Solid-liquid interfacial free energy of small colloidal hard-sphere crystals

Using free-energy calculations on small crystalline clusters, we estimate the free-energy density G;_SL for the solid-liquid equimolar interface of a system of hard-sphere colloids. By studying the behavior of a crystallite at coexistence, we determine the dependence of G;_SL on the radius of curvature of the interface. An extrapolation to infinite radius of curvature (flat interface), yields G;_SL(R?8) = 0.616(3), in good agreement with recent numerical estimates. Subsequently, we consider the dependence of the interfacial free-energy density on the degree of supersaturation. Our simulations suggest that the G;_SL associated with the equimolar surface is fairly insensitive to changes in supersaturation.