Crystallization kinetics of the Y3Al5O12 glass

Crystallization of glass prepared by flame technique from a crystalline YAG precursor synthesized by Pechini method was studied under non-isothermal conditions by differential scanning calorimetry. The crystallization peaks were mathematically deconvoluted into two peaks representing two overlapping thermal effects. These two peaks were examined in terms of the nucleation-growth Johnson-Mehl-Avrami model, autocatalytic Sestak - Berggren model and Malek z(α) and y(α) functions. At lower heating rates, the only process in the system was volume crystallization with the apparent activation energy of 555 ± 37 kJ*mol−1. At higher heating rates, partial change of crystallization mechanism was observed with significant contribution of surface crystallization and the activation energy of 606 ± 31 kJ*mol−1.