反钙钛矿Mn3Ga1-xSixN1-yCy体系负热膨胀性质的第一性原理研究

项目名称： 反钙钛矿Mn3Ga1-xSixN1-yCy体系负热膨胀性质的第一性原理研究

项目编号： No.51502010

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 王蕾

作者单位： 北京科技大学

项目金额： 21万元

中文摘要： 负热膨胀材料有着广泛的应用领域和发展前景。反钙钛矿化合物作为一类负热膨胀材料，其相关研究已经展开。其中，围绕着Mn3GaN负热膨胀的实验工作已有报道，但相关的理论研究仍然缺乏。共掺杂作为一种更为有效的调控方式，在Mn3GaN 的负热膨胀研究中还没有展开。鉴于此，本项目采用第一性原理方法研究双元素共掺杂体系Mn3Ga1-xSixN1-yCy的负热膨胀性质，母体Mn3GaN的研究作为本项目的基础，之后再开展C和Si分别掺杂的研究工作，探索不同位置的单原子掺杂对体系性质的影响，最后结合已掌握的基本物性和单原子掺杂规律，分析在C和Si共同作用下Mn3Ga1-xSixN1-yCy中电子、磁性和声子性质的变化规律，并在电子、磁性性质相对稳定的情况下，对声子进行调控，进而在整体上达到对体系的负热膨胀调控。此项目的开展可以为实验合理选择掺杂元素和掺杂浓度调控反钙钛矿锰基化合物的负热膨胀性质提供思路和参考。

中文关键词： 反钙钛矿；负热膨胀；第一性原理

英文摘要： Negative thermal expansion (NTE) materials have wide application fields and development prospects. Experimental work on the NTE properties of antiperovskite manganese–based compounds has been launched. At present, the experimental investigations on tuning NTE properties of Mn3GaN have been reported, however, the related theoretical research is absent. The co-doping method, as a more effective means for tuning NTE, has not been applied into Mn3GaN. In view of this, within the framework of first-principles calculations, this project is dedicated to a gradual in-depth research of the NTE properties of Mn3Ga1-xSixN1-yCy. The investigation of Mn3GaN forms the foundation in the project. Thereafter, the Mn3GaN-based systems doped separately by C and Si are explored in detail to study mechanism of the varying physical properties. Finally, the investigations of electronic, magnetic and phonon properties of Mn3Ga1-xSixN1-yCy system are performed. Under the condition of stable electronic and magnetic properties, it is committed to tune the phonon contribution to thermal behavior and further control the NTE behavior on the whole. This project will provide ideas and reference for experimental work to control the NTE of antiperovskite manganese–based compounds by choosing the doping elements and doping concentration reasonably.

英文关键词： antiperovskite;negative thermal expansion;first principles