Study on phase formation and sintering kinetics of BaTi0.6Zr0.4O3 powder synthesized through modified chemical route

Abstract

BaTi0.6Zr0.4O3 powder was prepared from barium oxalate hydrate, zirconium oxy-hydroxide and titanium dioxide precursors. Barium oxalate hydrate and zirconium oxy-hydroxide were precipitated from nitrate solution onto the surface of suspended TiO2. Phase formation behaviour of the materials was extensively studied using XRD. BaTiO3 (BT) and BaZrO3 (BZ) start forming separately in the system upon calcinations in the temperature range 600–700 °C. BT–BZ solid solution then forms by diffusion of BT into BZ from 1050 °C onwards. The precursor completely transforms into BaTi0.6Zr0.4O3 (BTZ) at 1200 °C for 2 h calcination. The activation energy (AE) of BT (134 kJ mol−1) formation was found to be less than that of BZ (167.5 kJ mol−1) formation. BTZ formation requires 503.6 kJ mol−1 of energy. The sintering kinetics of the powder was studied using thermal analyzer. The mean activation energy for sintering was found to be 550 kJ mol−1.