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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 | 2020/12/07 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Direct observation of the magnetic ordering process in the ferromagnetic semiconductor Ga1-xMnxAs via soft x-ray magnetic circular dichroism |
| 執筆形態 | その他 |
| 掲載誌名 | JOURNAL OF APPLIED PHYSICS |
| 出版社・発行元 | AMER INST PHYSICS |
| 巻・号・頁 | 128(21),pp.213902-213902 |
| 著者・共著者 | Yukiharu Takeda,Shinobu Ohya,Nam Hai Pham,Masaki Kobayashi,Yuji Saitoh,Hiroshi Yamagami,Masaaki Tanaka,Atsushi Fujimori |
| 概要 | In order to understand the mechanism of the ferromagnetism in the ferromagnetic semiconductor Ga1 - xMnxAs [(Ga,Mn)As], we have investigated the magnetic behavior on a microscopic level through systematic temperature (T)- and magnetic field (H)-dependent soft x-ray magnetic circular dichroism (XMCD) experiments at the MnL2 , 3 absorption edges. TheT andH dependences of XMCD intensities have been analyzed using a model consisting of the ferromagnetic (FM), paramagnetic, and superparamagnetic (SPM) components. Intriguingly, we have found a common behavior for the ferromagnetic ordering process in (Ga,Mn)As samples with different Mn concentrations (4% and 10.8%) and different Curie temperature (TC) values (65, 120, and 164K). In particular, the SPM component develops well aboveTC, indicating that local FM regions are formed well aboveTC. The present findings indicate that the onset of ferromagnetic ordering is triggered by local electronic states around the substitutional Mn ions rather than uniform electronic states considered by mean-field theories. Insight into the most representative ferromagnetic semiconductor, (Ga,Mn)As, provided by the present study will be an important step in understanding the mechanism of ferromagnetic ordering in various ferromagnetic semiconductor families. |
| DOI | 10.1063/5.0031605 |
| ISSN | 0021-8979/1089-7550 |
| PermalinkURL | http://aip.scitation.org/doi/pdf/10.1063/5.0031605 |