Dynamic self-diffusion behaviors of nickel adatoms on clusters with Wulff shape

Abstract

The dynamic self-diffusion behaviors of a nickel (Ni) adatom on the surface of the 4033-atom clusters with Wulff shape are studied. The interfacet and intrafacet self-diffusion processes are simulated via molecular dynamics (MDs) method, and the corresponding energy barriers are calculated by using the nudged elastic band (NEB) method. Based on the research and detailed analyses on all the possible diffusion processes, we found that the interfacet self-diffusion processes and intrafacet self-diffusion processes on the (100) facets are difficult to sustain at room-temperature because of high-energy barriers. However, the Ni adatoms can diffuse the inner (111) facet of the cluster easily either from the center of the facets to the step edges or along the step edges. This means that the epitaxial growth for Wulff[Formula: see text] cannot take place at low-temperature, and all facets of the cluster will grow uniformly.