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

Abstract

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 (Ea) for the first crystallization peak (Tp1) 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.