A theoretical model was proposed for the investigation of the surface self-diffusion of single adatoms on face-centered cubic metals. Calculations were performed for the channelled (110), densely-packed (111) and loosely packed (001) surfaces of Ir at 800K. Three model potentials (embedded atom, Sutton-Chen, Rosato-Guillope-Legrand) were used to describe the interactions of adatom/substrate systems. These potentials all involved the empirical fitting of bulk properties of solids and incorporated many-body effects. Together with these potentials, conventional molecular dynamics methods were used to obtain the trajectories of the atoms. On the (111) plane, the Einstein relationship, the estimated random walk exponential pre-factors and the activation energies exhibited an Arrhenius behavior which was in reasonable agreement with experimental results. On the (001) and (110) faces, theoretical evidence was found for diffusion via the exchange of adatoms with surface atoms. This was also in fairly good agreement with experiment.

K.D.Shiang, C.M.Wei, T.T.Tsong: Surface Science, 1994, 301[1-3], 136-50