Nanosized Tetragonal BaTiO₃ Powders Synthesized by a New Peroxo-Precursor Decomposition Method

A new peroxo-precursor decomposition method is developed for synthesis of BaTiO 3 . Peroxo-polytitanic acid solution is prepared by reaction between metallic titanium powder and H 2 O 2 aq, and the amorphous peroxo-precursor is prepared by mixing the peroxo-polytitanic acid with Ba(OH) 2 aq. The reaction time between the metallic titanium powder and H 2 O 2 aq is shortened from 72 to 6 h by increasing the concentration of H 2 O 2 aq from 30 to 70 wt %. BaTiO 3 with crystallite size of 14.7−419.7 nm and tetragonality c / a of 1.0037−1.0090 is obtained by heating the precursor for 1 h at 600−1150 °C in air. BaTiO 3 obtained at 650 °C shows a uniform size distribution in the field-emission scanning electron microscope (FE-SEM) image around 30 nm, and the dielectric constant of 360.