Investigation on synthesis of tetragonal BaTiO3 nanopowders by a new wet chemical method

In this paper, tetragonal barium titanate (BaTiO₃) nanopowders were synthesized by a new wet chemical route named sol-hydrothermal method. The effects of different temperatures, time and raw materials on the properties of BaTiO₃ were studied. The results showed that BaTiO₃ was not formed in the precursors. All powders were pure perovskite phase except for the powder prepared using BaCl₂ as raw material at 100 °C. The main morphology of the powders was near-spherical. With the increase of hydrothermal temperature and time, the agglomeration decreased, the crystallinity and the tetragonal content increased for the powders. The optimal conditions of tetragonal BaTiO₃ nanopowders synthesized by different raw materials were 120 °C (BaCl₂), 140 °C (BaAc₂) and 160 °C for 24 h [Ba(NO₃)₂], respectively. The size of the powders prepared by optimal conditions ranges of 125 nm ~ 250 nm in diameter. Moreover, a possible formation mechanism was proposed for BaTiO₃ nanopowders synthesized by the sol-hydrothermal method. The as-prepared tetragonal BaTiO₃ powders could be used as medium material for multilayer ceramic capacitors.