Preparation and melting of amorphous silicon by molecular-dynamics simulations

Molecular-dynamics simulations of amorphous silicon are described, using the two- and three-body interaction potentials constructed by Stillinger and Weber. The amorphous-material preparation procedure is described and the structural and dynamical properties of the amorphous phase are simulated and analyzed. The characteristics of the simulated amorphous phase compare favorably with experimental data and with structural models. Upon rapid heating, the amorphous sample melts via a first-order transition at a temperature of 230 K below the melting temperature of the crystalline material with a latent heat approximately equal to 0.2--0.4 of the latent heat of the crystalline-liquid transition. The nature of the transition and the magnitude of the latent heat maintain, but shift to a lower temperature, for melting of fully relaxed amorphous configurations at elevated temperatures.