在固体中进行过渡状态计算的高温效应.
Chengxuan Ke1, Chenxi Nie1, Guangfu Luo1,2
1Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
The Journal of chemical physics
|November 27, 2023
概括
计算高温固体动态在0K的过渡状态会引入错误. 这项研究量化了温度效应,显著减少了理论预测和实验扩散率之间的差异.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 计算材料科学科学 计算材料科学
背景情况:
- 过渡状态计算对于理解固态动态至关重要.
- 对于高温现象使用0K过渡状态数据会引入未知的错误.
- 准确预测固体中的高温动态过程需要考虑温度效应.
研究的目的:
- 为了比较主要温度影响对固体中缺陷扩散的影响.
- 为了评估高温动态0K过渡状态计算的准确性.
- 确定影响缺陷扩散的主导温度依赖因素.
主要方法:
- 运用第一原则计算来评估温度效应.
- 包括格子扩张,格子振动,电子激发和带边移动.
- 计算了缺陷形成能量,跳过障碍物和尝试频率.
主要成果:
- 包括温度效应在内显著减少了理论和实验扩散度之间的差异.
- 格子的膨胀和振动是降低缺陷形成能量和跳跃障碍的主要因素.
- 电子激发具有较小的影响,而带边移动对于半导体来说是显著的.
结论:
- 温度效应,特别是格子膨胀和振动,对于准确的高温缺陷扩散预测至关重要.
- 由于温度的影响,试验频率在不同材料 (例如,Al与4H-SiC) 上有很大差异.
- 这项工作为在高温下更准确地预测固体中的动态过程提供了框架.
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