Eu3+doped ferroelectric BaBi2Ta2O9 based glass-ceramic nanocomposites: Crystallization kinetics and energy storage properties

A comparative study of crystallization kinetics of Eu3+ doped K2O-SiO2-BaO-Bi2O3-Ta2O5 (BBTE) glass system is done using the linear (Kissinger, Augis-Bennett, Ozawa, Matusita) and nonlinear (nth dimension Avrami-Erofeev) model fitting methods. The activation energies (E-a) for the first crystallization peak (T-p1) are calculated from the reaction models. Homogenous, interface controlled bulk crystallization between two and three dimensions is predicted from the Avrami indices (n) obtained using Matusita (n = 3.5) and Avrami-Erofeev (n = 2.6) reaction models. The values of activation energy of crystallization determined using the linear and nonlinear reaction models have been compared and correlated with the values obtained using a differential model free Friedman method. Prediction of optimum ceramization (heat-treatment) schedule for controlled crystallization of BBTE glass-ceramics has been possible using the Avrami-Erofeev kinetic model. The heat-treatment schedule i.e., temperature and time, so predicted from kinetics analysis is experimentally validated to obtain transparent BBTE glass-ceramics. Hysteresis loops of heat-treated BBTE glass-ceramics have been measured at room temperature and maximum recoverable energy storage density has been calculated from the curve. (C) 2018 Elsevier B.V. All rights reserved.