2017 Fiscal Year Annual Research Report
Magnetic anisotropy and electron orbitals in magnetic thin films and multilayers studied by angle-dependent x-ray magnetic circular dichroism
Project/Area Number |
15K17696
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Research Institution | The University of Tokyo |
Principal Investigator |
芝田 悟朗 東京大学, 大学院理学系研究科(理学部), 助教 (20747026)
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Project Period (FY) |
2015-04-01 – 2018-03-31
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Keywords | 磁気異方性 / 薄膜 / 強磁性体 / X線磁気円二色性 / 遷移金属化合物 / 軌道磁気モーメント / 電子軌道 |
Outline of Annual Research Achievements |
・L10型FePt合金や(Ba,K)(Zn,Mn)2As2といった、垂直磁気異方性を示すいくつかの強磁性体に対して新たに磁場角度依存X線磁気円二色性(XMCD)の実験を行った。前年度までに行った(La,Sr)MnO3薄膜の場合と同様に、磁性原子内での電子軌道の形状が異方的になっていることが示され、これが垂直磁気異方性の起源に関わっている可能性が示唆された。 ・同じく垂直磁気異方性を示すスピネル型酸化物強磁性体CoFe2O4の薄膜について、薄膜上下の界面における磁気的不活性層の成因をXMCDスペクトルとモデル計算との詳細な比較により調べた。その結果、特に膜厚を減らした薄膜において、一部のCoイオンおよびFeイオンの結晶内における位置が期待とは逆になっていることが示され、磁気的不活性層がこれにより生じていることを示唆する結果となった。 ・トポロジカル絶縁体などとの関連から近年注目を集めている2次元(層状)強磁性体の一つ、Cr2Ge2Te6に対してXMCD測定を世界に先駆けて行い、磁場方向が層に平行な場合と垂直な場合とでスペクトル形状に大きな異方性が現れることを示した。現在、モデル計算によりこの結果を説明することを試みている。 ・研究期間全体を通じて、ベクトルマグネットXMCD装置の改良により、従来以上に精密な磁場角度依存XMCDの実験を行うことができるようになった。また、この手法を用いて強磁性体中の電子軌道の占有状態を調べるための具体的な方法論を確立した。さらに、磁性薄膜の磁気異方性を議論するためには、従来考えられていた軌道磁気モーメントの異方性だけでなく、電子軌道の異方性をも考慮に入れなければならないことを実験的に示した。
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[Journal Article] Anisotropic spin-density distribution and magnetic anisotropy of strained La1-xSrxMnO3 thin films: angle-dependent x-ray magnetic circular dichroism2018
Author(s)
G. Shibata, M. Kitamura, M. Minohara, K. Yoshimatsu, T. Kadono, K. Ishigami, T. Harano, M. Furuse, M. Okano, J.-i. Fujihira, S. Fujihira, A. Tanaka, H. Kumigashira, T. Koide, and A. Fujimori et al. (他9名)
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Journal Title
npj Quantum Materials
Volume: 3
Pages: 3--1-6
DOI
Peer Reviewed / Open Access
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[Journal Article] Magnetic anisotropy of L10-ordered FePt thin films studied by Fe and Pt L2,3-edges x-ray magnetic circular dichroism2017
Author(s)
K. Ikeda, T. Seki, G. Shibata, T. Kadono, K. Ishigami, Y. Takahashi, M. Horio, S. Sakamoto, Y. Nonaka, M. Sakamaki, K. Amemiya, N. Kawamura, M. Suzuki, K. Takanashi, and A. Fujimori
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Journal Title
Applied Physics Letters
Volume: 111
Pages: 142402--1-5
DOI
Peer Reviewed
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[Journal Article] Effects of cobalt substitution in L10-(Fe,Co)Pt thin films2017
Author(s)
S. Sakamoto, K. Srinivasan, R. Zhang, O. Krupin, K. Ikeda, G. Shibata, Y. Nonaka, Z. Chi, M. Sakamaki, K. Amemiya, A. Fujimori, and A. Ajan
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Journal Title
Physical Review B
Volume: 96
Pages: 144437--1-5
DOI
Peer Reviewed / Int'l Joint Research
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[Journal Article] Electronic structure and magnetic properties of magnetically dead layers in epitaxial CoFe2O4/Al2O3/Si(111) films studied by x-ray magnetic circular dichroism2017
Author(s)
Y. K. Wakabayashi, Y. Nonaka, Y. Takeda, S. Sakamoto, K. Ikeda, Z. Chi, G. Shibata, A. Tanaka, Y. Saitoh, H. Yamagami, M. Tanaka, A. Fujimori, and R. Nakane
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Journal Title
Physical Review B
Volume: 96
Pages: 104410--1-11
DOI
Peer Reviewed
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[Presentation] Orbital magnetic moment anisotropy at ferromagnet/heavy metal heterostructures studied by x-ray magnetic circular dichroism2018
Author(s)
Z. Chi, G. Shibata, S. Sakamoto, Y. Nonaka, K. Ikeda, Y.-X. Wan, Masahiro Suzuki, N. Kawamura, M. Mizumaki, Motohiro Suzuki, M. Sakamaki, K. Amemiya, Y.-C. Lau, M. Hayashi, and A. Fujimori
Organizer
Max Planck-UBC-UTokyo School for Quantum Materials
Int'l Joint Research
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[Presentation] Magnetic field angle-dependent XMCD study of L10-ordered FePt thin films with perpendicular magnetic anisotropy2018
Author(s)
K. Ikeda, T. Seki, G. Shibata, S. Sakamoto, Y. Nonaka, Z. Chi, Y.-X. Wan, M. Suzuki, M. Sakamaki, K. Amemiya, K. Takanashi, and A. Fujimori
Organizer
Max Planck-UBC-UTokyo School for Quantum Materials
Int'l Joint Research
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[Presentation] Magnetically-induced anisotropic charge distribution in La1-xSrxMnO3 thin films revealed by x-ray magnetic linear dichroism2018
Author(s)
G. Shibata, K. Yoshimatsu, K. Ishigami, T. Harano, Y. Takahashi, S. Sakamoto, Y. Nonaka, T. Kadono, M. Furuse, S. Fuchino, M. Okano, J.-i. Fujihira, A. Uchida, K. Watanabe, H. Fujihira, S. Fujihira, A. Tanaka, H. Kumigashira, T. Koide, and A. Fujimori
Organizer
18-th Taiwan-Japan-Korea Symposium on Strongly Correlated Electron Systems (TJK18)
Int'l Joint Research
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[Presentation] Magnetic field angle-dependent XMCD study of L10-ordered FePt thin films with perpendicular magnetic anisotropy2018
Author(s)
K. Ikeda, T. Seki, G. Shibata, S. Sakamoto, Y. Nonaka, Z. Chi, Y.-X. Wan, M. Suzuki, M. Sakamaki, K. Amemiya, K. Takanashi, and A. Fujimori
Organizer
18-th Taiwan-Japan-Korea Symposium on Strongly Correlated Electron Systems (TJK18)
Int'l Joint Research
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[Presentation] Orbital magnetic moment at ferromagnet/heavy metal heterointerfaces studied by x-ray magnetic circular dichroism2018
Author(s)
Z. Chi, G. Shibata, S. Sakamoto, Y. Nonaka, K. Ikeda, Y.-X. Wan, Masahiro Suzuki, N. Kawamura, M. Mizumaki, Motohiro Suzuki, M. Sakamaki, K. Amemiya, Y. Lau, M. Hayashi, and A. Fujimori
Organizer
第31回日本放射光学会年会・放射光科学合同シンポジウム
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[Presentation] Soft x-ray spectroscopy and first-principles calculation studies of the electronic structure of the novel high-TC ferromagnetic semiconductor (Ga,Fe)Sb2017
Author(s)
S. Sakamoto, N. Tu, Y. Takeda, S. Fujimori, P. Hai, L. Anh, Y. K. Wakabayashi, G. Shibata, M. Horio, K. Ikeda, Y. Saitoh, H. Yamagami, M. Tanaka, and A. Fujimori
Organizer
IEEE International Magnetics Conference (INTERMAG Europe 2017)
Int'l Joint Research
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[Presentation] Magnetic anisotropy and anisotropic spin-density distribution in strained La1-xSrxMnO3 thin films revealed by angle-dependent XMCD2017
Author(s)
G. Shibata, M. Kitamura, M. Minohara, K. Yoshimatsu, T. Kadono, K. Ishigami, T. Harano, M. Furuse, M. Okano, J.-i. Fujihira, S. Fujihira, H. Kumigashira, T. Koide, and A. Fujimori et al. (他9名)
Organizer
IUMRS-ICAM 2017 (15-th International Conference on Advanced Materials)
Int'l Joint Research
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[Presentation] Anisotropic spin-density distribution in strained La1-xSrxMnO3 thin films revealed by angle-dependent XMCD2017
Author(s)
G. Shibata, M. Kitamura, M. Minohara, K. Yoshimatsu, T. Kadono, K. Ishigami, T. Harano, M. Furuse, M. Okano, J.-i. Fujihira, S. Fujihira, H. Kumigashira, T. Koide, and A. Fujimori et al. (他9名)
Organizer
Junjiro Kanamori Memorial International Symposium
Int'l Joint Research
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[Presentation] XMCD study on large perpendicular magnetic anisotropy of the new ferromagnetic semiconductor (Ba,K)(Zn,Mn)2As2 single crystal2017
Author(s)
S. Sakamoto, G. Q. Zhao, G. Shibata, Z. Deng, K. Zhao, B. J. Chen, Y. Nonaka, K. Ikeda, Z. Chi, Y.-X. Wan, M. Suzuki, T. Koide, S. Maekawa, Y. J. Uemura, C. Q. Jin, and A. Fujimori
Organizer
Junjiro Kanamori Memorial International Symposium
Int'l Joint Research
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[Presentation] Cation distribution at the interface of epitaxial CoFe2O4/Al2O3/Si(111) films studied by x-ray magnetic circular dichroism2017
Author(s)
Y. Nonaka, Y. K. Wakabayashi, G. Shibata, Y. Takeda, S. Sakamoto, K. Ikeda, Z. Chi, A. Tanaka, Y. Saitoh, H. Yamagami, M. Tanaka, R. Nakane, and A. Fujimori
Organizer
Junjiro Kanamori Memorial International Symposium
Int'l Joint Research
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[Presentation] Anisotropic orbital magnetic moments in L10-ordered FePt thin films studied by Fe and Pt L2,3-edge x-ray magnetic circular dichroism2017
Author(s)
K. Ikeda, T. Seki, G. Shibata, T. Kadono, K. Ishigami, Y. Takahashi, M. Horio, S. Sakamoto, Y. Nonaka, M. Sakamaki, K. Amemiya, N. Kawamura, M. Suzuki, K. Takanashi, and A. Fujimori
Organizer
Junjiro Kanamori Memorial International Symposium
Int'l Joint Research
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[Presentation] Orbital magnetic moment and Dzyloshinskii-Moriya interaction in Co-heavy metal heterostructures2017
Author(s)
Z. Chi, G. Shibata, S. Sakamoto, Y. Nonaka, K. Ikeda, Y.-X. Wan, Masahiro Suzuki, N. Kawamura, M. Mizumaki, Motohiro Suzuki, M. Sakamaki, K. Amemiya, Y.-C. Lau, M. Hayashi, and A. Fujimori
Organizer
Junjiro Kanamori Memorial International Symposium
Int'l Joint Research
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[Presentation] Large perpendicular magnetic anisotropy of the new ferromagnetic semiconductor (Ba,K)(Zn,Mn)2As2 single crystal2017
Author(s)
S. Sakamoto, G. Zhao, G. Shibata, Z. Deng, K. Zhao, B. Chen, Y. Nonaka, K. Ikeda, Z. Chi, Y.-X. Wan, M. Suzuki, T. Koide, S. Maekawa, Y. Uemura, C. Q. Jin, and A. Fujimori
Organizer
第78回応用物理学会秋季講演会
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[Presentation] Orbital magnetic moment of heavy metals in Co-heavy metal heterostructures studied by x-ray magnetic circular dichroism2017
Author(s)
Z. Chi, G. Shibata, S. Sakamoto, Y. Nonaka, K. Ikeda, Y.-X. Wan, Masahiro Suzuki, N. Kawamura, M. Mizumaki, Motohiro Suzuki, M. Sakamaki, K. Amemiya, Y. Lau, M. Hayashi, and A. Fujimori
Organizer
第78回応用物理学会秋季講演会
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