Molecular dynamics simulation of solidification and devitrification in a one-component system

Abstract

A specially designed semi-empirical potential of the Finnis–Sinclair type was used to simulate the phase transformation in a disordered one-component system. The potential provides that the face-centered cubic (fcc) phase is the most stable phase in the system below the melting temperature, Tm; however, the potential does not lead to the fcc nucleation during molecular dynamics (MD) simulation, allowing studying the liquid–glass transformation. The potential also allows studying the fcc-liquid and fcc-glass interface migration. It was found that the liquid–glass transformation described by this potential is of the first order. The Wilson–Frenkel theory of the solid–liquid interface (SLI) migration satisfactory describes the results of the MD simulation in the temperature interval from 0.55Tm to Tm while the Broughton–Gilmer–Jackson theory is less accurate in describing the temperature dependence of the SLI velocity in the same temperature interval. Below 0.55Tm, the results of the MD simulation strongly depend on how the disordered phase model was prepared and none of the existing theories is capable of reproducing the temperature dependence of the interface velocity.