ABSTRACT
In this chapter, the basic concepts of the kinetic nucleation theory are presented and applied to liquid-tosolid phase transformations (Sections 1.1 through 1.3). Both homogeneous (Sections 1.1 through 1.5) and heterogeneous (Sections 1.6 through 1.10) nucleations are considered. The dissociation of molecules from the surface of the cluster of the solid phase is considered to be caused by Brownian motion that is governed, in general, by the Fokker-Planck equation for the joint distribution function in the phase space [1,2]. For homogeneous nucleation, the latter equation can be reduced to the backward Smoluchowski equation, which provides the mean passage of time for a molecule to overcome the potential barrier generated by a spherical cluster and, hence, the rate of dissociation (αj) of the surface molecules.
