Preparation, crystallization kinetics and microwave dielectric properties of CaO-ZnO-B2O3-P2O5-TiO2 glass-ceramics

Abstract The CaO-ZnO-B2O3-P2O5 glass-ceramics with various amounts of TiO2 as crystallized agent were prepared by solid-state method. The effects of TiO2 addition on the crystallization kinetics, microstructure and dielectric properties were systematically evaluated. Adding moderate content of TiO2 can obviously promote crystallization and improve the microstructure of the glass-ceramics, due to the reduction of crystallization activation energy. It is also found that with the content of TiO2 increasing, the dielectric constant (er) and quality factor (Q×f) of the glass-ceramics firstly increase and then decrease, however, temperature coefficient of resonance frequency (τf) moves to positive value. Meanwhile, the sintering temperature also has a direct influence on the dielectric properties of the glass-ceramics. The glass-ceramic with 0.5 wt% TiO2 sintered at 760 °C for 2 h possesses good dielectric properties of er = 4.75, Q×f= 23500 GHz, τf = −17 ppm/°C, which indicates that the as-prepared glass-ceramic is a promising candidate for low temperature co-firing ceramics.