物理化学学报 >> 2007, Vol. 23 >> Issue (12): 1912-1916.doi: 10.3866/PKU.WHXB20071215

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α-Al2O3阻氢微观机制研究

李磊; 桑革; 张鹏程; 蒋刚   

  1. 四川大学原子与分子物理研究所, 成都 610065; 表面物理与化学国家重点实验室, 四川 绵阳 621907
  • 收稿日期:2007-06-13 修回日期:2007-08-20 发布日期:2007-11-30
  • 通讯作者: 蒋刚 E-mail:gjiang@scu.edu.cn

Study of α-Al2O3 about Hydrogen Permeation Resistance and Micromechanism

LI Lei; SANG Ge; ZHANG Peng-Cheng; JIANG Gang   

  1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, P. R. China; National Key Laboratory for Surface Physics and Chemistry, Mianyang 621907, Sichuan Province, P. R. China
  • Received:2007-06-13 Revised:2007-08-20 Published:2007-11-30
  • Contact: JIANG Gang E-mail:gjiang@scu.edu.cn

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摘要： 采用基于密度泛函理论广义梯度近似下的平面波赝势方法研究了刚玉(α-Al2O3)的阻氢微观机制, 对氢原子在α-Al2O3中的占据结构进行了计算, 发现氢原子占据空隙位置时能量最低, 寻找其过渡态得到活化能为1.59 eV, 利用动力学计算得到了氢原子在α-Al2O3中的扩散系数表达式为D(T)=(3.37×10-7)exp(-1.59/kT). 结果表明, 氢原子占据在α-Al2O3八面体空隙处的结构最稳定; 低温时扩散难以发生; 高温时扩散沿着空隙方向.

关键词: α-Al2O3, 氢扩散, 密度泛函理论

Abstract: The diffusion of hydrogen in corundum was simulated using pseudopotential plane wave method which was based on the density functional theory(DFT) with the generalized gradient approximation(GGA) to the exchange-correlation energy. The hydrogen permeation resistance and micromechanism were studied by searching the transition state and diffusion route, and gained diffusion coefficient of hydrogen by applying dynamic calculations. The activation energy was 1.59 eVand the diffusion coefficient of hydrogen was D(T)=(3.37×10-7)exp(-1.59/kT). Analyzing the calculation results, it showed that the structure in which H atom occupied empty interstitial of α-Al2O3 was more stable. H diffusion was impossible at low temperature and occured along the empty interstitials at high temperature.

Key words: α-Al2O3, Hydrogen diffusion, Density functional theory