Nucleation kinetics at strong supersaturation

Nucleation in an arbitrary d-dimensional system is considered. Two nucleation regimes are predicted within an original kinetic approach. The first regime (for a weak supersaturation) is characterized by the formation of a critical nucleus (critical nucleus regime). The second regime (for a strong supersaturation) corresponds to an uncontrollable growth of a cluster of any size (runaway nucleation regime). It is established that the nucleation regime is controlled by the metastability parameter M of the system under consideration. The analytical properties of the free energy of the nucleation system are investigated. It is demonstrated that a change in the parameter M leads to a considerable transformation of the nucleation barrier topography. The effect of the nucleation barrier height on the kinetics of nonstationary nucleation is described.