Simulation of the melting behavior of small silicon clusters.

Abstract

We report Monte Carlo and molecular-dynamics simulations of the melting behavior of small silicon clusters interacting via a many-body potential. The study presents a unified description of different manifestations of the melting phenomenon in the silicon (Si) clusters. We show that upon heating the small Si clusters undergo a transition from the solid state to the liquid state, in a two-step process. In the first step of this transition the cluster, in its solid state, transforms into an intermediate phase which is neither a solid nor a liquid phase. Although the domain of existence of this intermediate phase is relatively narrow, several important precursor effects of the melting phenomenon manifest themselves. In the second step of the transition the cluster transforms into the liquid state. The melting temperature exhibits a strong dependence on cluster size.