ABSTRACT
The crystallization process involves several steps: an induction period, a crystal growth phase, and a period of recrystallization or crystal regrowth. Much of knowledge of nucleation and crystal growth comes from theoretical and experimental studies of crystallization from solution. The most successful nucleation theory started with the work of M. Volmer and of L. Farkas on the condensation of water droplets from supersaturated vapor. Josiah Willard Gibbs’ thermodynamic treatment was rediscovered 50 years later by Volmer, who applied it to the condensation of liquid droplets from a vapor. The earliest theoretical treatments of crystal growth, based on surface energy or thermodynamic considerations, were put forth by Gibbs and by P. Curie. The adsorption layer theory can also be formulated in terms of absolute reaction rate theory. Impurities in a phase-change material can have a profound effect on the nucleation and growth during crystallization, and particularly on the morphology of the crystals formed.
