Fe团簇在Fe(110)表面上扩散和结构稳定性的分子动力学研究

摘要

采用嵌入原子势和分子动力学方法研究了Fe的小团簇(小于10个原子)在Fe(110)表面上的结构稳定性和扩散特性.计算结果表明体心立方结构的Fe表面,四原子和七原子团簇有较高的转变能和扩散势垒,说明这两种团簇比其他原子团簇更稳定和容易观测到.这两种团簇可能是薄膜生长过程中的临界晶核.研究了三聚体的旋转扩散和团簇扩散过程中二聚体剪切机制,发现二聚体扩散可能是Fe的小团簇在Fe(110)表面扩散的一种重要扩散方式.%By using the embedded-atom-method (EAM) potential and molecular dynamics method, the diffusion and structure stabilities of Fen clusters (n <10) on Fe(110) surface were studied. The calculated results showed that the Fe4 and Fe7 clusters had larger transition energy and diffusion barriers than others. This indicated that these two clusters could be more stable and easily detectable in experiment. Therefore these two clusters might be the critical nucleus in surface film growth. Furthermore, the rotation diffusion of Fe3 cluster and dimer atom' s shear diffusion mechanism in surface diffusion were studied. The dimer atom' s shear diffusion mechanism might be an important diffusion way in surface diffusion.