Liquid nucleation, single component system

Single-Component System with Isotropic Interfaces and No Strain Energy. This relatively simple case could, for example, correspond to the nucleation of a pure solid in a liquid during solidification. For steady-state nucleation, Eq. 19.16 applies with AQC given by Eq. 19.4 and it is necessary only to develop an expression for /3C. In a condensed system, atoms generally must execute a thermally activated jump over a... 

Crystal nucleation from the melt is but one type of nucleation in the condensed phase. Other processes of interest include the nucleation of salt crystals from aqueous solution, of one crystalline phase from another or from a glass, and of liquid crystal phases from one another or from the isotropic liquid. In this review we discuss only the nucleation of crystals from the melt. The major emphasis will be on single-component systems, although crystallization of alloys and binary mixtures will also be considered. 

The whole new field that opens up is where the gas is present in relatively large amounts, and now the nucleation and phase change represent not the ebullition of the liquid, which in this case mainly acts as a carrier solvent for the dissolved gas, but the appearanee of bubbles of the previously dissolved gas itself, with a lesser contribution from the vapor pressure of the solvent. Of course, there is a continuum of behavior from pure boiling in a single component system consisting of the liquid, through the bubble evolution of essentially the pure gas from solution—and this continuity is reflected in the mathematical description of the process, with essentially one equation describing both extremes. 

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