Application of perturbation theory to the crystal–melt interface

Abstract

The Abraham–Singh perturbation theory is applied to the case of the interface between an fcc crystal and its melt. The starting point is the density distribution of a hard-sphere liquid near a hard wall. The perturbation theory corrects the hard-sphere fluid density distribution by accounting for the soft repulsive nature of the crystal face with respect to the fluid atoms, this interaction being approximated by its two-dimensional Boltzmann average potential. Account is taken of the thermal motion of the crystalline molecules at the interface. The theoretical density distribution is in good agreement with that obtained from a molecular dynamics experiment, for both (100) and (111) faces.