Heating-Rate and Particle-Size Effects on Melting Process of Au Nanoparticles

The atomic mechanisms of the melting process of gold nanoparticles were investigated by molecular dynamics simulations. Melting under a high heating rate is found to be much different from the near equilibrium melting and is a typical overheating process. The melting begins with the formation of a premelting layer near the surface, and the interface of the solid and premelting layer drives the nucleation of the liquid into the interior of nanoparticles. The high heating rate causes solid-liquid coexistence in a large temperature interval. These imply that the melting process can be controlled effectively by different heating ways.