The mass transport of Ag on stepped (111) surfaces was investigated by means of scanning Auger microscopy. Highly anisotropic surface diffusion of Ag ultra-thin films was observed on 0, 0.5, 3 and 6º vicinal (111). Mass transport in a direction which was parallel to the step edge was overwhelmingly greater than that perpendicular to the edge. Preferential mass transport towards the cathode, due to direct-current heating, was also observed. This increased with the resistivity of the (111) substrate. The anisotropic mass transport was related to the difference in the binding energies at step-edge sites and at terrace sites.

N.J.Wu, A.Natori, H.Yasunaga: Surface Science, 1991, 242[1-3], 191-4