|
 |
2022年3月以前の論文（岡本）
110. Large Magnetic-Field-Induced Strain at the
Spin-Reorientation Transition in A-Site Ordered Spinel Oxide LiFeCr4O8,
Yoshihiko Okamoto*, Tomoya Kanematsu, Yuki
Kubota, Takeshi Yajima, and Koshi Takenaka,
J. Phys. Soc. Jpn.
91, 023710 (2022)
(arXiv:2201.01897).
109. Structural Phase Transition and Negative Thermal
Expansion in Cu1.8Zn0.2V2–xPxO7 Solid Solutions,
Koshi Takenaka*, Masato
Kano, Ryota Kasugai, Kohei Takada, Koki Eto, Yoshifuji Kadowaki, Yasunori
Yokoyama, Naoyuki Katayama, and Yoshihiko Okamoto,
Appl.
Phys. Express 15, 025504 (2022).
108. Charge-Ordered State Satisfying the Anderson
Condition in LiRh2O4 Arising from Local Dimer Order,
Manabu Shiomi, Keita
Kojima, Naoyuki Katayama*, Shin Maeda, John A. Schneeloch, Syunsuke Yamamoto,
Koudai Sugimoto, Yukinori Ohta, Despina Louca, Yoshihiko Okamoto, Hiroshi Sawa,
Phys. Rev. B 105, L041103 (2022) (arXiv:2112.07118).
107. Structural Phase Transition and Giant Negative
Thermal Expansion in Pyrophosphate Zn2-xMgxP2O7,
Y. Kadowaki, R. Kasugai, Y.
Yokoyama, N. Katayama, Y. Okamoto, and K.
Takenaka*,
Appl.
Phys. Lett. 119, 201906 (2021).
(プレスリリース：環境にやさしい「温めると縮む」新材料発見
～電子デバイス分野を中心に幅広い応用に期待～)
(報道：化学工業日報2021年11月26日「温めると縮む新材料 熱膨張制御、電材向け 名古屋大が発見」)
106. Giant Negative Thermal Expansion of Polycrystalline
Ti2O3 Induced by Microstructural Effects,
Y. Kadowaki, R. Kasugai, Y.
Yokoyama, N. Katayama, Y. Okamoto, and K.
Takenaka*,
Appl.
Phys. Lett. 119, 171901 (2021).
105. Superconductivity in Nb2Pd3Te5 and
Chemically-Doped Ta2Pd3Te5,
Naoya Higashihara, Yoshihiko Okamoto*, Yuma
Yoshikawa, Youichi Yamakawa, Hiroshi Takatsu, Hiroshi Kageyama, and Koshi
Takenaka,
J. Phys. Soc.
Jpn. 90, 063705(1-4) (2021)
(arXiv:2105.01886).
(JPSJ Editors' Choice)
(JPSJ注目論文：そっくりな元素からなる物質に現れた超伝導と奇妙な絶縁体状態)
(報道：科学新聞2021年6月25日「同じ電子数・結晶構造なのに全く異なる物性 超伝導体、絶縁体に分かれる 名古屋大が解明」)
104. Large Magnetic-Field-Induced Strain
at the Magnetic Order Transition in Triangular Antiferromagnet AgCrS2,
Tomoya Kanematsu,
Yoshihiko Okamoto*, and Koshi Takenaka,
Appl. Phys. Lett.
118, 142404(1-5) (2021) (arXiv:2104.03471).
(プレスリリース：磁場により体積が大きく膨張する新機構の発見)
(報道：マイナビニュース2021年4月12日「名大、磁場を加えると従来にない機構で体積が大きく膨張する物質を発見」)
103. Emergence of Unconventional
Superconductivity in a Two-Dimensional sp Semimetal with Topological
Nodal Lines,
Yoshihiko Okamoto,
JPSJ News
Comments 18, 05 (2021).
102. Giant Magneto-Volume and
Magneto-Caloric Effects of Frustrated Antiferromagnet Mn3GaN under Hydrostatic
Pressure,
Koshi Takenaka*, Takuto Sugiura, Yoshifumi Kadowaki, Masaki Ozeki,
Yoshihiko Okamoto, and Asaya Fujita,
J. Phys. Soc. Jpn.
90, 044601(1-7) (2021).
101. Fabrication of Metal Matrix
Composite Containing Manganese Nitride Showing Giant Negative Thermal Expansion
by Compressive Torsion Processing,
Koshi Takenaka*, Kentaro Otsuka, Yoshihiko Okamoto,
Yuji Kume, and Makoto Kobashi,
Mater. Trans. 62,
590-595 (2021).
100. Large Thermoelectric Power Factor
in Whisker Crystals of Solid Solutions of the One-Dimensional Tellurides
Ta4SiTe4 and Nb4SiTe4,
Yuma Yoshikawa, Taichi Wada,
Yoshihiko Okamoto*, Yasuhiro Abe, and Koshi Takenaka,
Appl.
Phys. Express 13, 125505(1-4) (2020)
(arXiv:2011.10162).
99. Electrical and Thermal Transport
Properties of the β-Pyrochlore Oxide CsW2O6,
Yoshihiko Okamoto*, Kenta Niki, Rikuto Mitoka, and Koshi Takenaka,
J. Phys. Soc. Jpn.
89, 124710(1-5) (2020)
(arXiv:2010.11404).
98. High-Mobility Carriers Induced by
Chemical Doping in the Candidate Nodal-Line Semimetal CaAgP,
Yoshihiko Okamoto*, Kazushige Saigusa, Taichi
Wada, Youichi Yamakawa, Ai Yamakage, Takao Sasagawa, Naoyuki Katayama, Hiroshi
Takatsu, Hiroshi Kageyama, and Koshi Takenaka,
Phys. Rev. B
102, 115101(1-6) (2020) (arXiv:2008.06188).
97. Annealing Effects on Negative
Thermal Expansion Properties of Ball-Milled β-Cu1.8Zn0.2V2O7 Fine Particles,
V. Warne-Lang, M. Sato, M. Ozeki, Y. Kadowaki, Y. Yokoyama, N. Katayama, Y.
Okamoto, and K. Takenaka*,
Ceram. Int.
46, 27655-27659 (2020).
96. Sol-Gel Synthesis of Doped Cu2V2O7
Fine Particles Showing Giant Negative Thermal Expansion,
M. Sato, V. Warne-Lang, Y. Kadowaki, N. Katayama, Y.
Okamoto, and K. Takenaka*,
AIP Advances 10,
075207(1-6) (2020) (open access) .
95. Regular-Triangle Trimer and Charge
Order Preserving the Anderson Condition in the Pyrochlore Structure of CsW2O6,
Yoshihiko Okamoto*, Haruki Amano, Naoyuki
Katayama, Hiroshi Sawa, Kenta Niki, Rikuto Mitoka, Hisatomo Harima, Takumi
Hasegawa, Norio Ogita, Yu Tanaka, Masashi Takigawa, Yasunori Yokoyama, Kanji
Takehana, Yasutaka Imanaka, Yuto Nakamura, Hideo Kishida, and Koshi Takenaka,
Nat. Commun. 11,
3144(1-8) (2020) (open access) (arXiv:2006.11053).
(プレスリリース：固体物質における正三角形の分子の形成をとらえた！)
(Press
Release：Unusual
electron sharing found in cool crystal)
(報道：科学新聞2020年7月3日「名古屋大など 正三角形の分子形成 固体物質で初の発見」)
(紹介記事：academist Journal
2020年7月27日 「固体物質における「正三角形の分子」をとらえた！ – パイロクロア構造に現れた新しいタイプの電子の自己組織化」)
(解説動画：新学術領域研究「量子液晶」QLCチャンネル）
94. Thermal Expansion and Volume
Magnetostriction in Breathing Pyrochlore Magnets LiACr4X8 (A = Ga, In, X = O,
S),
Tomoya Kanematsu, Masaki Mori, Yoshihiko Okamoto*,
Takeshi Yajima, and Koshi Takenaka,
J. Phys. Soc.
Jpn. 89, 073708(1-4) (2020) (arXiv:2006.06187).
93. Annealing Effect on Local Structure
and Negative Thermal Expansion of Antiperovskite Manganese Nitride Fine
Particles,
Masaki Ozeki, Victoria Warne-Lang, Hirofumi Tsukasaki, Yuki Sakai, Naoyuki
Katayama, Yoshihiko Okamoto, Masaki Azuma,
Shigeo Mori, and Koshi Takenaka*,
Appl. Phys. Express 13, 075501(1-5) (2020).
92. Zero-Energy Excitation in Classical
Kagome Antiferromagnet NaBa2Mn3F11,
Shohei Hayashida, Hajime Ishikawa, Yoshihiko Okamoto,
Tsuyoshi Okubo, Zenji Hiroi, Gøran J.
Nilsen, Hannu Mutka, and Takatsugu Masuda,
Phys. Rev. B
101, 214409(1-6) (2020)
(arXiv:2006.01526).
91. Real Spin and Pseudospin Topologies
in the Noncentrosymmetric Topological Nodal-Line Semimetal CaAgAs,
Hishiro T. Hirose*, Taichi Terashima, Taichi Wada, Yoshitaka Matsushita,
Yoshihiko Okamoto, Koshi Takenaka, and Shinya
Uji,
Phys. Rev. B 101, 245104(1-10) (2020) (arXiv:2002.05597).
90. スプレードライ法によるβ-Cu1.8Zn0.2V2O7セラミック微粒子の負熱膨張特性、
竹中康司*、佐藤みく、西川智洋、大村卓也、山田展也、横山泰範、片山尚幸、岡本佳比古、
日本金属学会誌 84,
161-166 (2020).
89. Magnetization Process of the
Breathing Pyrochlore Magnet CuInCr4S8 in Ultra-High Magnetic Fields up to 150 T,
Masaki Gen*, Yoshihiko Okamoto, Masaki Mori,
Koshi Takenaka, and Yoshimitsu Kohama*,
Phys. Rev. B 101, 054434(1-9) (2020) (arXiv:1910.01315).
88. Spray-Dry
Synthesis of β-Cu1.8Zn0.2V2O7 Ceramic Fine Particles Showing Giant Negative
Thermal Expansion,
Koshi Takenaka*, Miku Sato, Masaya Mitamura, Yasunori Yokoyama, Naoyuki Katayama,
and Yoshihiko Okamoto,
J. Am. Ceram. Soc. 103, 2757-2763 (2020).
87. Effects of Y Substitution on the
Electronic Structure and Charge Dynamics of SmS,
Y. Yokoyama*, H. Hasegawa, Y. Mizuno, D. Asai,
Y. Okamoto, H. S. Suzuki, K. Takehana, Y.
Imanaka, and K. Takenaka,
Phys. Rev. B 100, 245143(1-7) (2019).
86. Superconductivity in PtSbS with a
Noncentrosymmetric Cubic Crystal Structure,
Ryosuke Mizutani, Yoshihiko Okamoto*, Hayate
Nagaso, Youichi Yamakawa, Hiroshi Takatsu, Hiroshi Kageyama, Shunichiro Kittaka,
Yohei Kono, Toshiro Sakakibara, and Koshi Takenaka,
J. Phys.
Soc. Jpn. 88, 093709(1-4) (2019)
(arXiv:1908.11507).
85.
Hole-Doped M4SiTe4 (M = Ta, Nb) as an Efficient p-Type
Thermoelectric Material for Low-Temperature Applications,
Yoshihiko Okamoto*, Yuma Yoshikawa, Taichi Wada, and Koshi Takenaka,
Appl.
Phys. Lett. 115, 043901(1-5) (2019)
(arXiv:1907.10254).
(Editor's Pick)
(プレスリリース：低温用の熱電素子に使用できる高性能材料の発見)
(報道：化学工業日報2019年7月30日「低温冷却素子に高性能材料 名古屋大」他)
(紹介記事：低温用の熱電素子に使用できる高性能材料,
岡本佳比古,
クリーンエネルギー 29, 1, 46-50 (2020).)
84.
Orbital Transitions and Frustrated Magnetism in the Kagome-Type Copper Mineral
Volborthite,
Zenji Hiroi*, Hajime Ishikawa, Hiroyuki Yoshida, Jun-ichi Yamaura, and Yoshihiko Okamoto,
Inorg.
Chem. 58, 11949-11960 (2019).
83.
Rattling Behavior in a Simple Perovskite NaWO3,
Yuya Ikeuchi, Hiroshi Takatsu, Cedric Tassel, Craig M. Brown,
Taito Murakami, Yuki Matsumoto, Yoshihiko Okamoto, and
Hiroshi Kageyama*,
Inorg. Chem.
58, 6790-6795 (2019).
82.
Valence Fluctuations and Giant Isotropic Negative Thermal
Expansion in Sm1-xRxS (R = Y, La, Ce, Pr, Nd),
D. Asai, Y. Mizuno, H. Hasegawa, Y. Yokoyama, Y. Okamoto,
N. Katayama, H. S. Suzuki, Y. Imanaka, and K. Takenaka*,
Appl.
Phys. Lett. 114, 141902(1-5) (2019).
81.
Giant Isotropic Negative Thermal Expansion in Y-Doped Samarium
Monosulfides by Intra-Atomic Charge Transfer,
Koshi Takenaka*, Daigo Asai, Ryoichi Kaizu, Yosuke Mizuno,
Yasunori Yokoyama, Yoshihiko Okamoto, Naoyuki Katayama,
Hiroyuki S. Suzuki, and Yasutaka Imanaka,
Sci. Rep.
9, 122(1-8) (2019). (open access)
(プレスリリース：「温めると縮む」革新的な新材料を開発！～電子デバイスや精密機器の熱膨張制御に期待～)
(報道：日本経済新聞2019年1月21日「半導体などの熱膨張を抑制」他)
80.
Ultra-High Magnetic Field Magnetic Phases up to 130 T in a
Breathing Pyrochlore Antiferromagnet LiInCr4O8,
Masaki Gen, Daisuke Nakamura, Yoshihiko Okamoto, and
Shojiro Takeyama*,
J. Magn.
Magn. Mater. 473, 387-393 (2019).
79.
Microstructural Effects on Negative Thermal Expansion Extending
over a Wide Temperature Range in β-Cu1.8Zn0.2V2O7,
N. Katayama*, K. Otsuka, M. Mitamura, Y. Yokoyama, Y. Okamoto,
and K. Takenaka,
Appl.
Phys. Lett. 113, 181902(1-5) (2018).
78.
Extended Operating Temperature Window of Giant Negative Thermal
Expansion in Sn-Doped Ca2RuO4,
K. Takenaka*, N. Inoue, Y. Mizuno, Y. Okamoto, N. Katayama,
Y. Sakai, T. Nishikubo, and M. Azuma,
Appl.
Phys. Lett. 113, 071902(1-5) (2018).
77.
Inelastic Neutron Scattering Study of the Spin Dynamics in the
Breathing Pyrochlore System LiGa0.95In0.05Cr4O8,
Yu Tanaka, Rafal Wawrzynczak*, Manh Duc Le, Tatiana Guidi, Yoshihiko
Okamoto, Takeshi Yajima, Zenji Hiroi, Masashi Takigawa, and Gøran J.
Nilsen*,
J. Phys.
Soc. Jpn. 87, 073710(1-4) (2018).
76.
Large Thermoelectric Power Factor in One-Dimensional Telluride Nb4SiTe4
and Substituted Compounds,
Yoshihiko Okamoto*, Taichi Wada, Youichi Yamakawa, Takumi
Inohara, and Koshi Takenaka,
Appl.
Phys. Lett. 112, 173905(1-5) (2018) (arXiv:1804.09867).
75.
Magnetic and Structural Properties of A-Site Ordered Chromium
Spinel Sulfides: Alternating Antiferromagnetic and Ferromagnetic
Interactions in the Breathing Pyrochlore Lattice,
Yoshihiko Okamoto*, Masaki Mori, Naoyuki Katayama, Atsushi
Miyake, Masashi Tokunaga, Akira Matsuo, Koichi Kindo, and Koshi
Takenaka,
J. Phys.
Soc. Jpn. 87, 034709(1-8) (2018) (arXiv:1801.07354).
74.
Magnetic State Selected by Magnetic Dipole Interaction in the
Kagome Antiferromagnet NaBa2Mn3F11,
Shohei Hayashida, Hajime Ishikawa, Yoshihiko Okamoto,
Tsuyoshi Okubo, Zenji Hiroi, Maxim Avdeev, Pascal Manuel, Masato
Hagihala, Minoru Soda, and Takatsugu Masuda,
Phys.
Rev. B, 97, 054411(1-7) (2018) (arXiv:1712.06740).
73.
Observation of Dirac-Like Energy Band and Ring-Torus Fermi
Surface Associated with the Nodal Line in Topological Insulator
CaAgAs,
Daichi Takane, Kosuke Nakayama, Seigo Souma, Taichi Wada, Yoshihiko
Okamoto, Koshi Takenaka, Youichi Yamakawa, Ai Yamakage,
Taichi Mitsuhashi, Koji Horiba, Hiroshi Kumigashira, Takashi
Takahashi, and Takafumi Sato*,
npj
Quamtum Mater. 3, 1(1-6) (2018) (open access) (arXiv:1708.06874).
(プレスリリース：ミラー対称性による新型トポロジカル絶縁体を発見～高効率電子デバイスの開発に光～)
(報道：オプトロニクスオンライン2018年1月12日「東北大ら、キラリティーが特徴のトポロジカル絶縁体を発見」他)
72.
Direct Visualization of Orbital-Flipping in Volborthite by Charge
Density Analysis using Detwinned Data,
Kento Sugawara, Kunihisa Sugimoto*, Tatsuya Fujii, Takafumi
Higuchi, Naoyuki Katayama, Yoshihiko Okamoto, and Hiroshi
Sawa*,
J. Phys.
Soc. Jpn. 87, 024601(1-5) (2018).
71.
Spin Dynamics in the High-Field Phases of Volborthite,
M. Yoshida*, K. Nawa, H. Ishikawa, M. Takigawa, M. Jeong, S.
Kramer, M. Horvatic, C. Berthier, K. Matsui, T. Goto, S. Kimura,
T. Sasaki, J. Yamaura, H. Yoshida, Y. Okamoto, and Z.
Hiroi,
Phys.
Rev. B, 96, 180413(1-5) (2017) (arXiv:1602.04028).
(PRB Editors' Suggestion)
70.
Collinear Spin-Density-Wave Order and Anisotropic Spin
Fluctuations in the Frustrated J1-J2 Chain Magnet NaCuMoO4(OH),
Kazuhiro Nawa*, Makoto Yoshida, Yoshihiko Okamoto, Masashi
Takigawa, and Zenji Hiroi,
Phys.
Rev. B, 96, 174433(1-9) (2017) (arXiv:1711.03175).
69.
Giant Negative Thermal Expansion in Fe-Doped Layered Ruthenate
Ceramics,
Koshi Takenaka, Tsubasa Shinoda, Naruhiro Inoue, Yoshihiko
Okamoto, Naoyuki Katayama, Yuki Sakai, Takumi Nishikubo, and
Masaki Azuma,
Appl.
Phys. Express 10, 115501(1-4) (2017).
(Spotlights 2017)
68.
Classical Spin Nematic Transition in LiGa0.95In0.05Cr4O8,
R. Wawrzynczak*, Y. Tanaka*, M. Yoshida, Y. Okamoto, P.
Manuel, N. Casati, Z. Hiroi, M. Takigawa, and G. J. Nilsen*,
Phys.
Rev. Lett. 119, 087201(1-5) (2017) (arXiv:1706.08409).
67.
Phase Diagram of Multiferroic KCu3As2O7(OD)3,
Gøran J.
Nilsen*, Virginie Simonet, Claire V. Colin, Ryutaro Okuma, Yoshihiko
Okamoto, Masashi Tokunaga, Thomas C. Hansen, Dmitry D.
Khalyavin, and Zenji Hiroi,
Phys.
Rev. B 95, 214415(1-10) (2017) (arXiv:1702.03268).
66.
Crossing-Line-Node Semimetals: General Theory and Application to
Rare-Earth Trihydrides,
Shingo Kobayashi, Youichi Yamakawa, Ai Yamakage, Takumi Inohara, Yoshihiko
Okamoto, and Yukio Tanaka,
Phys.
Rev. B 95, 245208(1-15) (2017) (arXiv:1703.03587).
65.
Large Thermoelectric Power Factor at Low Temperatures in One-Dimensional
Telluride Ta4SiTe4,
Takumi Inohara, Yoshihiko Okamoto*, Youichi Yamakawa, Ai
Yamakage, and Koshi Takenaka,
Appl.
Phys. Lett. 110, 183901(1-5) (2017) (arXiv:1705.00404).
(プレスリリース：低温で高い性能を示す熱電変換材料の発見)
(報道：化学工業日報2017年5月2日「低温でも高い性能 電子機器を局所冷却」他)
(Press Release: One-Dimensional
Crystals for Low-Temperature Thermoelectric Cooling)
64.
物質探索のための5d遷移金属化合物の結晶化学
(J-Physics 若手夏の学校：テキスト),
岡本佳比古,
物性研究・電子版
6, 061206(1-31) (2017) (open access).
63.
Magnetic Transitions under Ultrahigh Magnetic Fields of up to 130
T in the Breathing Pyrochlore Antiferromagnet LiInCr4O8,
Yoshihiko Okamoto*, Daisuke Nakamura, Atsushi Miyake,
Shojiro Takeyama, Masashi Tokunaga, Akira Matsuo, Koichi Kindo,
and Zenji Hiroi,
Phys.
Rev. B 95, 134438(1-5) (2017) (arXiv:1704.02784).
62.
Colossal Negative Thermal Expansion in Reduced Layered Ruthenate,
Koshi Takenaka*, Yoshihiko Okamoto, Tsubasa Shinoda,
Naoyuki Katayama, and Yuki Sakai,
Nat.
Commun. 8, 14102(1-7) (2017) (open access).
(Over 100 times cited in Web of Science)
(Highly Cited Paper in Essential Science Indicators, Thomson Reuters)
(プレスリリース：温めると縮む新材料を発見）
(報道：朝日新聞2017年1月11日「温めると縮む新材料 開発」他)
(Press Release: Record-Breaking
Material that Contracts When Heated)
61.
Low Carrier Density Metal Realized in Candidate Line-Node Dirac
Semimetals CaAgP and CaAgAs,
Yoshihiko Okamoto*, Takumi Inohara, Ai Yamakage, Youichi
Yamakawa, and Koshi Takenaka,
J. Phys.
Soc. Jpn. 85, 123701(1-5) (2016) (open access) (arXiv:1611.00490).
(Most Cited
Articles in 2017 from Vol. 85 (2016))
60.
Synthesis and Superconducting Properties of a Hexagonal Phosphide
ScRhP,
Takumi Inohara, Yoshihiko Okamoto*, Youichi Yamakawa, and
Koshi Takenaka,
J. Phys.
Soc. Jpn. 85, 094706(1-5) (2016) (arXiv:1608.05228).
59.
Terahertz ESR Measurements of Magnetically Aligned NaCuMoO4(OH),
Yoko Kitahara, Shigeo Hara, Takahiro Sakurai, Susumu Okubo,
Hitoshi Ohta, Fumiko Kimura, Tsunehisa Kimura, Kazuhiro Nawa, Yoshihiko
Okamoto, and Zenji Hiroi,
J. Jpn.
Soc. Infrared Science and Technology 26, 56-61 (2016).
(第7回日本赤外線学会論文賞)
58.
Thermoelectric Properties of Antiperovskite Calcium Oxides Ca3PbO
and Ca3SnO,
Yoshihiko Okamoto*, Akira Sakamaki, and Koshi Takenaka,
J. Appl.
Phys. 119, 205106(1-5) (2016) (arXiv:1604.06541).
57.
Superconductivity in the Hexagonal Ternary Phosphide ScIrP,
Yoshihiko Okamoto*, Takumi Inohara, Youichi Yamakawa, Ai
Yamakage, and Koshi Takenaka,
J. Phys.
Soc. Jpn. 85, 013704(1-5) (2016) (arXiv:1512.03864).
56.
Line-Node Dirac Semimetal and Topological Insulating Phase in
Noncentrosymmetric Pnictides CaAgX (X = P, As),
Ai Yamakage, Youichi Yamakawa, Yukio Tanaka, and Yoshihiko
Okamoto,
J. Phys.
Soc. Jpn. 85, 013708(1-4) (2016) (open access) (arXiv:1510.00202).
(Over 100 times cited in Web of Science)
(Highly Cited
Paper in Essential Science Indicators, Thomson Reuters)
(Most Cited Articles in 2017 from Vol. 85 (2016))
(日本物理学会第24回論文賞)
55.
Large Diamagnetic Susceptibility from Petit Fermi Surfaces in LaV2Al20,
Takahiro Hirose*, Yoshihiko Okamoto, Jun-ichi Yamaura, and
Zenji Hiroi,
J. Phys.
Soc. Jpn. 84, 113701(1-5) (2015).
54.
On the Microscopic Dynamics of the 'Einstein Solids' AlV2Al20 and
GaV2Al20, and of YV2Al20: A Benchmark System for 'Rattling'
Excitations,
Micael Marek Koza*, Hannu Mutka, Yoshihiko Okamoto, Jun-ichi
Yamaura, and Zenji Hiroi,
Phys.
Chem. Chem. Phys. 17(38) 24837-24850 (2015)(open access).
53.
Frozen State and Spin Liquid Physics in Na4Ir3O8: an NMR Study,
A. C. Shockley*, F. Bert, J-C. Orain, Y. Okamoto, and P.
Mendels*,
Phys.
Rev. Lett. 115, 047201(1-5) (2015) (arXiv:1505.04815).
52.
One-Third Magnetization Plateau with a Preceding Novel Phase in
Volborthite,
H. Ishikawa, M. Yoshida, K. Nawa, M. Jeong, S. Krämer, M.
Horvatic, C. Berthier, M. Takigawa, M. Akaki, A. Miyake, M.
Tokunaga, K. Kindo, J. Yamaura, Y. Okamoto, and Z. Hiroi,
Phys.
Rev. Lett. 114, 227202(1-5) (2015) (arXiv:1506.00076).
51.
Orbital Arrangements and Magnetic Interactions in the Quasi-One-Dimensional
Cuprates ACuMoO4(OH) (A = Na, K),
Kazuhiro Nawa*, Takeshi Yajima, Yoshihiko Okamoto, and
Zenji Hiroi,
Inorg.
Chem. 54(11), 5566-5570 (2015) (arXiv:1505.05332).
50.
Complex Magnetostructural Order in the Frustrated Spinel LiInCr4O8,
Gøran J.
Nilsen*, Yoshihiko Okamoto, Takatsugu Masuda, Juan
Rodriguez-Carvajal, Hannu Mutka, Thomas Hansen, and Zenji Hiroi,
Phys.
Rev. B 91, 174435(1-8) (2015).
(PRB Editors' Suggestion)
49.
Spinodally Decomposed Nanostructures in a TiO2-VO2 Crystal,
Zenji Hiroi*, Toru Yoshida, Jun-ichi Yamaura, and Yoshihiko
Okamoto,
APL
Mater. 3, 062508(1-8) (2015) (open access).
48.
Magnetic Phase Diagram of the Breathing Pyrochlore
Antiferromagnet LiGa1-xInxCr4O8,
Yoshihiko Okamoto*, Gøran J.
Nilsen, Taishi Nakazono, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 84, 043707(1-5) (2015) (arXiv:1503.08902).
47.
Lifshitz Metal-Insulator Transition Induced by the All-in/All-out
Magnetic Order in the Pyrochlore Oxide Cd2Os2O7,
Zenji Hiroi*, Jun-ichi Yamaura, Takahiro Hirose, Issei Nagashima,
and Yoshihiko Okamoto,
APL Mat.
3, 041501(1-11) (2015) (open access) (arXiv:1502.00191).
46.
Novel Phase Transitions in the Breathing Pyrochlore Lattice: 7Li-NMR
on LiInCr4O8 and LiGaCr4O8,
Yu Tanaka, Makoto Yoshida, Masashi Takigawa, Yoshihiko Okamoto,
and Zenji Hiroi,
Phys.
Rev. Lett. 113, 227204(1-5) (2014) (arXiv:1411.1577).
45.
NaCuMoO4(OH) as a Candidate Frustrated J1-J2
Chain Quantum Magnet,
Kazuhiro Nawa*, Yoshihiko Okamoto, Akira Matsuo, Koichi
Kindo, Yoko Kitahara, Syota Yoshida, Shohei Ikeda, Shigeo Hara,
Takahiro Sakurai, Susumu Okubo, Hitoshi Ohta, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 83, 103702(1-5) (2014) (arXiv:1409.1310).
44.
Thermoelectric Properties of Sr and Mg Double-Substituted LaCoO3
at Room Temperature,
Arreerat Jiamprasertboon, Yoshihiko Okamoto, Zenji
Hiroi, and Theeranun Siritanon*,
Ceram.
Int., 40, 12729-12735 (2014).
43.
Helical Order and Multiferroicity in the S = 1/2 Quasi-Kagome
System KCu3As2O7(OD)3,
G. J. Nilsen*, Y. Okamoto, H. Ishikawa, V. Shimonet, C. V.
Colin, A. Cano, L. C. Chapon, T. Hansen, H. Mutka, and Z. Hiroi,
Phys.
Rev. B 89, 140412(1-5) (2014) (arXiv:1404.3107).
42.
Kagome-Triangular Lattice Antiferromagnet NaBa2Mn3F11,
Hajime Ishikawa*, Tsuyoshi Okubo, Yoshihiko Okamoto, and
Zenji Hiroi,
J. Phys.
Soc. Jpn. 83, 043703(1-5) (2014) (arXiv:1403.2128).
41.
Novel K Rattling: A New Route to Thermoelectric Materials?,
Elvis Shoko*, Yoshihiko Okamoto, Gordon J. Kearley, Vanessa
K. Peterson, Gordon J. Thorogood,
J. Appl.
Phys. 115, 033703(1-8) (2014) (arXiv:1310.8382).
40.
Spinodal Decomposition in the TiO2-VO2 System,
Zenji Hiroi*, Hiroaki Hayamizu, Toru Yoshida, Yuji Muraoka, Yoshihiko
Okamoto, Jun-ichi Yamaura, and Yutaka Ueda,
Chem.
Mater. 25, 2202-2210 (2013) (arXiv:1306.2444).
39.
Magnetic Properties of the Spin-1/2 Deformed Kagome
Antiferromagnet Edwardsite,
Hajime Ishikawa*, Yoshihiko Okamoto, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 82, 063710(1-5) (2013) (arXiv:1305.2477).
38.
Pressure Effects on Rattling and Superconductivity in the
Einstein Solids,
Yoichi Ikeda*, Yasuhiro Kawasaki, Takafumi Shinohara, Shingo Araki,
Tatsuo C. Kobayashi, Atsushi Onosaka, Yoshihiko Okamoto,
Jun-ichi Yamaura, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 82, 063707(1-4) (2013).
37.
Breathing Pyrochlore Lattice Realized in A-site Ordered
Spinel Oxides LiGaCr4O8 and LiInCr4O8,
Yoshihiko Okamoto*, Gøran J.
Nilsen, J. Paul Attfield, and Zenji Hiroi,
Phys.
Rev. Lett. 110, 097203(1-5) (2013) (arXiv:1301.6936).
36.
YCr6Ge6 as a Candidate Compound for a Kagome Metal,
Yui Ishii*, Hisatomo Harima, Yoshihiko Okamoto, Jun-ichi
Yamaura, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 82, 023705(1-4) (2013) (arXiv:1212.1976).
35.
Magnetic Order in the Spin-1/2 Kagome Antiferromagnet Vesignieite,
Makoto Yoshida*, Yoshihiko Okamoto, Hiroyuki Yoshida,
Masashi Takigawa, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 82, 013702(1-4) (2013) (arXiv:1209.4693).
34.
Large Diamagnetism of AV2Al20 (A = Y and La),
Atsushi Onosaka, Yoshihiko Okamoto, Jun-ichi Yamaura,
Takahiro Hirose, and Zenji Hiroi*,
J. Phys.
Soc. Jpn. 81, 123702(1-4) (2012) (arXiv:1211.0066).
33.
Rattling and Superconducting Properties of the Cage Compound GaxV2Al20,
Zenji Hiroi, Atsushi Onosaka, Yoshihiko Okamoto, Jun-ichi
Yamaura, and Hisatomo Harima,
J. Phys.
Soc. Jpn. 81, 124707(1-11) (2012) (open access) (arXiv:1210.6461).
32.
Giant Phonon Softening and Enhancement of Superconductivity by
Phosphorus Doping of BaNi2As2,
K. Kudo*, M. Takasuga, Y. Okamoto, Z. Hiroi, and M. Nohara,
Phys.
Rev. Lett. 109, 097002(1-5) (2012) (arXiv:1204.4958).
31.
A Novel Crystal Polymorph of Volborthite Cu3V2O7(OH)2 2H2O,
Hajime Ishikawa*, Jun-ichi Yamaura, Yoshihiko Okamoto,
Hiroyuki Yoshida, Gøran J. Nilsen, and Zenji Hiroi,
Acta
Cryst. C68, i41-i44 (2012) (arXiv:1209.3162).
30.
Crystal Chemistry and Magnetic Properties of Manganese Zinc Alloy
"YMn2Zn20" Comprising a Mn Pyrochlore Lattice,
Yoshihiko Okamoto*, Takeshi Shimizu, Jun-ichi Yamaura, and
Zenji Hiroi,
J. Solid
State Chem. 191, 246-256 (2012) (arXiv:1203.4887).
29.
Orbital Switching in a Frustrated Magnet,
Hiroyuki Yoshida*, Jun-ichi Yamaura, Masaaki Isobe, Yoshihiko
Okamoto, Gøran J. Nilsen, and Zenji Hiroi,
Nat.
Commun. 3, 860(1-5) (2012).
(プレスリリース：「軌道スイッチング」現象を発見)
(報道：日経産業新聞2012年6月27日「物質内電子、温度で変化」他)
(紹介記事：UTokyo
Reserch)
28.
The Spin Dynamics in Distorted Kagome Lattices: a Comparative
Raman Study,
D. Wulferding*, P. Lemmens, Hiroyuki Yoshida, Yoshihiko Okamoto,
and Zenji Hiroi,
J. Phys.:
Condens. Matter, 24, 185602(1-5) (2012) (arXiv:1111.2167).
27.
Distorted Kagome Lattice Generated by a Unique Orbital
Arrangement in the Copper Mineral KCu3As2O7(OH)3,
Yoshihiko Okamoto*, Hajime Ishikawa, Gøran J. Nilsen,
and Zenji Hiroi,
J. Phys.
Soc. Jpn. 81, 033707(1-4) (2012) (arXiv:1202.2913).
26.
High-Field Phase Diagram and Spin Structure of Volborthite Cu3V2O7(OH)2
2H2O,
Makoto Yoshida*, Masashi Takigawa*, Steffen Krämer, Sutirtha
Mukhopadhyay, Mladen Horvatic, Claude Berthier, Hiroyuki Yoshida,
Yoshihiko Okamoto, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 81, 024703(1-9) (2012) (open access) (arXiv:1110.0260).
25.
Superconductivity in the Einstein Solid AxV2Al20 (A = Al and Ga),
Atsushi Onosaka, Yoshihiko Okamoto, Jun-ichi Yamaura, and
Zenji Hiroi*,
J. Phys.
Soc. Jpn. 81, 023703(1-4) (2012)
(arXiv:1112.5229).
24.
Superconductivity and Rattling under High Pressure in the β-Pyrochlore
Oxide RbOs2O6,
Nao Takeshita*, Hiroki Ogusu, Jun-ichi Yamaura, Yoshihiko
Okamoto, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 80, 104708(1-8) (2011) (arXiv:1109.5422).
23.
Heterogeneous Spin State in the Field-Induced Phase of
Volborthite as Seen via 51V Nuclear Magnetic Resonance,
Makoto Yoshida, Masashi Takigawa, Hiroyuki Yoshida, Yoshihiko
Okamoto, and Zenji Hiroi,
Phys.
Rev. B 84, 020410(1-4) (2011) (arXiv:1103.6137).
22.
A Magnetic Transition Probed by the Ce Ion in Square-Lattice
Antiferromagnet CeMnAsO,
Yuto Tsukamoto, Yoshihiko Okamoto, Kazuyuki Matsuhira,
Myung-Hwan Whangbo, and Zenji Hiroi*,
J. Phys.
Soc. Jpn. 80, 094708(1-5) (2011) (arXiv:1108.0121).
21.
Magnetization Plateaus of Spin-1/2 Kagome Antiferromagnets
Volborthite and Vesignieite,
Yoshihiko Okamoto*, Masashi Tokunaga, Hiroyuki Yoshida,
Akira Matsuo, Koichi Kindo, and Zenji Hiroi,
Phys.
Rev. B 83, 180407(R)(1-4) (2011) (arXiv:1103.3116).
(PRB Editors' Suggestion)
20.
Hard X-Ray Photoelectron Spectroscopy of Metal-Insulator
Transition in LiRh2O4,
Y. Nakatsu, A. Sekiyama, S. Imada, Y. Okamoto, S. Niitaka,
H. Takagi, A. Higashiya, M. Yabashi, K. Tamasaku, T. Ishikawa,
and S. Suga,
Phys.
Rev. B 83, 115120(1-4) (2011).
19.
Superconducting and Structural Transitions in the β-Pyrochlore
Oxide KOs2O6 under High Pressure,
Hiroki Ogusu, Nao Takeshita, Koichi Izawa, Jun-ichi Yamaura,
Yasuo Ohishi, Satoshi Tsutsui, Yoshihiko Okamoto, and
Zenji Hiroi*,
J. Phys.
Soc. Jpn. 79, 114710(1-6) (2010) (arXiv:1009.0355).
18.
Itinerant-Electron Magnet of the Pyrochlore Lattice: Indium-Doped
YMn2Zn20,
Yoshihiko Okamoto*, Takeshi Shimizu, Jun-ichi Yamaura, Yoko
Kiuchi, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 79, 093712(1-4) (2010) (arXiv:1008.0835).
(JPSJ Editors' Choice)
17.
Thermodynamic Properties of the Kagome Lattice in Volborthite,
Satoshi Yamashita, Tomoya Moriura, Yasuhiro Nakazawa*, Hiroyuki
Yoshida, Yoshihiko Okamoto, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 79, 083710(1-4) (2010) (arXiv:1008.1835).
16.
Resonant Photoemission Spectroscopy of Layered Triangular
Lattices Ag2MO2 (M = Ni and Mn); Evidence for M 3d States at
Fermi Level,
Ritsuko Eguchi*, Hiroyuki Yoshida, Yoshihiko Okamoto,
Ashish Chainani, Masaharu Matsunami, Yukiaki Ishida, Masaki Oura,
Yasunori Senba, Haruhiko Ohashi, Shik Shin, and Zenji Hiroi,
J. Phys.
Soc. Jpn. 79, 023704(1-4) (2010).
15.
High-Field ESR Measurements of S = 1/2 Kagome Lattice
Antiferromagnet BaCu3V2O8(OH)2,
Wei-min Zhang, Hitoshi Ohta, Susumu Okubo, Masashi Fujisawa,
Takahiro Sakurai, Yoshihiko Okamoto, Hiroyuki Yoshida, and
Zenji Hiroi,
J. Phys.
Soc. Jpn. 79, 023708(1-4) (2010) (open access) (arXiv:0912.4335).
14.
Discontinuous Lifshitz Transition Achieved by Band-Filling
Control in NaxCoO2,
Yoshihiko Okamoto, Atsushi Nishio, and Zenji Hiroi,
Phys.
Rev. B 81, 121102(R)(1-4) (2010) (arXiv:1002.4282).
13.
Evidence for Oxygen Holes due to d-p
Rehybridization in Thermoelectric Sr1-xRh2O4,
Y. Ishida, T. Baba, R. Eguchi, M. Matsunami, M. Taguchi, A.
Chainani, Y. Senba, Y. Okamoto, H. Takagi, and S. Shin,
Phys.
Rev. B 80, 081103(R)(1-4) (2009) (arXiv:0907.5455).
12.
Phase Diagram and Spin Dynamics in Volborthite with a Distorted
Kagome Lattice,
Makoto Yoshida, Masashi Takigawa, Hiroyuki Yoshida, Yoshihiko
Okamoto, and Zenji Hiroi,
Phys.
Rev. Lett. 103, 077207(1-4) (2009) (arXiv:0906.2846).
11.
Rattling-Induced Superconductivity in the β-Pyrochlore Oxides
AOs2O6,
Yohei Nagao, Junichi Yamaura, Hiroki Ogusu, Yoshihiko Okamoto,
and Zenji Hiroi*,
J. Phys.
Soc. Jpn. 78, 064702(1-21) (2009) (open access) (arXiv:0906.4656).
(JPSJ Editors' Choice)
(日本物理学会第17回論文賞)
(報道：科学新聞2009年6月26日「ラットリング現象で超伝導」)
10.
Magnetization "Steps" on a Kagome Lattice in
Volborthite,
Hiroyuki Yoshida, Yoshihiko Okamoto, Takashi Tayama,
Toshiro Sakakibara, Masashi Tokunaga, Akira Matsuo, Yasuo Narumi,
Koichi Kindo, Makoto Yoshida, Masashi Takigawa and Zenji Hiroi*,
J. Phys.
Soc. Jpn. 78, 043704(1-4) (2009) (arXiv:0902.3028).
9.
Structure and Photoemission Spectroscopy of Strain-Controlled
Metal-Insulator Transition in NdNiO3 Thin Films,
R. Eguchi*, Y. Okamoto, Z. Hiroi, S. Shin, A. Chainani, Y.
Tanaka, M. Matsunami, Y. Tanaka, Y. Nishino, K. Tamasaku, M.
Yabashi and T. Ishikawa,
J. Appl.
Phys. 105, 056103(1-3) (2009).
8.
Vesignieite BaCu3V2O8(OH)2 as a Candidate Spin-1/2 Kagome
Antiferromagnet,
Yoshihiko Okamoto*, Hiroyuki Yoshida and Zenji Hiroi,
J. Phys.
Soc. Jpn. 78, 033701(1-4) (2009) (open access) (arXiv:0901.2237).
(Over 100 times cited in Web of Science)
(JPSJ Editors' Choice)
(報道：科学新聞2009年4月3日「カゴメ格子に量子スピン配列 新物質を発見」)
(紹介記事：カゴメ格子上に配列したスピン：銅鉱物ベシニエ石,
岡本佳比古, 広井善二, 固体物理 44, 473 (2009).)
7.
Band Jahn-Teller Instability and Formation of Valence Bond Solid
in a Mixed-Valent Spinel Oxide LiRh2O4,
Yoshihiko Okamoto, Seiji Niitaka, Masaya Uchida, Takeshi
Waki, Masashi Takigawa, Yoshitaka Nakatsu, Akira Sekiyama,
Shigemasa Suga, Ryotaro Arita, and Hidenori Takagi,
Phys.
Rev. Lett. 101, 086404(1-4) (2008) (arXiv:0806.2504).
(紹介記事：RIKEN Research, 4
(1), 6 (2009), "Oxides flex their bonds".)
6.
Unique Phase Transition on Spin-2 Triangular Lattice of Ag2MnO2,
Hiroyuki Yoshida, Sascha Ahlert, Martin Jansen, Yoshihiko
Okamoto, Jun-ichi Yamaura, and Zenji Hiroi*,
J. Phys.
Soc. Jpn. 77, 074719(1-8) (2008) (arXiv:0805.3749).
5.
Spin-Liquid State in the S = 1/2 Hyperkagome
Antiferromagnet Na4Ir3O8,
Yoshihiko Okamoto, Minoru Nohara, Hiroko Aruga-Katori, and
Hidenori Takagi,
Phys.
Rev. Lett. 99, 137207(1-4) (2007) (arXiv:0705.2821).
(紹介記事：RIKEN Research, 3
(4), 3 (2008), "Exotic material keeps frustrated electrons
flipping".)
(Over 400 times
cited in Web of Science)
(Highly Cited Paper in Essential Science Indicators,
Thomson Reuters)
4.
Superconductivity in Rh2Ga9 and Ir2Ga9 without Inversion Symmetry,
Takeshi Shibayama, Minoru Nohara*, Hiroko Aruga-Katori, Yoshihiko
Okamoto, Zenji Hiroi, and Hidenori Takagi,
J. Phys.
Soc. Jpn. 76, 073708(1-4) (2007) (arXiv:0706.0577).
3.
Precise Control of Band Filling in NaxCoO2,
Daisuke Yoshizumi, Yuji Muraoka, Yoshihiko Okamoto, Yoko
Kiuchi, Jun-Ichi Yamaura, Masahito Mochizuki, Masao Ogata, and
Zenji Hiroi*,
J. Phys.
Soc. Jpn. 76, 063705(1-4) (2007) (arXiv:0704.1065).
2.
Metal-Insulator Transition in a Pyrochlore-type Ruthenium Oxide
Hg2Ru2O7,
Ayako Yamamoto*, Peter A. Sharma, Yoshihiko Okamoto, Aiko
Nakao, Hiroko Aruga-Katori, Seiji Niitaka, Daisuke Hashizume, and
Hidenori Takagi,
J. Phys.
Soc. Jpn. 76, 043703(1-4) (2007) (arXiv:cond-mat/0702411).
1.
Correlated Metallic Phase in a Doped Band Insulator Sr1-xRh2O4,
Yoshihiko Okamoto*, Minoru Nohara*, Fumiko Sakai and
Hidenori Takagi,
J. Phys.
Soc. Jpn. 75, 023704(1-4) (2006).