分子动力学模拟Gd原子在Cu(110)表面的扩散过程

为了分析Gd吸附原子在Cu(110)表面的扩散机理，用分子动力学对该扩散过程进行模拟.模拟 结果表明在［1 1 0］方向Gd原子通过跳跃机理扩散，而且多步跳跃频率很高.而在［0 0 1］方向则通过交换机理扩散.吸附原子在［1 1 0］方向的扩散能力要比［0 0 1］ 方向强.通过对扩散频率的拟合，发现两种扩散机理都符合Arrhenius公式，从而确定了跳跃 机理的扩散势垒为0.097eV，交换机理的扩散势垒为0.33eV.另外还用能量弛豫的方法确定了 跳跃机理的扩散势垒. 关键词： 分子动力学 表面扩散 跳跃机理 交换机理 扩散势垒

Molecular dynamics simulation of Gd adatom diffusion on Cu(110) surface

The diffusion mechanisms of Gd adatom on Cu(110) surface are investigated by means of molecular dynamics.The simulation results show that along 1 1 0] direction the Gd adatom diffuses by hopping,and the frequency of long jumps is very high.While along0 0 1]direction,the Gd adatom diffuses by exchanging.The frequency of hopping is higher than that of exchanging.The frequency of hopping and exchanging can be described by Arrhenius equation.The calculated diffusion barrier of hopping is 0.097eV and that of exchanging is 0.33eV.Moreover the diffusion barrier of hopping is calculated by energy relaxation method.