The diffusion of a single adatom on a low-index surface under various conditions (with and without the presence of other adatoms; near, and over, stepped surfaces) was studied by using the embedded-atom method and molecular statics simulations. The migration energies of a Cu adatom in the presence of other Cu adatoms were calculated. Calculations were also made of the formation and migration energies of an adatom and a vacancy in different layers, as well as of the formation energies of steps on various Cu surfaces. It was shown that the step-step interaction was repulsive, and was consistent with elasticity theory. The calculations predicted a lower activation energy for the diffusion of a vacancy, than of an adatom, for all 3 surfaces.

M.Karimi, T.Tomkowski, G.Vidali, O.Biham: Physical Review B, 1995, 52[7], 5364-74