Low-temperature syntheses of cubic BaTiO₃ nanoparticles in highly basic aqueous solution

Abstract

Cubic BaTiO₃ particles of ca. 100 nm in diameter were produced at 25 to 60°C in a highly basic aqueous solution system. The crystalline phase was purely formed by reaction of barium hydroxide and anatase TiO₂ nanoparticles under the highly basic condition. The formation of the pure phase at a lower temperature requires a higher concentration of NaOH and a longer reaction period. At room temperature (25°C), the crystalline BaTiO₃ was obtained through the reaction with 5.2 mol/kg of NaOH for 168 h. A specific mesocrystal architecture of BaTiO₃ consisting of oriented small units was formed as an intermediate at the initial stage of crystal growth.