物理化学学报 >> 2004, Vol. 20 >> Issue (12): 1423-1427.doi: 10.3866/PKU.WHXB20041205

研究论文 上一篇    下一篇

从头计算方法比较TiSi2的C54相和C49相

汪涛;戴永兵;欧阳斯可;沈荷生;王庆康;吴建生   

  1. 上海交通大学微纳米科学技术研究院;上海交通大学材料科学与工程学院,上海 200030
  • 收稿日期:2004-05-21 修回日期:2004-07-12 发布日期:2004-12-15
  • 通讯作者: 汪涛 E-mail:Email:wangtao@sjtu.edu.cn

Comparison between C54 and C49 Phase of TiSi2 by ab initio Calculaltions

Wang Tao;Dai Yong-Bing;Ouyang Si-Ke;Shen He-Sheng;Wang Qing-Kang;Wu Jian-Sheng   

  1. Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University; School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030
  • Received:2004-05-21 Revised:2004-07-12 Published:2004-12-15
  • Contact: WANG Tao E-mail:Email:wangtao@sjtu.edu.cn

摘要: 采用平面波超软赝势描述多电子体系,利用密度泛函理论和广义梯度近似,计算出C54相和C49相TiSi2的晶格常数、体弹性模量、形成能、电子态密度(DOS)和Mulliken电荷布居等性质.通过比较这两种物质的性质,发现尽管两者形成能很相近,但C49相结构对称性差、体弹性模量小、熔点低, Ti原子d轨道的反键强、离子性弱.这些性质上的差异和C49相TiSi2在固相反应中优先形成有关.

关键词: TiSi2, 体弹性模量, 从头计算, 超软赝势

Abstract: The ab initio plane-wave ultrasoft pseudopotential method based on generalized gradient approximation (GGA) has been utilized to compare C49 and C54 TiSi2 in terms of the structural, elastic and electronic properties. It has been and found out that C49 TiSi2 has less symmetry and smaller bulk modulus, lower melting point, stronger antibonding states above Femi level, weaker ionicity than C54 TiSi2, even though their formation energies are almost equal to each other.

Key words: TiSi2, Bulk modulus, Ab initio, Ultrasoft pseudopotential