压力诱导的变化在晶体结构和电导率的GeV4S8
Yuejian Wang1, Zhiwei Shen2, Dongzhou Zhang3
1Physics Department, Oakland University, Rochester, Michigan 48309, United States.
Chemistry of materials : a publication of the American Chemical Society
|April 15, 2024
概括
高压将硫化 (GeV4S8) 从34 GPa以上的立方体结构转变为正方体结构. 这种材料还表现出大约15GPa的半导体到非金属导体过渡.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 固态化学 固态化学
背景情况:
- 拉库纳斯皮内尔 (AM4X8) 是独特的三元化物,具有有趣的特性.
- 硫化 (GeV4S8) 是一种具有明显的电磁特征的显著的状旋转子.
- 以前的研究集中在低温行为上,忽视了压力的影响.
研究的目的:
- 研究高压对GeV4S8.8的结构和电气性能的影响.
- 为了确定压力诱导的相变及其机制.
- 阐明结构变化,电子性质和压力之间的关系.
主要方法:
- 使用钻石天细胞进行高压实验.
- 高能同步子X射线衍射和拉曼光谱用于结构分析.
- 四点探头测量和频段间隙评估电气性能.
- 理论计算,包括电子状态密度和带结构分析.
主要成果:
- 从立方到正方形阶段的结构转变发生在34GPa和54GPa之间.
- 在立方 (105 ± 4 GPa) 和正方形 (111 ± 12 GPa) 阶段确定了散装模块.
- 从半导体到非金属导体的电过渡观察到大约15GPa.
- 实验和计算数据证实了电过渡及其与V4集群价值电子的相关性,而不是晶体结构.
结论:
- 高压会导致GeV4S8.8的结构和电气发生重大变化.
- 半导体到非金属导体的转换主要是由V4集群内的价值电子行为驱动的.
- 理论计算支持实验发现,为压力诱导的电子相变提供了更深入的机械学理解.
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