Effect of Li and Bi co-substituted on structural and physical properties of BaTiO₃ ceramics

Abstract

Polycrystalline samples of Li and Bi co-substituted BaTiO₃ were synthesized using microwave assisted heating of the starting materials. This synthesis process extraordinarily reduced the processing time to 40 min, which includes heating and the dwell durations. The room temperature powder X-ray diffraction patterns reveals that the obtained compounds were of pure BaTiO₃ phase (BTO). The structural, morphological and dielectric behaviour of these compositions were studied. Improved dielectric properties have been observed with the substitute of Bi and Li. It is interesting to note that the loss tangent of the co-substituted compositions are lower than that of the parent composition and it decreases approximately with increasing extent of co-substitution. This property is quite useful to develop this material further for capacitor applications. The transition temperature has shifted from 120 °C of pure BaTiO₃ towards higher temperatures to 150, 160 and 175 °C with (Bi, Li)_x where x = (0.02, 0.04 and 0.08), respectively of co-substitution BaTiO₃. The change is linear with the degree of co-substitution.