Synthesis of Highly Tetragonal BaTiO_3 Nanopowders Using Acetone as a Solvent by Alkoxide-Hydroxide Route

摘要

BaTiO_3 (BT) nanopowders were synthesized in acetone to remove the TiO_2 second phase, which was formed in the specimens synthesized in the 2-methoxyethanol solvent at above 100℃ due to H_2O evaporation. No TiO_2 second phase was formed in the specimens synthesized in acetone, even at 260 ℃, due to the low boiling temperature of acetone which evaporated at above 55 ℃ and suppressed the H_2O evaporation by increasing the vapor pressure in the vessel. However, for the BT nanopowders synthesized at 250 ℃ for 60 h, TiO_2 second phase was formed at a Ba/Ti ratio of ≤1.5 and the BT nanopowders were agglomerated at a ratio of ≥3.0. Homogeneous BT nanopowders were obtained at a ratio of 2.0 and they exhibited a high c/a ratio of 1.0082 with a small size of 95.2 nm. Therefore, these nanopowders can be a good candidate for future multilayer ceramic capacitor.