Effect of sintering time on microstructure and electrical properties of lead-free sodium bismuth titanate perovskite

Abstract Sodium bismuth titanate (NBT) based perovskite is emerging as one of the future lead free alternative materials for electro-ceramic applications. In this present work, NBT ceramics were synthesized by cost effective solid state reaction method at a particular sintering temperature 1200 °C for various durations up to 24 hr and the effect of sintering duration on microstructure and subsequently the electrical conductivity behavior was investigated. The grain size increases from 2 to 5.2 µm and also the grain size distribution broadened with increasing the sintering duration from 1hr to 24 hr. The inter and intra grain as well as space charge contributions towards the total conductivity were distinctly demonstrated. The temperature and frequency dependent Z and ac conductivity as a function of sintering duration were analyzed correlating with the micro-structural changes to obtain useful information about the conductivity and relaxation mechanism.