在热电材料中调整高结构的局部化学波动
Wu Wang1, Shixuan Liu1, Yan Wang1
1Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
Science advances
|June 21, 2024
概括
高材料的局部化学波动显著影响材料的性能. 电子阴性和质量影响这些波动,通过控制晶格导热率来调整热电材料.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 高性材料表现出独特的特性,这是由于在结晶学地点的多个元素的局部化学波动.
- 了解这些波动是设计先进材料的关键,特别是在热电学领域.
研究的目的:
- 确定不同元素特性对高热电材料局部化学波动的贡献.
- 建立调整局部化学波动和格子导热性的基本原则.
主要方法:
- 利用原子分辨率化学绘图来分析局部化学波动.
- 研究了元素特征 (电子负性,质量,半径) 对这些波动的影响.
- 相关的化学键波动与组成依赖的晶格导热率.
主要成果:
- 发现电子阴性和质量对元素波动有相似的影响,而半径对元素波动有很小的影响.
- 通过元素选择调整局部化学波动,诱导了格子扭曲和应变波动,降低了格子的导热性.
- 由电子阴性差异驱动的化学键的波动,与质量和应变场的波动一起,对晶格导热率做出了重大贡献.
结论:
- 提供了对元素特征如何驱动高材料中局部化学波动的基本理解.
- 通过操纵化学和应变波动,演示了调整高热电中的晶格导热率的原理.
相关概念视频
02:19Le Chatelier's Principle: Changing Temperature
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Consistent with the law of mass action, an equilibrium stressed by a change in concentration will shift to re-establish equilibrium without any change in the value of the equilibrium constant, K. When an equilibrium shifts in response to a temperature change, however, it is re-established with a different relative composition that exhibits a different value for the equilibrium constant.
To understand this phenomenon, consider the elementary reaction:
To understand this phenomenon, consider the elementary reaction:
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02:38Third Law of Thermodynamics
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A pure, perfectly crystalline solid possessing no kinetic energy (that is, at a temperature of absolute zero, 0 K) may be described by a single microstate, as its purity, perfect crystallinity,and complete lack of motion means there is but one possible location for each identical atom or molecule comprising the crystal (W = 1). According to the Boltzmann equation, the entropy of this system is zero.
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