エレメント置換によるLa(Mn,Zn) AsO合金における室温半金属性
Xingxing Li1, Xiaojun Wu, Jinlong Yang
1Hefei National Laboratory for Physical Science at the Microscale, ‡CAS Key Laboratory of Materials for Energy Conversion and Department of Materials Science and Engineering, and §Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China.
Journal of the American Chemical Society
|March 29, 2014
まとめ
研究者らは,スピントロニックデバイス用の新しい半金属材料を設計した. La(Mn0.5Zn0.5) AsOにおける元素置換は,半金属の隙間が広く,キュリー温度が高くなり,スピントロニック装置の性能を向上させる.
科学分野:
- 材料科学 材料科学とは
- 凝縮物質物理学 凝縮物質物理学
- 固体化学 固体化学
背景:
- 高性能スピントロニックデバイスの開発には,高いキュリー温度,広い半金属のギャップ,大きな磁性アニソトロピーなどの特定の性質を持つ材料が必要です.
- 現在の材料は,しばしばこれらの理想的な特性には満たされないため,新しい化合物の探求が必要になります.
研究 の 目的:
- スピントロニックアプリケーションに望ましい性質を持つ実用的な半金属材料を設計する.
- 元素の置換が,層状のLa(Mn0.5Zn0.5) AsO.の電子および磁気特性に及ぼす影響を調査する.
主な方法:
- 材料の設計と分析に第一原理計算が用いられました.
- 元素置換 (ドーピング) は,系統的にLa(Mn0.5Zn0.5) AsO合金に導入されました.
- イーシングモデルに基づくモンテカルロシミュレーションを使用して,キュリー温度を予測しました.
主要な成果:
- 純粋なLa(Mn0.5Zn0.5) AsO合金は,反鉄磁性半導体である.
- 穴または電子ドーピングにより,0.74 eVの有意な半金属ギャップを持つ半金属性が誘発されました.
- 予測されたキュリー温度は475K (25%Caドーピング) と600K (50%Hドーピング) に達した.
- ドーピングされた合金は,大量のFe,Co,Niを上回る大きな磁性アニソトロピーエネルギーを表しています.
結論:
- 元素置換されたLa(Mn0.5Zn0.5) AsOは,高性能スピントロニックデバイスの有望な候補である.
- 設計された材料は,広い半金属の隙間,高いキュリー温度,および大きな磁性アニソトロピーの好ましい組み合わせを示しています.
- この研究は,高度なスピントロニック材料の開発のための実行可能な経路を提供します.
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