Dynamic Simulation of the Migration of Oxygen Vacancy Defects in Rutile TiO 2
Dynamic Simulation of the Migration of Oxygen Vacancy Defects in Rutile TiO 2
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金红石TiO 2 中氧空位缺陷迁移的动态模拟
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
T. Frauenheim
中科院分区：
文献类型：
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作者：
J. Knaup;Michael Wehlau;T. Frauenheim
采用密度泛函紧束缚（DFTB）方法，对金红石型TiO 2中氧空位缺陷漂移/扩散的热力学和动力学进行了模拟.进行了静态和动态仿真。结果表明，DFTB非常适合于研究二氧化钛中氧空位的动态行为。详细的分析表明，强模型尺寸依赖于不同的扩散过程之间的相对扩散势垒高度需要非常小心的缺陷扩散模拟二氧化钛。外电场影响的热力学结果表明，由于介电常数较大，对氧空位扩散的库仑驱动力很小。动态模拟电场对扩散的影响需要使用先进的分子动力学加速方案。
We simulate the thermodynamics and kinetics of the drift/diffusion of oxygen vacancy defects in rutile TiO 2 , using the density-functional based tight-binding (DFTB) method. Both static and dynamic simulations have been performed. Results indicate that DFTB is well suited to examine the dynamic behavior of oxygen vacancies in TiO 2 . Detailed analysis shows, that strong model size dependence in relative diffusion barrier heights between different diffusion processes requires great care in defect diffusion simulations in TiO 2 . Thermodynamic results on the influence of an external electric field show that, due to the large dielectric constant, the coulomb driving force on oxygen vacancy diffusion is very small. Dynamic simulation of the influence of electric fields on the diffusion requires the use of advanced molecular dynamics acceleration schemes.