Formation mechanism of barium titanate by thermal decomposition of barium titanyl oxalate

This study examined the formation mechanism of BaTiO3 from the thermal decomposition of barium titanyl oxalate. A significant amount of O2 evolution near 357 and 720 °C was observed by gas chromatography/mass spectroscopy, except for the previously known H2O, CO2, CO evolution. The metastable Ba2Ti2O5CO3(CO2) intermediate phase seemed to be transformed mainly to Ba2Ti2O5CO3, while a certain amount of crystalline BaCO3 and amorphous Ti-rich phase were formed simultaneously at 450–600 °C in air. A modification of the decomposition mechanism reported by Gopalakrishnamurthy et al. was proposed based on the experimental findings.