Universal Critical Behavior of Curvature-Dependent Interfacial Tension

From the analysis of Monte Carlo simulations of a binary Lennard-Jones mixture in the coexistence region, we provide evidence that the curvature dependence of the interfacial tension can be described by a simple theoretical function sigma(R)xi(2) = C-1/[1 + C-2(xi/R)(2)], where xi is the correlation length and R is the droplet radius. The universal constants C-1 and C-2 are estimated. In the model, a Tolman length is strictly absent, but, since its critical behavior is believed to be much weaker than xi, we argue that it only provides a correction to scaling and does not affect the leading critical behavior, which should be described by the above function for any system in the Ising universality class. The large value of C-2 similar or equal to 32 implies that conventional nucleation theory becomes inaccurate even for a significantly large droplet radius.