Kinetic self-stabilization of a stepped interface: binary alloy solidification

Abstract

For growth of a vicinal face at constant velocity, the effect of anisotropic interface kinetics on morphological stability is calculated for a binary alloy. The dependence of the interface kinetic coefficient on crystallographic orientation is based on the motion and density of steps. Anisotropic kinetics give rise to traveling waves along the crystal-melt interface, and can lead to a significant enhancement of morphological stability. This self-stabilization arises because the traveling step density wave creates a concentration wave which lags the step density wave. The stability enhancement increases as the orientation approaches a singular orientation and as the solidification velocity increases. Specific calculations are carried out for germanium-silicon alloys. © 1994.