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 simulations. The crystal structure and thermodynamic properties were chosen to correspond to bismuth doped silicon with k(eq) = 7 x 10(-4). Values for k(neq) were obtained for several orientations of the solid/liquid interface, including (111) and (001). For the same growth velocity, k(neq) was found to be greatest for solid/liquid interfaces parallel to 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.