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Fabrication and Optimization of Type II Silicon Clathrate Films
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在1大气压和高压下的一氧化:晶体或无形?
Khalid AlKaabi1, Dasari L V K Prasad, Peter Kroll
1Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.
Journal of the American Chemical Society
|February 6, 2014
概括
这项研究理论上研究了压力下的一氧化 (SiO) 结构. 它揭示了稳定的地面状态和高压相,发现SiO在高压下是金属的,但不成比例.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学计算化学
- 固态物理 固态物理
背景情况:
- 氧化 (SiO) 是异常的,因为它在环境条件下缺乏晶体相.
- 14组一氧化物表现出不同的稳定性和不成比例的行为.
研究的目的:
- 从理论上探索SiO在1大气中的有序基态和无形结构.
- 在高压下 (高达200 GPa) 调查晶体SiO相.
- 计算晶体SiO的形成和不成比例的热量.
主要方法:
- 在1大气层下对基态和无形结构的理论计算.
- 高压阶段探测高达200 GPa.
- 热力学计算形成热量和不成比例.
主要成果:
- 确定了几种在1 atm时对SiO具有竞争力的基态结构,其中包括Si-Si键和Si-O-Si桥.
- 无形SiO模型显示没有分离到Si和SiO2区域.
- 新的晶体结构在高压下演变,包括Si三角网/条纹和类似于stishovite的区域.
- 在14组单氧化物中,晶体SiO具有最负的形成热量.
- SiO与Si和SiO2的不成比例是外热的,与14组一氧化物趋势一致.
- 高压SiO相被发现是金属的.
结论:
- 在环境和高压下,SiO表现出复杂的结构,挑战其异常地位.
- 尽管形成热量为负,但SiO在不成比例地变成Si和SiO2时是不稳定的.
- 在SiO相中,压力诱导的金属性是一个重要的发现.
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