum Microscopy
E. Hashimoto 1, Y. Onuma1, F. Matsui2 and S. Koh1
1

Aoyama Gakuin University, 5-10-1, Fuchinobe, Chuo-ku, Sagamihara, 252-5258, JapanUVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki, 444-8585, Japan2

A photoelectron momentum microscopy (PMM) is acomplementary characterization tool to conventional
methods, e.g. Raman spectroscopy and atomic force
microscopy (AFM), for comprehensive and elementspecific characterization of 2D materials owing to its
multifunctionality. We have demonstrated by valenceband photoelectron spectroscopy (VB-PES) using
PMM that graphene grown by low-pressure chemical
vapor deposition (LP-CVD) on Ir(111)/α-Al2O3(0001)
had high single-crystallinity for several 100 μm2 [1]. In
this study, we performed region and-specific surface
observation for graphene by photoemission electron
microscopy (PEEM).
Graphene was grown on Ir(111)/α-Al2O3(0001)
substrates by LP-CVD using H2 and CH4 gases. Fig.
1(a) shows an AFM image (1.0 μm2) of the graphenesurface on Ir(111). Continuous step terraces of theIr(111), which were the nucleation sites of graphene,
were observed. The average step height corresponded
to the one-atomic step height of the Ir(111) surface.
Wrinkles, which were formed due to the mismatch of
the thermal expansion coeﬃcients between grapheneand Ir(111), were formed across the step terraces,indicating that graphene domains coalesced andcontinuous graphene films were formed.
Real space images for graphene/Ir(111) were obtainedby PEEM at the linearly polarized soft X-ray beamline
BL6U of the UVSOR-Ⅲ synchrotron [2]. The electronic
structure for graphene/Ir(111) were determined by VBPES. The PEEM images of graphene/Ir(111), whichhave non-uniformity, are shown in Figs. 1(b) and 1(c).
In Fig. 1(b), the photon energy was 85 eV andphotoelectron corresponding to the binding energy
from 2.0 to 3.5 eV was integrated. Intensity of graphene
M points contributes the most. Thus, the bright areas inFig. 1(b) correspond to the areas where graphene exists.
The iso-energy cross section of the 2D band dispersion
for the bright area in Fig.1(b) by VB-PES is shown in
Fig. 1(d). The 6-fold symmetry pattern is attributed tothe π band dispersion of graphene connecting the M
points. Fig. 1(c) shows the PEEM image at the sameobservation area as Fig.1(b). The photon energy was set
to 100 eV. Photoelectron corresponding to the binding
energy from 0 to 0.2 eV was integrated. The density ofstates at the Fermi level of Ir dominates in this condition.
Therefore, the bright areas correspond to the area where
the Ir surface was exposed. The iso-energy cross sectionof the 2D band dispersion for the bright areas in Fig.1(c)is shown in Fig.1(e). The pattern with 6-fold symmetry,
which corresponds to the energy dispersion of Ir(111),

was observed. The pattern of graphene was notobserved, which confirmed that the Ir surface was
exposed. We identified areas where covered bygraphene and where Ir(111) is exposed, by region andelement-specific PEEM for Gr/Ir(111) samples withlow single-crystallinity.
In this study, we observed surface irregularities of
Gr/Ir(111) samples that were not captured byconventional measurement methods such as Raman
spectroscopy and AFM observation, by performing
region and element-specific PEEM using PMM.
Element-specific measurements using PMM on
practical samples are very promising, and thecharacterization of detailed properties for high-quality
Gr/Ir(111) samples is expected.

Fig. 1. (a) AFM image and (b)-(c) PEEM images ofgraphene/Ir(111). Iso-energy cross sections of 2D band
dispersion of graphene/Ir(111), with photon energy of(d) 85 eV and (e) 100 eV.
[1] E. Hashimoto et al., Jpn. J. Appl. Phys. 61 (2022)
SD1015.
[2] F. Matsui et al., Jpn. J. Appl. Phys. 59 (2020)
067001.

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BL7U

High-resolution angle-resolved Photoemission Study on
MnBi2Te4/MnBi2Te4/Bi2Te3 Heterostructure
K. Ishihara1, H. Nishimichi1, K. Ide1, S. Ichinokura1, K. Tanaka2 and T. Hirahara1
1

Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan
2
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

Topological insulators (TI) are extensively studied
recently due to its peculiar properties [1]. The Diraccone surface states of TI are protected by time-reversal
symmetry (TRS) and backscattering among thesesurface states is prohibited. But when TRS is broken byapplication of a magnetic field or incorporating
magnetic materials, a gap opening in the Dirac cone is
expected and an intriguing phase called the quantum
anomalous Hall state can be realized [2]. This phase is
expected to show even more exotic phenomena such as
the topological magnetoelectic eﬀect. To realize suchstate, two types of sample fabrication techniques havebeen employed up to now: (1) magnetic doping while
growing the single crystal or thin film of TI [3], and (2)magnetic impurity deposition on the surface of TI [4].
While method (1) was successful and showed evidenceof the TRS violation, no one has succeeded using
method (2), which should be a more direct w ay to
examine the interaction between the topological surface
states and magnetism. We have previously foundanother novel technique to induce magnetism into TI,
namely the magnetic extension eﬀect [5]. By depositing
Mn and Se on Bi2Se3, we found that Mn and Se areincorporated in the topmost Bi2Se3 layer and a novel
heterostructure MnBi2Se4/Bi2Se3 is formed [5]. This
heterostructure showed a clear Dirac cone gap of 85
meV and the gap persisted up to room temperature.
From magnetic measurements it was revealed thatferromagnetism also persists up to room temperature inthis system. Taking all these facts into account, it can besaid that this system is promising to observe thequantum anomalous Hall eﬀect at room temperature.
However, the Dirac cone gap is not at the Fermi level
and there is no systematic method to control the Fermi
level position in Bi2Se3. Thus, we employed Bi2Te3 as
the parent TI and have deposited Mn and Te on Bi2Te3
to see if magnetic extension can also occur for thissystem. However, it was revealed that the Dirac cone
gap is absent in this MnB i2Te4/Bi2Te3 system [6], in
contrast to the theoretical prediction [7].
Therefore, in the present study, we have measured
the band structure of the MnBi2Te4/MnBi2Te4/Bi2Te3
system to verify whether an addition of another
MnBi2Te4 layer would influence the magnetic property

as well as the Dirac Cone gap opening. The experiments
were performed at BL 7U of UVSOR with the photon
energy of 19 eV. Figure 1 shows the measured band
dispersion at diﬀerent temperatures.
We found that in addition to the Dirac cone gap
opening which was observed from 6.6 K up to room
temperature, the lower Dirac cone showed somesplitting at 6.6 K. Furthermore, this splitting disappeared
once at 160 K, but revived at 250 K. Since the state at
higher binding energy showed photon energy
dependence, it can be regarded as a bulk state, although
our preliminary ab initio calculation suggested that it
can also be a surface state. This puzzling behavior is
unexpected from theory and calls for a comprehensive
study on the atomic structure as well as magnetism of
the system, which we hope to clarify in the future.

Fig. 1. Band dispersion image of the MnBi2Te4/
MnBi2Te4/Bi2Te3/MnBi2Se4 hetero structure measured
at 6.6 K, 160 K, and 250 K, respectively.
[1] M. Hasan and C. Kane, Rev. Mod. Phys. 82 (2010)3045.
[2] X.-L. Qi and S.-C. Zhang, Rev. Mod. Phys. 83(2011) 1057.
[3] For example, C. Z. Chang et al., Science 340 (2013)
167.
[4] For example, M. Ye et al., Phys. Rev. B 85 (2012)205317.
[5] T. Hirahara et al., Nano Lett. 17 (2017) 3493.
[6] T. Fukasawa et al., Phys. Rev. B 103 (2021) 205405.
[7] M. Otrokov et al., Phys. Rev. Lett. 122 (2019)107202; 2D Mate. 4 (2017) 025082.

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Ⅲ-4 Surface, Interface and Thin Films

BL7B

Electrochemical Attenuated Total Reflectance Ultraviolet (EC-ATR-UV)
Spectroscopy Applied for Organic Semiconductor / Ionic Liquids Interface
I. Tanabe, Y. Hanamori and K. Fukui
Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3,
Machikaneyama, Toyonaka, Osaka 560-8531, Japan

Electric double-layer organic field-eﬀect transistors(EDL-OFETs) have attracted much attention due totheir significantly low operating voltage (<1 V)compared to conventional SiO2-gated OFETs (>10 V).
In EDL-OFETs, a high electric field is generated in the
EDL that accumulates in the interfacial region between
the organic semiconductor and electrolyte, resulting ina low operation voltage. Therefore, the organic
semiconductor/electrolyte interface is of particularimportance. Recently, we developed a newspectroscopic system, namely electrochemicalattenuated total reflectance (EC-ATR) ultravioletvisible spectroscopy, which can access the interfacial
area [1, 2].
In this study, we fabricated ionic liquid gated organic
field-eﬀect transistors (IL-gated OFETs) on the ATR
prism. A two-layer single crystalline film of C9DNBDT-NW was used as an organic semiconductor,
and two kinds of ionic liquids (EMIM-TFSI and
HMIM-TFSI) were cast on the film. The only diﬀerence
between EMIM-TFSI and HMIM-TFSI is the length ofthe carbon chain: two for EMIM and six for HMIM. Au
films were evaporated to a thickness as the source anddrain electrodes (working electrodes) on both sides of
the ATR prism, and a Pt coil and a Pt wire were placedin the ionic liquids as pseudo counter and reference(gate) electrodes, respectively. In our previous study[2], we found that in response to the applied gate
voltage, the spectral peaks of the organic semiconductor
shifted and bleached, which was correlated with thedrain current.
The IL-gated OFETs fabricated on the ATR prism
were placed in the sample chamber in BL7B at UVSOR.
Figure 1 shows the diﬀerence spectra of C9-DNBDTNW films with EMIM-TFSI or HMIM-TFSI as afunction of the applied voltage. Despite the very slight
diﬀerence in the carbon chain length between EMIMTFSI and HMIM-TFSI, their spectral behaviors weresignificantly diﬀerent.
In the case of HMIM-TFSI (Fig. 1b), spectral
bleachings at ~300, 220, 210, 190, and 170 nm wereobserved. According to TD-DFT calculations, theseabsorbances are mainly due to electronic excitations in
the C9-DNBDT-NW molecule for ~300 nm and in
HMIM-TFSI for ~220, 210, 190, and 170 nm. There isa positive relationship between the amount of spectralchanges and applied voltage. On the other hand, in thecase of EMIM-TFSI (Fig. 1a), no obvious spectralchanges were detected. These results indicate adiﬀerence in the interaction between the organic

semiconductor and ionic liquid species underelectrochemical environments.
The development of the EC-ATR spectroscopic
system has the potential to greatly impact the field ofelectrochemical devices by enabling researchers toaccess and study the interfacial area between films andILs, leading to improved understanding of device
performance and the development of new, highperformance materials.

Fig. 1. Diﬀerence spectra of C9-DNBDT-NW films
with (a) EMIM-TFSI and (b) HMIM-TFSI as a functionof the applied voltage.
[1] I. Tanabe, A. Suyama, T. Sato and K. Fukui, Anal.
Chem. 91 (2019) 3436.
[2] I. Tanabe, I. Imoto, D. Okaue, M. Imai, S. Kumagai,
T. Makita, M. Mitani, T. Okamoto, J. Takeya and K.
Fukui, Commun. Chem. 4 (2021) 88.

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რLife, Earth andPlanetary Sciences

Ⅲ-5 Life, Earth and Planetary Sciences

BL3U

X-ray Absorption Spectra of Lipid Bilayer Membranes in Aqueous Solutions
R. Tero 1, Yu Kinjo1 and M. Nagasaka2
1

Toyohashi University of Technology, Toyohashi, 441-8580, Japan
2
Institute for Molecular Science, Okazaki 444-8585, JapanThe lipid bilayer is a self-assembled structure ofamphiphilic lipid molecules. It is the fundamental
structure of biomembranes such as cell membranes,
which are the fields for the transportation of materials,
information, and energy into and out of cells. All these
physiological reactions proceed in the presence ofelectrolytes. Ions in the aqueous solution significantly
influence to physical properties and structures of lipid
bilayers. Phosphatidylcholine (PC) is the most abundant
lipid of eukaryotic cell membranes. Cations bind to thephosphate and carbonyl groups of PC. However,aﬃnity of cations to PC and eﬀects of cations tomolecular orientation are still controversy especially inthe fields of theoretical simulations. We aim todetermine the binding aﬃnity of cations to lipids inaqueous solutions experimentally, by means of X-ray
absorption spectroscopy (XAS) [1, 2].
Supported lipid bilayers (SLBs) of dioleoyl-PC(DOPC) were formed on the Si3N4 membranes of the
XAS flow cell [1] by the vesicle fusion method in a
buﬀer solution (NaCl 100 mM, HEPES 25 mM/ pH 7.4
NaOH). The Na+ concentration ([Na+]) was varied byexchanging the buﬀer solution in the flow cell in in therange of [Na+] = 2.1 – 510.4 mM. The O-K edge XAS
spectra of SLB were obtained at the energy range of
527 – 535 eV at the Xray incident angle of 35º. The
XAS spectrum of the Si3N4 membrane without SLB
was subtracted from that with SLB.
The O-K-edge spectrum of DOPC appeared at 531 533 eV (Fig. 1). It is consisted of 1s→π* transitions ofdouble-bond oxygens in the phosphate and carbonylgroups on the PC headgroup: two components attributed
to the P=O in the former, and one component attributed
to the latter [3]. We measured XAS spectra at the X-ray
incident angle (T) of 35º to obtain the intensity of eachcomponent independently of the molecular orientation.
We obtained a specific dependence of the P=O peak at
the lower energy (P=O_low) on [Na+]: its position was
identical at [Na+] = 2.1 – 10.4 mM, shifted to higher
energy by 0.4 eV above [Na+] = 10.4 mM, and little
independent of [Na+] above 110.4 mM. The results
show the Na+ coordination to the phosphate group of
PC and its dependence of [Na+]. The inner-shell
quantum chemical calculation [4] of O K-edge spectrumof P=O indicated that coordination of Na+ to thephosphate group causes higher-energy shift of P=O
peaks. The dependence of the P=O peak intensity as
well as the P=O intensity on [Na+] is investigated indetail. The eﬀects of the cation species on the XAS
components will be investigated.

Fig. 1. O K-edge XAS spectra of DOPC-SLB at [Na+] =2.1 – 510.4 mM obtained at the X-ray incident angle of
35°. Black dotted curves represent raw data. Dashedcurves and red solid curves show deconvoluted
components and their summation, respectively.
[1] M. Nagasaka, H. Yuzawa, T. Horigome, and N.
Kosugi, J. Electron Spectros. Relat. Phenomena 224(2018) 93.
[2] R. Tero, Y. Kinjo and M. Nagasaka, UVSOR
Activity Report 49 (2021) 151.
[3] R. Tero, W.-Z. Goh and M. Nagasaka, UVSOR
Activity Report 48 (2020) 129.
[4] M. Nagasaka, J. Chem. Phys. 158 (2023) 024501.

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BL1U

Study on Chirality Emergence of Amino Acid Molecules Induced by
Circularly Polarized Lyman-α Light Irradiation
M. Kobayashi1, J. Takahashi2, H. Ota3, G. Fujimori2, K. Kobayashi2, K. Matsuo4, Y. Taira3,
M. Katoh3,4, H. Nakamura1 and Y. Kebukawa2
1

National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku,Yokohama 240-8501, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Myodaiji,Okazaki 444-8585, Japan
4
Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama,
Higashi-Hiroshima 739-0046, Japan2

The origin of homochirality in terrestrial biomolecules(L-amino acid and D-sugar dominant) remains one of
the most mysterious problems in the research for theorigins of life. One of the most attractive hypotheses in
the context of astrobiology is “Cosmic Scenario” [1, 2];Asymmetric reactions of prebiotic molecules oninterstellar dust surfaces in molecular cloud
circumstances were introduced by polarized quantum
radiation sources in space, that is “chiral radiations”.
Among the polarized quantum radiation sources,
circularly polarized light (CPL) in the spaceenvironment is thought to be one of the most likely
causes of the enantiomeric excesses of terrestrial
bioorganic molecules. In this study, we focused on ahydrogen Lyman-α wavelength of 121.6 nm, wherestrong emission lines are observed in star-forming
regions.
Alanine is selected as a chiral prebiotic molecules in
the interstellar space. We formed thin solid film samplesof racemic mixture of alanine (DL-alanine) on quartz
substrates from crystal powders of DL-alanine by using
a thermal-crucible vacuum-evaporation system at
HiSOR in Hiroshima university. A schematic of theirradiation system of BL1U is shown in Fig.1. The
121.6 nm wavelength radiation from the undulator isreflected by a gold-coated mirror (M0 focusing mirror)
located in the mirror chamber directly beam upstreamof the irradiation chamber and then enters the irradiationchamber. On the beam entrance side of the vacuum
sample chamber, a gate valve with an MgF2 vacuum
sealing window (0.5 mm in thickness) was mounted.
The use of gold-coated mirror reflections has made it
possible to suppress high-energy higher order lightfrom the undulator source, expecting to reduce thetransmittance loss of the MgF2 window due to highenergy radiation induced defects. The sample substrate
was set in the sample holder in the irradiation chamber,in which magnetic and electric fields can be applied toperpendicularly to the sample surface. The total photon
beam intensity irradiated on the sample was monitoredwith photoelectron current of a silicon photodiodesettled at the beam downstream side of the sample
holder.
CD spectra of the CPL irradiated films were measured
using the SR-CD beam line BL-12 of HiSOR to clarify

the optical activity emergence by CPL irradiation.
Figure 2(a) shows spectra of DL-alanine films irradiatedfor 30 min with L- or R-CPL at 121.6 nm in wavelength.
We clearly observe optical activity induced by the CPL
irradiation, which shows opposite sign in the CD
between right CPL and left CPL. In addition, we havealso examined the additional eﬀect of applying amagnetic field to the sample to investigate the eﬀect ofthe magnetic field in interstellar space (Fig. 2(b)). The
application of the magnetic field seems to alter the CD
spectra, suggesting a certain impact of symmetry
breaking of the optical activity caused by the CPL
irradiation. Detailed analysis of CD spectra is inprogress supported by quantum chemical calculations.

Fig. 1. A schematic of the CPL irradiation system at
BL1U.

Fig. 2. CD spectra of alanine sample after irradiation of(a) right (red) and left (black)-CPL, and (b) right CPL
with magnetic field application (blue:+0.7T, green:0.7T).
[1] W. A. Bonner, Orig. Life Evol. Biosph. 21 (1991)
407.
[2] J. Takahashi and K. Kobayashi, Symmetry 11(2019) 919.

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Ⅲ-5 Life, Earth and Planetary Sciences

BL3U

Attempts at Structural Analysis of Biological Macromolecules Using
Resonant Soft X-ray Scattering
Y. Sugimoto1 and H. Iwayama1,2
1
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI),
Okazaki 444-8585, Japan

2

Resonant soft X-ray scattering (RSoXS) is a powerful
technique to probe the nano-to-mesoscopic structure ofmolecules. Since this method observes scattered waves
due to resonance processes, RSoXS can reveal
structures with enhanced or tunable scattering contrast.
In particular, since soft X-ray regions include K-edgeenergies of light elements such as carbon, nitrogen, andoxygen, RSoXS is a suitable tool for investigating soft
matters. In UVSOR, the development of the RSoXS
instrument has begun since 2019, and we havesuccessfully measured the mesoscopic structure ofliquid crystal molecules [1].
Biomacromolecules, such as proteins, are also mainlycomposed of light-element atoms. Studying
biomacromolecule structures is crucial for elucidating
biological functions and developing therapeutic drugs.
Conventional electron microscopy (EM) and smallangle X-ray scattering (SAXS) are well-establishedmethods for investigating the structure of biologicalmacromolecules. The RSoXS method is expected tocomplement conventional methods due to its features,such as the selectivity of elements and functional grouporientations. In this work, we performed RSoXS
measurements for protein samples.
Our RSoXS measurements were performed at
UVSOR BL3U. Our sample is bovine milk casein as
the typical protein sample. Casein form micelles withcalcium phosphate dispersed inside [2]. We prepared
the bovine milk samples in the following step. First, wedissolved the bovine milk powder sample in water, thendropped samples onto a Si3N4 membrane and driedthem naturally. We set the samples in the vacuum
chamber and irradiated them with soft X-rays. We
measured the scattering intensity with a soft X-ray
CCD camera (Andor BN940P). The photon energies
were set to 270, 285, 348, and 350 eV. The measured
Q-range was 0.035-0.35 nm-1 at 270 eV and 0.055-0.45
nm-1 at 350 eV. The Guinier plot of the scattering
intensity yields the radius of gyration of ~55 nm,

measured at 270 eV below the carbon K-edge
absorption. This value is close to the structure of casein
micelles obtained in previous studies. The scattering
intensity measured at 350 eV, near the calcium L
absorption edge, showed a diﬀerent scattering intensity
than that at 348 eV (Fig. 1). The resonance-enhanced
structure of the spectrum suggests that RSoXS gives
insight into a more detailed structure of calcium
phosphate in casein micelles, compared to conventional
SAXS.
On the other hand, some structural changes inbiomolecules may come from drying process of thesample preparations. In addition, our equipment isdiﬃcult to measure small scattering-angle regions dueto the direct beam. We will introduce a new sample cellfor wet samples and improve our RSoXS spectrometerfor small scattering angle measurements.

Fig. 1. Q-spectra for casein at the calcium L absorptionedge.
[1] Y. Takanishi et al., RSC Adv. 12 (2022) 29346.
[2] H. Takagi et al., Food Chem. 393 (2022) 133389.

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BL3U

Water-Ion Interactions in Natural Lake Brines
1

Y. Hao , N. Fauré2, Y. Qiu1, M. Nagasaka3, E. Thomson2, S. Wang1 and X. Kong2
1

Department of Environmental Sciences, College of Urban and Environmental Sciences,
Northwest University, Xi’an, China
2
Department of Chemistry and Molecular Biology, Atmospheric Science, University of Gothenburg,
SE-412 96 Gothenburg, Sweden
3
Institute for Molecular Science, Okazaki 444-8585, Japan

Under climate change and enhanced water use
demands, arid regions are undergoing fastertransformations compared to humid areas due to theirgreater susceptibility to changes in precipitation. As aconsequence, the number and area of saline lakes arebeing impacted. Depending on the local circumstances,some saline lakes are being desiccated and transforming
to playa covered by evaporite salts, while others are
forming and expanding, such as the lakes in the
Qinghai-Tibet Plateau [1]. The increases volume andsurface area of saline lakes are expected to have impacts
on local environment and climate.
In this beamtime, we carried out Near Edge X-ray
Absorption Fine Structure (NEXAFS) measurementson brines from various saline lakes in the Qaidam
Basin, which is situated in the Qinghai-Tibet Plateau.
The sampling sites include eight saline lakes: Mang’ai
Feicui Lake (MA), Dalangtan Playa (DLT), West
Taijinar Lake (XT), East Taijinar Lake (DT), Qarhan
Lake (QH), Dezongmahai Lake (DZMH), Dachaidan
Lake (DCD), and Xiaochaidan Lake (XCD) (Figure 1).
The brine samples were taken 2 – 5 cm below the lake
surface, and then were stored in polyethylene bottles,
sealed with Parafilm membranes, and stored at 4 °C.
The NEXAFS measurements were performed at thesoft X-ray undulator beamline BL3U at UVSOR-Ⅲ
Synchrotron. In the liquid flow cell, a liquid layer issandwiched between two 100 nm thick Si3N4
membranes with the windows size of 2 × 2 mm2. Teflon
spacers with the thickness of 100 μm are set between
the support plates of the Si3N4 membranes. Liquidsamples are exchangeable in situ by using a tubing
pump. The temperature of all the liquid samples were
controlled at approx. 25 °C. The Si3N4 membrane
window was set to 200 × 200 μm2 to allow for suitable
photon fluxes.
In Figure 2, the O K-edge NEXAFS results arepresented, with 8 brines displayed in two panels forbetter visibility. The pure water case is also included inboth panels for comparison purposes. The spectra
exhibit three features: pre-edge (~535 eV), main-edge(~537 eV), and post-edge (~540 eV), with the spectrum
lines normalized to the maximum at the main-edge.
The post-edge intensities of the brines are lower thanthose of pure water, which is consistent with existing
literature [2]. The pre-edges have been zoomed in anddisplayed in the insets. Apart from the DZMH brine,
the other brines exhibit reduced and shifted pre-edge

peaks, which will be analyzed in more detail. The
DZMH brine displays a notably high pre-edge, likely
resulting from contamination.

Fig. 1. Eight saline lakes, as marked by red circles,
were sampled in the Qaidam Basin.

Fig. 2. O K-edge NEXAFS spectra of (a) pure waterand brines from MA, DLT, DCD, and QH lakes; (b)pure water and brines from DT, DZMH, XT, and XCD
lakes. The temperatures are around 25°C. The insets
zoom in the pre-edge regions.
[1] Zhang, G. et al., Earth Sci. Rev. 208 (2020) 103269.
[2] Nagasaka, et al., J. Phys. Chem. B, 121 (2017)10957-10964.

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Ⅲ-5 Life, Earth and Planetary Sciences

BL4U

Drug Administration Concepts Involving Redox Nanocarriers Aﬀect theSpatial Distribution of Topically Applied Formulations in Human Skin
G. Germer1, T. Ohigashi2, H. Yuzawa2, K. Rajes3, R. Haag3, F. Rancan4, A. Vogt4 and E. Rühl1
2

1
Physical Chemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
3
Organic Chemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
4
Charité Universitätsmedizin, 10117 Berlin, Germany

Diﬀerent drug administration concepts involving
redox-sensitive polymer nanocarriers topically applied
to human skin ex vivo have been investigated byscanning transmission X-ray microscopy (STXM). The
goal of this research is to understand how single andrepeated use of drug formulations containing
nanocarriers aﬀects the drug and nanocarrier
distribution in the top skin layers of inflamed skin.
Especially, the repeated use of drug formulations isfrequently used in therapy. STXM probes sensitively
and label-free the distribution of topically applied
formulations [1]. The results are of importance tounderstand the transport and penetration routes ofactives. Polymer nanocarriers are used for transporting
drugs that are barely penetrating the skin barriers [2, 3].
The present studies compare diﬀerent topical drugdelivery concepts of a single dose and repeated drug
administrations, reaching up to five days, respectively.
The skin barrier was initially modified for all samples
by topically applying the oxidizer di-benzoyl peroxide(DBPO) for 16 h prior to topical application of
rapamycin-loaded oxidation-sensitive nanocarriers(osCMS [2]). The osCMS samples (5 mg/mL, ≤2%drug loading) were formulated in HEC gel. 40 μL/cm2of this formulation were applied once for up to 1000
min to the skin samples ex vivo. In case of repeatedtreatments, the skin was four times treated every 24 hwith 40 μL/cm2 of a 1% rapamycin-osCMS formulation
with a final drug concentration of 8 μg/cm2. The STXM
experiments were performed at the BL4U beamline of
UVSOR III at the O 1s regime (520 – 565 eV). Key isthe acquisition of stacks of images by concentrating on
the top skin layers, i.e., the stratum corneum (SC) andthe viable epidermis (VE). Fig. 1 shows selected results,
where a comparison is made between the single
treatment (Fig. 1(a)) and multiple treatments (Fig.
1(b)). At the top of each Figure an X-ray micrographrecorded at 532 eV is shown, indicating the skinstructure of the vertical cuts of EPON-fixed skin, where
the skin surface is located at the right hand side. Each
Figure also contains the local concentrations of
rapamycin ① and osCMS ②, derived from theexperimental results and subsequent singular value
decomposition, similar to recent work [1]. Single
treatment shows primarily the species of interest in thestratum corneum (Fig. 1(a)), where the nanocarriers aremostly found in narrow spatial distribution in the lipids
separating the corneocytes, whereas the drug is foundin the corneocytes. Multiple treatments (Fig. 1(b))
show a diﬀerent distribution of both species: Most of
the drug has been transported in deeper skin layers,
only some of the rapamycin remains in corneocytes.
Nanocarriers are primarily found in the viableepidermis, and there they are localized near the cell
nuclei. This deep penetration of osCMS into the viable
parts of skin is likely the result of a damaged tightjunction barrier in the stratum granulosum due to initial
treatment by DBPO, as nanocarriers were not observed
before in the viable parts of intact skin after single
treatment [3]. These diﬀerences in drug and nanocarrier
distributions provide evidence that in inflamed skin the
drug is eﬃciently transported via nanocarriers to thesites of action, where it is needed for therapeutic
success, considering that the drug dissolved in ethanol
is barely taken up by intact skin [1].

Fig. 1. Results from STXM on diﬀerent drug delivery
concepts of human skin ex vivo initially treated by
DBPO: (a) single drug application (1000 min); (b)repeated use of drug administration (5 d). Top: X-ray
micrograph recorded at 532 eV, below: local
concentrations of ① rapamycin and ② osCMS. Scalebar: 5 μm.
[1] G. Germer et al., ACS Omega 6 (2021) 12213.
[2] K. Rajes et al., Pharmaceutics 13 (2021) 37; K.
Rajes et al., Biomater. Sci. Engin. 7 (2021) 2458.
[3] K. Yamamoto et al., J. Control. Release 242 (2016)64.

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BL4U

Absorption- Image and Spectra of Apoptosis Nuclei in P-L Edge
T. Ejima1 and S. Tone22

1
SRIS, Tohoku University, Sendai 980-8577, Japan
Sch. of Sci & Technol., Tokyo Denki University, Hatoyama 350-0394, Japan

Apoptosis is programmed death of cells that is an
important physiological function for the recycling ofcellular components and characterized by chromatincondensation in the cell nucleus. Detailed studies of thechromatin condensation process in isolated cell nuclei
have shown that this condensation process occurs inthree stages from the normal state of the cell nucleus(Stage 0) to ring condensation (Stage 1), necklace
condensation (Stage 2), and cell nuclear collapse/
disassembly (Stage 3) [1]. It has been suggested thatamong the transitions from Stage 0 to 3, Stage 1 to 2 iscaused by cleavage of phosphodiester bonds in DNA,
while protein kinases such as MST1 may be thecohesive factor in the transition from Stage 2 to 3 [1].
To investigate the change from Stage 0 to Stage 1,
infrared absorption experiments were performed,
focusing especially on the change in the vibrational
structure of PO2−, which is sensitive to the helicalstructure of DNA. As a result, the helical structure,
which was predominantly B-DNA in Stage 0, decreased
as the step progressed, and changed to A-DNA or
Z-DNA. This result suggests that the helical structureof DNA changes from Stage 0 to 1, DNA is cleaved inStage 1 to 2, and phosphate groups are transferred from
DNA in Stage 2 to 3. In this study, we focused on thischange in the phosphate group of DNA and thought that
we could capture the changes in DNA at each stage bymeasuring the P-L2,3 absorption edge structure of thecell nucleus.
The samples used in the experiments were obtained
according to the method reported by Tone et al [1]. The
isolated nuclei of each stage obtained were embedded
and sectioned into approximately 100 nm-thick section
samples using an ultramicrotome. The sectioned
samples were imaged under an optical microscope andcell nuclei showing representative shapes of each stage
were selected in the images. Isolated nuclei of Stage 0
and Stage 2 were selected for measurement due to time
limitations, and STXM measurements of the C-K and
P-L absorption edges were performed for each. The
obtained STXM images were analyzed by PCA andreconstructed after removing noise components fromthe PCA component images, and cluster analysis was
performed to the reconstructed images [2]. Figure
shows the STXM image of a Stage 2 isolated nucleus at
the P-L absorption edge and the obtained absorption
spectrum. The spectra show two peak structures, P-L2
and L3, split by spin-orbit interaction. We believe thatthe spectral shape of each peak is similar to that of PO4.
In combination with the image, it is considered that
DNA was degraded and transformed into PO4 clusters
as apoptosis progressed. This interpretation is consistent
with the result of IR absorption results.

Fig. 1. X-ray absorption image, (a), and X-ray
absorption spectrum, (b), of apoptosis nucleus in stage2
at P-L absorption edge. Bar is 2 μm in length.
References:[1] S. Tone et al., Exp. Cell Res. 313 (2007) 3635.
[2] M. Lerotic et al., JESRP 144-147 (2005) 1137.

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Ⅲ-5 Life, Earth and Planetary Sciences

BL4U

Embracing Natural and Anthropogenic Aerosol Particle Complexity
P. A. Alpert1, L. Li2, L. F. Escusa Dos Santos2, F. Mahrt1, M. Ammann1, L. Wu3, W. Hu3,
P. Fu3, M. Hallquist2, E. Thomson2 and X. Kong2
1

Laboratory for Environmental Chemistry, Paul Scherrer Institute, Villigen PSI, 5232, Switzerland
2
Atmospheric Science Research Group, Department of Chemistry and Molecular Biology,
University of Gothenburg, 41296 Gothenburg, Sweden
3
School of Earth Systems Science, Tianjin University, 300072 Tianjin, China

A considerable fraction of the global population lives
in coastal urban centers. People in these regions are
exposed to some of the most complex aerosol particles
containing mixtures of natural and anthropogenic
compounds. The chemical composition and morphologyof these particles are key for their environmental
impacts, but remain poorly understood. We haveinvestigated particles taken from ambient air that was
influenced by the ocean and mixed ocean-anthropogenic
sources to better understand their cloud-forming
potential, chemical reactivity and light-scattering
properties.
Sea spray aerosol particles contain sea-salts andorganic matter [1]. When mixed with anthropogenic
air, these particles can uniquely undergo aciddisplacement reactions forming organic salts andproducing inorganic acids, which evaporate from theparticles [2]. Mixed anthropogenic and natural aerosol
particles aerosolized from saline lakes have previously
been shown to act as cloud nuclei [3]. Additionally,
anthropogenic emissions from ships are known to havea variable ability to nucleate clouds depending on thetype of fuel used and its sulfur content [4].
To better understand such complex processes wecollected ambient particles from contrasting sources, i)
the Indian Ocean with minimal anthropogenic
influence, ii) the Indian Ocean with significant
anthropogenic influence and iii) Sanya Port, a coastal
city in China. At the Ultraviolet Synchrotron Orbital
Radiation Facility, we probed individual particles at the
carbon, oxygen and nitrogen K-edges, and the sulfur,
chlorine and calcium L-edges using scanningtransmission X-ray microscopy coupled to near-edge
X-ray absorption fine structure spectroscopy (STXM/
NEXAFS). We quantified how inorganics and organics
were mixed in individual particles and determined theorganic volume fraction (OVF) [5]. The OVF was
calculated from high spatial resolution images at 280
eV, 285.4 eV, 288.7 eV and 320 eV with a pixel size of
0.05 × 0.05 μm2.
Figure 1 shows optical density measured at 280 eV
and OVF for the same field of view of Indian Ocean
particles without anthropogenic influence. The opticaldensity image shows X-ray absorption primarily due toelements that are not carbon, such as Na and Cl, as wellas other sea salts and inorganic matter. Particle
morphology is largely cubic with submicrometer sizedneedle-like structures, as expected for sea spray aerosol
particles. Based on our STXM/NEXAFS measurements,
these needles were confirmed to be dominated bycalcium sulfate. The OVF image reveals a considerable
fraction of organic material close to salt cores. Carbon
K-edge spectra were dominated by carboxyl functionalgroups, similar to sea spray aerosol particles found overvarious ocean environments [1, 2, 5].
These data suggest that these particles will likely behighly hygroscopic and act as cloud condensation and
ice nuclei due to their high salt content and similar
carbon spectra as other ice nucleating particles [1].
Additionally, morphology and composition determinedfrom STXM/NEXAFS are similar to laboratorygenerated ice nucleating sea spray particles, implying arole for atmospheric ice particle production [1]. The
highest OVF appears close to the salt at values around
0.6 and decreases with distance away from the crystal.
This implies a small degree of aging, i.e., that organic
salts dominate likely due to acid displacement reaction
rather than pure organic coatings. Further work is
ongoing to identify diﬀerences in particles from various
sources and their importance for cloud microphysics
and aerosol chemistry.

Fig. 1. Optical density at 280 eV indicating X-ray
absorption primarily due to compounds other thancarbon. Organic volume fraction of the same particles
calculated for particles collected over the Indian Ocean.
Scale bar is 2 μm.
[1]P. A. Alpert et al., Sci. Adv. 8 (2022) eabq6842.
[2]A. Laskin et al., J. Geophys. Res.-Atmos. 117 (2012)
D15302.
[3]J. Li et al., Atmosphere 12 (2021) 1203.
[4]L. F. E. d. Santos et al., Environ. Sci.: Atmos. 3(2023) 182.
[5]M. Fraund et al., Atmos. Meas. Tech. 12 (2019)1619.

− 171 −BL4U

STXM in Characterizing Lysosomal Storage Materials in a Mouse Model
T. Mansikkala1,2 , T. Ohigashi3, H. Yuzawa3, I. Miinalainen2, S. M. Kangas4, M. Salo4,5,
N. Kosugi3, J. Uusimaa4, M. Huttula1, R. Hinttala 4,5 and M. Patanen1, 2
1Nano and Molecular Systems Research Unit, PO Box 3000, 90014 University of Oulu, Finland
2
Biocenter Oulu, PO Box 5000, 90014 University of Oulu, Finland
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
Research Unit of Clinical Medicine and Medical Research Center, Oulu University Hospitaland University of Oulu, 90014 Oulu, Finland
5
Transgenic and Tissue Phenotyping Core Facility, University of Oulu, Finland

In this work, we used scanning transmission X-ray
microscopy (STXM) technique at BL4U beamline to
study lysosomal storage disease (LSD) mouse model
liver and kidney tissues. LSDs are a large family of
diseases where e.g. enzymatic dysfunction leads toaccumulation of macromolecules in the tissues. This
study was part of a project to better understand them.
STXM hold promise to be a good tool to study LSDs if
the natural chemical contrast of accumulating material
and rest of the tissue is high enough. In our previous
beamtimes at UVSOR both human and mouse model
samples have been studied (Patanen 2018, Mansikkala2020). This time our aim was to diﬀerentiate the storage
material within the lysosomes. Liver and kidney tissue
samples were used. They both had clear ultrastructural
diﬀerences compared control samples in form of large
number of vacuoles, presumed to be lysosomes fitting
the description of the LSDs. Our preliminary studies
showed a distinct spectrum from lysosomes comparedto the rest of the tissue. This study was to verify thefinding in larger number of samples.
The tissue samples were fixed in 4% paraformaldehyde
and 2.5% glutaraldehyde in 0.1 M phosphate-buﬀeredsaline and then embedded in TTE:MMHA. The 150 nm
thick sections were imaged with TEM to find areas withlysosomes on the samples. The same area was thenmeasured with STXM from the subsequent thinsections.
We were able to find and image lysosomes in bothtissue types, an example shown in Fig. 1. When
analyzing the samples with aXis2000, we noticed thatthe spectrum from the lysosomes was very similar tothat of the TTE:MMHA resin (Fig. 2). To evaluate theresult, we subtracted the measured pure resin spectrum
from the measured lysosome spectrum shown in Fig. 3(green). There is only a small peak around 289 eV
diﬀerentiates the lysosome spectrum from a resin
spectrum. However, the spectrum from the extracellularspace (blue) is almost identical with just intensity
diﬀerences. The spectrum of cytosol diﬀers clearly,
indicating that the contents of the lysosomes are mostly
TTE:MMHA resin. While there is a small diﬀerence
between the resin and lysosomes and extra cellularspace, the spectra are overwhelmed by the resin signal,
and we were not able to diﬀerentiate the accumulationmaterial spectrum in the lysosomes. Our hypothesis isthat the sample preparation has substituted theaccumulation material in lysosomes with resin insteadof preserving it.

p

Fig. 1. STXM image of disease model mouse kidneywith visible ultrastructural changes. Lysosomes aremarked with 1, cytosol with 2 and extracellular spacewith 3. Scale bar is 5 μm.

Fig. 2. Comparison of spectra from lysosome (blue)
and pure resin (red).

Fig. 3. Spectra from lysosome (green), the extracellularspace (blue) and cytosol (red).
[1] T. Mansikkala et al., UVSOR Activity report 2019(2020) 155.
[2] M Patanen et al., UVSOR Activity report 2018(2019) 166.

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Ⅲ-5 Life, Earth and Planetary Sciences

BL4U

Determination of Spectral Changes in NEXAFS of Biomolecules Caused by
Radiation Eﬀects for Molecular Mapping of Biological Specimens
A. Ito1, K. Shinohara2, A. Matsuura3, S. Toné4, K. Tohya5, H. Yuzawa6 and T. Ohigashi6, 7
1
School of Engineering, Tokai University, Hiratsuka 259-1292, Japan
Graduate School of Health Sciences, Fujita Health University, Toyoake, 470-1192, Japan
3
Research Integrity Oﬃce, Fujita Health University, Toyoake, 470-1192, Japan
4
School of Science and Engineering, Tokyo Denki University, Hatoyama, 350-0394, Japan
5
Kansai University of Health Sciences, Kumatoricho, 590-0482, Japan
6
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
7
School of Physical Sciences, The Graduate University for Advanced Studies, Okazaki 444-8585, Japan2

1.4(Pm2/pg)

Mass absorption coefficient

(a)

(b)

1.2
1
0.8
0.6
0.4
0.2
0

281 eV
0

0.5

1

1.5

Absorbed dose (MGy)(Pm2/pg)

Mass absorption coefficient

1.4

(c)

1.2
1
0.8
0.6
0.4
0.2
0

393 eV
0

20

40

60

80

100

Absorbed dose (MGy)

120

1.4

(Pm2/pg)

Mass absorption coefficient

We have been working on a quantitative mapping of
nucleic acids (DNA and RNA) and proteins (histone
and bovine serum albumin abbreviated as BSA) in
chromosomes, cultured mammalian cells, and isolated
apoptotic nuclei using combined NEXAFS spectra at
the C, N and O K-edges [1-3]. The molecular mappingis based on the NEXAFS profiles of constituent
biomolecules obtained independently. However,increased exposure dose required for X-ray imaging
will modify NEXAFS profiles of biomolecules asreported previously [4]. For the precise molecularmapping of biological specimens, spectra measured at
the same exposure as that used in the specimen imaging
are required. Furthermore, the knowledge of the
exposure dependence of NEXAFS profiles would
improve the reliability of molecular mapping of
biological specimens whose images are taken at any
exposure time.
In our previous report, we detected a slight change of
NEXAFS profiles of DNA at C, N and O K-edges,
depending on the exposure time [4]. In the present
study, we extended our analysis to the absorbed dose
dependence of the mass absorption coeﬃcient for all
the energy points of NEXAFS, where absorbed dose iscalculated from the exposure.
We prepared dry thin films of DNA, RNA, histone,
BSA, actin, actin monomer and nucleosome on SiN
membrane. Each one micrometer square area in thespecimens was scanned with 10 x 10 pixels at theenergy of C, N and O K-edge regions mainly in thisorder with a dwell time of 6, 12 and 20 msec in addition
to 2 msec for DNA. For each dwell time the scannedarea was shifted to the diﬀerent area to avoid additionalradiation eﬀects to molecules.
Examples of the absorbed dose dependence of mass
absorption coeﬃcient are shown in Figure 1 at thelowest energies in the NEXAFS measurements of DNA
at the C, N and O K-edges. All data in the repeatedexperiments for several times were compiled in the
figures. The linear regression lines showed a slightdecrease with increasing absorbed dose, which meansthat radiation aﬀects the spectra of molecules.
Estimation of NEXAFS profiles at a given absorbed
dose is in progress.

1.2
1
0.8
0.6
0.4

524 eV

0.2
0

0

40

80

Absorbed dose (MGy)

120

160

Fig. 1. Eﬀects of soft X-rays on mass absorption
coeﬃcients in DNA at (a) C K, (b) N K, (c) O K- edges.
The solid lines show linear regression.
[1] K. Shinohara et al., Ultramicrosc. 194 (2018) 1.
[2] K. Shinohara et al., J. X-Ray Sci. Technol. 26(2018) 877.
[3] K. Shinohara et al., Cells 8 (2019) 8.
[4] A. Ito et al., UVSOR Activity Report 49 (2021) 152.

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BL4U

Attempt to Constrain the Initial Condition of Aqueous Alteration
on Cometary Organic Matter
H. Yabuta1, N. Nishii1, T. Araki2 and H. Yuzawa2
1

Department of Earth and Planetary Systems Science, Hiroshima University, Kagamiyama 1-3-1,
Hiroshima 739-8526 Japan
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

This study aims to understand the chemical evolutionof organic matter in the early stage of aqueous alterationof icy small bodies, through the freeze-thaw experimentof analogues of cometary organic matter.

(UCAMM) [3], supporting the formation of the
UCAMM with a very small amount of fluid on acometary body.

As a starting material, HCN polymer was synthesized
by heating formamide (0.3 ml) at 185℃ for 72 hours[1]. The HCN polymer in the same volume of Milli-Q
water was frozen with liquid nitrogen (-196℃), kept in
the freezer (-18℃), and thawed under room temperature.
This freeze-thaw cycle experiment was conducted 10,
20, 30, and 40 cycles. Each experimental products were
filtered to remove the residual formamide and once
dried.
For the scanning transmission x-ray microscopy(STXM) measurements, each experimental products
were suspended in methanol and dropped in SiOsupported Cu transmission electron microscopy (TEM)
grids. C- and N-XANES spectra of the samples wereacquired by STXM-XANES, beamline 4U, UVSOR.
Cody et al. (2008) [2] was referred to for the absorption
peak assignment.
Figure 1 shows the C-XANES spectra of the products
obtained from the freeze-thaw cycle experiments of
HCN polymer. The spectrum of the starting material (0cycle) contains the developed peak derived from nitrile
or N-heterocycles with the other three peaks derived
from aromatic carbon, carbonyls, and alcohol/ether.
Except for the freeze-thaw 10 cycle product showing
the high peaks of aliphatic and carbonyl carbons, thespectra of the other products are relatively similar tothat of the starting material, but peak intensities ofnitrile /N-heterocycles and carbonyls in the spectra of
the freeze-thaw 30 and 40 cycles products are lower
than those in starting material and the 20 cycle products.
The result shows that HCN polymer is likely hydrolyzed
and altered with the progress of low temperature freezethaw processes. In addition, the freeze-thaw 30 and 40
cycles products showed similar C-XANES spectra to
those of ultracarbonaceous Antarctic micrometeorites

Fig. 1. C-XANES spectra of the products obtained
from the freeze-thaw cycle experiments of HCN
polymer (0, 10, 20, 30, and 40 cycles). Peak A: 1s-π*transition for aromatic carbon (C=C*) at 285.6 eV, peak
B: 1s-π* transition for nitrile (C≡N*) or N-heterocycles(C-N*=C), at 286.6 eV, peak C: 1s-3p/s* transition for
aliphatic carbon (CHx) at 287.5 eV, peak D: 1s-π*transition for carbonyl carbon (OR(C*=O)-C) at 288.4–
288.7 eV, and peak E: 1s-3p/s* transition for alcohol or
ether (CHx-OR) at 289.3 eV.
[1] F. Cataldo, G. Patanè and G. Compagnini, J.
Macromol. Sci. Part A 33 (2009) 1039.
[2] G. D. Cody et al., Meteorit. Planet. Sci. 43 Nr 1/2
353.
[3] H. Yabuta, et al., Geochim. Cosmochim. Acta 214(2017) 172.

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Ⅲ-5 Life, Earth and Planetary Sciences

BL4U

Organics in Asteroid Ryugu Samples: Analytical Approach Utilizing Microand Multi Beam Techniques.
M. Ito1, N. Tomioka1, M. Uesugi2, A. Yamaguchi3,4, N. Imae3,4, N. Shirai5, T. Ohigashi4,6,
M. Kimura3, M-C, Liu7, R.C. Greenwood8, K. Uesugi2, A. Nakato9, K. Yogata9, H. Yuzawa6,
Y. Kodama$, A. Tsuchiyama10, M. Yasutake2, R. Findlay8, I.A. Franchi8, J.A. Malley8,
K.A. McCain7, N. Matsuda7, K.D. McKeegan7, K. Hirahara11, A. Takeuchi2, S. Sekimoto12,
I. Sakurai13, I. Okada13, Y. Karouji14, T. Yada9, M. Abe9, T. Usui9, S. Watanabe13 and Y. Tsuda4,91

JAMSTEC Kochi, 2JASRI/SPring-8, 3NIPR, 4SOKENDAI, 5Tokyo Met. Univ.,
6
UVSOR/IMS, 7UCLA, 8Open Univ., 9JAXA/ISAS, 10Ritsumeikan Univ.,
11
Osaka Univ., 12Kyoto Univ., 13Nagoya Univ., 14JAXA/JSEC, $Toyo Corp.

How the Earth gained its water and organics remains
an outstanding question in planetary science. While asmall fraction may have been inherited from the cloudof gas and dust present when the Solar System formed,
most was likely delivered to the inner Solar System
region by water- and carbonaceous-rich materials i.e.,
asteroids, meteorites, interplanetary dust particles andcomets that may be originated beyond the orbit ofJupiter. To better understand the origin of primitive
water- and carbonaceous-rich asteroids, JAXA sent the
Hayabusa2 spacecraft to asteroid Ryugu and returned
surface and subsurface samples from it in December
2020.
In June 2021, following the initial characterization
phase conducted at JAXA curation facility, a subset of
Ryugu materials were the subject of investigations byseparate research teams of six initial analysis and two
curation teams [1-8]. Based on the investigations ofbulk O isotopes, major elemental abundances and theirmineralogical characteristics [1-3,9], the samples
returned from Ryugu have shown that they closely
match the rare, water rich, Ivuna type (CI) chondritic
meteorites.
Analysis of the organic component in Ryugu particles
has been a major theme during this first intensive phaseof research activity. One of the successes of the work
carried out on the Ryugu materials has been theidentification of a clear relationship between coarse
grained phyllosilicates and organics indicating ofwater-mineral-organics interaction under a reducing
environment on the asteroid [1]. This was confirmed by
a STXM (UVSOR-BL4U), NanoSIMS (JAMSTEC,
Kochi) and TEM (JAMSTEC, Kochi) coordinatedmicroanalysis [1]. Approximately 20,000 organic
species consisting of carbon, hydrogen, nitrogen,oxygen, and/or sulfur, and at least 20 amino-acids havebeen identified by using high-sensitivity mass
spectrometry [1,6,7]. Studies of chiral amino acids in
Ryugu have shown that the abundance of the D- andL-enantiomers are approximately equal (D/L = 1),

indicating nonbiological origins [6]. The diversity oforganic matter found in Ryugu samples shows somesimilarities with that previously reported in primitive
carbonaceous chondrite groups [1,6,7].
Isotope analyses of the Ryugu particles have provided
clues to the original provenance of these Ryugu-derived
materials [1,10-12]. This indicates that materials from
Ryugu display similarities to other postulated outer
Solar System materials, including interplanetary dust
particles, returned cometary materials and spectroscopic
observations of comets. These results suggest that
Ryugu, and by inference other type asteroid, could haveformed in outer Solar System regions, such as are now
occupied by Uranus and Neptune. A finding of CO2bearing water in a Ryugu pyrrhotite is also anotherevidence of outer Solar System origin [4]. Ryugu-likeC-type asteroidal bodies may be present in the inner
Solar System as a result of giant planet migration [13].
The success of the Hayabusa2 mission and subsequent
analytical campaign [1-8] demonstrates the importanceof using state-of-the-art analytical techniques wheninvestigating spacecraft returned samples.
[1] M. Ito et al., Nat. Astron. 6 (2022) 1163.
[2] E. Nakamura et al., Proc. Jpn. Acad., Ser. B 98
(2022) 227.
[3] T. Yokoyama et al., Science 379 (2023) eabn7850.
[4] T. Nakamura, et al., Science 379 (2023) eabn8671.
[5] R. Okazaki et al., Science 379 (2023) eabo0431.
[6] H. Naraoka et al., Science 379 (2023) eabn9033.
[7] H. Yabuta et al., Science 379 (2023) eabn9057.
[8] T. Noguchi et al., Nat. Astron. 7 (2023) 170.
[9] R. C. Greenwood et al., Nat. Astron. 7 (2022) 29.
[10] N. Kawasaki et al., Sci. Adv. 8 (2022) eade2067.
[11] D. Nakashima et al., Nat. Commun. 14 (2023)
532.
[12] T. Hopp et al., Sci. Adv. 8 (2022) eadd8141.
[13] A. Morbidelli, et al., Meteorit. Planet. Sci. 35(2000) 1309.

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BL4U

Chemical Morphology of Biomass-Burning Particles Generated fromDiﬀerent Fuels under Varied Burning Conditions
J. Chen1, N. Faure2, Y. Hao3, Z. Kanji1, E. S. Thomson2, S. Wang3 and X. Kong2*
1
Institute for Atmospheric and Climate Science, ETH Zürich, Zurich, 8092, Switzerland
Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
3
Department of Environmental Sciences, College of Urban and Environmental Sciences,
Northwest University, Xi’an 710127, China

2

Biomass burning aerosols (BBA) from fires
worldwide have the potential to greatly disrupt theatmosphere-Earth climate system, as they directly
absorb solar radiation and also indirectly aﬀect theradiative properties of clouds. However, due to theintricate chemical composition of BBA produced froma variety of fuels under diﬀerent burning conditions,the environmental and climatic repercussions of BBA
remain highly uncertain.
In this study, BBA generated from laboratory burning
experiments were examined by scanning transmission
X-ray microscopy (STXM), in order to understand thefactors influencing the chemical morphologies of BBA.
Various types of biomasses (softwood, hardwood,leaves, peat) were burned under controlled conditions,
including flaming and smoldering conditions. The
generated BBA particles were transferred to the aerosolchamber and collected onto the TEM grid for chemicalmorphology analysis by. The STXM measurements
were performed at the BL4U beamline in UVSOR-III[1].
The images of example particles are shown in Fig.1,
including the BBA particles from softwood underflaming condition (Fig.1a), and softwood, peat, leaves
BBA particles from smoldering condition (Fig. 1b-1d).
The morphologies of particles varied between burning
conditions: particles formed under flaming condition
exhibit a chain-like structure (Fig. 1a), which is typicalfor fresh soot particles. As for particles collected under
the smoldering condition (Fig.1b-1d), they display acore-shell structure, implying a mixture of organics andsoot particles.
The carbon K-edge near edge X-ray absorption finestructure (NEXAFS) spectra of individual particles
from diﬀerent cases were shown in Fig. 2, where thecorresponding particles are displayed on the right. All
spectra show the absorbance around 285 eV (arisingfrom the C 1s→π*R(C*=C)R transition) and a boarder peakat 290 eV (attributing by C 1s→σ* aromatic C=C
transitions). This is one of the identifying features ofsoot particles. Thus, the strong absorbance at 285 eV ofwood-burning particles (softwood flaming andsmoldering) indicates the origin of soot particles. This
peak is relatively lower in peat and leaves smolderingcases, implying less contributions from soot particles.
Two specific peaks at 297.1 eV and 299.8 eV due to thetransitions of K L2 2p1/2→σ* and K L2 2p3/2→σ* wereobserved in the leaves smoldering case. The spectrafeature in the energy range from 285 eV to 290 eVvaried with samples, which is associated with oxygen-containing organic functional groups and needs further
investigation.
These results show that the BBA has distinct chemicalmorphology depending on biomass types and burning
conditions, and the SXTM serves as a useful tool tostudy the morphology and chemical natures of these
BBA particles.

Fig. 1. The morphology of BBA particles from burning
diﬀerent biomasses: (a) Softwood burned under flaming
condition; (b-d) softwood, peat and leaves burned
under smoldering conditions, respectively. The usedphoton energy was 300 eV.

Fig. 2. Left: NEXAFS C K-edge spectra of example
particles. Right: (a) softwood burned under flaming
condition; (b-d) softwood, peat and leaves burned
under smoldering conditions, respectively.
[1] T. Ohigashi et al., J. Phys. Conf. Ser., 463 (2013)
012006.

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Ⅲ-5 Life, Earth and Planetary Sciences

BL5B

Heat Resistance of SiC/Mo/Si Multilayer Mirrors at 30.4nm
S. Teramoto 2, K.Inoue1, A.Yamazaki1, T.Matsumoto2, S. Liu2, K. Yoshioka1,2 and I. Yoshikawa1,2
1Development of Earth and Planetary Science, Graduate School of Science,
The University of Tokyo, Tokyo 113-0033, Japan
2
Development of Complexity Science and Engineering, Graduate School of Frontier Sciences,
The University of Tokyo, Chiba 277-8561, Japan

Optical observations of planetary atmospheres are
conducted over a wide range of wavelengths. In
particular, ultraviolet light is useful for obtaining
various information about planetary upper atmospheres.
For example, by detecting the emission of He II (30.4nm), the distribution of plasma surrounding the Earthcan be observed. The behavior of plasma is related tosolar activity and is the key to understanding thephysics and evolution of the environment within thesolar system. However, the problem is that the signalto-noise ratio is small due to the low light intensity in
UV observations.
Therefore, technology using periodic multilayer forthe normal incidence optics in the EUV wavelength
ranges has been developed for many planetary science
missions, such as Nozomi [1], Kaguya, andEQQULEUS [2]. The normal incidence optics isnecessary to determine the distribution of plasma.
However, the problem is that the normal incidence
optics have low reflectance. We can solve this problem
by using multilayer mirrors.
Multilayer mirrors can dramatically improvereflectance due to the interference of reflected light ateach interface. In particular, the development of highreflectance multilayer mirrors for He II radiation at
30.4 nm is progressing. A Mo/Si mirror is widely used
due to its high stability.
Previously, we demonstrated the performance of a
new multilayer mirror consisting of 40 pairs of Mg and
SiC, achieving a maximum reflectivity of over 30%.
However, it was found that the Mg/SiC mirror had acritical flaw. The reflectivity decreases in hightemperature and high-humidity environments. In actual
observations, multilayer mirrors are exposed to hightemperature and humid environments before launchand extremely cold environments in space. Therefore,
it is necessary to develop observation equipment that is
resistant to such environmental changes.
Since a combination of Mo/Si is stable [3], we
designed a new multilayer mirror (SiC/Mo/Si). The
new mirror is manufactured by depositing the three
diﬀerent materials periodically. To evaluate its
resistance to high-temperature environments, we

conducted a heat environment test in a constanttemperature oven (50 degrees Celsius for 24 hours) andcompared the reflectances of the mirrors before andafter heating.
The synchrotron radiation was spectroscopic with
G3M5. It was led to the calibration chamber. EUV light
was irradiated onto the multilayer mirror, and its
wavelength dependence was evaluated. The
measurement was conducted three times.
Fig. 1 shows the reflectances for the S-polarization of
the mirror before and after high-temperature exposure(50 degrees Celsius for 24 hours). The reflectancedecreased by approximately 5% after the hightemperature exposure. The irregularity of the interface
may have aﬀected the result.
In the future, changing the manufacturing process
will make it possible to create a more stable mirror withhigher reflectance. We plan to improve the performanceof the mirror that is more resistant to environmental
changes and have higher reflectance in the next year.

Fig. 1. Reflectances of SiC/Mo/Si mirrors before(black dots) and after (orange dots) heat-temperature
exposure.
[1] I. Yoshikawa et al., Earth Planets Space 60 (2008)407.
[2] M. Kuwabara et al., JAXA Research andDevelopment Report (2019).
[3] L. Yunpeng et al., Appl. Surf. Sci. 317 (2014) 902.

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BL6B

Synchrotron-radiation Infrared Microspectroscopy Analysis of Persistent
Organic Compounds
T. Kawasaki 1, F. Teshima2 and K. Tanaka2
1

Accelerator Laboratory, High Energy Accelerator Research Organization, Tsukuba 305-0801, Japan
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

It is important for absorption of carbon dioxide underatmosphere to manage woody biomass properly. Lignin
is a part of ingredients of woods and is composed ofmany phenolic compounds. It has been known thatthose aromatic molecules such as coumaryl alcohol andconiferyl alcohol are useful for functional materials.
However, it is usually diﬃcult to degrade the lignin
construct unless using strong acids with extremely hightemperatures. We have found that soluble lignin thatwas prepared by alkaline treatment can be degraded to
produce several aromatic molecules by using infrared
free electron laser (IR-FEL) [1]. In this study, an
insoluble sulfonated lignin was tested as another model
sample for degradation by IR-FEL and far-infrared ray
from gyrotron [2]. After those irradiations, the complex
structure of the lignin was analyzed by usingsynchrotron-radiation infrared microspectroscopy. The
measurement was performed by reflection mode with
64 scans.
In the FT-IR spectra of lignin in the far-infrared
region (Fig. 1, upper), increases of absorption intensity
can be observed from 150 to 250 cm-1 in all of samples.
The inclinations in the cases of samples after the IRFEL irradiations at 7.1 μm and 3.5 μm are similar withthe case of the sample before irradiation (Nonirradiation). On the other hand, the irradiation by asubmillimeter wave at 1.4 mm from gyrotron gaveincrease of absorption at 150-200 cm-1. This may
indicate that the hydration of the lignin sample can be
occurred by the irradiation at longer wavelengths.
In the absorption spectra at mid-infrared region (Fig.
1, bottom), broad bands at 1000-1100 cm-1 can beobserved in all of samples. Especially, another peak canbe slightly detected after irradiations at 1.4 mm and 7.1
μm compared to that at 3.5 μm and the non-irradiation
sample (dotted line). This region contains carbonoxygen stretching vibrational modes, and the lignin isconstructed by many ether bonds (C-O-C). Therefore,
it can be considered that the structure of lignin can be
modified and partial cleavage of the ether bonds can be
induced by the submillimeter wave and the IR-FEL
irradiations. We are planning to perform mass analysis
to confirm the structural modification of the lignin.

Fig. 1. Infrared absorption spectra of lignin in the far(upper) and mid-(bottom) infrared regions. “1.4 mm”
means the wavelength of submillimeter wave fromgyrotron. Both of “7.1 μm” and “3.5 μm” arewavelengths of IR-FELs.
[1] T. Kawasaki et al., Polymers 14 (2022) 2401.
[2] T. Kawasaki et al., Biomolecules 12 (2022) 1326.

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Ⅲ-5 Life, Earth and Planetary Sciences

BL6B

Development of an Infrared Spectro-Microtomography Using a Mid-IR
Supercontinuum Laser: Preliminary Report
H. Yabuta1, Y. Ikemoto2, F. Teshima3 and K. Tanaka3
1

Department of Earth and Planetary Systems Science, Hiroshima University, Kagamiyama 1-3-1,
Hiroshima 739-8526 Japan
2
Japan Synchrotron Radiation Research Institute (JASRI) 1-1-1,
Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan

This study aims to develop a three-dimensional
infrared spectro-microtomography using a mid-infrared
supercontinuum laser, for investigating the threedimensional spatial distributions of micron-sizedorganic materials and hydrous minerals of
extraterrestrial samples and for understanding thechemical history in the early Solar System.

In the previous beamtime, the mapping measurements
were performed in the multipoint measurement modeof microscopy programs, but there is a problem of not
being able to access integral intensity plots. In addition,
the program is not equipped with a mode to extract only
the part of the linear array detector that are illuminatedby IR light. The element shift mapping software solves
these problems and is used for the measurement.

In the previous beamtime, an alignment procedure
has been established to guide the laser source to themicroscope for micro-spectroscopy. The activities ofthis beamtime were the following three points. The firstwas to adjust the beam size at the microscope focal
point, the second was to confirm the sample holding
technique, and the third was to confirm the IR imaging
measurement technique by rotating the sample. The
details are described in this order.
Fig. 1 shows the schematic illustration of the optical
path. The IR beam emitted from the laser are reflectedby BaF2 and reduced to about 1/100 of its original
intensity. The IR beam is further attenuated through an
ND filter to an intensity that does not damage theoptical components of the FTIR spectrometer, and thena spectrum is measured. The microscope at BL6B has
16 elements HgCdTe (MCT) linear array detector. In
previous experiments, it was found that due to the small
source size, the IR spot on the microscope was small
and the IR light was only on a part of the element. In
order to increase the number of elements that are
illuminated by IR light, a beam expander was installedin front of the FTIR to adjust the spot size.
Samples are glued to the tip of a glass capillary andmounted on a goniostage. Figure 2(a) shows aphotograph of the goniostage mounted on the
microscope. Figure 2(b) shows a micrograph of asample glued to the tip of the capillary. The sample wasa milled breadcrumb and the size was approximately 90
micrometers in longitudinal.

Fig. 1. Schematic illustration of the optical path

Fig. 2. (a) Photograph of the goniostage mounted on
the microscope. (b) Micrograph of a sample glued tothe tip of the capillary.

− 179 −UVSOR User 8

ს

List of Publications

Ⅳ List of Publications

List of Publications (2022)

D. Asakura, E. Hosono, M. Kitamura, K. Horiba, E. Magome, H. Setoyama, E. Kobayashi, H. Yuzawa, T. Ohigashi,
T. Sakai, R. Kanega, T. Funaki, Y. Sato and A. Ohira“Redox reaction in Ti-Mn redox flow battery studied by X-ray absorption spectroscopy”, Chem. Asian J.
(2022) e202201047.
A. Dorokhina, R. Ishihara, H. Kominami, V. Bakhmetyev, M. Sychov and T. Aoki, H. Morii“Solvothermal Synthesis of LaF3:Ce Nanoparticles for Use in Medicine: Luminescence, Morphology andSurface Properties”, Ceramics 6 (2023) 492.
O. Endo, F. Matsui, S. Kera, W-J. Chun, M. Nakamura, K. Amemiya and H. Ozaki“Observation of Hole States at perylene/Au(110) and Au(111) interfaces”, J. Phys. Chem. C 126 (2022) 15971.
T. Fuji, T. Kaneyasu, M. Fujimoto, Y. Okano, E. Salehi, M. Hosaka, Y. Takashima, A. Mano, Y. Hikosaka, S. Wada,and M. Katoh“Spectral phase interferometry for direct electric-field reconstruction of synchrotron radiation”, Optica 10-2(2023) 302.
Y. Hasegawa, F. Matsui and S. Kera
“Resonant Photoemission Spectroscopy of Highly-Oriented-Coronene Monolayer using Photoelectron
Momentum Microscope”, e-J. Surf. Sci. Nanotech. 20 (2022) 174.
E. Hashimoto, K. Tamura, H. Yamaguchi, T. Watanabe, F. Matsui and S. Koh“Characterization of Epitaxial CVD graphene on Ir(111)/α-Al2O3(0001) by Photoelectron Momentum
Microscopy”, Jpn. J. Appl. Phys. 61 (2022) SD1015.
Y. Hikosaka“Sequential Quadruple Auger Decay Pathways from the Xe 4s Core-Hole State”, Phys. Rev. A 106 (2022)
062814.
Y. Hikosaka and S. Fritzsche“Coster–Kronig and Super Coster–Kronig Transitions from the Xe 4s Core-Hole State”, Phys. Chem. Chem.
Phys. 24 (2022) 17535.
M. Ito, N. Tomioka, M. Uesugi, A. Yamaguchi, N. Shirai, T. Ohigashi, M-C. Liu, R. C. Greenwood, M. Kimura,
N. Imae, K. Uesugi, A. Nakato, K. Yogata, H. Yuzawa, Y. Kodama, A. Tsuchiyama, M. Yasutake, R. Findlay,
I. A. Franchi, J. A. Malley, K. A. McCain, N. Matsuda, K. D. McKeegan, K. Hirahara, A. Takeuchi, S. Sekimoto,I. Sakurai, I. Okada, Y. Karouji, M. Arakawa, A. Fujii, M. Fujimoto, M. Hayakawa, N. Hirata, N. Hirata, R. Honda,
C. Honda, S. Hosoda, Y. Iijima, H. Ikeda, M. Ishiguro, Y. Ishihara, T. Iwata, K. Kawahara, S. Kikuchi, K. Kitazato,
K. Matsumoto, M. Matsuoka, T. Michikami, Y. Mimasu, A. Miura, O. Mori, T. Morota, S. Nakazawa, N. Namiki,
H. Noda, R. Noguchi, N. Ogawa, K. Ogawa, T. Okada, C. Okamoto, G. Ono, M. Ozaki, T. Saiki, N. Sakatani,
H. Sawada, H. Senshu, Y. Shimaki, K. Shirai, S. Sugita, Y. Takei, H. Takeuchi, S. Tanaka, E. Tatsumi, F. Terui,
R. Tsukizaki, K. Wada, M. Yamada, T. Yamada, Y. Yamamoto, H. Yano, Y. Yokota, K. Yoshihara, M. Yoshikawa,
K. Yoshikawa, R. Fukai, S. Furuya, K. Hatakeda, T. Hayashi, Y. Hitomi, K. Kumagai, A. Miyazaki, M. Nishimura,
H. Soejima, A. Iwamae, D. Yamamoto, M. Yoshitake, T. Yada, M. Abe, T. Usui, S. Watanabe and Y. Tsuda“A pristine record of outer Solar System materials from asteroid Ryugu’s returned sample”, Nature Astronomy
6 (2022) 1163.
T. Kaneyasu, M. Hosaka, A. Mano, Y. Takashima, M. Fujimoto, E. Salehi, H. Iwayama, Y. Hikosaka and M. Katoh“Double-pulsed wave packets in spontaneous radiation from a tandem undulator”, Scienctific reports 12(2022) 9682.

− 183 −

T. Kaneyasu, Y. Hikosaka, M. Fujimoto, H. Iwayama and M. Katoh“Coherent Control of Atoms in the Extreme Ultraviolet and Attosecond Regime by Synchrotron Radiation”,
J. Phys.:Conf. Ser. 2380 (2022) 012115.
T. Kato, Y. Li, K. Nakayama, Z. Wang, S. Souma, F. Matsui, M. Kitamura, K. Horiba, H. Kumigashira, T. Takahashi,
Y. Yao and T. Sato
“Fermiology and Origin of Tc Enhancement in a Kagome Superconductor Cs(V1-xNbx)3Sb5”, Phys. Rev.
Lett. 129 (2022) 206402.
H. Kawaguchi, T. Muramatsu, M. Katoh, M. Hosaka and Y. Takashima“Time-Domain Eddy Current and Wake Fields Analysis of Pulsed Multipole Magnet Beam Injector in
Synchrotron Radiation Ring”, IEICE Trans. Electron. E105-C-4 (2022) 146.
T. Kawasaki, Y. Yamaguchi, H. Kitahara, A. Irizawa and M. Tani
“Exploring Biomolecular Self-Assembly with Far-Infrared Radiation”, Biomolecules 12 (2022) 1326.
S. Kimura, H. Watanabe, S. Tatsukawa and H. Tanida“Observation of Electronic Structure Modification in the Hidden Order Phase of CeCoSi”, J. Phys. Soc. Jpn.
92 (2023) 043704.
M. Kitaura, Y. Taira and S. Watanabe“Characterization of imperfections in scintilator crystals using gamma-ray induced positron annihilation
lifetime spectroscopy”, Optical Materials: X 14 (2022) 100156.
P. Krüger and F. Matsui“Observation and theory of strong circular dichroism in angle-revolved photoemission from graphite”, J.
Electron Spectrosc. Relat. Phenom. 258 (2022) 147219.
K. Kubota and T. Kawai“Optical characteristics of Tl+ centers in CsCaCl3, KCaCl3, and CsCl crystals”, J. Phys. Chem. Solids163(2022) 110592.
S. Kusaka, T. T. Sasaki, K. Sumida, S. Ichinokura, S. Ideta, K. Tanaka, K. Hono and T. Hirahara“Fabrication of (Bi2)m(Bi2Te3)n superlattice films by Te desorption from a pristine Bi2Te3 film”, Appl. Phys.
Lett. 120 (2022) 173102.
F. Matsui, Y. Okano, H. Matsuda, T. Yano, E. Nakamura, S. Kera and S. Suga
“Domain-Resolved Photoelectron Microscopy and micrometer-scale Momentum-Resolved Photoelectron
Spectroscopy of Graphite Armchair Edge Facet”, J. Phys. Soc. Jpn. 91 (2022) 094703.
F. Matsui and S. Suga
“Coupling of kz-dispersing π bands with surface localized states in graphite”, Phys. Rev. B 105 (2022) 235126.
H. Murata, T. Nakamura, R. Kawanabe, Y. Tokudome and A. Nakahira“Reaction of Stoichiometric Hydroxyapatite with Diﬀerent Crystallinity in Mg2+ Aqueous Solution”, J.
Ceram. Soc. Jpn. 131 (2023) 8.
D. Nabok, M. Tas, S. Kusaka, E. Durgun, C. Friedrich, G. Bihlmayer, S. Blügel, T. Hirahara and I. Aguilera“Bulk and surface electronic structure of Bi4Te3 from GW calculations and photoemission experiments”,
Phys. Rev. Mat. 6 (2022) 034204.
M. Nagasaka, M. Bouvier, H. Yuzawa and N. Kosugi“Hydrophobic Cluster Formation in Aqueous Ethanol Solutions Probed by Soft X-ray Absorption
Spectroscopy”, J. Phys. Chem. B 126 (2022) 4948.

− 184 −

Ⅳ List of Publications

M. Nagasaka“Site Selective Analysis of Water in Hydrogen Bond Network of Aqueous Dimethyl Sulfoxide Solutions by
Oxygen K-edge X-ray Absorption Spectroscopy”, J. Mol. Liq. 366 (2022) 120310.
M. Nagasaka“Carbon K-edge X-ray Absorption Spectra of Liquid Alcohols from Quantum Chemical Calculations ofLiquid Structures Obtained by Molecular Dynamics Simulations”, J. Chem. Phys. 158 (2023) 024501.
T. Nakamura, T. Nakaya, Y. Ohtsubo, H. Sugihara, K. Tanaka, R. Yukawa, M. Kitamura, H. Kumigashira, K. Imura,
H. S. Suzuki, N. K. Sato and S. Kimura“Surface valence transition in SmS by alkali metal adsorption”, Phys. Rev. B 107 (2023) L041102.
H. Ota, E. Salehi, M. Fujimoto, K. Hayashi, T. Horigome, H. Iwayama, M. Katoh, N. Kondo, S. Makita, F. Matsui,
H. Matsuda, T. Mizukawa, A. Minakuchi, E. Nakamura, M. Nagasaka, Y. Okano, T. Ohigashi, M. Sakai, K. Sugita,
K. Tanaka, Y. Taira, F. Teshima, J. Yamazaki, T. Yano, H. Yuzawa and S. Kera“UVSOR Synchrotron Facility Update”, J. Phys.: Conference Series. 2380 (2023) 012003.
E. Salehi, Y. Taira, M. Fujimoto, L. Guo and M. Katoh“Lattice design of the UVSOR-IV storage ring”, J. Phys.: Conf. Ser. 2420 (2023) 012062.
K. Sun, O. J. Silveira, Y. Ma, Y. Hasegawa, M. Matsumoto, S. Kera, O. Krejčí, A. S. Foster and S. Kawai“On-surface synthesis of disilabenzene-bridged covalent organic frameworks”, Nature Chemistry 14 (2022)
1071.
I. Suzuki, S. Kawanishi, K. Tanaka, T. Omata, S. Tanaka“Contribution of the Sn 5s state to the SnS valence band: direct observation via ARPES measurements”,
Electronic Structure 4 (2022) 025004.
I. Suzuki, S. Kawanishi, K. Tanaka, T. Omata and S. Tanaka“Experimental Identification of Atomic Orbital Contributions to SnS Valence Band using PolarizationDependent Angle-Resolved Photoemission Spectroscopy”, Phys. Status Solidi B (2023) 2200408.
Y. Taira, R. Yamamoto, K. Sugita, Y. Okano, T. Hirade, S. Namizaki, T. Ogawa and Y. Adachi“Development of gamma-ray-inducedpositron age–momentum correlationmeasurement”, Rev. Sci. Instrum.
93 (2022) 113304.
R. Takahashi, A. Hu, P. Gao, Y. Gao, Y. Pang, T. Seo, J. Jiang, S. Maeda , H. Takaya, K. Kubota and H. Ito“Mechanochemical synthesis of magnesium-based carbon nucleophiles in air and their use in organic
synthesis”, Nature Commun. 12 (2021) 6691.
Y. Takebuchi, M. Koshimizu, T. Kato, D. Nakauchi, N. Kawaguchi and T. Yanagida“Evaluation of Radiation-induced Luminescence Properties of Tb-doped LiCaPO4”, Radiation Physics andChemistry 197 (2022) 110180.
Y. Yamada, K. Morita, T. Sugiura, Y. Toyoda, N. Mihara, M. Nagasaka, H. Takaya, K. Tanaka, T. Koitaya,
N. Nakatani, H. Ariga-Miwa, S. Takakusagi, Y. Hitomi, T. Kudo, Y. Tsuji, K. Yoshizawa and K. Tanaka“Stacking of Cofacially Stacked Iron Phthalocyanine Dimer on Graphite Achieved High Catalytic CH4
Oxidation Activity Comparable to that of pMMO”, JACS Au 3 (2023) 823.
W. Zhang, E. Hosono, D. Asakura, H. Yuzawa, T. Ohigashi, M. Kobayashi, H. Kiuchi and Y. Harada“Chemical-state distributions in charged LiCoO2 cathode particles visualized by soft X-ray spectromicroscopy”,
Scientific Reports. 13 (2023) 4639.

− 185 −UVSOR User 9ტWorkshops

Ⅴ Workshops

UVSOR Symposium 2022
Date: November 26-27, 2022
Place: Okazaki Conference Center (face-to face), Zoom (online)

November 26th (Sat.)
13:00 ‑ 13:05

Opening remarks
H. Iwayama (UVSOR)<Session 1, Chair: F. Matsui (UVSOR)>
13:05 ‑ 13:25

Current status of UVSOR facilities and plans for the next fiscal year
S. Kera (UVSOR Director)

13:25 ‑ 13:45

LATTICE DESIGN FOR FUTURE PLAN OF UVSOR
E. Salehi (UVSOR)

13:45 ‑ 14:05

Applications of attosecond-controlled double pulses generated by tandem undulator
T. Kaneyasu (SAGA LS)

14:05 ‑ 14:35[Invited Lectures] Coordinated STXM-NEXAFS and TEM analysis of organic materials insamples returned by asteroid Ryugu
M. Uesugi (JASRI)

14:35 ‑ 14:50

Break Time

<Session 2, Chair: M. Kitaura (Yamagata Univ.)>
14:50 ‑ 15:20[Invited Lectures] Investigation of Active Organometallic Species by Soft-X-ray XAS
H. Takaya (Teikyo Univ. of Science)

15:20 ‑ 15:40

Structural and magnetic properties of FeNi and FeCo alloy thin films on Cu (001) grown by
nitrogen surfactant epitaxy
T. Miyamachi (Nagoya Univ.)

15:40 ‑ 16:00

Evaluation of X-ray photon counting capability of CMOS sensor aboard FOXSI-4 sounding
rocket for solar flare observation
R. Shimizu (SOKENDAI)

16:00 ‑ 16:20

Luminescence Properties of NaCl:Tl+ and NaCl:Au- Crystals
T. Kawai (Osaka Metropolitan Univ.)

16:20 ‑ 16:35

Break Time

16:35 ‑ 17:20

Short Presentation for Poster Session (Online video streaming)

17:30 ‑ 18:15

Poster Session (Remo) First half (Odd poster number)

18:15 ‑ 19:00

Poster Session (Remo) Second half (Even poster number)

19:00 ‑ 21:00

Banquet− 189 −

November 27th (Sun.)<Session 3, Chair: Y. Hikosaka (Toyama Univ.)>
9:00 ‑ 9:20

Exploring biopolymer aggregations with intense infrared radiation
T. Kawasaki (KEK)

9:20 ‑ 9:40

Current Status of Spin-Resolved ARPES at BL5U and Development for Automatic
Measurement at BL5U and BL7U
K. Tanaka (UVSOR)

9:40 ‑ 10:00

Surface valence transition in SmS by alkali metal adsorption
T. Nakamura (Osaka Univ.)

10:00 ‑ 10:20

Momentum-resolved resonant photoelectron spectroscopy at the Ti2p-3d edge of TiSe2:
interatomic interaction and negative q in Fano resonance.
S. Tanaka (Osaka Univ.)

10:20 ‑ 10:50[Invited Lectures] Spectroscopic study on the topological quantum phenomena of 2D magnets
T. Hirahara (Tokyo Inst. of Tech.)

10:50 ‑ 11:00

Break Time

11:00 ‑ 12:00

UVSOR USERS’ UNION meeting− 190 −

Ⅴ Workshops

The 5th workshop on prospects and construction plan of the next generationsynchrotron radiation facility: Cooperation between facilities II
Date: November 27, 2022
Place: Okazaki Conference Center (face-to face), Zoom (online)

November 27th (Sun.)
13:00 ‑ 13:30

Present status of NanoTerasu
H. Yamane ( PhoSiC )13:30 ‑ 14:00

Present status of AichiSR
T. Okajima ( AichiSR )14:00 ‑ 14:30

Future plan of AichiSR
H. Sonoeda ( AichiSR )14:30 ‑ 15:00

Progress on the future plan of UVSOR
S. Kera ( UVSOR Director )15:00 ‑ 15:30

General Discussion: cooperation between NanoTerasu, AichiSR and UVSOR
Partnership between NanoTerasu, AichiSR, and UVSOR− 191 −IMS Symposium“Resonant Soft X-ray Scattering and Reflectivity”
Date: November 8th, 2022
Place: Zoom Conference

November 8th (Tue.)
10:00 ‑ 10:10

Welcome & Introduction
T. Araki (Diamond Light Source)

10:10 ‑ 11:00

Keynote Lecture
Probing Morphology and Chemistry in Complex Soft Materials with In Situ Resonant Soft
X-ray Scattering
C. Wang (Advanced Light Source)

11:00 ‑ 11:15

Break

11:15 ‑ 11:40

Resonant X-Ray Scattering and Reflectivity Measurements of EUV Photoresist at
NewSUBARU Synchrotron Light Facility
T. Harada (Univ. of Hyogo)

11:40 ‑ 12:05

Development of Resonant Soft X-ray Scattering Equipment at UVSOR and Photon Factory
H. Iwayama (UVSOR)

12:05 ‑ 12:30

Concept of Thin Film Analysis Instrument with Soft X-ray Reflectometry and Absorption
Spectroscopy Under Wet Conditions
N. L. Yamada (KEK)

12:30 ‑ 13:30

Lunch Break

13:30 ‑ 13:55

Anomalous Small-angle Scattering of Alloys in Tender X-rays Region
H. Okuda (Kyoto Univ.)

13:55 ‑ 14:25

Nano-structure of Polymer Film Analyzed by Small Angle Scattering and Reflectivity Utilizing
Tender X-rays at BL15A2 in PF
K. Yamamoto (Nagoya Institute of Technology)

14:25 ‑ 14:50

Neutron Analysis of Polymer Electrolyte Fuel Cells
M. Harada (Toyota Central R&D Labs. Inc.)

14:50 ‑ 15:05

Break

15:05 ‑ 15:30

The Structure Analysis of Liquid Crystals by Resonant Soft X-ray Scattering
Y. Takanishi (Kyoto Univ.)

15:30 ‑ 15:55

Solvent-Induced Transition of Polymorphological Chiral Supermolecular Architectures in a
Bent-Core Liquid Crystal Dimer
F. Araoka (RIKEN)

15:55 ‑ 16:20

Characterizing Self-Assembled Nanoparticles of Drug Delivery by use of Solution Scattering
K. Sakurai (Univ. of Kitakyushu)

16:20 ‑ 16:30

Break

16:30 ‑ 17:10

Discussion

17:10 ‑ 17:15

Closing
S. Kera (IMS)− 192 −

Ⅴ Workshops

IMS Symposium“Symposium on Generation and Advanced Use of Various Quantum Beams in
UVSOR-III”
Date: November 28, 2022
Place: Okazaki Conference Center (face-to face), Zoom (online)

November 28th (Mon.)
8:50 ‑ 9:00

Purpose Definition
Y. Taira (UVSOR)<Chair: Y. Taira (UVSOR)>
9:00 ‑ 9:30

History of UVSOR light source development beamlines
M. Katoh (Hiroshima Univ.)

9:30 ‑ 10:00

Free electron laser development, utilization and future prospects
H. Zen (Kyoto Univ.)

10:00 ‑ 10:30

Development of coherent higher harmonic light sources in UVSOR
F. Sakamoto (National Inst. of Tech., Akita College)

10:30 ‑ 10:40

Break Time

<Chair: H. Zen (Kyoto Univ.)>
10:40 ‑ 11:10

Generation of attosecond controlled double pulses by tandem undulators and their application
to atomic and molecular experiments
T. Kaneyasu (SAGA LS)

11:10 ‑ 11:40

Control of spatio-temporal structure of synchrotron radiation and its potential applications
M. Katoh (Hiroshima Univ.)

11:40 ‑ 12:10

Study on chirality emergence in organic molecules by irradiation of ultraviolet circularly
polarized light
M. Kobayashi (Natl. Inst. for Fusion Sci.)

12:10 ‑ 13:30

Lunch Time

<Chair: M. Katoh (Hiroshima Univ.)>
13:30 ‑ 14:00

Development and utilization of gamma-ray source in UVSOR-III and its future development
Y. Taira (UVSOR)

14:00 ‑ 14:30

Current status of the NewSUBARU gamma-ray beamline BL01
S. Hashimoto (Univ. of Hyogo)

14:30 ‑ 15:00

Nuclear physics experiments using gamma-rays and their applications
H. Ohgaki (Kyoto Univ.)

15:00 ‑ 15:10

Break Time− 193 −

<Chair: H. Ohgaki (Kyoto Univ.)>
15:10 ‑ 15:40

Development and application of polarization detection Compton camera
K. Shimazoe (Tokyo Univ.)

15:10 ‑ 15:40

Fundamentals of positron annihilation method and expectations for pulsed gamma-ray induced
positron generator
M. Fujinami (Chiba Univ.)

16:10 ‑ 16:40

Probing the eﬀect of impurity addition to luminescent materials by looking at atomic vacancies
M. Kitaura (Yamagata Univ.)− 194 −UVSOR User 10

UVSOR User 11

Facts and Figures

Number of report

UVSOR ACTIVITY REPORT FIELDS STATISTICS
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0

6

7

26

8

20

14

14

60

13
2013

13

21

22

16

13

16

17
56

15

31

27

15

22

11

10

18

9

18

18

20

19

13
65

54

46

21
19

51

43

48

60

9

11

12

7

10

13

15

18

25

2014

2015

2016

2017

2018

2019

2020

2021

2022

38

Accelerators and Instruments

Material Sciences

Chemistry

Surface, Interface and Thin Films

Life, Earth and Planetary Sciences

NUMBER OF PAPERS
35

BL8B
BL7B

number of papers

30

BL6B
BL5B

25

BL4B

20

BL3B

15

BL2A

BL2B
BL1B

10

OthersLight Source

50Accelerators
BL7U

U

B

2012

U

B

2013

U

B

2014

U

B

2015

U

B

2016

U

B

2017

B : bending magnet

U

B

2018

U

B

U

2019

U : undulator− 198 −

B

2020

U

B

2021

U

B

2022

BL6U
BL5U
BL4U
BL3U
BL1U

Facts and Figures

NUMBER OF
OF USERSNUMBER
USERS
5000
5,000
4500
4,500
4000
4,000

39
341
458

4
311
235

Number of users
Number of users

3500
3,500
3000
3,000

34
518

25
630

538

406

3,406

3,376

29
549

43
692

63
417

51
719

489

472

623

326

3,480

3,526

3,506

3,562

61
743
36

70
424
140

45
580
73

2500
2,500
2000
2,000

3,396

3,246

1500
1,500

4,153

3934

3,056

1000
1,000
500 500
0

0 0

0

0

0

0 2 0 1 2 0 2 0 1 3 0 2 0 1 4 02 0 1 5

0

02 0 1 60

02 0 1 70

20 0 1 8

0

200 1 90200 2 0

0

2021

0

2 002 2

JapaneseJapanese private
private companies
companies
IMS
Overseas universities
universities andand researchresearch institutions
institutions
Overseas
Universities and Research Institutes in Japan
Universities and Research Institutes in JapanOPERATING HOURS
3500
3000
2500

Hour

2000
1500
1000
500
0

2012

2013

2014

2015

2016

2017

Annual operation / hour

− 199 −

2018

2019

2020

User beamtime / hour2021

Institute for Molecular Science
National Institutes of Natural Sciences
Okazaki 444-8585, Japan
Tel : +81-564-55-7402
Fax: +81-564-54-7079
http://www.uvsor.ims.ac.jp
Editorial Board: H. Katayanagi, K. Tanaka, H. Iwayama,
M. Ishihara, K. Kamo