2009S2-008
共鳴軟・硬X線散乱を相補的に用いた構造物性研究

Last modified 2021-04-28 by s-proposalpfiqst.kek.jp

●基本情報
　●実験責任者：中尾　裕則（PF）
　●課題有効期間：2009/10〜2012/9
　●実験ステーション：2A,3A,4C,8A,8B,16A
　●関連課題：2012S2-005（外場下共鳴軟X線散乱による構造物性研究）

●課題の概要
　近年、共鳴X線散乱(RXS)実験は、任意の元素の狙いの軌道の情報が得られる手法として確立してきた。そこで本研究課題は、PF BL-16Aにおいて立ち上げられてきた軟X線回折装置を高度化するとともに、既存のBL-4C, 3A におけるRXS実験装置を組み合わせることによって、硬X線領域だけなく軟X線領域でのRXS実験を相補的に行い、物性の鍵を握る原子の電子状態や、その変調構造の解明を目指すものである。
　強相関電子系では、電子の局在状態と遍歴状態の狭間で、通常の金属では見られない高温超伝導、巨大磁気抵抗効果といった特徴的な物性が頻繁に発現する。例えば、強相関電子系で発見された超伝導体は、スピン・電荷の秩序状態が抑制され消失する量子臨界点近傍に一般に位置していることが知られている。従って、局在性と遍歴性の競合した電子状態の研究が、新奇物性発現メカニズムの解明の上で極めて重要となる。そこで、硬X線、軟X線を組み合わせたRXS実験により、これまで注目して来た局在性の強い電子(遷移金属 3d電子,希土類 4f電子) だけなく、遍歴性の強い電子(酸素2pなど)状態を区別して捉えることを目指す。結果として、局在的電子だけでなく遍歴的電子も含めた新たな秩序状態、つまり"軌道混成秩序状態"を定量的に解明できると考えている。ここでは、結晶構造解析より求まる原子位置と混成との関係にも注目する。さらに外場（磁場、圧力、温度）制御による秩序状態融解過程において、この軌道混成状態をパラメータとして、系の電子自由度（電荷・スピン・軌道）秩序と物性発現機構の関連性を研究することが出来る。このような軌道混成状態をパラメータとした研究は今まで行われておらず、遍歴性と局在性の狭間で出現する新奇な物性発現機構に迫れるものと考えている。

●成果発表

　●論文

• "Electronic Ordering States in Strongly Correlated Electron System Studied by Resonant X-ray Scattering"
  Hironori Nakao and Yuichi Yamasaki
  JPS Conf. Proc., 25 (2019) 011020.
• "Charge disproportionation of Mn 3d and O 2p electronic states depending on strength of p−d hybridization in (LaMnO₃)₂(SrMnO₃)₂ superlattices"
  Hironori Nakao, Chihiro Tabata, Youichi Murakami, Yuichi Yamasaki, Hiroyuki Yamada, Sumio Ishihara, and Masashi Kawasaki
  Phys. Rev. B, 98 (2018) 245146.
• "Resonant x-ray scattering study on electronic hybridization in unconventional ordered phase of PrRu₄P₁₂"
  Hironori Nakao, Chihiro Tabata and Kazuaki Iwasa
  J. Phys.: Conf. Ser., 969 (2018) 012118.
• "Emergence and magnetic-field variation of chiral-soliton lattice and skyrmion lattice in the strained helimagnet Cu₂OSeO₃"
  Y. Okamura, Y. Yamasaki, D. Morikawa, T. Honda, V. Ukleev, H. Nakao, Y. Murakami, K. Shibata, F. Kagawa, S. Seki, T. Arima, and Y. Tokura
  Phys. Rev. B, 96 (2017) 174417.
• "Spin State of Co³⁺ in LaCo_1−xRh_xO₃ Studied Using X-ray Absorption Spectroscopy"
  Keisuke Tomiyasu, Syun-Ichi Koyama, Masanori Watahiki, Mika Sato, Kazuki Nishihara, Yuki Takahashi, Mitsugi Onodera, Kazuaki Iwasa, Tsutomu Takaaki Sudayama, Hironori Nakao, Yuichi Yamasaki, Youichi Murakami, Shinichiro Asai, Ryuji Okazaki, Yukio Yasui, and Ichiro Terasaki
  J. Phys. Soc. Jpn., 86 (2017) 094701.
• "Directional electric-field induced transformation from skyrmion lattice to distinct helices in multiferroic Cu₂OSeO₃"
  Y. Okamura, Y. Yamasaki, D. Morikawa, T. Honda, V. Ukleev, H. Nakao, Y. Murakami, K. Shibata, F. Kagawa, S. Seki, T. Arima, and Y. Tokura
  Phys. Rev. B, 95 (2017) 184411.
• "Microscopic Examinations of Co Valences and Spin States in Electron-Doped LaCoO₃"
  Keisuke Tomiyasu, Syun-Ichi Koyama, Masanori Watahiki, Mika Sato, Kazuki Nishihara, Yuki Takahashi, Mitsugi Onodera, Kazuaki Iwasa, Tsutomu Nojima, Hiroyuki Nojiri, Jun Okamoto, Di-Jing Huang, Yuuichi Yamasaki, Hironori Nakao, and Youichi Murakami
  J. Phys. Soc. Jpn., 85 (2016) 094702.
• "Surface Ordering of Orbitals at a Higher Temperature in LaCoO₃ Thin Film"
  Yuichi Yamasaki, Jun Fujioka, Hironori Nakao, Jun Okamoto, Takaaki Sudayama, Youichi Murakami, Masao Nakamura, Masashi Kawasaki, Takahisa Arima, and Yoshinori Tokura
  J. Phys. Soc. Jpn., 85 (2016) 023704.
• "Magnetic and Crystal Structures of the Room Temperature Ferrimagnet Sr₃YCo₄O_10.5"
  Akiko Nakao, Hironori Nakao, Kenji Ohoyama, Shuki Torii, Junrong Zhang, Takashi Kamiyama, Youichi Murakami, Wataru Kobayashi, and Ichiro Terasaki
  JPS Conf. Proc. 8 (2015) 034010.
• "Magnetic and electronic states in (LaMnO₃)₂(SrMnO₃)₂ superlattice exhibiting a large negative magnetoresistance"
  Hironori Nakao, Takaaki Sudayama, Masato Kubota, Jun Okamoto, Yuichi Yamasaki, Youichi Murakami, Hiroyuki Yamada, Akihito Sawa, and Kazuaki Iwasa
  Phys. Rev. B, 92 (2015) 245104.
• "Dynamical process of skyrmion-helical magnetic transformation of the chiral-lattice magnet FeGe probed by small-angle resonant soft x-ray scattering"
  Y. Yamasaki, D. Morikawa, T. Honda, H. Nakao, Y. Murakami, N. Kanazawa, M. Kawasaki, T. Arima, and Y. Tokura
  Phys. Rev. B, 92 (2015) 220421(R).
• "X-ray induced lock-in transition of cycloidal magnetic order in a multiferroic perovskite manganite"
  Y. Yamasaki, H. Nakao, Y. Murakami, T. Nakajima, A. Lafuente Sampietro, H. Ohsumi, M. Takata, T. Arima, and Y. Tokura
  Phys. Rev. B, 91 (2015) 100403.
• "Unconventional magnetism in the layered oxide LaSrRhO₄"
  Noriyasu Furuta, Shinichiro Asai, Taichi Igarashi, Ryuji Okazaki, Yukio Yasui, Ichiro Terasaki, Masami Ikeda, Takahito Fujita, Masayuki Hagiwara, Kensuke Kobayashi, Reiji Kumai, Hironori Nakao, and Youichi Murakami
  Phys. Rev. B, 90 (2014) 144402.
• "Magnetic and electronic properties of (LaMnO₃)₅(SrMnO₃)₅ superlattice revealed by resonant soft X-ray scattering"
  Masato Kubota, Hiroyuki Yamada, Hironori Nakao, Jun Okamoto, Yuichi Yamasaki, Akihito Sawa, and Youichi Murakami
  Jpn. J. Appl. Phys., 53 (2014) 05FH07.
• "Molecular electronic states in charge transfer complex studied by x-ray absorption spectroscopy"
  Y. Takahashi, H. Nakao, R. Kumai, S. Ishibashi, S. Horiuchi, M. Kohyama, K. Kobayashi, Y. Yamasaki, J. Okamoto, T. Sudayama, Y. Murakami and Y. Tokura
  J. Phys.: Conf. Ser., 502 (2014) 012036.
• "Development of an in-vacuum diffractometer for resonant soft X-ray scattering"
  H. Nakao, Y. Yamasaki, J. Okamoto, T. Sudayama, Y. Takahashi, K. Kobayashi, R. Kumai, and Y. Murakami
  J. Phys.: Conf. Ser., 502 (2014) 012015.
• "Possible Existence of Two Charge-Ordered Phases in Pr_1-xCa_xMnO₃ for 0.40 ≤ x ≤ 0.50"
  Partha Sarathi Mondal, Shinichiro Asai, Taichi Igarashi, Takahiro Suzuki, Ryuji Okazaki, Ichiro Terasaki, Yukio Yasui, Kensuke Kobayashi, Reiji Kumai, Hironori Nakao, and Youichi Murakami
  J. Phys. Soc. Jpn., 83 (2014) 064709.
• "Neutron magnetic scattering study in manganite thin film system"
  H. Nakao, H. Yamada, A. Sawa, K. Iwasa, J. Okamoto, T. Sudayama, Y. Yamasaki, Y. Murakami
  Solid State Commun., 185 (2014) 18.
• "Antiferromagnetic Order of the Co²⁺ High-Spin State with a Large Orbital Angular Momentum in La_1.5Ca_0.5CoO₄"
  Jun Okamoto, Hironori Nakao, Yuichi Yamasaki, Hiroki Wadati, Arata Tanaka, Masato Kubota, Kazumasa Horigane, Youichi Murakami, and Kazuyoshi Yamada
  J. Phys. Soc. Jpn., 83 (2014) 044705.
• "Spin State of Co³⁺ in LaCo_1-xRh_xO₃ Investigated by Structural Phenomena"
  Shinichiro Asai, Ryuji Okazaki, Ichiro Terasaki, Yukio Yasui, Wataru Kobayashi, Akiko Nakao, Kensuke Kobayashi, Reiji Kumai, Hironori Nakao, Youichi Murakami, Naoki Igawa, Akinori Hoshikawa, Toru Ishigaki, Outi Parkkima, Maarit Karppinen, Hisao Yamauchi
  J. Phys. Soc. Jpn., 82 (2013) 114606.
• "Spin-Orbital Superstructure in Strained Ferrimagnetic Perovskite Cobalt Oxide"
  J. Fujioka, Y. Yamasaki, H. Nakao, R. Kumai, Y. Murakami, M. Nakamura, M. Kawasaki, and Y. Tokura
  Phys. Rev. Lett., 111 (2013) 027206.
• "Spin-state responses to light impurity substitution in low-spin perovskite LaCoO₃"
  Keisuke Tomiyasu, Yuuki Kubota, Saya Shimomura, Mitsugi Onodera, Syun-Ichi Koyama, Tsutomu Nojima, Sumio Ishihara, Hironori Nakao, and Youichi Murakami
  Phys. Rev. B, 87 (2013) 224409.
• "Interplay Among Spin, Orbital, and Lattice Degrees of Freedom in a Frustrated Spinel Mn₃O₄"
  Y.Nii, H.Sagayama, H.Umetsu, N.Abe, K.Taniguchi and T.Arima
  Phys. Rev. B, 87 (2013) 195115.
• "Change of Electronic State and Crystal Structure by Postannealing in Superconducting SrFe₂(As_0.65P_0.35)₂"
  T. Kobayashi, S. Miyasaka, S. Tajima, T. Nakano, Y. Nozue, N. Chikumoto, H. Nakao, R. Kumai and Y. Murakami
  Phys. Rev. B, 87 (2013) 174520.
• "Resonant Soft X-Ray Scattering Study of the Magnetic Structures in La_1.5Ca_0.5CoO₄ using a High Vacuum Diffractormeter with a 4-Blade-Slit Detector System"
  J.Okamoto, K.Horigane, H.Nakao, K.Amemiya, M.Kubota, Y.Murakami and K.Yamada
  J. Phys.: Conf. Ser., 425 (2013) 202003.
• "Determination of Long-Range All-In-All-Out Ordering of Ir⁴⁺ Moments in a Pyrochlore Iridate Eu₂Ir₂O₇ by Resonant X-Ray Diffraction"
  H.Sagayama, D.Uematsu, T.Arima, K.Sugimoto, J.J.Ishikawa, E.O'Farrell and S.Nakatsuji
  Phys. Rev. B, 87 (2013) 100403(R).
• "Pseudogap-Related Charge Dynamics in the Layered Nickelate R_2-xSr_xNiO₄ (x ∼ 1)"
  M.Uchida, Y.Yamasaki, Y.Kaneko, K.Ishizaka, J.Okamoto, H.Nakao, Y.Murakami and Y.Tokura
  Phys. Rev. B, 86 (2012) 165126.
• "Orbital States of V Trimers in BaV₁₀O₁₅ Detected by Resonant X-Ray Scattering"
  K.Takubo, T.Kanzaki, Y.Yamasaki, H.Nakao, Y.Murakami, T.Oguchi and T.Katsufuji
  Phys. Rev. B, 86 (2012) 085141.
• "Correlation between T_c and Transport Properties in PrFeP_1-x As_xO_0.9F_0.1"
  A.Takemori, S.Saijo, S.Suzuki, S.Miyasaka, S.Tajima, A.Nakao, H.Nakao, R.Kumai and Y.Murakami
  J. Phys. Soc. Jpn., 81 (2012) SB043.
• "Cr- and Mo-Doping Effects on Structural and Orbital Order Phase Transition in Spinel-Type MnV₂O₄"
  K.Hemmi, R.Fukuta, E.Uykur, S.Miyasaka, S.Tajima, A.Nakao, H.Nakao, R.Kumai and Y.Murakami
  J. Phys. Soc. Jpn., 81 (2012) SB030.
• "High-Temperature Thermoelectric Properties of the Double-Perovskite Ruthenium Oxide (Sr_1-xLa_x)₂ErRuO₆"
  R.Takahashi, R.Okazaki, Y.Yasui, I.Terasaki, T.Sudayama, H.Nakao, Y.Yamasaki, J.Okamoto, Y.Murakami and Y.Kitajima
  J. Appl. Phys., 112 (2012) 073714.
• "Magnetic Phase Diagrams of YVO₃ and TbVO₃ under High Pressure"
  D.Bizen, H.Nakao, K.Iwasa, Y.Murakami, T.Osakabe, J.Fujioka, T.Yasue, S.Miyasaka and Y.Tokura
  J. Phys. Soc. Jpn., 81 (2012) 024715.
• "Origin of the Large Polarization in Multiferroic YMnO₃ Thin Films Revealed by Soft- and Hard-X-Ray Diffraction"
  H.Wadati, J.Okamoto, M.Garganourakis, V.Scagnoli, U.Staub, Y.Yamasaki, H.Nakao, Y.Murakami, M.Mochizuki, M.Nakamura, M.Kawasaki and Y.Tokura
  Phys. Rev. Lett., 108 (2012) 047203.
• "Effects of Cation-Size Variance on Spin and Orbital Orders in Eu_1-x(La_0.254Y_0.746)_xVO₃"
  R.Fukuta, S.Miyasaka, K.Hemmi, S.Tajima, D.Kawana, K.Ikeuchi, Y.Yamasaki, A.Nakao, H.Nakao, Y.Murakami and K.Iwasa
  Phys. Rev. B, 84 (2011) 140409(R).
• "Anisotropic Thermoelectric Properties Associated with Dimensional Crossover in Quasi-One-Dimensional SrNbO_3.4+d (d ∼ 0.03)"
  W.Kobayashi, Y.Hayashi, M.Matsushita, Y.Yamamoto, I.Terasaki, A.Nakao, H.Nakao, Y.Murakami, Y.Moritomo, H.Yamauchi and M.Karppinen
  Phys. Rev. B, 84 (2011) 085118.
• "Displacement-Type Ferroelectricity with Off-Center Magnetic Ions in Perovskite Sr_1-xBa_xMnO₃"
  H.Sakai, J.Fujioka, T.Fukuda, D.Okuyama, D.Hashizume, F.Kagawa, H.Nakao, Y.Murakami, T.Arima, A.Q.R.Baron, Y.Taguchi and Y.Tokura
  Phys. Rev. Lett., 107 (2011) 137601.
• "Multiferroicity in NiBr₂ with Long-Wavelength Cycloidal Spin Structure on a Triangular Lattice"
  Y.Tokunaga, D.Okuyama, T.Kurumaji, T.Arima, H.Nakao, Y.Murakami, Y.Taguchi and Y.Tokura
  Phys. Rev. B, 84 (2011) 060406.
• "Garnet Superlattice as a Transparent Above-Room-Temperature Polar Magnet"
  Y.Krockenberger, J.S.Lee, D.Okuyama, H.Nakao, Y.Murakami, M.Kawasaki and Y.Tokura
  Phys. Rev. B, 83 (2011) 214414.
• "Stepwise Neutral-Ionic Phase Transitions in a Covalently Bonded Donor/Acceptor Chain Compound"
  H.Miyasaka, N.Motokawa, T.Chiyo, M.Takemura, M.Yamashita, H.Sagayama and T.Arima
  J. Am. Chem. Soc., 133 (2011) 5338.
• "Electron Doping in the Cubic Perovskite SrMnO₃: Isotropic Metal Versus Chainlike Ordering of Jahn-Teller Polarons"
  H.Sakai, S.Ishiwata, D.Okuyama, A.Nakao, H.Nakao, Y.Murakami, Y.Taguchi and Y.Tokura
  Phys. Rev. B, 82 (2010) 180409.