Interfacial energy in phase-field emulation of void nucleation and growth

Phase-field model of void nucleation and growth is analyzed. The Ginzburg-type gradient energy term conventionally used under the diffuse-interface assumption is found to make only partial contribution to the interfacial energy. A similar, or even larger, contribution from the bulk terms in the free energy functional also has to be included. Only then, the critical radius for void nucleation under classical nucleation theory can be correctly reproduced.