3次元金属原子の磁性アニソトロピーの限界に達する
Ileana G Rau1, Susanne Baumann2, Stefano Rusponi3
1IBM Almaden Research Center, 650 Harry Road, San Jose, CA 95120, USA.
まとめ
研究者は,コバルト原子をMgO表面に固定することで,単一のコバルト原子の最大磁性アニソトロピーを達成しました. この画期的な発見は,性能を向上した先端のナノ磁石の開発の道を開く.
科学分野:
- マテリアルサイエンス 材料科学
- 凝縮物質物理学 凝縮物質物理学
- 表面科学とは,地表科学である.
背景:
- ナノ磁石の設計には,磁性アニソトロピーが大きいシステムが必要です.
- 現在の単分子磁石と鉄磁石膜は,原子あたりの磁性アニソトロピーエネルギーが理論上の限界を大幅に下回っている.
- 原子のスピン・軌道相互作用は,磁性アニソトロピーの理論的最大値を決定する.
研究 の 目的:
- 3次元移行金属原子の最大磁性アニソトロピーを達成するために.
- 強化された磁性特性を得るために,単一のコバルト原子をMgO{100}) 表面に調整する可能性を調査する.
主な方法:
- マグネシウム酸化物 (MgO) の表面 (MgO) の酸素 (O) 部位に単一のコバルト (Co) 原子の調整.
- 磁気アニソトロピーを測定するためのスキャニングトンネルスペクトロスコーピー (STS).
- 軌道磁気モメントを検知するために,X線磁気円形二重化 (XMCD) を用いる.
主要な成果:
- 58ミリエレクトロンボルト (meV) の記録的なゼロフィールド分裂が,単一のCO原子で達成されました.
- コアトムの磁気化の緩やかな緩和が観察され,安定した磁気状態を示した.
- O吸附部位における支配的な軸性リガンドフィールドは,平面外単軸性アニソトロピーの起源として特定されました.
結論:
- この研究は,3次元移行金属原子の最大磁性アニソトロピーの実現を実証しています.
- 単一の Co 原子を MgO の O 部位 ((100) 表面に固定することは,高度にアニゾトロピックなナノスコピック磁石を作成するための実行可能な戦略です.
- この発見は,高度な磁気ストレージとスピントロニックデバイスの開発に新たな道を開く.
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