The dynamical behavior of periodic surface profiles on metals under the influence of anisotropic surface energy

Abstract

The kinetics of shaping of periodic surface profiles under the action of surface selfdiffusion were calculated for the special case of anisotropic surface energy. The orientation-dependent surface energy was allowed to contain a local minimum of very high curvature (cusp). The orientation of this cusp was equal to the macroscopic orientation of the crystal surface. The periodic surface profiles exhibited in all cases extended, nearly flat regions centered at the cusp orientation. This type of faceting which causes the profile to be trapezoidal in shape agrees well with experimentally observed profiles on (111) and (100) Ni single crystal surfaces. A procedure is outlined by which the orientation-dependent surface energy along a certain azimuth and the surface self-diffusion coefficient can be extracted from the decay kinetics of faceted periodic surface profiles. This procedure demands the accurate experimental assessment of profile shapes and amplitudes.