Abstract
A unified model, free of any adjustable parameters, for the size-dependence and dimension-dependence of melting point depression and superheating of nanocrystals is developed. In terms of the consideration of the surface/volume ratio of nanocrystals, the suppression of melting point of nanocrystals and superheating of embedded nanocrystals are predicted. The model predictions for the melting temperatures of nanocrystals are consistent with the experimental results and molecular dynamics simulations.