Effects of asymmetry and external field on phase transitions in the presence of an intermediate metastable state

Discovery of the anomalous generation and extinction of crystal nuclei in nonequilibrium supercooled liquids reflects essentially the effects of the real heterogeneous structure and its irreversible relaxation on the stability of the nucleus. The kinetic model involving one order parameter was developed to study the impact of both asymmetry and external field on crystallization, thus allowing looking, in particular, into the heterogeneous structure relaxation in such materials. The role of asymmetry and external field on phase transitions in the presence of an intermediate metastable state is described in comparison with such generic model. We found that the influence of the external field on the system with an intermediate metastable state is to reduce the stability of phases, and, therefore, the crystal nuclei generation could be slowed or even stopped. Meanwhile the role of cubic term in order parameter of the Landau-type potential associated to the asymmetry of the system is to increase the stability of new phase for the suitably varied control parameter. Finally, the cases which allow analytical solution of the problem and the realization of different transition scenarios are discussed.