ORIENTATION DEPENDENCE OF THE DISTRIBUTION COEFFICIENT OBTAINED FROM A SPIN-1 ISING-MODEL

The nonequilibrium distribution coefficient (k(neq)) as a function of solid-liquid interface velocity and orientation was investigated for a spin-1 Ising model for binary alloys using Monte Carlo computer simul ations. The crystal structure and thermodynamic properties were chosen to correspond to bismuth doped silicon with k(eq) = 7 x 10(-4). Value s for k(neq) were obtained for several orientations of the solid/liqui d interface, including (111) and (001). For the same growth velocity, k(neq) was found to be greatest for solid/liquid interfaces parallel t o the(111) plane. The orientation dependence is related to variations in the kink site density at the interface. The simulation results are compared with experimental results reported by Aziz et al.