Shape transition and coalescence of Au islands on Ag (110) by molecular dynamics simulation.

We have used molecular dynamics simulations based on many body semi-empirical potentials described by the embedded atom method, to analyze and understand the diffusion and coalescence phenomena of Au-clusters during the heteroepitaxial growth on Ag (110) surface. Temperature ranging from 300 to 700 K were considered. In this study, we examined the heterogeneous system Aun/Ag(110), where n is the number of atoms in each cluster/island (with n = 15, ….35). Our results show that the clusters diffuse on the Ag (110) surface via different diffusion processes, namely, the exchange mechanism and the simple jump, which generate a 2D to 3D transition. Formation and adsorption energies of clusters with different sizes have been computed using static simulations. The dynamic study of coalescence for two islands of system Au15; Au0 - 9/Ag(110) at different temperatures makes it possible to deduce the detail of cluster shape and the influence of its temperature on the stability of the system and its growth during this evolution.