项目名称: 纳米结构AgSbTe2化合物的非平衡态工艺制备、热电性能及热力学稳定性研究
项目编号: No.51202060
项目类型: 青年科学基金项目
立项/批准年度: 2013
项目学科: 无机非金属材料学科
项目作者: 杜保立
作者单位: 河南理工大学
项目金额: 25万元
中文摘要: AgSbTe2化合物本征具有强烈的晶格振动非简谐性和特殊的电子能带结构,是一种极具潜力的中温热电材料。但其低温下复杂的相组成和潜在的热力学不稳定性严重阻碍了材料的实用化进程。本项目着眼于控制样品制备过程中的动力学参数,通过熔体旋甩快速凝固和放电等离子烧结快速致密化等非平衡制备工艺的联合使用,制备出热力学性质较为稳定的高纯单相多晶样品,实现对其相结构和微结构的同时调控;利用微结构表征,研究其最初的成核、生长机理及特殊纳米孔结构的形成机制;通过少量元素置换改变化合物的成键特性,研究成分改良结合非平衡态工艺制备样品的热电输运特性与微结构、工艺参数的对应关系;评估本工艺制备样品的热力学稳定性,同时论证本工艺及所得特殊纳米结构在热电材料制备中的普遍实用性。
中文关键词: 热电材料;AgSbTe2;掺杂;熔体旋甩;热导率
英文摘要: AgSbTe2 compound is considered as a promising p-type medium-temperature thermoelectric material for a long time due to a special electron band structure and an extreme anharmonicity of the lattice vibrational spectrum. However, the complex phase structure and potential thermodynamic instability at low temperature seriously hinder its practical utilization. In present work, for manipulating the phase composition and microstructure simultaneously, much effort will be put into optimizing the thermodynamic parameter of a non-equilibrium preparation route combining use of melt-spinning fast solidification and spark plasma sintering fast densification techniques. We will explore the nucleation and growth mechanism of the crystals and try to understand the formation mechanism of novel nanopores by microstructure analysis. Then, the combined influences of non-equilibrium preparation route and Se substitute Te on bonds, microstructure, and thermoelectric properties will be investigated systemically. Finally, we will consider the thermodynamic stability of the as-prepared samples. Meanwhile, the general applicability of the non-equilibrium preparation route in other thermoelectric materials will also be studied.
英文关键词: Thermoelectric Materials;AgSbTe2;Doping;Melting Spinning;Thermal Conductivity