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サマリウムフルレリドの温度によるバレンスの移行と関連する格子崩壊
J Arvanitidis1, Konstantinos Papagelis, Serena Margadonna
1Department of Chemistry, University of Sussex, Brighton BN1 9QJ, UK.
Nature
|October 10, 2003
まとめ
稀土フラーリドは,結合電子系によりユニークな性質を呈する. Sm2.75C60を冷却すると,相変遷が起こり,相差が大きくなり,相差が大きくなり,相差が大きくなり,相差が大きくなり,相差が大きくなり,相変遷が起こります.
科学分野:
- 凝縮物質物理学 凝縮物質物理学
- マテリアルサイエンス 材料科学
- 化学 化学は化学です.
背景:
- 強く相関する電子系は,異常な物理的特性を有する.
- rare-earth fulleridesは, rare-earthとC60のサブラットと結合し,興味深い材料となっている.
- これらのシステムは理論的にモデル化することが困難です.
研究 の 目的:
- 稀土フラーリドの物理的性質を調査する.
- Sm2.75C60.0における相変化を特徴づける.
- これらの材料における負の熱膨張の背後にあるメカニズムを理解する.
主な方法:
- 高解像度のシンクロトロンX線微分.
- 磁気感受性の測定 磁気感受性の測定 磁気感受性の測定
- 熱膨張分析. 熱膨張分析. 熱膨張分析. 熱膨張分析. 熱膨張分析. 熱膨張分析. 熱膨張分析.
主要な成果:
- Sm2.75C60で32 K.近くで同対称な相移行が観察されました.
- この移行は,劇的な同位体体積増加とサマリウムのバレンスの変化を伴う.
- 典型的な金属酸化物よりも40倍大きい前例のない負の熱膨張が観察されました.
結論:
- 観測された負の熱膨張は,サマリウムのほぼ連続したバレンスの移行に起因する.
- この振る舞いは,中間値のコンドー断熱器のバレンスの移行に類似しています.
- 稀土のフルレライドは,強く相関する電子現象を研究するための新しいプラットフォームを提供します.
関連する概念動画
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In a nonhomogeneous rod made up of steel and brass, restrained at both ends and subjected to a temperature change, several steps are involved in calculating the stress and compressive load. Due to the problem's static indeterminacy, one end support is disconnected, allowing the rod to experience the temperature change freely. Next, an unknown force is applied at the free end, triggering deformations in the rod's steel and brass portions. These deformations are then calculated and added together...

