Transition State of Matter in the Fluctuation Model of Crystal Growth.

Two mechanisms of the effect of the transition state of building particles (activated complexes, according to Arrhenius) on the crystal growth rate in the framework of the fluctuation model of dislocation growth are discussed. The transition state clusters adsorbed on the surface of a growing face act as an impurity lowering the crystal surface energy at instants between free energy fluctuations. Thus, the transition state of the crystallizing material, according to the first mechanism, affects the relaxation rate of the secondary adsorption of impurities and shortens the attachment time of building particles to the crystal face. Other clusters formed in solution reduce the number of free particles and, at low concentrations of the building material, may decrease the crystallization rate. Nevertheless, in a natural multicomponent crystallization environment, under the conditions of low building material concentration, essential thermal crystallization effect, and small deviations from equilibrium, the role of the transition state in the crystal growth is on the whole insignificant. [ABSTRACT FROM AUTHOR]