Solidification kinetics in SiGe alloys

The solidification kinetics of SiGe alloys, modeled by the Stillinger-Weber potential, are investigated using nonequilibrium molecular-dynamics computer simulation techniques. Interface response functions and solute redistribution at the regrowing solid/liquid interface are investigated. The maximum crystallization velocity of SiGe alloys is found to decrease below the pure component values, in agreement with the results of explosive crystallization measurements. The results of solidification velocity versus interface temperature (i.e., one of the interface response functions) obtained from the simulation for SiGe alloys compare well, in most cases, with Aziz’s continuous growth model assuming short-range diffusion-limited growth. Mutual trapping of Si in Ge and Ge in Si is found in both Si-rich and Ge-rich alloys, in agreement with Aziz’s solute trapping theory and with experiment.