聚酸盐和缺陷矿的合成和特性 [He2- □ ][CaNb]F6
Shangye Ma1, Brett R Hester1, Anthony J Lloyd1
1School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States.
概括
在高压下,可以插入CaNbF6,形成一个缺陷的双矿. 这种的结合改变了材料的特性,包括减少负热膨胀和增加其散装模量.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 高压物理 高压物理
背景情况:
- 在压力下,CaNbF6表现出负热膨胀和立方到方形相转换.
- 了解材料在高压下的行为对于开发新技术至关重要.
研究的目的:
- 为了研究将插入到CaNbF6.6中.
- 为了描述由此产生的缺陷,双矿的结构和特性.
- 确定结合对CaNbF6.6的相位行为和机械性能的影响.
主要方法:
- 通过将插入CaNbF6.6中进行高压合成.
- 用于结构分析和量化的中子粉衍射.
- 气体插入和释放的测量.
- 使用兰迈尔异热法进行气体吸附分析.
- 在压缩下进行相位过渡研究的X射线衍射.
主要成果:
- 一种缺陷双矿,[He2- □ ][CaNb]F6,通过在高压下将插入CaNbF6中,成功合成了.
- 的吸收遵循兰格穆尔等热法,吸收度大约为+3(1) kJ mol-1的度,表明度有利.
- 扩散发生在低至~150K的温度下,但被困在100K以下.
- 的结合减少了负热膨胀,增加了散量模量,并使CaNbF6的立方相稳定到>3.7 GPa,防止了先前观察到的相位过渡.
结论:
- 在CaNbF6中插入会产生一种新的缺陷双矿,其特性发生了显著变化.
- 稳定立方相和修改的机械性能对极端条件下的材料有影响.
- 这项研究表明,通过高压气体融入来调整材料性能的新途径.
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