Diffusion and growth on fcc(1 1 0) metal surfaces: a computational study

We use molecular dynamics simulation to produce a map of the adatom migration barriers on several fcc(1 1 0) metal surfaces. The metals have been modeled by many-body potentials within the second moment approximation to the tight-binding model. The estimated barriers are found to be influenced by the proximity of steps and by terrace size. For each metal, the onset temperatures of some important diffusion processes are estimated through a 1-d exactly solvable growth model constructed to describe the growth along the [0 0 1] and the [ 1 1 ¯ 0 ] directions separately. We give for some metals the exact surface profile in the two directions on small samples at low temperatures. The latter suggests the existence of cross-channel ripples at the onset of in-channel jump diffusion in the steady growth state on each fcc(1 1 0) surface due to the strong anisotropy in the intralayer diffusion barriers. These findings are confirmed by kinetic Monte Carlo simulation at relatively low temperatures.