Effects of Surface Area of Titanium Dioxide Precursors on the Hydrothermal Synthesis of Barium Titanate by Dissolution–Precipitation

We have attempted to study the formation of BaTiO 3 by hydrothermal synthesis and our experiments reveal the reaction by dissolution–precipitation as the dominant operating mechanism. Two major formation mechanisms of BaTiO 3 by hydrothermal synthesis involving either in situ transformation or dissolution–precipitation have been previously proposed. However, the exact formation mechanism is yet to be clarified unambiguously. To investigate the mechanism in detail, we used Ba(OH) 2 and three types of TiO 2 nanoparticles as precursors for the synthesis. The morphology of the BaTiO 3 obtained was cubic (with rounded edges), regardless of the morphology of the TiO 2 used, which indicated that the synthesis followed the dissolution–precipitation mechanism. In this mechanism, the surface area of TiO 2, which affects its dissolution rate, played a critical role in determining the crystal size of the BaTiO 3 product. In this paper, we have also discussed the effects of the synthesis conditions on BaTiO 3 particle formation.