Calculations were made of the activation energy barriers to various processes, which involved an atom diffusing around a step edge on the (111), (100) or (110) surfaces, using the nudged elastic band method and interaction potentials that were based upon the embedded atom method. In the presence of a neighboring step, the Ehrlich-Schwoebel barrier to an adatom undergoing jumping or exchange at a step edge was found to be independent of the separation between the steps unless they were two atom-widths apart. In that case, the barrier was larger than that for an isolated step. The influence of the local step geometry upon the diffusion energetics was also considered.

Effect of Step-Step Separation on Surface Diffusion Processes. S.Durukanoğlu, O.S.Trushin, T.S.Rahman: Physical Review B, 2006, 73[12], 125426 (6pp)