Crystallization kinetics and dielectric properties of barium strontium titanate based glass–ceramics

The crystallization kinetics in the glass system BaxSr1−xTiO3–Al2O3–SiO2 prepared via the conventional melt-quenching technique has been studied by isothermal method using differential scanning calorimetry (DSC). X-ray powder diffraction studies carried out on heat-treated (850–1100 °C) glasses reveal the evolution of BaxSr1−xTiO3 crystalline phase along with a second phase of BaAl2Si2O8. The exponent n in the Johnson–Mehl–Avrami (JMA) equation applied to the isothermal process is in the range of 2.3–2.73. The apparent activation energy for BaxSr1−xTiO3 crystal growth obtained from JMA equation under isothermal condition is 457 kJ mol−1, which is close to the dissociation energy of Si–O bonds. Moreover, there is no remarkably different effect between one-stage and two-stage heat treatment procedures on the microstructures and dielectric properties of barium strontium titanate based glass–ceramics in the present study, according to structure–property analysis.