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向後 純也*; 藤原 秀紀*; 関山 明*; 斎藤 祐児; 梅津 理恵*; 二木 かおり*
Journal of the Physical Society of Japan, 91(3), p.034702_1 - 034702_12, 2022/03
被引用回数:0 パーセンタイル:0(Physics, Multidisciplinary)We report magnetic circular dichroism in extended X-ray absorption fine structure (EXAFS) in a prototypical halfmetallic ferromagnet, CoMnSi. The EXAFS oscillations at the Mn L edges are analyzed to obtain parameters used in the analysis of the magnetic EXAFS (MEXAFS). Theoretical calculations of MEXAFS spectra in CoMnSi show that the linear-path scatterings have larger contributions than the multiple triangular-path scatterings. Furthermore, the period of the oscillations in the MEXAFS spectra is shorter than that in the EXAFS spectra indicating that the far site contributions from the second to the fourth nearest neighbor Co and the third nearest Si atoms can strongly influence the MEXAFS oscillations, while the Mn atoms, despite the large magnetic moment, can have little contributions due to the interference of the spin components.
藤原 秀紀*; 梅津 理恵*; 黒田 文彬*; 宮脇 淳*; 樫内 利幸*; 西本 幸平*; 永井 浩大*; 関山 明*; 入澤 明典*; 竹田 幸治; et al.
Scientific Reports (Internet), 11(1), p.18654_1 - 18654_9, 2021/09
被引用回数:0 パーセンタイル:0(Multidisciplinary Sciences)Band-gap engineering is one of the fundamental techniques in semiconductor technology. To fully utilize the spintronic material, it is essential to optimize the spin-dependent electronic structure in operando conditions by applying the magnetic and/or electric fields. Here we present a new spectroscopic technique to probe the spin-polarized electronic structures by using magnetic circular dichroism (MCD) in resonant inelastic soft X-ray scattering (RIXS) under an external magnetic field. Thanks to the spin-selective dipole-allowed transitions in the RIXS-MCD, we have successfully demonstrated the direct evidence of the perfectly spin-polarized electronic structures for the prototypical halfmetallic Heusller alloy, CoMnSi. The RIXS-MCD is a promising tool to probe the spin-dependent carriers and band-gap with element specific way induced in buried magnetic layers under operando conditions.
吉川 智己*; Antonov, V. N.*; 河野 嵩*; 鹿子木 将明*; 角田 一樹; 宮本 幸治*; 竹田 幸治; 斎藤 祐児; 後藤 一希*; 桜庭 裕弥*; et al.
Physical Review B, 102(6), p.064428_1 - 064428_7, 2020/08
被引用回数:2 パーセンタイル:12.54(Materials Science, Multidisciplinary)X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) spectroscopy were applied at the Ge (Ga) edge to unravel the spin-resolved unoccupied electronic states of CoMnGe (Ga). Complicated spectral features were observed in both XAS and XMCD spectra. For their interpretation, we compared the experimental XAS and XMCD spectra with the calculated Ge (Ga) 4 and 4 orbital partial density of states. The comparison enabled a qualitative explanation of the XMCD spectra as the difference between the majority and minority-spin unoccupied density of states summed over the 4 and 4 orbitals. Our finding provides a new approach to uncover the spin-split partial density of states above the Fermi level.
河野 嵩*; 鹿子木 将明*; 吉川 智己*; Wang, X.*; 角田 一樹*; 宮本 幸治*; 室 隆桂之*; 竹田 幸治; 斎藤 祐児; 後藤 一希*; et al.
Physical Review B, 100(16), p.165120_1 - 165120_6, 2019/10
被引用回数:5 パーセンタイル:27.17(Materials Science, Multidisciplinary)Resonant photoelectron spectroscopy at the Co and Mn 2 core absorption edges of half-metallic CoMnGe has been performed to determine the element-specific density of states (DOS). A significant contribution of the Mn 3 partial DOS near the Fermi level () was clarified by measurement at the Mn 2 absorption edge. Further analysis by first-principles calculation revealed that it has symmetry, which must be responsible for the electrical conductivity along the line perpendicular to the film plane. The dominant normal Auger contribution observed at the Co 2 absorption edge indicates delocalization of photoexcited Co 3 electrons. The difference in the degrees of localization of the Mn 3 and Co 3 electrons in CoMnGe is explained by the first-principles calculation.
永井 浩大*; 藤原 秀紀*; 荒谷 秀和*; 藤岡 修平*; 右衛門佐 寛*; 中谷 泰博*; 木須 孝幸*; 関山 明*; 黒田 文彬*; 藤井 将*; et al.
Physical Review B, 97(3), p.035143_1 - 035143_8, 2018/01
被引用回数:22 パーセンタイル:69.75(Materials Science, Multidisciplinary)フェリ磁性体MnVAl単結晶の電子構造を軟X線吸収磁気円二色性(XMCD)、軟X線共鳴非弾性散乱(RIX)によって調べた。全ての構成元素のXMCD信号を観測した。Mn L XMCDの結果は、密度汎関数理論を基にしたスペクトル計算により再現でき、Mn 3状態の遍歴的性質が明らかとなった。V LXMCDの結果はイオンモデル計算によって定性的に説明され、V 3電子はかなり局在的である。この描像は、V L RIXSで明らかとなった局所的な遷移と矛盾しない。