KINETIC SELF-STABILIZATION OF A STEPPED INTERFACE - BINARY ALLOY SOLIDIFICATION

For growth of a vicinal face at constant velocity, the effect of aniso tropic interface kinetics on morphological stability is calculated for a binary alloy. The dependence of the interface kinetic coefficient o n crystallographic orientation is based on the motion and density of s teps. Anisotropic kinetics give rise to traveling waves along the crys tal-melt interface, and can lead to a significant enhancement of morph ological stability. This self-stabilization arises because the traveli ng step density wave creates a concentration wave which lags the step density wave. The stability enhancement increases as the orientation a pproaches a singular orientation and as the solidification velocity in creases. Specific calculations are carried out for germanium-silicon a lloys.