Kinetics of crystal dissolution for a Stillinger-Weber model of silicon

We present a method combining nonequilibrium molecular-dynamics simulation with Markovian data analysis techniques suitable for the study of both the growth and dissolution of crystalline "embryos" in the liquid phase. The feasibility of studying growth processes is demonstrated, but the majority of the studies concern crystal dissolution at temperatures slightly above the melting point. Molecular-dynamics simulations using the Stillinger-Weber potential were performed by embedding crystallites of 400-800 atoms in a liquid phase consisting of approximately 3600-7200 atoms, respectively. During each simulation, the time evolution of the size and shape of the embryo was followed until it became indistinguishable from the liquid. These simulations provide information on the atomic processes involved in dissolution and on the macroscopic kinetics of small clusters. The sensitivity of the results to different temperatures, system sizes, initial cluster shapes, and the criteria used to distinguish between solid and liquid are demonstrated.