A theoretical model was proposed for investigating the surface self-diffusion of single adatoms on the face-centered cubic metals. Calculations were performed on both close-packed (111) and loosely packed (001) planes of rhodium and nickel. Two realistic model potentials were applied to describe the interatomic interaction of the adatom/substrate systems. The first model was a Morse-type potential, which involved several empirical fitting of bulk properties of solid. A second potential was introduced by Sutton and Chen, which incorporated many-body effects. With these potentials, conventional molecular dynamics was used to obtain the trajectories of the atoms. The averaged square displacements were computed for a range of initial kinetic energies, and the surface diffusion constants could be obtained by means of the Einstein relation. The estimated random walk exponential pre-factors and activation energies exhibited Arrhenius behavior, which were confirmed with previous results. Surface migration by an exchange mechanism for self-diffusion on the Ni(001) plane was also considered.

Molecular Dynamics Simulation of Adatom Diffusion on Metal Surfaces. Shiang, K.D.:  The Journal of Chemical Physics, 1993, 99[12], 9994-10000