Cu在Pt表面扩散激活能和扩散系数的ASED-MO计算

本文应用ASED-MO方法,计算研究了Cu在Pt(111),(100),(110)表面的扩散问题。Cu原子在上述三个表面上的扩散激活能的计算结果分别为0.167eV,0.162eV和0.668eV;300K时的扩散系数分别为3.04×10¹⁰m²/s,3.69×10^-10m²/s和2.42×10^-18m²/s。计算结果表明,Cu原子在Pt(111)和(100)面上,扩散激活能很小,极易迁移,而在(110)面上,激活能较大,扩散系数甚小。

ASED-MO STUDY OF ACTIVATION ENERGIES AND DIFFUSION COEFFICIENTS OF Cu ON Pt SURFACES

Using the ASED-MO method, the chemisorption and surface diffusion of Cu on Pt (111), (100), (110) are studied.The activation energies and the diffusion coefficients at 300K. of Cu atoms on these three Pt Surfaces are 0.167eV, 0.162eV, 0.667eV and 3.04×10¹⁰m²/s,3.69×10^-10m²/s,2.42×10^-18m²/s respectively. It is Shown that,the activation energies are rather small and Cu atomes have a high mobility on Pt (111) and (100) Surfaces;But on Pt(110),the activation energy is comparatively large and the diffusion eoefficient is small.