磁気は,原子から鉄,コバルト,ニッケル・クラスターの質量まで広がる
Science (New York, N.Y.)
|September 16, 1994
まとめ
鉄,コバルト,ニッケル・クラスターの磁性は,小さなサイズでも現れます. 磁気モメントはクラスターの大きさとともに大きくなり,塊の値に近づき,振動はおそらくスピン密度波によるものである.
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:
- ナノスケール材料の磁気性を理解することは,新しい技術の開発に不可欠です.
- クラスターの大きさ,温度,磁気特性の関係については,詳細な調査が必要である.
研究 の 目的:
- 鉄,コバルト,ニッケル・クラスターにおける磁力の発展を調査する.
- 磁気特性をクラスタサイズと温度と相関させるため.
- これらのクラスターにおける磁気力の根本的なメカニズムを解明する.
主な方法:
- 分子ビームの傾斜測定を用いた.
- 実験は,80~1000Kの温度範囲で実施されました.
- クラスターの大きさは,数十から数百の原子まで様々でした.
主要な成果:
- 鉄磁気は,最小のクラスターでも観察されました.
- 磁気モメントはクラスターの大きさとともに増加し,鉄,コバルト,ニッケルの大量値に近づきました.
- 磁気モメントの振動が検出され,表面に誘発されたスピン密度波による可能性がある.
- 鉄のクラスターでは,高磁気モーメントから低磁気モーメントへの結晶学的相変化が確認されました.
結論:
- 磁気殻モデルは,磁気における観測された傾向を効果的に説明します.
- 表面効果は,これらのクラスターの磁気行動に重要な役割を果たします.
- 大きさに依存する磁気と相変遷は,鉄,コバルト,ニッケル・クラスターの重要な特徴である.
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