近来热电材料研究领域取得重要突破，报道称MgAgSb基热电材料在近室温温区具有高品质因数且峰值温区较宽，在温差热发电和固态制冷领域应用前景广阔。本项目将主要借助先进的中子散射技术在材料结构及动力学属性研究中的优势，用宽Q区间高分辨中子衍射结合Rietveld方法和对分布函数方法（PDF）重点研究材料的微观结构特征；非弹性中子散射测绘材料中的声子态密度，并尝试使用动力学对分布函数(Dynamic PDF)方法精细化分析局域动力学属性，深入探究声子热导机制。在MgAgSb基体系内，通过在Ag位和Sb位进行组分调控，系统地研究其晶体结构、动力学属性和热电物性随温度、压力及成分等演化的规律，结合第一性原理计算，理解材料的热电属性与微观结构及动力学属性之间的关系，深入探究此材料优越热电性能背后的物理机制，为进一步寻找新型的热电材料提供指导。

A breakthrough on thermoelectric materials was recently reported in MgAgSb-based compounds with high ZT value in a wide temperature range near-room-temperature, simulating the new prospect on the room-temperature application of thermoelectric generation and solid-state cooling. In this project, we will focus on the advantages of neutron scattering techniques in the study of materials structure and dynamic properties. Wide Q-range high resolution neutron diffraction technical will be employed to investigate the sample crystallographic structure by means of the Rietveld method and pair distribution function (PDF) method. Inelastic neutron scattering will be selected to study the phonon properties, and the dynamic PDF analysis will be tried to refine local dynamic properties to go deep into the mechanism of phonon heat conduction. The evolution of the crystallographic structure, atomic dynamics and thermoelectric properties in MgAgSb-based materials will be systematically studied as a function of temperature, pressure and the species and concentration of Ag or Sb ions. In combination of the first principle calculation, the correlation among the thermoelectric properties, crystallographic structure and dynamic characteristics will be interpreted. All those results must be helpful to seek for novel high-ZT thermoelectric materials.