Enhancement of Ag cluster mobility on Ag surfaces by chloridation

摘要

To understand the role of chlorine in the stability and the observed fragmentation of Ag dendritic nanostructures, we have studied computationally two model systems using density functional theory. The first one relates to diffusion of Ag_n and Ag_nCl_m (n = 1-4) clusters on an Ag(111) surface, and the second demonstrates interaction strength of (Ag55)2 dimers with and without chloridation. Based on our calculated energy barriers, Ag_nCl_m clusters are more mobile than Ag_n clusters for n = 1-4. The binding energy between two Ag55 clusters is significantly reduced by surface chloridation. Bond weakening and enhanced mobility are two important mechanisms underlying corrosion and fragmentation processes.