Re-examination of the temperature dependence of the classical nucleation rate: Homogeneous crystal nucleation in glass

Abstract

A comparison is made between the experimentally determined and predicted (Classical Nucleation Theory) temperature dependence of the homogeneous crystal nucleation rate in glass. Literature data for several glass-forming systems are analyzed. It is shown that the standard assumptions which are invoked to replace the free energy of activation for transport across the liquid-crystal interface, ΔG D, in favor of a more easily measured parameter (viscosity) are not required. It is demonstrated that ΔG D may be found experimentally by determining the temperature dependence of the nucleation transient time. Furthermore, it is shown that precise thermodynamic data are not necessarily required in order to make comparisons between the theoretically predicted and experimentally determined temperature variation of the nucleation rate. It is concluded that the temperature dependence of the classical homogeneous nucleation rate is still a matter of controversy.