计算物理 ›› 2004, Vol. 21 ›› Issue (5): 439-442.

• 研究论文 • 上一篇    下一篇

Mg-Si基热电材料量子化学计算

姜洪义, 刘琼珍, 张联盟, 闵新民   

  1. 武汉理工大学材料学院, 湖北 武汉 430070
  • 收稿日期:2003-05-19 修回日期:2004-01-18 出版日期:2004-09-25 发布日期:2004-09-25
  • 作者简介:姜洪义(196l-),男,山东烟台,教授,硕士,从事功能陶瓷材料方面的研究,武汉市洪山区珞狮路122号.

Calculation of Quantum Chemistry for Mg-Si Based Thermoelectric Material

JIANG Hong-yi, LIU Qiong-zhen, ZHANG Lian-meng, MIN Xin-min   

  1. Department of Material Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
  • Received:2003-05-19 Revised:2004-01-18 Online:2004-09-25 Published:2004-09-25

摘要: 对于掺杂合适的元素Sb,Te,Ag,Cu使得Mg-Si基热电材料的热电性能大幅度提高的实验事实,欲从理论和计算上寻求支持,试图从原子、分子的层次上对此现象作出解释,因此建立了简化的Mg2Si量子化学计算模型,采用密度泛函离散变分Xα量子化学计算法,计算了物质内部的结构信息,如共价键级和态密度等.计算结果表明,掺杂以后,晶体的共价键级被削弱,态密度图中的禁带宽度明显变窄,这与实验测试的结果是一致的.

关键词: 热电转换效应, Mg2Si, 掺杂, 量子化学计算

Abstract: Doping of moderate elements Sb,Te,Ag,Cu can greatly improve the thermoelectric properties of Mg2Si. For explaning the experimental result,a calculable model is presented.It applies DV-Xα quantum chemistry computation to reveal the micro-structure information, such as the covalent bond grade and the density of state. The calculated results imply that the covalent bond grade of Mg-Si are decreased and the forbidden gaps become narrower after doping. This results appears to be consistent with the experiments.

Key words: thermoelectric conversion effect, Mg2Si, doping, quantum chemistry computation

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