Kinetic investigations within the transition region from polyhedral to skeletal growth mode (III). Growth kinetics of the basal face of zinc single crystals and its edge under diffusion conditions

Abstract

AbstractThe growth kinetics of the basal face and its edge of zinc single crystals grown from zinc vapours in the presence of argon at pressures 5 – 250 Torr has been investigated simultaneously. The alterations of the crystal size R and the length of the basal edge a with time t have been measured at constant temperature and supersaturation. It is shown that the R2(t) and a2(t) dependences change their initial shape into linear at one and the same moment. It is established that the transition from a kinetic to a diffusion regime can be determined both by the kinetic critical size Rk and by the kinetic critical size ak. It is found also that in the kinetic regime the lateral growth rate of the basal edge is higher than the normal growth rate of the {0001} face. During the growth in a diffusion regime the R2(t) and a2(t) curves of a given single crystal become parallel, due to the isotropic character of the transport processes of the material. The rate determining role of the diffusion in the parent phase on the growth of the basal face and its edge is demonstrated.