Size Dependence of the Melting Point of Silicon Nanoparticles: Molecular Dynamics and Thermodynamic Simulation

The size dependence of the melting point of Si nanoparticles is investigated using molecular dynamics and thermodynamic simulation based on the Thomson's formula. The atomistic modeling data obtained using the Stillinger-Weber potential agree with the results reported by other authors and thermodynamic-simulation data and predict a decrease in the melting point T-m of Si nanoparticles with an increase in their reciprocal radius R-1 according to linear law. The available experimental data predict lower T-m values, including the limiting value T-m((infinity)) , which corresponds to the linear extrapolation of experimental points to R-1 -> 0 (to the radius R -> infinity); the underestimation is 200-300 K as compared with the reference melting point of silicon (1688 K). It is concluded that the molecular-dynamics data on T-m(R-1) obtained using the Stillinger-Weber potential are more adequate than the available experimental data.