Decay of an island on a facet via surface diffusion

We study the decay process of a small island formed on a facet by numerical integration of a simple model and by theoretical analysis. The relaxation proceeds via surface diffusion without evaporation and impingement of atoms . Steps on the top of the island shrink due to the step tension and a small facet appears. The size of the facet increases as the power of time R-f si milar to t(v), where the exponent v depends on the initial shape and the ra te limiting process. In the kinetics-limited case, step bunching occurs fro m the bottom and the enlargement of the facet stops at some stage. Analytic al expressions for the bunch velocity and the island profile are found.