Hybridization of Cr 3d-N 2p-Ga 4s in the wide band-gap diluted magnetic semiconductor Ga1-xCrxN
問い合わせ番号
SOL-0000000942
ビームライン
BL47XU（マイクロCT）
学術利用キーワード
| A. 試料 | 無機材料 |
|---|---|
| B. 試料詳細 | 半導体, 磁性体 |
| C. 手法 | 光電離、二次電子 |
| D. 手法の詳細 | 光電子分光 |
| E. 付加的測定条件 | 界面 |
| F. エネルギー領域 | Ｘ線（4～40 keV) |
| G. 目的・欲しい情報 | 機能発現, 電子状態、バンド構造, スピン・磁性構造 |
産業利用キーワード
| 階層1 | 半導体 |
|---|---|
| 階層2 | 化合物半導体 |
| 階層3 | 電極 |
| 階層4 | 電子状態, 化学状態 |
| 階層5 | XPS |
分類
A40.40 表面・界面化学, A80.12 半導体・電子材料, A80.14 磁性材料, M50.10 光電子分光
利用事例本文
Hole-mediated ferromagnetism has produced reliable estimates of Curie temperature (Tc) for diluted magnetic semiconductors (DMS) such as GaMnAs and predicts that GaMnN will have a Tc above room temperature (RT). However, since doped transition metals introduce deep levels in wide band gap semiconductors like GaN and carriers are localized in these states, it may be difficult to apply the hole-mediated ferromagnetism model to wide band gap GaN-based DMS. Therefore, a different mechanism for magnetism will play a role in GaN-based DMS rather than hole-mediated ferromagnetism. In order to get insight into the mechanism of the magnetism, an electronic structure investigation of GaN-based DMS is necessary. In this research, we have investigated the electronic structure of Cr-doped GaN observed by bulk sensitive hard X-ray photoemission spectroscopy at the excitation energy of 5.95keV. Figure shows the normalized energy distribution curves (EDC’s) of undoped GaN, that of Ga0.899Cr0.101N, and the difference spectrum between them, respectively. The Cr-doping does introduce, clearly, new electronic levels in the band gap (C) and causes some change in the valence band structure (A and B). Considering atomic subshell cross section at the excitation energy, the main contribution of the valence band spectra is Ga 4s. The decrease of the intensity in the valence band spectrum by Cr-doping is not only due to the decrease of Ga content but also to the effect of Cr-doping. Namely, the Cr-doping effect on the valence band of GaN and make the in-gap energy state by hybridization between Cr 3d and the second neighbor Ga 4s via the formation of Cr-N bonds. In the Ga 2p core level study, we also observed that the Cr doping influences the second neighbor Ga via the formation of Cr-N bonds. The strong hybridization between Cr 3d and the second neighbor Ga 4s induce the long range interaction between Cr 3d electrons and may an important role in the ferromagnetism of Ga1-xCrxN.
The normalized energy distribution curves (EDC’s) of undoped GaN, that of Ga0.899Cr0.101N, and the difference spectrum between them, respectively.
[ J.-J. Kim, H. Makino, K. Kobayashi, Y. Takata, T. Yamamoto, T. Hanada, M.-W. Cho, E. Ikenaga, M. Yabashi, D. Miwa, Y. Nishino, K. Tamasaku, T. Ishikawa, S. Shin and T. Yao, Physical Review B 70, 161315(R) (2004), Fig. 1,
©2004 American Physical Society ]
画像ファイルの出典
原著論文/解説記事
誌名
Phys.Rev.B70, 161315(R)(2004)
図番号
測定手法
In this research, we have investigated the electronic structure of Cr-doped GaN observed by bulk sensitive hard X-ray photoemission spectroscopy at the excitation energy of 5.95 keV.
画像ファイルの出典
原著論文/解説記事
誌名
Phys.Rev.B70, 161315(R) (2004)
図番号
測定準備に必要なおおよその時間
１ シフト
測定装置
| 装置名 | 目的 | 性能 |
|---|---|---|
| Hard X-ray Photoemission Spectroscopy System | Analysis of electronic states in solid and/or interface | Total Energy Resolution: 85meV |
参考文献
関連する手法
アンケート
SPring-8だからできた測定。他の施設では不可能もしくは難しい
本ビームラインの主力装置を使っている
最近2年以内に導入した装置を使った事例
測定の難易度
初心者でもOK
データ解析の難易度
中程度
図に示した全てのデータを取るのにかかったシフト数
4～9シフト