Effect of Calcination Temperature on Phase Transformation and Particle size of Barium Titanate Fine Powders Synthesized by the Catecholate Process

Abstract

A modified catecholate process has been developed for the synthesis of high purity barium titanate fine powders. The barium titanium-catechol complex, Ba[Ti(C6H4O2)3] was prepared from TiCl4, C6H4(OH)2 and BaCO3. The complex was freeze-dried and calcined for 3 hours at temperatures ranging from 700 to 1100°C. Phase transformation and particle size of the calcined powders have been investigated as a function of calcination temperature by room-temperature X-ray diffraction and scanning electron microscopy techniques. It is seen that the perovskite-like phase of BaTiO3 was successfully obtained. With increasing calcining temperature, BaTiO3 transformed from the cubic to the tetragonal phase. Higher temperatures clearly favoured particle growth and the formation of large and hard agglomerates. After calcination at 700°C, the average particle size ranged between 0.1-0.2 µm.