It was recalled that the diffusion of individual metal atoms on a metal was usually viewed as being a random walk between adjacent sites. The actual jump processes which participated in atomic migration were determined here by measuring the distribution of displacements for a single W or Pd atom on W(211), where diffusion was 1-dimensional. In the case of the self-diffusion of a W adatom, only jumps between nearest-neighbor sites contributed. However, in the case of relatively weakly bound Pd atoms, significant contributions which arose from jumps that spanned 2 or 3 nearest-neighbor distances were identified.

D.C.Senft, G.Ehrlich: Physical Review Letters, 1995, 74[2], 294-7