It was recalled that interlayer diffusion was controlled by the probability that an atom would hop from a higher to a lower level. This probability depended upon the additional step-edge barrier which an atom experienced at a step because of the lower coordination as it moved over the barrier, and perhaps because of the differing pre-factors for an atom at the step rather than on the terrace. A re-analysis was made of scanning tunnelling microscopic measurements of the fraction of islands with second-layer occupation at various deposition temperatures. This showed how the 2 contributions could be identified. A diffraction-based method was also developed that measured the step density of nucleated islands as they competed, for atom capture, with steps on the perimeter of the terraces. Reflection high-energy electron diffraction data for Ag on Ag(111) yielded an activation energy of 0.15eV.

Prefactor and Step Edge Barrier Determination for Interlayer Diffusion in Homoepitaxial Systems: Ag/Ag(111). K.R.Roos, M.C.Tringides: Surface Review and Letters, 1998, 5[3-4], 833-40