Nucleation theory for diffuse interfaces

A diffuse interface theory of nucleation is proposed on the basis of a parametrization of the cross-interfacial enthalpy and entropy distributions, relating thus the excess free energy of nuclei to macroscopic quantities. The model is applied for vapour condensation, to crystal nucleation from liquid and glass, and to phase separation in a liquid miscibility gap. The results imply that for large deviations from equilibrium the proposed model is in better agreement with experiments than the classical theory, while for small deviations the two descriptions are equivalent.