在热电充满的 skutterudites 的温度诱导带重新规范化的第一原则研究
Jinyan Ning1, Wenxin Lei1, Jiong Yang1,2
1Materials Genome Institute, Shanghai University, Shanghai 200444, China. jiongy@t.shu.edu.cn.
Physical chemistry chemical physics : PCCP
|September 23, 2023
概括
温度影响热电 skutterudites 的带结构. 电子 - 声波合会影响带间隙和分散,随着温度的增加影响材料特性.
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:
- 带间隙和分散等带结构属性对于材料的功能至关重要.
- 由于格子膨胀和原子振动,温度变化显著影响这些电子性质.
- 热电 (TE) 材料对于能量转换至关重要,了解它们的温度依赖性行为是关键.
研究的目的:
- 为了研究 TE 填充 skutterudites 的带结构上的温度影响: BaCo4Sb12, BaFe4Sb12 和 YbFe4Sb12.
- 分析电子 - 声子相互作用如何随着温度的变化而改变带特征.
- 提供有关电子结构和TE性能之间的关系的见解.
主要方法:
- 使用第一原则的电子 - 声子重规范化方法.
- 在不同温度下计算和比较带结构.
- 分析频段间隙变化,频段分散和电子能量线宽.
主要成果:
- 与CoSb3.3相比,BaCo4Sb12的带隙随着温度的增加而减慢.
- 在BaFe4Sb12 (~0.222 eV) 和YbFe4Sb12 (~0.201 eV) 中观察到显著的带间隙减少,从0K到800K.
- 在高温下 Γ 点附近的波段分散保持相似,但在费米水平附近的线宽增加,表明更强的电子 - 声波合.
结论:
- 声波振动诱导电子结构障碍,影响带属性和TE性能.
- 在被研究的 skutterudites 中,电子 - 声子合强度各不相同.
- 这项研究增强了对充满 skutterudites 的温度依赖带结构及其对热电应用的影响的理解.
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