Facile sonochemical synthesis of near spherical barium zirconate titanate (BaZr1−yTiyO3; BZT); perovskite stability and formation mechanism

Abstract

The multicationic oxides of perovskite Ba(Zr,Ti)O₃ were synthesized successfully by the sonochemical method without a calcination step. Detailed exploration considering the role of sodium hydroxide (NaOH) concentration, synthesis atmosphere, ultrasonic reaction time and precursor concentration on the perovskite phase formation and particle size was presented. It was found that nanocrystals were formed directly before being oriented and aggregated into large particles in aqueous solution under ultrasonic irradiation. The nucleation in the sonocrystallization process was accelerated by the implosive collapse of bubbles, while the crystal growth process was inhibited or delayed by shock waves and turbulent flow created by ultrasonic radiation. A pure complex perovskite phase of spherical shape was formed completely in a short irradiation time without the calcination process. Sonochemical irradiation could accelerate spherical shape formation of the particles significantly. These results provide new insights into the development and design of better nanomaterial synthesis methods.