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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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| 言語種別 | 英語 |
| 発行・発表の年月 | 2017/01 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Origin of the large positive magnetoresistance of Ge1-xMnx granular thin films |
| 執筆形態 | その他 |
| 掲載誌名 | PHYSICAL REVIEW B |
| 出版社・発行元 | AMER PHYSICAL SOC |
| 巻・号・頁 | 95(1),pp.014417 |
| 著者・共著者 | Yuki K. Wakabayashi,Ryota Akiyama,Yukiharu Takeda,Masafumi Horio,Goro Shibata,Shoya Sakamoto,Yoshisuke Ban,Yuji Saitoh,Hiroshi Yamagami,Atsushi Fujimori,Masaaki Tanaka,Shinobu Ohya |
| 概要 | Ge1-xMnx (GeMn) granular thin films are a unique and promising material for spintronic applications owing to their large positive magnetoresistance (MR). Previous studies of GeMn have suggested that the large MR is related to the nanospinodal decomposition of GeMn into Mn-rich ferromagnetic nanoparticles and a Mn-poor paramagnetic matrix. However, the microscopic origin of the MR has not yet been clarified. Here, we develop a method to separately investigate the magnetic properties of the nanoparticles and the matrix, utilizing the extremely high sensitivity of x-ray magnetic circular dichroism (XMCD) to the local magnetic state of each atom. We find that the MR ratio is proportional to the product of the magnetizations originating from the nanoparticles and the matrix. This result indicates that the spin-polarized holes in the nanoparticles penetrate into the matrix and that these holes undergo first order magnetic scattering by the paramagnetic Mn atoms in the matrix, which induces the large MR. |
| DOI | 10.1103/PhysRevB.95.014417 |
| ISSN | 2469-9950/2469-9969 |