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在萨马富勒里德中,温度诱导的价值过渡和相关的晶格崩
J Arvanitidis1, Konstantinos Papagelis, Serena Margadonna
1Department of Chemistry, University of Sussex, Brighton BN1 9QJ, UK.
Nature
|October 10, 2003
概括
稀土富勒化物由于合电子系统而表现出独特的特性. 冷却Sm2.75C60诱导具有显著负热膨胀的相位过渡,与价值变化有关.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 化学 化学 化学
背景情况:
- 强烈相关的电子系统表现出不寻常的物理特性.
- 稀土富勒里德,与合稀土和C60子网格,是有趣的材料.
- 这些系统在理论上很难建模.
研究的目的:
- 研究稀土富勒里德的物理特性.
- 描述Sm2.75C60.0中相变的情况.
- 了解这些材料负热膨胀背后的机制.
主要方法:
- 高分辨率的同步龙X射线衍射.
- 测量磁感应度的测量.
- 热扩张分析.
主要成果:
- 在32K附近的Sm2.75C60中观察到同对称的相位过渡.
- 这种过渡涉及到显著的同位素体积增加和萨玛价值变化.
- 观察到前所未有的负热膨胀,比典型的金属氧化物大40倍.
结论:
- 观察到的负热膨胀归因于萨马的近乎连续的价值转换.
- 这种行为类似于中间价值Kondo绝缘体中的价值过渡.
- 稀土富勒里德为研究强烈相关的电子现象提供了一个新的平台.
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