Statistical Mechanical Perturbation Theory of Solid−Vapor Interfacial Free Energy

The solid–vapor interfacial free energy γsv plays an important role in a number of physical phenomena, such as adsorption, wetting, and adhesion. We propose a closed form expression for the orientation averaged value of this quantity using a statistical mechanical perturbation approach developed in the theory of liquids. Calculations of γsv along the sublimation line for systems characterized by truncated and shifted Lennard-Jones potential are presented. Within the temperature range studied—not far from the triple point—model predictions are in good agreement with molecular dynamics simulations. At the triple point itself the model yields interfacial tensions between the three coexisting phases—solid–vapor, liquid–vapor, and solid–liquid. The latter is obtained by means of Antonow’s rule. All three triple point values perfectly agree with simulation results.