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ヤマガミ ヒロシ
YAMAGAMI HIROSHI
山上 浩志 所属 京都産業大学 理学部 物理科学科 職種 教授 |
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| 発行・発表の年月 | 2017/02/08 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Origin of robust nanoscale ferromagnetism in Fe-doped Ge revealed by angle-resolved photoemission spectroscopy and first-principles calculation |
| 執筆形態 | その他 |
| 掲載誌名 | Physical Review B |
| 出版社・発行元 | American Physical Society (APS) |
| 巻・号・頁 | 95(7) |
| 著者・共著者 | S. Sakamoto,Y. K. Wakabayashi,Y. Takeda,S.-i. Fujimori,H. Suzuki,Y. Ban,H. Yamagami,M. Tanaka,S. Ohya,A. Fujimori |
| 概要 | © 2017 American Physical Society. Ge1-xFex (Ge:Fe) shows ferromagnetic behavior up to a relatively high temperature of 210 K and hence is a promising material for spintronic applications compatible with Si technology. Unlike the prototypical system (Ga,Mn)As where itinerant holes induce long-range ferromagnetic order of the Mn spins, however, its ferromagnetism evolves from robust nanoscale ferromagnetic domains formed in Fe-rich regions. We have studied its underlying electronic structure by soft x-ray angle-resolved photoemission spectroscopy measurements and first-principles supercell calculation. We observed finite Fe 3d components in the states at the Fermi level (EF) in a wide region of momentum space, and the EF was located ∼0.35 eV above the valence-band maximum of the host Ge. Our calculation indicates that the EF is also within the deep acceptor-level impurity band induced by the strong p-d(t2) hybridization. We conclude that the additional minority-spin d(e) electron characteristic of the Fe2+ state is responsible for the short-range ferromagnetic coupling between Fe atoms, making the magnetism markedly different from that of (Ga,Mn)As. |
| DOI | 10.1103/physrevb.95.075203 |
| ISSN | 2469-9950/2469-9969 |
| PermalinkURL | https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85013066362&origin=inward |