LIGHT-ATOM DIFFUSION AND CLUSTERING AT CRYSTAL-SURFACES

The diffusion of light atoms at a crystal surface is: considered. Nume rical experiments on diffusion at crystal surfaces of different crysta llographic orientation demonstrate the diffusion to be suppressed by t he clusterization process. If bound states of two adatoms do not exist at the surface, a quasi-two-dimensional Wigner crystal is formed, res ulting thus in a drastic decrease in the diffusion coefficient.