The diffusion of vacancies and adatoms at thermal equilibrium on stepped metallic surfaces in the random walk limit was considered. For the simplest models of generation of adatoms and vacancies from the opposite edges of a terrace it was pointed out that, in the absence of annihilation, the coverage on a terrace was usually uniform. When terrace edge barriers imperfectly confined the walkers, their average coverage exhibited a linear decrease away from the generating edge. When adatom–vacancy annihilation processes were included, the average coverage exhibited an approximately parabolic dependence upon the distance from the generating terrace edge.

Diffusion of Vacancies and Adatoms on Stepped Crystalline Surfaces. G.Hare, L.D.Roelofs: Surface Science, 2002, 511[1-3], 283-93