Surface and Volume Diffusion Controlling Step Movement

Abstract

One of the aspects of crystal growth is the transport of growth units. They are furnished from what we shall call the mother phase. In many experimental situations the mother phase will be well mixed due to convection, turbulence etc. Close to the crystalsurface, however, the flowis retarded and the contribution of diffusion to the transport of growth units increases relative to the convective contribution. If the growth units reach the crystal surface they can be incorporated directly into the steps; the direct incorporation or Chernov mechanism¹⁾. Alternatively, however, they can be depositedon the relatively smooth regions between steps and reach the steps after surface diffusion: the indirect incorporation or Gilmer, Ghez and Cabrera^2–4 mechanism.