Molecular dynamics simulation of the melting of uranium dioxide nanocrystals

The melting of vacuum-isolated uranium dioxide (UO₂) nanocrystals is studied by molecular dynamics simulation using the approximation of pair potentials and point ions. The size dependences of the melting temperature, the heat of melting, and the density jump of cubic crystals up to 1000 nm³ in size are measured for the ten most relevant sets of pair potentials. The linear and parabolic extrapolations of these dependences to macroscopic sizes are considered, and the parabolic extrapolation is found to be better for analyzing data on the melting temperature and heat.