Molecular Dynamics Simulation of Deposition of Cu Clusters on a Stepped Cu(111) Surface

Molecular dynamics simulation was used to study the effect of the deposition energy of Cu small clusters (up to 55 atoms) adsorbed on a stepped Cu(111) surface. We have investigated the relation between the deposition energy and the structural stability of the clusters. The Sutton-Chen many-body interatomic potential was adopted to model the energetics and dynamics of both the substrate and the clusters. We have shown that clusters deposited on a stepped surface undergo less change in their structure than those deposited on a smooth surface. The dependence of the shape of the smaller clusters, Cu-13 (magic) and Cu-18 (non-magic), on the deposition energy diminished as compared with deposition on a smooth surface. It is shown that for a deposition energy of 0.9 eV/atom, the clusters retain most of their similarity to their original shapes. It is also found that, while on a smooth surface the Cu-18 cluster formed a monolayer at a deposition energy of 0.5 eV/atom, on a stepped surface this cluster and also the Cu-13 formed 3 layers for the same deposition energy.