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磁性および金属Tb ((Co,Fe) 2インターメタリック化合物におけるゼロ熱膨張
Yuzhu Song1, Jun Chen1, Xinzhi Liu2
1Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
Journal of the American Chemical Society
|January 3, 2018
まとめ
研究者らは磁性Tb (Co,Fe) 2インターメタリック化合物におけるゼロ熱膨張 (ZTE) を発見した. この希少な金属材料は,広い温度範囲で軽微な熱膨張を示し,高度なアプリケーションに有望です.
科学分野:
- 材料科学
- 凝縮物質物理学
- マグネティズム
背景:
- ゼロ熱膨張 (ZTE) 材料は,温度変化に際して寸法的な安定性を要求するアプリケーションに非常に求められています.
- 金属ベースのZTE化合物は特に稀で,材料開発において重要な課題を提示しています.
- 磁気配列と格子ダイナミクスの相互作用を理解することは,新しいZTE材料の設計に不可欠です.
研究 の 目的:
- 磁気金属間化合物の新しいクラスでゼロ熱膨張 (ZTE) の発見を報告する.
- Tb ((Co,Fe) 2におけるZTEの温度範囲と特性を調査する.
- 観察された ZTE 性質の背後にある物理的メカニズムを解明する.
主な方法:
- Tb ((Co,Fe) 2インターメタリック化合物の合成と特徴付け.
- 広範囲の温度 (123〜307K) で,ディラトメトリーを用いた熱膨張係数の測定.
- 磁気特性の測定と構造分析により,フェリ磁気順序と磁気圧縮効果が理解される.
主要な成果:
- Tb (Co,Fe) 2でゼロの熱膨張 (ZTE) を観測し,Tb (Co,Fe) 0.1で軽微な熱膨張係数 (αl = 0.48 × 10-6 K-1) を観測した.
- 化合物は,C軸に沿ってTbとCo/Feの磁気モメントの反パラレル並列を持つフェリ磁気構造を示している.
- ZTEは,負の自発磁圧 (Tbモメントから) と正の格子膨張のバランスから生じる.
結論:
- Tb ((Co,Fe) 2化合物は,非常に広い温度範囲で希少な金属ベースのゼロ熱膨張 (ZTE) 性質を示しています.
- ZTEの行動は,磁気順序と格子ダイナミクスのユニークな相互作用に起因しています.
- これらの材料は,寸法安定性,高い電気,熱伝導性から恩恵を受けるアプリケーションの可能性を秘めています.
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