在一个广泛的温度范围内,零热膨胀和铁磁力在立方 Sc(1-x) M(x) F3 (M = Ga,Fe) 中
Lei Hu1, Jun Chen, Longlong Fan
1Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
Journal of the American Chemical Society
|September 19, 2014
概括
研究人员在300-900 K的 (Sc1-xMx) F3材料中实现了不寻常的同位热零热膨胀 (ZTE). 这一突破为高级应用提供了在高温下罕见的,稳定的ZTE特性.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 晶体学 晶体学是指结晶学.
背景情况:
- 零热膨胀 (ZTE) 是一种罕见的特性,材料在温度变化时既不膨胀也不收缩.
- 大多数已知的ZTE材料仅在室温以下的温度下表现出这种行为.
- 在高温下实现同位素ZTE是一个重大的科学挑战.
研究的目的:
- 报告在一个扩展的高温范围内发现非传统的同位素ZTE的立方体 (Sc1-xMx) F3 (M = Ga, Fe).
- 通过局部和宏观的结构分析来调查ZTE财产的结构起源.
- 探索这些ZTE材料中多功能性质的潜力.
主要方法:
- 立方体 (Sc1-xMx) F3化合物的合成和表征.
- 用于宏观晶体结构分析的X射线衍射 (XRD).
- 对分布函数 (PDF) 对同步子辐射X射线总散射的分析,用于局部结构确定.
主要成果:
- 在 (Sc0.85Ga0.05Fe0.1) F3中观察到非常规的同位素ZTE,温度范围广泛 (300-900K),线性CTE为2.34×10−7K−1).
- 宏观立方体结构 (Pm3̅m) 通过XRD证实,而局部结构分析显示了轻微的圆角面扭曲.
- 假设局部结构扭曲减弱了负热膨胀贡献,使得中兴通讯成为可能.
结论:
- 该研究成功地在高温下证明了在 (Sc1-xMx) F3 材料中具有同位素的 ZTE,这与现有的 ZTE 材料相比是显著的进步.
- 由阴离子替代引起的局部结构扭曲被确定为实现ZTE这一属性的关键机制.
- 这些ZTE材料显示出多功能性的潜力,包括高Tc铁磁性和窄间隙半导体特性,为未来的应用铺平了道路.
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