单原子填充方钴矿热电材料微观力学行为的分子动力学模拟研究

项目名称： 单原子填充方钴矿热电材料微观力学行为的分子动力学模拟研究

项目编号： No.11302156

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 杨绪秋

作者单位： 武汉理工大学

项目金额： 26万元

中文摘要： 填充式方钴矿是通过在方钴矿化合物的本征晶格孔洞中部分填充杂质原子的一类最具应用价值的中温热电材料。已有的研究表明，填充原子的引入可实现电热输运的协同调控，从而大幅度提高方钴矿的热电性能，但填充原子的引入对方钴矿力学行为的影响规律目前尚不明确。本项目以三类典型原子（碱金属、碱土金属与稀土金属原子）单填充方钴矿晶体为研究对象，以揭示单原子填充对方钴矿晶体力学行为的影响规律及其物理机制为目标，研究填充原子与框架原子之间的相互作用特性和填充原子的引入对框架原子之间相互作用的影响，以此建立填充式方钴矿晶体的原子间作用势，发展分子动力学模拟方法，获得填充式方钴矿晶体在不同温度下的力学行为，研究填充原子种类和填充量对单原子填充方钴矿热电材料本征力学性能的影响规律及其物理机制，并探索微缺陷对材料力学性能的影响规律，为发展高性能填充方钴矿热电材料奠定力学基础。

中文关键词： 热电材料；填充方钴矿；力学性能；分子动力学；锑化钴

英文摘要： Filled skutterudites, i.e., partially filling the intrinsic crystal voids of skutterudites with various filler atoms, is a class of novel medium-temperature thermoelectric materials. It is sufficiently understood that the inducing of filler atoms can realize the collaborative controlling of electric and thermal transport, and thus significantly promote the thermoelectric performances. However, the effect of atom filling on the mechanical behavior of skutterudites is not very clear so far. The present program aims to reveal the impact pattern and its physical mechanism of single filling on the mechanical behavior of crystalline skutterudites, for the three typical single-filled (alkali metal, alkaline-earth metal, and rare-earth metal) skutterudites. The interatomic interaction features between the filling atoms and the host atoms, and the impact of inducing filling atoms on the interatomic interactions of host atoms are studied, then the interatomic potentials are constructed to carry out the molecular dynamics simulations. The mechanical behavior of filled crystalline skutterudites is obtained at different temperatures. The impact pattern and its physical mechanism of single filling of different filling atoms or different filling fractions on the intrinsic mechanical performances of skutterudites are revealed.

英文关键词： Thermoelectric Materials；Filled Skutterudites；Mechanical Properties；Molecular Dynamics；CoSb3