Simulated effects of transient nucleation on the crystallization of glass samples

The kinetics of crystallization have been re-examined by taking into account the transient nucleation time and numerical methods were used to obtain the dependence of fraction crystallized on temperature, heating rate and nucleation conditions (temperature and time). These solutions were used to analyze the applicability of approximate models which were based on the assumption of steady state nucleation. The transient nucleation time, which precedes nucleation in as quenched samples, was taken into account to re-examine the deviations expected for relatively short nucleation time, and/or for cases when the actual nucleation temperature is displaced from the corresponding nucleation peak. Additional solutions were computed to obtain the dependence of crystallization peak temperature on the nucleation temperature. It was found that the crystallization peak temperature reaches its lowest value after nucleation at a temperature which can be significantly higher than the peak temperature of steady state nucleation.