Synthesis of barium titanate nanopowder using polymeric precursor method

Barium titanate powder was prepared by a polymerized complex method based on the Pechini type reaction route, where barium and titanium ions were polymerized in mixed solution of citric acid, ethylene glycol, to form a transparent resin, which was used as a precursor. Barium titanate powder was formed by heat treating the polymeric precursor in air at 500–900 °C. The thermal decomposition of (Ba, Ti) polymeric precursor was studied by thermal analysis. The crystal structure was investigated by X-ray powder diffractometry and Raman spectroscopy. The particle size and morphology of BaTiO3 were examined by X-ray diffraction and transmission electron microscopy. Cubic BaTiO3 with some traces of hexagonal phase was present at 500 °C and tetragonal BaTiO3 at 600 °C and above. However, Raman spectrum showed a mixture of cubic, tetragonal and hexagonal BaTiO3 at 500 °C and tetragonal BaTiO3 at 600 °C and above. X-ray line broadening studies of 900 °C heat-treated powders showed average crystallite size of 20 nm. Agglomerated spherical grains are observed at 600 °C. The sintering behavior and dielectric properties of the nanopowders were also studied.