Diffusion and adsorption of dimers on reconstructed Pt(1Â 1Â 0) surfaces: First principle and EAM studies

We present a density functional theory (DFT) and embedded atom method (EAM) studies of Pt2, Au2 and AuPt dimers adsorption and diffusion on the clean Pt(110)(1×1) surface and (1×2)(1×3) and (1×4) missing row reconstructed geometries. As a first step, adsorption energies are calculated for all considered dimers, and their stability is checked by computing the binding energies. Furthermore, the energy barriers for the elementary diffusion mechanisms (concerted jump, dissociation-reassociation and leapfrog) are calculated for dimers diffusion on all considered geometries. The potential energy profile for the leapfrog mechanism is provided for dimers diffusion on the (1×2)(1×3) and (1×4) missing row reconstructed geometries. Our results show that each of the three dimers exhibits a qualitatively different behaviours. In addition, the obtained results provide interesting atomistic information about dimers stability and mobility, which is required for understanding the macroscopic kinetics of crystal growth.