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.