CePd3+xGa8-x的结构和相变:BaHg11结构类型的新变体
Melanie C Francisco1, Christos D Malliakas, Robin T Macaluso
1Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
Journal of the American Chemical Society
|August 2, 2012
概括
合成了立方BaHg11结构类型的新的扭曲变体. 这些 (cerium palladium gallium) 化合物表现出可逆相变和潜在的复杂磁性行为,为材料科学研究提供了新的途径.
科学领域:
- 固态化学 固态化学
- 材料科学 材料科学 材料科学
- 晶体学 晶体学是指结晶学.
背景情况:
- 立方体BaHg11结构类型作为新材料合成的基础.
- 了解结构变化和相位过渡对于开发新的功能材料至关重要.
研究的目的:
- 合成和描述BaHg11结构类型的新的扭曲变体.
- 研究CePd3+xGa8-x及其稀土类型的结构性质,相位过渡和潜在物理现象.
主要方法:
- 在Ga流中合成新的化合物.
- 用X射线衍射 (粉末和单晶) 进行结构确定.
- 差异热分析和现场温度依赖的X射线衍射用于相位过渡研究.
- 用于物理性质分析的磁感应,电阻和热容量测量.
主要成果:
- 根据合成条件,成功合成了多个CePd3+xGa8-x相,其结构不同 (正方体,圆柱体,立方体超结构).
- 在640°C左右的低温正方体/圆柱体和高温立方体相之间观察可逆相变.
- 结构分析揭示了与BaHg11类型的轻微扭曲,包括类似卡戈梅的Ce原子排列.
- 合成了稀土类似物 (REPd3+xGa8-x),在较低对称空间组中结晶.
- 物理属性的低温异常表明了孔多,晶体电场和磁效应的存在.
结论:
- 已经成功合成了BaHg11结构类型的新扭曲变体,特别是CePd3+xGa8-x及其类似物.
- 这些材料表现出复杂的结构行为,包括可逆相变和与母结构的扭曲.
- 观察到的物理特性表明复杂的电子和磁相互作用,需要进一步调查.
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