物理化学学报 >> 2010, Vol. 26 >> Issue (06): 1664-1668.doi: 10.3866/PKU.WHXB20100607

量子化学及计算化学 上一篇    下一篇

TiO2的相变和热力学性质

胡燕飞, 蒋刚, 蒙大桥, 孔凡杰   

  1. 四川大学原子与分子物理研究所, 成都 610065; 中国工程物理研究院表面物理与化学国家重点实验室, 四川 绵阳 621907
  • 收稿日期:2010-01-11 修回日期:2010-01-31 发布日期:2010-05-28
  • 通讯作者: 蒋刚 E-mail:gjiang@scu.edu.cn

Phase Transition and Thermodynamic Properties of TiO2

HU Yan-Fei, JIANG Gang, MENG Da-Qiao, KONG Fan-Jie   

  1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, P. R. China; National Key Laboratory for Surface Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621907, Sichuan Province, P. R. China
  • Received:2010-01-11 Revised:2010-01-31 Published:2010-05-28
  • Contact: JIANG Gang E-mail:gjiang@scu.edu.cn

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摘要：

利用第一性原理平面波赝势密度泛函理论方法对TiO2从金红石结构到萤石结构的相变进行了理论研究, 并且通过准谐德拜模型分别得到了金红石和萤石结构TiO2的热力学性质. 计算结果与实验值以及其它理论计算的结果都符合得很好, 通过吉布斯能的计算得到TiO2从金红石结构到萤石结构的相变压强为47.74 GPa, 并成功地获得了相对体积(V/V0)、德拜温度(Θ)和热容(CV)随压强(p)和温度(T)的变化关系.

关键词: 密度泛函理论, TiO2, 热力学性质, 相变, 准谐德拜模型

Abstract:

The phase transition of TiO2 from the rutile structure to the fluorite structure under pressure was investigated by the first principles plane-wave pseudopotential density functional theory method. The thermodynamic properties of the rutile and fluorite structures for TiO2 were obtained by the quasi-harmonic Debye model. The results obtained are in good agreement with the experimental data and other theoretical results. We found that the rutile-to-fluorite transition of TiO2 occurred at 47.74 GPa from the Gibbs energy calculations. Moreover, the dependence of the relative volume (V/V0 ), the Debye temperature (Θ) and the heat capacity (CV) on the pressure (p)as well as the heat capacity (CV) on the temperature (T) were also successfully obtained.

Key words: Density functional theory, TiO2, Thermodynamic property, Phase transition, Quasi-harmonic Debye model

MSC2000: 

  • O641