The influence of an interface in the promotion of melting

The effect of the presence of a solid/liquid interface in preventing the superheating and supercooling found in previous surfaceless systems is investigated using isothermal (constant-NVT) molecular dynamics. The particles interact via a Lennard-Jones potential cut at c = 2·5. Computer simulations are performed at temperatures around the expected melting point for three different pressures, close to P* = 0·0, 0·67 and 9·0. The results show that there is no evidence of any superheating of the lattice or supercooling of the liquid. This points to the significant importance of the presence of an interface in melting and freezing phenomena. Since only thermodynamically stable points are produced, the method can be used to determine the melting point of the system. It is shown that the melting point thus produced is more accurate than that obtained using the hysteresis loop found in surfaceless systems. This is particularly apparent at higher pressures.